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Sample records for acl reconstruction methods

  1. ACL reconstruction

    MedlinePlus

    ... Tissue taken from a donor is called an allograft. The procedure is usually performed with the help ... This increases the chance you may have a meniscus tear. ACL reconstruction may be used for these ...

  2. ACL reconstruction - discharge

    MedlinePlus

    Anterior cruciate ligament reconstruction - discharge; ACL reconstruction - discharge ... had surgery to reconstruct your anterior cruciate ligament (ACL). The surgeon drilled holes in the bones of ...

  3. ACL reconstruction

    MedlinePlus

    ... replace your ACL by following these steps: The torn ligament will be removed with a shaver or ... ligaments are also injured When your meniscus is torn Before surgery, talk to your health care provider ...

  4. PRP Augmentation for ACL Reconstruction

    PubMed Central

    Di Matteo, Berardo; Kon, Elizaveta; Marcacci, Maurilio

    2015-01-01

    Current research is investigating new methods to enhance tissue healing to speed up recovery time and decrease the risk of failure in Anterior Cruciate Ligament (ACL) reconstructive surgery. Biological augmentation is one of the most exploited strategies, in particular the application of Platelet Rich Plasma (PRP). Aim of the present paper is to systematically review all the preclinical and clinical papers dealing with the application of PRP as a biological enhancer during ACL reconstructive surgery. Thirty-two studies were included in the present review. The analysis of the preclinical evidence revealed that PRP was able to improve the healing potential of the tendinous graft both in terms of histological and biomechanical performance. Looking at the available clinical evidence, results were not univocal. PRP administration proved to be a safe procedure and there were some evidences that it could favor the donor site healing in case of ACL reconstruction with patellar tendon graft and positively contribute to graft maturation over time, whereas the majority of the papers did not show beneficial effects in terms of bony tunnels/graft area integration. Furthermore, PRP augmentation did not provide superior functional results at short term evaluation. PMID:26064903

  5. PRP Augmentation for ACL Reconstruction.

    PubMed

    Andriolo, Luca; Di Matteo, Berardo; Kon, Elizaveta; Filardo, Giuseppe; Venieri, Giulia; Marcacci, Maurilio

    2015-01-01

    Current research is investigating new methods to enhance tissue healing to speed up recovery time and decrease the risk of failure in Anterior Cruciate Ligament (ACL) reconstructive surgery. Biological augmentation is one of the most exploited strategies, in particular the application of Platelet Rich Plasma (PRP). Aim of the present paper is to systematically review all the preclinical and clinical papers dealing with the application of PRP as a biological enhancer during ACL reconstructive surgery. Thirty-two studies were included in the present review. The analysis of the preclinical evidence revealed that PRP was able to improve the healing potential of the tendinous graft both in terms of histological and biomechanical performance. Looking at the available clinical evidence, results were not univocal. PRP administration proved to be a safe procedure and there were some evidences that it could favor the donor site healing in case of ACL reconstruction with patellar tendon graft and positively contribute to graft maturation over time, whereas the majority of the papers did not show beneficial effects in terms of bony tunnels/graft area integration. Furthermore, PRP augmentation did not provide superior functional results at short term evaluation. PMID:26064903

  6. Graft Diameter matters in Hamstring ACL reconstruction

    PubMed Central

    Clatworthy, Mark

    2016-01-01

    Objective: Recently techniques have been developed to increase graft diameter in hamstring ACL reconstruction with the hope to decrease graft failure. To date there is limited evidence to show that a smaller graft diameter results in a higher ACL failure rate. Method: The factors for failure in 1480 consecutive single surgeon hamstring ACL reconstructions were evaluated prospectively. Patients were followed for 2-15 years. A multivariate analysis was performed which looked at graft size, age, sex, time to surgery, meniscal integrity, meniscal repair and ACL graft placement to determine whether graft diameter matters in determining the failure of hamstring ACL reconstruction. Results: Graft diameters ranged from 6-10 mm. The mean graft diameter for all patients was 7.75 mm. 83 ACL reconstructions failed. The mean size of graft failures was 7.55 mm ACL reconstructions that failed had a significantly smaller hamstring graft diameter p=0.001. The Hazard Ratio for a smaller diameter graft is 0.517 p=<0.0001. For every 1 mm decrease in graft diameter there is a 48.3% higher chance of failure. The multivariate analysis showed a hazard ratio of 0.543 p=0.002. For every 1 mm decrease in graft diameter there is a 45.7% higher chance of failure. Conclusion: Smaller diameter hamstring grafts do have a higher failure rate. Grafts ≤ 7.5 mm had twice the failure rate of grafts ≥8 mm using a multivariate analysis for every 1 mm decrease in graft diameter there is a 45.7% higher chance of failure.

  7. NFL Combine Athletic Performance after ACL Reconstruction

    PubMed Central

    Marshall, Nathan E.; Keller, Robert A.; Mehran, Nima; Austin, William; Moutzouros, Vasilios

    2016-01-01

    Objectives: The purpose of this study was to determine the functional performance of NFL combine participants after ACL reconstruction compared with an age-, size-, and position-matched control group. The hypothesis was that there would be no difference between players after ACL reconstruction as compared with controls in functional athletic performance. Methods: A total of 98 NFL-caliber athletes who had undergone primary ACL reconstruction and participated in the NFL scouting combine between 2010 and 2014 were reviewed and compared with an age-, size-, and position-matched control group. Data recorded for each player included a 40-yard dash, vertical leap, broad jump, shuttle drill, and 3-cone drill. Results: With regard to speed and acceleration, the mean 40-yard dash time for ACL-reconstructed players was 4.74 seconds (range, 4.33-5.55 seconds) compared with controls at 4.74 seconds (range, 4.34-5.38 seconds; P = .96). Jumping performance was also similar, with a mean vertical leap for ACL-reconstructed players of 33.35 inches (range, 23-43 inches) and broad jump of 113.9 inches (range, 96-136 inches) compared with respective values for the controls of 33.22 inches (range, 23.5-43.5 inches; P = .84) and 113.9 inches (range, 92-134 inches; P = .99). Agility and quickness testing measures also did not show a statistically significantly difference, with ACL-reconstructed players performing the shuttle drill in 4.37 seconds (range, 4.02-4.84 seconds) and the 3-cone drill in 7.16 seconds (range, 6.45-8.14 seconds), respectively, compared with respective times for the controls of 4.37 seconds (range, 3.96-5.00 seconds; P = .91) and 7.18 seconds (range, 6.64-8.24 seconds; P = .75). Conclusion: This study suggests that after ACL reconstruction, high-caliber athletes can achieve equivalent levels of perfor- mance with no statistically significant differences compared with matched controls. This information is unique when advising high-level athletes on athletic

  8. Bilateral ACL Reconstructions with Hamstring Autografts.

    PubMed

    Panigrahi, Ranajit; Mahapatra, Amita Kumari; Priyadarshi, Ashok; Palo, Nishit; Biswal, Manas R

    2016-07-01

    Bilateral anterior cruciate ligament (ACL) injuries are rare with incidence between 2 and 4%, and presently no definitive guidelines for proper management exist. Ideal treatment protocol remains controversial between a single-stage and two-stage bilateral ACL reconstruction. The purpose of this study is to evaluate the outcome of single-stage bilateral ACL reconstruction with hamstring tendon autografts in bilateral ACL injuries. A prospective study was undertaken including a total of 14 consecutive patients with bilateral ACL deficient knee who underwent single-stage bilateral ACL reconstruction with hamstring tendon autograft with a mean follow-up duration of 28 months (24-38 months). Functional outcomes were evaluated by range of movements, International Knee Documentation Committee (IKDC), Lysholm and Tegner activity score, and stability tests. The mean age was 30 years (range 18-42 years). Average duration of rehabilitation was 8 weeks. Time to return to full-time work and full sports was 5.6 weeks and 6.2 months, respectively. Clinical examination demonstrated full range of motion; a total of 12 patients (86%) had a negative Lachman test and 13 patients (93%) had a negative pivot shift at the final follow-ups. The mean IKDC evaluation score was 89 points, the mean Tegner activity score was 7 points, and the mean Lysholm knee score was 91 points. A total of 12 patients (86%) returned to their preinjury level of activity and an overall greater than 90% satisfaction rate was achieved. Single-stage bilateral ACL reconstruction using hamstring autografts is clinically safe, effective, and cost-effective with better patient compliance and with comparable functional outcome as opposed to two-stage ACL reconstructions. PMID:26408992

  9. Transphyseal ACL Reconstruction in Skeletally Immature Patients

    PubMed Central

    Cruz, Aristides I.; Lakomkin, Nikita; Fabricant, Peter D.; Lawrence, J. Todd R.

    2016-01-01

    Background: Most studies examining the safety and efficacy of transphyseal anterior cruciate ligament (ACL) reconstruction for skeletally immature patients utilize transtibial drilling. Independent femoral tunnel drilling may impart a different pattern of distal femoral physeal involvement. Purpose: To radiographically assess differences in distal femoral physeal disruption between transtibial and independent femoral tunnel drilling. We hypothesized that more oblique tunnels associated with independent drilling involve a significantly larger area of physeal disruption compared with vertically oriented tunnels. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We analyzed skeletally immature patients aged between 10 and 15 years who underwent transphyseal ACL reconstruction utilizing an independent femoral tunnel drilling technique between January 1, 2008, and March 31, 2011. These patients were matched with a transtibial technique cohort based on age and sex. Radiographic measurements were recorded from preoperative magnetic resonance imaging and postoperative radiographs. Results: Ten patients in each group were analyzed. There were significant differences between independent drilling and transtibial drilling cohorts in the estimated area of physeal disruption (1.64 vs 0.74 cm2; P < .001), femoral tunnel angles (32.1° vs 72.8°; P < .001), and medial/lateral location of the femoral tunnel (24.2 vs 36.1 mm from lateral cortex; P = .001), respectively. There was a significant inverse correlation between femoral tunnel angle and estimated area of distal femoral physeal disruption (r = –0.8255, P = .003). Conclusion: Femoral tunnels created with an independent tunnel drilling technique disrupt a larger area of the distal femoral physis and create more eccentric tunnels compared with a transtibial technique. Clinical Relevance: As most studies noting the safety of transphyseal ACL reconstruction have utilized a central, vertical femoral tunnel

  10. Stability Outcomes following Computer-Assisted ACL Reconstruction

    PubMed Central

    Christino, Melissa A.; Vopat, Bryan G.; Matson, Andrew P.; Reinert, Steven E.; Shalvoy, Robert M.

    2015-01-01

    Purpose. The purpose of this study was to determine whether intraoperative prereconstruction stability measurements and/or patient characteristics were associated with final knee stability after computer-assisted ACL reconstruction. Methods. This was a retrospective review of all patients who underwent computer-assisted single-bundle ACL reconstruction by a single surgeon. Prereconstruction intraoperative stability measurements were correlated with patient characteristics and postreconstruction stability measurements. 143 patients were included (87 male and 56 female). Average age was 29.8 years (SD ± 11.8). Results. Females were found to have significantly more pre- and postreconstruction internal rotation than males (P < 0.001 and P = 0.001, resp.). Patients with additional intra-articular injuries demonstrated more prereconstruction anterior instability than patients with isolated ACL tears (P < 0.001). After reconstruction, these patients also had higher residual anterior translation (P = 0.01). Among all patients with ACL reconstructions, the percent of correction of anterior translation was found to be significantly higher than the percent of correction for internal or external rotation (P < 0.001). Conclusion. Anterior translation was corrected the most using a single-bundle ACL reconstruction. Females had higher pre- and postoperative internal rotation. Patients with additional injuries had greater original anterior translation and less operative correction of anterior translation compared to patients with isolated ACL tears. PMID:25883804

  11. PROPRIOCEPTION, BODY BALANCE AND FUNCTIONALITY IN INDIVIDUALS WITH ACL RECONSTRUCTION

    PubMed Central

    Furlanetto, Tássia Silveira; Peyré-Tartaruga, Leonardo Alexandre; do Pinho, Alexandre Severo; Bernardes, Emanuele da Silva; Zaro, Milton Antonio

    2016-01-01

    Objective : To evaluate and compare proprioception, body balance and knee functionality of individuals with or without unilateral anterior cruciate ligament (ACL) reconstruction. Methods : Forty individuals were divided in two groups: Experimental group, 20 individuals with ACL reconstruction at six months postoperative, and control group, 20 individuals with no history of lower limb pathologies. In the experimental group, we assessed lower limbs with reconstructed ACL and contralateral limb; in the control group the dominant and the non-dominant lower limbs were assessed. All subjects were submitted to joint position sense test to evaluate proprioception, postural control measure in single-limb, and step up and down (SUD) test for functional assessment. Results : There were no deficits in proprioception and postural control. In the SUD test, a 5% decrease in lift up force was found in reconstructed ACL lower limbs, however, a statistically not significant difference. The impact and step down force during the course of test were 30% greater in anatomic ACL than in control lower limbs. Conclusion : The individuals with ACL reconstruction at six months postoperative did not show changes in proprioception and postural control, but showed motor control changes, influencing knee functionality. Level of Evidence IV, Prognostic Studies. PMID:26981038

  12. Transtibial Versus Anteromedial Portal ACL Reconstruction

    PubMed Central

    Jennings, Jonathan Kelsie; Leas, Daniel; Fleischli, James E.; D’Alessandro, Donald; Peindl, Richard Dennis; Habet, Nahir A.; Piasecki, Dana P.

    2016-01-01

    Objectives: A number of studies suggest improved biomechanical and clinical results when ACL grafts are placed anatomically. Worldwide, the most common transtibial (TT) technique has been shown less anatomic than an anteromedial portal (AM) technique, though is much more familiar and less technically challenging. A hybrid transtibial approach (HTT) - using AM portal guidance of a flexible transtibial guide wire without knee hyperflexion - may offer anatomic graft placement while maintaining the relative ease of a transtibial technique. Our objective is to evaluate the anatomic and biomechanical performance of HTT, when compared to TT and AM approaches. Methods: A total of 36 paired, fresh-frozen human knees were used. 24 knees (12 pairs) - each using a standard tibial tunnel - underwent all three techniques (TT, AM, HTT) for femoral tunnel placement, with direct measurement of femoral insertional overlap and femoral tunnel length for each technique. The remaining 12 knees (6 pairs) were used to evaluate graft kinematics and tunnel orientation. Among these knees, 3 size-matched groups (four specimens each) were assigned to each of TT, AM and HTT techniques. Specimens were tested in quad-load induced extension from 90o to 10o of flexion with a distal weight used to simulate half-shank, ankle and foot passive load. Bony kinematics were assessed using a trakSTAR motion tracking system with three sensors installed in each femur and tibia. After femoral tunnel preparation, two sensors were installed in each tunnel to relate tunnel orientation and tunnel inlet location within the joint to the sensors used for motion tracking for the femur and tibia of each specimen. Bone-patellar-bone autografts were harvested from each specimen and used for the assigned reconstructive technique. Analysis included determination of ACL graft length changes, ACL-to-femoral tunnel angle and ACL-to-tibial tunnel angle at five flex/ext angles. Data was analyzed for three flex/ext tests on each

  13. Femoral tunnel malposition in ACL revision reconstruction.

    PubMed

    Morgan, Joseph A; Dahm, Diane; Levy, Bruce; Stuart, Michael J

    2012-11-01

    The Multicenter Anterior Cruciate Ligament (ACL) Revision Study (MARS) group was formed to study a large cohort of revision ACL reconstruction patients. The purpose of this subset analysis study of the MARS database is to describe specific details of femoral tunnel malposition and subsequent management strategies that surgeons chose in the revision setting. The design of this study is a case series. The multicenter MARS database is compiled from a questionnaire regarding 460 ACL reconstruction revision cases returned by 87 surgeons. This subset analysis described technical aspects and operative findings in specifically those cases in which femoral tunnel malposition was cited as the cause of primary ACL reconstruction failure. Of the 460 revisions included for study, 276 (60%) cases cited a specific "technical cause of failure." Femoral tunnel malposition was cited in 219 (47.6%) of 460 cases. Femoral tunnel malposition was cited as the only cause of failure in 117 cases (25.4%). Surgeons judged the femoral tunnel too vertical in 42 cases (35.9%), too anterior in 35 cases (29.9%), and too vertical and anterior in 31 cases (26.5%). Revision reconstruction involved the drilling of an entirely new femoral tunnel in 91 cases (82.1%). For primary reconstruction, autograft tissue was used in 82 cases (70.1%). For revision reconstruction, autograft tissue was used in 61 cases (52.1%) and allograft tissue in 56 cases (47.9%). Femoral tunnel malposition in primary ACL reconstruction was the most commonly cited reason for graft failure in this cohort. Graft selection is widely variable among surgeons. PMID:23150344

  14. Femoral Tunnel Malposition in ACL Revision Reconstruction

    PubMed Central

    Morgan, Joseph A.; Dahm, Diane; Levy, Bruce; Stuart, Michael J.

    2013-01-01

    The Multicenter Anterior Cruciate Ligament (ACL) Revision Study (MARS) group was formed to study a large cohort of revision ACL reconstruction patients. The purpose of this subset analysis study of the MARS database is to describe specific details of femoral tunnel malposition and subsequent management strategies that surgeons chose in the revision setting. The design of this study is a case series. The multicenter MARS database is compiled from a questionnaire regarding 460 ACL reconstruction revision cases returned by 87 surgeons. This subset analysis described technical aspects and operative findings in specifically those cases in which femoral tunnel malposition was cited as the cause of primary ACL reconstruction failure. Of the 460 revisions included for study, 276 (60%) cases cited a specific “technical cause of failure.” Femoral tunnel malposition was cited in 219 (47.6%) of 460 cases. Femoral tunnel malposition was cited as the only cause of failure in 117 cases (25.4%). Surgeons judged the femoral tunnel too vertical in 42 cases (35.9%), too anterior in 35 cases (29.9%), and too vertical and anterior in 31 cases (26.5%). Revision reconstruction involved the drilling of an entirely new femoral tunnel in 91 cases (82.1%). For primary reconstruction, autograft tissue was used in 82 cases (70.1%). For revision reconstruction, autograft tissue was used in 61 cases (52.1%) and allograft tissue in 56 cases (47.9%). Femoral tunnel malposition in primary ACL reconstruction was the most commonly cited reason for graft failure in this cohort. Graft selection is widely variable among surgeons. PMID:23150344

  15. Articular cartilage of the knee 3 years after ACL reconstruction

    PubMed Central

    Bae, Ji-Hoon; Hosseini, Ali; Wang, Yang; Torriani, Martin; Gill, Thomas J; Grodzinsky, Alan J

    2015-01-01

    Background and purpose T1ρ or T2 relaxation imaging has been increasingly used to evaluate the cartilage of the knee. We investigated the cartilage of ACL-reconstructed knees 3 years after surgery using T2 relaxation times. Patients and methods 10 patients with a clinically successful unilateral ACL reconstruction were examined 3 years after surgery. Multiple-TE fast-spin echo sagittal images of both knees were acquired using a 3T MRI scanner for T2 mapping of the tibiofemoral cartilage. T2 values of the superficial and deep zones of the tibiofemoral cartilage were analyzed in sub-compartmental areas and compared between the ACL-reconstructed and uninjured contralateral knees. Results Higher T2 values were observed in 1 or more sub-compartmental areas of each ACL-reconstructed knee compared to the uninjured contralateral side. Most of the T2 increases were observed at the superficial zones of the cartilage, especially at the medial compartment. At the medial compartment of the ACL-reconstructed knee, the T2 values of the femoral and tibial cartilage were increased by 3–81% compared to the uninjured contralateral side, at the superficial zones of the weight-bearing areas. T2 values in the superficial zone of the central medial femoral condyle differed between the 2 groups (p = 0.002). Interpretation The articular cartilage of ACL-reconstructed knees, although clinically satisfactory, had higher T2 values in the superficial zone of the central medial femoral condyle than in the uninjured contralateral side 3 years after surgery. Further studies are warranted to determine whether these patients would undergo cartilage degeneration over time. PMID:25854533

  16. Patient Perception of Reimbursement for Arthroscopic Meniscectomy and ACL Reconstruction

    PubMed Central

    Okoroha, Kelechi; Keller, Robert A.; Marshall, Nathan E.; Guest, John-Michael; Lynch, Jonathan; Lock, Terrence R.; Rill, Brian K.

    2016-01-01

    Objectives: Healthcare policy changes and decreases in Medicare physician reimbursement continue to change the landscape of healthcare. Historically, patient perceptions of surgeon reimbursement have been exaggerated compared to actual reimbursement. Currently there is limited evidence for patient perception for arthroscopic meniscectomy and ACL reconstruction. The purpose of this study was to evaluate patient perception of physician reimbursement for arthroscopic meniscectomy and ACL reconstruction and to compare health care perceptions between urban and suburban clinics. Methods: Surveys were given to 231 consecutive patients, 127 in an urban clinic and 104 in a suburban clinic. Patients were asked their estimation of reasonable reimbursement for arthroscopic meniscectomy and ACL reconstruction as well as their perception on actual Medicare reimbursement to physicians. They were also asked how much would they be willing to pay out of pocket for the procedures. After revealing actual reimbursement rates, patients were asked if reimbursement levels were appropriate, whether surgeon subspecialty training was important, and if additional compensation should be associated with subspecialty training. Survey responses were compared with respondents in an urban versus a suburban setting as well as amongst income and education level. Results: Patients on average reported surgeons should receive $8,096 for a meniscectomy and $11,794 for an ACL reconstruction, 14 times and 11 times as much as actually reimbursed, respectively. Patients estimated that Medicare paid physicians $5,442 for a meniscectomy and $6,667 for an ACL reconstruction. Patients were willing to pay $2,286 out of pocket for a meniscectomy and $11,793 for an ACL reconstruction. Sixty five percent of patients believed reimbursement for meniscectomy was too low and 57% of patients believe reimbursement for ACL reconstruction was too low. Less than 2% of patients believed physician salaries should be cut

  17. Update on rehabilitation following ACL reconstruction

    PubMed Central

    Nyland, John; Brand, Emily; Fisher, Brent

    2010-01-01

    As anterior cruciate ligament (ACL) reconstruction has evolved to less invasive, more anatomical approaches, rehabilitation of the injured athlete has likewise become more progressive and innovative, with a sound understanding of graft and fixation strength and biologic healing-remodeling constraints. This review discusses these innovations including specific considerations before surgery, when planning rehabilitation timetables, and the importance of reestablishing nonimpaired active and passive knee range of motion and biarticular musculotendinous extensibility in positions of function. Concepts of self-efficacy or confidence and reestablishing the “athlete role” are also addressed. Since ACL injury and reinjury are largely related to the influence of structure-form-function on dynamic knee joint stability, the interrelationships between sensorimotor, neuromuscular, and conventional resistance training are also discussed. Although pivot shift “giving way” relates to function loss following ACL injury, anterior translational laxity often does not. Although there is growing evidence that progressive eccentric training may benefit the patient following ACL reconstruction, there is less evidence supporting the use of functional ACL knee braces. Of considerable importance is selecting and achieving a criteria-based progression to sports-specific training, reestablishing osseous homeostasis and improved bone density, blending open and closed kinetic chain exercises at the appropriate time period, and appreciating the influence of the trunk, upper extremities, and sports equipment use on knee loads. We believe that knee dysfunction and functional recovery should be considered from a local, regional, and global perspective. These concepts are consolidated into our approach to prepare patients for return to play including field testing and maintenance training. PMID:24198553

  18. Risk Factors and Predictors Of Subsequent ACL Injury After ACL Reconstruction: Prospective Analysis Of 2801 Primary ACL Reconstructions

    PubMed Central

    Kaeding, Christopher C.; Pedroza, Angela; Reinke, Emily; Huston, Laura J.; Spindler, Kurt P.

    2014-01-01

    Objectives: Retear of an ACL after an ACL reconstruction (ACLR) is devastating for all involved. Understanding risk factors and predictors of subsequent ACL tear after an ACLR is vital for patient education of subsequent risk of injury and if a predictor is modifiable, to make adjustments to minimize the risk of repeat ACL tear. The objectives of this study were 1) to identify the risk factors and predictors for ispilateral and contralateral ACL tears after primary ACLR and 2) to compare retear risk between the 2002/03 and 2007/08 cohorts. This is the largest and most comprehensive prospective analysis of this kind in the literature. Methods: Data from the 2002-2008 MOON database was used to identify risk factors for ACL retear. Subjects who had a primary ACLR with no history of contralateral knee surgery and had 2 year follow-up data were included. Subjects who had multiligament surgery were excluded. Graft type (auto-BTB, auto-hamstring, allograft), age, Marx score at time of index surgery, sport played post ACLR, sex, smoking status, lateral meniscus tear at the time of ACLR, medial meniscus tear at the time of ACLR, BMI, and MOON site were evaluated to determine their contribution to both ipsilateral retear and contralateral ACL tear. The analysis was repeated using the 2002/3 and 2007/8 cohort and included age, graft, sex, and Marx. An ANOVA with post-hoc analysis was performed to detect significant differences in age and Marx score by graft type over time. Results: A total of 2801 subjects met all inclusion/exclusion criteria. There were 165/2801 (5.89%) ipsilateral and 177/2801 (6.32%) contralateral ACL tears identified in the cohort at the two year follow-up. The odds of ipsilateral retear are 1.68 times greater for hamstring autograft (p=0.04) and 4.67 times greater for an allograft (p<0.001) compared to auto-BTB. The odds of ipsilateral retear decrease by 8% for every yearly increase in age (p < 0.001) and increases by 6% for every increased point on the

  19. Return to sport after ACL reconstruction.

    PubMed

    Harris, Joshua D; Abrams, Geoffrey D; Bach, Bernard R; Williams, Donna; Heidloff, Dave; Bush-Joseph, Charles A; Verma, Nikhil N; Forsythe, Brian; Cole, Brian J

    2014-02-01

    Objective guidelines permitting safe return to sport following anterior cruciate ligament (ACL) reconstruction are infrequently used. The purpose of this study was to determine the published return to sport guidelines following ACL reconstruction in Level I randomized controlled trials. A systematic review was performed using Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Level I randomized controlled trials were included if they reported a minimum 2-year follow-up after ACL reconstruction and return to sport criteria. Outcomes analyzed were the timing of initiation of return to sport, follow-up duration, and use of quantitative/qualitative criteria to determine return to sport. Forty-nine studies were included (N=4178; 68% male; mean patient age, 27.5±3.2 years; mean follow-up, 3.0±1.9 years; mean time from injury to reconstruction, 379±321 days). Ninety-six percent of reconstructions used autograft and 87% were single-bundle reconstructions. Lysholm score, single-leg hop, isokinetic strength, and KT-1000 or KT-2000 arthrometer (MEDmetric, San Diego, California) testing were performed in 67%, 31%, 31%, and 82% of studies, respectively. Only 5 studies reported whether patients were able to successfully return to sport. Ninety percent and 65% of studies failed to use objective criteria or any criteria, respectively, to permit return to sport. Description of permission/allowance to return to sport was highly variable and poor. Twenty-four percent of studies failed to report when patients were allowed return to sport without restrictions. Overall, 39%, 45%, and 51% of studies permitted running at 3 months, return to cutting/pivoting sports at 6 months, and return to sport without restrictions at 6 months, respectively. Further research into validated return to sport guidelines is necessary to fill the existing void in contemporary literature and to guide clinical practice. PMID:24679194

  20. ACL Reconstruction: Choosing the Graft

    PubMed Central

    Cerulli, Giuliano; Placella, Giacomo; Sebastiani, Enrico; Tei, Matteo Maria; Speziali, Andrea; Manfreda, Francesco

    2013-01-01

    Summary Rupture of the anterior cruciate ligament is one of the most common ligament injuries in sports traumatology. The need for surgical anterior cruciate ligament reconstruction is justified by its anatomical characteristics. Key considerations when choosing a graft include the potential for bone integration and the risk of failure. Bone sclerosis around the tunnel affects the integration of the graft. For this reason, one aspect upon which orthopedic surgeons should focus is the biology of the bone-graft interface. Although the BPTB graft is still used, hamstrings and synthetic grafts have become increasingly widespread and popular over the years. An allograft certainly requires more long-term follow-up to validate its use in response to functional, clinical and biological requirements. PMID:25606507

  1. The Effect of ACL Reconstruction on Kinematics of the Knee with Combined ACL Injury and Subtotal Medial Meniscectomy - an in-vitro robotic investigation

    PubMed Central

    Seon, Jong Keun; Gadikota, Hemanth R.; Kozanek, Michal; Oh, Luke S.; Gill, Thomas J.; Li, Guoan

    2009-01-01

    Purpose The aims of this study were to determine: 1) the kinematic effect of subtotal medial meniscectomy on ACL deficient knee and 2) the effect of ACL reconstruction on kinematics of the knee with combined ACL deficiency and subtotal medial meniscectomy under an anterior tibial and a simulated quadriceps loads. Methods Eight human cadaveric knees were sequentially tested using a robotic testing system under 4 conditions: intact, ACL deficiency, ACL deficiency with subtotal medial meniscectomy, and single bundle ACL reconstruction using a bone-patellar tendon-bone graft. Knee kinematics were measured at 0°, 15°, 30°, 60°, and 90° of flex ion under an anterior tibial load of 130 N and a quadriceps muscle load of 400 N. Results Subtotal medial meniscectomy in ACL deficient knee significantly increased anterior and lateral tibial translations under the anterior tibial and quadriceps loads (P < 0.05). These kinematic changes were larger at high flexion (≥ 60°) than at low flexion angles. ACL reconstructio n in knees with ACL deficiency and subtotal medial meniscectomy significantly reduced the increased anterior tibial translation, but could not restore anterior translation to the intact level with differences ranging from 2.6 mm at 0° to 5.5 mm at 30° of flexion. ACL reconstruction did not significantly affect the medial-lateral translation and internal-external tibial rotation in the presence of subtotal meniscectomy. Conclusions Subtotal medial meniscectomy in knees with ACL deficiency altered knee kinematics, especially at high flexion angles. ACL reconstruction significantly reduced the increased tibial translation in knees with combined ACL deficiency and subtotal medial meniscectomy, but could not restore the knee kinematics to the intact knee level. Clinical Relevance This study suggests that meniscus is an important secondary stabilizer against anterior and lateral tibial translations and should be preserved in the setting of ACL reconstruction for

  2. Incidence of Second ACL Injuries 2 Years After Primary ACL Reconstruction and Return to Sport

    PubMed Central

    Paterno, Mark V.; Rauh, Mitchell J.; Schmitt, Laura C.; Ford, Kevin R.; Hewett, Timothy E.

    2014-01-01

    Background The incidence of second anterior cruciate ligament (ACL) injuries in the first 12 months after ACL reconstruction (ACLR) and return to sport (RTS) in a young, active population has been reported to be 15 times greater than that in a previously uninjured cohort. There are no reported estimates of whether this high relative rate of injury continues beyond the first year after RTS and ACLR. Hypothesis The incidence rate of a subsequent ACL injury in the 2 years after ACLR and RTS would be less than the incidence rate reported within the first 12 months after RTS but greater than the ACL injury incidence rate in an uninjured cohort of young athletes. Study Design Cohort study; Level of evidence, 2. Methods Seventy-eight patients (mean age, 17.1 ± 3.1 years) who underwent ACLR and were ready to return to a pivoting/ cutting sport and 47 controls (mean age, 17.2 ± 2.6 years) who also participated in pivoting/cutting sports were prospectively enrolled. Each participant was followed for injury and athlete exposure (AE) data for a 24-month period after RTS. Twenty-three ACLR and 4 control participants suffered an ACL injury during this time. Incidence rate ratios (IRRs) were calculated to compare the rates (per 1000 AEs) of ACL injury in athletes in the ACLR and control groups. For the ACLR group, similar comparisons were conducted for side of injury by sex. Results The overall incidence rate of a second ACL injury within 24 months after ACLR and RTS (1.39/1000 AEs) was nearly 6 times greater (IRR, 5.71; 95% CI, 2.0–22.7; P = .0003) than that in healthy control participants (0.24/1000 AEs). The rate of injury within 24 months of RTS for female athletes in the ACLR group was almost 5 times greater (IRR, 4.51; 95% CI, 1.5–18.2; P = .0004) than that for female controls. Although only a trend was observed, female patients within the ACLR group were twice as likely (IRR, 2.43; 95% CI, 0.8–8.6) to suffer a contralateral injury (1.13/1000 AEs) than an

  3. Surgical Predictors of Clinical Outcome following Revision ACL Reconstruction

    PubMed Central

    Wright, Rick W.

    2016-01-01

    Objectives: Revision ACL reconstruction has been documented to have worse outcomes compared with primary ACL reconstructions. The reasons why remain unknown. The purpose of this study was to determine either previous or current surgical factors noted at the time of ACL revision reconstruction predicts activity level, sports function, and OA symptoms at two year follow-up. Methods: Revision ACL reconstruction patients were identified and prospectively enrolled between 2006 and 2011. Data collected included baseline demographics, surgical technique and pathology, and a series of validated patient reported outcome instruments (IKDC, KOOS, WOMAC, and Marx activity rating score). Patients were followed up for 2 years, and asked to complete the identical set of outcome instruments. Regression analysis was used to control for age, gender, BMI, activity level, baseline outcome scores, revision number, time since last ACLR, and a variety of previous and current surgical variables, in order to assess the surgical risk factors for clinical outcomes 2 years after revision ACL reconstruction. Results: 1205 patients met the inclusion criteria and were successfully enrolled. 697 (58%) were males, with a median cohort age of 26 years. The median time since their last ACL reconstruction was 3.4 years. Baseline characteristics of the cohort are summarized in Table 1. At 2 years, follow-up was obtained on 82% (989/1205). Both previous as well as current surgical factors were found to be significant drivers of poorer outcomes at 2 years (Table 2). The most consistent surgical factors driving outcome in revision patients were prior surgical technique, prior tibial tunnel position, current femoral fixation and having a notchplasty. Having a previous arthrotomy compared to the one incision technique resulted in significantly poorer outcomes on the IKDC (odds ratio=0.41; 95% CI=0.17-0.95; p=0.037) and KOOS pain, sports/rec, and QOL subscales (OR range=0.23-0.42; 95% CI=0.10-0.97; p<0

  4. Double bundle or single bundle plus extraarticular tenodesis in ACL reconstruction? A CAOS study.

    PubMed

    Monaco, E; Labianca, L; Conteduca, F; De Carli, A; Ferretti, A

    2007-10-01

    Anatomic reconstructions of anterior cruciate ligament (ACL) with double bundle gracilis and semitendonosus tendons graft, reproducing AM and PL bundles, have been introduced to offer a better biomechanical outcome, especially during rotatory loads. On the other hand, many methods of tenodesing the lateral aspect of the tibia to the femur to reduce internal rotation (IR) of the tibia and minimize anterior translation of the tibia relative to the femur as a backup for intra-articular reconstruction, have been also suggested. The goal of this study is to evaluate the effect, on the IR of the tibia, of a lateral reconstruction in addition to a standard single bundle ACL reconstruction as compared with an anatomic double bundle ACL reconstruction. Computer assisted ACL reconstruction has been used because it could be very effective in evaluating the global kinematic performance of the reconstructed knee. We selected 20 consecutive ACL reconstruction procedures to be performed in males in our hospital. Patients were alternately assigned to one of the two groups--group A: standard single bundle ACL reconstruction with doubled gracilis and semitendinosus tendons graft with an arthroscopically assisted two incisions technique and a lateral extraarticular reconstruction; group B: double bundle ACL reconstruction with doubled gracilis and semitendinosus tendons graft with an arthroscopically assisted two incisions technique. In all ACL reconstruction procedures navigation process was performed. Both surgical techniques reduced significantly AP displacement, IR and external rotation (ER) of the tibia respect to pre-operative ACL deficient condition (p<0.05). Comparing the group A after the single bundle reconstruction and the group B after the AM bundle fixation, non differences were found in AP displacement, IR and ER of the tibia (p=0.75, p=0.07 and p=0.07 respectively; power: 0.94). Comparing the group A after the addition of the lateral tenodesis and group B after the PL

  5. Rehabilitation Predictors of Clinical Outcome following Revision ACL Reconstruction

    PubMed Central

    Wright, Rick W.; Group, Mars

    2016-01-01

    Objectives: Revision ACL reconstruction has been documented to have worse outcomes compared with primary ACL reconstructions. The reasons why remain unknown. The purpose of this study was to determine whether rehabilitation-related factors prescribed at the time of ACL revision reconstruction significantly influence two year outcomes, as well as the incidence of incurring a subsequent re-operation. Our hypothesis was that immediate versus passive, active range of motion (ROM) and weightbearing will result in improved outcomes without incidence of subsequent surgery. Use of postoperative and functional return to sport braces will not improve return to sports function. Methods: Revision ACL reconstruction patients were identified and prospectively enrolled between 2006 and 2011. Data collected included baseline demographics, surgical technique and pathology, prescribed post-op and rehabilitation instructions (ie. timing of weightbearing, timing of passive and active ROM, use of postoperative and return to sport braces) and a series of validated patient reported outcome instruments (IKDC, KOOS, and Marx activity rating score). Patients were followed up for 2 years, and asked to complete the identical set of outcome instruments. Because meniscal repair, meniscal transplants, HTOs, concurrent ligamentous reconstructions, and certain chondral treatments (ie. microfracture, abrasion arthroplasty, mosiacplasty, etc) are known to affect prescribed rehab treatments, patients with these pathologies were excluded from the analyses. Regression analysis was used to control for age, gender, activity level, baseline outcome scores, and the above-mentioned rehabilitation-related variables, in order to assess the risk factors for clinical outcomes 2 years after revision ACL reconstruction. Results: A total of 843 patients met the inclusion criteria and were successfully enrolled. 482 (57%) were males, with a median cohort age of 27 years. Baseline characteristics of the cohort are

  6. Increased Platelet Concentration does not Improve Functional Graft Healing in Bio-Enhanced ACL Reconstruction

    PubMed Central

    Fleming, Braden C.; Proffen, Benedikt L.; Vavken, Patrick; Shalvoy, Matthew R.; Machan, Jason T.; Murray, Martha M.

    2014-01-01

    Purpose The use of an extra-cellular matrix scaffold (ECM) combined with platelets to enhance healing of an ACL graft (“bio-enhanced ACL reconstruction”) has shown promise in animal models. However, the effects of platelet concentration on graft healing remains unknown. The objectives of this study were to determine if increasing the platelet concentration in the ECM scaffold would; 1) improve the graft biomechanical properties, and 2) decrease cartilage damage after surgery. Methods Fifty-five adolescent minipigs were randomized to 5 treatment groups; untreated ACL transection (n=10), conventional ACL reconstruction (n=15), and bio-enhanced ACL reconstruction using 1X (n=10), 3X (n=10) or 5X (n=10) platelet-rich plasma. The graft biomechanical properties, anteroposterior (AP) knee laxity, graft histology and macroscopic cartilage integrity were measured at 15 weeks. Results The mean linear stiffness of the bio-enhanced ACL reconstruction procedure using the 1X preparation was significantly greater than traditional reconstruction while the 3X and 5X preparations were not. The failure loads of all the ACL reconstructed groups were equivalent but significantly greater than untreated ACL transection. There were no significant differences in the ligament maturity index or AP laxity between reconstructed knees. Macroscopic cartilage damage was relatively minor, though significantly less when the ECM-platelet composite was used. Conclusions Only the 1X platelet concentration improved healing over traditional ACL reconstruction. Increasing the platelet concentration from 1X to 5X in the ECM scaffold did not further improve the graft mechanical properties. The use of an ECM-platelet composite decreased the amount of cartilage damage seen after ACL surgery. PMID:24633008

  7. ACL reconstruction with BPTB autograft and irradiated fresh frozen allograft*

    PubMed Central

    Sun, Kang; Tian, Shao-qi; Zhang, Ji-hua; Xia, Chang-suo; Zhang, Cai-long; Yu, Teng-bo

    2009-01-01

    Objective: To analyze the clinical outcomes of arthroscopic anterior cruciate ligament (ACL) reconstruction with irradiated bone-patellar tendon-bone (BPTB) allograft compared with non-irradiated allograft and autograft. Methods: All BPTB allografts were obtained from a single tissue bank and the irradiated allografts were sterilized with 2.5 mrad of irradiation prior to distribution. A total of 68 patients undergoing arthroscopic ACL reconstruction were prospectively randomized consecutively into one of the two groups (autograft and irradiated allograft groups). The same surgical technique was used in all operations done by the same senior surgeon. Before surgery and at the average of 31 months of follow-up (ranging from 24 to 47 months), patients were evaluated by the same observer according to objective and subjective clinical evaluations. Results: Of these patients, 65 (autograft 33, irradiated allograft 32) were available for full evaluation. When the irradiated allograft group was compared to the autograft group at the 31-month follow-up by the Lachman test, the anterior drawer test (ADT), the pivot shift test, and KT-2000 arthrometer test, statistically significant differences were found. Most importantly, 87.8% of patients in the autograft group and just only 31.3% in the irradiated allograft group had a side-to-side difference of less than 3 mm according to KT-2000. The failure rate of the ACL reconstruction with irradiated allograft (34.4%) was higher than that with autograft (6.1%). The anterior and rotational stabilities decreased significantly in the irradiated allograft group. According to the overall International Knee Documentation Committee (IKDC), functional and subjective evaluations, and activity level testing, no statistically significant differences were found between the two groups. Besides, patients in the irradiated allograft group had a shorter operation time and a longer duration of postoperative fever. When the patients had a fever, the

  8. ACL reconstruction in a teenage athlete with fibular hemimelia.

    PubMed

    Mascarenhas, Randy; Simon, David; Forsythe, Brian; Harner, Christopher D

    2014-03-01

    Fibular hemimelia exists as a rare cause of ACL insufficiency. This case report concerns the diagnosis and treatment of anterior cruciate ligament insufficiency in a teenage football player with fibular hemimelia. While ACL reconstruction has been described to allow activities of daily living in this patient population, this is the first report in the literature of anterior cruciate ligament reconstruction in an athlete with fibular hemimelia. We believe that ACL reconstruction is a viable and beneficial treatment option in the care of a symptomatic patient with congenital absence of the ACL and can allow athletes with this condition to return not only to their previous functional level, but also to their previous level of play. PMID:24238853

  9. Physeal Disruption During ACL Reconstruction in Skeletally Immature Patients

    PubMed Central

    Cruz, Aristides Ignacio; Lakomkin, Nikita; Fabricant, Peter D.; Lawrence, John Todd R.

    2016-01-01

    Objectives: The purpose of this study was to radiographically assess differences in distal femoral physeal disruption between transtibial and independent femoral tunnel drilling techniques following ACL reconstruction in skeletally immature patients. Methods: A retrospective, matched comparative cohort study was performed of skeletally immature patients who underwent transphyseal ACL reconstruction between January 1, 2008 and March 31, 2011. All skeletally immature patients between ten and fifteen years old who underwent independent femoral tunnel drilling and had adequate baseline and post-operative radiographs were analyzed. These patients were matched with a transtibial technique cohort based on age and sex. Demographic characteristics and peri-operative metrics were collected. Radiographic measurements were recorded from pre-operative MRI and post-operative plain radiographs. Results: Twenty patients were analyzed. Between groups, there were significant differences between independent tunnel drilling and transtibial tunnel drilling in the estimated area of physeal disruption (1.64 cm2 vs. 0.74 cm2, P<0.001), femoral (32.1º vs. 72.8º, P<0.001) and tibial (50.1º vs. 60.5º, P=0.003) tunnel angles, medial/lateral location of the femoral tunnel (24.2 mm vs. 36.1 mm from lateral cortex, P=0.001), and distance from the lateral aspect of the distal femoral physis and the femoral tunnel exit (4.7 mm vs. 26.7 mm from the perichondrial ring, P<0.001), respectively. All patients who underwent femoral tunnel drilling at an angle of less than 25º from the transverse axis experienced a greater than 6% disruption of physeal area. There was a significant inverse correlation between femoral tunnel angle and estimated area of femoral physeal involvement (r=-0.8255, P=0.003). Conclusion: With femoral tunnel drilling techniques that create more oblique tunnels, the area of distal femoral physeal damage is larger, more eccentric and closer to the perichondrial ring. Since most

  10. ACL mismatch reconstructions: influence of different tunnel placement strategies in single-bundle ACL reconstructions on the knee kinematics.

    PubMed

    Herbort, Mirco; Lenschow, Simon; Fu, Freddie H; Petersen, Wolf; Zantop, Thore

    2010-11-01

    To evaluate the influence of tibial and femoral tunnel position in ACL reconstruction on knee kinematics, we compared ACL reconstruction with a tibial and femoral tunnel in anteromedial (AM-AM reconstruction) and in posterolateral footprint (PL-PL reconstruction) with a reconstruction technique with tibial posterolateral and femoral anteromedial tunnel placement (PL-AM reconstruction). In 9 fresh-frozen human cadaveric knees, the knee kinematics under simulated Lachman (134 N anterior tibial load) and a simulated pivot shift test (10 N/m valgus and 4 N/m internal tibial torque) were determined at 0°, 30°, 60°, and 90° of flexion. Kinematics were recorded for intact, ACL-deficient, and single-bundle ACL reconstructed knees using three different reconstruction strategies in randomized order: (1) PL-AM, (2) AM-AM and (3) PL-PL reconstructions. Under simulated Lachman test, single-bundle PL-AM reconstruction and PL-PL reconstructions both showed significantly increased anterior tibial translation (ATT) at 60° and 90° when compared to the intact knee. At all flexion angles, AM-AM reconstruction did not show any statistical significant differences in ATT compared to the intact knee. Under simulated pivot shift, PL-AM reconstruction resulted in significantly higher ATT at 0°, 30°, and 60° knee flexion and AM-AM reconstructions showed significantly higher ATT at 30° compared to the intact knee. PL-PL reconstructions did not show any significant differences to the intact knee. AM-AM reconstructions restore the intact knee kinematics more closely when compared to a PL-AM technique resembling a transtibial approach. PL-PL reconstructions showed increased ATT at higher flexion angles, however, secured the rotational stability at all flexion angles. Due to the independent tibial and femoral tunnel location, a medial portal technique may be superior to a transtibial approach. PMID:20461359

  11. Biomechanical Evaluation of Knee Kinematics after ACL Reconstructions in Anatomic SB and DB - Technique with Additional Medial Meniscus Suture

    PubMed Central

    Lorbach, Olaf; Herbort, Mirco; Engelhardt, Martin; Kieb, Matthias

    2013-01-01

    Objectives: Biomechanical evaluation of knee laxity after single- and double-bundle ACL reconstruction with additional medial meniscus suture. Methods: Kinematics of the intact knee were determined in 12 human cadaver specimens in response to a 134-N anterior tibial load (aTT) and a combined rotatory load of 10 Nm valgus and 4 Nm internal tibial rotation using a robotic/universal force moment sensor testing system. Subsequently, the ACL was resected following the creation of a bucket-handle tear of the medial meniscus. A standard repair of the medial meniscus was performed using 3 inside-out horizontal sutures. Finally, The ACL was reconstructed using an anatomic single-bundle (6) or double-bundle technique (6). Knee kinematics were determined following every sub-step. Results: Significant increase of aTT in the ACL-deficient knee was found with significant increase in the ACL-deficient knee with additional medial meniscal injury (p=.003; p=.009). ACL reconstructions significantly decreased aTT compared to the ACL-deficient knee. No significant differences were found between the intact knee and the ACL reconstructed knee with additional meniscal repair. In response to a simulated pivot shift, aTT in the intact knee significantly increased in the ACL-deficient knee as well as in the meniscus injured/meniscus-sutured knee (p=.003;p=.007). No significant differences were found between the ACL-deficient and ACL reconstructed knee with additional meniscal repair. SB as well as DB ACL reconstruction with additional medial meniscal repair restored knee kinematics compared to the intact knee. Comparison of SB versus DB ACL reconstruction did not reveal any significant differences neither in a simulated Lachman test nor in response to a simulated pivot shift (p=.05). Conclusion: aTT as well as aTT in response to a combined rotatory load significantly increased with ACL deficiency compared to the intact knee, additional medial meniscal injury further increased aTT. Anatomic

  12. Quality of Movement for Athletes Six Months Post ACL Reconstruction

    PubMed Central

    deMille, Polly; Nguyen, Joseph; Brown, Allison; Do, Huong; Selvaggio, Elizabeth; Chiaia, Theresa

    2016-01-01

    Objectives: Anterior cruciate ligament (ACL) injury prevention programs evaluate quality of movement (QM) to identify and correct high-risk movement patterns. However, return to play (RTP) decisions post-ACL reconstruction (ACLR) are often based on non-sport relatedquantitative measures such as isokinetic tests and/or time from surgery, with six months post-ACLR being a common expectation for RTP. The purpose of this study was to evaluate whether athletes are ready to RTP 6 months post ACLR using a QM assessment (QMA). Methods: A QMA including nine dynamic tasks (squat, single leg [SL] stance, step down, SL squat, jump in place, side to side jump, broad jump, hop to opposite, SL hop) progressing from double- to single-limb vertical and horizontal movements was administered to 136 athletes at five to seven months post-ACLR. Tasks were viewed from the frontal and sagittal planes by a physical therapist and performance specialist. Movements were evaluated live for risk factors associated with ACL injury (strategy, depth, control, symmetry, and alignment). The proportion of patients exhibiting risky movement patterns for each task was calculated. Fisher’s Exact test was used to determine if there were differences in movement patterns between males and females. Results: The proportion of patients demonstrating risky movement patterns for a task ranged from 48% to 100%. All 136 patients exhibited risky movement patterns for at least one task and 60% of patients displayed risky movement patterns in five or more of the nine tasks. Rates of risky movement patterns were not different between males and females for all tasks (P>0.1 for all tasks). Conclusion: Six months has been cited as a probable time for RTP post-ACLR; thus this is the expectation of the athlete. Our data show that athletes demonstrate multiple QM patterns associated with initial ACL injury, as well as 2nd injury at five to seven months post-operatively. Altered movement patterns evident in tasks as

  13. USE OF SPATIOTEMPORAL GAIT PARAMETERS TO DETERMINE RETURN TO SPORTS AFTER ACL RECONSTRUCTION

    PubMed Central

    LEPORACE, GUSTAVO; METSAVAHT, LEONARDO; ZEITOUNE, GABRIEL; MARINHO, THIAGO; OLIVEIRA, TAINÁ; PEREIRA, GLAUBER RIBEIRO; OLIVEIRA, LISZT PALMEIRA DE; BATISTA, LUIZ ALBERTO

    2016-01-01

    Objective : To compare gait spatiotemporal parameters of healthy and ACL reconstructed subjects in order to classify the status of gait normality. Methods : Fourteen healthy subjects and eight patients submitted to ACL reconstruction walked along a walkway while the lower limbs movement was captured by an infrared camera system. The frames where the initial contact and toe-off took place were determined and the following dependent variables, which were compared between groups through the Mann-Whitney test (a=0.05) were calculated: percentage of time in initial double stance, percentage of time in single stance, percentage of time in terminal double stance, stride length and gait velocity. Initially, all variables were compared between groups using a Mann-Whitney test. A logistic regression was applied, including all dependent variables, to create a model that could differentiate healthy and ACL reconstructed subjects. Results : ACL reconstructed group showed no differences in any spatiotemporal parameter of gait (p > 0.05) in relation to the control group, although the angular kinematic differences of the knee remained altered, as evidenced in a study with a similar sample. Conclusion : The regression classified all subjects as healthy, including the ACL reconstructed group, suggesting the spatiotemporal variables should not be used as the sole criterion of return to sports activities at the same level as prior to injury. Level of Evidence III, Case Control Study. PMID:26981039

  14. Quality of life assessment scores after ACL reconstruction. 223 patients from the Unisports clinic

    PubMed Central

    Rosenfeldt, MP; Stanley, J; Walsh, SJ; Twaddle, BC; Tietjens, BR

    2016-01-01

    Objective: Determination of the effectiveness of ACL reconstruction requires outcome measures. Traditionally these have been based on a clinical assessment by the surgeon. The most important outcomes to measure are those that are important to the patient themselves. Methods: Over a 5-year period all eligible patients completed a validated ACL-QOL outcome measure. This proved to be a very difficult group to follow with only 22% of eligible patients completing all data forms. Results: ACL provided improved function across of categories on 1 year ACL-QOL scores. There remained a significant deficit to a “normal” knee score. Conclusion: Highlighting the importance of prospective data collection, patients had worse retrospective scores at 1 year than they had prospectively.

  15. Knee instability scores for ACL reconstruction.

    PubMed

    Rahnemai-Azar, Ata A; Naendrup, Jan-Hendrik; Soni, Ashish; Olsen, Adam; Zlotnicki, Jason; Musahl, Volker

    2016-06-01

    Despite abundant biological, biomechanical, and clinical research, return to sport after anterior cruciate ligament (ACL) injury remains a significant challenge. Residual rotatory knee laxity has been identified as one of the factors responsible for poor functional outcome. To improve and standardize the assessment of knee instability, a variety of instability scoring systems is available. Recently, devices to objectively quantify static and dynamic clinical exams have been developed to complement traditional subjective grading systems. These devices enable an improved evaluation of knee instability and possible associated injuries. This additional information may promote the development of new treatment algorithms and allow for individualized treatment. In this review, the different subjective laxity scores as well as complementary objective measuring systems are discussed, along with an introduction of injury to an individualized treatment algorithm. PMID:26980119

  16. The Effects of Balance Training on Static and Dynamic Postural Stability Indices After Acute ACL Reconstruction

    PubMed Central

    Akbari, Asghar; Ghiasi, Fateme; Mir, Mohsen; Hosseinifar, Mohammad

    2016-01-01

    Background: Proprioception and postural stability play an important role in knee movements. However, there are controversies about the overall recovery time of proprioception following knee surgery and onset of balance and neuromuscular training after ACL reconstruction. Therefore, it is necessary to evaluate the effect of balance training in early stage of knee rehabilitation after anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to evaluate the effect of balance exercises on postural stability indices in subjects with anterior cruciate ligament (ACL) reconstruction. Methods: The study was a controlled randomized trial study. Twenty four patients who had ACL reconstructed (balance training group) and twenty four healthy adults without any knee injury (control group) were recruited in the study. The balance exercises group performed balance exercises for 2 weeks. Before and after the interventions, overall, anteroposterior, and mediolateral stability indices were measured with a Biodex Balance System in bilateral and unilateral stance positions with the eyes open and closed. T-tests were used for statistical analysis (p<0.05). Results: Results showed that amount of static stability indices did not change after training and there were not significant differences in static stability indices before and after balance training (p>0.05). Although amount of dynamic stability indices decreased, there were not significant differences in dynamic stability indices before and after balance training (p>0.05). Amount of dynamic stability indices were decreased in balance training group, however, there were not significant differences between groups (p>0.05). Conclusion: These results support that balance exercise could partially improved dynamic stability indices in early stage of ACL reconstruction rehabilitation. The results of this study suggest that balance exercises should be part of the rehabilitation program following ACL reconstruction. PMID

  17. KNEE SYNERGISM DURING GAIT REMAIN ALTERED ONE YEAR AFTER ACL RECONSTRUCTION

    PubMed Central

    LEPORACE, GUSTAVO; METSAVAHT, LEONARDO; PEREIRA, GLAUBER RIBEIRO; OLIVEIRA, LISZT PALMEIRA DE; CRESPO, BERNARDO; BATISTA, LUIZ ALBERTO

    2016-01-01

    ABSTRACT Objective: To compare the activation of the vastus lateralis (VL) and biceps femoris (BF) muscles during gait, as well VL/BF muscular co-contraction (MCC) between healthy (CG) and anterior cruciate ligament reconstructed (ACL-R) subjects. Methods: Nineteen subjects, ten controls and nine ACL-R patients had a VL and BF electromyogram (EMG) captured to calculate the MCC ratio. A Principal Component (PC) Analysis was applied to reduce the dimensionality effect of each of the MCC, VL and BF curves for both healthy and ACL reconstructed groups. The PC scores were used to calculate the standard distance (SD). SD values were employed in order to compare each dependent variable (MCC, VL and BF) between the two groups using unpaired t-test. Results: ACL-R group presented a lower VL activation at the beginning and at the end of the gait cycle, as compared to the control group. However, no difference was found for BF or VL/BF MCC. Conclusion: The gait analysis of ACL reconstructed patients demonstrated a persistent deficit in VL activation when compared to the control group, even one year after surgery. Level of Evidence III. Case Control Study PMID:27217814

  18. Growth disturbances without growth arrest after ACL reconstruction in children.

    PubMed

    Chotel, Franck; Henry, Julien; Seil, Romain; Chouteau, Julien; Moyen, Bernard; Bérard, Jérôme

    2010-11-01

    Growth arrest is a major concern after ACL reconstruction in children. It usually occurs in patients near to closure of the growth plates. Growth disturbances without growth arrest are also possible and more vicious; the authors analyse the mechanism of two patients with growth disturbance due to overgrowth following ACL reconstruction. One was a symmetrical overgrowth process with 15 mm limb length discrepancy treated with percutaneous epiphysiodesis. Full correction at the time of skeletal maturity was achieved. The second patient developed an asymmetrical overgrowth with progressive tibial valgus deformity. This mechanism was similar to a posttraumatic tibial valgus deformity. After nonoperative treatment, a spontaneous correction of the deformity was noticed. Both children were young (7 and 10 years old) at the time of ACL reconstruction with an autologous iliotibial band graft. The clinical relevance of overgrowth disturbance is usually limited when compared to growth arrest but could require a second surgical procedure as reported in this study. Parents must be informed that even in experienced hands, and despite the use of a physeal sparing technique, this specific risk of growth disturbance is still present. PMID:20182870

  19. Predictors of Lateral Compartment Joint Space Difference at a Minimum of Two Years after ACL Reconstruction

    PubMed Central

    Jones, Morgan H.; Reinke, Emily; Duryea, Jeffrey; Fleming, Braden C.; Obuchowski, Nancy; Winalski, Carl S.; Spindler, Kurt P.

    2016-01-01

    Objectives: ACL reconstruction effectively restores knee stability and allows a return to athletic activities after ACL injury, but patients are still at higher risk of developing post-traumatic OA. Patient reported outcomes from the Multicenter Orthopaedic Outcomes Network (MOON) prospective longitudinal cohort of over 1500 patients undergoing ACL reconstruction showed no increase in OA symptoms (KOOS subscale) at 2 or 6 years after surgery. Therefore, identification of structural changes of OA that may precede the onset of symptoms is of critical importance for determining risk factors for the initiation and progression of post-traumatic OA in addition to measuring the effectiveness of potential disease-modifying treatments. One structural measure of OA is radiographic joint space width (JSW). We previously demonstrated that meniscus treatment and age predict narrower medial compartment JSW. Methods: 335 patients from the MOON cohort (154 males, 181 females, median age 18 years at the time of surgery) were recruited at a minimum of 2 years following surgery for on-site evaluations including bilateral metatarsophalangeal joint (MTP) radiographs to assess JSW. To minimize bias related to pre-existing knee injury or OA, subjects were 35 years or younger, were injured playing a sport, had primary ACL reconstruction without prior meniscus or articular cartilage surgery, did not undergo subsequent ACL revision, and had a surgically normal contralateral knee. Radiographic JSW was measured in the lateral compartment of both knees using a validated semiautomated method. The association of age, sex, BMI, meniscus treatment, and articular cartilage treatment with lateral compartment JSW differences (JSD) between the reconstructed and normal knees was examined using multivariable generalized linear models. The Holm-Bonferroni method was used to account for multiple comparisons. Results: The mean lateral compartment JSW was 7.73 mm and (95% CI 7.61-7.85 mm) for ACL

  20. Recovery of Psychological Readiness May Differ Between Genders Following ACL Reconstruction in Adolescent Athletes

    PubMed Central

    Milewski, Matthew David; Kostyun, Regina; Iannicelli, Julie P.; Kostyun, Kyle J.; Solomito, Matthew; Nissen, Carl W.

    2016-01-01

    Objectives: Injury to the anterior cruciate ligament (ACL) is a traumatic and emotional event for adolescent athletes. Preparation to return to play (RTP) and the potential risk of re-injury are often equally as emotional as the injury, and have been identified as possible limiting factors to a successful rehabilitation and RTP. In order to create a comprehensive rehabilitation model, further understanding of psychological readiness following surgical intervention is needed. The purpose of this study was to determine if clinical outcomes of subjective knee function and psychological readiness differ between genders following ACL reconstruction surgery in adolescent athletes, and if higher knee function and physiological readiness was associated with an earlier to RTP. Methods: Athletes who underwent ACL reconstruction surgery and were successfully returned back to unrestricted sport were included in the analysis. At approximately six months post surgery, knee function was assessed using the validated International Knee Documentation Committee (IKDC) Subjective Form, and psychological readiness was assessed using the validated ACL-Return to Sport after Injury (ACL-RSI) scale. Formal clearance to resume unrestricted sport was obtained from clinic notes. A T-test was used to determine if demographics, IKDC and ACL-RSI scores between genders. A mixed effects random intercept regression model was used to determine the association of time to RTP with IKDC and ACL-RSI scores. Results: A total of 45 adolescent athletes (23 females) were included in this analysis. No significant differences were found between males and females for age (16.2±1.5 years, 16.3±2.2 years) and average time to RTP (7.3±2.0 months, 7.3±1.8 months). No significant differences in IKDC scores were found between males and females (88±10%, 87±10%). A trend was identified that males demonstrated higher ACL-RSI scores at six month post surgery than females (81±14%, 72±17%, p = 0.063). In females

  1. Strength Asymmetry and Landing Mechanics at Return to Sport after ACL Reconstruction

    PubMed Central

    Schmitt, Laura C.; Paterno, Mark V.; Ford, Kevin R.; Myer, Gregory D.; Hewett, Timothy E.

    2014-01-01

    Purpose Evidence-based quadriceps femoris muscle (QF) strength guidelines for return to sport following anterior cruciate ligament (ACL) reconstruction are lacking. This study investigated the impact of QF strength asymmetry on knee landing biomechanics at the time of return to sport following ACL reconstruction. Methods Seventy-seven individuals (17.4 years) at the time of return to sport following primary ACL reconstruction (ACLR group) and 47 uninjured control individuals (17.0 years) (CTRL group) participated. QF strength was assessed and Quadriceps Index calculated (QI = [involved strength/uninvolved strength]*100%). The ACLR group was sub-divided based on QI: High Quadriceps (HQ, QI≥90%) and Low-Quadriceps (LQ, QI<85%). Knee kinematic and kinetic variables were collected during a drop vertical jump maneuver. Limb symmetry during landing, and discrete variables were compared among the groups with multivariate analysis of variance and linear regression analyses. Results The LQ group demonstrated worse asymmetry in all kinetic and ground reaction force variables compared to the HQ and CTRL groups, including reduced involved limb peak knee external flexion moments (p<.001), reduced involved limb (p=.003) and increased uninvolved limb (p=.005) peak vertical ground reaction forces, and higher uninvolved limb peak loading rates (p<.004). There were no differences in the landing patterns between the HQ and CTRL groups on any variable (p>.05). In the ACLR group, QF strength estimated limb symmetry during landing after controlling for graft type, meniscus injury, knee pain and symptoms. Conclusion At the time of return to sport, individuals post-ACL reconstruction with weaker QF demonstrate altered landing patterns. Conversely, those with nearly symmetrical QF strength demonstrate landing patterns similar to uninjured individuals. Consideration of an objective QF strength measure may aid clinical decision-making to optimize sports participation following ACL

  2. Evaluation of Proximal Joint Kinematics and Muscle Strength Following ACL Reconstruction Surgery in Female Athletes

    PubMed Central

    Noehren, Brian; Abraham, Autumn; Curry, Melisa; Johnson, Darren; Ireland, Mary Lloyd

    2015-01-01

    Background\\Purpose Despite the intense focus on outcomes following an anterior cruciate ligament (ACL) reconstruction, it is not yet known whether unresolved abnormal hip and trunk neuromuscular control exists. The purpose of this study was to compare trunk and hip kinematics during running, hip abductor and external rotator strength, and trunk control between females who had undergone an ACL reconstruction and healthy control participants. Methods We compared 20 ACL reconstructed females to 20 healthy individuals, measuring abduction and external rotation strength, a trunk control test, and performed an instrumented gait evaluation during running. Comparisons between groups were made for non-sagittal peak hip angles, forward trunk lean, trunk ipsilateral lean at initial contact, trunk control and hip abduction and external rotation strength. Results We found no significant differences in hip abduction (p = 0.25), hip external rotation strength (p = 0.63), peak hip adduction (p = 0.11) or hip internal rotation angle (p = 0.47). The ACL group did have a significantly greater ipsilateral trunk lean (p = 0.028), forward lean (p = 0.004), and had higher errors on the trunk stability test (p = 0.007). Conclusion We found significant differences in trunk control, suggesting further attention should be devoted to this component of rehabilitation. PMID:25044305

  3. Fifteen Year Prospective Comparison of Patellar & Hamstring Tendon Grafts for ACL Reconstruction

    PubMed Central

    Roe, Justin; Salmon, Lucy; Kok, Alison; Linklater, James; Pinczewski, Leo

    2016-01-01

    Objective: This prospective longitudinal study compares isolated endoscopic ACL reconstruction utilizing 4-strand hamstring tendon (HT) or patellar tendon (PT) autograft over a 15-year period with respect to clinical outcomes and the development of osteoarthritis. Method: 90 consecutive patients with isolated ACL rupture were reconstructed with a PT autograft and 90 patients received HT autograft, with an identical surgical technique. Patients were assessed at 2, 5, 7, 10 and 15 years. Assessment included the IKDC Knee Ligament Evaluation including radiographic evaluation, KT1000, kneeling pain, and clinical outcomes. Results: Subjects who received the PT graft had significantly worse outcomes at 15 years for the variables of radiologically detectable osteoarthritis (p=0.001), motion loss (p=0.02), single leg hop test (p=0.002), participation in strenuous activity (p=0.03), knee related decrease in activity level (p=0.002) and kneeling pain (p=0.03). There was no significant difference between the HT and PT groups in overall IKDC grade (p=0.28). ACL graft rupture occurred in 16% of HT group and 8% of the PT group (p=0.10). Contralateral ACL rupture occurred in significantly more PT patients (24%) than HT patients (12%) (p=0.03). Conclusion: Significant differences have developed at 15 years after surgery which were not seen at earlier reviews. Compared to the HT Group, the PT group had significantly worse outcomes with respect to radiological osteoarthritis, range of motion and functional tests but no significant difference in laxity was identified. There was a high incidence of ACL injury after reconstruction, to both the reconstructed and the contralateral knee.

  4. A complication following ACL reconstruction using bioabsorbable cross-pins.

    PubMed

    Vecchini, Eugenio; Micheloni, Gian Mario; Corbo, Valentina Rita; Perusi, Francesco; Dib, Giovanni; Magnan, Bruno

    2016-01-01

    This is a case of a proximal pin migration after ACL reconstruction in medial soft tissue with pain, inflammatory reaction and functional reduction. 33-year-old male presented at our clinic with a complete ACL rupture. Reconstruction with autogenous gracilis and semitendinosus hamstring tendons was performed and graft fixed in the femoral canal with two PLLA bioabsorbable pins (RIGIDFIX® Cross Pin System). Two months postoperatively the patient presented swelling and pain on the medial side of the knee, full range of motion and negative results at the Lachman and Pivot shift tests. MRI examination showed the superior femoral tunnel crossing both the lateral and medial cortex lodging the pin in the knee's medial soft tissue corresponding to the swelling area reported by the patient. The tendon graft was properly positioned. After surgical removal of the pin through a small skin incision, the pain and swelling promptly subsided allowing the patient return to normal activities in few weeks without any pain. In our opinion the painful swelling of the knee was due to a displacement of the pin that had been accidentally lodged in the soft tissues instead of the bone causing a foreign-body reaction resulting in granuloma formation with local inflammation. This dislodgement could have been due to an inappropriately long femoral tunnel. PMID:27104331

  5. Prediction of Patient-Reported Outcome After Single-Bundle ACL Reconstruction

    PubMed Central

    Kowalchuk, Deborah A.; Harner, Christopher D.; Fu, Freddie H.; Irrgang, James J.

    2010-01-01

    Purpose To identify pre-operative and intra-operative factors that predict patient-oriented outcome as measured by the IKDC Subjective Knee Form after ACL reconstruction. Methods We identified 402 subjects who had undergone primary single-bundle arthroscopic ACL reconstruction at a mean follow-up of 6.3 years (range 2-15 years). The International Knee Documentation Committee Subjective Knee Form (IKDC) was used to measure patient-reported outcome and was dichotomized as above or below the patient-specific age and gender matched population average. Potential predictor variables included subject demographics, activity level prior to surgery, previous meniscectomy, and surgical variables. Multivariate logistic regression analysis was performed to identify the best subset of predictors for determining the likelihood that the IKDC score was better than the age- and sex-matched population average. Results The dichotomized IKDC score was associated with BMI, smoking status, education, previous medial meniscectomy, and medial chondrosis at the time of ACL reconstruction. The multivariate model containing only factors known before surgery included BMI and smoking status. Subjects with a BMI > 30 had 0.35 times the odds of success than subjects with a normal BMI. Subjects who smoked had 0.36 times the odds of success as subjects who did not smoke. A model including medial chondrosis at the time of surgery had a slightly higher discriminatory power (area under the ROC curve 0.65 versus 0.61) and negative predictive value (71.4 versus 60.0), but similar positive predictive power (86.3 versus 85.9). Conclusions Lower patient-reported outcome following ACL reconstruction was strongly associated with obesity, smoking, and severe chondrosis at time of surgery. PMID:19409302

  6. Intra-articular bupivacaine or bupivacaine and morphine after ACL reconstruction

    PubMed Central

    Danieli, Marcus Vinicius; Cavazzani Neto, Antonio; Herrera, Paulo Adilson

    2012-01-01

    Objective Reconstructive surgery of the ACL is one of the most commonly performed surgeries today and the control of postoperative pain is part of the priorities of the surgeon. Within the arsenal of analgesia we have the intra-articular application of drugs, and the most studied one is bupivacaine with or without morphine. This study compared the application of bupivacaine with or without morphine with a control group after ACL reconstruction with flexor tendon graft. Methods Forty-five patients were randomized into three groups: in group I, 20 ml of saline were applied intra-articularly at the end of the surgery; in group II, 20 ml of bupivacaine 0.25%; and in group III, bupivacaine 0.25% associated with 1 mg of morphine. The groups were assessed for degree of pain by the Visual Analog Scale at 6, 24 and 48 hours postoperatively. Results Group III had less pain at all times, but the pain was not as intense in all groups to the point of needing extra medications beyond the established protocol. Conclusion The intra-articular application of these medications after ACL reconstruction with flexor tendon graft when performed under spinal anesthesia is not useful enough to use regularly. Level of Evidence II, Lesser quality RCT PMID:24453613

  7. Use of Supercritical Sterilized Bone Allograft in Two Stage Revision ACL Reconstruction

    PubMed Central

    Roe, Justin; Rutten, Sjoerd; Bonnar, Fiona; Salmon, Lucy; Pinczewski, Leo

    2016-01-01

    Objectives: Revision ACL-reconstruction can be compromised by bone loss as result of tunnel widening or poorly placed tunnels. Two-stage revision ACL consist of initial removal of the old fixation hardware and remaining ACL-graft tissue, followed by bone grafting of the tunnels. After a period of graft incorporation and bone remodeling, an ACL-reconstruction is performed. Our primary aim is to examine the use of supercritical carbon dioxide sterilized bone allograft for tunnel grafting in order to determine the bone quality, graft incorporation and remodeling, by using histology and histomorphometric analysis. Secondarily, we aimed to determine whether the histological findings correlate with the timing of the second stage revision procedure. Methods: Case Series. 12 subjects underwent 2-stage revision ACL reconstruction. Femoral and tibial tunnels were bone grafted with supercritical carbon dioxide sterilized bone allograft (Australian Biotechnologies). Mean time from bone grafting to 2nd stage was 8.8 months (range, 5.6 to 21.3 months). Bone biopsies were taken at the time of the 2nd surgery and decalcified and embedded in paraffin. Sections were hematoxylin and eosin stained for microscopic analysis. Results: The graft material was easily identified by its necrotic appearance with empty osteocytes lacunes within the lamellar trabecular bone. In all tissue samples predominately lamellar host bone apposition was seen on the surface of graft fragments known as creeping substitution. Separate bone graft fragments were bridged by newly formed woven bone. In the histological sections of 2 subjects some small islands of chondral cell differentiation were seen, which may relate to endochondral ossification. Active bone remodeling and resorption through combined osteoclastic and osteoblastic activity was present in 2 subjects (7.0 and 6.3 months post grafting), suggesting more advanced phases of graft incorporation. Mean bone volume was 68% over tissue volume (range 33

  8. Anatomic Double Bundle single tunnel Foreign Material Free ACL-Reconstruction – a technical note

    PubMed Central

    Felmet, Gernot

    2011-01-01

    Summary The anterior cruciate ligament (ACL) consists of two bundles, the anteromedial (AM) and posterolateral bundle (PM). Double bundle reconstructions appear to give better rotational stability. The usual technique is to make two tunnels in the femur and two in the tibia. This is difficult and in small knees may not even be possible. We have developed a foreign material free press fit fixation for double bundle ACL reconstruction using a single femoral tunnel (R). This is based on the ALL PRESS FIT ACL reconstruction. It is suitable for the most common medium and, otherwise difficult, small sizes of knees. Method: Using diamond edged wet grinding hollow reamers, bone cylinders in different diameters are harvested from the implantation tunnels of the tibia and femur and used for the press fit fixation. Using the press fit technique the graft is first fixed in tibia. It is then similarly fixed under tension in the femoral side with the knee in 120 degree flexion. This is called Bottom To Top Fixation (BTT). On extending the knee the graft tension is self adapting. Depending on the size of the individual knee, the diameter of the femoral bone plug is varied from 8 to 13 mm to achieve an anatomic spread with a double bundle-like insertion. The tibia tunnel can be applied with two 7 or 8 mm diameter tunnels overlapping to a semi oval tunnel between 10 to 13 mm. Results: Since May 2003 we have carried out ACL-reconstructions with Hamstring grafts without foreign material using the ALL PRESS FIT technique. Initially, an 8 mm press fit fixation was used proximally with good results. Since April 2008, the range of diameters was increased up to 13 mm. The results of the Lachman tests have been good to excellent. Results of the Pivot shift test suggested more stability with femoral broader diameters of 9,5 to 13 mm. Conclusions: The foreign material free fixation of ham-string in the ALL PRESS FIT Bottom To Top Fixation is a successful method for ACL Reconstruction. The

  9. Acute Vs Delayed ACL Reconstruction. Early Differences and Preliminary Two Year Results

    PubMed Central

    Eriksson, Karl; Barenius, Björn

    2016-01-01

    Objectives: Historically acute ACL reconstruction has been avoided due to reports of early rehabilitation problems with stiffness. Are these reports still valid today with modern arthroscopic techniques? Methods: 70 patients with a high recreational activity level (Tegner ≥6) who presented with a acute ACL injury were randomized to an acute reconstruction within 8 days from the injury or delayed reconstruction after 6-10 weeks. Four surgeons performed the ACL reconstructions with quadrupled semitendinosus tendon grafts and endobutton and metallic interference screw fixation. The rehabilitation training was performed at the same physiotherapy center for all patients. The follow up at 6 and 24 months included ROM, Lachman, Rolimeter, pivot shift, one leg hop, IKDC, KOOS, Lysholm and Tegner activity level. Results: There were no differences between the groups in ROM, IKDC, activity level or laxity at 6 months. Four patients had a combined extension and flexion deficit of more than 15 degrees, two from each group. In the acute group 79% had an objective IKDC grade A or B compared with 73% in the delayed group. The one leg hop index above 90% was found in 50% in the acute group and 24% in the delayed group (p=0.04). Functional data for the 2-year follow up are not available at the time of abstract writing. The median activity level according to Tegner was restored to pre-injury levels in both groups after one year, and was stationary at 2 years. The visual analogue scale (VAS) response to the question “How is your knee working on a scale from 0-100? (100 = best)” revealed 81 in the acute and 71 in the delayed group (p=0.1). To the question “How does your knee affect your activity level on a scale from 0-100? (100 = no affection)” the mean score was 75 in the acute group and 67 in the delayed group (p=0.3). At one and two years the KOOS was statistically similar between the groups but with slightly higher subscale “Sport and recreation” scores, 85 in the

  10. Utilization of Modified NFL Combine Testing to Identify Functional Deficits in Athletes Following ACL Reconstruction

    PubMed Central

    MYER, GREGORY D.; SCHMITT, LAURA C.; BRENT, JENSEN L.; FORD, KEVIN R.; BARBER FOSS, KIM D.; SCHERER, BRADLEY J.; HEIDT, ROBERT S.; DIVINE, JON G.; HEWETT, TIMOTHY E.

    2012-01-01

    STUDY DESIGN Case control. OBJECTIVES To use modified NFL Combine testing methodology to test for functional deficits in athletes following anterior cruciate ligament (ACL) reconstruction following return to sport. BACKGROUND There is a need to develop objective, performance-based, on-field assessment methods designed to identify potential lower extremity performance deficits and related impairments in this population. METHODS Eighteen patients (mean ± SD age, 16.9 ± 2.1 years; height, 170.0 ± 8.7 cm; body mass, 71.9 ± 21.8 kg) who returned to their sport within a year following ACL reconstruction (95% CI: 7.8 to 11.9 months from surgery) participated (ACLR group). These individuals were asked to bring 1 or 2 teammates to serve as control participants, who were matched for sex, sport, and age (n = 20; mean ± SD age, 16.9 ± 1.1 years; height, 169.7 ± 8.4 cm; body mass, 70.1 ± 20.7 kg). Functional performance was tested using the broad jump, vertical jump, modified long shuttle, modified pro shuttle, modified agility T-test, timed hop, triple hop, single hop, and crossover hop tests. A 1-way multivariate analysis of variance (MANOVA) was used to evaluate group differences for dependent performance variables. RESULTS The functional performance measurements of skills requiring bilateral involvement of both lower extremities showed no group differences between the ACLR and control groups (P>.05). An overall group difference (P = .006) was observed for the combined limb symmetry index (LSI) measures. However, the modified double-limb performance tasks (long shuttle, modified agility T-test, and pro shuttle) were not, independently, sufficiently sensitive to detect limb deficits in individuals with ACL reconstruction. Conversely, the LSI on the distance measures of the single-limb performance tasks all provided moderate to large effect sizes to differentiate between the ACLR and control groups, as the individuals who had ACL reconstruction demonstrated involved

  11. EVALUATION OF THE RESULTS OF ARTHROSCOPIC ACL RECONSTRUCTION WITH AUTOGENOUS FLEXOR TENDONS

    PubMed Central

    Almeida, Alexandre; Valin, Múrcio Rangel; Ferreira, Ramon; Roveda, Gilberto; de Almeida, Nayvaldo Couto; Agostini, Ana Paula

    2015-01-01

    Objective: To evaluate the results from reconstruction of the anterior cruciate ligament (ACL) using with flexor tendon autografts from the thigh, with analysis on data relating to sex, body mass index (BMI) and associations with lower limb fracture. Methods: A group of 265 patients who underwent knee arthroscopy for the purposes of ACL reconstruction using an ipsilateral graft from the flexor tendon of the thigh between July 6, 2000, and November 19, 2007, were evaluated. Results: One hundred and seventy-six patients were evaluated over a mean period of 34.95 ± 18.8 months (median: 31 months) (IQR: 20-48 months). The minimum evaluation period was 12 months and the maximum was 87 months. One hundred and thirty-eight patients (78.4%) had excellent results, 22 (12.5%) had good results, eight (4.5%) had fair results and eight (4.5%) had poor results. Higher incidence of good and excellent results for the following categories was not considered to be significant: males (p = 0.128), patients with BMI < 25 (p = 0.848), or patients with ACL injuries unrelated to an initial traumatic episode of lower-limb fracture (p = 0.656). Conclusion: The ACL reconstruction technique using tendon autografts from the thigh showed good and excellent results for 91.4% of the sample. Male patients seemed to present a greater tendency towards good and excellent results. No statistically significant difference was found when the results were analyzed in relation to BMI or associations with initial traumatic fracture episodes in the lower limbs. PMID:27022571

  12. Effects of Initial Graft Tension on the Tibiofemoral Compressive Forces and Joint Position Following ACL Reconstruction

    PubMed Central

    Brady, Mark F.; Bradley, Michael P.; Fleming, Braden C.; Fadale, Paul D.; Hulstyn, Michael J.; Banerjee, Rahul

    2007-01-01

    Background The initial tension applied to an ACL graft at the time of fixation modulates knee motion and the tibiofemoral compressive loads. Purpose To establish the relationships between initial graft tension, tibiofemoral compressive force, and the neutral tibiofemoral position in the cadaver knee. Study Design Controlled Laboratory Study. Methods The tibiofemoral compressive forces and joint positions were determined in the ACL-intact knee at 0°, 20° and 90° knee flexion. The ACL was excised and reconstructed with a patellar tendon graft using graft tensions of 1, 15, 30, 60 and 90 N applied at 0°, 20° and 90° knee flexion. The compressive forces and neutral positions were compared between initial tension conditions and the ACL-intact knee. Results Increasing initial graft tension increased the tibiofemoral compressive forces. The forces in the medial compartment were 1.8 times those in the lateral compartment. The compressive forces were dependent on the knee angle at which the tension was applied. The greatest compressive forces occurred when the graft was tensioned with the knee in extension. An increase in initial graft tension caused the tibia to rotate externally compared to the ACL-intact knee. Increases in initial graft tension also caused a significant posterior translation of the tibia relative to the femur. Conclusions Different initial graft tension protocols produced predictable changes in the tibiofemoral compressive forces and joint positions. Clinical Relevance The tibiofemoral compressive force and neutral joint position were best replicated with a low graft tension (1–15 N) when using a patellar tendon graft. PMID:17218659

  13. Meniscus treatment and age associated with narrower radiographic joint space width 2 – 3 years after ACL reconstruction: Data from the MOON onsite cohort

    PubMed Central

    Jones, Morgan H.; Spindler, Kurt P.; Fleming, Braden C.; Duryea, Jeffrey; Obuchowski, Nancy A.; Scaramuzza, Erica A.; Oksendahl, Heidi L.; Winalski, Carl S.; Duong, Carol L.; Huston, Laura J.; Parker, Richard D.; Kaeding, Christopher C.; Andrish, Jack T.; Flanigan, David C.; Dunn, Warren R.; Reinke, Emily K.

    2015-01-01

    Objective To identify risk factors for radiographic signs of post-traumatic OA 2–3 years after ACL reconstruction through multivariable analysis of minimum joint space width (mJSW) differences in a specially designed nested cohort. Methods A nested cohort within the Multicenter Orthopaedic Outcomes Network cohort included 262 patients (148 females, average age 20) injured in sport who underwent ACL reconstruction in a previously uninjured knee, were 35 or younger, and did not have ACL revision or contralateral knee surgery. mJSW on semi-flexed radiographs was measured in the medial compartment using a validated computerized method. A multivariable generalized linear model was constructed to assess mJSW difference between the ACL reconstructed and contralateral control knees while adjusting for potential confounding factors. Results Unexpectedly, we found the mean mJSW was 0.35 mm wider in ACL reconstructed than in control knees (5.06 mm (95% CI 4.96 – 5.15 mm) versus 4.71 mm (95% CI 4.62 – 4.80 mm), p<0.001). However, ACL reconstructed knees with meniscectomy had narrower mJSW compared to contralateral normal knees by 0.64 mm (95% C.I. 0.38 – 0.90 mm) (p<0.001). Age (p<0.001) and meniscus repair (p=0.001) were also significantly associated with mJSW difference. Conclusion Semi-flexed radiographs can detect differences in mJSW between ACL reconstructed and contralateral normal knees 2–3 years following ACL reconstruction, and the unexpected wider mJSW in ACL reconstructed knees may represent the earliest manifestation of post-traumatic osteoarthritis and warrants further study. PMID:25559582

  14. Prognosis and predictors of ACL reconstructions using the MOON cohort: a model for comparative effectiveness studies.

    PubMed

    Spindler, Kurt P; Parker, Richard D; Andrish, Jack T; Kaeding, Christopher C; Wright, Rick W; Marx, Robert G; McCarty, Eric C; Amendola, Annunziato; Dunn, Warren R; Huston, Laura J; Harrell, Frank E

    2013-01-01

    Injury to the anterior cruciate ligament (ACL) threatens an active lifestyle and exposes the patient to risk of early osteoarthritis (OA). ACL reconstruction is typically chosen by individuals to allow a return to their previous work and sports activities. Primary ACL reconstruction (ACLR) has in general been effective at restoring functional stability, but patients' modifiable predictors of both short- and long-term validated outcomes and OA are largely unknown. The Multicenter Orthopaedic Outcomes Network (MOON) consortium was established in 2002 to enroll and longitudinally follow a population cohort of ACL reconstructed patients. The objective was to establish patient-specific predictive models of clinically important outcomes. Over the past 10 years, the overarching aims of this NIAMS-funded prospective multicenter cohort of ACL reconstructions has been threefold: (1) to identify both short- and long-term prognosis and predictors of sports function, activity level, and general health through validated patient-reported outcomes, (2) to identify the symptoms and signs of OA, and (3) to quantify the incidence of ACL reconstruction graft and/or contralateral ACL failures and additional surgical procedures. This manuscript summarizes the Kappa Delta Ann Doner Vaughan Award paper and presentation at the 2012 ORS/AAOS Annual Meeting. PMID:22912340

  15. Effects of Gaps Induced Into the ACL Tendon Graft on Tendon-Bone Healing in a Rodent ACL Reconstruction Model

    PubMed Central

    Lovric, Vedran; Kanazawa, Tomonoshin; Nakamura, Yoshinari; Oliver, Rema A.; Yu, Yan; Walsh, William Robert

    2011-01-01

    Summary Graft necrosis following ACL reconstruction is often associated with the use of autologous grafts. Host cells rather than graft cells contribute to the repair of the tendon-bone interface and the remodeling of the autologous graft. The native tendon-bone interface is not recreated and the biomechanical properties are not restored back to native values. We examined the effects of introducing gaps within the tendon graft prior to ACL reconstruction in a rodent model. We hypothesised that gaps will make physical way for host cells to infiltrate and repopulate the graft and thus enhance healing. Animals were sacrificed at seven, fourteen, and twenty-eight days for biomechanical testing and histology. Our findings indicate that graft necrosis, usually observed in the initial two weeks of the healing process, is averted. Histological observations showed that tendon-bone healing stages were hastened however this didn’t translate into improved biomechanical properties. PMID:23738254

  16. Inter-segmental Postural Coordination Measures Differentiate Athletes with ACL Reconstruction from Uninjured Athletes

    PubMed Central

    Kiefer, Adam W.; Ford, Kevin R.; Paterno, Mark V.; Schmitt, Laura C.; Myer, Gregory D.; Riley, Michael A.; Shockley, Kevin; Hewett, Timothy E.

    2012-01-01

    Athletes who sustain non-contact anterior cruciate ligament (ACL) injuries and undergo surgical reconstruction exhibit deficits in sensorimotor control, which often impairs lower-limb movement coordination. The purpose of this experiment was to measure the influence of sensorimotor deficits on the ankle-hip coordination of a postural coordination task in athletes following ACL reconstruction. Twenty-two female athletes who were cleared to return to sports participation following ACL reconstruction and 22 uninjured female athletes performed a unilateral dynamic postural rhythmic coordination task at two movement frequencies (0.2 and 0.7 Hz). Athletes with ACL-reconstruction exhibited greater ankle-hip relative phase variability and reduced regularity of coupling than uninjured athletes, especially during the 0.2 Hz condition. The results of this study show altered lower extremity coordination patterns in athletes following ACL reconstruction and return to sports participation. The results also indicate that dynamical coordination measures may provide objective measures of sensorimotor deficits following ACL reconstruction and can potentially guide rehabilitation interventions following reconstruction. PMID:23219784

  17. ACL reconstruction by patellar tendon. A comparison of length by magnetic resonance imaging.

    PubMed

    Högerle, S; Letsch, R; Sievers, K W

    1998-01-01

    In 50 knees the length of the anterior cruciate ligament (ACL), the patellar tendon, and the distance between the tibial tuberosity and the femoral origin of the ACL were evaluated by means of three-dimensional magnetic resonance imaging (MRI), which permits subsequent reconstruction of any sectional view. The measurements showed that the patellar tendon was always markedly longer than the ACL (mean 14.4 mm), but always shorter than the distance between the tibial tuberosity and the femoral insertion of the ACL (mean 19.2 mm). The mean lengths of the ACL and the patellar tendon were 38.2 mm and 52.6 mm, respectively. The mean distance between the femoral ACL origin and the tibial insertion of the patellar tendon was 71.8 mm. These results demonstrate that a distally based patellar tendon autograft alone (with the patellar bone block but without extension into the periosteum of the patella or the quadriceps tendon) cannot be placed anatomically correctly to the isometric femoral insertion of the ACL. When the patellar tendon is used for ACL reconstruction, it must be implanted as a free autograft. Nevertheless, considerable variations of length must be taken into account. PMID:9457339

  18. Knee Hyperextension as a Predictor of Failure in Revision ACL Reconstruction

    PubMed Central

    Cooper, Daniel E.; Dunn, Warren R.; Wright, Rick W.; Haas, Amanda; Huston, Laura J.

    2016-01-01

    Objectives: We studied the minimum 2 year follow-up outcomes in an ACL revision cohort. The hypothesis is that knees that hyperextend will have a worse outcome and greater odds of graft failure than knees that do not hyperextend. The null hypothesis is that there is no difference in outcomes or graft rupture between the two groups. Methods: Revision ACL reconstruction patients were identified and prospectively enrolled between 2006 and 2011. Data collected included baseline demographics, surgical technique and pathology, and a series of validated patient reported outcome instruments (IKDC, KOOS, WOMAC, and Marx activity rating score). Patients were followed up for 2 years, and asked to complete the identical set of outcome instruments. A regression model using graft failure as the dependent variable included graft type, age, and hyperextension greater than or equal to 5 degrees yes/no (HE) in order to assess these potential surgical risk factors for clinical outcomes 2 years after revision ACL reconstruction. Results: There were 1,145 subjects included in the analyses. The median age of the cohort was 26 (IQR= 20, 35), and 58% were male. The proportion that were enrolled for their first revision surgery was 88%, their second 10%, and third or greater 2%. The number of subjects categorized as HE was 375 (33%). The median age of subjects that failed was 18, compared to 26 for those with intact grafts. All three variables included in our regression model were significant predictors of graft failure: younger age, inter-quartile range odds ratio (IQROR) = 3.32 (95%CI 1.5, 7.2) p= 0.002; use of allograft OR = 3.1 (95%CI 1.4, 6.9) p= 0.01, and HE 2.1 (95%CI 1.02, 4.42) p= 0.04. Conclusion: The MARS Study Group has previously reported that young age and the use of allograft as a graft source are independent predictors (over 3X odds ratio) of graft rupture after revision ACLR. This study found that knee hyperextension greater than or equal to 5 degrees is present in 1/3 of

  19. Acute ACL Surgery Decreases First Year Socio Economic Costs Compared to Delayed Reconstruction

    PubMed Central

    Eriksson, Karl; von Essen, Christoffer; Barenius, Björn

    2016-01-01

    Objectives: Clinical practice has been to avoid acute ACL reconstruction due to the risk of complications, especially arthrofibrosis. Thus, a general rule has been to wait with reconstruction until he knee is “calm” which usually means 4-8 weeks following injury. Furthermore there is often also a prolonged waiting time due to operating space and other logistic factors. Since most of the patients undergoing ACL reconstruction are of working age, there is a potentially large socio-economic loss due to the fact that many of these patients are unable to work from the time of injury to the time of reconstruction. The aim of this study was to assess and compare the total number of sick leave days caused by the knee injury from the day of injury and over the first year between sub acute and delayed reconstruction. Methods: 70 patients with high recreational activity level, Tegner level of 6 or more, who presented with an acute ACL injury were randomized to acute reconstruction within 8 days from the injury or delayed reconstruction 6-10 weeks post injury. Four surgeons performed the ACL reconstructions with quadrupled semitendinosus tendon grafts. Patients were assessed at 6,12 and 24 months and these follow ups included Biodex strength test, Lachman, Rolimeter, pivot shift, one leg hop, IKDC, KOOS, Lysholm and Tegner activity level. With data from the Swedish Social Insurance Agency (Försäkringskassan) information about the number of sick leave days from the day of the knee injury and over the following twelve months was collected. The data was recalled based on diagnostic numbers related to the specific knee-injury and compared between the two groups. Results: Seventy percent of the patients were males, mean age at the time of inclusion was 27 years (18 -41) and the pre-injury median Tegner level was 9 (5-10), with no differences between the groups. 15/70 patients were students without registered compensation for sick leave, 5 in the acute and 10 in the delayed

  20. Radioprotection provides functional mechanics but delays healing of irradiated tendon allografts after ACL reconstruction in sheep.

    PubMed

    Seto, Aaron U; Culp, Brian M; Gatt, Charles J; Dunn, Michael

    2013-12-01

    Successful protection of tissue properties against ionizing radiation effects could allow its use for terminal sterilization of musculoskeletal allografts. In this study we functionally evaluate Achilles tendon allografts processed with a previously developed radioprotective treatment based on (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) crosslinking and free radical scavenging using ascorbate and riboflavin, for ovine anterior cruciate ligament reconstruction. Arthroscopic anterior cruciate ligament (ACL) reconstruction was performed using double looped allografts, while comparing radioprotected irradiated and fresh frozen allografts after 12 and 24 weeks post-implantation, and to control irradiated grafts after 12 weeks. Radioprotection was successful at preserving early subfailure mechanical properties comparable to fresh frozen allografts. Twelve week graft stiffness and anterior-tibial (A-T) translation for radioprotected and fresh frozen allografts were comparable at 30 % of native stiffness, and 4.6 and 5 times native A-T translation, respectively. Fresh frozen allograft possessed the greatest 24 week peak load at 840 N and stiffness at 177 N/mm. Histological evidence suggested a delay in tendon to bone healing for radioprotected allografts, which was reflected in mechanical properties. There was no evidence that radioprotective treatment inhibited intra-articular graft healing. This specific radioprotective method cannot be recommended for ACL reconstruction allografts, and data suggest that future efforts to improve allograft sterilization procedures should focus on modifying or eliminating the pre-crosslinking procedure. PMID:23842952

  1. Magnetic Resonance Imaging of Cartilage Contact and Bound Water in ACL-Deficient and ACL Reconstructed Knees

    PubMed Central

    Baer, Geoffrey Scott; Kaiser, Jarred; Vignos, Michael; Liu, Fang; Smith, Colin Robert; Kijowski, Richard; Thelen, Darryl

    2016-01-01

    Objectives: Osteoarthritis (OA) is common following ACL-reconstructive (ACLR) surgery (6). The cause of early OA is not understood, but theories have focused on osteochondral damage at the time of injury (2) and abnormal joint mechanics following surgical repair (7). In this study, we investigate the inter-relationship of cartilage mechanics and biomarkers of OA in both ACL-deficient (ACLD) and ACLR knees. Our approach employs a novel dynamic MR sequence to measure joint mechanics (3) and the recently developed mcDESPOT to assess regional variations in water bound to proteoglycan (PG) (5). We hypothesize that bound water will be diminished in the cartilage of ACLD knees and, after surgery, will continue to adapt in a manner that reflects altered cartilage loading. This abstract presents initial observations on a cross-section of healthy, ACLD and ACLR knees. Methods: The dominant knees of 8 healthy controls, ACLD knees of 5 patients and ACLR knees of 8 patients were imaged in a 3 T MRI scanner (Table). Controls had no history of pain, injury, or surgery to their knee. Patients had no additional ligament injury and no meniscal damage. ACLD subjects were imaged prior to reconstructive surgery. Femoral and tibial cartilage were segmented from MR images and cartilage thickness was calculated. The mcDESPOT sequence provided a fraction map of water bound to PG (Fpg). Subjects flexed their knee against an inertial load at 0.5 Hz, while a SPGR-VIPR sequence continuously acquired volumetric data. Kinematics were obtained using model tracking of the dynamic images (3). Cartilage was registered to the bone segments for all frames, and contact patterns were characterized by the proximity between surfaces. Spatial representations of tibial cartilage contact, thickness and Fpg were co-registered for each subject. Results: Our initial images suggest lower Fpg values in ACLD knees, primarily on the posterior-lateral tibia. This is also observed in ACLR knees, with additional

  2. Quadriceps function relates to muscle size following ACL reconstruction.

    PubMed

    Kuenze, Christopher M; Blemker, Silvia S; Hart, Joseph M

    2016-09-01

    It remains unclear what role reduced volume and cross-section area (CSA) of individual quadriceps muscles may play in persistent quadriceps weakness and more global dysfunction following ACL reconstruction (ACLR). The purpose of this investigation was to establish the relationship between cross-sectional area of the quadriceps muscle group and measures of knee related and quadriceps function following ACLR. Thirty participants with a history of primary, unilateral ACLR experiencing persistent quadriceps activation failure participated in this cohort study. Clinical factors including International Knee Documentation Committee (IKDC) score, normalized knee extension MVIC torque (Nm/kg) and quadriceps central activation ratio (CAR, %) were assessed in addition to CSA. Quadriceps CSA was measured via magnetic resonance imaging (MRI; Siemens Avanto 1.5T). Quadriceps CSA (cm(2) ) and quadriceps volume (cm(3) ) as well as individual muscle estimates were identified within a 10 cm mid-thigh capture area. Pearson's product-moment correlation coefficients (r) established relationships between CSA and all other variables. Stepwise linear regression established which CSA factors were able to successfully predict clinical factors. Knee extension MVIC torque was strongly correlated with Vastus Intermedius (VI; r =  0.857, p < 0.001) CSA as well as partial VI (r = 0.849, p < 0.001) and quadriceps (r = 0.830, p < 0.001) volume. Partial VI (r = 0.365, p = 0.047) volume was weakly correlated with IKDC score. Knee extension MVIC torque was strongly predicted using VI CSA alone (R(2)  = 0.725) or in combination with Vastus Medialis CSA (VM; R(2)  = 0.756). Statement of Clinical Significance: Atrophy of the VI and VM muscles negatively impacts knee extension strength following ACLR. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1656-1662, 2016. PMID:26763833

  3. Effects of ACL Reconstructive Surgery on Temporal Variations of Cytokine Levels in Synovial Fluid

    PubMed Central

    Bigoni, Marco; Gandolla, Marta; Sacerdote, Paola; Piatti, Massimiliano; Castelnuovo, Alberto; Franchi, Silvia; Gorla, Massimo; Munegato, Daniele; Gaddi, Diego; Pedrocchi, Alessandra; Omeljaniuk, Robert J.; Locatelli, Vittorio; Torsello, Antonio

    2016-01-01

    Anterior cruciate ligament (ACL) reconstruction restores knee stability but does not reduce the incidence of posttraumatic osteoarthritis induced by inflammatory cytokines. The aim of this research was to longitudinally measure IL-1β, IL-6, IL-8, IL-10, and TNF-α levels in patients subjected to ACL reconstruction using bone-patellar tendon-bone graft. Synovial fluid was collected within 24–72 hours of ACL rupture (acute), 1 month after injury immediately prior to surgery (presurgery), and 1 month thereafter (postsurgery). For comparison, a “control” group consisted of individuals presenting chronic ACL tears. Our results indicate that levels of IL-6, IL-8, and IL-10 vary significantly over time in reconstruction patients. In the acute phase, the levels of these cytokines in reconstruction patients were significantly greater than those in controls. In the presurgery phase, cytokine levels in reconstruction patients were reduced and comparable with those in controls. Finally, cytokine levels increased again with respect to control group in the postsurgery phase. The levels of IL-1β and TNF-α showed no temporal variation. Our data show that the history of an ACL injury, including trauma and reconstruction, has a significant impact on levels of IL-6, IL-8, and IL-10 in synovial fluid but does not affect levels of TNF-α and IL-1β. PMID:27313403

  4. A Comparison of Dynamic Postural Stability Between Asymptomatic Controls and Male Patients One Year After ACL Reconstruction (Pilot Study)

    PubMed Central

    Ataoglu, Muhammed Baybars; Hazar, Zeynep; Kafa, Nihan; Özer, Mustafa; Citaker, Seyit

    2014-01-01

    Objectives: The purpose of this study was to determine if dynamic postural stability gained one year after ACL reconstruction in patients who received rehabilitation. Methods: Seven male patients (mean age=32,66 ±6,47) who had previously undergone ACL reconstruction (ACL-R) and 7 sex-and general physical activity matched uninjured controls included to study. Mean time since original injury was 13±3,31 months. Dynamic postural control was assessed with 20° knee flexion with Star Excursion Balance test. Each participant performed 3 trials of the anterior, posterior-medial, and posterior-lateral directional components of the SEBT. Reach distances for each directional component were compared with non-injured leg and healthy controls’. Results: There was no significant difference in all directions of Star Excursion Balance test between neither the operated and uninjured knees of patients nor between patients and healthy controls (p>0,05). Conclusion: No deficits in dynamic postural stability were present average one year after ACL reconstruction in patients who received rehabilitation. It can be said that rehabilitation is effective in the recovery of dynamic postural stability.

  5. Differences in Mechanisms of Failure, Intraoperative Findings, and Surgical Characteristics Between Single- and Multiple-Revision ACL Reconstructions

    PubMed Central

    Chen, James L.; Allen, Christina R.; Stephens, Thomas E.; Haas, Amanda K.; Huston, Laura J.; Wright, Rick W.; Feeley, Brian T.

    2013-01-01

    Background The factors that lead to patients failing multiple anterior cruciate ligament (ACL) reconstructions are not well understood. Hypothesis Multiple-revision ACL reconstruction will have different characteristics than first-time revision in terms of previous and current graft selection, mode of failure, chondral/meniscal injuries, and surgical charactieristics. Study Design Case-control study; Level of evidence, 3. Methods A prospective multicenter ACL revision database was utilized for the time period from March 2006 to June 2011. Patients were divided into those who underwent a single-revision ACL reconstruction and those who underwent multiple-revision ACL reconstructions. The primary outcome variable was Marx activity level. Primary data analyses between the groups included a comparison of graft type, perceived mechanism of failure, associated injury (meniscus, ligament, and cartilage), reconstruction type, and tunnel position. Data were compared by analysis of variance with a post hoc Tukey test. Results A total of 1200 patients (58% men; median age, 26 years) were enrolled, with 1049 (87%) patients having a primary revision and 151 (13%) patients having a second or subsequent revision. Marx activity levels were significantly higher (9.77) in the primary-revision group than in those patients with multiple revisions (6.74). The most common cause of reruptures was a traumatic, noncontact ACL graft injury in 55% of primary-revision patients; 25% of patients had a nontraumatic, gradual-onset recurrent injury, and 11% had a traumatic, contact injury. In the multiple-revision group, a nontraumatic, gradual-onset injury was the most common cause of recurrence (47%), followed by traumatic noncontact (35%) and nontraumatic sudden onset (11%) (P < .01 between groups). Chondral injuries in the medial compartment were significantly more common in the multiple-revision group than in the single-revision group, as were chondral injuries in the patellofemoral

  6. Single-Bundle Versus Double-Bundle Acl Reconstructions in Isolation and in Conjunction with Extra-Articular Iliotibial Band Tenodesis

    PubMed Central

    Butler, Paul D.; Mellecker, Chloe J.; Rudert, M. James; Albright, John P.

    2013-01-01

    Background Intra-articular anterior cruciate ligament (ACL) reconstruction has been the primary treatment option for isolated ACL injuries for many years. An anatomic double-bundle reconstruction has been devised in an effort to improve rotational control. The role of the extra-articular iliotibial band tenodesis in ACL injuries has evolved from primary treatment, to an adjuvant secondary procedure, to being used more selectively in revision ACL reconstructions. Hypotheses: 1) Single-bundle and doublebundle intra-articular ACL reconstructions will both restore pre-injury laxity measurements in an isolated ACL injury cadaver model. 2) The deep iliotibial band structures contribute to rotational control and in a dual ACL + ITB injury cadaver model, ACL reconstruction alone cannot restore rotational control. Study Design Controlled Laboratory Design Methods 17 fresh frozen cadavers received intra-articular reconstructions, seven single-bundle and ten double-bundle; laxity was measured with the ACL intact/ITB intact, ACL reconstructed/ITB intact, after cutting the ITB, and after an ITB tenodesis procedure; laxity measurements of anterior tibial translation(ATT) and internal rotation(IR) were measured following applications of an anterior shear force, an internal torque and a coupled anterior shear force-internal torque at 30 and 90 degrees of flexion. Results Single-bundle and double-bundle ACL reconstructions both restored IR to a native knee state under isolated internal torques and under coupled forces. Both reconstruction techniques also re-established anterior tibial translation to at least the pre-ACL injury level, with over-constraint in the double-bundle subgroup [5.00 (+2.11) to 3.50(+1.18), p-value 0.026] under coupled loads at 30 degrees of flexion. With the individual ACL reconstructions held constant, under coupled forces mean IR increased in the single-bundle subgroup [13.7(+1.1) to 17.6(+1.2), p-value 0.004] and the double-bundle subgroup [9.5(+1.0) to

  7. Comparison of grafts for anatomical reconstruction of the ACL: patellar versus semitendinosus/gracilis☆

    PubMed Central

    Bitun, Patrícia Barros; Miranda, Carlos Roberto; Escudero, Ricardo Boso; Araf, Marcelo; de Souza, Daphnis Gonçalves

    2015-01-01

    Objective To compare the functional results from surgical treatment for anatomical reconstruction of the anterior cruciate ligament (ACL) with a single band, using two types of autologous grafts. Methods Twenty-seven patients who underwent anatomical reconstruction of the ACL by means of the Chambat technique were evaluated prospectively. They were divided into two groups: A, with 14 patients, using grafts from flexor tendons; and B, with 13 patients, using grafts from the patellar tendon. In both groups, fixation was performed using an absorbable interference screw. Results Based on the Lysholm score, group A presented a mean score of 71.6 in the first month, while B presented 75. At the end of the sixth month, both groups presented 96.6. Evaluation of the total IKDC showed that in the first month, the majority of the patients, both in group A (85.7%) and in group B (76.9%), presented a knee assessment that was close to normal. In the sixth month, 92.9% of group A had normal presentations, and 100% of group B. Conclusion According to the Lysholm functional evaluation and the IKDC subjective assessment, there was no statistically significant difference in the results between the groups, and the results were better in the sixth month. PMID:26229896

  8. Avoiding Complications and Technical Variability During Arthroscopically Assisted Transtibial ACL Reconstructions by Using a C-Arm With Image Intensifier

    PubMed Central

    Trentacosta, Natasha; Fillar, Allison Liefeld; Liefeld, Cynthia Pierce; Hossack, Michael D.; Levy, I. Martin

    2014-01-01

    Background: Surgical reconstruction of the anterior cruciate ligament (ACL) can be complicated by incorrect and variable tunnel placement, graft tunnel mismatch, cortical breaches, and inadequate fixation due to screw divergence. This is the first report describing the use of a C-arm with image intensifier employed for the sole purpose of eliminating those complications during transtibial ACL reconstruction. Purpose: To determine if the use of a C-arm with image intensifier during arthroscopically assisted transtibial ACL reconstruction (IIAA-TACLR) eliminated common complications associated with bone–patellar tendon–bone ACL reconstruction, including screw divergence, cortical breaches, graft-tunnel mismatch, and improper positioning of the femoral and tibial tunnels. Study Design: Case series; Level of evidence, 4. Methods: A total of 110 consecutive patients (112 reconstructed knees) underwent identical IIAA-TACLR using a bone–patellar tendon–bone autograft performed by a single surgeon. Intra- and postoperative radiographic images and operative reports were evaluated for each patient looking for evidence of cortical breeching and screw divergence. Precision of femoral tunnel placement was evaluated using a sector map modified from Bernard et al. Graft recession distance and tibial α angles were recorded. Results: There were no femoral or tibial cortical breaches noted intraoperatively or on postoperative images. There were no instances of loss of fixation screw major thread engagement. There were no instances of graft-tunnel mismatch. The positions of the femoral tunnels were accurate and precise, falling into the desired sector of our location map (sector 1). Tibial α angles and graft recession distances varied widely. Conclusion: The use of the C-arm with image intensifier enabled accurate and precise tunnel placement and completely eliminated cortical breach, graft-tunnel mismatch, and screw divergence during IIAA-TACLR by allowing incremental

  9. Differences in muscle strength after ACL reconstruction do not influence cardiorespiratory responses to isometabolic exercise

    PubMed Central

    Andrade, Marília S.; Lira, Claudio A. B.; Vancini, Rodrigo L.; Nakamoto, Fernanda P.; Cohen, Moisés; Silva, Antonio C.

    2014-01-01

    Objectives To investigate whether the muscle strength decrease that follows anterior cruciate ligament (ACL) reconstruction would lead to different cardiorespiratory adjustments during dynamic exercise. Method Eighteen active male subjects were submitted to isokinetic evaluation of knee flexor and extensor muscles four months after ACL surgery. Thigh circumference was also measured and an incremental unilateral cardiopulmonary exercise test was performed separately for both involved and uninvolved lower limbs in order to compare heart rate, oxygen consumption, minute ventilation, and ventilatory pattern (breath rate, tidal volume, inspiratory time, expiratory time, tidal volume/inspiratory time) at three different workloads (moderate, anaerobic threshold, and maximal). Results There was a significant difference between isokinetic extensor peak torque measured in the involved (116.5±29.1 Nm) and uninvolved (220.8±40.4 Nm) limbs, p=0.000. Isokinetic flexor peak torque was also lower in the involved limb than in the uninvolved limb (107.8±15.4 and 132.5±26.3 Nm, p=0.004, respectively). Lower values were also found in involved thigh circumference as compared with uninvolved limb (46.9±4.3 and 48.5±3.9 cm, p=0.005, respectively). No differences were found between the lower limbs in any of the variables of the incremental cardiopulmonary tests at all exercise intensities. Conclusions Our findings indicate that, four months after ACL surgery, there is a significant deficit in isokinetic strength in the involved limb, but these differences in muscle strength requirement do not produce differences in the cardiorespiratory adjustments to exercise. Based on the hypotheses from the literature which explain the differences in the physiological responses to exercise for different muscle masses, we can deduce that, after 4 months of a rehabilitation program after an ACL reconstruction, individuals probably do not present differences in muscle oxidative and peripheral

  10. Meniscal tears in the ACL-deficient knee: correlation between meniscal tears and the timing of ACL reconstruction.

    PubMed

    Papastergiou, Stergios G; Koukoulias, Nikolaos E; Mikalef, Petros; Ziogas, Evangelos; Voulgaropoulos, Harilaos

    2007-12-01

    Despite the fact that anterior cruciate ligament reconstruction (ACLR) is a common procedure, no clear guideline regarding the timing of reconstruction has been established. We hypothesized that there is a point in post injury period, after which significant increase in meniscal tears occurs. The purpose of this study was to derive a guideline in order to reduce the rate of secondary meniscal tears in the ACL-deficient knee. A total of 451 patients were retrospectively studied and divided into six groups according to the time from injury to ACLR: (a) 105 patients had undergone ACLR within 1.5 months post injury, (b) 93 patients within 1.5-3 months, (c) 72 patients within fourth to sixth month, (d) 56 patients within seventh to twelfth month, (e) 45 patients within the second year and (f) 80 patients within the third to fifth year. The presence of meniscal tears was noted at the time of ACL reconstruction and then recorded and statistically analysed. Fifty-three (50.5%) patients from group a, 46 (49.5%) from group b, 39 (54.2%) from group c, 31 (68.9%) from group d, 28 (62.2%) from group e and 54 (67.5%) from group f had meniscal tear requiring treatment. The statistical analysis demonstrated that the earliest point of significantly higher incidence of meniscal tears was in patients undergoing ACLR more than 3 months post injury. Therefore, ACLR should be carried out within the first 3 months post injury in order to minimise the risk of secondary meniscal tears. PMID:17899001

  11. Mechanical energy fluctuations during walking of healthy and ACL-reconstructed subjects.

    PubMed

    Winiarski, Sławomir

    2008-01-01

    In a clinical gait analysis, mechanical energy is the gait variable which can validate the energetic state of the disorder of patient's movement. The purpose of this study was to explore the possibilities of employing the total mechanical energy in estimating the mechanical cost of transport in normal and pathological human gait. One of the basic methods of determining mechanical energy (inverted pendulum model) was used to estimate the external mechanical work performed by the walking subjects based on externally observable measurements. Gait data was collected for healthy able-bodied men and patients after ACL reconstruction during physiotherapy process who demonstrate larger lateral center of gravity (CoG) excursions during gait. Based on predictions of the body's CoG trajectory during walking, algorithms were developed to determine the changes in components of total mechanical energy in normal and pathological gait. The utility of calculating mechanical energy in a patient population is questioned. PMID:19031999

  12. Single-Bundle Anterior Cruciate Ligament Reconstruction with Semitendinosus Tendon Using the PINN-ACL CrossPin System: Minimum 4-Year Follow-up

    PubMed Central

    Baek, Seung-Gil; Lee, Byoung-Joo; Lee, Chang-Hwa

    2015-01-01

    Purpose This study evaluated mid-term results of anterior cruciate ligament (ACL) reconstruction using the PINN-ACL CrossPin system that allowed for short graft fixation. Materials and Methods Forty-three patients underwent single-bundle ACL reconstruction with a 4-strand semitendinosus tendon graft using the PINN-ACL CrossPin system. Femoral fixation was done using the PINN-ACL CrossPin system, and the tibial side was fixed with post-tie and a bioabsorbable interference screw. The mean follow-up period was 50 months. Evaluation was done using the Lachman test, pivot-shift test, International Knee Documentation Committee (IKDC) score and grade. Anterior displacement was assessed. Results There was improvement in the Lachman test and pivot-shift test at final follow-up, form grade II (n=40) or III (n=3) to grade I (n=3) or 0 (n=40) and from grade I (n=20) or II (n=10) to grade I (n=8) or 0 (n=22), respectively. The mean IKDC score was 88.7, and grade A and B were 93.0% at final follow-up. Side-to-side difference was improved from 6.7 mm to 2.1 mm at final follow-up. Complications occurred in 3 patients, a re-ruptured due to trauma at 2 years after surgery and a deep infection and a superficial infection. Conclusions The mid-term follow-up results of ACL reconstruction with the PINN-ACL CrossPin system were satisfactory. The PINN-ACL CrossPin can be considered as a useful instrument for short graft fixation. PMID:25750893

  13. Knee functional recovery and limb-to-limb symmetry restoration after anterior cruciate ligament (ACL) rupture and ACL reconstruction

    NASA Astrophysics Data System (ADS)

    Nawasreh, Zakariya Hussein

    Anterior cruciate ligament (ACL) rupture is a common sport injury of young athletes who participate in jumping, cutting, and pivoting activities. Although ACL reconstruction (ACLR) surgery has the goal of enabling athletes to return to preinjury activity levels, treatment results often fall short of this goal. The outcomes after ACLR are variable and less than optimal with low rate of return to preinjury activity level and high risk for second ACL injury. Factors related to the knee functional limitations, strength deficits, and limb-to-limb movement asymmetry may be associated with poor outcomes after ACLR. Additionally, the criteria that are used to determine a patient's readiness to return to the preinjury activity level are undefined which may also be associated with poor outcomes after ACLR. The clinical decision-making to clear patients' for safe and successful return to high physical activities should be based on a universal comprehensive set of objective criteria that ensure normal knee function and limb-to-limb symmetry. A battery of return to activity criteria (RTAC) that emphases normal knee function and limb-to-limb movement symmetry has been constituted to better ensure safe and successful return to preinjury activity level. Yet, only variables related to patients' demographics, concomitant injuries, and treatment measures have been used to predict return to preinjury activity levels after ACLR. However, the ability of RTAC variables that ensure normal knee function and limb movement symmetry to predict the return to participate in the same preinjury activity level after ACLR has not been investigated. In light of this background, the first aim of the present study was to compare functional knee performance-based and patient-reported measures of those who PASS and who FAIL on RTAC at 6 months (6-M) following ACLR with those at 12 months (12-M) and 24 months (24-M) following ACLR and to determine how performance-based and patient-reported measures

  14. ACL reconstruction using bone-tendon-bone graft engineered from the semitendinosus tendon by injection of recombinant BMP-2 in a rabbit model.

    PubMed

    Hashimoto, Yusuke; Naka, Yoshifumi; Fukunaga, Kenji; Nakamura, Hiroaki; Takaoka, Kunio

    2011-12-01

    We attempted to generate a bone-tendon-bone structure by injecting human-type recombinant human bone morphogenetic protein-2 (rhBMP-2) into the semitendinosus tendon, and an anterior cruciate ligament (ACL) defect was reconstructed by grafting the engineered bone-tendon-bone graft. Two ossicles with a separation distance of 1 cm were generated within the left semitendinosus tendon of a rabbit 6 weeks after the injection of rhBMP-2 (15 µg at each site). The engineered bone-tendon-bone graft was transplanted in order to reconstruct the ACL by passing the graft through the bone tunnels. In the control group, the ACL was reconstructed with the semitendinosus tendon without BMP-2 using the same methods as those used in the experimental group. The animals were harvested at 4 or 8 weeks after surgery and examined by radiographic, histological, and biomechanical methods. In the experimental group, ossicles in the bone-tendon-bone graft were successfully integrated into the host bone of the femur and tibia. Histological analysis revealed that characteristic features identical to the normal direct insertion morphology had been restored. Biomechanical pull-out testing showed that the ultimate failure load and stiffness of the reconstructed ACL in the experimental group were significantly higher than those in the control group at both 4 and 8 weeks (p < 0.05). These results indicate the potential of regenerative reconstruction of the ACL, and the reconstruction resulted in the restoration of morphology and function equivalent to those of the normal ACL. PMID:21557301

  15. The effect of accelerated, brace free, rehabilitation on bone tunnel enlargement after ACL reconstruction using hamstring tendons: a CT study.

    PubMed

    Vadalà, Antonio; Iorio, Raffaele; De Carli, Angelo; Argento, Giuseppe; Di Sanzo, Vincenzo; Conteduca, Fabio; Ferretti, Andrea

    2007-04-01

    The mechanism of bone tunnel enlargement following anterior cruciate ligament (ACL) reconstruction is not yet clearly understood. Many authors hypothesized that aggressive rehabilitation protocols may be a potential factor for bone tunnel enlargement, especially in reconstructions performed with hamstrings autograft. The purpose of this study was to evaluate the effect of a brace free rehabilitation on the tunnel enlargement after ACL reconstruction using doubled semitendinosus and gracilis tendons (DGST): our hypothesis was that early post-operative knee motion increase the diameters of the tibial and femoral bone tunnels. Forty-five consecutive patients undergoing ACL reconstruction for chronic ACL deficiency were selected. All patients were operated by the same surgeon using autologous DGST and the same fixation devices. Patients with associated ligaments injuries and or severe chondral damage were excluded. The patients were randomly assigned to enter the control group (group A, standard post-operative rehabilitation) and the study group (group B, brace free accelerated rehabilitation). A CT scan was used to exactly determine the diameters of both femoral and tibial tunnels at various levels of lateral femoral condyle and proximal tibia, using a previously described method [17]. Measurements were done by an independent radiologist in a blinded fashion the day after the operation and at a mean follow-up of 10 months (range 9-11). Statistical analysis was performed using paired t-test. The mean femoral tunnel diameter increased significantly from 9.04 +/- 0.05 (post-operative) to 9.30 +/- 0.8 mm (follow-up) in group A and from 9.04 +/- 0.03 to 9.94 +/- 1.12 mm in group B. The mean tibial tunnel diameter increased significantly from 9.03 +/- 0.04 to 10.01 +/- 0.80 mm in group A and from 9.04 +/- 0.03 to 10.60 +/- 0.78 mm in group B. The increase in femoral and tunnel diameters observed in the study group was significantly higher than that observed in the control

  16. Knee functional recovery and limb-to-limb symmetry restoration after anterior cruciate ligament (ACL) rupture and ACL reconstruction

    NASA Astrophysics Data System (ADS)

    Nawasreh, Zakariya Hussein

    Anterior cruciate ligament (ACL) rupture is a common sport injury of young athletes who participate in jumping, cutting, and pivoting activities. Although ACL reconstruction (ACLR) surgery has the goal of enabling athletes to return to preinjury activity levels, treatment results often fall short of this goal. The outcomes after ACLR are variable and less than optimal with low rate of return to preinjury activity level and high risk for second ACL injury. Factors related to the knee functional limitations, strength deficits, and limb-to-limb movement asymmetry may be associated with poor outcomes after ACLR. Additionally, the criteria that are used to determine a patient's readiness to return to the preinjury activity level are undefined which may also be associated with poor outcomes after ACLR. The clinical decision-making to clear patients' for safe and successful return to high physical activities should be based on a universal comprehensive set of objective criteria that ensure normal knee function and limb-to-limb symmetry. A battery of return to activity criteria (RTAC) that emphases normal knee function and limb-to-limb movement symmetry has been constituted to better ensure safe and successful return to preinjury activity level. Yet, only variables related to patients' demographics, concomitant injuries, and treatment measures have been used to predict return to preinjury activity levels after ACLR. However, the ability of RTAC variables that ensure normal knee function and limb movement symmetry to predict the return to participate in the same preinjury activity level after ACLR has not been investigated. In light of this background, the first aim of the present study was to compare functional knee performance-based and patient-reported measures of those who PASS and who FAIL on RTAC at 6 months (6-M) following ACLR with those at 12 months (12-M) and 24 months (24-M) following ACLR and to determine how performance-based and patient-reported measures

  17. ALL‐EPIPHYSEAL ACL RECONSTRUCTION: A THREE‐YEAR FOLLOW‐UP

    PubMed Central

    Akinleye, Sheriff D.; Sewick, Amy

    2013-01-01

    Background/Introduction: With an increasing number of pre‐adolescents participating in sports, anterior cruciate ligament injuries and resultant reconstruction in the skeletally immature athlete are becoming more common. Many different surgical techniques and rehabilitation protocols have been proposed for the treatment of anterior cruciate ligament (ACL) injuries, but there is a lack of agreement as to which approach results in the best outcome. Rehabilitation protocols have marked variation regarding postoperative weight bearing, immobilization, bracing, and length. Case description: This is a case of a ten year old female who sustained bilateral ACL tears within the period of a year. The purpose of this case report is to describe the early result and subsequent rehabilitation following bilateral physeal‐sparing all‐epiphyseal ACL reconstructions on a skeletally immature patient with a three‐year follow‐up. Outcomes: The early post‐surgical recovery period on the first injured knee was complicated by knee stiffness requiring manipulation. Following this minor setback, the patient met all physical therapy goals and had no additional complications. The rehabilitation after the second surgery followed a typical course. At three‐year follow‐up, the patient had grown an additional seven inches, with radiographic evidence of symmetric physeal growth and joint stability. She has returned to playing competitive sports. Discussion and Conclusion: This innovative physeal‐sparing technique has huge implications as, historically; the feared complication of growth disturbance and angular deformity from transphyseal ACL reconstruction has complicated the management of ACL injuries in children and pre‐adolescents. This case report demonstrates the success of this technique, and the subsequent rehabilitation, as this patient did not experience a reduction in long‐term bone growth. Level of Evidence: 5 Case Report PMID:23772346

  18. Persistent Biomechanical Alterations After ACL Reconstruction Are Associated With Early Cartilage Matrix Changes Detected by Quantitative MR

    PubMed Central

    Amano, Keiko; Pedoia, Valentina; Su, Favian; Souza, Richard B.; Li, Xiaojuan; Ma, C. Benjamin

    2016-01-01

    Background: The effectiveness of anterior cruciate ligament (ACL) reconstruction in preventing early osteoarthritis is debated. Restoring the original biomechanics may potentially prevent degeneration, but apparent pathomechanisms have yet to be described. Newer quantitative magnetic resonance (qMR) imaging techniques, specifically T1ρ and T2, offer novel, noninvasive methods of visualizing and quantifying early cartilage degeneration. Purpose: To determine the tibiofemoral biomechanical alterations before and after ACL reconstruction using magnetic resonance imaging (MRI) and to evaluate the association between biomechanics and cartilage degeneration using T1ρ and T2. Study Design: Cohort study; Level of evidence, 2. Methods: Knee MRIs of 51 individuals (mean age, 29.5 ± 8.4 years) with unilateral ACL injuries were obtained prior to surgery; 19 control subjects (mean age, 30.7 ± 5.3 years) were also scanned. Follow-up MRIs were obtained at 6 months and 1 year. Tibial position (TP), internal tibial rotation (ITR), and T1ρ and T2 were calculated using an in-house Matlab program. Student t tests, repeated measures, and regression models were used to compare differences between injured and uninjured sides, observe longitudinal changes, and evaluate correlations between TP, ITR, and T1ρ and T2. Results: TP was significantly more anterior on the injured side at all time points (P < .001). ITR was significantly increased on the injured side prior to surgery (P = .033). At 1 year, a more anterior TP was associated with elevated T1ρ (P = .002) and T2 (P = .026) in the posterolateral tibia and with decreased T2 in the central lateral femur (P = .048); ITR was associated with increased T1ρ in the posteromedial femur (P = .009). ITR at 6 months was associated with increased T1ρ at 1 year in the posteromedial tibia (P = .029). Conclusion: Persistent biomechanical alterations after ACL reconstruction are related to significant changes in cartilage T1ρ and T2 at 1 year

  19. Sex-specific gait adaptations prior to and up to six months after ACL reconstruction

    PubMed Central

    Stasi, Stephanie L. Di; Hartigan, Erin H.; Snyder-Mackler, Lynn

    2015-01-01

    STUDY DESIGN Controlled longitudinal laboratory study. OBJECTIVES Compare sagittal plane gait mechanics of men and women before and up to 6 months after anterior cruciate ligament reconstruction (ACLR). BACKGROUND Aberrant gait patterns are ubiquitous after anterior cruciate ligament (ACL) rupture and persist after ACLR despite skilled physical therapy. Sex influences post-operative function and second ACL injury risk, but its influence on gait adaptations after injury have not been investigated. METHODS Sagittal plane knee and hip joint excursions during midstance and internal knee and hip extension moments at peak knee flexion were collected on 12 women and 27 men using 3-dimensional gait analysis before (Screen) and after pre-operative physical therapy (Pre-sx), and 6 months after ACLR (6mo). Repeated measures analysis of variance models were used to determine whether limb asymmetries changed differently over time in men and women. RESULTS Significant time x limb x sex interactions were identified for hip and knee excursions and internal knee extension moments (P≤.007). Both sexes demonstrated smaller knee excursions on the involved compared to the uninvolved knee at each time point (P≤.007), but only women demonstrated a decrease in the involved knee excursion from pre-sx to 6mo (P=.03). Women also demonstrated smaller hip excursions (P<.001) and internal knee extension moments (P=.005) on the involved limb compared to the uninvolved limb at 6mo. Men demonstrated smaller hip excursions and knee moments on the involved limb compared to the uninvolved limb (main effects, P<.001). CONCLUSION The persistence of limb asymmetries in men and women 6 months after ACLR indicates that current rehabilitation efforts are inadequate for some individuals following ACLR. PMID:25627155

  20. Balance Ability and Proprioception after Single-Bundle, Single-Bundle Augmentation, and Double-Bundle ACL Reconstruction

    PubMed Central

    Ma, Yubao; Iwaki, Daisuke; Asaeda, Makoto; Adachi, Nobuo; Ochi, Mitsuo

    2014-01-01

    Purpose. The present study sought to determine the influences of single-bundle (SB), single-bundle augmentation (SBA), and double-bundle (DB) reconstructions on balance ability and proprioceptive function. Methods. 67 patients who underwent a single- or double-bundle ACL reconstruction or a SBA using multistranded autologous hamstring tendons were included in this study with a 1-year follow-up. Body sway and knee kinesthesia (using the threshold to detect passive motion test (TTDPM)) were measured to indicate balance ability and proprioceptive function, respectively. Additionally, within-subject differences in anterior-posterior stability of the tibia and lower extremity muscle strength were evaluated before and after surgery. Results. At 6 and 12 months after surgery, DB reconstruction resulted in better balance and proprioceptive function than SB reconstruction (P < 0.05). Although no significant difference was observed in balance ability or proprioceptive function between the SBA and DB reconstructions, knee stability was significantly better with SBA and DB reconstructions than SB reconstruction (P < 0.05). No significant differences were found in quadriceps and hamstrings strength among the three reconstruction techniques. Conclusions. Our findings consider that joint stability, proprioceptive function, and balance ability were superior with SBA and DB reconstructions compared to SB reconstruction at 6 and 12 months after surgery. PMID:25614884

  1. Use of ultra-high molecular weight polycaprolactone scaffolds for ACL reconstruction.

    PubMed

    Leong, Natalie L; Kabir, Nima; Arshi, Armin; Nazemi, Azadeh; Jiang, Jie; Wu, Ben M; Petrigliano, Frank A; McAllister, David R

    2016-05-01

    Previously, we reported on the implantation of electrospun polycaprolactone (PCL) grafts for use in ACL tissue engineering in a small animal model. In the present study, we hypothesized that grafts fabricated from ultra-high molecular weight polycaprolactone (UHMWPCL) would have similarly favorable biologic properties but superior mechanical properties as compared to grafts fabricated from PCL. Two forms of polycaprolactone were obtained (UHMWPCL, MW = 500 kD, and PCL, MW = 80 kD) and electrospun into scaffolds that were used to perform ACL reconstruction in 7-8 week old male Lewis rats. The following groups were examined: UHMWPCL, PCL, flexor digitorum longus (FDL) allograft, native ACL, as well as sham surgery in which the ACL was transsected. At 16 weeks post-operatively, biomechanical testing, histology, and immunohistochemistry (IHC) were performed. Analysis of cellularity indicated that there was no significant difference among the UHMWPCL, PCL, and FDL allograft groups. Quantification of birefringence from picrosirius red staining demonstrated significantly more aligned collagen fibers in the allograft than the PCL group, but no difference between the UHMWPCL and allograft groups. The peak load to failure of the UHMWPCL grafts was significantly higher than PCL, and not significantly different from FDL allograft. This in vivo study establishes the superiority of the higher molecular weight version of polycaprolactone over PCL as a scaffold material for ACL reconstruction. By 16 weeks after implantation, the UHMWPCL grafts were not significantly different from the FDL allografts in terms of cellularity, peak load to failure, stiffness, and collagen fiber alignment. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:828-835, 2016. PMID:26497133

  2. Effects of ACL Reconstruction on In-Vivo, Dynamic Knee Function

    PubMed Central

    Tashman, Scott; Araki, Daisuke

    2012-01-01

    Synopsis The purposes of this article are to discuss key factors for assessing joint function, to present some recent findings and to address the future directions for evaluating the function of the ACL-injured/reconstructed knees. Well-designed studies, using state-of-the art tools to assess knee kinematics under in vivo, dynamic, high-loading conditions, are necessary to evaluate the relative performance of different procedures for restoring normal joint motion. PMID:23177461

  3. Which one Enhances Muscular Performance in ACL Reconstructed Subjects

    PubMed Central

    Harput, Gulcan; Ulusoy, Burak; Atay, Ahmet Ozgur; Baltacı, Gul

    2014-01-01

    Objectives: The aim of this study was to investigate the effects of functional knee brace and kinesiotaping on muscular performance in anterior cruciate ligament reconstructed subjects who reached return to sport phase of the rehabilitation. Methods: Twenty (17 males, 3 females, Age: 24.7±7.1 years, Body weight: 74.4±12.0 kg, Height: 177.9±6.5 cm, BMI: 23.9±3.6 kg/m2) subjects who underwent anterior cruciate ligament reconstruction by using hamstring tendon auto graft were included in this study. When the subjects reached the return to sports phase of rehabilitation which was 6th months after surgery, knee muscle strength, jump performance and balance tests were performed 3 times: bare, with knee brace and with kinesio taping. The order of the tests were randomized to eliminate the effects of fatigue and motor learning. Quadriceps and hamstring muscle strength was measured on an isokinetic dynamometer at 180 °/s and 60°/s angular velocities. Vertical Jump (VJ) and One Leg Hop Tests (OLHT) were used to assess jump performance. Star Excursion Balance Test (SEBT) with anterior, posteromedial and posterolateral reach distance was used to assess the dynamic balance. When all tests were performed, the subjects were asked under which test condition they felt more confident. Repeated measures of ANOVA was used to analyze the difference among three test conditions (bare, kinesiotaping, knee brace). Bonferroni post hoc test was used for pairwise comparison. Results: SEBT posteromedial (PM)and posterolateral (PL) reach distances were found significantly different among three test conditions(PM: F(2,38)=3.42,p=0.04), PL: F(2,38)=4.37,p=0.02). Kinesiotaping increased posteromedial reach distance (p=0.03). On the other hand, brace decreased posterolateral reach distance (p=0.04). VJ and OLHT performance were also found significantly different between three test conditions (VJ: F (2,38)=3.44,p=0.04, OLHT: (F(2,38)=4.04,p=0.02). Kinesio taping increased one leg hop distance

  4. Tibial tunnel widening after bioresorbable poly-lactide calcium carbonate interference screw usage in ACL reconstruction.

    PubMed

    Foldager, Casper; Jakobsen, Bent W; Lund, Bent; Christiansen, Svend Erik; Kashi, Lotte; Mikkelsen, Lone R; Lind, Martin

    2010-01-01

    Developing bio-absorbable interference screws for anterior cruciate ligament (ACL) reconstruction has proven to be a challenging task. The aim of this study was to investigate the osteogenetic response of poly-lactide carbonate (PLC) interference screws in ACL reconstruction in humans. Ten patients (median age, 28 years) underwent arthroscopic ACL reconstruction with semitendinosus/gracilis tendon graft and a PLC interference screw. The patients were scanned with a multi-slice CT scanner 2 weeks and 1 year postoperatively. Fourteen days postoperatively a mean tunnel widening of 78% [52%; 110%] was observed. At 1-year follow-up, the mean tunnel widening was 128% [84%; 180%]. No sign of bone replacement or bone ingrowth was observed. Factors such as accelerated rehabilitation, micro-motions, and early screw degradation might be responsible for this large tunnel widening. Our results demonstrate the difficulty in translation of preclinical data. This study illustrates the need for extensive preclinical investigation of new materials for clinical purposes. PMID:19609505

  5. A tale of 10 European centres – 2010 APOSSM travelling fellowship review in ACL surgery

    PubMed Central

    2012-01-01

    The purpose of ESSKA- APOSSM Travelling fellowship is to better understand the epidemiology, management and surgical techniques for sports across continents. There has been a progressive evolution in ACL reconstruction and there is variation in technique in ACL reconstruction amongst the most experienced surgeons in different continents. During this one month fellowship, we saw various ACL reconstruction techniques using different graft sources, with a variety of graft fixation methods, with the common aim of recreating an anatomical ACL reconstruction. PMID:22839644

  6. Giant Cell Tumor within the Proximal Tibia after ACL Reconstruction

    PubMed Central

    Takahashi, Takashi; MacCormick, Lauren; Ellermann, Jutta; Clohisy, Denis; Marette, Shelly

    2016-01-01

    26-year-old female with prior anterior cruciate ligament reconstruction developed an enlarging lytic bone lesion around the tibial screw with sequential imaging over the course of one year demonstrating progression of this finding, which was confirmed histologically to be a giant cell tumor of bone. The lesion originated around the postoperative bed, making the diagnosis challenging during the early course of the presentation. The case demonstrates giant cell tumor which originated in the metaphysis and subsequently grew to involve the epiphysis; therefore, early course of the disease not involving the epiphysis should not exclude this diagnosis. PMID:26981302

  7. Assessing 3D tunnel position in ACL reconstruction using a novel single image 3D-2D registration

    NASA Astrophysics Data System (ADS)

    Kang, X.; Yau, W. P.; Otake, Y.; Cheung, P. Y. S.; Hu, Y.; Taylor, R. H.

    2012-02-01

    The routinely used procedure for evaluating tunnel positions following anterior cruciate ligament (ACL) reconstructions based on standard X-ray images is known to pose difficulties in terms of obtaining accurate measures, especially in providing three-dimensional tunnel positions. This is largely due to the variability in individual knee joint pose relative to X-ray plates. Accurate results were reported using postoperative CT. However, its extensive usage in clinical routine is hampered by its major requirement of having CT scans of individual patients, which is not available for most ACL reconstructions. These difficulties are addressed through the proposed method, which aligns a knee model to X-ray images using our novel single-image 3D-2D registration method and then estimates the 3D tunnel position. In the proposed method, the alignment is achieved by using a novel contour-based 3D-2D registration method wherein image contours are treated as a set of oriented points. However, instead of using some form of orientation weighting function and multiplying it with a distance function, we formulate the 3D-2D registration as a probability density estimation using a mixture of von Mises-Fisher-Gaussian (vMFG) distributions and solve it through an expectation maximization (EM) algorithm. Compared with the ground-truth established from postoperative CT, our registration method in an experiment using a plastic phantom showed accurate results with errors of (-0.43°+/-1.19°, 0.45°+/-2.17°, 0.23°+/-1.05°) and (0.03+/-0.55, -0.03+/-0.54, -2.73+/-1.64) mm. As for the entry point of the ACL tunnel, one of the key measurements, it was obtained with high accuracy of 0.53+/-0.30 mm distance errors.

  8. PATIENT-SPECIFIC AND SURGERY-SPECIFIC FACTORS THAT AFFECT RETURN TO SPORT AFTER ACL RECONSTRUCTION

    PubMed Central

    Lynch, Andrew; Rabuck, Stephen; Lynch, Brittany; Davin, Sarah; Irrgang, James

    2016-01-01

    Context Anterior cruciate ligament (ACL) reconstruction is frequently performed to allow individuals to return to their pre-injury levels of sports participation, however, return to pre-injury level of sport is poor and re-injury rates are unacceptably high. Re-injury is likely associated with the timeframe and guidelines for return to sport (RTS). It is imperative for clinicians to recognize risk factors for re-injury and to ensure that modifiable risk factors are addressed prior to RTS. The purpose of this commentary is to summarize the current literature on the outcomes following return to sport after ACL reconstruction and to outline the biologic and patient-specific factors that should be considered when counseling an athlete on their progression through rehabilitation. Evidence Acquisition A comprehensive literature search was performed to identify RTS criteria and RTS rates after ACL reconstruction with consideration paid to graft healing, anatomic reconstruction, and risk factors for re-injury and revision. Results were screened for relevant original research articles and review articles, from which results were summarized. Study Design Clinical Review of the Literature Results Variable RTS rates are presented in the literature due to variable definitions of RTS ranging from a high threshold (return to competition) to low threshold (physician clearance for return to play). Re-injury and contralateral injury rates are greater than the risk for primary ACL injury, which may be related to insufficient RTS guidelines based on time from surgery, which do not allow for proper healing or resolution of post-operative impairments and elimination of risk factors associated with both primary and secondary ACL injuries. Conclusions RTS rates to pre-injury level of activity after ACLR are poor and the risk for graft injury or contralateral injury requiring an additional surgery is substantial. Resolving impairments while eliminating movement patterns associated with

  9. THE ROLE AND IMPLEMENTATION OF ECCENTRIC TRAINING IN ATHLETIC REHABILITATION: TENDINOPATHY, HAMSTRING STRAINS, AND ACL RECONSTRUCTION

    PubMed Central

    Reiman, Michael

    2011-01-01

    The benefits and proposed physiological mechanisms of eccentric exercise have previously been elucidated and eccentric exercise has been used for well over seventy years. Traditionally, eccentric exercise has been used as a regular component of strength training. However, in recent years, eccentric exercise has been used in rehabilitation to manage a host of conditions. Of note, there is evidence in the literature supporting eccentric exercise for the rehabilitation of tendinopathies, muscle strains, and in anterior cruciate ligament (ACL) rehabilitation. The purpose of this Clinical Commentary is to discuss the physiologic mechanism of eccentric exercise as well as to review the literature regarding the utilization of eccentric training during rehabilitation. A secondary purpose of this commentary is to provide the reader with a framework for the implementation of eccentric training during rehabilitation of tendinopathies, muscle strains, and after ACL reconstruction. PMID:21655455

  10. Do Newer-Generation Bioabsorbable Screws Become Incorporated into Bone at Two Years After ACL Reconstruction with Patellar Tendon Graft?

    PubMed Central

    Cox, Charles L.; Spindler, Kurt P.; Leonard, James P.; Morris, Brent J.; Dunn, Warren R.; Reinke, Emily K.

    2014-01-01

    Background: Bioabsorbable interference screws are used frequently for graft fixation in ACL (anterior cruciate ligament) reconstruction. The resorption properties of many available screws that are marketed as bioabsorbable are not well defined. The CALAXO (Smith & Nephew Endoscopy) and MILAGRO (DePuy Synthes) bioabsorbable screws contain polymers of poly(lactic-co-glycolic acid) (PLGA) plus additives to encourage osseointegration over time. The purpose of this study was to evaluate radiographic and magnetic resonance imaging (MRI) properties and compare patient-reported outcomes at a minimum of two years of follow-up after ACL reconstruction using CALAXO or MILAGRO bioabsorbable interference screws. Methods: A cohort of patients who underwent ACL reconstruction in which the fixation used was either CALAXO or MILAGRO screws returned for repeat radiographs for evaluation of tunnel widening, repeat MRI for evaluation of graft integrity and screw breakdown, and completion of the pain and symptom items of the KOOS (Knee injury and Osteoarthritis Outcome Score) questionnaire. Results: At a mean of three years (range, 2.5 to 4.0 years) after surgery, thirty-one patients with sixty-two CALAXO screws and thirty-six patients with seventy-two MILAGRO screws returned for repeat evaluation. Two blinded, independent reviewers found no significant differences between the two screw types when comparing radiographs for tibial or femoral tunnel widening or MRIs for graft integrity, tibial and femoral foreign body reactions, or femoral screw degradation. Both reviewers found a significant difference between the two screw types when comparing tibial screw degradation properties (p < 0.01). All analyzed CALAXO screws were rated as partially intact or degraded; the MILAGRO screws were more likely to be rated as intact. No significant differences were noted between the two screw types when comparing the two KOOS subscales. Conclusions: CALAXO screws in the tibial tunnel were more likely

  11. The role of the anterolateral ligament in ACL insufficient and reconstructed knees on rotatory stability: A biomechanical study on human cadavers.

    PubMed

    Tavlo, M; Eljaja, S; Jensen, J T; Siersma, V D; Krogsgaard, M R

    2016-08-01

    Studies suggest that the anterolateral ligament (ALL) is important for knee stability. The purpose was to clarify ALL's effect on rotatory and anterior-posterior stability in the anterior cruciate ligament (ACL)-insufficient and reconstructed knees and the effect of reconstruction of an insufficient ALL. Eighteen cadaveric knees were included. Stability was tested for intact (+ALL), detached (-ALL) and reconstructed (+ reALL) ALL, with ACL removed (-ACL) and reconstructed (+ACL) in six combinations. All were tested in 0, 30, 60, and 90 °C flexion. Anterior-posterior stability was measured with a rolimeter. Rotation with a torque of 8.85 Nm was measured photographically. The ALL was well defined in 78% of knees. ACL reconstruction had a significant effect on anterior-posterior stability. Detaching the ALL had a significant effect on internal rotatory stability and on anterior-posterior stability in ACL-insufficient knees. Reconstruction of ACL and ALL reestablished knee stability. The appearance of the ALL was not uniform. The ALL was an internal rotational stabilizer. Anatomical ALL reconstruction in combination with ACL reconstruction could reestablish stability. ALL reconstruction might be considered in patients with combined ACL and ALL tears, but the clinical effect should be established in a controlled clinical study. PMID:26247376

  12. Combination of Eccentric Exercise and Neuromuscular Electrical Stimulation to Improve Quadriceps Function Post-ACL Reconstruction

    PubMed Central

    Lepley, Lindsey K.; Wojtys, Edward M.; Palmieri-Smith, Riann M.

    2014-01-01

    Background Neuromuscular electrical stimulation (NMES) has been shown to reduce quadriceps activation failure (QAF), and eccentric exercise has been shown lessen muscle atrophy post-ACL reconstruction. Given that these are two critical components of quadriceps strength, intervention combining these therapies may be effective at reinstituting quadriceps function post-anterior cruciate ligament (ACL) reconstruction. Objectives To evaluate the effectiveness of a combined NMES and eccentric exercise intervention to improve the recovery of quadriceps activation and strength post-reconstruction. Design Parallel longitudinal design. Setting Laboratory. Participants Thirty-six individuals post-injury were placed into four treatment groups (N&E, NMES and eccentrics; E-only, eccentrics only; N-only, NMES-only; STND, standard of care) and ten healthy controls participated. Intervention N&E and N-only received the NMES protocol 2x per week for the first six weeks post-reconstruction. N&E and E-only received the eccentric exercise protocol 2x per week beginning six weeks post-reconstruction. Main outcome measure Quadriceps activation was assessed via the superimposed burst technique and quantified via the central activation ratio. Quadriceps strength was assessed via maximal voluntary isomeric contractions (Nm/kg). Data was gathered on three occasions: pre-operative, 12-weeks-post-surgery and at return-to-play. Results No differences in pre-operative measures existed (P>0.05). E-only recovered quadriceps activation better than N-only or STND (P<0.05). N&E and E-only recovered strength better than N-only or the STND (P<0.05) and had strength values that were similar to healthy individuals at return-to-play (P>0.05). Conclusion Eccentric exercise was capable of restoring levels of quadriceps activation and strength that were similar to those of healthy adults and better than NMES alone. PMID:25819154

  13. Validation of GAITRite and PROMIS as High-Throughput Physical Function Outcome Measures Following ACL Reconstruction

    PubMed Central

    Papuga, M. Owen; Beck, Christopher A.; Kates, Stephen L.; Schwarz, Edward M.; Maloney, Michael D.

    2014-01-01

    New healthcare demands for quality measures of elective procedures, such as anterior cruciate ligament (ACL) reconstructive surgery, warrant the establishment of high through-put outcomes for high volume clinics. To this end we evaluated the PROMIS and GAITRite as physical function outcome measures to quantify early healing and post-operative complications in 106 patients at pre-op and 3, 10, 20 and 52 weeks post-ACL reconstruction with bone-tendon-bone autograft, and compared the results to the current IKDC validated outcome measure. The results showed that both PROMIS and GAITRite were significantly quicker to administer versus IKDC (p < 0.0001). Additional advantages were that PROMIS and GAITRite detected a significant decrease in physical function at 3 weeks post-op, and a significant improvement at 10 weeks post-op, versus pre-op (p<0.001), which were not detected with IKDC. GAITRite was limited by a low ceiling that could not detect improvement of physical function beyond 20 weeks, while both PROMIS and IKDC detected significant improvement out to 52 weeks postop (p<0.001). Linear regressions demonstrated a significant relationship between IKDC and PROMIS, with a combined correlation value of 0.8954 (p<.001) for all time points. Finally, ROC curve analysis demonstrated that PROMIS is a diagnostic test for poor outcomes. PMID:24532421

  14. Persons with reconstructed ACL exhibit altered knee mechanics during high-speed maneuvers.

    PubMed

    Lee, S-P; Chow, J W; Tillman, M D

    2014-06-01

    Anterior cruciate ligament (ACL) injury is a sports trauma that causes long-term disability. The function of the knee during dynamic activities can be severely limited even after successful surgical reconstruction. This study examined the effects of approach velocity during side-step cutting on knee joint mechanics in persons with reconstructed ACL (ACLR). 22 participants (11 with unilateral ACLR, 11 matched-controls) participated. Knee joint mechanics were tested in 3 approach conditions: counter-movement, one-step, and running. Dependent variables, including peak knee flexion, extension, valgus, varus, internal rotation, external rotation angles and corresponding peak joint moments, were assessed during the stance phase of cutting. Two 2×3 ("group" by "approach condition") mixed MANOVA tests were used to examine the effects of ACLR and approach velocity on knee mechanics. ACLR participants exhibited higher knee internal rotator moment (0.22 vs. 0.13 Nm/kg, p=0.003). Inter-group comparisons revealed that the ACLR participants exhibited significantly higher abductor and internal rotator moments only in the running condition (1.86 vs. 1.16 Nm/kg, p=0.018; 0.28 vs. 0.17 Nm/kg, p=0.010, respectively). Our findings suggested that patients with ACLR may be at increased risk of re-injury when participating in high-demand physical activities. Task demand should be considered when prescribing progressive therapeutic interventions to ACLR patients. PMID:24408765

  15. Return to sport after ACL reconstruction: how, when and why? A narrative review of current evidence.

    PubMed

    Zaffagnini, Stefano; Grassi, Alberto; Serra, Margherita; Marcacci, Maurilio

    2015-01-01

    Allowing a patient to return to sport and unrestricted physical activity after ACL injury and reconstruction is one of the most challenging and difficult decisions an orthopaedic surgeon has to make. Indeed, many factors have to be taken into account before it can be considered safe for a patients to load a reconstructed knee. The current literature contains plenty of studies aimed at evaluating return to sport, and the factors that may affect or predict this outcome, e.g. intrinsic factors like genetics, biology, type of lesion, anatomical features, motivation and psychology, and extrinsic factors such as graft type, surgical technique, rehabilitation protocols, and biological support. It is possible that awareness of these issues could help the clinician to optimise outcomes, and possibly avoid failures too, although as yet no universal criteria for resuming sport have been produced. PMID:26151036

  16. Return to sport after ACL reconstruction: how, when and why? A narrative review of current evidence

    PubMed Central

    ZAFFAGNINI, STEFANO; GRASSI, ALBERTO; SERRA, MARGHERITA; MARCACCI, MAURILIO

    2015-01-01

    Allowing a patient to return to sport and unrestricted physical activity after ACL injury and reconstruction is one of the most challenging and difficult decisions an orthopaedic surgeon has to make. Indeed, many factors have to be taken into account before it can be considered safe for a patients to load a reconstructed knee. The current literature contains plenty of studies aimed at evaluating return to sport, and the factors that may affect or predict this outcome, e.g. intrinsic factors like genetics, biology, type of lesion, anatomical features, motivation and psychology, and extrinsic factors such as graft type, surgical technique, rehabilitation protocols, and biological support. It is possible that awareness of these issues could help the clinician to optimise outcomes, and possibly avoid failures too, although as yet no universal criteria for resuming sport have been produced. PMID:26151036

  17. COMPARATIVE STUDY OF ACL RECONSTRUCTION WITH ANATOMICAL POSITIONING OF THE TUNNELS USING THE PATELLAR TENDON VERSUS HAMSTRING TENDON

    PubMed Central

    de Pádua, Vitor Barion Castro; Maldonado, Hilário; Vilela, Júlio César Rodrigues; Provenza, Alexandre Ribeira; Monteiro, Cleverson; de Oliveira Neto, Heleno Cavalcante

    2015-01-01

    Objective: To compare ACL reconstruction with anatomical positioning of the tunnels using the hamstring or patellar tendons. Methods: We prospectively evaluated 52 patients who underwent ACL reconstruction using the Chambat's technique, with anatomical positioning of the tunnels drilled outside in. They were divided into group A, with 27 patients, using the patellar tendon as a graft, and group B, with 25 patients, using the hamstring. Results: In group A 26 patients were very satisfied or satisfied and 1 unhappy, in group B. 25 patients were very satisfied or satisfied with the procedure (p = 0.990). According to the Lysholm scale, group A had a mean score of 96.11 and group B, 95.32 (p=0.594). In relation to preoperative IKDC, 100% of the patients in group A and 92% of those in group B were IKDC C or D (p = 0.221); in the assessment with a minimum of two-year follow-up, 96% of group A and 92% of group B were IKDC A or B (p = 0.256). The Lachman test, pivot shift, return to sports activities, and the comparative difference in anterior translation (RolimeterTM) also showed no statistically significant difference. In group A, 5 patients (18.5%) were unable to kneel on a hard surface, whereas no patient in group B had this complaint. Conclusion: The anterior cruciate ligament reconstruction presents similar results using the hamstring or patellar tendon with anatomical positioning of the tunnels. Drilling the femoral tunnel outside in is a reproducible and accurate option in the correct placement the femoral tunnel. PMID:27027082

  18. Comparison Between Strength of Muscles Rotating the Knee in Healthy Individuals and Patients one Year after an ACL Reconstruction

    PubMed Central

    Popieluch, Marcın; Śmigıelski, Robert; Straszewski, Darıusz; Plenzler, Marcın; Stanıszewski, Mıchał

    2014-01-01

    Objectives: In this study we have made an attempt to establish torque value of the muscles rotating the knee of patients who had ruptured their ACLs during an amateur football practise on an artificial turf. In this study we presented biomechanical research on torques of muscles responsible for internal and external rotation of the lower leg. We presented a method whereby it is possible to measure the muscle strength before and after the ACL rupture but also during the process of rehabilitation and after its finish. The available literature on measurements of torque of the knee is quite extensive though it mainly describes torques of muscles flexing and extending the joint. In Polish literature there is scarcity of studies focused on torques of muscles rotating the knee. In foreign literature there is an increasing emphasis on the role of lower leg rotation, as the element greatly impacting, for instance, the position of the foot. Methods: The study presents results of 22 patients and 50 healthy individuals (not practising any particular sport regularly) being the control group. All patients had their ACLs reconstructed using the double-bundle technique. The material for the graft was obtained from the hamstrings. The aim was to measure the maximal torque of the muscles responsible for external and internal rotation of the knee (lower leg in a static state using a special device). The device allowed measurement of the torque of muscles rotating the lower leg in its axis by stabilizing the ankle with special emphasis on foot mounting (stabilization of footwear). The special device was connected to a PC with CPS/HMF software. The software enabled observation and recording of increase in the value of the torque until it reached its maximum. The measurements were taken in two knee positions: 30 degrees and 90 degrees flexion. Results: The result were analyzed statistically, means and SDs were calculated. Only right-legged subjects were included in the analysis. The

  19. In vivo bone tunnel remodeling in symptomatic patients after ACL reconstruction: a retrospective comparison of articular and extra-articular fixation

    PubMed Central

    Mathis, Dominic T.; Rasch, Helmut; Hirschmann, Michael T.

    2015-01-01

    Summary Background there is only a paucity of studies dealing with bone remodeling within the tunnels after anterior cruciate ligament (ACL) reconstruction. The objective of this study was to evaluate the influence of tendon graft type and surgical fixation technique on bone tunnel remodeling in patients with symptomatic knees after ACL reconstruction. Methods in a retrospective study 99mTc-HDP bone tracer uptake (BTU) in SPECT/CT of 57 knees with symptoms of pain and/or instability after ACL reconstruction was investigated. All 57 knees were subdivided according their anatomy (femur and tibia), fixation (articular versus extra-articular fixation) and graft types into eight groups: femoral-articular versus extra-articular fixation using bone-patellar tendon-bone (BPTB) and hamstring autografts; tibial-articular versus extra-articular fixation using patellar tendon and hamstring autografts; BTU grading for each area of the localisation scheme were recorded. Tunnel diameter and length was measured in the CT scans. Results BTU was higher for the articular fixation in the femur and for the extra-articular fixation in the tibial tunnel. Patellar tendon graft fixation showed a significantly higher BTU in the superior-lateral and posterior-central area of the tibia, meaning the areas of the tibial tunnel near the entrance into the joint. Tunnel enlargement correlated significantly with increased BTU (p<0.05). Conclusion assessment of in vivo bone tunnel remodelling in symptomatic patients after ACL reconstruction revealed different patterns of BTU with regards to graft and fixation method. PMID:26958543

  20. Predictors of Activity Level Two years after ACL Reconstruction: MOON ACLR Cohort Study

    PubMed Central

    Dunn, Warren R.; Spindler, Kurt P.; Amendola, Annunziato; Andrish, Jack T.; Bergfeld, John A.; Flanigan, David C.; Jones, Morgan H.; Kaeding, Christopher C.; Marx, Robert G.; Matava, Matthew J.; McCarty, Eric C.; Parker, Richard D.; Wolcott, Michelle; Vidal, Armando; Wolf, Brian R.; Wright, Rick W.; Harrell, Frank E.; Dittus, Robert S.

    2013-01-01

    Objective ACL deficient subjects are at risk of knee injury with cutting and pivoting activities; in accord, ACL reconstructions (ACLR) are performed to restore stability to allow for return to cutting and pivoting activities. The Marx activity level is a validated patient-reported measure to quantify the amount and frequency of running, cutting, decelerating, and pivoting performed. Our objective was to quantify activity level 2 yrs after ACLR and identify explanatory variables measured at baseline (demographics, concomitant meniscal/articular cartilage injuries and their treatment) associated with activity level at short-term follow-up (2 yrs). Methods In 2002, the multicenter consortium began enrolling subjects undergoing ACLR at six recruitment sites. This ongoing multicenter cohort study targets follow-up at 2, 6, and 10 years. The current study reports two-year follow-up of subjects enrolled in 2002. Participants in the multicenter ACLR cohort completed a series of validated, patient-oriented questionnaires that included activity level assessment. Follow-up questionnaires were collected by mail between 1/01/04 and 6/01/05 to assess changes. Measurement of intraarticular pathology, techniques of ACLR, and secondary procedures were recorded at baseline by participating surgeons. Multivariable proportional odds ordinal logistic regression was used to assess predictors of activity level after adjusting for baseline patient characteristics. Interquartile range (IQR) odds ratios (OR) are given for continuous variables, IQROR demonstrate the effect of increasing a baseline variable from its first quartile to its third quartile. The fitted model that used OR to specify predicted probabilities of exceeding any activity level was translated into predicted mean activity level and is presented in a nomogram for more interpretability. Results Of the 446 subjects that underwent unilateral ACLR, follow-up was obtained on 393 (88%). The cohort is 56% male, median age 23 yrs

  1. Knee stability, athletic performance and sport-specific tasks in non-professional soccer players after ACL reconstruction: comparing trans-tibial and antero-medial portal techniques

    PubMed Central

    Tudisco, Cosimo; Bisicchia, Salvatore; Cosentino, Andrea; Chiozzi, Federica; Piva, Massimo

    2015-01-01

    Summary Background a wrong position of bone tunnels, in particular on the femur, is one of the most frequent causes of a failed anterior cruciate ligament (ACL) reconstruction. Several studies demonstrated that drilling the femoral tunnel through the antero-medial portal (AMP) allows a more anatomical placement on the lateral femoral condyle and higher knee stability, compared to trans-tibial (TT) technique. The aim of this study was to retrospectively evaluate two groups of soccer players operated on for ACL reconstruction according to either one of these two techniques. Methods two groups of non-professional soccer players operated on for a single bundle ACL reconstruction with hamstrings autograft using either a TT (20 patients) or an AMP (23 patients) technique were retrospectively evaluated with KT-1000 arthrometer, manual pivot shift test, isokinetic test, the incremental treadmill-running test, athletic and sport specific tasks, and knee scores (IKDC, Lysholm and KOOS). Results the AMP group showed better results at pivot shift test and KOOS, but lower flexion angles at single leg squat test. There were no differences in all the other considered outcomes. Conclusions the better rotational stability of the knee achieved in AMP group did not lead to significantly better clinical and functional results in our patients. Level of evidence III. Treatment study Case-control study. PMID:26605191

  2. Predictive mathematical modeling of knee static laxity after ACL reconstruction: in vivo analysis.

    PubMed

    Signorelli, C; Bonanzinga, T; Grassi, A; Lopomo, N; Zaffagnini, S; Marcacci, M

    2016-11-01

    Previous studies did not take into consideration such large variety of surgery variables which describe the performed anterior cruciate ligament (ACL) reconstruction and the interaction among them in the definition of postoperative outcome. Seventeen patients who underwent navigated Single Bundle plus Lateral Plasty ACL reconstruction were enrolled in the study. Static laxity was evaluated as the value of anterior/posterior displacement at 30° and at 90° of flexion, internal/external rotation at 30° and 90° of knee flexion, varus/valgus test at 0° and 30° of flexion. The evaluated surgical variables were analyzed through a multivariate analysis defining the following models: AP30estimate, AP90estimate, IE30estimate, IE90estimate, VV0estimate, VV30estimate. Surgical variables has been defined as the angles between the tibial tunnel and the three planes, the lengths of the tunnel and the relationship between native footprints and tunnels. An analogous characterization was performed for the femoral side. Performance and significance of the defined models have been quantified by the correlation ratio (η(2)) and the corresponding p-value (*p < 0.050). The analyzed models resulted to be statistically significant (p < 0.05) for prediction of postoperative static laxity values. The only exception was the AP90estimate model. The η(2) ranged from 0.568 (IE90estimate) to 0.995 (IE30estimate). The orientation of the tibial tunnel resulted to be the most important surgical variable for the performed laxity estimation. Mathematical models for postoperative knee laxity is a useful tool to evaluate the effects of different surgical variables on the postoperative outcome. PMID:27123692

  3. Is there significant variation in the material properties of four different allografts implanted for ACL reconstruction.

    PubMed

    Penn, David; Willet, Thomas L; Glazebrook, Mark; Snow, Martyn; Stanish, William D

    2009-03-01

    The aims of our study were to: (1) determine if there are differences in the material properties of tendon obtained from implanted tibialis anterior, achilles, bone-patella- bone and tibialis posterior allografts; (2) determine the variability in material properties between the implanted specimens. A total of 60 specimens were collected from fresh frozen allografts implanted at ACL reconstruction. Specimens collected included 15 tibialis anterior, 15 tibialis posterior, 15 achilles and 15 bone-patella-bone tendons. Each specimen was mounted in a custom made cryogrip. The mounted specimens were loaded onto a MTS Testline servo-hydraulic testing machine in a uni-axial tensile test configuration. Specimens were subjected to a strain rate of 5% per second until the ultimate tensile stress (UTS), failure strain and high strain modulus was calculated for each specimen after being normalized for specimen dimensions. Individual material properties were tested using one way analysis of variance (ANOVA) and post hoc Tukey's B test with a P value of <0.05 considered significant. Homogeneity of variance was assessed using the Levene's test. As a result, no significant difference was found between all four grafts with regards to UTS, failure strain or high strain linear modulus. The UTS was plotted against the modulus demonstrating a linear relationship which is typical of soft tissues. Significant variability in the results were observed. In conclusion, there was no significant statistical difference between the material properties of the four tendon allografts tested. But significant variability in results was observed within groups and between groups, which may provide one explanation for the range of results in allograft ACL reconstruction reported in the literature. PMID:19039574

  4. Calcium phosphate-hybridized tendon graft to enhance tendon-bone healing two years after ACL reconstruction in goats

    PubMed Central

    2011-01-01

    Background We developed a novel technique to improve tendon-bone attachment by hybridizing calcium phosphate (CaP) with a tendon graft using an alternate soaking process. However, the long-term result with regard to the interface between the tendon graft and the bone is unclear. Methods We analyzed bone tunnel enlargement by computed tomography and histological observation of the interface and the tendon graft with and without the CaP hybridization 2 years after anterior cruciate ligament (ACL) reconstruction in goats using EndoButton and the postscrew technique (CaP, n = 4; control, n = 4). Results The tibial bone tunnel enlargement rates in the CaP group were lower than those in the control group (p < 0.05). In the CaP group, in the femoral and tibial bone tunnels at the anterior and posterior of the joint aperture site, direct insertion-like formation that contained a cartilage layer without tidemarks was more observed at the tendon-bone interface than in the control group (p < 0.05). Moreover, the gap area between the tendon graft and the bone was more observed at the femoral bone tunnel of the joint aperture site in the control group than in the CaP group (p < 0.05). The maturation of the tendon grafts determined using the ligament tissue maturation index was similar in both groups. Conclusions The CaP-hybridized tendon graft enhanced the tendon-bone healing 2 years after ACL reconstruction in goats. The use of CaP-hybridized tendon grafts can reduce the bone tunnel enlargement and gap area associated with the direct insertion-like formation in the interface near the joint. PMID:22166674

  5. Femoral press-fit fixation in ACL reconstruction using bone-patellar tendon-bone autograft: results at 15 years follow-up

    PubMed Central

    2012-01-01

    Background If anterior cruciate ligament (ACL) reconstruction is to be performed, decision regarding graft choice and its fixation remains one of the most controversial. Multiple techniques for ACL reconstruction are available. To avoid disadvantages related to fixation devices, a hardware-free, press-fit ACL reconstruction technique was developed. The aim of this study was to evaluate clinical outcome and osteoarthritis progression in long term after ACL reconstruction with central third patellar-tendon autograft fixed to femur by press-fit technique. Methods Fifty two patients met inclusion/excusion criteria for this study. The patients were assessed preoperatively and at 15 years after surgery with International Knee Documentation Committee Knee Ligament Evaluation Form, Lysholm knee score, Tegner activity scale and radiographs. Results Good overall clinical outcomes and self-reported assessments were documented, and remained good at 15 years. The mean Lysholm and Tegner scores improved from 59.7 ± 18.5 and 4.2 ± 1.0 preoperatively to 86.4 ± 5.6 (p = 0.004) and 6.9 ± 1.4 (p = 0.005) respectively at follow-up. The IKDC subjective score improved from 60.1 ± 9.2 to 80.2 ± 8.1 (p = 0.003). According to IKDC objective score, 75% of patients had normal or nearly normal knee joints at follow-up. Grade 0 or 1 results were seen in 85% of patients on laxity testing. Degenerative changes were found in 67% of patients. There was no correlation between arthritic changes and stability of knee and subjective evaluation (p > 0.05). Conclusions ACL reconstruction with patellar tendon autograft fixed to femur with press-fit technique allows to achieve good self-reported assessments and clinical ligament evaluation up to 15 years. Advantages of the bone-patellar-tendon-bone (BPTB) press-fit fixation include unlimited bone-to-bone healing, cost effectiveness, avoidance of disadvantages associated with hardware, and ease for

  6. Functional and muscle morphometric effects of ACL reconstruction. A prospective CT study with 1 year follow-up.

    PubMed

    Lindström, M; Strandberg, S; Wredmark, T; Felländer-Tsai, L; Henriksson, M

    2013-08-01

    Computed tomography (CT) was used to explore if changes in muscle cross-sectional area and quality after anterior cruciate ligament (ACL) injury and reconstruction would be related to knee function. Fourteen females and 23 males (16-54 years) underwent clinical tests, subjective questionnaires, and CT 1 week before and 1 year after ACL surgery with semitendinosus-gracilis (STG) graft and rehabilitation. Postoperatively, knee laxity was decreased and functional knee measures and subjective patient scores improved. The most obvious remaining deficit was the quadriceps atrophy, which was significantly larger if the right leg was injured. Right-leg injury also tended to cause larger compensatory hypertrophy of the combined knee flexor and tibial internal rotator muscles (preoperatively). The quadriceps atrophy was significantly correlated with the scores and functional tests, the latter also being related to the remaining size of the gracilis muscle. Biceps femoris hypertrophy and, in males only, semimembranosus hypertrophy was observed following the ACL reconstruction. The lack of semimembranosus hypertrophy in the women could, via tibial internal rotation torque deficit, contribute to the less favorable functional and subjective outcome recorded for the women. The results indicate that the quadriceps, the combined knee flexor/tibial internal rotator muscles, side of ACL injury, and sex are important to consider in rehabilitation after STG graft. PMID:22107159

  7. BIOMECHANICAL STUDY OF TRANSCORTICAL OR TRANSTRABECULAR BONE FIXATION OF PATELLAR TENDON GRAFT WITH BIOABSORBABLE PINS IN ACL RECONSTRUCTION IN SHEEP

    PubMed Central

    Albano, Mauro Batista; Borges, Paulo César; Namba, Mario Massatomo; da Silva, João Luiz Vieira; de Assis Pereira Filho, Francisco; Filho, Edmar Stieven; Matias, Jorge Eduardo Fouto

    2015-01-01

    Objective: To determine the initial resistance of fixation using the Rigid Fix® system, and compare it with traditional fixation methods using metal interference screws; and to evaluate the resistance of the fixation with the rigid fix system when the rotational position of the bone block is altered in the interior of the femoral tunnel. Methods: forty ovine knee specimens (stifle joints) were submitted to anterior cruciate ligament reconstruction (ACL) using a bone-tendon-bone graft. In twenty specimens, the Rigid Fix method was used; this group was subdivided into two groups: ten knees the pins transfixed only the spongious area of the bone block, and ten for fixation passing through the layer of cortical bone. In the twenty remaining specimens, the graft was fixed with 9mm metal interference screws. Results: comparison of the RIGIDFIX® method with the metal interference screw fixation method did not show any statistically significant differences in terms of maximum load and rigidity; also, there were no statistically significant differences when the rotational position of the bone block was altered inside the femoral tunnel. For these evaluations, a level of significance of p < 0.017 was considered. Conclusion: fixation of the bone-tendon-bone graft with 2 bioabsorbable pines, regardless of the rotational position inside the femoral tunnel, gave a comparable fixation in terms of initial resistance to the metal interference screw, in this experimental model. PMID:27027081

  8. Original Rehabilitation Programme after Anatomical ACL Reconstruction Based on MRI Evaluated Graft Remodelling

    PubMed Central

    Plenzler, Marcin; Straszewski, Dariusz; Ciszkowska-Łysoń, Beata; Śmigielski, Robert; Popieluch, Marcin

    2014-01-01

    Objectives: This study was carried out to design a rehabilitation program allowing for complete functional post-surgical recovery of the limb, that would not affect the remodelling process of the transplanted graft evaluated on MRI imaging. The main reason for changing the rehabilitation protocol was the 14 months of observation of the MRI images (a series of 9 MRIs performed over a two year period) among the patients after ACL reconstruction, in whom the adverse characteristics in remodelling of the graft were observed in line with the implementation of the traditional rehabilitation program. Methods: A 23 years old patient, a professional hi-rank skateboarder, took part in this pilot study. He had a torsion injury of the left knee joint. The main concepts of the rehabilitation program were: functional training in CKC that would involve muscles of the entire kinetic chain of the operated limb; the co-contraction training under the axial load, active extension training, the avoidance of static flexor stretching for at least 24 weeks after the surgery, no passive movements while exercising, the use of posterior translation of the tibia while doing the exercises, and no knee joint extensor strengthening activities in OKC for at least six months after the surgery. In order to evaluate the remodelling of the graft, seven oblique axial MR images (DOA) were taken, on which the graft’s cross-sectional area was measured. The MRI's were performed in the second, sixth, and twelfth week; then in the fourth, sixth, and ninth month, and, finally a year after the surgery. The angle of the graft and PCL was also measured. Additionally, the quality of tendon signal was assessed. For the functional evaluation, isokinetic and isometric tests of the knee extensor and the flexor muscles, along with the tibial rotator functions were performed using Humac Norm device. Postural stability based on COP parameter was established, as well, using the stabilometric platform HUR. For the

  9. An intelligent recovery progress evaluation system for ACL reconstructed subjects using integrated 3-D kinematics and EMG features.

    PubMed

    Malik, Owais A; Senanayake, S M N Arosha; Zaheer, Dansih

    2015-03-01

    An intelligent recovery evaluation system is presented for objective assessment and performance monitoring of anterior cruciate ligament reconstructed (ACL-R) subjects. The system acquires 3-D kinematics of tibiofemoral joint and electromyography (EMG) data from surrounding muscles during various ambulatory and balance testing activities through wireless body-mounted inertial and EMG sensors, respectively. An integrated feature set is generated based on different features extracted from data collected for each activity. The fuzzy clustering and adaptive neuro-fuzzy inference techniques are applied to these integrated feature sets in order to provide different recovery progress assessment indicators (e.g., current stage of recovery, percentage of recovery progress as compared to healthy group, etc.) for ACL-R subjects. The system was trained and tested on data collected from a group of healthy and ACL-R subjects. For recovery stage identification, the average testing accuracy of the system was found above 95% (95-99%) for ambulatory activities and above 80% (80-84%) for balance testing activities. The overall recovery evaluation performed by the proposed system was found consistent with the assessment made by the physiotherapists using standard subjective/objective scores. The validated system can potentially be used as a decision supporting tool by physiatrists, physiotherapists, and clinicians for quantitative rehabilitation analysis of ACL-R subjects in conjunction with the existing recovery monitoring systems. PMID:24801517

  10. Preoperative predictors for noncopers to pass return to sports criteria after ACL reconstruction.

    PubMed

    Hartigan, Erin H; Zeni, Joseph; Di Stasi, Stephanie; Axe, Michael J; Snyder-Mackler, Lynn

    2012-08-01

    Less than 50% of athletes pass criteria to return to sports (RTS) 6 months after ACL reconstruction (ACLR). Using data on 38 noncopers, we hypothesized that preoperative age, quadriceps strength index (QI), and knee flexion moments (KFM) during gait would predict the ability to pass/fail RTS criteria and that preoperative quadriceps strength gains would be predictive of passing RTS criteria. Gait analysis and strength data were collected before and after a preoperative intervention and 6 months after ACLR. Age, QI, and KFM each contributed to the predictability to pass or fail RTS criteria 6 months after ACLR. Collectively, the variables predict 69% who would pass and 82% who would fail RTS criteria 6 months after ACLR. Younger athletes who have symmetrical quadriceps strength and greater KFM were more likely to pass RTS criteria. Further, 63% of those who increased preoperative quadriceps strength passed RTS criteria, whereas 73% who did not failed. Increasing quadriceps strength in noncopers before ACLR seems warranted. PMID:22983930

  11. Lower limb asymmetry in mechanical muscle function: A comparison between ski racers with and without ACL reconstruction.

    PubMed

    Jordan, M J; Aagaard, P; Herzog, W

    2015-06-01

    Due to a high incidence of anterior cruciate ligament (ACL) re-injury in alpine ski racers, this study aims to assess functional asymmetry in the countermovement jump (CMJ), squat jump (SJ), and leg muscle mass in elite ski racers with and without anterior cruciate ligament reconstruction (ACL-R). Elite alpine skiers with ACL-R (n = 9; 26.2 ± 11.8 months post-op) and uninjured skiers (n = 9) participated in neuromuscular screening. Vertical ground reaction force during the CMJ and SJ was assessed using dual force plate methodology to obtain phase-specific bilateral asymmetry indices (AIs) for kinetic impulse (CMJ and SJ phase-specific kinetic impulse AI). Dual x-ray absorptiometry scanning was used to assess asymmetry in lower body muscle mass. Compared with controls, ACL-R skiers had increased AI in muscle mass (P < 0.001), kinetic impulse AI in the CMJ concentric phase (P < 0.05), and the final phase of the SJ (P < 0.05). Positive associations were observed between muscle mass and AI in the CMJ concentric phase (r = 0.57, P < 0.01) as well as in the late SJ phase (r = 0.66, P < 0.01). Future research is required to assess the role of the CMJ and SJ phase-specific kinetic impulse AI as a part of a multifaceted approach for improving outcome following ACL-R in elite ski racers. PMID:25212216

  12. Evaluation of strength muscle recovery with isokinetic, squat jump and stiffness tests in athletes with ACL reconstruction: a case control study.

    PubMed

    Jacopetti, Marco; Pasquini, Andrea; Costantino, Cosimo

    2016-01-01

    BackgroundThe anterior cruciate ligament (ACL) rupture accounting for about 50% of all knee ligament injuries. The rehabilitation program requires a long time to rebuild muscle strength and to reestablish joint mobility and neuromuscular control. The purpose of the study is to evaluate the muscle strength recovery in athletes with ACL reconstruction. MethodsWe enrolled soccer atlethes, with isolated anterior cruciate ligament rupture treated with bone-patellar tendon-bone autograft artroscopic reconstruction. Each patients were evaluated comparing operated and controlateral limb by isokinetic test and triaxial accelerometer test. Isokinetic movements tested were knee flexion-extension with concentric-concentric contraction. Accelerometer test were Squat Jump Test (SJT)  and Stiffness Test (ST). Results17 subjects were selected, there was no significant difference in isokinetic quadriceps and hamstrings results in strength and endurance values. Parameters of ST were comparable between the operated and unoperated side. In SJT a significant statistical difference was in height of jump (p=0,02) no statistical difference was evidenced in the other measures.ConclusionCurrently complete recovery of symmetric explosive strength seems to be an important parameter for evaluating the performance after ACL reconstruction and the symmetry in test results jump could be associated with an adequate return to sports. In our study the explosive strenght is lower in the limb operated than the healthy one. Explosive strength recovery with pliometric training should be included in the post-surgical rehabilitation protocol and its measurement should be performed to assess the full recovery before the restart of sport activities. PMID:27163899

  13. Self-reported Knee Function Can Identify Athletes Who Fail Return to Activity Criteria up to 1 Year after Anterior Cruciate Ligament Reconstruction. A Delaware-Oslo ACL Cohort Study

    PubMed Central

    Logerstedt, David; Stasi, Stephanie Di; Grindem, Hege; Lynch, Andrew; Eitzen, Ingrid; Engebretsen, Lars; Risberg, May Arna; Axe, Michael J; Snyder-Mackler, Lynn

    2014-01-01

    STUDY DESIGN Cohort study, cross-sectional. OBJECTIVES To determine if self-reported knee function assessed with the International Knee Documentation Committee 2000 Subjective Knee Form (IKDC2000) could discriminate between successful and non-successful performance on return to activity criteria (RTAC) tests after anterior cruciate ligament (ACL) reconstruction. BACKGROUND Rehabilitation specialists are challenged in selecting appropriate performance-based and patient-reported tests that can detect side-to-side asymmetries, assess global knee function, and determine a participant's readiness to return to activity after ACL reconstruction. A simple tool or questionnaire that could identify athletes with neuromuscular impairments or activity limitations could provide rehabilitation specialists crucial data pertinent to their current knee function and their readiness to return to higher level activities. METHODS One hundred fifty-eight Level I/II athletes 6 months after ACL reconstruction and 141 athletes 12 months after ACL reconstruction completed a functional test battery to determine readiness to return to activity and the IKDC2000 to determine self-reported knee function. For each athlete, status on return to activity tests criteria was dichotomized as “Passed” or ”Failed” and status on the IKDC2000 scores was dichotomized as being “within” or “below age- and sex-matched normal ranges”. Comparisons were made between status on RTAC and IKDC2000 using Chi-square tests. Accuracy statistics were also calculated. RESULTS Six months after ACL reconstruction, 112 athletes (70.9%) failed RTAC and 76 (48.1%) were classified as having self-reported knee function below normal ranges. Among the 76 participants with IKDC2000 scores below normal ranges, 69 (90.8%) failed RTAC test battery (P<.001). However, among the 82 participants whose IKDC2000 scores were within normal limits at 6 months, only 39 (47.6%) passed RTAC test battery (P=.74). Twelve months after

  14. Functional Outcome Following Arthroscopic ACL Reconstruction with Rigid Fix: A Retrospective Observational Study

    PubMed Central

    Shervegar, Satish; Nagaraj, Prashanth; Grover, Amit; DJ, Niranthara Ganesh; Ravoof, Abdul

    2015-01-01

    Background: No uniform consensus exists to decide type of fixation for arthroscopic anterior cruciate ligament reconstruction. Hypothsis: There is similar functional outcome after rigid fix compared to other methods of fixation which has been published. Study design: Retrospective observational study. Methods: A total of 50 patients underwent arthroscopic anterior cruciate ligament reconstruction with hamstring tendons using femoral Rigid fix cross-pin and interference screw tibial fixation. The evaluation methods were clinical examination, IKDC scores, Lysholm and pre injury and post reconstruction Tegner score. Patients were followed up from minimum of 6 months to 4 year seven months. Results: C In our study of sample size 50 we found that mean age of patients was 30.8 Years with male preponderance. Mean post operative IKDC and Lysholm score has been 75.6 and 84.4 respectively. Mean Tegner pre-injury score and post reconstruction score has been 5.4 and 4.26. Box plot comparison of pre injury and post operativeTegner score reveals a statistically significant difference with respect to paired t test P<0.001. Conclusions: Arthroscopic anterior cruciate ligament reconstruction with femoral rigid fix cross pins and tibial interference screws results in comparable short term to midterm functional results compared to other types of fixation PMID:26550591

  15. Assessing the progress of rehabilitation in patients with ACL reconstruction using the International Knee Documentation Committee Subjective Knee Form

    NASA Astrophysics Data System (ADS)

    Leguizamon, J. H.; Braidot, A.; Catalfamo Formento, P.

    2011-12-01

    There are numerous assessment tools designed to provide information on the results of reconstructive surgery of anterior cruciate ligament (ACL). They are also used for monitoring progress and facilitating clinical decision-making during the rehabilitation process. A brief summary of some existing tools specifically designed to evaluate knee ligament injuries is presented in this article. Then, one of those outcome measures, the International Knee Documentation Committee Subjective Knee Form (IKDC) was applied to a group of patients (N = 10) who had undergone surgery for ACL reconstruction. The patients attended the same physiotherapy service and followed a unified rehabilitation protocol. The assessment was performed twice: four and six months after surgery. The results showed an improvement in the rehabilitation of most patients tested (verified by a difference equal to or greater than 9 points on the IKDC outcome between measurements 1 and 2). The IKDC probed to be an instrument of quick and easy application. It provided quantitative data about the progress of rehabilitation and could be applied in everyday clinical physiotherapy practice. However, the results suggested considering the IKDC as one component of an evaluation kit to make decisions regarding the progress of the rehabilitation treatment.

  16. Methods of Voice Reconstruction

    PubMed Central

    Chen, Hung-Chi; Kim Evans, Karen F.; Salgado, Christopher J.; Mardini, Samir

    2010-01-01

    This article reviews methods of voice reconstruction. Nonsurgical methods of voice reconstruction include electrolarynx, pneumatic artificial larynx, and esophageal speech. Surgical methods of voice reconstruction include neoglottis, tracheoesophageal puncture, and prosthesis. Tracheoesophageal puncture can be performed in patients with pedicled flaps such as colon interposition, jejunum, or gastric pull-up or in free flaps such as perforator flaps, jejunum, and colon flaps. Other flaps for voice reconstruction include the ileocolon flap and jejunum. Laryngeal transplantation is also reviewed. PMID:22550443

  17. Risk Factors at Time of Primary ACL Reconstruction that Contribute to Significant Chondral Surface Change at Time of Revision ACL Reconstruction

    PubMed Central

    Kaeding, Christopher C.; Group, Mars

    2016-01-01

    Objectives: Articular cartilage health is an important issue following primary anterior cruciate ligament reconstruction (ACLR). It is not clear what risk factors at the time of primary reconstruction affect future articular cartilage health. The purpose of this study was to examine risk factors affecting chondral surface change in a cohort from the time of primary ACLR to revision ACLR. Methods: Subjects who had both primary and revision data contained in the MOON and MARS registries were included. Data included chondral surface status (grade and size) at time of primary and revision, meniscal status (no treatment/repair, ≤33% excision, >33% excision) at time of primary, time from primary to revision ACLR, and age, sex, BMI, Marx, KOOS, and IKDC at time of revision. Significant chondral surface change was defined as >25% deterioration between time of primary and revision in the femoral condyle, tibial plateau, patella, or trochlea. Logistic regression was used to test each variable’s contribution to significant chondral surface change in the medial compartment, lateral compartment, and patellofemoral compartment. Results: 134 subjects met our inclusion criteria. 34/134 (25.4%) had significant lateral compartment chondral surface change, 32/134 (23.9%) had significant medial compartment chondral surface change, and 31/134 (23.1%) had significant patellofemoral chondral surface change. Median age at time of revision was 19.5 years [IQ range 17-25] and median time from primary to revision was 462.5 days [IQ range 292-1049]. KOOS and IKDC at revision were not associated with significant chondral surface change in any compartment. Patients with >33% of their lateral meniscus excised had 13.5 times the odds of having significant lateral compartment surface change compared to subjects who either did not have lateral meniscal damage, had it repaired, or had an excision of ≤33% controlling for age (p<0.001). Patients with ≤33% excision of their medial meniscus had

  18. Effect of graft choice on the outcome of revision anterior cruciate ligament reconstruction in the Multicenter ACL Revision Study (MARS) Cohort

    PubMed Central

    Wright, Rick W.; Huston, Laura J.; Haas, Amanda K.; Spindler, Kurt P.; Nwosu, Sam K.; Allen, Christina R.; Anderson, Allen F.; Cooper, Daniel E.; DeBerardino, Thomas M.; Dunn, Warren R.; Lantz, Brett (Brick) A.; Stuart, Michael J.; Garofoli, Elizabeth A.; Albright, John P.; Amendola, Annunziato (Ned); Andrish, Jack T.; Annunziata, Christopher C.; Arciero, Robert A.; Bach, Bernard R.; Baker, Champ L.; Bartolozzi, Arthur R.; Baumgarten, Keith M.; Bechler, Jeffery R.; Berg, Jeffrey H.; Bernas, Geoffrey A.; Brockmeier, Stephen F.; Brophy, Robert H.; Bush-Joseph, Charles A.; Butler, J. Brad; Campbell, John D.; Carey, James L.; Carpenter, James E.; Cole, Brian J.; Cooper, Jonathan M.; Cox, Charles L.; Creighton, R. Alexander; Dahm, Diane L.; David, Tal S.; Flanigan, David C.; Frederick, Robert W.; Ganley, Theodore J.; Gatt, Charles J.; Gecha, Steven R.; Giffin, James Robert; Hame, Sharon L.; Hannafin, Jo A.; Harner, Christopher D.; Harris, Norman Lindsay; Hechtman, Keith S.; Hershman, Elliott B.; Hoellrich, Rudolf G.; Hosea, Timothy M.; Johnson, David C.; Johnson, Timothy S.; Jones, Morgan H.; Kaeding, Christopher C.; Kamath, Ganesh V.; Klootwyk, Thomas E.; Levy, Bruce A.; Ma, C. Benjamin; Maiers, G. Peter; Marx, Robert G.; Matava, Matthew J.; Mathien, Gregory M.; McAllister, David R.; McCarty, Eric C.; McCormack, Robert G.; Miller, Bruce S.; Nissen, Carl W.; O'Neill, Daniel F.; Owens, Brett D.; Parker, Richard D.; Purnell, Mark L.; Ramappa, Arun J.; Rauh, Michael A.; Rettig, Arthur C.; Sekiya, Jon K.; Shea, Kevin G.; Sherman, Orrin H.; Slauterbeck, James R.; Smith, Matthew V.; Spang, Jeffrey T.; Svoboda, Steven J.; Taft, Timothy N.; Tenuta, Joachim J.; Tingstad, Edwin M.; Vidal, Armando F.; Viskontas, Darius G.; White, Richard A.; Williams, James S.; Wolcott, Michelle L.; Wolf, Brian R.; York, James J.

    2015-01-01

    Background Most surgeons believe that graft choice for ACL reconstruction is an important factor related to outcome. Although graft choice may be limited in the revision setting based on previously used grafts, it is still felt to be important. Hypothesis The purpose of this study was to determine if revision ACL graft choice predicts outcomes related to sports function, activity level, OA symptoms, graft re-rupture, and reoperation at two years following revision reconstruction. We hypothesized that autograft use would result in increased sports function, increased activity level, and decreased OA symptoms (as measured by validated patient reported outcome instruments). Additionally, we hypothesized that autograft use would result in decreased graft failure and reoperation rate 2 years following revision ACL reconstruction. Study Design Prospective cohort study; Level of evidence, 2. Methods Revision ACL reconstruction patients were identified and prospectively enrolled by 83 surgeons over 52 sites. Data collected included baseline demographics, surgical technique and pathology, and a series of validated patient reported outcome instruments (IKDC, KOOS, WOMAC, and Marx activity rating score). Patients were followed up at 2 years, and asked to complete the identical set of outcome instruments. Incidence of additional surgery and reoperation due to graft failure were also recorded. Multivariate regression models were used to determine the predictors (risk factors) of IKDC, KOOS, WOMAC, Marx scores, graft re-rupture, and reoperation rate at 2 years following revision surgery. Results 1205 patients were successfully enrolled with 697 (58%) males. Median age was 26. In 88% this was their first revision. 341 (28%) were undergoing revision by the surgeon that had performed the previous reconstruction. 583 (48%) underwent revision reconstruction utilizing an autograft, 590 (49%) allograft, and 32 (3%) both autograft and allograft. Median time since their last ACL

  19. Comparison of the retro screw and standard interference screw for ACL reconstruction.

    PubMed

    Wang, Robert Y; Arciero, Robert A; Obopilwe, Elifho; Mazzocca, Augustus D

    2012-07-01

    The objective of the study was to compare the load to failure between a retro screw (RS) and a standard interference screw (IS) for tibial-sided anterior cruciate ligament (ACL) fixation. We used 20 bovine tibia and extensor tendons for the study. A group of 10 specimens underwent IS fixation while the other 10 underwent RS fixation. Within each group, five specimens had graft suture in contact (interdigitating) with the screw threads. All specimens were tested on the MTS 858 Mini Bionix II (MTS Systems, Shakopee, MN). There was no statistically significant difference between the RS and IS with respect to peak load to failure. IS with suture interdigitation failed at an average of 520 N (range: 358 to 793 N), while the RS with suture interdigitation failed at 613 N (range: 438 to 1089 N). The IS without suture interdigitation failed at 654 N and the RS without suture interdigitation at 531 N. Specimens with a whipstitch in contact with the screw did not demonstrate higher pull out strength. The RS fixation strength appears to equal the IS. Graft suture contact with screw threads does not increase fixation strength. Based on this study, using a RS for tibial ACL soft tissue graft fixation is feasible and provides equal fixation strength compared with the standard IS. PMID:23057142

  20. Histological Predictors of Maximum Failure Loads Differ Between the Healing ACL and ACL Grafts After 6 and 12 Months In Vivo

    PubMed Central

    Proffen, Benedikt L.; Fleming, Braden C.; Murray, Martha M.

    2013-01-01

    Background: Bioenhanced anterior cruciate ligament (ACL) repair, where the suture repair is supplemented with a biological scaffold, is a promising novel technique to stimulate healing after ACL rupture. However, the histological properties of a successfully healing ACL and how they relate to the mechanical properties have not been fully described. Purpose: To determine which histological features best correlate with the mechanical properties of the healing ACL repairs and ACL grafts in a porcine model at 6 and 12 months after injury. Study Design: Controlled laboratory study. Methods: A total of 48 Yucatan mini-pigs underwent ACL transection followed by: (1) conventional ACL reconstruction with bone–patellar tendon–bone (BPTB) allograft, (2) bioenhanced ACL reconstruction with BPTB allograft using a bioactive scaffold, or (3) bioenhanced ACL repair using the same bioactive scaffold. After 6 and 12 months of healing, structural properties of the ACL or graft (yield and failure load, linear stiffness) were measured. Following mechanical testing, ACL specimens were histologically analyzed for cell and vascular density and qualitatively assessed using the advanced Ligament Maturity Index. Results: After 6 months of healing, the cellular organization subscore was most predictive of yield load (r 2 = 0.98), maximum load (r 2 = 0.89), and linear stiffness (r 2 = 0.95) of the healing ACL, while at 12 months, the collagen subscore (r 2 = 0.68) became the best predictor of maximum load. For ACL grafts, the reverse was true, with the collagen subscore predictive of yield and maximum loads at 6 months (r 2 = 0.55) and graft cellularity predictive of maximum load of the graft at 12 months (r 2 = 0.50). Conclusion: These findings suggest there may be key biological differences in development and maintenance of ACL tissue after repair or reconstruction, with early ligament function dependent on cellular population of the repair but early graft function dependent on the

  1. Effect of Intraoperative Platelet-Rich-Plasma Treatment on Post Operative Donor Site Knee Pain in Patellar Tendon Autograft ACL Reconstruction

    PubMed Central

    Walters, Brian L.; Hobart, Sarah; Porter, David; Hogan, Daniel E.; McHugh, Malachy P.; Bedford, Benjamin B.; Nicholas, Stephen J.; Klein, Devon; Harousseau, Kendall

    2016-01-01

    Objectives: Donor site morbidity in the form of anterior knee pain is a frequent complication after bone-patellar tendon-bone (BPTB) autograft ACL reconstruction. The purpose of this Level I study was to examine the effect of the intraoperative administration of platelet-rich plasma on post operative knee pain and patellar defect healing. Methods: Fifty-nine patients (29±12 y/o) undergoing BPTB ACL reconstruction and eligible to enter the study, were randomized to the treatment (PRP; n=31) or non treatment (sham n=28) arms of the study just prior to surgery. In either case, 10 cc of venous blood was drawn prior to the induction of anesthesia and either discarded (sham) or processed (PRP) for preparation of a PRP gel to be later mixed with donor site bone chips and inserted into the patellar defect. At 12 weeks and 6 months after surgery, patients completed IKDC forms and VAS pain scores for ADLs and kneeling (0-10 scale). Healing indices at the donor site were assessed by MRI at 6 months and included the following measurements taken from axial sequences: AP tendon dimensions at the level of the superior tibial cortex, roof of the intercondylar notch and width at the largest patella graft deficit. Mixed model ANOVA was used to assess the effect of PRP on patient symptoms and MRI indices of donor site healing. The primary dependent variable was VAS kneeling pain. It was estimated that with 25 patients per group there would be 80% power to detect a 1.5-point difference in kneeling pain between treatments at P<0.05. A between group difference of 1.5-points in VAS for kneeling pain was deemed to represent a clinically relevant difference. Results: VAS Kneeling Pain at 12 weeks tended to be lower in the PRP versus placebo group (4.5±3.6 vs. 6.2±2.4, P=0.051) but no difference was apparent at 6 months (3.7±3.2 vs. 4.4±2.9, P=0.41). Kneeling pain decreased from 12 weeks to 6 months (P<0.001) with a trend for a greater decrease in the placebo group (Time by Treatment P

  2. ACL Roof Impingement Revisited

    PubMed Central

    Tanksley, John Anthony; Conte, Evan J.; Werner, Brian C.; Gwathmey, Frank Winston; Brockmeier, Stephen F.; Miller, Mark D.

    2015-01-01

    Objectives: Anatomic femoral tunnel placement for single-bundle ACL reconstruction is now well accepted. The ideal location for the tibial tunnel, however, has not been studied extensively. A wide range of anterior to posterior (A-P) tibial tunnel locations are considered acceptable. Biomechanical data suggests that the anterior fibers of the native ACL are more functional. Similarly, ACL grafts placed more anteriorly in the footprint have resulted in improved clinical results in at least one study. However, the concern for intercondylar roof impingement has tempered enthusiasm for a more anterior tibial tunnel placement. Investigations by Howell and others on roof impingement have focused only on the transtibial technique. Our study seeks to characterize intercondylar roof impingement in a 3-D cadaveric model with both transtibial and independent femoral tunnel drilling techniques in the setting of an anteriorly positioned tibial tunnel. Methods: Twelve fresh frozen cadaver knees (six matched pairs) were randomized to either a transtibial or an independent femoral (IF) drilling technique. Tibial guide pins were placed in the anterior half of the ACL tibial footprint following arthroscopic debridement of the native ACL. A fluoroscopic calculation of the tibial guide pin location using the technique described by Staubli was used to ensure a relatively anterior position of the tibial tunnel (Staubli < 35). All efforts were made to place the femoral tunnel anatomically in the center of the footprint. An 8 mm Gore-Tex smoother was passed into the knee to function as a radiopaque surrogate graft, and the knees then underwent computed tomography in maximal extension. Graft-visualized 3D-CT reformatting was used to evaluate for roof impingement by analyzing the Impingement Review Index (IRI) as described by Iriuchishima. Tunnel morphology, knee flexion, and intra-articular graft angles were also recorded. Results: Two grafts (2/6, 33.3 %) in the TT group impinged upon the

  3. ACL reconstruction in sports active people: transtibial DB technique with ST/G vs. transtibial SB technique with BPTB: preliminary results.

    PubMed

    Volpi, Piero; Cervellin, Matteo; Denti, Matteo; Bait, Corrado; Melegati, Gianluca; Quaglia, Alessandro; de Girolamo, Laura

    2010-11-01

    The single-bundle ACL reconstruction ensures good outcomes and it is a well-established and widespread technique. Nevertheless, some patients still present residual pain and instability. Recent studies have showed that the double-bundle technique restores better natural ACL-fitting kinematics. Long-term clinical studies comparing the two surgical techniques are not frequent and there is no instrument to evaluate function and kinematics during the knee rotation in vivo. In this randomised prospective study performed on sportive people, we compare the BPTB single-bundle ACL reconstruction technique, which is the most common surgical technique performed on these patients' category, with the ACL double-bundle reconstruction technique (DB), in order to evaluate possible differences between the groups. Comparing the two groups, no statistically significant difference regarding the post-operative Lysholm score (p=0.368) the Tegner activity scale (p=0.519) and the arthrometric evaluation with KT-1000 (p=0.74) have been observed. On the contrary, the IKDC evaluation showed a statistically significant difference (p=0.004) better results of the DB group. Moreover, as assessed by the Tegner activity scale, only patients of the DB group were able to return to sports at a pre-injury level. Our data suggest that the double bundle ST/G ACL reconstruction technique results into slightly better outcome than the traditional technique of single-bundle BPTB. The verification and quantification of the advantages of this technique is anticipated with future studies focusing to the accurate measurement of knee rotation during different activities. PMID:20934698

  4. Analytical Chemistry Laboratory (ACL) procedure compendium. Volume 4, Organic methods

    SciTech Connect

    Not Available

    1993-08-01

    This interim notice covers the following: extractable organic halides in solids, total organic halides, analysis by gas chromatography/Fourier transform-infrared spectroscopy, hexadecane extracts for volatile organic compounds, GC/MS analysis of VOCs, GC/MS analysis of methanol extracts of cryogenic vapor samples, screening of semivolatile organic extracts, GPC cleanup for semivolatiles, sample preparation for GC/MS for semi-VOCs, analysis for pesticides/PCBs by GC with electron capture detection, sample preparation for pesticides/PCBs in water and soil sediment, report preparation, Florisil column cleanup for pesticide/PCBs, silica gel and acid-base partition cleanup of samples for semi-VOCs, concentrate acid wash cleanup, carbon determination in solids using Coulometrics` CO{sub 2} coulometer, determination of total carbon/total organic carbon/total inorganic carbon in radioactive liquids/soils/sludges by hot persulfate method, analysis of solids for carbonates using Coulometrics` Model 5011 coulometer, and soxhlet extraction.

  5. Increased Risk of Revision after ACL Reconstruction with Soft Tissue Allograft Compared to Autograft

    PubMed Central

    Maletis, Gregory; Chen, Jason; Inacio, Maria Carolina Secorun; Love, Rebecca; Funahashi, Tadashi Ted

    2016-01-01

    Objectives: The use of allograft tissue for anterior cruciate ligament reconstruction (ACLR) remains controversial. Numerous meta-analysis and systematic reviews of small clinical studies have not found differences between autograft and allograft outcomes but large registry studies have shown an increased risk of revision with allografts. The purpose of this study was to compare the risk of aseptic revision between bone-patellar tendon-bone (BPTB) autografts, hamstring tendon autografts and soft tissue allografts. Methods: A retrospective cohort study of prospectively collected data was conducted using an US ACLR Registry. A cohort of primary unilateral ACLR cases reconstructed with BPTB autografts, hamstring autografts and soft tissue allografts (from any site) was identified. Aseptic revision was the end point of the study. Type of graft and allograft processing methods (non-processed, <1.8Mrads with and without chemical processing (Allowash or AlloTrue methods), >1.8 Mrads irradiation with and without chemical processing, and chemical processing alone (BioCleanse)) were the exposures of interest evaluated. Time from surgery was evaluated as an effect modifier. All analyses were adjusted for age, gender, and race. Kaplan-Meier curves and Cox proportional hazard models were employed. Hazard ratios (HR), 95% confidence intervals (CI) are provided. Results: The cohort had 14015 cases, 8924 (63.7%) were male, 6397 (45.6%) were White, 4557 (32.5%) cases used BPTB autograft, 3751 (26.8%) cases used soft tissue allograft and 5707 (40.7%) cases used hamstring autograft. The median age was 34.6 years-old (IQR 24.1-43.2) for allograft cases and 24.3 years-old (IQR 17.7-33.8) for hamstring autograft cases, and 22.0 years-old (IQR 17.6-30.0) for BPTB autograft cases. Compared to hamstring tendon autografts, an increased risk of revision was found in allografts processed with >1.8Mrads without chemical processing after 2.5 years (HR: 3.88 95%CI 1.48-10.12), and >1.8Mrads with

  6. Electromechanical delay of the knee extensor muscles is not altered after harvesting the patellar tendon as a graft for ACL reconstruction: implications for sports performance.

    PubMed

    Georgoulis, A D; Ristanis, S; Papadonikolakis, A; Tsepis, E; Moebius, U; Moraiti, C; Stergiou, N

    2005-09-01

    Although the scar tissue, which heals the donor site defect, has different elasticity from the neighbouring patellar tissue, it remains unclear if this scar tissue can lead to the changes of the electromechanical delay (EMD) of the knee extensor muscles. If such changes do exist, they can possibly affect both the utilization of the stored energy in the series elastic component, as well as the optimal performance of the knee joint movement. The purpose of this study was to investigate the influence of harvesting the patellar tendon during anterior cruciate ligament (ACL) reconstruction and the associated patellar tendon scar tissue development on the EMD of the rectus femoris (RF) and vastus medialis (VM) muscles. Seventeen patients who underwent an ACL reconstruction using the medial third of the patellar tendon were divided in two groups based upon their post-operative time interval. Maximal voluntary contraction from the knee extensors, surface EMG activity, and ultrasonographic measurements of the patellar tendon cross-section area were obtained from both knees. Our results revealed that no significant changes for the maximal voluntary contraction of the knee extensors and for the EMD of the RF and the VM muscles due to patellar scar tissue development after harvesting the tendon for ACL reconstruction. The EMD, as a component of the stretch reflex, is important for the utilization of the stored energy in the series elastic component and thus, optimal sports performance. However, from our results, it can be implied that the ACL reconstruction using a patellar tendon graft would not impair sports performance as far as EMD is concerned. PMID:15968530

  7. Biomechanical Deficiencies in Women with Semitendinosus-Gracilis ACL Reconstruction During Drop Jumps

    PubMed Central

    Ortiz, Alexis; Capo-Lugo, Carmen E.; Venegas-Rios, Heidi L.

    2014-01-01

    Objective To compare landing mechanics and neuromuscular recruitment strategies between women with semitendinosus-gracilis anterior cruciate ligament reconstruction (SG-ACLr) and non-injured women during double and single-legged drop jumps. Design Cross-sectional biomechanical study Setting Single university-based biomechanics laboratory Participants Fourteen women 1–5 years post SG-ACLr and 16 non-injured women participated in this study. Methods After anthropometric measurements, warm-up, and familiarization procedures, participants performed five trials of a double and single-legged drop jumps. Main Outcome Measurements Dynamic knee valgus was measured as the distance between knee joints during the landing phase of the double-leg drop jumps. Medial knee displacement was the outcome considered during the landing phase of the single-leg drop jumps. For both drop jumps tasks neuromuscular recruitment was evaluated through rectified normalized electromyography (EMG) activity of the quadriceps and hamstrings (amplitude and latency), and quadriceps/hamstrings EMG co-contraction ratio. Results Although the SG- ACLr group demonstrated a tendency towards a greater dynamic knee valgus during both drop jumps, these differences did not reach statistical significance. EMG data revealed different neuromuscular strategies for each group depending on the specific jump. Conclusions These findings suggest that women with SG-ACLr have a tendency towards greater dynamic knee valgus which could predispose to additional knee injuries. Rehabilitation specialists need to be aware of existing kinematic and neuromuscular deficiencies years after SG-ACLr. Taking this into consideration will aid in prescribing appropriate interventions designed to prevent re-injury. PMID:25043260

  8. Epidural bleeding after ACL reconstruction under regional anaesthesia: a case report

    PubMed Central

    Poultsides, Lazaros A; Gougoulias, Nikolaos E; Liakou, Paraskevi D; Karachalios, Theofilos S; Malizos, Konstantinos N

    2009-01-01

    Introduction Epidural bleeding as a complication of catheterization or epidural catheter removal is often associated with perioperative thromboprophylaxis especially in adult reconstructive surgery. Case presentation We report on a case of a 19 years old male athlete that underwent anterior cruciate ligament reconstruction, receiving low molecular weight heparin for thromboprophylaxis and developed an epidural hematoma and subsequent cauda equina syndrome two days after removal of the epidural catheter. An urgent magnetic resonance imaging scan revealed an epidural hematoma from the level of L3 to L4. Emergent decompression and hematoma evacuation resulted in patient's significant neurological improvement immediately postoperatively. Conclusion A high index of clinical suspicion and surgical intervention are necessary to prevent such potentially disabling complications especially after procedures on a day-case basis and early patient's discharge. PMID:19829853

  9. MRI Evaluation of Patella Alignment Before and After Anatomical Reconstruction of ACL Undergoing Unified Rehabilitation Programme Introduced by CMC Physical Therapy Team

    PubMed Central

    Straszewski, Dariusz; Plenzler, Marcin; Szczepaniak, Joanna; Śmigielski, Robert; Ciszkowska-Łysoń, Beata; Popieluch, Marcin; Kopko, Szymon

    2014-01-01

    Objectives: The aim of the study was to asses the impact of the functional rehabilitation on patella alignment with MRI imaging in patients who underwent the ACL reconstruction. The surgical approach with the use of patellar tendon graft is known to carry the risk of lowering patella height (patella baja), which, in turn, may lead to accelerated cartilage wear in patellofemoral joint. Methods: 30 patients after the anatomical reconstruction of ACL took part in this study (23 male, and 7 female, mean age = 28 ± 10,6 years). During the procedure a patellar tendon graft was used. The Insali-Salvati ratio measured with MRI (images taken pre-procedural, and 9 months after the surgery) was used for the assessment of patellar alignment. The measurements were taken by one radiology specialist on MRI scans in sagittal view in PD sequence. During the examination, patellar joint was in flexion (approx.10 degrees). As the point of reference for patella’s position ISR ratio was in the range of 0.8 - 1.2. All patients were operated on by the same team of surgeons and underwent an unified rehabilitation programme led by a team of selected physiotherapists. The main features of the programme were: an early muscle activation (second day after the procedure); mobilisation of the patella and tissues of the anterior compartment of the knee; weight bearing co-contraction exercises, and the sensomotoric training of the entire kinetic chain of the lower limb. The data recorded was statistically analysed using the Wilcoxon signed-rank test in order to establish parameters’ changes within the study group.. Results: The mean ISR value before the procedure was 0.84 (± 0,1), whereas 9 months after the surgery it was 0.85 (± 0,1). The results’ analysis did not show any statistically significant changes between ISR values. Nine months after the procedure patella baja has not been observed in any of the evaluated patients. Conclusion: The functional rehabilitation programme designed by

  10. Descriptive Epidemiology of the Multicenter ACL Revision Study (MARS) Cohort

    PubMed Central

    2013-01-01

    Background Revision anterior cruciate ligament (ACL) reconstruction has worse outcomes than primary reconstructions. Predictors for these worse outcomes are not known. The Multicenter ACL Revision Study (MARS) Group was developed to perform a multisurgeon, multicenter prospective longitudinal study to obtain sufficient subjects to allow multivariable analysis to determine predictors of clinical outcome. Purpose To describe the formation of MARS and provide descriptive analysis of patient demographics and clinical features for the initial 460 enrolled patients to date in this prospective cohort. Study Design Cross-sectional study; Level of evidence, 2. Methods After training and institutional review board approval, surgeons began enrolling patients undergoing revision ACL reconstruction, recording patient demographics, previous ACL reconstruction methods, intra-articular injuries, and current revision techniques. Enrolled subjects completed a questionnaire consisting of validated patient-based outcome measures. Results As of April 1, 2009, 87 surgeons have enrolled a total of 460 patients (57% men; median age, 26 years). For 89%, the reconstruction was the first revision. Mode of failure as deemed by the revising surgeon was traumatic (32%), technical (24%), biologic (7%), combination (37%), infection (<1%), and no response (<1%). Previous graft present at the time of injury was 70% autograft, 27% allograft, 2% combination, and 1% unknown. Sixty-two percent were more than 2 years removed from their last reconstruction. Graft choice for revision ACL reconstruction was 45% autograft, 54% allograft, and more than 1% both allograft and autograft. Meniscus and/or chondral damage was found in 90% of patients. Conclusion The MARS Group has been able to quickly accumulate the largest revision ACL reconstruction cohort reported to date. Traumatic reinjury is deemed by surgeons to be the most common single mode of failure, but a combination of factors represents the most

  11. Anatomical versus Non-Anatomical Single Bundle Anterior Cruciate Ligament Reconstruction: A Cadaveric Study of Comparison of Knee Stability

    PubMed Central

    Lim, Hong-Chul; Yoon, Yong-Cheol; Wang, Joon-Ho

    2012-01-01

    Background The purpose of this study was to compare the initial stability of anatomical and non-anatomical single bundle anterior cruciate ligament (ACL) reconstruction and to determine which would better restore intact knee kinematics. Our hypothesis was that the initial stability of anatomical single bundle ACL reconstruction would be superior to that of non-anatomical single bundle ACL reconstruction. Methods Anterior tibial translation (ATT) and internal rotation of the tibia were measured with a computer navigation system in seven pairs of fresh-frozen cadaveric knees under two testing conditions (manual maximum anterior force, and a manual maximum anterior force combined with an internal rotational force). Tests were performed at 0, 30, 60, and 90 degrees of flexion with the ACL intact, the ACL transected, and after reconstruction of one side of a pair with either anatomical or non-anatomical single bundle ACL reconstruction. Results Under manual maximal anterior force, both reconstruction techniques showed no significant difference of ATT when compared to ACL intact knee state at 30° of knee flexion (p > 0.05). Under the combined anterior and internal rotatory force, non-anatomical single-bundle ACL reconstruction showed significant difference of ATT compared to those in ACL intact group (p < 0.05). In contrast, central anatomical single bundle ACL reconstruction showed no significant difference of ATT compared to those in ACL intact group (p > 0.05). Internal rotation of the tibia showed no significant difference in the ACL intact, the ACL transected, non-anatomical reconstructed and anatomical reconstructed knees. Conclusions Anatomical single bundle ACL reconstruction restored the initial stability closer to the native ACL under combined anterior and internal rotational forces when compared to non-anatomical ACL single bundle reconstruction. PMID:23205233

  12. Are Articular Cartilage Lesions and Meniscus Tears Predictive of IKDC, KOOS, and Marx Activity Level Outcomes after ACL Reconstruction? A 6-Year Multicenter Cohort Study

    PubMed Central

    Cox, Charles L.; Huston, Laura J.; Dunn, Warren R.; Reinke, Emily K.; Nwosu, Samuel K.; Parker, Richard D.; Wright, Rick W.; Kaeding, Christopher C.; Marx, Robert G.; Amendola, Annunziata; McCarty, Eric C.; Wolf, Brian R.; Harrell, Frank E.; Spindler, Kurt P.

    2014-01-01

    Background Identifying risk factors for inferior outcomes after ACL reconstruction (ACLR) is important for prognosis and future treatment. The goal of this study was to determine whether articular cartilage and meniscal variables are predictive of 3 validated sports outcome instruments after ACLR. Hypothesis/Purpose We hypothesized that articular cartilage lesions and meniscus tears/treatment would be predictors of the IKDC, KOOS (all 5 subscales), and Marx activity level at 6 years following ACLR. Study Design Prospective cohort, Level 1 Methods Between 2002 and 2004, 1512 ACLR subjects were prospectively enrolled and followed longitudinally with the IKDC, KOOS, and Marx activity score completed at entry, 2, and 6 years. A logistic regression model was built incorporating variables from patient demographics, surgical technique, articular cartilage injuries, and meniscus tears/treatment to determine the predictors (risk factors) of IKDC, KOOS, and Marx at 6 years. Results We completed a minimum follow-up on 86% (1307/1512) of our cohort at 6 years. The cohort was 56% male, had a median age of 23 years at the time of enrollment, with 76% reporting a non-contact injury mechanism. Incidence of concomitant pathology at the time of surgery consisted of the following: articular cartilage (medial femoral condyle [MFC]-25%, lateral femoral condyle [LFC]-20%, medial tibial plateau [MTP]-6%, lateral tibial plateau [LTP]-12%, patella-20%, trochlear-9%) and meniscal (medial-38%, lateral-46%). Both articular cartilage lesions and meniscal tears were significant predictors of 6-year outcomes on IKDC and KOOS. Grade 3 or 4 articular cartilage lesions (excluding patella) significantly reduced IKDC and KOOS scores at 6 years. IKDC demonstrated worse outcomes with the presence of a grade 3-4 chondral lesion on the MFC, MTP, and LFC. Likewise, KOOS was negatively affected by cartilage injury. The sole significant predictor of reduced Marx activity was the presence of a grade 4 lesion

  13. Outcome of combined autologous chondrocyte implantation and anterior cruciate ligament reconstruction

    PubMed Central

    Dhinsa, Baljinder S; Nawaz, Syed Z; Gallagher, Kieran R; Skinner, John; Briggs, Tim; Bentley, George

    2015-01-01

    Background: Instability of the knee joint, after anterior cruciate ligament (ACL) injury, is contraindication to osteochondral defect repair. This prospective study is to investigate the role of combined autologous chondrocyte implantation (ACI) with ACL reconstruction. Materials and Methods: Three independent groups of patients with previous ACL injuries undergoing ACI were identified and prospectively followed up. The first group had ACI in combination with ACL reconstruction (combined group); the 2nd group consisted of individuals who had an ACI procedure having had a previously successful ACL reconstruction (ACL first group); and the third group included patients who had an ACI procedure to a clinically stable knee with documented nonreconstructed ACL disruption (No ACL group). Their outcomes were assessed using the modified cincinnati rating system, the Bentley functional (BF) rating system (BF) and a visual analog scale (VAS). Results: At a mean followup of 64.24 months for the ACL first group, 63 months for combined group and 78.33 months for the No ACL group; 60% of ACL first patients, 72.73% of combined group and 83.33% of the No ACL group felt their outcome was better following surgery. There was no significant difference demonstrated in BF and VAS between the combined and ACL first groups. Results revealed a significant affect of osteochondral defect size on outcome measures. Conclusion: The study confirms that ACI in combination with ACL reconstruction is a viable option with similar outcomes as those patients who have had the procedures staged. PMID:26015603

  14. Anteromedial portal versus transtibial drilling techniques in ACL reconstruction: a blinded cross-sectional study at two- to five-year follow-up

    PubMed Central

    Alentorn-Geli, Eduard; Samitier, Gonzalo; Álvarez, Pedro; Steinbacher, Gilbert

    2010-01-01

    Drilling of the femoral tunnel with the transtibial (TT) technique is widely used in bone-patellar tendon-bone (BPTB) anterior cruciate ligament (ACL) reconstruction. Recent studies suggest higher knee stability with the use of the anteromedial portal (AMP). The purpose of this study was to compare functional and clinical outcomes of BPTB ACL reconstruction using the TT or the AMP technique for drilling the femoral tunnel. All ACL reconstructions between January 2003 and April 2006 were approached for eligibility. Forty-seven patients met inclusion criteria (21 TT group and 26 AMP group). Blinded assessments of IKDC score, knee stability and range of motion, one-leg hop test, mid-quadriceps circumference, VAS for satisfaction with surgery, Lysholm and Tegner scores, and SF-12 questionnaire were obtained for both groups. Data on preoperative and postoperative surgical timing were retrospectively reviewed through the charts. The AMP group demonstrated a significantly lower recovery time from surgery to walking without crutches (p < 0.01), to return to normal life (p < 0.03), to return jogging (p < 0.03), to return training (p < 0.03), and to return to play (p < 0.03). Knee stability values measured with KT-1000, Lachman test, pivot-shift sign, and objective IKDC score assessments were significantly better for the AMP compared to TT group (p < 0.002, p < 0.03, p < 0.02, p < 0.015, respectively). No differences were found for VAS for satisfaction with surgery, Lysholm, Tegner, and SF-12 between both groups. The use of the AMP technique significantly improved the anterior-posterior and rotational knee stability, IKDC scores, and recovery time from surgery compared to the TT technique. PMID:20401753

  15. Knee imaging after anterior cruciate ligament reconstruction.

    PubMed

    Rodrigues, M B; Silva, J J; Homsi, C; Stump, X M; Lecouvet, F E

    2001-01-01

    An increasing number of reconstructions of the anterior cruciate ligament (ACL) are performed every year, due to both the increasing occurrence of sport related injuries and the development of diagnostic and surgical techniques. The most used surgical procedure for the torn ACL reconstruction is the use of autogenous material, most often the patellar and semitendinosus tendons. Magnetic resonance (MR) imaging and spiral-CT performed after arthrography with multiplanar reconstructions are the imaging methods of choice for post-operative evaluation of ACL ligamentoplasty. This paper provides a brief bibliographic and more extensive pictorial review of the normal evolution and possible complications after ACL repair. PMID:11817479

  16. ACL reconstruction - discharge

    MedlinePlus

    ... MD, Thompson SR, eds. DeLee and Drez's Orthopaedic Sports Medicine. 4th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap ... by: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, ...

  17. Time to get rid of the clock: intraobserver and interobserver reliability in determination of the o'clock position of the femoral tunnel in ACL reconstruction.

    PubMed

    Wittstein, Jocelyn Ross; Garrett, William E

    2014-02-01

    This study evaluates intraobserver and interobserver agreement in reporting the o'clock position of the femoral tunnel during anterior cruciate ligament (ACL) reconstruction. Four PGY2 residents, four PGY5 residents, and four sports medicine orthopedic surgeons reported the o'clock position of the femoral ACL tunnel in 10 arthroscopic pictures on two occasions 3 months apart. Intraobserver agreement was determined using the intraobserver correlation coefficient (r > 0.576 for 0.05 significance level). Interobserver agreement between members of each group and between reviewer groups was evaluated with the intraclass correlation coefficient (ICC > 0.75 considered good agreement). Poor interobserver agreement was demonstrated between the attending and PGY2 groups (ICC = 0.1685), between the attending and PGY5 groups (ICC = 0.2982), and between the PGY5 and PGY2 groups (ICC = 0.267). Attending surgeons, PGY5s, and PGY2s demonstrated poor interobserver agreement amongst themselves (ICC = 0.2244, 0.471, and 0.0859, respectively). PGY2s and PGY5s demonstrated good intraobserver agreement, but attending surgeons demonstrated poor intraobserver agreement. Attending orthopedic surgeons and residents of different levels of training interpret the o'clock position of the femoral tunnel differently. Greater years of experience does not improve intraobserver or interobserver agreement on the o'clock position. The clock face terminology for femoral tunnel placement may not be a reliable descriptor for scientific investigations or clinical instruction. PMID:24227399

  18. Novel methods of instruction in ACL injury prevention programs, a systematic review.

    PubMed

    Benjaminse, Anne; Welling, Wouter; Otten, Bert; Gokeler, Alli

    2015-05-01

    Anterior cruciate ligament (ACL) injury prevention programs have been successful in the short term. Motor learning strategies with an internal focus (IF) to body movements have traditionally been utilized, but may be less suitable than an external focus (EF) for the acquisition and control of complex motor skills required for sport. To investigate the available literature and provide an overview of the effect of IF and EF instructions on jump landing technique. Systematic searches were conducted in PubMed (1966 to May 2014), CINAHL (1981 to May 2014) and PsycInfo (1989 to May 2014). A priori defined inclusion criteria were: (i) full text; (ii) published in English, German or Dutch; (iii) healthy adult subjects (mean age ≥18 years); (iv) jump and landing performance tested and (v) study used comparison between an EF and IF. Performance (jump height and distance) and technique (kinematics and kinetics) were the primary outcome variables of interest. Nine papers were included. Significant better motor performance and movement technique was found with an EF compared to an IF. Considering the beneficial results in the included studies when utilizing an EF, it is suggested to implement these strategies into ACL injury prevention programs. PMID:25042094

  19. The Effect of NeuroMuscular Electrical Stimulation on Quadriceps Strength and Knee Function in Professional Soccer Players: Return to Sport after ACL Reconstruction

    PubMed Central

    Taradaj, J.; Halski, T.; Kucharzewski, M.; Walewicz, K.; Smykla, A.; Ozon, M.; Slupska, L.; Dymarek, R.; Ptaszkowski, K.; Rajfur, J.; Pasternok, M.

    2013-01-01

    The aim of this study was to assess the clinical efficacy and safety of NMES program applied in male soccer players (after ACL reconstruction) on the quadriceps muscle. The 80 participants (NMES = 40, control = 40) received an exercise program, including three sessions weekly. The individuals in NMES group additionally received neuromuscular electrical stimulation procedures on both right and left quadriceps (biphasic symmetric rectangular pulses, frequency of impulses: 2500 Hz, and train of pulses frequency: 50 Hz) three times daily (3 hours of break between treatments), 3 days a week, for one month. The tensometry, muscle circumference, and goniometry pendulum test (follow-up after 1 and 3 months) were applied. The results of this study show that NMES (in presented parameters in experiment) is useful for strengthening the quadriceps muscle in soccer athletes. There is an evidence of the benefit of the NMES in restoring quadriceps muscle mass and strength of soccer players. In our study the neuromuscular electrical stimulation appeared to be safe for biomechanics of knee joint. The pathological changes in knee function were not observed. This trial is registered with Australian and New Zealand Clinical Trials Registry ACTRN12613001168741. PMID:24381943

  20. The effect of neuromuscular electrical stimulation on quadriceps strength and knee function in professional soccer players: return to sport after ACL reconstruction.

    PubMed

    Taradaj, J; Halski, T; Kucharzewski, M; Walewicz, K; Smykla, A; Ozon, M; Slupska, L; Dymarek, R; Ptaszkowski, K; Rajfur, J; Pasternok, M

    2013-01-01

    The aim of this study was to assess the clinical efficacy and safety of NMES program applied in male soccer players (after ACL reconstruction) on the quadriceps muscle. The 80 participants (NMES = 40, control = 40) received an exercise program, including three sessions weekly. The individuals in NMES group additionally received neuromuscular electrical stimulation procedures on both right and left quadriceps (biphasic symmetric rectangular pulses, frequency of impulses: 2500 Hz, and train of pulses frequency: 50 Hz) three times daily (3 hours of break between treatments), 3 days a week, for one month. The tensometry, muscle circumference, and goniometry pendulum test (follow-up after 1 and 3 months) were applied. The results of this study show that NMES (in presented parameters in experiment) is useful for strengthening the quadriceps muscle in soccer athletes. There is an evidence of the benefit of the NMES in restoring quadriceps muscle mass and strength of soccer players. In our study the neuromuscular electrical stimulation appeared to be safe for biomechanics of knee joint. The pathological changes in knee function were not observed. This trial is registered with Australian and New Zealand Clinical Trials Registry ACTRN12613001168741. PMID:24381943

  1. Greater fear of re-injury and increased tibial translation in patients who later sustain an ACL graft rupture or a contralateral ACL rupture: a pilot study.

    PubMed

    Tagesson, Sofi; Kvist, Joanna

    2016-01-01

    The aim was to compare fear of re-injury, patient reported function, static and dynamic tibial translation and muscle strength assessed before and 5 weeks after an anterior cruciate ligament (ACL) reconstruction between individuals who sustained a subsequent ACL graft rupture or a contralateral ACL injury within 5 years after the reconstruction, and individuals with no subsequent injury. Nineteen patients were investigated before, and 5 weeks after an ACL reconstruction with a quadruple hamstring tendon graft. At 5 years follow up, 3 patients had sustained an ACL graft rupture and 2 patients had sustained a contralateral ACL rupture. Fear of re-injury, confidence with the knee, patient reported function, activity level, static and dynamic tibial translation and muscle strength were assessed. The re-injured group reported greater fear of re-injury and had greater static tibial translation in both knees before the ACL reconstruction compared to those who did not sustain another ACL injury. There were no other differences between groups. In conclusion, fear of re-injury and static tibial translation before the index ACL reconstruction were greater in patients who later on suffered an ACL graft rupture or a contralateral ACL rupture. These factors may predict a subsequent ACL injury. PMID:25894209

  2. Tripeptide-copper complex GHK-Cu (II) transiently improved healing outcome in a rat model of ACL reconstruction.

    PubMed

    Fu, Sai-Chuen; Cheuk, Yau-Chuk; Chiu, Wai-Yin Vivien; Yung, Shu-Hang; Rolf, Christer G; Chan, Kai-Ming

    2015-07-01

    After anterior cruciate ligament reconstruction (ACLR), the biological healing of the graft is a rate-limiting step which can contribute to graft failure. The tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu(II) (GHK-Cu) is a well-known activator of tissue remodeling. We investigated whether GHK-Cu can improve graft healing following ACLR. Seventy-two rats underwent unilateral ACLR were randomized to saline, 0.3 or 3 mg/ml GHK-Cu groups (n = 24). Post-operational intra-articular injections were given from week 2, once a week, for 4 weeks. Gait analysis was performed pre-injury and at harvesting time. At 6 or 12 weeks post-operation, knee specimens were harvested for knee laxity test, graft pull-out test, and histology. At 6 weeks post-ACLR, GHK-Cu groups resulted in a smaller side-to-side difference in knee laxity as compared to the saline group (p = 0.009), but there was no significant difference at 12 weeks post-operation. The graft complex in the 0.3 mg/ml GHK-Cu group had higher stiffness than saline group at 6 weeks post-operation (p = 0.026), but there was no significant difference in ultimate load, gait parameters, and histological scores among treatment groups. All grafts failed mid-substance during pull-out test. Intra-articular supplementation with a bioactive small molecule GHK-Cu improved graft healing following ACLR in rat, but the beneficial effects could not last as treatment discontinued. PMID:25731775

  3. Line profile reconstruction: validation and comparison of reconstruction methods

    NASA Astrophysics Data System (ADS)

    Tsai, Ming-Yi; Yost, Michael G.; Wu, Chang-Fu; Hashmonay, Ram A.; Larson, Timothy V.

    Currently, open path Fourier transform infrared (OP-FTIR) spectrometers have been applied in some fenceline monitoring, but their use has been limited because path-integrated concentration measurements typically only provide an estimate of the average concentration. We present a series of experiments that further explore the use of path-integrated measurements to reconstruct various pollutant distributions along a linear path. Our experiments were conducted in a ventilation chamber using an OP-FTIR instrument to monitor a tracer-gas release over a fenceline configuration. These experiments validate a line profile method (1-D reconstruction). Additionally, we expand current reconstruction techniques by applying the Bootstrap to our measurements. We compared our reconstruction results to our point samplers using the concordance correlation factor (CCF). Of the four different release types, three were successfully reconstructed with CCFs greater than 0.9. The difficult reconstruction involved a narrow release where the pollutant was limited to one segment of the segmented beampath. In general, of the three reconstruction methods employed, the average of the bootstrapped reconstructions was found to have the highest CCFs when compared to the point samplers. Furthermore, the bootstrap method was the most flexible and allowed a determination of the uncertainty surrounding our reconstructions.

  4. Arthroscopic anatomical double bundle anterior cruciate ligament reconstruction: A prospective longitudinal study

    PubMed Central

    Devgan, Ashish; Singh, Amanpreet; Gogna, Paritosh; Singla, Rohit; Magu, Narender Kumar; Mukhopadhyay, Reetadyuti

    2015-01-01

    Background: Single bundle anterior cruciate ligament (ACL) reconstruction has been the current standard of treatment for ACL deficiency. However, a significant subset of patients continue to report residual symptoms of instability with a poor pivot control. Cadaveric biomechanical studies have shown double bundle (DB) ACL reconstructions to restore the knee kinematics better. This study evaluates the outcome of DB ACL reconstruction. Materials and Methods: 30 consecutive patients who underwent anatomic DB ACL reconstruction were included in this prospective longitudinal study. There were all males with a mean age of 25 ± 7.45 years. All patients were prospectively evaluated using GeNouRoB (GNRB) arthrometer, functional knee scores (International Knee Documentation Committee [IKDC] and Lysholm) and postoperative magnetic resonance imaging (MRI) for comparing the graft orientation and footprint of the reconstructed ACL with that of the normal knee. Results: The average followup was 36.2 months. At the time of final followup the mean Lysholm score was 93.13 ± 3.31. As per the objective IKDC score, 26 patients (86.6%) were in Group A while 4 patients (13.3%) were in Group B. The mean differential anterior tibial translation by GNRB, arthrometer was 1.07 ± 0.8 mm (range 0.1-2.3 mm). All cases had a negative pivot shift test. MRI scans of operated and the contralateral normal knee showed the mean sagittal ACL tibial angle coronal ACL tibial angle and tibial ACL footprint to be in accordance with the values of the contralateral, normal knee. Conclusion: The study demonstrates that DB ACL reconstruction restores the ACL anatomically in terms of size and angle of orientation. However, long term studies are needed to further substantiate its role in decreasing the incidence of early osteoarthritic changes compared to the conventional single bundle reconstructions. PMID:26015600

  5. An integrated approach to change the outcome part I: neuromuscular screening methods to identify high ACL injury risk athletes.

    PubMed

    Myer, Gregory D; Ford, Kevin R; Brent, Jensen L; Hewett, Timothy E

    2012-08-01

    An important step for treatment of a particular injury etiology is the appropriate application of a treatment targeted to the population at risk. An anterior cruciate ligament (ACL) injury risk algorithm has been defined that employs field-based techniques in lieu of laboratory-based motion analysis systems to identify athletes with high ACL injury risk landing strategies. The resultant field-based assessment techniques, in combination with the developed prediction algorithm, allow for low-cost identification of athletes who may be at increased risk of sustaining ACL injury. The combined simplicity and accuracy of the field-based tool facilitate its use to identify specific factors that may increase risk of injury in female athletes. The purpose of this report is to demonstrate novel algorithmic techniques to accurately capture and analyze measures of knee valgus motion, knee flexion range of motion, body mass, tibia length and quadriceps to hamstrings ratio with video analysis software typically used by coaches, strength and conditioning specialists, and athletic trainers. The field-based measurements and software analyses were used in a prediction algorithm to identify those at potential risk of noncontact ACL injury that may directly benefit from neuromuscular training. PMID:22580976

  6. Analytical Chemistry Laboratory (ACL) procedure compendium. Volume 2, Sample preparation methods

    SciTech Connect

    Not Available

    1993-08-01

    This volume contains the interim change notice for sample preparation methods. Covered are: acid digestion for metals analysis, fusion of Hanford tank waste solids, water leach of sludges/soils/other solids, extraction procedure toxicity (simulate leach in landfill), sample preparation for gamma spectroscopy, acid digestion for radiochemical analysis, leach preparation of solids for free cyanide analysis, aqueous leach of solids for anion analysis, microwave digestion of glasses and slurries for ICP/MS, toxicity characteristic leaching extraction for inorganics, leach/dissolution of activated metal for radiochemical analysis, extraction of single-shell tank (SST) samples for semi-VOC analysis, preparation and cleanup of hydrocarbon- containing samples for VOC and semi-VOC analysis, receiving of waste tank samples in onsite transfer cask, receipt and inspection of SST samples, receipt and extrusion of core samples at 325A shielded facility, cleaning and shipping of waste tank samplers, homogenization of solutions/slurries/sludges, and test sample preparation for bioassay quality control program.

  7. Analytical Chemistry Laboratory (ACL) procedure compendium. Volume 3, Inorganic instrumental methods

    SciTech Connect

    Not Available

    1993-08-01

    The methods cover: C in solutions, F (electrode), elements by atomic emission spectrometry, inorganic anions by ion chromatography, Hg in water/solids/sludges, As, Se, Bi, Pb, data calculations for SST (single shell tank?) samples, Sb, Tl, Ag, Pu, O/M ratio, ignition weight loss, pH value, ammonia (N), Cr(VI), alkalinity, U, C sepn. from soil/sediment/sludge, Pu purif., total N, water, C and S, surface Cl/F, leachable Cl/F, outgassing of Ge detector dewars, gas mixing, gas isotopic analysis, XRF of metals/alloys/compounds, H in Zircaloy, H/O in metals, inpurity extraction, reduced/total Fe in glass, free acid in U/Pu solns, density of solns, Kr/Xe isotopes in FFTF cover gas, H by combustion, MS of Li and Cs isotopes, MS of lanthanide isotopes, GC operation, total Na on filters, XRF spectroscopy QC, multichannel analyzer operation, total cyanide in water/solid/sludge, free cyanide in water/leachate, hydrazine conc., ICP-MS, {sup 99}Tc, U conc./isotopes, microprobe analysis of solids, gas analysis, total cyanide, H/N{sub 2}O in air, and pH in soil.

  8. Patients With Isolated PCL Injuries Improve From Surgery as Much as Patients With ACL Injuries After 2 Years

    PubMed Central

    Owesen, Christian; Sivertsen, Einar Andreas; Engebretsen, Lars; Granan, Lars-Petter; Årøen, Asbjørn

    2015-01-01

    Background: Reports on outcome after posterior cruciate ligament (PCL) reconstruction often contain both isolated PCL and combined knee ligament injuries. This makes it difficult to conclude on the outcome after reconstruction of isolated PCL injuries. Purpose: To investigate the outcome after PCL reconstruction in patients with an isolated PCL injury and to compare this with the outcome of patients treated with reconstruction after isolated anterior cruciate ligament (ACL) injuries. Study Design: Cohort study; Level of evidence, 3. Methods: Seventy-one patients with an isolated PCL injury that was reconstructed surgically and who had registered in the Norwegian Knee Ligament Registry between 2004 and 2010 were included in this study. Patients with isolated ACL reconstructions (n = 9661) who had registered in the same period were included for comparison. Knee Injury and Osteoarthritis Outcome Score (KOOS) was used as the patient-reported outcome measure. Preoperative and 2-year postoperative KOOS scores were compared. Changes in KOOS score reported by the PCL patients were compared with changes reported by the ACL patients. Results: At the 2-year postoperative follow-up of the PCL-reconstructed patients, the patient-reported outcome was improved, measured by KOOS as follows: pain, 15.1 (95% CI, 8.5-21.8; P < .001); symptoms, 0.9 (95% CI, –6.6 to 8.3; P = .82); activities of daily living, 13.2 (95% CI, 6.6-13.9; P < .001); sports, 20.7 (95% CI, 11.8-29.4; P < .001); and quality of life, 26.6 (95% CI, 18.9-34.2; P < .001). According to the KOOS, the incremental improvements were similar for PCL and ACL patients. Time from injury to surgery was longer for the PCL patients compared with ACL patients (median, 21.5 vs 8.0 months; P < .001). Conclusion: Patients undergoing PCL reconstruction can expect the same improvements in KOOS score as patients undergoing ACL reconstruction. However, PCL patients start out with an inferior score on average and consequently end up

  9. Method for position emission mammography image reconstruction

    DOEpatents

    Smith, Mark Frederick

    2004-10-12

    An image reconstruction method comprising accepting coincidence datat from either a data file or in real time from a pair of detector heads, culling event data that is outside a desired energy range, optionally saving the desired data for each detector position or for each pair of detector pixels on the two detector heads, and then reconstructing the image either by backprojection image reconstruction or by iterative image reconstruction. In the backprojection image reconstruction mode, rays are traced between centers of lines of response (LOR's), counts are then either allocated by nearest pixel interpolation or allocated by an overlap method and then corrected for geometric effects and attenuation and the data file updated. If the iterative image reconstruction option is selected, one implementation is to compute a grid Siddon retracing, and to perform maximum likelihood expectation maiximization (MLEM) computed by either: a) tracing parallel rays between subpixels on opposite detector heads; or b) tracing rays between randomized endpoint locations on opposite detector heads.

  10. Reconstructive methods in hearing disorders - surgical methods

    PubMed Central

    Zahnert, Thomas

    2005-01-01

    Restoration of hearing is associated in many cases with resocialisation of those affected and therefore occupies an important place in a society where communication is becoming ever faster. Not all problems can be solved surgically. Even 50 years after the introduction of tympanoplasty, the hearing results are unsatisfactory and often do not reach the threshold for social hearing. The cause of this can in most cases be regarded as incomplete restoration of the mucosal function of the middle ear and tube, which leads to ventilation disorders of the ear and does not allow real vibration of the reconstructed middle ear. However, a few are also caused by the biomechanics of the reconstructed ossicular chain. There has been progress in reconstructive middle ear surgery, which applies particularly to the development of implants. Implants made of titanium, which are distinguished by outstanding biocompatibility, delicate design and by biomechanical possibilities in the reconstruction of chain function, can be regarded as a new generation. Metal implants for the first time allow a controlled close fit with the remainder of the chain and integration of micromechanical functions in the implant. Moreover, there has also been progress in microsurgery itself. This applies particularly to the operative procedures for auditory canal atresia, the restoration of the tympanic membrane and the coupling of implants. This paper gives a summary of the current state of reconstructive microsurgery paying attention to the acousto-mechanical rules. PMID:22073050

  11. Can Platelet rich plasma stimulate human ACL growth in culture? A preliminary experience

    PubMed Central

    Dhillon, Mandeep Singh; Karna, Saroj Kumar; Dhatt, Sarvdeep Singh; Behera, Prateek; Bhatia, Alka

    2015-01-01

    Summary Introduction Platelet Rich Plasma (PRP) contains numerous growth factors; Platelet poor plasma (PPP) is plasma proteins without platelets, containing growth factors other than platelet derived. We planned to evaluate the effect of both autologous PRP & PPP on human ACL cell growth characteristics in culture conditions to see if one was better than the other. Methods ACL remnants were collected from eleven patients during ACL reconstruction surgery; PPP and PRP were prepared from blood of these patients. Cells were isolated, identified and cultured and were then divided into six groups. Groups A–D had Fetal Bovine Serum (FBS) added to them along with different concentrations of PRP and PPP. Groups E and F had 5% and 10% PRP respectively but lacked FBS. Cell viability was assayed by MTT and Annexin V assay, and DNA content was evaluated by propidium iodide staining and flow cytometry. Results analysis of cultured cells showed that addition of PRP (5 or 10%) increased the viability of ACL cells in 4 out of 11 and promoted cell proliferation in 8 of 11 donor samples; 10% PRP was more effective than 5% PRP. However, the difference in effectiveness of 10% PRP was not significantly better than 5% PRP. 5% PPP had no significant effect on cell viability, but it led to an increase in DNA content in 5 of 11. There was no statistically significant effect of either PRP or PPP in preventing cell death (depicted by apoptosis rate). Conclusion PRP may have an enhancing effect on ACL cell viability and promotion of cell proliferation but the ideal concentration of PRP for these positive effects needs to be determined before it could be used in clinical settings for enhancing primary repair of torn ACL. Also larger, more controlled and better studies are needed to confirm its clinical utility. PMID:26605188

  12. Remnant-Preserving Anterior Cruciate Ligament Reconstruction Using a Three-Dimensional Fluoroscopic Navigation System

    PubMed Central

    Inui, Hiroshi; Sanada, Takaki; Nakamura, Kensuke; Yamagami, Ryota; Masuda, Hironari; Tanaka, Sakae; Nakagawa, Takumi

    2014-01-01

    Introduction Recently, remnant-preserving anterior cruciate ligament (ACL) reconstruction has been increasingly performed to achieve revascularization, cell proliferation, and recovery of high-quality proprioception. However, poor arthroscopic visualization makes accurate socket placement during remnant-preserving ACL reconstruction difficult. This study describes a surgical technique used to create an anatomical femoral socket with a three-dimensional (3D) fluoroscopy based navigation system during technically demanding remnant-preserving ACL reconstruction. Surgical Technique After a reference frame was attached to the femur, an intraoperative image of the distal femur was obtained, transferred to the navigation system and reconstructed into a 3D image. A navigation computer helped the surgeon visualize the entire lateral wall of the femoral notch and lateral intercondylar ridge, even when the remnant of the ruptured ACL impeded arthroscopic visualization of the bone surface. When a guide was placed, the virtual femoral tunnel overlapped the reconstructed 3D image in real time; therefore, only minimal soft tissue debridement was required. Materials and Methods We treated 47 patients with remnant-preserving ACL reconstruction using this system. The center of the femoral socket aperture was calculated according to the quadrant technique using 3D computed tomography imaging. Results The femoral socket locations were considered to be an anatomical footprint in accordance with previous cadaveric studies. Conclusions The 3D fluoroscopy-based navigation can assist surgeons in creating anatomical femoral sockets during remnant-preserving ACL reconstruction. PMID:25229047

  13. PET Image Reconstruction Using Kernel Method

    PubMed Central

    Wang, Guobao; Qi, Jinyi

    2014-01-01

    Image reconstruction from low-count PET projection data is challenging because the inverse problem is ill-posed. Prior information can be used to improve image quality. Inspired by the kernel methods in machine learning, this paper proposes a kernel based method that models PET image intensity in each pixel as a function of a set of features obtained from prior information. The kernel-based image model is incorporated into the forward model of PET projection data and the coefficients can be readily estimated by the maximum likelihood (ML) or penalized likelihood image reconstruction. A kernelized expectation-maximization (EM) algorithm is presented to obtain the ML estimate. Computer simulations show that the proposed approach can achieve better bias versus variance trade-off and higher contrast recovery for dynamic PET image reconstruction than the conventional maximum likelihood method with and without post-reconstruction denoising. Compared with other regularization-based methods, the kernel method is easier to implement and provides better image quality for low-count data. Application of the proposed kernel method to a 4D dynamic PET patient dataset showed promising results. PMID:25095249

  14. PET image reconstruction using kernel method.

    PubMed

    Wang, Guobao; Qi, Jinyi

    2015-01-01

    Image reconstruction from low-count positron emission tomography (PET) projection data is challenging because the inverse problem is ill-posed. Prior information can be used to improve image quality. Inspired by the kernel methods in machine learning, this paper proposes a kernel based method that models PET image intensity in each pixel as a function of a set of features obtained from prior information. The kernel-based image model is incorporated into the forward model of PET projection data and the coefficients can be readily estimated by the maximum likelihood (ML) or penalized likelihood image reconstruction. A kernelized expectation-maximization algorithm is presented to obtain the ML estimate. Computer simulations show that the proposed approach can achieve better bias versus variance trade-off and higher contrast recovery for dynamic PET image reconstruction than the conventional maximum likelihood method with and without post-reconstruction denoising. Compared with other regularization-based methods, the kernel method is easier to implement and provides better image quality for low-count data. Application of the proposed kernel method to a 4-D dynamic PET patient dataset showed promising results. PMID:25095249

  15. Bridge-Enhanced ACL Repair: A Review of the Science and the Pathway through FDA Investigational Device Approval

    PubMed Central

    Proffen, Benedikt L.; Perrone, Gabriel S.; Roberts, Gordon; Murray, Martha M.

    2016-01-01

    Injuries to the anterior cruciate ligament (ACL) are currently treated with replacement of the torn ligament with a graft of tendon harvested from elsewhere in the knee. This procedure, called "ACL reconstruction," is excellent for restoring gross stability to the knee; however, there are relatively high graft failure rates in adolescent patients,4, 12, 60 and the ACL reconstruction procedure does not prevent the premature osteoarthritis seen in patients after an ACL injury.1, 46, 52 Thus, new solutions are needed for ACL injuries. Researchers have been investigating the use of scaffolds, growth factors and cells to supplement a suture repair of the ACL (bio-enhanced repair). In this paper, we will review the varied approaches, which have been investigated for stimulating ACL healing and repair in preclinical models and how one of these technologies was able to move from promising preclinical results to FDA acceptance of an Investigational Device Exemption (IDE) application for a first-in-human study. PMID:25631206

  16. Bullet trajectory reconstruction - Methods, accuracy and precision.

    PubMed

    Mattijssen, Erwin J A T; Kerkhoff, Wim

    2016-05-01

    Based on the spatial relation between a primary and secondary bullet defect or on the shape and dimensions of the primary bullet defect, a bullet's trajectory prior to impact can be estimated for a shooting scene reconstruction. The accuracy and precision of the estimated trajectories will vary depending on variables such as, the applied method of reconstruction, the (true) angle of incidence, the properties of the target material and the properties of the bullet upon impact. This study focused on the accuracy and precision of estimated bullet trajectories when different variants of the probing method, ellipse method, and lead-in method are applied on bullet defects resulting from shots at various angles of incidence on drywall, MDF and sheet metal. The results show that in most situations the best performance (accuracy and precision) is seen when the probing method is applied. Only for the lowest angles of incidence the performance was better when either the ellipse or lead-in method was applied. The data provided in this paper can be used to select the appropriate method(s) for reconstruction and to correct for systematic errors (accuracy) and to provide a value of the precision, by means of a confidence interval of the specific measurement. PMID:27044032

  17. THE EFFECT OF CONSERVATIVELY TREATED ACL INJURY ON KNEE JOINT POSITION Sense

    PubMed Central

    Herrington, Lee

    2016-01-01

    ABSTRACT Background Proprioception is critical for effective movement patterns. However, methods of proprioceptive measurement in previous research have been inconsistent and lacking in reliability statistics making it applications to clinical practice difficult. Researchers have suggested that damage to the anterior cruciate ligament (ACL) can alter proprioceptive ability due to a loss of functioning mechanoreceptors. The majority of patients opt for reconstructive surgery following this injury. However, some patients chose conservative rehabilitation options rather than surgical intervention. Purpose The purpose of this study was to determine the effect of ACL deficiency on knee joint position sense following conservative, non-operative treatment and return to physical activity. A secondary purpose was to report the reliability and measurement error of the technique used to measure joint position sense, (JPS) and comment on the clinical utility of this measurement. Study Design Observational study design using a cross-section of ACL deficient patients and matched uninjured controls. Methods Twenty active conservatively treated ACL deficient patients who had returned to physical activity and twenty active matched controls were included in the study. Knee joint position sense was measured using a seated passive-active reproductive angle technique. The average absolute angle of error score, between 10 °-30 ° of knee flexion was determined. This error score was derived from the difference between the target and repositioning angle. Results The ACL deficient patients had a greater error score (7.9 °±3.6) and hence poorer static proprioception ability that both the contra-lateral leg (2.0 °±1.6; p = 0.0001) and the control group (2.6 °±0.9; p = 0.0001). The standard error of the mean (SEM) of this JPS technique was 0.5 ° and 0.2 ° and the minimum detectable change (MDC) was 1.3 ° and 0.4 ° on asymptomatic and symptomatic subjects

  18. Magnetic flux reconstruction methods for shaped tokamaks

    SciTech Connect

    Tsui, Chi-Wa

    1993-12-01

    The use of a variational method permits the Grad-Shafranov (GS) equation to be solved by reducing the problem of solving the 2D non-linear partial differential equation to the problem of minimizing a function of several variables. This high speed algorithm approximately solves the GS equation given a parameterization of the plasma boundary and the current profile (p` and FF` functions). The author treats the current profile parameters as unknowns. The goal is to reconstruct the internal magnetic flux surfaces of a tokamak plasma and the toroidal current density profile from the external magnetic measurements. This is a classic problem of inverse equilibrium determination. The current profile parameters can be evaluated by several different matching procedures. Matching of magnetic flux and field at the probe locations using the Biot-Savart law and magnetic Green`s function provides a robust method of magnetic reconstruction. The matching of poloidal magnetic field on the plasma surface provides a unique method of identifying the plasma current profile. However, the power of this method is greatly compromised by the experimental errors of the magnetic signals. The Casing Principle provides a very fast way to evaluate the plasma contribution to the magnetic signals. It has the potential of being a fast matching method. The performance of this method is hindered by the accuracy of the poloidal magnetic field computed from the equilibrium solver. A flux reconstruction package has been implemented which integrates a vacuum field solver using a filament model for the plasma, a multi-layer perception neural network as an interface, and the volume integration of plasma current density using Green`s functions as a matching method for the current profile parameters. The flux reconstruction package is applied to compare with the ASEQ and EFIT data. The results are promising.

  19. Combined anterolateral ligament and anatomic anterior cruciate ligament reconstruction of the knee.

    PubMed

    Smith, James O; Yasen, Sam K; Lord, Breck; Wilson, Adrian J

    2015-11-01

    Although anatomic anterior cruciate ligament (ACL) reconstruction is established for the surgical treatment of anterolateral knee instability, there remains a significant cohort of patients who continue to experience post-operative instability. Recent advances in our understanding of the anatomic, biomechanical and radiological characteristics of the native anterolateral ligament (ALL) of the knee have led to a resurgent interest in reconstruction of this structure as part of the management of knee instability. This technical note describes our readily reproducible combined minimally invasive technique to reconstruct both the ACL and ALL anatomically using autologous semitendinosus and gracilis grafts. This method of ALL reconstruction can be easily integrated with all-inside ACL reconstruction, requiring minimal additional operative time, equipment and expertise. Level of evidence V. PMID:26387120

  20. Association Between Previous Meniscal Surgery and the Incidence of Chondral Lesions at Revision Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Brophy, Robert H.; Wright, Rick W.; David, Tal S.; McCormack, Robert G.; Sekiya, Jon K.; Svoboda, Steven J.; Huston, Laura J.; Haas, Amanda K.; Steger-May, Karen

    2013-01-01

    Background Knees undergoing revision anterior cruciate ligament (ACL) reconstruction typically have more intra-articular injuries than do knees undergoing primary reconstruction. Hypothesis Previous partial meniscectomy (PM) is associated with a higher rate of chondral lesions at revision ACL reconstruction, whereas previous meniscal repair (MR) is not associated with a higher rate of chondral lesions at revision ACL reconstruction, compared with knees undergoing revision ACL with no previous meniscal surgery. Study design Cohort study (Prevalence); Level of evidence, 2. Methods Data from a multicenter cohort was reviewed to determine the history of prior meniscal surgery (PM/MR) and the presence of grade II/III/IV chondral lesions at revision ACL reconstruction. The association between previous meniscal surgery and the incidence of chondral lesions was examined. Patient age was included as a covariate to determine if surgery type contributes predictive information independent of patient age. Results The cohort included 725 ACL revision surgeries. Chondrosis was associated with patient age (P < .0001) and previous meniscal surgery (P < .0001). After adjusting for patient age, knees with previous PM were more likely to have chondrosis than knees with previous MR (P = .003) or no previous meniscal surgery (P < .0001). There was no difference between knees without previous meniscal surgery and knees with previous MR (P = .7). Previous partial meniscectomy was associated with a higher rate of chondrosis in the same compartment compared with knees without previous meniscal surgery (P < .0001) and knees with previous MR (P ≤ .03). Conclusion The status of articular cartilage at the time of revision ACL reconstruction relates to previous meniscal surgery independent of the effect of patient age. Previous partial meniscectomy is associated with a higher incidence of articular cartilage lesions, whereas previous meniscal repair is not. Although this association may

  1. Reconstruction of the anterior cruciate ligament.

    PubMed

    Seedhom, B B

    1992-01-01

    Ligaments are strong collagenous structures that act as constraints on joint motion, thus confining the articular surfaces to more or less the same paths. In so doing they prevent arbitrary apposition of these surfaces from occurring and resulting in abnormal stresses which may damage the joint surfaces. Ligaments rupture due to excessive loads, particularly those resulting from trauma occurring during sporting events or motor vehicle accidents. Knee and ankle joints have the highest frequency of ligamentous injuries. This paper is a brief review of the current approaches to the reconstruction of the knee ligaments with specific reference to the anterior cruciate ligament (ACL) being the most frequently reconstructed. This is not only because it is frequently injured but also because of the debilitating consequences of such an injury. Approaches ranging from the conservative to those that advocate the use of frank prosthetic replacement have been adopted by surgeons at both ends of the spectrum. Following a discussion of the rationale for reconstruction of the ACL, the mechanical and biological considerations of the reconstructive procedure are discussed. The different methods of ACL reconstruction are reviewed. These include: (a) primary repair, (b) reconstruction with different tissues, including autogenous allografts and xenografts, (c) reconstruction employing different synthetic devices. A brief discussion of the procedures used for reconstruction with different types of tissue and of the surviving examples of the synthetic devices will follow. PMID:1418190

  2. Athletic Performance at the National Basketball Association Combine After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Mehran, Nima; Williams, Phillip N.; Keller, Robert A.; Khalil, Lafi S.; Lombardo, Stephen J.; Kharrazi, F. Daniel

    2016-01-01

    Background: Anterior cruciate ligament (ACL) injuries are significant injuries in elite-level basketball players. In-game statistical performance after ACL reconstruction has been demonstrated; however, few studies have reviewed functional performance in National Basketball Association (NBA)–caliber athletes after ACL reconstruction. Purpose: To compare NBA Combine performance of athletes after ACL reconstruction with an age-, size-, and position-matched control group of players with no previous reported knee injury requiring surgery. We hypothesized that there is no difference between the 2 groups in functional performance. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 1092 NBA-caliber players who participated in the NBA Combine between 2000 and 2015 were reviewed. Twenty-one athletes were identified as having primary ACL reconstruction prior to participation in the combine. This study group was compared with an age-, size-, and position-matched control group in objective functional performance testing, including the shuttle run test, lane agility test, three-quarter court sprint, vertical jump (no step), and maximum vertical jump (running start). Results: With regard to quickness and agility, both ACL-reconstructed athletes and controls scored an average of 11.5 seconds in the lane agility test and 3.1 seconds in the shuttle run test (P = .745 and .346, respectively). Speed and acceleration was measured by the three-quarter court sprint, in which both the study group and the control group averaged 3.3 seconds (P = .516). In the maximum vertical jump, which demonstrates an athlete’s jumping ability with a running start, the ACL reconstruction group had an average height of 33.6 inches while the controls averaged 33.9 inches (P = .548). In the standing vertical jump, the ACL reconstruction group averaged 28.2 inches while the control group averaged 29.2 inches (P = .067). Conclusion: In athletes who are able to return to sport

  3. Anterior Cruciate Ligament (ACL) Injuries

    MedlinePlus

    ... get ACL injuries usually play contact sports (like football) or sports that feature swift, abrupt movements such ... the things you love — like running or playing football, field hockey, or softball — can be frustrating. Recovering ...

  4. Delay to Reconstruction of the Adolescent Anterior Cruciate Ligament

    PubMed Central

    Newman, Justin T.; Carry, Patrick M.; Terhune, Elizabeth B.; Spruiell, Murray; Heare, Austin; Mayo, Meredith; Vidal, Armando F.

    2014-01-01

    Background: A delay in pediatric and adolescent anterior cruciate ligament (ACL) reconstruction is associated with an increase in the number of concomitant meniscal and chondral injuries. Factors that contribute to this delay have not been well described. Hypothesis: Socioeconomic and demographic factors are related to ACL surgery timing. Study Methods: Cohort study; Level of evidence, 3. Methods: All subjects who underwent primary ACL reconstruction at a single tertiary pediatric hospital between 2005 and 2012 were retrospectively reviewed. Variables included concomitant knee injuries (cartilage or meniscus injuries requiring additional operative treatment) and chronologic, demographic, and socioeconomic factors. Multivariable Cox proportional-hazards analyses were used to identify factors related to ACL surgery timing. Results: The mean age of the 272 subjects was 15.2 ± 2.12 years. Time to surgery was significantly different among subjects who required multiple additional surgical procedures at time of ACL reconstruction (median, 3.3 months) compared with subjects with 1 (median, 2.0 months) or no additional injuries (median, 1.6 months). Subjects underwent ACL reconstruction significantly sooner if they were older at the time of injury (hazard ratio [HR], 1.2 per 1 year; 95% CI, 1.1-1.2; P < .0001) or were covered by a commercial insurance plan (HR, 2.0; 95% CI, 1.6-2.6; P < .0001). Median time to ACL surgery was 1.5 months (95% CI, 1.3-1.7) for subjects with commercial insurance plans compared with 3.0 months (95% CI, 2.3-3.3) for subjects with noncommercial insurance coverage. Conclusion: The risk of delayed ACL surgery was significantly higher among pediatric and adolescent subjects who were less affluent, who were covered by a noncommercial insurance plan, and who were younger. This study also confirms previous studies that have reported an association between a delay in ACL surgery and the presence of additional knee injuries requiring operative treatment

  5. Big Five Personality Characteristics and Adherence to Clinic-Based Rehabilitation Activities after ACL Surgery: A Prospective Analysis

    PubMed Central

    Hilliard, Robert C.; Brewer, Britton W.; Cornelius, Allen E.; Van Raalte, Judy L.

    2015-01-01

    Purpose A prospective, longitudinal study was conducted to examine Big Five personality characteristics as predictors of adherence to clinic-based rehabilitation activities following anterior cruciate ligament (ACL) reconstruction surgery. Method Participants (72 men, 36 women) completed a questionnaire assessing Big Five personality dimensions prior to surgery. For the first 7 weeks after surgery, participants' rehabilitation session attendance was recorded and rehabilitation professionals rated participants' adherence during rehabilitation sessions.. Results Results of multiple regression analyses indicated that the 5 personality factors explained 11 percent of the variance in attendance and 17 percent of the variance in adherence ratings, that agreeableness was a significant positive predictor of attendance, and that conscientiousness and openness to experience were significant positive predictors of adherence ratings. Conclusion As a potential contributor to adherence, personality warrants consideration when implementing rehabilitation programs after ACL surgery. PMID:25663952

  6. A Comparison between Clinical Results of Selective Bundle and Double Bundle Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Yoo, Yon-Sik; Song, Si Young; Yang, Cheol Jung; Ha, Jong Mun; Kim, Yoon Sang

    2016-01-01

    Purpose The purpose of this study was to compare the clinical outcomes of arthroscopic anatomical double bundle (DB) anterior cruciate ligament (ACL) reconstruction with either selective anteromedial (AM) or posterolateral (PL) bundle reconstruction while preserving a relatively healthy ACL bundle. Materials and Methods The authors evaluated 98 patients with a mean follow-up of 30.8±4.0 months who had undergone DB or selective bundle ACL reconstructions. Of these, 34 cases underwent DB ACL reconstruction (group A), 34 underwent selective AM bundle reconstruction (group B), and 30 underwent selective PL bundle reconstructions (group C). These groups were compared with respect to Lysholm and International Knee Documentation Committee (IKDC) score, side-to-side differences of anterior laxity measured by KT-2000 arthrometer at 30 lbs, and stress radiography and Lachman and pivot shift test results. Pre- and post-operative data were objectively evaluated using a statistical approach. Results The preoperative anterior instability measured by manual stress radiography at 90° of knee flexion in group A was significantly greater than that in groups B and C (all p<0.001). At last follow-up, mean side-to-side instrumented laxities measured by the KT-2000 and manual stress radiography were significantly improved from preoperative data in all groups (all p<0.001). There were no significant differences between the three groups in anterior instability measured by KT-2000 arthrometer, pivot shift, or functional scores. Conclusion Selective bundle reconstruction in partial ACL tears offers comparable clinical results to DB reconstruction in complete ACL tears. PMID:27401652

  7. An Athlete's Nightmare: Tearing the ACL

    MedlinePlus

    ... Dr. Boden's ACL patients. There are many different theories as to why young women suffer a higher ... ACL injuries. Dr. Boden says there are other theories based on how estrogen affects the ligament, as ...

  8. Body Mass Index, Modulated by Lateral Posterior Tibial Slope, Predicts ACL Injury Risk

    PubMed Central

    Bojicic, Katherine M.; Beaulieu, Melanie L.; Krieger, Daniel Imaizumi; Ashton-Miller, James A.; Wojtys, Edward M.

    2016-01-01

    Objectives: Intervention strategies to prevent ACL injury rely on increasing knowledge of risk factors. While several modifiable and non-modifiable risk factors for ACL rupture have been identified, the interaction between them remains unknown. The aim of this study was to quantify the relationship between BMI and several knee geometries as potential risk factors for ACL injury. We hypothesized that an increased BMI in the presence of an increased posterior tibial slope or middle cartilage slope would increase risk of ACL injury. We also hypothesized that an increased BMI in the presence of a decreased posterior meniscal height or meniscal bone angle would result in an increased risk of ACL injury. Methods: Sagittal knee MRI files from 76 ACL-injured and 42 non-injured subjects were gathered from the institution’s archive. The PTS, MCS, PMH, and MBA were measured using the circle method and compared with BMI from the subject demographic. Data were analyzed using univariate and multivariate logistical regression. Figure 1 details measurements made for each knee geometry. Results: Univariate analysis of PTS showed increases in PTS significantly increase the odds of ACL tear (p = 0.043, OR =1.12). Univariate analysis of MCS showed increases of MCS significantly increase the odds of ACL tear (p = 0.037, OR = 1.12). Multivariate analysis of PTS and BMI centered around the mean (PTS*cBMI) showed increases of PTS in combination with increases in cBMI significantly increases the odds of ACL rupture (p value = .050, OR = 1.03). Table 1 shows predicted increases in ACL injury risk for combinations of increases in PTS and BMI. Conclusion: An increase in BMI will increase the risk of ACL tear when an increase in lateral posterior tibial slope is present. An increase in lateral posterior tibial slope or lateral middle cartilage slope increases the risk of an ACL tear.

  9. A Comparative Study of Different Reconstruction Schemes for a Reconstructed Discontinuous Galerkin Method on Arbitrary Grids

    SciTech Connect

    Hong Luo; Hanping Xiao; Robert Nourgaliev; Chunpei Cai

    2011-06-01

    A comparative study of different reconstruction schemes for a reconstruction-based discontinuous Galerkin, termed RDG(P1P2) method is performed for compressible flow problems on arbitrary grids. The RDG method is designed to enhance the accuracy of the discontinuous Galerkin method by increasing the order of the underlying polynomial solution via a reconstruction scheme commonly used in the finite volume method. Both Green-Gauss and least-squares reconstruction methods and a least-squares recovery method are implemented to obtain a quadratic polynomial representation of the underlying discontinuous Galerkin linear polynomial solution on each cell. These three reconstruction/recovery methods are compared for a variety of compressible flow problems on arbitrary meshes to access their accuracy and robustness. The numerical results demonstrate that all three reconstruction methods can significantly improve the accuracy of the underlying second-order DG method, although the least-squares reconstruction method provides the best performance in terms of both accuracy and robustness.

  10. Visualization of postoperative anterior cruciate ligament reconstruction bone tunnels

    PubMed Central

    2011-01-01

    Background and purpose Non-anatomic bone tunnel placement is the most common cause of a failed ACL reconstruction. Accurate and reproducible methods to visualize and document bone tunnel placement are therefore important. We evaluated the reliability of standard radiographs, CT scans, and a 3-dimensional (3D) virtual reality (VR) approach in visualizing and measuring ACL reconstruction bone tunnel placement. Methods 50 consecutive patients who underwent single-bundle ACL reconstructions were evaluated postoperatively by standard radiographs, CT scans, and 3D VR images. Tibial and femoral tunnel positions were measured by 2 observers using the traditional methods of Amis, Aglietti, Hoser, Stäubli, and the method of Benereau for the VR approach. Results The tunnel was visualized in 50–82% of the standard radiographs and in 100% of the CT scans and 3D VR images. Using the intraclass correlation coefficient (ICC), the inter- and intraobserver agreement was between 0.39 and 0.83 for the standard femoral and tibial radiographs. CT scans showed an ICC range of 0.49–0.76 for the inter- and intraobserver agreement. The agreement in 3D VR was almost perfect, with an ICC of 0.83 for the femur and 0.95 for the tibia. Interpretation CT scans and 3D VR images are more reliable in assessing postoperative bone tunnel placement following ACL reconstruction than standard radiographs. PMID:21999625

  11. A new target reconstruction method considering atmospheric refraction

    NASA Astrophysics Data System (ADS)

    Zuo, Zhengrong; Yu, Lijuan

    2015-12-01

    In this paper, a new target reconstruction method considering the atmospheric refraction is presented to improve 3D reconstruction accuracy in long rang surveillance system. The basic idea of the method is that the atmosphere between the camera and the target is partitioned into several thin layers radially in which the density is regarded as uniform; Then the reverse tracking of the light propagation path from sensor to target was carried by applying Snell's law at the interface between layers; and finally the average of the tracked target's positions from different cameras is regarded as the reconstructed position. The reconstruction experiments were carried, and the experiment results showed that the new method have much better reconstruction accuracy than the traditional stereoscopic reconstruction method.

  12. Magnetic Field Configuration Models and Reconstruction Methods: a comparative study

    NASA Astrophysics Data System (ADS)

    Al-haddad, Nada; Möstl, Christian; Roussev, Ilia; Nieves-Chinchilla, Teresa; Poedts, Stefaan; Hidalgo, Miguel Angel; Marubashi, Katsuhide; Savani, Neel

    2012-07-01

    This study aims to provide a reference to different magnetic field models and reconstruction methods. In order to understand the dissimilarities of those models and codes, we analyze 59 events from the CDAW list, using four different magnetic field models and reconstruction techniques; force- free reconstruction (Lepping et al.(1990); Lynch et al.(2003)), magnetostatic reconstruction, referred as Grad-Shafranov (Hu & Sonnerup(2001); Mostl et al.(2009)), cylinder reconstruction (Marubashi & Lepping(2007)), elliptical, non-force free (Hidalgo et al.(2002)). The resulted parameters of the reconstructions, for the 59 events are compared, statistically, as well as in more details for some cases. The differences between the reconstruction codes are discussed, and suggestions are provided as how to enhance them. Finally we look at 2 unique cases under the microscope, to provide a comprehensive idea of the different aspects of how the fitting codes work.

  13. EFFECT OF THE GRAFTING SECTION AREA ON ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION SURGERY – HISTOLOGICAL STUDY ON DOGS

    PubMed Central

    Pereira, Ricardo Violante; Müller, Sérgio Swain; Vannini, Rodrigo; Felisbino, Sérgio Luiz; Curcelli, Emilio Carlos; Pereira, Gilberto José Caçdo; de Almeida Silvares, Paulo Roberto

    2015-01-01

    Objective: To correlate the initial grafting section area with the outcomes from anterior cruciate ligament (ACL) reconstruction surgery. Eight dogs underwent operations, divided into two groups according to graft size: Group A, 25% and Group B, 40% of the patellar ligament (PL) width. Methods: After eight months, the dogs were sacrificed for macroscopic and histological analysis on the reconstructed ligaments. Each dog's contralateral knee was used as a control. Results: In both groups, all the reconstructed ligaments were seen to be viable and hypertrophied. The morphology of the PL grafting had changed, which was observed by measuring the crimp and cellularity, and it resembled that of the ACL. Conclusion: The grafting section area did not influence the histological outcomes from ACL reconstruction surgery in dogs. PMID:27047857

  14. Spectrum reconstruction based on the constrained optimal linear inverse methods.

    PubMed

    Ren, Wenyi; Zhang, Chunmin; Mu, Tingkui; Dai, Haishan

    2012-07-01

    The dispersion effect of birefringent material results in spectrally varying Nyquist frequency for the Fourier transform spectrometer based on birefringent prism. Correct spectral information cannot be retrieved from the observed interferogram if the dispersion effect is not appropriately compensated. Some methods, such as nonuniform fast Fourier transforms and compensation method, were proposed to reconstruct the spectrum. In this Letter, an alternative constrained spectrum reconstruction method is suggested for the stationary polarization interference imaging spectrometer (SPIIS) based on the Savart polariscope. In the theoretical model of the interferogram, the noise and the total measurement error are included, and the spectrum reconstruction is performed by using the constrained optimal linear inverse methods. From numerical simulation, it is found that the proposed method is much more effective and robust than the nonconstrained spectrum reconstruction method proposed by Jian, and provides a useful spectrum reconstruction approach for the SPIIS. PMID:22743461

  15. Knee Bracing After Anterior Cruciate Ligament Reconstruction.

    PubMed

    Rodríguez-Merchán, E Carlos

    2016-07-01

    Although some articles in the literature are in favor of the use of a postoperative brace after anterior cruciate ligament (ACL) reconstruction, this review found that several systematic reviews and other reports on the topic do not support the use of a postoperative brace after ACL reconstruction. There is no scientific evidence so far to support the routine use of a functional knee brace following a successful ACL reconstruction in the postoperative course. Most authors believe that bracing is not necessary. There is insufficient evidence to inform current practice. Good-quality randomized trials are required to remedy this situation. Future studies should better define the role of a brace following ACL surgery. A search of MEDLINE for articles published between January 1, 1995, and September 30, 2013, was performed. Key search terms used were ACL reconstruction and knee brace. Ninety-one articles were found, but only 28 focused on the subject of bracing after ACL reconstruction and were selected for this review. Several systematic reviews and randomized, controlled trials on the topic do not recommend the use of postoperative brace after ACL reconstruction. Postoperative bracing after ACL reconstruction does not seem to help with pain, function, rehabilitation, and stability. The literature does not support the use of a postoperative brace following ACL reconstruction. [Orthopedics. 2016; 39(4):e602-e609.]. PMID:27203412

  16. Infections in Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Stucken, Charlton; Garras, David N.; Shaner, Julie L.; Cohen, Steven B.

    2013-01-01

    Context: Anterior cruciate ligament (ACL) reconstruction is a safe, common, and effective method of restoring stability to the knee after injury, but evolving techniques of reconstruction carry inherent risk. Infection after ACL reconstruction, while rare, carries a high morbidity, potentially resulting in a poor clinical outcome. Evidence Acquisition: Data were obtained from previously published peer-reviewed literature through a search of the entire PubMed database (up to December 2012) as well as from textbook chapters. Results: Treatment with culture-specific antibiotics and debridement with graft retention is recommended as initial treatment, but with persistent infection, consideration should be given to graft removal. Graft type likely has no effect on infection rates. Conclusion: The early diagnosis of infection and appropriate treatment are necessary to avoid the complications of articular cartilage damage and arthrofibrosis. PMID:24427432

  17. The ACL Message Passing Library

    SciTech Connect

    Painter, J.; McCormick, P.; Krogh, M.; Hansen, C.; Colin de Verdiere, G.

    1995-09-01

    This paper presents the ACL (Advanced Computing Lab) Message Passing Library. It is a high throughput, low latency communications library, based on Thinking Machines Corp.`s CMMD, upon which message passing applications can be built. The library has been implemented on the Cray T3D, Thinking Machines CM-5, SGI workstations, and on top of PVM.

  18. PERI-INCISIONAL DYSESTHESIA FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING CENTRAL THIRD OF PATELLAR TENDON

    PubMed Central

    de Carvalho Júnior, Lúcio Honório; Machado, Soares Luiz Fernando; Gonçalves, Matheus Braga Jacques; Júnior, Paulo Randal Pires; Baumfeld, Daniel Soares; Pereira, Marcelo Lobo; Lessa, Rodrigo Rosa; Costa, Lincoln Paiva; Bisinoto, Henrique Barra

    2015-01-01

    Objective: To evaluate the prevalence and type of dysesthesia around the incision used to obtain the patellar tendon for anterior cruciate ligament (ACL) reconstruction surgery. Methods: Out of a population of 1368 ACL reconstructions using the central third of the patellar tendon, 102 patients (111 knees) were evaluated by means of telephone interview. Results: The mean follow-up was 52 months (ranging from 12 to 88 months). The patients' ages ranged from 16 to 58 years (mean: 34.7 years). There was some degree of peri-incisional dysesthesia in 66 knees (59.46%). In 40.54% of the knees, this condition was not found. In all the cases of dysesthesia, the type encountered was Highet's type II. Conclusion: Peri-incisional dysesthesia following ACL reconstruction using the central third of the patellar tendon is highly prevalent. It affected more than half of the cases in this series. PMID:27026983

  19. Comparison of Clinical Outcome of Autograft and Allograft Reconstruction for Anterior Cruciate Ligament Tears

    PubMed Central

    Jia, Yu-Hua; Sun, Peng-Fei

    2015-01-01

    Background: Hamstring (HS) autograft and bone-patellar tendon-bone allograft are the most common choice for reconstruction of anterior cruciate ligament (ACL). There was a little report about the clinical outcome and difference of arthroscopic ACL reconstruction using allograft and autograft. This study aimed to compare the clinical outcome of autograft and allograft reconstruction for ACL tears. Methods: A total of 106 patients who underwent surgery because of ACL tear were included in this study. The patients were randomly divided into two groups, including 53 patients in each group. The patients in group I underwent standard ACL reconstruction with HS tendon autografts, while others in group II underwent reconstruction with bone-patellar tendon-bone allograft. All the patients were followed up and analyzed; the mean follow-up was 81 months (range: 28–86 months). Clinical outcomes were evaluated using the International Knee Documentation Committee (IKDC), Lysholm scores, physical instability tests, and patient satisfaction questionnaires. The complication rates of both groups were compared. Tibial and femoral tunnel widening were assessed using lateral and anteroposterior radiographs. Results: At the end of follow-up, no significant differences were found between the groups in terms of IKDC, Lysholm scores, physical instability tests, patient satisfaction questionnaires, and incidences of arthrofibrosis. Tibial and femoral tunnel widening was less in the HS tendon autografts. This difference was more significant on the tibial side. Conclusions: In the repair of ACL tears, allograft reconstruction is as effective as the autograft reconstruction, but the allograft can lead to more tunnel widening evidently in the tibial tunnel, particularly. PMID:26612290

  20. Intra-articular Findings in Primary and Revision Anterior Cruciate Ligament Reconstruction Surgery

    PubMed Central

    Borchers, James R.; Kaeding, Christopher C.; Pedroza, Angela D.; Huston, Laura J.; Spindler, Kurt P.; Wright, Rick W.

    2013-01-01

    Background At the time of anterior cruciate ligament (ACL) reconstruction, there are usually concurrent meniscal and articular cartilage injuries. It is unclear if there is a significant difference between intra-articular injuries at the time of a primary ACL reconstruction compared with revision ACL reconstruction. Purpose To compare the meniscal and articular cartilage injuries found at the time of primary and revision ACL reconstruction surgery and to determine associations between primary and revision surgery and specific intra-articular findings. Study Design Cohort study (prevalence); Level of evidence, 2. Methods Primary and revision ACL surgeries were identified from the Multicenter Orthopedic Outcomes Network (MOON) and Multicenter ACL Revision Study (MARS) study groups, respectively, from January 1, 2007 to November 1, 2008. Demographic data on individual patients were analyzed including age, body mass index (BMI), and gender. Intra-articular findings including the presence of medial or lateral meniscal tears and chondral damage to articular surfaces were analyzed for each patient. Comparisons of intra-articular findings at the time of surgery for the 2 groups were analyzed. Chondral damage in the medial and lateral compartments was analyzed considering previous meniscal tear as a possible confounder. Results There were 508 patients undergoing primary ACL reconstruction and 281 patients undergoing revision ACL reconstruction who were identified for inclusion. There were no differences in the mean age, BMI, and gender in the 2 study groups. There was a decreased odds ratio (OR) of new untreated lateral meniscal tears (OR, 0.54; P <.01) but not of medial meniscal tears (OR, 0.86; P = .39) in revision compared with primary ACL reconstruction. There was an increased OR of Outerbridge grade 3 and 4 articular cartilage injury in revision compared with primary ACL reconstruction in the lateral compartment (OR, 1.73; P = .04) and in the patellar

  1. High resolution x-ray CMT: Reconstruction methods

    SciTech Connect

    Brown, J.K.

    1997-02-01

    This paper qualitatively discusses the primary characteristics of methods for reconstructing tomographic images from a set of projections. These reconstruction methods can be categorized as either {open_quotes}analytic{close_quotes} or {open_quotes}iterative{close_quotes} techniques. Analytic algorithms are derived from the formal inversion of equations describing the imaging process, while iterative algorithms incorporate a model of the imaging process and provide a mechanism to iteratively improve image estimates. Analytic reconstruction algorithms are typically computationally more efficient than iterative methods; however, analytic algorithms are available for a relatively limited set of imaging geometries and situations. Thus, the framework of iterative reconstruction methods is better suited for high accuracy, tomographic reconstruction codes.

  2. Multigrid hierarchical simulated annealing method for reconstructing heterogeneous media.

    PubMed

    Pant, Lalit M; Mitra, Sushanta K; Secanell, Marc

    2015-12-01

    A reconstruction methodology based on different-phase-neighbor (DPN) pixel swapping and multigrid hierarchical annealing is presented. The method performs reconstructions by starting at a coarse image and successively refining it. The DPN information is used at each refinement stage to freeze interior pixels of preformed structures. This preserves the large-scale structures in refined images and also reduces the number of pixels to be swapped, thereby resulting in a decrease in the necessary computational time to reach a solution. Compared to conventional single-grid simulated annealing, this method was found to reduce the required computation time to achieve a reconstruction by around a factor of 70-90, with the potential of even higher speedups for larger reconstructions. The method is able to perform medium sized (up to 300(3) voxels) three-dimensional reconstructions with multiple correlation functions in 36-47 h. PMID:26764849

  3. Reconstructing ENSO - Methods, Proxy Data and Teleconnections

    NASA Astrophysics Data System (ADS)

    Wilson, R.; Cook, E.; D'Arrigo, R.; Riedwyl, N.; Evans, M.; Tudhope, A.; Allan, R.

    2009-04-01

    The El Niño/Southern Oscillation (ENSO) is globally important and influences climate at interannual and decadal time-scales with resultant links with extreme weather events and associated socio-economic problems. An understanding of the ENSO system is therefore crucial to allow for a better understanding of how ENSO will ‘react' under current global warming. Palaeoclimate reconstructions of ENSO variability allow extension prior to the relatively short instrumental record. However, due to the paucity of relevant annually resolved proxy archives (e.g. corals) in the central and eastern Pacific, reconstructions must rely on proxy data that are located in regions where the local climate is teleconnected with the tropical Pacific. In this study we compare three newly developed independent NINO3.4 SST reconstructions using data from (1) the central Pacific (corals), (2) the TexMex region of the United States (tree-rings), and (3) other regions in the tropics (corals and an ice-core) which are teleconnected with central Pacific SSTs in the 20th century. Although these three reconstructions are strongly calibrated and well verified, inter-proxy comparison shows a significant weakening in inter-proxy coherence in the 19th century. This break down in common signal could be related to insufficient data, dating errors in some of the proxy records or a break down in ENSO's influence on other regions. However, spectral analysis indicates that each reconstruction portrays ENSO-like spectral properties. Superposed epoch analysis also shows that each reconstruction shows a generally consistent ‘El-Niño-like' response to major volcanic events in the following year, while during years T+4 to T+7, ‘La Niña-like' conditions prevail. These results suggest that each of the series expresses ENSO-like ‘behaviour' but this ‘behaviour' however does not appear to be spatially or temporally consistent. This result may reflect published observations that there appear to be

  4. Comparison of the Insall-Salvati ratio of the patella in patients with and without an ACL tear.

    PubMed

    Lin, Chien-Fu Jeff; Wu, Jiunn-Jer; Chen, Teng-Shung; Huang, Tung-Fu

    2005-01-01

    The object of this prospective study is to compare the Insall-Salvati ratio between the patients who have an anterior cruciate ligament (ACL) tear and receive arthroscopic-assistant ACL reconstruction and the patients who have no ACL tear but do have an internal disorder of the knee and receive arthroscopic surgery. We prospectively and consecutively collected into two groups a total of 217 patients who had sport injuries and received arthroscopic surgery. The study group included 115 patients who had an ACL tear and received arthroscopic-assistant ACL reconstruction with middle-third bone-patella tendon-bone graft. The control group included 102 patients with internal disorders of the knee joint, including meniscus tear, plicae, or other chondral lesion, but without an ACL tear. We measured the patellar Insall-Salvati ratio [12] on the pre-operative X-ray films for all patients. The Insall-Salvati ratio in the ACL-tear study group is significantly smaller than the control group of internal disorders of the knee (0.99+/-0.11 vs 1.05+/-0.12, p=0.001). There is no significant difference in age, gender, the side of the involved knee, duration of symptoms, patella length and patella tendon length between the two groups. In conclusion, our study shows that patella infra has an association with ACL tears, and patella infra may be a risk factor for ACL tears. In patients with an ACL tear who had patella baja, the middle-third patellar tendon may not be an ideal graft for reconstruction. PMID:15654645

  5. The female ACL: why is it more prone to injury?

    PubMed

    Ireland, Mary Lloyd

    2002-10-01

    Multiple factors are responsible for ACL tears. The key factor in the gender discrepancy appears to be dynamic, not static, and proximal, not distal. The factors involved in evaluating the female ACL are multiple. However, it is the dynamic movement patterns ot hip and knee position with increased flexion and a coordinated proximal muscle firing pattern to keep the body in a safe landing position that are the most critical factors. An ACL injury at an early age is a life-changing event. We can very successfully reconstruct and rehabilitate an ACL, but we cannot stop there. We must now go into the prevention arena. In the United States there is tremendous variation in the exposure and acquisition of skills of physical activities in our youth. Today, children are often playing inside, using computers and watching television-missing out on the opportunity to learn safe movement patterns. Therefore, physical movement classes should occur very early in life, teaching children to land safely and in control, similar to the cry of "get down, stay down" routinely heard during youth soccer. Similarly, specific strength training programs can address landing as well as foot movements during cutting in basketball. Coaches should issue stern warnings when athletes demonstrate a high-risk movement patterns such as one-leg landings, out-of-control baseline landings, or straight-leg landings. The warnings may serve to keep the athlete from "touching the hot stove again" for fear of getting burned. No athlete feels she will be the one to get injured. Therefore, prospective analysis is likely to be received more warmly by the athletes if the program is presented with an emphasis on performance improvement rather than injury prevention. With increased participation in these programs, multiple-center analysis will have the power necessary to determine which factors significantly predispose athletes to ACL injury. The future for injury prevention is bright. We must rise to the challenge

  6. An Ambulatory Method of Identifying Anterior Cruciate Ligament Reconstructed Gait Patterns

    PubMed Central

    Patterson, Matthew R.; Delahunt, Eamonn; Sweeney, Kevin T.; Caulfield, Brian

    2014-01-01

    The use of inertial sensors to characterize pathological gait has traditionally been based on the calculation of temporal and spatial gait variables from inertial sensor data. This approach has proved successful in the identification of gait deviations in populations where substantial differences from normal gait patterns exist; such as in Parkinsonian gait. However, it is not currently clear if this approach could identify more subtle gait deviations, such as those associated with musculoskeletal injury. This study investigates whether additional analysis of inertial sensor data, based on quantification of gyroscope features of interest, would provide further discriminant capability in this regard. The tested cohort consisted of a group of anterior cruciate ligament reconstructed (ACL-R) females and a group of non-injured female controls, each performed ten walking trials. Gait performance was measured simultaneously using inertial sensors and an optoelectronic marker based system. The ACL-R group displayed kinematic and kinetic deviations from the control group, but no temporal or spatial deviations. This study demonstrates that quantification of gyroscope features can successfully identify changes associated with ACL-R gait, which was not possible using spatial or temporal variables. This finding may also have a role in other clinical applications where small gait deviations exist. PMID:24451464

  7. An analytic reconstruction method for PET based on cubic splines

    NASA Astrophysics Data System (ADS)

    Kastis, George A.; Kyriakopoulou, Dimitra; Fokas, Athanasios S.

    2014-03-01

    PET imaging is an important nuclear medicine modality that measures in vivo distribution of imaging agents labeled with positron-emitting radionuclides. Image reconstruction is an essential component in tomographic medical imaging. In this study, we present the mathematical formulation and an improved numerical implementation of an analytic, 2D, reconstruction method called SRT, Spline Reconstruction Technique. This technique is based on the numerical evaluation of the Hilbert transform of the sinogram via an approximation in terms of 'custom made' cubic splines. It also imposes sinogram thresholding which restricts reconstruction only within object pixels. Furthermore, by utilizing certain symmetries it achieves a reconstruction time similar to that of FBP. We have implemented SRT in the software library called STIR and have evaluated this method using simulated PET data. We present reconstructed images from several phantoms. Sinograms have been generated at various Poison noise levels and 20 realizations of noise have been created at each level. In addition to visual comparisons of the reconstructed images, the contrast has been determined as a function of noise level. Further analysis includes the creation of line profiles when necessary, to determine resolution. Numerical simulations suggest that the SRT algorithm produces fast and accurate reconstructions at realistic noise levels. The contrast is over 95% in all phantoms examined and is independent of noise level.

  8. Reconstruction of the anterior cruciate ligament in skeletally immature patients: an individualized approach☆☆☆

    PubMed Central

    Lopes Júnior, Osmar Valadão; Saggin, Paulo Renato; Matos do Nascimento, Gilberto; Kuhn, André; Saggin, José; Inácio, André Manoel

    2014-01-01

    Objective to evaluate a series of skeletally immature patients who underwent three surgical techniques for anterior cruciate ligament (ACL) reconstruction according to each patient's growth potential. Methods a series of 23 skeletally immature patients who underwent ACL reconstruction surgery at ages ranging from 7 to 15 years was evaluated prospectively. The surgical technique was individualized according to the Tanner sexual maturity score. The surgical techniques used were transphyseal reconstruction, partial transphyseal reconstruction and extraphyseal reconstruction. Four patients underwent the extraphyseal technique, seven the partial transphyseal technique and twelve the full transphyseal technique, on the ACL. The postoperative evaluation was based on the Lysholm score, clinical analysis on the knee and the presence of angular deformity or dysmetria of the lower limb. Results the mean Lysholm score was 96.34 (±2.53). None of the patients presented differences in length and/or clinical or radiographic misalignment abnormality of the lower limbs. Conclusion ACL reconstruction using flexor tendon grafts in skeletally immature patients provided satisfactory functional results. Use of individualized surgical techniques according to growth potential did not give rise to physeal lesions capable of causing length discrepancies or misalignments of the lower limbs, even in patients with high growth potential. PMID:26229809

  9. A comparison of ancestral state reconstruction methods for quantitative characters.

    PubMed

    Royer-Carenzi, Manuela; Didier, Gilles

    2016-09-01

    Choosing an ancestral state reconstruction method among the alternatives available for quantitative characters may be puzzling. We present here a comparison of seven of them, namely the maximum likelihood, restricted maximum likelihood, generalized least squares under Brownian, Brownian-with-trend and Ornstein-Uhlenbeck models, phylogenetic independent contrasts and squared parsimony methods. A review of the relations between these methods shows that the maximum likelihood, the restricted maximum likelihood and the generalized least squares under Brownian model infer the same ancestral states and can only be distinguished by the distributions accounting for the reconstruction uncertainty which they provide. The respective accuracy of the methods is assessed over character evolution simulated under a Brownian motion with (and without) directional or stabilizing selection. We give the general form of ancestral state distributions conditioned on leaf states under the simulation models. Ancestral distributions are used first, to give a theoretical lower bound of the expected reconstruction error, and second, to develop an original evaluation scheme which is more efficient than comparing the reconstructed and the simulated states. Our simulations show that: (i) the distributions of the reconstruction uncertainty provided by the methods generally make sense (some more than others); (ii) it is essential to detect the presence of an evolutionary trend and to choose a reconstruction method accordingly; (iii) all the methods show good performances on characters under stabilizing selection; (iv) without trend or stabilizing selection, the maximum likelihood method is generally the most accurate. PMID:27234644

  10. Preconditioning methods for improved convergence rates in iterative reconstructions

    SciTech Connect

    Clinthorne, N.H.; Chiao, Pingchun; Rogers, W.L. . Div. of Nuclear Medicine); Pan, T.S. . Dept. of Nuclear Medicine); Stamos, J.A. . Dept. of Nuclear Engineering)

    1993-03-01

    Because of the characteristics of the tomographic inversion problem, iterative reconstruction techniques often suffer from poor convergence rates--especially at high spatial frequencies. By using preconditioning methods, the convergence properties of most iterative methods can be greatly enhanced without changing their ultimate solution. To increase reconstruction speed, the authors have applied spatially-invariant preconditioning filters that can be designed using the tomographic system response and implemented using 2-D frequency-domain filtering techniques. In a sample application, the authors performed reconstructions from noiseless, simulated projection data, using preconditioned and conventional steepest-descent algorithms. The preconditioned methods demonstrated residuals that were up to a factor of 30 lower than the unassisted algorithms at the same iteration. Applications of these methods to regularized reconstructions from projection data containing Poisson noise showed similar, although not as dramatic, behavior.

  11. Electrospinning polymer blends for biomimetic scaffolds for ACL tissue engineering

    NASA Astrophysics Data System (ADS)

    Garcia, Vanessa Lizeth

    The anterior cruciate ligament (ACL) rupture is one of the most common knee injuries. Current ACL reconstructive strategies consist of using an autograft or an allograft to replace the ligament. However, limitations have led researchers to create tissue engineered grafts, known as scaffolds, through electrospinning. Scaffolds made of natural and synthetic polymer blends have the potential to promote cell adhesion while having strong mechanical properties. However, enzymes found in the knee are known to degrade tissues and affect the healing of intra-articular injuries. Results suggest that the natural polymers used in this study modify the thermal properties and tensile strength of the synthetic polymers when blended. Scanning electron microscopy display bead-free and enzyme biodegradability of the fibers. Raman spectroscopy confirms the presence of the natural and synthetic polymers in the scaffolds while, amino acid analysis present the types of amino acids and their concentrations found in the natural polymers.

  12. Reconstruction-classification method for quantitative photoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Malone, Emma; Powell, Samuel; Cox, Ben T.; Arridge, Simon

    2015-12-01

    We propose a combined reconstruction-classification method for simultaneously recovering absorption and scattering in turbid media from images of absorbed optical energy. This method exploits knowledge that optical parameters are determined by a limited number of classes to iteratively improve their estimate. Numerical experiments show that the proposed approach allows for accurate recovery of absorption and scattering in two and three dimensions, and delivers superior image quality with respect to traditional reconstruction-only approaches.

  13. Baseline Predictors of Health-Related Quality of Life After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Dunn, Warren R.; Wolf, Brian R.; Harrell, Frank E.; Reinke, Emily K.; Huston, Laura J.; Spindler, Kurt P.; Nwosu, Samuel K.; Kaeding, Christopher C.; Parker, Richard D.; Wright, Rick W.; Andrish, Jack T.; McCarty, Eric C.; Amendola, Annunziato; Marx, Robert G.; Wolcott, Michelle L.; Liu, Zhouwen; Alvarez, JoAnn M.

    2015-01-01

    Background: Limited information exists regarding predictors of general quality of life following anterior cruciate ligament (ACL) reconstruction with up to six-year follow-up. We hypothesized that certain variables evaluated at the time of ACL reconstruction will predict the general quality of life as measured by the Short Form-36 (SF-36). Methods: All unilateral ACL reconstructions from 2002 to 2004 in patients currently enrolled in a prospective multicenter cohort were evaluated. Patients preoperatively completed the SF-36 validated outcome instrument. Surgeons documented intra-articular pathological conditions and treatment, as well as the ACL reconstruction surgical technique. At baseline and at a minimum of two and six years postoperatively, patients completed the SF-36. Longitudinal analysis was performed for the two-year and six-year end points. Results: Of the initial 1512 subjects, at least one follow-up questionnaire was obtained from 1411 subjects (93%). The cohort was 44% female, and the median patient age at enrollment was twenty-three years. The mean scores were 41.9 points for the Physical Component Summary (PCS) and 51.7 points for the Mental Component Summary (MCS) at baseline, 53.6 points for the PCS and 52.0 points for the MCS at two years, and 54.0 points for the PCS and 52.4 points for the MCS at six years. Significant predictors of a higher PCS score were a higher baseline PCS score, younger age, lower baseline body mass index, having >50% of the lateral meniscus excised, or having no treatment done on a lateral meniscal tear. In contrast, significant predictors of a lower PCS score were a shorter follow-up time since surgery, revision ACL reconstruction, smoking at baseline, fewer years of education, and chondromalacia of the lateral tibial plateau. The mean utility gained at six years after ACL reconstruction was 5.3 quality-adjusted life years (QALYs). Conclusions: Large improvements in the PCS (with an effect size of 1.2) were noted at two

  14. Systematic Review of Biological Modulation of Healing in Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Fu, Sai-Chuen; Cheuk, Yau-Chuk; Yung, Shu-Hang; Rolf, Christer Gustav; Chan, Kai-Ming

    2014-01-01

    Background: Whether biological modulation is effective to promote healing in anterior cruciate ligament (ACL) reconstruction remains unclear. Purpose: To perform a systematic review of both clinical and experimental evidence of preclinical animal studies on biological modulation to promote healing in ACL reconstruction. Study Design: Systematic review; Level of evidence, 2. Methods: A systematic search was performed using the PubMed, Ovid, and Scopus search engines. Inclusion criteria were clinical and animal studies involving subjects with ACL injury with the use of biological modulation to promote healing outcomes. Methodological quality of clinical studies was evaluated using the Critical Appraisal Skill Programme (CASP) appraisal tool, and animal studies were evaluated by a scoring system based on a published checklist of good animal studies. Results: Ten clinical studies and 50 animal studies were included. Twenty-five included studies were regarded as good quality, with a methodological score ≥5. These studies suggested that transforming growth factor–beta (TGF-β), mesenchymal stem cells, osteogenic factors, and modalities that reduce local inflammation may be beneficial to promote graft healing in ACL reconstruction. Conclusion: This systematic review suggests that biological modulation is able to promote healing on top of surgical treatment for ACL injuries. This treatment strategy chiefly works through promotion of healing at the tunnel-graft interface, but the integrity of the intra-articular midsubstance of the graft would be another target for biological modulation. PMID:26535311

  15. Reconstruction methods for phase-contrast tomography

    SciTech Connect

    Raven, C.

    1997-02-01

    Phase contrast imaging with coherent x-rays can be distinguished in outline imaging and holography, depending on the wavelength {lambda}, the object size d and the object-to-detector distance r. When r << d{sup 2}{lambda}, phase contrast occurs only in regions where the refractive index fastly changes, i.e. at interfaces and edges in the sample. With increasing object-to-detector distance we come in the area of holographic imaging. The image contrast outside the shadow region of the object is due to interference of the direct, undiffracted beam and a beam diffracted by the object, or, in terms of holography, the interference of a reference wave with the object wave. Both, outline imaging and holography, offer the possibility to obtain three dimensional information of the sample in conjunction with a tomographic technique. But the data treatment and the kind of information one can obtain from the reconstruction is different.

  16. Anterior cruciate ligament- specialized post-operative return-to-sports (ACL-SPORTS) training: a randomized control trial

    PubMed Central

    2013-01-01

    Background Anterior cruciate ligament reconstruction (ACLR) is standard practice for athletes that wish to return to high-level activities; however functional outcomes after ACLR are poor. Quadriceps strength weakness, abnormal movement patterns and below normal knee function is reported in the months and years after ACLR. Second ACL injuries are common with even worse outcomes than primary ACLR. Modifiable limb-to-limb asymmetries have been identified in individuals who re-injure after primary ACLR, suggesting a neuromuscular training program is needed to improve post-operative outcomes. Pre-operative perturbation training, a neuromuscular training program, has been successful at improving limb symmetry prior to surgery, though benefits are not lasting after surgery. Implementing perturbation training after surgery may be successful in addressing post-operative deficits that contribute to poor functional outcomes and second ACL injury risk. Methods/Design 80 athletes that have undergone a unilateral ACLR and wish to return to level 1 or 2 activities will be recruited for this study and randomized to one of two treatment groups. A standard care group will receive prevention exercises, quadriceps strengthening and agility exercises, while the perturbation group will receive the same exercise program with the addition of perturbation training. The primary outcomes measures will include gait biomechanics, clinical and functional measures, and knee joint loading. Return to sport rates, return to pre-injury level of activity rates, and second injury rates will be secondary measures. Discussion The results of this ACL-Specialized Post-Operative Return To Sports (ACL-SPORTS) Training program will help clinicians to better determine an effective post-operative treatment program that will improve modifiable impairments that influence outcomes after ACLR. Trial registration Randomized Control Trial NIH 5R01AR048212-07. ClinicalTrials.gov: NCT01773317 PMID:23522373

  17. Multicenter Orthopaedic Outcome Network Early Anti-inflammatory Treatment in Patients with Acute ACL Tear” (MOON-AAA) Clinical Trial

    PubMed Central

    Lattermann, Christian; Proffitt, Mary; Huston, Laura J.; Gammon, Lee; Johnson, Darren L.; Kraus, Virginia B.; Spindler, Kurt P.

    2016-01-01

    Objectives: We present the early results from the “Multicenter Orthopaedic Outcome Network Early Anti-inflammatory Treatment in Patients with Acute ACL Tear and Painful Effusions” (MOON-AAA) clinical trial (figure 1). This trial allows for a well controlled prospective cohort of patients with isolated ACL injury at risk for OA. We compared the effect of a single versus a repeated dosage of Kenalog within the first two weeks after ACL injury and its effect on chondral degradation in the first 4 weeks prior to surgical reconstruction of the ACL. Methods: 49 patients with isolated ACL tears were enrolled. Knee joints were aspirated and patients received an injection with 40 mg Kenalog either within 4 days, 10 days, both time points or not at all (saline injection control). Serum, synovial fluid and urine were collected at 3 time points. Permutated block randomization, triple blinding, independent monitoring and standardized x-ray was performed to comply with GCP standards. Patient reported outcomes were collected at 6 time points up to 6 months post-ACL reconstruction(IKDC, KOOS and Marx activity level). A standardized synovial fluid biomarker panel was analyzed according to OARSI guidelines. Statistical analysis were performed using SAS mixed models analysis. Results: Serum analysis shows significant change after injury. Chondrodegradatory markers such as CTX-II, MMP-1 and MMP-3 as well as COMP indicate a progressive destruction of chondral matrix and collagen breakdown . There is a dramatic (250%) increase of CTX-II in the first 4 weeks. Matrix proteins such as MMP-1 and 3 as well as COMP show an initial increase and then a steep decline (see figure 1). Inflammatory markers (IL-1 alpha, IL-1beta, IRAP) show a decline from the time of injury. IL-1 alpha, however shows a dramatic uptake after week 2. This longitudinal data confirms a dramatic onset of early osteoarthritic biomarker profiles immediately after ACL injury as measured in synovial fluid

  18. New method for 3D reconstruction in digital tomosynthesis

    NASA Astrophysics Data System (ADS)

    Claus, Bernhard E. H.; Eberhard, Jeffrey W.

    2002-05-01

    Digital tomosynthesis mammography is an advanced x-ray application that can provide detailed 3D information about the imaged breast. We introduce a novel reconstruction method based on simple backprojection, which yields high contrast reconstructions with reduced artifacts at a relatively low computational complexity. The first step in the proposed reconstruction method is a simple backprojection with an order statistics-based operator (e.g., minimum) used for combining the backprojected images into a reconstructed slice. Accordingly, a given pixel value does generally not contribute to all slices. The percentage of slices where a given pixel value does not contribute, as well as the associated reconstructed values, are collected. Using a form of re-projection consistency constraint, one now updates the projection images, and repeats the order statistics backprojection reconstruction step, but now using the enhanced projection images calculated in the first step. In our digital mammography application, this new approach enhances the contrast of structures in the reconstruction, and allows in particular to recover the loss in signal level due to reduced tissue thickness near the skinline, while keeping artifacts to a minimum. We present results obtained with the algorithm for phantom images.

  19. Anatomic Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Murawski, Christopher D.; Wolf, Megan R.; Araki, Daisuke; Muller, Bart; Tashman, Scott

    2013-01-01

    Anatomic anterior cruciate ligament (ACL) reconstruction is common procedure performed by orthopedic surgeons, particularly in association with sports-related injuries. Whereas traditional reconstruction techniques used a single bundle graft that was typically placed in a non-anatomic position, a renewed interest in anatomy has facilitated the popularization of anatomic reconstruction techniques. Recently, a focus has been placed on individualizing ACL surgery based on each patient’s native anatomical characteristics (e.g., insertion site size, notch size, and shape), thereby dictating the ultimate procedure of choice. As subjective outcome measurements have demonstrated varying outcomes with respect to single- versus double-bundle ACL reconstruction, investigators have turned to more objective techniques, such as in vivo kinematics, as a means of evaluating joint motion and cartilage contact mechanics. Further investigation in this area may yield important information with regard to the potential progression to osteoarthritis after ACL reconstruction, including factors affecting or preventing it. PMID:26069663

  20. Sex, Age, and Graft Size as Predictors of ACL Re-tear

    PubMed Central

    Nguyen, Duong

    2016-01-01

    Objectives: The minimum size required for a successful quadrupled hamstring autograft ACL reconstruction remains controversial. The risks of ACL re-tear in younger patients who tend to participate in a higher level of sports activity, and female athletes who have numerous predisposing factors, are poorly defined. Purpose: To identify risk factors for graft re-tears within 2 years of ACL surgery. The hypotheses are that female sex, a smaller size graft, and younger patients will increase the odds of failure. Study Design Cohort Study. Level of evidence, 3. Methods: A cohort of 503 athletes undergoing primary, autograft hamstring ACL reconstruction, performed by a single surgeon using the same surgical technique and rehabilitation protocol, between September-December 2012, was followed for a total duration of 2 years. Return to play was allowed between 6 and 12 months post-surgery upon completion of functional testing. Exclusion criteria included infections, revisions, double bundle techniques, multi-ligament injuries, non-compliance, BTB/allografts/hybrid grafts. Primary outcome consisted of binary data (ACL graft re-tear or no tear) as measured on physical exam (Lachman and pivot shift) and MRI. Multivariate logistic regression statistical analysis with model fitting was used to investigate the predictive value of sex, age, and graft size on ACL re-tear. Secondary sensitivity analyses were performed on the adolescent subgroup, age and graft size as categorical variables, and testing for interactions among variables. Sample size was calculated based on the rule of 10 events per independent variable for logistic regression. Results: The mean age of the 503 athletes was 27.5 (SD 10.6; range = 12-61). There were 235 females (47%) and 268 males (53%) with a 6% rate of re-tears (28 patients; 17 females). Mean graft size was 7.9 (SD 0.6; range = 6-10). Univariate analyses of graft size, sex, and age only in the model showed that younger age (odds ratio [OR] = 0.86; 95

  1. Long-term Outcomes After Anterior Cruciate Ligament Reconstruction in Patients 60 Years and Older

    PubMed Central

    Baker, Champ L.; Jones, Jaclyn C.; Zhang, Jeff

    2014-01-01

    Background: Studies evaluating the benefit of surgical reconstruction of the anterior cruciate ligament (ACL) in middle-aged patients have shown promising results, but study populations were limited primarily to patients who were 40 to 60 years old. Some authors have suggested that surgery may benefit these older patients. Hypothesis: Patients aged ≥60 years with functional instability after ACL injury would benefit from ACL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: Medical records from 1984 through 2010 were searched for patients aged ≥60 years who had undergone primary arthroscopic ACL reconstruction at a single institution. Fifteen patients (15 knees) were identified as meeting the above criteria. All patients were contacted for a telephone interview, and they completed Short Form–36 and modified Cincinnati Knee Score forms. One patient was deceased, and 1 had undergone revision to total knee arthroplasty. Among the remaining 13 patients, the mean age at surgery was 63.5 years (range, 60-73 years), and the mean patient age at the time of follow-up was 73 years (range, 65-85 years). Preoperative radiographs showed no obvious evidence of arthritis in 10 (77%) of the 13 patients; small osteophytes without loss of joint space were seen in 3 (23%) patients. The mean length of follow up was 115.7 months (range, 53-193 months). Results: At their last clinic visits, all 13 patients had regained full range of motion and returned to sports or exercise, such as tennis, golf, gym exercise, and yoga. Twelve patients reported no joint laxity. Conclusion: Patients aged ≥60 years with symptomatic instability from ACL injury can have good to excellent subjective outcomes with surgical reconstruction. Clinical Relevance: Physicians who treat active patients older than 60 years should not exclude ACL reconstruction based on the patient’s age alone. PMID:26535289

  2. Outcome of Simultaneous Arthroscopic Anterior Cruciate Ligament and Posterior Cruciate Ligament Reconstruction With Hamstring Tendon Autograft: A Multicenter Prospective Study

    PubMed Central

    Panigrahi, Ranajit; Kumari Mahapatra, Amita; Priyadarshi, Ashok; Singha Das, Dibya; Palo, Nishit; Ranjan Biswal, Manas

    2016-01-01

    Background: Multiligamentous injuries of knee are a complex problem in orthopaedics. Combined ACL-PCL injuries are uncommon, usually associated with knee dislocations. Extremity vascular status is essential because of possible arterio-venous compromise. These complex injuries require a systematic evaluation and treatment. Single setting simultaneous arthroscopic ACL and PCL reconstruction or a staged approach can be adopted to treat these cases. Objectives: To evaluate functional outcome of simultaneous arthroscopic ACL and PCL reconstruction with hamstring tendon autograft in multiligamentous knee injuries. Patients and Methods: This prospective study was performed on 20 patients with combined ACL-PCL injuries who underwent simultaneous arthroscopic ACL-PCL reconstruction with hamstring tendon. Evaluation of functional outcome was by IKDC and Lysholm-Tegner scores. Results: In 20 patients, mean age 34 years, return to full-time work and to full sports was 8 weeks and 6.2 months respectively. All patients had full range of motion except 2 patients with < 5 degrees flexion loss; 90% had negative Lachmann test; 95% had negative pivot shift and 10% patients had mild posterior drawer at 90 degrees (1+) at final follow up. Mean IKDC score was 90 (range 81 - 94); mean Tegner activity score was 7 and mean Lysholm knee score was 89. 85% returned to preinjury activity level and a 90% satisfaction rate. Conclusions: Simultaneous arthroscopic ACL and PCL reconstructions using hamstring tendon for combined ACL and PCL injuries is a clinically effective, safe, time saving and cost-effective procedure with better patient compliance and reproducible for a timely return of motion, strength, and function with favorable outcome. PMID:27217932

  3. RADIOLOGICAL ANALYSIS OF BONE TUNNEL POSITION IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION SURGERY: COMPARISON BETWEEN THE OPEN TECHNIQUE AND ARTHROSCOPY VIA AN ANTEROMEDIAL PORTAL

    PubMed Central

    Dambrós, Jean Marcel; Florêncio, Rodrigo; Júnior, Osmar Valadão Lopes; Kuhn, André; Saggin, José; de Freitas Spinelli, Leandro

    2015-01-01

    Objectives: To evaluate and compare bone tunnel positioning in anterior cruciate ligament (ACL) reconstruction surgery using the arthroscopic technique and the open technique consisting of arthrotomy. Method: A comparative retrospective study on 70 patients with ACL lesions was conducted. Thirty-five patients underwent ACL reconstruction by means of the open technique and 35 by means of the arthroscopic technique using an anteromedial portal. All the patients underwent ACL reconstruction using an autologous graft from the middle third of the patellar tendon, fixed using interference screws. The postoperative radiographs were reviewed and the positioning of the femoral tunnel was evaluated using the methods proposed by Harner et al. and Aglietti et al., while the tibial tunnel was assessed using the method proposed by Rauschning and Stäubli. Results: Fifty-four of the patients were male and 16 were female. Their mean age at the time of the procedure was 34 years and 3 months, with a range from 17 to 58 years. The arthroscopic technique was shown to be more accurate than the open technique for positioning both the femoral and the tibial bone tunnels. Conclusions: Radiological analysis on the knees subjected to ACL reconstruction showed that the positioning of both the femoral and the tibial bone tunnels presented less variation when the surgery was performed arthroscopically. PMID:27027019

  4. Anterior cruciate ligament reconstruction and rehabilitation: predictors of functional outcome

    PubMed Central

    DELLA VILLA, FRANCESCO; RICCI, MARGHERITA; PERDISA, FRANCESCO; FILARDO, GIUSEPPE; GAMBERINI, JACOPO; CAMINATI, DANIELE; DELLA VILLA, STEFANO

    2015-01-01

    Surgical reconstruction of an injured anterior cruciate ligament (ACL) leads to full recovery of function and sports activity in a high percentage of cases. The aim of the present study was to analyze variables related to the patient, the surgical technique and the post-surgical rehabilitation methods, seeking to identify predictors of outcome and recovery time after ACL reconstruction. One hundred and four patients (81 M, 23 F) undergoing a step-based rehabilitation protocol after ACL reconstruction were evaluated. 43.2% of them had an isolated ACL lesion, whereas 56.8% had one or more concurrent injuries. Data relating to personal characteristics, surgery and post-operative management were collected and analyzed for correlation. Clinical outcome was evaluated with IKDC subjective score and the Tegner score, and the time to reach full recovery was noted as well. Young patients with a higher pre-injury Tegner activity level or who practice sport at professional level, no concurrent capsular lesions and no postoperative knee bracing had better clinical results and took shorter time to recover. Also, a higher percentage of on-the-field rehabilitation sessions, and absence of significant muscle strength deficits at the first knee isokinetic test emerged as rehabilitation-related factors leading to a better post-surgical outcome. Personal, surgical and rehabilitation factors should be considered in order to optimize patient management and maximize the expected results. Further studies are needed to find the strongest factors in different patients. Level of evidence Level IV, retrospective study. PMID:26904523

  5. Trends in Anterior Cruciate Ligament Reconstruction in the United States

    PubMed Central

    Buller, Leonard T.; Best, Matthew J.; Baraga, Michael G.; Kaplan, Lee D.

    2014-01-01

    Background: The anterior cruciate ligament (ACL) is the most frequently injured ligament in the knee for which surgery is performed. United States national estimates of ACL reconstruction vary widely. Purpose: This study sought to use the most recently available Centers for Disease Control and Prevention data to investigate changes in the utilization of inpatient and ambulatory surgery for ACL tears in the United States. Study Design: Descriptive epidemiology study. Methods: The National Survey of Ambulatory Surgery, conducted in 1994, 1995, 1996, and 2006 (data from 1994, 1996, and 2006 were used in the study), and the National Hospital Discharge Survey, conducted between 1990 and 2007, were used to identify cases of ACL reconstruction. The data were analyzed for trends in demographics, treatment, and utilization. Results: Between 1994 and 2006, the population-adjusted estimate of the rate of ACL reconstructions increased by 37% (33.0/100,000 capita or 86,837 total procedures to 45.1/100,000 capita or 134,421 total procedures). There was an increase in the proportion of females undergoing reconstruction in both the ambulatory (30% to 40%) and inpatient (29% to 47%) settings over the study period, with a 304% increase in the sex-adjusted estimate of the rate of female ambulatory procedures between 1994 and 2006. Age-adjusted estimates of the rates of ambulatory ACL reconstruction increased among all age groups, with a 924% increase in patients less than 15 years of age. Concurrent meniscectomy remained relatively constant in the ambulatory (37% to 40%) and inpatient (37% to 33%) settings between 1994 and 2007. Private insurance was the largest compensator, representing 77% of cases in 2006. Between 1994 and 2006, the use of peripheral nerve blocks during ambulatory surgery increased from 0.7% to 30.8%. Conclusion: The rate of ACL reconstruction increased dramatically between 1990 and 2007 based on the National Survey of Ambulatory Surgery and National Hospital

  6. Anterior Cruciate Ligament Reconstruction Using a Combination of Autograft and Allograft Tendon

    PubMed Central

    Darnley, James E.; Léger-St-Jean, Benjamin; Pedroza, Angela D.; Flanigan, David C.; Kaeding, Christopher C.; Magnussen, Robert A.

    2016-01-01

    Background: Anterior cruciate ligament (ACL) reconstruction with hamstring autografts less than 8.5 mm in diameter is associated with worse patient-reported outcome scores and increased risk of revision surgery compared with reconstructions performed with larger grafts. One proposed solution to small autograft harvest is to create a hybrid graft by augmenting autografts with allograft tissue to increase graft diameter. Purpose: To compare hybrid autograft/allograft ACL reconstruction to autograft ACL reconstruction, specifically analyzing the patient-reported outcome scores and the risk of revision surgery at 2 years postoperative. Study Design: Cohort study; Level of evidence, 3. Methods: From the years 2002 to 2009, a total of 34 patients were identified from a prospectively collected database as having undergone hybrid ACL reconstruction. Twenty-seven of 34 (79.4%) patients had a 2-year follow-up. These 27 patients were matched by age (within 1 year) and sex to 27 patients who underwent hamstring autograft ACL reconstruction during the same period. At the 2-year mark, revision surgery risk and patient-reported outcome scores were compared between the 2 groups. Results: The mean age for the hybrid and matched groups (±SD) was 20.9 ± 7.0 years. Both the hybrid and control groups had 17 males and 10 females. There was no significant difference in preoperative patient-reported outcome scores, meniscus tears, or cartilage lesions between the 2 groups. Graft size was larger in the hybrid group (9.5 ± 0.6 mm) than in the autograft group (8.4 ± 0.9 mm) (P < .001). At 2 years postoperative, patient-reported outcome scores were similar between the hybrid and autograft groups. Revision surgery was required in 5 (18.5%) patients who underwent hybrid reconstruction compared with 2 (7.4%) of those who underwent autograft reconstruction (P = .26). Conclusion: Patients who undergo ACL reconstruction with hybrid hamstring grafts and hamstring autografts report similar

  7. Revision Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Wilde, Jeffrey; Bedi, Asheesh; Altchek, David W.

    2014-01-01

    Context: Reconstruction of the anterior cruciate ligament (ACL) is one of the most common surgical procedures, with more than 200,000 ACL tears occurring annually. Although primary ACL reconstruction is a successful operation, success rates still range from 75% to 97%. Consequently, several thousand revision ACL reconstructions are performed annually and are unfortunately associated with inferior clinical outcomes when compared with primary reconstructions. Evidence Acquisition: Data were obtained from peer-reviewed literature through a search of the PubMed database (1988-2013) as well as from textbook chapters and surgical technique papers. Study Design: Clinical review. Level of Evidence: Level 4. Results: The clinical outcomes after revision ACL reconstruction are largely based on level IV case series. Much of the existing literature is heterogenous with regard to patient populations, primary and revision surgical techniques, concomitant ligamentous injuries, and additional procedures performed at the time of the revision, which limits generalizability. Nevertheless, there is a general consensus that the outcomes for revision ACL reconstruction are inferior to primary reconstruction. Conclusion: Excellent results can be achieved with regard to graft stability, return to play, and functional knee instability but are generally inferior to primary ACL reconstruction. A staged approach with autograft reconstruction is recommended in any circumstance in which a single-stage approach results in suboptimal graft selection, tunnel position, graft fixation, or biological milieu for tendon-bone healing. Strength-of-Recommendation Taxonomy (SORT): Good results may still be achieved with regard to graft stability, return to play, and functional knee instability, but results are generally inferior to primary ACL reconstruction: Level B. PMID:25364483

  8. Reconstruction of radiating sound fields using minimum energy method.

    PubMed

    Bader, Rolf

    2010-01-01

    A method for reconstructing a pressure field at the surface of a radiating body or source is presented using recording data of a microphone array. The radiation is assumed to consist of many spherical radiators, as microphone positions are present in the array. These monopoles are weighted using a parameter alpha, which broadens or narrows the overall radiation directivity as an effective and highly intuitive parameter of the radiation characteristics. A radiation matrix is built out of these weighted monopole radiators, and for different assumed values of alpha, a linear equation solver reconstructs the pressure field at the body's surface. It appears that from these many arbitrary reconstructions, the correct one minimizes the reconstruction energy. The method is tested, localizing the radiation points of a Balinese suling flute, reconstructing complex radiation from a duff frame drum, and determining the radiation directivity for the first seven modes of an Usbek tambourine. Stability in terms of measurement noise is demonstrated for the plain method, and additional highly effective algorithm is added for a noise level up to 0 dB. The stability of alpha in terms of minimal reconstruction energy is shown over the whole range of possible values for alpha. Additionally, the treatment of unwanted room reflections is discussed, still leading to satisfactory results in many cases. PMID:20058977

  9. Yeast Ancestral Genome Reconstructions: The Possibilities of Computational Methods

    NASA Astrophysics Data System (ADS)

    Tannier, Eric

    In 2006, a debate has risen on the question of the efficiency of bioinformatics methods to reconstruct mammalian ancestral genomes. Three years later, Gordon et al. (PLoS Genetics, 5(5), 2009) chose not to use automatic methods to build up the genome of a 100 million year old Saccharomyces cerevisiae ancestor. Their manually constructed ancestor provides a reference genome to test whether automatic methods are indeed unable to approach confident reconstructions. Adapting several methodological frameworks to the same yeast gene order data, I discuss the possibilities, differences and similarities of the available algorithms for ancestral genome reconstructions. The methods can be classified into two types: local and global. Studying the properties of both helps to clarify what we can expect from their usage. Both methods propose contiguous ancestral regions that come very close (> 95% identity) to the manually predicted ancestral yeast chromosomes, with a good coverage of the extant genomes.

  10. A Comparison of Methods for Ocean Reconstruction from Sparse Observations

    NASA Astrophysics Data System (ADS)

    Streletz, G. J.; Kronenberger, M.; Weber, C.; Gebbie, G.; Hagen, H.; Garth, C.; Hamann, B.; Kreylos, O.; Kellogg, L. H.; Spero, H. J.

    2014-12-01

    We present a comparison of two methods for developing reconstructions of oceanic scalar property fields from sparse scattered observations. Observed data from deep sea core samples provide valuable information regarding the properties of oceans in the past. However, because the locations of sample sites are distributed on the ocean floor in a sparse and irregular manner, developing a global ocean reconstruction is a difficult task. Our methods include a flow-based and a moving least squares -based approximation method. The flow-based method augments the process of interpolating or approximating scattered scalar data by incorporating known flow information. The scheme exploits this additional knowledge to define a non-Euclidean distance measure between points in the spatial domain. This distance measure is used to create a reconstruction of the desired scalar field on the spatial domain. The resulting reconstruction thus incorporates information from both the scattered samples and the known flow field. The second method does not assume a known flow field, but rather works solely with the observed scattered samples. It is based on a modification of the moving least squares approach, a weighted least squares approximation method that blends local approximations into a global result. The modifications target the selection of data used for these local approximations and the construction of the weighting function. The definition of distance used in the weighting function is crucial for this method, so we use a machine learning approach to determine a set of near-optimal parameters for the weighting. We have implemented both of the reconstruction methods and have tested them using several sparse oceanographic datasets. Based upon these studies, we discuss the advantages and disadvantages of each method and suggest possible ways to combine aspects of both methods in order to achieve an overall high-quality reconstruction.

  11. Cheng's method for reconstruction of a functionally sensitive penis.

    PubMed

    Cheng, K X; Zhang, R H; Zhou, S; Jiang, K C; Eid, A E; Huang, W Y

    1997-01-01

    This article introduces a new surgical method for one-stage reconstruction of the penis. It is applied to the reconstruction of the microphallus as well as to traumatic cases with the residual stump of the amputated penis not less than 3 cm long. By transferring the original glans or the residual penile stump to the anterior portion of the newly reconstructed penile body with microsurgical techniques, we have thus rebuilt a penis with more satisfactory results in both appearance and erotic sensation. Seven patients are reported here who were operated on by this method and who have been followed up for 18 months to 10 years. The good results achieved and the method's advantages over other methods are demonstrated and discussed. PMID:8982190

  12. Digital holographic method for tomography-image reconstruction

    NASA Astrophysics Data System (ADS)

    Liu, Cheng; Yan, Changchun; Gao, Shumei

    2004-02-01

    A digital holographic method for three-dimensional reconstruction of tomography images is demonstrated theoretically and experimentally. In this proposed method, a numerical hologram is first computed by calculating the total diffraction field of all transect images of a detected organ. Then, the numerical hologram is transferred to the usual recording medium to generate a physical hologram. Last, all the transect images are reconstructed in their original position by illuminating the physical hologram with a laser, thereby forming a three-dimensional transparent image of the organ detected. Due to its true third dimension, the reconstructed image using this method is much more vivid and accurate than that of other methods. Potentially, it may have great prospects for application in medical engineering.

  13. Path method for reconstructing images in fluorescence optical tomography

    SciTech Connect

    Kravtsenyuk, Olga V; Lyubimov, Vladimir V; Kalintseva, Natalie A

    2006-11-30

    A reconstruction method elaborated for the optical diffusion tomography of the internal structure of objects containing absorbing and scattering inhomogeneities is considered. The method is developed for studying objects with fluorescing inhomogeneities and can be used for imaging of distributions of artificial fluorophores whose aggregations indicate the presence of various diseases or pathological deviations. (special issue devoted to multiple radiation scattering in random media)

  14. Matrix-based image reconstruction methods for tomography

    SciTech Connect

    Llacer, J.; Meng, J.D.

    1984-10-01

    Matrix methods of image reconstruction have not been used, in general, because of the large size of practical matrices, ill condition upon inversion and the success of Fourier-based techniques. An exception is the work that has been done at the Lawrence Berkeley Laboratory for imaging with accelerated radioactive ions. An extension of that work into more general imaging problems shows that, with a correct formulation of the problem, positron tomography with ring geometries results in well behaved matrices which can be used for image reconstruction with no distortion of the point response in the field of view and flexibility in the design of the instrument. Maximum Likelihood Estimator methods of reconstruction, which use the system matrices tailored to specific instruments and do not need matrix inversion, are shown to result in good preliminary images. A parallel processing computer structure based on multiple inexpensive microprocessors is proposed as a system to implement the matrix-MLE methods. 14 references, 7 figures.

  15. Sparse Reconstruction for Bioluminescence Tomography Based on the Semigreedy Method

    PubMed Central

    Guo, Wei; Jia, Kebin; Zhang, Qian; Liu, Xueyan; Feng, Jinchao; Qin, Chenghu; Ma, Xibo; Yang, Xin; Tian, Jie

    2012-01-01

    Bioluminescence tomography (BLT) is a molecular imaging modality which can three-dimensionally resolve the molecular processes in small animals in vivo. The ill-posedness nature of BLT problem makes its reconstruction bears nonunique solution and is sensitive to noise. In this paper, we proposed a sparse BLT reconstruction algorithm based on semigreedy method. To reduce the ill-posedness and computational cost, the optimal permissible source region was automatically chosen by using an iterative search tree. The proposed method obtained fast and stable source reconstruction from the whole body and imposed constraint without using a regularization penalty term. Numerical simulations on a mouse atlas, and in vivo mouse experiments were conducted to validate the effectiveness and potential of the method. PMID:22927887

  16. A fast-convergence POCS seismic denoising and reconstruction method

    NASA Astrophysics Data System (ADS)

    Ge, Zi-Jian; Li, Jing-Ye; Pan, Shu-Lin; Chen, Xiao-Hong

    2015-06-01

    The efficiency, precision, and denoising capabilities of reconstruction algorithms are critical to seismic data processing. Based on the Fourier-domain projection onto convex sets (POCS) algorithm, we propose an inversely proportional threshold model that defines the optimum threshold, in which the descent rate is larger than in the exponential threshold in the large-coefficient section and slower than in the exponential threshold in the small-coefficient section. Thus, the computation efficiency of the POCS seismic reconstruction greatly improves without affecting the reconstructed precision of weak reflections. To improve the flexibility of the inversely proportional threshold, we obtain the optimal threshold by using an adjustable dependent variable in the denominator of the inversely proportional threshold model. For random noise attenuation by completing the missing traces in seismic data reconstruction, we present a weighted reinsertion strategy based on the data-driven model that can be obtained by using the percentage of the data-driven threshold in each iteration in the threshold section. We apply the proposed POCS reconstruction method to 3D synthetic and field data. The results suggest that the inversely proportional threshold model improves the computational efficiency and precision compared with the traditional threshold models; furthermore, the proposed reinserting weight strategy increases the SNR of the reconstructed data.

  17. MR Image Reconstruction Using Block Matching and Adaptive Kernel Methods

    PubMed Central

    Schmidt, Johannes F. M.; Santelli, Claudio; Kozerke, Sebastian

    2016-01-01

    An approach to Magnetic Resonance (MR) image reconstruction from undersampled data is proposed. Undersampling artifacts are removed using an iterative thresholding algorithm applied to nonlinearly transformed image block arrays. Each block array is transformed using kernel principal component analysis where the contribution of each image block to the transform depends in a nonlinear fashion on the distance to other image blocks. Elimination of undersampling artifacts is achieved by conventional principal component analysis in the nonlinear transform domain, projection onto the main components and back-mapping into the image domain. Iterative image reconstruction is performed by interleaving the proposed undersampling artifact removal step and gradient updates enforcing consistency with acquired k-space data. The algorithm is evaluated using retrospectively undersampled MR cardiac cine data and compared to k-t SPARSE-SENSE, block matching with spatial Fourier filtering and k-t ℓ1-SPIRiT reconstruction. Evaluation of image quality and root-mean-squared-error (RMSE) reveal improved image reconstruction for up to 8-fold undersampled data with the proposed approach relative to k-t SPARSE-SENSE, block matching with spatial Fourier filtering and k-t ℓ1-SPIRiT. In conclusion, block matching and kernel methods can be used for effective removal of undersampling artifacts in MR image reconstruction and outperform methods using standard compressed sensing and ℓ1-regularized parallel imaging methods. PMID:27116675

  18. MR Image Reconstruction Using Block Matching and Adaptive Kernel Methods.

    PubMed

    Schmidt, Johannes F M; Santelli, Claudio; Kozerke, Sebastian

    2016-01-01

    An approach to Magnetic Resonance (MR) image reconstruction from undersampled data is proposed. Undersampling artifacts are removed using an iterative thresholding algorithm applied to nonlinearly transformed image block arrays. Each block array is transformed using kernel principal component analysis where the contribution of each image block to the transform depends in a nonlinear fashion on the distance to other image blocks. Elimination of undersampling artifacts is achieved by conventional principal component analysis in the nonlinear transform domain, projection onto the main components and back-mapping into the image domain. Iterative image reconstruction is performed by interleaving the proposed undersampling artifact removal step and gradient updates enforcing consistency with acquired k-space data. The algorithm is evaluated using retrospectively undersampled MR cardiac cine data and compared to k-t SPARSE-SENSE, block matching with spatial Fourier filtering and k-t ℓ1-SPIRiT reconstruction. Evaluation of image quality and root-mean-squared-error (RMSE) reveal improved image reconstruction for up to 8-fold undersampled data with the proposed approach relative to k-t SPARSE-SENSE, block matching with spatial Fourier filtering and k-t ℓ1-SPIRiT. In conclusion, block matching and kernel methods can be used for effective removal of undersampling artifacts in MR image reconstruction and outperform methods using standard compressed sensing and ℓ1-regularized parallel imaging methods. PMID:27116675

  19. Operative and nonoperative treatment options for ACL tears in the adult patient: a conceptual review.

    PubMed

    Bogunovic, Ljiljana; Matava, Matthew J

    2013-11-01

    Injury to the anterior cruciate ligament (ACL) is common among athletic individuals. Both nonoperative and operative treatment options exist. The optimal treatment of an adult with an ACL tear depends on several patient-specific factors, including age, occupation, and desired activity level. In less active patients with sedentary jobs, nonoperative management, consisting of physical therapy, bracing, and activity modification can yield successful results. In active patients who want to resume participation in jumping, cutting, or pivoting sports, patients who have physically demanding occupations, or patients who fail a trial of nonoperative management, ACL reconstruction is recommended. Reconstruction utilizing autograft tissue is preferred over allograft, especially in the younger athlete, but allograft tissue is a reasonable option in the older (aged > 40 years) and less active adult, as well. Successful results have been achieved with both patellar tendon and hamstring grafts. The optimal treatment in adult patients with ACL tears should be based on careful consideration of the patient's goals for return to activity, knee-specific comorbidities, such as coexistent meniscal pathology or osteoarthritis, and his or her willingness to follow a detailed rehabilitation regimen. Our article provides an overview of current nonoperative and operative treatment options for adults with ACL tears, considers the outcomes of both nonoperative and operative strategies, and provides general recommendations as to the ideal management for a given patient. PMID:24231595

  20. An Event Reconstruction Method for the Telescope Array Fluorescence Detectors

    SciTech Connect

    Fujii, T.; Ogio, S.; Yamazaki, K.; Fukushima, M.; Ikeda, D.; Sagawa, H.; Takahashi, Y.; Tameda, Y.; Hayashi, K.; Ishimori, R.; Kobayashi, Y.; Tokuno, H.; Tsunesada, Y.; Honda, K.; Tomida, T.; Udo, S.

    2011-09-22

    We measure arrival directions, energies and mass composition of ultra-high energy cosmic rays with air fluorescence detector telescopes. The longitudinal profile of the cosmic ray induced extensive air shower cascade is imaged on focal plane of the telescope camera. Here, we show an event reconstruction method to obtain the primary information from data collected by the Telescope Array Fluorescence Detectors. In particular, we report on an ''Inverse Monte Carlo (IMC)'' method in which the reconstruction process searches for an optimum solution via repeated Monte Carlo simulations including characteristics of all detectors, atmospheric conditions, photon emission and scattering processes.

  1. Tomographic fluorescence reconstruction by a spectral projected gradient pursuit method

    NASA Astrophysics Data System (ADS)

    Ye, Jinzuo; An, Yu; Mao, Yamin; Jiang, Shixin; Yang, Xin; Chi, Chongwei; Tian, Jie

    2015-03-01

    In vivo fluorescence molecular imaging (FMI) has played an increasingly important role in biomedical research of preclinical area. Fluorescence molecular tomography (FMT) further upgrades the two-dimensional FMI optical information to three-dimensional fluorescent source distribution, which can greatly facilitate applications in related studies. However, FMT presents a challenging inverse problem which is quite ill-posed and ill-conditioned. Continuous efforts to develop more practical and efficient methods for FMT reconstruction are still needed. In this paper, a method based on spectral projected gradient pursuit (SPGP) has been proposed for FMT reconstruction. The proposed method was based on the directional pursuit framework. A mathematical strategy named the nonmonotone line search was associated with the SPGP method, which guaranteed the global convergence. In addition, the Barzilai-Borwein step length was utilized to build the new step length of the SPGP method, which was able to speed up the convergence of this gradient method. To evaluate the performance of the proposed method, several heterogeneous simulation experiments including multisource cases as well as comparative analyses have been conducted. The results demonstrated that, the proposed method was able to achieve satisfactory source localizations with a bias less than 1 mm; the computational efficiency of the method was one order of magnitude faster than the contrast method; and the fluorescence reconstructed by the proposed method had a higher contrast to the background than the contrast method. All the results demonstrated the potential for practical FMT applications with the proposed method.

  2. Bubble reconstruction method for wire-mesh sensors measurements

    NASA Astrophysics Data System (ADS)

    Mukin, Roman V.

    2016-08-01

    A new algorithm is presented for post-processing of void fraction measurements with wire-mesh sensors, particularly for identifying and reconstructing bubble surfaces in a two-phase flow. This method is a combination of the bubble recognition algorithm presented in Prasser (Nuclear Eng Des 237(15):1608, 2007) and Poisson surface reconstruction algorithm developed in Kazhdan et al. (Poisson surface reconstruction. In: Proceedings of the fourth eurographics symposium on geometry processing 7, 2006). To verify the proposed technique, a comparison was done of the reconstructed individual bubble shapes with those obtained numerically in Sato and Ničeno (Int J Numer Methods Fluids 70(4):441, 2012). Using the difference between reconstructed and referenced bubble shapes, the accuracy of the proposed algorithm was estimated. At the next step, the algorithm was applied to void fraction measurements performed in Ylönen (High-resolution flow structure measurements in a rod bundle (Diss., Eidgenössische Technische Hochschule ETH Zürich, Nr. 20961, 2013) by means of wire-mesh sensors in a rod bundle geometry. The reconstructed bubble shape yields bubble surface area and volume, hence its Sauter diameter d_{32} as well. Sauter diameter is proved to be more suitable for bubbles size characterization compared to volumetric diameter d_{30}, proved capable to capture the bi-disperse bubble size distribution in the flow. The effect of a spacer grid was studied as well: For the given spacer grid and considered flow rates, bubble size frequency distribution is obtained almost at the same position for all cases, approximately at d_{32} = 3.5 mm. This finding can be related to the specific geometry of the spacer grid or the air injection device applied in the experiments, or even to more fundamental properties of the bubble breakup and coagulation processes. In addition, an application of the new algorithm for reconstruction of a large air-water interface in a tube bundle is

  3. Reconstruction method for curvilinear structures from two views

    NASA Astrophysics Data System (ADS)

    Hoffmann, Matthias; Brost, Alexander; Jakob, Carolin; Koch, Martin; Bourier, Felix; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

    2013-03-01

    Minimally invasive interventions often involve tools of curvilinear shape like catheters and guide-wires. If the camera parameters of a fluoroscopic system or a stereoscopic endoscope are known, a 3-D reconstruction of corresponding points can be computed by triangulation. Manual identification of point correspondences is time consuming, but there exist methods that automatically select corresponding points along curvilinear structures. The focus here is on the evaluation of a recent published method for catheter reconstruction from two views. A previous evaluation of this method using clinical data yielded promising results. For that evaluation, however, no 3-D ground truth data was available such that the error could only be estimated using the forward-projection of the reconstruction. In this paper, we present a more extensive evaluation of this method based on both clinical and phantom data. For the evaluation using clinical images, 36 data sets and two different catheters were available. The mean error found when reconstructing both catheters was 0.1mm +/- 0.1mm. To evaluate the error in 3-D, images of a phantom were acquired from 13 different angulations. For the phantom, A 3D C-arm CT voxel data set of the phantom was also available. A reconstruction error was calculated by comparing the triangulated 3D reconstruction result to the 3D voxel data set. The evaluation yielded an average error of 1.2mm +/- 1.2mm for the circumferential mapping catheter and 1.3mm +/- 1.0mm for the ablation catheter.

  4. Injury patterns in patients presenting with a recurrent anterior cruciate ligament tear following primary reconstruction

    PubMed Central

    Sayampanathan, Andrew A.; Bin Abd Razak, Hamid Rahmatullah; Chong, Hwei Chi; Tan, Hwee-Chye Andrew

    2016-01-01

    Background An anterior cruciate ligament (ACL) graft rupture or a primary ACL injury in the contralateral knee is one of the greatest concerns of patients following primary anterior cruciate ligament reconstruction (ACLR). Our study describes the epidemiology and presence of concomitant meniscal injuries of patients with a graft rupture following primary ACLR or a primary rupture of the contralateral ACL following primary ACLR of the ipsilateral knee. Methods We reviewed the medical records of 42 patients who underwent a second ACLR. ACLR was performed using the ipsilateral semitendinosus and gracilis autograft. Variables extracted included the presence of concomitant MM and LM injuries intra-operatively, the patients’ level of intensity of sport (light, moderate, strenuous), duration of rehabilitation and mechanism of injury (contact, non-contact). Results Twenty-four (57.1%) patients had graft rupture of a previously reconstructed ACL of which 20 (83.3%) were male and 18 (42.9%) patients had a primary ACL tear of the contralateral knee following ACLR of the ipsilateral knee of which 18 (100%) were male. Patient who sustained a graft rupture were younger (29.5 vs. 31.9 years), had a higher body mass index (BMI) (26.42 vs. 25.10 kg/m2) and had a longer time before re-injury (6.18 vs. 4.94 years). Concomitant meniscal injury rates were comparable in both groups and the medial meniscus was injured more often. Conclusions This study describes the demographics of 2nd ACL injuries in the Asian population. Additional studies that investigate the differences in knee anatomy of Asians and Caucasians and their impact on ACL injuries should be performed. PMID:27429958

  5. Method for 3D fibre reconstruction on a microrobotic platform.

    PubMed

    Hirvonen, J; Myllys, M; Kallio, P

    2016-07-01

    Automated handling of a natural fibrous object requires a method for acquiring the three-dimensional geometry of the object, because its dimensions cannot be known beforehand. This paper presents a method for calculating the three-dimensional reconstruction of a paper fibre on a microrobotic platform that contains two microscope cameras. The method is based on detecting curvature changes in the fibre centreline, and using them as the corresponding points between the different views of the images. We test the developed method with four fibre samples and compare the results with the references measured with an X-ray microtomography device. We rotate the samples through 16 different orientations on the platform and calculate the three-dimensional reconstruction to test the repeatability of the algorithm and its sensitivity to the orientation of the sample. We also test the noise sensitivity of the algorithm, and record the mismatch rate of the correspondences provided. We use the iterative closest point algorithm to align the measured three-dimensional reconstructions with the references. The average point-to-point distances between the reconstructed fibre centrelines and the references are 20-30 μm, and the mismatch rate is low. Given the manipulation tolerance, this shows that the method is well suited to automated fibre grasping. This has also been demonstrated with actual grasping experiments. PMID:26695385

  6. Meta-analysis of In vitro and Intra-operative Laxities after Single Bundle and Double Bundle Anterior Cruciate Ligament Reconstructions

    PubMed Central

    Gadikota, Hemanth R; Seon, Jong Keun; Chen, Chih-Hui; Wu, Jia-Lin; Gill, Thomas J; Li, Guoan

    2010-01-01

    Purpose The purpose of this study was to objectively evaluate if the double bundle ACL reconstruction can better restore the normal translational and rotational laxities than the conventional single bundle ACL reconstruction among the reported biomechanical studies. Methods A systematic literature search was conducted to identify in vitro and in vivo (intra-operative) biomechanical studies that compared the laxities (anterior or anteroposterior or rotational) between single and double bundle ACL reconstructions. Due to a large variability among the loading conditions and testing methods used to determine the rotational laxities between the studies, a meta-analysis of rotational laxities was not feasible. Results Seven in vitro and three in vivo studies were included in this analysis based on the predefined inclusion criteria. The overall mean difference calculated by the random effects model in the anteroposterior laxity between the single bundle and double bundle ACL reconstruction techniques at 0°, 30°, 60° and 90° of flexion were 0.99 mm, 0.38 mm, 0.34 mm, and 0.07 mm respectively. No statistical significant difference was noted between the two treatments at all flexion angles. Among the nine studies that compared the rotational laxity of single bundle and double bundle ACL reconstructions, four studies reported that double bundle reconstruction can provide a better rotational control compared to the single bundle reconstruction. The other five studies could not identify any significant difference between the two reconstructions in terms of the rotational laxity. Conclusions Both single and double bundle treatment options for anterior cruciate ligament injury result in similar anteroposterior knee joint laxity at time-zero. No 1 conclusive evidence on the superiority of one reconstruction technique over the other in terms of rotation laxity can be obtained due to several variations in the experimental protocol and the parameters used to measure the

  7. Factors affecting isokinetic muscle strength before and after anterior cruciate ligament reconstruction.

    PubMed

    Yüksel, Halil Yalçin; Erkan, Serkan; Uzun, Macit

    2011-06-01

    The purpose of this study was to evaluate the factors affecting muscle strength of ACL-deficient knees before and after ACL reconstruction. The study included 122 male patients who underwent primary ACL reconstruction with a bone-patellar tendon-bone autograft. Preoperative loss and change in muscle strength in both extensor and flexor muscle groups after ACL reconstruction were calculated separately at 60 degrees/sec and 180 degrees/sec angular velocities. We evaluated the effect of surgical delay on the preoperative deficit and on its change after surgery. Muscle strength change after ACL reconstruction was also evaluated in relation to patient compliance to treatment. The longer the delay of ACL reconstruction the more the muscle strength deficit of flexor and extensor muscles increased. In the ACL deficient knees with high strength deficit, improvement in muscle strength was higher after ACL reconstruction for both muscle groups. When delay of ACL reconstruction was short and the patient was compliant to treatment, flexor muscle strength recovery was early. Shortening the delay to reconstruction had a positive influence on muscle strength after ACL reconstruction when preoperative muscle strength deficit was high. PMID:21846002

  8. An improved reconstruction method for cosmological density fields

    NASA Technical Reports Server (NTRS)

    Gramann, Mirt

    1993-01-01

    This paper proposes some improvements to existing reconstruction methods for recovering the initial linear density and velocity fields of the universe from the present large-scale density distribution. We derive the Eulerian continuity equation in the Zel'dovich approximation and show that, by applying this equation, we can trace the evolution of the gravitational potential of the universe more exactly than is possible with previous approaches based on the Zel'dovich-Bernoulli equation. The improved reconstruction method is tested using N-body simulations. When the Zel'dovich-Bernoulli equation describes the formation of filaments, then the Zel'dovich continuity equation also follows the clustering of clumps inside the filaments. Our reconstruction method recovers the true initial gravitational potential with an rms error about 3 times smaller than previous methods. We examine the recovery of the initial distribution of Fourier components and find the scale at which the recovered phases are scrambled with respect their true initial values. Integrating the Zel'dovich continuity equation back in time, we can improve the spatial resolution of the reconstruction by a factor of about 2.

  9. Reconstructing Program Theories: Methods Available and Problems To Be Solved.

    ERIC Educational Resources Information Center

    Leeuw, Frans L.

    2003-01-01

    Discusses methods for reconstructing theories underlying programs and policies, focusing on three approaches: (1) an empirical approach that focuses on interviews, documents, and argumentational analysis; (2) an approach based on strategic assessment, group dynamics, and dialogue; and (3) an approach based on cognitive and organizational…

  10. Robust Methods for Sensing and Reconstructing Sparse Signals

    ERIC Educational Resources Information Center

    Carrillo, Rafael E.

    2012-01-01

    Compressed sensing (CS) is an emerging signal acquisition framework that goes against the traditional Nyquist sampling paradigm. CS demonstrates that a sparse, or compressible, signal can be acquired using a low rate acquisition process. Since noise is always present in practical data acquisition systems, sensing and reconstruction methods are…

  11. Anatomical Single-bundle Anterior Cruciate Ligament Reconstruction Using a Freehand Transtibial Technique

    PubMed Central

    Nha, Kyung-Wook; Han, Jae-Hwi; Kwon, Jae-Ho; Kang, Kyung-Woon; Park, Hyung-Joon

    2015-01-01

    Purpose In anatomical single-bundle (SB) anterior cruciate ligament (ACL) reconstruction, the traditional transtibial approach can limit anatomical placement of the femoral tunnel. Surgical Technique We present a novel three-point freehand technique that allows for anatomic SB ACL reconstruction with the transtibial technique. Materials and Methods Between January 2012 and December 2012, 55 ACL reconstructions were performed using the three-point freehand technique. All the patients were followed for a minimum of 12 months post-operatively. Clinical evaluation was done using the Lysholm score and International Knee Documentation Committee (IKDC) grade. All patients were analyzed by 3-dimensional computed tomography (3D CT) at 1 week after surgery. Results The mean Lysholm score improved from 68.2±12.7 points preoperatively to 89.2±8.2 points at final follow-up. At final follow-up, the IKDC grade was normal in 42 patients and nearly normal in 13 patients. None of the patients had a positive pivot shift test, anterior drawer test and Lachman test at final follow-up. The anatomical position of the femoral tunnel was confirmed on 3D CT scans. Conclusions The three-point freehand technique for SB transtibial ACL reconstruction is a simple, anatomic technique showing good clinical results. PMID:26060611

  12. Testing the global flow reconstruction method on coupled chaotic oscillators

    NASA Astrophysics Data System (ADS)

    Plachy, Emese; Kolláth, Zoltán

    2010-03-01

    Irregular behaviour of pulsating variable stars may occur due to low dimensional chaos. To determine the quantitative properties of the dynamics in such systems, we apply a suitable time series analysis, the global flow reconstruction method. The robustness of the reconstruction can be tested through the resultant quantities, like Lyapunov dimension and Fourier frequencies. The latter is specially important as it is directly derivable from the observed light curves. We have performed tests using coupled Rossler oscillators to investigate the possible connection between those quantities. In this paper we present our test results.

  13. 3D reconstruction methods of coronal structures by radio observations

    NASA Astrophysics Data System (ADS)

    Aschwanden, Markus J.; Bastian, T. S.; White, Stephen M.

    1992-11-01

    The ability to carry out the three dimensional (3D) reconstruction of structures in the solar corona would represent a major advance in the study of the physical properties in active regions and in flares. Methods which allow a geometric reconstruction of quasistationary coronal structures (for example active region loops) or dynamic structures (for example flaring loops) are described: stereoscopy of multi-day imaging observations by the VLA (Very Large Array); tomography of optically thin emission (in radio or soft x-rays); multifrequency band imaging by the VLA; and tracing of magnetic field lines by propagating electron beams.

  14. Method for image reconstruction of moving radionuclide source distribution

    DOEpatents

    Stolin, Alexander V.; McKisson, John E.; Lee, Seung Joon; Smith, Mark Frederick

    2012-12-18

    A method for image reconstruction of moving radionuclide distributions. Its particular embodiment is for single photon emission computed tomography (SPECT) imaging of awake animals, though its techniques are general enough to be applied to other moving radionuclide distributions as well. The invention eliminates motion and blurring artifacts for image reconstructions of moving source distributions. This opens new avenues in the area of small animal brain imaging with radiotracers, which can now be performed without the perturbing influences of anesthesia or physical restraint on the biological system.

  15. Method for reconstructing the history of pollution emissions

    SciTech Connect

    Not Available

    1986-05-01

    This paper examines the methods for reconstructing the history of pollution emissions. Since very few direct measurements were made in the past, documentary evidence of releases is drawn mainly from the records of economic activity. The available data are integrated into a routing network for the flow of each pollutant, from raw materials through processing, shipment of products, consumption, and finally to waste disposal. This process, called the mass balance approach, is much like reconstructing a fossil skeleton. It was the process was used in the pilot historical study of the pollution of the Hudson region.

  16. 3D reconstruction methods of coronal structures by radio observations

    NASA Technical Reports Server (NTRS)

    Aschwanden, Markus J.; Bastian, T. S.; White, Stephen M.

    1992-01-01

    The ability to carry out the three dimensional (3D) reconstruction of structures in the solar corona would represent a major advance in the study of the physical properties in active regions and in flares. Methods which allow a geometric reconstruction of quasistationary coronal structures (for example active region loops) or dynamic structures (for example flaring loops) are described: stereoscopy of multi-day imaging observations by the VLA (Very Large Array); tomography of optically thin emission (in radio or soft x-rays); multifrequency band imaging by the VLA; and tracing of magnetic field lines by propagating electron beams.

  17. Efficient method for content reconstruction with self-embedding.

    PubMed

    Korus, Paweł; Dziech, Andrzej

    2013-03-01

    This paper presents a new model of the content reconstruction problem in self-embedding systems, based on an erasure communication channel. We explain why such a model is a good fit for this problem, and how it can be practically implemented with the use of digital fountain codes. The proposed method is based on an alternative approach to spreading the reference information over the whole image, which has recently been shown to be of critical importance in the application at hand. Our paper presents a theoretical analysis of the inherent restoration trade-offs. We analytically derive formulas for the reconstruction success bounds, and validate them experimentally with Monte Carlo simulations and a reference image authentication system. We perform an exhaustive reconstruction quality assessment, where the presented reference scheme is compared to five state-of-the-art alternatives in a common evaluation scenario. Our paper leads to important insights on how self-embedding schemes should be constructed to achieve optimal performance. The reference authentication system designed according to the presented principles allows for high-quality reconstruction, regardless of the amount of the tampered content. The average reconstruction quality, measured on 10000 natural images is 37 dB, and is achievable even when 50% of the image area becomes tampered. PMID:23193455

  18. Anterolateral Extra-articular Soft Tissue Reconstruction in Anterolateral Rotatory Instability of the Knee.

    PubMed

    Kernkamp, Willem A; van de Velde, Samuel K; Bakker, Eric W P; van Arkel, Ewoud R A

    2015-12-01

    Anterolateral rotatory instability (ALRI) occurs after injury to the anterior cruciate ligament (ACL) and the anterolateral structures of the knee. We present a technique for anterolateral extra-articular soft-tissue (ALES) reconstruction of the knee that can be used in revision ACL reconstruction cases, cases of persistent ALRI after adequate ACL reconstruction, and cases with severe ALRI after primary ACL rupture. The surgeon performs ALES reconstruction with a strip of iliotibial tract autograft while respecting the anatomic origin and insertion of the anterolateral ligament. The purpose of this reconstruction is to restore the normal anterolateral rotatory stability of the knee in ALES-deficient patients. PMID:27284525

  19. Runx2-Modified Adipose-Derived Stem Cells Promote Tendon Graft Integration in Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Zhang, Xin; Ma, Yong; Fu, Xin; Liu, Qiang; Shao, Zhenxing; Dai, Linghui; Pi, Yanbin; Hu, Xiaoqing; Zhang, Jiying; Duan, Xiaoning; Chen, Wenqing; Chen, Ping; Zhou, Chunyan; Ao, Yingfang

    2016-01-01

    Runx2 is a powerful osteo-inductive factor and adipose-derived stem cells (ADSCs) are multipotent. However, it is unknown whether Runx2-overexpressing ADSCs (Runx2-ADSCs) could promote anterior cruciate ligament (ACL) reconstruction. We evaluated the effect of Runx2-ADSCs on ACL reconstruction in vitro and in vivo. mRNA expressions of osteocalcin (OCN), bone sialoprotein (BSP) and collagen I (COLI) increased over time in Runx2-ADSCs. Runx2 overexpression inhibited LPL and PPARγ mRNA expressions. Runx2 induced alkaline phosphatase activity markedly. In nude mice injected with Runx2-ADSCs, promoted bone formation was detected by X-rays 8 weeks after injection. The healing of tendon-to-bone in a rabbit model of ACL reconstruction treated with Runx2-ADSCs, fibrin glue only and an RNAi targeting Runx2, was evaluated with CT 3D reconstruction, histological analysis and biomechanical methods. CT showed a greater degree of new bone formation around the bone tunnel in the group treated with Runx2-ADSCs compared with the fibrin glue group and RNAi Runx2 group. Histology showed that treatment with Runx2-ADSCs led to a rapid and significant increase at the tendon-to-bone compared with the control groups. Biomechanical tests demonstrated higher tendon pullout strength in the Runx2-ADSCs group at early time points. The healing of the attachment in ACL reconstruction was enhanced by Runx2-ADSCs. PMID:26743583

  20. Return to Sport: When to Resume Full Activity After an ACL Surgery.

    PubMed

    2014-12-01

    Although surgery to fix a torn anterior cruciate ligament (ACL) is common, knowing when it is safe to return to activities and sports after ACL reconstruction is not always clear. As part of their rehabilitation, patients often fill out surveys, such as the International Knee Documentation Committee survey, that ask questions about how patients think they are recovering. It is not clear, though, how well these surveys truly predict an athlete's readiness to get back to activities and sports. A study published in the December 2014 issue of JOSPT provides new insight and evidence-based tools to help answer this question. PMID:25434851

  1. Preferential Loading of the ACL Compared With the MCL During Landing

    PubMed Central

    Quatman, Carmen E.; Kiapour, Ata M.; Demetropoulos, Constantine K.; Kiapour, Ali; Wordeman, Samuel C.; Levine, Jason W.; Goel, Vijay K.; Hewett, Timothy E.

    2014-01-01

    Background Strong biomechanical and epidemiological evidence associates knee valgus collapse with isolated, noncontact anterior cruciate ligament (ACL) injuries. However, a concomitant injury to the medial collateral ligament (MCL) would be expected under valgus collapse, based on the MCL’s anatomic orientation and biomechanical role in knee stability. Purpose/Hypothesis The purpose of this study was to investigate the relative ACL to MCL strain patterns during physiological simulations of a wide range of high-risk dynamic landing scenarios. We hypothesized that both knee abduction and internal tibial rotation moments would generate a disproportionate increase in the ACL strain relative to the MCL strain. However, the physiological range of knee abduction and internal tibial rotation moments that produce ACL injuries are not of sufficient magnitude to compromise the MCL’s integrity consistently. Study Design Controlled laboratory study. Methods A novel in sim approach was used to test our hypothesis. Seventeen cadaveric lower extremities (mean age, 45 ± 7 years; 9 female and 8 male) were tested to simulate a broad range of landings after a jump under anterior tibial shear force, knee abduction, and internal tibial rotation at 25° of knee flexion. The ACL and MCL strains were quantified using differential variable reluctance transducers. An extensively validated, detailed finite element model of the lower extremity was used to help better interpret experimental findings. Results Anterior cruciate ligament failure occurred in 15 of 17 specimens (88%). Increased anterior tibial shear force and knee abduction and internal tibial rotation moments resulted in significantly higher ACL:MCL strain ratios (P < .05). Under all modes of single-planar and multiplanar loading, the ACL:MCL strain ratio remained greater than 1.7, while the relative ACL strain was significantly higher than the relative MCL strain (P < .01). Relative change in the ACL strain was demonstrated

  2. A new method of morphological comparison for bony reconstructive surgery: maxillary reconstruction using scapular tip bone

    NASA Astrophysics Data System (ADS)

    Chan, Harley; Gilbert, Ralph W.; Pagedar, Nitin A.; Daly, Michael J.; Irish, Jonathan C.; Siewerdsen, Jeffrey H.

    2010-02-01

    esthetic appearance is one of the most important factors for reconstructive surgery. The current practice of maxillary reconstruction chooses radial forearm, fibula or iliac rest osteocutaneous to recreate three-dimensional complex structures of the palate and maxilla. However, these bone flaps lack shape similarity to the palate and result in a less satisfactory esthetic. Considering similarity factors and vasculature advantages, reconstructive surgeons recently explored the use of scapular tip myo-osseous free flaps to restore the excised site. We have developed a new method that quantitatively evaluates the morphological similarity of the scapula tip bone and palate based on a diagnostic volumetric computed tomography (CT) image. This quantitative result was further interpreted as a color map that rendered on the surface of a three-dimensional computer model. For surgical planning, this color interpretation could potentially assist the surgeon to maximize the orientation of the bone flaps for best fit of the reconstruction site. With approval from the Research Ethics Board (REB) of the University Health Network, we conducted a retrospective analysis with CT image obtained from 10 patients. Each patient had a CT scans including the maxilla and chest on the same day. Based on this image set, we simulated total, subtotal and hemi palate reconstruction. The procedure of simulation included volume segmentation, conversing the segmented volume to a stereo lithography (STL) model, manual registration, computation of minimum geometric distances and curvature between STL model. Across the 10 patients data, we found the overall root-mean-square (RMS) conformance was 3.71+/- 0.16 mm

  3. Biomechanical Analysis of Simulated Clinical Testing and Reconstruction of the Anterolateral Ligament of the Knee

    PubMed Central

    Spencer, Luke; Burkhart, Timothy A.; Tran, Michael N.; Rezansoff, Alex James; Deo, Shaneel; Caterine, Scott; Getgood, Alan M

    2016-01-01

    Background: Anatomic anterolateral ligament (ALL) reconstruction has been proposed to assist anterior cruciate ligament (ACL) reconstruction in controlling anterolateral rotational laxity of the knee. However, the biomechanical effects have not been reported. Purpose: (1) To investigate the effect of ALL transection on rotational knee kinematics and (2) to determine the effect on knee biomechanics of ALL reconstruction procedures compared with lateral extra-articular tenodesis (LET). Study Design: Controlled laboratory study. Methods: A total of 12 cadaveric knee specimens were tested in the following sequence: (1) ACLintact, (2) anteromedial bundle of ACL sectioned (ACLamb), (3) complete ACL sectioned (ACLfull), (4) ALL sectioned (ALLsec), (5) anatomic ALL reconstruction (ALLanat), and (6) LET. Biomechanical anterior drawer and Lachman tests were performed in which a 90-N load was applied to the posterior tibia, and anterior translation was measured. A combined load to simulate the early phase of the pivot-shift test was executed in which a 5-N·m internal rotation moment was applied to a fully extended knee; anterior translation and internal rotation were measured. Results: Anterior translation increased across conditions for the biomechanical tests. Internal rotation during the simulated early-phase pivot-shift test was significantly different between ACLfull and ALLsec. Anatomic ALL reconstruction did not significantly reduce internal rotation or anterior translation during the simulated early-phase pivot-shift test. After LET, a significant decrease in anterior translation was found. There was no evidence of over-constraint of the knee with either anatomic ALL reconstruction or LET. Conclusion: The ALL demonstrated a role in controlling anterolateral laxity. LET had a composite effect in governing both anterior and rotational laxity. Anatomic ALL reconstruction did not reduce anterolateral rotational laxity. Clinical Relevance: Profiling the biomechanical

  4. A structured light method for underwater surface reconstruction

    NASA Astrophysics Data System (ADS)

    Sarafraz, Amin; Haus, Brian K.

    2016-04-01

    A new structured-light method for 3D imaging has been developed which can simultaneously estimate both the geometric shape of the water surface and the geometric shape of underwater objects. The method requires only a single image and thus can be applied to dynamic as well as static scenes. Experimental results show the utility of this method in non-invasive underwater 3D reconstruction applications. The performance of the new method is studied through a sensitivity analysis for different parameters of the suggested method.

  5. Pseudocyclops: two cases of ACL graft partial tears mimicking cyclops lesions on MRI.

    PubMed

    Simpfendorfer, Claus; Miniaci, Anthony; Subhas, Naveen; Winalski, Carl S; Ilaslan, Hakan

    2015-08-01

    Arthroscopic reconstruction of the anterior cruciate ligament (ACL) using autografts or allografts is a common surgical procedure, particularly in young athletes. Although the procedure has excellent success rates, complications such as mechanical impingement, graft rupture, and arthrofibrosis can occur, often necessitating additional surgery. Magnetic resonance (MR) imaging has become a valuable tool in evaluating complications after ACL reconstruction. We report two cases of ACL reconstruction complicated by arthroscopically proven partial graft tears. In both cases the torn anterior graft fibers were flipped into the intercondylar notch, mimicking anterior arthrofibrosis, i.e., a "cyclops lesion," on MR imaging. Careful review of the direction of graft fibers on MR imaging in the "pseudocyclops" lesions can help differentiate these partial tears from the fibrosis of a true cyclops. The "pseudocyclops" lesion is a previously undescribed MR imaging sign of partial ACL graft tear. Larger studies are required to determine the sensitivity and specificity of the sign, as well as the clinical importance of these partial graft tears. PMID:25620690

  6. Patient Outcomes and Predictors of Success After Revision Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Johnson, William R.; Makani, Amun; Wall, Andrew J.; Hosseini, Ali; Hampilos, Perry; Li, Guoan; Gill, Thomas J.

    2015-01-01

    Background: Patient outcomes and predictors of success after revision anterior cruciate ligament (ACL) reconstruction are currently limited in the literature. Existing studies either have a small study size or are difficult to interpret because of the multiple surgeons involved in the care of the study sample. Purpose: To determine patient outcomes and predictors of success or failure after a single-stage revision ACL reconstruction by a single fellowship-trained senior surgeon at a single institution. Study Design: Case series; Level of evidence, 4. Methods: A total of 78 patients who underwent revision ACL reconstruction by a single surgeon from 2010 to 2014 were contacted and available for follow-up. The mean time from revision procedure to follow-up was 52 months. Those patients who were able to participate in the study sent in a completed Tegner activity level scale, International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, and IKDC Current Health Assessment Form. The patients’ medical records were also thoroughly reviewed. Results: Five patients had subsequent failure after revision surgery. The median Tegner score was 6 at follow-up, and the mean subjective IKDC score was 72.5. There was no statistically significant difference in outcome scores when comparing revision graft type, body mass index, sex, need for bone grafting, and time from failure to revision. Patients with failures after primary ACL reconstruction secondary to a traumatic event were found to have statistically significantly higher IKDC scores (mean, 76.6) after revision when compared with nontraumatic failures (mean, 67.1), even when controlling for confounders (P < .017). Conclusion: Revision ACL reconstruction is effective in improving patient activity levels and satisfaction. However, the subjective IKDC results are quite variable and likely based on multiple factors. Patients with traumatic injuries contributing to graft failure after primary ACL reconstruction

  7. Iterative reconstruction methods for high-throughput PET tomographs.

    PubMed

    Hamill, James; Bruckbauer, Thomas

    2002-08-01

    A fast iterative method is described for processing clinical PET scans acquired in three dimensions, that is, with no inter-plane septa, using standard computers to replace dedicated processors used until the late 1990s. The method is based on sinogram resampling, Fourier rebinning, Monte Carlo scatter simulation and iterative reconstruction using the attenuation-weighted OSEM method and a projector based on a Gaussian pixel model. Resampling of measured sinogram values occurs before Fourier rebinning, to minimize parallax and geometric distortions due to the circular geometry, and also to reduce the size of the sinogram. We analyse the geometrical and statistical effects of resampling, showing that the lines of response are positioned correctly and that resampling is equivalent to about 4 mm of post-reconstruction filtering. We also present phantom and patient results. In this approach, multi-bed clinical oncology scans can be ready for diagnosis within minutes. PMID:12200928

  8. The gridding method for image reconstruction by Fourier transformation

    SciTech Connect

    Schomberg, H.; Timmer, J.

    1995-09-01

    This paper explores a computational method for reconstructing an n-dimensional signal f from a sampled version of its Fourier transform {cflx f}. The method involves a window function {cflx w} and proceeds in three steps. First, the convolution {cflx g} = {cflx w} * {cflx f} is computed numerically on a Cartesian grid, using the available samples of {cflx f}. Then, g = wf is computed via the inverse discrete Fourier transform, and finally f is obtained as g/w. Due to the smoothing effect of the convolution, evaluating {cflx w} * {cflx f} is much less error prone than merely interpolating {cflx f}. The method was originally devised for image reconstruction in radio astronomy, but is actually applicable to a broad range of reconstructive imaging methods, including magnetic resonance imaging and computed tomography. In particular, it provides a fast and accurate alternative to the filtered backprojection. The basic method has several variants with other applications, such as the equidistant resampling of arbitrarily sampled signals or the fast computation of the Radon (Hough) transform.

  9. Iterative reconstruction methods in X-ray CT.

    PubMed

    Beister, Marcel; Kolditz, Daniel; Kalender, Willi A

    2012-04-01

    Iterative reconstruction (IR) methods have recently re-emerged in transmission x-ray computed tomography (CT). They were successfully used in the early years of CT, but given up when the amount of measured data increased because of the higher computational demands of IR compared to analytical methods. The availability of large computational capacities in normal workstations and the ongoing efforts towards lower doses in CT have changed the situation; IR has become a hot topic for all major vendors of clinical CT systems in the past 5 years. This review strives to provide information on IR methods and aims at interested physicists and physicians already active in the field of CT. We give an overview on the terminology used and an introduction to the most important algorithmic concepts including references for further reading. As a practical example, details on a model-based iterative reconstruction algorithm implemented on a modern graphics adapter (GPU) are presented, followed by application examples for several dedicated CT scanners in order to demonstrate the performance and potential of iterative reconstruction methods. Finally, some general thoughts regarding the advantages and disadvantages of IR methods as well as open points for research in this field are discussed. PMID:22316498

  10. Improving automated 3D reconstruction methods via vision metrology

    NASA Astrophysics Data System (ADS)

    Toschi, Isabella; Nocerino, Erica; Hess, Mona; Menna, Fabio; Sargeant, Ben; MacDonald, Lindsay; Remondino, Fabio; Robson, Stuart

    2015-05-01

    This paper aims to provide a procedure for improving automated 3D reconstruction methods via vision metrology. The 3D reconstruction problem is generally addressed using two different approaches. On the one hand, vision metrology (VM) systems try to accurately derive 3D coordinates of few sparse object points for industrial measurement and inspection applications; on the other, recent dense image matching (DIM) algorithms are designed to produce dense point clouds for surface representations and analyses. This paper strives to demonstrate a step towards narrowing the gap between traditional VM and DIM approaches. Efforts are therefore intended to (i) test the metric performance of the automated photogrammetric 3D reconstruction procedure, (ii) enhance the accuracy of the final results and (iii) obtain statistical indicators of the quality achieved in the orientation step. VM tools are exploited to integrate their main functionalities (centroid measurement, photogrammetric network adjustment, precision assessment, etc.) into the pipeline of 3D dense reconstruction. Finally, geometric analyses and accuracy evaluations are performed on the raw output of the matching (i.e. the point clouds) by adopting a metrological approach. The latter is based on the use of known geometric shapes and quality parameters derived from VDI/VDE guidelines. Tests are carried out by imaging the calibrated Portable Metric Test Object, designed and built at University College London (UCL), UK. It allows assessment of the performance of the image orientation and matching procedures within a typical industrial scenario, characterised by poor texture and known 3D/2D shapes.

  11. Methods of graph network reconstruction in personalized medicine.

    PubMed

    Danilov, A; Ivanov, Yu; Pryamonosov, R; Vassilevski, Yu

    2016-08-01

    The paper addresses methods for generation of individualized computational domains on the basis of medical imaging dataset. The computational domains will be used in one-dimensional (1D) and three-dimensional (3D)-1D coupled hemodynamic models. A 1D hemodynamic model employs a 1D network of a patient-specific vascular network with large number of vessels. The 1D network is the graph with nodes in the 3D space which bears additional geometric data such as length and radius of vessels. A 3D hemodynamic model requires a detailed 3D reconstruction of local parts of the vascular network. We propose algorithms which extend the automated segmentation of vascular and tubular structures, generation of centerlines, 1D network reconstruction, correction, and local adaptation. We consider two modes of centerline representation: (i) skeletal segments or sets of connected voxels and (ii) curved paths with corresponding radii. Individualized reconstruction of 1D networks depends on the mode of centerline representation. Efficiency of the proposed algorithms is demonstrated on several examples of 1D network reconstruction. The networks can be used in modeling of blood flows as well as other physiological processes in tubular structures. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26462139

  12. Anatomic Single Bundle Anterior Cruciate Ligament Reconstruction by Low Accessory Anteromedial Portal Technique: An In Vivo 3D CT Study

    PubMed Central

    Lee, Kwang Won; Chi, Yong Joo; Yang, Dae Suk; Kim, Ha Yong; Choy, Won Sik

    2014-01-01

    Purpose Proper femoral tunnel position is important for anatomical reconstruction of the anterior cruciate ligament (ACL). The purpose of this study was to evaluate the positions of femoral and tibial tunnels created using an accessory anteromedial portal technique in single bundle ACL reconstruction. Materials and Methods The femoral tunnel was targeted at the mid-portion of the ACL bundles. We evaluated postoperative computed tomography scans of 32 patients treated by ACL reconstruction using a free-hand low accessory anteromedial portal technique. On the tibial side, the tunnel position was evaluated using Tsukada's method. On the femoral side, the position was evaluated using 1) the quadrant method, 2) Mochizuki's method, 3) Mochizuki's method, and 4) Takahashi's method. Tunnel obliquity was also evaluated. Results The mean tibial tunnel position was located at 44.6%±2.5% anterior from the anterior margin and 48.0%±3.0% in medial from the medial margin. The mean femoral tunnel position was located at the center between the anteromedial and posterolateral bundles: Quadrant method, 26.7%±2.7%/30.0%±2.9%; Watanabe's method, 37.7%±2.5%/26.6%±2.2%; Mochizuki's method, 38.7%±2.7%; Takahashi's method, 21.8%±2.2%. The mean femoral tunnel obliquity was 57.7°±6.2° in the sagittal plane and 49.9°±5.6° in the coronal plane. Conclusions In anatomic single bundle ACL reconstruction, the low anteromedial portal technique can restore accurate position of the native footprint. Accurate femoral tunnel position facilitates recovery of stability and decreases graft failure rate. PMID:24944975

  13. Risk Factors for Surgical Site Infections Following Anterior Cruciate Ligament Reconstruction.

    PubMed

    Murphy, Michael V; Du, Dongyi Tony; Hua, Wei; Cortez, Karoll J; Butler, Melissa G; Davis, Robert L; DeCoster, Thomas A; Johnson, Laura; Li, Lingling; Nakasato, Cynthia; Nordin, James D; Ramesh, Mayur; Schum, Michael; Von Worley, Ann; Zinderman, Craig; Platt, Richard; Klompas, Michael

    2016-07-01

    OBJECTIVE To determine the effect of graft choice (allograft, bone-patellar tendon-bone autograft, or hamstring autograft) on deep tissue infections following anterior cruciate ligament (ACL) reconstructions. DESIGN Retrospective cohort study. SETTING AND POPULATION Patients from 6 US health plans who underwent ACL reconstruction from January 1, 2000, through December 31, 2008. METHODS We identified ACL reconstructions and potential postoperative infections using claims data. A hierarchical stratified sampling strategy was used to identify patients for medical record review to confirm ACL reconstructions and to determine allograft vs autograft tissue implanted, clinical characteristics, and infection status. We estimated infection rates overall and by graft type. We used logistic regression to assess the association between infections and patients' demographic characteristics, comorbidities, and choice of graft. RESULTS On review of 1,452 medical records, we found 55 deep wound infections. With correction for sampling weights, infection rates varied by graft type: 0.5% (95% CI, 0.3%-0.8%) with allografts, 0.6% (0.1%-1.5%) with bone-patellar tendon-bone autografts, and 2.5% (1.9%-3.1%) with hamstring autograft. After adjusting for potential confounders, we found an increased infection risk with hamstring autografts compared with allografts (odds ratio, 5.9; 95% CI, 2.8-12.8). However, there was no difference in infection risk among bone-patellar tendon-bone autografts vs allografts (odds ratio, 1.2; 95% CI, 0.3-4.8). CONCLUSIONS The overall risk for deep wound infections following ACL reconstruction is low but it does vary by graft type. Infection risk was highest in hamstring autograft recipients compared with allograft recipients and bone-patellar tendon-bone autograft recipients. Infect Control Hosp Epidemiol 2016;37:827-833. PMID:27340734

  14. Linear method of fluorescent source reconstruction in a diffusion medium.

    PubMed

    Janunts, Edgar; Pöschinger, Thomas; Brünner, Holger; Langenbucher, Achim

    2008-01-01

    A new method is described for obtaining a 2D reconstruction of a fluorescent source distribution inside a diffusion medium from planar measurements of the emission light at the surface after excitation by a plane wave. Point sources are implanted at known locations of a rectangular phantom. The forward model of the photon transport is based on the diffusion approximation of the radiative transport equation (RTE) for homogeneous media. This can be described by a hierarchical system of two time-independent RTE's, one for the excitation plane wave originating from the external light source to the medium and another one for the fluorescence emission originating from the fluorophore marker to the detector. A linear inverse source problem was solved for image reconstruction. The applicability of the theoretical method is demonstrated in some representative working examples. For an optimization of the problem we used least squares minimization technique. PMID:18826162

  15. PET iterative reconstruction incorporating an efficient positron range correction method.

    PubMed

    Bertolli, Ottavia; Eleftheriou, Afroditi; Cecchetti, Matteo; Camarlinghi, Niccolò; Belcari, Nicola; Tsoumpas, Charalampos

    2016-02-01

    Positron range is one of the main physical effects limiting the spatial resolution of positron emission tomography (PET) images. If positrons travel inside a magnetic field, for instance inside a nuclear magnetic resonance (MR) tomograph, the mean range will be smaller but still significant. In this investigation we examined a method to correct for the positron range effect in iterative image reconstruction by including tissue-specific kernels in the forward projection operation. The correction method was implemented within STIR library (Software for Tomographic Image Reconstruction). In order to obtain the positron annihilation distribution of various radioactive isotopes in water and lung tissue, simulations were performed with the Monte Carlo package GATE [Jan et al. 2004 [1

  16. Optical Sensors and Methods for Underwater 3D Reconstruction.

    PubMed

    Massot-Campos, Miquel; Oliver-Codina, Gabriel

    2015-01-01

    This paper presents a survey on optical sensors and methods for 3D reconstruction in underwater environments. The techniques to obtain range data have been listed and explained, together with the different sensor hardware that makes them possible. The literature has been reviewed, and a classification has been proposed for the existing solutions. New developments, commercial solutions and previous reviews in this topic have also been gathered and considered. PMID:26694389

  17. Optical Sensors and Methods for Underwater 3D Reconstruction

    PubMed Central

    Massot-Campos, Miquel; Oliver-Codina, Gabriel

    2015-01-01

    This paper presents a survey on optical sensors and methods for 3D reconstruction in underwater environments. The techniques to obtain range data have been listed and explained, together with the different sensor hardware that makes them possible. The literature has been reviewed, and a classification has been proposed for the existing solutions. New developments, commercial solutions and previous reviews in this topic have also been gathered and considered. PMID:26694389

  18. In vivo determination of knee kinematics in patients with a hamstring or patellar tendon ACL graft.

    PubMed

    Mahfouz, Mohamed R; Traina, Steven M; Komistek, Richard D; Dennis, Douglas A

    2003-10-01

    Video fluoroscopy was used to assess the in vivo kinematics for patients with a patellar-tendon-bone or double-looped semitendinosus gracilis anterior cruciate ligament (ACL) graft. Patients with a double-looped semitendinosus gracilis ACL graft experienced kinematic patterns more similar to the normal knee than patients with a patellar-tendon-bone reconstruction. Patients with a double-looped semitendinosus gracilis reconstruction also experienced more anterior contact at full extension and throughout the flexion cycle than patients with a patellar-tendon-bone reconstruction, which resulted in patients with double-looped semitendinosus gracilis grafts experiencing more posterior femoral rollback. Therefore, removal of the central third of the patella ligament leads to a decrease in quadriceps mechanism efficiency, which resulted in the more posterior contact positions demonstrated by the patients with patellar-tendon-bone grafts in this study. PMID:14584831

  19. Efficient finite element method for grating profile reconstruction

    NASA Astrophysics Data System (ADS)

    Zhang, Ruming; Sun, Jiguang

    2015-12-01

    This paper concerns the reconstruction of grating profiles from scattering data. The inverse problem is formulated as an optimization problem with a regularization term. We devise an efficient finite element method (FEM) and employ a quasi-Newton method to solve it. For the direct problems, the FEM stiff and mass matrices are assembled once at the beginning of the numerical procedure. Then only minor changes are made to the mass matrix at each iteration, which significantly saves the computation cost. Numerical examples show that the method is effective and robust.

  20. Computational methods estimating uncertainties for profile reconstruction in scatterometry

    NASA Astrophysics Data System (ADS)

    Gross, H.; Rathsfeld, A.; Scholze, F.; Model, R.; Bär, M.

    2008-04-01

    The solution of the inverse problem in scatterometry, i.e. the determination of periodic surface structures from light diffraction patterns, is incomplete without knowledge of the uncertainties associated with the reconstructed surface parameters. With decreasing feature sizes of lithography masks, increasing demands on metrology techniques arise. Scatterometry as a non-imaging indirect optical method is applied to periodic line-space structures in order to determine geometric parameters like side-wall angles, heights, top and bottom widths and to evaluate the quality of the manufacturing process. The numerical simulation of the diffraction process is based on the finite element solution of the Helmholtz equation. The inverse problem seeks to reconstruct the grating geometry from measured diffraction patterns. Restricting the class of gratings and the set of measurements, this inverse problem can be reformulated as a non-linear operator equation in Euclidean spaces. The operator maps the grating parameters to the efficiencies of diffracted plane wave modes. We employ a Gauss-Newton type iterative method to solve this operator equation and end up minimizing the deviation of the measured efficiency or phase shift values from the simulated ones. The reconstruction properties and the convergence of the algorithm, however, is controlled by the local conditioning of the non-linear mapping and the uncertainties of the measured efficiencies or phase shifts. In particular, the uncertainties of the reconstructed geometric parameters essentially depend on the uncertainties of the input data and can be estimated by various methods. We compare the results obtained from a Monte Carlo procedure to the estimations gained from the approximative covariance matrix of the profile parameters close to the optimal solution and apply them to EUV masks illuminated by plane waves with wavelengths in the range of 13 nm.

  1. Sediment core and glacial environment reconstruction - a method review

    NASA Astrophysics Data System (ADS)

    Bakke, Jostein; Paasche, Øyvind

    2010-05-01

    Alpine glaciers are often located in remote and high-altitude regions of the world, areas that only rarely are covered by instrumental records. Reconstructions of glaciers has therefore proven useful for understanding past climate dynamics on both shorter and longer time-scales. One major drawback with glacier reconstructions based solely on moraine chronologies - by far the most common -, is that due to selective preservation of moraine ridges such records do not exclude the possibility of multiple Holocene glacier advances. This problem is true regardless whether cosmogenic isotopes or lichenometry have been used to date the moraines, or also radiocarbon dating of mega-fossils buried in till or underneath the moraines themselves. To overcome this problem Karlén (1976) initially suggested that glacial erosion and the associated production of rock-flour deposited in downstream lakes could provide a continuous record of glacial fluctuations, hence overcoming the problem of incomplete reconstructions. We want to discuss the methods used to reconstruct past glacier activity based on sediments deposited in distal glacier-fed lakes. By quantifying physical properties of glacial and extra-glacial sediments deposited in catchments, and in downstream lakes and fjords, it is possible to isolate and identify past glacier activity - size and production rate - that subsequently can be used to reconstruct changing environmental shifts and trends. Changes in average sediment evacuation from alpine glaciers are mainly governed by glacier size and the mass turnover gradient, determining the deformation rate at any given time. The amount of solid precipitation (mainly winter accumulation) versus loss due to melting during the ablation-season (mainly summer temperature) determines the mass turnover gradient in either positive or negative direction. A prevailing positive net balance will lead to higher sedimentation rates and vice versa, which in turn can be recorded in downstream

  2. Track and vertex reconstruction: From classical to adaptive methods

    SciTech Connect

    Strandlie, Are; Fruehwirth, Rudolf

    2010-04-15

    This paper reviews classical and adaptive methods of track and vertex reconstruction in particle physics experiments. Adaptive methods have been developed to meet the experimental challenges at high-energy colliders, in particular, the CERN Large Hadron Collider. They can be characterized by the obliteration of the traditional boundaries between pattern recognition and statistical estimation, by the competition between different hypotheses about what constitutes a track or a vertex, and by a high level of flexibility and robustness achieved with a minimum of assumptions about the data. The theoretical background of some of the adaptive methods is described, and it is shown that there is a close connection between the two main branches of adaptive methods: neural networks and deformable templates, on the one hand, and robust stochastic filters with annealing, on the other hand. As both classical and adaptive methods of track and vertex reconstruction presuppose precise knowledge of the positions of the sensitive detector elements, the paper includes an overview of detector alignment methods and a survey of the alignment strategies employed by past and current experiments.

  3. Sex Influences the Biomechanical Outcomes of Anterior Cruciate Ligament Reconstruction in a Pre-Clinical Large Animal Model

    PubMed Central

    Kiapour, Ata M.; Fleming, Braden C.; Proffen, Benedikt L.; Murray, Martha M.

    2015-01-01

    Background The risk of anterior cruciate ligament (ACL) injury is 2-10 times greater in women than men. While the role of sex on injury risk is well established, its effects on surgical outcomes remain controversial. Purpose To investigate whether the biomechanical outcomes of ACL reconstruction are affected by sex using an established porcine model that displays similar sex-specific differences in knee anatomy and ligament structural properties to humans. We hypothesized there are sex differences in ACL reconstruction outcomes with regards to the graft structural properties, knee laxity and cartilage damage. Study Design Controlled Laboratory Study. Methods A total of 41 (23 M, 18 F) adolescent Yucatan minipigs underwent unilateral ACL transection and ACL reconstruction using sex-matched bone-patellar tendon-bone allografts (with or without additional bio-enhancement). Graft biomechanical and histological properties, knee laxity and cartilage damage were assessed after 15 weeks. A two-factor ANOVA was used to investigate the effect of sex on all the measured outcomes after adjusting for the treatment effect. Results After 15 weeks of healing, female pigs had a significantly lower mean normalized graft yield load (by 18.5±7.7%; p=0.023) and linear stiffness (by 11.9±5.6%; p=0.043), compared to males. Female pigs had a significantly greater side-to-side differences in AP knee laxity at 30° (by 1.4±0.6 mm; p=0.028) and 90° (by 1.8±0.8 mm; p=0.032). Female pigs had a lower graft vascular density (by 0.8±0.3 [analog scoring];p=0.021) with similar cellular and collagen-based histologic scores in both sexes (p>0.6). Female pigs also had a significantly larger area of cartilage damage (by 43.3±14.8 mm2; p=0.014) after conventional ACL reconstruction than their male counterparts. Conclusion Female pigs had significantly worse outcomes (i.e., graft structural properties, knee laxity and cartilage damage) compared to males in this translational model after 15 weeks

  4. The Lateral Meniscus as a Guide to Anatomical Tibial Tunnel Placement During Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Kassam, A.M.; Tillotson, L.; Schranz, P.J.; Mandalia, V.I.

    2015-01-01

    Purpose: The aim of the study is to show, on an MRI scan, that the posterior border of the anterior horn of the lateral meniscus (AHLM) could guide tibial tunnel position in the sagittal plane and provide anatomical graft position. Method: One hundred MRI scans were analysed with normal cruciate ligaments and no evidence of meniscal injury. We measured the distance between the posterior border of the AHLM and the midpoint of the ACL by superimposing sagittal images. Results: The mean distance between the posterior border of the AHLM and the ACL midpoint was -0.1mm (i.e. 0.1mm posterior to the ACL midpoint). The range was 5mm to -4.6mm. The median value was 0.0mm. 95% confidence interval was from -0.5 to 0.3mm. A normal, parametric distribution was observed and Intra- and inter-observer variability showed significant correlation (p<0.05) using Pearsons Correlation test (intra-observer) and Interclass correlation (inter-observer). Conclusion: Using the posterior border of the AHLM is a reproducible and anatomical marker for the midpoint of the ACL footprint in the majority of cases. It can be used intra-operatively as a guide for tibial tunnel insertion and graft placement allowing anatomical reconstruction. There will inevitably be some anatomical variation. Pre-operative MRI assessment of the relationship between AHLM and ACL footprint is advised to improve surgical planning. Level of Evidence: Level 4. PMID:26962379

  5. Reverse optimization reconstruction method in non-null aspheric interferometry

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Liu, Dong; Shi, Tu; Yang, Yongying; Chong, Shiyao; Shen, Yibing; Bai, Jian

    2015-10-01

    Aspheric non-null test achieves more flexible measurements than the null test. However, the precision calibration for retrace error has always been difficult. A reverse optimization reconstruction (ROR) method is proposed for the retrace error calibration as well as the aspheric figure error extraction based on system modeling. An optimization function is set up with system model, in which the wavefront data from experiment is inserted as the optimization objective while the figure error under test in the model as the optimization variable. The optimization is executed by the reverse ray tracing in the system model until the test wavefront in the model is consistent with the one in experiment. At this point, the surface figure error in the model is considered to be consistent with the one in experiment. With the Zernike fitting, the aspheric surface figure error is then reconstructed in the form of Zernike polynomials. Numerical simulations verifying the high accuracy of the ROR method are presented with error considerations. A set of experiments are carried out to demonstrate the validity and repeatability of ROR method. Compared with the results of Zygo interferometer (null test), the measurement error by the ROR method achieves better than 1/10λ.

  6. Increased Compliance With Supervised Rehabilitation Improves Functional Outcome and Return to Sport After Anterior Cruciate Ligament Reconstruction in Recreational Athletes

    PubMed Central

    Han, Fucai; Banerjee, Anirban; Shen, Liang; Krishna, Lingaraj

    2015-01-01

    Background: Successful return to sport is an important outcome measure after anterior cruciate ligament (ACL) reconstruction and a reason for patients’ decisions to elect surgery. Rehabilitation programs supervised by physical therapists are routinely prescribed after ACL reconstruction surgery. However, the added advantage of supervised physical therapy after ACL reconstruction is still debatable. Hypothesis: Attending more supervised physical therapy sessions after arthroscopic ACL reconstruction in recreational athletes increases their chance of successful return to sport. Study Design: Cohort study; Level of evidence, 3. Methods: The authors analyzed 93 recreational athletes who underwent arthroscopic ACL reconstruction. After arthroscopic single-bundle ACL reconstruction, patients were advised to attend 20 supervised physical therapy sessions. Patients’ demographics, surgical details, and outcome measures (Knee injury and Osteoarthritis Outcome Score [KOOS], Lysholm scale, and Short Form–36 Health Survey [SF-36]) were recorded presurgery and at 1-year follow-up. Ability to return to sports was documented through patients’ self-report. The attendance at physical therapy by each patient was obtained by examining database records and assessed as fully compliant (>15 sessions), moderately compliant (6-15 sessions), or noncompliant (<6 sessions). Results: Patients in the fully compliant group had significantly greater odds (odds ratio [OR], 18.5; 95% CI, 1.9-184.5; P = .013) of a successful return to sport as compared with the noncompliant group. Patients in the moderately compliant group also had greater odds of returning to sport as compared with the noncompliant group (OR, 4.2; 95% CI, 1.0-16.6; P = .043). Patients in the fully compliant group had significantly greater scores on the Lysholm (P < .001), KOOS Sports and Recreation subscale (P = .021), KOOS Symptoms subscale (P = .040), and SF-36 physical component summary (PCS) (P = .012) as compared with

  7. Accelerated signal encoding and reconstruction using pixon method

    DOEpatents

    Puetter, Richard; Yahil, Amos; Pina, Robert

    2005-05-17

    The method identifies a Pixon element, which is a fundamental and indivisible unit of information, and a Pixon basis, which is the set of possible functions from which the Pixon elements are selected. The actual Pixon elements selected from this basis during the reconstruction process represents the smallest number of such units required to fit the data and representing the minimum number of parameters necessary to specify the image. The Pixon kernels can have arbitrary properties (e.g., shape, size, and/or position) as needed to best fit the data.

  8. Image reconstruction by the speckle-masking method.

    PubMed

    Weigelt, G; Wirnitzer, B

    1983-07-01

    Speckle masking is a method for reconstructing high-resolution images of general astronomical objects from stellar speckle interferograms. In speckle masking no unresolvable star is required within the isoplanatic patch of the object. We present digital applications of speckle masking to close spectroscopic double stars. The speckle interferograms were recorded with the European Southern Observatory's 3.6-m telescope. Diffraction-limited resolution (0.03 arc see) was achieved, which is about 30 times higher than the resolution of conventional astrophotography. PMID:19718124

  9. Accelerated signal encoding and reconstruction using pixon method

    DOEpatents

    Puetter, Richard; Yahil, Amos

    2002-01-01

    The method identifies a Pixon element, which is a fundamental and indivisible unit of information, and a Pixon basis, which is the set of possible functions from which the Pixon elements are selected. The actual Pixon elements selected from this basis during the reconstruction process represents the smallest number of such units required to fit the data and representing the minimum number of parameters necessary to specify the image. The Pixon kernels can have arbitrary properties (e.g., shape size, and/or position) as needed to best fit the data.

  10. Accelerated signal encoding and reconstruction using pixon method

    DOEpatents

    Puetter, Richard; Yahil, Amos

    2002-01-01

    The method identifies a Pixon element, which is a fundamental and indivisible unit of information, and a Pixon basis, which is the set of possible functions from which the Pixon elements are selected. The actual Pixon elements selected from this basis during the reconstruction process represents the smallest number of such units required to fit the data and representing the minimum number of parameters necessary to specify the image. The Pixon kernels can have arbitrary properties (e.g., shape, size, and/or position) as needed to best fit the data.

  11. Algebraic filter approach for fast approximation of nonlinear tomographic reconstruction methods

    NASA Astrophysics Data System (ADS)

    Plantagie, Linda; Batenburg, Kees Joost

    2015-01-01

    We present a computational approach for fast approximation of nonlinear tomographic reconstruction methods by filtered backprojection (FBP) methods. Algebraic reconstruction algorithms are the methods of choice in a wide range of tomographic applications, yet they require significant computation time, restricting their usefulness. We build upon recent work on the approximation of linear algebraic reconstruction methods and extend the approach to the approximation of nonlinear reconstruction methods which are common in practice. We demonstrate that if a blueprint image is available that is sufficiently similar to the scanned object, our approach can compute reconstructions that approximate iterative nonlinear methods, yet have the same speed as FBP.

  12. Correlation Analysis of Potential Factors Influencing Graft Maturity After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Li, Hong; Chen, Shuang; Tao, Hongyue; Li, Hongyun; Chen, Shiyi

    2014-01-01

    Background: Postoperatively, signal changes of the reconstructed anterior cruciate ligament (ACL) graft on magnetic resonance imaging (MRI) images commonly occurs, which may be a cause for concern. The signal intensity changes are usually expressed by signal/noise quotient (SNQ) value, representing graft maturity. To date, little is known about the factors influencing the SNQ value of the reconstructed ACL graft. Purpose: To evaluate ACL graft SNQ value and associated factors after ACL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: Male patients who underwent ACL reconstruction using autograft or allograft tendon from September 2004 to September 2011 were randomly invited to take part in this investigation, including functional scores, physical examination, and MRI scan. The femoral side graft was fixed with Endobutton CL or Rigidfix pins, and the tibial side graft was fixed with a bio-intrafix. SNQ values of each graft were measured on MRI to represent graft maturity. Sagittal ACL angle, ACL–Blumensaat line angle, and medial and lateral posterior tibial slope (PTS) were measured using MRI 3-dimensional dual-echo steady-state images. Potential risk factors, including age, body mass index, postoperative time, Tegner activity scale (TAS), sagittal ACL angle, ACL–Blumensaat line angle, medial PTS, lateral PTS, and primary graft diameter, were tested for their association with the graft SNQ value by multivariate stepwise regression analysis. Results: A total of 104 male subjects (mean follow-up, 30.7 months) were examined, including 62 allograft and 42 autograft reconstructions. There was a significant association between graft SNQ and postoperative time (r = −0.431, P < .001), TAS (r = 0.295, P = .002), and ACL–Blumensaat line angle (r = −0.304, P = .002). Univariate regression analysis showed that TAS (β = 6.15, P < .001) positively correlated, postoperative time (β = −0.26, P < .001) negatively correlated, and ACL

  13. RELIABILITY AND VALIDITY OF A MODIFIED ISOMETRIC DYNAMOMETER IN THE ASSESSMENT OF MUSCULAR PERFORMANCE IN INDIVIDUALS WITH ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

    PubMed Central

    de Vasconcelos, Rodrigo Antunes; Bevilaqua-Grossi, Débora; Shimano, Antonio Carlos; Paccola, Cleber Jansen; Salvini, Tânia Fátima; Prado, Christiane Lanatovits; Junior, Wilson A. Mello

    2015-01-01

    Objectives: The aim of this study was to evaluate the reliability and validity of a modified isometric dynamometer (MID) in performance deficits of the knee extensor and flexor muscles in normal individuals and in those with ACL reconstructions. Methods: Sixty male subjects were invited to participate of the study, being divided into three groups with 20 subjects each: control group (GC), group of individuals with ACL reconstruction with patellar tendon graft (GTP, and group of individuals with ACL reconstruction with hamstrings graft (GTF). All individuals performed isometric tests in the MID, muscular strength deficits collected were subsequently compared to the tests performed on the Biodex System 3 operating in the isometric and isokinetic mode at speeds of 60°/s and 180o/s. Intraclass ICC correlation calculations were done in order to assess MID reliability, specificity, sensitivity and Kappa's consistency coefficient calculations, respectively, for assessing the MID's validity in detecting muscular deficits and intra- and intergroup comparisons when performing the four strength tests using the ANOVA method. Results: The modified isometric dynamometer (MID) showed excellent reliability and good validity in the assessment of the performance of the knee extensor and flexor muscles groups. In the comparison between groups, the GTP showed significantly greater deficits as compared to the GTF and GC groups. Conclusion: Isometric dynamometers connected to mechanotherapy equipments could be an alternative option to collect data concerning performance deficits of the extensor and flexor muscles groups of the knee in subjects with ACL reconstruction. PMID:27004175

  14. A New Method for Coronal Magnetic Field Reconstruction

    NASA Astrophysics Data System (ADS)

    Yi, Sibaek; Choe, Gwangson; Lim, Daye

    2015-08-01

    We present a new, simple, variational method for reconstruction of coronal force-free magnetic fields based on vector magnetogram data. Our method employs vector potentials for magnetic field description in order to ensure the divergence-free condition. As boundary conditions, it only requires the normal components of magnetic field and current density so that the boundary conditions are not over-specified as in many other methods. The boundary normal current distribution is initially fixed once and for all and does not need continual adjustment as in stress-and-relax type methods. We have tested the computational code based on our new method in problems with known solutions and those with actual photospheric data. When solutions are fully given at all boundaries, the accuracy of our method is almost comparable to best performing methods in the market. When magnetic field data are given only at the photospheric boundary, our method excels other methods in most “figures of merit” devised by Schrijver et al. (2006). Furthermore the residual force in the solution is at least an order of magnitude smaller than that of any other method. It can also accommodate the source-surface boundary condition at the top boundary. Our method is expected to contribute to the real time monitoring of the sun required for future space weather forecasts.

  15. Comparison of Clinical and Radiological Parameters with Two Different Surgical Methods for Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Çiloğlu, Osman; Çiçek, Hakan; Yılmaz, Ahmet; Özalay, Metin; Söker, Gökhan; Leblebici, Berrin

    2014-01-01

    Objectives: We investigated the effects anatomic or nonanatomic femoral tunnel positions and tunnel fixation methods obtained using two different surgery methods on tunnel widening and clinical results in anterior cruciate ligament (ACL) reconstructions. Methods: Patients with isolated anterior cruciate ligament rupture are included to study who don’t have intra-and extra-articular additional pathology of the knee, without previously a history of operations of both knees. 2 groups were created. Group 1 Aperfix implant were used which can be able to perform non anatomical femoral tunnel and intra tunnel fixation with transtibial technique. In Group 2 Endobutton CL implant were used which can make fixation from outside the cortex with anatomic femoral tunnel in use of anteromedial portal techniques. 27 patients (average age 29,33, range 18 to 55 years) in group 1 and 27 patients (average age 27,51, range 16 to 45 years) in group 2 totally 54 patients were performed surgery. All patients were assessed using the IKDC (International knee documentation committee), Tegner Activity Scala and Lysholm II Functional Scores. Muscle strength measurements in both groups compared to intact knee was measured with an isokinetic dynamometer Biodex System 3 Pro. The location of the femoral tunnel aperture and tunnel widening were imaged with 3D reconstructive computed tomography. All measurements were performed using the same software application by the same radiologist. Results: The two groups were similar with respect to age and sex distribution, operated side, the size of the tunnel created, and follow-up period (p>0.05). After surgery in both groups, the clinical scores showed significant improvement compared to preoperative (p=0,0001). However, postoperative clinical outcomes in the two groups did not show a difference significantly (p>0,005). Isokinetic muscle strength study showed significant differences between the two groups (p=0,0001). Location of femoral tunnel aperture

  16. 3D scanning modeling method application in ancient city reconstruction

    NASA Astrophysics Data System (ADS)

    Ren, Pu; Zhou, Mingquan; Du, Guoguang; Shui, Wuyang; Zhou, Pengbo

    2015-07-01

    With the development of optical engineering technology, the precision of 3D scanning equipment becomes higher, and its role in 3D modeling is getting more distinctive. This paper proposed a 3D scanning modeling method that has been successfully applied in Chinese ancient city reconstruction. On one hand, for the existing architectures, an improved algorithm based on multiple scanning is adopted. Firstly, two pieces of scanning data were rough rigid registered using spherical displacers and vertex clustering method. Secondly, a global weighted ICP (iterative closest points) method is used to achieve a fine rigid registration. On the other hand, for the buildings which have already disappeared, an exemplar-driven algorithm for rapid modeling was proposed. Based on the 3D scanning technology and the historical data, a system approach was proposed for 3D modeling and virtual display of ancient city.

  17. Acute, simultaneous tear of patellar tendon and ACL: possible mechanism of injury and rationality of the two-stage surgical treatment

    PubMed Central

    Koukoulias, Nikolaos E; Koumis, Panagiotis; Papadopoulos, Alexis; Kyparlis, Dimitris; Papastergiou, Stergios G

    2011-01-01

    The authors report a case of a 47-year-old professional driver with an acute, simultaneous tear of patellar tendon and anterior cruciate ligament (ACL). The patient was treated in two stages. Acute patellar tendon repair and delayed (6-month postinjury) ACL reconstruction was performed. The authors discuss the possible mechanism of injury and the rationality of the two-stage surgical treatment. PMID:22687668

  18. Acute, simultaneous tear of patellar tendon and ACL: possible mechanism of injury and rationality of the two-stage surgical treatment.

    PubMed

    Koukoulias, Nikolaos E; Koumis, Panagiotis; Papadopoulos, Alexis; Kyparlis, Dimitris; Papastergiou, Stergios G

    2011-01-01

    The authors report a case of a 47-year-old professional driver with an acute, simultaneous tear of patellar tendon and anterior cruciate ligament (ACL). The patient was treated in two stages. Acute patellar tendon repair and delayed (6-month postinjury) ACL reconstruction was performed. The authors discuss the possible mechanism of injury and the rationality of the two-stage surgical treatment. PMID:22687668

  19. A reconstruction method for gappy and noisy arterial flow data.

    PubMed

    Yakhot, Alexander; Anor, Tomer; Karniadakis, George Em

    2007-12-01

    Proper orthogonal decomposition (POD), Kriging interpolation, and smoothing are applied to reconstruct gappy and noisy data of blood flow in a carotid artery. While we have applied these techniques to clinical data, in this paper in order to rigorously evaluate their effectiveness we rely on data obtained by computational fluid dynamics (CFD). Specifically, gappy data sets are generated by removing nodal values from high-resolution 3-D CFD data (at random or in a fixed area) while noisy data sets are formed by superimposing speckle noise on the CFD results. A combined POD-Kriging procedure is applied to planar data sets mimicking coarse resolution "ultrasound-like" blood flow images. A method for locating the vessel wall boundary and for calculating the wall shear stress (WSS) is also proposed. The results show good agreement with the original CFD data. The combined POD-Kriging method, enhanced by proper smoothing if needed, holds great potential in dealing effectively with gappy and noisy data reconstruction of in vivo velocity measurements based on color Doppler ultrasound (CDUS) imaging or magnetic resonance angiography (MRA). PMID:18092738

  20. Reducing the Risk of ACL Injury in Female Athletes

    ERIC Educational Resources Information Center

    McDaniel, Larry W.; Rasche, Adrienna; Gaudet, Laura; Jackson, Allen

    2010-01-01

    The Anterior Cruciate Ligament (ACL) is located behind the kneecap (patella) and connects the thigh bone (femur) to the shin bone (tibia). Stabilizing the knee joint is the primary responsibility of the ACL. Injuries that affect the ACL are three to five times more common in females than males. This is a result of anatomical, biomechanical,…

  1. Strain distribution in the ligament using photoelasticity. A direct application to the human ACL.

    PubMed

    Yamamoto, K; Hirokawa, S; Kawada, T

    1998-04-01

    Large and highly variable deformations of the anterior cruciate ligament (ACL) in the human knee cannot be adequately quantified by one-dimensional and/or localized measurements. In order to measure strains in the entire area of the ACL, we employed the photoelastic coating method to analyze stress on the basis of the strains. A specific kind of polyurethane possessing optically high fringe-sensitivity was found to be most suitable for the measurement purposes. Although the photoelastic method has been successfully applied in various fields for stress analyses, its use in studying large deformations of biological tissues has not been reported. Therefore, before proceeding with our main study, we first examined the effects of polyurethane film on the mechanical properties of the ligament. We found that the film had a negligible effect on the tissues' properties, and closely reflected the strain behavior of the tissues. We then applied the method to measure strains on an actual ACL during free flexion-extension of the knee. A specially designed apparatus was used to allow a natural motion of the knee. A portion of the femoral bone was removed to expose the ACL to view. Measurement and analysis gave continuous information about strain distribution, including the variations of strain along the principal strain directions in the ACL. PMID:9690485

  2. [Image quality evaluation of new image reconstruction methods applying the iterative reconstruction].

    PubMed

    Takata, Tadanori; Ichikawa, Katsuhiro; Hayashi, Hiroyuki; Mitsui, Wataru; Sakuta, Keita; Koshida, Haruka; Yokoi, Tomohiro; Matsubara, Kousuke; Horii, Jyunsei; Iida, Hiroji

    2012-01-01

    The purpose of this study was to evaluate the image quality of an iterative reconstruction method, the iterative reconstruction in image space (IRIS), which was implemented in a 128-slices multi-detector computed tomography system (MDCT), Siemens Somatom Definition Flash (Definition). We evaluated image noise by standard deviation (SD) as many researchers did before, and in addition, we measured modulation transfer function (MTF), noise power spectrum (NPS), and perceptual low-contrast detectability using a water phantom including a low-contrast object with a 10 Hounsfield unit (HU) contrast, to evaluate whether the noise reduction of IRIS was effective. The SD and NPS were measured from the images of a water phantom. The MTF was measured from images of a thin metal wire and a bar pattern phantom with the bar contrast of 125 HU. The NPS of IRIS was lower than that of filtered back projection (FBP) at middle and high frequency regions. The SD values were reduced by 21%. The MTF of IRIS and FBP measured by the wire phantom coincided precisely. However, for the bar pattern phantom, the MTF values of IRIS at 0.625 and 0.833 cycle/mm were lower than those of FBP. Despite the reduction of the SD and the NPS, the low-contrast detectability study indicated no significant difference between IRIS and FBP. From these results, it was demonstrated that IRIS had the noise reduction performance with exact preservation for high contrast resolution and slight degradation of middle contrast resolution, and could slightly improve the low contrast detectability but with no significance. PMID:22516592

  3. Randomized Trial of a Novel ACLS Teaching Tool: Does it Improve Student Performance?

    PubMed Central

    Nacca, Nicholas; Holliday, Jordan; Ko, Paul Y.

    2014-01-01

    Introduction Mounting evidence suggests that high-fidelity mannequin-based (HFMBS) and computer-based simulation are useful adjunctive educational tools for advanced cardiac life support (ACLS) instruction. We sought to determine whether access to a supplemental, online computer-based ACLS simulator would improve students’ performance on a standardized Mega Code using high-fidelity mannequin based simulation (HFMBS). Methods Sixty-five third-year medical students were randomized. Intervention group subjects (n = 29) each received a two-week access code to the online ACLS simulator, whereas the control group subjects (n = 36) did not. Primary outcome measures included students’ time to initiate chest compressions, defibrillate ventricular fibrillation, and pace symptomatic bradycardia. Secondary outcome measures included students’ subjective self-assessment of ACLS knowledge and confidence. Results Students with access to the online simulator on average defibrillated ventricular fibrillation in 112 seconds, whereas those without defibrillated in 149.9 seconds, an average of 38 seconds faster [p<.05]. Similarly, those with access to the simulator paced symptomatic bradycardia on average in 95.14 seconds whereas those without access paced on average 154.9 seconds a difference of 59.81 seconds [p<.05]. On a subjective 5-point scale, there was no difference in self-assessment of ACLS knowledge between the control (mean 3.3) versus intervention (mean 3.1) [p-value =.21]. Despite having outperformed the control group subjects in the standardized Mega Code test scenario, the intervention group felt less confident on a 5-point scale (mean 2.5) than the control group. (mean 3.2) [p<.05] Conclusion The reduction in time to defibrillate ventricular fibrillation and to pace symptomatic bradycardia among the intervention group subjects suggests that the online computer-based ACLS simulator is an effective adjunctive ACLS instructional tool. PMID:25493153

  4. [The method of the isolated reconstruction by gastropancreatoduodenal resection].

    PubMed

    Shchepotin, I B; Vasil'ev, O V; Lukashenko, A V; Rozumiĭ, D A; Priĭmak, V V

    2011-01-01

    The modification of the reconstructive stage of gastropancreatoduodenal resection aims to increase the security of the pancreatojejunoanastomosis by minimizing the impact of such aggressive substances as bile and pancreatic juice. The modification represents the isolated pancreatojejunoanastomosis on the Roux-en-Y intestinal loop and gastro- and hepaticojejunoanastomoses on the second intestinal loop, separated with the use of the stub. Thus, the method allows the separate passage of pancreatic juice, bile and gastric contents, excluding their impact on other anastomoses. The described modification was performed in 6 patients. There were no cases of the anastomotic insufficiency. The mean hospital stay was 10,5 days. Thus. The method proved to be effective and safe, providing good initial results. PMID:22334901

  5. Functional Performance Testing After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Abrams, Geoffrey D.; Harris, Joshua D.; Gupta, Anil K.; McCormick, Frank M.; Bush-Joseph, Charles A.; Verma, Nikhil N.; Cole, Brian J.; Bach, Bernard R.

    2014-01-01

    Background: When to allow an athlete to return to unrestricted sporting activity after anterior cruciate ligament (ACL) reconstruction remains controversial. Purpose: To report the results of functional performance testing reported in the literature for individuals at differing time points following ACL reconstruction and to examine differences between graft types. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review of Medline, Scopus, and Cochrane Central Register of Controlled Trials was performed using PRISMA guidelines. Inclusion criteria were English-language studies that examined any functional rehabilitation test from 6 months to 2 years following ACL reconstruction. All patient-, limb-, and knee-specific demographics were extracted from included investigations. All functional rehabilitation tests were analyzed and compared when applicable. Results: The search term returned a total of 890 potential studies, with 88 meeting inclusion and exclusion criteria. A total of 4927 patients were included, of which 66% were male. The mean patient age was 26.5 ± 3.4 years. The predominant graft choices for reconstruction were bone–patellar tendon–bone (BPTB) autograft (59.8%) and hamstring autograft (37.9%). The most commonly reported functional tests were the hop tests. The results of these functional tests, as reported in the Limb Symmetry Index (LSI), improved with increasing time, with nearly all results greater than 90% at 1 year following primary ACL reconstruction. At 6 months postoperatively, a number of isokinetic strength measurements failed to reach 80% LSI, most commonly isokinetic knee extension testing in both BPTB and hamstring autograft groups. The knee flexion strength deficit was significantly less in the BPTB autograft group as compared with those having hamstring autograft at 1 year postoperatively, while no significant differences were found in isokinetic extension strength between the 2 groups. Conclusion: Hop

  6. Results of meniscectomy and meniscal repair in anterior cruciate ligament reconstruction

    PubMed Central

    DELEDDA, DAVIDE; ROSSO, FEDERICA; COTTINO, UMBERTO; BONASIA, DAVIDE EDOARDO; ROSSI, ROBERTO

    2015-01-01

    Meniscal tears are commonly associated with anterior cruciate ligament (ACL) injuries. A deficient medial meniscus results in knee instability and could lead to higher stress forces on the ACL reconstruction. Comparison of results in meniscectomy and meniscal repairs revealed worse clinical outcomes in meniscectomy, but higher re-operation rates in meniscal repairs. Our aim was to review the results of ACL reconstruction associated with meniscectomy or meniscal repair. PMID:26889472

  7. Comparison of image reconstruction methods for structured illumination microscopy

    NASA Astrophysics Data System (ADS)

    Lukeš, Tomas; Hagen, Guy M.; Křížek, Pavel; Švindrych, Zdeněk.; Fliegel, Karel; Klíma, Miloš

    2014-05-01

    Structured illumination microscopy (SIM) is a recent microscopy technique that enables one to go beyond the diffraction limit using patterned illumination. The high frequency information is encoded through aliasing into the observed image. By acquiring multiple images with different illumination patterns aliased components can be separated and a highresolution image reconstructed. Here we investigate image processing methods that perform the task of high-resolution image reconstruction, namely square-law detection, scaled subtraction, super-resolution SIM (SR-SIM), and Bayesian estimation. The optical sectioning and lateral resolution improvement abilities of these algorithms were tested under various noise level conditions on simulated data and on fluorescence microscopy images of a pollen grain test sample and of a cultured cell stained for the actin cytoskeleton. In order to compare the performance of the algorithms, the following objective criteria were evaluated: Signal to Noise Ratio (SNR), Signal to Background Ratio (SBR), circular average of the power spectral density and the S3 sharpness index. The results show that SR-SIM and Bayesian estimation combine illumination patterned images more effectively and provide better lateral resolution in exchange for more complex image processing. SR-SIM requires one to precisely shift the separated spectral components to their proper positions in reciprocal space. High noise levels in the raw data can cause inaccuracies in the shifts of the spectral components which degrade the super-resolved image. Bayesian estimation has proven to be more robust to changes in noise level and illumination pattern frequency.

  8. A CLASS OF RECONSTRUCTED DISCONTINUOUS GALERKIN METHODS IN COMPUTATIONAL FLUID DYNAMICS

    SciTech Connect

    Hong Luo; Yidong Xia; Robert Nourgaliev

    2011-05-01

    A class of reconstructed discontinuous Galerkin (DG) methods is presented to solve compressible flow problems on arbitrary grids. The idea is to combine the efficiency of the reconstruction methods in finite volume methods and the accuracy of the DG methods to obtain a better numerical algorithm in computational fluid dynamics. The beauty of the resulting reconstructed discontinuous Galerkin (RDG) methods is that they provide a unified formulation for both finite volume and DG methods, and contain both classical finite volume and standard DG methods as two special cases of the RDG methods, and thus allow for a direct efficiency comparison. Both Green-Gauss and least-squares reconstruction methods and a least-squares recovery method are presented to obtain a quadratic polynomial representation of the underlying linear discontinuous Galerkin solution on each cell via a so-called in-cell reconstruction process. The devised in-cell reconstruction is aimed to augment the accuracy of the discontinuous Galerkin method by increasing the order of the underlying polynomial solution. These three reconstructed discontinuous Galerkin methods are used to compute a variety of compressible flow problems on arbitrary meshes to assess their accuracy. The numerical experiments demonstrate that all three reconstructed discontinuous Galerkin methods can significantly improve the accuracy of the underlying second-order DG method, although the least-squares reconstructed DG method provides the best performance in terms of both accuracy, efficiency, and robustness.

  9. Contact Stress and Kinematic Analysis of All-Epiphyseal and Over-the-Top Pediatric Reconstruction Techniques for the Anterior Cruciate Ligament

    PubMed Central

    McCarthy, Moira M.; Tucker, Scott; Nguyen, Joseph T.; Green, Daniel W.; Imhauser, Carl W.; Cordasco, Frank A.

    2014-01-01

    Background Anterior cruciate ligament (ACL) injuries are an increasingly recognized problem in the pediatric population. Unfortunately, outcomes with conservative treatment are extremely poor. Furthermore, adult reconstruction techniques may be inappropriate to treat skeletally immature patients due to the risk of physeal complications. “Physeal-sparing” reconstruction techniques exist but their ability to restore knee stability and contact mechanics is not well understood. Purpose (1) To assess the ability of the all-epiphyseal (AE) and over-the-top (OT) reconstructions to restore knee kinematics; (2) to assess whether these reconstructions decrease the high posterior contact stresses seen with ACL deficiency; (3) to determine whether the AE or OT produce abnormal tibiofemoral contact stresses. Hypothesis The AE reconstruction will restore contact mechanics and kinematics similarly to that of the ACL intact knee. Methods Ten fresh-frozen human cadaveric knees were tested using a robotic manipulator. Tibiofemoral motions were recorded with the ACL intact, after sectioning the ACL, and after both reconstructions in each of the 10 specimens. The AE utilized an all-inside technique with tunnels exclusively within the epiphysis and fixed with suspensory cortical fixation devices. The OT had a central and vertical tibial tunnel with an over-the-top femur position and was fixed with staples and posts on both ends. Anterior stability was assessed with 134N anterior force at 0, 15, 30, 60, and 90° of knee flexion. Rotational stability was assessed with combined 8 Nm and 4 Nm of abduction and internal rotation, respectively, at 5, 15, and 30° of knee flexion. Results Both reconstruction techniques offloaded the posterior aspect of the tibial plateau compared to the ACL deficient knee in response to both anterior loads and combined moments as demonstrated by reduced contact stresses in this region at all flexion angles. Compared to the ACL intact condition, both the AE

  10. Vector intensity reconstruction using the data completion method.

    PubMed

    Langrenne, Christophe; Garcia, Alexandre

    2013-04-01

    This paper presents an application of the data completion method (DCM) for vector intensity reconstructions. A mobile array of 36 pressure-pressure probes (72 microphones) is used to perform measurements near a planar surface. Nevertheless, since the proposed method is based on integral formulations, DCM can be applied with any kind of geometry. This method requires the knowledge of Cauchy data (pressure and velocity) on a part of the boundary of an empty domain in order to evaluate pressure and velocity on the remaining part of the boundary. Intensity vectors are calculated in the interior domain surrounded by the measurement array. This inverse acoustic problem requires the use of a regularization method to obtain a realistic solution. An experiment in a closed wooden car trunk mock-up excited by a shaker and two loudspeakers is presented. In this case, where the volume of the mock-up is small (0.61 m(3)), standing-waves and fluid structure interactions appear and show that DCM is a powerful tool to identify sources in a confined space. PMID:23556589

  11. Anatomical considerations in hamstring tendon harvesting for anterior cruciate ligament reconstruction

    PubMed Central

    Charalambous, Charalambos Panayiotou; Kwaees, Tariq Adam

    2012-01-01

    Summary Hamstring tendons are widely used for anterior cruciate ligament (ACL) reconstruction of the knee. Certain anatomical considerations must be taken into account when harvesting the hamstring tendons to be used in ACL reconstruction. These anatomical considerations are discussed in this review article. PMID:23738306

  12. An iterative method for the reconstruction of the coronary arteries from rotational x-ray angiography

    NASA Astrophysics Data System (ADS)

    Hansis, Eberhard; Schäfer, Dirk; Grass, Michael; Dössel, Olaf

    2007-03-01

    Three-dimensional (3D) reconstruction of the coronary arteries offers great advantages in the diagnosis and treatment of cardiovascular diseases, compared to two-dimensional X-ray angiograms. Besides improved roadmapping, quantitative analysis of vessel lesions is possible. To perform 3D reconstruction, rotational projection data of the selectively contrast agent enhanced coronary arteries are acquired with simultaneous ECG recording. For the reconstruction of one cardiac phase, the corresponding projections are selected from the rotational sequence by nearest-neighbor ECG gating. This typically provides only 5-10 projections per cardiac phase. The severe angular undersampling leads to an ill-posed reconstruction problem. In this contribution, an iterative reconstruction method is presented which employs regularizations especially suited for the given reconstruction problem. The coronary arteries cover only a small fraction of the reconstruction volume. Therefore, we formulate the reconstruction problem as a minimization of the L I-norm of the reconstructed image, which results in a spatially sparse object. Two additional regularization terms are introduced: a 3D vesselness prior, which is reconstructed from vesselness-filtered projection data, and a Gibbs smoothing prior. The regularizations favor the reconstruction of the desired object, while taking care not to over-constrain the reconstruction by too detailed a-priori assumptions. Simulated projection data of a coronary artery software phantom are used to evaluate the performance of the method. Human data of clinical cases are presented to show the method's potential for clinical application.

  13. The transosseous ACL Refixation and biological Augmentation "TARBA". Preliminary Results of a new Operation Technique

    PubMed Central

    Hinterwimmer, Stefan; Achten, Manfred; Bathish, Einal

    2016-01-01

    Aims and Objectives: Differentiated gradings of anterior cruciate ligament (ACL) tear-types allow us to perform a more and more differentiated treatment of this injury. Especially in the tears close to the insertion ACL preserving techniques like "healing response" together with growth factors or synthetic augmentations of the original ACL like the "dynamic intraligamentous stabilization DIS" have increasing importance. Disadvantages of the mentioned techniques are the limited indications and the high need of material. That led us to the development of the "transosseous ACL refixation and biological augmentation TARBA", in which the original ACL is refixed to the femoral insertion and augmented with the patient’s doubled gracilis tendon. In the following we will present the first results with this technique. Materials and Methods: From 12/2013 to 02/2015 we used this technique in 56 patients (28x m, 28x f, age 30.7years). All patients had ACL tears in the proximal third close to the femoral insertion. The original ACL was fixed arthroscopically with 2 PDS fibres. Those were pulled out of the femur through a 5mm channel. The original-ACL was augmented with a doubled ipsilateral gracilis tendon. This tendon graft was pulled into the joint via another tibial 5mm channel and fixed at the femur with an endobutton and at the tibia with a cortical anchor screw. Both channels were placed exactly adjacent to the centre of the femoral and tibial anatomic insertion sites. The treatment result was controlled after 3, 6, 9 and 12 months with clinical examination and various scores (patient satisfaction, VAS, Lysholm, Tegner, Activity Rating Scale). After 6 months an instrumented stability test (Rolimeter) was performed. All patients were matched with 47 patients who had a complete ACL tear treated with 4-strand stemitendinosus tendon (control group). Results: Until now all patients with "TARBA" were satisfied with their operation. The range of motion was equal to the healthy

  14. Sex differences in knee strength deficit 1 year after anterior cruciate ligament reconstruction

    PubMed Central

    Kim, Do Kyung; Park, Won Hah

    2015-01-01

    [Purpose] Little is known about the outcome differences between men and women after anterior cruciate ligament (ACL) reconstruction. Therefore, the present study aimed to compare knee muscle strength between men and women 1 year after ACL reconstruction. [Subjects and Methods] Retrospective and outcome study. Between 2012 and 2015, 35 males (mean age, 29.7 ± 010.7 years) and 35 females (mean age, 28.2 ± 11.3 years) who had undergone primary ACL reconstruction were recruited from Samsung medical centers. We assessed the strength deficit in the quadriceps (extensor) and hamstrings (flexor) at 60°/sec and 180°/sec with isokinetic testing equipment. Statistical analysis was conducted with a t-test to determine if sex differences existed in knee strength deficit. [Results] Significant differences were noted between men and women with respect to extensor muscle strength deficit. Women reported less extensor muscle strength than men did, at the angular velocities 60°/sec and 180°/sec. However, no significant sex differences were found at either velocity with respect to the strength deficit of the knee flexor muscles. [Conclusion] Compared to male patients, female patients reported significantly less extensor muscle strength and less improvement 1 year after reconstruction. PMID:26834366

  15. Evaluation of back projection methods for breast tomosynthesis image reconstruction.

    PubMed

    Zhou, Weihua; Lu, Jianping; Zhou, Otto; Chen, Ying

    2015-06-01

    Breast cancer is the most common cancer among women in the USA. Compared to mammography, digital breast tomosynthesis is a new imaging technique that may improve the diagnostic accuracy by removing the ambiguities of overlapped tissues and providing 3D information of the breast. Tomosynthesis reconstruction algorithms generate 3D reconstructed slices from a few limited angle projection images. Among different reconstruction algorithms, back projection (BP) is considered an important foundation of quite a few reconstruction techniques with deblurring algorithms such as filtered back projection. In this paper, two BP variants, including α-trimmed BP and principal component analysis-based BP, were proposed to improve the image quality against that of traditional BP. Computer simulations and phantom studies demonstrated that the α-trimmed BP may improve signal response performance and suppress noise in breast tomosynthesis image reconstruction. PMID:25384538

  16. Reconstructing palaeoclimatic variables from fossil pollen using boosted regression trees: comparison and synthesis with other quantitative reconstruction methods

    NASA Astrophysics Data System (ADS)

    Salonen, J. Sakari; Luoto, Miska; Alenius, Teija; Heikkilä, Maija; Seppä, Heikki; Telford, Richard J.; Birks, H. John B.

    2014-03-01

    We test and analyse a new calibration method, boosted regression trees (BRTs) in palaeoclimatic reconstructions based on fossil pollen assemblages. We apply BRTs to multiple Holocene and Lateglacial pollen sequences from northern Europe, and compare their performance with two commonly-used calibration methods: weighted averaging regression (WA) and the modern-analogue technique (MAT). Using these calibration methods and fossil pollen data, we present synthetic reconstructions of Holocene summer temperature, winter temperature, and water balance changes in northern Europe. Highly consistent trends are found for summer temperature, with a distinct Holocene thermal maximum at ca 8000-4000 cal. a BP, with a mean Tjja anomaly of ca +0.7 °C at 6 ka compared to 0.5 ka. We were unable to reconstruct reliably winter temperature or water balance, due to the confounding effects of summer temperature and the great between-reconstruction variability. We find BRTs to be a promising tool for quantitative reconstructions from palaeoenvironmental proxy data. BRTs show good performance in cross-validations compared with WA and MAT, can model a variety of taxon response types, find relevant predictors and incorporate interactions between predictors, and show some robustness with non-analogue fossil assemblages.

  17. An iterative reconstruction method of complex images using expectation maximization for radial parallel MRI

    NASA Astrophysics Data System (ADS)

    Choi, Joonsung; Kim, Dongchan; Oh, Changhyun; Han, Yeji; Park, HyunWook

    2013-05-01

    In MRI (magnetic resonance imaging), signal sampling along a radial k-space trajectory is preferred in certain applications due to its distinct advantages such as robustness to motion, and the radial sampling can be beneficial for reconstruction algorithms such as parallel MRI (pMRI) due to the incoherency. For radial MRI, the image is usually reconstructed from projection data using analytic methods such as filtered back-projection or Fourier reconstruction after gridding. However, the quality of the reconstructed image from these analytic methods can be degraded when the number of acquired projection views is insufficient. In this paper, we propose a novel reconstruction method based on the expectation maximization (EM) method, where the EM algorithm is remodeled for MRI so that complex images can be reconstructed. Then, to optimize the proposed method for radial pMRI, a reconstruction method that uses coil sensitivity information of multichannel RF coils is formulated. Experiment results from synthetic and in vivo data show that the proposed method introduces better reconstructed images than the analytic methods, even from highly subsampled data, and provides monotonic convergence properties compared to the conjugate gradient based reconstruction method.

  18. An iterative reconstruction method of complex images using expectation maximization for radial parallel MRI.

    PubMed

    Choi, Joonsung; Kim, Dongchan; Oh, Changhyun; Han, Yeji; Park, HyunWook

    2013-05-01

    In MRI (magnetic resonance imaging), signal sampling along a radial k-space trajectory is preferred in certain applications due to its distinct advantages such as robustness to motion, and the radial sampling can be beneficial for reconstruction algorithms such as parallel MRI (pMRI) due to the incoherency. For radial MRI, the image is usually reconstructed from projection data using analytic methods such as filtered back-projection or Fourier reconstruction after gridding. However, the quality of the reconstructed image from these analytic methods can be degraded when the number of acquired projection views is insufficient. In this paper, we propose a novel reconstruction method based on the expectation maximization (EM) method, where the EM algorithm is remodeled for MRI so that complex images can be reconstructed. Then, to optimize the proposed method for radial pMRI, a reconstruction method that uses coil sensitivity information of multichannel RF coils is formulated. Experiment results from synthetic and in vivo data show that the proposed method introduces better reconstructed images than the analytic methods, even from highly subsampled data, and provides monotonic convergence properties compared to the conjugate gradient based reconstruction method. PMID:23588215

  19. Advanced Cardiac Life Support (ACLS) utilizing Man-Tended Capability (MTC) hardware onboard Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Smith, M.; Barratt, M.; Lloyd, C.

    1992-01-01

    Because of the time and distance involved in returning a patient from space to a definitive medical care facility, the capability for Advanced Cardiac Life Support (ACLS) exists onboard Space Station Freedom. Methods: In order to evaluate the effectiveness of terrestrial ACLS protocols in microgravity, a medical team conducted simulations during parabolic flights onboard the KC-135 aircraft. The hardware planned for use during the MTC phase of the space station was utilized to increase the fidelity of the scenario and to evaluate the prototype equipment. Based on initial KC-135 testing of CPR and ACLS, changes were made to the ventricular fibrillation algorithm in order to accommodate the space environment. Other constraints to delivery of ACLS onboard the space station include crew size, minimum training, crew deconditioning, and limited supplies and equipment. Results: The delivery of ACLS in microgravity is hindered by the environment, but should be adequate. Factors specific to microgravity were identified for inclusion in the protocol including immediate restraint of the patient and early intubation to insure airway. External cardiac compressions of adequate force and frequency were administered using various methods. The more significant limiting factors appear to be crew training, crew size, and limited supplies. Conclusions: Although ACLS is possible in the microgravity environment, future evaluations are necessary to further refine the protocols. Proper patient and medical officer restraint is crucial prior to advanced procedures. Also emphasis should be placed on early intubation for airway management and drug administration. Preliminary results and further testing will be utilized in the design of medical hardware, determination of crew training, and medical operations for space station and beyond.

  20. ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING THE DOUBLE-BUNDLE TECHNIQUE – EVALUATION IN THE BIOMECHANICS LABORATORY

    PubMed Central

    D'Elia, Caio Oliveira; Bitar, Alexandre Carneiro; Castropil, Wagner; Garofo, Antônio Guilherme Padovani; Cantuária, Anita Lopes; Orselli, Maria Isabel Veras; Luques, Isabela Ugo; Duarte, Marcos

    2015-01-01

    Objective: The objective of this study was to describe the methodology of knee rotation analysis using biomechanics laboratory instruments and to present the preliminary results from a comparative study on patients who underwent anterior cruciate ligament (ACL) reconstruction using the double-bundle technique. Methods: The protocol currently used in our laboratory was described. Three-dimensional kinematic analysis was performed and knee rotation amplitude was measured on eight normal patients (control group) and 12 patients who were operated using the double-bundle technique, by means of three tasks in the biomechanics laboratory. Results: No significant differences between operated and non-operated sides were shown in relation to the mean amplitudes of gait, gait with change in direction or gait with change in direction when going down stairs (p > 0.13). Conclusion: The preliminary results did not show any difference in the double-bundle ACL reconstruction technique in relation to the contralateral side and the control group. PMID:27027003

  1. High-quality image reconstruction method for ptychography with partially coherent illumination

    NASA Astrophysics Data System (ADS)

    Yu, Wei; Wang, Shouyu; Veetil, Suhas; Gao, Shumei; Liu, Cheng; Zhu, Jianqiang

    2016-06-01

    The influence of partial coherence on the image reconstruction in ptychography is analyzed, and a simple method is proposed to reconstruct a clear image for the weakly scattering object with partially coherent illumination. It is demonstrated numerically and experimentally that by illuminating a weakly scattering object with a divergent radiation beam, and doing the reconstruction only from the bright-field diffraction data, the mathematical ambiguity and corresponding reconstruction errors related to the partial coherency can be remarkably suppressed, thus clear reconstructed images can be generated even under seriously incoherent illumination.

  2. Direct Visualization of Existing Footprint and Outside-In Drilling of the Femoral Tunnel in Anterior Cruciate Ligament Reconstruction in the Knee

    PubMed Central

    Sutter, E. Grant; Anderson, John A.; Garrett, William E.

    2015-01-01

    Improper femoral tunnel placement in anterior cruciate ligament (ACL) reconstruction is a significant problem and may be a cause of ACL graft failure and abnormal kinematics, which may lead to late degenerative changes after reconstruction. Recently, there has been concern that the transtibial approach may contribute to nonanatomic placement of the femoral tunnel, resulting in abnormal knee kinematics. Tibial-independent techniques can provide more anatomic placement of the ACL graft, but these can be technically demanding. This technical note describes the senior author's technique to directly identify the femoral ACL remnant and use the center of the femoral ACL footprint and retrograde drilling to create an anatomic femoral socket for single-bundle reconstruction. This technique provides femoral tunnel placement based on identification of a patient-specific ACL footprint instead of averaged anatomic measurements from large groups. This technique has been shown to produce anatomic ACL graft position and orientation and restore more normal knee kinematics. PMID:26052485

  3. Anterior Cruciate Ligament Reconstruction and Osteoarthritis

    PubMed Central

    Duthon, Victoria; Servien, Elvire; Neyret, Philippe

    2013-01-01

    Objective: The goals of this study are to address several questions, the answers to which are key to the understanding and eventually to the prevention of this frequent source of morbidity. These questions include the following: (1) What is the natural history of anterior cruciate ligament (ACL) deficiency? (2) How important is the status of the meniscus at the time of reconstruction? (3) Does ACL reconstruction prevent the development of osteoarthritis in the long term? (4) Can we predict which patients will develop osteoarthritis? (5) What can be done? Design: This study addresses the key questions above through the long-term follow-up of a cohort of patients treated with ACL reconstruction by Professor Henri Dejour in Lyon, France, supplemented with a review of the relevant literature. Results: The prevalence of osteoarthritis in ACL-deficient knees is about 40% after 15 years and close to 90% after 25 to 35 years. It remains unclear whether reconstruction of the ACL significantly reduces this risk. The status of the meniscus at the time of ACL reconstruction is a strong predictor of the risk of osteoarthritis: Patients who undergo total meniscectomy are at 2- to 10-fold increased risk of developing osteoarthritis relative to those with intact menisci. Patients showing early evidence of arthritis at short- to medium-term follow-up are at high risk for progression over subsequent years. Numerous emerging techniques may provide tools to more effectively prevent and treat osteoarthritis following ACL injury in the future. Conclusion: Osteoarthritis following ACL injury continues to be a major problem requiring further research. PMID:26069662

  4. Patellar tendon or hamstring graft anterior cruciate ligament reconstructions in patients aged above 50 years

    PubMed Central

    Bali, Tarun; Nagraj, Raghu; Kumar, Malhar N; Chandy, Thomas

    2015-01-01

    Background: The treatment of anterior cruciate ligament (ACL) injury consists of arthroscopic ACL reconstruction with patellar tendon or hamstring graft. Satisfactory results have been reported so far in the younger age group. Dilemma arises regarding the suitability of ACL reconstruction in patients aged 50 years and above. This retrospective analyses the outcome of ACL reconstruction in patients aged 50 years and above. Materials and Methods: 55 patients aged 50 years and above presented to our institution with symptomatic ACL tear and were managed with arthroscopic reconstruction with patellar tendon/hamstring graft. 22 patients underwent ACL reconstruction with bone- patellar tendon-bone graft and the remaining 33 with a hamstring graft. Evaluation of functional outcome was performed using International Knee Documentation Committee (IKDC) and Lysholm scoring in the preoperative period, at the end of 1 year and at the final followup. Radiographic evaluation was performed using the Kellgren–Lawrence grading system. Results: The mean preoperative IKDC score was 39.7 ± 3.3. At the end of 1-year following the operation, the mean IKDC score was 73.6 ± 4.9 and at the final followup was 67.8 ± 7.7. The mean preoperative Lysholm score was 40.4 ± 10.3. At the end of 1-year following the intervention, the mean Lysholm score was 89.7 ± 2.1 and at final followup was 85.3 ± 2.5. Overall, 14 out of 42 patients who underwent radiographic assessment showed progression of osteoarthritis changes at the final followup after the intervention. Conclusion: In our study, there was a statistically significant improvement in the IKDC and Lysholm scores following the intervention. There was a slight deterioration in the scores at the final followup but the overall rate of satisfaction was still high and most of the patients were able to do their routine chores and light exercises suitable for their age group. Around one-third of patients show progression of radiographic changes

  5. Kinesiophobia After Anterior Cruciate Ligament Rupture and Reconstruction: Noncopers Versus Potential Copers

    PubMed Central

    Hartigan, Erin H.; Lynch, Andrew D.; Logerstedt, David S.; Chmielewski, Terese L.; Snyder-Mackler, Lynn

    2016-01-01

    STUDY DESIGN Secondary-analysis, longitudinal cohort study. OBJECTIVES To compare kinesiophobia levels in noncopers and potential copers at time points spanning pre– and post–anterior cruciate ligament (ACL) reconstruction and to examine the association between changes in kinesiophobia levels and clinical measures. BACKGROUND After ACL injury, a screening examination may be used to classify patients as potential copers or noncopers based on dynamic knee stability. Quadriceps strength, single-leg hop performance, and self-reported knee function are worse in noncopers. High kinesiophobia levels after ACL reconstruction are associated with poorer self-reported knee function and lower return-to-sport rates. Kinesiophobia levels have not been examined before ACL reconstruction, across the transition from presurgery to postsurgery, or based on potential coper and noncoper classification. METHODS Quadriceps strength indexes, single-leg hop score indexes, self-reported knee function (Knee Outcome Survey activities of daily living subscale, global rating scale), and kinesiophobia (Tampa Scale of Kinesiophobia [TSK-11]) scores were compiled for potential copers (n = 50) and noncopers (n = 61) from 2 clinical trial databases. A repeated-measures analysis of variance was used to compare TSK-11 scores between groups and across 4 time points (before preoperative treatment, after preoperative treatment, 6 months post–ACL reconstruction, and 12 months post–ACL reconstruction). Correlations determined the association of kinesiophobia levels with other clinical measures. RESULTS Presurgery TSK-11 scores were significantly higher in noncopers than in potential copers. Postsurgery, no group differences existed. TSK-11 scores in both groups decreased across all time points; however, TSK-11 scores decreased more in noncopers in the interval between presurgery and postsurgery. In noncopers, the decreases in TSK-11 scores from presurgery to postsurgery and after surgery were

  6. Simultaneous segmentation and reconstruction: A level set method approach for limited view computed tomography

    SciTech Connect

    Yoon, Sungwon; Pineda, Angel R.; Fahrig, Rebecca

    2010-05-15

    Purpose: An iterative tomographic reconstruction algorithm that simultaneously segments and reconstructs the reconstruction domain is proposed and applied to tomographic reconstructions from a sparse number of projection images. Methods: The proposed algorithm uses a two-phase level set method segmentation in conjunction with an iterative tomographic reconstruction to achieve simultaneous segmentation and reconstruction. The simultaneous segmentation and reconstruction is achieved by alternating between level set function evolutions and per-region intensity value updates. To deal with the limited number of projections, a priori information about the reconstruction is enforced via penalized likelihood function. Specifically, smooth function within each region (piecewise smooth function) and bounded function intensity values for each region are assumed. Such a priori information is formulated into a quadratic objective function with linear bound constraints. The level set function evolutions are achieved by artificially time evolving the level set function in the negative gradient direction; the intensity value updates are achieved by using the gradient projection conjugate gradient algorithm. Results: The proposed simultaneous segmentation and reconstruction results were compared to ''conventional'' iterative reconstruction (with no segmentation), iterative reconstruction followed by segmentation, and filtered backprojection. Improvements of 6%-13% in the normalized root mean square error were observed when the proposed algorithm was applied to simulated projections of a numerical phantom and to real fan-beam projections of the Catphan phantom, both of which did not satisfy the a priori assumptions. Conclusions: The proposed simultaneous segmentation and reconstruction resulted in improved reconstruction image quality. The algorithm correctly segments the reconstruction space into regions, preserves sharp edges between different regions, and smoothes the noise

  7. High knee abduction moments are common risk factors for patellofemoral pain (PFP) and anterior cruciate ligament (ACL) injury in girls: Is PFP itself a predictor for subsequent ACL injury?

    PubMed Central

    Myer, Gregory D; Ford, Kevin R; Di Stasi, Stephanie L; Foss, Kim D Barber; Micheli, Lyle J; Hewett, Timothy E

    2014-01-01

    Background Identifying risk factors for knee pain and anterior cruciate ligament (ACL) injury can be an important step in the injury prevention cycle. Objective We evaluated two unique prospective cohorts with similar populations and methodologies to compare the incidence rates and risk factors associated with patellofemoral pain (PFP) and ACL injury. Methods The ‘PFP cohort’ consisted of 240 middle and high school female athletes. They were evaluated by a physician and underwent anthropometric assessment, strength testing and three-dimensional landing biomechanical analyses prior to their basketball season. 145 of these athletes met inclusion for surveillance of incident (new) PFP by certified athletic trainers during their competitive season. The ‘ACL cohort’ included 205 high school female volleyball, soccer and basketball athletes who underwent the same anthropometric, strength and biomechanical assessment prior to their competitive season and were subsequently followed up for incidence of ACL injury. A one-way analysis of variance was used to evaluate potential group (incident PFP vs ACL injured) differences in anthropometrics, strength and landing biomechanics. Knee abduction moment (KAM) cut-scores that provided the maximal sensitivity and specificity for prediction of PFP or ACL injury risk were also compared between the cohorts. Results KAM during landing above 15.4 Nm was associated with a 6.8% risk to develop PFP compared to a 2.9% risk if below the PFP risk threshold in our sample. Likewise, a KAM above 25.3 Nm was associated with a 6.8% risk for subsequent ACL injury compared to a 0.4% risk if below the established ACL risk threshold. The ACL-injured athletes initiated landing with a greater knee abduction angle and a reduced hamstrings-to-quadriceps strength ratio relative to the incident PFP group. Also, when comparing across cohorts, the athletes who suffered ACL injury also had lower hamstring/quadriceps ratio than the players in the PFP

  8. Synchronous quadriceps tendon rupture and unilateral ACL tear in a weightlifter, associated with anabolic steroid use.

    PubMed

    Fenelon, Christopher; Dalton, David M; Galbraith, John G; Masterson, Eric L

    2016-01-01

    Synchronous quadriceps tendon rupture is rare. A 29-year-old man, an amateur weight lifter, taking androgenic-anabolic steroids (AAS), developed sudden onset bilateral pain and swelling of his anterior thighs when attempting to squat 280 kg (620 lb). Examination revealed gross swelling superior to the patella and palpable gaps in both quadriceps tendons. He underwent successful operative repair. MRI revealed a partial tear of the anterior cruciate ligament (ACL) of the right knee. This was not reconstructed. Only a few case reports of the association between AAS and quadriceps rupture exist in the literature, with none to the best of our knowledge in the past 10 years. ACL rupture coexisting is very rare, with only two reported cases. PMID:27154985

  9. Cerec: correlation, an accurate and practical method for occlusal reconstruction.

    PubMed

    Prévost, A P; Bouchard, Y

    2001-07-01

    The correlation technique explained here shows one of the possibilities for occlusal reconstruction offered by the Cerec approach. The various stages of this technique are described and illustrated. The most current applications are reviewed. PMID:11862885

  10. LARS Artificial Ligament Versus ABC Purely Polyester Ligament for Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Iliadis, Dimitrios Ph.; Bourlos, Dimitrios N.; Mastrokalos, Dimitrios S.; Chronopoulos, Efstathios; Babis, George C.

    2016-01-01

    Background: Graft choice for anterior cruciate ligament (ACL) reconstruction is of critical importance. Various grafts have been used so far, with autografts long considered the optimal solution for the treatment of ACL-deficient knees. Limited data are available on the long-term survivorship of synthetic grafts. Purpose: To compare the functional outcome and survivorship of ACL reconstructions performed using the LARS (ligament augmentation and reconstruction system) ligament and the ABC (active biosynthetic composite) purely polyester ligament. Study Design: Case series; Level of evidence, 4. Methods: The results of 72 patients who underwent primary arthroscopic ACL reconstruction with the LARS ligament and 31 cases with an ABC purely polyester ligament were reviewed. The mean follow-up periods for the LARS and ABC groups were 9.5 and 5.1 years, respectively. A survivorship analysis of the 2 synthetic grafts was performed using the Kaplan-Meier method with a log-rank test (Mantel-Cox, 95% CI). Lysholm, Tegner activity, Knee injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC) scores as well as laxity measurements obtained using a KT-1000 arthrometer were recorded for all intact grafts, and a Mann-Whitney U test was used for comparison reasons. Results: The rupture rates for LARS and ABC grafts were 31% (95% CI, 20%-42%) and 42% (95% CI, 25%-59%), respectively. For intact grafts, the mean Lysholm score was good for both groups (90 for the LARS group and 89 for the ABC group), with the majority of patients returning to their preinjury level of activities, and the mean IKDC score was 90 for the LARS group and 86 for the ABC group. Conclusion: The rupture rates of both LARS and ABC grafts were both high. However, the LARS ligament provided significantly better survivorship compared with the ABC ligament at short- to midterm follow-up (95% CI). PMID:27453894

  11. The Local Front Reconstruction Method for direct simulation of two- and three-dimensional multiphase flows

    NASA Astrophysics Data System (ADS)

    Shin, Seungwon; Yoon, Ikroh; Juric, Damir

    2011-07-01

    We present a new interface reconstruction technique, the Local Front Reconstruction Method (LFRM), for incompressible multiphase flows. This new method falls in the category of Front Tracking methods but it shares automatic topology handling characteristics of the previously proposed Level Contour Reconstruction Method (LCRM). The LFRM tracks the phase interface explicitly as in Front Tracking but there is no logical connectivity between interface elements thus greatly easing the algorithmic complexity. Topological changes such as interfacial merging or pinch off are dealt with automatically and naturally as in the Level Contour Reconstruction Method. Here the method is described for both two- and three-dimensional flow geometries. The interfacial reconstruction technique in the LFRM differs from that in the LCRM formulation by foregoing using an Eulerian distance field function. Instead, the LFRM uses information from the original interface elements directly to generate the new interface in a mass conservative way thus showing significantly improved local mass conservation. Because the reconstruction procedure is independently carried out in each individual reconstruction cell after an initial localization process, an adaptive reconstruction procedure can be easily implemented to increase the accuracy while at the same time significantly decreasing the computational time required to perform the reconstruction. Several benchmarking tests are performed to validate the improved accuracy and computational efficiency as compared to the LCRM. The results demonstrate superior performance of the LFRM in maintaining detailed interfacial shapes and good local mass conservation especially when using low-resolution Eulerian grids.

  12. Analysis of method of 3D shape reconstruction using scanning deflectometry

    NASA Astrophysics Data System (ADS)

    Novák, Jiří; Novák, Pavel; Mikš, Antonín.

    2013-04-01

    This work presents a scanning deflectometric approach to solving a 3D surface reconstruction problem, which is based on measurements of a surface gradient of optically smooth surfaces. It is shown that a description of this problem leads to a nonlinear partial differential equation (PDE) of the first order, from which the surface shape can be reconstructed numerically. The method for effective finding of the solution of this differential equation is proposed, which is based on the transform of the problem of PDE solving to the optimization problem. We describe different types of surface description for the shape reconstruction and a numerical simulation of the presented method is performed. The reconstruction process is analyzed by computer simulations and presented on examples. The performed analysis confirms a robustness of the reconstruction method and a good possibility for measurements and reconstruction of the 3D shape of specular surfaces.

  13. Tomographic bioluminescence imaging reconstruction via a dynamically sparse regularized global method in mouse models.

    PubMed

    Liu, Kai; Tian, Jie; Qin, Chenghu; Yang, Xin; Zhu, Shouping; Han, Dong; Wu, Ping

    2011-04-01

    Generally, the performance of tomographic bioluminescence imaging is dependent on several factors, such as regularization parameters and initial guess of source distribution. In this paper, a global-inexact-Newton based reconstruction method, which is regularized by a dynamic sparse term, is presented for tomographic reconstruction. The proposed method can enhance higher imaging reliability and efficiency. In vivo mouse experimental reconstructions were performed to validate the proposed method. Reconstruction comparisons of the proposed method with other methods demonstrate the applicability on an entire region. Moreover, the reliable performance on a wide range of regularization parameters and initial unknown values were also investigated. Based on the in vivo experiment and a mouse atlas, the tolerance for optical property mismatch was evaluated with optical overestimation and underestimation. Additionally, the reconstruction efficiency was also investigated with different sizes of mouse grids. We showed that this method was reliable for tomographic bioluminescence imaging in practical mouse experimental applications. PMID:21529085

  14. Blockwise conjugate gradient methods for image reconstruction in volumetric CT.

    PubMed

    Qiu, W; Titley-Peloquin, D; Soleimani, M

    2012-11-01

    Cone beam computed tomography (CBCT) enables volumetric image reconstruction from 2D projection data and plays an important role in image guided radiation therapy (IGRT). Filtered back projection is still the most frequently used algorithm in applications. The algorithm discretizes the scanning process (forward projection) into a system of linear equations, which must then be solved to recover images from measured projection data. The conjugate gradients (CG) algorithm and its variants can be used to solve (possibly regularized) linear systems of equations Ax=b and linear least squares problems minx∥b-Ax∥2, especially when the matrix A is very large and sparse. Their applications can be found in a general CT context, but in tomography problems (e.g. CBCT reconstruction) they have not widely been used. Hence, CBCT reconstruction using the CG-type algorithm LSQR was implemented and studied in this paper. In CBCT reconstruction, the main computational challenge is that the matrix A usually is very large, and storing it in full requires an amount of memory well beyond the reach of commodity computers. Because of these memory capacity constraints, only a small fraction of the weighting matrix A is typically used, leading to a poor reconstruction. In this paper, to overcome this difficulty, the matrix A is partitioned and stored blockwise, and blockwise matrix-vector multiplications are implemented within LSQR. This implementation allows us to use the full weighting matrix A for CBCT reconstruction without further enhancing computer standards. Tikhonov regularization can also be implemented in this fashion, and can produce significant improvement in the reconstructed images. PMID:22325240

  15. Non-contact ACL Injuries: Mechanisms and Risk Factors

    PubMed Central

    Boden, Barry P.; Sheehan, Frances T.; Torg, Joseph S.; Hewett, Timothy E.

    2013-01-01

    Significant advances have recently been made in understanding the mechanisms involved in noncontact anterior cruciate ligament (ACL) injury. Most ACL injuries involve minimal to no contact. Female athletes sustain a two- to eightfold greater rate of injury than do their male counterparts. Recent videotape analyses demonstrate significant differences in average leg and trunk positions during injury compared with control subjects. These findings as well as those of cadaveric and MRI studies indicate that axial compressive forces are a critical component in noncontact ACL injury. A complete understanding of the forces and risk factors associated with noncontact ACL injury should lead to the development of improved preventive strategiess for this devastating injury. PMID:20810933

  16. Fetal ACL Fibroblasts Exhibit Enhanced Cellular Properties Compared with Adults

    PubMed Central

    Stalling, Simone S.

    2008-01-01

    Fetal tendons and skin heal regeneratively without scar formation. Cells isolated from these fetal tissues exhibit enhanced cellular migration and collagen production in comparison to cells from adult tissue. We determined whether fetal and adult fibroblasts isolated from the anterior cruciate ligament (ACL), a tissue that does not heal regeneratively, exhibit differences in cell migration rates and collagen elaboration. An in vitro migration assay showed fetal ACL fibroblasts migrated twice as fast as adult ACL fibroblasts at a rate of 38.90 ± 7.69 μm per hour compared with 18.88 ± 4.18 μm per hour, respectively. Quantification of Type I collagen elaboration by enzyme-linked immunosorbent assay showed fetal ACL fibroblasts produced four times the amount of Type I collagen compared with adult ACL fibroblasts after 7 days in culture. We observed no differences in Type III collagen with time for adult or fetal ACL fibroblasts. Our findings indicate fetal ACL fibroblasts are intrinsically different from adult ACL fibroblasts, suggesting the healing potential of the ACL may be age-dependent. PMID:18648900

  17. Exploring Normalization and Network Reconstruction Methods using In Silico and In Vivo Models

    EPA Science Inventory

    Abstract: Lessons learned from the recent DREAM competitions include: The search for the best network reconstruction method continues, and we need more complete datasets with ground truth from more complex organisms. It has become obvious that the network reconstruction methods t...

  18. A combined reconstruction-classification method for diffuse optical tomography.

    PubMed

    Hiltunen, P; Prince, S J D; Arridge, S

    2009-11-01

    We present a combined classification and reconstruction algorithm for diffuse optical tomography (DOT). DOT is a nonlinear ill-posed inverse problem. Therefore, some regularization is needed. We present a mixture of Gaussians prior, which regularizes the DOT reconstruction step. During each iteration, the parameters of a mixture model are estimated. These associate each reconstructed pixel with one of several classes based on the current estimate of the optical parameters. This classification is exploited to form a new prior distribution to regularize the reconstruction step and update the optical parameters. The algorithm can be described as an iteration between an optimization scheme with zeroth-order variable mean and variance Tikhonov regularization and an expectation-maximization scheme for estimation of the model parameters. We describe the algorithm in a general Bayesian framework. Results from simulated test cases and phantom measurements show that the algorithm enhances the contrast of the reconstructed images with good spatial accuracy. The probabilistic classifications of each image contain only a few misclassified pixels. PMID:19820265

  19. Tibiofemoral cartilage contact biomechanics in patients after reconstruction of a ruptured anterior cruciate ligament.

    PubMed

    Hosseini, Ali; Van de Velde, Samuel; Gill, Thomas J; Li, Guoan

    2012-11-01

    We investigated the in vivo cartilage contact biomechanics of the tibiofemoral joint in patients after reconstruction of a ruptured anterior cruciate ligament (ACL). A dual fluoroscopic and MR imaging technique was used to investigate the cartilage contact biomechanics of the tibiofemoral joint during in vivo weight-bearing flexion of the knee in eight patients 6 months following clinically successful reconstruction of an acute isolated ACL rupture. The location of tibiofemoral cartilage contact, size of the contact area, cartilage thickness at the contact area, and magnitude of the cartilage contact deformation of the ACL-reconstructed knees were compared with those previously measured in intact (contralateral) knees and ACL-deficient knees of the same subjects. Contact biomechanics of the tibiofemoral cartilage after ACL reconstruction were similar to those measured in intact knees. However, at lower flexion, the abnormal posterior and lateral shift of cartilage contact location to smaller regions of thinner tibial cartilage that has been described in ACL-deficient knees persisted in ACL-reconstructed knees, resulting in an increase of the magnitude of cartilage contact deformation at those flexion angles. Reconstruction of the ACL restored some of the in vivo cartilage contact biomechanics of the tibiofemoral joint to normal. Clinically, recovering anterior knee stability might be insufficient to prevent post-operative cartilage degeneration due to lack of restoration of in vivo cartilage contact biomechanics. PMID:22528687

  20. On multigrid methods for image reconstruction from projections

    SciTech Connect

    Henson, V.E.; Robinson, B.T.; Limber, M.

    1994-12-31

    The sampled Radon transform of a 2D function can be represented as a continuous linear map R : L{sup 1} {yields} R{sup N}. The image reconstruction problem is: given a vector b {element_of} R{sup N}, find an image (or density function) u(x, y) such that Ru = b. Since in general there are infinitely many solutions, the authors pick the solution with minimal 2-norm. Numerous proposals have been made regarding how best to discretize this problem. One can, for example, select a set of functions {phi}{sub j} that span a particular subspace {Omega} {contained_in} L{sup 1}, and model R : {Omega} {yields} R{sup N}. The subspace {Omega} may be chosen as a member of a sequence of subspaces whose limit is dense in L{sup 1}. One approach to the choice of {Omega} gives rise to a natural pixel discretization of the image space. Two possible choices of the set {phi}{sub j} are the set of characteristic functions of finite-width `strips` representing energy transmission paths and the set of intersections of such strips. The authors have studied the eigenstructure of the matrices B resulting from these choices and the effect of applying a Gauss-Seidel iteration to the problem Bw = b. There exists a near null space into which the error vectors migrate with iteration, after which Gauss-Seidel iteration stalls. The authors attempt to accelerate convergence via a multilevel scheme, based on the principles of McCormick`s Multilevel Projection Method (PML). Coarsening is achieved by thickening the rays which results in a much smaller discretization of an optimal grid, and a halving of the number of variables. This approach satisfies all the requirements of the PML scheme. They have observed that a multilevel approach based on this idea accelerates convergence at least to the point where noise in the data dominates.

  1. Digital reconstructed radiography quality control with software methods

    NASA Astrophysics Data System (ADS)

    Denis, Eloise; Beaumont, Stephane; Guedon, JeanPierre

    2005-04-01

    Nowadays, most of treatments for external radiotherapy are prepared with Treatment Planning Systems (TPS) which uses a virtual patient generated by a set of transverse slices acquired with a CT scanner of the patient in treatment position 1 2 3. In the first step of virtual simulation, the TPS is used to define a ballistic allowing a good target covering and the lowest irradiation for normal tissues. This parameters optimisation of the treatment with the TPS is realised with particular graphic tools allowing to: ×Contour the target, ×Expand the limit of the target in order to take into account contouring uncertainties, patient set up errors, movements of the target during the treatment (internal movement of the target and external movement of the patient), and beam's penumbra, ×Determine beams orientation and define dimensions and forms of the beams, ×Visualize beams on the patient's skin and calculate some characteristic points which will be tattooed on the patient to assist the patient set up before treating, ×Calculate for each beam a Digital Reconstructed Radiography (DRR) consisting in projecting the 3D CT virtual patient and beam limits with a cone beam geometry onto a plane. These DRR allow one for insuring the patient positioning during the treatment, essentially bone structures alignment by comparison with real radiography realized with the treatment X-ray source in the same geometric conditions (portal imaging). Then DRR are preponderant to insure the geometric accuracy of the treatment. For this reason quality control of its computation is mandatory4 . Until now, this control is realised with real test objects including some special inclusions4 5 . This paper proposes to use some numerical test objects to control the quality DRR calculation in terms of computation time, beam angle, divergence and magnification precision, spatial and contrast resolutions. The main advantage of this proposed method is to avoid a real test object CT acquisition

  2. Reconstruction method for data protection in telemedicine systems

    NASA Astrophysics Data System (ADS)

    Buldakova, T. I.; Suyatinov, S. I.

    2015-03-01

    In the report the approach to protection of transmitted data by creation of pair symmetric keys for the sensor and the receiver is offered. Since biosignals are unique for each person, their corresponding processing allows to receive necessary information for creation of cryptographic keys. Processing is based on reconstruction of the mathematical model generating time series that are diagnostically equivalent to initial biosignals. Information about the model is transmitted to the receiver, where the restoration of physiological time series is performed using the reconstructed model. Thus, information about structure and parameters of biosystem model received in the reconstruction process can be used not only for its diagnostics, but also for protection of transmitted data in telemedicine complexes.

  3. Dictionary-Learning-Based Reconstruction Method for Electron Tomography

    PubMed Central

    LIU, BAODONG; YU, HENGYONG; VERBRIDGE, SCOTT S.; SUN, LIZHI; WANG, GE

    2014-01-01

    Summary Electron tomography usually suffers from so-called “missing wedge” artifacts caused by limited tilt angle range. An equally sloped tomography (EST) acquisition scheme (which should be called the linogram sampling scheme) was recently applied to achieve 2.4-angstrom resolution. On the other hand, a compressive sensing inspired reconstruction algorithm, known as adaptive dictionary based statistical iterative reconstruction (ADSIR), has been reported for X-ray computed tomography. In this paper, we evaluate the EST, ADSIR, and an ordered-subset simultaneous algebraic reconstruction technique (OS-SART), and compare the ES and equally angled (EA) data acquisition modes. Our results show that OS-SART is comparable to EST, and the ADSIR outperforms EST and OS-SART. Furthermore, the equally sloped projection data acquisition mode has no advantage over the conventional equally angled mode in this context. PMID:25104167

  4. INFLUENCE OF ANTERIOR PAIN ON RESULTS FROM ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

    PubMed Central

    Vasconcelos, Wilson; Santos, Claudinei; Ferracini, Antonio Marcos; Dejour, David

    2015-01-01

    Objective: To examine the impact of residual pain on functional outcomes two years after arthroscopic anterior cruciate ligament (ACL) reconstruction and compare the types of graft used during the procedure (patellar vs. flexor). Method: A retrospective epidemiological study on 129 ACL reconstructions with a mean follow-up of 28 months was conducted. The presence, intensity and location of the anterior pain were investigated. Pain provocation tests were conducted, sensitivity was analyzed and functional scores were applied (IKDC, femoropatellar and SF-36), comparing the results with the type of graft used. Results: Anterior pain was present in 28% of patients with a mean intensity of 2.9 in 10. When pain was present, the functional scores decreased significantly. Abnormalities of knee sensitivity and gait occurred frequently with use of the patellar tendon, but there was no statistical difference regarding the presence of pain. Conclusion: The presence of anterior pain in ACL reconstructions, even if minimal, has a deleterious effect on the final outcome over the medium term. Because of the influence of graft harvesting on the presence of abnormalities of knee sensitivity and gait, choosing the graft should take into account the patient's professional and sports activities. PMID:27026984

  5. Immediate effects of neuromuscular joint facilitation intervention after anterior cruciate ligament reconstruction.

    PubMed

    Wang, Lei

    2016-07-01

    [Purpose] The aim of this study was to examine the immediate effects of neuromuscular joint facilitation (NJF) on the functional activity level after rehabilitation of anterior cruciate ligament (ACL) reconstruction. [Subjects and Methods] Ten young subjects (8 males and 2 females) who underwent ACL reconstruction were included in the study. The subjects were divided into two groups, namely, knee joint extension muscle strength training (MST) group and knee joint extension outside rotation pattern of NJF group. Extension strength was measured in both groups before and after the experiment. Surface electromyography (sEMG) of the vastus medialis and vastus lateralis muscles and joint position error (JPE) test of the knee joint were also conducted. [Results] JPE test results and extension strength measurements in the NJF group were improved compared with those in the MST group. Moreover, the average discharge of the vastus medialis and vastus lateralis muscles on sEMG in the NJF group was significantly increased after MST and NJF treatments. [Conclusion] The obtained results suggest that NJF training in patients with ACL reconstruction can improve knee proprioception ability and muscle strength. PMID:27512270

  6. Immediate effects of neuromuscular joint facilitation intervention after anterior cruciate ligament reconstruction

    PubMed Central

    Wang, Lei

    2016-01-01

    [Purpose] The aim of this study was to examine the immediate effects of neuromuscular joint facilitation (NJF) on the functional activity level after rehabilitation of anterior cruciate ligament (ACL) reconstruction. [Subjects and Methods] Ten young subjects (8 males and 2 females) who underwent ACL reconstruction were included in the study. The subjects were divided into two groups, namely, knee joint extension muscle strength training (MST) group and knee joint extension outside rotation pattern of NJF group. Extension strength was measured in both groups before and after the experiment. Surface electromyography (sEMG) of the vastus medialis and vastus lateralis muscles and joint position error (JPE) test of the knee joint were also conducted. [Results] JPE test results and extension strength measurements in the NJF group were improved compared with those in the MST group. Moreover, the average discharge of the vastus medialis and vastus lateralis muscles on sEMG in the NJF group was significantly increased after MST and NJF treatments. [Conclusion] The obtained results suggest that NJF training in patients with ACL reconstruction can improve knee proprioception ability and muscle strength. PMID:27512270

  7. A new method to combine 3D reconstruction volumes for multiple parallel circular cone beam orbits

    PubMed Central

    Baek, Jongduk; Pelc, Norbert J.

    2010-01-01

    Purpose: This article presents a new reconstruction method for 3D imaging using a multiple 360° circular orbit cone beam CT system, specifically a way to combine 3D volumes reconstructed with each orbit. The main goal is to improve the noise performance in the combined image while avoiding cone beam artifacts. Methods: The cone beam projection data of each orbit are reconstructed using the FDK algorithm. When at least a portion of the total volume can be reconstructed by more than one source, the proposed combination method combines these overlap regions using weighted averaging in frequency space. The local exactness and the noise performance of the combination method were tested with computer simulations of a Defrise phantom, a FORBILD head phantom, and uniform noise in the raw data. Results: A noiseless simulation showed that the local exactness of the reconstructed volume from the source with the smallest tilt angle was preserved in the combined image. A noise simulation demonstrated that the combination method improved the noise performance compared to a single orbit reconstruction. Conclusions: In CT systems which have overlap volumes that can be reconstructed with data from more than one orbit and in which the spatial frequency content of each reconstruction can be calculated, the proposed method offers improved noise performance while keeping the local exactness of data from the source with the smallest tilt angle. PMID:21089770

  8. L1/2 regularization based numerical method for effective reconstruction of bioluminescence tomography

    NASA Astrophysics Data System (ADS)

    Chen, Xueli; Yang, Defu; Zhang, Qitan; Liang, Jimin

    2014-05-01

    Even though bioluminescence tomography (BLT) exhibits significant potential and wide applications in macroscopic imaging of small animals in vivo, the inverse reconstruction is still a tough problem that has plagued researchers in a related area. The ill-posedness of inverse reconstruction arises from insufficient measurements and modeling errors, so that the inverse reconstruction cannot be solved directly. In this study, an l1/2 regularization based numerical method was developed for effective reconstruction of BLT. In the method, the inverse reconstruction of BLT was constrained into an l1/2 regularization problem, and then the weighted interior-point algorithm (WIPA) was applied to solve the problem through transforming it into obtaining the solution of a series of l1 regularizers. The feasibility and effectiveness of the proposed method were demonstrated with numerical simulations on a digital mouse. Stability verification experiments further illustrated the robustness of the proposed method for different levels of Gaussian noise.

  9. Comparison of reconstruction methods and quantitative accuracy in Siemens Inveon PET scanner

    NASA Astrophysics Data System (ADS)

    Ram Yu, A.; Kim, Jin Su; Kang, Joo Hyun; Moo Lim, Sang

    2015-04-01

    PET reconstruction is key to the quantification of PET data. To our knowledge, no comparative study of reconstruction methods has been performed to date. In this study, we compared reconstruction methods with various filters in terms of their spatial resolution, non-uniformities (NU), recovery coefficients (RCs), and spillover ratios (SORs). In addition, the linearity of reconstructed radioactivity between linearity of measured and true concentrations were also assessed. A Siemens Inveon PET scanner was used in this study. Spatial resolution was measured with NEMA standard by using a 1 mm3 sized 18F point source. Image quality was assessed in terms of NU, RC and SOR. To measure the effect of reconstruction algorithms and filters, data was reconstructed using FBP, 3D reprojection algorithm (3DRP), ordered subset expectation maximization 2D (OSEM 2D), and maximum a posteriori (MAP) with various filters or smoothing factors (β). To assess the linearity of reconstructed radioactivity, image quality phantom filled with 18F was used using FBP, OSEM and MAP (β =1.5 & 5 × 10-5). The highest achievable volumetric resolution was 2.31 mm3 and the highest RCs were obtained when OSEM 2D was used. SOR was 4.87% for air and 3.97% for water, obtained OSEM 2D reconstruction was used. The measured radioactivity of reconstruction image was proportional to the injected one for radioactivity below 16 MBq/ml when FBP or OSEM 2D reconstruction methods were used. By contrast, when the MAP reconstruction method was used, activity of reconstruction image increased proportionally, regardless of the amount of injected radioactivity. When OSEM 2D or FBP were used, the measured radioactivity concentration was reduced by 53% compared with true injected radioactivity for radioactivity <16 MBq/ml. The OSEM 2D reconstruction method provides the highest achievable volumetric resolution and highest RC among all the tested methods and yields a linear relation between the measured and true

  10. Anatomical reconstruction of the anterior cruciate ligament: a logical approach

    PubMed Central

    Gali, Julio Cesar

    2015-01-01

    We describe the surgical approach that we have used over the last years for anterior cruciate ligament (ACL) reconstruction, highlighting the importance of arthroscopic viewing through the anteromedial portal (AMP) and femoral tunnel drilling through an accessory anteromedial portal (AMP). The AMP allows direct view of the ACL femoral insertion site on the medial aspect of the lateral femoral condyle, does not require guides for anatomic femoral tunnel reaming, prevents an additional lateral incision in the distal third of the thigh (as would be unavoidable when the outside-in technique is used) and also can be used for double-bundle ACL reconstruction. PMID:26417571

  11. [Intra-articular reinforcement of a partially torn anterior cruciate ligament (ACL) using newly developed UHMWPE biomaterial in combination with Hexalon ACL/PCL screws: ex-vivo mechanical testing of an animal knee model].

    PubMed

    Fedorová, P; Srnec, R; Pěnčík, J; Dvořák, M; Krbec, M; Nečas, A

    2015-01-01

    PURPOSE OF THE STUDY Recent trends in the experimental surgical management of a partial anterior cruciate ligament (ACL) rupture in animals show repair of an ACL lesion using novel biomaterials both for biomechanical reinforcement of a partially unstable knee and as suitable scaffolds for bone marrow stem cell therapy in a partial ACL tear. The study deals with mechanical testing of the newly developed ultra-high-molecular-weight polyethylene (UHMWPE) biomaterial anchored to bone with Hexalon biodegradable ACL/PCL screws, as a new possibility of intra-articular reinforcement of a partial ACL tear. MATERIAL AND METHODS Two groups of ex vivo pig knee models were prepared and tested as follows: the model of an ACL tear stabilised with UHMWPE biomaterial using a Hexalon ACL/PCL screw (group 1; n = 10) and the model of an ACL tear stabilised with the traditional, and in veterinary medicine used, extracapsular technique involving a monofilament nylon fibre, a clamp and a Securos bone anchor (group 2; n = 11). The models were loaded at a standing angle of 100° and the maximum load (N) and shift (mm) values were recorded. RESULTS In group 1 the average maximal peak force was 167.6 ± 21.7 N and the shift was on average 19.0 ± 4.0 mm. In all 10 specimens, the maximum load made the UHMWPE implant break close to its fixation to the femur but the construct/fixation never failed at the site where the material was anchored to the bone. In group 2, the average maximal peak force was 207.3 ± 49.2 N and the shift was on average 24.1 ± 9.5 mm. The Securos stabilisation failed by pullout of the anchor from the femoral bone in nine out of 11 cases; the monofilament fibre ruptured in two cases. CONCLUSIONS It can be concluded that a UHMWPE substitute used in ex-vivo pig knee models has mechanical properties comparable with clinically used extracapsular Securos stabilisation and, because of its potential to carry stem cells and bioactive substances, it can meet the requirements for

  12. The point-source method for 3D reconstructions for the Helmholtz and Maxwell equations

    NASA Astrophysics Data System (ADS)

    Ben Hassen, M. F.; Erhard, K.; Potthast, R.

    2006-02-01

    We use the point-source method (PSM) to reconstruct a scattered field from its associated far field pattern. The reconstruction scheme is described and numerical results are presented for three-dimensional acoustic and electromagnetic scattering problems. We give new proofs of the algorithms, based on the Green and Stratton-Chu formulae, which are more general than with the former use of the reciprocity relation. This allows us to handle the case of limited aperture data and arbitrary incident fields. Both for 3D acoustics and electromagnetics, numerical reconstructions of the field for different settings and with noisy data are shown. For shape reconstruction in acoustics, we develop an appropriate strategy to identify areas with good reconstruction quality and combine different such regions into one joint function. Then, we show how shapes of unknown sound-soft scatterers are found as level curves of the total reconstructed field.

  13. Do ACL-injured copers exhibit differences in knee kinematics?: An MRI study.

    PubMed

    Barrance, Peter J; Williams, Glenn N; Snyder-Mackler, Lynn; Buchanan, Thomas S

    2007-01-01

    Kinematic changes after anterior cruciate ligament (ACL) injury may play a role in the long-term development of osteoarthritis (OA). Some ACL-injured patients (copers) successfully return to demanding activities without the reconstructive surgery usually recommended for functionally unstable patients (noncopers). We determined whether copers exhibit less disruption to kinematics than noncopers, perhaps because of lower impairment of muscular control as observed in earlier studies. We used dynamic magnetic resonance imaging and model-based tracking to investigate anteroposterior (AP) and internal-external tibial positioning in copers, presurgical noncopers, and uninjured control subjects during dynamic nonloaded knee extension. Copers and control subjects showed similar levels of side-to-side differences in AP tibial positioning (1.1 +/- 4.9 mm and 1.4 +/- 2.7 mm, respectively), whereas noncopers exhibited anterior tibial positioning in their injured knees (2.6 +/- 3 mm) that differed from control subjects. Copers were the most variable of the three groups, and contrary to our hypothesis, tibial positioning in copers was not different from that of noncopers. Differences in tibial positioning did not correlate with side-to-side differences in AP laxity in any of the groups, and we identified no changes to tibial axial rotation patterns associated with ACL deficiency. PMID:17091013

  14. A method for investigating system matrix properties in optimization-based CT reconstruction

    NASA Astrophysics Data System (ADS)

    Rose, Sean D.; Sidky, Emil Y.; Pan, Xiaochuan

    2016-04-01

    Optimization-based iterative reconstruction methods have shown much promise for a variety of applications in X-ray computed tomography (CT). In these reconstruction methods, the X-ray measurement is modeled as a linear mapping from a finite-dimensional image space to a finite dimensional data-space. This mapping is dependent on a number of factors including the basis functions used for image representation1 and the method by which the matrix representing this mapping is generated.2 Understanding the properties of this linear mapping and how it depends on our choice of parameters is fundamental to optimization-based reconstruction. In this work, we confine our attention to a pixel basis and propose a method to investigate the effect of pixel size in optimization-based reconstruction. The proposed method provides insight into the tradeoff between higher resolution image representation and matrix conditioning. We demonstrate this method for a particular breast CT system geometry. We find that the images obtained from accurate solution of a least squares reconstruction optimization problem have high sensitivity to pixel size within certain regimes. We propose two methods by which this sensitivity can be reduced and demonstrate their efficacy. Our results indicate that the choice of pixel size in optimization-based reconstruction can have great impact on the quality of the reconstructed image, and that understanding the properties of the linear mapping modeling the X-ray measurement can help guide us with this choice.

  15. An automated 3D reconstruction method of UAV images

    NASA Astrophysics Data System (ADS)

    Liu, Jun; Wang, He; Liu, Xiaoyang; Li, Feng; Sun, Guangtong; Song, Ping

    2015-10-01

    In this paper a novel fully automated 3D reconstruction approach based on low-altitude unmanned aerial vehicle system (UAVs) images will be presented, which does not require previous camera calibration or any other external prior knowledge. Dense 3D point clouds are generated by integrating orderly feature extraction, image matching, structure from motion (SfM) and multi-view stereo (MVS) algorithms, overcoming many of the cost, time limitations of rigorous photogrammetry techniques. An image topology analysis strategy is introduced to speed up large scene reconstruction by taking advantage of the flight-control data acquired by UAV. Image topology map can significantly reduce the running time of feature matching by limiting the combination of images. A high-resolution digital surface model of the study area is produced base on UAV point clouds by constructing the triangular irregular network. Experimental results show that the proposed approach is robust and feasible for automatic 3D reconstruction of low-altitude UAV images, and has great potential for the acquisition of spatial information at large scales mapping, especially suitable for rapid response and precise modelling in disaster emergency.

  16. A new nonlinear reconstruction method based on total variation regularization of neutron penumbral imaging.

    PubMed

    Qian, Weixin; Qi, Shuangxi; Wang, Wanli; Cheng, Jinming; Liu, Dongbing

    2011-09-01

    Neutron penumbral imaging is a significant diagnostic technique in laser-driven inertial confinement fusion experiment. It is very important to develop a new reconstruction method to improve the resolution of neutron penumbral imaging. A new nonlinear reconstruction method based on total variation (TV) regularization is proposed in this paper. A TV-norm is used as regularized term to construct a smoothing functional for penumbral image reconstruction in the new method, in this way, the problem of penumbral image reconstruction is transformed to the problem of a functional minimization. In addition, a fixed point iteration scheme is introduced to solve the problem of functional minimization. The numerical experimental results show that, compared to linear reconstruction method based on Wiener filter, the TV regularized nonlinear reconstruction method is beneficial to improve the quality of reconstructed image with better performance of noise smoothing and edge preserving. Meanwhile, it can also obtain the spatial resolution with 5 μm which is higher than the Wiener method. PMID:21974584

  17. A new nonlinear reconstruction method based on total variation regularization of neutron penumbral imaging

    SciTech Connect

    Qian Weixin; Qi Shuangxi; Wang Wanli; Cheng Jinming; Liu Dongbing

    2011-09-15

    Neutron penumbral imaging is a significant diagnostic technique in laser-driven inertial confinement fusion experiment. It is very important to develop a new reconstruction method to improve the resolution of neutron penumbral imaging. A new nonlinear reconstruction method based on total variation (TV) regularization is proposed in this paper. A TV-norm is used as regularized term to construct a smoothing functional for penumbral image reconstruction in the new method, in this way, the problem of penumbral image reconstruction is transformed to the problem of a functional minimization. In addition, a fixed point iteration scheme is introduced to solve the problem of functional minimization. The numerical experimental results show that, compared to linear reconstruction method based on Wiener filter, the TV regularized nonlinear reconstruction method is beneficial to improve the quality of reconstructed image with better performance of noise smoothing and edge preserving. Meanwhile, it can also obtain the spatial resolution with 5 {mu}m which is higher than the Wiener method.

  18. Method for reconstruction of shape of specular surfaces using scanning beam deflectometry

    NASA Astrophysics Data System (ADS)

    Miks, Antonin; Novak, Jiri; Novak, Pavel

    2013-07-01

    A new method is presented for reconstruction of the shape of specular surfaces using scanning beam deflectometry. A description and an analysis of a deflectometric technique for 3D measurements of specular surfaces is provided and it is derived that a surface reconstruction problem leads to a theoretical description by a nonlinear partial differential equation. The surface shape can be calculated by solution of the derived equation. A method was proposed, which makes possible to find effectively the solution of the deflectometric differential equation for the shape reconstruction. The presented method is noncontact and no reference surface is needed as in interferometry.

  19. High tibial osteotomy in the ACL-deficient knee with medial compartment osteoarthritis.

    PubMed

    Herman, Benjamin V; Giffin, J Robert

    2016-09-01

    High tibial osteotomy (HTO) has traditionally been used to treat varus gonarthrosis in younger, active patients. Varus malalignment increases the risk of progression of medial compartment osteoarthritis and an HTO can be performed to realign the mechanical axis of the lower limb towards the lateral compartment, thereby decreasing contact pressures in the medial compartment. Anterior cruciate ligament (ACL) insufficiency may lead to post-traumatic arthritis due to altered joint loading and associated injuries to the menisci and articular cartilage. Understanding the importance of posterior tibial slope and its role in sagittal knee stability has led to the development of biplane osteotomies designed to flatten the posterior tibial slope in the ACL deficient knee. Altering the alignment in both the sagittal and coronal planes helps improve stability as well as alter the load in the medial compartment. Detailed history, physical exam and radiographic analysis guide treatment decisions in this high demand patient population. Lateral closing wedge (LCW) and medial opening wedge (MOW) HTOs have been performed and their potential advantages and disadvantages have been well described. Given the triangular shape of the proximal tibia, it is imperative that the surgeon pay close attention to the geometry of the osteotomy "gap" when performing MOW HTO to avoid inadvertently increasing the posterior tibial slope. Simultaneous ACL reconstruction may require technique modifications depending on the type of HTO and ACL graft chosen. With appropriate patient selection and good surgical technique, it is reasonable to expect patients to return to activities of daily living and recreational sports without debilitating pain or instability. PMID:27358200

  20. Sparse Reconstruction Techniques in Magnetic Resonance Imaging: Methods, Applications, and Challenges to Clinical Adoption.

    PubMed

    Yang, Alice C; Kretzler, Madison; Sudarski, Sonja; Gulani, Vikas; Seiberlich, Nicole

    2016-06-01

    The family of sparse reconstruction techniques, including the recently introduced compressed sensing framework, has been extensively explored to reduce scan times in magnetic resonance imaging (MRI). While there are many different methods that fall under the general umbrella of sparse reconstructions, they all rely on the idea that a priori information about the sparsity of MR images can be used to reconstruct full images from undersampled data. This review describes the basic ideas behind sparse reconstruction techniques, how they could be applied to improve MRI, and the open challenges to their general adoption in a clinical setting. The fundamental principles underlying different classes of sparse reconstructions techniques are examined, and the requirements that each make on the undersampled data outlined. Applications that could potentially benefit from the accelerations that sparse reconstructions could provide are described, and clinical studies using sparse reconstructions reviewed. Lastly, technical and clinical challenges to widespread implementation of sparse reconstruction techniques, including optimization, reconstruction times, artifact appearance, and comparison with current gold standards, are discussed. PMID:27003227

  1. The Correlation of Tunnel Position, Orientation and Tunnel Enlargement in Outside-in Single-Bundle Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Ko, Young Won; Rhee, Seung Jun; Kim, In Woo

    2015-01-01

    Purpose Tunnel widening after anterior cruciate ligament (ACL) reconstruction is a frequently described phenomenon. The possible etiology is multi-factorial with some mechanical and biological factors. Among those, we intended to determine the relation between the location and orientation of the femoral tunnel and the femoral tunnel enlargement after outside-in single-bundle ACL reconstruction. Materials and Methods A retrospective study including 42 patients who received single-bundle ACL reconstruction with the outside-in technique was conducted. Femoral and tibial tunnel locations were evaluated with the quadrant method and bird's-eye view using volume-rendering computed tomography. The angle and diameter of bone tunnel and the degree of tunnel enlargement were evaluated using standard radiographs. Results The degree of femoral tunnel enlargements were 42% and 36% on the anteroposterior (AP) and lateral radiographs, respectively, and the degree of tibial tunnel enlargements were 22% and 23%, respectively. Shallower location of the femoral tunnel was significantly correlated with greater femoral tunnel enlargement on the AP radiograph (r=0.998, p=0.004) and the lateral radiograph (r=0.72, p=0.005) as was the higher location of the femoral tunnel on the AP radiograph (r=-0.47, p=0.01) and the lateral radiograph (r=-0.36, p=0.009) at 12 months after surgery. Conclusions This study revealed that more anterior and higher location and more horizontal orientation of the femoral tunnel in coronal plane could result in widening of the femoral tunnel in outside-in single-bundle ACL reconstruction. PMID:26672479

  2. Improvement of the background optical property reconstruction of the two-layered slab sample based on a region-stepwise-reconstruction method

    NASA Astrophysics Data System (ADS)

    Liu, Ming; Qin, Zhuanping; Jia, Mengyu; Zhao, Huijuan; Gao, Feng

    2015-03-01

    Two-layered slab is a rational simplified sample to the near-infrared functional brain imaging using diffuse optical tomography (DOT).The quality of reconstructed images is substantially affected by the accuracy of the background optical properties. In this paper, region step wise reconstruction method is proposed for reconstructing the background optical properties of the two-layered slab sample with the known geometric information based on continuous wave (CW) DOT. The optical properties of the top and bottom layers are respectively reconstructed utilizing the different source-detector-separation groups according to the depth of maximum brain sensitivity of the source-detector-separation. We demonstrate the feasibility of the proposed method and investigate the application range of the source-detector-separation groups by the numerical simulations. The numerical simulation results indicate the proposed method can effectively reconstruct the background optical properties of two-layered slab sample. The relative reconstruction errors are less than 10% when the thickness of the top layer is approximate 10mm. The reconstruction of target caused by brain activation is investigated with the reconstructed optical properties as well. The quantitativeness ratio of the ROI is about 80% which is higher than that of the conventional method. The spatial resolution of the reconstructions (R) with two targets is investigated, and it demonstrates R with the proposed method is better than that with the conventional method as well.

  3. The New Method of Tsunami Source Reconstruction With r-Solution Inversion Method

    NASA Astrophysics Data System (ADS)

    Voronina, T. A.; Romanenko, A. A.

    2016-04-01

    Application of the r- solution method to reconstructing the initial tsunami waveform is discussed. This methodology is based on the inversion of remote measurements of water-level data. The wave propagation is considered within the scope of a linear shallow-water theory. The ill-posed inverse problem in question is regularized by means of a least square inversion using the truncated Singular Value Decomposition method. As a result of the numerical process, an r-solution is obtained. The method proposed allows one to control the instability of a numerical solution and to obtain an acceptable result in spite of ill posedness of the problem. Implementation of this methodology to reconstructing of the initial waveform to 2013 Solomon Islands tsunami validates the theoretical conclusion for synthetic data and a model tsunami source: the inversion result strongly depends on data noisiness, the azimuthal and temporal coverage of recording stations with respect to the source area. Furthermore, it is possible to make a preliminary selection of the most informative set of the available recording stations used in the inversion process.

  4. Simultaneous denoising and reconstruction of 5D seismic data via damped rank-reduction method

    NASA Astrophysics Data System (ADS)

    Chen, Yangkang; Zhang, Dong; Jin, Zhaoyu; Chen, Xiaohong; Zu, Shaohuan; Huang, Weilin; Gan, Shuwei

    2016-06-01

    The Cadzow rank-reduction method can be effectively utilized in simultaneously denoising and reconstructing 5D seismic data that depends on four spatial dimensions. The classic version of Cadzow rank-reduction method arranges the 4D spatial data into a level-four block Hankel/Toeplitz matrix and then applies truncated singular value decomposition (TSVD) for rank-reduction. When the observed data is extremely noisy, which is often the feature of real seismic data, traditional TSVD cannot be adequate for attenuating the noise and reconstructing the signals. The reconstructed data tends to contain a significant amount of residual noise using the traditional TSVD method, which can be explained by the fact that the reconstructed data space is a mixture of both signal subspace and noise subspace. In order to better decompose the block Hankel matrix into signal and noise components, we introduced a damping operator into the traditional TSVD formula, which we call the damped rank-reduction method. The damped rank-reduction method can obtain a perfect reconstruction performance even when the observed data has extremely low signal-to-noise ratio (SNR). The feasibility of the improved 5D seismic data reconstruction method was validated via both 5D synthetic and field data examples. We presented comprehensive analysis of the data examples and obtained valuable experience and guidelines in better utilizing the proposed method in practice. Since the proposed method is convenient to implement and can achieve immediate improvement, we suggest its wide application in the industry.

  5. Simultaneous denoising and reconstruction of 5-D seismic data via damped rank-reduction method

    NASA Astrophysics Data System (ADS)

    Chen, Yangkang; Zhang, Dong; Jin, Zhaoyu; Chen, Xiaohong; Zu, Shaohuan; Huang, Weilin; Gan, Shuwei

    2016-09-01

    The Cadzow rank-reduction method can be effectively utilized in simultaneously denoising and reconstructing 5-D seismic data that depend on four spatial dimensions. The classic version of Cadzow rank-reduction method arranges the 4-D spatial data into a level-four block Hankel/Toeplitz matrix and then applies truncated singular value decomposition (TSVD) for rank reduction. When the observed data are extremely noisy, which is often the feature of real seismic data, traditional TSVD cannot be adequate for attenuating the noise and reconstructing the signals. The reconstructed data tend to contain a significant amount of residual noise using the traditional TSVD method, which can be explained by the fact that the reconstructed data space is a mixture of both signal subspace and noise subspace. In order to better decompose the block Hankel matrix into signal and noise components, we introduced a damping operator into the traditional TSVD formula, which we call the damped rank-reduction method. The damped rank-reduction method can obtain a perfect reconstruction performance even when the observed data have extremely low signal-to-noise ratio. The feasibility of the improved 5-D seismic data reconstruction method was validated via both 5-D synthetic and field data examples. We presented comprehensive analysis of the data examples and obtained valuable experience and guidelines in better utilizing the proposed method in practice. Since the proposed method is convenient to implement and can achieve immediate improvement, we suggest its wide application in the industry.

  6. Application of Symmetry Adapted Function Method for Three-Dimensional Reconstruction of Octahedral Biological Macromolecules

    PubMed Central

    Zeng, Songjun; Liu, Hongrong; Yang, Qibin

    2010-01-01

    A method for three-dimensional (3D) reconstruction of macromolecule assembles, that is, octahedral symmetrical adapted functions (OSAFs) method, was introduced in this paper and a series of formulations for reconstruction by OSAF method were derived. To verify the feasibility and advantages of the method, two octahedral symmetrical macromolecules, that is, heat shock protein Degp24 and the Red-cell L Ferritin, were utilized as examples to implement reconstruction by the OSAF method. The schedule for simulation was designed as follows: 2000 random orientated projections of single particles with predefined Euler angles and centers of origins were generated, then different levels of noises that is signal-to-noise ratio (S/N) = 0.1, 0.5, and 0.8 were added. The structures reconstructed by the OSAF method were in good agreement with the standard models and the relative errors of the structures reconstructed by the OSAF method to standard structures were very little even for high level noise. The facts mentioned above account for that the OSAF method is feasible and efficient approach to reconstruct structures of macromolecules and have ability to suppress the influence of noise. PMID:20150955

  7. A Parallel Reconstructed Discontinuous Galerkin Method for the Compressible Flows on Aritrary Grids

    SciTech Connect

    Hong Luo; Amjad Ali; Robert Nourgaliev; Vincent A. Mousseau

    2010-01-01

    A reconstruction-based discontinuous Galerkin method is presented for the solution of the compressible Navier-Stokes equations on arbitrary grids. In this method, an in-cell reconstruction is used to obtain a higher-order polynomial representation of the underlying discontinuous Galerkin polynomial solution and an inter-cell reconstruction is used to obtain a continuous polynomial solution on the union of two neighboring, interface-sharing cells. The in-cell reconstruction is designed to enhance the accuracy of the discontinuous Galerkin method by increasing the order of the underlying polynomial solution. The inter-cell reconstruction is devised to remove an interface discontinuity of the solution and its derivatives and thus to provide a simple, accurate, consistent, and robust approximation to the viscous and heat fluxes in the Navier-Stokes equations. A parallel strategy is also devised for the resulting reconstruction discontinuous Galerkin method, which is based on domain partitioning and Single Program Multiple Data (SPMD) parallel programming model. The RDG method is used to compute a variety of compressible flow problems on arbitrary meshes to demonstrate its accuracy, efficiency, robustness, and versatility. The numerical results demonstrate that this RDG method is third-order accurate at a cost slightly higher than its underlying second-order DG method, at the same time providing a better performance than the third order DG method, in terms of both computing costs and storage requirements.

  8. Neuromuscular Changes After Aerobic Exercise in People with Anterior Cruciate Ligament– Reconstructed Knees

    PubMed Central

    Dalton, Elizabeth C.; Pfile, Kate R.; Weniger, Gerald R.; Ingersoll, Christopher D.; Herman, Daniel; Hart, Joseph M.

    2011-01-01

    Context: Anterior cruciate ligament (ACL) reconstructions are common, especially in young, active people. The lower extremity neuromuscular adaptations seen after aerobic exercise provide information about how previously injured patients perform and highlight deficits and, hence, areas for focused treatment. Little information is available about neuromuscular performance after aerobic exercise in people with ACL reconstructions. Objective: To compare dynamic balance, gluteus medius muscle activation, vertical jump height, and hip muscle strength after aerobic exercise in people with ACL-reconstructed knees. Design: Case-control study. Setting: Research laboratory. Patients or Other Participants: Of 34 recreationally active volunteers, 17 had a unilateral primary ACL reconstruction at least 2 years earlier and 17 were matched controls. Intervention(s): All participants performed 20 minutes of aerobic exercise on a treadmill. Main Outcome Measure(s): We recorded dynamic, single-legged balance electromyographic gluteus medius muscle activation, single-legged vertical jump height, and maximum isometric strength for hip abduction, extension, and external rotation preexercise and postexercise. Results: Participants with ACL reconstructions exhibited shorter reach distances during dynamic balance tasks, indicating poorer dynamic balance, and less gluteus medius muscle electromyographic activation. Reductions in hip abduction and extension strength after exercise were noted in all participants; however, those with ACL reconstructions displayed greater hip extensor strength loss after aerobic exercise than did the control group. Conclusions: Neuromuscular changes after aerobic exercise exist in both patients with ACL reconstructions and controls. The former group may experience greater deficits in hip extensor strength after aerobic exercise. Reduced reach distances in people with ACL reconstructions may represent a protective mechanism against excessive tibiofemoral

  9. A Wearable Neuromuscular Device Reduces ACL Injury Risk in Female Soccer Athletes

    PubMed Central

    Decker, Michael John; Shaw, Matthew; Maddan, Casey; Campbell, Julie; Davidson, Bradley

    2016-01-01

    Objectives: Female soccer athletes have a three-fold greater risk of sustaining an ACL injury compared with their male counterparts yet only 1 in 5 teams engage in ACL risk reduction programs due to several participation barriers. The purpose of this study was to determine the effects of a wearable neuromuscular (WNM) device on postural control, performance and ACL injury risk in female soccer athletes. Methods: Seventy-nine elite youth and collegiate female soccer athletes (age range: 12-25 y) trained with a WNM device that applied bi-lateral, topical pressure to the medial quadriceps and hamstrings muscles (Topical Gear, Austin, TX). The athletes performed 7-9 weeks of pre-season training with the WNM device consisting of strength and conditioning exercises and on-field team practices (46-64 total hours of exposure). Postural control was measured in 15 athletes with and without the WNM device before and after the training program; and performance was measured in 25 athletes without the WNM device before and after the training program. Postural control was determined from a single-leg landing on a force plate from a horizontal distance normalized to leg length. The athletes were instructed to gain their balance as fast as possible upon landing and remain balanced for 5 seconds. The peak ground reaction forces (GRF) and the medial-lateral, anterior-posterior and net center of pressure (COP) velocities and displacement ranges were calculated during 2 seconds of single-leg stance. Performance measures including speed, power and endurance were measured from the 40 yard dash, vertical jump for height and the Beep test, respectively. A two-way repeated measures ANOVA and post-hoc comparisons were used to compare the postural variables; and t-tests were used to compare the performance tests (p=.05). ACL injury rates, the absolute risk reduction (ARR) and the number needed to treat (NNT) to prevent one ACL injury were calculated between the WNM intervention group and 11

  10. Iterative reconstruction methods in atmospheric tomography: FEWHA, Kaczmarz and Gradient-based algorithm

    NASA Astrophysics Data System (ADS)

    Ramlau, R.; Saxenhuber, D.; Yudytskiy, M.

    2014-07-01

    The problem of atmospheric tomography arises in ground-based telescope imaging with adaptive optics (AO), where one aims to compensate in real-time for the rapidly changing optical distortions in the atmosphere. Many of these systems depend on a sufficient reconstruction of the turbulence profiles in order to obtain a good correction. Due to steadily growing telescope sizes, there is a strong increase in the computational load for atmospheric reconstruction with current methods, first and foremost the MVM. In this paper we present and compare three novel iterative reconstruction methods. The first iterative approach is the Finite Element- Wavelet Hybrid Algorithm (FEWHA), which combines wavelet-based techniques and conjugate gradient schemes to efficiently and accurately tackle the problem of atmospheric reconstruction. The method is extremely fast, highly flexible and yields superior quality. Another novel iterative reconstruction algorithm is the three step approach which decouples the problem in the reconstruction of the incoming wavefronts, the reconstruction of the turbulent layers (atmospheric tomography) and the computation of the best mirror correction (fitting step). For the atmospheric tomography problem within the three step approach, the Kaczmarz algorithm and the Gradient-based method have been developed. We present a detailed comparison of our reconstructors both in terms of quality and speed performance in the context of a Multi-Object Adaptive Optics (MOAO) system for the E-ELT setting on OCTOPUS, the ESO end-to-end simulation tool.

  11. The Results of All-Inside Meniscus Repair Using the Viper Repair System Simultaneously with Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Kang, Hong Je; Kim, Kwang Mee; Cho, Hang Hwan; Espinosa, Johnsel C.

    2015-01-01

    Background Meniscus tears are commonly associated with anterior cruciate ligament (ACL) ruptures. It is essential to repair meniscal tears as much as possible to prevent early osteoarthritis and to gain additional stability in the knee joint. We evaluated the results of arthroscopic all-inside repair using the Meniscal Viper Repair System (Arthrex) on meniscus tears simultaneously with ACL reconstruction. Methods Nineteen out of 22 patients who were treated with arthroscopic all-inside repair using the Meniscal Viper Repair System for meniscus tear associated with ACL rupture were evaluated. ACL reconstructions were performed at the same period. The mean follow-up period was 16.5 months (range, 12 to 24 months). The clinical results of the meniscus repair were evaluated by symptoms (such as catching or locking), tenderness, effusion, range of motion limitation, and the McMurray test. Clinical success was defined by negative results in all five categories. The Hospital for Special Surgery (HSS) score was evaluated. Objective results were evaluated with secondary look arthroscopy or magnetic resonance imaging (MRI). The MRI results were categorized as completely repaired, incompletely repaired, and failure by Henning's classification. The results of second-look arthroscopy were evaluated with the criteria of meniscal healing. Results The clinical success rate was 95.4% and the HSS scores were 93.9 ± 5.4 at the final follow-up. According to Henning's classification, 15 out of 18 cases showed complete healing (83.3%) and two cases (11.1%) showed incomplete healing. Seventeen out of 18 cases that underwent second-look arthroscopy showed complete healing (94.4%) according to the criteria of meniscal healing. Only one case showed failure and the failure was due to a re-rupture at the sutured area. Complications of ACL reconstruction or meniscus repair were not present. Conclusions The results demonstrate that arthroscopic all-inside repair using the Meniscal Viper Repair

  12. A general few-projection method for tomographic reconstruction of samples consisting of several distinct materials

    NASA Astrophysics Data System (ADS)

    Myers, Glenn R.; Thomas, C. David L.; Paganin, David M.; Gureyev, Timur E.; Clement, John G.

    2010-01-01

    We present a method for tomographic reconstruction of objects containing several distinct materials, which is capable of accurately reconstructing a sample from vastly fewer angular projections than required by conventional algorithms. The algorithm is more general than many previous discrete tomography methods, as: (i) a priori knowledge of the exact number of materials is not required; (ii) the linear attenuation coefficient of each constituent material may assume a small range of a priori unknown values. We present reconstructions from an experimental x-ray computed tomography scan of cortical bone acquired at the SPring-8 synchrotron.

  13. A general few-projection method for tomographic reconstruction of samples consisting of several distinct materials

    SciTech Connect

    Myers, Glenn R.; Thomas, C. David L.; Clement, John G.; Paganin, David M.; Gureyev, Timur E.

    2010-01-11

    We present a method for tomographic reconstruction of objects containing several distinct materials, which is capable of accurately reconstructing a sample from vastly fewer angular projections than required by conventional algorithms. The algorithm is more general than many previous discrete tomography methods, as: (i) a priori knowledge of the exact number of materials is not required; (ii) the linear attenuation coefficient of each constituent material may assume a small range of a priori unknown values. We present reconstructions from an experimental x-ray computed tomography scan of cortical bone acquired at the SPring-8 synchrotron.

  14. MR-guided dynamic PET reconstruction with the kernel method and spectral temporal basis functions.

    PubMed

    Novosad, Philip; Reader, Andrew J

    2016-06-21

    Recent advances in dynamic positron emission tomography (PET) reconstruction have demonstrated that it is possible to achieve markedly improved end-point kinetic parameter maps by incorporating a temporal model of the radiotracer directly into the reconstruction algorithm. In this work we have developed a highly constrained, fully dynamic PET reconstruction algorithm incorporating both spectral analysis temporal basis functions and spatial basis functions derived from the kernel method applied to a co-registered T1-weighted magnetic resonance (MR) image. The dynamic PET image is modelled as a linear combination of spatial and temporal basis functions, and a maximum likelihood estimate for the coefficients can be found using the expectation-maximization (EM) algorithm. Following reconstruction, kinetic fitting using any temporal model of interest can be applied. Based on a BrainWeb T1-weighted MR phantom, we performed a realistic dynamic [(18)F]FDG simulation study with two noise levels, and investigated the quantitative performance of the proposed reconstruction algorithm, comparing it with reconstructions incorporating either spectral analysis temporal basis functions alone or kernel spatial basis functions alone, as well as with conventional frame-independent reconstruction. Compared to the other reconstruction algorithms, the proposed algorithm achieved superior performance, offering a decrease in spatially averaged pixel-level root-mean-square-error on post-reconstruction kinetic parametric maps in the grey/white matter, as well as in the tumours when they were present on the co-registered MR image. When the tumours were not visible in the MR image, reconstruction with the proposed algorithm performed similarly to reconstruction with spectral temporal basis functions and was superior to both conventional frame-independent reconstruction and frame-independent reconstruction with kernel spatial basis functions. Furthermore, we demonstrate that a joint spectral

  15. MR-guided dynamic PET reconstruction with the kernel method and spectral temporal basis functions

    NASA Astrophysics Data System (ADS)

    Novosad, Philip; Reader, Andrew J.

    2016-06-01

    Recent advances in dynamic positron emission tomography (PET) reconstruction have demonstrated that it is possible to achieve markedly improved end-point kinetic parameter maps by incorporating a temporal model of the radiotracer directly into the reconstruction algorithm. In this work we have developed a highly constrained, fully dynamic PET reconstruction algorithm incorporating both spectral analysis temporal basis functions and spatial basis functions derived from the kernel method applied to a co-registered T1-weighted magnetic resonance (MR) image. The dynamic PET image is modelled as a linear combination of spatial and temporal basis functions, and a maximum likelihood estimate for the coefficients can be found using the expectation-maximization (EM) algorithm. Following reconstruction, kinetic fitting using any temporal model of interest can be applied. Based on a BrainWeb T1-weighted MR phantom, we performed a realistic dynamic [18F]FDG simulation study with two noise levels, and investigated the quantitative performance of the proposed reconstruction algorithm, comparing it with reconstructions incorporating either spectral analysis temporal basis functions alone or kernel spatial basis functions alone, as well as with conventional frame-independent reconstruction. Compared to the other reconstruction algorithms, the proposed algorithm achieved superior performance, offering a decrease in spatially averaged pixel-level root-mean-square-error on post-reconstruction kinetic parametric maps in the grey/white matter, as well as in the tumours when they were present on the co-registered MR image. When the tumours were not visible in the MR image, reconstruction with the proposed algorithm performed similarly to reconstruction with spectral temporal basis functions and was superior to both conventional frame-independent reconstruction and frame-independent reconstruction with kernel spatial basis functions. Furthermore, we demonstrate that a joint spectral

  16. Adaptive region of interest method for analytical micro-CT reconstruction.

    PubMed

    Yang, Wanneng; Xu, Xiaochun; Bi, Kun; Zeng, Shaoqun; Liu, Qian; Chen, Shangbin

    2011-01-01

    The real-time imaging is important in automatic successive inspection with micro-computerized tomography (micro-CT). Generally, the size of the detector is chosen according to the most probable size of the measured object to acquire all the projection data. Given enough imaging area and imaging resolution of X-ray detector, the detector is larger than specimen projection area, which results in redundant data in the Sinogram. The process of real-time micro-CT is computation-intensive because of the large amounts of source and destination data. The speed of the reconstruction algorithm can't always meet the requirements of real-time applications. A preprocessing method called adaptive region of interest (AROI), which detects the object's boundaries automatically to focus the active Sinogram regions, is introduced into the analytical reconstruction algorithm in this paper. The AROI method reduces the volume of the reconstructing data and thus directly accelerates the reconstruction process. It has been further shown that image quality is not compromised when applying AROI, while the reconstruction speed is increased as the square of the ratio of the sizes of the detector and the specimen slice. In practice, the conch reconstruction experiment indicated that the process is accelerated by 5.2 times with AROI and the imaging quality is not degraded. Therefore, the AROI method improves the speed of analytical micro-CT reconstruction significantly. PMID:21422587

  17. Direct reconstruction of pharmacokinetic parameters in dynamic fluorescence molecular tomography by the augmented Lagrangian method

    NASA Astrophysics Data System (ADS)

    Zhu, Dianwen; Zhang, Wei; Zhao, Yue; Li, Changqing

    2016-03-01

    Dynamic fluorescence molecular tomography (FMT) has the potential to quantify physiological or biochemical information, known as pharmacokinetic parameters, which are important for cancer detection, drug development and delivery etc. To image those parameters, there are indirect methods, which are easier to implement but tend to provide images with low signal-to-noise ratio, and direct methods, which model all the measurement noises together and are statistically more efficient. The direct reconstruction methods in dynamic FMT have attracted a lot of attention recently. However, the coupling of tomographic image reconstruction and nonlinearity of kinetic parameter estimation due to the compartment modeling has imposed a huge computational burden to the direct reconstruction of the kinetic parameters. In this paper, we propose to take advantage of both the direct and indirect reconstruction ideas through a variable splitting strategy under the augmented Lagrangian framework. Each iteration of the direct reconstruction is split into two steps: the dynamic FMT image reconstruction and the node-wise nonlinear least squares fitting of the pharmacokinetic parameter images. Through numerical simulation studies, we have found that the proposed algorithm can achieve good reconstruction results within a small amount of time. This will be the first step for a combined dynamic PET and FMT imaging in the future.

  18. Fast wave-front reconstruction by solving the Sylvester equation with the alternating direction implicit method

    NASA Astrophysics Data System (ADS)

    Ren, Hongwu; Dekany, Richard

    2004-07-01

    Large degree-of-freedom real-time adaptive optics (AO) control requires reconstruction algorithms that are computationally efficient and readily parallelized for hardware implementation. In particular, we find the wave-front reconstruction for the Hudgin and Fried geometry can be cast into a form of the well-known Sylvester equation using the Kronecker product properties of matrices. We derive the filters and inverse filtering formulas for wave-front reconstruction in two-dimensional (2-D) Discrete Cosine Transform (DCT) domain for these two geometries using the Hadamard product concept of matrices and the principle of separable variables. We introduce a recursive filtering (RF) method for the wave-front reconstruction on an annular aperture, in which, an imbedding step is used to convert an annular-aperture wave-front reconstruction into a squareaperture wave-front reconstruction, and then solving the Hudgin geometry problem on the square aperture. We apply the Alternating Direction Implicit (ADI) method to this imbedding step of the RF algorithm, to efficiently solve the annular-aperture wave-front reconstruction problem at cost of order of the number of degrees of freedom, O(n). Moreover, the ADI method is better suited for parallel implementation and we describe a practical real-time implementation for AO systems of order 3,000 actuators.

  19. Reconstruction for 3D PET Based on Total Variation Constrained Direct Fourier Method

    PubMed Central

    Yu, Haiqing; Chen, Zhi; Zhang, Heye; Loong Wong, Kelvin Kian; Chen, Yunmei; Liu, Huafeng

    2015-01-01

    This paper presents a total variation (TV) regularized reconstruction algorithm for 3D positron emission tomography (PET). The proposed method first employs the Fourier rebinning algorithm (FORE), rebinning the 3D data into a stack of ordinary 2D data sets as sinogram data. Then, the resulted 2D sinogram are ready to be reconstructed by conventional 2D reconstruction algorithms. Given the locally piece-wise constant nature of PET images, we introduce the total variation (TV) based reconstruction schemes. More specifically, we formulate the 2D PET reconstruction problem as an optimization problem, whose objective function consists of TV norm of the reconstructed image and the data fidelity term measuring the consistency between the reconstructed image and sinogram. To solve the resulting minimization problem, we apply an efficient methods called the Bregman operator splitting algorithm with variable step size (BOSVS). Experiments based on Monte Carlo simulated data and real data are conducted as validations. The experiment results show that the proposed method produces higher accuracy than conventional direct Fourier (DF) (bias in BOSVS is 70% of ones in DF, variance of BOSVS is 80% of ones in DF). PMID:26398232

  20. Implementation of Open and Closed Kinetic Chain Quadriceps Strengthening Exercises after Anterior Cruciate Ligament Reconstruction.

    ERIC Educational Resources Information Center

    Ross, Michael D.; Denegar, Craig R.; Winzenried, Jay A.

    2001-01-01

    Reviews the effects of open kinetic chain (OKC) and closed kinetic chain (CKC) exercise on anterior cruciate ligament (ACL) strain and patellofemoral joint stress, suggesting a combination of the two for quadriceps strengthening after ACL reconstruction. Both OKC and CKC exercises may be modified and implemented for quadriceps strengthening after…

  1. Development of threedimensional optical correction method for reconstruction of flow field in droplet

    NASA Astrophysics Data System (ADS)

    Ko, Han Seo; Gim, Yeonghyeon; Kang, Seung-Hwan

    2015-11-01

    A three-dimensional optical correction method was developed to reconstruct droplet-based flow fields. For a numerical simulation, synthetic phantoms were reconstructed by a simultaneous multiplicative algebraic reconstruction technique using three projection images which were positioned at an offset angle of 45°. If the synthetic phantom in a conical object with refraction index which differs from atmosphere, the image can be distorted because a light is refracted on the surface of the conical object. Thus, the direction of the projection ray was replaced by the refracted ray which occurred on the surface of the conical object. In order to prove the method considering the distorted effect, reconstruction results of the developed method were compared with the original phantom. As a result, the reconstruction result of the method showed smaller error than that without the method. The method was applied for a Taylor cone which was caused by high voltage between a droplet and a substrate to reconstruct the three-dimensional flow fields for analysis of the characteristics of the droplet. This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Korean government (MEST) (No. 2013R1A2A2A01068653).

  2. Reconstruction of vibroacoustic responses of a highly nonspherical structure using Helmholtz equation least-squares method.

    PubMed

    Lu, Huancai; Wu, Sean F

    2009-03-01

    The vibroacoustic responses of a highly nonspherical vibrating object are reconstructed using Helmholtz equation least-squares (HELS) method. The objectives of this study are to examine the accuracy of reconstruction and the impacts of various parameters involved in reconstruction using HELS. The test object is a simply supported and baffled thin plate. The reason for selecting this object is that it represents a class of structures that cannot be exactly described by the spherical Hankel functions and spherical harmonics, which are taken as the basis functions in the HELS formulation, yet the analytic solutions to vibroacoustic responses of a baffled plate are readily available so the accuracy of reconstruction can be checked accurately. The input field acoustic pressures for reconstruction are generated by the Rayleigh integral. The reconstructed normal surface velocities are validated against the benchmark values, and the out-of-plane vibration patterns at several natural frequencies are compared with the natural modes of a simply supported plate. The impacts of various parameters such as number of measurement points, measurement distance, location of the origin of the coordinate system, microphone spacing, and ratio of measurement aperture size to the area of source surface of reconstruction on the resultant accuracy of reconstruction are examined. PMID:19275312

  3. Reconstruction Method for Optical Tomography Based on the Linearized Bregman Iteration with Sparse Regularization

    PubMed Central

    Leng, Chengcai; Yu, Dongdong; Zhang, Shuang; An, Yu; Hu, Yifang

    2015-01-01

    Optical molecular imaging is a promising technique and has been widely used in physiology, and pathology at cellular and molecular levels, which includes different modalities such as bioluminescence tomography, fluorescence molecular tomography and Cerenkov luminescence tomography. The inverse problem is ill-posed for the above modalities, which cause a nonunique solution. In this paper, we propose an effective reconstruction method based on the linearized Bregman iterative algorithm with sparse regularization (LBSR) for reconstruction. Considering the sparsity characteristics of the reconstructed sources, the sparsity can be regarded as a kind of a priori information and sparse regularization is incorporated, which can accurately locate the position of the source. The linearized Bregman iteration method is exploited to minimize the sparse regularization problem so as to further achieve fast and accurate reconstruction results. Experimental results in a numerical simulation and in vivo mouse demonstrate the effectiveness and potential of the proposed method. PMID:26421055

  4. Apparatus And Method For Reconstructing Data Using Cross-Parity Stripes On Storage Media

    DOEpatents

    Hughes, James Prescott

    2003-06-17

    An apparatus and method for reconstructing missing data using cross-parity stripes on a storage medium is provided. The apparatus and method may operate on data symbols having sizes greater than a data bit. The apparatus and method makes use of a plurality of parity stripes for reconstructing missing data stripes. The parity symbol values in the parity stripes are used as a basis for determining the value of the missing data symbol in a data stripe. A correction matrix is shifted along the data stripes, correcting missing data symbols as it is shifted. The correction is performed from the outside data stripes towards the inner data stripes to thereby use previously reconstructed data symbols to reconstruct other missing data symbols.

  5. Reconstruction Method for Optical Tomography Based on the Linearized Bregman Iteration with Sparse Regularization.

    PubMed

    Leng, Chengcai; Yu, Dongdong; Zhang, Shuang; An, Yu; Hu, Yifang

    2015-01-01

    Optical molecular imaging is a promising technique and has been widely used in physiology, and pathology at cellular and molecular levels, which includes different modalities such as bioluminescence tomography, fluorescence molecular tomography and Cerenkov luminescence tomography. The inverse problem is ill-posed for the above modalities, which cause a nonunique solution. In this paper, we propose an effective reconstruction method based on the linearized Bregman iterative algorithm with sparse regularization (LBSR) for reconstruction. Considering the sparsity characteristics of the reconstructed sources, the sparsity can be regarded as a kind of a priori information and sparse regularization is incorporated, which can accurately locate the position of the source. The linearized Bregman iteration method is exploited to minimize the sparse regularization problem so as to further achieve fast and accurate reconstruction results. Experimental results in a numerical simulation and in vivo mouse demonstrate the effectiveness and potential of the proposed method. PMID:26421055

  6. FUNCTIONAL PERFORMANCE AND KNEE LAXITY IN NORMAL INDIVIDUALS AND IN INDIVIDUALS SUBMITTED TO ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

    PubMed Central

    de Vasconcelos, Rodrigo Antunes; Bevilaqua-Grossi, Débora; Shimano, Antonio Carlos; Jansen Paccola, Cleber Antonio; Salvini, Tânia Fátima; Prado, Christiane Lanatovits; Mello Junior, Wilson A.

    2015-01-01

    The aim of this study was to analyze the correlation between deficits in the isokinetic peak torque of the knee extensors and flexors with hop tests, postoperative knee laxity and functional scores in normal and ACL- reconstructed subjects with patellar tendon and hamstring tendon autografts. Methods: Sixty male subjects were enrolled and subdivided into three groups: Twenty subjects without knee injuries (GC group) and two groups of 20 subjects submitted to ACL reconstruction with patellar tendon (GTP group) and hamstrings autograft (GTF group). Results: The results showed significant correlation between knee extensors peak torque and performance in the hop tests for GTF and GC groups. There are no significantly correlations between post op knee laxity and Lysholm score compared with the hop tests and peak torque deficits. Concerning the differences between groups, the GTP group showed greater peak torque deficits in knee extensors, worst Lysholm scores and higher percentage of individuals with lower limb symmetry index (ISM) < 90% in both hop tests when compared to the other two groups. Conclusion: It is not recommendable to use only one measurement instrument for the functional evaluation of ACL-reconstructed patients, because significant correlation between peak torque, subject's functional score, knee laxity and hop tests were not observed in all groups. PMID:26998464

  7. Review of evolution of tunnel position in anterior cruciate ligament reconstruction

    PubMed Central

    Rayan, Faizal; Nanjayan, Shashi Kumar; Quah, Conal; Ramoutar, Darryl; Konan, Sujith; Haddad, Fares S

    2015-01-01

    Anterior cruciate ligament (ACL) rupture is one of the commonest knee sport injuries. The annual incidence of the ACL injury is between 100000-200000 in the United States. Worldwide around 400000 ACL reconstructions are performed in a year. The goal of ACL reconstruction is to restore the normal knee anatomy and kinesiology. The tibial and femoral tunnel placements are of primordial importance in achieving this outcome. Other factors that influence successful reconstruction are types of grafts, surgical techniques and rehabilitation programmes. A comprehensive understanding of ACL anatomy has led to the development of newer techniques supplemented by more robust biological and mechanical concepts. In this review we are mainly focussing on the evolution of tunnel placement in ACL reconstruction, focusing on three main categories, i.e., anatomical, biological and clinical outcomes. The importance of tunnel placement in the success of ACL reconstruction is well researched. Definite clinical and functional data is lacking to establish the superiority of the single or double bundle reconstruction technique. While there is a trend towards the use of anteromedial portals for femoral tunnel placement, their clinical superiority over trans-tibial tunnels is yet to be established. PMID:25793165

  8. The feasibility of images reconstructed with the method of sieves

    SciTech Connect

    Veklerov, E.; Llacer, J.

    1989-04-01

    The concept of sieves has been applied with the Maximum likelihood Estimator (MLE) to image reconstruction. While it makes it possible to recover smooth images consistent with the data, the degree of smoothness provided by it is arbitrary. It is shown that the concept of feasibility is able to resolve this arbitrariness. By varying the values of parameters determining the degree of smoothness, one can generate images on both sides of the feasibility region, as well as within the region. Feasible images recovered by using different sieve parameters are compared with feasible results of other procedures. One- and two-dimensional examples using both simulated and real data sets are considered. 12 refs., 3 figs., 2 tabs.

  9. Possible methods of reconstructing conveyor gallery span structures

    SciTech Connect

    Kolesnichenko, V.G.; Beizer, V.N.; Raskina, A.M.

    1983-01-01

    Problems of reconstruction of industrial buildings and structures are acquiring increasing national economic importance. The Makeevka Construction Engineering Institute of the conducted investigations of the design of the conveyor galleries at the Yasinovka and Makeevka Coke Works, in operation for 20-40 years. The bearing constructions of the span structures are generally welded (in the old galleries riveted) metal trusses. The principal trusses are predominantly made discontinuous with spans of 10-40 m, supported by hinges on intermediate lattice columns, connected through the upper and lower horizontal strips by ties (see figure, a). The height of the main trusses corresponds to the height of the galleries (2.3-3.4 m). The width of a gallery depends on the width and number of conveyors; for galleries with a single conveyor it is 3.1-3.8 m, and 5.5-7.1 m for a gallery with two conveyors.

  10. Modified Method of Increasing of Reconstruction Quality of Diffractive Optical Elements Displayed with LC SLM

    NASA Astrophysics Data System (ADS)

    Krasnov, V. V.; Cheremkhin, P. A.; Erkin, I. Yu.; Evtikhiev, N. N.; Starikov, R. S.; Starikov, S. N.

    Modified method of increasing of reconstruction quality of diffractive optical elements (DOE) displayed with liquid crystal (LC) spatial light modulators (SLM) is presented. Method is based on optimization of DOE synthesized with conventional method by application of direct search with random trajectory method while taking into account LC SLM phase fluctuations. Reduction of synthesis error up to 88% is achieved.

  11. Compensation for acoustic heterogeneities in photoacoustic computed tomography using a variable temporal data truncation reconstruction method

    NASA Astrophysics Data System (ADS)

    Poudel, Joemini; Matthews, Thomas P.; Anastasio, Mark A.; Wang, Lihong V.

    2016-03-01

    Photoacoustic computed tomography (PACT) is an emerging computed imaging modality that exploits optical contrast and ultrasonic detection principles to form images of the absorbed optical energy density within tissue. If the object possesses spatially variant acoustic properties that are unaccounted for by the reconstruction algorithm, the estimated image can contain distortions. While reconstruction algorithms have recently been developed for compensating for this effect, they generally require the objects acoustic properties to be known a priori. To circumvent the need for detailed information regarding an objects acoustic properties, we have previously proposed a half-time reconstruction method for PACT. A half-time reconstruction method estimates the PACT image from a data set that has been temporally truncated to exclude the data components that have been strongly aberrated. In this approach, the degree of temporal truncation is the same for all measurements. However, this strategy can be improved upon it when the approximate sizes and locations of strongly heterogeneous structures such as gas voids or bones are known. In this work, we investigate PACT reconstruction algorithms that are based on a variable temporal data truncation (VTDT) approach that represents a generalization of the half-time reconstruction approach. In the VTDT approach, the degree of temporal truncation for each measurement is determined by the distance between the corresponding transducer location and the nearest known bone or gas void location. Reconstructed images from a numerical phantom is employed to demonstrate the feasibility and effectiveness of the approach.

  12. Magnetic Field Configuration Models and Reconstruction Methods for Interplanetary Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Al-Haddad, N.; Nieves-Chinchilla, T.; Savani, N. P.; Möstl, C.; Marubashi, K.; Hidalgo, M. A.; Roussev, I. I.; Poedts, S.; Farrugia, C. J.

    2013-05-01

    This study aims to provide a reference for different magnetic field models and reconstruction methods for interplanetary coronal mass ejections (ICMEs). To understand the differences in the outputs of these models and codes, we analyzed 59 events from the Coordinated Data Analysis Workshop (CDAW) list, using four different magnetic field models and reconstruction techniques; force-free fitting, magnetostatic reconstruction using a numerical solution to the Grad-Shafranov equation, fitting to a self-similarly expanding cylindrical configuration and elliptical, non-force-free fitting. The resulting parameters of the reconstructions for the 59 events are compared statistically and in selected case studies. The ability of a method to fit or reconstruct an event is found to vary greatly; this depends on whether the event is a magnetic cloud or not. We find that the magnitude of the axial field is relatively consistent across models, but that the axis orientation of the ejecta is not. We also find that there are a few cases with different signs of the magnetic helicity for the same event when we leave the boundaries free to vary, which illustrates that this simplest of parameters is not necessarily always clearly constrained by fitting and reconstruction models. Finally, we examine three unique cases in depth to provide a comprehensive idea of the different aspects of how the fitting and reconstruction codes work.

  13. Addition of Autologous Mesenchymal Stem Cells to Whole Blood for Bio-Enhanced ACL Repair has No Benefit in the Porcine Model

    PubMed Central

    Proffen, Benedikt L.; Vavken, Patrick; Haslauer, Carla M.; Fleming, Braden C.; Harris, Chad E.; Machan, Jason T.; Murray, Martha M.

    2015-01-01

    Background Co-culture of mesenchymal stem cells (MSCs) from the retropatellar fat pad and peripheral blood has been shown to stimulate anterior cruciate ligament (ACL) fibroblast proliferation and collagen production in vitro. Current techniques of bio-enhanced ACL repair in animal studies involve adding a biologic scaffold, in this case an extracellular matrix based scaffold saturated with autologous whole blood, to a simple suture repair of the ligament. Whether the enrichment of whole blood with MSCs would further improve the in vivo results of bio-enhanced ACL repair was investigated. Hypothesis/Purpose The hypothesis was that the addition of MSCs derived from adipose tissue or peripheral blood to the blood-extracellular matrix composite, which is used in bio-enhanced ACL repair to stimulate healing, would improve the biomechanical properties of a bio-enhanced ACL repair after 15 weeks of healing. Study Design Controlled laboratory study. Methods Twenty-four adolescent Yucatan mini-pigs underwent ACL transection followed by: 1) bio-enhanced ACL repair, 2) bio-enhanced ACL repair with the addition of autologous adipose-derived MSCs and 3) bio-enhanced ACL repair with the addition of autologous peripheral blood derived MSCs. After fifteen weeks of healing, structural properties of the ACL (yield & failure load, linear stiffness) were measured. Cell and vascular density were measured in the repaired ACL via histology, and its tissue structure was qualitatively evaluated using the Advanced Ligament Maturity Index. Results After fifteen weeks of healing, there were no significant improvements in the biomechanical or histological properties with the addition of adipose-derived MSCs. The only significant change with the addition of peripheral blood MSCs was an increase in knee anteroposterior (AP) laxity when measured at 30 degrees of flexion. Conclusions These findings suggest that the addition of adipose or peripheral blood MSCs to whole blood prior to saturation of

  14. Tibial Tunnel Cyst Formation after Anterior Cruciate Ligament Reconstruction Using a Non-Bioabsorbable Interference Screw

    PubMed Central

    Joshi, Yogesh V.; Phaltankar, Padmanabh M.; Charalambous, Charalambos P.

    2015-01-01

    Tibial cyst formation following the use of bioabsorbable interference screws in anterior cruciate ligament (ACL) reconstruction is well-described; however, cyst formation after the use of metallic interference screws is not well-documented. We describe a case of osteolytic lesion of the proximal tibia presenting to us 20 years after ACL reconstruction using an autologous bone-tendon-bone graft. The original graft fixation technique was interference fixation with a metal screw in the tibial and femoral tunnels. A two-stage revision reconstruction of the ACL was undertaken with curettage and bone grafting of the tibial lesion in the first stage and reconstruction using a four-strand hamstring tendon in the second stage. The patient recovered satisfactorily with complete healing of the cyst and returned to pre-injury level of activities. We have reviewed case reports and case series that describe the aetiology of intra-osseous cyst formation following ACL reconstruction. PMID:26673117

  15. Tibial Tunnel Cyst Formation after Anterior Cruciate Ligament Reconstruction Using a Non-Bioabsorbable Interference Screw.

    PubMed

    Joshi, Yogesh V; Bhaskar, Deepu; Phaltankar, Padmanabh M; Charalambous, Charalambos P

    2015-12-01

    Tibial cyst formation following the use of bioabsorbable interference screws in anterior cruciate ligament (ACL) reconstruction is well-described; however, cyst formation after the use of metallic interference screws is not well-documented. We describe a case of osteolytic lesion of the proximal tibia presenting to us 20 years after ACL reconstruction using an autologous bone-tendon-bone graft. The original graft fixation technique was interference fixation with a metal screw in the tibial and femoral tunnels. A two-stage revision reconstruction of the ACL was undertaken with curettage and bone grafting of the tibial lesion in the first stage and reconstruction using a four-strand hamstring tendon in the second stage. The patient recovered satisfactorily with complete healing of the cyst and returned to pre-injury level of activities. We have reviewed case reports and case series that describe the aetiology of intra-osseous cyst formation following ACL reconstruction. PMID:26673117

  16. Wide-spectrum reconstruction method for a birefringence interference imaging spectrometer.

    PubMed

    Zhang, Chunmin; Jian, Xiaohua

    2010-02-01

    We present a mathematical method used to determine the spectrum detected by a birefringence interference imaging spectrometer (BIIS). The reconstructed spectrum has good precision over a wide spectral range, 0.4-1.0 microm. This method considers the light intensity as a function of wavelength and avoids the fatal error caused by birefringence effect in the conventional Fourier transform method. The experimental interferogram of the BIIS is processed in this new way, and the interference data and reconstructed spectrum are in good agreement, proving this method to be very exact and useful. Application of this method will greatly improve the instrument performance. PMID:20125723

  17. Adaptive Forward Modeling Method for Analysis and Reconstructions of Orientation Image Map

    SciTech Connect

    Frankie Li, Shiu Fai

    2014-06-01

    IceNine is a MPI-parallel orientation reconstruction and microstructure analysis code. It's primary purpose is to reconstruct a spatially resolved orientation map given a set of diffraction images from a high energy x-ray diffraction microscopy (HEDM) experiment (1). In particular, IceNine implements the adaptive version of the forward modeling method (2, 3). Part of IceNine is a library used to for conbined analysis of the microstructure with the experimentally measured diffraction signal. The libraries is also designed for tapid prototyping of new reconstruction and analysis algorithms. IceNine is also built with a simulator of diffraction images with an input microstructure.

  18. Comparison of kinoform synthesis methods for image reconstruction in Fourier plane

    NASA Astrophysics Data System (ADS)

    Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Porshneva, Liudmila A.; Rodin, Vladislav G.; Starikov, Sergey N.

    2014-05-01

    Kinoform is synthesized phase diffractive optical element which allows to reconstruct image by its illumination with plane wave. Kinoforms are used in image processing systems. For tasks of kinoform synthesis iterative methods had become wide-spread because of relatively small error of resulting intensity distribution. There are articles in which two or three iterative methods are compared but they use only one or several test images. The goal of this work is to compare iterative methods by using many test images of different types. Images were reconstructed in Fourier plane from synthesized kinoforms displayed on phase-only LCOS SLM. Quality of reconstructed images and computational resources of the methods were analyzed. For kinoform synthesis four methods were implemented in programming environment: Gerchberg-Saxton algorithm (GS), Fienup algorithm (F), adaptive-additive algorithm (AA) and Gerchberg-Saxton algorithm with weight coefficients (GSW). To compare these methods 50 test images with different characteristics were used: binary and grayscale, contour and non-contour. Resolution of images varied from 64×64 to 1024×1024. Occupancy of images ranged from 0.008 to 0.89. Quantity of phase levels of synthesized kinoforms was 256 which is equal to number of phase levels of SLM LCOS HoloEye PLUTO VIS. Under numerical testing it was found that the best quality of reconstructed images provides the AA method. The GS, F and GSW methods showed worse results but roughly similar between each other. Execution time of single iteration of the analyzed methods is minimal for the GS method. The F method provides maximum execution time. Synthesized kinoforms were optically reconstructed using phase-only LCOS SLM HoloEye PLUTO VIS. Results of optical reconstruction were compared to the numerical ones. The AA method showed slightly better results than other methods especially in case of gray-scale images.

  19. A Penalized Linear and Nonlinear Combined Conjugate Gradient Method for the Reconstruction of Fluorescence Molecular Tomography

    PubMed Central

    Shang, Shang; Bai, Jing; Song, Xiaolei; Wang, Hongkai; Lau, Jaclyn

    2007-01-01

    Conjugate gradient method is verified to be efficient for nonlinear optimization problems of large-dimension data. In this paper, a penalized linear and nonlinear combined conjugate gradient method for the reconstruction of fluorescence molecular tomography (FMT) is presented. The algorithm combines the linear conjugate gradient method and the nonlinear conjugate gradient method together based on a restart strategy, in order to take advantage of the two kinds of conjugate gradient methods and compensate for the disadvantages. A quadratic penalty method is adopted to gain a nonnegative constraint and reduce the illposedness of the problem. Simulation studies show that the presented algorithm is accurate, stable, and fast. It has a better performance than the conventional conjugate gradient-based reconstruction algorithms. It offers an effective approach to reconstruct fluorochrome information for FMT. PMID:18354740

  20. A Fast Edge Preserving Bayesian Reconstruction Method for Parallel Imaging Applications in Cardiac MRI

    PubMed Central

    Singh, Gurmeet; Raj, Ashish; Kressler, Bryan; Nguyen, Thanh D.; Spincemaille, Pascal; Zabih, Ramin; Wang, Yi

    2010-01-01

    Among recent parallel MR imaging reconstruction advances, a Bayesian method called Edge-preserving Parallel Imaging with GRAph cut Minimization (EPIGRAM) has been demonstrated to significantly improve signal to noise ratio (SNR) compared to conventional regularized sensitivity encoding (SENSE) method. However, EPIGRAM requires a large number of iterations in proportion to the number of intensity labels in the image, making it computationally expensive for high dynamic range images. The objective of this study is to develop a Fast EPIGRAM reconstruction based on the efficient binary jump move algorithm that provides a logarithmic reduction in reconstruction time while maintaining image quality. Preliminary in vivo validation of the proposed algorithm is presented for 2D cardiac cine MR imaging and 3D coronary MR angiography at acceleration factors of 2-4. Fast EPIGRAM was found to provide similar image quality to EPIGRAM and maintain the previously reported SNR improvement over regularized SENSE, while reducing EPIGRAM reconstruction time by 25-50 times. PMID:20939095

  1. On climate reconstruction using bivalves: three methods to interpret the chemical signature of a shell.

    PubMed

    Bauwens, Maite; Ohlsson, Henrik; Barbé, Kurt; Beelaerts, Veerle; Dehairs, Frank; Schoukens, Johan

    2011-11-01

    To improve our understanding of the climate process and to assess the human impact on current global warming, past climate reconstruction is essential. The chemical composition of a bivalve shell is strongly coupled to environmental variations and therefore ancient shells are potential climate archives. The nonlinear nature of the relation between environmental condition (e.g. the seawater temperature) and proxy composition makes it hard to predict the former from the latter, however. In this paper we compare the ability of three nonlinear system identification methods to reconstruct the ambient temperature from the chemical composition of a shell. The comparison shows that nonlinear multi-proxy approaches are potentially useful tools for climate reconstructions and that manifold based methods result in smoother and more precise temperature reconstruction. PMID:20888663

  2. A two-step Hilbert transform method for 2D image reconstruction.

    PubMed

    Noo, Frédéric; Clackdoyle, Rolf; Pack, Jed D

    2004-09-01

    The paper describes a new accurate two-dimensional (2D) image reconstruction method consisting of two steps. In the first step, the backprojected image is formed after taking the derivative of the parallel projection data. In the second step, a Hilbert filtering is applied along certain lines in the differentiated backprojection (DBP) image. Formulae for performing the DBP step in fanbeam geometry are also presented. The advantage of this two-step Hilbert transform approach is that in certain situations, regions of interest (ROIs) can be reconstructed from truncated projection data. Simulation results are presented that illustrate very similar reconstructed image quality using the new method compared to standard filtered backprojection, and that show the capability to correctly handle truncated projections. In particular, a simulation is presented of a wide patient whose projections are truncated laterally yet for which highly accurate ROI reconstruction is obtained. PMID:15470913

  3. Evaluation of time-efficient reconstruction methods in digital breast tomosynthesis.

    PubMed

    Svahn, T M; Houssami, N

    2015-07-01

    Three reconstruction algorithms for digital breast tomosynthesis were compared in this article: filtered back-projection (FBP), iterative adapted FBP and maximum likelihood-convex iterative algorithms. Quality metrics such as signal-difference-to-noise ratio, normalised line-profiles and artefact-spread function were used for evaluation of reconstructed tomosynthesis images. The iterative-based methods offered increased image quality in terms of higher detectability and reduced artefacts, which will be further examined in clinical images. PMID:25855075

  4. Novel l2,1-norm optimization method for fluorescence molecular tomography reconstruction

    PubMed Central

    Jiang, Shixin; Liu, Jie; An, Yu; Zhang, Guanglei; Ye, Jinzuo; Mao, Yamin; He, Kunshan; Chi, Chongwei; Tian, Jie

    2016-01-01

    Fluorescence molecular tomography (FMT) is a promising tomographic method in preclinical research, which enables noninvasive real-time three-dimensional (3-D) visualization for in vivo studies. The ill-posedness of the FMT reconstruction problem is one of the many challenges in the studies of FMT. In this paper, we propose a l2,1-norm optimization method using a priori information, mainly the structured sparsity of the fluorescent regions for FMT reconstruction. Compared to standard sparsity methods, the structured sparsity methods are often superior in reconstruction accuracy since the structured sparsity utilizes correlations or structures of the reconstructed image. To solve the problem effectively, the Nesterov’s method was used to accelerate the computation. To evaluate the performance of the proposed l2,1-norm method, numerical phantom experiments and in vivo mouse experiments are conducted. The results show that the proposed method not only achieves accurate and desirable fluorescent source reconstruction, but also demonstrates enhanced robustness to noise. PMID:27375949

  5. 50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the ABC recommended by the SSC. (1) (2) Periodicity. The tilefish commercial ACL may be established on...-year ABC recommendations. (b) Performance review. The Tilefish Monitoring Committee shall conduct...

  6. 50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the ABC recommended by the SSC. (1) (2) Periodicity. The tilefish commercial ACL may be established on...-year ABC recommendations. (b) Performance review. The Tilefish Monitoring Committee shall conduct...

  7. 50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the ABC recommended by the SSC. (1) (2) Periodicity. The tilefish commercial ACL may be established on...-year ABC recommendations. (b) Performance review. The Tilefish Monitoring Committee shall conduct...

  8. 50 CFR 648.160 - Bluefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the ABC recommended by the SSC. (1) Periodicity. The bluefish fishery ACL may be established on an... ABC recommendations. (2) (b) Performance review. The Bluefish Monitoring Committee shall conduct...

  9. 50 CFR 648.160 - Bluefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the ABC recommended by the SSC. (1) Periodicity. The bluefish fishery ACL may be established on an... ABC recommendations. (2) (b) Performance review. The Bluefish Monitoring Committee shall conduct...

  10. 50 CFR 648.160 - Bluefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the ABC recommended by the SSC. (1) Periodicity. The bluefish fishery ACL may be established on an... ABC recommendations. (2) (b) Performance review. The Bluefish Monitoring Committee shall conduct...

  11. Repaired ACL More Likely to Tear Again in Young Women

    MedlinePlus

    ... a repeat tear of the knee's anterior cruciate ligament (ACL) after surgery to repair it, a new ... 7 at the society's annual meeting in Colorado Springs, Colo. Research presented at medical meetings is typically ...

  12. An adaptive total variation image reconstruction method for speckles through disordered media

    NASA Astrophysics Data System (ADS)

    Gong, Changmei; Shao, Xiaopeng; Wu, Tengfei

    2013-09-01

    Multiple scattering of light in highly disordered medium can break the diffraction limit of conventional optical system combined with image reconstruction method. Once the transmission matrix of the imaging system is obtained, the target image can be reconstructed from its speckle pattern by image reconstruction algorithm. Nevertheless, the restored image attained by common image reconstruction algorithms such as Tikhonov regularization has a relatively low signal-tonoise ratio (SNR) due to the experimental noise and reconstruction noise, greatly reducing the quality of the result image. In this paper, the speckle pattern of the test image is simulated by the combination of light propagation theories and statistical optics theories. Subsequently, an adaptive total variation (ATV) algorithm—the TV minimization by augmented Lagrangian and alternating direction algorithms (TVAL3), which is based on augmented Lagrangian and alternating direction algorithm, is utilized to reconstruct the target image. Numerical simulation experimental results show that, the TVAL3 algorithm can effectively suppress the noise of the restored image and preserve more image details, thus greatly boosts the SNR of the restored image. It also indicates that, compared with the image directly formed by `clean' system, the reconstructed results can overcoming the diffraction limit of the `clean' system, therefore being conductive to the observation of cells and protein molecules in biological tissues and other structures in micro/nano scale.

  13. Functional results from reconstruction of the anterior cruciate ligament using the central third of the patellar ligament and flexor tendons☆

    PubMed Central

    de Souza Leao, Marcos George; Pampolha, Abelardo Gautama Moreira; Orlando Junior, Nilton

    2015-01-01

    Objectives To evaluate knee function in patients undergoing reconstruction of the anterior cruciate ligament (ACL) using the central third of the patellar ligament or the medial flexor tendons of the knee, i.e. quadruple ligaments from the semitendinosus and gracilis (ST-G), by means of the Knee Society Score (KSS) and the Lysholm scale. Methods This was a randomized prospective longitudinal study on 40 patients who underwent arthroscopic ACL reconstruction between September 2013 and August 2014. They comprised 37 males and three females, with ages ranging from 16 to 52 years. The patients were numbered randomly from 1 to 40: the even numbers underwent surgical correction using the ST-G tendons and the odd numbers, using the patellar tendon. Functional evaluations were made using the KSS and Lysholm scale, applied in the evening before the surgical procedure and six months after the operation. Results From the statistical analysis, it could be seen that the patients’ functional capacity was significantly greater after the operation than before the operation. There was strong evidence that the two forms of therapy had similar results (p = >0.05), in all the comparisons. Conclusions The results from the ACL reconstructions were similar with regard to functional recovery of the knee and improvement of quality of life, independent of the type of graft. It was not possible to identify the best method of surgical treatment. The surgeon's clinical and technical experience and the patient are the factors that determine the choice of graft type for use in ACL surgery. PMID:27218084

  14. A Reconstructed Discontinuous Galerkin Method for the Compressible Euler Equations on Arbitrary Grids

    SciTech Connect

    Hong Luo; Luquing Luo; Robert Nourgaliev; Vincent Mousseau

    2009-06-01

    A reconstruction-based discontinuous Galerkin (DG) method is presented for the solution of the compressible Euler equations on arbitrary grids. By taking advantage of handily available and yet invaluable information, namely the derivatives, in the context of the discontinuous Galerkin methods, a solution polynomial of one degree higher is reconstructed using a least-squares method. The stencils used in the reconstruction involve only the van Neumann neighborhood (face-neighboring cells) and are compact and consistent with the underlying DG method. The resulting DG method can be regarded as an improvement of a recovery-based DG method in the sense that it shares the same nice features as the recovery-based DG method, such as high accuracy and efficiency, and yet overcomes some of its shortcomings such as a lack of flexibility, compactness, and robustness. The developed DG method is used to compute a variety of flow problems on arbitrary meshes to demonstrate the accuracy and efficiency of the method. The numerical results indicate that this reconstructed DG method is able to obtain a third-order accurate solution at a slightly higher cost than its second-order DG method and provide an increase in performance over the third order DG method in terms of computing time and storage requirement.

  15. Reconstructed imaging of acoustic cloak using time-lapse reversal method

    NASA Astrophysics Data System (ADS)

    Zhou, Chen; Cheng, Ying; Xu, Jian-yi; Li, Bo; Liu, Xiao-jun

    2014-08-01

    We proposed and investigated a solution to the inverse acoustic cloak problem, an anti-stealth technology to make cloaks visible, using the time-lapse reversal (TLR) method. The TLR method reconstructs the image of an unknown acoustic cloak by utilizing scattered acoustic waves. Compared to previous anti-stealth methods, the TLR method can determine not only the existence of a cloak but also its exact geometric information like definite shape, size, and position. Here, we present the process for TLR reconstruction based on time reversal invariance. This technology may have potential applications in detecting various types of cloaks with different geometric parameters.

  16. CuRe - A new wavefront reconstruction method for SH-WFS measurements

    NASA Astrophysics Data System (ADS)

    Obereder, Andreas; Ramlau, Ronny; Rosensteiner, Matthias; Zhariy, Mariya

    2011-09-01

    In order to fulfill the real-time requirements for AO on ELTs, one has to either invest in (very) high performance hardware or spend some effort on the development of highly efficient reconstruction algorithms for wavefront sensors. The AAO (Austrian Adaptive Optics) team is involved in deriving wavefront reconstructors for SH- and Pyramid-WFS measurements utilizing the mathematical properties of the forward operators for these wavefront sensors. At the moment, we focus mainly on direct reconstructors with complexity O(n) (where n denotes the number of subapertures of the WFS) to make the reconstruction scalable for large telescopes. In this talk we will introduce a new algorithm, the Cumulative Reconstructor (CuRe), present its properties, namely error propagation of the method and the numerical effort for the reconstruction of the incoming wavefront, as well as first results concerning the quality of the method (dependent on different noise sources). Further improvements of the algorithm, especially a domain decomposition method for enhancing reconstruction quality and improving the overall speed of the algorithm will be presented and analyzed. A speed comparison with different wavefront reconstruction algorithms will be presented to point out the enormous gain of the new CuReD (Cumulative Reconstructor with Domain Decomposition) algorithm concerning numerical performance and applicability for real life telescope adaptive optics applications. In the outlook of the talk we will present first XAO results utilizing a variant of the CuReD for the reconstruction of modulated Pyramid WFS measurements.

  17. Psychological Factors Associated With Anterior Cruciate Ligament Reconstruction Recovery

    PubMed Central

    Christino, Melissa A.; Fleming, Braden C.; Machan, Jason T.; Shalvoy, Robert M.

    2016-01-01

    Background: Psychological factors may have underappreciated effects on surgical outcomes after anterior cruciate ligament (ACL) reconstruction; however, few studies have investigated the relationship between specific psychological factors, objective clinical data, and patient-oriented outcomes. Purpose: Psychological factors are significantly associated with patient perceptions and functional outcomes after ACL reconstruction. The purpose of this study was to demonstrate relationships between self-esteem, health locus of control, and psychological distress with objective clinical outcomes, patient-oriented outcomes, and return to sport. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Twenty-seven patients who were 6 to 24 months post–computer-assisted ACL reconstruction by a single surgeon consented to participate in the study (52% response rate). Participants had a 1-time visit with a physician consisting of: a physical examination, a single-leg hop test, KT-1000 arthrometer measurements, and survey completion. Psychological measures included the Multidimensional Health Locus of Control Scale, Rosenberg Self-Esteem Scale, and Brief Profile of Mood States. Outcome measures included the Tegner activity scale, International Knee Documentation Committee (IKDC) Subjective Knee Score, Knee injury and Osteoarthritis Outcome Score–Quality of Life subscale (KOOS-QOL), and Short Form–36 (SF-36). Patient charts were also reviewed for pertinent operative details. Results: The mean age of patients (±SD) was 25.7 ± 8.4 years, and the mean duration of time since surgery was 16.5 ± 5.9 months. The majority (89%) of the patients identified themselves as athletes, and of these, 65% reported returning to sports at a competitive level. Sport returners were found to have higher levels of self-esteem (P = .002) and higher reported KOOS-QOL scores (P = .02). Self-esteem was significantly associated with IKDC scores (r = 0.46, P < .05), KOOS-QOL scores (r = 0

  18. Tests of one Brazilian facial reconstruction method using three soft tissue depth sets and familiar assessors.

    PubMed

    Fernandes, Clemente Maia S; Serra, Mônica da Costa; da Silva, Jorge Vicente Lopes; Noritomi, Pedro Yoshito; Pereira, Frederico David Alencar de Sena; Melani, Rodolfo Francisco Haltenhoff

    2012-01-10

    Facial reconstruction is a method that seeks to recreate a person's facial appearance from his/her skull. This technique can be the last resource used in a forensic investigation, when identification techniques such as DNA analysis, dental records, fingerprints and radiographic comparison cannot be used to identify a body or skeletal remains. To perform facial reconstruction, the data of facial soft tissue thickness are necessary. Scientific literature has described differences in the thickness of facial soft tissue between ethnic groups. There are different databases of soft tissue thickness published in the scientific literature. There are no literature records of facial reconstruction works carried out with data of soft tissues obtained from samples of Brazilian subjects. There are also no reports of digital forensic facial reconstruction performed in Brazil. There are two databases of soft tissue thickness published for the Brazilian population: one obtained from measurements performed in fresh cadavers (fresh cadavers' pattern), and another from measurements using magnetic resonance imaging (Magnetic Resonance pattern). This study aims to perform three different characterized digital forensic facial reconstructions (with hair, eyelashes and eyebrows) of a Brazilian subject (based on an international pattern and two Brazilian patterns for soft facial tissue thickness), and evaluate the digital forensic facial reconstructions comparing them to photos of the individual and other nine subjects. The DICOM data of the Computed Tomography (CT) donated by a volunteer were converted into stereolitography (STL) files and used for the creation of the digital facial reconstructions. Once the three reconstructions were performed, they were compared to photographs of the subject who had the face reconstructed and nine other subjects. Thirty examiners participated in this recognition process. The target subject was recognized by 26.67% of the examiners in the reconstruction

  19. A novel digital tomosynthesis (DTS) reconstruction method using a deformation field map

    SciTech Connect

    Ren Lei; Zhang Junan; Thongphiew, Danthai; Godfrey, Devon J.; Jackie Wu, Q.; Zhou Sumin; Yin Fangfang

    2008-07-15

    We developed a novel digital tomosynthesis (DTS) reconstruction method using a deformation field map to optimally estimate volumetric information in DTS images. The deformation field map is solved by using prior information, a deformation model, and new projection data. Patients' previous cone-beam CT (CBCT) or planning CT data are used as the prior information, and the new patient volume to be reconstructed is considered as a deformation of the prior patient volume. The deformation field is solved by minimizing bending energy and maintaining new projection data fidelity using a nonlinear conjugate gradient method. The new patient DTS volume is then obtained by deforming the prior patient CBCT or CT volume according to the solution to the deformation field. This method is novel because it is the first method to combine deformable registration with limited angle image reconstruction. The method was tested in 2D cases using simulated projections of a Shepp-Logan phantom, liver, and head-and-neck patient data. The accuracy of the reconstruction was evaluated by comparing both organ volume and pixel value differences between DTS and CBCT images. In the Shepp-Logan phantom study, the reconstructed pixel signal-to-noise ratio (PSNR) for the 60 deg. DTS image reached 34.3 dB. In the liver patient study, the relative error of the liver volume reconstructed using 60 deg. projections was 3.4%. The reconstructed PSNR for the 60 deg. DTS image reached 23.5 dB. In the head-and-neck patient study, the new method using 60 deg. projections was able to reconstruct the 8.1 deg. rotation of the bony structure with 0.0 deg. error. The reconstructed PSNR for the 60 deg. DTS image reached 24.2 dB. In summary, the new reconstruction method can optimally estimate the volumetric information in DTS images using 60 deg. projections. Preliminary validation of the algorithm showed that it is both technically and clinically feasible for image guidance in radiation therapy.

  20. Reducing the effects of acoustic heterogeneity with an iterative reconstruction method from experimental data in microwave induced thermoacoustic tomography

    SciTech Connect

    Wang, Jinguo; Zhao, Zhiqin Song, Jian; Chen, Guoping; Nie, Zaiping; Liu, Qing-Huo

    2015-05-15

    Purpose: An iterative reconstruction method has been previously reported by the authors of this paper. However, the iterative reconstruction method was demonstrated by solely using the numerical simulations. It is essential to apply the iterative reconstruction method to practice conditions. The objective of this work is to validate the capability of the iterative reconstruction method for reducing the effects of acoustic heterogeneity with the experimental data in microwave induced thermoacoustic tomography. Methods: Most existing reconstruction methods need to combine the ultrasonic measurement technology to quantitatively measure the velocity distribution of heterogeneity, which increases the system complexity. Different to existing reconstruction methods, the iterative reconstruction method combines time reversal mirror technique, fast marching method, and simultaneous algebraic reconstruction technique to iteratively estimate the velocity distribution of heterogeneous tissue by solely using the measured data. Then, the estimated velocity distribution is used subsequently to reconstruct the highly accurate image of microwave absorption distribution. Experiments that a target placed in an acoustic heterogeneous environment are performed to validate the iterative reconstruction method. Results: By using the estimated velocity distribution, the target in an acoustic heterogeneous environment can be reconstructed with better shape and higher image contrast than targets that are reconstructed with a homogeneous velocity distribution. Conclusions: The distortions caused by the acoustic heterogeneity can be efficiently corrected by utilizing the velocity distribution estimated by the iterative reconstruction method. The advantage of the iterative reconstruction method over the existing correction methods is that it is successful in improving the quality of the image of microwave absorption distribution without increasing the system complexity.

  1. An efficient MR image reconstruction method for arbitrary K-space trajectories without density compensation.

    PubMed

    Song, Jiayu; Liu, Q H

    2006-01-01

    Non-Cartesian sampling is widely used for fast magnetic resonance imaging (MRI). The well known gridding method usually requires density compensation to adjust the non-uniform sampling density, which is a major source of reconstruction error. Minimum-norm least square (MNLS) reconstruction, on the other hand, does not need density compensation, but requires intensive computations. In this paper, a new version of MNLS reconstruction method is developed using maximum likelihood and is speeded up by incorporating novel non-uniform fast Fourier transform (NUFFT) and bi-conjugate gradient fast Fourier transform (BCG-FFT) techniques. Studies on computer-simulated phantoms and a physically scanned phantom show improved reconstruction accuracy and signal-to-noise ratio compared to gridding method. The method is shown applicable to arbitrary k-space trajectory. Furthermore, we find that the method in fact performs un-blurring in the image space as an equivalent of density compensation in the k-space. Equalizing MNLS solution with gridding algorithm leads to new approaches of finding optimal density compensation functions (DCF). The method has been applied to radially encoded cardiac imaging on small animals. Reconstructed dynamic images of an in vivo mouse heart are shown. PMID:17946203

  2. A Reconstructed Discontinuous Galerkin Method for the Compressible Navier-Stokes Equations on Arbitrary Grids

    SciTech Connect

    Hong Luo; Luqing Luo; Robert Nourgaliev; Vincent A. Mousseau

    2010-09-01

    A reconstruction-based discontinuous Galerkin (RDG) method is presented for the solution of the compressible Navier–Stokes equations on arbitrary grids. The RDG method, originally developed for the compressible Euler equations, is extended to discretize viscous and heat fluxes in the Navier–Stokes equations using a so-called inter-cell reconstruction, where a smooth solution is locally reconstructed using a least-squares method from the underlying discontinuous DG solution. Similar to the recovery-based DG (rDG) methods, this reconstructed DG method eliminates the introduction of ad hoc penalty or coupling terms commonly found in traditional DG methods. Unlike rDG methods, this RDG method does not need to judiciously choose a proper form of a recovered polynomial, thus is simple, flexible, and robust, and can be used on arbitrary grids. The developed RDG method is used to compute a variety of flow problems on arbitrary meshes to demonstrate its accuracy, efficiency, robustness, and versatility. The numerical results indicate that this RDG method is able to deliver the same accuracy as the well-known Bassi–Rebay II scheme, at a half of its computing costs for the discretization of the viscous fluxes in the Navier–Stokes equations, clearly demonstrating its superior performance over the existing DG methods for solving the compressible Navier–Stokes equations.

  3. A Reconstructed Discontinuous Galerkin Method for the Compressible Navier-Stokes Equations on Arbitrary Grids

    SciTech Connect

    Hong Luo; Luqing Luo; Robert Nourgaliev; Vincent A. Mousseau

    2010-01-01

    A reconstruction-based discontinuous Galerkin (RDG) method is presented for the solution of the compressible Navier-Stokes equations on arbitrary grids. The RDG method, originally developed for the compressible Euler equations, is extended to discretize viscous and heat fluxes in the Navier-Stokes equations using a so-called inter-cell reconstruction, where a smooth solution is locally reconstructed using a least-squares method from the underlying discontinuous DG solution. Similar to the recovery-based DG (rDG) methods, this reconstructed DG method eliminates the introduction of ad hoc penalty or coupling terms commonly found in traditional DG methods. Unlike rDG methods, this RDG method does not need to judiciously choose a proper form of a recovered polynomial, thus is simple, flexible, and robust, and can be used on arbitrary grids. The developed RDG method is used to compute a variety of flow problems on arbitrary meshes to demonstrate its accuracy, efficiency, robustness, and versatility. The numerical results indicate that this RDG method is able to deliver the same accuracy as the well-known Bassi-Rebay II scheme, at a half of its computing costs for the discretization of the viscous fluxes in the Navier-Stokes equations, clearly demonstrating its superior performance over the existing DG methods for solving the compressible Navier-Stokes equations.

  4. Noninvasive reconstruction of cardiac transmembrane potentials using a kernelized extreme learning method

    NASA Astrophysics Data System (ADS)

    Jiang, Mingfeng; Zhang, Heng; Zhu, Lingyan; Cao, Li; Wang, Yaming; Xia, Ling; Gong, Yinglan

    2015-04-01

    Non-invasively reconstructing the cardiac transmembrane potentials (TMPs) from body surface potentials can act as a regression problem. The support vector regression (SVR) method is often used to solve the regression problem, however the computational complexity of the SVR training algorithm is usually intensive. In this paper, another learning algorithm, termed as extreme learning machine (ELM), is proposed to reconstruct the cardiac transmembrane potentials. Moreover, ELM can be extended to single-hidden layer feed forward neural networks with kernel matrix (kernelized ELM), which can achieve a good generalization performance at a fast learning speed. Based on the realistic heart-torso models, a normal and two abnormal ventricular activation cases are applied for training and testing the regression model. The experimental results show that the ELM method can perform a better regression ability than the single SVR method in terms of the TMPs reconstruction accuracy and reconstruction speed. Moreover, compared with the ELM method, the kernelized ELM method features a good approximation and generalization ability when reconstructing the TMPs.

  5. R-L Method and BLS-GSM Denoising for Penumbra Image Reconstruction

    NASA Astrophysics Data System (ADS)

    Zhang, Mei; Li, Yang; Sheng, Liang; Li, Chunhua; Wei, Fuli; Peng, Bodong

    2013-12-01

    When neutron yield is very low, reconstruction of coding penumbra image is rather difficult. In this paper, low-yield (109) 14 MeV neutron penumbra imaging was simulated by Monte Carlo method. The Richardson Lucy (R-L) iteration method was proposed to incorporated with Bayesian least square-Gaussian scale mixture model (BLS-GSM) wavelet denoising for the simulated image. Optimal number of R-L iterations was gotten by a large number of tests. The results show that compared with Wiener method and median filter denoising, this method is better in restraining background noise, the correlation coefficient Rsr between the reconstructed and the real images is larger, and the reconstruction result is better.

  6. Runout error correction in tomographic reconstruction by intensity summation method.

    PubMed

    Kwon, Ik Hwan; Lim, Jun; Hong, Chung Ki

    2016-09-01

    An alignment method for correction of the axial and radial runout errors of the rotation stage in X-ray phase-contrast computed tomography has been developed. Only intensity information was used, without extra hardware or complicated calculation. Notably, the method, as demonstrated herein, can utilize the halo artifact to determine displacement. PMID:27577781

  7. Gender Dimorphic ACL Strain In Response to Combined Dynamic 3D Knee Joint Loading: Implications for ACL Injury Risk

    PubMed Central

    Mizuno, Kiyonori; Andrish, Jack T.; van den Bogert, Antonie J.; McLean, Scott G.

    2009-01-01

    While gender-based differences in knee joint anatomies/laxities are well documented, the potential for them to precipitate gender-dimorphic ACL loading and resultant injury risk has not been considered. To this end, we generated gender-specific models of ACL strain as a function of any six degrees of freedom (6DOF) knee joint load state via a combined cadaveric and analytical approach. Continuously varying joint forces and torques were applied to five male and five female cadaveric specimens and recorded along with synchronous knee flexion and ACL strain data. All data (~10,000 samples) were submitted to specimen-specific regression analyses, affording ACL strain predictions as a function of the combined 6 DOF knee loads. Following individual model verifications, generalized gender-specific models were generated and subjected to 6 DOF external load scenarios consistent with both a clinical examination and a dynamic sports maneuver. The ensuing model-based strain predictions were subsequently examined for gender-based discrepancies. Male and female specimen specific models predicted ACL strain within 0.51% ± 0.10% and 0.52% ± 0.07% of the measured data respectively, and explained more than 75% of the associated variance in each case. Predicted female ACL strains were also significantly larger than respective male values for both of simulated 6 DOF load scenarios. Outcomes suggest that the female ACL will rupture in response to comparatively smaller external load applications. Future work must address the underlying anatomical/laxity contributions to knee joint mechanical and resultant ACL loading, ultimately affording prevention strategies that may cater to individual joint vulnerabilities. PMID:19464897

  8. Noise reduction in computed tomography using a multiplicative continuous-time image reconstruction method

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Yusaku; Kojima, Takeshi; Yoshinaga, Tetsuya

    2016-03-01

    In clinical X-ray computed tomography (CT), filtered back-projection as a transform method and iterative reconstruction such as the maximum-likelihood expectation-maximization (ML-EM) method are known methods to reconstruct tomographic images. As the other reconstruction method, we have presented a continuous-time image reconstruction (CIR) system described by a nonlinear dynamical system, based on the idea of continuous methods for solving tomographic inverse problems. Recently, we have also proposed a multiplicative CIR system described by differential equations based on the minimization of a weighted Kullback-Leibler divergence. We prove theoretically that the divergence measure decreases along the solution to the CIR system, for consistent inverse problems. In consideration of the noisy nature of projections in clinical CT, the inverse problem belongs to the category of ill-posed problems. The performance of a noise-reduction scheme for a new (previously developed) CIR system was investigated by means of numerical experiments using a circular phantom image. Compared to the conventional CIR and the ML-EM methods, the proposed CIR method has an advantage on noisy projection with lower signal-to-noise ratios in terms of the divergence measure on the actual image under the same common measure observed via the projection data. The results lead to the conclusion that the multiplicative CIR method is more effective and robust for noise reduction in CT compared to the ML-EM as well as conventional CIR methods.

  9. A Reconstructed Discontinuous Galerkin Method for the Compressible Flows on Unstructured Tetrahedral Grids

    SciTech Connect

    Hong Luo; Yidong Xia; Robert Nourgaliev; Chunpei Cai

    2011-06-01

    A reconstruction-based discontinuous Galerkin (RDG) method is presented for the solution of the compressible Navier-Stokes equations on unstructured tetrahedral grids. The RDG method, originally developed for the compressible Euler equations, is extended to discretize viscous and heat fluxes in the Navier-Stokes equations using a so-called inter-cell reconstruction, where a smooth solution is locally reconstructed using a least-squares method from the underlying discontinuous DG solution. Similar to the recovery-based DG (rDG) methods, this reconstructed DG method eliminates the introduction of ad hoc penalty or coupling terms commonly found in traditional DG methods. Unlike rDG methods, this RDG method does not need to judiciously choose a proper form of a recovered polynomial, thus is simple, flexible, and robust, and can be used on unstructured grids. The preliminary results indicate that this RDG method is stable on unstructured tetrahedral grids, and provides a viable and attractive alternative for the discretization of the viscous and heat fluxes in the Navier-Stokes equations.

  10. Anterior cruciate ligament reconstruction: a look at prosthetics - past, present and possible future

    PubMed Central

    Mascarenhas, Randy; MacDonald, Peter B.

    2008-01-01

    Biological tissue autograft reconstruction using the patellar tendon or quadrupled semitendinosus/gracilis tendons has become the most popular procedure in surgical treatment of a ruptured ACL. This article provides a review of the history of the use of prosthetics with respect to ACL reconstruction grafts including Carbon Fibre, Gore-Tex and Dacron prosthetics as well as the Leeds-Keio Artificial Ligament and the Kennedy Ligament Augmentation Device (LAD). Emphasis is placed on the Ligament Advanced Reinforcement System (LARS) as preliminary investigations of its use have been encouraging. Significant progress has been made recently with respect to the understanding of ACL anatomy, composition, biomechanics, and healing processes, leading to innovative techniques using approaches based in tissue engineering principles and computer – assisted surgery. While research into improved ACL treatment options continues, the synthesis of recent advancements provides a new optimism towards the regeneration of an ACL mirroring its original stability, function, and longevity. PMID:18523530

  11. Anterior cruciate ligament reconstruction: a look at prosthetics--past, present and possible future.

    PubMed

    Mascarenhas, Randy; MacDonald, Peter B

    2008-01-01

    Biological tissue autograft reconstruction using the patellar tendon or quadrupled semitendinosus/gracilis tendons has become the most popular procedure in surgical treatment of a ruptured ACL. This article provides a review of the history of the use of prosthetics with respect to ACL reconstruction grafts including Carbon Fibre, Gore-Tex and Dacron prosthetics as well as the Leeds-Keio Artificial Ligament and the Kennedy Ligament Augmentation Device (LAD). Emphasis is placed on the Ligament Advanced Reinforcement System (LARS) as preliminary investigations of its use have been encouraging. Significant progress has been made recently with respect to the understanding of ACL anatomy, composition, biomechanics, and healing processes, leading to innovative techniques using approaches based in tissue engineering principles and computer - assisted surgery. While research into improved ACL treatment options continues, the synthesis of recent advancements provides a new optimism towards the regeneration of an ACL mirroring its original stability, function, and longevity. PMID:18523530

  12. Correlation between the result from arthroscopic reconstruction of the anterior cruciate ligament of the knee and the return to sports activity☆

    PubMed Central

    Almeida, Alexandre; Valin, Márcio Rangel; Ferreira, Ramon; de Almeida, Nayvaldo Couto; Agostini, Ana Paula

    2014-01-01

    Objective To evaluate the return to pre-injury sports activity in a group of patients who underwent anterior cruciate ligament (ACL) reconstruction, in relation to age, sex, body mass index (BMI) and associations with upper-limb fractures. Methods A group of 265 patients who underwent ACL reconstruction using an ipsilateral graft from the thigh flexor tendons, between July 2000 and November 2007, was analyzed. Results A total of 176 patients was evaluated after a mean period of 34.95 ± 18.8 months (median: 31 months) (interquartile range: 20–48 months). The minimum evaluation period was 12 months and the maximum was 87 months. The number of patients who returned to their sports activity prior to tearing the ACL was 121/176 (68.8%). Patients under 30 years of age more frequently returned to sports activity and this was considered significant: p = 0.016; odds ratio, OR = 0.44 (95% confidence interval, CI: 0.22–0.86). Returning to previous sports activity more frequently was not considered significant for male sex (p = 0.273), individuals with BMI < 25 (p = 0.280) or patients with an ACL injury unrelated to an initial traumatic episode with upper-limb fracturing (p = 0.353). Conclusions The rate of return to the sports activity prior to ACL injury was 68.8%. It was found that patients under the age of 30 years had a significantly greater rate of return to sports activity after the surgery. In relation to sex, BMI and association with an initial traumatic episode of upper-limb fracturing, there was no statistical difference in the return to sports activity. PMID:26229807

  13. The Extratropical Northern Hemisphere Temperature Reconstruction during the Last Millennium Based on a Novel Method.

    PubMed

    Xing, Pei; Chen, Xin; Luo, Yong; Nie, Suping; Zhao, Zongci; Huang, Jianbin; Wang, Shaowu

    2016-01-01

    Large-scale climate history of the past millennium reconstructed solely from tree-ring data is prone to underestimate the amplitude of low-frequency variability. In this paper, we aimed at solving this problem by utilizing a novel method termed "MDVM", which was a combination of the ensemble empirical mode decomposition (EEMD) and variance matching techniques. We compiled a set of 211 tree-ring records from the extratropical Northern Hemisphere (30-90°N) in an effort to develop a new reconstruction of the annual mean temperature by the MDVM method. Among these dataset, a number of 126 records were screened out to reconstruct temperature variability longer than decadal scale for the period 850-2000 AD. The MDVM reconstruction depicted significant low-frequency variability in the past millennium with evident Medieval Warm Period (MWP) over the interval 950-1150 AD and pronounced Little Ice Age (LIA) cumulating in 1450-1850 AD. In the context of 1150-year reconstruction, the accelerating warming in 20th century was likely unprecedented, and the coldest decades appeared in the 1640s, 1600s and 1580s, whereas the warmest decades occurred in the 1990s, 1940s and 1930s. Additionally, the MDVM reconstruction covaried broadly with changes in natural radiative forcing, and especially showed distinct footprints of multiple volcanic eruptions in the last millennium. Comparisons of our results with previous reconstructions and model simulations showed the efficiency of the MDVM method on capturing low-frequency variability, particularly much colder signals of the LIA relative to the reference period. Our results demonstrated that the MDVM method has advantages in studying large-scale and low-frequency climate signals using pure tree-ring data. PMID:26751947

  14. The Extratropical Northern Hemisphere Temperature Reconstruction during the Last Millennium Based on a Novel Method

    PubMed Central

    Xing, Pei; Chen, Xin; Luo, Yong; Nie, Suping; Zhao, Zongci; Huang, Jianbin; Wang, Shaowu

    2016-01-01

    Large-scale climate history of the past millennium reconstructed solely from tree-ring data is prone to underestimate the amplitude of low-frequency variability. In this paper, we aimed at solving this problem by utilizing a novel method termed “MDVM”, which was a combination of the ensemble empirical mode decomposition (EEMD) and variance matching techniques. We compiled a set of 211 tree-ring records from the extratropical Northern Hemisphere (30–90°N) in an effort to develop a new reconstruction of the annual mean temperature by the MDVM method. Among these dataset, a number of 126 records were screened out to reconstruct temperature variability longer than decadal scale for the period 850–2000 AD. The MDVM reconstruction depicted significant low-frequency variability in the past millennium with evident Medieval Warm Period (MWP) over the interval 950–1150 AD and pronounced Little Ice Age (LIA) cumulating in 1450–1850 AD. In the context of 1150-year reconstruction, the accelerating warming in 20th century was likely unprecedented, and the coldest decades appeared in the 1640s, 1600s and 1580s, whereas the warmest decades occurred in the 1990s, 1940s and 1930s. Additionally, the MDVM reconstruction covaried broadly with changes in natural radiative forcing, and especially showed distinct footprints of multiple volcanic eruptions in the last millennium. Comparisons of our results with previous reconstructions and model simulations showed the efficiency of the MDVM method on capturing low-frequency variability, particularly much colder signals of the LIA relative to the reference period. Our results demonstrated that the MDVM method has advantages in studying large-scale and low-frequency climate signals using pure tree-ring data. PMID:26751947

  15. A physics-based intravascular ultrasound image reconstruction method for lumen segmentation.

    PubMed

    Mendizabal-Ruiz, Gerardo; Kakadiaris, Ioannis A

    2016-08-01

    Intravascular ultrasound (IVUS) refers to the medical imaging technique consisting of a miniaturized ultrasound transducer located at the tip of a catheter that can be introduced in the blood vessels providing high-resolution, cross-sectional images of their interior. Current methods for the generation of an IVUS image reconstruction from radio frequency (RF) data do not account for the physics involved in the interaction between the IVUS ultrasound signal and the tissues of the vessel. In this paper, we present a novel method to generate an IVUS image reconstruction based on the use of a scattering model that considers the tissues of the vessel as a distribution of three-dimensional point scatterers. We evaluated the impact of employing the proposed IVUS image reconstruction method in the segmentation of the lumen/wall interface on 40MHz IVUS data using an existing automatic lumen segmentation method. We compared the results with those obtained using the B-mode reconstruction on 600 randomly selected frames from twelve pullback sequences acquired from rabbit aortas and different arteries of swine. Our results indicate the feasibility of employing the proposed IVUS image reconstruction for the segmentation of the lumen. PMID:27235803

  16. Meshless reconstruction method for fluorescence molecular tomography based on compactly supported radial basis function.

    PubMed

    An, Yu; Liu, Jie; Zhang, Guanglei; Ye, Jinzuo; Mao, Yamin; Jiang, Shixin; Shang, Wenting; Du, Yang; Chi, Chongwei; Tian, Jie

    2015-10-01

    Fluorescence molecular tomography (FMT) is a promising tool in the study of cancer, drug discovery, and disease diagnosis, enabling noninvasive and quantitative imaging of the biodistribution of fluorophores in deep tissues via image reconstruction techniques. Conventional reconstruction methods based on the finite-element method (FEM) have achieved acceptable stability and efficiency. However, some inherent shortcomings in FEM meshes, such as time consumption in mesh generation and a large discretization error, limit further biomedical application. In this paper, we propose a meshless method for reconstruction of FMT (MM-FMT) using compactly supported radial basis functions (CSRBFs). With CSRBFs, the image domain can be accurately expressed by continuous CSRBFs, avoiding the discretization error to a certain degree. After direct collocation with CSRBFs, the conventional optimization techniques, including Tikhonov, L1-norm iteration shrinkage (L1-IS), and sparsity adaptive matching pursuit, were adopted to solve the meshless reconstruction. To evaluate the performance of the proposed MM-FMT, we performed numerical heterogeneous mouse experiments and in vivo bead-implanted mouse experiments. The results suggest that the proposed MM-FMT method can reduce the position error of the reconstruction result to smaller than 0.4 mm for the double-source case, which is a significant improvement for FMT. PMID:26451513

  17. Meshless reconstruction method for fluorescence molecular tomography based on compactly supported radial basis function

    NASA Astrophysics Data System (ADS)

    An, Yu; Liu, Jie; Zhang, Guanglei; Ye, Jinzuo; Mao, Yamin; Jiang, Shixin; Shang, Wenting; Du, Yang; Chi, Chongwei; Tian, Jie

    2015-10-01

    Fluorescence molecular tomography (FMT) is a promising tool in the study of cancer, drug discovery, and disease diagnosis, enabling noninvasive and quantitative imaging of the biodistribution of fluorophores in deep tissues via image reconstruction techniques. Conventional reconstruction methods based on the finite-element method (FEM) have achieved acceptable stability and efficiency. However, some inherent shortcomings in FEM meshes, such as time consumption in mesh generation and a large discretization error, limit further biomedical application. In this paper, we propose a meshless method for reconstruction of FMT (MM-FMT) using compactly supported radial basis functions (CSRBFs). With CSRBFs, the image domain can be accurately expressed by continuous CSRBFs, avoiding the discretization error to a certain degree. After direct collocation with CSRBFs, the conventional optimization techniques, including Tikhonov, L1-norm iteration shrinkage (L1-IS), and sparsity adaptive matching pursuit, were adopted to solve the meshless reconstruction. To evaluate the performance of the proposed MM-FMT, we performed numerical heterogeneous mouse experiments and in vivo bead-implanted mouse experiments. The results suggest that the proposed MM-FMT method can reduce the position error of the reconstruction result to smaller than 0.4 mm for the double-source case, which is a significant improvement for FMT.

  18. Local and Non-local Regularization Techniques in Emission (PET/SPECT) Tomographic Image Reconstruction Methods.

    PubMed

    Ahmad, Munir; Shahzad, Tasawar; Masood, Khalid; Rashid, Khalid; Tanveer, Muhammad; Iqbal, Rabail; Hussain, Nasir; Shahid, Abubakar; Fazal-E-Aleem

    2016-06-01

    Emission tomographic image reconstruction is an ill-posed problem due to limited and noisy data and various image-degrading effects affecting the data and leads to noisy reconstructions. Explicit regularization, through iterative reconstruction methods, is considered better to compensate for reconstruction-based noise. Local smoothing and edge-preserving regularization methods can reduce reconstruction-based noise. However, these methods produce overly smoothed images or blocky artefacts in the final image because they can only exploit local image properties. Recently, non-local regularization techniques have been introduced, to overcome these problems, by incorporating geometrical global continuity and connectivity present in the objective image. These techniques can overcome drawbacks of local regularization methods; however, they also have certain limitations, such as choice of the regularization function, neighbourhood size or calibration of several empirical parameters involved. This work compares different local and non-local regularization techniques used in emission tomographic imaging in general and emission computed tomography in specific for improved quality of the resultant images. PMID:26714680

  19. L{sub 1/2} regularization based numerical method for effective reconstruction of bioluminescence tomography

    SciTech Connect

    Chen, Xueli E-mail: jimleung@mail.xidian.edu.cn; Yang, Defu; Zhang, Qitan; Liang, Jimin E-mail: jimleung@mail.xidian.edu.cn

    2014-05-14

    Even though bioluminescence tomography (BLT) exhibits significant potential and wide applications in macroscopic imaging of small animals in vivo, the inverse reconstruction is still a tough problem that has plagued researchers in a related area. The ill-posedness of inverse reconstruction arises from insufficient measurements and modeling errors, so that the inverse reconstruction cannot be solved directly. In this study, an l{sub 1/2} regularization based numerical method was developed for effective reconstruction of BLT. In the method, the inverse reconstruction of BLT was constrained into an l{sub 1/2} regularization problem, and then the weighted interior-point algorithm (WIPA) was applied to solve the problem through transforming it into obtaining the solution of a series of l{sub 1} regularizers. The feasibility and effectiveness of the proposed method were demonstrated with numerical simulations on a digital mouse. Stability verification experiments further illustrated the robustness of the proposed method for different levels of Gaussian noise.

  20. A diffusion-based truncated projection artifact reduction method for iterative digital breast tomosynthesis reconstruction

    NASA Astrophysics Data System (ADS)

    Lu, Yao; Chan, Heang-Ping; Wei, Jun; Hadjiiski, Lubomir M.

    2013-02-01

    Digital breast tomosynthesis (DBT) has strong promise to improve sensitivity for detecting breast cancer. DBT reconstruction estimates the breast tissue attenuation using projection views (PVs) acquired in a limited angular range. Because of the limited field of view (FOV) of the detector, the PVs may not completely cover the breast in the x-ray source motion direction at large projection angles. The voxels in the imaged volume cannot be updated when they are outside the FOV, thus causing a discontinuity in intensity across the FOV boundaries in the reconstructed slices, which we refer to as the truncated projection artifact (TPA). Most existing TPA reduction methods were developed for the filtered backprojection method in the context of computed tomography. In this study, we developed a new diffusion-based method to reduce TPAs during DBT reconstruction using the simultaneous algebraic reconstruction technique (SART). Our TPA reduction method compensates for the discontinuity in background intensity outside the FOV of the current PV after each PV updating in SART. The difference in voxel values across the FOV boundary is smoothly diffused to the region beyond the FOV of the current PV. Diffusion-based background intensity estimation is performed iteratively to avoid structured artifacts. The method is applicable to TPA in both the forward and backward directions of the PVs and for any number of iterations during reconstruction. The effectiveness of the new method was evaluated by comparing the visual quality of the reconstructed slices and the measured discontinuities across the TPA with and without artifact correction at various iterations. The results demonstrated that the diffusion-based intensity compensation method reduced the TPA while preserving the detailed tissue structures. The visibility of breast lesions obscured by the TPA was improved after artifact reduction.

  1. A diffusion-based truncated projection artifact reduction method for iterative digital breast tomosynthesis reconstruction.

    PubMed

    Lu, Yao; Chan, Heang-Ping; Wei, Jun; Hadjiiski, Lubomir M

    2013-02-01

    Digital breast tomosynthesis (DBT) has strong promise to improve sensitivity for detecting breast cancer. DBT reconstruction estimates the breast tissue attenuation using projection views (PVs) acquired in a limited angular range. Because of the limited field of view (FOV) of the detector, the PVs may not completely cover the breast in the x-ray source motion direction at large projection angles. The voxels in the imaged volume cannot be updated when they are outside the FOV, thus causing a discontinuity in intensity across the FOV boundaries in the reconstructed slices, which we refer to as the truncated projection artifact (TPA). Most existing TPA reduction methods were developed for the filtered backprojection method in the context of computed tomography. In this study, we developed a new diffusion-based method to reduce TPAs during DBT reconstruction using the simultaneous algebraic reconstruction technique (SART). Our TPA reduction method compensates for the discontinuity in background intensity outside the FOV of the current PV after each PV updating in SART. The difference in voxel values across the FOV boundary is smoothly diffused to the region beyond the FOV of the current PV. Diffusion-based background intensity estimation is performed iteratively to avoid structured artifacts. The method is applicable to TPA in both the forward and backward directions of the PVs and for any number of iterations during reconstruction. The effectiveness of the new method was evaluated by comparing the visual quality of the reconstructed slices and the measured discontinuities across the TPA with and without artifact correction at various iterations. The results demonstrated that the diffusion-based intensity compensation method reduced the TPA while preserving the detailed tissue structures. The visibility of breast lesions obscured by the TPA was improved after artifact reduction. PMID:23318346

  2. Neuromuscular Fatigue Alters Postural Control and Sagittal Plane Hip Biomechanics in Active Females With Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Frank, Barnett S.; Gilsdorf, Christine M.; Goerger, Benjamin M.; Prentice, William E.; Padua, Darin A.

    2014-01-01

    Background: Females with history of anterior cruciate ligament (ACL) injury and subsequent ligament reconstruction are at high risk for future ACL injury. Fatigue may influence the increased risk of future injury in females by altering lower extremity biomechanics and postural control. Hypothesis: Fatigue will promote lower extremity biomechanics and postural control deficits associated with ACL injury. Study Design: Descriptive laboratory study. Methods: Fourteen physically active females with ACL reconstruction (mean age, 19.64 ± 1.5 years; mean height, 163.52 ± 6.18 cm; mean mass, 62.6 ± 13.97 kg) volunteered for this study. Postural control and lower extremity biomechanics were assessed in the surgical limb during single-leg balance and jump-landing tasks before and after a fatigue protocol. Main outcome measures were 3-dimensional hip and knee joint angles at initial contact, peak angles, joint angular displacements and peak net joint moments, anterior tibial shear force, and vertical ground reaction force during the first 50% of the loading phase of the jump-landing task. During the single-leg stance task, the main outcome measure was center of pressure sway speed. Results: Initial contact hip flexion angle decreased (t = −2.82, P = 0.01; prefatigue, 40.98° ± 9.79°; postfatigue, 36.75° ± 8.61°) from pre- to postfatigue. Hip flexion displacement (t = 2.23, P = 0.04; prefatigue, 45.19° ± 14.1°; postfatigue, 47.48° ± 14.21°) and center of pressure sway speed (t = 3.95, P < 0.05; prefatigue, 5.18 ± 0.96 cm/s; postfatigue, 6.20 ± 1.72 cm/s) increased from pre- to postfatigue. There was a trending increase in hip flexion moment (t = 2.14, P = 0.05; prefatigue, 1.66 ± 0.68 Nm/kg/m; postfatigue, 1.91 ± 0.62 Nm/kg/m) from pre- to postfatigue. Conclusion: Fatigue may induce lower extremity biomechanics and postural control deficits that may be associated with ACL injury in physically active females with ACL reconstruction. Clinical Relevance

  3. A sampling method for the reconstruction of a periodic interface in a layered medium

    NASA Astrophysics Data System (ADS)

    Sun, Guanying; Zhang, Ruming

    2016-07-01

    In this paper, we consider the inverse problem of reconstructing periodic interfaces in a two-layered medium with TM-mode. We propose a sampling-type method to recover the top periodic interface from the near-field data measured on a straight line above the total structure. Finally, numerical experiments are illustrated to show the effectiveness of the method.

  4. A Comparison of Affect Ratings Obtained with Ecological Momentary Assessment and the Day Reconstruction Method

    ERIC Educational Resources Information Center

    Dockray, Samantha; Grant, Nina; Stone, Arthur A.; Kahneman, Daniel; Wardle, Jane; Steptoe, Andrew

    2010-01-01

    Measurement of affective states in everyday life is of fundamental importance in many types of quality of life, health, and psychological research. Ecological momentary assessment (EMA) is the recognized method of choice, but the respondent burden can be high. The day reconstruction method (DRM) was developed by Kahneman and colleagues ("Science,"…

  5. Method and apparatus for reconstructing in-cylinder pressure and correcting for signal decay

    DOEpatents

    Huang, Jian

    2013-03-12

    A method comprises steps for reconstructing in-cylinder pressure data from a vibration signal collected from a vibration sensor mounted on an engine component where it can generate a signal with a high signal-to-noise ratio, and correcting the vibration signal for errors introduced by vibration signal charge decay and sensor sensitivity. The correction factors are determined as a function of estimated motoring pressure and the measured vibration signal itself with each of these being associated with the same engine cycle. Accordingly, the method corrects for charge decay and changes in sensor sensitivity responsive to different engine conditions to allow greater accuracy in the reconstructed in-cylinder pressure data. An apparatus is also disclosed for practicing the disclosed method, comprising a vibration sensor, a data acquisition unit for receiving the vibration signal, a computer processing unit for processing the acquired signal and a controller for controlling the engine operation based on the reconstructed in-cylinder pressure.

  6. Potential benefit of the CT adaptive statistical iterative reconstruction method for pediatric cardiac diagnosis

    NASA Astrophysics Data System (ADS)

    Miéville, Frédéric A.; Ayestaran, Paul; Argaud, Christophe; Rizzo, Elena; Ou, Phalla; Brunelle, Francis; Gudinchet, François; Bochud, François; Verdun, Francis R.

    2010-04-01

    Adaptive Statistical Iterative Reconstruction (ASIR) is a new imaging reconstruction technique recently introduced by General Electric (GE). This technique, when combined with a conventional filtered back-projection (FBP) approach, is able to improve the image noise reduction. To quantify the benefits provided on the image quality and the dose reduction by the ASIR method with respect to the pure FBP one, the standard deviation (SD), the modulation transfer function (MTF), the noise power spectrum (NPS), the image uniformity and the noise homogeneity were examined. Measurements were performed on a control quality phantom when varying the CT dose index (CTDIvol) and the reconstruction kernels. A 64-MDCT was employed and raw data were reconstructed with different percentages of ASIR on a CT console dedicated for ASIR reconstruction. Three radiologists also assessed a cardiac pediatric exam reconstructed with different ASIR percentages using the visual grading analysis (VGA) method. For the standard, soft and bone reconstruction kernels, the SD is reduced when the ASIR percentage increases up to 100% with a higher benefit for low CTDIvol. MTF medium frequencies were slightly enhanced and modifications of the NPS shape curve were observed. However for the pediatric cardiac CT exam, VGA scores indicate an upper limit of the ASIR benefit. 40% of ASIR was observed as the best trade-off between noise reduction and clinical realism of organ images. Using phantom results, 40% of ASIR corresponded to an estimated dose reduction of 30% under pediatric cardiac protocol conditions. In spite of this discrepancy between phantom and clinical results, the ASIR method is as an important option when considering the reduction of radiation dose, especially for pediatric patients.

  7. Revisiting the analog method to obtain uncertainty estimates for proxy surrogate reconstructions

    NASA Astrophysics Data System (ADS)

    Bothe, Oliver

    2015-04-01

    Proxy surrogate reconstructions are a computationally cheap method to combine information from spatially sparse proxy records or instrumental data series with the spatially complete fields from climate simulations to increase our knowledge about past climates. The method assumes that the analog pool includes the entire bandwidth of the state-space of the variable under consideration. As proxy records are uncertain indicators of the state of past climate variables, the analog search should ideally allow for the inclusion of the variance unexplained by the proxy indicator in the variable of interest, i.e. it should quantify the uncertainty of the reconstructions based on the signal strength in the proxy records. Upto this point traditional implementations have not considered this uncertainty. This presentation details assumptions based on the calibration correlation of the proxies which result in an ensemble pool of analogs consistent with the proxy record at each data point and explicitly considering the noise in the proxy record. The proxy-pool of the Euro2K-reconstruction and the MPI-ESM-COSMOS ensemble of simulations of the last millennium provide the data to obtain a set of proxy surrogate field estimates for the June, July and August summer near surface air temperature of the last 750 years for the European domain. The restrictions imposed on the analog selection can result in failure to find suitable analogs. The underlying assumptions allow to construct an uncertainty envelope for the areal mean of the field reconstructions. The ensemble of fields further highlights the ambiguity of field reconstructions constrained by a limited set of proxies. Additionally, the uncertainty envelope, its median estimate and the respective best estimate can be used to easily validate reconstructions obtained with more complex methods. That is, the proxy surrogate reconstruction estimates agree very well with the Euro2K-reconstruction over the last 750 years. They also well

  8. Secure fixation of femoral bone plug with a suspensory button in anatomical anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft

    PubMed Central

    TAKETOMI, SHUJI; INUI, HIROSHI; NAKAMURA, KENSUKE; YAMAGAMI, RYOTA; TAHARA, KEITARO; SANADA, TAKAKI; MASUDA, HIRONARI; TANAKA, SAKAE; NAKAGAWA, TAKUMI

    2015-01-01

    Purpose the efficacy and safety of using a suspensory button for femoral fixation in anatomical anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BPTB) graft have not been established. The purpose of the current study was to evaluate bone plug integration onto the femoral socket and migration of the bone plug and the EndoButton (EB) (Smith & Nephew, Andover, MA, USA) after rectangular tunnel ACL reconstruction with BPTB autograft. Methods thirty-four patients who underwent anatomical rectangular ACL reconstruction with BPTB graft using EB for femoral fixation and in whom three-dimensional (3D) computed tomography (CT) was performed one week and one year after surgery were included in this study. Bone plug integration onto the femoral socket, bone plug migration, soft tissue interposition, EB migration and EB rotation were evaluated on 3D CT. The clinical outcome was also assessed and correlated with the imaging outcomes. Results the bone plug was integrated onto the femoral socket in all cases. The incidence of bone plug migration, soft tissue interposition, EB migration and EB rotation was 15, 15, 9 and 56%, respectively. No significant association was observed between the imaging outcomes. The postoperative mean Lysholm score was 97.1 ± 5.0 points. The postoperative side-to-side difference, evaluated using a KT-2000 arthrometer, averaged 0.5 ± 1.3 mm. There were no complications associated with EB use. Imaging outcomes did not affect the postoperative KT side-to-side difference. Conclusions the EB is considered a reliable device for femoral fixation in anatomical rectangular tunnel ACL reconstruction with BPTB autograft. Level of evidence Level IV, therapeutic case series. PMID:26889465

  9. Comparison of Parallel MRI Reconstruction Methods for Accelerated 3D Fast Spin-Echo Imaging

    PubMed Central

    Xiao, Zhikui; Hoge, W. Scott; Mulkern, R.V.; Zhao, Lei; Hu, Guangshu; Kyriakos, Walid E.

    2014-01-01

    Parallel MRI (pMRI) achieves imaging acceleration by partially substituting gradient-encoding steps with spatial information contained in the component coils of the acquisition array. Variable-density subsampling in pMRI was previously shown to yield improved two-dimensional (2D) imaging in comparison to uniform subsampling, but has yet to be used routinely in clinical practice. In an effort to reduce acquisition time for 3D fast spin-echo (3D-FSE) sequences, this work explores a specific nonuniform sampling scheme for 3D imaging, subsampling along two phase-encoding (PE) directions on a rectilinear grid. We use two reconstruction methods—2D-GRAPPA-Operator and 2D-SPACE RIP—and present a comparison between them. We show that high-quality images can be reconstructed using both techniques. To evaluate the proposed sampling method and reconstruction schemes, results via simulation, phantom study, and in vivo 3D human data are shown. We find that fewer artifacts can be seen in the 2D-SPACE RIP reconstructions than in 2D-GRAPPA-Operator reconstructions, with comparable reconstruction times. PMID:18727083

  10. Clinical Outcomes After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Tibor, Lisa M.; Long, Joy L.; Schilling, Peter L.; Lilly, Ryan J.; Carpenter, James E.; Miller, Bruce S.

    2010-01-01

    Background: Clinical outcomes of autograft and allograft anterior cruciate ligament (ACL) reconstructions are mixed, with some reports of excellent to good outcomes and other reports of early graft failure or significant donor site morbidity. Objective: To determine if there is a difference in functional outcomes, failure rates, and stability between autograft and allograft ACL reconstructions. Data Sources: Medline, Cochrane Central Register of Controlled Trials (Evidence Based Medicine Reviews Collection), Cochrane Database of Systematic Reviews, Web of Science, CINAHL, and SPORTDiscus were searched for articles on ACL reconstruction. Abstracts from annual meetings of the American Academy of Orthopaedic Surgeons, American Orthopaedic Society for Sports Medicine, and Arthroscopy Association of North America were searched for relevant studies. Study Selection: Inclusion criteria for studies were as follows: primary unilateral ACL injuries, mean patient age less than 41 years, and follow-up for at least 24 months postreconstruction. Exclusion criteria for studies included the following: skeletally immature patients, multiligament injuries, and publication dates before 1990. Data Extraction: Joint stability measures included Lachman test, pivot-shift test, KT-1000 arthrometer assessment, and frequency of graft failures. Functional outcome measures included Tegner activity scores, Cincinnati knee scores, Lysholm scores, and IKDC (International Knee Documentation Committee) total scores. Results: More than 5000 studies were identified. After full text review of 576 studies, 56 were included, of which only 1 directly compared autograft and allograft reconstruction. Allograft ACL reconstructions were more lax when assessed by the KT-1000 arthrometer. For all other outcome measures, there was no statistically significant difference between autograft and allograft ACL reconstruction. For all outcome measures, there was strong evidence of statistical heterogeneity between

  11. Cosmic web reconstruction through density ridges: method and algorithm

    NASA Astrophysics Data System (ADS)

    Chen, Yen-Chi; Ho, Shirley; Freeman, Peter E.; Genovese, Christopher R.; Wasserman, Larry

    2015-11-01

    The detection and characterization of filamentary structures in the cosmic web allows cosmologists to constrain parameters that dictate the evolution of the Universe. While many filament estimators have been proposed, they generally lack estimates of uncertainty, reducing their inferential power. In this paper, we demonstrate how one may apply the subspace constrained mean shift (SCMS) algorithm (Ozertem & Erdogmus 2011; Genovese et al. 2014) to uncover filamentary structure in galaxy data. The SCMS algorithm is a gradient ascent method that models filaments as density ridges, one-dimensional smooth curves that trace high-density regions within the point cloud. We also demonstrate how augmenting the SCMS algorithm with bootstrap-based methods of uncertainty estimation allows one to place uncertainty bands around putative filaments. We apply the SCMS first to the data set generated from the Voronoi model. The density ridges show strong agreement with the filaments from Voronoi method. We then apply the SCMS method data sets sampled from a P3M N-body simulation, with galaxy number densities consistent with SDSS and WFIRST-AFTA, and to LOWZ and CMASS data from the Baryon Oscillation Spectroscopic Survey (BOSS). To further assess the efficacy of SCMS, we compare the relative locations of BOSS filaments with galaxy clusters in the redMaPPer catalogue, and find that redMaPPer clusters are significantly closer (with p-values <10-9) to SCMS-detected filaments than to randomly selected galaxies.

  12. An extended stochastic reconstruction method for catalyst layers in proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Kang, Jinfen; Moriyama, Koji; Kim, Seung Hyun

    2016-09-01

    This paper presents an extended, stochastic reconstruction method for catalyst layers (CLs) of Proton Exchange Membrane Fuel Cells (PEMFCs). The focus is placed on the reconstruction of customized, low platinum (Pt) loading CLs where the microstructure of CLs can substantially influence the performance. The sphere-based simulated annealing (SSA) method is extended to generate the CL microstructures with specified and controllable structural properties for agglomerates, ionomer, and Pt catalysts. In the present method, the agglomerate structures are controlled by employing a trial two-point correlation function used in the simulated annealing process. An off-set method is proposed to generate more realistic ionomer structures. The variations of ionomer structures at different humidity conditions are considered to mimic the swelling effects. A method to control Pt loading, distribution, and utilization is presented. The extension of the method to consider heterogeneity in structural properties, which can be found in manufactured CL samples, is presented. Various reconstructed CLs are generated to demonstrate the capability of the proposed method. Proton transport properties of the reconstructed CLs are calculated and validated with experimental data.

  13. Performance of climate field reconstruction methods over multiple seasons and climate variables

    NASA Astrophysics Data System (ADS)

    Dannenberg, Matthew P.; Wise, Erika K.

    2013-09-01

    Studies of climate variability require long time series of data but are limited by the absence of preindustrial instrumental records. For such studies, proxy-based climate reconstructions, such as those produced from tree-ring widths, provide the opportunity to extend climatic records into preindustrial periods. Climate field reconstruction (CFR) methods are capable of producing spatially-resolved reconstructions of climate fields. We assessed the performance of three commonly used CFR methods (canonical correlation analysis, point-by-point regression, and regularized expectation maximization) over spatially-resolved fields using multiple seasons and climate variables. Warm- and cool-season geopotential height, precipitable water, and surface temperature were tested for each method using tree-ring chronologies. Spatial patterns of reconstructive skill were found to be generally consistent across each of the methods, but the robustness of the validation metrics varied by CFR method, season, and climate variable. The most robust validation metrics were achieved with geopotential height, the October through March temporal composite, and the Regularized Expectation Maximization method. While our study is limited to assessment of skill over multidecadal (rather than multi-centennial) time scales, our findings suggest that the climate variable of interest, seasonality, and spatial domain of the target field should be considered when assessing potential CFR methods for real-world applications.

  14. Methods of bronchial tree reconstruction and camera distortion corrections for virtual endoscopic environments.

    PubMed

    Socha, Mirosław; Duplaga, Mariusz; Turcza, Paweł

    2004-01-01

    The use of three-dimensional visualization of anatomical structures in diagnostics and medical training is growing. The main components of virtual respiratory tract environments include reconstruction and simulation algorithms as well as correction methods of endoscope camera distortions in the case of virtually-enhanced navigation systems. Reconstruction methods rely usually on initial computer tomography (CT) image segmentation to trace contours of the tracheobronchial tree, which in turn are used in the visualization process. The main segmentation methods, including relatively simple approaches such as adaptive region-growing algorithms and more complex methods, e.g. hybrid algorithms based on region growing and mathematical morphology methods, are described in this paper. The errors and difficulties in the process of tracheobronchial tree reconstruction depend on the occurrence of distortions during CT image acquisition. They are usually related to the inability to exactly fulfil the sampling theorem's conditions. Other forms of distortions and noise such as additive white Gaussian noise, may also appear. The impact of these distortions on the segmentation and reconstruction may be diminished through the application of appropriately selected image prefiltering, which is also demonstrated in this paper. Methods of surface rendering (ray-casting, ray-tracing techniques) and volume rendering will be shown, with special focus on aspects of hardware and software implementations. Finally, methods of camera distortions correction and simulation are presented. The mathematical camera models, the scope of their applications and types of distortions were have also been indicated. PMID:15718617

  15. A Reconstructed Discontiuous Galerkin Method for the Magnetohydrodynamics on Arbitrary Grids

    NASA Astrophysics Data System (ADS)

    Halashi, Behrouz Karami

    A reconstructed discontinuous Galerkin (RDG) method based on a Hierarchical Weighted Essentially Non-oscillatory (WENO) reconstruction using a Taylor basis, designed not only to enhance the accuracy of discontinuous Galerkin methods but also to ensure the nonlinear stability of the RDG method, is developed for the solution of the magnetohydro dynamics (MHD) on arbitrary grids. In this method, a quadratic polynomial solution (P2) is first reconstructed using a Hermite WENO (HWENO) reconstruction from the underlying linear polynomial (P 1) discontinuous Galerkin solution to ensure the linear stability of the RDG method and to improve the efficiency of the underlying DG method. By taking advantage of handily available and yet invaluable information, namely the derivatives in the DG formulation, the stencils used in the reconstruction involve only Von Neumann neighborhood (adjacent face-neighboring cells) and thus are compact and consistent with the underlying DG method. The gradients (first moments) of the quadratic polynomial solution are then reconstructed using a WENO reconstruction in order to eliminate spurious oscillations in the vicinity of strong discontinuities, thus ensuring the nonlinear stability of the RDG method. Temporal discretization is done using a 4th order explicit Runge-Kutta method. The HLLD Riemann solver, introduced in the literature for one dimensional MHD problems, is extended to three dimensional problems on unstructured grids and used to compute the flux functions at interfaces in the present work. Divergence free constraint is satisfied using the so-called Locally Divergence Free (LDF) approach. The LDF formulation is especially attractive in the context of DG methods, where the gradients of independent variables are handily available and only one of the computed gradients needs simply to be modified by the divergence-free constraint at the end of each time step. The developed RDG method is used to compute a variety of fluid dynamics and

  16. A novel building boundary reconstruction method based on lidar data and images

    NASA Astrophysics Data System (ADS)

    Chen, Yiming; Zhang, Wuming; Zhou, Guoqing; Yan, Guangjian

    2013-09-01

    Building boundary is important for the urban mapping and real estate industry applications. The reconstruction of building boundary is also a significant but difficult step in generating city building models. As Light detection and ranging system (Lidar) can acquire large and dense point cloud data fast and easily, it has great advantages for building reconstruction. In this paper, we combine Lidar data and images to develop a novel building boundary reconstruction method. We use only one scan of Lidar data and one image to do the reconstruction. The process consists of a sequence of three steps: project boundary Lidar points to image; extract accurate boundary from image; and reconstruct boundary in Lidar points. We define a relationship between 3D points and the pixel coordinates. Then we extract the boundary in the image and use the relationship to get boundary in the point cloud. The method presented here reduces the difficulty of data acquisition effectively. The theory is not complex so it has low computational complexity. It can also be widely used in the data acquired by other 3D scanning devices to improve the accuracy. Results of the experiment demonstrate that this method has a clear advantage and high efficiency over others, particularly in the data with large point spacing.

  17. A comparative study of limited-angle cone-beam reconstruction methods for breast tomosynthesis

    SciTech Connect

    Zhang Yiheng; Chan, H.-P.; Sahiner, Berkman; Wei, Jun; Goodsitt, Mitchell M.; Hadjiiski, Lubomir M.; Ge Jun; Zhou Chuan

    2006-10-15

    Digital tomosynthesis mammography (DTM) is a promising new modality for breast cancer detection. In DTM, projection-view images are acquired at a limited number of angles over a limited angular range and the imaged volume is reconstructed from the two-dimensional projections, thus providing three-dimensional structural information of the breast tissue. In this work, we investigated three representative reconstruction methods for this limited-angle cone-beam tomographic problem, including the backprojection (BP) method, the simultaneous algebraic reconstruction technique (SART) and the maximum likelihood method with the convex algorithm (ML-convex). The SART and ML-convex methods were both initialized with BP results to achieve efficient reconstruction. A second generation GE prototype tomosynthesis mammography system with a stationary digital detector was used for image acquisition. Projection-view images were acquired from 21 angles in 3 deg. increments over a {+-}30 deg. angular range. We used an American College of Radiology phantom and designed three additional phantoms to evaluate the image quality and reconstruction artifacts. In addition to visual comparison of the reconstructed images of different phantom sets, we employed the contrast-to-noise ratio (CNR), a line profile of features, an artifact spread function (ASF), a relative noise power spectrum (NPS), and a line object spread function (LOSF) to quantitatively evaluate the reconstruction results. It was found that for the phantoms with homogeneous background, the BP method resulted in less noisy tomosynthesized images and higher CNR values for masses than the SART and ML-convex methods. However, the two iterative methods provided greater contrast enhancement for both masses and calcification, sharper LOSF, and reduced interplane blurring and artifacts with better ASF behaviors for masses. For a contrast-detail phantom with heterogeneous tissue-mimicking background, the BP method had strong blurring

  18. The least error method for sparse solution reconstruction

    NASA Astrophysics Data System (ADS)

    Bredies, K.; Kaltenbacher, B.; Resmerita, E.

    2016-09-01

    This work deals with a regularization method enforcing solution sparsity of linear ill-posed problems by appropriate discretization in the image space. Namely, we formulate the so called least error method in an ℓ 1 setting and perform the convergence analysis by choosing the discretization level according to an a priori rule, as well as two a posteriori rules, via the discrepancy principle and the monotone error rule, respectively. Depending on the setting, linear or sublinear convergence rates in the ℓ 1-norm are obtained under a source condition yielding sparsity of the solution. A part of the study is devoted to analyzing the structure of the approximate solutions and of the involved source elements.

  19. An integrand reconstruction method for three-loop amplitudes

    NASA Astrophysics Data System (ADS)

    Badger, Simon; Frellesvig, Hjalte; Zhang, Yang

    2012-08-01

    We consider the maximal cut of a three-loop four point function with massless kinematics. By applying Gröbner bases and primary decomposition we develop a method which extracts all ten propagator master integral coefficients for an arbitrary triple-box configuration via generalized unitarity cuts. As an example we present analytic results for the three loop triple-box contribution to gluon-gluon scattering in Yang-Mills with adjoint fermions and scalars in terms of three master integrals.

  20. A limited-angle CT reconstruction method based on anisotropic TV minimization

    NASA Astrophysics Data System (ADS)

    Chen, Zhiqiang; Jin, Xin; Li, Liang; Wang, Ge

    2013-04-01

    This paper presents a compressed sensing (CS)-inspired reconstruction method for limited-angle computed tomography (CT). Currently, CS-inspired CT reconstructions are often performed by minimizing the total variation (TV) of a CT image subject to data consistency. A key to obtaining high image quality is to optimize the balance between TV-based smoothing and data fidelity. In the case of the limited-angle CT problem, the strength of data consistency is angularly varying. For example, given a parallel beam of x-rays, information extracted in the Fourier domain is mostly orthogonal to the direction of x-rays, while little is probed otherwise. However, the TV minimization process is isotropic, suggesting that it is unfit for limited-angle CT. Here we introduce an anisotropic TV minimization method to address this challenge. The advantage of our approach is demonstrated in numerical simulation with both phantom and real CT images, relative to the TV-based reconstruction.

  1. Reconstruction from Uniformly Attenuated SPECT Projection Data Using the DBH Method

    SciTech Connect

    Huang, Qiu; You, Jiangsheng; Zeng, Gengsheng L.; Gullberg, Grant T.

    2008-03-20

    An algorithm was developed for the two-dimensional (2D) reconstruction of truncated and non-truncated uniformly attenuated data acquired from single photon emission computed tomography (SPECT). The algorithm is able to reconstruct data from half-scan (180o) and short-scan (180?+fan angle) acquisitions for parallel- and fan-beam geometries, respectively, as well as data from full-scan (360o) acquisitions. The algorithm is a derivative, backprojection, and Hilbert transform (DBH) method, which involves the backprojection of differentiated projection data followed by an inversion of the finite weighted Hilbert transform. The kernel of the inverse weighted Hilbert transform is solved numerically using matrix inversion. Numerical simulations confirm that the DBH method provides accurate reconstructions from half-scan and short-scan data, even when there is truncation. However, as the attenuation increases, finer data sampling is required.

  2. Application of information theory methods to food web reconstruction

    USGS Publications Warehouse

    Moniz, L.J.; Cooch, E.G.; Ellner, S.P.; Nichols, J.D.; Nichols, J.M.

    2007-01-01

    In this paper we use information theory techniques on time series of abundances to determine the topology of a food web. At the outset, the food web participants (two consumers, two resources) are known; in addition we know that each consumer prefers one of the resources over the other. However, we do not know which consumer prefers which resource, and if this preference is absolute (i.e., whether or not the consumer will consume the non-preferred resource). Although the consumers and resources are identified at the beginning of the experiment, we also provide evidence that the consumers are not resources for each other, and the resources do not consume each other. We do show that there is significant mutual information between resources; the model is seasonally forced and some shared information between resources is expected. Similarly, because the model is seasonally forced, we expect shared information between consumers as they respond to the forcing of the resources. The model that we consider does include noise, and in an effort to demonstrate that these methods may be of some use in other than model data, we show the efficacy of our methods with decreasing time series size; in this particular case we obtain reasonably clear results with a time series length of 400 points. This approaches ecological time series lengths from real systems.

  3. A comparative study of interface reconstruction methods for multi-material ALE simulations

    SciTech Connect

    Kucharik, Milan; Garimalla, Rao; Schofield, Samuel; Shashkov, Mikhail

    2009-01-01

    In this paper we compare the performance of different methods for reconstructing interfaces in multi-material compressible flow simulations. The methods compared are a material-order-dependent Volume-of-Fluid (VOF) method, a material-order-independent VOF method based on power diagram partitioning of cells and the Moment-of-Fluid method (MOF). We demonstrate that the MOF method provides the most accurate tracking of interfaces, followed by the VOF method with the right material ordering. The material-order-independent VOF method performs some-what worse than the above two while the solutions with VOF using the wrong material order are considerably worse.

  4. An audit of tunnel position in anterior cruciate ligament reconstruction.

    PubMed

    Topliss, C; Webb, J

    2001-03-01

    We audited 114 primary anterior cruciate ligament (ACL) reconstructions. Notes were reviewed and tunnel positions assessed on lateral and AP radiographs. A literature review established optimal tunnel position. Sixteen surgeons performed 57 arthroscopic and 57 open reconstructions, using 24 hamstring and 90 bone-tendon-bone autografts. Eighty-five sets of radiographs were available for review. Sixty-five percent of femoral tunnels and 59% of the tibial tunnels were malpositioned in the sagittal plane. Guidelines for best practice are required for key procedures in each speciality. Tunnel position in ACL reconstruction can be easily measured and should be correct in at least 90% of cases. PMID:11248570

  5. Comparison of the calorimetric and kinematic methods of neutrino energy reconstruction in disappearance experiments

    SciTech Connect

    Ankowski, Artur M.; Benhar, Omar; Coloma, Pilar; Huber, Patrick; Jen, Chun -Min; Mariani, Camillo; Meloni, Davide; Vagnoni, Erica

    2015-10-22

    To be able to achieve their physics goals, future neutrino-oscillation experiments will need to reconstruct the neutrino energy with very high accuracy. In this work, we analyze how the energy reconstruction may be affected by realistic detection capabilities, such as energy resolutions, efficiencies, and thresholds. This allows us to estimate how well the detector performance needs to be determined a priori in order to avoid a sizable bias in the measurement of the relevant oscillation parameters. We compare the kinematic and calorimetric methods of energy reconstruction in the context of two νμ → νμ disappearance experiments operating in different energy regimes. For the calorimetric reconstruction method, we find that the detector performance has to be estimated with an O(10%) accuracy to avoid a significant bias in the extracted oscillation parameters. Thus, in the case of kinematic energy reconstruction, we observe that the results exhibit less sensitivity to an overestimation of the detector capabilities.

  6. Comparison of the calorimetric and kinematic methods of neutrino energy reconstruction in disappearance experiments

    DOE PAGESBeta

    Ankowski, Artur M.; Benhar, Omar; Coloma, Pilar; Huber, Patrick; Jen, Chun -Min; Mariani, Camillo; Meloni, Davide; Vagnoni, Erica

    2015-10-22

    To be able to achieve their physics goals, future neutrino-oscillation experiments will need to reconstruct the neutrino energy with very high accuracy. In this work, we analyze how the energy reconstruction may be affected by realistic detection capabilities, such as energy resolutions, efficiencies, and thresholds. This allows us to estimate how well the detector performance needs to be determined a priori in order to avoid a sizable bias in the measurement of the relevant oscillation parameters. We compare the kinematic and calorimetric methods of energy reconstruction in the context of two νμ → νμ disappearance experiments operating in different energymore » regimes. For the calorimetric reconstruction method, we find that the detector performance has to be estimated with an O(10%) accuracy to avoid a significant bias in the extracted oscillation parameters. Thus, in the case of kinematic energy reconstruction, we observe that the results exhibit less sensitivity to an overestimation of the detector capabilities.« less