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Sample records for acl reconstruction technique

  1. ACL reconstruction in children: a transphyseal technique.

    PubMed

    Lemaitre, G; Salle de Chou, E; Pineau, V; Rochcongar, G; Delforge, S; Bronfen, C; Haumont, T; Hulet, C

    2014-06-01

    The annual incidence of ACL tears is increasing steadily in pediatric patients. Chronic anterior instability causes meniscal lesions at a frequency that increases significantly with the injury-to-surgery interval. Conservative therapy, simple suturing, and isolated extra-articular tendon reconstruction are associated with high failure rates. Intra-articular arthroscopy-assisted tendon reconstruction is a good treatment method, although several different techniques have been described. We used a transphyseal technique with a hamstring tendon graft to treat 14 knees in 13 patients with a mean age of 13 years and 7 months. Mean injury-to-surgery interval was 6 months. Strict compliance with technical rules is required when using this technique. Bone tunnel diameter must not exceed 8 mm. Bone tunnels must be as vertical and central as possible. The fixation material must not bridge the physis (at the femur, cortical fixation; and at the tibia, fixation using a resorbable screw no longer than 25 mm combined with a staple). Meniscal lesions were present in half the knees and meniscal preservation considered mandatory. Conservative treatment of concomitant lesions was performed routinely. After a mean follow-up of 15 months, no recurrent tears or revision procedures for meniscectomy had been recorded. The IKDC grade was A or B in 93% of knees. The mean subjective IKDC score was 83.3 and the Lysholm score was in the excellent or good range in 93% of knees. Of the 14 knees, 2 exhibited signs suggesting femoral epiphysiodesis, with 4° of valgus deformity compared to the contra-lateral knee and no clinical consequences. Transphyseal reconstruction with open physes conducted in strict compliance with technical rules can be performed to control the instability and preserve the menisci. Nevertheless, this technique carries a risk of epiphysiodesis, chiefly at the femur.

  2. ACL reconstruction

    MedlinePlus

    ... This increases the chance you may have a meniscus tear. ACL reconstruction may be used for these ... When other ligaments are also injured When your meniscus is torn Before surgery, talk to your health ...

  3. 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 ...

  4. ACL Reconstruction

    MedlinePlus

    ... of the major ligaments in your knee. ACL injuries most commonly occur during sports that involve sudden stops and changes in direction — such as basketball, soccer, football, tennis, downhill skiing, volleyball and gymnastics. In ...

  5. Modified Transtibial versus Anteromedial Portal Technique in Single Bundle ACL Reconstruction

    PubMed Central

    Salinas, Emiliano Alvarez; Etcheto, Horacio Rivarola; Blanchod, Cristian Collazo; Escobar, Gonzalo; Zordan, Jesuan; Autorino, Carlos María

    2017-01-01

    Objectives: The aim of this study is to determine whether it is possible to achieves a similar anatomical placement of the femoral tunnel with a modified transtibial ACL single bundle reconstruction tecnique compared to anteromedial transportal technique. Results were evaluated by tomographic comparisons between patients from both groups. Methods: 36 patients (36 knees) who were candidates for an ACL single bundle reconstruction with patellar bone graft were included in the study. Patients were randomly allocated using a computerized sequence into two groups. 18 patients were assigned each group (modified transtibial vs AM transportal technique). Surgery was performed by the same surgical team in both groups. Femoral tunnel quadrant placement, oblicuity in the coronal and sagittal planes and diameter of the femoral tunnel were assesed tomographically blinded by two observers and statistical comparison between groups was realized. Results: Average distance measured from posterior edge of the condyle to the femoral tunnel ( measured as a proportion respect to the T line) was similar in both groups ( Group I : 32.7 % +- 5.1% ; Group 2: 32.4 % +-4.4% , p = 0.85). Average distance measured from the Blumensaat line to the femoral tunnel (measured as a proportion respect to the H line) was similar in both groups ( Group I: 28.5% 4.49 % Group II , 31.5% of 4.83% p = 0.06). Average angulation values of the femoral tunnel in the coronal plane were lower in Group I than in Group II (Group I = 34.8 ° range 32.7 ° - 38.6 ° and 41.2 ° range Group II 36.7 ° - 43.1 ° P = 0.0016 ). Average angulation values of the femoral tunnel in the sagittal plane were similar in both groups (Group I 40.2 ° range 38.4 ° - 43.4 ° ; Group II 38 1 ° range 36.6 ° - 40.2 ° p = 0.17).. The average diameter of the femoral tunnel was significantly higher in group I than in Group II (Group I 11 mm 0.84 mm and 10.2 mm Group II 0.65mm p = 0.007) . Conclusion: The modified transtibial technique

  6. Mycotic Infection post ACL Reconstruction

    PubMed Central

    Costa-Paz, Matias; Ayerza, Miguel; Carbo, Lisandro; Sanchez, Marisa; Yacuzzi, Carlos; Muscolo, Luis

    2017-01-01

    Objectives: There are several studies in literature of septic arthritis after the ACL arthroscopic reconstruction related to bacterial germs. However, fungi infection is likely infrequent generating a massive bone loss with a catastrophic result. The purpose of this study was to describe preventive measures to decrease the mycotic infection after ACL reconstruction. Methods: Since 2005, we have diagnosed and treated 22 immunocompetent patients who underwent a surgery of an ACL lesion in other institutions in the country. Form these cases, we analyzed 19 which developed mycotic infection and an oncologic debridement was performed to control the pathology. In this series, we considered the initial surgery, the number of toilettes performed until their referral, magnitude of bone loss and final outcome. There were 5 other patients who consulted for mucormycosis, who finally were treated in other hospitals. Results: Epidemiology of mucormycosis is not clear. The exact cause is unknown due to heterogeneous data, different places and surgeons, facilities and type of surgical instruments in this series. In spite of not knowing the cause of the infection, several alternatives were evaluated in a non systematic way. Most of them related to the surgery room, sterilization place of the surgical tools, use of sterilizing liquids, cleanliness of lumen and cannulated bits. Instruments used during surgery were also evaluated: fields, shaver blades, drill types, ACL reconstruction fixation method. It is doubtful if the type of graft to reconstruct the ACL had any relation with infections. Among ideal preventive measures, the following are described: Surgery room with temperature and humidity control. Not using sterilizing liquids. Optimal preparation of surgical tools with adequate cleanliness of lumen and cannulated bits performed by adequate personnel. Sterilize in the same place where the surgery will be performed. Use of adequate instruments. The use of the central third of

  7. 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

  8. Partial ACL tears: anatomic reconstruction versus nonanatomic augmentation surgery.

    PubMed

    Buda, Roberto; Ruffilli, Alberto; Parma, Alessandro; Pagliazzi, Gherardo; Luciani, Deianira; Ramponi, Laura; Castagnini, Francesco; Giannini, Sandro

    2013-09-01

    Treatment of partial anterior cruciate ligament (ACL) tears requires ACL remnant preservation. The goal of this study was to compare the outcome of anatomic reconstruction of the torn bundle with nonanatomic augmentation using the over-the-top femoral route. Fifty-two athletes (mean age, 23.3 years) with partial ACL lesions underwent anatomic reconstruction (n=26) or nonanatomic augmentation (n=26). Intraoperative damage of the healthy bundle that required a standard ACL reconstruction occurred in 2 patients in the anatomic reconstruction group. International Knee Documentation Committee (IKDC) score, Tegner score, and arthrometer evaluation were used pre-operatively and at follow-up for up to 5 years postoperatively. One failure occurred in the anatomic reconstruction group. Mean IKDC subjective score at follow-up was 88.2 ± 5.7 in the anatomic reconstruction group and 90.2 ± 4.7 in the nonanatomic augmentation group. According to the IKDC objective score at final follow-up, 96% of knees in the nonanatomic augmentation group were normal vs 87.5% in the anatomic reconstruction group. No significative differences were observed between the 2 groups at final follow-up. Anteromedial bundle reconstruction showed significantly lower IKDC subjective and objective scores and higher residual instability values as evaluated with the arthrometer compared with posterolateral bundle reconstruction (P=.017). The surgical treatment of ACL partial tears is demanding. Adapted portals, perfect control of the tunnel drilling process, and intercondylar space management are required in anatomic reconstruction. The nonanatomic augmentation technique is simpler, providing excellent durable results over time with a lower complication rate. Anteromedial bundle reconstruction is associated with a poorer outcome, especially when performed with anatomic reconstruction.

  9. From open to arthroscopic anatomical ACL-reconstructions: the long way round. A statement paper.

    PubMed

    Arnold, Markus P; Friederich, Niklaus F; Müller, Werner; Hirschmann, Michael T

    2013-07-01

    The single-incision anterior cruciate ligament (ACL) reconstruction evidently has its shortcomings. In an attempt to improve the biomechanical but also the biological state of the knees after an ACL-reconstruction, double, even triple-bundle reconstructions have been popularised recently. As a positive side effect, details concerning ACL-insertion anatomy were brought back into the focus. In our opinion it would be more straight forward and logical to replace the non-anatomical single-incision technique with a more anatomic single-bundle ACL-reconstruction technique.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. Knee extension torque variability after exercise in ACL reconstructed knees.

    PubMed

    Goetschius, John; Kuenze, Christopher M; Hart, Joseph M

    2015-08-01

    The purpose of this study was to compare knee extension torque variability in patients with ACL reconstructed knees before and after exercise. Thirty two patients with an ACL reconstructed knee (ACL-R group) and 32 healthy controls (control group) completed measures of maximal isometric knee extension torque (90° flexion) at baseline and following a 30-min exercise protocol (post-exercise). Exercise included 30-min of repeated cycles of inclined treadmill walking and hopping tasks. Dependent variables were the coefficient of variation (CV) and raw-change in CV (ΔCV): CV = (torque standard deviation/torque mean x 100), ΔCV = (post-exercise - baseline). There was a group-by-time interaction (p = 0.03) on CV. The ACL-R group demonstrated greater CV than the control group at baseline (ACL-R = 1.07 ± 0.55, control = 0.79 ± 0.42, p = 0.03) and post-exercise (ACL-R = 1.60 ± 0.91, control = 0.94 ± 0.41, p = 0.001). ΔCV was greater (p = 0.03) in the ACL-R group (0.52 ± 0.82) than control group (0.15 ± 0.46). CV significantly increased from baseline to post-exercise (p = 0.001) in the ACL-R group, while the control group did not (p = 0.06). The ACL-R group demonstrated greater knee extension torque variability than the control group. Exercise increased torque variability more in the ACL-R group than control group.

  17. Isokinetic Testing in Evaluation Rehabilitation Outcome After ACL Reconstruction

    PubMed Central

    Cvjetkovic, Dragana Dragicevic; Bijeljac, Sinisa; Palija, Stanislav; Talic, Goran; Radulovic, Tatjana Nozica; Kosanovic, Milkica Glogovac; Manojlovic, Slavko

    2015-01-01

    Introduction: Numerous rehab protocols have been used in rehabilitation after ACL reconstruction. Isokinetic testing is an objective way to evaluate dynamic stability of the knee joint that estimates the quality of rehabilitation outcome after ACL reconstruction. Our investigation goal was to show importance of isokinetic testing in evaluation thigh muscle strength in patients which underwent ACL reconstruction and rehabilitation protocol. Subjects and methods: In prospective study, we evaluated 40 subjects which were divided into two groups. Experimental group consisted of 20 recreational males which underwent ACL reconstruction with hamstring tendon and rehabilitation protocol 6 months before isokinetic testing. Control group (20 subjects) consisted of healthy recreational males. In all subjects knee muscle testing was performed on a Biodex System 4 Pro isokinetic dynamo-meter et velocities of 60°/s and 180°/s. We followed average peak torque to body weight (PT/BW) and classic H/Q ratio. In statistical analysis Student’s T test was used. Results: There were statistically significant differences between groups in all evaluated parameters except of the mean value of PT/BW of the quadriceps et velocity of 60°/s (p>0.05). Conclusion: Isokinetic testing of dynamic stabilizers of the knee is need in diagnostic and treatment thigh muscle imbalance. We believe that isokinetic testing is an objective parameter for return to sport activities after ACL reconstruction. PMID:25870471

  18. ACL reconstruction: in vivo measurement of patellar tendon graft elongation.

    PubMed

    Berruto, M; Howe, J G; Beynnon, B D; Johnson, R J; Nichols, C E; Pope, M H

    1991-06-01

    The implantation of a free autogenous patellar tendon graft is the surgical technique that currently offers the best results in anterior cruciate ligament reconstruction. However, numerous aspects regarding both technique and postoperative rehabilitation can still be improved. The aim of this study was to measure the elongation of the patellar tendon in vivo in the operating room after reconstructive surgery, subjecting the knee to normal strain such as passive mobilization or anterior displacement of the tibia. Three volunteers were studied. Our results were different from those reported in a previous study conducted in vivo on a normal anterior cruciate ligament (ACL). In spite of the isometric position of the tendon, passive mobilization provoked a progressive increase in the elongation of the graft within each cycle of flexion-extension and between one cycle and the next. This also occurred during the Lachman test. These findings suggest that the graft undergoes a process of tensile adjustment when it is first put under strain. Continued elongation once this process appears stabilized raises doubts as to the reliability of isometric measuring devices.

  19. Anterior cruciate ligament reconstruction using cryopreserved irradiated bone-ACL-bone-allograft transplants.

    PubMed

    Goertzen, M J; Clahsen, H; Schulitz, K P

    1994-01-01

    Bone-ACL-bone allograft transplantation has been investigated as a potential solution to reconstruction of the anterior cruciate ligament (ACL). To minimize disease transmission (e.g. the acquired immuno deficiency syndrome), bony and collagenous tissues should be sterilized. Recent animal studies indicate that gamma irradiation and ethylene oxide sterilization result in diminished histological and biomechanical properties. The purpose of the present study was biomechanical and histological determination of the fate of deep-frozen gamma-irradiated (2.5 Mrad) canine bone-ACL-bone allografts with argon gas protection. Particular attention was paid to collagenous and neuroanatomical morphology 3, 6 and 12 months after implantation, by comparison to a non-irradiated control group. Sixty skeletally mature foxhounds were operated on in this study, divided up in two groups of 30 dogs each. In group A animals the ACL was replaced by a deep-frozen (-80 degrees C) bone-ACL-bone LAD-augmented allograft subjected to 2.5 Mrad gamma irradiation with argon gas protection. The animals in group B received an LAD-augmented ACL-allograft transplant without gamma irradiation. All knees from both groups were evaluated 3, 6 and 12 months after implantation in regard to biomechanical properties, collagen morphology and routine histology (haematoxylin and eosin stain, polarization microscopy), neuroanatomical morphology (silver and gold chloride stain) and microvasculature (modified Spalteholz technique). The irradiated ACL allografts withstood a maximum load that was 63.8% (718.3 N) of the maximum load of normal ACLs after 12 months. By contrast, the non-irradiated allografts failed at 69.1% (780.1 N) of the maximum load of normal control ACLs.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Risk Factors and Predictors of Subsequent ACL Injury in either Knee after ACL Reconstruction: Prospective Analysis of 2488 Primary ACL Reconstructions from the MOON Cohort

    PubMed Central

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

    2015-01-01

    Background Anterior cruciate ligament (ACL) re-injury results in worse outcomes and increases risk of post-traumatic osteoarthritis. Objectives To identify the risk factors for both ipsilateral and contralateral ACL tears after primary ACL reconstruction (ACLR). Study Design Cohort study; Level of evidence, 3. Methods Data from the Multicenter Orthopaedic Outcomes Network (MOON), a prospective longitudinal cohort, were used to identify risk factors for ACL retear. Subjects with primary ACLR, no history of contralateral knee surgery, and a minimum of 2-year follow-up data were included. Age, sex, Marx activity score, graft type, lateral meniscus tear, medial meniscus tear, sport played at index injury, and surgical facility were evaluated to determine their contribution to both ipsilateral retear and contralateral ACL tear. Results A total of 2683 subjects with average age of 27 ± 11 years (1498 men; 56%) met all study inclusion/exclusion criteria. Overall there were 4.4% ipsilateral graft tears and 3.5% contralateral ACL tears. The odds of ipsilateral retear were 5.2 times greater for an allograft (p<0.01) compared with a bone-patellar tendon-bone (BTB) autograft; the odds of retear were not significantly different between BTB autograft and hamstring autograft (p=0.12). The odds of an ipsilateral ACL retear decreased by 0.09 for every yearly increase in age (p<0.01) and increased by 0.11 for every increased point on the Marx score (p< 0.01). The odds were not significantly influenced by sex, smoking status, sport played, medial or lateral meniscus tear, or consortium site (p>0.05). The odds of a contralateral ACL tear decreased by 0.04 for every yearly increase in age (p=0.04) and increased by 0.12 for every increased point on the Marx score (p<0.01); these odds were not significantly different between sex, smoking status, sport played, graft type, medial meniscal tear, and lateral meniscal tear (p>0.05). Conclusions Younger age, higher activity level, and

  1. Outcome of ACL Reconstruction for Chronic ACL Injury in Knees without the Posterior Horn of the Medial Meniscus: Comparison with ACL Reconstructed Knees with An Intact Medial Meniscus

    PubMed Central

    Syam, Kevin; Chouhan, Devendra K.; Dhillon, Mandeep Singh

    2017-01-01

    Purpose Cadaveric studies have shown that deficiency of the posterior horn of the medial meniscus (PHMM) increases strain on the anterior cruciate ligament (ACL) graft. However, its influence on the clinical and radiological outcome after ACL reconstruction is less discussed and hence evaluated in this study. Materials and Methods This study included 77 cases of ACL reconstruction with a minimum 18-month follow-up. Of the 77 cases, 41 patients with intact menisci were compared clinically and radiologically with 36 patients with an injury to the PHMM that required various grades of meniscectomy. The knees were evaluated using subjective International Knee Documentation Committee (IKDC) score and Orthopadische Arbeitsgruppe Knie (OAK) score. Results Cases with intact menisci showed better stability (p=0.004) at an average of 44.51 months after surgery. No significant differences were noted in the overall OAK score, subjective IKDC score, and functional OAK score (p=0.082, p=0.526, and p=0.363, respectively). The incidence of radiological osteoarthrosis was significantly higher in the posterior horn deficient knees (p=0.022). Conclusions The tendency toward relatively higher objective instability and increased incidence of osteoarthrosis in the group with absent posterior horn reinforces its importance as a secondary stabiliser of the knee. PMID:28231647

  2. Pretibial Cyst Formation after ACL Reconstruction. A series of 14 cases with different etiologies

    PubMed Central

    Zicaro, Juan Pablo; Ranalletta, Maximiliano; Avila, Christian Garcia; Yacuzzi, Carlos; Costa-Paz, Matias

    2017-01-01

    Objectives: Among complications following an ACL reconstruction, the formation of a pre-tibial cyst in the site of the tibial tunnel is rare and might happen even years after surgery. The purpose of this study was to analyze 14 patients with pretibial cyst after ACL reconstruction. Methods: We retrospectively evaluated patients between 2008 and 2016. The inclusion criteria were patients who underwent an ACL reconstruction, and developed an extra-articular cyst at the tibial tunnel level. For recurrence evaluation, patients with less than one-year follow-up were excluded. A pre and postoperative clinical and radiological evaluation was performed. We analyzed the graft selection and surgical technique for ACL reconstruction, the time between primary surgery and onset of symptoms, and the clinical presentation. A pre and postoperative radiological evaluation was performed for every patient. Surgical technique for cyst excision, histological analysis and culture results were also analyzed. The recurrence rate was evaluated at final follow-up. Results: Nine patients were male, with an average age of 38 years. The average follow-up was of 35 months. All ACL reconstructions were performed using hamstrings graft and a trans-tibial technique. Tibial fixation was performed with a biodegradable screw in 9 patients, three of them associated with the use of a staple. In four patients hamstrings tibial insertion was left in situ with an open stripper and fixed in the tibia using non-absorbable Ethibond 2 sutures. The average time between primary ACL surgery and onset of the cyst was 29 months. All patients presented a palpable tumor at proximal tibia and a stable knee. The cyst size varied between 1 and 3 cm. In all cases, Rx and MRI showed a widening of the tibial tunnel, though no articular communication could be confirmed. The arthroscopic evaluation revealed no graft loosening. All cysts were approached through the previous tibial incision and staples or screws where removed

  3. 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

  4. 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

  5. Asymmetrical lower extremity loading after ACL reconstruction: more than meets the eye.

    PubMed

    Chmielewski, Terese L

    2011-06-01

    Sports fans know that movement patterns are important for athletic performance. Similarly, clinicians know that addressing abnormal movement patterns after an anterior cruciate ligament (ACL) reconstruction is important for a successful return to sport. The kinematic (motion) component of movement patterns is more easily observed than the kinetic (forces) component, thus more commonly addressed in ACL reconstruction rehabilitation. Ignoring the kinetic component, though, could impede a successful return to sport. Asymmetrical lower extremity loading has been reported in a variety of activities following ACL reconstruction, and may contribute to both short- and long-term consequences. It is important that clinicians become aware of the potential for asymmetrical lower extremity loading to affect patient outcomes and for researchers to enlarge the body of knowledge.

  6. 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

  7. 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.

  8. The use of platelets to affect functional healing of an anterior cruciate ligament (ACL) autograft in a caprine ACL reconstruction model.

    PubMed

    Spindler, Kurt P; Murray, Martha M; Carey, James L; Zurakowski, David; Fleming, Braden C

    2009-05-01

    Many anterior cruciate ligament (ACL) reconstructions have increased laxity postoperatively. We hypothesized that enhancing an ACL graft with a collagen-platelet composite (CPC) would improve knee laxity and graft structural properties. We also hypothesized the platelet concentration in the CPC would affect these parameters. Twelve goats underwent ACL reconstruction with autologous patellar tendon graft. In six goats, a collagen-platelet composite was placed around the graft (CPC group). In the remaining six goats, the collagen scaffold only was used (COLL group). Three goats were excluded due to complications. After 6 weeks in vivo, anterior-posterior (AP) laxity and tensile properties of the ACL reconstructed knees were measured and normalized against the contralateral intact knee. At a knee flexion angle of 30 degrees, the average increase in AP laxity was 40% less in the CPC group than the COLL group (p = 0.045). At 60 degrees, the AP laxity was 30% less in the CPC group, a difference that was close to statistical significance (p = 0.080). No differences were found between treatment groups with respect to the structural properties (p > 0.30). However, there were significant correlations between serum platelet concentration and AP laxity (R2 = 0.643; p = 0.009), maximum load (R2 = 0.691; p = 0.006), and graft stiffness (R2 = 0.840; p < 0.001). In conclusion, use of a CPC to enhance healing of an allograft ACL reconstruction inversely correlated with early sagittal plane laxity and the systemic platelet count was highly predictive of ACL reconstruction graft strength and stiffness at 6 weeks. These findings emphasize the importance of further research on delineating the effect of platelets in treating of ACL injuries.

  9. In vivo analysis of the pivot shift phenomenon during computer navigated ACL reconstruction.

    PubMed

    Lane, Clayton G; Warren, Russell F; Stanford, Fatima C; Kendoff, Daniel; Pearle, Andrew D

    2008-05-01

    ACL insufficiency can be documented clinically with the pivot shift maneuver, but the specific pathologic kinematics of the pivot shift is difficult to quantify. Navigation provides an opportunity to analyze in vivo the motions that comprise the pivot shift and the kinematic changes that are inherent after ACL reconstruction. We hypothesized that tibial rotation, anterior tibial translation (ATT), acceleration of posterior translation (APT) and the newly described angle of P, quantified during navigated pivot shift examination, correlate with clinical grading of the pivot shift phenomena. Navigation data from 12 patients who underwent navigated ACL surgery were retrospectively reviewed. A characteristic P-shaped track of motion is recorded by the navigation software during the pivot-shift examination. The "angle of P" was developed as a means characterizing this track of motion and was measured in all cases. The tibial rotation, maximum anterior tibial translation and acceleration of posterior translation during the pivot shift were also measured. The charts of these patients were reviewed to obtain information on the clinical grading of the pivot-shift before and after ACL reconstruction. Spearman correlation analysis was then used to identify significant correlations between clinical grade of the pivot shift and the angle of p measured with computer navigation. After reconstruction, the clinical grade of the pivot shift was zero in all patients. The tibial rotation, maximum ATT, APT and the angle of p also decreased. On analysis of 24 EUAs, 12 before reconstruction and 12 after, there was excellent and significant correlation between the clinical grade of pivot shift examination and the angle of P (R2 = 0.97, p < 0.001). Only good correlation was noted between the clinical pivot shift and the rotation (R2 = 0.77, p < 0.0001), maximum ATT (R2 = 0.87, p < 0.0001) and APT (R2 = 0.81, p < 0.0001). There was a stepwise increase of 6-7 mm of translation and 5-6 degrees

  10. 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

  11. Bioresorbable scaffolds for anterior cruciate ligament reconstruction: do we need an off-the-shelf ACL substitute?

    PubMed

    Richmond, John C; Weitzel, Paul P

    2010-03-01

    Currently available anterior cruciate ligament (ACL) graft sources, autograft and allograft, present potential problems that a natural biomaterial ACL graft might be able to solve. Earlier efforts in the development of synthetic ACL grafts were less than optimal, and those devices have largely been abandoned. We can learn from these past failures, and potentially develop a bioresorbable scaffold for ACL reconstruction, which will provide immediate stability, promote and direct tissue in growth, and degrade at an appropriate rate, without harmful wear debris. We have developed a modified silk scaffold, which is currently being evaluated in humans in a pilot study.

  12. 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

  13. Return to sports after ACL reconstruction: a new functional test protocol

    PubMed Central

    Bisciotti, Gian Nicola; Quaglia, Alessandro; Belli, Andrea; Carimati, Giulia; Volpi, Piero

    2016-01-01

    Summary Background In literature, there are lack of studies proposing clear and rationally designed test battery to be performed after an ACL reconstruction. Methods From 2006 to 2015, 80 football players were subjected, after ACL reconstruction, to a newly conceived test battery analyzing: Isometric and isokinetic force production The different phases during the jump The correct control of the landing phase after jump The control of valgus during landing after jump and cutting movements. Results The isokinetic and isometric test do not show any significant relationship with the another test. The laboratory test as well the field test showed them a significant correlation. Conclusions The results showed that a normal force production during the laboratory does not guarantee an equally satisfactory production of force during the field test. Study design Case series (Level III). PMID:28217573

  14. Correlation between fixation systems elasticity and bone tunnel widening after ACL reconstruction

    PubMed Central

    Giorgio, Nicola; Moretti, Lorenzo; Pignataro, Paolo; Carrozzo, Massimiliano; Vicenti, Giovanni; Moretti, Biagio

    2016-01-01

    Summary Background Femoral and tibial tunnel widening (TW) after ACL reconstruction is a phenomenon increasing talk in the literature. It is underlying biological and mechanical causes. Objective The aim of this study was to evaluate the relationship between bone tunnel enlargement and two different ACL fixation systems. Patients and Methods 40 patient underwent ACL reconstruction with hamstring; randomly divided into group A with 20 patients treated with stiff systems (femoral Rigidfix and tibial interference screw), and into group B, with 20 patients treated with morel elastic system (femoral and tibial Tight-rope). Evaluated postoperatively with knee MRI at 40 days, 3 months, 6 months to measure bone tunnel diameters widening. Results At 40 days tunnel widening between two groups shows no statistically difference. At 3 months postoperatively, femoral bone tunnel widening amounted on average to 1.84 mm in middle of tunnel and 1 mm at the mouth in joint in group A, and respectively 3.2 mm and 2.5 mm in group B (p<0.05). Tibial tunnel widening was 1.24 mm at the mouth in joint and 1.3 mm in middle in group A and respectively 2.26 mm and 2.43 mm in group B (p<0.05). At 6 months femoral tunnel widening amounted on average to 2.45 mm in middle and 1.35 mm at the mouth in joint in group A and respectively 3.5 mm and 2.7 mm in group B (p<0.01). Tibial tunnel widening amounted on average to 1.27 at mouth in joint and 1 mm in middle of tunnel in group A and respectively 2.6 mm and 2.3 mm in group B (p<0.01). Conclusions This study results suggest elastic fixation system increases bone tunnel enlargement after ACL reconstruction with hamstring without correlation with worse clinical performance. Level of evidence IV. PMID:28217568

  15. 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

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

    PubMed

    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.

  17. 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

  18. Effect of Calcium Phosphate–Hybridized Tendon Graft in Anatomic Single-Bundle ACL Reconstruction in Goats

    PubMed Central

    Mutsuzaki, Hirotaka; Fujie, Hiromichi; Nakajima, Hiromi; Fukagawa, Makoto; Nomura, Shunsuke; Sakane, Masataka

    2016-01-01

    Background: We previously developed a novel technique using an alternate soaking process that improves tendon-bone healing by hybridizing the tendon graft with calcium phosphate (CaP). However, the effects of the CaP-hybridized tendon graft on anatomic single-bundle anterior cruciate ligament (ACL) reconstruction remain unclear. Purpose: To determine the effects of CaP-hybridized tendon grafts compared with untreated tendon grafts 6 months after anatomic single-bundle ACL reconstruction using a goat model. Study Design: Controlled laboratory study. Methods: Animals were divided into a CaP group (n = 5 goats) and a control group (n = 5 goats), and we analyzed (1) knee kinematics and in situ forces under applied anterior tibial loads of 50 N and internal tibial torque of 2.0 N·m in the grafts at full extension and at 60° and 90° of knee flexion, (2) the mean percentage of bone tunnel enlargement using computed tomography (CT), and (3) the histology of the tendon-bone interface. Results: The in situ forces under applied anterior tibial loads of 50 N at 60° and 90° of knee flexion in the CaP group were greater than those in the control group (P < .05). The red safranin-O–stained area, indicating glycosaminoglycans in the cartilage layers at the joint aperture sites of the anterior femoral and posterior tibial bone tunnel, was greater in the CaP group than that in the control group (P < .05). The lengths of the nonbonding gap area between the anterior femoral and posterior tibial bone tunnels in the control group were greater than those in the CaP group (P < .05). No significant difference could be detected in the mean percentage of bone tunnel enlargement between the 2 groups. Conclusion: The CaP-hybridized tendon graft enhanced tendon-bone healing at the joint aperture site in both anterior femoral and posterior tibial tunnels 6 months after anatomic single-bundle ACL reconstruction in goats. The in situ forces under applied anterior tibial loads at greater

  19. Anterior cruciate ligament- and hamstring tendon-derived cells: in vitro differential properties of cells involved in ACL reconstruction.

    PubMed

    Ghebes, Corina Adriana; Kelder, Cindy; Schot, Thomas; Renard, Auke J; Pakvis, Dean F M; Fernandes, Hugo; Saris, Daniel B

    2015-03-11

    Anterior cruciate ligament (ACL) reconstruction involves the replacement of the torn ligament with a new graft, often a hamstring tendon (HT). Described as similar, the ACL and HT have intrinsic differences related to their distinct anatomical locations. From a cellular perspective, identifying these differences represents a step forward in the search for new cues that enhance recovery after the reconstruction. The purpose of this study was to characterize the phenotype and multilineage potential of ACL- and HT-derived cells. ACL- and HT-derived cells were isolated from tissue harvest from patients undergoing total knee arthroplasty (TKA) or ACL reconstruction. In total, three ACL and three HT donors were investigated. Cell morphology, self-renewal potential (CFU-F), surface marker profiling, expression of tendon/ligament-related markers (PCR) and multilineage potential were analysed for both cell types; both had fibroblast-like morphology and low self-renewal potential. No differences in the expression of tendon/ligament-related genes or a selected set of surface markers were observed between the two cell types. However, differences in their multilineage potential were observed: while ACL-derived cells showed a high potential to differentiate into chondrocytes and adipocytes, but not osteoblasts, HT-derived cells showed poor potential to form adipocytes, chondrocytes and osteoblasts. Our results demonstrated that HT-derived cells have low multilineage potential compared to ACL-derived cells, further highlighting the need for extrinsic signals to fully restore the function of the ACL upon reconstruction. Copyright © 2015 John Wiley & Sons, Ltd.

  20. Physeal-Sparing Technique for Femoral Tunnel Drilling in Pediatric Anterior Cruciate Ligament Reconstruction Using a Posteromedial Portal

    PubMed Central

    Lemos, Stephen E.; Keating, Patrick M.; Scott, Timothy P.; Siwiec, Ryan M.

    2013-01-01

    Pediatric anterior cruciate ligament (ACL) tears present a technical dilemma for orthopaedic surgeons. Multiple surgical techniques have been described to protect the distal femoral and proximal tibial physes. We present an ACL reconstruction technique performed on a 12-year-old girl with open physes who sustained an ACL tear after a noncontact twisting injury while playing soccer. A hamstring autograft reconstruction was performed by use of a posteromedial portal to drill the femoral tunnel in an all-epiphyseal fashion at the anatomic footprint of the native ACL. This case provides a new surgical technique to achieve anatomic fixation for ACL reconstruction in a skeletally immature individual using a posteromedial portal to drill a physeal-sparing lateral femoral tunnel for anatomic ACL reconstruction. This advancement may make drilling the femoral tunnel less technically challenging compared with other proposed methods while maintaining the lateral wall of the distal femur. PMID:24892013

  1. 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

  2. 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

  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. Rehabilitation of Patients Following Autogenic Bone-Patellar Tendon-Bone ACL Reconstruction: A 20-Year Perspective

    PubMed Central

    De Carlo, Mark S.; McDivitt, Ryan

    2006-01-01

    Rehabilitation of patients following anterior cruciate ligament (ACL) reconstruction has undergone remarkable improvements over the past two decades. During this time, ACL research has been at the forefront of many orthopaedic and sports physical therapy clinics. With over 20 years of ACL rehabilitation experience (senior author) and prior collaboration with accelerated ACL rehabilitation pioneer K. Donald Shelbourne, the authors wish to present a unique perspective on the evolution of ACL rehabilitation. Prior to the classic article by Paulos et al in 1981,1 literature on ACL rehabilitation was quite sparse. The basis for ACL rehabilitation at this time was founded in basic science studies conducted with animal models. In an effort to protect the graft, emphasis was placed on immobilization, extension limitation, restricted weight bearing, and delayed return to activity. Despite achieving good ligamentous stability, patients often experienced a spectrum of complications. In 1990, Shelbourne and Nitz2 proposed an accelerated rehabilitation protocol following ACL reconstruction based on clinical experience. Their program emphasized delayed surgery, earlier range of motion and weight bearing, and full extension. As a result, patients experienced better clinical outcomes while maintaining knee stability. The rehabilitation program presented in this paper is still largely based on the principles of the accelerated protocol. As evidence-based practice and the call for prospective, randomized clinical research continues, the continued progress in treating patients with this injury will be enhanced. Furthermore, clinicians are urged not to lose sight of the clinical reasoning that helped evolve the ACL rehabilitation process where it is today. PMID:21522223

  5. Deficits in Quadriceps Strength and Patient-Oriented Outcomes at Return to Activity After ACL Reconstruction

    PubMed Central

    Lepley, Lindsey K.

    2015-01-01

    Context: Side-to-side quadriceps strength deficits are linked to hazardous lower extremity mechanics and reduced function at a time when individuals are returned to activity after anterior cruciate ligament (ACL) reconstruction. As a result, generalized criteria have emerged in the literature, wherein researchers are recommending that patients be cleared for participation once side-to-side differences in strength are ≤10% of the noninjured limb. Similar recommendations exist for patient-oriented outcomes (ie, self-reported function and hop tests), where deficits of ≤10% are considered ideal at return to activity. It is unclear how many studies actually achieve these clinically recommended results. Evidence Acquisition: Articles that reported quadriceps strength deficits as compared to the contralateral limb were collected from peer-reviewed sources available on Medline and Web of Science databases (1990 through August 2014). Search terms included the following: anterior cruciate ligament OR ACL AND muscle weakness, anterior cruciate ligament OR ACL AND strength; return-to-activity AND strength; anterior cruciate ligament OR ACL AND quadriceps. Study Design: Clinical review. Level of Evidence: Level 4. Results: Average side-to-side strength deficits at 6 months postreconstruction were 23% ± 8% (range, 3%-40%), while the average at 12 months postsurgery was found to be 14% ± 6% (range, 3%-28%). The average deficits in self-reported function at 6 months (mean, 14% ± 5%) and 12 months postsurgery (mean, 13% ± 6%) were also found to be >10%. Performance on hop tests was found to be less than optimal at 6 months postsurgery (mean, 11% ± 7%), but improved at 12 months postsurgery (mean, 1.3% ± 2%). Conclusion: This review provides an up-to-date account of the typical deficits in strength and patient-oriented outcomes that exist when formalized physical therapy concludes after ACL reconstruction. Based on the studies included, it seems pertinent that researchers

  6. The anatomy of the proximal tibia in pediatric and adolescent patients: implications for ACL reconstruction and prevention of physeal arrest.

    PubMed

    Shea, Kevin G; Apel, Peter J; Pfeiffer, Ronald P; Traughber, Paul D

    2007-04-01

    Although the treatment of anterior cruciate ligament (ACL) tears in skeletally immature patients is still controversial, several studies have advocated ACL reconstruction in selected patients to prevent secondary injury. The proximal tibial physis is a structure at risk during ACL reconstruction in young patients, and physeal growth complications have been reported after surgery in this area. The relationship between the ACL and the proximal tibial physeal/apophyseal regions is poorly understood. This study examined the MRI anatomy of the ACL and the proximal tibia apophysis and epiphysis. MRIs of 59 skeletally immature knees were reviewed (Average age = 12.75 years, range 6-15) to define the anatomy of the epiphyseal and apophyseal regions. Measurements were recorded in three parasagittal planes: (1) at the lateral border of the patellar tendon, (2) the lateral edge of the ACL insertion, and (3) the medial edge of the ACL insertion. A single three-dimensional (3D) computed tomography (CT) scan was used to evaluate the position of standard drill holes used in ACL reconstruction to assess for potential degree of injury to the epiphyseal and apophyseal growth plates. In the parasagittal planes, the average height of the epiphysis was 19.6, 20.7, and 21.5 mm at the lateral border of the patellar tendon, the lateral border of the ACL, and the medial border of the ACL, respectively. At the level of the same landmarks, the apophysis extended below the physis at an average of 20.2, 16.8, and 7.0 mm, respectively. Expressed as a percentage of epiphysis height this was an average of 104, 82, and 33%, respectively. Examination of 3D CT images revealed that variations in drill hole placement had effects on the volume of injury to the proximal tibial physis and apophysis. Drill holes that started more medial, distal, and with a steeper angle of inclination reduced the amount of physis and apophysis violated when compared with holes placed more lateral, proximal, and with a

  7. Hop tests correlate with IKDC and KOOS at minimum of 2 years after primary ACL reconstruction

    PubMed Central

    Reinke, Emily K.; Lorring, Dawn; Jones, Morgan H.; Schmitz, Leah; Flanigan, David C.; An, Angel Qi; Quiram, Amanda R.; Preston, Emily; Martin, Michael; Schroeder, Bettina; Parker, Richard D.; Kaeding, Christopher C.; Borzi, Lynn; Pedroza, Angela; Huston, Laura J.; Harrell, Frank E.; Dunn, Warren R.

    2012-01-01

    Purpose The hypothesis of this study was that single-legged horizontal hop test ratios would correlate with IKDC, KOOS, and Marx activity level scores in patients 2 years after primary ACL reconstruction. Methods Individual patient-reported outcome tools and hop test ratios on 69 ACL reconstructed patients were compared using correlations and multivariable modeling. Correlations between specific questions on the IKDC and KOOS concerning the ability to jump and hop ratios were also performed. Results The triple-hop ratio was moderately but significantly correlated with the IKDC, KOOS Sports and Recreation subscale, and the KOOS Knee Related Quality of Life subscale, as well as with the specific questions related to jumping. Similar but weaker relationship patterns were found for the single-hop ratio and timed hop. No significant correlations were found for the Marx activity level or crossover-hop ratio. Multivariable modeling showed almost no significant additional contribution to predictability of the IKDC or KOOS subscores by gender, BMI, or the number of faults on either leg. Conclusions The triple-hop test is most significantly correlated with patient-reported outcome scores. Multivariable modeling indicates that less than a quarter of the variability in outcome scores can be explained by hop test results. This indicates that neither test can serve as a direct proxy for the other; however, assessment of patient physical function by either direct report using validated outcome tools or by the hop test will provide relatively comparable data. Level of evidence II. PMID:21445595

  8. Correlation between body mass index and quadrupled hamstring tendon autograft size in ACL reconstruction

    PubMed Central

    ATBAŞI, ZAFER; ERÇIN, ERSIN; ERDEM, YUSUF; EMRE, TULUHAN YUNUS; ATILLA, HALIS ATIL; PARLAK, ADEM

    2016-01-01

    Purpose the aim of this study was to assess the relationship of patient weight, height and body mass index (BMI) with the size of the quadrupled hamstring tendon used in anterior cruciate ligament (ACL) reconstruction. Methods from patient records, we retrospectively assessed the weight, height, BMI and graft sizes of 126 patients who underwent ACL reconstruction using a quadrupled hamstring tendon autograft between January 2010 and January 2013 at our institution. The data obtained from perioperative measurements were studied using correlation analysis. Results statistically significant relationships were found between patient height and graft diameter (p = 0.033, r = 0.19) and between patient weight and graft diameter (p < 0.0001, r = 0.33). No statistically significant relationships were found between graft diameter and BMI or between graft length and patient height, weight and BMI (p > 0.05). Conclusions patient height and weight were found to be related to quadrupled hamstring graft diameter in our patient population. BMI was not related to the quadrupled hamstring graft size. The exact size of the graft cannot be predicted preoperatively on the basis of these variables. Level of evidence Level IV, retrospective case series. PMID:28217655

  9. 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.

  10. In vivo bone tunnel evaluation of nanoparticle-grafts using an ACL reconstruction rabbit model.

    PubMed

    Grant, Sheila A; Smith, Sarah E; Schmidt, Hilary; Pfeiffer, Ferris; Kuroki, Kei; Sherman, Seth; White, Richard; Grant, David A

    2017-04-01

    Acellular human gracilis tendons conjugated with gold nanoparticles (AuNP) and hydroxyapatite nanoparticles (nano-HAp) were used as a graft in an anterior cruciate ligament (ACL) reconstruction rabbit model. The ACLs of 11 New Zealand rabbits were reconstructed using grafts conjugated without nanoparticles, with AuNP only, and with both AuNP and nano-HAp. Semi-quantitative histological scoring of bone tunnel portion of grafts was performed after 14 weeks. Bone tunnels were scored for graft degeneration, graft remodeling, percentage of new host fibrous connective, collateral connection, head-to-head connection, graft collagen fiber organization, new host fibrous connective tissue organization, and graft and interface vascularity. All grafts were intact at 14 weeks. Results of bone tunnel scoring indicate remodeling in all graft types with new organized host fibrous connective tissue, head-to-head connection to bone and mild inflammation associated with remodeling. Components of the 20 nm AuNP grafts have significantly more graft degeneration, more new host fibrous connective tissue, and more vascularity compared to crosslinked grafts. Comparison between femoral and tibial tunnel scores indicate more degeneration in femoral tunnels compared to tibial tunnels. Overall results indicated potentially enhanced remodeling from the use of 20 nm AuNP grafts. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1071-1082, 2017.

  11. 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

  12. 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

  13. 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

  14. Degeneration in ACL Injured Knees with and without Reconstruction in Relation to Muscle Size and Fat Content—Data from the Osteoarthritis Initiative

    PubMed Central

    Baum, Thomas; Nevitt, Michael C.; Nardo, Lorenzo; Gersing, Alexandra S.; Lane, Nancy E.; McCulloch, Charles E.; Rummeny, Ernst J.; Link, Thomas M.

    2016-01-01

    Background Anterior cruciate ligaments (ACL) injuries represent a major risk factor for early osteoarthritis (OA). Purpose To evaluate the prevalence and 4-year progression of knee OA measured with 3T MR-imaging in individuals with ruptured, reconstructed or normal ACL and to assess the impact of thigh muscle characteristics. Methods A total of 54 knees (23/54 male, 31/54 female) were recruited from the Osteoarthritis Initiative (OAI). At baseline, 15/54 subjects had prevalent ACL ruptures and 15/54 subjects had prevalent ACL reconstruction (24/54 normal ACL). Western Ontario and McMasters Universities Arthritis Index (WOMAC) scores, Physical Activity Scores of the Elderly (PASE) and thigh muscle characteristics including strength, fat infiltration (Goutallier score) and thigh muscle cross-sectional area (CSA) MR measurements were obtained at baseline. Whole-organ MR-imaging Scores (WORMS) were obtained at baseline and at a 4-year follow-up time-point. Multivariate regression models, adjusting for covariates (age, gender, body mass index), were used for statistical analysis. Results At baseline, subjects with prevalent ACL ruptures had worse WORMS total scores (mean±SEM, 44.1±3.5) than subjects with ACL reconstruction (30.8±4.0; P = 0.015) and worse than subjects with normal ACL (21.3±3.0; P<0.001). Cartilage scores were worse in both femorotibial compartments in ACL injured knees than in knees with normal ACL (P<0.05). Knees with ACL reconstruction showed an increased degeneration of the medial meniscus (P = 0.036), cartilage degeneration at the medial femoral condyle (P = 0.011). In a multivariate regression model, including both ACL groups and total muscle characteristics as influence parameters, high thigh muscle CSA, high muscle/ fat ratio and low Goutallier scores were associated with less degenerative changes at the knee, independent of ACL status. Knees with ACL reconstruction showed an increased progression of cartilage degeneration at the medial tibia

  15. Frontal plane knee mechanics and medial cartilage MR relaxation times in individuals with ACL reconstruction : A pilot study

    PubMed Central

    Kumar, Deepak; Kothari, Abbas; Souza, Richard B.; Wu, Samuel; Ma, C. Benjamin; Li, Xiaojuan

    2014-01-01

    Background The objective of this pilot study was to evaluate cartilage T1ρ and T2 relaxation times and knee mechanics during walking and drop-landing for individuals with anterior cruciate ligament reconstruction (ACL-R). Methods Nine patients (6 men and 3 women, Age 35.8±5.4 years, BMI 23.5±2.5 kg/m2) participated 1.5±0.8 years after single-bundle two-tunnel ACL reconstruction. Peak knee adduction moment (KAM), flexion moment (KFM), extension moment (KEM), and peak varus were calculated from kinematic and kinetic data obtained during walking and drop-landing tasks. T1ρ and T2 times were calculated for medial femur (MF), and medial tibia (MT) cartilage and compared between subjects with low KAM and high KAM. Biomechanical variables were compared between limbs. Results The high KAM group had higher T1ρ for MT (p = 0.01), central MT (p = 0.05), posterior MF (p = 0.04), posterior MT (p = 0.01); and higher T2 for MT (p = 0.02), MF (p = 0.05) posterior MF (p = 0.002) and posterior MT (p = 0.01). During walking, ACL-R knees had greater flexion at initial contact (p =0.04), and lower KEM (p = 0.02). During drop-landing, the ACL-R knees had lower KAM (p = 0.03) and KFM (p = 0.002). Conclusion Patients with ACL-R who have higher KAM during walking had elevated MR relaxation times in the medial knee compartments. These data suggest that those individuals who have undergone ACL-R and have higher frontal plane loading, may be at a greater risk of knee osteoarthritis. PMID:24993277

  16. 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

  17. Evaluation of an intact, an ACL-deficient, and a reconstructed human knee joint finite element model.

    PubMed

    Vairis, Achilles; Stefanoudakis, George; Petousis, Markos; Vidakis, Nectarios; Tsainis, Andreas-Marios; Kandyla, Betina

    2016-02-01

    The human knee joint has a three-dimensional geometry with multiple body articulations that produce complex mechanical responses under loads that occur in everyday life and sports activities. Understanding the complex mechanical interactions of these load-bearing structures is of use when the treatment of relevant diseases is evaluated and assisting devices are designed. The anterior cruciate ligament (ACL) in the knee is one of four main ligaments that connects the femur to the tibia and is often torn during sudden twisting motions, resulting in knee instability. The objective of this work is to study the mechanical behavior of the human knee joint and evaluate the differences in its response for three different states, i.e., intact, ACL-deficient, and surgically treated (reconstructed) knee. The finite element models corresponding to these states were developed. For the reconstructed model, a novel repair device was developed and patented by the author in previous work. Static load cases were applied, as have already been presented in a previous work, in order to compare the calculated results produced by the two models the ACL-deficient and the surgically reconstructed knee joint, under the exact same loading conditions. Displacements were calculated in different directions for the load cases studied and were found to be very close to those from previous modeling work and were in good agreement with experimental data presented in literature. The developed finite element model for both the intact and the ACL-deficient human knee joint is a reliable tool to study the kinematics of the human knee, as results of this study show. In addition, the reconstructed human knee joint model had kinematic behavior similar to the intact knee joint, showing that such reconstruction devices can restore human knee stability to an adequate extent.

  18. Gait Patterns Differ Between ACL-Reconstructed Athletes Who Pass Return-to-Sport Criteria and Those Who Fail

    PubMed Central

    Di Stasi, Stephanie L.; Logerstedt, David; Gardinier, Emily S.; Snyder-Mackler, Lynn

    2013-01-01

    Background The current standard of practice for an athlete to return to sport after anterior cruciate ligament (ACL) reconstruction is varied. Attempt to return to activity is typically advised 6 months after surgery, but functional performance deficits and gait abnormalities are often still evident and may have important implications on future function. Hypothesis When comparing the involved and uninvolved limbs, patients who failed return-to-sport (RTS) criteria would demonstrate (1) smaller peak knee angles, extensor moments, and peak power absorption at the knee of the involved limb and (2) larger peak hip angles, extensor moments, and peak power generation of the involved limb. Study Design Controlled laboratory study. Methods A total of 42 patients completed functional and biomechanical gait assessment 6 months after ACL reconstruction. Functional testing involved an isometric quadriceps strength test, 4 single-legged hop tests, and 2 self-report questionnaires. Three-dimensional motion analysis was used to measure sagittal plane kinematics and kinetics of the hip and knee. A mixed-model analysis of variance and post hoc t tests were used to compare the limb symmetry of those who passed and those who did not pass RTS criteria. Minimal clinically important differences were calculated from healthy gait data and used to further define meaningful limb asymmetries. Results Twenty of the 42 (48%) patients passed RTS criteria 6 months after ACL reconstruction. Patients who did not pass the criteria demonstrated statistically significant differences between limbs on all kinematic and kinetic variables at the knee (P ≤ .027). Clinically meaningful asymmetries at the hip were also identified in this group. Only kinetic asymmetries at the knee were identified in the patients who passed RTS criteria. Conclusion Athletes who demonstrate superior functional performance 6 months after ACL reconstruction may have fewer abnormal and asymmetrical gait behaviors than their

  19. ACL Revision in Synthetic ACL graft failure

    PubMed Central

    Etcheto, H. Rivarola; Zordán, J.; Escobar, G.; Collazo, C.; Palanconi, M.; Autorino, C.; Salinas, E. Alvarez

    2017-01-01

    The development of synthetic grafts as an alternative to biological grafts for reconstruction of the anterior cruciate ligament dates from 1980. The interest is awakened due to the potential advantages of: The absence of morbidity associated with donor site, and early return to sport. However, this surgical technique has had multiple complications associated with graft: mechanical failures (synthetic graft failure, loss of fixation), synovial foreign body reaction, recurrent stroke, recurrent instability and ultimately, early osteoarthritis. Objectives: We describe the synthetic graft failure LCA, intraoperative findings and details of surgical technique. Methods: Patient 35 years old, with a history of ACL reconstruction four years of evolution in another health center, consultation with the Service knee arthroscopy for acute knee pain left knee during secondary sporting event to a rotation mechanism with fixed foot. On physical examination, presents and positive Lachman maneuver Pivot. Radiografia in a widening of the tibial tunnel is observed. NMR shows a discontinuity of fibers of synthetic graft. Results: First time arthroscopic revision where synthetic plastic LCA identifies with Disruption fiber pattern. Intraoperatively, hypertrophic chronic synovitis localized predominantly in intercóndilo is observed. debridement thereof is performed, and proceeds to the extraction of the synthetic ligament. Then he was made prior cruentado and revival of the edges of the tunnel, filling them with non-irradiated structural bone allograft. At four months as planned and after confirmation by studies incorporating bone graft was performed the second time with the new plastic ACL. It was planned like a primary graft surgery with autologous hamstring prepared in fourfold form, and fixation with modified transtibial technique Biotransfix system proximal and distal screw Biocomposite (arthrex®). A quadruple graft 9 mm was obtained, making good positioning of tunnels and stable

  20. The effect of platelet concentrates on graft maturation and graft-bone interface healing in ACL reconstruction in human patients

    PubMed Central

    Vavken, Patrick; Sadoghi, Patrick; Murray, Martha M

    2011-01-01

    Purpose To systematically review the current evidence for effects of platelet concentrates on (1) graft maturation and (2) graft-bone interface healing in ACL reconstruction in human, controlled trials, and for ensuing differences in clinical outcomes. Methods A systematic search of PubMed, CINAHL, EMBASE, CCTR and CDSR was performed for controlled trials of human ACL reconstruction with and without platelet concentrates. Data validity was assessed and data were collected on graft maturation, graft-bone interface healing and clinical outcome. Results Eight studies met the inclusion criteria. Seven studies reported on graft maturation with significantly better outcomes in the platelet groups in four, and large differences in means in two (underpowered) studies. Five studies report on tunnel healing, but four found no difference between groups. Three studies assessed clinical outcome but found no differences, regardless whether they had shown a benefical (1/3) or no effect (2/3) of platelets on graft and tunnel healing. Conclusion The current best evidence suggests that the addition of platelet concentrates to ACL reconstruction may have a beneficial effect on graft maturation and could improve it by 20–30% on average, but with substantial variability. The most likely mode of action is that treatment with platelets accelerates graft repopulation and remodeling, and this interpretation is supported by the existing data and biologically plausible. However, the current evidence also shows only a very limited influence of platelet concentrates on graft-bone interface healing and no significant difference in clinical outcomes. Clinical Relevance This systematic review collected evidence that the use of platelet concentrates may be a safe and inexpensive way to optimize graft maturation after ACL reconstruction, but there is no evidence for improved graft-bone interface healing or a significant difference in clinical outcomes. Level of Evidence Level IV, systematic

  1. Preoperative Predictors for Noncopers to Pass Return to Sports Criteria After ACL Reconstruction

    PubMed Central

    Zeni, Joseph; Di Stasi, Stephanie; Axe, Michael J.; Snyder-Mackler, Lynn

    2013-01-01

    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

  2. Kinematic Analysis of Five Different Anterior Cruciate Ligament Reconstruction Techniques.

    PubMed

    Gadikota, Hemanth R; Hosseini, Ali; Asnis, Peter; Li, Guoan

    2015-06-01

    Several anatomical anterior cruciate ligament (ACL) reconstruction techniques have been proposed to restore normal joint kinematics. However, the relative superiorities of these techniques with one another and traditional single-bundle reconstructions are unclear. Kinematic responses of five previously reported reconstruction techniques (single-bundle reconstruction using a bone-patellar tendon-bone graft [SBR-BPTB], single-bundle reconstruction using a hamstring tendon graft [SBR-HST], single-tunnel double-bundle reconstruction using a hamstring tendon graft [STDBR-HST], anatomical single-tunnel reconstruction using a hamstring tendon graft [ASTR-HST], and a double-tunnel double-bundle reconstruction using a hamstring tendon graft [DBR-HST]) were systematically analyzed. The knee kinematics were determined under anterior tibial load (134 N) and simulated quadriceps load (400 N) at 0°, 15°, 30°, 60°, and 90° of flexion using a robotic testing system. Anterior joint stability under anterior tibial load was qualified as normal for ASTR-HST and DBR-HST and nearly normal for SBR-BPTB, SBR-HST, and STDBR-HST as per the International Knee Documentation Committee knee examination form categorization. The analysis of this study also demonstrated that SBR-BPTB, STDBR-HST, ASTR-HST, and DBR-HST restored the anterior joint stability to normal condition while the SBR-HST resulted in a nearly normal anterior joint stability under the action of simulated quadriceps load. The medial-lateral translations were restored to normal level by all the reconstructions. The internal tibial rotations under the simulated muscle load were over-constrained by all the reconstruction techniques, and more so by the DBR-HST. All five ACL reconstruction techniques could provide either normal or nearly normal anterior joint stability; however, the techniques over-constrained internal tibial rotation under the simulated quadriceps load.

  3. 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.

  4. An Integrated Approach to Change the Outcome Part II: Targeted Neuromuscular Training Techniques to Reduce Identified ACL Injury Risk Factors

    PubMed Central

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

    2014-01-01

    Prior reports indicate that female athletes who demonstrate high knee abduction moments (KAMs) during landing are more responsive to neuromuscular training designed to reduce KAM. Identification of female athletes who demonstrate high KAM, which accurately identifies those at risk for noncontact anterior cruciate ligament (ACL) injury, may be ideal for targeted neuromuscular training. Specific neuromuscular training targeted to the underlying biomechanical components that increase KAM may provide the most efficient and effective training strategy to reduce noncontact ACL injury risk. The purpose of the current commentary is to provide an integrative approach to identify and target mechanistic underpinnings to increased ACL injury in female athletes. Specific neuromuscular training techniques will be presented that address individual algorithm components related to high knee load landing patterns. If these integrated techniques are employed on a widespread basis, prevention strategies for noncontact ACL injury among young female athletes may prove both more effective and efficient. PMID:22580980

  5. Computer-assisted anterior cruciate ligament reconstruction. Four generations of development and usage.

    PubMed

    Klos, Tiburtius V S

    2014-12-01

    The purpose of this paper is to review the literature about the contribution of navigation in anterior cruciate ligament (ACL) reconstruction. The evolution of computer-assisted surgery (CAS) for ACL reconstruction has undergone several steps. These steps were divided into 4 subsequent developments: (1) positioning of ACL graft placement; (2) laxity measurement of ACL reconstruction (quality control); (3) kinematic evaluation during ACL reconstruction (navigated pivot shift); (4) case-specific individual ACL reconstruction with adjustments and additional reconstruction options. CAS has shown to improve femoral tunnel positioning, even if clinical outcomes do not improve results of manual techniques. CAS technology has helped researchers better understand the effects of different ACL reconstruction techniques and bundles replacements on joint laxity and to describe tunnel positioning in relation to native ACL insertion. CAS in ACL surgery can improve results at time zero and can improve knowledge in this field.

  6. 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

  7. THE CLINICAL UTILITY OF FUNCTIONAL PERFORMANCE TESTS WITHIN ONE-YEAR POST-ACL RECONSTRUCTION: A SYSTEMATIC REVIEW

    PubMed Central

    Narducci, Elizabeth; Waltz, Amanda; Gorski, Katheryn; Leppla, Lucas

    2011-01-01

    Introduction: A tear of the anterior cruciate ligament (ACL) represents a significant injury for an athlete that requires substantial time away from sport, and significant rehabilitation after reconstruction. The physical therapist is responsible to determine when a patient is capable of tolerating the physical demands of daily activities and to attempt to prevent re-injury. Physical or functional performance tests (FPTs) are one mechanism used to evaluate the athlete's physical skills and capabilities prior to returning to sports participation. The purpose of this systematic review is to critically examine the clinical utility of functional performance tests used with patients less than or equal to one year post ACL reconstruction. Methods: A systematic review of the relevant literature was performed using PRISMA guidelines. A total of twelve studies were included for analysis. Results: Two independent blinded reviewers then analyzed and rated the final included articles (n=12) utilizing the Newcastle-Ottawa Scale (NOS). Percent overall agreement between raters for the NOS was 88% with a fixed-marginal kappa (κ) of 0.80. Of the 12 included articles, the FPTs were utilized as an outcome measure within the study design (41.7%) or studied as a measure of function (58.3%). Among those studies that used FPTs as a “measure of function” 71.4% studied a battery of FPTs, while 28.6% studied a single test. None of the studies utilized FPTs as a measure to determine readiness to return to sport. Discussion: FPTs are being utilized with patients, less than or equal to one year post ACL reconstruction, either as an assessment of functional performance or as an outcome measure. No studies identified a FPT or test battery that has construct or predictive validity for “return to sport” in athletic population one-year post-ACL reconstruction. The identification of the critical elements within the return to sport construct may allow lower extremity performance tests to be

  8. Finite element study on the anatomic transtibial technique for single-bundle anterior cruciate ligament reconstruction.

    PubMed

    Bae, Ji Yong; Kim, Geon-Hee; Seon, Jong Keun; Jeon, Insu

    2016-05-01

    The anatomic transtibial (TT) technique is proposed as a new approach for single-bundle anterior cruciate ligament (ACL) reconstruction. Geometric models of the anatomic TT and anteromedial (AM) portal techniques were fabricated with a reconstructed knee joint model and virtual surgical operations. Grafts of 7 mm diameter were modeled and inserted into tunnels drilled in each model. In the models, the shape of the graft between the femur and the tibia, the lengths of the bone tunnels, and the femoral graft bending angles were evaluated. To evaluate the biomechanical effects of both techniques on the grafts, the contact pressures and maximum principal stresses in the grafts were calculated using the finite element method. The anatomic TT technique placed the femoral tunnel to the anatomic position of the native ACL femoral attachment site. In addition, it decreased the peak contact pressure and the maximum principal stress at the full extension position of the graft compared with the AM portal technique. The anatomic TT technique may be regarded as a superior surgical technique compared with the conventional TT and AM portal techniques. Because of the easy surgical operation involved, the technique decreases the operation time for ACL reconstruction and it provides a deformation behavior of grafts similar to that in the native ACL in a knee joint. With its few side effects, the anatomic TT technique may considerably help patients.

  9. FUNCTIONAL TESTING TO DETERMINE READINESS TO DISCONTINUE BRACE USE, ONE YEAR AFTER ACL RECONSTRUCTION

    PubMed Central

    Hunter‐Giordano, Airelle; Axe, Michael J.; Snyder‐Mackler, Lynn

    2013-01-01

    Background: While the use of functional knee braces for return to sports or high level physical activity after ACL reconstruction (ACLR) is controversial, brace use is still prevalent.1,2,3,4,5 All active patients in the practice are braced after ACLR and must pass a battery of sports tests before they return to play in their brace. Criteria include a 90% score on 4 one‐legged hop tests9 burst superimposition strength test,10 Knee Outcome Survey Activities of Daily Living Scale,8 and a global rating of knee function. Purpose: The purpose of this study was to describe the use of criterion‐based guidelines to determine if athletes who had undergone an ACLR function better with or without their functional brace, one year after surgery. Study Design: Cross‐Sectional Study Methods: Sixty‐four patients post ACLR performed 4 one‐legged hop tests,9 burst superimposition strength test,10 and completed the Knee Outcome Survey Activities of Daily Living Scale,8 and a global rating of knee function one year after surgery with and without their brace. Results: Participants included 35 men and 29 women with a mean age of 25 years. The Mean Knee Outcome Survey Activities of Daily Living score was 98%, and the global rating was 97%. Of the subjects, one patient failed hop testing by at least one criterion with and without the brace. Three additional patients failed the test while braced but passed un‐braced, and one patient passed with the brace, but failed without the brace. Subjects performed significantly better un‐braced than braced in all hop tests: single leg hop braced = 101%; un‐braced = 107% (p<0.001); cross‐over hop braced = 100%; un‐braced = 105% (p<0.001); triple hop braced = 99%; un‐braced = 101% (p=0.003); timed hop braced = 98%; un‐braced = 103% (p = 0.004). Conclusions: Sixty‐two of 64 patients continued to score above return to play criteria one year after ACLR. All but two subjects in the cohort performed better un‐braced than braced

  10. Patients With Ligament Hiperlaxity With Rupture Of Previous Plastic For ACL. Reconstruction With Intra-articular And Extra-articular Combined Technics

    PubMed Central

    Astore, Ignacio; Agotegaray, Juan Ignacio; Comba, Ignacio; Bisiach, Luciana

    2017-01-01

    Introduction: In cases of patients with ligament hiperlaxity with rupture of ACL, the use of a BTB graft is recommended for its reconstruction. Our job consists of the clinical and functional assessment of a group of 10 patients with ligament laxaty according to Beighton scale, who, after surgery for ACL rupture with BTB technique, suffered a rupture of the plastic. For its reconstruction a combination of intra-articular and extra-articular techniques was used with a BTB graft in the contralateral knee, associated with a modified Lemaire technique. Methods: The series consists of 10 patients, male, average age of 24.2 years, amateur athletes, operated for a second time in March, 2011 and November, 2013, with a minimum follow-up of 24 months. They were evaluated before surgery and 24 months after surgery based on Lysholm scale, IKDC evaluation form and a physical exam (Lachman - Pivot Shift). Results: After surgery, the average in Lysholm scale was of 87.6 and 86.3 for the IKDC subjetive form. In the physical exam, 8 patients showed Lachman 1+, while none of the patients showed Pivot Shift positive. 7 patients were able to return to their usual sport activities. As a postoperative disadvantage, 6 patients reported pain in the external face of the knee in the first 6 months. And 4 patients reported a subjetive loss of full extension that did not interfere with their sport activities. Conclusion: Based on our experience and literature, we believe that the combination of both techniques, intra-articular (BTB) and extra-articular (Lemaire), is a good alternative for patients with ligament laxaty, providing positive clinical and functional results.

  11. KNEE KINEMATICS FOLLOWING ACL RECONSTRUCTION IN FEMALES; THE EFFECT OF VISION ON PERFORMANCE DURING A CUTTING TASK

    PubMed Central

    Di Fabio, Richard P.

    2011-01-01

    Purpose/Background: Specific movement patterns have been identified as influential in ACL injury; however several key kinematic variables that might be predictive of future performance have not been fully investigated. The purpose of this research was to: 1) determine if subjects with ACL reconstruction display different displacement, velocity, and time to peak ground reaction force (GRF) during cutting activities than healthy subjects, 2) observe if subjects with visual disruption display differences in these variables, and 3) determine if visual disruption alters these variables in subjects with ACL reconstruction relative to healthy subjects. Methods: Seventeen healthy female subjects and 17 female subjects with unilateral ACL reconstruction (ACLR) performed 40 trials of a cutting movement during which knee position was measured via a 3D electromagnetic system. Visual conditions were randomized to disrupt vision for 1 second as the subject began the cutting movement, or allow full vision for movement duration. Independent variables were lead/push off leg (ACLR limb or healthy non-dominant limb) and vision (disrupted or full). 2-way ANOVAs were utilized to determine differences between knee kinematics using dependent variables of displacement (m), absolute velocity (m/sec), and time to reach peak GRF (% of cut). Results: Knee displacement was significantly less for ACLR (.76±.11; .75±.16) than non-dominant (.85±.08; .87±.12). Knee velocity was significantly slower for ACLR (.81±.14; .84±.16) than non-dominant (.92±.11; .97±.14). A significant interaction was noted for displacement and average velocity (p<.05). Time to reach peak GRF was significantly longer for ACLR (79.41±2.28) than non-dominant (76.65±4.41). Conclusions: Subjects with ACLR displayed less knee displacement, slower velocity, and an increased time to reach peak GRF relative to healthy subjects' non-dominant knee. Visual disruption appeared to have some effect on movement, as noted by

  12. 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.

  13. 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.

  14. Neuromuscular Coordination Deficit Persists 12 Months after ACL Reconstruction But Can Be Modulated by 6 Weeks of Kettlebell Training: A Case Study in Women's Elite Soccer

    PubMed Central

    Andersen, Christoffer H.; Bencke, Jesper; Ørntoft, Christina; Linnebjerg, Connie; Hölmich, Per

    2017-01-01

    The aim of the present single-case study was to investigate the effect of 6 weeks' kettlebell training on the neuromuscular risk profile for ACL injury in a high-risk athlete returning to sport after ACL reconstruction. A female elite soccer player (age 21 years) with no previous history of ACL injury went through neuromuscular screening as measured by EMG preactivity of vastus lateralis and semitendinosus during a standardized sidecutting maneuver. Subsequently, the player experienced a noncontact ACL injury. The player was screened again following postreconstruction rehabilitation, then underwent 6-week kettlebell training, and was subsequently screened again at 6-week follow-up. Prior to and after postreconstruction rehabilitation the player demonstrated a neuromuscular profile during sidecutting known to increase the risk for noncontact ACL injury, that is, reduced EMG preactivity for semitendinosus and elevated EMG preactivity for vastus lateralis. Subsequently, the 6-week kettlebell training increased semitendinosus muscle preactivity during sidecutting by 38 percentage points to a level equivalent to a neuromuscular low-risk profile. An ACL rehabilitated female athlete with a high-risk neuromuscular profile changed to low-risk in response to 6 weeks of kettlebell training. Thus, short-term kettlebell exercise with documented high levels of medial hamstring activation was found to transfer into high medial hamstring preactivation during a sidecutting maneuver. PMID:28197354

  15. Neuromuscular Coordination Deficit Persists 12 Months after ACL Reconstruction But Can Be Modulated by 6 Weeks of Kettlebell Training: A Case Study in Women's Elite Soccer.

    PubMed

    Zebis, Mette K; Andersen, Christoffer H; Bencke, Jesper; Ørntoft, Christina; Linnebjerg, Connie; Hölmich, Per; Thorborg, Kristian; Aagaard, Per; Andersen, Lars L

    2017-01-01

    The aim of the present single-case study was to investigate the effect of 6 weeks' kettlebell training on the neuromuscular risk profile for ACL injury in a high-risk athlete returning to sport after ACL reconstruction. A female elite soccer player (age 21 years) with no previous history of ACL injury went through neuromuscular screening as measured by EMG preactivity of vastus lateralis and semitendinosus during a standardized sidecutting maneuver. Subsequently, the player experienced a noncontact ACL injury. The player was screened again following postreconstruction rehabilitation, then underwent 6-week kettlebell training, and was subsequently screened again at 6-week follow-up. Prior to and after postreconstruction rehabilitation the player demonstrated a neuromuscular profile during sidecutting known to increase the risk for noncontact ACL injury, that is, reduced EMG preactivity for semitendinosus and elevated EMG preactivity for vastus lateralis. Subsequently, the 6-week kettlebell training increased semitendinosus muscle preactivity during sidecutting by 38 percentage points to a level equivalent to a neuromuscular low-risk profile. An ACL rehabilitated female athlete with a high-risk neuromuscular profile changed to low-risk in response to 6 weeks of kettlebell training. Thus, short-term kettlebell exercise with documented high levels of medial hamstring activation was found to transfer into high medial hamstring preactivation during a sidecutting maneuver.

  16. Quadriceps Strength Asymmetry Following ACL Reconstruction Alters Knee Joint Biomechanics and Functional Performance at Time of Return to Activity

    PubMed Central

    Palmieri-Smith, RM; Lepley, LK

    2016-01-01

    Background Quadriceps strength deficits are observed clinically following anterior cruciate injury and reconstruction and are often not overcome despite rehabilitation. Given that quadriceps strength may be important for achieving symmetrical joint biomechanics and promoting long-term joint health, determining the magnitude of strength deficits that lead to altered mechanics is critical. Purpose To determine if the magnitude of quadriceps strength asymmetry alters knee and hip biomechanical symmetry, as well as functional performance and self-reported function. Study Design Cross-Sectional study. Methods Seventy-three patients were tested at the time they were cleared for return to activity following ACL reconstruction. Quadriceps strength and activation, scores on the International Knee Documentation Committee form, the hop for distance test, and sagittal plane lower extremity biomechanics were recorded while patients completed a single-legged hop. Results Patients with high and moderate quadriceps strength symmetry had larger central activation ratios as well as greater limb symmetry indices on the hop for distance compared to patients with low quadriceps strength symmetry (P<0.05). Similarly, knee flexion angle and external moment symmetry was higher in the patients with high and moderate quadriceps symmetry compared to those with low symmetry (P<0.05). Quadriceps strength was found to be associated with sagittal plane knee angle and moment symmetry (P<0.05). Conclusion Patients with low quadriceps strength displayed greater movement asymmetries at the knee in the sagittal plane. Quadriceps strength was related to movement asymmetries and functional performance. Rehabilitation following ACL reconstruction needs to focus on maximizing quadriceps strength, which likely will lead to more symmetrical knee biomechanics. PMID:25883169

  17. The potential for primary repair of the ACL

    PubMed Central

    Vavken, Patrick; Murray, Martha M

    2011-01-01

    The objective of this work is to assess the feasibility of successfully repairing the torn ACL. Two major motivators for developing a new treatment for ACL injuries are the recently reported high rates of osteoarthritis after conventional ACL reconstruction as well as the problem of how to safely treat skeletally immature patients. A key factor in developing such a technique was the identification of the main inhibitor of intrinsic ACL healing – the lack of clot formation between the two torn ends of the ligament. A bioactive and biocompatible scaffold which could be placed in the wound site to enhance cellular proliferation and biosynthesis was developed. This biomaterial has shown promising functional outcomes in several large animal models of primary repair of partial and complete ACL transection over 4 to 14 weeks, suggesting potential for a successful, future clinical application. PMID:21293237

  18. Continuous ACL graft, results

    PubMed Central

    Díaz, Jorge Luis; Vega, Marcelo; Matesevach, Ivan

    2017-01-01

    Objectives: describe our technique using hamstring graft that respects the proximal continuity of Semitendinosus and uses the superior biological potential of the distal periosteum., preserving and stressing the ST reinforce the retropulsión and dynamic control of external rotation of the knee. Here the technique, results, difficulties and foundations. Methods: The sample of this research was composed of 229 cases operated between 01/03/97 and 01/03/13 in Arthroscopy Private Center., 166 male and 63 female, the postop follow-up was 86 months. Evaluated with IKDC, Lysholm, Hamstring EMG. Comparative histology study in rabbits. Results: IKDC and Lysholm score showed 93% of very good results. Conclusion: Dynamic ACL reconstruction achieves a static-dynamic stabilization of the knee. Grafts have a plus in their biological potential (proximal continuity - osteo-periosteal insertion of the tendons in the femoral tunnel). The hamstring maintains its functionality (EMG). 93% satisfactory results (IKDC, Lysholm). It is a valid surgical option in ACL injuries.

  19. All-Epiphyseal, All-Inside Anterior Cruciate Ligament Reconstruction Technique for Skeletally Immature Patients

    PubMed Central

    McCarthy, Moira M.; Graziano, Jessica; Green, Daniel W.; Cordasco, Frank A.

    2012-01-01

    Anterior cruciate ligament (ACL) injuries are an increasingly recognized problem in the juvenile population. Unfortunately, outcomes with conservative treatment are extremely poor. Adult reconstruction techniques are inappropriate to treat skeletally immature patients because of the risk of physeal complications, including limb-length discrepancy and angular deformities. “Physeal-sparing” reconstruction techniques exist, but their ability to restore knee stability is not well understood. We describe an all-epiphyseal ACL reconstruction for use in skeletally immature patients. This is an all-inside technique with the femoral tunnel drilled retrograde and the tibial tunnel drilled retrograde; both tunnels are entirely within the epiphysis. Fixation of the hamstring autograft is achieved with soft-tissue buttons on both the femur and tibia. We present case examples for 2 patients who underwent the all-inside, all-epiphyseal reconstruction and our postoperative rehabilitation protocol. We present a novel surgical technique for an all-inside, all-epiphyseal ACL reconstruction in skeletally immature patients. PMID:23767001

  20. Mandibular reconstruction with different techniques.

    PubMed

    Torroni, Andrea; Marianetti, Tito Matteo; Romandini, Mario; Gasparini, Giulio; Cervelli, Daniele; Pelo, Sandro

    2015-05-01

    Traumas, malformative or dysplastic pathologies, atrophy, osteoradionecrosis, and benign or malignant neoplasm can cause bone deficits in the mandible. Consequent mandibular defects can determine aesthetic and functional problems; therefore, being able to perform a good reconstruction is of critical importance.Several techniques have been proposed for mandibular reconstruction over the years. In this article, we present and discuss the evolution during the time of the methods of mandible reconstruction as well as pros and cons of each procedure on the basis of experience of 10 years in the maxillofacial department of the Catholic University of Sacred Heart of Rome.Free flaps represent the gold standard method of reconstruction of large mandibular defects: the fibula bone flap represents the best choice for large defects involving the arch and the mandibular ramus, whereas the deep circumflex iliac artery represents a valid alternative for mandibular defects involving the posterior region.In cases where free flap reconstructions are contraindicated, the use of regional pedicle flap combined with autologous bone grafts still represents a valid choice. Patients who are not deemed suitable for long and demanding surgery can still be treated using alloplastic materials in association with regional pedicle flap or, when adjuvant radiation therapy is needed, by simple locoregional pedicle flap. Finally, in selected cases, the bone transporting technique should be considered as a valid alternative to the more "traditional" reconstructive methods because of the extraordinary potential and its favorable cost-benefit ratio.

  1. A Novel Mass-Spring-Damper Model Analysis to Identify Landing Deficits in Athletes Returning to Sport after ACL Reconstruction.

    PubMed

    Schneider, Daniel K; Gokeler, Alli; Otten, Bert; Ford, Kevin R; Hewett, Timothy E; Divine, Jon; Colosimo, Angelo J; Heidt, Robert S; Myer, Gregory D

    2016-07-19

    A mass-spring-damper model may serve as an extension of biomechanical data from three-dimensional motion analysis and epidemiological data which help to delineate populations at-risk for anterior cruciate ligament (ACL) injuries. The purpose of this study was to evaluate such a model.\\Thirty-six ACL reconstruction (ACLR) group subjects and 67 controls (CTRL) completed single-leg drop landing and single-leg broad jump tasks. Landing ground reaction force data were collected and analyzed with a mass-spring damper model. Medians, interquartile ranges, and limb symmetry indices were calculated and comparisons were made within and between groups.During a single-leg drop landing, the ACLR group had a lower spring LSI than the CTRL group (P = 0.015) and landed with decreased stiffness in the involved limb relative to the uninvolved limb (P = 0.021). The ACLR group also had an increased damping LSI relative to the CTRL group (P = 0.045). The ACLR subjects landed with increased stiffness (P = 0.006) and decreased damping (P = 0.003) in their involved limbs compared to CTRL subjects non-dominant limbs. During a single-leg forward broad jump, the ACLR group had a greater spring LSI value than the CTRL group (P = 0.045). The CTRL group also recorded decreased damping values on their non-dominant limbs compared to the involved limbs of the ACLR group (P = 0.046).Athletes who have undergone ACLR display different lower limb dynamics than healthy controls according to a mass-spring damper model. Quadriceps dominance and leg dominance are components of ACLR athletes' landing strategies and may be identified with a mass-spring-damper model and addressed during rehabilitation.

  2. Anterolateral Ligament Reconstruction

    PubMed Central

    Zordan, J.; Etcheto, H. Rivarola; Blanchod, C. Collazo; Palanconi, M.; Salinas, E. Álvarez; Autorino, CM; Escobar, G.

    2017-01-01

    Anterior cruciate ligament (ACL) reconstruction is a common procedure in daily practice with 75 to 97% excellent long-term results. But in certain cases, some patients perceive rotational instability, for this reason the revision rate can be 10 to 15%. Objectives: evaluate functional outcome in revisions of ACL reconstruction associated with ALL. Methods: Between July 2015 and February 2016 (11 knees) Eleven Revision ACL reconstruction were performed with ALL with double incision technique performed by the same surgical team. Inclusion criteria were: ACL reconstruction failures with a grade 2 or 3 Lachman test, a grade 3 pivot-shift without other ligamentary injury lesions associated and complete range of motion. Results: The concept of rotational instability associated with ACL injury has been described more than a decade ago. However, there is no consensus on how to quantify rotational instability in ACL injuries; so when associating an extracapsular technique. Currently there is a lack of high-level evidence comparing isolated ACL repair and associated with the modified reconstruction of ALL that allows us to define therapeutic approaches. The ALL reconstruction associate an ACL reconstruction remains a matter of study. Conclusion: We obtain excellent results in antero – posterior and rotational stability after performing the procedure.

  3. All-Epiphyseal Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients: A Surgical Technique Using a Split Tibial Tunnel

    PubMed Central

    Lykissas, Marios G.; Nathan, Senthil T.; Wall, Eric J.

    2012-01-01

    Many techniques have been described for anterior cruciate ligament (ACL) reconstruction in skeletally immature patients, including extra-articular, complete or partial transphyseal, and physeal-sparing techniques. An all-epiphyseal technique places the tendon and its tunnels and fixation all within the child's epiphysis, leaving the growth plates untouched. We describe an all-epiphyseal quadruple-hamstring ACL reconstruction using a split tibial tunnel. The split tibial tunnels drop the tunnel size down to 4.5 to 5.5 mm from 7 to 8 mm because only half the total graft diameter passes through each of the split tunnels. This increases the safety margin for keeping the tunnel within the tibial epiphysis, in addition to avoiding damage into the growth plate. The bone bridge between the 2 tunnels serves as a solid low-profile fixation post. Femoral graft fixation is achieved with an interference screw, which allows precise tensioning and low-profile fixation entirely within the femoral tunnel. By placing the graft at the native ACL's anatomic attachment points without spanning or violating the growth plates at any step of the procedure, an all-epiphyseal ACL reconstruction with a split tibial tunnel theoretically minimizes the risk of growth disturbance in an ACL-deficient child. PMID:23766968

  4. Predictors of Revision Surgery After Primary Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Yabroudi, Mohammad A.; Björnsson, Haukur; Lynch, Andrew D.; Muller, Bart; Samuelsson, Kristian; Tarabichi, Majd; Karlsson, Jón; Fu, Freddie H.; Harner, Christopher D.; Irrgang, James J.

    2016-01-01

    Background: Revision anterior cruciate ligament (ACL) reconstruction surgery occurs in 5% to 15% of individuals undergoing ACL reconstruction. Identifying predictors for revision ACL surgery is of essence in the pursuit of creating adequate prevention programs and to identify individuals at risk for reinjury and revision. Purpose: To determine predictors of revision ACL surgery after failed primary ACL reconstruction. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 251 participants (mean age ± SD, 26.1 ± 9.9 years) who had undergone primary ACL reconstruction 1 to 5 years earlier completed a comprehensive survey to determine predictors of revision ACL surgery at a mean 3.4 ± 1.3 years after the primary ACL reconstruction. Potential predictors that were assessed included subject characteristics (age at the time of surgery, time from injury to surgery, sex, body mass index, preinjury activity level, return to sport status), details of the initial injury (mechanism; concomitant injury to other ligaments, menisci, and cartilage), surgical details of the primary reconstruction (Lachman and pivot shift tests under anesthesia, graft type, femoral drilling technique, reconstruction technique), and postoperative course (length of rehabilitation, complications). Univariate and multivariate logistic regression analyses were performed to identify factors that predicted the need for revision ACL surgery. Results: Overall, 21 (8.4%) subjects underwent revision ACL surgery. Univariate analysis showed that younger age at the time of surgery (P = .003), participation in sports at a competitive level (P = .023), and double-bundle ACL reconstruction (P = .024) predicted increased risk of revision ACL surgery. Allograft reconstructions also demonstrated a trend toward greater risk of revision ACL surgery (P = .076). No other variables were significantly associated with revision ACL surgery. Multivariate analysis revealed that revision ACL surgery was

  5. The Influence of Task Complexity on Knee Joint Kinetics Following ACL Reconstruction

    PubMed Central

    Schroeder, Megan J.; Krishnan, Chandramouli; Dhaher, Yasin Y.

    2015-01-01

    Background Previous research indicates that subjects with anterior cruciate ligament reconstruction exhibit abnormal knee joint movement patterns during functional activities like walking. While the sagittal plane mechanics have been studied extensively, less is known about the secondary planes, specifically with regard to more demanding tasks. This study explored the influence of task complexity on functional joint mechanics in the context of graft-specific surgeries. Methods In 25 participants (10 hamstring tendon graft, 6 patellar tendon graft, 9 matched controls), three-dimensional joint torques were calculated using a standard inverse dynamics approach during level walking and stair descent. The stair descent task was separated into two functionally different sub-tasks—step-to-floor and step-to-step. The differences in external knee moment profiles were compared between groups; paired differences between the reconstructed and non-reconstructed knees were also assessed. Findings The reconstructed knees, irrespective of graft type, typically exhibited significantly lower peak knee flexion moments compared to control knees during stair descent, with the differences more pronounced in the step-to-step task. Frontal plane adduction torque deficits were graft-specific and limited to the hamstring tendon knees during the step-to-step task. Internal rotation torque deficits were also primarily limited to the hamstring tendon graft group during stair descent. Collectively, these results suggest that task complexity was a primary driver of differences in joint mechanics between anterior cruciate ligament reconstructed individuals and controls, and such differences were more pronounced in individuals with hamstring tendon grafts. Interpretation The mechanical environment experienced in the cartilage during repetitive, cyclical tasks such as walking and other activities of daily living has been argued to contribute to the development of degenerative changes to the joint

  6. Comparing Transtibial and Anteromedial Drilling Techniques for Single-bundle Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Sukur, Erhan; Akman, , Yunus Emre; Senel, , Ahmet; Unkar, Ethem Ayhan; Topcu, , Huseyin Nevzat; Ozturkmen, , and Yusuf

    2016-01-01

    Background: Among the many factors that determine the outcome following anterior cruciate ligament (ACL) reconstruction, the position of the femoral tunnel is known to be critically important and is still the subject of extensive research. Objective: We aimed to retrospectively compare the outcomes of arthroscopic ACL reconstruction using transtibial (TT) or anteromedial (AMP) drilling techniques for femoral tunnel placement. Methods: ACL reconstruction was performed using the TT technique in 49 patients and the AMP technique in 56 patients. Lachman and pivot-shift tests, the Lysholm Knee Scale, International Knee Documentation Committee (IKDC) score, Tegner activity scale and visual analog scale (VAS) were used for the clinical and functional evaluation of patients. Time to return to normal life and time to jogging were assessed in addition to the radiological evaluation of femoral tunnel placement. Results: In terms of the Lysholm, IKDC, Tegner score, and stability tests, no significant differences were found between the two groups (p > 0.05). Statistical analysis revealed reduced time to return to normal life and jogging in the AMP group (p < 0.05). The VAS score was also significantly reduced in the AMP group (p < 0.05). The position of the femoral tunnel was anatomically appropriate in 51 patients in the AMP group and 5 patients in the TT group. Conclusion: The AMP technique is superior to the TT technique in creating anatomical femoral tunnel placement during single-bundle ACL reconstruction and provides faster recovery in terms of return to normal life and jogging at short-term follow-up. PMID:27733884

  7. Arthroscopic Control for Safe and Secure Seating of Suspensory Devices for Femoral Fixation in Anterior Cruciate Ligament Reconstruction Using Three Different Techniques

    PubMed Central

    Kang, Seo Goo; Lee, Yong Seuk

    2017-01-01

    Purpose The purpose of this study was to evaluate the efficacy of our technique that allows direct visualization of seating of suspensory devices in anterior cruciate ligament (ACL) reconstruction. Materials and Methods Three different suspensory devices (TightRope RT, RetroButton, and EndoButton) were used in ACL reconstruction using 3 different techniques (outside-in, anteromedial [AM] portal, and transtibial techniques). Positioning of a guiding material and seating pattern of the suspensory devices were evaluated according to the surgical technique and suspensory device used. Results On the transtibial technique, 21 of total 26 cases (81%) of single bundle reconstructions and 22 of total 22 cases (100%) of double bundle reconstructions required superolateral capsulotomy where buttons were found in 21 of total 21 cases (100%) and 17 of 22 cases (77%), respectively. On the AM portal technique, all patients required capsulotomy and the button was found in only 18 of total 32 cases (56%) even after capsulotomy. On the outside-in technique, all patients required capsulotomy and the button was found in 86 of total 86 cases (100%). Conclusions Our technique for direct visualization of seating of the suspensory devices was more effective in outside-in and single bundle transtibial ACL reconstruction. However, it was less effective in double bundle transtibial and AM portal ACL reconstructions. PMID:28231646

  8. Changes of early post-traumatic osteoarthritis in an ovine model of simulated ACL reconstruction are associated with transient acute post-injury synovial inflammation and tissue catabolism.

    PubMed

    Heard, B J; Solbak, N M; Achari, Y; Chung, M; Hart, D A; Shrive, N G; Frank, C B

    2013-12-01

    The study described here tested the hypothesis that early intra-articular inflammation is associated with the development of post-traumatic osteoarthritis (PTOA) in a sheep model. We extended previously published work in which we investigated joint gross morphology and synovial mRNA expression of inflammatory and catabolic molecules 2 weeks after anatomic Anterior cruciate ligament (ACL) autograft reconstructive surgery (ACL-R). The same variables have been analyzed at 20 weeks post surgery together with new experimental variables at both time points. Animals were sacrificed at 20 weeks post ACL-R surgery and their joints graded for signs of PTOA. Synovial samples were harvested for histological grading plus mRNA and protein analysis for a panel of inflammatory and catabolic molecules. The mRNA expression levels for this panel plus connective tissue matrix turnover molecules were also investigated in cartilage samples. Results of gross morphological assessments at 20 weeks post surgery showed some changes consistent with early OA, but indicated little progression of damage from the 2 week time point. While significant alterations in mRNA levels for synovial inflammatory and catabolic molecules were detected at 2 weeks, values had normalized by 20 weeks. Similarly, all mRNA expression levels for inflammatory and catabolic molecules in articular cartilage had returned to normal levels by 20 weeks post ACL-R surgery. We conclude that synovial inflammatory processes are initiated very early after ACL-R surgery and may instigate events that lead to the gross cartilage and joint abnormalities observed as early as 2 weeks. However, the absence of sustained inflammation and joint instability may prevent OA progression.

  9. The immunosuppressive effect of Siglecs on tendon-bone healing after ACL reconstruction.

    PubMed

    Hu, Jiang; Yao, Bin; Yang, Xiao; Ma, Fang

    2015-01-01

    The quality of the bone-tendon healing is very important to the surgery outcome after anterior cruciate ligament reconstruction. The necrosis of autograft and local new blood vessels occur after the surgery. The fibroblasts and mesenchymal cells presenting in the tendon-bone interface as well as the infiltrated of neutrophils and macrophages improve the biomechanical properties of the healing. We hypothesize that immunosuppressive effect of Siglecs which present on the surface of neutrophils and macrophages play the important roles to regulate acute local inflammatory reaction, maintain the physiological environment and induce the differentiation of the pluripotent cells to form the accepted histologic structure healing of the tendon-bone interface. It might be helpful to understand the mechanism of tendon-bone healing.

  10. Mid-Term Outcomes of Anterior Cruciate Ligament Reconstruction with Far Anteromedial Portal Technique

    PubMed Central

    Jeon, Yoon Sang; Choi, Sung Wook; Park, Ju Hyun; Yoon, Jae Sik; Shin, Jung Sub; Kim, Myung Ku

    2017-01-01

    Purpose The purpose of this study was to evaluate the mid-term outcomes of anatomic anterior cruciate ligament (ACL) reconstruction using two anteromedial (AM) portals by comparing with short-term follow-up results. Materials and Methods Fifty patients who were treated by ACL reconstruction using a two AM portal technique were evaluated retrospectively. The follow-up period was at least 5 years. The mean follow-up period was 68.5±13.9 months. The mid-term clinical outcomes were compared with short-term (≥12 months) results. For the assessment of knee stability, anterior tibial translation was evaluated using the Lachman test and the KT-2000. Rotational stability was evaluated using pivot shift test. For clinical assessment, the Lysholm and International Knee Documentation Committee scores were used. Results The average anterior translation was 2.1±1.4 mm at the short-term follow-up and 2.8±1.8 mm at the mid-term follow-up. Stability and midterm clinical outcomes were not significantly improved compared to the short-term follow-up results. At the mid-term follow-up, anteroposterior (AP) instability assessed by the KT-2000 was slightly increased, but still acceptable. On the other clinical physical evaluation, there was no statistically significant difference. Conclusions The short-term and mid-term outcomes of ACL reconstruction using the two AM portal technique were not significantly different except for AP stability although the value was less than 3 mm at both follow-ups. Therefore, this operative technique could be considered a satisfactory alternative for ACL reconstruction. PMID:28231644

  11. Hamstring Contracture After ACL Reconstruction Is Associated With an Increased Risk of Cyclops Syndrome

    PubMed Central

    Pinto, Francisco Guerra; Thaunat, Mathieu; Daggett, Matt; Kajetanek, Charles; Marques, Tiago; Guimares, Tales; Quelard, Bénédicte; Sonnery-Cottet, Bertrand

    2017-01-01

    Background: Cyclops syndrome is characterized by loss of terminal knee extension due to proliferative fibrous nodule formation in the intercondylar notch. This complication occurs in the early postoperative period after anterior cruciate ligament reconstruction (ACLR). The pathogenesis of Cyclops syndrome is not well understood. Hypothesis: Persistent hamstring contracture after ACLR is associated with an increased risk of subsequent Cyclops syndrome. Study Design: Case-control study; Level of evidence, 3. Methods: The files of 45 patients who underwent arthroscopic debridement of a Cyclops lesion after ACLR were analyzed. Recorded data included demographic information and technical details of surgery. Preoperative magnetic resonance images were also analyzed, and patients with femoral bone bruising were identified. Passive and active range of motion were recorded in all patients preoperatively and at 3 and 6 weeks after surgery to address the Cyclops lesion. Passive extension deficit was evaluated in comparison with the contralateral limb and classified as secondary to hamstring contracture when contracture was observed and palpated in the prone position and when the extension deficit was reversed after exercises performed to fatigue the hamstrings. A control group was selected using a random numbers table among our entire ACLR cohort. Statistical analysis was performed to analyze differences between the 2 groups. Results: There was no significant difference between the groups with regard to age at ACLR, sex distribution, time from injury to surgery (P > .05), proportion of professional athletes, presence of femoral bone bruise, or technical aspects of surgery. The overall extension deficit incidence was significantly higher in the Cyclops group at 3 weeks (Cyclops, 71%; control, 22%) (P < .001) and at 6 weeks (Cyclops, 60%; control, 7%) (P < .001). The extension deficit related to hamstring contracture was significantly higher in the Cyclops group at 3 weeks

  12. 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

  13. Effects of ACL reconstruction surgery on muscle activity of the lower limb during a jump-cut maneuver in males and females

    PubMed Central

    Coats-Thomas, Margaret S.; Miranda, Daniel L.; Badger, Gary J.; Fleming, Braden C.

    2013-01-01

    We compared muscle activity of the quadriceps, hamstring, and gastrocnemius muscles when ACL-intact (ACLINT) and ACL-reconstructed (ACLREC) male and female subjects performed a jump-cut task. Surface electromyography sensors were used to evaluate time to peak muscle activity and muscle activity ratios. Rectus femoris (RF) and vastus medialis (VM) peak timing was 71 ms and 78 ms earlier in ACLINT than in ACLREC subjects, respectively. Biceps femoris (BF) peak timing was 90 ms earlier in ACLINT than in ACLREC subjects and 75 ms earlier in females than in males. Medial gastrocnemius (MG) muscle peak timing was 77 ms earlier in ACLINT than in ACLREC subjects. Lateral gastrocnemius (LG) and MG muscle peak times were 106 ms and 87 ms earlier in females than in males, respectively. The RF, VM, BF and MG peaked later in ACLREC than in ACLINT subjects. There was evidence suggesting that the loading phase quadriceps:hamstring (quad:ham) muscle activity ratio was greater in ACLREC than in ACLINT subjects. Finally, the injury risk phase quad:ham muscle activity ratio was found to be 4.8 times greater in females than in males. In conclusion, there are differences in muscle activity related to ACL status and sex that could potentially help explain graft failure risk and the sex bias. PMID:23966333

  14. 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

    2016-05-06

    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.

  15. Whole Body Vibration Exercise Protocol versus a Standard Exercise Protocol after ACL Reconstruction: A Clinical Randomized Controlled Trial with Short Term Follow-Up

    PubMed Central

    Berschin, Gereon; Sommer, Björn; Behrens, Antje; Sommer, Hans-Martin

    2014-01-01

    The suitability and effectiveness of whole body vibration (WBV) exercise in rehabilitation after injury of the anterior cruciate ligament (ACL) was studied using a specially designed WBV protocol. We wanted to test the hypothesis if WBV leads to superior short term results regarding neuromuscular performance (strength and coordination) and would be less time consuming than a current standard muscle strengthening protocol. In this prospective randomized controlled clinical trial, forty patients who tore their ACL and underwent subsequent ligament reconstruction were enrolled. Patients were randomized to the whole body vibration (n=20) or standard rehabilitation exercise protocol (n=20). Both protocols started in the 2nd week after surgery. Isometric and isokinetic strength measurements, clinical assessment, Lysholm score, neuromuscular performance were conducted weeks 2, 5, 8 and 11 after surgery. Time spent for rehabilitation exercise was reduced to less than a half in the WBV group. There were no statistically significant differences in terms of clinical assessment, Lysholm score, isokinetic and isometric strength. The WBV group displayed significant better results in the stability test. In conclusion, preliminary data indicate that our whole body vibration muscle exercise protocol seems to be a good alternative to a standard exercise program in ACL-rehabilitation. Despite of its significant reduced time requirement it is at least equally effective compared to a standard rehabilitation protocol. Key points In this prospective randomized controlled clinical trial, we tested the hypothesis if WBV leads to superior short term results regarding neuromuscular performance (strength and coordination) and would be less time consuming than a current standard muscle strengthening protocol in forty patients who underwent ACL reconstruction. Time spent for rehabilitation exercise was reduced to less than a half in the WBV group as compared to the standard exercise group. Both

  16. The anatomy of the anterior cruciate ligament and its relevance to the technique of reconstruction.

    PubMed

    Śmigielski, R; Zdanowicz, U; Drwięga, M; Ciszek, B; Williams, A

    2016-08-01

    Anterior cruciate ligament (ACL) reconstruction is commonly performed and has been for many years. Despite this, the technical details related to ACL anatomy, such as tunnel placement, are still a topic for debate. In this paper, we introduce the flat ribbon concept of the anatomy of the ACL, and its relevance to clinical practice. Cite this article: Bone Joint J 2016;98-B:1020-6.

  17. Anterior cruciate ligament (ACL) injury

    MedlinePlus

    ... proper techniques when playing sports or exercising. Some college sports programs teach athletes how to reduce stress placed on the ACL. The use of knee braces during vigorous athletic activity ( ...

  18. ACL Revision

    PubMed Central

    Costa-Paz, Matias; Dubois, Julieta Puig; Zicaro, Juan Pablo; Rasumoff, Alejandro; Yacuzzi, Carlos

    2017-01-01

    Objectives: The purpose of this study was to evaluate a series of patients one year after an ACL revision with clinical evaluation and MRI, to consider their condition before returning to sports activities. Methods: A descriptive, prospective and longitudinal study was performed. A series of patients who underwent an ACL revision between March 2014 and March 2015 were evaluated after one year post surgery. They were evaluated using the Lysholm score, IKDC, Tegner, artrometry and MRI (3.0 t). A signal pattern and osteointegration was determined in the MRI. Graft signal intensity of the ACL graft using the signal/noise quotient value (SNQ) was also determined to evaluate the ligamentatization process state. Results: A total of 18 male patients were evaluated with a mean age of 31 years old.Average scores were: Lysholm 88 points, IKDC 80 points, Pre-surgical Tegner 9 points and postoperative 4 points. Artrhometry (KT1000) at 20 newtons showed a side to side difference of less than 3 mm in 88%. Only 44% of patients returned to their previous sport activity one year after revision.The MRI showed a heterogeneous signal in neoligaments in 34% of patients. SNQ showed graft integration in only 28%. Synovial fluid was found in bone-graft interphase in 44% of tunnels, inferring partial osteointegration. The heterogeneous signal was present in 50% of patients who did not return to the previous sport level activity. (Fisher statistics: p = 0.043) There were no meaningful differences in patients with auto or allografts. Conclusion: Although the clinical evaluation was satisfactory, only 44% of patients returned to the previous level of sport activity one year after the ACL surgery. The ligamentatization process was found in 28% of knees evaluated with MRI one year later. Partial osteointegration is inferred in 44%. Results showed a meaningful relation between the signal of neoligaments in the MRI and the return to sport activity in said series of patients. MRI is a useful tool

  19. Niche reconstructive techniques for complex abdominal wall reconstruction: a review.

    PubMed

    Sue, Gloria R; Narayan, Deepak

    2014-04-01

    Abdominal wall defects resulting from recurrent hernias, trauma, and radiation necrosis are difficult and challenging to repair given the high rates of recurrence and surgical morbidity. Complex abdominal wall defects often require the transposition of autologous material to bridge the fascial gap. We present a review of niche reconstructive techniques that have been used in complex abdominal wall repair. The specific techniques reviewed include use of delayed and tunneled pedicled tensor fascia lata myofascial flap, de-epithelialized flap closure, free latissimus dorsi myocutaneous flap with or without innervation, and abdominal wall transplant. These niche surgical techniques have great potential to reduce recurrence rates when used in the proper setting for complex abdominal wall reconstruction. More studies are needed to evaluate the relative use of these techniques with the more widely established surgical methods of reconstruction.

  20. Anterior cruciate ligament reconstruction using the Bio-TransFix femoral fixation device and anteromedial portal technique.

    PubMed

    Hantes, Michael E; Dailiana, Zoe; Zachos, Vasilios C; Varitimidis, Sokratis E

    2006-05-01

    The cross-pin femoral fixation technique for soft tissue grafts is a popular option in anterior cruciate ligament (ACL) reconstruction. One of these devices is the Bio-TransFix (Arthrex Inc., Naples, FL, USA) which provides high fixation strength. According to the manufacturer, the femoral tunnel is created by placing the femoral aiming device through the tibial tunnel (transtibial technique). However, using this technique it is very difficult or even impossible to place the graft at the anatomical ACL attachment site at the "10 o'clock" position. In this report, we describe the use of the Bio-TransFix device with an anteromedial portal technique. Using this technique, the surgeon has more freedom to place the graft in an anatomical position, while combining the advantages of the excellent biomechanical properties of this device.

  1. Clinical Results of Technique for Double Bundle Anterior Cruciate Ligament Reconstruction Using Hybrid Femoral Fixation and Retroscrew

    PubMed Central

    Kim, Doo-Sup; Yi, Chang-Ho; Chung, Hoi-Jung

    2011-01-01

    Background Anatomic anterior cruciate ligament (ACL) reconstruction has been presented as a means to more accurately restore the native anatomy of this ligament. This article describes a new method that uses a double bundle to perform ACL reconstruction and to evaluate the clinical outcome. Methods Grafts are tibialis anterior tendon allograft for anteromedial bundle (AMB) and hamstring tendon autograft without detachment of the tibial insertion for posterolateral bundle (PLB). This technique creates 2 tunnels in both the femur and tibia. Femoral fixation was done by hybrid fixation using Endobutton and Rigidfix for AMB and by biointerference screw for PLB. Tibial fixations are done by Retroscrew for AMB and by native insertion of hamstring tendon for PLB. Both bundles are independently and differently tensioned. We performed ACL reconstruction in 63 patients using our new technique. Among them, 47 participated in this study. The patients were followed up with clinical examination, Lysholm scales and International Knee Documentation Committee (IKDC) scoring system and radiological examination with a minimum 12 month follow-up duration. Results Significant improvement was seen on Lachman test and pivot-shift test between preoperative and last follow-up. Only one of participants had flexion contracture about 5 degrees at last follow-up. In anterior drawer test by KT-1000, authors found improvement from average 8.3 mm (range, 4 to 18 mm) preoperatively to average 1.4 mm (range, 0 to 6 mm) at last follow-up. Average Lysholm score of all patients was 72.7 ± 8.8 (range, 54 to 79) preoperatively and significant improvement was seen, score was 92.2 ± 5.3 (range, 74 to 97; p < 0.05) at last follow-up. Also IKDC score was normal in 35 cases, near normal in 11 cases, abnormal in 1 case at last follow-up. Conclusions Our new double bundle ACL reconstruction technique used hybrid fixation and Retroscrew had favorable outcomes. PMID:22162791

  2. 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

  3. 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

  4. Anterior Cruciate Ligament (ACL) Injuries

    MedlinePlus

    ... Week of Healthy Breakfasts Shyness Anterior Cruciate Ligament (ACL) Injuries KidsHealth > For Teens > Anterior Cruciate Ligament (ACL) ... and Recovery Coping With an ACL Injury About ACL Injuries A torn anterior cruciate ligament (ACL) is ...

  5. Tissue transfer techniques in reconstructive urology

    PubMed Central

    Bryk, Darren J; Yamaguchi, Yuka

    2015-01-01

    Tissue transfer techniques are an essential part of the reconstructive urologist's armamentarium. Flaps and graft techniques are widely used in genital and urethral reconstruction. A graft is tissue that is moved from a donor site to a recipient site without its native blood supply. The main types of grafts used in urology are full thickness grafts, split thickness skin grafts and buccal mucosa grafts. Flaps are transferred from the donor site to the recipient site on a pedicle containing its native blood supply. Flaps can be classified based on blood supply, elevation methods or the method of transfer. The most used flaps in urology include penile, preputial, and scrotal skin. We review the various techniques used in reconstructive urology and the outcomes of these techniques. PMID:26175866

  6. COMPLICATIONS OF THE SCREW/WASHER TIBIAL FIXATION TECHNIQUE FOR KNEE LIGAMENT RECONSTRUCTION

    PubMed Central

    Almeida, Alexandre; Roveda, Gilberto; Valin, Márcio Rangel; Almeida, Nayvaldo Couto de; Sartor, Vanderlei; Alves, Soraya Melina

    2015-01-01

    To evaluate the presence of pain at the site of the surgical incision and the need to remove the tibial fixation screw in anterior cruciate ligament (ACL) reconstruction, in relation to sex and body mass index (BMI). Methods: A group of 265 patients who underwent ACL reconstruction with ipsilateral flexor tendon grafts from the thigh in which the tibial fixation technique consisted of using a cortical screw and metal washer, between July 2000 and November 2007, were evaluated. Results: 176 patients were evaluated for an average of 33.3 ± 19.5 months; median of 29.5 months; IIQ: 17-45 months; minimum of 8 and maximum of 87 months. There was no statistical difference regarding complaints of pain at the site of the screw (p = 0.272) and the need to remove the tibial screw (p = 0.633) between sexes. There was no statistical difference regarding complaints of pain at the site of the screw (p = 0.08) and the need to remove the tibial screw (p = 0.379) according to BMI. Conclusion: The pain complaint rate at the screw site from the screw and metal washer method used for tibial fixation in ACL reconstruction was of the order of 25%, and the screw had to be removed in 10.8% of the cases. There was no predominance of pain complaints at the surgical wound between the sexes. There was a greater tendency to complain about pain among patients with BMI < 25. There was no predominance of screw and washer removal between the sexes or between individuals with different BMIs. PMID:27022587

  7. A review of ligament augmentation with the InternalBrace™: the surgical principle is described for the lateral ankle ligament and ACL repair in particular, and a comprehensive review of other surgical applications and techniques is presented.

    PubMed

    Mackay, Gordon M; Blyth, Mark J G; Anthony, Iain; Hopper, Graeme P; Ribbans, William J

    2015-05-01

    This article reviews the surgical decision-making considerations when preparing to undertake an anatomic ligament repair with augmentation using the InternalBrace™. Lateral ankle ligament stabilization of the Broström variety and ACL repair in particular are used to illustrate its application. The InternalBrace™ supports early mobilization of the repaired ligament and allows the natural tissues to progressively strengthen. The principle established by this experience has resulted in its successful application to other distal extremity ligaments including the deltoid, spring, and syndesmosis complex. Knee ligament augmentation with the InternalBrace™ has been successfully applied to all knee ligaments including anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), lateral collateral ligament (LCL), anterolateral ligament (ALL), and patellofemoral ligament (PFL). The surgical technique and early results will be reviewed including multi-ligament presentations. Upper limb experience with acromioclavicular (AC) joint augmentation and ulnar collateral ligament (UCL) repair of the elbow with the InternalBrace™ will also be discussed. This article points to a change in orthopaedic practice positioning reconstruction as a salvage procedure that has additional surgical morbidity and should be indicated only if the tissues fail to heal adequately after augmentation and repair.

  8. Biomechanical Outcomes After Bio-enhanced Anterior Cruciate Ligament Repair and Anterior Cruciate Ligament Reconstruction Are Equal in a Porcine Model

    PubMed Central

    Vavken, Patrick; Fleming, Braden C.; Mastrangelo, Ashley N.; Machan, Jason T.; Murray, Martha M.

    2011-01-01

    Purpose The objective of this study was to compare the biomechanical outcomes of a new method of anterior cruciate ligament (ACL) treatment, bio-enhanced ACL repair, with ACL reconstruction in a large animal model. Methods Twenty-four skeletally immature pigs underwent unilateral ACL transection and were randomly allocated to receive bio-enhanced ACL repair with a collagen-platelet composite, allograft (bone–patellar tendon– bone) reconstruction, or no further treatment (n = 8 for each group). The structural properties and anteroposterior laxity of the experimental and contralateral ACL-intact knees were measured 15 weeks postoperatively. All dependent variables were normalized to those of the contralateral knee and compared by use of generalized linear mixed models. Results After 15 weeks, bio-enhanced ACL repair and ACL reconstruction produced superior biomechanical outcomes to ACL transection. However, there were no significant differences between bio-enhanced ACL repair and ACL reconstruction for maximum load (P = .4745), maximum displacement (P = .4217), or linear stiffness (P = .6327). There were no significant differences between the 2 surgical techniques in anteroposterior laxity at 30° (P = .7947), 60° (P = .6270), or 90° (P = .9008). Conclusions Bio-enhanced ACL repair produced biomechanical results that were not different from ACL reconstruction in a skeletally immature, large animal model, although the variability associated with both procedures was large. Both procedures produced significantly improved results over ACL transection, showing that both were effective in this model. Clinical Relevance Bio-enhanced ACL repair may 1 day provide an alternative treatment option for ACL injury. PMID:22261137

  9. 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.

  10. 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

  11. Laser-guided placement of the tibial guide in the transtibial technique for anterior cruciate ligament reconstruction.

    PubMed

    Takahashi, Toshiaki; Takeda, Haruhiko; Watanabe, Seiji; Yamamoto, Haruyasu

    2009-02-01

    In anterior cruciate ligament (ACL) reconstruction, it is important to determine the location and direction of the femoral bone tunnel when using the transtibial technique. Accurately identifying the anatomic location at which to make the femoral bone tunnel for double-bundle ACL reconstruction is not a straightforward procedure. We describe a new method in which the centrum of the femoral tunnel is marked with an awl and a laser beam-guided technique is used to place the tibial pin. This procedure allows us to mark the desired location of the femoral tunnel before drilling the tibial bone tunnel when using the transtibial technique. This is the first report of a laser-guided technique used in arthroscopic surgery. We used a laser beam to determine the location of the femoral tunnel--the anatomic site needed to perform the intra-articular drilling in the tibia. In this technique, a laser pointer is set at the tibial guide, which reflects the laser beam and illuminates the point where the femoral bone tunnel should be made. Our method offers an easy and accurate way to reconfirm the tibial placement before drilling.

  12. Application Of Iterative Reconstruction Techniques To Conventional Circular Tomography

    NASA Astrophysics Data System (ADS)

    Ghosh Roy, D. N.; Kruger, R. A.; Yih, B. C.; Del Rio, S. P.; Power, R. L.

    1985-06-01

    Two "point-by-point" iteration procedures, namely, Iterative Least Square Technique (ILST) and Simultaneous Iterative Reconstructive Technique (SIRT) were applied to classical circular tomographic reconstruction. The technique of tomosynthetic DSA was used in forming the tomographic images. Reconstructions of a dog's renal and neck anatomy are presented.

  13. Biomechanics of the anterior cruciate ligament: Physiology, rupture and reconstruction techniques

    PubMed Central

    Domnick, Christoph; Raschke, Michael J; Herbort, Mirco

    2016-01-01

    The influences and mechanisms of the physiology, rupture and reconstruction of the anterior cruciate ligament (ACL) on kinematics and clinical outcomes have been investigated in many biomechanical and clinical studies over the last several decades. The knee is a complex joint with shifting contact points, pressures and axes that are affected when a ligament is injured. The ACL, as one of the intra-articular ligaments, has a strong influence on the resulting kinematics. Often, other meniscal or ligamentous injuries accompany ACL ruptures and further deteriorate the resulting kinematics and clinical outcomes. Knowing the surgical options, anatomic relations and current evidence to restore ACL function and considering the influence of concomitant injuries on resulting kinematics to restore full function can together help to achieve an optimal outcome. PMID:26925379

  14. Novel Biliary Reconstruction Techniques During Liver Transplantation

    PubMed Central

    Carmody, Ian C.; Romano, John; Bohorquez, Humberto; Bugeaud, Emily; Bruce, David S.; Cohen, Ari J.; Seal, John; Reichman, Trevor W.; Loss, George E.

    2017-01-01

    Background: Biliary complications remain a significant problem following liver transplantation. Several surgical options can be used to deal with a significant size mismatch between the donor and recipient bile ducts during the biliary anastomosis. We compared biliary transposition to recipient biliary ductoplasty in cadaveric liver transplant. Methods: A total of 33 reconstructions were performed from January 1, 2005 to December 31, 2013. In the biliary transposition group (n=23), 5 reconstructions were performed using an internal stent (5 or 8 French pediatric feeding tube), and 18 were performed without. Of the 10 biliary ductoplasties, 2 were performed with a stent. All patients were managed with standard immunosuppression and ursodiol. Follow-up ranged from 2 months to 5 years. Results: No patients in the biliary transposition group required reoperation; 1 patient had an internal stent removed for recurrent unexplained leukocytosis, and 2 patients required endoscopic retrograde cholangiography and stent placement for evidence of stricture. Three anastomotic leaks occurred in the biliary ductoplasty group, and 2 patients in the biliary ductoplasty group required reoperation for biliary complications. Conclusion: Our results indicate that biliary reconstruction can be performed with either biliary transposition or biliary ductoplasty. These techniques are particularly useful when a significant mismatch in diameter exists between the donor and recipient bile ducts. PMID:28331447

  15. Incidence and Characterization of Injury to the Infrapatellar Branch of the Saphenous Nerve after ACL Reconstruction: A Prospective Study

    PubMed Central

    Cohen, Steven B.; Ciccotti, Michael C.; Dodson, Christopher C.; Tjoumakaris, Fotios P.; Salvo, John P.; Marchetto, Paul A.; Watson, Ryan A.; Salminen, Matthew Robert; Flato, Russell R.; O'Brien, Daniel Francis

    2014-01-01

    Objectives: The infrapatellar branch of the saphenous nerve is commonly injured in anterior cruciate ligament reconstruction (ACLR) causing sensory deficits around the knee. The primary purpose of this prospective study was to determine the incidence of patient reported sensory deficits around the knee following ACLR. The secondary purpose was to determine if sensory deficits caused by intraoperative injury present at 6 weeks changed in severity and total area after 6 months and 1 year postoperatively. Methods: Two-hundred and fifty patients that underwent ACLR with or without meniscal repair were prospectively enrolled. Variables for each patient included: type of graft, direction of tibial incision, number of portals, and length of surgical incision. The grafts used were categorized into three types: Allograft (allo), hamstring autograft (HS), or patella tendon autograft (BTB). At 6 weeks, patients completed a questionnaire to ascertain any sensory deficits over their knee. Patients rated their sensory deficit on a scale from 0-10 (“0” = (no deficit) to “10” (complete lack of sensation) and shaded areas on a picture of a knee split into nine rectangular segments (3 by 3 grid) to determine the location of any numbness. Patients completed the same questionnaire at 6 months and 1 year. Any patient that was noted to have no stated numbness at 6 weeks or 6 months was noted to have completed the study. A mixed effects linear regression model was used to identify variables which were predictors for the patient-reported severity of numbness. Results: Overall, 67/221 (30.3%) patients who underwent ACLR stated that they had no numbness at 6 weeks. Of those patients who reported numbness at 6 weeks, 16.6% (25/151) considered their numbness completely resolved by six months. At 1 year, 73.2% (90/123) reported their numbness had gotten better and 14.2% (18/123) considered their numbness resolved. The most common location of numbness was along the inferolateral aspect

  16. A new technique for femoral and tibial tunnel bone grafting using the OATS harvesters in revision anterior cruciate ligament reconstruction.

    PubMed

    Said, Hatem G; Baloch, Khalid; Green, Marcus

    2006-07-01

    Revision anterior cruciate ligament (ACL) reconstruction is becoming more frequent, especially in specialized centers, because of the large numbers of primary ACL procedures performed. In 2-stage revisions, bone grafting of the tunnels may be undertaken if the primary position was inaccurate or if osteolysis has caused widening of the tunnels. This will allow the desired placement of the new tunnels without the risk of loss of structural integrity. It is technically difficult to deliver and impact bone graft into the femoral tunnel with the standard surgical and arthroscopic instruments. We describe a new technique for femoral and tibial tunnel impaction grafting in 2-stage ACL revisions, using the OATS grafting instruments (Osteochondral Autologous Transfer System; Arthrex, Naples, FL). The appropriately sized OATS harvester is chosen 1 mm larger than the tunnel size and is used to harvest bone graft from the iliac crest through a percutaneous approach. This provides a cylindrical graft, which is delivered to the femoral tunnel through the arthroscopic portal. The inside punch of the harvester is tapped and this allows delivery of the graft in a controlled manner and its impaction into the tunnel. The same is repeated for the tibial tunnel while providing support for the proximal end of the tunnel.

  17. 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.

  18. Event Reconstruction Techniques in NOvA

    NASA Astrophysics Data System (ADS)

    Baird, M.; Bian, J.; Messier, M.; Niner, E.; Rocco, D.; Sachdev, K.

    2015-12-01

    The NOvA experiment is a long-baseline neutrino oscillation experiment utilizing the NuMI beam generated at Fermilab. The experiment will measure the oscillations within a muon neutrino beam in a 300 ton Near Detector located underground at Fermilab and a functionally-identical 14 kiloton Far Detector placed 810 km away. The detectors are liquid scintillator tracking calorimeters with a fine-grained cellular structure that provides a wealth of information for separating the different particle track and shower topologies. Each detector has its own challenges with the Near Detector seeing multiple overlapping neutrino interactions in each event and the Far Detector having a large background of cosmic rays due to being located on the surface. A series of pattern recognition techniques have been developed to go from event records, to spatially and temporally separating individual interactions, to vertexing and tracking, and particle identification. This combination of methods to achieve the full event reconstruction will be discussed.

  19. Anatomical reconstruction of the anterior cruciate ligament: a logical approach.

    PubMed

    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.

  20. 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

  1. Protein fragment reconstruction using various modeling techniques

    NASA Astrophysics Data System (ADS)

    Boniecki, Michal; Rotkiewicz, Piotr; Skolnick, Jeffrey; Kolinski, Andrzej

    2003-11-01

    Recently developed reduced models of proteins with knowledge-based force fields have been applied to a specific case of comparative modeling. From twenty high resolution protein structures of various structural classes, significant fragments of their chains have been removed and treated as unknown. The remaining portions of the structures were treated as fixed - i.e., as templates with an exact alignment. Then, the missed fragments were reconstructed using several modeling tools. These included three reduced types of protein models: the lattice SICHO (Side Chain Only) model, the lattice CABS (Cα + Cβ + Side group) model and an off-lattice model similar to the CABS model and called REFINER. The obtained reduced models were compared with more standard comparative modeling tools such as MODELLER and the SWISS-MODEL server. The reduced model results are qualitatively better for the higher resolution lattice models, clearly suggesting that these are now mature, competitive and complementary (in the range of sparse alignments) to the classical tools of comparative modeling. Comparison between the various reduced models strongly suggests that the essential ingredient for the sucessful and accurate modeling of protein structures is not the representation of conformational space (lattice, off-lattice, all-atom) but, rather, the specificity of the force fields used and, perhaps, the sampling techniques employed. These conclusions are encouraging for the future application of the fast reduced models in comparative modeling on a genomic scale.

  2. Enhancement of tendon-bone healing for anterior cruciate ligament (ACL) reconstruction using bone marrow-derived mesenchymal stem cells infected with BMP-2.

    PubMed

    Dong, Yu; Zhang, Qingguo; Li, Yunxia; Jiang, Jia; Chen, Shiyi

    2012-10-22

    At present, due to the growing attention focused on the issue of tendon-bone healing, we carried out an animal study of the use of genetic intervention combined with cell transplantation for the promotion of this process. Here, the efficacy of bone marrow stromal cells infected with bone morphogenetic protein-2 (BMP-2) on tendon-bone healing was determined. A eukaryotic expression vector containing the BMP-2 gene was constructed and bone marrow-derived mesenchymal stem cells (bMSCs) were infected with a lentivirus. Next, we examined the viability of the infected cells and the mRNA and protein levels of BMP-2-infected bMSCs. Gastrocnemius tendons, gastrocnemius tendons wrapped by bMSCs infected with the control virus (bMSCs+Lv-Control), and gastrocnemius tendons wrapped by bMSCs infected with the recombinant BMP-2 virus (bMSCs+Lv-BMP-2) were used to reconstruct the anterior cruciate ligament (ACL) in New Zealand white rabbits. Specimens from each group were harvested four and eight weeks postoperatively and evaluated using biomechanical and histological methods. The bMSCs were infected with the lentivirus at an efficiency close to 100%. The BMP-2 mRNA and protein levels in bMSCs were significantly increased after lentiviral infection. The bMSCs and BMP-2-infected bMSCs on the gastrocnemius tendon improved the biomechanical properties of the graft in the bone tunnel; specifically, bMSCs infected with BMP-2 had a positive effect on tendon-bone healing. In the four-week and eight-week groups, bMSCs+Lv-BMP-2 group exhibited significantly higher maximum loads of 29.3 ± 7.4 N and 45.5 ± 11.9 N, respectively, compared with the control group (19.9 ± 6.4 N and 21.9 ± 4.9 N) (P = 0.041 and P = 0.001, respectively). In the eight-week groups, the stiffness of the bMSCs+Lv-BMP-2 group (32.5 ± 7.3) was significantly higher than that of the bMSCs+Lv-Control group (22.8 ± 7.4) or control groups (12.4 ± 6.0) (p = 0.036 and 0.001, respectively). Based on the histological

  3. Quantitative topographic anatomy of the femoral ACL footprint: a micro-CT analysis.

    PubMed

    Norman, Daniel G; Getgood, Alan; Thornby, John; Bird, Jonathan; Turley, Glen A; Spalding, Tim; Williams, Mark A

    2014-11-01

    The femoral footprint of the anterior cruciate ligament (ACL) is a much-studied anatomic structure, predominantly due to its importance during ACL reconstruction surgery. A new technique utilising high-resolution micro-computed tomography (micro-CT) is described, allowing detailed three-dimensional (3D) quantitative analysis of this structure. Seven cadaveric knees were scanned using micro-CT, yielding 3D data with a reconstructed voxel size of 60 μm. A novel method of 3D surface extraction was developed and validated, facilitating both qualitative observation of surface details and quantitative topographic assessment using colour-coded relief maps. Images were displayed on an immersive 3D visualisation wall, and ten experienced ACL clinicians were surveyed as to the presence and morphology of osseous landmarks, providing qualitative assessment of whether such features can be reliably identified for navigation during surgery. Both quantitative analysis and qualitative assessment of the footprints in this study showed significant variability in the presence and morphology of osseous landmarks, with the lateral intercondylar ridge being objectively present in four out of seven relief maps, although reportedly seen in six out of seven cases in the qualitative study, suggesting an element of subjectivity and interpretation. This is the first study to utilise micro-CT in the study of ACL anatomy.

  4. Three-Dimensional Reconstruction Computed Tomography Evaluation of the Tunnel Location and Angle in Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction: A Comparison of the Anteromedial Portal and Outside-in Techniques

    PubMed Central

    Kim, Kang-Il; Lee, Sang Hak; Bae, Chanil; Bae, Sung Hae

    2017-01-01

    Purpose The purpose of this study was to compare the geometry and position of the femoral tunnel between the anteromedial portal (AMP) and outside-in (OI) techniques after anatomic single-bundle anterior cruciate ligament (ACL) reconstruction. Materials and Methods We evaluated 82 patients undergoing single-bundle ACL reconstruction with hamstring autografts using either the AMP (n=40) or OI (n=42) technique. The locations of the tunnel apertures were assessed by postoperative 3-dimensional computed tomography imaging. The femoral graft bending angle, femoral tunnel aperture shape, femoral tunnel length, and posterior wall breakage were also measured. Results The mean femoral tunnel position parallel to the Blumensaat line was more caudally positioned in the AMP group than in the OI group (p=0.025) The mean femoral graft angle in the OI group (99.6°±7.1°) was significantly more acute than that of the AMP group (108.9°±10.2°, p<0.001). The mean height/width ratio of the AMP group (1.21±0.20) was significantly more ellipsoidal than that of the OI group (1.07±0.09, p<0.001). Conclusions The mean femoral tunnel position was significantly shallower in the AMP technique than in the OI technique. The OI technique might be more disadvantageous than the AMP technique in terms of the more acute bending angle. PMID:28231643

  5. Bone marrow edema-like lesions (BMELs) are associated with higher T1ρ and T2 values of cartilage in anterior cruciate ligament (ACL)-reconstructed knees: a longitudinal study

    PubMed Central

    Gong, Jingshan; Pedoia, Valentina; Facchetti, Luca; Link, Thomas M.; Ma, C. Benjamin

    2016-01-01

    Background To evaluate the longitudinal changes of bone marrow edema-like lesions (BMELs) in patients after anterior cruciate ligament (ACL) reconstruction and to investigate the effect of BMELs on cartilage matrix composition changes measured using MR T1ρ and T2 mapping. Methods Patients with acute ACL tear were enrolled in a prospective study. MR imaging was performed at baseline (before surgeries) and at 6-month, 1-year and 2-year after ACL reconstruction. MR imaging included sagittal high-resolution, 3D fast spin-echo (CUBE) sequences for BMEL evaluation, and 3D T1ρ mapping and T2 mapping for cartilage assessment. BMELs were assessed using whole-organ magnetic resonance imaging score (WORMS), and the volume of BMELs was measured by a semi-automatic method. Generalized estimating equation (GEE) was used to explore association between BMELs at baseline and cartilage changes during follow-up. Results Fifty four patients were included in the present study and 39 patients had completed 2-year follow-up. BMELs were noted in 42 injured knees (77.8%) with 105 lesions and in 7 contralateral knees (13.0%) with 9 lesions (χ2=45.763, P<0.001) at the baseline. The WORMS and volume of BMELs of the injured knees were 2.36±0.65 and 386.98±382.54 mm3 (r=0.681, P<0.001), respectively. 87 BMELs were found at baseline in 34 patients (87.2%) of the 39 patients who had completed 2 years follow-up. During the follow-up, 18 (20.7%), 12 (13.8%), and 5 (5.7%) baseline lesions were still seen at 6-month, 1-year and 2-year, respectively. The changes of BMELs prevalence regarding bone compartments over time points were statistically significant (χ2=163.660, P<0.001). Except T2 value at 6 months, T1ρ and T2 values of cartilage overlying baseline BMELs in the injured knees were higher than that of anatomically matched cartilage in the contralateral knees at baseline and each follow-up time-point. In the injured knees, GEE analysis showed that baseline BMELs were significantly

  6. [Surgical reconstruction of maxillary defects using computer-assisted techniques].

    PubMed

    Zhang, W B; Yu, Y; Wang, Y; Liu, X J; Mao, C; Guo, C B; Yu, G Y; Peng, X

    2017-02-18

    The maxilla is the most important bony support of the mid-face skeleton and is critical for both esthetics and function. Maxillary defects, resulting from tumor resection, can cause severe functional and cosmetic deformities. Furthermore, maxillary reconstruction presents a great challenge for oral and maxillofacial surgeons. Nowadays, vascularized composite bone flap transfer has been widely used for functional maxillary reconstruction. In the last decade, we have performed a comprehensive research on functional maxillary reconstruction with free fibula flap and reported excellent functional and acceptable esthetic results. However, this experience based clinical procedure still remainssome problems in accuracy and efficiency. In recent years, computer assisted techniques are now widely used in oral and maxillofacial surgery. We have performed a series of study on maxillary reconstruction with computer assisted techniques. The computer assisted techniques used for maxillary reconstruction mainly include: (1) Three dimensional (3D) reconstruction and tumor mapping: providing a 3D view of maxillary tumor and adjacent structures and helping to make the diagnosis of maxillary tumor accurate and objective; (2) Virtual planning: simulating tumor resection and maxillectomy as well as fibula reconstruction on the computer, so that to make an ideal surgical plan; (3) 3D printing: producing a 3D stereo model for prebending individualized titanium mesh and also providing template or cutting guide for the surgery; (4) Surgical navigation: the bridge between virtual plan and real surgery, confirming the virtual plan during the surgery and guarantee the accuracy; (5) Computer assisted analyzing and evaluating: making a quantitative and objective of the final result and evaluating the outcome. We also performed a series of studies to evaluate the application of computer assisted techniques used for maxillary reconstruction, including: (1) 3D tumor mapping technique for accurate

  7. Nonlinear auto-adjusting iterative reconstruction technique for interferometric tomography

    NASA Astrophysics Data System (ADS)

    Song, Yizhong; Sun, Tao; Qu, Peishu

    2013-07-01

    A new algebraic reconstruction technique (ART), nonlinear auto-adjusting iterative reconstruction technique (NAIRT), is proposed and applied to reconstruct a section of an actual thermal air flow field. With numerical simulation, NAIRT was tested to reconstruct a complicated field to demonstrate its superior reconstructive capability. In contrast, three typical ARTs, the basic ART, simultaneous ART (SART), and a modified SART (MSART), were simulated to demonstrate the reconstructive capability improvement attained through the use of the proposed NAIRT. The calculated results were discussed with mean square error (MSE) and peak error (PE). A thermal air flow field was produced with an alcohol burner and was detected by a laser beam. With laser beam projections, a cross-section of the field was reconstructed by NAIRT. As a result, the reconstructive capability was improved much by NAIRT. The MSE decreased by 95.5%, and PE by 97.2% from that of the basic ART. Only NAIRT converged without filters while its reconstructive accuracy improved. By increasing the projections from 42 to 84, the accuracy of NAIRT without filters was improved significantly. NAIRT could effectively reconstruct the section of the thermal field. The proposed NAIRT needed no filter for its convergence and it had the highest reconstructive accuracy and simplest iterative expression of those analyzed.

  8. Computational Techniques in Radio Neutrino Event Reconstruction

    NASA Astrophysics Data System (ADS)

    Beydler, M.; ARA Collaboration

    2016-03-01

    The Askaryan Radio Array (ARA) is a high-energy cosmic neutrino detector constructed with stations of radio antennas buried in the ice at the South Pole. Event reconstruction relies on the analysis of the arrival times of the transient radio signals generated by neutrinos interacting within a few kilometers of the detector. Because of its depth dependence, the index of refraction in the ice complicates the interferometric directional reconstruction of possible neutrino events. Currently, there is an ongoing endeavor to enhance the programs used for the time-consuming computations of the curved paths of the transient wave signals in the ice as well as the interferometric beamforming. We have implemented a fast, multi-dimensional spline table lookup of the wave arrival times in order to enable raytrace-based directional reconstructions. Additionally, we have applied parallel computing across multiple Graphics Processing Units (GPUs) in order to perform the beamforming calculations quickly.

  9. 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.

  10. Discrete algebraic reconstruction technique: a new approach for superresolution reconstruction of license plates

    NASA Astrophysics Data System (ADS)

    Zarei Zefreh, Karim; van Aarle, Wim; Batenburg, K. Joost; Sijbers, Jan

    2013-10-01

    A new superresolution algorithm is proposed to reconstruct a high-resolution license plate image from a set of low-resolution camera images. The reconstruction methodology is based on the discrete algebraic reconstruction technique (DART), a recently developed reconstruction method. While DART has already been successfully applied in tomographic imaging, it has not yet been transferred to the field of camera imaging. DART is introduced for camera imaging through a demonstration of how prior knowledge of the colors of the license plate can be directly exploited during the reconstruction of a high-resolution image from a set of low-resolution images. Simulation experiments show that DART can reconstruct images with superior quality compared to conventional reconstruction methods.

  11. Does the lateral intercondylar ridge disappear in ACL deficient patients?

    PubMed

    van Eck, Carola F; Morse, Kenneth R; Lesniak, Bryson P; Kropf, Eric J; Tranovich, Michael J; van Dijk, C Niek; Fu, Freddie H

    2010-09-01

    The aim of this study was to determine whether there is a difference in the presence of the lateral intercondylar ridge and the lateral bifurcate ridge between patients with sub-acute and chronic ACL injuries. We hypothesized that the ridges would be present less often with chronic ACL deficiency. Twenty-five patients with a chronic ACL injury were matched for age and gender to 25 patients with a sub-acute ACL injury. The lateral intercondylar ridge and lateral bifurcate ridge were scored as either present, absent, or indeterminate due to insufficient visualization by three blinded observers. The kappa for the three observers was .61 for the lateral intercondylar ridge and .58 for the lateral bifurcate ridge. The lateral intercondylar ridge was present in 88% of the sub-acute patients and 88% of the chronic patients. The lateral bifurcate ridge was present in 48% of the sub-acute and 48% of the chronic patients. This matched-pairs case-control study was unable to show a difference in the presence of the femoral bony ridges between patients with acute and chronic ACL injuries. The authors would suggest looking for the ridges as a landmark of the native ACL insertion site during ACL reconstruction in both acute and chronic ACL injuries.

  12. Modern reconstructive techniques for abdominal wall defects after oncologic resection.

    PubMed

    Khansa, Ibrahim; Janis, Jeffrey E

    2015-04-01

    Resection of abdominal wall tumors often leaves patients with debilitating soft tissue defects. Modern reconstructive techniques can be used to restore abdominal wall integrity. In this article, we present an overview of preoperative patient evaluation, analysis of the defect, surgical planning, and the spectrum of available surgical techniques, ranging from simple to complex. The established clinical evidence in the field of abdominal wall reconstruction is summarized and a case example is provided.

  13. Pixel-based reconstruction (PBR) promising simultaneous techniques for CT reconstructions.

    PubMed

    Fager, R S; Peddanarappagari, K V; Kumar, G N

    1993-01-01

    Algorithms belonging to the class of pixel-based reconstruction (PBR) algorithms, which are similar to simultaneous iterative reconstruction techniques (SIRTs) for reconstruction of objects from their fan beam projections in X-ray transmission tomography, are discussed. The general logic of these algorithms is discussed. Simulation studies indicate that, contrary to previous results with parallel beam projections, the iterative algebraic algorithms do not diverge when a more logical technique of obtaining the pseudoprojections is used. These simulations were carried out under conditions in which the number of object pixels exceeded (double) the number of detector pixel readings, i.e., the equations were highly underdetermined. The effect of the number of projections on the reconstruction and the convergence (empirical) to the exact solution is shown. For comparison, the reconstructions obtained by convolution backprojection are also given.

  14. Preventing ACL Injuries in Females: What Physical Educators Need to Know

    ERIC Educational Resources Information Center

    Toscano, Lisa; Carroll, Brianne

    2015-01-01

    Anterior cruciate ligament (ACL) injuries happen at a frequent rate, especially in girls and women. While there are many factors that contribute to ACL tears, teaching proper landing techniques and strengthening certain muscles can decrease the incidence of ACL tears, especially in women. This article reviews some of the high-risk factors that…

  15. Anterior cruciate ligament reconstruction and knee osteoarthritis

    PubMed Central

    Paschos, Nikolaos K

    2017-01-01

    Anterior cruciate ligament (ACL) injury is a traumatic event that can lead to significant functional impairment and inability to participate in high-level sports-related activities. ACL reconstruction is considered the treatment of choice for symptomatic ACL-deficient patients and can assist in full functional recovery. Furthermore, ACL reconstruction restores ligamentous stability to normal, and, therefore, can potentially fully reinstate kinematics of the knee joint. As a consequence, the natural history of ACL injury could be potentially reversed via ACL reconstruction. Evidence from the literature is controversial regarding the effectiveness of ACL reconstruction in preventing the development of knee cartilage degeneration. This editorial aims to present recent high-level evidence in an attempt to answer whether ACL injury inevitably leads to osteoarthritis and whether ACL reconstruction can prevent this development or not. PMID:28361013

  16. Feedback Techniques to Target Functional Deficits Following Anterior Cruciate Ligament Reconstruction: Implications for Motor Control and Reduction of Second Injury Risk

    PubMed Central

    Benjaminse, Anne; Hewett, Timothy E.; Paterno, Mark V.; Ford, Kevin R.; Otten, Egbert; Myer, Gregory D.

    2014-01-01

    Primary anterior cruciate ligament (ACL) injury prevention training has been shown to reduce the risk of injury. Less is known about the effect of prevention on second injury after ACL reconstruction (ACLR). Given recent findings that second injury rates exceed 20 % in only the first year following the return to sport, it is imperative that rehabilitation after ACLR is scrutinized so that second injury preventative strategies can be optimized. A potential limitation of current rehabilitative processes following ACLR could be a deficiency in the transition from conscious awareness achieved during rehabilitation sessions to unexpected and automatic movements required for athletic activities on the field. Learning strategies with an internally directed focus have traditionally been utilized but may be less suitable for acquisition of control of complex motor skills required for sport reintegration. Conversely, an externally focused rehabilitation strategy may enhance skill acquisition more efficiently and increase the potential to transfer to competitive sport. This article presents new insights gained from the motor learning domain that may improve neuromuscular training programmes via increased retention from improved techniques and may ultimately reduce the incidence of second ACL injuries. PMID:24062274

  17. Posterior Wall Blowout in Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Mitchell, Justin J.; Dean, Chase S.; Chahla, Jorge; Menge, Travis J.; Cram, Tyler R.; LaPrade, Robert F.

    2016-01-01

    Violation of the posterior femoral cortex, commonly referred to as posterior wall blowout, can be a devastating intraoperative complication in anterior cruciate ligament (ACL) reconstruction and lead to loss of graft fixation or early graft failure. If cortical blowout occurs despite careful planning and adherence to proper surgical technique, a thorough knowledge of the anatomy and alternative fixation techniques is imperative to ensure optimal patient outcomes. This article highlights anatomic considerations for femoral tunnel placement in ACL reconstruction and techniques for avoidance and salvage of a posterior wall blowout. PMID:27335885

  18. GPU implementation of simultaneous iterative reconstruction techniques for computed tomograpy

    NASA Astrophysics Data System (ADS)

    Xin, Junjun; Bardel, Chuck; Udpa, Lalita; Udpa, Satish

    2013-01-01

    This paper presents implementation of simultaneous iteration reconstruction techniques on GPU with parallel computing languages using CUDA and its intrinsic libraries on four different Graphic Processing (GPU) cards. GPUs are highly parallel computing structures that enable acceleration of scientific and engineering computations. The GPU implementations offer significant performance improvement in reconstruction times. Initial results on the Shepp-Logan phantom of size ranging from 16×16 to 256×256 pixels are presented.

  19. 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

  20. Relationship Between Posterior-Inferior Tibial Slope and Bilateral Noncontact ACL Injury.

    PubMed

    Hendrix, Steven T; Barrett, Austin M; Chrea, Bopha; Replogle, William H; Hydrick, Josie M; Barrett, Gene R

    2016-10-18

    Is there a correlation between increased posterior-inferior tibial slope angle and noncontact anterior cruciate ligament (ACL) injury? Does increasing the posterior-inferior tibial slope angle increase the risk of bilateral ACL injury? A computerized relational database (Access 2007; Microsoft Inc, Redmond, Washington) was used to conduct a retrospective review of patients undergoing bilateral or unilateral ACL reconstruction surgery or treatment by a single surgeon between 1995 and 2013. Included in the study were patients with bilateral and unilateral ACL injuries and patellofemoral pain syndrome with no associated ACL deficiency. Exclusion criteria included concomitant ligament injury, previous ACL reconstruction, and previous knee surgery. Also excluded were patients who did not have plain lateral radiographs. Fifty patients were randomly selected from each group. After controlling for age and Tegner activity level, the authors found that the posterior-inferior tibial slope angle was a significant predictor (P=.002) of noncontact ACL injury. Mean posterior-inferior tibial slope angle for the bilateral, unilateral, and control groups was 11.8°±2.3°, 9.3°±2.4°, and 7.5°±2.3°, respectively. In the group with unilateral ACL injury vs the group without ACL deficiency, a 1° increase in posterior-inferior tibial slope angle (P=.03) was associated with a 20% increase in unilateral ACL injury. In those with bilateral ACL injury vs those without ACL deficiency, a 1° increase in posterior-inferior tibial slope angle (P=.001) increased bilateral knee injury by 34%. The difference between the mean angles of the control group without ACL deficiency and both the bilateral injury and unilateral injury cohorts was statistically significant (P=.003). Increased posterior-inferior tibial slope angle is associated with an increased risk of noncontact bilateral and unilateral ACL injury. [Orthopedics. 201x; xx(x):xx-xx.].

  1. Reconstruction of 3D angiography data using the algebraic reconstruction technique (ART)

    NASA Astrophysics Data System (ADS)

    Hampton, Carnell J.; Hemler, Paul F.

    2001-07-01

    Three-dimensional angiographic reconstrcution has emerged as an alternative to the traditional depiction of aneurysm angioarchitecture provided by 2-D perspective projections acquired by digital subtraction angiography (DSA) and fluoroscopy. One clinical application of research involving 3-D angiographic reconstruction is intraoperative localization and visualization during aneurysm embolization procedures. For this procedure, reconstruction quality is important for the 3-D reconstruction of anatomy as well as for the reconstrucution of intraaneurysm coils imaged endovascularly and subsequently rendered within an existing 3-D anatomic representation. Rotational angiography involves the acquisition of a series of 2-D, cone-beam projections of intracranial anatomy by a rotating x-ray gantry following a single injection of contrast media. Our investigation focuses on the practicality of using methods that employ algebraic reconstruction techniques (ART) to reconstruct 3-D data from 2-D cone-beam projections acquired using rotational angiography during embolization procedures. Important to our investigation are issues that arise within the implementation of the projection, correction and backprojection steps of the reconstruction algorithm that affect reconstruction quality. Several methods are discussed to perform accurate voxel grid projection and backprojection. Various parameters of the reconstruction algorithm implementation are also investigated. Preliminary results indicating that quality 3-D reconstructions from 2-D projections of synthetic volumes are presented. Further modifications to our implementation hold the promise of achieving accurate reconstruction results with a lower computation cost than the algorithm implemention used for this study. We have concluded that methods to extend the traditional ART algorithm for cone-beam projection acquisition produce quality 3-D reconstructions.

  2. Reconstruction Techniques for Sparse Multistatic Linear Array Microwave Imaging

    SciTech Connect

    Sheen, David M.; Hall, Thomas E.

    2014-06-09

    Sequentially-switched linear arrays are an enabling technology for a number of near-field microwave imaging applications. Electronically sequencing along the array axis followed by mechanical scanning along an orthogonal axis allows dense sampling of a two-dimensional aperture in near real-time. In this paper, a sparse multi-static array technique will be described along with associated Fourier-Transform-based and back-projection-based image reconstruction algorithms. Simulated and measured imaging results are presented that show the effectiveness of the sparse array technique along with the merits and weaknesses of each image reconstruction approach.

  3. Tropospheric wet refractivity tomography using multiplicative algebraic reconstruction technique

    NASA Astrophysics Data System (ADS)

    Xiaoying, Wang; Ziqiang, Dai; Enhong, Zhang; Fuyang, K. E.; Yunchang, Cao; Lianchun, Song

    2014-01-01

    Algebraic reconstruction techniques (ART) have been successfully used to reconstruct the total electron content (TEC) of the ionosphere and in recent years be tentatively used in tropospheric wet refractivity and water vapor tomography in the ground-based GNSS technology. The previous research on ART used in tropospheric water vapor tomography focused on the convergence and relaxation parameters for various algebraic reconstruction techniques and rarely discussed the impact of Gaussian constraints and initial field on the iteration results. The existing accuracy evaluation parameters calculated from slant wet delay can only evaluate the resultant precision of the voxels penetrated by slant paths and cannot evaluate that of the voxels not penetrated by any slant path. The paper proposes two new statistical parameters Bias and RMS, calculated from wet refractivity of the total voxels, to improve the deficiencies of existing evaluation parameters and then discusses the effect of the Gaussian constraints and initial field on the convergence and tomography results in multiplicative algebraic reconstruction technique (MART) to reconstruct the 4D tropospheric wet refractivity field using simulation method.

  4. Anterior cruciate ligament reconstruction tunnel size: causes of tunnel enlargement and implications for single versus two-stage revision reconstruction.

    PubMed

    Rizer, Magda; Foremny, Gregory Brian; Rush, Augustus; Singer, Adam D; Baraga, Michael; Kaplan, Lee D; Jose, Jean

    2017-02-01

    Anterior cruciate ligament (ACL) reconstructions have increased over the past 25 years. The increased incidence of ACL reconstructions has translated into a larger number of graft failures and revision ACL procedures. It is important to understand the causes of graft failure when evaluating for a revision ACL reconstruction and to appreciate changes in tunnel anatomy over time prior to planning revision surgery. In this manuscript, tunnel size for ACL reconstruction and implications for single-stage versus two-stage revision ACL reconstruction will be discussed, as well as causes of tunnel enlargement, including mechanical and biological factors.

  5. Flame slice algebraic reconstruction technique reconstruction algorithm based on radial total variation

    NASA Astrophysics Data System (ADS)

    Zhang, Shufang; Wang, Fuyao; Zhang, Cong; Xie, Hui; Wan, Minggang

    2016-09-01

    The engine flame is an important representation of the combustion process in the cylinder, and the three-dimensional (3-D) shape reconstruction of the flame can provide more information for the quantitative analysis of the flame, so as to contribute to further research on the mechanism of the combustion flame. One important method of 3-D shape reconstruction is to reconstruct the two-dimensional (2-D) projection image of the flame, so the optimization problem of the flame 2-D slice reconstruction algorithm is studied in this paper. According to the gradient sparsity characteristics in the total variation (TV) domain and radial diffusion characteristics of the engine combustion flame, a flame 2-D slice algebraic reconstruction technique (ART) reconstruction algorithm based on radial TV (ART-R-TV) is proposed. Numerical simulation results show that the new proposed ART-R-TV algorithm can reconstruct flame slice images more stably and have a better robustness than the two traditional ART algorithms especially in a limited-angle situation.

  6. 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

  7. Using Family Reconstruction Techniques with Families in Therapy.

    ERIC Educational Resources Information Center

    Sheras, Peter L.

    An examination of the technique of Family Reconstruction employed by Satir and others attempting to establish an appreciation of the client's personhood through the understanding of their parents' personhood is presented. In addition, the feeling of continuity with the family and the facilitation of integration is explored to further reveal the…

  8. Algebraic reconstruction techniques in CT and their implementation

    NASA Astrophysics Data System (ADS)

    Sun, Fengrong; Liu, Jiren; Zhu, Benren

    2001-09-01

    In the paper, we analyze comprehensively the mathematics of the Algebraic Reconstruction Techniques (ART) in the Computerized Tomography (CT), obtain some illumining conclusions, and then we design the procedure of ART simulation. The experiment result is also presented in the paper.

  9. A modified technique for firm elevation of the reconstructed auricle.

    PubMed

    Shan, Jing; Guo, Ying; Chang, Kay W; Zhang, Tianyu

    2016-10-01

    Reconstruction of the external ear for microtia remains one of the most challenging clinical problems in reconstructive surgery. Whether the reconstructive effort replicates a normal ear relates to making a delicate ear cartilage framework and achieving a firm projection of the constructed auricle. In this study, we present a new technique to create a firm elevation. 46 patients with congenital microtia, 30 male and 16 female, are included in this series. We used a modified Nagata's two-stage technique. In the second stage, instead of using a temporoparietal fascial flap to wrap a cartilage wedge, we developed a new technique using the retroauricular fascial flap wrapping a porous polyethylene (Medpor) wedge as the strut. None of the patients demonstrated any necrosis for the implanted auricle and grafted skin. None of the patients had postoperative exposure of the porous polyethylene wedge. The height of the protrusion for point 1 (the protrusion at superaurale level) and point 2 (the inferior end of the helix, where it connects with the lobule) ranged from 1.1 to 1.6 cm with the median of 1.23 cm, and from 0.8 to 1.1 cm with the median of 0.93 cm, respectively. The advantages of this technique are safe, practical and straightforward. The retroauricular fascial flap can help to fix the wedge and provide good vascular supply to the grafted skin. The porous polyethylene wedge provides excellent projection for the reconstructed auricle.

  10. The effects of ACL injury on quadriceps and hamstring torque, work and power.

    PubMed

    Pincivero, Danny M; Heller, Brandan M; Hou, Su-I

    2002-09-01

    The aim of this study was to assess isokinetic torque, work and power between non-injured, ACL (anterior cruciate ligament)-deficient and ACL-reconstructed individuals. Ten healthy, non-injured individuals, seven unilateral ACL-deficient individuals and six unilateral ACL-reconstructed individuals were assessed for isokinetic quadriceps and hamstring strength at 1.05 and 3.14 rad.s-1. Peak torque, total work, average power and the ratio of peak torque to body mass were computed for both velocities. Peak torque was also corrected for body mass, using allometric modelling. The non-injured individuals showed significantly greater quadriceps peak torque to body mass ratios than the ACL-deficient and ACL-reconstructed individuals at both velocities, and greater hamstring peak torque to body mass ratios than the ACL-deficient group at 3.14 rad.s-1 (P < 0.05). The ACL-deficient individuals displayed greater quadriceps and hamstring peak torque, total work and average power than the non-injured individuals at 1.05 rad.s-1 (P < 0.05). The ACL-deficient individuals also displayed significantly greater peak torque, total work and average power than the ACL-reconstructed individuals for the quadriceps at both velocities (P < 0.05). The ACL-deficient individuals demonstrated greater hamstring peak torque and total work than the non-injured individuals at both velocities (P < 0.05). The allometrically modelled peak torques at both isokinetic velocities demonstrated that the quadriceps muscle values were significantly higher in the non-involved than the involved limb. The hamstring peak torques corrected for body mass were significantly higher in the non-involved than the involved limb only at 1.05 rad.s-1. The main finding from the present study is that isokinetic measures in ratio-scaled or absolute units yield a different outcome and, hence, interpretation compared with the allometric approach.

  11. Reconstruction of reflectance data using an interpolation technique.

    PubMed

    Abed, Farhad Moghareh; Amirshahi, Seyed Hossein; Abed, Mohammad Reza Moghareh

    2009-03-01

    A linear interpolation method is applied for reconstruction of reflectance spectra of Munsell as well as ColorChecker SG color chips from the corresponding colorimetric values under a given set of viewing conditions. Hence, different types of lookup tables (LUTs) have been created to connect the colorimetric and spectrophotometeric data as the source and destination spaces in this approach. To optimize the algorithm, different color spaces and light sources have been used to build different types of LUTs. The effects of applied color datasets as well as employed color spaces are investigated. Results of recovery are evaluated by the mean and the maximum color difference values under other sets of standard light sources. The mean and the maximum values of root mean square (RMS) error between the reconstructed and the actual spectra are also calculated. Since the speed of reflectance reconstruction is a key point in the LUT algorithm, the processing time spent for interpolation of spectral data has also been measured for each model. Finally, the performance of the suggested interpolation technique is compared with that of the common principal component analysis method. According to the results, using the CIEXYZ tristimulus values as a source space shows priority over the CIELAB color space. Besides, the colorimetric position of a desired sample is a key point that indicates the success of the approach. In fact, because of the nature of the interpolation technique, the colorimetric position of the desired samples should be located inside the color gamut of available samples in the dataset. The resultant spectra that have been reconstructed by this technique show considerable improvement in terms of RMS error between the actual and the reconstructed reflectance spectra as well as CIELAB color differences under the other light source in comparison with those obtained from the standard PCA technique.

  12. Reconstruction techniques for sparse multistatic linear array microwave imaging

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; Hall, Thomas E.

    2014-06-01

    Sequentially-switched linear arrays are an enabling technology for a number of near-field microwave imaging applications. Electronically sequencing along the array axis followed by mechanical scanning along an orthogonal axis allows dense sampling of a two-dimensional aperture in near real-time. The Pacific Northwest National Laboratory (PNNL) has developed this technology for several applications including concealed weapon detection, groundpenetrating radar, and non-destructive inspection and evaluation. These techniques form three-dimensional images by scanning a diverging beam swept frequency transceiver over a two-dimensional aperture and mathematically focusing or reconstructing the data into three-dimensional images. Recently, a sparse multi-static array technology has been developed that reduces the number of antennas required to densely sample the linear array axis of the spatial aperture. This allows a significant reduction in cost and complexity of the linear-array-based imaging system. The sparse array has been specifically designed to be compatible with Fourier-Transform-based image reconstruction techniques; however, there are limitations to the use of these techniques, especially for extreme near-field operation. In the extreme near-field of the array, back-projection techniques have been developed that account for the exact location of each transmitter and receiver in the linear array and the 3-D image location. In this paper, the sparse array technique will be described along with associated Fourier-Transform-based and back-projection-based image reconstruction algorithms. Simulated imaging results are presented that show the effectiveness of the sparse array technique along with the merits and weaknesses of each image reconstruction approach.

  13. Microsurgical clip reconstruction techniques for aneurysms with significant calcified neck.

    PubMed

    H Turkmani, Ali; Day, Arthur L; Kim, Dong H; Chen, Peng Roc

    2015-07-01

    A common surgical complication of clipping aneurysms with a calcified neck is the calcified atheroma compromising the parent arteries after clipping the neck. Clips can slip downward at the calcified neck or cause calcified atheroma encroaching the parent arteries. This video demonstrates a reconstructive clip technique to avoid these issues. A fenes-trated clip is placed first to reconstruct the distal parent artery-aneurysm neck with the fenestrated ring over the thickest calcification. Then, a straight clip reconstructs the proximal artery-aneurysm junction, leaving the thickest point of calcified walls pinching together by themselves to achieve aneurysm occlusion while preserving the parent arteries. The video can be found here: http://youtu.be/9CM3o5_qlNQ.

  14. A Technique of Superficial Medial Collateral Ligament Reconstruction Using an Adjustable-Loop Suspensory Fixation Device.

    PubMed

    Deo, Shaneel; Getgood, Alan

    2015-06-01

    This report describes superficial medial collateral ligament reconstruction of the knee using a novel method of graft fixation with the ACL Tightrope RT (Arthrex, Naples, FL). After tibial fixation with either a standard interference screw or staple, femoral fixation of the semitendinosus tendon is performed with the adjustable-loop suspensory fixation device, which allows for both initial graft tensioning and re-tensioning after cyclical knee range of motion. This provides the ability for the graft to accommodate for resultant soft-tissue creep and stress relaxation, thereby allowing for optimal soft-tissue tension and reduction in laxity at the end of the procedure.

  15. 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

  16. Comparison of endoscopic and two-incision techniques for reconstructing a torn anterior cruciate ligament using hamstring tendons.

    PubMed

    Howell, S M; Deutsch, M L

    1999-09-01

    This study compared the differences in clinical outcome between an endoscopic (67 of 70) and two-incision (41 of 49) technique used to reconstruct tom anterior cruciate ligaments (ACL) using a double-looped semitendinosus and gracilis (DLSTG) graft. In both techniques, the graft was placed without roof impingement, the looped end of the graft was fixed around a post with bone compaction, and the free ends were fixed with either double staples or a soft tissue washer(s). No graft required suture fixation. The postoperative treatment featured an aggressive rehabilitation protocol without a brace, and allowed unrestricted sports participation 4 months after reconstruction. Age, sex distribution, duration from injury to surgery, and preoperative laxity were not significantly different between treatment groups. The operative time for the endoscopic technique averaged 48 minutes less than the two-incision technique. There were no significant differences in thigh circumference, knee extension, stability, and the single leg hop test between the two treatment groups at 4 and 24 months. Ninety-one percent of the knees in the endoscopic group and 90% in the two-incision group had less than a 3 mm increase in anterior translation compared with the normal knee using the manual maximum test (KT-1000) and had either a normal or near normal knee (IKDC score) at 2 years. A second surgery for removal of painful, prominent hardware was required in 21% of the subjects in the endoscopic group and 12% of the subjects in the two-incision treatment group. Patients preferred the endoscopic technique because the result was more cosmetic and aggressive rehabilitation could be accomplished without the assistance of a physical therapist. Unfortunately, objective stability could not be restored in about 10% of knees with either technique. Reoperation for removal of prominent staples and washers continues to be the primary source of postoperative morbidity.

  17. A maximum entropy reconstruction technique for tomographic particle image velocimetry

    NASA Astrophysics Data System (ADS)

    Bilsky, A. V.; Lozhkin, V. A.; Markovich, D. M.; Tokarev, M. P.

    2013-04-01

    This paper studies a novel approach for reducing tomographic PIV computational complexity. The proposed approach is an algebraic reconstruction technique, termed MENT (maximum entropy). This technique computes the three-dimensional light intensity distribution several times faster than SMART, using at least ten times less memory. Additionally, the reconstruction quality remains nearly the same as with SMART. This paper presents the theoretical computation performance comparison for MENT, SMART and MART, followed by validation using synthetic particle images. Both the theoretical assessment and validation of synthetic images demonstrate significant computational time reduction. The data processing accuracy of MENT was compared to that of SMART in a slot jet experiment. A comparison of the average velocity profiles shows a high level of agreement between the results obtained with MENT and those obtained with SMART.

  18. Evaluation of the spline reconstruction technique for PET

    SciTech Connect

    Kastis, George A. Kyriakopoulou, Dimitra; Gaitanis, Anastasios; Fernández, Yolanda; Hutton, Brian F.; Fokas, Athanasios S.

    2014-04-15

    Purpose: The spline reconstruction technique (SRT), based on the analytic formula for the inverse Radon transform, has been presented earlier in the literature. In this study, the authors present an improved formulation and numerical implementation of this algorithm and evaluate it in comparison to filtered backprojection (FBP). Methods: The SRT is based on the numerical evaluation of the Hilbert transform of the sinogram via an approximation in terms of “custom made” cubic splines. By restricting reconstruction only within object pixels and by utilizing certain mathematical symmetries, the authors achieve a reconstruction time comparable to that of FBP. The authors have implemented SRT in STIR and have evaluated this technique using simulated data from a clinical positron emission tomography (PET) system, as well as real data obtained from clinical and preclinical PET scanners. For the simulation studies, the authors have simulated sinograms of a point-source and three digital phantoms. Using these sinograms, the authors have created realizations of Poisson noise at five noise levels. In addition to visual comparisons of the reconstructed images, the authors have determined contrast and bias for different regions of the phantoms as a function of noise level. For the real-data studies, sinograms of an{sup 18}F-FDG injected mouse, a NEMA NU 4-2008 image quality phantom, and a Derenzo phantom have been acquired from a commercial PET system. The authors have determined: (a) coefficient of variations (COV) and contrast from the NEMA phantom, (b) contrast for the various sections of the Derenzo phantom, and (c) line profiles for the Derenzo phantom. Furthermore, the authors have acquired sinograms from a whole-body PET scan of an {sup 18}F-FDG injected cancer patient, using the GE Discovery ST PET/CT system. SRT and FBP reconstructions of the thorax have been visually evaluated. Results: The results indicate an improvement in FWHM and FWTM in both simulated and real

  19. Continuous analog of multiplicative algebraic reconstruction technique for computed tomography

    NASA Astrophysics Data System (ADS)

    Tateishi, Kiyoko; Yamaguchi, Yusaku; Abou Al-Ola, Omar M.; Kojima, Takeshi; Yoshinaga, Tetsuya

    2016-03-01

    We propose a hybrid dynamical system as a continuous analog to the block-iterative multiplicative algebraic reconstruction technique (BI-MART), which is a well-known iterative image reconstruction algorithm for computed tomography. The hybrid system is described by a switched nonlinear system with a piecewise smooth vector field or differential equation and, for consistent inverse problems, the convergence of non-negatively constrained solutions to a globally stable equilibrium is guaranteed by the Lyapunov theorem. Namely, we can prove theoretically that a weighted Kullback-Leibler divergence measure can be a common Lyapunov function for the switched system. We show that discretizing the differential equation by using the first-order approximation (Euler's method) based on the geometric multiplicative calculus leads to the same iterative formula of the BI-MART with the scaling parameter as a time-step of numerical discretization. The present paper is the first to reveal that a kind of iterative image reconstruction algorithm is constructed by the discretization of a continuous-time dynamical system for solving tomographic inverse problems. Iterative algorithms with not only the Euler method but also the Runge-Kutta methods of lower-orders applied for discretizing the continuous-time system can be used for image reconstruction. A numerical example showing the characteristics of the discretized iterative methods is presented.

  20. RISKS AND CONSEQUENCES OF USING THE TRANSPORTAL TECHNIQUE IN RECONSTRUCTING THE ANTERIOR CRUCIATE LIGAMENT: RELATIONSHIPS BETWEEN THE FEMORAL TUNNEL, LATERAL SUPERIOR GENICULAR ARTERY AND LATERAL EPICONDYLE OF THE FEMORAL CONDYLE

    PubMed Central

    Astur, Diego Costa; Aleluia, Vinicius; Santos, Ciro Veronese; Arliani, Gustavo Gonçalves; Badra, Ricardo; Oliveira, Saulo Gomes; Kaleka, Camila Cohen; Cohen, Moisés

    2015-01-01

    Objective: Define a security zone to avoid possibles vascular and ligamentar complications during anterior cruciate ligament reconstruction. Methods: Arthroscopic reconstruction using the transtibial and transportal technique in cadaver knees was performed followed by dissection and measurement of the distance between the femoral tunnel and the proximal attachment of the lateral collateral ligament and the femoral tunnel and the lateral superior genicular artery. Results: The measure of the analysed distances show us an aproximation between the major branch of the lateral superior genicular artery and the femoral insertion of the colateral lateral ligament and the femoral tunnel during the transportal technique. Conclusion: We realize that the use of technical ship it to arthroscopic ACL reconstruction has a higher probability of injury to the lateral geniculate artery and insertion of the lateral collateral ligament, promoting post-surgical complications such as instability of the knee, osteonecrosis of the femoral condyle and ligamentização graft. PMID:27047873

  1. Anatomic Anterolateral Ligament Reconstruction Improves Postoperative Clinical Outcomes Combined with Anatomic Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Qiu, Man; Zhou, Aiguo; Zhang, Jian; Jiang, Dianming

    2016-01-01

    A significant cohort of patients is plagued by postoperative rotational instability after the anatomic anterior cruciate ligament (ACL) reconstruction surgery. Anatomic anterolateral ligament (ALL) reconstruction was performed in this study with the aim to assess the clinical role of ALL in knee’s stability and joint functions. Sixty patients were recruited and divided into three groups to perform the operations of anatomic single-bundle ACL reconstruction, anatomic double-bundle ACL reconstruction, and anatomic single-bundle ACL reconstruction + anterolateral ligament reconstruction, respectively. And then postoperative knee’s stability and joint functions were evaluated to compare the clinical outcomes among the three different kind of operations. The postoperative knee’s stability and joint functions of the anatomic double-bundle ACL reconstruction group and the anatomic single-bundle ACL reconstruction + ALL reconstruction group were better than the anatomic single-bundle ACL reconstruction group. No significant difference was observed between the anatomic double-bundle ACL reconstruction group and the anatomic single-bundle ACL reconstruction + ALL reconstruction group. The anatomic anterolateral ligament reconstruction could improve the clinical outcomes after patients performed the anatomic single-bundle anterior cruciate ligament reconstruction. This indicates that the anterolateral ligament plays a crucial role in knee’s stability and joint function, especially the rotational stability. Key points Anatomic anterolateral ligament reconstruction combined with anatomic anterior cruciate ligament reconstruction was performed to treat the patients with ACL rupture. Compared to the anatomic single-bundle ACL reconstruction group, the anatomic single-bundle ACL reconstruction + ALL reconstruction group achieve a better clinical outcomes. The results suggest that the anterolateral ligament plays a crucial role in knee’s stability and joint function

  2. Surgical technique of orthotopic liver transplantation in rats: the Kamada technique and a new splint technique for hepatic artery reconstruction.

    PubMed

    Ishii, Eiichi; Shimizu, Akira; Takahashi, Mikiko; Terasaki, Mika; Kunugi, Shinobu; Nagasaka, Shinya; Terasaki, Yasuhiro; Ohashi, Ryuji; Masuda, Yukinari; Fukuda, Yuh

    2013-01-01

    Orthotopic liver transplantation (OLT) in rats is technically feasible and useful for the assessment of clinical liver transplantation and analysis of inflammatory liver diseases. OLT in rats was pioneered by Lee et al. in 1973 using hand-suture techniques of all vessels. This model has not been widely used due to the long operative time and technical demand. The cuff method was introduced by Kamada in 1979, and today, the Kamada technique is the one most commonly used worldwide. However, this technique does not include hepatic artery reconstruction, although this procedure is routinely performed in clinical transplantation. Nevertheless, several techniques for hepatic artery reconstruction in rat OLT have been reported recently, and our group also developed a simple splint technique from recipient right renal artery to donor celiac axis bearing the hepatic artery. In the present article, we describe the Kamada technique, as a standard surgical method for rat OLT. In addition, we also describe our splint technique for hepatic artery reconstruction. Then, we compare the features of Kamada technique and our splint technique for hepatic artery reconstruction and all other surgical techniques currently in use for rat OLT. The widespread use of the rat OLT model should help to provide full assessment of transplant immunology and the mechanism and treatment of inflammatory liver diseases.

  3. KOOS Pain as a Marker for Significant Knee Pain Two and Six Years after Primary ACL Reconstruction: A Multicenter Orthopaedic Outcomes Network (MOON) Prospective Longitudinal Cohort Study

    PubMed Central

    Wasserstein, D; Huston, LJ; Nwosu, S; Spindler, KP

    2015-01-01

    Objective The prevalence of radiographic osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR) approaches 50%, yet the prevalence of significant knee pain is unknown. We applied three different models of Knee injury and Osteoarthritis Outcome Score (KOOS) thresholds for significant knee pain to an ACLR cohort to identify prevalence and risk factors. Design Multicenter Orthopaedic Outcomes Network (MOON) prospective cohort patients with a unilateral primary ACLR and normal contralateral knee were assessed at 2 and 6 years. Independent variables included patient demographics, validated Patient Reported Outcomes (PRO; Marx activity score, KOOS), and surgical characteristics. Models included: (1) KOOS criteria for a painful knee = quality of life subscale <87.5 and ≥2 of: KOOSpain <86.1, KOOSsymptoms <85.7, KOOSADL <86.8, or KOOSsports/rec <85.0; (2) KOOSpain subscale score ≤72 (≥2 standard deviations below population mean); (3) 10-point KOOSpain drop from 2 to 6 years. Proportional odds models (alpha≤0.05) were used. Results 1,761 patients of median age 23 years, median BMI 24.8 kg/m2 and 56% male met inclusion, with 87% (1530/1761) and 86% (1506/1761) follow-up at 2 and 6 years, respectively. At 6 years, n=592 (39%), n=131 (9%) and n=169 (12%) met criteria for models #1 through #3, respectively. The most consistent and strongest independent risk factor at both time-points was subsequent ipsilateral knee surgery. Low 2-year Marx activity score increased the odds of a painful knee at 6 years. Conclusions Significant knee pain is prevalent after ACLR; with those who undergo subsequent ipsilateral surgery at greatest risk. The relationship between pain and structural OA warrants further study. PMID:26072385

  4. Femoral and Tibial Tunnel Diameter and Bioabsorbable Screw Findings After Double-Bundle ACL Reconstruction in 5-Year Clinical and MRI Follow-up

    PubMed Central

    Kiekara, Tommi; Paakkala, Antti; Suomalainen, Piia; Huhtala, Heini; Järvelä, Timo

    2017-01-01

    Background: Tunnel enlargement is frequently seen in short-term follow-up after anterior cruciate ligament reconstruction (ACLR). According to new evidence, tunnel enlargement may be followed by tunnel narrowing, but the long-term evolution of the tunnels is currently unknown. Hypothesis/Purpose: The hypothesis was that tunnel enlargement is followed by tunnel narrowing caused by ossification as seen in follow-up using magnetic resonance imaging (MRI). The purpose of this study was to evaluate the ossification pattern of the tunnels, the communication of the 2 femoral and 2 tibial tunnels, and screw absorption findings in MRI. Study Design: Case series; Level of evidence, 4. Methods: Thirty-one patients underwent anatomic double-bundle ACLR with hamstring grafts and bioabsorbable interference screw fixation and were followed with MRI and clinical evaluation at 2 and 5 years postoperatively. Results: The mean tunnel enlargement at 2 years was 58% and reduced to 46% at 5 years. Tunnel ossification resulted in evenly narrowed tunnels in 44%, in conical tunnels in 48%, and fully ossified tunnels in 8%. Tunnel communication increased from 13% to 23% in the femur and from 19% to 23% in the tibia between 2 and 5 years and was not associated with knee laxity. At 5 years, 54% of the screws were not visible, with 35% of the screws replaced by a cyst and 19% fully ossified. Tunnel cysts were not associated with worse patient-reported outcomes or knee laxity. Patients with a tibial anteromedial tunnel cyst had higher Lysholm scores than patients without a cyst (93 and 84, P = .03). Conclusion: Tunnel enlargement was followed by tunnel narrowing in 5-year follow-up after double-bundle ACLR. Tunnel communication and tunnel cysts were frequent MRI findings and not associated with adverse clinical evaluation results. PMID:28203605

  5. Effect of Timing of Surgery in Partially Injured ACLs.

    PubMed

    Li, Bin; Bai, Lunhao; Fu, Yonghui; Wang, Guangbin; He, Ming; Wang, Jiashi

    2012-05-01

    The purpose of this study was to explore the optimal timing for surgical intervention of partially injured anterior cruciate ligaments (ACL). Thirty-eight patients were divided into early (n=17) or delayed (n=21) surgery groups based on the interval between injury and surgery. Minimum follow-up was 2 years. The outcome measures used were the International Knee Documentation Committee score, Lysholm knee score, Tegner activity rating, range of motion, and arthrometer measurements. The findings of this study indicate that early surgical reconstruction of partially ruptured ACLs did not result in arthrofibrosis but may prevent secondary loosening of the intact bundles and further meniscal and chondral injury.

  6. Reconstruction of anterior cruciate ligament and anterolateral ligament using interlinked hamstrings - technical note.

    PubMed

    Ferreira, Marcio de Castro; Zidan, Flavio Ferreira; Miduati, Francini Belluci; Fortuna, Caio Cesar; Mizutani, Bruno Moreira; Abdalla, Rene Jorge

    2016-01-01

    Recent anatomical and biomechanical studies on the anterolateral ligament (ALL) of the knee have shown that this structure has an important function in relation to joint stability, especially when associated with anterior cruciate ligament (ACL) injury. However, the criteria for its reconstruction have not yet been fully established and the surgical techniques that have been described present variations regarding anatomical points and fixation materials. This study presents a reproducible technique for ALL and ACL reconstruction using hamstring tendons, in which three interference screws are used for fixation.

  7. Anterior Cruciate Ligament (ACL) Injuries

    MedlinePlus

    ... what the surgeon advises. previous continue Rehab and Recovery Recovery from ACL surgery can take from 6 months ... frequent therapy, but they won't necessarily speed recovery. In the early stages of recovery, a doctor ...

  8. Basket-Weave Technique for Medial Patellofemoral Ligament Reconstruction

    PubMed Central

    Kodkani, Pranjal S.

    2015-01-01

    The anatomy of the medial patellofemoral ligament (MPFL) has been well defined, with parts of its uppermost fibers having a soft-tissue insertion onto the vastus intermedius. Bone tunnels and implants on the patellar side therefore cannot replicate this anatomic construct precisely. Because of implants and tunnels, complications have been reported with bone tunnel fracture. Similarly, on the femoral side, rigid fixation with implants can result in over-constraint with compromised results. Moreover, bone tunnels cannot be used in skeletally immature cases. To overcome issues related to bone tunneling and implants, as well as to reconstruct the MPFL in a precise anatomic manner, an all–soft-tissue fixation technique was devised. Bony landmarks were used as reference points instead of radiologic markers to achieve a more precise construct and to eliminate intraoperative radiography. Hamstring graft was used to reconstruct the MPFL. Special suturing techniques were used to achieve optimal graft fixation with minimal suture knots. A special tissue elevator–suture passer device was designed to facilitate graft passage and ease in performing the procedure. This technique permits differential tensioning, and therefore one achieves stability throughout the range of motion. PMID:26258044

  9. Fast Multigrid Techniques in Total Variation-Based Image Reconstruction

    NASA Technical Reports Server (NTRS)

    Oman, Mary Ellen

    1996-01-01

    Existing multigrid techniques are used to effect an efficient method for reconstructing an image from noisy, blurred data. Total Variation minimization yields a nonlinear integro-differential equation which, when discretized using cell-centered finite differences, yields a full matrix equation. A fixed point iteration is applied with the intermediate matrix equations solved via a preconditioned conjugate gradient method which utilizes multi-level quadrature (due to Brandt and Lubrecht) to apply the integral operator and a multigrid scheme (due to Ewing and Shen) to invert the differential operator. With effective preconditioning, the method presented seems to require Omicron(n) operations. Numerical results are given for a two-dimensional example.

  10. Frequency domain simultaneous algebraic reconstruction techniques: algorithm and convergence

    NASA Astrophysics Data System (ADS)

    Wang, Jiong; Zheng, Yibin

    2005-03-01

    We propose a simultaneous algebraic reconstruction technique (SART) in the frequency domain for linear imaging problems. This algorithm has the advantage of efficiently incorporating pixel correlations in an a priori image model. First it is shown that the generalized SART algorithm converges to the weighted minimum norm solution of a weighted least square problem. Then an implementation in the frequency domain is described. The performance of the new algorithm is demonstrated with fan beam computed tomography (CT) examples. Compared to the traditional SART and its major alternative ART, the new algorithm offers superior image quality and potential application to other modalities.

  11. Anterior Cruciate Ligament Reconstruction: Clinical Outcomes of Patella Tendon and Hamstring Tendon Grafts

    PubMed Central

    Gulick, Dawn T.; Yoder, Heather N.

    2002-01-01

    An injury to the ACL can result in significant functional impairment. It has been estimated that more than 100,000 new ACL injuries occur each year. Surgeons employ numerous techniques for reconstruction of the ACL. Of critical importance is the source of the graft to replace the damaged ACL. The graft choices include autografts (the patient's own tissue), allografts (donor tendon), and synthetic/prosthetic ligaments. Tissue harvest sites for autografting include the middle third of the patella tendon, the quadriceps tendon, semitendinosus tendon, gracilis tendon, iliotibial band, tensor fascia lata, and the Achilles tendon. Selection of the type of graft material is predicated upon the tissue's ability to tolerate high levels of stress. Likewise, the clinical presentation and functional outcome is related to the graft material selected. This manuscript specifically examined the patella tendon and hamstring tendon grafts. Numerous manuscripts that studied the outcomes of these graft materials were compiled to help the clinician appreciate the advantages and disadvantages of each of the graft materials. Outcome measures such as thigh circumference, knee range of motion, isokinetic strength, knee stability, pain, and vertical jump/1-leg hop were incorporated. The purpose of this manuscript was to compare and contrast the clinical presentation of patients who underwent an ACL reconstruction using the patella tendon versus the hamstring tendons. This information can be valuable to the clinician when considering the rehabilitation protocol after ACL reconstruction. PMID:24701126

  12. Technique renovation of the Grad-Shafranov (GS) reconstruction

    NASA Astrophysics Data System (ADS)

    Li, Huijun; Feng, Xueshang

    Grad-Shafranov (GS) reconstruction is now a novel tool in observational study on the flux rope events in solar winds and in magnetospheric plasmas. Meanwhile, mathematic flaws constraint its further application in structure recovery with the spacecraft data. In this talk, we report some new results in an ambition of the technique renovation of the GS reconstructions. (1) A pair of Hilbert transforms is proofed existing there on the boundary of any 2-dimensional potential field, and the essential technique of GS reconstruction is reformulated into the inverse boundary value problems (IBVPs) for Laplace’s equation. (2) The famous problem, i.e. the ill-posedness of the IBVPs, is also solved with the help of the introduced Hilbert transforms: It’s proofed that the specified IBVPs have unique solution, given the known Dirichlet and Neumann conditions on the partial boundary. Even when the known boundary is reduced to only one point, it can be inferred logically that the unique solution still exists there on the remaining boundary. (3) According to linearity of the elliptic operator in GS equation, its solution can be divided into two parts. One is solved from a semi-linear elliptic equation with an homogeneous Dirichlet boundary condition. The other is solved from the IBVP of Laplace’s equation. It is concluded that there exists a unique solution for the so-called elliptic Cauchy problem for the essential technique of GS reconstruction. (4) The new solution approach is also developed with the introduced Hilbert transforms, and an iterated Tikhonov regularization scheme is applied to deal with the ill-posed linear operators appearing in the discretization of the new approach. The special case on the circular boundary is benchmarked with the analytic solutions. Numerical experiments highlight the efficiency and robustness of the proposed method. (5) After a conformal mapping procedure, the new solution approach has also been extended from the circle boundary to any

  13. Healing of the Acutely Injured Anterior Cruciate Ligament: Functional Treatment with the ACL-Jack, a Dynamic Posterior Drawer Brace

    PubMed Central

    Reischl, Nikolaus; Rönn, Karolin; Magnusson, Robert A.; Gautier, Emanuel; Jakob, Roland P.

    2016-01-01

    Background. The injured anterior cruciate ligament (ACL) has a limited healing capacity leading to persisting instability. Hypothesis/Purpose. To study if the application of a brace, producing a dynamic posterior drawer force, after acute ACL injury reduces initial instability. Study Design. Cohort study. Methods. Patients treated with the ACL-Jack brace were compared to controls treated with primary ACL reconstruction und controls treated nonsurgically with functional rehabilitation. Measurements included anterior laxity (Rolimeter), clinical scores (Lysholm, Tegner, and IKDC), and MRI evaluation. Patients were followed up to 24 months. Results. Patients treated with the ACL-Jack brace showed a significant improvement of anterior knee laxity comparable to patients treated with ACL reconstruction, whereas laxity persisted after nonsurgical functional rehabilitation. The failure risk (secondary reconstruction necessary) of the ACL-Jack group was however 21% (18 of 86) within 24 months. Clinical scores were similar in all treatment groups. Conclusion. Treatment of acute ACL tears with the ACL-Jack brace leads to improved anterior knee laxity compared to nonsurgical treatment with functional rehabilitation. PMID:28053787

  14. Healing of the Acutely Injured Anterior Cruciate Ligament: Functional Treatment with the ACL-Jack, a Dynamic Posterior Drawer Brace.

    PubMed

    Jacobi, Matthias; Reischl, Nikolaus; Rönn, Karolin; Magnusson, Robert A; Gautier, Emanuel; Jakob, Roland P

    2016-01-01

    Background. The injured anterior cruciate ligament (ACL) has a limited healing capacity leading to persisting instability. Hypothesis/Purpose. To study if the application of a brace, producing a dynamic posterior drawer force, after acute ACL injury reduces initial instability. Study Design. Cohort study. Methods. Patients treated with the ACL-Jack brace were compared to controls treated with primary ACL reconstruction und controls treated nonsurgically with functional rehabilitation. Measurements included anterior laxity (Rolimeter), clinical scores (Lysholm, Tegner, and IKDC), and MRI evaluation. Patients were followed up to 24 months. Results. Patients treated with the ACL-Jack brace showed a significant improvement of anterior knee laxity comparable to patients treated with ACL reconstruction, whereas laxity persisted after nonsurgical functional rehabilitation. The failure risk (secondary reconstruction necessary) of the ACL-Jack group was however 21% (18 of 86) within 24 months. Clinical scores were similar in all treatment groups. Conclusion. Treatment of acute ACL tears with the ACL-Jack brace leads to improved anterior knee laxity compared to nonsurgical treatment with functional rehabilitation.

  15. Air data position-error calibration using state reconstruction techniques

    NASA Technical Reports Server (NTRS)

    Whitmore, S. A.; Larson, T. J.; Ehernberger, L. J.

    1984-01-01

    During the highly maneuverable aircraft technology (HiMAT) flight test program recently completed at NASA Ames Research Center's Dryden Flight Research Facility, numerous problems were experienced in airspeed calibration. This necessitated the use of state reconstruction techniques to arrive at a position-error calibration. For the HiMAT aircraft, most of the calibration effort was expended on flights in which the air data pressure transducers were not performing accurately. Following discovery of this problem, the air data transducers of both aircraft were wrapped in heater blankets to correct the problem. Additional calibration flights were performed, and from the resulting data a satisfactory position-error calibration was obtained. This calibration and data obtained before installation of the heater blankets were used to develop an alternate calibration method. The alternate approach took advantage of high-quality inertial data that was readily available. A linearized Kalman filter (LKF) was used to reconstruct the aircraft's wind-relative trajectory; the trajectory was then used to separate transducer measurement errors from the aircraft position error. This calibration method is accurate and inexpensive. The LKF technique has an inherent advantage of requiring that no flight maneuvers be specially designed for airspeed calibrations. It is of particular use when the measurements of the wind-relative quantities are suspected to have transducer-related errors.

  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. Registration based on projective reconstruction technique for augmented reality systems.

    PubMed

    Yuan, M L; Ong, S K; Nee, A Y C

    2005-01-01

    In AR systems, registration is one of the most difficult problems currently limiting their application. In this paper, we propose a simple registration method using projective reconstruction. This method consists of two steps: embedding and tracking. Embedding involves specifying four points to build the world coordinate system on which a virtual object will be superimposed. In tracking, a projective reconstruction technique is used to track these four specified points to compute the model view transformation for augmentation. This method is simple, as only four points need to be specified at the embedding stage and the virtual object can then be easily augmented onto a real scene from a video sequence. In addition, it can be extended to a scenario using the projective matrix that has been obtained from previous registration results using the same AR system. The proposed method has three advantages: 1) It is fast because the linear least square method can be used to estimate the related matrix in the algorithm and it is not necessary to calculate the fundamental matrix in the extended case. 2) A virtual object can still be superimposed on a related area even if some parts of the specified area are occluded during the whole process. 3) This method is robust because it remains effective even when not all the reference points are detected during the whole process, as long as at least six pairs of related reference points correspondences can be found. Some experiments have been conducted to validate the performance of the proposed method.

  18. ACL Injury, Return To Play And Reinjury In The Elite, Collegiate Athlete: An Analysis Of A Single, Division I NCAA Cohort

    PubMed Central

    Kamath, Ganesh V.; Murphy, Timothy; Creighton, Robert A.; Taft, Timothy N.; Spang, Jeffrey T.

    2014-01-01

    Objectives: Graft survivorship, reinjury rates, and career length are poorly understood after ACL reconstruction in the elite, NCAA Division-I athlete. The purpose of this study was to examine the outcomes of ACL reconstruction in a Division-I athlete cohort. Methods: Retrospective chart review was performed of all Division-I athletes at a single, public university from 2000 to 2009 until completion of eligibility. Athletes with a Pre-collegiate (PC) and Intra-collegiate (IC) ACL reconstruction were separated into two cohorts. Graft survivorship, reoperation rates, and career length information was collected. Results: 35 athletes were identified with a pre-collegiate (PC) ACL reconstruction; 60 with an intra-collegiate (IC) reconstruction. The PC group had a 17.1% injury rate to the original graft, with a 20.0% rate of contralateral ACL injury. For the IC group, the reinjury rates were 1.9% to the ACL graft, with a 9.2% rate of contralateral ACL injury after an IntraCollegiate ACL reconstruction. The PC group used 78% of their total eligibility (avg 3.11 yrs). Athletes in the IC group used an average of 77% of their remaining NCAA eligibility. 88.3% of the IC group played an additional non-redshirt year after their injury. Reoperation rate for the PC group was 51.4% and 20.3% for the IC group. Conclusion: Reoperation and reinjury rates are high after ACL reconstruction in the Division-I athlete. Pre-collegiate ACL reconstruction is associated with a very high rate of repeat ACL reinjury to the graft or opposite knee (37.1%). The majority of athletes are able to return to play after successful reconstruction.

  19. Reconstruction of the anterior cruciate ligament in the skeletally immature athlete: a review of current concepts: AAOS exhibit selection.

    PubMed

    Fabricant, Peter D; Jones, Kristofer J; Delos, Demetris; Cordasco, Frank A; Marx, Robert G; Pearle, Andrew D; Warren, Russell F; Green, Daniel W

    2013-03-06

    Intrasubstance tears of the anterior cruciate ligament (ACL) were once considered a rare injury in skeletally immature athletes but are now observed with increasing frequency. Treatment strategies have evolved as recent studies have identified unique considerations specific to the skeletally immature patient. The current literature now supports the trend toward early operative treatment to restore knee stability and prevent progressive meniscal and/or articular cartilage damage, but the optimal approach to ACL reconstruction in this age group remains controversial. Despite the reported clinical success of transphyseal reconstruction, iatrogenic growth disturbance secondary to physeal damage remains a genuine concern. The reluctance to place drill-holes across open physes has led to the development of numerous "physeal-sparing" reconstruction techniques using anatomic femoral and tibial footprints that have adequately restored anteroposterior and rotational knee stability in biomechanical studies but have demonstrated mixed results in the clinical setting. The intent of this review is to (1) highlight the unique anatomic considerations pertaining to ACL reconstruction in the skeletally immature athlete, (2) discuss preoperative clinical and radiographic assessment of the pediatric patient with a suspected ACL injury, (3) review transphyseal and physeal-sparing reconstruction techniques and highlight surgical technical considerations, (4) present clinical outcomes according to patient and technique-specific factors, and (5) review age-specific injury prevention treatment strategies and a novel treatment algorithm based on skeletal maturity. ACL reconstruction in the skeletally immature athlete typically results in a successful clinical outcome, yet the optimal surgical technique is still controversial. This review will help guide the management of ACL injuries in the pediatric athlete.

  20. Simulation and data reconstruction for NDT phased array techniques.

    PubMed

    Chatillon, S; de Roumilly, L; Porre, J; Poidevin, C; Calmon, P

    2006-12-22

    Phased array techniques are now widely employed for industrial NDT applications in various contexts. Indeed, phased array present a great adaptability to the inspection configuration and the application of suitable delay laws allows to optimize the detection and characterization performances by taking into account the component geometry, the material characteristics, and the aim of the inspection. In addition, the amount of potential information issued from the inspection is in general greatly enhanced. It is the case when the employed method involve sequences of shots (sectorial scanning, multiple depth focusing etc) or when signals received on the different channels are stored. At last, application of electronic commutation make possible higher acquisition rates. Accompanying these advantages, it is clear that an optimal use of such techniques require the application of simulation-based algorithms at the different stages of the inspection process: When designing the probe by optimizing number and characteristics of element; When conceiving the inspection method by selecting suitable sequences of shots, computing optimized delay laws and evaluating the performances of the control in terms of zone coverage or flaw detection capabilities; When analysing the results by applying simulation-helped visualization and data reconstruction algorithms. For many years the CEA (French Atomic Energy Commission) has been being greatly involved in the development of such phased arrays simulation-based tools. In this paper, we will present recent advances of this activity and show different examples of application carried out on complex situations.

  1. Single-Stage Reconstruction of Both Cruciate Ligaments

    PubMed Central

    Andreoli, Mauro; Zicaro, Juan Pablo; Yacuzzi, Carlos; Costa-Paz, Matias

    2017-01-01

    Objectives: Isolated Anterior Cruciate Ligament (ACL) and Posterior Cruciate Ligament (PCL), or central pivot lesions are rare. These are frequently associated with collateral ligaments injuries. The purpose of this retrospective study was to evaluate clinical and functional outcomes of 4 patients with acute ACL and PCL injury who underwent a simultaneous single-stage arthroscopic reconstruction. Methods: The inclusion criteria were patients with isolated ACL and PCL injuries, with a minimum follow-up of 2 years. We evaluated the type of graft used, the surgical technique and postoperative complications. The scales used for clinical evaluation were the Knee Society Score (KSS), IKDC, Lysholm and Tegner. Knee stability was assessed using the KT-1000 arthrometer. Results: Three men and one woman, with an average age of 48 years (45 to 56 years) were evaluated. Three presented a sport injury and one a car accident. Mean follow-up was 8 years. In all patients allograft was used for ligament reconstruction. Average postoperative results were: KSS 74-82, Lysholm 76, IKDC 63 and Tegner 6. KT-1000 arthrometer showed an average difference of 4mm compared to the contralateral knee. One patient underwent reintervention due to meniscal injury. Conclusion: ACL and PCL simultaneous single-stage reconstruction is a really demanding surgery. We achieved good results using allograft for both ligaments reconstruction. No clinical or functional postoperative complications were recorded.

  2. 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.

  3. Advances in Surgical Reconstructive Techniques in the Management of Penile, Urethral, and Scrotal Cancer.

    PubMed

    Bickell, Michael; Beilan, Jonathan; Wallen, Jared; Wiegand, Lucas; Carrion, Rafael

    2016-11-01

    This article reviews the most up-to-date surgical treatment options for the reconstructive management of patients with penile, urethral, and scrotal cancer. Each organ system is examined individually. Techniques and discussion for penile cancer reconstruction include Mohs surgery, glans resurfacing, partial and total glansectomy, and phalloplasty. Included in the penile cancer reconstruction section is the use of penile prosthesis in phalloplasty patients after penectomy, tissue engineering in phallic regeneration, and penile transplantation. Reconstruction following treatment of primary urethral carcinoma and current techniques for scrotal cancer reconstruction using split-thickness skin grafts and flaps are described.

  4. A Novel Nipple Reconstruction Technique for Maintaining Nipple Projection: The Boomerang Flap

    PubMed Central

    Kim, Young-Eun; Hong, Ki Yong; Minn, Kyung Won

    2016-01-01

    Nipple-areolar complex (NAC) reconstruction is the final step in the long journey of breast reconstruction for mastectomy patients. Successful NAC reconstruction depends on the use of appropriate surgical techniques that are simple and reliable. To date, numerous techniques have been used for nipple reconstruction, including contralateral nipple sharing and various local flaps. Recently, it has been common to utilize local flaps. However, the most common nipple reconstruction problem encountered with local flaps is the loss of nipple projection; there can be approximately 50% projection loss in reconstructed nipples over long-term follow-up. Several factors might contribute to nipple projection loss, and we tried to overcome these factors by performing nipple reconstructions using a boomerang flap technique, which is a modified C–V flap that utilizes the previous mastectomy scar to maintain long-term nipple projection. PMID:27689057

  5. Reconstruction after chronic extensor pollicis longus ruptures: a new technique.

    PubMed

    Bullón, Adrián; Bravo, Elena; Zarbahsh, Shirin; Barco, Raúl

    2007-09-01

    Different types of secondary reconstruction of extensor pollicis longus tendon injuries have been reported, with repair using the extensor indicis proprius being the gold standard. This technique, however, may decrease extension strength and independent extension of the index finger. We presumed repair with the accessory abductor pollicis longus would achieve functional motion of the thumb and avoid donor site morbidity. We retrospectively report the results for 11 consecutive patients who had repair with the accessory abductor pollicis longus and were followed prospectively for a minimum of 2 years. Study-specific outcome measures were used to assess function in activities of daily living, pain, and patient satisfaction. According to the score described by Geld-macher et al, good or excellent results were achieved in all cases. Mean abduction deficit of the thumb was 10 degrees compared with the uninjured side. Using a 0- to 10-point visual analog scale self-reporting questionnaire, patients obtained mean results of 7.9 points for pain, 7.5 points for activities of daily living, and 7.6 points for patient satisfaction. We recommend the accessory abductor pollicis longus as an alternative for extensor pollicis longus tendon repair.

  6. "The Superficial Quad Technique" for Medial Patellofemoral Ligament Reconstruction: The Surgical Video Technique.

    PubMed

    Goyal, Deepak

    2015-10-01

    With the introduction of the superficial quad technique, there has been a recent revival of interest in the quadriceps tendon as a graft choice for medial patellofemoral ligament (MPFL) reconstruction. The superficial quad technique has many anatomic advantages because the length, breadth, and thickness of the graft are similar to those of the native MPFL; moreover, the graft provides a continuous patellar attachment at the superior half of the medial border of the patella. The technique requires neither a patellar bony procedure nor patellar hardware. Biomechanically, the mean strength and stiffness of the graft are very similar to those of the native MPFL. The anatomic and biomechanical advantages depend on correct identification of the anatomic superficial lamina of the quadriceps tendon; hence the correct harvesting technique for the superficial lamina is crucial. Various sub-techniques for harvesting the quadriceps graft have emerged recently, such as superficial strip, pedicled, or partial graft harvesting; these can create confusion for surgeons. Additional confusion related to the preparation and fixation of the graft should also be addressed to avoid any potential complications. A step-by-step video of the superficial quad technique is presented, covering the exact dissection of the graft material and its preparation, delivery, and fixation.

  7. Pre-calculation of the image quality of the simultaneous iterative reconstruction technique

    NASA Astrophysics Data System (ADS)

    Kunze, Holger; Härer, Wolfgang; Stierstorfer, Karl

    2007-03-01

    Iterative reconstruction methods possess many advantages over analytical reconstruction methods especially if constraints can be used to regularize the reconstruction. However the main problem of iterative reconstruction algorithms is to decide when to stop the iteration. For the Simultaneous Iterative Reconstruction Technique (SIRT) without constraints we derived a mathematical formula with which the quality of the reconstruction after a given number of iterations can be calculated. The image quality is expressed here by a special filter kernel for a FBP reconstruction which creates images with the same sharpness and noise properties as SIRT. Further on the formula can be used to analyze the numerical stability of a certain implementation of SIRT. Experiments show the validity of these "iteration-equivalent"-kernels with respect to sharpness and noise properties of the reconstructed images.

  8. Review of NASA ACLS research

    NASA Technical Reports Server (NTRS)

    Daugherty, R. H.

    1983-01-01

    An experimental investigation was conducted to evaluate a method of maintaining stability of an air cushion vehicle and also to evaluate several concepts to brake and steer an ACLS-equipped vehicle. The investigation used a modified airboat equipped with an air cushion landing system. The pressure relief door stability concept was characterized by the ACLS pressure time histories. The pressure relief doors vented excess cavity and lobe pressures and consistently maintained vehicle heave and pitch stability. Braking concepts were characterized by the average deceleration of the vehicle. Reduced lobe flow and cavity venting braking concepts were evaluated in this program. The cavity venting concept demonstrated the best performance, producing decelerations on the test vehicle on the same order as moderate braking with conventional wheel brakes. Steering concepts were evaluated by recording the path taken while attempting to follow a prescribed maneuver. The steering concepts evaluated included using rudders only, using differential lobe flow, and using rudders combined with a lightly loaded, nonsteering center wheel. The latter concept proved to be the most accurate means of steering the vehicle on the ACLS, producing translational deviations which, while two to three times higher than those from conventional nose gear steering, were still felt to provide reasonably precise steering control for this type vehicle.

  9. [Surgical reconstruction of maxillary defects using a computer-assisted techniques].

    PubMed

    Zhang, W B; Yu, Y; Wang, Y; Liu, X J; Mao, C; Guo, C B; Yu, G Y; Peng, X

    2017-02-18

    The maxilla is the most important bony support of the mid-face skeleton and is critical for both esthetics and function. Maxillary defects, resulting from tumor resection, can cause severe functional and cosmetic deformities. Furthermore, maxillary reconstruction presents a great challenge for oral and maxillofacial surgeons. Nowadays, vascularized composite bone flap transfer has been widely used for functional maxillary reconstruction. In the last decade, we have performed a comprehensive research on functional maxillary reconstruction with free fibula flap and reported excellent functional and acceptable esthetic results. However, this experience based clinical procedure still remainssome problems in accuracy and efficiency. In recent years, computer assisted techniques are now widely used in oral and maxillofacial surgery. We have performed a series of study on maxillary reconstruction with computer assisted techniques. The computer assisted techniques used for maxillary reconstruction mainly include: (1) Three dimensional (3D) reconstruction and tumor mapping: providing a 3D view of maxillary tumor and adjacent structures and helping to make the diagnosis of maxillary tumor accurate and objective; (2) Virtual planning: simulating tumor resection and maxillectomy as well as fibula reconstruction on the computer, so that to make an ideal surgical plan; (3) 3D printing: producing a 3D stereo model for prebending individualized titanium mesh and also providing template or cutting guide for the surgery; (4) Surgical navigation: the bridge between virtual plan and real surgery, confirming the virtual plan during the surgery and guarantee the accuracy; (5) Computer assisted analyzing and evaluating: making a quantitative and objective of the final result and evaluating the outcome. We also performed a series of studies to evaluate the application of computer assisted techniques used for maxillary reconstruction, including: (1) 3D tumor mapping technique for accurate

  10. Convergence rate calculation of simultaneous iterative reconstruction technique algorithm for diffuse optical tomography image reconstruction: A feasibility study

    NASA Astrophysics Data System (ADS)

    Chuang, Ching-Cheng; Tsai, Jui-che; Chen, Chung-Ming; Yu, Zong-Han; Sun, Chia-Wei

    2012-04-01

    Diffuse optical tomography (DOT) is an emerging technique for functional biological imaging. The imaging quality of DOT depends on the imaging reconstruction algorithm. The SIRT has been widely used for DOT image reconstruction but there is no criterion to truncate based on any kind of residual parameter. The iteration loops will always be decided by experimental rule. This work presents the CR calculation that can be great help for SIRT optimization. In this paper, four inhomogeneities with various shapes of absorption distributions are simulated as imaging targets. The images are reconstructed and analyzed based on the simultaneous iterative reconstruction technique (SIRT) method. For optimization between time consumption and imaging accuracy in reconstruction process, the numbers of iteration loop needed to be optimized with a criterion in algorithm, that is, the root mean square error (RMSE) should be minimized in limited iterations. For clinical applications of DOT, the RMSE cannot be obtained because the measured targets are unknown. Thus, the correlations between the RMSE and the convergence rate (CR) in SIRT algorithm are analyzed in this paper. From the simulation results, the parameter CR reveals the related RMSE value of reconstructed images. The CR calculation offers an optimized criterion of iteration process in SIRT algorithm for DOT imaging. Based on the result, the SIRT can be modified with CR calculation for self-optimization. CR reveals an indicator of SIRT image reconstruction in clinical DOT measurement. Based on the comparison result between RMSE and CR, a threshold value of CR (CRT) can offer an optimized number of iteration steps for DOT image reconstruction. This paper shows the feasibility study by utilizing CR criterion for SIRT in simulation and the clinical application of DOT measurement relies on further investigation.

  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. Unilateral Stance Strategies of Athletes With ACL Deficiency

    PubMed Central

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

    2013-01-01

    Aberrant movement strategies are characteristic of ACL-deficient athletes with recurrent knee instability (non-copers), and may instigate premature or accelerate joint degradation. Biomechanical evaluation of kinematic changes over time may elucidate noncopers’ responses to neuromuscular intervention and ACL reconstruction (ACLR). Forty noncopers were randomized into a perturbation group or a strength training only group. We evaluated the effects of perturbation training, and then gender on knee angle and tibial position during a unilateral standing task before and after ACLR. No statistically significant interactions were found. Before surgery, the strength training only group demonstrated knee angle asymmetry, but 6 months after ACLR, both groups presented with similar knee flexion between limbs. Aberrant and asymmetrical tibial position was found only in females following injury and ACLR. Neither treatment group showed distinct unilateral standing strategies following intervention; however, males and female noncopers appear to respond uniquely to physical therapy and surgery. PMID:22983931

  13. 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.

  14. Regularized versus non-regularized statistical reconstruction techniques

    NASA Astrophysics Data System (ADS)

    Denisova, N. V.

    2011-08-01

    An important feature of positron emission tomography (PET) and single photon emission computer tomography (SPECT) is the stochastic property of real clinical data. Statistical algorithms such as ordered subset-expectation maximization (OSEM) and maximum a posteriori (MAP) are a direct consequence of the stochastic nature of the data. The principal difference between these two algorithms is that OSEM is a non-regularized approach, while the MAP is a regularized algorithm. From the theoretical point of view, reconstruction problems belong to the class of ill-posed problems and should be considered using regularization. Regularization introduces an additional unknown regularization parameter into the reconstruction procedure as compared with non-regularized algorithms. However, a comparison of non-regularized OSEM and regularized MAP algorithms with fixed regularization parameters has shown very minor difference between reconstructions. This problem is analyzed in the present paper. To improve the reconstruction quality, a method of local regularization is proposed based on the spatially adaptive regularization parameter. The MAP algorithm with local regularization was tested in reconstruction of the Hoffman brain phantom.

  15. Functional Outcome of Transphyseal Reconstruction of the Anterior Cruciate Ligament in Skeletally Immature Patients

    PubMed Central

    Kim, Sung-Jae; Shim, Dong-Woo

    2012-01-01

    Purpose In anterior cruciate ligament (ACL) injury, conventional adult reconstruction techniques have to face the potential risk of growth disturbance or angular deformities in skeletally immature patients. The aim of this study was to evaluate the clinical outcomes of ACL reconstruction by conventional transphyseal tunnel technique. Materials and Methods On a retrospective basis, we reviewed 25 skeletally immature patients; all the patients showed skeletal maturity at last follow-up, and the mean age was 16.4 years. The average injury to surgery interval was 12.6 months. Clinical outcomes were assessed at a mean of 74.4 months postoperatively using the Lysholm Knee Scoring Scale, the Tegner activity level, the International Knee Documentation Committee (IKDC), and plain radiographs. Results All the patients had undergone transphyseal reconstruction of ACL. The mean Lysholm score was 48.36 points preoperatively and 93.32 points postoperatively; the mean Tegner activity level was changed from 3.0 points to 5.6 points. The mean IKDC level was categorized as C preoperatively and changed to A postoperatively. Conclusions Our midterm outcome at an average 6 years after surgery was satisfactory without significant leg length discrepancies or abnormal alignment of the knee joint. Transphyseal reconstruction of ACL is a good treatment modality in the skeletally immature patient. PMID:22977795

  16. Allergic reaction to biodegradable interference poly-L-lactic acid screws after anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft.

    PubMed

    Mastrokalos, Dimitrios S; Paessler, Hans H

    2008-06-01

    We report a case of a systemic allergic reaction to biodegradable poly-L-lactic acid (PLLA) interference screws after anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone graft. A 30-year-old patient complained of certain symptoms, such as an inability to focus mentally, rash on the right femur, chronic fatigue, decreased sex drive, and localized alopecia, 3 months after ACL reconstruction in the right knee. Two biodegradable PLLA interference screws had been used for proximal and distal graft fixation. Allergy testing showed a value of 7 in PLLA antigen. After removal of 1 screw in August 2000, the patient reported marked improvement, but some symptoms remained. In July 2001 he underwent arthroscopic revision ACL reconstruction with hamstrings via an implant-free technique with intensive debridement of the tunnels and removal of all scar tissue and screw rests. All symptoms disappeared, and the PLLA antigen number fell from 3 to "concentrate" 2 months postoperatively.

  17. A Comparative Animal Study of Tendon Grafts Healing After Remnant-Preserving Versus Conventional Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Zhang, Lei; Jiang, Kan; Chai, Hao; Zhou, Mei; Bai, Jingping

    2016-01-01

    Background The aim of this study was to determine if anterior cruciate ligament (ACL) reconstruction by remnant preservation promotes cell proliferation, vascularization, proprioception recovery, and improved biomechanical properties of the tendon grafts. Material/Methods 75 New Zealand rabbits were randomly assigned into the control group (group A), conventional ACL reconstruction group (group B), ACL reconstruction using remnant preservation and graft through remnant sleeve technique group (group C), and ACL reconstruction using remnant preservation and remnant tensioning technique group (group D). The remnant and healing of tendon grafts in groups C and D were observed at 3, 6, and 12 weeks after surgery, and the mRNA expression levels of VEGF, NT-3 and GAP-43 in ACL (group A) or tendon graft samples (groups B, C, and D) were determined by real-time PCR. Tendon graft cell count, microvessel density (MVD), and proprioceptors were determined by H&E staining, CD34, and S-100 immunohistochemical staining. The biomechanical properties of the tendon graft at week 12 in groups B, C, and D were examined by using a tensile strength test. Results Remnant and tendon grafts were not healed at 3, 6, and 12 weeks after the operation in groups C and D. VEGF, NT-3, and GAP-43 mRNA expressions in groups B, C, and D were higher than those in group A (P<0.05), but no significant difference was observed between groups B, C, and D (P>0.05). Furthermore, tendon graft cell count, MVD, proprioception, and biomechanical properties showed no significant differences (P>0.05) among groups B, C, and D at various time points. Conclusions There was no significant difference in cell proliferation, vascularization, proprioception recovery, or biomechanical properties of the tendon grafts between remnant-preserving and conventional ACL reconstruction methods. PMID:27669454

  18. All-Arthroscopic Technique for Reconstruction of Acute Acromioclavicular Joint Dislocations

    PubMed Central

    Cutbush, Kenneth; Hirpara, Kieran M.

    2015-01-01

    Acromioclavicular joint dislocations are a common injury particularly among contact sports players. There has been an increasing trend toward arthroscopic management of these injuries. To date, these reconstructions have primarily addressed superoinferior instability by reconstructing the coracoclavicular ligaments. We describe an all-arthroscopic technique for reconstruction of the coracoclavicular ligaments using Arthrex ABS TightRopes (Arthrex, Naples, FL), with additional stabilization of the superior acromioclavicular joint capsule using an anchor-based suture bridge to address anteroposterior instability. PMID:26697307

  19. Partial Breast Reconstruction with Goldilocks Technique After Excision of Giant Fibroadenoma: A Case Report

    PubMed Central

    Ter Louw, Ryan P.; Bruce, Sara B.

    2017-01-01

    Summary: Giant juvenile fibroadenomas are relatively rare, accounting for less than 1% fibroadenomas. Large breast tumors create significant asymmetry and provide unique reconstructive challenges after removal. In this case, we describe a 21-year-old female with delayed presentation of a giant fibroadenoma of the right breast. This represents an unusual presentation of benign breast disease requiring reduction of the skin envelope, extensive glandular resection, lower pole reconstruction, and free nipple grafting to achieve symmetry with the opposite breast. A novel modification of the Goldilocks mastectomy technique is described for partial breast reconstruction. Adaptation of the Goldilocks mastectomy technique provides adequate soft tissue for partial breast reconstruction. Using the lower pole deepithelialization breast skin flap provides autologous vascularized tissue to supplement volume loss after tumor and glandular excision. Benign breast disease can create significant breast deformities. Application and combination of the Goldilocks mastectomy technique allow for partial breast reconstruction without the need for an additional donor site or prosthetic devices. PMID:28203501

  20. Posteromedial Corner Reconstruction

    PubMed Central

    Ferrer, Gonzalo; Leon, Agustín; Wirth, Hans; Mena, Adolfo; Tuca, María José; Espinoza, Gonzalo

    2017-01-01

    Objective: Report the experience, after 1-year follow-up, of 30 patients who underwent anatomical knee reconstruction of posteromedial corner (PMC) injuries, using La Prade´s Technique. Methods: Retrospective cohort study of 30 consecutive patients with PMC injuries operated between November 2010 and May 2014 by the same surgical team. Inclusion criteria: patients with clinical presentation and images (stress radiographs and MRI) compatible with PMC injury, who maintained a grade III chronic instability in spite of at least 3 months of orthopedic treatment, who were reconstructed using La Prade’s anatomical technique, and completed at least 12 months of follow-up. Exclusion criteria: discordance between clinical and image studies, grade I or II medial instability, and surgery performed through a different technique. Data was collected by reviewing the electronic files and images. Functional scores (IKDC and Lysholm) were applied and registered in the preoperative evaluation, and then 6 and 12 months after surgery. Results: Thirty patients (28 men and 2 women) met the inclusion criteria. Mean age was 43 years (24-69). The vast majority (28 patients) had a high-energy mechanism of injury. Twenty patients were diagnosed in the acute setting, while 10 had a delayed diagnosis after poor results of concomitant ligament reconstructions. With the exception of 2 patients, who presented with isolated PMC injury, the majority had associated injuries as detailed: 11 cases had PMC + anterior cruciate ligament (ACL) injury, 3 patients had PMC + posterior cruciate ligament (PCL) injury, 3 patients had PMC + meniscal tears, 9 patients had PMC + ACL + PCL injuries, and there were 2 cases of PMC + ACL + PCL + lateral collateral ligament injuries. Mean time for PMC reconstruction surgery was 5 months (range 2-32). Lysholm and IKDC scores were 18,2 (2-69) and 24,3 (9,2-52,9) respectively in the preoperative setting, improving to 76,7 (44-94) and 70,7 (36,8-95,4) after 1-year follow

  1. Total Reconstruction of the Auricle: Our Experiences on Indications and Recent Techniques

    PubMed Central

    Storck, K.; Staudenmaier, R.; Buchberger, M.; Strenger, T.; Kreutzer, K.; von Bomhard, A.; Stark, T.

    2014-01-01

    Introduction. Auricular reconstruction is a great challenge in facial plastic surgery. With the advances in surgical techniques and biotechnology, different options are available for consideration. The aim of this paper is to review the knowledge about the various techniques for total auricular reconstruction based on the literature and our experience. Methods. Approximately 179 articles published from 1980 to 2013 were identified, and 59 articles were included. We have focused on the current status of total auricular reconstruction based on our personal experience and on papers of particular interest, published within the period of review. We have also included a prospective view on the tissue engineering of cartilage. Results. Most surgeons still practice total auricular reconstruction by employing techniques developed by Brent, Nagata, and Firmin with autologous rib cartilage. Within the last years, alloplastic frameworks for reconstruction have become well established. Choosing the reconstruction techniques depends mainly on the surgeon's preference and experience. Prosthetic reconstruction is still reserved for special conditions, even though the material is constantly improving. Tissue engineering has a growing potential for clinical applicability. Conclusion. Auricular reconstruction still receives attention of plastic/maxillofacial surgeons and otolaryngologists. Even though clinical applicability lags behind initial expectations, the development of tissue-engineered constructs continues its potential development. PMID:24822198

  2. Effect of ACL graft material on joint forces during a simulated in vivo motion in the porcine knee: examining force during the initial cycles.

    PubMed

    Boguszewski, Daniel V; Wagner, Christopher T; Butler, David L; Shearn, Jason T

    2014-11-01

    This study compared three-dimensional forces in knees containing anterior cruciate ligament (ACL) graft materials versus the native porcine ACL. A six-degree-of-freedom (DOF) robot simulated gait while recording the joint forces and moments. Knees were subjected to 10 cycles of simulated gait in intact, ACL-deficient, and ACL-reconstructed knee states to examine time zero biomechanical performance. Reconstruction was performed using bone-patellar tendon-bone allograft (BPTB), reconstructive porcine tissue matrix (RTM), and an RTM-polymer hybrid (Hybrid). Forces and moments were examined about anatomic DOFs throughout the gait cycle and at three key points during gait: heel strike (HS), mid stance (MS), toe off (TO). Compared to native ACL, each graft restored antero-posterior (A-P) forces throughout gait. However, all failed to mimic normal joint forces in other DOFs. For example, each reconstructed knee showed greater compressive forces at HS and TO compared to the native ACL knee. Overall, the Hybrid graft restored more of the native ACL forces following reconstruction than did BPTB, while RTM grafts were the least successful. If early onset osteoarthritis is in part caused by altered knee kinematics, then understanding how reconstruction materials restore critical force generation during gait is an essential step in improving a patient's long-term prognosis.

  3. Fast tokamak plasma flux and electron density reconstruction technique

    SciTech Connect

    Chiang, K.L.; Hallock, G.A.; Wootton, A.J.; Wang, L.

    1997-01-01

    Density profiles in TEXT-U are obtained using a vertical viewing far-infrared (FIR) interferometer. To obtain the local (inverted) density, we have developed a simple analytic model of the plasma equilibrium configuration which is faster than EFIT (a flux surface reconstruction program) and can be easily computed between discharges. This analytic solution of the Grad{endash}Shafranov equation is valid as long as the pressure p is a function of poloidal flux {psi}, i.e., p=p({psi}). The procedure incorporates both magnetic and FIR density data to solve the Grad{endash}Shafranov equation, and provides a density profile which is self-consistent with the reconstructed equilibrium flux surfaces. Examples are presented. {copyright} {ital 1997 American Institute of Physics.}

  4. Studies in Interactive Techniques and Systems for Reconstruction of Fleet Exercise.

    DTIC Science & Technology

    general performance, design, development and test requirements study for the Fleet Analysis and Reconstruction of Exercise Facility (FAREF); and research and testing of interactive techniques and computer algorithms . (Author)

  5. Simultaneous iterative reconstruction technique for diffuse optical tomography imaging: iteration criterion and image recognition

    NASA Astrophysics Data System (ADS)

    Yu, Zong-Han; Wu, Chun-Ming; Lin, Yo-Wei; Chuang, Ming-Lung; Tsai, Jui-che; Sun, Chia-Wei

    2008-02-01

    Diffuse optical tomography (DOT) is an emerging technique for biomedical imaging. The imaging quality of the DOT strongly depends on the reconstruction algorithm. In this paper, four inhomogeneities with various shapes of absorption distributions are simulated by a continues-wave DOT system. The DOT images are obtained based on the simultaneous iterative reconstruction technique (SIRT) method. To solve the trade-off problem between time consumption of reconstruction process and accuracy of reconstructed image, the iteration process needs a optimization criterion in algorithm. In this paper, the comparison between the root mean square error (RMSE) and the convergence rate (CR) in SIRT algorithm are demonstrated. From the simulation results, the CR reveals the information of global minimum in the iteration process. Based on the CR calculation, the SIRT can offer higher efficient image reconstructing in DOT system.

  6. ACLS.

    PubMed

    Handley, A J

    2001-09-01

    It must be emphasised that the published International Guidelines 2000 contain an in-depth presentation of the scientific evidence behind advanced life support. The exact interpretation of this evidence, and the algorithms adopted by a national resuscitation council will depend upon various factors such as local interpretation of the evidence, local practice and availability of drugs. The ERC is publishing its own summaries of the guideline changes and the sequences of action for both BLS and ALS and these papers are recommended for further reading.

  7. Comparison of ACL strain estimated via a data-driven model with in vitro measurements.

    PubMed

    Weinhandl, Joshua T; Hoch, Matthew C; Bawab, Sebastian Y; Ringleb, Stacie I

    2016-11-01

    Computer modeling and simulation techniques have been increasingly used to investigate anterior cruciate ligament (ACL) loading during dynamic activities in an attempt to improve our understanding of injury mechanisms and development of injury prevention programs. However, the accuracy of many of these models remains unknown and thus the purpose of this study was to compare estimates of ACL strain from a previously developed three-dimensional, data-driven model with those obtained via in vitro measurements. ACL strain was measured as the knee was cycled from approximately 10° to 120° of flexion at 20 deg s(-1) with static loads of 100, 50, and 50 N applied to the quadriceps, biceps femoris and medial hamstrings (semimembranosus and semitendinosus) tendons, respectively. A two segment, five-degree-of-freedom musculoskeletal knee model was then scaled to match the cadaver's anthropometry and in silico ACL strains were then determined based on the knee joint kinematics and moments of force. Maximum and minimum ACL strains estimated in silico were within 0.2 and 0.42% of that measured in vitro, respectively. Additionally, the model estimated ACL strain with a bias (mean difference) of -0.03% and dynamic accuracy (rms error) of 0.36% across the flexion-extension cycle. These preliminary results suggest that the proposed model was capable of estimating ACL strains during a simple flexion-extension cycle. Future studies should validate the model under more dynamic conditions with variable muscle loading. This model could then be used to estimate ACL strains during dynamic sporting activities where ACL injuries are more common.

  8. Image reconstruction using wavelet multi-resolution technique for time-domain diffuse optical tomography

    NASA Astrophysics Data System (ADS)

    Yang, Fang; Gao, Feng; Jiao, Yuting; Zhao, Huijuan

    2010-02-01

    It is generally believed that the inverse problem in diffuse optical tomography (DOT) is highly ill-posed and its solution is always under-determined and sensitive to noise, which is the main problem in the application of DOT. In this paper, we propose a method on image reconstruction for time-domain diffuse optical tomography based on panel detection and Finite-Difference Method, and introduce an approach to reduce the number of unknown parameters in the reconstruction process. We propose a multi-level scheme to reduce the number of unknowns by parameterizing the spatial distribution of optical properties via wavelet transform and then reconstruct the coefficients of this transform. Compared with previous traditional uni-level full spatial domain algorithm, this method can efficiently improve the reconstruction quality. Numerical simulations show that wavelet-based multi-level inversion is superior to the uni-level algebraic reconstruction technique.

  9. Sibship reconstruction in hierarchical population structures using Markov chain Monte Carlo techniques.

    PubMed

    Thomas, Stuart C; Hill, William G

    2002-06-01

    Markov chain Monte Carlo procedures allow the reconstruction of full-sibships using data from genetic marker loci only. In this study, these techniques are extended to allow the reconstruction of nested full- within half-sib families, and to present an efficient method for calculating the likelihood of the observed marker data in a nested family. Simulation is used to examine the properties of the reconstructed sibships, and of estimates of heritability and common environmental variance of quantitative traits obtained from those populations. Accuracy of reconstruction increases with increasing marker information and with increasing size of the nested full-sibships, but decreases with increasing population size. Estimates of variance component are biased, with the direction and magnitude of bias being dependent upon the underlying errors made during pedigree reconstruction.

  10. Exploring Childhood Memories with Adult Survivors of Sexual Abuse: Concrete Reconstruction and Visualization Techniques.

    ERIC Educational Resources Information Center

    Roland, Catherine B.

    1993-01-01

    Describes two memory-enhancing techniques, visualization and concrete reconstruction, that have been successful in counseling adult survivors of sexual abuse. Includes suggested implementations, case examples, and implications for incorporating memory techniques into counseling process. Describes various risk factors involved in using these…

  11. Reconstruction of elongated bubbles fusing the information from multiple optical probes through a Bayesian inference technique

    NASA Astrophysics Data System (ADS)

    Chakraborty, Shubhankar; Roy Chaudhuri, Partha; Das, Prasanta Kr.

    2016-07-01

    In this communication, a novel optical technique has been proposed for the reconstruction of the shape of a Taylor bubble using measurements from multiple arrays of optical sensors. The deviation of an optical beam passing through the bubble depends on the contour of bubble surface. A theoretical model of the deviation of a beam during the traverse of a Taylor bubble through it has been developed. Using this model and the time history of the deviation captured by the sensor array, the bubble shape has been reconstructed. The reconstruction has been performed using an inverse algorithm based on Bayesian inference technique and Markov chain Monte Carlo sampling algorithm. The reconstructed nose shape has been compared with the true shape, extracted through image processing of high speed images. Finally, an error analysis has been performed to pinpoint the sources of the errors.

  12. Stochastic mass-reconstruction: a new technique to reconstruct resonance masses of heavy particles decaying into tau lepton pairs

    SciTech Connect

    Maruyama, Sho

    2015-12-15

    The invariant mass of tau lepton pairs turns out to be smaller than the resonant mass of their mother particle and the invariant mass distribution is stretched wider than the width of the resonant mass as significant fraction of tau lepton momenta are carried away by neutrinos escaping undetected at collider experiments. This paper describes a new approach to reconstruct resonant masses of heavy particles decaying to tau leptons at such experiments. A typical example is a Z or Higgs boson decaying to a tau pair. Although the new technique can be used for each tau lepton separately, I combine two tau leptons to improve mass resolution by requiring the two tau leptons are lined up in a transverse plane. The method is simple to implement and complementary to the collinear approximation technique that works well when tau leptons are not lined up in a transverse plane. The reconstructed mass can be used as another variable in analyses that already use a visible tau pair mass and missing transverse momentum as these variables are not explicitly used in the stochastic mass-reconstruction to select signal-like events.

  13. 50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... detailed review of fishery performance relative to the sector ACLs at least every 5 years. (1) If the ACL... recommendations to the MAFMC for changes in measures intended to ensure ACLs are not as frequently exceeded. (2...) Performance reviews shall not substitute for annual reviews that occur to ascertain if prior year ACLs...

  14. 50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... detailed review of fishery performance relative to the sector ACLs at least every 5 years. (1) If the ACL... recommendations to the MAFMC for changes in measures intended to ensure ACLs are not as frequently exceeded. (2...) Performance reviews shall not substitute for annual reviews that occur to ascertain if prior year ACLs...

  15. 50 CFR 648.290 - Tilefish Annual Catch Limit (ACL).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... detailed review of fishery performance relative to the sector ACLs at least every 5 years. (1) If the ACL... recommendations to the MAFMC for changes in measures intended to ensure ACLs are not as frequently exceeded. (2...) Performance reviews shall not substitute for annual reviews that occur to ascertain if prior year ACLs...

  16. Compartment pressure monitoring during anterior cruciate ligament reconstruction.

    PubMed

    Amendola, A; Faber, K; Willits, K; Miniaci, A; Labib, S; Fowler, P

    1999-09-01

    A prospective double blind randomized study was carried out using 20 healthy males with anterior cruciate ligament (ACL) insufficiency undergoing bone-patellar tendon-bone ACL reconstruction. The subjects were randomized into either water or saline irrigation and then underwent identical reconstructive procedures using an arthroscopic pump. Continuous preoperative, intraoperative, and postoperative pressures were monitored using the slit catheter technique. Blood pressure and compartment pressure measurements were continuously recorded and noted at all stages of the procedure. Mean preoperative anterior and posterior compartment pressures were similar in both groups. No significant differences were noted between the anterior and posterior compartments of each group. No difference between water and saline irrigation was identified throughout the procedure. In both groups, postoperative pressures were slightly lower in the anterior and posterior compartments compared with preoperative pressures, but not significantly.

  17. Selection of Tendon Grafts for Distal Radioulnar Ligament Reconstruction and Report of a Modified Technique

    PubMed Central

    Jang, Eugene; Dy, Christopher J.

    2014-01-01

    Purpose To investigate the graft length necessary to complete a distal radioulnar ligament reconstruction and assess the suitability of several tendon graft sources. Methods We measured the graft length needed to complete the distal radioulnar ligament reconstruction in 7 fresh-frozen cadaver specimens. The pure tendon lengths of 7 tendon graft sources were measured: palmaris longus, extensor indicis proprius, slips of extensor digiti minimi and abductor pollicis longus, and portions of flexor carpi ulnaris, flexor carpi radialis, and extensor carpi ulnaris. A modified technique which allows for a shorter length of graft is also described, and the suitability of each graft source for this technique was assessed. Results The mean graft length needed to complete the original and modified reconstructions were 138 mm and 89 mm, respectively. The average length of the tendon graft when measured as pure tendon were: palmaris longus (127 mm), slip of extensor digiti minimi (112 mm), extensor indicis proprius (100 mm), partial flexor carpi radialis (87 mm), slip of abductor pollicis longus (69 mm), partial flexor carpi ulnaris (67 mm), and partial extensor carpi ulnaris (67 mm). The palmaris longus was too short for the original technique in the majority of specimens but was sufficient to complete the modified technique in every specimen that had a palmaris longus. Six specimens also had an extensor indicis proprius of suitable length for the modified technique. Discussion The length of donor graft required for the modified reconstruction was significantly less than that needed for the original reconstruction. Three specimens had no donor tendons sufficiently long to complete the original technique if a pure tendon graft were used, whereas the modified technique could be completed in all specimens. Clinical Relevance Many tendon graft sources in the upper extremity are of insufficient length to complete the distal radioulnar ligament reconstruction as described. A modified

  18. Reconstruction of an Extensive Midfacial Defect Using Additive Manufacturing Techniques.

    PubMed

    Fernandes, Nelson; van den Heever, Jacobus; Hoogendijk, Christiaan; Botha, Sarel; Booysen, Gerrie; Els, Johan

    2016-10-01

    Malignant peripheral nerve sheath tumors are extremely rare tumors arising in peripheral nerves. Only 17 cases involving the trigeminal nerve have ever been reported. These tumors have a very poor prognosis and very high rates of recurrence and metastases. Their recommended treatment involves complete tumor resection followed by radiation. This can be problematic in the head and neck region. We present a clinical case involving a 33-year-old female patient presenting with a slow-growing, exophytic mass of the anterior maxilla. Incisional biopsy and subsequent histological examination revealed a diagnosis of a malignant peripheral nerve sheath tumor. Surgical resection involved a complete maxillectomy, rhinectomy, and resection of the upper lip and aspects of the left and right cheeks. Reconstruction of the subsequent defect incorporated the placement of four zygomatic oncology implants to aid in retention of a facial prosthesis. These implants, however, were subsequently lost; and an anatomical model of the hard tissues was manufactured via 3D printing. This model was used to design and manufacture a titanium frame (customized implant) for the patient. The frame was then fixated and secured intraoperatively with 21 cortical screws. A maxillary denture and silicone facial prosthesis were also made to fit onto this frame. This is the first known case where additive manufacturing, via the use of rapid prototyping and 3D printing, was employed to manufacture a facial prosthesis.

  19. Dynamic medial patellofemoral ligament reconstruction in recurrent patellar instability: A surgical technique

    PubMed Central

    Kiran, Kopuri Ravi; Srikanth, I Muni; Chinnusamy, Lenin; Deepti, K

    2015-01-01

    The medial patellofemoral ligament (MPFL) is the primary stabilizer of the patellofemoral joint; its reconstruction has been recommended in adults over the past decade after recurrent patellar instability. However, there has been no standardized technique for reconstruction, therefore, ideal graft and technique for reconstruction are yet undetermined. However, dynamic MPFL reconstruction studies claim to be superior to other procedures as it is more anatomical. This preliminary study aims at assessing the outcomes of MPFL reconstruction in a dynamic pattern using hamstring graft. We performed this procedure in four consecutive patients with chronic patellar instability following trauma. MPFL reconstruction was done with hamstring tendons detached distally and secured to patellar periosteum after being passed through a bony tunnel in the patella without an implant and using the medial collateral ligament as a pulley. In all 4 knees, the MPFL reconstruction was isolated and was not associated with any other realignment procedures. No recurrent episodes of dislocation or subluxation were reported at 24 months followup. PMID:26806970

  20. Three-dimensional magnetic field determination in magnetic nanoparticles using iterative reconstruction techniques

    NASA Astrophysics Data System (ADS)

    Humphrey, Emma Margaret

    Improving processing methods have consistently decreased the length scales of many magnetic devices. Methods to quantify the physical and magnetic domain structure of magnetic materials are needed to optimize their performance. However, magnetic characterization methods typically only measure one or two components of the magnetic properties. For instance, Lorentz microscopy is used to construct a two-dimensional projection of the magnetic induction. The vector field electron tomography (VFET) method uses Lorentz microscopy and tomography techniques to reconstruct the three-dimensional magnetic induction and magnetic vector potential of a sample. However, these reconstructions suffer from errors due to factors such as missing wedge information due to the nature of the samples and the physical constraints of the transmission electron microscope. Iterative tomographic techniques and the use of prior knowledge have been used in the literature to compensate for missing wedge data. In this work, we present several tools to construct iterative VFET (IVFET) algorithms. The iterative tomography algorithms Simultaneous Iterative Reconstruction Technique (SIRT), Discrete Algebraic Reconstruction Technique (DART), and Model-Based Iterative Reconstruction (MBIR) are summarized, and their relative merits are discussed. A novel approach to solving the Transport of Intensity Equation (TIE) that incorporates phase separation is presented, along with a comparison to the standard method. A model for simulating VFET images of a chain of nanoparticles and tomographic reconstructions using the model are shown. A spherical voxel forward projection model that can be used to update a single voxel of a VFET reconstruction and its projections is presented as a method for updating the reconstruction during iterative tomography.

  1. Bilateral phalangeal fillet technique for metacarpal pad reconstruction in a dog

    PubMed Central

    Shaw, Tania; James, Fleur; Beierer, Lucas; Hosgood, Giselle

    2014-01-01

    Loss of the metacarpal or metatarsal pad requires reconstruction with other pad tissue to allow functional weight-bearing on the limb. This report describes the use of a bilateral phalangeal fillet technique to reconstruct a weight-bearing surface in a dog following complete excision of its right metacarpal pad for malignant melanoma. This resulted in a functional weight-bearing limb. PMID:25320383

  2. Hip Labral Reconstruction: The "Kite Technique" for Improved Efficiency and Graft Control.

    PubMed

    Bhatia, Sanjeev; Chahla, Jorge; Dean, Chase S; Ellman, Michael B

    2016-04-01

    Although the merits of labral reconstruction have been well established, the technical difficulty of presently used reconstruction techniques-particularly with graft passage and fixation-limit its efficacy and potentiates the risk of iatrogenic damage within the hip joint. The unwieldy nature of a floating labral graft anchored on one end may impede accurate fixation of the other end, which is critical for restoration of the fluid hip seal and preservation of graft integrity. In this technique narrative, we present a "kite technique" for introduction, control, and efficient fixation of a labral reconstruction graft. The principles of this method are founded on the belief that a soft-tissue graft in an arthroscopic environment is much easier to guide into position with 2 control sutures using a pulley system similar to flying a kite with 2 fly lines. Although we herein detail the technique as it applies to labral reconstruction in the hip, the concept of the kite technique may also be employed in arthroscopic-assisted soft-tissue reconstructions of other joints.

  3. Computer-Assisted Mandibular Reconstruction using a Patient-Specific Reconstruction Plate Fabricated with Computer-Aided Design and Manufacturing Techniques.

    PubMed

    Wilde, Frank; Cornelius, Carl-Peter; Schramm, Alexander

    2014-06-01

    We investigated the workflow of computer-assisted mandibular reconstruction that was performed with a patient-specific mandibular reconstruction plate fabricated with computer-aided design and computer-aided manufacturing (CAD/CAM) techniques and a fibula flap. We assessed the feasibility of this technique from virtual planning to the completion of surgery. Computed tomography (CT) scans of a cadaveric skull and fibula were obtained for the virtual simulation of mandibular resection and reconstruction using ProPlan CMF software (Materialise(®)/DePuy Synthes(®)). The virtual model of the reconstructed mandible provided the basis for the computer-aided design of a patient-specific reconstruction plate that was milled from titanium using a five-axis milling machine and CAM techniques. CAD/CAM techniques were used for producing resection guides for mandibular resection and cutting guides for harvesting a fibula flap. Mandibular reconstruction was simulated in a cadaveric wet laboratory. No problems were encountered during the procedure. The plate was fixed accurately to the residual bone without difficulty. The fibula segments were attached to the plate rapidly and reliably. The fusion of preoperative and postoperative CT datasets demonstrated high reconstruction precision. Computer-assisted mandibular reconstruction with CAD/CAM-fabricated patient-specific reconstruction plates appears to be a promising approach for mandibular reconstruction. Clinical trials are required to determine whether these promising results can be translated into successful practice and what further developments are needed.

  4. Quadriceps Muscle Function After Rehabilitation With Cryotherapy in Patients With Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Hart, Joseph M.; Kuenze, Christopher M.; Diduch, David R.; Ingersoll, Christopher D.

    2014-01-01

    Context: Persistent muscle weakness after anterior cruciate ligament (ACL) reconstruction may be due to underlying activation failure and arthrogenic muscle inhibition (AMI). Knee-joint cryotherapy has been shown to improve quadriceps function transiently in those with AMI, thereby providing an opportunity to improve quadriceps muscle activation and strength in patients with a reconstructed ACL. Objective: To compare quadriceps muscle function in patients with a reconstructed ACL who completed a 2-week intervention including daily cryotherapy (ice bag), daily exercises, or both. Design: Cross-sectional study. Setting: Laboratory. Patients or Other Participants: A total of 30 patients with reconstructed ACLs who were at least 6 months post-index surgery and had measurable quadriceps AMI. Intervention(s): The patients attended 4 supervised visits over a 2-week period. They were randomly assigned to receive 20 minutes of knee-joint cryotherapy, 1 hour of therapeutic rehabilitation exercises, or cryotherapy followed by exercises. Main Outcome Measure(s): We measured quadriceps Hoffmann reflex, normalized maximal voluntary isometric contraction torque, central activation ratio using the superimposed-burst technique, and patient-reported outcomes before and after the intervention period. Results: After the 2-week intervention period, patients who performed rehabilitation exercises immediately after cryotherapy had higher normalized maximal voluntary isometric contraction torques (P = .002, Cohen d effect size = 1.4) compared with those who received cryotherapy alone (P = .16, d = 0.58) or performed exercise alone (P = .16, d = 0.30). Conclusions: After ACL reconstruction, patients with AMI who performed rehabilitation exercises immediately after cryotherapy experienced greater strength gains than those who performed cryotherapy or exercises alone. PMID:25299442

  5. Comparative validation of single-shot optical techniques for laparoscopic 3-D surface reconstruction.

    PubMed

    Maier-Hein, L; Groch, A; Bartoli, A; Bodenstedt, S; Boissonnat, G; Chang, P-L; Clancy, N T; Elson, D S; Haase, S; Heim, E; Hornegger, J; Jannin, P; Kenngott, H; Kilgus, T; Müller-Stich, B; Oladokun, D; Röhl, S; Dos Santos, T R; Schlemmer, H-P; Seitel, A; Speidel, S; Wagner, M; Stoyanov, D

    2014-10-01

    Intra-operative imaging techniques for obtaining the shape and morphology of soft-tissue surfaces in vivo are a key enabling technology for advanced surgical systems. Different optical techniques for 3-D surface reconstruction in laparoscopy have been proposed, however, so far no quantitative and comparative validation has been performed. Furthermore, robustness of the methods to clinically important factors like smoke or bleeding has not yet been assessed. To address these issues, we have formed a joint international initiative with the aim of validating different state-of-the-art passive and active reconstruction methods in a comparative manner. In this comprehensive in vitro study, we investigated reconstruction accuracy using different organs with various shape and texture and also tested reconstruction robustness with respect to a number of factors like the pose of the endoscope as well as the amount of blood or smoke present in the scene. The study suggests complementary advantages of the different techniques with respect to accuracy, robustness, point density, hardware complexity and computation time. While reconstruction accuracy under ideal conditions was generally high, robustness is a remaining issue to be addressed. Future work should include sensor fusion and in vivo validation studies in a specific clinical context. To trigger further research in surface reconstruction, stereoscopic data of the study will be made publically available at www.open-CAS.com upon publication of the paper.

  6. A facial reconstruction and identification technique for seriously devastating head wounds.

    PubMed

    Joukal, Marek; Frišhons, Jan

    2015-07-01

    Many authors have focused on facial identification techniques, and facial reconstructions for cases when skulls have been found are especially well known. However, a standardized facial identification technique for an unknown body with seriously devastating head injuries has not yet been developed. A reconstruction and identification technique was used in 7 cases of accidents involving trains striking pedestrians. This identification technique is based on the removal of skull bone fragments, subsequent fixation of soft tissue onto a universal commercial polystyrene head model, precise suture of dermatomuscular flaps, and definitive adjustment using cosmetic treatments. After reconstruction, identifying marks such as scars, eyebrows, facial lines, facial hair and partly hairstyle become evident. It is then possible to present a modified picture of the reconstructed face to relatives. After comparing the results with photos of the person before death, this technique has proven to be very useful for identifying unknown bodies when other identification techniques are not available. This technique is useful for its being rather quick and especially for its results.

  7. Current concept in dysplastic hip arthroplasty: Techniques for acetabular and femoral reconstruction

    PubMed Central

    Bicanic, Goran; Barbaric, Katarina; Bohacek, Ivan; Aljinovic, Ana; Delimar, Domagoj

    2014-01-01

    Adult patients with developmental dysplasia of the hip develop secondary osteoarthritis and eventually end up with total hip arthroplasty (THA) at younger age. Because of altered anatomy of dysplastic hips, THA in these patients represents technically demanding procedure. Distorted anatomy of the acetabulum and proximal femur together with conjoined leg length discrepancy present major challenges during performing THA in patients with developmental dysplasia of the hip. In addition, most patients are at younger age, therefore, soft tissue balance is of great importance (especially the need to preserve the continuity of abductors) to maximise postoperative functional result. In this paper we present a variety of surgical techniques available for THA in dysplastic hips, their advantages and disadvantages. For acetabular reconstruction following techniques are described: Standard metal augments (prefabricated), Custom made acetabular augments (3D printing), Roof reconstruction with vascularized fibula, Roof reconstruction with pedicled iliac graft, Roof reconstruction with autologous bone graft, Roof reconstruction with homologous bone graft, Roof reconstruction with auto/homologous spongious bone, Reinforcement ring with the hook in combination with autologous graft augmentation, Cranial positioning of the acetabulum, Medial protrusion technique (cotyloplasty) with chisel, Medial protrusion technique (cotyloplasty) with reaming, Cotyloplasty without spongioplasty. For femoral reconstruction following techniques were described: Distraction with external fixator, Femoral shortening through a modified lateral approach, Transtrochanteric osteotomies, Paavilainen osteotomy, Lesser trochanter osteotomy, Double-chevron osteotomy, Subtrochanteric osteotomies, Diaphyseal osteotomies, Distal femoral osteotomies. At the end we present author’s treatment method of choice: for acetabulum we perform cotyloplasty leaving only paper-thin medial wall, which we break during

  8. Relationship of ACL Injury and Posterior Tibial Slope With Patient Age, Sex, and Race

    PubMed Central

    Waiwaiole, Alana; Gurbani, Ajay; Motamedi, Kambiz; Seeger, Leanne; Sim, Myung Shin; Nwajuaku, Patricia; Hame, Sharon L.

    2016-01-01

    Background: Posterior tibial slope (PTS) has been proposed as a potential risk factor for anterior cruciate ligament (ACL) injury; however, studies that have examined this relationship have provided inconclusive and sometimes contradictory results. Further characterization of this relationship may enable the medical community to identify individuals at greater risk for ACL injury and possibly characterize an anatomic target during surgical reconstruction. Purpose: The primary goal was to investigate the relationship between PTS and ACL injury. The secondary goal was to determine whether there are any patient factors, such as age, race, or sex, that correlate with ACL injury and PTS. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Medical records of 221 patients who underwent magnetic resonance imaging (MRI) of the knee between January 2003 and December 2009 were reviewed. Patients were separated into 2 groups: a study group of those subjects who had undergone surgery for ACL injury (n = 107) and a control group of patients diagnosed with patellofemoral syndrome (n = 114). Demographic data were collected, and MRI images from both groups were analyzed using imaging software to obtain medial and lateral tibial slope measurements. Data were then analyzed using analysis of variance (ANOVA) comparison and a multivariable regression model to determine which, if any, patient factors were related to probability of having an ACL injury. Results: ANOVA comparison demonstrated that the study group had significantly greater values for lateral PTS (6° ± 4°; P < .001) and medial PTS (7° ± 4°; P = .002) compared with controls (5° ± 3° and 5° ± 4°, respectively). After stepwise elimination of nonsignificant variables, the final multivariable logistic regression model determined that age (odds ratio [OR], 0.94; P < .001) and lateral PTS (OR, 1.12; P = .002) had statistically significant relationships with ACL injury. Medial PTS, race, and sex were not

  9. An Athlete's Nightmare: Tearing the ACL

    MedlinePlus

    ... women's knees tends to bend inward when women land." Some researchers believe that this inward bend may ... any athlete suffers ACL damage is because they land in a flat-footed position, as opposed to ...

  10. Establishing the skill of climate field reconstruction techniques for precipitation with pseudoproxy experiments

    NASA Astrophysics Data System (ADS)

    Gómez-Navarro, Juan José; Werner, Johannes; Wagner, Sebastian; Luterbacher, Jürg; Zorita, Eduardo

    2015-09-01

    This study aims at assessing the skill of several climate field reconstruction techniques (CFR) to reconstruct past precipitation over continental Europe and the Mediterranean at seasonal time scales over the last two millennia from proxy records. A number of pseudoproxy experiments are performed within the virtual reality of a regional paleoclimate simulation at 45 km resolution to analyse different aspects of reconstruction skill. Canonical Correlation Analysis (CCA), two versions of an Analog Method (AM) and Bayesian hierarchical modeling (BHM) are applied to reconstruct precipitation from a synthetic network of pseudoproxies that are contaminated with various types of noise. The skill of the derived reconstructions is assessed through comparison with precipitation simulated by the regional climate model. Unlike BHM, CCA systematically underestimates the variance. The AM can be adjusted to overcome this shortcoming, presenting an intermediate behaviour between the two aforementioned techniques. However, a trade-off between reconstruction-target correlations and reconstructed variance is the drawback of all CFR techniques. CCA (BHM) presents the largest (lowest) skill in preserving the temporal evolution, whereas the AM can be tuned to reproduce better correlation at the expense of losing variance. While BHM has been shown to perform well for temperatures, it relies heavily on prescribed spatial correlation lengths. While this assumption is valid for temperature, it is hardly warranted for precipitation. In general, none of the methods outperforms the other. All experiments agree that a dense and regularly distributed proxy network is required to reconstruct precipitation accurately, reflecting its high spatial and temporal variability. This is especially true in summer, when a specifically short de-correlation distance from the proxy location is caused by localised summertime convective precipitation events.

  11. A comparison study of linear reconstruction techniques for diffuse optical tomographic imaging of absorption coefficient

    NASA Astrophysics Data System (ADS)

    Gaudette, Richard J.; Brooks, Dana H.; Di Marzio, Charles A.; Kilmer, Misha E.; Miller, Eric L.; Gaudette, Thomas; Boas, David A.

    2000-04-01

    We compare, through simulations, the performance of four linear algorithms for diffuse optical tomographic reconstruction of the three-dimensional distribution of absorption coefficient within a highly scattering medium using the diffuse photon density wave approximation. The simulation geometry consisted of a coplanar array of sources and detectors at the boundary of a half-space medium. The forward solution matrix is both underdetermined, because we estimate many more absorption coefficient voxels than we have measurements, and ill-conditioned, due to the ill-posedness of the inverse problem. We compare two algebraic techniques, ART and SIRT, and two subspace techniques, the truncated SVD and CG algorithms. We compare three-dimensional reconstructions with two-dimensional reconstructions which assume all inhomogeneities are confined to a known horizontal slab, and we consider two `object-based' error metrics in addition to mean square reconstruction error. We include a comparison using simulated data generated using a different FDFD method with the same inversion algorithms to indicate how our conclusions are affected in a somewhat more realistic scenario. Our results show that the subspace techniques are superior to the algebraic techniques in localization of inhomogeneities and estimation of their amplitude, that two-dimensional reconstructions are sensitive to underestimation of the object depth, and that an error measure based on a location parameter can be a useful complement to mean squared error.

  12. A novel data processing technique for image reconstruction of penumbral imaging

    NASA Astrophysics Data System (ADS)

    Xie, Hongwei; Li, Hongyun; Xu, Zeping; Song, Guzhou; Zhang, Faqiang; Zhou, Lin

    2011-06-01

    CT image reconstruction technique was applied to the data processing of the penumbral imaging. Compared with other traditional processing techniques for penumbral coded pinhole image such as Wiener, Lucy-Richardson and blind technique, this approach is brand new. In this method, the coded aperture processing method was used for the first time independent to the point spread function of the image diagnostic system. In this way, the technical obstacles was overcome in the traditional coded pinhole image processing caused by the uncertainty of point spread function of the image diagnostic system. Then based on the theoretical study, the simulation of penumbral imaging and image reconstruction was carried out to provide fairly good results. While in the visible light experiment, the point source of light was used to irradiate a 5mm×5mm object after diffuse scattering and volume scattering. The penumbral imaging was made with aperture size of ~20mm. Finally, the CT image reconstruction technique was used for image reconstruction to provide a fairly good reconstruction result.

  13. Scapholunate interosseus ligament reconstruction on a cadaver: A technique

    PubMed Central

    Arenas-Prat, Joan

    2014-01-01

    Background: Acute rupture of the scapholunate interosseus ligament is a relatively frequent occurrence which can be repaired primarily by direct suturing. However, patients are often seen a few weeks after injury when most of the ligament fibers have degenerated. This poses a challenge because direct repair can be difficult and long term results have not been satisfying. In the present study, a technique is presented to address this problem and its possible advantages are discussed. Materials and Methods: A fresh frozen wrist cadaver specimen, thawed to room temperature, was used to carry out the procedure. The scapholunate joint was exposed through a dorsal approach and stabilized using two percutaneous Kirschner wires. Using a U shaped chisel, a groove along the scapholunate articular margin was created to accommodate a strip from the extensor retinaculum as a ligament plasty. This has been secured using six anchor sutures and several pictures taken during the procedure to expose the key steps. Results: The ligamentoplasty presented in this article preserves most of the articular surface of proximal carpus and at the same time stabilizes the scapholunate joint. However, more in vivo research should be carried out to validate this treatment. Conclusion: The technique suggests a possible way to repair a ruptured scapholunate interosseus ligament that cannot be repaired primarily. Because osteointegration of the ligament strips is not possible in the present experiment, biomechanics of the construct cannot be fully tested. PMID:25298562

  14. Non-contact ACL injuries in female athletes: an International Olympic Committee current concepts statement.

    PubMed

    Renstrom, P; Ljungqvist, A; Arendt, E; Beynnon, B; Fukubayashi, T; Garrett, W; Georgoulis, T; Hewett, T E; Johnson, R; Krosshaug, T; Mandelbaum, B; Micheli, L; Myklebust, G; Roos, E; Roos, H; Schamasch, P; Shultz, S; Werner, S; Wojtys, E; Engebretsen, L

    2008-06-01

    The incidence of anterior cruciate ligament (ACL) injury remains high in young athletes. Because female athletes have a much higher incidence of ACL injuries in sports such as basketball and team handball than male athletes, the IOC Medical Commission invited a multidisciplinary group of ACL expert clinicians and scientists to (1) review current evidence including data from the new Scandinavian ACL registries; (2) critically evaluate high-quality studies of injury mechanics; (3) consider the key elements of successful prevention programmes; (4) summarise clinical management including surgery and conservative management; and (5) identify areas for further research. Risk factors for female athletes suffering ACL injury include: (1) being in the preovulatory phase of the menstrual cycle compared with the postovulatory phase; (2) having decreased intercondylar notch width on plain radiography; and (3) developing increased knee abduction moment (a valgus intersegmental torque) during impact on landing. Well-designed injury prevention programmes reduce the risk of ACL for athletes, particularly women. These programmes attempt to alter dynamic loading of the tibiofemoral joint through neuromuscular and proprioceptive training. They emphasise proper landing and cutting techniques. This includes landing softly on the forefoot and rolling back to the rearfoot, engaging knee and hip flexion and, where possible, landing on two feet. Players are trained to avoid excessive dynamic valgus of the knee and to focus on the "knee over toe position" when cutting.

  15. Repair or Reconstruction in Acute Posterolateral Instability of the Knee: Decision Making and Surgical Technique Introduction.

    PubMed

    Stannard, James P; Stannard, James T; Cook, James L

    2015-12-01

    Complex knee injury surgeons must frequently decide whether to repair or reconstruct an acute posterolateral corner (PLC) injury. If repair is not feasible or fails, reconstruction is often necessary. Several studies have found that reconstruction has better outcomes and lower failure rates. Careful studies of the anatomy of the corner have led to the development of "two-tailed" reconstruction techniques which are becoming widely used in the field. Repair should not be completely disregarded as there are times when it is necessary, especially when no donor allograft tissue is readily available or when aggressive postoperative rehabilitation will not be performed. Optimally, if the patient has high quality tissue available for repair, it is best to combine reconstruction with repair. The authors have developed a new PLC reconstruction technique which applies the functional anatomy that has been increasingly defined. We detail these methods here, which include the use of cortical button suspensory fixation and interference screw fixation of allografts in sockets. This allows for individual and sequential intraoperative tensioning of the grafts to obtain optimal knee stability and motion.

  16. Development of Acoustic Model-Based Iterative Reconstruction Technique for Thick-Concrete Imaging

    SciTech Connect

    Almansouri, Hani; Clayton, Dwight A; Kisner, Roger A; Polsky, Yarom; Bouman, Charlie; Santos-Villalobos, Hector J

    2015-01-01

    Ultrasound signals have been used extensively for non-destructive evaluation (NDE). However, typical reconstruction techniques, such as the synthetic aperture focusing technique (SAFT), are limited to quasi-homogenous thin media. New ultrasonic systems and reconstruction algorithms are in need for one-sided NDE of non-homogenous thick objects. An application example space is imaging of reinforced concrete structures for commercial nuclear power plants (NPPs). These structures provide important foundation, support, shielding, and containment functions. Identification and management of aging and degradation of concrete structures is fundamental to the proposed long-term operation of NPPs. Another example is geothermal and oil/gas production wells. These multi-layered structures are composed of steel, cement, and several types of soil and rocks. Ultrasound systems with greater penetration range and image quality will allow for better monitoring of the well s health and prediction of high-pressure hydraulic fracturing of the rock. These application challenges need to be addressed with an integrated imaging approach, where the application, hardware, and reconstruction software are highly integrated and optimized. Therefore, we are developing an ultrasonic system with Model-Based Iterative Reconstruction (MBIR) as the image reconstruction backbone. As the first implementation of MBIR for ultrasonic signals, this paper document the first implementation of the algorithm and show reconstruction results for synthetically generated data.

  17. Development of Acoustic Model-Based Iterative Reconstruction Technique for Thick-Concrete Imaging

    SciTech Connect

    Almansouri, Hani; Clayton, Dwight A; Kisner, Roger A; Polsky, Yarom; Bouman, Charlie; Santos-Villalobos, Hector J

    2016-01-01

    Ultrasound signals have been used extensively for non-destructive evaluation (NDE). However, typical reconstruction techniques, such as the synthetic aperture focusing technique (SAFT), are limited to quasi-homogenous thin media. New ultrasonic systems and reconstruction algorithms are in need for one-sided NDE of non-homogenous thick objects. An application example space is imaging of reinforced concrete structures for commercial nuclear power plants (NPPs). These structures provide important foundation, support, shielding, and containment functions. Identification and management of aging and degradation of concrete structures is fundamental to the proposed long-term operation of NPPs. Another example is geothermal and oil/gas production wells. These multi-layered structures are composed of steel, cement, and several types of soil and rocks. Ultrasound systems with greater penetration range and image quality will allow for better monitoring of the well's health and prediction of high-pressure hydraulic fracturing of the rock. These application challenges need to be addressed with an integrated imaging approach, where the application, hardware, and reconstruction software are highly integrated and optimized. Therefore, we are developing an ultrasonic system with Model-Based Iterative Reconstruction (MBIR) as the image reconstruction backbone. As the first implementation of MBIR for ultrasonic signals, this paper document the first implementation of the algorithm and show reconstruction results for synthetically generated data.

  18. Development of acoustic model-based iterative reconstruction technique for thick-concrete imaging

    NASA Astrophysics Data System (ADS)

    Almansouri, Hani; Clayton, Dwight; Kisner, Roger; Polsky, Yarom; Bouman, Charles; Santos-Villalobos, Hector

    2016-02-01

    Ultrasound signals have been used extensively for non-destructive evaluation (NDE). However, typical reconstruction techniques, such as the synthetic aperture focusing technique (SAFT), are limited to quasi-homogenous thin media. New ultrasonic systems and reconstruction algorithms are in need for one-sided NDE of non-homogenous thick objects. An application example space is imaging of reinforced concrete structures for commercial nuclear power plants (NPPs). These structures provide important foundation, support, shielding, and containment functions. Identification and management of aging and degradation of concrete structures is fundamental to the proposed long-term operation of NPPs. Another example is geothermal and oil/gas production wells. These multi-layered structures are composed of steel, cement, and several types of soil and rocks. Ultrasound systems with greater penetration range and image quality will allow for better monitoring of the well's health and prediction of high-pressure hydraulic fracturing of the rock. These application challenges need to be addressed with an integrated imaging approach, where the application, hardware, and reconstruction software are highly integrated and optimized. Therefore, we are developing an ultrasonic system with Model-Based Iterative Reconstruction (MBIR) as the image reconstruction backbone. As the first implementation of MBIR for ultrasonic signals, this paper document the first implementation of the algorithm and show reconstruction results for synthetically generated data.1

  19. New signal processing technique for density profile reconstruction using reflectometry

    SciTech Connect

    Clairet, F.; Bottereau, C.; Ricaud, B.; Briolle, F.; Heuraux, S.

    2011-08-15

    Reflectometry profile measurement requires an accurate determination of the plasma reflected signal. Along with a good resolution and a high signal to noise ratio of the phase measurement, adequate data analysis is required. A new data processing based on time-frequency tomographic representation is used. It provides a clearer separation between multiple components and improves isolation of the relevant signals. In this paper, this data processing technique is applied to two sets of signals coming from two different reflectometer devices used on the Tore Supra tokamak. For the standard density profile reflectometry, it improves the initialization process and its reliability, providing a more accurate profile determination in the far scrape-off layer with density measurements as low as 10{sup 16} m{sup -1}. For a second reflectometer, which provides measurements in front of a lower hybrid launcher, this method improves the separation of the relevant plasma signal from multi-reflection processes due to the proximity of the plasma.

  20. Neural Excitability Alterations After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Pietrosimone, Brian G.; Lepley, Adam S.; Ericksen, Hayley M.; Clements, Amy; Sohn, David H.; Gribble, Phillip A.

    2015-01-01

    Context Neuromuscular dysfunction is common after anterior cruciate ligament reconstruction (ACL-R). However, little is known about quadriceps spinal-reflex and descending corticomotor excitability after ACL-R. Understanding the effects of ACL-R on spinal-reflex and corticomotor excitability will help elucidate the origins of neuromuscular dysfunction. Objective To determine whether spinal-reflex excitability and corticomotor excitability differed between the injured and uninjured limbs of patients with unilateral ACL-R and between these limbs and the matched limbs of healthy participants. Design Case-control study. Setting Laboratory. Patients or Other Participants A total of 28 patients with unilateral ACL-R (9 men, 19 women; age = 21.28 ± 3.79 years, height = 170.95 ± 10.04 cm, mass = 73.18 ± 18.02 kg, time after surgery = 48.10 ± 36.17 months) and 29 participants serving as healthy controls (9 men, 20 women; age = 21.55 ± 2.70 years, height = 170.59 ± 8.93 cm, mass = 71.89 ± 12.70 kg) volunteered. Main Outcome Measure(s) Active motor thresholds (AMTs) were collected from the vastus medialis (VM) using transcranial magnetic stimulation. We evaluated VM spinal reflexes using the Hoffmann reflex normalized to maximal muscle responses (H : M ratio). Voluntary quadriceps activation was measured with the superimposed-burst technique and calculated using the central activation ratio (CAR). We also evaluated whether ACL-R patients with high or low voluntary activation had different outcomes. Results The AMT was higher in the injured than in the uninjured limb in the ACL-R group (t27 = 3.32, P = .003) and in the matched limb of the control group (t55 = 2.05, P = .04). The H : M ratio was bilaterally higher in the ACL-R than the control group (F1,55 = 5.17, P = .03). The quadriceps CAR was bilaterally lower in the ACL-R compared with the control group (F1,55 = 10.5, P = .002). The ACL-R group with low voluntary activation (CAR < 0.95) had higher AMT than

  1. Fuzzy zoning for feature matching technique in 3D reconstruction of nasal endoscopic images.

    PubMed

    Rattanalappaiboon, Surapong; Bhongmakapat, Thongchai; Ritthipravat, Panrasee

    2015-12-01

    3D reconstruction from nasal endoscopic images greatly supports an otolaryngologist in examining nasal passages, mucosa, polyps, sinuses, and nasopharyx. In general, structure from motion is a popular technique. It consists of four main steps; (1) camera calibration, (2) feature extraction, (3) feature matching, and (4) 3D reconstruction. Scale Invariant Feature Transform (SIFT) algorithm is normally used for both feature extraction and feature matching. However, SIFT algorithm relatively consumes computational time particularly in the feature matching process because each feature in an image of interest is compared with all features in the subsequent image in order to find the best matched pair. A fuzzy zoning approach is developed for confining feature matching area. Matching between two corresponding features from different images can be efficiently performed. With this approach, it can greatly reduce the matching time. The proposed technique is tested with endoscopic images created from phantoms and compared with the original SIFT technique in terms of the matching time and average errors of the reconstructed models. Finally, original SIFT and the proposed fuzzy-based technique are applied to 3D model reconstruction of real nasal cavity based on images taken from a rigid nasal endoscope. The results showed that the fuzzy-based approach was significantly faster than traditional SIFT technique and provided similar quality of the 3D models. It could be used for creating a nasal cavity taken by a rigid nasal endoscope.

  2. Evaluating climate field reconstruction techniques using improved emulations of real-world conditions

    NASA Astrophysics Data System (ADS)

    Wang, J.; Emile-Geay, J.; Guillot, D.; Smerdon, J. E.; Rajaratnam, B.

    2014-01-01

    Pseudoproxy experiments (PPEs) have become an important framework for evaluating paleoclimate reconstruction methods. Most existing PPE studies assume constant proxy availability through time and uniform proxy quality across the pseudoproxy network. Real multiproxy networks are, however, marked by pronounced disparities in proxy quality, and a steep decline in proxy availability back in time, either of which may have large effects on reconstruction skill. A suite of PPEs constructed from a millennium-length general circulation model (GCM) simulation is thus designed to mimic these various real-world characteristics. The new pseudoproxy network is used to evaluate four climate field reconstruction (CFR) techniques: truncated total least squares embedded within the regularized EM (expectation-maximization) algorithm (RegEM-TTLS), the Mann et al. (2009) implementation of RegEM-TTLS (M09), canonical correlation analysis (CCA), and Gaussian graphical models embedded within RegEM (GraphEM). Each method's risk properties are also assessed via a 100-member noise ensemble. Contrary to expectation, it is found that reconstruction skill does not vary monotonically with proxy availability, but also is a function of the type and amplitude of climate variability (forced events vs. internal variability). The use of realistic spatiotemporal pseudoproxy characteristics also exposes large inter-method differences. Despite the comparable fidelity in reconstructing the global mean temperature, spatial skill varies considerably between CFR techniques. Both GraphEM and CCA efficiently exploit teleconnections, and produce consistent reconstructions across the ensemble. RegEM-TTLS and M09 appear advantageous for reconstructions on highly noisy data, but are subject to larger stochastic variations across different realizations of pseudoproxy noise. Results collectively highlight the importance of designing realistic pseudoproxy networks and implementing multiple noise realizations of PPEs

  3. 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.

  4. Development of a GNSS water vapour tomography system using algebraic reconstruction techniques

    NASA Astrophysics Data System (ADS)

    Bender, Michael; Dick, Galina; Ge, Maorong; Deng, Zhiguo; Wickert, Jens; Kahle, Hans-Gert; Raabe, Armin; Tetzlaff, Gerd

    2011-05-01

    A GNSS water vapour tomography system developed to reconstruct spatially resolved humidity fields in the troposphere is described. The tomography system was designed to process the slant path delays of about 270 German GNSS stations in near real-time with a temporal resolution of 30 min, a horizontal resolution of 40 km and a vertical resolution of 500 m or better. After a short introduction to the GPS slant delay processing the framework of the GNSS tomography is described in detail. Different implementations of the iterative algebraic reconstruction techniques (ART) used to invert the linear inverse problem are discussed. It was found that the multiplicative techniques (MART) provide the best results with least processing time, i.e., a tomographic reconstruction of about 26,000 slant delays on a 8280 cell grid can be obtained in less than 10 min. Different iterative reconstruction techniques are compared with respect to their convergence behaviour and some numerical parameters. The inversion can be considerably stabilized by using additional non-GNSS observations and implementing various constraints. Different strategies for initialising the tomography and utilizing extra information are discussed. At last an example of a reconstructed field of the wet refractivity is presented and compared to the corresponding distribution of the integrated water vapour, an analysis of a numerical weather model (COSMO-DE) and some radiosonde profiles.

  5. All-inside ACL: retroconstruction controversies.

    PubMed

    Lubowitz, James H

    2010-03-01

    All-inside anterior cruciate ligament reconstruction is controversial because the technique is new; as a result, evidence-based clinical outcome studies have yet to be published. The purpose of this article is to consider the following controversies (considered alphabetically): anatomy, biomechanics, biology, bioabsorbables, divergence of the femoral interference screw, expansion or widening of tunnels, fixation, future considerations, graft choice, the learning curve, technique, tensioning, and tibia blow-out fracture. The technique should be learned in stages. In the opinion of the author, the history of sports medicine and arthroscopy has been a progression toward less invasive techniques. In the future, all-inside anterior cruciate ligament reconstruction techniques should become more simple and reproducible, and clinical outcomes must be analyzed with long-term follow-up.

  6. [Technique and immediate results of the Moreno Gonzalez-Carboni reconstruction after total gastrectomy].

    PubMed

    Carboni, M; Catarci, M; Proposito, D; Saputelli, A; Zaraca, F; Gossetti, F; Flati, G; Guadagni, S; Tuscano, D; Negro, P

    1992-04-01

    Reconstruction following total gastrectomy for gastric cancer is still matter of debate. The Roux-en-Y esophagojejunostomy and the interposed loop esophago-jejunoduodenostomy are the techniques commonly employed. The Authors describe their modification of Henley's jejunal interposition and report early results achieved in a series of 60 consecutive patients.

  7. Reconstruction of a nonhealing lick granuloma in a dog using a phalangeal fillet technique.

    PubMed

    Demetriou, Jackie L; Shales, Christopher J; Hamilton, Michael H; Sissener, Thomas R

    2007-01-01

    A 6.5-year-old, castrated male Dalmatian was presented with a 3-month history of a chronic, nonhealing wound related to a previously excised lick granuloma. Reconstruction of the wound on the lateral metatarsal region was achieved using a phalangeal fillet technique, without digital pad transposition. The skin flap healed successfully with very good cosmetic and functional results.

  8. Fast and accurate computation of system matrix for area integral model-based algebraic reconstruction technique

    NASA Astrophysics Data System (ADS)

    Zhang, Shunli; Zhang, Dinghua; Gong, Hao; Ghasemalizadeh, Omid; Wang, Ge; Cao, Guohua

    2014-11-01

    Iterative algorithms, such as the algebraic reconstruction technique (ART), are popular for image reconstruction. For iterative reconstruction, the area integral model (AIM) is more accurate for better reconstruction quality than the line integral model (LIM). However, the computation of the system matrix for AIM is more complex and time-consuming than that for LIM. Here, we propose a fast and accurate method to compute the system matrix for AIM. First, we calculate the intersection of each boundary line of a narrow fan-beam with pixels in a recursive and efficient manner. Then, by grouping the beam-pixel intersection area into six types according to the slopes of the two boundary lines, we analytically compute the intersection area of the narrow fan-beam with the pixels in a simple algebraic fashion. Overall, experimental results show that our method is about three times faster than the Siddon algorithm and about two times faster than the distance-driven model (DDM) in computation of the system matrix. The reconstruction speed of our AIM-based ART is also faster than the LIM-based ART that uses the Siddon algorithm and DDM-based ART, for one iteration. The fast reconstruction speed of our method was accomplished without compromising the image quality.

  9. Nipple Reconstruction Using the C-V Flap Technique: Long-Term Outcomes and Patient Satisfaction

    PubMed Central

    Jalini, Lona; Lund, Jonathan; Kurup, Vijay

    2017-01-01

    BACKGROUND Nipple creation using the C-V flap technique is often the final step in breast reconstruction. The aim of this study was to subjectively and objectively assess the cosmetic outcomes and satisfaction of patients undergoing C-V flap nipple reconstruction. METHODS Subjective assessments of patient satisfaction with the neo-nipple were recorded by visual analogue scoring (VAS; 0-10). Objective measurements were performed using a calliper to measure nipple projection relative to the native breast. Descriptive data analysis was performed with differences in projection assessed with the Mann-Whitney test and mean and median VAS scores (with inter-quartile ranges; IQR) calculated to describe satisfaction. RESULTS Thirty-three C-V flap nipple reconstructions were performed. 87.9% received latissimus dorsi (LD) reconstructions with implants and 12.1% had transverse rectus abdominis muscle (TRAM) reconstructions. The median projection of reconstructed nipples was 4.7 mm (range 4-10.2 mm) at 4.6 years mean follow-up, which was not significantly different from the contralateral nipple (p = 0.34). Patient satisfaction was 9 (IQR: 8-10) with shape, 9 (IQR: 7.5-10) with projection, 5 (IQR: 2-9.6) with sensation, and 8.5 (IQR: 6-9.5) with symmetry. Median overall satisfaction was 9 (IQR: 8-10). Three patients had complete nipple loss, of whom two had undergone nipple piercing post procedure and none had received radiotherapy. CONCLUSION C-V flap nipple reconstructions provide a simple and reliable method to reconstruct the nipple that enhances confidence and perception of body image. Satisfaction was high with long-term outcomes in terms of projection equivalent to the contralateral breast. PMID:28289616

  10. Characterization of a constrained paired-view technique in iterative reconstruction for breast tomosynthesis

    SciTech Connect

    Wu, Gang; Yaffe, Martin J.; Mainprize, James G.

    2013-10-15

    Purpose: The order in which the projection views are employed in the reconstruction of tomosynthesis by iterative algorithms, such as simultaneous algebraic reconstruction technique and maximum likelihood, has a strong effect on the rate of convergence, accuracy, and the edge-blurring artifacts in the reconstructed image. The purpose of this investigation was to characterize and evaluate the effects of ordering schemes on image quality for breast tomosynthesis reconstruction and to explore a new constrained paired-view technique that could provide reduction of reconstruction artifacts. In this work, the authors compared several different ordering schemes and characterized the image quality and the formation of out-of-plane artifacts. Furthermore, a new normalization method is presented. It produces more accurate reconstructions with reduced artifacts comparing to the standard method of sequential ordering.Methods: In addition to visual assessment of image quality, several indices such as the signal-difference-to-noise ratio, the artifact-spread function, and the lesion detectability (d{sup ′}) were computed to quantitatively evaluate the effect of ordering scheme. The sets of breast tomosynthesis projection images were simulated for reconstruction; one set had uniform background (white noise only) and the other two contained both anatomic background and quantum noise. Clinical breast images were also studied for comparison.Results: The authors have quantified the image quality in reconstructed slices for a range of tumor sizes. The authors’ proposed method provides better performance for all of the metrics tested (contrast, d{sup ′}, and the level of artifacts) both for the uniform phantom case and in the presence of anatomical structure.Conclusions: The paired projection normalization provides better performance in the image quality of the reconstructed slices, and results in a lower level of artifacts in the Z direction. This implies that even a relatively

  11. A new ionospheric tomographic algorithm — constrained multiplicative algebraic reconstruction technique (CMART)

    NASA Astrophysics Data System (ADS)

    Wen, Debao; Liu, Sanzhi

    2010-08-01

    For the limitation of the conventional multiplicative algebraic reconstruction technique (MART), a constrained MART (CMART) is proposed in this paper. In the new tomographic algorithm, a popular two-dimensional multi-point finite difference approximation of the second order Laplacian operator is used to smooth the electron density field. The feasibility and superiority of the new method are demonstrated by using the numerical simulation experiment. Finally, the CMART is used to reconstruct the regional electron density field by using the actual GNSS data under geomagnetic quiet and disturbed days. The available ionosonde data from Beijing station further validates the superiority of the new method.

  12. Reconstruction of plasma current profile of tokamaks using combinatorial optimization techniques

    SciTech Connect

    Kishimoto, Maki; Sakasai, Kaoru; Ara, Katuyuki; Suzuki, Yasuo; Fujita, Takaaki

    1996-04-01

    New methods to reconstruct plasma shape and plasma current distribution from magnetic measurements are proposed. The reconstruction of plasma current profile from magnetic measurements is regarded as an optimum allocation problem of currents into cross section of the vacuum vessel of the tokamak. For solving this optimization problem, the authors use two types of solutions: a genetic algorithm and a combined method of a Hopfield neural network and a genetic algorithm. The effectiveness of these methods is shown by the application of these techniques to JT-60U plasmas.

  13. New techniques of determining focus position in gamma knife operation using 3D image reconstruction

    NASA Astrophysics Data System (ADS)

    Xiong, Yingen; Wang, Dezong; Zhou, Quan

    1994-09-01

    In this paper, new techniques of determining the focus of a disease position in a gamma knife operation are presented. In these techniques, the transparent 3D color image of the human body organ is reconstructed using a new three-dimensional reconstruction method, and then the position, the area, and the volume of focus of a disease such as cancer or a tumor are calculated. They are used in the gamma knife operation. The CT pictures are input into a digital image processing system. The useful information is extracted and the original data are obtained. Then the transparent 3D color image is reconstructed using these original data. By using this transparent 3D color image, the positions of the human body organ and the focus of a disease are determined in a coordinate system. While the 3D image is reconstructed, the area and the volume of human body organ and focus of a disease can be calculated at the same time. It is expressed through actual application that the positions of human body organ and focus of a disease can be determined exactly by using the transparent 3D color image. It is very useful in gamma knife operation or other surgical operation. The techniques presented in this paper have great application value.

  14. Cicatricial eyebrow reconstruction with a dense-packing one- to two-hair grafting technique.

    PubMed

    Wang, Jiping; Fan, Jincai

    2004-11-01

    Scarring eyebrow loss is usually repaired with a hair-bearing island scalp flap or scalp strip grafting technique. The results, however, are usually not desirable with regard to appearance. In this article, a one- or two-hair graft with a dense-packing technique was developed for cicatricial eyebrow reconstruction. It was carried out by harvesting a scalp strip close to the hairline of the back, then dividing it into a series of one- or two-hair grafts, and finally implanting the grafts into the prepared recipient holes of the eyebrow with a desired hair direction. With the authors' experience in treating 96 patients (154 eyebrows) in cases of burn, skin grafting, traumatic scarring, and chemical peeling scar after tattoo removal, the eyebrows could be restored in only one session. In general, 150 to 200 grafts with 200 to 250 hairs were needed for a complete male eyebrow reconstruction and 100 to 150 grafts with 150 to 200 hairs were needed for a complete female eyebrow reconstruction. The maximal hair density was 91.5 hairs/cm per session. Over a 6-month follow-up period, the mean graft survival rate reached 98.1 percent. All of the patients achieved satisfactory results, with a very natural appearance. These results indicate that the above-mentioned technique could be a practical, effective, and probably ideal method for cicatricial eyebrow reconstruction.

  15. New horizons for study of the cardiopulmonary and circulatory systems. [image reconstruction techniques

    NASA Technical Reports Server (NTRS)

    Wood, E. H.

    1976-01-01

    The paper discusses the development of computer-controlled three-dimensional reconstruction techniques designed to determine the dynamic changes in the true shape and dimensions of the epi- and endocardial surfaces of the heart, along with variable time base (stop-action to real-time) displays of the transmural distribution of the coronary microcirculation and the three-dimensional anatomy of the macrovasculature in all regions of the body throughout individual cardiac and/or respiratory cycles. A technique for reconstructing a cross section of the heart from multiplanar videoroentgenograms is outlined. The capability of high spatial and high temporal resolution scanning videodensitometry makes possible measurement of the appearance, mean transit and clearance of roentgen opaque substances in three-dimensional space through the myocardium with a degree of simultaneous anatomic and temporal resolution not obtainable by current isotope techniques. The distribution of a variety of selected chemical elements or biologic materials within a body portion can also be determined.

  16. A review of the surgical management of breast cancer: plastic reconstructive techniques and timing implications.

    PubMed

    Rosson, Gedge D; Magarakis, Michael; Shridharani, Sachin M; Stapleton, Sahael M; Jacobs, Lisa K; Manahan, Michele A; Flores, Jaime I

    2010-07-01

    The oncologic management of breast cancer has evolved over the past several decades from radical mastectomy to modern-day preservation of chest and breast structures. The increased rate of mastectomies over recent years made breast reconstruction an integral part of the breast cancer management. Plastic surgery now offers patients a wide variety of reconstruction options from primary closure of the skin flaps to performance of microvascular and autologous tissue transplantation. Well-coordinated partnerships between surgical oncologists, plastic surgeons, and patients address concerns of tumor control, cosmesis, and patients' wishes. The gamut of breast reconstruction options is reviewed, particularly noting state-of-the-art techniques, as well as the advantages and disadvantages of various timing modalities.

  17. Preliminary results of technique for electron density profile reconstruction from weakly oblique sounding data

    NASA Astrophysics Data System (ADS)

    Kim, Anton G.; Kotovich, Galina V.

    2008-02-01

    In this work the technique for reconstruction of height profile of electron density N(h) from oblique sounding data was applied to weakly oblique sounding data. During the calculations it was supposed that height-frequency characteristics (HFC), obtained at the short path (the path length is ~126 km), is equal to distance-frequency characteristics (DFC), which can be recalculated into HFC of path mid-point. Recalculating of DFC into HFC was made according to modified Smith method in frames of spherically symmetric ionosphere without consideration of Earth's magnetic field. The profile N(h) was reconstructed from recalculated HFC according to Huang-Reinisch method, which is widely used in world digisonde network. Results of comparison between reconstructed N(h)-profiles with profiles obtained according to observations data of FMCW-ionosonde of ISTP, obtained at weakly oblique sounding path Usolie-Tory, and Digisonde DPS-4 in Irkutsk, near the path mid-point, are presented.

  18. The Comparative Efficacy of the Masquelet versus Titanium Mesh Cage Reconstruction Techniques for the Treatment of Large Long Bone Deficiencies

    DTIC Science & Technology

    2014-10-01

    Efficacy of the Masquelet versus Titanium Mesh Cage Reconstruction Techniques for the Treatment of Large Long Bone Deficiencies 5a. CONTRACT NUMBER...and compare the functional outcome of patients with large segmental bone defects reconstructed with the Masquelet technique (MT) versus the titanium ...Masquelet technique; Titanium mesh cage technique 16. SECURITY CLASSIFICATION OF: U 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF

  19. ACL Tears on The Rise Among Kids, Especially Girls

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_163730.html ACL Tears on the Rise Among Kids, Especially Girls ... A common knee injury -- an anterior cruciate ligament (ACL) tear -- has steadily increased among 6- to 18- ...

  20. Force reconstruction using the sum of weighted accelerations technique -- Max-Flat procedure

    SciTech Connect

    Carne, T.G.; Mayes, R.L.; Bateman, V.I.

    1993-12-31

    Force reconstruction is a procedure in which the externally applied force is inferred from measured structural response rather than directly measured. In a recently developed technique, the response acceleration time-histories are multiplied by scalar weights and summed to produce the reconstructed force. This reconstruction is called the Sum of Weighted Accelerations Technique (SWAT). One step in the application of this technique is the calculation of the appropriate scalar weights. In this paper a new method of estimating the weights, using measured frequency response function data, is developed and contrasted with the traditional SWAT method of inverting the mode-shape matrix. The technique uses frequency response function data, but is not based on deconvolution. An application that will be discussed as part of this paper is the impact into a rigid barrier of a weapon system with an energy-absorbing nose. The nose had been designed to absorb the energy of impact and to mitigate the shock to the interior components.

  1. A novel technique for three-dimensional reconstruction for surgical simulation around the craniocervical junction region.

    PubMed

    Liu, Guang-Jiu; Zhang, Shao-Xiang; Qiu, Ming-Guo; Tan, Li-Wen; Li, Qi-Yu; Li, Kai

    2011-01-01

    Performing surgeries on the craniocervical junction presents a technical challenge for operating surgeons. Three-dimensional (3D) reconstruction and surgical simulation have improved the efficacy and success rate of surgeries. The aim of this study was to create a 3D, digitized visible model of the craniocervical junction region to help realize accurate simulation of craniocervical surgery on a graphic workstation. Transverse sectional anatomy data for the study were chosen from the first Chinese visible human. Manual axial segmentation of the skull base, cervical spine, cerebellum, vertebral artery, internal carotid artery, sigmoid sinus, internal jugular vein, brain stem, and spinal cord were carried out by using Photoshop software. The segmented structures were reconstructed in 3 dimensions with surface and volume rendering to accurately display 3D models spatially. In contrast to conventional 3D reconstruction techniques that are based on computed tomography and magnetic resonance imaging Digital Imaging and Communications in Medicine (DICOM) inputs and provide mostly osseous details, this technique can help to illustrate the surrounding soft tissue structure and provide a realistic surgical simulation. The reconstructed 3D model was successfully used in simulating complex procedures in the virtual environment, including the transoral approach, bone drillings, and clivus resection.

  2. 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,…

  3. 50 CFR 648.120 - Scup Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... shall recommend to the MAFMC separate ACLs for the commercial and recreational scup fisheries, the sum... and recreational fishing sector ACLs will be established consistent with the allocation guidelines... recreational sector ACLs may be established on an annual basis for up to 3 years at a time, dependent...

  4. 50 CFR 648.120 - Scup Annual Catch Limit (ACL).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... shall recommend to the MAFMC separate ACLs for the commercial and recreational scup fisheries, the sum... and recreational fishing sector ACLs will be established consistent with the allocation guidelines... recreational sector ACLs may be established on an annual basis for up to 3 years at a time, dependent...

  5. 50 CFR 648.120 - Scup Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... shall recommend to the MAFMC separate ACLs for the commercial and recreational scup fisheries, the sum... and recreational fishing sector ACLs will be established consistent with the allocation guidelines... recreational sector ACLs may be established on an annual basis for up to 3 years at a time, dependent...

  6. Better innovate than compromise: a novel hepatic outflow reconstruction technique in pediatric living donor liver transplantation.

    PubMed

    Cherian, P Thomas; Mishra, Ashish K; Bangaari, Ashish; Kota, Venugopal; Sathyanarayanan, Mohan; Raya, Ravichandra; Rela, Mohamed

    2015-05-01

    Pediatric LDLT using donors with unfavorable vascular anatomy is challenging in terms of donor safety, and complexity of reconstruction in the recipient. We describe an innovative technique of hepatic venous outflow reconstruction involving the recipient RHV, in the presence of a rudimentary RHV in the donor. The postoperative course of the donor and recipient was uneventful with satisfactory venous outflow in both. This technique avoided the use of prosthetic material, an important consideration given the recipient age and requirement for growth. This shows that donors previously considered unsuitable for donation can be utilized safely as long as principles of vascular anastomosis are adhered to. Moreover, it highlights that innovation is sometimes necessary to avoid compromise in donor safety.

  7. Technique of Dorsal Transversely Oriented Transposition Flap for Web Reconstruction in Toe Syndactyly Surgery.

    PubMed

    Saito, Susumu; Suzuki, Yoshihisa; Suzuki, Shigehiko

    2015-01-01

    In toe desyndactyly, a dorsal or plantar commissural flap, combined with skin grafts, will ensure an acceptable result. However, the parallel unsightly scars in the longitudinal direction on the dorsum of the toes will sometimes fail to satisfy the patient's and/or the parents' aesthetic expectations. To address this issue, we developed a technique using a transversely oriented transposition flap for web reconstruction, which can spare the dorsal interdigital skin maximally to shift the dorsal scars plantarly such that they become inconspicuous. The design of the flap is simple and uncomplicated surgically. Moreover, the donor site morbidity is minimal, owing to the good healing potential of the transverse scars. This technique could be an alternative in web reconstruction of toe desyndactyly, especially in cases with high cosmetic priority.

  8. Laparoscopic Free Omental Flap for Craniofacial Reconstruction: A Video Article Demonstrating Operative Technique and Surgical Applications.

    PubMed

    McIntyre, Benjamin C; Lobb, David; Navarro, Fernando; Nottingham, James

    2017-03-01

    The omental flap is a well described pedicled flap for surgical reconstruction of multiple body locations. As a laparoscopically harvested free flap, the omentum offers a minimally invasive solution to many reconstructive problems including extremity and head and neck wounds. This video article highlights the operative technique involved in flap harvest and inset for a cranial defect. An illustrative case involving a 23-year-old female's traumatic scalp degloving injury that was resurfaced by free omental flap and split-thickness skin graft is presented. This patient had stable long-term wound coverage for a very severe injury. Through video media we demonstrate that the laparoscopically harvested free omental flap is a minimally invasive, 2-team operation that provides soft tissue coverage of severe, remote wounds. This video demonstrates a safe operative technique and nuances specific to laparoscopic harvest of this flap.

  9. Thin superficial circumflex iliac artery perforator flap and supermicrosurgery technique for face reconstruction.

    PubMed

    Choi, Dong Hoon; Goh, Terence; Cho, Jae Young; Hong, Joon Pio

    2014-11-01

    Distant free flaps have become a routine option for reconstruction of large, complicated facial soft tissue defects. The challenge is to find a flap that is pliable to provide good contour and function. The purpose of this paper was to evaluate the use of superficial circumflex iliac artery perforator (SCIP) flaps for facial defects. From November 2010 to June 2013, facial reconstruction was performed on 6 patients (age range, 15-79 years). The harvesting technique was modified to elevate above the deep fat, and the pedicles were taken above or just below the deep fascia. The mean size of the flap was 75.6 cm2, with a thickness of 7 mm; the mean pedicle length was 4.9 cm; and the mean artery caliber was 0.7 mm. The supermicrosurgery technique was used successfully in all 6 cases. Donor sites were all closed primarily. The mean follow-up was 16.7 months. All flaps survived without flap loss, and the donor sites healed without complications including lymphorrhea. The patients were satisfied with contour and function after reconstruction. The result of these 6 cases suggested that the SCIP flap can be a reliable flap for moderate-sized to large defects in the face. The use of new instrumentation and supermicrosurgical techniques allows use of the SCIP flap reliably while providing patients with a good contour, function, and minimal donor site morbidity.

  10. Computerized tomography technique for reconstruction of obstructed temperature field in infrared thermography

    NASA Astrophysics Data System (ADS)

    Sham, F. C.; Huang, Y. H.; Liu, L.; Chen, Y. S.; Hung, Y. Y.; Lo, T. Y.

    2010-01-01

    Infrared thermography is a rapid, non-invasive and full-field technique for non-destructive testing and evaluation (NDT&E). With all the achievements on IR instrumentation and image processing techniques attained, it has been extended far beyond simple hot-spot detection and becomes one of the most promising NDT&E techniques in the last decades. It has achieved increasing acceptance in different sectors include medical imaging, manufacturing component fault detection and buildings diagnostic. However, one limitation of IR thermography is that the testing results are greatly affected by object surface emissivity. Surface with various emissivities may lead to difficult discrimination between area of defect and area with different emissivity. Therefore, many studies have been carried out on eliminating emissivity, for example, the time derivative approach, lock-in processing and differential contrast measurements. In these methods, sequence of themo-data/images are recorded and being processed in order to eliminate differences of emissivity. Another problem of IR thermography is that any obstruction may limit stimulations and imaging which leads to the observation of unclear defect image. To solve this problem, this paper proposes an algorithm based on the principle of computerized tomography which permits the reconstruction of unavailable/partially available temperature distribution of the affected area using the measured surrounding temperature field. In the process, a set of imaginary rays are projected from many different directions across the area. For each ray, integration of the temperature derivatives along the ray is equals to the temperature difference between the boundary points intercepted by the ray. Therefore, a set of linear equations can be established by considering the multiple rays. Each equation expresses the unknown temperature derivatives in the affected area in terms of the measured boundary temperature data. Solution of the set of simultaneous

  11. Effect of ACL Transection on Internal Tibial Rotation in an in Vitro Simulated Pivot Landing

    PubMed Central

    Oh, Youkeun K.; Kreinbrink, Jennifer L.; Ashton-Miller, James A.; Wojtys, Edward M.

    2011-01-01

    , under the large forces associated with a simulated pivot landing, but it leads to a significant increase in anterior tibial translation. Clinical Relevance: An ACL reconstruction that restores both ligament orientation and stiffness will provide major resistance to anterior tibial translation while providing minor resistance to axial tibial rotation. PMID:21325589

  12. Noise properties of reconstructed images in a kilo-voltage on-board imaging system with iterative reconstruction techniques: a phantom study.

    PubMed

    Lee, S; Kim, H-J

    2014-05-01

    X-ray computed tomography (CT) images obtained with a kilo-voltage (kV) on-board imaging (OBI) system improve the accuracy of patient setup and treatment planning. The use of iterative reconstruction techniques (IRTs) for CT imaging can also reduce radiation dose compared to analytic reconstruction techniques. Despite these improvements, the image quality varies with IRTs, and the noise structure of reconstructed images can be distorted by IRTs. In this study, the noise properties and spatial resolution of the images reconstructed by IRTs were evaluated in terms of conventional noise metrics, high-order statistics, noise spectral density (NSD) and modulation transfer function (MTF) at different radiation doses. A kV OBI system mounted on a Varian Trilogy machine and a CATPHAN600 phantom were used to obtain projections, and the projections were reconstructed by Feldkamp (FDK), algebraic reconstruction technique (ART), maximum-likelihood expectation-maximization (MLEM) and total variation (TV) minimization algorithms. The reconstructed images were compared according to mean, standard deviation, skewness, kurtosis, NSD and MTF at different radiation doses. The results demonstrated that the noise properties and spatial resolution of reconstructed images depend on the type of IRT and the radiation dose. The noise structures are altered by IRTs and can be characterized by high-order statistics and NSD, as well as conventional noise metrics. In conclusion, high-order statistics and NSD should be considered in order to provide detailed information for the images reconstructed by IRTs. Also, trade-off among noise properties, spatial resolution and contrast is important to optimize image quality obtained using IRTs.

  13. Modified technique for reconstructing the visceral arteries in thoracoabdominal aortic repair.

    PubMed

    Kondoh, Haruhiko; Funatsu, Toshihiro; Taniguchi, Kazuhiro

    2013-01-01

    We present a modified technique for reconstructing the visceral arteries in thoracoabdominal aortic repair. After the proximal and distal anastomosis of a main tubular graft with four pre-sewn side branches, each visceral artery is cannulated and perfused with 25 °C blood (sum total, 800 mL/min). Then, each side branch is placed around the main graft, forming a gently curved loop around it. Finally, the orifice of each visceral artery is sutured to a side branch. This technique prevents kinking of the side branches and enables hemostasis to be secured with a clear view of all the suture lines.

  14. Wavefront printing technique with overlapping approach toward high definition holographic image reconstruction

    NASA Astrophysics Data System (ADS)

    Wakunami, K.; Oi, R.; Senoh, T.; Sasaki, H.; Ichihashi, Y.; Yamamoto, K.

    2016-06-01

    A hologram recording technique, generally called as "wavefront printer", has been proposed by several research groups for static three-dimensional (3D) image printing. Because the pixel number of current spatial light modulators (SLMs) is not enough to reconstruct the entire wavefront in recording process, typically, hologram data is divided into a set of subhologram data and each wavefront is recorded sequentially as a small sub-hologram cell in tiling manner by using X-Y motorized stage. However since previous works of wavefront printer do not optimize the cell size, the reconstructed images were degraded by obtrusive split line due to visible cell size caused by too large cell size for human eyesight, or by diffraction effect due to discontinuity of phase distribution caused by too small cell size. In this paper, we introduce overlapping recording approach of sub-holograms to achieve both conditions: enough smallness of apparent cell size to make cells invisible and enough largeness of recording cell size to suppress diffraction effect by keeping the phase continuity of reconstructed wavefront. By considering observing condition and optimization of the amount of overlapping and cell size, in the experiment, the proposed approach showed higher quality 3D image reconstruction while the conventional approach suffered visible split lines and cells.

  15. Parasagittal meningiomas: Our surgical experience and the reconstruction technique of the superior sagittal sinus

    PubMed Central

    Ricci, Alessandro; Di Vitantonio, Hambra; De Paulis, Danilo; Del Maestro, Mattia; Gallieni, Massimo; Dechcordi, Soheila Raysi; Marzi, Sara; Galzio, Renato Juan

    2017-01-01

    Background: The radical resection of parasagittal meningiomas without complications and recurrences is the goal of the neurosurgeon. Nowadays, different managements are proposed. This study describes our surgical technique during the lesional excision and the reconstruction of the superior sagittal sinus (SSS). Methods: The total removal (Simpson I and II) of parasagittal meningiomas (WHO grade I and II) was obtained in 75 patients from September 2000 to January 2010. The indocyanine green videoangiography was used before the dural opening and, when necessary, to identify and preserve the cortical veins. The surgery of the SSS was performed in accordance with Sindou's classification, and its reconstruction was achieved through the use of a patch of galea capitis. Results: We had no cases of recurrence and thrombotic occlusion of the SSS in 5 years after the reconstruction. No complications were observed in 65 patients, and no cases of mortality were reported. Neurological focal deficits were observed in 5 patients. A brain swelling and a venous infarction were observed in 1 patient. Only one case of thrombotic occlusion was observed. A cerebrospinal fluid leak was observed in 2 patients, and a systemic complication was found in 1 patient. Conclusion: Several factors contribute to the success of the parasagittal meningioma surgery. We consider the preservation of the cortical veins to be important, and, when possible, we recommend the reconstruction of the anterior third of the SSS. Our experience has led us to believe that until now surgery is a winning choice if practiced by expert hands. PMID:28217380

  16. Effect of knee angle on quadriceps strength and activation after anterior cruciate ligament reconstruction

    PubMed Central

    Theuerkauf, Paul

    2015-01-01

    Quadriceps strength and activation deficits after anterior cruciate ligament (ACL) injury or surgery are typically evaluated at joint positions that are biomechanically advantageous to the quadriceps muscle. However, the effect of knee joint position and the associated changes in muscle length on strength and activation is currently unknown in this population. Here, we examined the effect of knee angle on quadriceps strength, activation, and electrically evoked torque in individuals with ACL reconstruction. Furthermore, we evaluated whether knee angle mediated the relationship between quadriceps weakness and functional performance after ACL reconstruction. Knee strength and activation were tested bilaterally at 90° and 45° of knee flexion in 11 subjects with ACL reconstruction using an interpolated triplet technique. The magnitude of electrically evoked torque at rest was used to quantify peripheral muscle contractile property changes, and the single-leg hop for distance test was used to evaluate functional performance. The results indicated that although quadriceps strength deficits were similar between knee angles, voluntary activation deficits were significantly higher in the reconstructed leg at 45° of knee flexion. On the contrary, the side-to-side evoked torque at rest ratio [i.e., (reconstructed/nonreconstructed) × 100] was significantly lower at 90° than at 45° of knee flexion. The association between quadriceps strength and functional performance was stronger at 45° of knee flexion. The results provide novel evidence that quadriceps activation is selectively affected at 45° of knee flexion and emphasize the importance of assessing quadriceps strength and activation at this position when feasible because it better captures activation deficits. PMID:25997949

  17. Sagittal Plane Knee Biomechanics and Vertical Ground Reaction Forces Are Modified Following ACL Injury Prevention Programs

    PubMed Central

    Padua, Darin A.; DiStefano, Lindsay J.

    2009-01-01

    feedback on proper technique. Conclusion: ACL injury prevention programs that are aimed at modifying sagittal plane knee biomechanics and VGRF should use an integrated training approach that incorporates instruction and feedback on proper movement technique. PMID:23015868

  18. An improved phase shift reconstruction algorithm of fringe scanning technique for X-ray microscopy

    SciTech Connect

    Lian, S.; Yang, H.; Kudo, H.; Momose, A.; Yashiro, W.

    2015-02-15

    The X-ray phase imaging method has been applied to observe soft biological tissues, and it is possible to image the soft tissues by using the benefit of the so-called “Talbot effect” by an X-ray grating. One type of the X-ray phase imaging method was reported by combining an X-ray imaging microscope equipped by a Fresnel zone plate with a phase grating. Using the fringe scanning technique, a high-precision phase shift image could be obtained by displacing the grating step by step and measuring dozens of sample images. The number of the images was selected to reduce the error caused by the non-sinusoidal component of the Talbot self-image at the imaging plane. A larger number suppressed the error more but increased radiation exposure and required higher mechanical stability of equipment. In this paper, we analyze the approximation error of fringe scanning technique for the X-ray microscopy which uses just one grating and proposes an improved algorithm. We compute the approximation error by iteration and substitute that into the process of reconstruction of phase shift. This procedure will suppress the error even with few sample images. The results of simulation experiments show that the precision of phase shift image reconstructed by the proposed algorithm with 4 sample images is almost the same as that reconstructed by the conventional algorithm with 40 sample images. We also have succeeded in the experiment with real data.

  19. Lateral eyelid rotation flap: a novel technique for reconstruction of full thickness eyelid defect.

    PubMed

    Pushker, Neelam; Batra, Jyoti; Meel, Rachna; Bajaj, Mandeep S; Chawla, Bhavna; Ghose, Supriyo

    2015-12-01

    The purpose of this study was to study anatomical, functional, and cosmetic outcomes of a novel technique, 'Lateral Eyelid Rotation Flap' for reconstruction of full thickness eyelid defect. In this prospective interventional study, 10 patients with full thickness eyelid defect measuring 1/2-2/3rd of eyelid width were included. Eyelid reconstruction was performed by single surgeon, using lateral eyelid rotation flap. Anatomic outcome was assessed by analyzing horizontal and vertical palpebral apertures (HPA and VPA), eyelid contour, and lateral canthus. Functional outcome was assessed by measuring tear film break-up time (TBUT) and Schirmer's test in both the eyes. Cosmetic outcome was evaluated by patients. Median age of patients was 56 years. Nine cases had full thickness defect following the excision of eyelid malignancy. The mean horizontal defect size was 17 ± 4.2 mm. HPA did not change significantly after surgery. VPA was statistically comparable to contralateral eye at 1-month follow-up. Lateral canthus angle recovered by 3rd month after surgery. TBUT and Schirmer's tests were comparable to contralateral eye. Eight patients graded cosmetic outcome as good to excellent. This is a new, single-stage technique for reconstruction of full thickness eyelid defects, with full thickness eyelid tissue including margin.

  20. RIT — A new robust iterative technique for image reconstruction in emission tomography

    NASA Astrophysics Data System (ADS)

    Tsupko-Sitnikov, Mikhail V.

    1991-02-01

    Emission tomography is a reliable tool for testing nuclear fuel elements. The conventional algebraic reconstruction methods of computer tomography are non-robust and can be fatally affected by outliers in the input data, i.e. by data having unexpectedly high errors due to some unpredictable effects. In the present paper, a robust iterative technique (RIT) for emission tomography is described. RIT is based on robust M-estimation methods and on a new algorithm for computing the M-estimates. RIT needs no filtering of the input data. It's computational expenses do not exceed those of SIRT method. RIT is included in the TOMODAT program and is being used for testing the fuel elements after irradiation in the reactors. The fuel distributions reconstructed by RIT are practically not affected by outliers in the input data, while the ART, SIRT and MENT give quite unstable results for the same spoiled data.

  1. A "watch window" technique for monitoring buried free jejunum flaps during circumferential pharyngolaryngectomy reconstruction.

    PubMed

    Li, Quan; Zhang, Xin-Rui; Liu, Xue-Kui; Zhang, Zhi-Gang; Liu, Wei-Wei; Li, Hao; Guo, Zhu-Ming

    2012-07-01

    The free jejunum flap approach is the optimal option for circumferential pharyngolaryngectomy reconstruction. In this study, we designed a "watch window" for monitoring buried free jejunum flaps, thereby allowing us to assess graft viability. From 2007 to 2011, 14 patients with hypopharyngeal cancer underwent circumferential pharyngolaryngectomy that was reconstructed using a free jejunum flap at the Sun Yat-sen University Cancer Centre. During the closing of the neck incision, a "watch window" was designed for postoperative monitoring. Two patients experienced thrombosis of the pedicle. One was detected early and successfully rescued by removal of the thrombosis, the other one managed with a second free jejunum flap. The success rate of the buried flaps was 92.9%. No pharyngocutaneous fistulas or strictures occurred. All patients eventually resumed oral feeding and swallowing. The "watch window" technique for monitoring buried free jejunum flaps is simple, reliable and useful for finding vascular problems. Level of evidence Case series.

  2. Estimation of variance in single-particle reconstruction using the bootstrap technique.

    PubMed

    Penczek, Pawel A; Yang, Chao; Frank, Joachim; Spahn, Christian M T

    2006-05-01

    Density maps of a molecule obtained by single-particle reconstruction from thousands of molecule projections exhibit strong changes in local definition and reproducibility, as a consequence of conformational variability of the molecule and non-stoichiometry of ligand binding. These changes complicate the interpretation of density maps in terms of molecular structure. A three-dimensional (3-D) variance map provides an effective tool to assess the structural definition in each volume element. In this work, the different contributions to the 3-D variance in a single-particle reconstruction are discussed, and an effective method for the estimation of the 3-D variance map is proposed, using a bootstrap technique of sampling. Computations with test data confirm the viability, computational efficiency, and accuracy of the method under conditions encountered in practical circumstances.

  3. Imaging Techniques for Dense 3D reconstruction of Swimming Aquatic Life using Multi-view Stereo

    NASA Astrophysics Data System (ADS)

    Daily, David; Kiser, Jillian; McQueen, Sarah

    2016-11-01

    Understanding the movement characteristics of how various species of fish swim is an important step to uncovering how they propel themselves through the water. Previous methods have focused on profile capture methods or sparse 3D manual feature point tracking. This research uses an array of 30 cameras to automatically track hundreds of points on a fish as they swim in 3D using multi-view stereo. Blacktip sharks, sting rays, puffer fish, turtles and more were imaged in collaboration with the National Aquarium in Baltimore, Maryland using the multi-view stereo technique. The processes for data collection, camera synchronization, feature point extraction, 3D reconstruction, 3D alignment, biological considerations, and lessons learned will be presented. Preliminary results of the 3D reconstructions will be shown and future research into mathematically characterizing various bio-locomotive maneuvers will be discussed.

  4. Image reconstruction algorithms for electrical capacitance tomography based on ROF model using new numerical techniques

    NASA Astrophysics Data System (ADS)

    Chen, Jiaoxuan; Zhang, Maomao; Liu, Yinyan; Chen, Jiaoliao; Li, Yi

    2017-03-01

    Electrical capacitance tomography (ECT) is a promising technique applied in many fields. However, the solutions for ECT are not unique and highly sensitive to the measurement noise. To remain a good shape of reconstructed object and endure a noisy data, a Rudin–Osher–Fatemi (ROF) model with total variation regularization is applied to image reconstruction in ECT. Two numerical methods, which are simplified augmented Lagrangian (SAL) and accelerated alternating direction method of multipliers (AADMM), are innovatively introduced to try to solve the above mentioned problems in ECT. The effect of the parameters and the number of iterations for different algorithms, and the noise level in capacitance data are discussed. Both simulation and experimental tests were carried out to validate the feasibility of the proposed algorithms, compared to the Landweber iteration (LI) algorithm. The results show that the SAL and AADMM algorithms can handle a high level of noise and the AADMM algorithm outperforms other algorithms in identifying the object from its background.

  5. Bypass flap reconstruction, a novel technique for distal revascularization: outcome of first 10 clinical cases.

    PubMed

    Malikov, Serguei; Magnan, Pierre-Edouard; Casanova, Dominique; Lepantalo, Mauri; Valerio, Nicolas; Ayari, Raouf; Champsaur, Pierre; Branchereau, Alain

    2009-01-01

    Combined distal venous bypass grafting and free flap transfer can achieve successful treatment of soft tissue defects due to advanced leg ischemia. However, this combined approach is a complex technique involving multiple anastomoses on the same arterial axis with an increased risk of thrombosis. To reduce this risk, we have proposed a new bypass-flap (BF) reconstruction technique using an arterial graft and a free flap supplied by a collateral branch of the graft. The purpose of this report is to document the outcome in the first 10 patients treated using the BF reconstruction technique. From 2002 to 2004, a total of 10 patients with a mean age of 67 years (range 55-78) were treated using a BF. All patients presented critical ischemia with soft tissue defects resulting in exposure of tendons and muscles on the foot or ankle. Distal anastomosis was made between the distal branch of the BF and the pedal artery in five cases, the posterior tibial artery or plantar artery in four cases, and the peroneal artery in one case. In six cases proximal anastomosis was performed between the leg artery and arterial autograft. In the remaining four cases proximal anastomosis required extension of the bypass using a venous graft. The mean duration of hospitalization was 25 days. During the postoperative period, one patient died due to stercoral peritonitis and one patient required major amputation due to unrelenting sepsis. Bypass occlusion was not observed. Mean follow-up was 24 months (range 14-36). No patient was lost to follow-up and no patient died after the first 30 postoperative days. Follow-up examinations including clinical assessment and Doppler ultrasound imaging were performed at 3 months and every 6 months thereafter. Findings demonstrated bypass patency and healing of the covered defect in all cases. Outcome in this initial series demonstrates the clinical feasibility of the new BF reconstruction technique, which allows revascularization and coverage of tissue

  6. The Horizontal and Stepped Osteotomy Technique for Mandibular Reconstruction Using Fibular Free Flap

    PubMed Central

    Aleid, Wesam; Jones, Keith; Laugharne, David

    2011-01-01

    The mandible is an important component of the orofacial skeleton, and resection of part of the mandible as part of head and neck oncological procedures can have dramatic impact on both function and cosmesis. In this article, we describe a new technique in the resection osteotomy and flap fixation that improves the stability and aesthetic outcome of the reconstruction. The mandibular resection is performed utilizing a horizontal osteotomy above the mandibular angle on one side and a stepped body or angle osteotomy on the other side. Our technique is unique as it allows flexibility in adjusting the chin point projection to give the best possible aesthetic outcome; it allows more bone-to-bone contact, which increases the stability; it reduces rotation; and it allows for use of miniplate fixation, facilitating future rehabilitation with implants. We have been using this technique with great success in our hospital, and we recommend its use for its improved flexibility, stability, and aesthetic outcome. PMID:22942945

  7. The horizontal and stepped osteotomy technique for mandibular reconstruction using fibular free flap.

    PubMed

    Aleid, Wesam; Jones, Keith; Laugharne, David

    2011-09-01

    The mandible is an important component of the orofacial skeleton, and resection of part of the mandible as part of head and neck oncological procedures can have dramatic impact on both function and cosmesis. In this article, we describe a new technique in the resection osteotomy and flap fixation that improves the stability and aesthetic outcome of the reconstruction. The mandibular resection is performed utilizing a horizontal osteotomy above the mandibular angle on one side and a stepped body or angle osteotomy on the other side. Our technique is unique as it allows flexibility in adjusting the chin point projection to give the best possible aesthetic outcome; it allows more bone-to-bone contact, which increases the stability; it reduces rotation; and it allows for use of miniplate fixation, facilitating future rehabilitation with implants. We have been using this technique with great success in our hospital, and we recommend its use for its improved flexibility, stability, and aesthetic outcome.

  8. Digital reconstruction and donor site resurfacing: a two-flap technique.

    PubMed

    Kang, Qing-Lin; Chai, Yi-Ming; Chen, Weijia; Zeng, Bing-Fang

    2007-01-01

    Use of a great toe pulp flap is one of the methods to repair partial soft-tissue defect of the thumb or other digits. However, the conventional application of free skin grafts to close the donor site may bring donor-site morbidity. The authors present a two-flap technique that a reverse first dorsal metatarsal artery (FDMA) flap resurfaces the defect of the free great toe pulp flap. Six patients with soft-tissue defects of the thumbs or fingers were treated with this technique. Both the pulp and reverse flaps survived uneventfully after reconstruction of the thumbs and fingers. The reverse flap to resurface the donor site on the great toe was sensate and durable. Satisfactory appearance and function were gained in all patients. Results revealed that this technique can be accepted as an alternative method when treating soft tissue defect of the thumb or finger.

  9. Reconstruction of the Distal Oblique Bundle of the Interosseous Membrane: A Technique to Restore Distal Radioulnar Joint Stability.

    PubMed

    Riggenbach, Michael D; Wright, Thomas W; Dell, Paul C

    2015-11-01

    The distal radioulnar ligament reconstruction is a technique that may be used for distal radioulnar joint instability without arthritis and failed nonsurgical management; clinical results demonstrate resolved or improved stability. Recent literature has focused on the distal oblique bundle of the interosseous membrane and its contributions to stability. This article describes a technically simple surgical technique to reconstruct the distal oblique bundle and restore distal radioulnar joint stability.

  10. Reanalysis of COMPTEL Measurements with the Latest Compton Event and Image Reconstruction Techniques

    NASA Astrophysics Data System (ADS)

    Zoglauer, Andreas C.; Collmar, W.; Boggs, S. E.; Hartmann, D. H.; Kippen, M.; Novikova, E. I.; Weidenspointner, G.; Wunderer, C. B.

    2010-03-01

    A decade after de-orbiting CGRO, COMPTEL's 1-30 MeV all-sky imaging data set remains unsurpassed, and no current or planned mission is capable of challenging COMPTEL's performance in the near future. Since the nineties, when the original COMPTEL data analysis techniques were developed, the performance of state-of-the-art computers has increased by orders of magnitude, enabling new and improved techniques that were out of reach at that time. We are in the progress of reanalyzing selected COMPTEL data sets with the latest Compton event and image reconstruction techniques with the goal to improve the imaging sensitivity of COMPTEL. The first step of the analysis is to reproduce the COMPTEL measurements with ab-initio simulations to achieve a better understanding of the background, to verify the simulation tools in this energy range, and to develop the capability of simulating improved response matrices. The second step is to apply modern, multi-dimensional Compton event reconstruction and selections (e.g. Bayesian event selections) to the COMPTEL data to better separate source photons from background events, and thus improving the signal to noise ratio. Finally, we developed a new imaging approach based on a partially-binned-response list-mode ML-EM, with a higher-fidelity response model than that of the original COMPTEL imaging response, which leads to improved image quality. We report on the status of the data conversion, simulations, event selections, and imaging reconstruction, and show first results from selected COMPTEL observations (e.g. Galactic anti-center, SN1998bu). This work was funded in part by NASA grant NNX08AJ38G.

  11. Reconstruction techniques of erythemal UV-radiation and future UV predictions

    NASA Astrophysics Data System (ADS)

    Wagner, J. E.; Rieder, H. E.; Simic, S.; Weihs, P.

    2009-04-01

    Since the discovery of anthropogenic ozone depletion more than 30 year ago, the scientific community has shown an increasing interest in UV-B radiation and started to monitor UV-radiation. However, difficulties involved in the routine operation and maintenance of the instruments have limited the length of reliable data records to about two decades. Further the number of places where they were measured, resulting in a set of observations too short and too sparse for a good understanding of past UV changes. Moreover state of the art climate models do not calculate future scenarios of UV-doses. Therefore detailed information about past and future UV-trends are lacking. Reconstruction techniques are indispensable to derive long-term time series of UV-radiation and fill this gap. Apart from the astronomical parameters, like solar zenith angle and sun-earth-distance, UV radiation is strongly influenced by clouds, ozone and surface albedo. We developed and evaluated a reconstruction technique for UV-doses that first calculates the UV-doses under clear-sky condition and afterwards applies corrections in order to take cloud effects into account. Since the input parameters cloud cover, total ozone column and surface albedo are available from the Regional Climate Model (REMO), we applied our reconstruction technique also for future scenarios using REMO data as input. Hence we are able to derive a seamless UV long-term time series from the past to the future. Our method was applied for the high alpine station Hoher Sonnblick (3108m) situated in Austrian Alps.

  12. Prehospital ACLS--does it work?

    PubMed

    Maheshwari, Alok; Mehrotra, Avanti; Gupta, Anoop K; Thakur, Ranjan K

    2002-11-01

    Cardiac disease is the most common cause of death in the United States, and sudden cardiac arrest frequently claims the lives of men and women during their most productive years. It is believed that much better survival rates can be achieved for victims of cardiac arrest through optimizing the "chain of survival" as described by the American Heart Association. The relative and incremental benefit of full prehospital ACLS over basic life support and defibrillation is unproven, however. This is an important issue in this era of cost containment. Some of the ongoing studies including the OPALS study may clarify the cost effectiveness and relative efficacy of rapid defibrillation and full ACLS programs for victims of prehospital cardiac arrest [6].

  13. Selective laser melted titanium implants: a new technique for the reconstruction of extensive zygomatic complex defects.

    PubMed

    Rotaru, Horatiu; Schumacher, Ralf; Kim, Seong-Gon; Dinu, Cristian

    2015-12-01

    The restoration of extensive zygomatic complex defects is a surgical challenge owing to the difficulty of accurately restoring the normal anatomy, symmetry, proper facial projection and facial width. In the present study, an extensive post-traumatic zygomatic bone defect was reconstructed using a custom-made implant that was made with a selective laser melting (SLM) technique. The computer-designed implant had the proper geometry and fit perfectly into the defect without requiring any intraoperative adjustments. A one-year follow-up revealed a stable outcome with no complications.

  14. ACLED Country Report: Central African Republic

    DTIC Science & Technology

    2015-01-01

    violence between January 1997 and September 2014. Almost 8,000 fatalities have occurred during this time, making it the fourteenth most fatal country in...the dataset in this regard. However, violence has escalated sharply in recent years: the majority of these events occurred since the outbreak of the...CAR) is the fifteenth most violent country in the ACLED dataset, with over 2,000 recorded events of political violence between January 1997 and

  15. Soft tissue reconstruction for type IV-D duplicated thumb: a new surgical technique.

    PubMed

    Tien, Yin-Chun; Chih, Tsai-Tung; Wang, Tai-Lung; Fu, Yin-Chih; Chen, Jian-Chih

    2007-06-01

    Type IV-D duplicated thumb has the most complex anomalies and difficulties for treatment among polydatyly. Double osteotomy is usually recommended to gain the best cosmetic and functional outcome. However, 4 cases of type IV-D duplicated thumb were treated only by soft tissue procedure in this study. At operation, a conjoined A2 pulley was routinely identified, and the flexor pollicis longus (FPL) was found bifurcated distal to the conjoined pulley in every of these cases. Instead of double osteotomy, a soft tissue procedure that included centralization of FPL and A2 pulley reconstruction was pursued to correct these special anomalies. The overall clinical results were evaluated by a modification of the Tada scoring system based on the range of motion, joint stability, alignment of the remaining thumb, and subjective opinion regarding the reconstructed thumb after an average follow-up of 3.3 years (range, 2.5-4.7 years). According to the scoring system, the results were rated as good in 3 cases and fair in 1 case. From the results, the A2 pulley reconstruction and FPL centralization could prove to be an effective method for the treatment of type IV-D duplicated thumb and could efficiently avoid the residual angular deformities. Therefore, we recommend this soft tissue procedure as an alternative surgical technique to the double-osteotomy procedure for treating a type IV-D duplicated thumb in a very young child, whose bone is still not mature enough for holding the fixing pins.

  16. Class of backpropagation techniques for limited-angle reconstruction in microwave tomography

    SciTech Connect

    Paladhi, P. Roy; Tayebi, A.; Udpa, L.; Udpa, S.; Sinha, A.

    2015-03-31

    Filtered backpropagation (FBPP) is a well-known technique used in Diffraction Tomography (DT). For accurate reconstruction using FBPP, full 360° angular coverage is necessary. However, it has been shown that using some inherent redundancies in the projection data in a tomographic setup, accurate reconstruction is still possible with 270° coverage which is called the minimal-scan angle range. This can be done by applying weighing functions (or filters) on projection data of the object to eliminate the redundancies and accurately reconstruct the image from 270° coverage. This paper demonstrates procedures to generate many general classes of these weighing filters. These are all equivalent at 270° coverage but vary in performance at lower angular coverages and in presence of noise. This paper does a comparative analysis of different filters when angular coverage is lower than minimal-scan angle of 270°. Simulation studies have been done to find optimum weight filters for sub-minimal angular coverage (<270°)

  17. Neutron imaging with coded sources: new challenges and the implementation of a simultaneous iterative reconstruction technique

    SciTech Connect

    Santos-Villalobos, Hector J; Bingham, Philip R; Gregor, Jens

    2013-01-01

    The limitations in neutron flux and resolution (L/D) of current neutron imaging systems can be addressed with a Coded Source Imaging system with magnification (xCSI). More precisely, the multiple sources in an xCSI system can exceed the flux of a single pinhole system for several orders of magnitude, while maintaining a higher L/D with the small sources. Moreover, designing for an xCSI system reduces noise from neutron scattering, because the object is placed away from the detector to achieve magnification. However, xCSI systems are adversely affected by correlated noise such as non-uniform illumination of the neutron source, incorrect sampling of the coded radiograph, misalignment of the coded masks, mask transparency, and the imperfection of the system Point Spread Function (PSF). We argue that a model-based reconstruction algorithm can overcome these problems and describe the implementation of a Simultaneous Iterative Reconstruction Technique algorithm for coded sources. Design pitfalls that preclude a satisfactory reconstruction are documented.

  18. Weighted simultaneous algebraic reconstruction technique for tomosynthesis imaging of objects with high-attenuation features

    SciTech Connect

    Levakhina, Y. M.; Mueller, J.; Buzug, T. M.; Duschka, R. L.; Vogt, F.; Barkhausen, J.

    2013-03-15

    Purpose: This paper introduces a nonlinear weighting scheme into the backprojection operation within the simultaneous algebraic reconstruction technique (SART). It is designed for tomosynthesis imaging of objects with high-attenuation features in order to reduce limited angle artifacts. Methods: The algorithm estimates which projections potentially produce artifacts in a voxel. The contribution of those projections into the updating term is reduced. In order to identify those projections automatically, a four-dimensional backprojected space representation is used. Weighting coefficients are calculated based on a dissimilarity measure, evaluated in this space. For each combination of an angular view direction and a voxel position an individual weighting coefficient for the updating term is calculated. Results: The feasibility of the proposed approach is shown based on reconstructions of the following real three-dimensional tomosynthesis datasets: a mammography quality phantom, an apple with metal needles, a dried finger bone in water, and a human hand. Datasets have been acquired with a Siemens Mammomat Inspiration tomosynthesis device and reconstructed using SART with and without suggested weighting. Out-of-focus artifacts are described using line profiles and measured using standard deviation (STD) in the plane and below the plane which contains artifact-causing features. Artifacts distribution in axial direction is measured using an artifact spread function (ASF). The volumes reconstructed with the weighting scheme demonstrate the reduction of out-of-focus artifacts, lower STD (meaning reduction of artifacts), and narrower ASF compared to nonweighted SART reconstruction. It is achieved successfully for different kinds of structures: point-like structures such as phantom features, long structures such as metal needles, and fine structures such as trabecular bone structures. Conclusions: Results indicate the feasibility of the proposed algorithm to reduce typical

  19. CT reconstruction techniques for improved accuracy of lung CT airway measurement

    SciTech Connect

    Rodriguez, A.; Ranallo, F. N.; Judy, P. F.; Gierada, D. S.; Fain, S. B.

    2014-11-01

    Purpose: To determine the impact of constrained reconstruction techniques on quantitative CT (qCT) of the lung parenchyma and airways for low x-ray radiation dose. Methods: Measurement of small airways with qCT remains a challenge, especially for low x-ray dose protocols. Images of the COPDGene quality assurance phantom (CTP698, The Phantom Laboratory, Salem, NY) were obtained using a GE discovery CT750 HD scanner for helical scans at x-ray radiation dose-equivalents ranging from 1 to 4.12 mSv (12–100 mA s current–time product). Other parameters were 40 mm collimation, 0.984 pitch, 0.5 s rotation, and 0.625 mm thickness. The phantom was sandwiched between 7.5 cm thick water attenuating phantoms for a total length of 20 cm to better simulate the scatter conditions of patient scans. Image data sets were reconstructed using STANDARD (STD), DETAIL, BONE, and EDGE algorithms for filtered back projection (FBP), 100% adaptive statistical iterative reconstruction (ASIR), and Veo reconstructions. Reduced (half) display field of view (DFOV) was used to increase sampling across airway phantom structures. Inner diameter (ID), wall area percent (WA%), and wall thickness (WT) measurements of eight airway mimicking tubes in the phantom, including a 2.5 mm ID (42.6 WA%, 0.4 mm WT), 3 mm ID (49.0 WA%, 0.6 mm WT), and 6 mm ID (49.0 WA%, 1.2 mm WT) were performed with Airway Inspector (Surgical Planning Laboratory, Brigham and Women’s Hospital, Boston, MA) using the phase congruency edge detection method. The average of individual measures at five central slices of the phantom was taken to reduce measurement error. Results: WA% measures were greatly overestimated while IDs were underestimated for the smaller airways, especially for reconstructions at full DFOV (36 cm) using the STD kernel, due to poor sampling and spatial resolution (0.7 mm pixel size). Despite low radiation dose, the ID of the 6 mm ID airway was consistently measured accurately for all methods other than STD

  20. CT reconstruction techniques for improved accuracy of lung CT airway measurement

    PubMed Central

    Rodriguez, A.; Ranallo, F. N.; Judy, P. F.; Gierada, D. S.; Fain, S. B.

    2014-01-01

    Purpose: To determine the impact of constrained reconstruction techniques on quantitative CT (qCT) of the lung parenchyma and airways for low x-ray radiation dose. Methods: Measurement of small airways with qCT remains a challenge, especially for low x-ray dose protocols. Images of the COPDGene quality assurance phantom (CTP698, The Phantom Laboratory, Salem, NY) were obtained using a GE discovery CT750 HD scanner for helical scans at x-ray radiation dose-equivalents ranging from 1 to 4.12 mSv (12–100 mA s current–time product). Other parameters were 40 mm collimation, 0.984 pitch, 0.5 s rotation, and 0.625 mm thickness. The phantom was sandwiched between 7.5 cm thick water attenuating phantoms for a total length of 20 cm to better simulate the scatter conditions of patient scans. Image data sets were reconstructed using STANDARD (STD), DETAIL, BONE, and EDGE algorithms for filtered back projection (FBP), 100% adaptive statistical iterative reconstruction (ASIR), and Veo reconstructions. Reduced (half) display field of view (DFOV) was used to increase sampling across airway phantom structures. Inner diameter (ID), wall area percent (WA%), and wall thickness (WT) measurements of eight airway mimicking tubes in the phantom, including a 2.5 mm ID (42.6 WA%, 0.4 mm WT), 3 mm ID (49.0 WA%, 0.6 mm WT), and 6 mm ID (49.0 WA%, 1.2 mm WT) were performed with Airway Inspector (Surgical Planning Laboratory, Brigham and Women’s Hospital, Boston, MA) using the phase congruency edge detection method. The average of individual measures at five central slices of the phantom was taken to reduce measurement error. Results: WA% measures were greatly overestimated while IDs were underestimated for the smaller airways, especially for reconstructions at full DFOV (36 cm) using the STD kernel, due to poor sampling and spatial resolution (0.7 mm pixel size). Despite low radiation dose, the ID of the 6 mm ID airway was consistently measured accurately for all methods other than STD

  1. The Effects of Rehabilitation Protocol on Functional Recovery After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Dragicevic-Cvjetkovic, Dragana; Jandric, Slavica; Bijeljac, Sinisa; Palija, Stanislav; Manojlovic, Slavko; Talic, Goran

    2014-01-01

    ABSTRACT Introduction: The use of rehabilitation protocol which corresponds to surgical technique results in optimal postoperative outcome and functional recovery of patients to a pre-injury level of activity. The aim of this paper is to show the effects of the official rehabilitation protocol in our Institute on functional recovery of patients after anterior cruciate ligament (ACL) reconstruction. Patients and methods: In prospective study, we evaluated 70 males after ACL reconstruction using hamstring graft. Patients were divided into two groups according to the manner of conducting the postoperative rehabilitation. Group A consisted of 35 patients that followed postoperative rehabilitation according to the rehabilitation protocol. Group B also 35 patients, which did not undergo the rehabilitation protocol. We evaluated thigh muscle circumference and modified Tegner Lysholm Score, preoperatively and postoperatively after 1,3,6 and 12 months. In the statistical analysis, the Studentov T-test was used. Results: In the first postoperative month, the difference between groups in thigh muscle circumference is statistically significant (p<0,05). This difference between groups is statistically highly significant after 3, 6, and 12 months postoperative (p<0,01). Results of the modified Tegner Lysholm Score is statistically highly significant in 1, 3 and 6 postoperative months in patients from the experimental group (p<0,01). Conclusion: The positive effects of the rehabilitation protocol results in significant increase of the thigh muscle circumference and faster functional recovery of patients after ACL reconstruction. PMID:25568570

  2. [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

  3. Eversion-Inversion Labral Repair and Reconstruction Technique for Optimal Suction Seal

    PubMed Central

    Moreira, Brett; Pascual-Garrido, Cecilia; Chadayamurri, Vivek; Mei-Dan, Omer

    2015-01-01

    Labral tears are a significant cause of hip pain and are currently the most common indication for hip arthroscopy. Compared with labral debridement, labral repair has significantly better outcomes in terms of both daily activities and athletic pursuits in the setting of femoral acetabular impingement. The classic techniques described in the literature for labral repair all use loop or pass-through intrasubstance labral sutures to achieve a functional hip seal. This hip seal is important for hip stability and optimal joint biomechanics, as well as in the prevention of long-term osteoarthritis. We describe a novel eversion-inversion intrasubstance suturing technique for labral repair and reconstruction that can assist in restoration of the native labrum position by re-creating an optimal seal around the femoral head. PMID:26870648

  4. The development and application of a diatom-based quantitative reconstruction technique in forensic science.

    PubMed

    Horton, Benjamin P; Boreham, Steve; Hillier, Caroline

    2006-05-01

    Diatoms are a group of unicellular algae that have been recorded and classified for over 200 years and have been used in a range of applications in forensic science. We have developed a quantitative diatom-based reconstruction technique to confirm drowning as a cause of death and localize the site of drowning in two recent, high-profile, case studies. In both case studies we collected diatom samples from the local and/or regional area to act as a control in the examination of diatom assemblages associated with lungs and clothing. In Case Study 1 the modern analog technique suggested that all lung and clothing samples have statistically significant similarities to control samples from shallow water habitats. In Case Study 2, the analog matching suggested that the majority of lung samples show a statistically significant relationship to samples from a pond, indicating that this was the drowning medium.

  5. Analysis of Sileye-3/Alteino data with a neural network technique: Particle discrimination and energy reconstruction

    NASA Astrophysics Data System (ADS)

    Scrimaglio, R.; Rantucci, E.; Segreto, E.; Nurzia, G.; Finetti, N.; Di Gaetano, A.; Tassoni, A.; Picozza, P.; Narici, L.; Casolino, M.; Di Fino, L.; Rinaldi, A.; Zaconte, V.

    In this work, we present the data analysis of the Sileye-3/Alteino experiment with neural network technique. Sileye-3/Alteino is composed of two devices: the cosmic ray-advanced silicon telescope (an 8 plane, 32 strip silicon detector) and an electroencephalograph. It was placed on board the ISS on April the 27th 2002 to investigate on the Light Flash phenomenon and the radiation environment in space. We show the possibility of using neural networks as an useful tool for real-time data analysis. A feed-forward neural network (Multi-Layer Perceptron MLP) has been implemented and trained (with Monte Carlo data) to perform on line particle identification for ions with Atomic Number (Z) ⩽8 and incident kinetic energy reconstruction for ions Z > 2. The result of the analysis of Sileye-3/Alteino real data with the neural network and the improvements over classical analysis techniques are discussed.

  6. Should critical care nurses be ACLS-trained?

    PubMed

    Hagyard-Wiebe, Tammy

    2007-01-01

    The aim of resuscitation is to sustain life with intact neurological functioning and the same quality of life previously experienced by the patient. Advanced cardiac life support (ACLS) was designed to achieve this aim. However the requirement for ACLS training for critical care nurses working in Canadian critical care units is inconsistent across the country. The purposes of this article are to explore the evidence surrounding ACLS training for critical care nurses and its impact on resuscitation outcomes, and to review the evidence surrounding ACLS knowledge and skill degradation with strategies to support code blue team efficiency for an effective resuscitation. Using the search terms ACLS training, resuscitation, critical care, and nursing, two databases, CINAHL and MEDLINE, were used. The evidence supports the need for ACLS training for critical care nurses. The evidence also supports organized ongoing refresher courses, multidisciplinary mock code blue practice using technologically advanced simulator mannequins, and videotaped reviews to prevent knowledge and skill degradation for effective resuscitation efforts.

  7. The characteristics of EEG power spectra changes after ACL rupture

    PubMed Central

    Miao, Xin; Huang, Hongshi; Hu, Xiaoqing; Li, Dai; Yu, Yuanyuan; Ao, Yingfang

    2017-01-01

    Background Reestablishing knee stability is the core of the treatment of ACL (Anterior Cruciate Ligament) injury. Some patients still have a feeling of instability of the knee after ACL injury treatment. This unstable feeling may be caused by central nervous system changes after ACL rupture. Methods To identify the central changes after ACL rupture, EEG spectra were recorded to compare ACL patients and healthy controls when they were walking, jogging, and landing. Results There was a significant increase in delta, theta, alpha and beta band power during walking, jogging and landing in ACL patients. We also found an asymmetry phenomenon of EEG only in the ACL patients, mainly in the frontal area and central-parietal area. The asymmetry of beta band power extended to the frontal and the central area during jogging and landing task. Conclusions There were significant differences in EEG power spectra between the ACL patients and healthy people. ACL patients showed high EEG band power activities and an asymmetry phenomenon. EEG power changes were affected by movements, the asymmetry extended when performing more complicated movements. PMID:28182627

  8. Repositioning template for mandibular reconstruction with fibular free flaps: an alternative technique to pre-plating and virtual surgical planning.

    PubMed

    Berrone, M; Crosetti, E; Succo, G

    2014-08-01

    Oral malignancies involving the mandibular bone require a complex reconstructive plan. Mandibular reconstruction with a fibular free flap is currently considered the best choice for functional and aesthetic rehabilitation after oncological surgery. This flap can be modelled with multiple osteotomies and can provide bone, muscle and skin for composite reconstruction. One of the most delicate aspects of mandibular reconstruction is the technique of bone modelling; the risk of prolonging the period of ischaemia and not restoring the correct maxillomandibular and occlusal relationships can ultimately lead to a higher rate of complications as well as poor aesthetic and functional results. Recently, there has been rising interest in virtual surgical planning and computer-assisted mandibular reconstruction in pre-operative planning; however, this is not always possible because of the costs involved and the set-up time for the entire procedure. In this paper, we present a simple and inexpensive technique for fibular free flap modelling and repositioning after segmental resection of the mandible; the technique entails the pre-operative preparation of a resin repositioning template on a stereolithographic model. This technique has been successfully applied in four cases: two cases underwent resection involving only the mandibular body, one case involving the mandibular body and symphysis and one case in which a ramus to ramus resection was performed. In this preliminary report, we show that the resin repositioning template is an easy, safe and useful tool for mandibular reconstruction with a fibular free flap.

  9. 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

  10. Fracture Strength of Weakened Anterior Teeth Associated to Different Reconstructive Techniques.

    PubMed

    Ferro, Mariana Carolina de Lara; Colucci, Vivian; Marques, Artur Gaiotto; Ribeiro, Ricardo Faria; Silva-Sousa, Yara T C; Gomes, Erica Alves

    2016-01-01

    This study evaluated the fracture strength of endodontically treated teeth submitted to reconstructive techniques through dynamic and static tests. Forty human anterior teeth were divided into 4 groups (n=10): GNW (non-weakened) - root restored with glass fiber post (GFP), GW - weakened root restored with GFP, GDA - weakened root restored with direct anatomic GFP, and GIA - weakened root restored with indirect anatomic GFP. The teeth were endodontically treated considering that experimental groups (GW, GDA and GIA) simulated weakened roots for restoration with GFP using different techniques. The GFP was luted with resin cement and the coronal portion was restored with composite resin and metallic crowns. All samples were submitted to chewing simulation at 60 cycles/min in a total of 300,000 cycles. The survival samples were further exposed to compressive loading at a crosshead speed of 1.0 mm/min in a universal testing machine. The load was applied at 135° to the long axis of the tooth until failure. Data were analyzed by ANOVA (a=0.05). After chewing simulation were observed: GNW: 100% of survival roots; GW: 70% of survival roots, and GDA and GIA: 80% of survival roots. The mean fracture strength values (N) were 280.6 (GNW), 239.0 (GW), 221.3 (GDA), and 234.1 (GIA) without significant difference among the groups (p=0.7476). The results suggested similar fracture strength in both weakened and non-weakened teeth regardless the reconstructive technique of root internal wall. Higher incidence of catastrophic fracture was observed in weakened teeth without restoration of the root internal wall.

  11. Comparison of PDE based and other techniques for speckle reduction from digitally reconstructed holographic images

    NASA Astrophysics Data System (ADS)

    Srivastava, Rajeev; Gupta, JRP; Parthasarthy, Harish

    2010-05-01

    In this paper, the partial differential equation (PDE) based homomorphic filtering technique is proposed for speckle reduction from digitally reconstructed holographic images based on the concepts of complex diffusion processes. For digital implementations, the proposed scheme was discretized using finite differences scheme. Further, the performance of the proposed PDE-based technique is compared with other speckle reduction techniques such as homomorphic anisotropic diffusion filter based on extended concept of Perona and Malik (1990) [2], homomorphic Weiner filter, Lee filter, Frost filter, Kuan filter, speckle reducing anisotropic diffusion (SRAD) filter and hybrid filter in the context of digital holography. For the comparison of various speckle reduction techniques, the performance is evaluated quantitatively in terms of all possible parameters that justify the applicability of a scheme for a specific application. The chosen parameters are mean-square-error (MSE), normalized mean-square-error (NMSE), peak signal-to-noise ratio (PSNR), speckle index, average signal-to-noise ratio (SNR), effective number of looks (ENL), correlation parameter (CP), mean structure similarity index map (MSSIM) and execution time in seconds. For experimentation and computer simulation MATLAB 7.0 has been used and the performance is evaluated and tested for various sample holographic images for varying amount of speckle variance. The results obtained justify the applicability of proposed schemes.

  12. The effect of the variation in ACL constitutive model on joint kinematics and biomechanics under different loads: a finite element study.

    PubMed

    Wan, Chao; Hao, Zhixiu; Wen, Shizhu

    2013-04-01

    The biomechanics and function of the anterior cruciate ligament (ACL) have been widely studied using both experimental and simulation methods. It is known that a constitutive model of joint tissue is a critical factor in the numerical simulation. Some different ligament constitutive models have been presented to describe the ACL material behavior. However, the effect of the variation in the ligament constitutive model on joint kinematics and biomechanics has still not been studied. In this paper, a three-dimensional finite element model of an intact tibiofemoral joint was reconstructed. Three ACL constitutive models were compared under different joint loads (such as anterior tibial force, varus tibial torque, and valgus tibial torque) to investigate the effect of the change of the ACL constitutive model. The three constitutive models corresponded to an isotropic hyperelasticity model, a transversely isotropic hyperelasticity model with neo-Hookean ground substance description, and a transversely isotropic hyperelastic model with nonlinear ground substance description. Although the material properties of these constitutive equations were fitted on the same uniaxial tension stress-strain curve, the change of the ACL material constitutive model was found to induce altered joint kinematics and biomechanics. The effect of different ACL constitutive equations on joint kinematics depended on both deformation direction and load type. The variation in the ACL constitutive models would influence the joint kinematic results greatly in both the anterior and internal directions under anterior tibial force as well as some other deformations such as the anterior and medial tibial translations under valgus tibial torque, and the medial tibial translation and internal rotation under varus torque. It was revealed that the transversely isotropic hyperelastic model with nonlinear ground substance description (FE model III) was the best representation of the realistic ACL property by a

  13. A novel technique to incorporate structural prior information into multi-modal tomographic reconstruction

    NASA Astrophysics Data System (ADS)

    Kazantsev, Daniil; Ourselin, Sébastien; Hutton, Brian F.; Dobson, Katherine J.; Kaestner, Anders P.; Lionheart, William R. B.; Withers, Philip J.; Lee, Peter D.; Arridge, Simon R.

    2014-06-01

    There has been a rapid expansion of multi-modal imaging techniques in tomography. In biomedical imaging, patients are now regularly imaged using both single photon emission computed tomography (SPECT) and x-ray computed tomography (CT), or using both positron emission tomography and magnetic resonance imaging (MRI). In non-destructive testing of materials both neutron CT (NCT) and x-ray CT are widely applied to investigate the inner structure of material or track the dynamics of physical processes. The potential benefits from combining modalities has led to increased interest in iterative reconstruction algorithms that can utilize the data from more than one imaging mode simultaneously. We present a new regularization term in iterative reconstruction that enables information from one imaging modality to be used as a structural prior to improve resolution of the second modality. The regularization term is based on a modified anisotropic tensor diffusion filter, that has shape-adapted smoothing properties. By considering the underlying orientations of normal and tangential vector fields for two co-registered images, the diffusion flux is rotated and scaled adaptively to image features. The images can have different greyscale values and different spatial resolutions. The proposed approach is particularly good at isolating oriented features in images which are important for medical and materials science applications. By enhancing the edges it enables both easy identification and volume fraction measurements aiding segmentation algorithms used for quantification. The approach is tested on a standard denoising and deblurring image recovery problem, and then applied to 2D and 3D reconstruction problems; thereby highlighting the capabilities of the algorithm. Using synthetic data from SPECT co-registered with MRI, and real NCT data co-registered with x-ray CT, we show how the method can be used across a range of imaging modalities.

  14. Anterior cruciate ligament reconstruction using quadriceps tendon autograft for adolescents with open physes- a technical note

    PubMed Central

    2011-01-01

    Background One major concern in the treatment of ACL lesions in children and adolescents with open physes is the risk of iatrogenic damage to the physes and a possibly resulting growth disturbance. Purpose The primary purpose of this article is to describe our technique of a transphyseal ACL reconstruction using quadriceps tendon-bone autograft in children and adolescents with open growth plates. The secondary aim is to report our early results in terms of postoperative growth disturbances which are considered to be a major concern in this challenging group of patients. It was our hypothesis that with our proposed technique no significant growth disturbances would occur. Methods From January 1997 to December 2007 49 consecutive children and adolescents with open growth plates were treated for a torn ACL using the aforementioned surgical technique. The patients (28 males and 21 females) with a median age at surgery of 13 (range 8-15) years were retrospectively evaluated. Outcome measures were follow-up radiographs (weight-bearing long leg radiographs of the injured and uninjured knee, anteroposterior and lateral views, a tangential view of the patella and a tunnel view of the injured knee) and follow-up notes (6 weeks, 3, 6, 12 months and until closing of physes) for occurrence of any tibial and/or femoral growth changes. Results: All of the 49 patients had a sufficient clinical and radiological follow-up (minimum 5 years, rate 100%). 48 cases did not show any clinical and radiological growth disturbance. One case of growth disturbance in a 10.5 years old girl was observed. She developed a progressive valgus-flexion deformity which was attributed to a malplacement of the autograft bone block within the femoral posterolateral epiphyseal plate leading to an early localized growth stop. None of the patients were reoperated due to ACL graft failure. Five of the patients underwent revision ACL surgery due to another adequate sports trauma after the growth-stop. The

  15. Analysis of algebraic reconstruction technique for accurate imaging of gas temperature and concentration based on tunable diode laser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Hui-Hui, Xia; Rui-Feng, Kan; Jian-Guo, Liu; Zhen-Yu, Xu; Ya-Bai, He

    2016-06-01

    An improved algebraic reconstruction technique (ART) combined with tunable diode laser absorption spectroscopy(TDLAS) is presented in this paper for determining two-dimensional (2D) distribution of H2O concentration and temperature in a simulated combustion flame. This work aims to simulate the reconstruction of spectroscopic measurements by a multi-view parallel-beam scanning geometry and analyze the effects of projection rays on reconstruction accuracy. It finally proves that reconstruction quality dramatically increases with the number of projection rays increasing until more than 180 for 20 × 20 grid, and after that point, the number of projection rays has little influence on reconstruction accuracy. It is clear that the temperature reconstruction results are more accurate than the water vapor concentration obtained by the traditional concentration calculation method. In the present study an innovative way to reduce the error of concentration reconstruction and improve the reconstruction quality greatly is also proposed, and the capability of this new method is evaluated by using appropriate assessment parameters. By using this new approach, not only the concentration reconstruction accuracy is greatly improved, but also a suitable parallel-beam arrangement is put forward for high reconstruction accuracy and simplicity of experimental validation. Finally, a bimodal structure of the combustion region is assumed to demonstrate the robustness and universality of the proposed method. Numerical investigation indicates that the proposed TDLAS tomographic algorithm is capable of detecting accurate temperature and concentration profiles. This feasible formula for reconstruction research is expected to resolve several key issues in practical combustion devices. Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 61205151), the National Key Scientific Instrument and Equipment Development Project of China (Grant

  16. Prophylactic Bilateral Nipple-sparing Mastectomy and a Staged Breast Reconstruction Technique: Preliminary Results

    PubMed Central

    Tondu, Thierry; Thiessen, Filip; Tjalma, Wiebren A.A.

    2016-01-01

    More high-risk women with breast cancer are identified using genetic testing at a younger age. These young women often opt for prophylactic surgery. Most patients are reluctant for extra donor-site scars besides infections and necrosis. In order to reduce these risks, a two-stage breast reconstruction technique is used for high-risk women with large or ptotic breasts. We presume that this procedure will reduce the risk of skin envelope and nipple–areola complex (NAC) necrosis to less than 1%. In the first stage, an inferior pedicle reduction is performed to obtain large volume reduction with maximal safety for the NAC. The ptosis, skin excess, and malpositioning of the NAC are corrected safely at this stage. In the second stage, the skin-sparing mastectomy is performed with or without nipple sparing. During this procedure, the areola is never removed. A bilateral breast reconstruction is then performed with an immediate subpectoral prothesis or delayed with the use of a subpectoral tissue expander. In this way, we aim to meet the patient’s wish to undergo bilateral risk reducing mastectomy in breasts that need ptosis correction without donor-site scarring. This article describes the procedure and reports the preliminary data. PMID:27867298

  17. Computational estimation of resolution in reconstruction techniques utilizing sparsity, total variation, and nonnegativity

    NASA Astrophysics Data System (ADS)

    Dillon, Keith; Fainman, Yeshaiahu; Wang, Yu-Ping

    2016-09-01

    Techniques which exploit properties such as sparsity and total variation have provided the ability to reconstruct images that surpass the conventional limits of imaging. This leads to difficulties in assessing the result, as conventional metrics for resolution are no longer valid. We develop a numerical approach to evaluating the second-order statistics of the estimate by relating a confidence interval on the solution to a confidence interval on a pixel value, and from this we formulate an approach to estimating the spatial resolution. With this estimate, we can calculate the resolution at each point subject to chosen bounds on the desired precision and confidence. We demonstrate the method for limited-angle tomographic reconstructions utilizing nonnegativity, sparse regularization, total-variation minimization, and their combinations. This provides a means to visualize and understand the effect on the image inherent in these penalties and constraints. Examples are provided using simulated data for different methods, and the results are shown to agree with resolution calculated empirically via the local edge response.

  18. A mass reconstruction technique for a heavy resonance decaying to τ + τ -

    NASA Astrophysics Data System (ADS)

    Xia, Li-Gang

    2016-11-01

    For a resonance decaying to τ + τ -, it is difficult to reconstruct its mass accurately because of the presence of neutrinos in the decay products of the τ leptons. If the resonance is heavy enough, we show that its mass can be well determined by the momentum component of the τ decay products perpendicular to the velocity of the τ lepton, p ⊥, and the mass of the visible/invisible decay products, m vis/inv, for τ decaying to hadrons/leptons. By sampling all kinematically allowed values of p ⊥ and m vis/inv according to their joint probability distributions determined by the MC simulations, the mass of the mother resonance is assumed to lie at the position with the maximal probability. Since p ⊥ and m vis/inv are invariant under the boost in the τ lepton direction, the joint probability distributions are independent upon the τ’s origin. Thus this technique is able to determine the mass of an unknown resonance with no efficiency loss. It is tested using MC simulations of the physics processes pp → Z/h(125)/h(750) + X → ττ + X at 13 TeV. The ratio of the full width at half maximum and the peak value of the reconstructed mass distribution is found to be 20%-40% using the information of missing transverse energy. Supported by General Financial Grant from the China Postdoctoral Science Foundation (2015M581062)

  19. Tibial plateau fracture following gracilis-semitendinosus anterior cruciate ligament reconstruction: The tibial tunnel stress-riser.

    PubMed

    Sundaram, R O; Cohen, D; Barton-Hanson, N

    2006-06-01

    Tibial plateau fractures following anterior cruciate ligament (ACL) reconstruction are extremely rare. This is the first reported case of a tibial plateau fracture following four-strand gracilis-semitendinosus autograft ACL reconstruction. The tibial tunnel alone may behave as a stress riser which can significantly reduce bone strength.

  20. Three-Class EEG-Based Motor Imagery Classification Using Phase-Space Reconstruction Technique

    PubMed Central

    Djemal, Ridha; Bazyed, Ayad G.; Belwafi, Kais; Gannouni, Sofien; Kaaniche, Walid

    2016-01-01

    Over the last few decades, brain signals have been significantly exploited for brain-computer interface (BCI) applications. In this paper, we study the extraction of features using event-related desynchronization/synchronization techniques to improve the classification accuracy for three-class motor imagery (MI) BCI. The classification approach is based on combining the features of the phase and amplitude of the brain signals using fast Fourier transform (FFT) and autoregressive (AR) modeling of the reconstructed phase space as well as the modification of the BCI parameters (trial length, trial frequency band, classification method). We report interesting results compared with those present in the literature by utilizing sequential forward floating selection (SFFS) and a multi-class linear discriminant analysis (LDA), our findings showed superior classification results, a classification accuracy of 86.06% and 93% for two BCI competition datasets, with respect to results from previous studies. PMID:27563927

  1. Galaxy cluster mass reconstruction project - I. Methods and first results on galaxy-based techniques

    NASA Astrophysics Data System (ADS)

    Old, L.; Skibba, R. A.; Pearce, F. R.; Croton, D.; Muldrew, S. I.; Muñoz-Cuartas, J. C.; Gifford, D.; Gray, M. E.; der Linden, A. von; Mamon, G. A.; Merrifield, M. R.; Müller, V.; Pearson, R. J.; Ponman, T. J.; Saro, A.; Sepp, T.; Sifón, C.; Tempel, E.; Tundo, E.; Wang, Y. O.; Wojtak, R.

    2014-06-01

    This paper is the first in a series in which we perform an extensive comparison of various galaxy-based cluster mass estimation techniques that utilize the positions, velocities and colours of galaxies. Our primary aim is to test the performance of these cluster mass estimation techniques on a diverse set of models that will increase in complexity. We begin by providing participating methods with data from a simple model that delivers idealized clusters, enabling us to quantify the underlying scatter intrinsic to these mass estimation techniques. The mock catalogue is based on a Halo Occupation Distribution (HOD) model that assumes spherical Navarro, Frenk and White (NFW) haloes truncated at R200, with no substructure nor colour segregation, and with isotropic, isothermal Maxwellian velocities. We find that, above 1014M⊙, recovered cluster masses are correlated with the true underlying cluster mass with an intrinsic scatter of typically a factor of 2. Below 1014M⊙, the scatter rises as the number of member galaxies drops and rapidly approaches an order of magnitude. We find that richness-based methods deliver the lowest scatter, but it is not clear whether such accuracy may simply be the result of using an over-simplistic model to populate the galaxies in their haloes. Even when given the true cluster membership, large scatter is observed for the majority non-richness-based approaches, suggesting that mass reconstruction with a low number of dynamical tracers is inherently problematic.

  2. Breast volumetric analysis for aesthetic planning in breast reconstruction: a literature review of techniques

    PubMed Central

    Rozen, Warren Matthew; Spychal, Robert T.; Hunter-Smith, David J.

    2016-01-01

    Background Accurate volumetric analysis is an essential component of preoperative planning in both reconstructive and aesthetic breast procedures towards achieving symmetrization and patient-satisfactory outcome. Numerous comparative studies and reviews of individual techniques have been reported. However, a unifying review of all techniques comparing their accuracy, reliability, and practicality has been lacking. Methods A review of the published English literature dating from 1950 to 2015 using databases, such as PubMed, Medline, Web of Science, and EMBASE, was undertaken. Results Since Bouman’s first description of water displacement method, a range of volumetric assessment techniques have been described: thermoplastic casting, direct anthropomorphic measurement, two-dimensional (2D) imaging, and computed tomography (CT)/magnetic resonance imaging (MRI) scans. However, most have been unreliable, difficult to execute and demonstrate limited practicability. Introduction of 3D surface imaging has revolutionized the field due to its ease of use, fast speed, accuracy, and reliability. However, its widespread use has been limited by its high cost and lack of high level of evidence. Recent developments have unveiled the first web-based 3D surface imaging program, 4D imaging, and 3D printing. Conclusions Despite its importance, an accurate, reliable, and simple breast volumetric analysis tool has been elusive until the introduction of 3D surface imaging technology. However, its high cost has limited its wide usage. Novel adjunct technologies, such as web-based 3D surface imaging program, 4D imaging, and 3D printing, appear promising. PMID:27047788

  3. [New abdominal wall reconstruction technique with a plastic-rehabilitative intent (back pain improvement)].

    PubMed

    Palmieri, Beniamino; Grappolini, Simone; Blandini, Daniele; De-Anna, Dino; Savio, Stefano; Ferrari, Paolo; Ferrari, Giovanni; William, Pillosu; Campanini, Isabella; Guido, Vezzosi; Tenchini, Paolo; Benuzzi, Giorgia; Palmieri, Lucia

    2004-01-01

    Many abdominal wall reconstruction techniques have generally failed to pay attention to a number of anatomical considerations concerning the continuity of the thoraco-lumboabdominal fascia that envelops the dorsal and ventral muscles. We have introduced a new surgical technique (round mesh) developed to improve the abdominal wall weakness or pathology (hernia, laparocele) with the aim of restoring the muscular synergy between the anterior and posterior trunk compartments, thus improving sacroiliac stability, posture, and standing effort endurance. One hundred patients of both sexes were enrolled in this investigation. All were affected by abdominal wall impairment, frank hernia or laparocele, and had been complaining of lumbar and sciatic pain for long periods without any definite intervertebral disk pathology. They underwent pre- and postoperative subjective and objective evaluation and insertion of a prefascial polypropylene mesh with a posterior martingale that passes across the spine and paravertebral muscles, ending in two wider rectangles that are criss-crossed ventrally and finally sutured to the iliopubic brim. All the patients improved either subjectively or objectively with the round mesh procedure. This new technique is particularly useful in cases of reduction or impairment of the recti abdominis, transverse and oblique muscles, because simple suture and plication of these muscles is no guarantee of long-term functional restoration.

  4. New perspectives on ACL injury: On the role of repetitive sub-maximal knee loading in causing ACL fatigue failure.

    PubMed

    Wojtys, Edward M; Beaulieu, Mélanie L; Ashton-Miller, James A

    2016-12-01

    In this paper, we review a series of studies that we initiated to examine mechanisms of anterior cruciate ligament (ACL) injury in the hope that these injuries, and their sequelae, can be better prevented. First, using the earliest in vitro model of a simulated single-leg jump landing or pivot cut with realistic knee loading rates and trans-knee muscle forces, we identified the worst-case dynamic knee loading that causes the greatest peak ACL strain: Combined knee compression, flexion, and internal tibial rotation. We also identified morphologic factors that help explain individual susceptibility to ACL injury. Second, using the above knee loading, we introduced a possible paradigm shift in ACL research by demonstrating that the human ACL can fail by a sudden rupture in response to repeated sub-maximal knee loading. If that load is repeated often enough over a short time interval, the failure tended to occur proximally, as observed clinically. Third, we emphasize the value of a physical exam of the hip by demonstrating how limited internal axial rotation at the hip both increases the susceptibility to ACL injury in professional athletes, and also increases peak ACL strain during simulated pivot landings, thereby further increasing the risk of ACL fatigue failure. When training at-risk athletes, particularly females with their smaller ACL cross-sections, rationing the number and intensity of worst-case knee loading cycles, such that ligament degradation is within the ACL's ability to remodel, should decrease the risk for ACL rupture due to ligament fatigue failure.© 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2059-2068, 2016.

  5. Autologous Hamstring Anterior Cruciate Ligament Graft Failure Using the Anteromedial Portal Technique With Suspensory Femoral Fixation

    PubMed Central

    Galdi, Balazs; Reyes, Allan; Brabston, Eugene W.; Levine, William N.

    2015-01-01

    Background: The anteromedial portal technique for drilling of the femoral tunnel during anterior cruciate ligament (ACL) reconstruction has been advocated by many surgeons as allowing improved access to the anatomical footprint. Furthermore, suspensory fixation of soft tissue grafts has become popularized because of complications associated with cross-pin fixation. Concerns regarding the use of both have recently arisen. Purpose: To raise awareness of the increased risk of graft failure when using the anteromedial portal technique with suspensory femoral fixation during ACL reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: From November 1998 to August 2012, a total of 465 primary ACL reconstructions were performed using quadrupled hamstring autograft tendons, with drilling of the femoral tunnel performed via the transtibial portal. Graft fixation on the femur was achieved with cross-pin fixation, while interference screw fixation was used on the tibia. From September 2012 to October 2013, there were 69 reconstructions performed through an anteromedial portal. While there was no change in graft choice, a change was made to using suspensory femoral fixation. No other surgical or postoperative rehabilitation changes were made. Results: During the 14-year period in which ACL reconstructions were performed via the transtibial portal and with cross-pin fixation, 2 graft failures (0.4% failure rate) were reported. After switching to the anteromedial portal with suspensory fixation, 7 graft failures (10.1% failure rate) were reported over a 13-month period. These were 5 male and 2 female patients, with a mean age of 18.8 years—all elite athletes. The same surgical technique was used in all patients, and all patients had at least an 8 mm–diameter graft. Patients were cleared to return to sport at an average of 8.4 months postoperatively, after completing functional performance tests. Of the 7 patients, 6 sustained a rerupture of the graft within

  6. WE-G-18C-08: Real Time Tumor Imaging Using a Novel Dynamic Keyhole MRI Reconstruction Technique

    SciTech Connect

    Lee, D; Pollock, S; Whelan, B; Keall, P; Greer, P; Kim, T

    2014-06-15

    Purpose: To test the hypothesis that the novel Dynamic Keyhole MRI reconstruction technique can accelerate image acquisition whilst maintaining high image quality for lung cancer patients. Methods: 18 MRI datasets from 5 lung cancer patients were acquired using a 3T MRI scanner. These datasets were retrospectively reconstructed using (A) The novel Dynamic Keyhole technique, (B) The conventional keyhole technique and (C) the conventional zero filling technique. The dynamic keyhole technique in MRI refers to techniques in which previously acquired k-space data is used to supplement under sampled data obtained in real time. The novel Dynamic Keyhole technique utilizes a previously acquired a library of kspace datasets in conjunction with central k-space datasets acquired in realtime. A simultaneously acquired respiratory signal is utilized to sort, match and combine the two k-space streams with respect to respiratory displacement. Reconstruction performance was quantified by (1) comparing the keyhole size (which corresponds to imaging speed) required to achieve the same image quality, and (2) maintaining a constant keyhole size across the three reconstruction methods to compare the resulting image quality to the ground truth image. Results: (1) The dynamic keyhole method required a mean keyhole size which was 48% smaller than the conventional keyhole technique and 60% smaller than the zero filling technique to achieve the same image quality. This directly corresponds to faster imaging. (2) When a constant keyhole size was utilized, the Dynamic Keyhole technique resulted in the smallest difference of the tumor region compared to the ground truth. Conclusion: The dynamic keyhole is a simple and adaptable technique for clinical applications requiring real-time imaging and tumor monitoring such as MRI guided radiotherapy. Based on the results from this study, the dynamic keyhole method could increase the imaging frequency by a factor of five compared with full k

  7. Three-dimensional reconstruction of flame temperature and emissivity distribution using optical tomographic and two-colour pyrometric techniques

    NASA Astrophysics Data System (ADS)

    Moinul Hossain, Md; Lu, Gang; Sun, Duo; Yan, Yong

    2013-07-01

    This paper presents an experimental investigation, visualization and validation in the three-dimensional (3D) reconstruction of flame temperature and emissivity distributions by using optical tomographic and two-colour pyrometric techniques. A multi-camera digital imaging system comprising eight optical imaging fibres and two RGB charged-couple device (CCD) cameras are used to acquire two-dimensional (2D) images of the flame simultaneously from eight equiangular directions. A combined logical filtered back-projection (LFBP) and simultaneous iterative reconstruction and algebraic reconstruction technique (SART) algorithm is utilized to reconstruct the grey-level intensity of the flame for the two primary colour (red and green) images. The temperature distribution of the flame is then determined from the ratio of the reconstructed grey-level intensities and the emissivity is estimated from the ratio of the grey level of a primary colour image to that of a blackbody source at the same temperature. The temperature measurement of the system was calibrated using a blackbody furnace as a standard temperature source. Experimental work was undertaken to validate the flame temperature obtained by the imaging system against that obtained using high-precision thermocouples. The difference between the two measurements is found no greater than ±9%. Experimental results obtained on a laboratory-scale propane fired combustion test rig demonstrate that the imaging system and applied technical approach perform well in the reconstruction of the 3D temperature and emissivity distributions of the sooty flame.

  8. Irradiated homologous tarsal plate banking: A new alternative in eyelid reconstruction. Part I. Technique and animal research

    SciTech Connect

    Jordan, D.R.; Tse, D.T.; Anderson, R.L.; Hansen, S.O. )

    1990-01-01

    Reconstruction of full thickness eyelid defects requires the correction of both posterior lamella (tarsus, conjunctiva) and anterior lamella (skin, muscle). Tarsal substitutes including banked sclera, nasal cartilage, ear cartilage, and periosteum can be beneficial for posterior lamellar repair, while anterior lamellar replacement, including skin grafts, pedicle flaps, advancement flaps, etc., is important to cover the posterior reconstructed portion. At times, due to extensive tissue loss, the eyelid reconstruction can be particularly challenging. We have found an alternative posterior lamellar reconstructive technique utilizing irradiated homologous tarsal plate that can be particularly useful in selected cases of severe tissue loss. The experimental surgical procedure in monkeys and the histological fate of the implanted tarsus is described in Part I, and followed in Part II by our experience with this tissue in six human patients.

  9. A pseudo-discrete algebraic reconstruction technique (PDART) prior image-based suppression of high density artifacts in computed tomography

    NASA Astrophysics Data System (ADS)

    Pua, Rizza; Park, Miran; Wi, Sunhee; Cho, Seungryong

    2016-12-01

    We propose a hybrid metal artifact reduction (MAR) approach for computed tomography (CT) that is computationally more efficient than a fully iterative reconstruction method, but at the same time achieves superior image quality to the interpolation-based in-painting techniques. Our proposed MAR method, an image-based artifact subtraction approach, utilizes an intermediate prior image reconstructed via PDART to recover the background information underlying the high density objects. For comparison, prior images generated by total-variation minimization (TVM) algorithm, as a realization of fully iterative approach, were also utilized as intermediate images. From the simulation and real experimental results, it has been shown that PDART drastically accelerates the reconstruction to an acceptable quality of prior images. Incorporating PDART-reconstructed prior images in the proposed MAR scheme achieved higher quality images than those by a conventional in-painting method. Furthermore, the results were comparable to the fully iterative MAR that uses high-quality TVM prior images.

  10. Muscle function is associated with future patient-reported outcomes in young adults with ACL injury

    PubMed Central

    Flosadottir, Vala; Roos, Ewa M; Ageberg, Eva

    2016-01-01

    Background/aim Consequences of an anterior cruciate ligament (ACL) injury include worse patient-reported outcomes (PROs) and a decrease in activity level. Muscle function can be improved by targeted exercise. Our aims were to investigate cross-sectional and longitudinal associations among lower extremity muscle function and PROs after ACL injury. Methods Fifty-four participants (15 women, mean 30 years) with ACL injury or reconstruction, from the Knee Anterior Cruciate Ligament, Nonsurgical versus Surgical Treatment (KANON) trial (ISRCTN84752559), were assessed with hop performance, muscle power and postural orientation 3 years (SD 0.85) after ACL injury. PROs at 3 and 5 years after injury included Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales Function in sport and recreation (KOOS Sport/rec) and Knee-related Quality of life (KOOS QoL), KOOS item Q3 (KOOS Q3), Tegner Activity Scale and Activity Rating Scale (ARS). Partial Spearman's rank-order correlation was used to analyse correlations between muscle function and PROs, controlling for gender and treatment. Results Numerous cross-sectional correlations were observed between muscle function and PROs (rsp≈0.3–0.5, p≤0.045). Worse hop performance and worse postural orientation were associated with worse KOOS scores 2 years later (rsp≥0.280, p≤0.045). Worse muscle power was associated with lower future ARS scores (rsp=0.281, p=0.044). Conclusions The moderate associations suggest that improving muscle function during rehabilitation could improve present and future PROs. PMID:27900196

  11. Simulation and Track Reconstruction Techniques for the J-PARC muon g-2 experiment

    NASA Astrophysics Data System (ADS)

    Tsilias, Paschalis; Lee, Myeong Jae

    2017-03-01

    The Muon g-2/EDM proposed experiment at J-PARC is a promising and innovative attempt at the field of Precision Physics. The sensitivity goal of 0.1 ppm will test the limits of our current understanding, and may probe for Beyond the Standard Model observations. This paper seeks out to investigate the computational techniques required by the experiment. The GEANT4 [1] framework was used to simulate the detector setup, according to the experiment's Conceptual Design Report (CDR) [2]. This allowed to observe the event hierarchy in different energies, generate signal hit data, and construct an event-selection algorithm. ROOT and GDML enabled us to use the geometry and parsed output data in a platform-independent way. Using techniques pertaining to Machine Learning and Image Feature extraction, such as the Canny Edge detection and the Hough Transform, we were able to construct a generic representation of `track families' from each event category. Finally, the modular GENFIT2 [3] framework was used to implement the Kalman Filter [4] along with an Deterministic Annealing Filter (DAF) [5] and the Runge-Kutta stepper to reconstruct tracks from a few digitized, smeared singular event data.

  12. La reconstruction du sourcil par greffon composite du cuir chevelu: une astuce pour faciliter la technique

    PubMed Central

    El Omari, Mounia; El Mazouz, Samir; Gharib, Noureddine; EL Abbassi, Abdallah

    2015-01-01

    Les sourcils jouent un rôle important dans l’équilibre esthétique du visage. Leur reconstruction ou ophriopoïése, après séquelle de brûlure fait partie intégrante du programme de réhabilitation de la face brûlée. Plusieurs techniques ont été décrites. Nous insistons ici sur l'intérêt d'une technique simple, à la portée de tous les chirurgiens, et dont la méthode et les résultats peuvent être améliorés par un dessin bien planifié des zones donneuse et receveuse: la greffe composite prélevée au niveau du cuir chevelu dessinée à l'aide d'un calque du sourcil controlatéral. PMID:26401195

  13. Reconstructing source terms from atmospheric concentration measurements: Optimality analysis of an inversion technique

    NASA Astrophysics Data System (ADS)

    Turbelin, Grégory; Singh, Sarvesh Kumar; Issartel, Jean-Pierre

    2014-12-01

    In the event of an accidental or intentional contaminant release in the atmosphere, it is imperative, for managing emergency response, to diagnose the release parameters of the source from measured data. Reconstruction of the source information exploiting measured data is called an inverse problem. To solve such a problem, several techniques are currently being developed. The first part of this paper provides a detailed description of one of them, known as the renormalization method. This technique, proposed by Issartel (2005), has been derived using an approach different from that of standard inversion methods and gives a linear solution to the continuous Source Term Estimation (STE) problem. In the second part of this paper, the discrete counterpart of this method is presented. By using matrix notation, common in data assimilation and suitable for numerical computing, it is shown that the discrete renormalized solution belongs to a family of well-known inverse solutions (minimum weighted norm solutions), which can be computed by using the concept of generalized inverse operator. It is shown that, when the weight matrix satisfies the renormalization condition, this operator satisfies the criteria used in geophysics to define good inverses. Notably, by means of the Model Resolution Matrix (MRM) formalism, we demonstrate that the renormalized solution fulfils optimal properties for the localization of single point sources. Throughout the article, the main concepts are illustrated with data from a wind tunnel experiment conducted at the Environmental Flow Research Centre at the University of Surrey, UK.

  14. Improving the accuracy of mandibular reconstruction with vascularized iliac crest flap: Role of computer-assisted techniques.

    PubMed

    Zhang, Wen-Bo; Yu, Yao; Wang, Yang; Mao, Chi; Liu, Xiao-Jing; Guo, Chuan-Bin; Yu, Guang-Yan; Peng, Xin

    2016-11-01

    While vascularized iliac crest flap is widely used for mandibular reconstruction, it is often challenging to predict the clinical outcome in a conventional operation based solely on the surgeon's experience. Herein, we aimed to improve this procedure by using computer-assisted techniques. We retrospectively reviewed records of 45 patients with mandibular tumor who underwent mandibulectomy and reconstruction with vascularized iliac crest flap from January 2008 to June 2015. Computer-assisted techniques including virtual plan, stereomodel, pre-bending individual reconstruction plate, and surgical navigation were used in 15 patients. The other 30 patients underwent conventional surgery based on the surgeon's experience. Condyle position and reconstructed mandible contour were evaluated based on post-operative computed tomography. Complications were also evaluated during the follow-up. Flap success rate of the patients was 95.6% (43/45). Those in the computer-assisted group presented with better outcomes of the mandibular contour (p = 0.001) and condyle position (p = 0.026). Further, they also experienced beneficial dental restoration (p = 0.011) and postoperative appearance (p = 0.028). The difference between postoperative effect and virtual plan was within the acceptable error margin. There is no significant difference in the incidence of post-operative complications. Thus, computer-assisted techniques can improve the clinical outcomes of mandibular reconstruction with vascularized iliac crest flap.

  15. 3D kinematic in-vitro comparison of posterolateral corner reconstruction techniques in a combined injury model.

    PubMed

    Nau, Thomas; Chevalier, Yan; Hagemeister, Nicola; Duval, Nicolas; deGuise, Jacques A

    2005-10-01

    With the variable injury pattern to the posterolateral structures (PLS) of the knee, a number of reconstructive procedures have been introduced. It was the aim of the present study to evaluate the resulting 3D kinematics following three different surgical techniques of reconstruction in a combined posterior cruciate ligament (PCL)/PLS injury model. In nine human cadaveric knees, 3D kinematics were recorded during the path of flexion-extension using a computer based custom made 6-degree-of-freedom (DOF) testing apparatus. Additional laxity tests were conducted at 30 and 90 degrees of flexion. Testing was performed before and after cutting the PLS and PCL, followed by PCL reconstruction alone. Reconstructing the posterolateral corner, three surgical techniques were compared: (a) the posterolateral corner sling procedure (PLCS), (b) the biceps tenodesis (BT), and (c) a bone patellar-tendon bone (BTB) allograft reconstruction. Posterior as well as rotational laxity were significantly increased after PCL/PLS transection at 30 and 90 degrees of flexion. Isolated PCL reconstruction resulted in a remaining external rotational deficiency for both tested flexion angles. Additional PLS reconstruction closely restored external rotation as well as posterior translation to intact values by all tested procedures. Compared to the intact knee, dynamic testing revealed a significant internal tibial rotation for (b) BT (mean=3.9 degrees, p=0.043) and for (c) BTB allograft (mean=4.3 degrees, p=0.012). (a) The PLCS demonstrated a tendency to internal tibial rotation between 0 and 60 degrees of flexion (mean=2.2 degrees, p=0.079). Varus/valgus rotation as well as anterior/posterior translation did not show significant differences for any of the tested techniques. The present study shows that despite satisfying results in static laxity testing, pathological 3D knee kinematics were not restored to normal, demonstrated by a nonphysiological internal tibial rotation during the path of

  16. Arthroscopic Labral Reconstruction of the Hip Using Iliotibial Band Allograft and Front-to-Back Fixation Technique

    PubMed Central

    White, Brian J.; Herzog, Mackenzie M.

    2016-01-01

    Labral repair has been shown to be an effective treatment option with excellent early outcomes; however, in cases of severe labral damage or when the labral tissue is too large or diminutive, labral repair may be less effective. The purpose of this article is to present a modified technique for hip labral reconstruction using iliotibial band allograft tissue and a front-to-back fixation technique. The described technique is modified from the original report of a technique for arthroscopic labral reconstruction. The front-to-back technique allows the surgeon to make a graft that is longer than necessary and cut excess graft after front-to-back fixation, resulting in the correct graft size and a reproducible procedure. Allograft tissue offers several advantages, including the ability to control graft thickness and length, as well as the ability to eliminate donor-site morbidity. This procedure adds to the available techniques for treatment of labral pathology by providing a labral reconstruction technique using allograft tissue. PMID:27073784

  17. Biological enhancement of graft-tunnel healing in anterior cruciate ligament reconstruction

    PubMed Central

    SACCOMANNO, MARISTELLA F.; CAPASSO, LUIGI; FRESTA, LUCA; MILANO, GIUSEPPE

    2016-01-01

    The sites where graft healing occurs within the bone tunnel and where the intra-articular ligamentization process takes place are the two most important sites of biological incorporation after anterior cruciate ligament (ACL) reconstruction, since they help to determine the mechanical behavior of the femur-ACL graft-tibia complex. Graft-tunnel healing is a complex process influenced by several factors, such as type of graft, preservation of remnants, bone quality, tunnel length and placement, fixation techniques and mechanical stress. In recent years, numerous experimental and clinical studies have been carried out to evaluate potential strategies designed to enhance and optimize the biological environment of the graft-tunnel interface. Modulation of inflammation, tissue engineering and gene transfer techniques have been applied in order to obtain a direct-type fibrocartilaginous insertion of the ACL graft, similar to that of native ligament, and to accelerate the healing process of tendon grafts within the bone tunnel. Although animal studies have given encouraging results, clinical studies are lacking and their results do not really support the use of the various strategies in clinical practice. Further investigations are therefore needed to optimize delivery techniques, therapeutic concentrations, maintenance of therapeutic effects over time, and to reduce the risk of undesirable effects in clinical practice. PMID:27900311

  18. Reconstruction of Kuwada grade IV chronic achilles tendon rupture by minimally invasive technique

    PubMed Central

    Miao, Xudong; Wu, Yongping; Tao, Huimin; Yang, Disheng; Huang, Lu

    2016-01-01

    Background: Transfer of a flexor hallucis longus (FHL) tendon can not only reconstruct the Achilles tendon but also provide ischemic tendinous tissues with a rich blood supply to enhance wound healing. This retrospective study aims to investigate clinical outcomes in patients who underwent repair of Kuwada grade IV chronic Achilles tendon rupture with long hallucis longus tendons harvested using a minimally invasive technique. Materials and Methods: 35 patients who were treated for Kuwada grade IV Achilles tendon injuries from July 2006 to June 2011 were included in this retrospective study. The age ranged between 23 and 71 years. The duration from primary injury to surgery ranged from 29 days to 34 months (mean value, 137.6 days). All 35 patients had difficulties in lifting their calves. Thirty two were followed up for a mean 32.2 months (range 18–72 months), whereas three were lost to followup. Magnetic resonance imaging (MRI) showed that the tendon rupture gap ranged from 6.0 to 9.2 cm. During surgery, a 2.0 cm minor incision was made vertically in the medial plantar side of the midfoot, and a 1.5 cm minor transverse incision was made in the plantar side of the interphalangeal articulation of the great toe to harvest the FHL tendon, and the tendon was fixed to the calcaneus with suture anchors. Postoperative appearance and function were evaluated by physiotherapists based American Orthopedic Foot and Ankle Society-ankle and hindfoot score (AOFAS-AH), and Leppilahti Achilles tendon ratings. Results: Results were assessed in 32 patients. Except for one patient who suffered complications because of wound disruption 10 days after the operation, all other patients had primary wound healing, with 28 of 32 able to go up on their toes at last followup. The AOFAS-AH score was increased from preoperative (51.92 ± 7.08) points to (92.56 ± 6.71) points; Leppilahti Achilles tendon score was increased from preoperative (72.56 ± 7.43) to (92.58 ± 5.1). There were

  19. 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

  20. Successive binary algebraic reconstruction technique: an algorithm for reconstruction from limited angle and limited number of projections decomposed into individual components.

    PubMed

    Khaled, Alia S; Beck, Thomas J

    2013-01-01

    Relatively high radiation CT techniques are being widely used in diagnostic imaging raising the concerns about cancer risk especially for routine screening of asymptomatic populations. An important strategy for dose reduction is to reduce the number of projections, although doing so with high image quality is technically difficult. We developed an algorithm to reconstruct discrete (limited gray scale) images decomposed into individual tissue types from a small number of projections acquired over a limited view angle. The algorithm was tested using projection simulations from segmented CT scans of different cross sections including mid femur, distal femur and lower leg. It can provide high quality images from as low as 5-7 projections if the skin boundary of the cross section is used as prior information in the reconstruction process, and from 11-13 projections if the skin boundary is unknown.

  1. A new technique for enlargement and reconstruction of digital sensor imagery

    NASA Technical Reports Server (NTRS)

    Rhea, W. Joseph

    1991-01-01

    A new image enlargement and reconstruction routine, the digital image enlarging balanced reconstruction algorithm (DIEBRA), is described. Using a highly modified form of 'balanced' two-dimensional polynomial interpolation, this program enlarges digital imagery, creating synthetic high spatial resolution images. Statistical analysis shows the DIEBRA-generated imagery to be significantly closer to true high spatial resolution imagery at all frequencies than imagery generated by a cubic convolutional reconstruction filter.

  2. The effects of endothelial cells-preserving technique on microsurgical vascular reconstruction in biliary tract malignancy: report of twenty cases.

    PubMed

    Miyagi, Shigehito; Nakanishi, Wataru; Kawagishi, Naoki; Yoshida, Hiroshi; Unno, Michiaki; Ohuchi, Noriaki

    2014-01-01

    We describe our experience of resectional surgery with microsurgical reconstruction of the hepatic arteries in 20 cases with biliary tract malignancy. Hepatic artery thrombosis (HAT) is a lethal complication; therefore, it is important to perform microsurgical reconstruction safely. Recently, we adopted the back wall support suture technique with double needle sutures that does not require the damaged short arteries to be turned over. In this technique, each stitch is placed from the inner side to the outer side to keep endothelial cells. The purpose of this study was to develop safety methods. From 2003 to 2012, 20 patients with biliary tract malignancy with possible involvement of the hepatic arteries underwent resectional surgery with microvascular reconstruction (cholangiocarcinoma: n = 15; others: n = 5). For this cohort study, patients were divided into two groups: group I (n = 5) included patients who underwent the conventional 'twist technique' and group II (n = 15) included patients who underwent the microsurgical back wall support suture technique with double needle sutures and received gabexate mesilate, a strong serine protease inhibitor (40 mg/kg/day) for 7 days. We investigated HAT using Doppler ultrasonography for 10 days. No postoperative mortality was observed. The incidence of HAT was only one case in group I, and there was no significant difference between the two groups. However, the value of the pulsatile index and acceleration time were significantly improved in group II. In conclusion, the back wall support suture technique with gabexate mesilate administration during microvascular reconstruction was found to be safe. It is important to keep endothelial cells healthy for microvascular reconstruction.

  3. Reconstructing the past: methods and techniques for the digital restoration of fossils

    PubMed Central

    2016-01-01

    During fossilization, the remains of extinct organisms are subjected to taphonomic and diagenetic processes. As a result, fossils show a variety of preservational artefacts, which can range from small breaks and cracks, disarticulation and fragmentation, to the loss and deformation of skeletal structures and other hard parts. Such artefacts can present a considerable problem, as the preserved morphology of fossils often forms the basis for palaeontological research. Phylogenetic and taxonomic studies, inferences on appearance, ecology and behaviour and functional analyses of fossil organisms strongly rely on morphological information. As a consequence, the restoration of fossil morphology is often a necessary prerequisite for further analyses. Facilitated by recent computational advances, virtual reconstruction and restoration techniques offer versatile tools to restore the original morphology of fossils. Different methodological steps and approaches, as well as software are outlined and reviewed here, and advantages and disadvantages are discussed. Although the complexity of the restorative processes can introduce a degree of interpretation, digitally restored fossils can provide useful morphological information and can be used to obtain functional estimates. Additionally, the digital nature of the restored models can open up possibilities for education and outreach and further research. PMID:27853548

  4. Reconstructing the past: methods and techniques for the digital restoration of fossils

    NASA Astrophysics Data System (ADS)

    Lautenschlager, Stephan

    2016-10-01

    During fossilization, the remains of extinct organisms are subjected to taphonomic and diagenetic processes. As a result, fossils show a variety of preservational artefacts, which can range from small breaks and cracks, disarticulation and fragmentation, to the loss and deformation of skeletal structures and other hard parts. Such artefacts can present a considerable problem, as the preserved morphology of fossils often forms the basis for palaeontological research. Phylogenetic and taxonomic studies, inferences on appearance, ecology and behaviour and functional analyses of fossil organisms strongly rely on morphological information. As a consequence, the restoration of fossil morphology is often a necessary prerequisite for further analyses. Facilitated by recent computational advances, virtual reconstruction and restoration techniques offer versatile tools to restore the original morphology of fossils. Different methodological steps and approaches, as well as software are outlined and reviewed here, and advantages and disadvantages are discussed. Although the complexity of the restorative processes can introduce a degree of interpretation, digitally restored fossils can provide useful morphological information and can be used to obtain functional estimates. Additionally, the digital nature of the restored models can open up possibilities for education and outreach and further research.

  5. 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…

  6. Knee biomechanics during a jump-cut maneuver: Effects of gender & ACL surgery

    PubMed Central

    Miranda, Daniel L.; Fadale, Paul D.; Hulstyn, Michael J.; Shalvoy, Robert M.; Machan, Jason T.; Fleming, Braden C.

    2012-01-01

    Purpose The purpose of this study was to compare kinetic and knee kinematic measurements from male and female ACL-intact (ACLINT) and ACL-reconstructed (ACLREC) subjects during a jump-cut maneuver using biplanar videoradiography. Methods Twenty subjects were recruited; 10 ACLINT (5 males, 5 females) and 10 ACLREC (4 males, 6 females; five years post surgery). Each subject performed a jump-cut maneuver by landing on a single leg and performing a 45° side-step cut. Ground reaction force was measured by a force plate and expressed relative to body weight. Six-degree-of-freedom knee kinematics were determined from a biplanar videoradiography system and an optical motion capture system. Results ACLINT female subjects landed with a larger peak vertical GRF (p<0.001) compared to ACLINT male subjects. ACLINT subjects landed with a larger peak vertical GRF (p≤0.036) compared to ACLREC subjects. Regardless of ACL reconstruction status, female subjects underwent less knee flexion angle excursion (p=0.002) and had an increased average rate of anterior tibial translation (0.05±0.01%/millisecond; p=0.037) after contact compared to male subjects. Furthermore, ACLREC subjects had a lower rate of anterior tibial translation compared to ACLINT subjects (0.05±0.01%/millisecond; p=0.035). Finally, no striking differences were observed in other knee motion parameters. Conclusion Women permit a smaller amount of knee flexion angle excursion during a jump-cut maneuver, resulting in a larger peak vertical GRF and increased rate of anterior tibial translation. Notably, ACLREC subjects also perform the jump cut maneuver with lower GRF than ACLINT subjects five years post surgery. This study proposes a causal sequence whereby increased landing stiffness (larger peak vertical GRF combined with less knee flexion angle excursion) leads to an increased rate of anterior tibial translation while performing a jump-cut maneuver. PMID:23190595

  7. Assessment of sub-milli-sievert abdominal computed tomography with iterative reconstruction techniques of different vendors

    PubMed Central

    Padole, Atul; Sainani, Nisha; Lira, Diego; Khawaja, Ranish Deedar Ali; Pourjabbar, Sarvenaz; Lo Gullo, Roberto; Otrakji, Alexi; Kalra, Mannudeep K

    2016-01-01

    AIM: To assess diagnostic image quality of reduced dose (RD) abdominal computed tomography (CT) with 9 iterative reconstruction techniques (IRTs) from 4 different vendors to the standard of care (SD) CT. METHODS: In an Institutional Review Board approved study, 66 patients (mean age 60 ± 13 years, 44 men, and 22 women) undergoing routine abdomen CT on multi-detector CT (MDCT) scanners from vendors A, B, and C (≥ 64 row CT scanners) (22 patients each) gave written informed consent for acquisition of an additional RD CT series. Sinogram data of RD CT was reconstructed with two vendor-specific and a vendor-neutral IRTs (A-1, A-2, A-3; B-1, B-2, B-3; and C-1, C-2, C-3) and SD CT series with filtered back projection. Subjective image evaluation was performed by two radiologists for each SD and RD CT series blinded and independently. All RD CT series (198) were assessed first followed by SD CT series (66). Objective image noise was measured for SD and RD CT series. Data were analyzed by Wilcoxon signed rank, kappa, and analysis of variance tests. RESULTS: There were 13/50, 18/57 and 9/40 missed lesions (size 2-7 mm) on RD CT for vendor A, B, and C, respectively. Missed lesions includes liver cysts, kidney cysts and stone, gall stone, fatty liver, and pancreatitis. There were also 5, 4, and 4 pseudo lesions (size 2-3 mm) on RD CT for vendor A, B, and C, respectively. Lesions conspicuity was sufficient for clinical diagnostic performance for 6/24 (RD-A-1), 10/24 (RD-A-2), and 7/24 (RD-A-3) lesions for vendor A; 5/26 (RD-B-1), 6/26 (RD-B-2), and 7/26 (RD-B-3) lesions for vendor B; and 4/20 (RD-C-1) 6/20 (RD-C-2), and 10/20 (RD-C-3) lesions for vendor C (P = 0.9). Mean objective image noise in liver was significantly lower for RD A-1 compared to both RD A-2 and RD A-3 images (P < 0.001). Similarly, mean objective image noise lower for RD B-2 (compared to RD B-1, RD B-3) and RD C-3 (compared to RD C-1 and C-2) (P = 0.016). CONCLUSION: Regardless of IRTs and MDCT vendors

  8. Quantitative evaluation of ASiR image quality: an adaptive statistical iterative reconstruction technique

    NASA Astrophysics Data System (ADS)

    Van de Casteele, Elke; Parizel, Paul; Sijbers, Jan

    2012-03-01

    Adaptive statistical iterative reconstruction (ASiR) is a new reconstruction algorithm used in the field of medical X-ray imaging. This new reconstruction method combines the idealized system representation, as we know it from the standard Filtered Back Projection (FBP) algorithm, and the strength of iterative reconstruction by including a noise model in the reconstruction scheme. It studies how noise propagates through the reconstruction steps, feeds this model back into the loop and iteratively reduces noise in the reconstructed image without affecting spatial resolution. In this paper the effect of ASiR on the contrast to noise ratio is studied using the low contrast module of the Catphan phantom. The experiments were done on a GE LightSpeed VCT system at different voltages and currents. The results show reduced noise and increased contrast for the ASiR reconstructions compared to the standard FBP method. For the same contrast to noise ratio the images from ASiR can be obtained using 60% less current, leading to a reduction in dose of the same amount.

  9. Physiotherapy after reconstruction of anterior cruciate ligament

    PubMed Central

    Pereira, Maitê; Vieira, Neiva de Souza; Brandão, Eduardo da Rosa; Ruaro, João Afonso; Grignet, Rodrigo Juliano; Fréz, Andersom Ricardo

    2012-01-01

    The purpose of this study was to evaluate the existence of differences in the rehabilitation of patients after ACL reconstruction using bone-patellar tendon-bone graft and the four-strand semitendinosus and gracilis tendon grafts, through a literature revision. The researched databases were MEDLINE, EMBASE, LILACS, COCHRANE and PEDro. The inclusion criteria were published studies with methodology draw from randomized clinical trials with or without meta-analysis, individuals with ACL injury, associated or not to meniscal injury, submitted to ligamentoplasty using the bone-patellar tendon-bone graft and the four-strand semitendinosus and gracilis tendon grafts and physiotherapy; clinical trials comparing the differences in the rehabilitation of these patients, in Portuguese, English and Spanish, from 1990 to June, 2011. Five clinical trials were reviewed. No difference was observed between the techniques, however, with a recommendation for a less aggressive rehabilitation and greater attention to the strengthening of the hamstring when they are used as grafts. PMID:24453634

  10. Can course format influence the performance of students in an advanced cardiac life support (ACLS) program?

    PubMed

    Garrido, F D; Romano, M M D; Schmidt, A; Pazin-Filho, A

    2011-01-01

    Advanced cardiac life support (ACLS) is a problem-based course that employs simulation techniques to teach the standard management techniques of cardiovascular emergencies. Its structure is periodically revised according to new versions of the American Heart Association guidelines. Since it was introduced in Brazil in 1996, the ACLS has been through two conceptual and structural changes. Detailed documented reports on the effect of these changes on student performance are limited. The objective of the present study was to evaluate the effect of conceptual and structural changes of the course on student ACLS performance at a Brazilian training center. This was a retrospective study of 3266 students divided into two groups according to the teaching model: Model 1 (N = 1181; 1999-2003) and Model 2 (N = 2085; 2003-2007). Model 2 increased practical skill activities to 75% of the total versus 60% in Model 1. Furthermore, the teaching material provided to the students before the course was more objective than that used for Model 1. Scores greater than 85% in the theoretical evaluation and approval in the evaluation of practice by the instructor were considered to be a positive outcome. Multiple logistic regression was used to adjust for potential confounders (specialty, residency, study time, opportunity to enhance practical skills during the course and location where the course was given). Compared to Model 1, Model 2 presented odds ratios (OR) indicating better performance in the theoretical (OR = 1.34; 95%CI = 1.10-1.64), practical (OR = 1.19; 95%CI = 0.90-1.57), and combined (OR = 1.38; 95%CI = 1.13-1.68) outcomes. Increasing the time devoted to practical skills did not improve the performance of ACLS students.

  11. Mechanoreceptor Reinnervation of Autografts Versus Allografts After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Young, Simon W.; Valladares, Roberto D.; Loi, Florence; Dragoo, Jason L.

    2016-01-01

    Background: Loss of proprioceptive function occurs after anterior cruciate ligament (ACL) rupture. Clinical, motor, and proprioceptive function is known to improve after ACL reconstruction but does not return to normal. While histological studies of human ACL allografts have been unable to demonstrate mechanoreceptor reinnervation, animal data suggest that reinnervation may occur when an autograft is used. Purpose: To compare the presence or absence of mechanoreceptors between allograft versus autograft after ACL reconstruction in humans. Study Design: Cohort study; Level of evidence, 3. Methods: Ten patients with previous ACL reconstruction presenting for either revision ACL surgery or knee arthroscopy for other reasons were enrolled in a prospective, comparative study. Five patients had a previous autograft ACL and 5 patients had an allograft. Biopsies, either from intact or ruptured grafts, were taken from identical locations as close to the femoral and tibial insertions as possible. Specimens were stained with hematoxylin-eosin (H-E) and monoclonal antibodies against neurofilament protein (NFP), known to be present in mechanoreceptor tissue. Immunohistochemical examination was carried out, and the number of NFP+ neural tissue analogs was counted and compared with that of native ACL tissue. Results: The mean time between original graft and biopsy was 6.9 years (range, 0.5-15 years). Histological examination showed significantly less NFP+ neural analogs in allograft and autograft patients than control tissue (mean number of NFP+ analogs per high-power field, 0.7 ± 0.9 [allograft] and 0.5 ± 0.8 [autograft] vs 4.7 ± 0.9 [controls]; P < .0001). There was no significant difference in NFP analogs between autograft and allograft tissue. Conclusion: We found a reduced concentration of NFP+ neural analogs in ACL grafts compared with native ACL tissue. This deficit exists irrespective of whether allograft or autograft is used. These findings may explain the continued

  12. Assessing reconstruction techniques of the Atlantic Ocean circulation variability during the last millennium

    NASA Astrophysics Data System (ADS)

    Moreno-Chamarro, Eduardo; Ortega, Pablo; González-Rouco, Fidel; Montoya, Marisa

    2017-02-01

    We assess the use of the meridional thermal-wind transport estimated from zonal density gradients to reconstruct the oceanic circulation variability during the last millennium in a forced simulation with the ECHO-G coupled climate model. Following a perfect-model approach, model-based pseudo-reconstructions of the Atlantic meridional overturning circulation (AMOC) and the Florida Current volume transport (FCT) are evaluated against their true simulated variability. The pseudo-FCT is additionally verified as proxy for AMOC strength and compared with the available proxy-based reconstruction. The thermal-wind component reproduces most of the simulated AMOC variability, which is mostly driven by internal climate dynamics during the preindustrial period and by increasing greenhouse gases afterwards. The pseudo-reconstructed FCT reproduces well the simulated FCT and reasonably well the variability of the AMOC strength, including the response to external forcing. The pseudo-reconstructed FCT, however, underestimates/overestimates the simulated variability at deep/shallow levels. Density changes responsible for the pseudo-reconstructed FCT are mainly driven by zonal temperature differences; salinity differences oppose but play a minor role. These results thus support the use of the thermal-wind relationship to reconstruct the oceanic circulation past variability, in particular at multidecadal timescales. Yet model-data comparison highlights important differences between the simulated and the proxy-based FCT variability. ECHO-G simulates a prominent weakening in the North Atlantic circulation that contrasts with the reconstructed enhancement. Our model results thus do not support the reconstructed FC minimum during the Little Ice Age. This points to a failure in the reconstruction, misrepresented processes in the model, or an important role of internal ocean dynamics.

  13. The Effects of Endothelial Cells-Preserving Technique on Microsurgical Vascular Reconstruction in Biliary Tract Malignancy: Report of Twenty Cases

    PubMed Central

    Miyagi, Shigehito; Nakanishi, Wataru; Kawagishi, Naoki; Yoshida, Hiroshi; Unno, Michiaki; Ohuchi, Noriaki

    2014-01-01

    We describe our experience of resectional surgery with microsurgical reconstruction of the hepatic arteries in 20 cases with biliary tract malignancy. Hepatic artery thrombosis (HAT) is a lethal complication; therefore, it is important to perform microsurgical reconstruction safely. Recently, we adopted the back wall support suture technique with double needle sutures that does not require the damaged short arteries to be turned over. In this technique, each stitch is placed from the inner side to the outer side to keep endothelial cells. The purpose of this study was to develop safety methods. From 2003 to 2012, 20 patients with biliary tract malignancy with possible involvement of the hepatic arteries underwent resectional surgery with microvascular reconstruction (cholangiocarcinoma: n = 15; others: n = 5). For this cohort study, patients were divided into two groups: group I (n = 5) included patients who underwent the conventional ‘twist technique’ and group II (n = 15) included patients who underwent the microsurgical back wall support suture technique with double needle sutures and received gabexate mesilate, a strong serine protease inhibitor (40 mg/kg/day) for 7 days. We investigated HAT using Doppler ultrasonography for 10 days. No postoperative mortality was observed. The incidence of HAT was only one case in group I, and there was no significant difference between the two groups. However, the value of the pulsatile index and acceleration time were significantly improved in group II. In conclusion, the back wall support suture technique with gabexate mesilate administration during microvascular reconstruction was found to be safe. It is important to keep endothelial cells healthy for microvascular reconstruction. PMID:24574945

  14. Current Trends in Anterior Cruciate Ligament Reconstruction: A Review.

    PubMed

    Vaishya, Raju; Agarwal, Amit Kumar; Ingole, Sachin; Vijay, Vipul

    2015-11-13

    Anterior cruciate ligament reconstruction (ACLR) is an accepted and established surgical technique for anterior cruciate ligament (ACL) injuries and is now being practiced across the globe in increasing numbers. Although most patients get good to excellent results in the short-term after ACLR, its consequences in the long-term in prevention or acceleration of knee osteoarthritis (OA) are not yet well-defined. Still, there are many debatable issues related to ACLR, such as the appropriate timing of surgery, graft selection, fixation methods of the graft, operative techniques, rehabilitation after surgery, and healing augmentation techniques. Most surgeons prefer not to wait long after an ACL injury to do an ACLR, as delayed reconstruction is associated with secondary damages to the intra- and periarticular structures of the knee. Autografts are the preferred choice of graft in primary ACLR, and hamstring tendons are the most popular amongst surgeons. Single bundle ACLR is being practiced by the majority, but double bundle ACLR is getting popular due to its theoretical advantage of providing more anatomical reconstruction. A preferred construct is the interference fixation (Bio-screw) at the tibial site and the suspensory method of fixation at the femoral site. In a single bundle hamstring graft, a transportal approach for creating a femoral tunnel has recently become more popular than the trans-tibial technique. Various healing augmentation techniques, including the platelet rich plasma (PRP), have been tried after ACLR, but there is still no conclusive proof of their efficacy. Accelerated rehabilitation is seemingly more accepted immediately after ACLR.

  15. Rhomboid Flap Technique in Breast-conserving Surgery: An Alternative Method for the Reconstruction of Lumpectomy Defects

    PubMed Central

    Menekşe, Ebru; Özyazıcı, Sefa; Karateke, Faruk; Turan, Ümit; Kuvvetli, Adnan; Gökler, Cihan; Özdoğan, Mehmet; Önel, Safa

    2015-01-01

    Objective We aimed to present our experience with rhomboid flap reconstruction, which is a simple technique, in breast cancer patients who underwent breast-conserving surgery. Methods We reviewed the medical records of 13 patients with breast cancer who underwent rhomboid flap reconstruction. The patients were evaluated for tumor size, safe surgical margin, and other clinical and pathological features. Results The mean age of the patients was 43.1 years (range: 28–69 years). The mean tumor diameter was 30.8 mm (range: 15–60 mm). The mean of the safe margin of resection was evaluated to be 17.8 mm (range: 5–30 mm). Re-excision was required for one patient in the same session. Conclusion Rhomboid flap reconstruction can facilitate the applicability of breast-conserving surgery in early breast cancer patients with large tumor-to-breast-size ratio or tumors close to the skin.

  16. 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

  17. Orthopedic Practice Patterns Relating to Anterior Cruciate Ligament Reconstruction in Elite Athletes.

    PubMed

    Erickson, Brandon J; Harris, Joshua D; Fillingham, Yale A; Cvetanovich, Gregory L; Bush-Joseph, Charles; Cole, Brian J; Bach, Bernard R; Verma, Nikhil N

    2015-12-01

    We conducted an online survey of National Hockey League (NHL), Major League Soccer (MLS), and US Olympic/World Cup Ski/Snowboard (Olympic) team orthopedic surgeons to determine practice patterns relating to anterior cruciate ligament (ACL) reconstruction in elite athletes. Of the 94 team orthopedic surgeons surveyed, 47 (50%) responded. Mean (SD) experience as a team physician was 7.73 (5.33) years for NHL, 6.77 (6.64) years for MLS, and 1.14 (0.36) years for Olympic. Mean (SD) number of ACL reconstructions performed in 2012 was 101 (51) for NHL, 78 (38) for MLS, and 110 (105) for Olympic. Overall, 33 surgeons (70.2%) indicated they would use bone-patellar tendon-bone (BPTB) autograft to treat their starting athletes. Twenty-one (44.7%) drilled the femoral tunnel through a transtibial portal, 36.2% through an anteromedial portal, and 12.8% by a 2-incision technique. All the surgeons used a single-bundle technique. Thirty-three (70.2%) did not recommend a brace for their elite athletes during play on return to sport (RTS). Twenty-seven NHL and MLS surgeons (81.8%) recommended RTS only after an athlete has passed a series of RTS tests (eg, Vail, single-leg hop). Most of the NHL, MLS, and Olympic team orthopedic surgeons who were surveyed perform their ACL reconstructions using BPTB autograft, using a single-bundle technique, and through a transtibial portal, and do not require bracing for their athletes returning to sport. Most required their athletes to complete a series of RTS tests before resuming competitive play.

  18. A technique for on-board CT reconstruction using both kilovoltage and megavoltage beam projections for 3D treatment verification.

    PubMed

    Yin, Fang-Fang; Guan, Huaiqun; Lu, Wenkai

    2005-09-01

    The technologies with kilovoltage (kV) and megavoltage (MV) imaging in the treatment room are now available for image-guided radiation therapy to improve patient setup and target localization accuracy. However, development of strategies to efficiently and effectively implement these technologies for patient treatment remains challenging. This study proposed an aggregated technique for on-board CT reconstruction using combination of kV and MV beam projections to improve the data acquisition efficiency and image quality. These projections were acquired in the treatment room at the patient treatment position with a new kV imaging device installed on the accelerator gantry, orthogonal to the existing MV portal imaging device. The projection images for a head phantom and a contrast phantom were acquired using both the On-Board Imager kV imaging device and the MV portal imager mounted orthogonally on the gantry of a Varian Clinac 21EX linear accelerator. MV projections were converted into kV information prior to the aggregated CT reconstruction. The multilevel scheme algebraic-reconstruction technique was used to reconstruct CT images involving either full, truncated, or a combination of both full and truncated projections. An adaptive reconstruction method was also applied, based on the limited numbers of kV projections and truncated MV projections, to enhance the anatomical information around the treatment volume and to minimize the radiation dose. The effects of the total number of projections, the combination of kV and MV projections, and the beam truncation of MV projections on the details of reconstructed kV/MV CT images were also investigated.

  19. Automatic Carrier Landing System (ACLS) Category 3 Certification Manual

    DTIC Science & Technology

    1982-07-01

    INSTRUMENT LANDING SYSTEM .... ......... J-1 APPENDIX K: FRESNEL LENS OPTICAL LANDING SYSTEM .. ......... K-I APPENDIX L: PILOT ACLS RATINGS...surface elements of the ACLS consist of the AN/SPN-42A Landing Control Central with the AN/SPN-41 Instrument Landing System and Fresnel Lens Optical...radar antennas. c. The Fresnel lens calibration pole and three hand held radios be provided. d. Instrumentation seivicing and recording playback

  20. Neural network based multi-criterion optimization image reconstruction technique for imaging two- and three-phase flow systems using electrical capacitance tomography

    NASA Astrophysics Data System (ADS)

    Warsito, W.; Fan, L.-S.

    2001-12-01

    In this work a new image reconstruction technique for imaging two- and three-phase flows using electrical capacitance tomography (ECT) has been developed. A brief review on reconstruction techniques developed recently for ECT is also given. The reconstruction technique proposed here is based on multi-criterion optimization using an analogue neural network, hereafter referred to as neural network multi-criteria optimization image reconstruction (NN-MOIRT). The reconstruction technique is a combination between a multi-criterion optimization image reconstruction technique for linear tomography, and the so-called linear back projection (LBP) technique commonly used for capacitance tomography. The multi-criterion optimization image reconstruction problem is solved using Hopfield model dynamic neural network computing. For three-component imaging, the single-step sigmoid function in the Hopfield networks is replaced by a double-step sigmoid function, allowing the neural computation to converge to three distinct stable regions in the output space corresponding to the three components, enabling differentiation among the single phases. The technique has been tested on a capacitance data set obtained from simulated measurement as well as experiment using a 12-electrode sensor. The performance of the technique has been compared with other commonly used iterative techniques, i.e. iterative linear back projection technique (ILBP) and the simultaneous image reconstruction technique (SIRT) for two-phase system imaging, and has shown great improvements in the accuracy and the consistency as compared with those techniques. The technique has also shown the capability of three-phase image reconstruction with high accuracy.

  1. Three-dimensional reconstruction techniques to study ditches eco-hydrology

    NASA Astrophysics Data System (ADS)

    Vinatier, Fabrice; Bailly, Jean-Stéphane; Combemale, David

    2015-04-01

    Agricultural ditches are common linear features of cultivated landscapes assuming several primary functions: soil water drainage, retention of pollutants, soil erosion prevention. In Mediterranean hilly areas, ditches shape a network over a catchment in order to convey surface runoff out of the plots during short but intense storms. Furthermore, these man made ditches provide valuable habitat for fauna and flora. Our study aims at exploring how the hydraulic functioning of ditches is affected by biotic activities occurring at ditch scale, such as plant development (canopy height, vegetation covering and blockage factor which is the fraction of the channel cross-section blocked by vegetation, which all determines the flow resistance due to vegetation) and soil disturbance by burrowing herbivores. To this end, we applied a stereophotogrammetric study to monitor vegetation and ditch geometry on a 100 meters long ditch segment. The study was conducted from April to December 2014 on an agricultural ditch in South of France. Plant species were collected for referencing and manifestation of soil disturbance by Mediterranean Pine Vole were noticed. The data collected gathered a chronosequence of twenty point clouds at 1 mm resolution. Clouds coherence and precision were confronted to Terrestrial Lidar Scans acquired in April and September 2014 for validation. Clouds were classified to disentangle the ground from the canopy vegetation . The Pine Vole excavations and the plant species were classified inside the ground and vegetation clouds, respectively. Different vegetation metrics related to ditch hydraulics were estimated and map from the chronosequence : the canopy height dynamics, the vegetation cover dynamics and the blockage factors dynamic.. Vegetation metrics appears to be highly variable temporally and spatially, mainly due to plant development and species traits. Thanks to these three-dimensional reconstruction techniques, data clouds at high resolution linked to

  2. Costs incurred by applying computer-aided design/computer-aided manufacturing techniques for the reconstruction of maxillofacial defects.

    PubMed

    Rustemeyer, Jan; Melenberg, Alex; Sari-Rieger, Aynur

    2014-12-01

    This study aims to evaluate the additional costs incurred by using a computer-aided design/computer-aided manufacturing (CAD/CAM) technique for reconstructing maxillofacial defects by analyzing typical cases. The medical charts of 11 consecutive patients who were subjected to the CAD/CAM technique were considered, and invoices from the companies providing the CAD/CAM devices were reviewed for every case. The number of devices used was significantly correlated with cost (r = 0.880; p < 0.001). Significant differences in mean costs were found between cases in which prebent reconstruction plates were used (€3346.00 ± €29.00) and cases in which they were not (€2534.22 ± €264.48; p < 0.001). Significant differences were also obtained between the costs of two, three and four devices, even when ignoring the cost of reconstruction plates. Additional fees provided by statutory health insurance covered a mean of 171.5% ± 25.6% of the cost of the CAD/CAM devices. Since the additional fees provide financial compensation, we believe that the CAD/CAM technique is suited for wide application and not restricted to complex cases. Where additional fees/funds are not available, the CAD/CAM technique might be unprofitable, so the decision whether or not to use it remains a case-to-case decision with respect to cost versus benefit.

  3. A Fourier-based compressed sensing technique for accelerated CT image reconstruction using first-order methods.

    PubMed

    Choi, Kihwan; Li, Ruijiang; Nam, Haewon; Xing, Lei

    2014-06-21

    As a solution to iterative CT image reconstruction, first-order methods are prominent for the large-scale capability and the fast convergence rate [Formula: see text]. In practice, the CT system matrix with a large condition number may lead to slow convergence speed despite the theoretically promising upper bound. The aim of this study is to develop a Fourier-based scaling technique to enhance the convergence speed of first-order methods applied to CT image reconstruction. Instead of working in the projection domain, we transform the projection data and construct a data fidelity model in Fourier space. Inspired by the filtered backprojection formalism, the data are appropriately weighted in Fourier space. We formulate an optimization problem based on weighted least-squares in the Fourier space and total-variation (TV) regularization in image space for parallel-beam, fan-beam and cone-beam CT geometry. To achieve the maximum computational speed, the optimization problem is solved using a fast iterative shrinkage-thresholding algorithm with backtracking line search and GPU implementation of projection/backprojection. The performance of the proposed algorithm is demonstrated through a series of digital simulation and experimental phantom studies. The results are compared with the existing TV regularized techniques based on statistics-based weighted least-squares as well as basic algebraic reconstruction technique. The proposed Fourier-based compressed sensing (CS) method significantly improves both the image quality and the convergence rate compared to the existing CS techniques.

  4. A mini-invasive adductor magnus tendon transfer technique for medial patellofemoral ligament reconstruction: a technical note.

    PubMed

    Sillanpää, Petri J; Mäenpää, Heikki M; Mattila, Ville M; Visuri, Tuomo; Pihlajamäki, Harri

    2009-05-01

    Patellar dislocations are associated with injuries to the medial patellofemoral ligament (MPFL). Several techniques for MPFL reconstruction have been recently published with some disadvantages involved, including large skin incisions and donor site morbidity. Arthroscopic stabilizing techniques carry the potential of inadequate restoration of MPFL function. We present a minimally invasive technique for MPFL reconstruction using adductor magnus tendon autograft. This technique is easily performed, safe, and provides a stabilizing effect equal to current MPFL reconstructions. Skin incision of only 3-4 cm is located at the level of the proximal half of the patella. After identifying the distal insertion of the adductor magnus tendon, a tendon harvester is introduced to harvest the medial two-thirds of the tendon, while the distal insertion is left intact. The adductor magnus tendon is cut at 12-14 cm from its distal insertion and transferred into the patellar medial margin. Two suture anchors are inserted through the same incision at the superomedial aspect of the patella in the anatomic MPFL origin. The graft is tightened at 30 degrees knee flexion. Aftercare includes 4 weeks of brace treatment with restricted range of motion.

  5. Low-Shapiro hydrostatic reconstruction technique for blood flow simulation in large arteries with varying geometrical and mechanical properties

    NASA Astrophysics Data System (ADS)

    Ghigo, A. R.; Delestre, O.; Fullana, J.-M.; Lagrée, P.-Y.

    2017-02-01

    The purpose of this work is to construct a simple, efficient and accurate well-balanced numerical scheme for one-dimensional (1D) blood flow in large arteries with varying geometrical and mechanical properties. As the steady states at rest are not relevant for blood flow, we construct two well-balanced hydrostatic reconstruction techniques designed to preserve low-Shapiro number steady states that may occur in large network simulations. The Shapiro number Sh = u / c is the equivalent of the Froude number for shallow water equations and the Mach number for compressible Euler equations. The first is the low-Shapiro hydrostatic reconstruction (HR-LS), which is a simple and efficient method, inspired from the hydrostatic reconstruction technique (HR). The second is the subsonic hydrostatic reconstruction (HR-S), adapted here to blood flow and designed to exactly preserve all subcritical steady states. We systematically compare HR, HR-LS and HR-S in a series of single artery and arterial network numerical tests designed to evaluate their well-balanced and wave-capturing properties. The results indicate that HR is not adapted to compute blood flow in large arteries as it is unable to capture wave reflections and transmissions when large variations of the arteries' geometrical and mechanical properties are considered. On the contrary, HR-S is exactly well-balanced and is the most accurate hydrostatic reconstruction technique. However, HR-LS is able to compute low-Shapiro number steady states as well as wave reflections and transmissions with satisfying accuracy and is simpler and computationally less expensive than HR-S. We therefore recommend using HR-LS for 1D blood flow simulations in large arterial network simulations.

  6. Hydrogel fibers for ACL prosthesis: design and mechanical evaluation of PVA and PVA/UHMWPE fiber constructs.

    PubMed

    Bach, Jason S; Detrez, Fabrice; Cherkaoui, Mohammed; Cantournet, Sabine; Ku, David N; Corté, Laurent

    2013-05-31

    Prosthetic devices for anterior cruciate ligament (ACL) reconstruction have been unsuccessful due to mechanical failure or chronic inflammation. Polymer hydrogels combine biocompatibility and unique low friction properties; however, their prior use for ligament reconstruction has been restricted to coatings due to insufficient tensile mechanics. Here, we investigate new constructs of polyvinyl alcohol (PVA) hydrogel fibers. In water, these fibers swell to an equilibrium water content of 50% by weight, retaining a tensile modulus greater than 40 MPa along the fiber axis at low strain. Rope constructs were assembled for ACL replacement and mechanical properties were compared with data from the literature. Pure PVA hydrogel constructs closely reproduce the non-linear tensile stiffness of the native ACL with an ultimate strength of about 2000 N. An additional safety factor in tensile strength was achieved with composite braids by adding ultrahigh molecular weight polyethylene (UHMWPE) fibers around a core of PVA cords. Composition and braiding angle are adjusted to produce a non-linear tensile behavior within the range of the native ligament that can be predicted by a simple rope model. This design was found to sustain over one million cycles between 50 and 450 N with limited damage and less than 20% creep. The promising mechanical performances of these systems provide justification for more extensive in vivo evaluation.

  7. Reconstruction of large alopecia with old technique: V-Y-S plasty.

    PubMed

    Sahin, Baris

    2016-10-01

    Treatment of alopecia following burns, trauma or tumour surgery is challenging. Local flaps for small or medium sized defects and tissue expansion for larger defects is the common approach. Tissue expansion is a two-stage procedure and the inflation process causes difficulty for patients. V-Y-S plasty is safe and one-stage method of tissue reconstruction for scalp, face and other parts of the body. We performed this method safely for very large alopecia reconstructions in the scalp.

  8. Reconstruction of craniofacial image using rational cubic Ball interpolant and soft computing technique

    NASA Astrophysics Data System (ADS)

    Majeed, Abdul; Piah, Abd Rahni Mt

    2015-10-01

    Spline has been used extensively in engineering design and modelling for representation, analysis and manufacturing purposes. This paper presents an application of spline methods in bio-medical modelling. We reconstruct craniofacial fractured skull bone images using rational cubic Ball interpolant with two free parameters. The free parameters are optimized with the help of genetic algorithm. Our emphasis is placed on the accuracy and smoothness of the reconstructed images.

  9. 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

  10. Amiodarone for ACLS: a critical evaluation.

    PubMed

    Stewart, C E

    2001-09-01

    Years ago, William Osler taught physicians, "Be not the first nor the last to adopt a therapy." This continues to be sage advice. Clinicians should be cautious in considering the use of amiodarone in a field setting for cardiac arrest until studies clearly show a benefit over drugs currently in use. The endpoint of the only cardiac arrest study available shows improved survival when amiodarone is combined with other drugs over placebo until the patient gets to the emergency department, but is not a comparison with other current drugs nor had any effect on long-term survival or functioning neurologic status. As previously cited, amiodarone was comparable with bretylium in treating recurrent VT/VF in one controlled study. Further study of this and other ACLS drugs is imperative. In summary, amiodarone should be reclassified as either a class indeterminate agent when used alone ("no harm but no benefit ... evidence insufficient to support final class decision") or a class IIb agent ("acceptable and useful ... supported by fair to good evidence") when used in addition to other therapies in the treatment of ventricular fibrillation and pulseless ventricular tachycardia. There is not sufficient evidence to move amiodarone to first-line therapy in the "out-of-hospital" cardiac arrest. This evidence may be available in the future and would then change this recommendation.

  11. Hip and knee joint kinematics during a diagonal jump landing in anterior cruciate ligament reconstructed females.

    PubMed

    Delahunt, Eamonn; Prendiville, Anna; Sweeney, Lauren; Chawke, Mark; Kelleher, Judy; Patterson, Matt; Murphy, Katie

    2012-08-01

    Anterior cruciate ligament (ACL) injury is a common injury encountered by sport medicine clinicians. Surgical reconstruction is the recommended treatment of choice for those athletes wishing to return to full-contact sports participation and for sports requiring multi-directional movement patterns. The aim of ACL reconstruction is to restore knee joint mechanical stability such that the athlete can return to sporting participation. However, knowledge regarding the extent to which lower limb kinematic profiles are restored following ACL reconstruction is limited. In the present study the hip and knee joint kinematic profiles of 13 ACL reconstructed (ACL-R) and 16 non-injured control subjects were investigated during the performance of a diagonal jump landing task. The ACL-R group exhibited significantly less peak knee joint flexion (P=0.01). Significant between group differences were noted for time averaged hip joint sagittal plane (P<0.05) and transverse plane (P<0.05) kinematic profiles, as well as knee joint frontal plane (P<0.05) and sagittal plane (P<0.05) kinematic profiles. These results suggest that aberrant hip and knee joint kinematic profiles are present following ACL reconstruction, which could influence future injury risk.

  12. Arthroscopic-Assisted Acromioclavicular Joint Reconstruction Using the TightRope Device With Allograft Augmentation: Surgical Technique

    PubMed Central

    Frank, Rachel M.; Trenhaile, Scott W.

    2015-01-01

    Surgical management of acromioclavicular (AC) joint separations remains challenging, especially in the revision setting. Most commonly, Rockwood type I and II injuries are managed nonoperatively whereas type IV, V, and VI injuries are managed with surgery. Type III separations are more controversial, with evidence supporting both nonoperative and operative treatment options. Multiple different arthroscopic techniques have been described; however, there is no current gold standard. AC joint reconstruction with the TightRope device (Arthrex, Naples, FL) with the patient in the lateral decubitus position is a method of restoring joint stability that allows for a minimally invasive, low-profile fixation construct using a single drill hole through the clavicle. Allograft augmentation of this fixation construct helps to eliminate the stress risers potentially created by this device while increasing overall repair construct stability. The purpose of this article is to describe the surgical technique for arthroscopic AC joint reconstruction using a TightRope device with allograft augmentation. PMID:26759765

  13. High-efficient computer-generated integral imaging based on the backward ray-tracing technique and optical reconstruction.

    PubMed

    Xing, Shujun; Sang, Xinzhu; Yu, Xunbo; Duo, Chen; Pang, Bo; Gao, Xin; Yang, Shenwu; Guan, YanXin; Yan, Binbin; Yuan, Jinhui; Wang, Kuiru

    2017-01-09

    A high-efficient computer-generated integral imaging (CGII) method is presented based on the backward ray-tracing technique. In traditional CGII methods, the total rendering time is long, because a large number of cameras are established in the virtual world. The ray origin and the ray direction for every pixel in elemental image array are calculated with the backward ray-tracing technique, and the total rendering time can be noticeably reduced. The method is suitable to create high quality integral image without the pseudoscopic problem. Real time and non-real time CGII rendering images and optical reconstruction are demonstrated, and the effectiveness is verified with different types of 3D object models. Real time optical reconstruction with 90 × 90 viewpoints and the frame rate above 40 fps for the CGII 3D display are realized without the pseudoscopic problem.

  14. SU-D-12A-05: Iterative Reconstruction Techniques to Enable Intrinsic Respiratory Gated CT in Mice

    SciTech Connect

    Sun, T; Sun, N; Tan, S; Liu, Y; Mistry, N

    2014-06-01

    Purpose: Longitudinal studies of lung function in mice need the ability to image different phases of ventilation in free-breathing mice using retrospective gating. However, retrospective gating often produces under-sampled and uneven angular samples, resulting in severe reconstruction artifacts when using traditional FDK based reconstruction algorithms. We wanted to demonstrate the utility of iterative reconstruction method to enable intrinsic respiratory gating in small-animal CT. Methods: Free-breathing mice were imaged using a Siemens Inveon PET/micro-CT system. Evenly distributed projection images were acquired at 360 angles. Retrospective respiratory gating was performed using an intrinsic marker based on the average intensity in a region covering the diaphragm. Projections were classified into 4 and 6 phases (finer temporal resolution) resulting in 138 and 67 projections respectively. Reconstruction was carried out using 3 Methods: conventional FDK, iterative penalized least-square (PWLS) with total variation (TV), and PWLS with edge-preserving penalty. The performance of the methods was compared using contrast-to-noise (CNR) in a region of interest (ROI). Line profile through a specific region was plotted to evaluate the preserving of edges. Results: In both the cases with 4 and 6 phases, inadequate and non-uniform angular sampling results in artifacts using conventional FDK. However, such artifacts are minimized using both the iterative methods. Using both 4 and 6 phases, the iterative techniques outperformed FDK in terms of CNR and maintaining sharp edges. This is further evidenced especially with increased artifacts using FDK for 6 phases. Conclusion: This work indicates fewer artifacts and better image details can be achieved with iterative reconstruction methods in non-uniform under-sampled reconstruction. Using iterative methods can enable free-breathing intrinsic respiratory gating in small-animal CT. Further studies are needed to compare the

  15. Verification and source-position error analysis of film reconstruction techniques used in the brachytherapy planning systems.

    PubMed

    Chang, Liyun; Ho, Sheng-Yow; Chui, Chen-Shou; Du, Yi-Chun; Chen, Tainsong

    2009-09-01

    A method was presented that employs standard linac QA tools to verify the accuracy of film reconstruction algorithms used in the brachytherapy planning system. Verification of reconstruction techniques is important as suggested in the ESTRO booklet 8: "The institution should verify the full process of any reconstruction technique employed clinically." Error modeling was also performed to analyze seed-position errors. The "isocentric beam checker" device was used in this work. It has a two-dimensional array of steel balls embedded on its surface. The checker was placed on the simulator couch with its center ball coincident with the simulator isocenter, and one axis of its cross marks parallel to the axis of gantry rotation. The gantry of the simulator was rotated to make the checker behave like a three-dimensional array of balls. Three algorithms used in the ABACUS treatment planning system: orthogonal film, 2-films-with-variable-angle, and 3-films-with-variable-angle were tested. After exposing and digitizing the films, the position of each steel ball on the checker was reconstructed and compared to its true position, which can be accurately calculated. The results showed that the error is dependent on the object-isocenter distance, but not the magnification of the object. The averaged errors were less than 1 mm within the tolerance level defined by Roué et al. ["The EQUAL-ESTRO audit on geometric reconstruction techniques in brachytherapy," Radiother. Oncol. 78, 78-83 (2006)]. However, according to the error modeling, the theoretical error would be greater than 2 mm if the objects were located more than 20 cm away from the isocenter with a 0.5 degrees reading error of the gantry and collimator angles. Thus, in addition to carefully performing the QA of the gantry and collimator angle indicators, it is suggested that the patient, together with the applicators or seeds inside, should be placed close to the isocenter as much as possible. This method could be used to

  16. Verification and source-position error analysis of film reconstruction techniques used in the brachytherapy planning systems

    SciTech Connect

    Chang Liyun; Ho, Sheng-Yow; Chui, Chen-Shou; Du, Yi-Chun; Chen Tainsong

    2009-09-15

    A method was presented that employs standard linac QA tools to verify the accuracy of film reconstruction algorithms used in the brachytherapy planning system. Verification of reconstruction techniques is important as suggested in the ESTRO booklet 8: ''The institution should verify the full process of any reconstruction technique employed clinically.'' Error modeling was also performed to analyze seed-position errors. The ''isocentric beam checker'' device was used in this work. It has a two-dimensional array of steel balls embedded on its surface. The checker was placed on the simulator couch with its center ball coincident with the simulator isocenter, and one axis of its cross marks parallel to the axis of gantry rotation. The gantry of the simulator was rotated to make the checker behave like a three-dimensional array of balls. Three algorithms used in the ABACUS treatment planning system: orthogonal film, 2-films-with-variable-angle, and 3-films-with-variable-angle were tested. After exposing and digitizing the films, the position of each steel ball on the checker was reconstructed and compared to its true position, which can be accurately calculated. The results showed that the error is dependent on the object-isocenter distance, but not the magnification of the object. The averaged errors were less than 1 mm within the tolerance level defined by Roueet al. [''The EQUAL-ESTRO audit on geometric reconstruction techniques in brachytherapy,'' Radiother. Oncol. 78, 78-83 (2006)]. However, according to the error modeling, the theoretical error would be greater than 2 mm if the objects were located more than 20 cm away from the isocenter with a 0.5 deg. reading error of the gantry and collimator angles. Thus, in addition to carefully performing the QA of the gantry and collimator angle indicators, it is suggested that the patient, together with the applicators or seeds inside, should be placed close to the isocenter as much as possible. This method could be used

  17. COMBINED INSIDE-OUT AND ALL-INSIDE TECHNIQUE IN BUCKET-HANDLE MENISCUS TEARS

    PubMed Central

    Yılmaz, Serdar; Cankaya, Deniz; Fırat, Ahmet; Devecı, Alper; Ozkurt, Bulent; Bozkurt, Murat

    2016-01-01

    ABSTRACT Objective: To determine the outcomes after combined inside-out and all-inside repair technique of bucket-handle meniscus tears. Methods: A retrospective review was made of patients with bucket-handle meniscus tears repaired with combined techniques, using the all-inside technique in posterior meniscal tears and the inside-out technique in the middle part of the meniscal tears. Meniscal healing was assessed clinically using Barrett's criteria and MRI. Results: The study comprised 52 patients with a mean age of 28.4 years old (range, 19-52 years old). The mean follow-up period was 31.3 months (range, 24-59 months). Two patients had ACL re-rupture, and complete meniscal healing was achieved in all but one patient. Although improved from preoperative status, Tegner and Lysholm scores were lower in the ACL reconstructed patients than in the intact ACL patients. Conclusion: Combined inside-out and all-inside meniscal repair technique is a successful and cost-effective treatment method in bucket-handle meniscus tears. Level of Evidence IV, Therapeutic Study. PMID:28243169

  18. Reconstruction of Through-and-through Oromandibular Defect: Comparison of Four Different Techniques

    PubMed Central

    Wu, John Chung-Han; Lee, Yi-Chieh; Cheng, Yu-Chun; Wu, Chih-Wei

    2017-01-01

    Background: Through-and-through oromandibular defects originate from surgical intervention of tumors of the oral cavity involving external skin, soft tissue, bone, and oral lining. Reconstruction of such composite defects is primarily achieved by 4 methods using distinct flaps in Chang Gung Memorial Hospital, including a single anterolateral thigh (ALT) flap, a single fibula flap, an osteomyocutaneous peroneal artery-based combined flap, and a combination of a fibular flap and an ALT flap, also known as a double flap. Methods: In this retrospective study, 41 patients with through-and-through oromandibular defects reconstructed in Chang Gung Memorial Hospital Linkou branch from July 2007 to June 2009 using either of the 4 flaps were evaluated. Patients were divided into 4 groups according to the choice of flap, and their surgical outcomes, immediate and late complications, and their general condition were studied. Group 1 included 12 patients reconstructed with a single ALT flap, whereas group 2 included 15 patients using fibular flaps. Group 3 included 8 patients with osteomyocutaneous peroneal artery-based combined flaps, and group 4 included 6 patients who underwent reconstruction with double flaps. Results: Among all statistical results, we found that none of the differences regarding either patient demography or surgical outcomes between groups were statistically significant, except for squamous cell carcinoma staging. Conclusions: Although the results were insignificant, trends within the data could be seen that support previous notions regarding each reconstruction method. For future studies, we strongly recommend a larger sample size. PMID:28280659

  19. Anterior Cruciate Ligament Reconstruction with cadaveric graft in Adolescents with Active Growth Cartilage

    PubMed Central

    Mantilla, Ronnald; Rosell, Italo; Pedregal, Carlos; Revoredo, Rafael; Makino, Arturo

    2017-01-01

    The immature skeleton ACL reconstruction is controversial, due to the possibility of injuring the physis, producing discrepancies in length and angular deformities. The purpose of this study, is presenting our experience of 11 cases, describing the surgical technique Arthroscopic intra-articular respecting them physis. Objectives: The purpose of this study is to present our surgical technique, control and monitoring in patients with active growth cartilage. Material and Methods: Between 2010 and 2015 treated 11 patients from 12 to 16 years, with a injury of the ACL with active growth cartilage evaluated clinically and radiologically. We use a scale of Tanner, x-ray of wrist and MRI for evaluation. They showed no tibial spine avulsions. The acute injury was inclusive criterion. We indicate Arthroscopic cadaveric graft reconstruction, without passing through the physis. We use rehabilitation protocol, immobilizer and crutches. Tracking through scale IKDC and resonance. Description of the surgical technique: Arthroscopic portals habitual plus supramedial accesory portal, identified the injury of the ACL; using fluoroscopy identified the physis active, put kirschner’s pins as guides without crossing them physis, drilled tunnels, check indemnity of the physis, spent the graft, fixing femoral with endobutton and tibial with biodegradable screw. Results: Of the 11 patients, there were 3 meniscal injuries, only 1 sutured. We didn’t have cartilaginous lesions. One patient presented surface Erythema that solved with antibiotic. Slight pain according to scale of pain. Not instability was present. The 60% had sport return without complications. There were no failures of the graft or comorbidities. They showed no growth disorders. Conclusion: The discussion is in repair without producing complications, considering that the natural evolution will lead to a potential damage. Authors show reports of shortening by perforation of the physis, our series presents one more

  20. Simultaneous iterative reconstruction technique software for spectral-spatial EPR imaging

    NASA Astrophysics Data System (ADS)

    Spitzbarth, Martin; Drescher, Malte

    2015-08-01

    Continuous wave electron paramagnetic resonance imaging (EPRI) experiments often suffer from low signal to noise ratio. The increase in spectrometer time required to acquire data of sufficient quality to allow further analysis can be counteracted in part by more processing effort during the image reconstruction step. We suggest a simultaneous iterative reconstruction algorithm (SIRT) for reconstruction of continuous wave EPRI experimental data as an alternative to the widely applied filtered back projection algorithm (FBP). We show experimental and numerical test data of 2d spatial images and spectral-spatial images. We find that for low signal to noise ratio and spectral-spatial images that are limited by the maximum magnetic field gradient strength SIRT is more suitable than FBP.

  1. An Innovative Technique for Columellar Reconstruction using ‘Flip-Over’ Buccal Mucosa Flap

    PubMed Central

    Agrawal, Kapil S.; Pabari, Mansi

    2016-01-01

    Loss of columella is a significant deformity and its reconstruction proves to be quite difficult. An 18-year-old lady had loss of columella due to burn while steam inhalation at a young age and required reconstruction for the same. Labial mucosa has been used as a source of tissue for columellar reconstruction since long. We describe a modification of the buccal mucosal flap to manage a difficult case of columellar deficiency. The buccal mucosa flap was used to cover the columellar defect in the usual manner in the first stage and in second stage, along with division of the base, the residual length of the mucosal flap was used to add to the thickness of columella by doubling it on itself. PMID:27630898

  2. Anomaly detection in reconstructed quantum states using a machine-learning technique

    NASA Astrophysics Data System (ADS)

    Hara, Satoshi; Ono, Takafumi; Okamoto, Ryo; Washio, Takashi; Takeuchi, Shigeki

    2014-02-01

    The accurate detection of small deviations in given density matrices is important for quantum information processing. Here we propose a method based on the concept of data mining. We demonstrate that the proposed method can more accurately detect small erroneous deviations in reconstructed density matrices, which contain intrinsic fluctuations due to the limited number of samples, than a naive method of checking the trace distance from the average of the given density matrices. This method has the potential to be a key tool in broad areas of physics where the detection of small deviations of quantum states reconstructed using a limited number of samples is essential.

  3. Image reconstruction technique of electrical capacitance tomography for low-contrast dielectrics using Calderon's method

    NASA Astrophysics Data System (ADS)

    Cao, Zhang; Xu, Lijun; Wang, Huaxiang

    2009-10-01

    Calderon's method was introduced to electrical capacitance tomography in this paper. It is a direct algorithm of the image reconstruction for low-contrast dielectrics, as no matrix inversion or iterative process is needed. It was implemented through numerical integration. Since the Gauss-Legendre quadrature was applied and can be predetermined, the image reconstruction process was fast and resulted in images of high quality. Simulations were carried out to study the effect of different dielectric contrasts and different electrode numbers. Both simulated and experimental results validated the feasibility and effectiveness of Calderon's method in electrical capacitance tomography for low-contrast dielectrics.

  4. A very efficient RCS data compression and reconstruction technique, volume 4

    NASA Technical Reports Server (NTRS)

    Tseng, N. Y.; Burnside, W. D.

    1992-01-01

    A very efficient compression and reconstruction scheme for RCS measurement data was developed. The compression is done by isolating the scattering mechanisms on the target and recording their individual responses in the frequency and azimuth scans, respectively. The reconstruction, which is an inverse process of the compression, is granted by the sampling theorem. Two sets of data, the corner reflectors and the F-117 fighter model, were processed and the results were shown to be convincing. The compression ratio can be as large as several hundred, depending on the target's geometry and scattering characteristics.

  5. Anterior cruciate ligament reconstruction combined with valgus tibial osteotomy (combined procedure).

    PubMed

    Boss, A; Stutz, G; Oursin, C; Gächter, A

    1995-01-01

    We assessed the patients who were operated on in a combined procedure from 1980 to 1992 with anterior cruciate ligament (ACL) insufficiency, cartilaginous lesions of the medial compartment, lesion of medial meniscus and varus malalignment. The combined operative procedure was autologous intra-articular ACL reconstruction with the middle third of the patellar ligament--partially augmented with Kennedy-ligament augmentation device (LAD) in hot dog technique--and high tibial osteotomy. The patients were examined according to the criteria of IKDC including testing of anterior stability with the KT-1000 arthrometer. Radiographically we checked axis and arthritis according to a modified score of Kannus. Twenty-seven of 34 patients who fulfilled the inclusion criteria could be followed up in three categories (2-5 years post-operatively, 5-10 years postoperatively, over 10 years post-operatively). Total qualification was good in 37%; there were no perioperative complications. Rehabilitation was not prolonged. Eighty-nine percent practised their preoperative job, over 50% had a higher level of sports activities than preoperatively, and more than 25% regained their pretraumatic sports capacity. Two-thirds had no giving way and less than 3 mm translation difference in comparison to the contralateral knee. Seventy-five percent of patients would accept the operation again. Radiological findings had no correlation to overall qualification. The encouraging results with respect to many of the criteria suggest using the combined procedure in a young patient with ACL insufficiency, varus malalignment and medial compartment damage including medial meniscus lesion.

  6. A Novel Technique of Preserving Internal Mammary Artery Perforators in Nipple Sparing Breast Reconstruction

    PubMed Central

    Swistel, Alexander; Small, Kevin; Dent, Briar; Cohen, Oriana; Devgan, Lara

    2014-01-01

    Summary: As nipple-sparing mastectomy with implant-based reconstruction has increased, attention must be paid to the viability of the nipple-areolar complex. This article describes the use of preoperative Doppler ultrasound to identify the internal mammary artery perforators. Preserving the internal mammary artery improves vascular supply to the nipple-areolar complex. PMID:25426381

  7. HOW CAN BONE TUNNEL ENLARGEMENT IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION SURGERY BE MEASURED? DESCRIPTION OF A TECHNIQUE

    PubMed Central

    Aguiar Leonardi, Adriano Barros de; Severino, Nilson Roberto; Junior, Aires Duarte

    2015-01-01

    To assess the presence of tibial bone tunnel enlargement after surgery to reconstruct the anterior cruciate ligament using quadruple flexor tendon grafts, and to propose a new technique for its measurement. Methods: The study involved 25 patients aged 18-43 years over a six-month period. The assessment was based on radiographs taken immediately postoperatively and in the third and sixth months of evolution after operations to reconstruct the anterior cruciate ligament using grafts from the tendons of the semitendinosus and gracilis muscles, fixed in the femur with a transverse metal screw and in the tibia with an interference screw. The radiographs were evaluated in terms of the relative value between the diameter of the tunnel and the bone, both at 2 cm below the medial tibial condyle. Results: There were significant increases in tunnel diameters: 20.56% for radiographs in anteroposterior view and 26.48% in lateral view. Enlargement was present in 48% of anteroposterior and lateral radiographs, but was present in both views in only 16% of the cases. Conclusions: Bone tunnel enlargement is a phenomenon found in the first months after surgery to reconstruct the anterior cruciate ligament. The measurement technique proposed in this study was sufficient to detect it. PMID:27027030

  8. Early anterior cruciate ligament reconstruction can save meniscus without any complications

    PubMed Central

    Hur, Chang-Ik; Song, Eun-Kyoo; Kim, Sung-Kyu; Lee, Seung-Hun; Seon, Jong-Keun

    2017-01-01

    Background: Early ACL reconstruction, before retuning to activity eliminates recurrent episodes of instability and thereby decreases chances of meniscal and cartilage injury. However, there are no clear and uniform guidelines regarding the timing of ACL reconstruction or clarity in the definition of early and delayed reconstruction to reduce the complications after reconstruction in the ACL injured knee. The purpose of this study was to compare the clinical outcome, stability, muscle power, and postural control after early and delayed anterior cruciate ligament (ACL) reconstruction. Materials and Methods: Patients who had ACL reconstruction with a quadruple hamstring tendon with a minimum 2-year followup were evaluated. Early (within 3 weeks) reconstruction group was 48 knees and delayed (more than 3 months) group was 43 knees. We compared the two groups with regard to Lysholm knee score, range of motion (ROM), Lachman test, Tegner activity scale, associated meniscal or chondral injuries, and anterior laxity. We also compared muscle strength with an isokinetic dynamometer and postural control with computed dynamic posturography at the final followup. Results: While 50% of early and 70% of delayed group had meniscal injuries (P = 0.06), of which were reparable in 42% of early group and 17% of delayed group (P = 0.04). However, there was no significant difference in cartilage injury (P = 0.14). At the final followup, no significant differences were found between two groups for Lysholm score (P = 0.28), Tegner activity scale (P = 0.27), and ROM. The stabilities regarding Lachman and pivot-shift tests, and anterior laxity also showed no significant differences between two groups. The mean extension and flexion muscles power, and postural control showed no significant inter-group differences (P > 0.05). Conclusions: Early ACL reconstruction had excellent clinical results and stability as good as delayed reconstruction without the problem of knee motion, muscle power

  9. Penile reconstruction

    PubMed Central

    Garaffa, Giulio; Sansalone, Salvatore; Ralph, David J

    2013-01-01

    During the most recent years, a variety of new techniques of penile reconstruction have been described in the literature. This paper focuses on the most recent advances in male genital reconstruction after trauma, excision of benign and malignant disease, in gender reassignment surgery and aphallia with emphasis on surgical technique, cosmetic and functional outcome. PMID:22426595

  10. Reconstruction of defects of maxillary sinus wall after removal of a huge odontogenic lesion using prebended 3D titanium-mesh and CAD/CAM technique

    PubMed Central

    2011-01-01

    A 63 year-old male with a huge odontogenic lesion of sinus maxillaris was treated with computer-assisted surgery. After resection of the odontogenic lesion, the sinus wall was reconstructed with a prebended 3D titanium-mesh using CAD/CAM technique. This work provides a new treatment device for maxillary reconstruction via rapid prototyping procedures. PMID:22070833

  11. Accelerating Monte Carlo image reconstruction of a PMMA phantom through variance reduction techniques for quality control in digital mammography.

    PubMed

    Ramos, M; Ferrer, S; Verdu, G

    2005-01-01

    Mammography is a non-invasive technique used for the detection of breast lesions. The use of this technique in a breast screening program requires a continuous quality control testing in mammography units for ensuring a minimum absorbed glandular dose without modifying image quality. Digital mammography has been progressively introduced in screening centers, since recent evolution of photostimulable phosphor detectors. The aim of this work is the validation of a methodology for reconstructing digital images of a polymethyl-methacrylate (PMMA) phantom (P01 model) under pure Monte Carlo techniques. A reference image has been acquired for this phantom under automatic exposure control (AEC) mode (28 kV and 14 mAs). Some variance reduction techniques (VRT) have been applied to improve the efficiency of the simulations, defined as the number of particles reaching the imaging system per starting particle. All images have been used and stored in DICOM format. The results prove that the signal-to-noise ratio (SNR) of the reconstructed images have been increased with the use of the VRT, showing similar values between different employed tallies. As a conclusion, these images could be used during quality control testing for showing any deviation of the exposition parameters from the desired reference level.

  12. Endonasal management of pediatric congenital transsphenoidal encephaloceles: nuances of a modified reconstruction technique. Technical note and report of 3 cases.

    PubMed

    Zeinalizadeh, Mehdi; Sadrehosseini, Seyed Mousa; Habibi, Zohreh; Nejat, Farideh; Silva, Harley Brito da; Singh, Harminder

    2017-03-01

    OBJECTIVE Congenital transsphenoidal encephaloceles are rare malformations, and their surgical treatment remains challenging. This paper reports 3 cases of transsphenoidal encephalocele in 8- to 24-month-old infants, who presented mainly with airway obstruction, respiratory distress, and failure to thrive. METHODS The authors discuss the surgical management of these lesions via a minimally invasive endoscopic endonasal approach, as compared with the traditional transcranial and transpalatal approaches. A unique endonasal management algorithm for these lesions is outlined. The lesions were repaired with no resection of the encephalocele sac, and the cranial base defects were reconstructed with titanium mesh plates and vascular nasoseptal flaps. RESULTS Reduction of the encephalocele and reconstruction of the skull base was successfully accomplished in all 3 cases, with favorable results. CONCLUSIONS The described endonasal management algorithm for congenital transsphenoidal encephaloceles is a safe, viable alternative to traditional transcranial and transpalatal approaches, and avoids much of the morbidity associated with these open techniques.

  13. Posterolateral Corner Reconstruction Alone Using a Fibular-Based Technique in a Patient with Persistent Unstable Revision Total Knee Arthroplasty

    PubMed Central

    Cline, Joseph T.; Alentorn-Geli, Eduard; Choi, J. H. James; Stuart, Joseph J.; Kruger, Terry; Moorman III, Claude T.

    2015-01-01

    Posterolateral rotatory instability is a relatively uncommon cause of unstable total knee arthroplasty (TKA). In most cases, surgical treatment requires revision TKA into a more constrained design or thicker polyethylene liner. We present a case of a patient with unstable TKA who remained unstable after increasing thickness of the polyethylene liner and undergoing more constrained TKA. After several revision surgeries, the patient was still unstable. Posterolateral corner reconstruction with a fibular-based technique using a tibialis anterior allograft was performed. At 1-year follow-up, the patient was stable and asymptomatic and with excellent function. A soft-tissue procedure only (fibular-based posterolateral corner reconstruction) can be effective at restoring posterolateral rotatory stability in a patient with persistent instability after revision TKA. PMID:26881160

  14. Quadriceps Strength, Muscle Activation Failure, and Patient-Reported Function at the Time of Return to Activity in Patients Following Anterior Cruciate Ligament Reconstruction: A Cross-sectional Study

    PubMed Central

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

    2016-01-01

    Study Design Cross-sectional. Objectives To determine if quadriceps activation failure (QAF) moderates the relationship between quadriceps strength and physical function in individuals post-anterior cruciate ligament (ACL) reconstruction. Background QAF may impair the recovery of physical function post ACL reconstruction, given that QAF reduces strength, and strength is related to physical function. Evidence of this relationship has been found in individuals with knee osteoarthritis, wherein patients with lower strength and greater QAF had lower levels of physical function. Methods Participants consisted of 52 individuals who were cleared for return to activity at an average ± SD of 7.4 ± 1.2 months post ACL reconstruction. QAF was assessed using the superimposed burst technique and quadriceps strength was assessed using concentric isokinetic contractions (Nm/kg). Physical function was quantified using a combined variable of physical (single leg hop for distance) and self-reported function (International Knee Documentation Committee form) calculated using a principal component analysis (PCPF). Simple correlations were then performed to determine the order in which variables were entered into the regression model to evaluate if QAF moderates the relationship between quadriceps strength and physical function. Results The combination of quadriceps strength and the interaction of strength-by-QAF predicted 30% of the variance in physical function (R2=0.30, P<.001; PCPF = -0.61strength + 0.20interaction - 1.896); however the interaction of strength-by-QAF only accounted for 7% of the capabilities of the model (P=.023). Conclusion Physical function is largely influenced by the recovery of quadriceps strength and minimally attenuated by QAF. These data suggest that QAF may affect individuals post ACL reconstruction differently, and to a lesser extent, than knee individuals with knee osteoarthritis. PMID:26471854

  15. The Effect of Different Sagittal Angles of the Tibial Guide on Aperture Widening of the Tibial Tunnel during Modified Transtibial Anterior Cruciate Ligament Reconstruction: A Randomized In Vivo Study

    PubMed Central

    Kim, Young Chan; Tawonsawatruk, Tulyapruek; Woon, Hyeong Hwa; Yum, Ji Woong; Shin, Myung Jin; Bravo, Rodolfo S.; Nha, Kyung Wook

    2017-01-01

    Purpose The effect of sagittal plane angle of the tibial tunnel on the severity of tibial intra-articular aperture expansion caused by iatrogenic re-reaming in anterior cruciate ligament (ACL) reconstruction using a modified transtibial technique is unknown. The purpose of this study was to compare the severity of intra-articular aperture widening at different angles (40°, 45°, and 50°) of the tibial guide (TG). Materials and Methods Ninety-seven patients who underwent modified transtibial ACL reconstruction were randomly allocated to TG 40°, 45°, and 50° groups. Intra-articular tibial aperture width (TW) and tibial tunnel length (TTL) were measured intraoperatively using an arthroscopic ruler and a depth gauge. Results The TG 50° group had significantly greater tibial aperture widening than the TG 40° group. There was a significant difference among TG 40°, 45°, and 50° groups and the percentage of knees with TTL <35 mm was 8%, 9% and 3%, respectively. There were 2 females with TTL <35 mm in TG 40° and 45° groups each. The average mediolateral length of the tibial plateau was 75 mm. Conclusions This study shows that the TG angle of 40° would reduce the severity of intra-articular aperture widening of the tibial tunnel compared to 45° or 50° in modified transtibial ACL reconstruction. PMID:28231645

  16. Rapid Late Holocene glacier fluctuations reconstructed from South Georgia lake sediments using novel analytical and numerical techniques

    NASA Astrophysics Data System (ADS)

    van der Bilt, Willem; Bakke, Jostein; Werner, Johannes; Paasche, Øyvind; Rosqvist, Gunhild

    2016-04-01

    The collapse of ice shelves, rapidly retreating glaciers and a dramatic recent temperature increase show that Southern Ocean climate is rapidly shifting. Also, instrumental and modelling data demonstrate transient interactions between oceanic and atmospheric forcings as well as climatic teleconnections with lower-latitude regions. Yet beyond the instrumental period, a lack of proxy climate timeseries impedes our understanding of Southern Ocean climate. Also, available records often lack the resolution and chronological control required to resolve rapid climate shifts like those observed at present. Alpine glaciers are found on most Southern Ocean islands and quickly respond to shifts in climate through changes in mass balance. Attendant changes in glacier size drive variations in the production of rock flour, the suspended product of glacial erosion. This climate response may be captured by downstream distal glacier-fed lakes, continuously recording glacier history. Sediment records from such lakes are considered prime sources for paleoclimate reconstructions. Here, we present the first reconstruction of Late Holocene glacier variability from the island of South Georgia. Using a toolbox of advanced physical, geochemical (XRF) and magnetic proxies, in combination with state-of-the-art numerical techniques, we fingerprinted a glacier signal from glacier-fed lake sediments. This lacustrine sediment signal was subsequently calibrated against mapped glacier extent with the help of geomorphological moraine evidence and remote sensing techniques. The outlined approach enabled us to robustly resolve variations of a complex glacier at sub-centennial timescales, while constraining the sedimentological imprint of other geomorphic catchment processes. From a paleoclimate perspective, our reconstruction reveals a dynamic Late Holocene climate, modulated by long-term shifts in regional circulation patterns. We also find evidence for rapid medieval glacier retreat as well as a

  17. Management of Acute Combined ACL-Medial and Posteromedial Instability of the Knee.

    PubMed

    Medvecky, Michael J; Tomaszewski, Paul

    2015-06-01

    Medial collateral ligament (MCL) injuries are the most common ligamentous injury of the knee. The extent of injury can range from a minor first-degree (1-degree) sprain to an extensive third-degree (3-degree) sprain that can propagate across the knee, rupturing one or both cruciate ligaments, and result in a knee subluxation or dislocation. A common pattern involves the combined anterior cruciate ligament (ACL) and MCL injury that is the focus of this chapter. The vast majority of these combined medial-sided injuries are treated nonoperatively with delayed reconstruction of the ACL injury in athletically active individuals. The MCL and associated medial structures are carefully assessed on physical examination, and classification of injury is based upon abnormal limits of joint motion. In vitro cadaveric biomechanical testing has given us a better understanding of ligament deficiency and altered joint motion. Consistency in terminology is necessary for proper classification of injury and reproducible categorization of injury patterns to be able to compare both nonoperative and operative treatment of various injury patterns.

  18. Holocene Temperature Reconstructions from Arctic Lakes based on Alkenone Paleothermometry and Non-Destructive Scanning Techniques

    NASA Astrophysics Data System (ADS)

    D'Andrea, W. J.; Balascio, N. L.; Bradley, R. S.; Bakke, J.; Gjerde, M.; Kaufman, D. S.; Briner, J. P.; von Gunten, L.

    2014-12-01

    Generating continuous, accurate and quantitative Holocene temperature estimates from the Arctic is an ongoing challenge. In many Arctic regions, tree ring-based approaches cannot be used and lake sediments provide the most valuable repositories for extracting paleotemperature information. Advances in lacustrine alkenone paleothermometry now allow for quantitative reconstruction of lake-water temperature based on the UK37 values of sedimentary alkenones. In addition, a recent study demonstrated the efficacy of non-destructive scanning reflectance spectroscopy in the visible range (VIS-RS) for high-resolution quantitative temperature reconstruction from arctic lake sediments1. In this presentation, I will report a new UK37-based temperature reconstruction and a scanning VIS-RS record (using the RABD660;670 index as a measure of sedimentary chlorin content) from Kulusuk Lake in southeastern Greenland (65.6°N, 37.1°W). The UK37 record reveals a ~3°C increase in summer lake water temperatures between ~10ka and ~7ka followed by sustained warmth until ~4ka and a gradual (~3°C) cooling until ~400 yr BP. The strong correlation between UK37 and RABD660;670 measured in the same sediment core provides further evidence that in arctic lakes where temperature regulates primary productivity, and thereby sedimentary chlorin content, these proxies can be combined to develop high-resolution quantitative temperature records. The Holocene temperature history of Kulusuk Lake determined using this approach corresponds to changes in the size of the glaciers adjacent to the lake, as inferred from sediment minerogenic properties measured with scanning XRF. Glaciers retreated during early Holocene warming, likely disappeared during the period of mid-Holocene warmth, and advanced after 4ka. I will also discuss new UK37 and RABD660;670 reconstructions from northwestern Svalbard and the central Brooks Range of Alaska within the framework of published regional temperature reconstructions and

  19. Intermediate- to Long-Term Results of Combined Anterior Cruciate Ligament Reconstruction and Autologous Chondrocyte Implantation

    PubMed Central

    Pike, Andrew N.; Bryant, Tim; Ogura, Takahiro; Minas, Tom

    2017-01-01

    Background: Cartilage injury associated with anterior cruciate ligament (ACL) ruptures is common; however, relatively few reports exist on concurrent cartilage repair with ACL reconstruction. Autologous chondrocyte implantation (ACI) has been utilized successfully for treatment of moderate to large chondral defects. Hypothesis: ACL insufficiency with relatively large chondral defects may be effectively managed with concurrent ACL reconstruction and ACI. Study Design: Case series; Level of evidence, 4. Methods: Patients undergoing concurrent ACL primary or revision reconstruction with ACI of single or multiple cartilage defects were prospectively evaluated for a minimum 2 years. Pre- and postoperative outcome measures included the modified Cincinnati Rating Scale (MCRS), Western Ontario and McMaster Universities Osteoarthritis Index, visual analog pain scales, and postsurgery satisfaction surveys. ACI graft failure or persistent pain without functional improvement were considered treatment failures. Results: Twenty-six patients were included, with 13 primary and 13 revision ACL reconstructions performed. Mean defect total surface area was 8.4 cm2, with a mean follow-up of 95 months (range, 24-240 months). MCRS improved from 3.62 ± 1.42 to 5.54 ± 2.32, Western Ontario and McMaster Universities Osteoarthritis Index from 45.31 ± 17.27 to 26.54 ± 17.71, and visual analog pain scale from 6.19 ± 1.27 to 3.65 ± 1.77 (all Ps <.001). Eight patients were clinical failures, 69% of patients were improved at final follow-up, and 92% stated they would likely undergo the procedure again. No outcome correlation was found with regard to age, body mass index, sex, defect size/number, follow-up time, or primary versus revision ACL reconstruction. In subanalysis, revision ACL reconstructions had worse preoperative MCRS scores and greater defect surface areas. However, revision MCRS score improvements were greater, resulting in similar final functional scores when compared with

  20. Parallel-scanning tomosynthesis using a slot scanning technique: Fixed-focus reconstruction and the resulting image quality

    SciTech Connect

    Shibata, Koichi; Notohara, Daisuke; Sakai, Takihito

    2014-11-01

    Purpose: Parallel-scanning tomosynthesis (PS-TS) is a novel technique that fuses the slot scanning technique and the conventional tomosynthesis (TS) technique. This approach allows one to obtain long-view tomosynthesis images in addition to normally sized tomosynthesis images, even when using a system that has no linear tomographic scanning function. The reconstruction technique and an evaluation of the resulting image quality for PS-TS are described in this paper. Methods: The PS-TS image-reconstruction technique consists of several steps (1) the projection images are divided into strips, (2) the strips are stitched together to construct images corresponding to the reconstruction plane, (3) the stitched images are filtered, and (4) the filtered stitched images are back-projected. In the case of PS-TS using the fixed-focus reconstruction method (PS-TS-F), one set of stitched images is used for the reconstruction planes at all heights, thus avoiding the necessity of repeating steps (1)–(3). A physical evaluation of the image quality of PS-TS-F compared with that of the conventional linear TS was performed using a R/F table (Sonialvision safire, Shimadzu Corp., Kyoto, Japan). The tomographic plane with the best theoretical spatial resolution (the in-focus plane, IFP) was set at a height of 100 mm from the table top by adjusting the reconstruction program. First, the spatial frequency response was evaluated at heights of −100, −50, 0, 50, 100, and 150 mm from the IFP using the edge of a 0.3-mm-thick copper plate. Second, the spatial resolution at each height was visually evaluated using an x-ray test pattern (Model No. 38, PTW Freiburg, Germany). Third, the slice sensitivity at each height was evaluated via the wire method using a 0.1-mm-diameter tungsten wire. Phantom studies using a knee phantom and a whole-body phantom were also performed. Results: The spatial frequency response of PS-TS-F yielded the best results at the IFP and degraded slightly as the

  1. Fungal osteomyelitis after arthroscopic anterior cruciate ligament reconstruction: a case report with review of the literature.

    PubMed

    Sun, Lei; Zhang, Lei; Wang, Kai; Wang, Wei; Tian, Min

    2012-10-01

    Fungal osteomyelitis is a very rare complication after anterior cruciate ligament (ACL) reconstruction associated with catastrophic consequences. Herein, we present a case of such disastrous complication after ACL reconstruction. A 23-year-old man developed fever, swelling and pain of the affected knee from 18 days after arthroscopic ACL reconstruction. Therefore, he underwent arthroscopic debridement, removal of the graft and internal fixators, irrigation and suction drainage, successively. Negative results for serial bacterial cultures and smear examinations are obtained. However, computer tomography and X-ray examination showed massive bone destruction at 48 days after ACL reconstruction. As the first open debridement was performed at 50 days after ACL reconstruction, fungal infection was diagnosed based on finding Aspergillus hyphae in pathologic examination of the debrided bone sample. After the final debridement, a 12-cm bone loss in the distal femur was treated by Ilizarov's bone transport. The patient got solid arthrodesis of the affected knee without clinical infection at a year after the initial operation. In addition, a review of the literature regarding case reports of fungal osteomyelitis after ACL reconstruction is presented.

  2. The use of autologous chondrocyte implantation following and combined with anterior cruciate ligament reconstruction

    PubMed Central

    Bartlett, W.; Gooding, C. R.; Sood, M.; Skinner, J. A.; Carrington, R. W.J.; Briggs, T. W.R.; Bentley, G.

    2005-01-01

    We report our experience of using autologous chondrocyte implantation (ACI) to treat osteochondral defects of the knee in combination with anterior cruciate ligament (ACL) reconstruction. The outcome of symptomatic osteochondral lesions treated with ACI following previous successful ACL reconstruction is also reviewed. Patients were followed for a mean of 23 months. Nine patients underwent ACL reconstruction in combination with ACI. Mean modified Cincinnati knee scores improved from 42 to 69 following surgery. Seven patients described their knee as better and two as the same. A second group of nine patients underwent ACI for symptomatic articular cartilage defects following previous ACL reconstruction. In this group, the mean modified Cincinnati knee score improved from 53 to 62 after surgery. Six patients described their knee as better and three as worse. Combined treatment using ACI with ACL reconstruction is technically feasible and resulted in sustained improvement in pain and function. The results following previous ACL reconstruction also resulted in clinical improvement, although results were not as good as following the combined procedure. PMID:16320051

  3. Reconstruction of the oral commissure with the use of a new technique: the asterisk design.

    PubMed

    Sari, Alper; Aksoy, Alper; Basterzi, Yavuz; Unal, Sakir

    2009-07-01

    Microstomia reconstruction due to the presence a blunted oral commissure is a challenging task because it requires the restoration of intricately balanced distinct layers of tissues: the oral mucosa, the orbicular muscle, the vermilion border, and the perioral skin. The reliability of commissural reconstruction depends on 2 factors: the first one is breaking the contraction vectors causing blunting of the commissure and the second one is restoring the integrity of the oral sphincter. We have used local skin, vermilion border-muscle, and mucosa flaps designed in an asterisk pattern to break the contraction vectors and have paid certain attention to the restoration of the sphincter function of the circular muscle fibers. Our results have shown that, with the use of our asterisk design, a new commissure aesthetically comparable to the natural one can be created with the reestablishment of reliable oral competence.

  4. Anterior cruciate ligament reconstruction with a novel porcine xenograft: the initial Italian experience

    PubMed Central

    ZAFFAGNINI, STEFANO; GRASSI, ALBERTO; MUCCIOLI, GIULIO MARIA MARCHEGGIANI; DI SARSINA, TOMMASO ROBERTI; RAGGI, FEDERICO; BENZI, ANDREA; MARCACCI, MAURILIO

    2015-01-01

    At the current state of the art in anterior cruciate ligament (ACL) reconstruction, multiple techniques have been presented but none has given clearly defined and improved results. One of the main issues concerns the choice of graft. The concept of using xenograft tissue, defined as a graft tissue from one species and destined for implantation in an unlike species, was introduced in order to try to overcome the mechanical and biological concerns associated with synthetic materials and the safety and quality concerns and availability problems of allograft tissue. Xenograft tissue carries the risk of producing an immunological reaction. In order to try to overcome or attenuate the immune response against porcine xenograft tissue, the Z-Process® (Aperion Biologics Inc, San Antonio, Texas, USA) has been developed and used to produce the Z-Lig® family of devices for ACL reconstruction procedures. Z-Lig® is a tendon graft with or without bone blocks, sourced from animal tissue in a manner consistent with what has normally been sourced from human tissue, and processed to overcome anti-Gal-mediated rejection and to attenuate other immunological recognition in humans. All this while ensuring sterility, viral inactivation and preservation of mechanical proprieties appropriate for an ACL reconstruction device. The Z-Lig® device has been tested in skeletally mature monkeys and given interesting and promising results from the preclinical performance and safety profile point of view. On this basis, it was possible to proceed with the first clinical trial involving humans, which gave similar encouraging results. The Z-Lig® device has also been implanted in Italy at the Rizzoli Orthopaedic Institute in Bologna, as a part of international multicenter prospective randomized blinded controlled study aimed at comparing xenograft with allograft tissue. PMID:26605257

  5. Maneuver reconstruction techniques for open-loop spin-stabilized spacecraft

    NASA Technical Reports Server (NTRS)

    Frauenholz, R. B.

    1980-01-01

    The Pioneer missions were supported by spin-stabilized spacecraft designs using open-loop control and blow-down propulsion subsystems. Reliable estimates of the ever-changing performance inherent to these subsystems were needed to effectively design and reconstruct trajectory correction maneuver (TCM) strategies. These performance updates were obtained by adjusting model parameters to match independent telemetric and radiometric observations to define the simultaneous changes in attitude, velocity, and spin rate during a maneuver sequence.

  6. Multivariable robust controller design of ACLS using loop-shaping approach

    NASA Astrophysics Data System (ADS)

    Dong, Chaoyang; Cui, Haihua; Wang, Qing

    2008-10-01

    In this paper a multivariable robust controller design approach of the ACLS is accomplished by using robust loop-shaping techniques. In order to avoid the inefficient way of choosing the weight functions by trial-and-error method, the structured genetic algorithm (SGA) approach is introduced, which is capable of simultaneously searching the orders and coefficients of the pre- and post-compensator for weight matrices. According to this approach, engineers can achieve an ideal loop-shape which lies in an appropriate region relating to the desired performance specifications. The effectiveness of this approach is illustrated by the longitudinal equations of a carrier-based aircraft's motion design example.

  7. A paleoclimate rainfall reconstruction in the Murray-Darling Basin (MDB), Australia: 1. Evaluation of different paleoclimate archives, rainfall networks, and reconstruction techniques

    NASA Astrophysics Data System (ADS)

    Ho, Michelle; Kiem, Anthony S.; Verdon-Kidd, Danielle C.

    2015-10-01

    From ˜1997 to 2009 the Murray-Darling Basin (MDB), Australia's largest water catchment and reputed "food bowl," experienced a severe drought termed the "Millennium Drought" or "Big Dry" followed by devastating floods in the austral summers of 2010/2011, 2011/2012, and 2012/2013. The magnitude and severity of these extreme events highlight the limitations associated with assessing hydroclimatic risk based on relatively short instrumental records (˜100 years). An option for extending hydroclimatic records is through the use of paleoclimate records. However, there are few in situ proxies of rainfall or streamflow suitable for assessing hydroclimatic risk in Australia and none are available in the MDB. In this paper, available paleoclimate records are reviewed and those of suitable quality for hydroclimatic risk assessments are used to develop preinstrumental information for the MDB. Three different paleoclimate reconstruction techniques are assessed using two instrumental rainfall networks: (1) corresponding to rainfall at locations where rainfall-sensitive Australian paleoclimate archives currently exist and (2) corresponding to rainfall at locations identified as being optimal for explaining MDB rainfall variability. It is shown that the optimized rainfall network results in a more accurate model of MDB rainfall compared to reconstructions based on rainfall at locations where paleoclimate rainfall proxies currently exist. This highlights the importance of first identifying key locations where existing and as yet unrealized paleoclimate records will be most useful in characterizing variability. These results give crucial insight as to where future investment and research into developing paleoclimate proxies for Australia could be most beneficial, with respect to better understanding instrumental, preinstrumental and potential future variability in the MDB.

  8. Temporal resolved x-ray penumbral imaging technique using heuristic image reconstruction procedure and wide dynamic range x-ray streak camera

    SciTech Connect

    Fujioka, Shinsuke; Shiraga, Hiroyuki; Azechi, Hiroshi; Nishimura, Hiroaki; Izawa, Yasukazu; Nozaki, Shinya; Chen, Yen-wei

    2004-10-01

    Temporal resolved x-ray penumbral imaging has been developed using an image reconstruction procedure of the heuristic method and a wide dynamic range x-ray streak camera (XSC). Reconstruction procedure of the penumbral imaging is inherently intolerant to noise, a reconstructed image is strongly distorted by artifacts caused by noise in a penumbral image. Statistical fluctuation in the number of detected photon is the dominant source of noise in an x-ray image, however acceptable brightness of an image is limited by dynamic range of an XSC. The wide dynamic range XSC was used to obtain penumbral images bright enough to be reconstructed. Additionally, the heuristic method was introduced in the penumbral image reconstruction procedure. Distortion of reconstructed images is sufficiently suppressed by these improvements. Density profiles of laser driven brominated plastic and tin plasma were measured with this technique.

  9. An effective ultrasonic strain measurement-based shear modulus reconstruction technique for superficial tissues - demonstration on in vitro pork ribs and in vivo human breast tissues

    NASA Astrophysics Data System (ADS)

    Sumi, Chikayoshi; Nakayama, Kiyoshi; Kubota, Mitsuhiro

    2000-06-01

    An effective shear modulus reconstruction technique is described which uses ultrasonic strain measurements for diagnosis of superficial tissues, i.e. our previously developed ultrasonic strain measurement and shear modulus reconstruction methods are combined and enhanced. The technique realizes very low computational load, yet yields fairly high quantitativeness, high stability and spatial resolution, and large dynamic range. The suitability of the method is demonstrated on in vitro pork ribs and in vivo human breast tissues (fibroadenoma and scirrhous carcinoma).

  10. Osteoclasts and their precursors are present in the induced-membrane during bone reconstruction using the Masquelet technique.

    PubMed

    Gouron, Richard; Petit, Laurent; Boudot, Cédric; Six, Isabelle; Brazier, Michel; Kamel, Said; Mentaverri, Romuald

    2017-02-01

    In 2000, Masquelet reported a long bone reconstruction technique using an induced membrane formed around a polymethylmethacrylate (PMMA) spacer placed in the defect with appropriate stabilization followed by secondary bone graft after PMMA removal. This reconstruction procedure allows rapid and safe bone reformation for septic, traumatic, neoplastic or congenital bone defects. A rat model of the Masquelet technique was developed to further characterize the biological activities of this induced membrane. Our model allows healing of a critical-sized femoral defect (8 mm) by means of this procedure over a period of 18 weeks. Comparison of induced membranes obtained 3, 4, 5 and 6 weeks after PMMA insertion indicated that this tissue changes over time. Several mineralization spots and bone cells were observed in contact with the PMMA, when assessed by Alizarin Red, Von Kossa, Alkaline phosphatase and Tartrate-resistant acid phosphatase staining of the membranes. CTR (calcitonin receptor)- and RANK (Receptor Activator of Nuclear factor Kappa B)- positive mononuclear cells were detected in the induced membrane, confirming the presence of osteoclasts in this tissue. These cells were observed in a thin, highly cellular layer in the induced membrane in contact with the PMMA. Together, these findings suggest that the membrane is able to promote osteointegration of autologous corticocancellous bone grafts during the Masquelet technique by creating local conditions that may be favourable to graft bone remodelling and osteointegration. Copyright © 2014 John Wiley & Sons, Ltd.

  11. SU-E-T-18: A Comparison of Planning Techniques for Bilateral Reconstructed Chest Wall Patients Undergoing Whole Breast Irradiation

    SciTech Connect

    Volpe, T; Margiasso, R; Saleh, Z; Kuo, L; Hong, L; Ballangrud, A; Gelblum, D; Zinovoy, M; Deasy, J; Tang, X

    2015-06-15

    Purpose: As we continuously see more bilateral reconstructed chest wall cases, new challenges are being presented to deliver left-sided breast irradiation. We herein compare three Deep Inspiration Breath Hold (DIBH) planning techniques (tangents, VMAT, and IMRT) and two free breathing techniques (VMAT and IMRT). Methods: Three left-sided chest wall patients with bilateral implants were studied. Tangents, VMAT, and IMRT plans were created for DIBH scans. VMAT and IMRT plans were created for free breathing scans. All plans were normalized so that 95% of the prescription dose was delivered to 95% of the planning target volume (PTV). The maximum point dose was constrained to less than 120% of the prescription dose. Since the success of DIBH delivery largely depends on patient’s ability to perform consistent breath hold during beam on time, smaller number of Monitor Units (MU) is in general desired. For each patient, the following information was collected to compare the planning techniques: heart mean dose, left and right lung V20 Gy, contra-lateral (right) breast mean dose, cord max dose, and MU. Results: The average heart mean dose over all patients are 1561, 692, 985, 1245, and 1121 cGy, for DIBH tangents, VMAT, IMRT, free breathing VMAT and IMRT, respectively. For left lung V20 are 60%, 28%, 26%, 30%, and 29%. For contra-lateral breast mean dose are 244, 687, 616, 783, 438 cGy. MU are 253, 853, 2048, 1035, and 1874 MUs. Conclusion: In the setting of bilateral chest wall reconstruction, opposed tangent beams cannot consistently achieve desired heart and left lung sparing. DIBH consistently achieves better healthy tissue sparing. VMAT appears to be preferential to IMRT for planning and delivering radiation to patients with bilaterally reconstructed chest walls being treated with DIBH.

  12. Computer-assisted versus traditional freehand technique in fibular free flap mandibular reconstruction: a morphological comparative study.

    PubMed

    De Maesschalck, Thibault; Courvoisier, Delphine S; Scolozzi, Paolo

    2017-01-01

    The purpose of the study was to compare the accuracy of computer-assisted surgery (CAS) and the traditional freehand technique for fibular free flap mandibular reconstruction as well as to evaluate the accuracy of the CAS planning. The medical records of 18 patients who underwent mandibular reconstruction with fibular free flap were reviewed. The CAS group (n = 7) benefited from virtual surgical planning and custom patient-specific plates and surgical cutting guides. The Control group (n = 11) was treated by conventional surgery. Morphometric comparison was done by calculating the differences in specific linear and angular parameters on pre- and postoperative CT-scans for both groups by using ProPlan CMF(®) software. Symmetry was also assessed by calculating the ratio of the affected versus the nonaffected side. In the CAS group, planned and postoperative CT-scans were compared to evaluate accuracy. The morphometric comparison showed no statistically significant differences between the groups except for the axial angle on the nonaffected side (mean difference 1.0° in the CAS group versus 2.9° in the Control group; p = 0.03). Ratios of the affected side over the nonaffected side showed no differences between the two groups. In the CAS group, the accuracy assessment showed a mean distance deviation of 2.3 mm for mandibular osteotomies and 1.9 mm for fibular osteotomies. Our results indicated that CAS and the conventional freehand techniques were comparable in their ability to provide a satisfactory morphological fibular free flap mandibular reconstruction. Moreover, the accuracy of the CAS technique was within the range reported in the literature.

  13. Position reconstruction in fission fragment detection using the low pressure MWPC technique for the JLab experiment E02-017

    SciTech Connect

    Xi-Yu, Qiu; Tang, Liguang; Margaryan, Amur T.; Jin-Zhang, Xu; Bi-Tao, Hu; Xi-Meng, Chen

    2014-07-01

    When a lambda hyperon was embedded in a nucleus, it can form a hypernucleus. The lifetime and its mass dependence of stable hypernuclei provide information about the weak decay of lambda hyperon inside nuclear medium. This work will introduce the Jefferson Lab experiment (E02-017) which aims to study the lifetime of the heavy hypernuclei using a specially developed fission fragment detection technique, a multi-wire proportional chamber operated under low gas pressure (LPMWPC). Presented here are the method and performance of the reconstruction of fission position on the target foil, the separation of target materials at different regions and the comparison and verification with the Mote Carlo simulation.

  14. Pulley Reconstruction As Part of the Surgical Treatment for de Quervain Disease: Surgical Technique with Medium-Term Results.

    PubMed

    van der Wijk, Jacobien; Goubau, Jean F; Mermuys, Koen; van Hoonacker, Petrus; Vanmierlo, Bert; Kerckhove, Diederick; Berghs, Bart

    2015-08-01

    Background Simple decompression of the first extensor compartment is commonly used for treating de Quervain disease, with the possible complication of subluxation of the tendons of the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) over the radial styloid. To prevent this painful subluxation of the tendons, several methods of reconstructing the pulley have been proposed. Questions/Purposes The purpose of our study was to evaluate a new technique for reconstructing the first extensor compartment following a release for de Quervain disease. Patients and Methods A retrospective study (mean length 40.4 months) was performed in 45 patients. The outcome assessment involved two different questionnaires and ultrasound evaluation of any tendon subluxation. Results None of the patients required reoperation for tendon instability or incomplete decompression of the first extensor compartment. Two patients experienced clicking around the radial styloid after surgery. This was not related to the amount of volar migration of the tendons. Conclusions We believe the reconstruction proposed here is an effective method of preventing painful subluxation of the APL and EPB following a release of the first extensor compartment.

  15. Pulley Reconstruction As Part of the Surgical Treatment for de Quervain Disease: Surgical Technique with Medium-Term Results

    PubMed Central

    van der Wijk, Jacobien; Goubau, Jean F.; Mermuys, Koen; van Hoonacker, Petrus; Vanmierlo, Bert; Kerckhove, Diederick; Berghs, Bart

    2015-01-01

    Background Simple decompression of the first extensor compartment is commonly used for treating de Quervain disease, with the possible complication of subluxation of the tendons of the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) over the radial styloid. To prevent this painful subluxation of the tendons, several methods of reconstructing the pulley have been proposed. Questions/Purposes The purpose of our study was to evaluate a new technique for reconstructing the first extensor compartment following a release for de Quervain disease. Patients and Methods A retrospective study (mean length 40.4 months) was performed in 45 patients. The outcome assessment involved two different questionnaires and ultrasound evaluation of any tendon subluxation. Results None of the patients required reoperation for tendon instability or incomplete decompression of the first extensor compartment. Two patients experienced clicking around the radial styloid after surgery. This was not related to the amount of volar migration of the tendons. Conclusions We believe the reconstruction proposed here is an effective method of preventing painful subluxation of the APL and EPB following a release of the first extensor compartment. PMID:26261747

  16. Contributions of the anterolateral complex and the anterolateral ligament to rotatory knee stability in the setting of ACL Injury: a roundtable discussion.

    PubMed

    Musahl, Volker; Getgood, Alan; Neyret, Philippe; Claes, Steven; Burnham, Jeremy M; Batailler, Cecile; Sonnery-Cottet, Bertrand; Williams, Andy; Amis, Andrew; Zaffagnini, Stefano; Karlsson, Jón

    2017-03-12

    Persistent rotatory knee laxity is increasingly recognized as a common finding after anterior cruciate ligament (ACL) reconstruction. While the reasons behind rotator knee laxity are multifactorial, the impact of the anterolateral knee structures is significant. As such, substantial focus has been directed toward better understanding these structures, including their anatomy, biomechanics, in vivo function, injury patterns, and the ideal procedures with which to address any rotatory knee laxity that results from damage to these structures. However, the complexity of lateral knee anatomy, varying dissection techniques, differing specimen preparation methods, inconsistent sectioning techniques in biomechanical studies, and confusing terminology have led to discrepancies in published studies on the topic. Furthermore, anatomical and functional descriptions have varied widely. As such, we have assembled a panel of expert surgeons and scientists to discuss the roles of the anterolateral structures in rotatory knee laxity, the healing potential of these structures, the most appropriate procedures to address rotatory knee laxity, and the indications for these procedures. In this round table discussion, KSSTA Editor-in-Chief Professor Jón Karlsson poses a variety of relevant and timely questions, and experts from around the world provide answers based on their personal experiences, scientific study, and interpretations of the literature. Level of evidence V.

  17. 50 CFR 648.100 - Summer flounder Annual Catch Limit (ACL).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) The Summer Flounder Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial... recommended by the SSC. (1) Sector allocations. The commercial and recreational fishing sector ACLs will be... sector ACLs may be established on an annual basis for up to 3 years at a time, dependent on whether...

  18. 50 CFR 648.64 - Yellowtail flounder sub-ACLs and AMs for the scallop fishery.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Yellowtail flounder sub-ACLs and AMs for...-ACLs and AMs for the scallop fishery. (a) As specified in § 648.55(d), and pursuant to the biennial... Georges Bank and Southern New England/Mid-Atlantic stocks of yellowtail flounder. The sub-ACLs for...

  19. 50 CFR 648.100 - Summer flounder Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) The Summer Flounder Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial... recommended by the SSC. (1) Sector allocations. The commercial and recreational fishing sector ACLs will be... sector ACLs may be established on an annual basis for up to 3 years at a time, dependent on whether...

  20. 50 CFR 648.230 - Spiny dogfish Annual Catch Limits (ACLs).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Spiny dogfish Annual Catch Limits (ACLs... Management Measures for the Spiny Dogfish Fishery § 648.230 Spiny dogfish Annual Catch Limits (ACLs). (a) The... make recommendations to the Councils for changes in measures intended to ensure ACLs are not...

  1. 50 CFR 648.140 - Black sea bass Annual Catch Limit (ACL).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Black Sea Bass Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial and...) Sector allocations. The commercial and recreational fishing sector ACLs will be established consistent... Management Plan. (2) Periodicity. The black sea bass commercial and recreational sector ACLs may...

  2. 50 CFR 648.100 - Summer flounder Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) The Summer Flounder Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial... recommended by the SSC. (1) Sector allocations. The commercial and recreational fishing sector ACLs will be... sector ACLs may be established on an annual basis for up to 3 years at a time, dependent on whether...

  3. 50 CFR 648.64 - Yellowtail flounder sub-ACLs and AMs for the scallop fishery.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Yellowtail flounder sub-ACLs and AMs for...-ACLs and AMs for the scallop fishery. (a) As specified in § 648.55(d), and pursuant to the biennial... Georges Bank and Southern New England/Mid-Atlantic stocks of yellowtail flounder. The sub-ACLs for...

  4. 50 CFR 648.140 - Black sea bass Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Black Sea Bass Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial and...) Sector allocations. The commercial and recreational fishing sector ACLs will be established consistent... Management Plan. (2) Periodicity. The black sea bass commercial and recreational sector ACLs may...

  5. 50 CFR 648.230 - Spiny dogfish Annual Catch Limits (ACLs).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Spiny dogfish Annual Catch Limits (ACLs... Management Measures for the Spiny Dogfish Fishery § 648.230 Spiny dogfish Annual Catch Limits (ACLs). (a) The... make recommendations to the Councils for changes in measures intended to ensure ACLs are not...

  6. 50 CFR 648.140 - Black sea bass Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Black Sea Bass Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial and...) Sector allocations. The commercial and recreational fishing sector ACLs will be established consistent... Management Plan. (2) Periodicity. The black sea bass commercial and recreational sector ACLs may...

  7. 50 CFR 648.230 - Spiny dogfish Annual Catch Limits (ACLs).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Spiny dogfish Annual Catch Limits (ACLs... Management Measures for the Spiny Dogfish Fishery § 648.230 Spiny dogfish Annual Catch Limits (ACLs). (a) The... make recommendations to the Councils for changes in measures intended to ensure ACLs are not...

  8. 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

  9. Craniofacial approaches and reconstruction in skull base surgery: techniques for the oral and maxillofacial surgeon.

    PubMed

    Treasure, Trevor E; Dean, Jeffrey S; Gear, Robert D

    2013-12-01

    Skull base surgery (SBS) is considered the standard of care in treating benign and malignant lesions of the cranial base. SBS is a multidisciplinary team approach used to treat these complex lesions that may have intracranial extension. SBS can be broken down into 3 steps. Transfacial access is performed, followed by resection with sound oncologic principles, and then reconstruction of the cranial base and facial structures. Functional and esthetic concerns must be addressed by the surgeons. Oral and maxillofacial surgeons frequently perform elective facial osteotomies and treat victims of cranial base trauma. These same principles can be applied to SBS as a part of the skull base team.

  10. Enhanced product realization techniques using as-built and model reconstruction technologies

    SciTech Connect

    Dolin, R.M.; Hefele, J.; Tsai, C.S.; Maes, G.J.

    1995-10-01

    Los Alamos National Laboratory`s Center for Advanced Engineering Technology has developed a product realization process designed to enhance the complexity and comprehensiveness of the information fed back to the designer after the analytical and manufacturing operations have been completed. This process uses principles of As-Built Engineering and Model Reconstruction in a Models Based Engineering environment, allowing optimization in the manufacturing and assembly operations and providing information as to the As-Built configuration to engineering and physics designers for evaluation. As-Built Engineers is a product realization methodology founded on the notion that life-cycle engineering should be based on what is actually produced and not on what is nominally designed. It enables customization in mass production environments and questions nominal based methods of engineering. Model Reconstruction provides the capability of subjecting a design to adverse conditions within the computer aided environment and building a stereolithography model and simulated radiograph from the analytical finite element information of the simulated damaged part. Models Based Engineering is an information management tool and a key driver toward the development of adaptive product realization infrastructures. It encompasses the breadth of engineering information, from concept through design to product application.

  11. The ACLS Survey of Scholars: Views on Publications, Computers, Libraries.

    ERIC Educational Resources Information Center

    Morton, Herbert C.; Price, Anne Jamieson

    1986-01-01

    Reviews results of a survey by the American Council of Learned Societies (ACLS) of 3,835 scholars in the humanities and social sciences who are working both in colleges and universities and outside the academic community. Areas highlighted include professional reading, authorship patterns, computer use, and library use. (LRW)

  12. The Humanities in the Schools. ACLS Occasion Paper, No. 20.

    ERIC Educational Resources Information Center

    American Council of Learned Societies, New York, NY.

    Designed to serve as a record of the initial public activity of the American Council of Learned Societies (ACLS) Program in Humanities Curriculum Development, this collection of three articles offers different perspectives on the humanities in the schools. In the first article, "The Humanities and Public Education," Stanley N. Katz discusses the…

  13. Individuality of Item Interpretation in Interchangeable ACL Scales

    ERIC Educational Resources Information Center

    Fiske, Donald W.; Barack, Leonard I.

    1976-01-01

    The diversity among interpretations of single items in personality questionnaires has been noted previously. Using adjectives from the Adjective Check List (ACL), the study sought evidence bearing on these questions: Does such diversity make the responses to an item not comparable across subjects? If so, what are the implications for scores based…

  14. Neuromuscular efficiency of the vastus medialis obliquus and postural balance in professional soccer athletes after anterior cruciate ligament reconstruction

    PubMed Central

    Chaves, Shalimá Figueirêdo; Marques, Natália Pereira; Silva, Rômulo Lemos e; Rebouças, Nahra Santos; de Freitas, Luise Monteiro; de Paula Lima, Pedro Olavo; de Oliveira, Rodrigo Ribeiro

    2012-01-01

    Summary The purpose of this study was to evaluate the neuromuscular efficiency of the vastus medialis obliquus and postural balance in high-performance soccer athletes after anterior cruciate ligament (ACL) reconstruction, compared to the uninvolved leg. A cross-sectional study was conducted with 22 male professional soccer players after ACL reconstruction (4–12 months postoperatively). The athletes were submitted to functional rehabilitation with an accelerated protocol on the soccer team. They were evaluated using isokinetic dynamometer, surface electromyography and electronic baropodometer. There was no decrease or difference between neuromuscular efficiency of the VMO when comparing both the limbs after ACL reconstruction in the professional soccer athletes under treatment. The same result was found in postural balance. It can be concluded that the NME of the VMO in the involved member and postural balance were successfully re-established after the reconstruction procedure of the ACL in the sample group studied. PMID:23738285

  15. Technique to Improve Tracheostomy Speaking Valve Tolerance after Head and Neck Free Flap Reconstruction.

    PubMed

    Stranix, John T; Danziger, Keri M; Dumbrava, Veturia L; Mars, Ginger; Hirsch, David L; Levine, Jamie P

    2016-12-01

    Increased upper airway resistance from postoperative changes after major head and neck surgery may cause elevated transtracheal pressures and result in tracheostomy speaking valve intolerance. This may be particularly true among patients with baseline pulmonary disease. We describe a patient recovering from oral cancer resection and flap reconstruction who demonstrated prolonged ventilator dependence and tracheostomy speaking valve intolerance with abnormal tracheal manometry. We attempted to improve speaking valve tolerance through the adaptation of a valve modification intended to reduce transtracheal pressures. Drilling holes into the 1-way speaking valve allowed for excess air egress and resulted in normalization of transtracheal pressures with improved speaking valve tolerance. This 1-way speaking valve modification may serve as a simple method to allow for earlier restoration of voicing and potentially reduce the number of ventilator- dependent days in this patient population.

  16. Technique to Improve Tracheostomy Speaking Valve Tolerance after Head and Neck Free Flap Reconstruction

    PubMed Central

    Danziger, Keri M.; Dumbrava, Veturia L.; Mars, Ginger; Hirsch, David L.; Levine, Jamie P.

    2016-01-01

    Summary: Increased upper airway resistance from postoperative changes after major head and neck surgery may cause elevated transtracheal pressures and result in tracheostomy speaking valve intolerance. This may be particularly true among patients with baseline pulmonary disease. We describe a patient recovering from oral cancer resection and flap reconstruction who demonstrated prolonged ventilator dependence and tracheostomy speaking valve intolerance with abnormal tracheal manometry. We attempted to improve speaking valve tolerance through the adaptation of a valve modification intended to reduce transtracheal pressures. Drilling holes into the 1-way speaking valve allowed for excess air egress and resulted in normalization of transtracheal pressures with improved speaking valve tolerance. This 1-way speaking valve modification may serve as a simple method to allow for earlier restoration of voicing and potentially reduce the number of ventilator- dependent days in this patient population. PMID:28293493

  17. One-stage bone strip reconstruction technique with balloon sinus dilatation surgery for chronic maxillary atelectasis

    PubMed Central

    Kashima, Tomoyuki; Goldberg, Robert A; Kohn, Jocelyne C; Rootman, Daniel B

    2016-01-01

    Purpose Chronic maxillary atelectasis is characterized by unilateral spontaneous enophthalmos and hypoglobus due to increased orbital volume secondary to maxillary sinus inward deformation. Reformation of the sinus architecture and reconstruction of the orbit are key to a successful outcome. Here, we introduce a one-staged surgery that addresses both these goals. Patients and methods We retrospectively reviewed 11 patients treated with one-stage orbital and sinus surgery. A transconjunctival subperiosteal approach was used to create slats in the thinned orbital floor. A nasal endoscopic approach was utilized to access the maxillary sinus and place a modified Foley catheter balloon through the enlarged maxillary ostium. A bridge graft of nasal septal, ear cartilage, or LactSorb was placed on the reconstructed and balloon-supported orbital floor. The balloon was deflated and removed at 10–14 days. All patients underwent complete ophthalmic and orbital evaluation, including standardized photography and radiologic imaging. Results Eleven patients, mean age 39.5 years, presented with diplopia in upgaze, superior sulcus deformity, and at least 2 mm of relative enophthalmos. After initial overcorrection, enophthalmos improved in all cases. Symmetry within 1 mm was accomplished in 10 of 11 cases. Follow-up time was 259±320 days. Full motility was recovered in all patients. Conclusion We describe a one-staged surgery consisting of cutting slats in the orbital floor, dilating the maxillary sinus with a balloon, and stabilizing the orbital floor with a cartilage graft placement. Our anecdotal experience suggests that this surgical approach can safely achieve normalization of the pathologic sinus outflow and restoration of the orbit anatomy. The balloon ensures orbital floor stability during the healing process, and it may act to stent open the sinus ostium during early mucosal healing. PMID:27932858

  18. Reconstruction of three-dimensional auroral ionospheric conductivities via an assimilative technique

    NASA Astrophysics Data System (ADS)

    McGranaghan, R. M.; Knipp, D. J.; Matsuo, T.; Solomon, S. C.

    2015-12-01

    Energy redistribution in the magnetosphere-ionosphere-thermosphere (MIT) system is largely controlled by a complex system of field-aligned, Hall, and Pedersen currents, and the electrodynamics underlying their distributions. Application of Ohm's law to the auroral zone requires knowledge of the ionospheric conductivity, whose estimation has often been simplified by invoking Maxwellian behavior of the impacting particles and height independent conductance. Though these assumptions have allowed us to study height-integrated conductivities (conductances), they have also limited our ability to understand how the MIT system operates as a whole. We are now in a position to address conductivity variations, and thus energy redistribution, in three dimensions. We present an objective analysis of the fully three-dimensional (3-D) ionospheric Hall and Pedersen auroral conductivities for the November 30, 2011 coronal mass ejection event. We show: 1) a fundamental picture of ionospheric conductivity variability organized into empirical orthogonal functions [McGranaghan et al., 2015; accepted] and 2) an event reconstruction of the ionospheric conductivities. Figure 1 provides a proof of concept for part 1 by showing the first primary mode of variability (EOF1) of the Hall conductivity at four altitudes through the E- and lower F-regions. Our reconstruction relies on a data assimilation scheme that optimally combines Defense Meteorological Satellite Program (DMSP) satellite observations with an error covariance model created from the conductivity EOFs. We find significant 3-D structure in the ionospheric conductivities that can drastically modify the E- and lower F-region behavior. We suggest an exciting opportunity to extend these analyses to other data sets, such as the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC).

  19. Outcome of double bundle anterior cruciate ligament reconstruction using crosspin and aperture fixation

    PubMed Central

    Joshi, Deepak; Jain, Vineet; Goyal, Ankit; Bahl, Vibhu; Modi, Prashant; Chaudhary, Deepak

    2014-01-01

    Background: Double bundle anterior cruciate ligament (DBACL) reconstruction is said to reproduce the native anterior cruciate ligament (ACL) anatomy better than single bundle anterior cruciate ligament, whether it leads to better functional results is debatable. Different fixation methods have been used for DBACL reconstruction, the most common being aperture fixation on tibial side and cortical suspensory fixation on the femoral side. We present the results of DBACL reconstruction technique, wherein on the femoral side anteromedial (AM) bundle is fixed with a crosspin and aperture fixation was done for the posterolateral (PL) bundle. Materials and Methods: Out of 157 isolated ACL injury patients who underwent ACL reconstruction, 100 were included in the prospective study. Arthroscopic DBACL reconstruction was done using ipsilateral hamstring autograft. AM bundle was fixed using Transfix (Arthrex, Naples, FL, USA) on the femoral side and bio interference screw (Arthrex, Naples, FL, USA) on the tibial side. PL bundle was fixed on femoral as well as on tibial side with a biointerference screw. Patients were evaluated using KT-1000 arthrometer, Lysholm score, International Knee Documentation Committee (IKDC) Score and isokinetic muscle strength testing. Methods: Out of 157 isolated ACL injury patients who underwent ACL reconstruction, 100 were included in the prospective study. Arthroscopic DBACL reconstruction was done using ipsilateral hamstring autograft. AM bundle was fixed using Transfix (Arthrex, Naples, FL, USA) on the femoral side and bio interference screw (Arthrex, Naples, FL, USA) on the tibial side. PL bundle was fixed on femoral as well as on tibial side with a biointerference screw. Patients were evaluated using KT-1000 arthrometer, Lysholm score, International Knee Documentation Committee (IKDC) Score and isokinetic muscle strength testing. Results: The KT-1000 results were evaluated using paired t test with the P value set at 0.001. At the end of 1

  20. A Time Series Separation and Reconstruction (TSSR) Technique to Estimate Daily Suspended Sediment Concentrations

    EPA Science Inventory

    High suspended sediment concentrations (SSCs) from natural and anthropogenic sources are responsible for biological impairments of many streams, rivers, lakes, and estuaries, but techniques to estimate sediment concentrations or loads accurately at the daily temporal resolution a...

  1. Arterial complications, venous thromboembolism and deep venous thrombosis prophylaxis after anterior cruciate ligament reconstruction: A systematic review

    PubMed Central

    Janssen, Rob Paulus Augustinus; Reijman, Max; Janssen, Daan Martijn; van Mourik, Jan Bernardus Antonius

    2016-01-01

    AIM To summarize the current knowledge on vascular complications and deep venous thrombosis (DVT) prophylaxis after anterior cruciate ligament (ACL) reconstruction. METHODS A systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement. MEDLINE, EMBASE, Cochrane, Web of Science, CINAHL, PubMed publisher, and Google scholar medical literature databases were searched up to November 10, 2015. Any arthroscopic surgical method of primary or revision intra-articular ACL reconstruction of all graft types in humans was included. A risk of bias assessment was determined. RESULTS Fourty-seven studies were included in the review. Pseudaneurysms were the most frequently reported arterial complication after ACL reconstruction, irrespective of graft type or method of graft fixation with an incidence of 0.3%. The time to diagnosis of arterial complications after ACL reconstruction varied from days to mostly weeks but even years. After ACL reconstruction without thromboprophylaxis, the incidence of DVT was 9.7%, of which 2.1% was symptomatic. The incidence of pulmonary embolism was 0.1%. Tourniquet time > 2 h was related to venous thromboembolism. Thromboprophylaxis is indicated in patients with risk factors for venous thromboembolism. CONCLUSION After ACL reconstruction, the incidence of arterial complications, symptomatic DVT and pulmonary embolism was 0.3%, 2.1% and 0.1% respectively. Arterial complications may occur with all types of arthroscopic ACL reconstruction, methods of graft fixation as well as any type of graft. Patients considered to be at moderate or high risk of venous thromboembolism should routinely receive thromboprophylaxis after ACL reconstruction. PMID:27672574

  2. The Effects of a Valgus Collapse Knee Position on In Vivo ACL Elongation

    PubMed Central

    Utturkar, G. M.; Irribarra, L. A.; Taylor, K. A.; Spritzer, C. E.; Taylor, D. C.; Garrett, W. E.; DeFrate, Louis E.

    2013-01-01

    There are conflicting data regarding what motions increase ACL injury risk. More specifically, the mechanical role of valgus collapse positions during ACL injury remains controversial. Our objective was to evaluate ACL elongation in a model that mimics knee movements thought to occur during ACL injury. Eight healthy male subjects were imaged using MR and biplanar fluoroscopy to measure the in vivo elongation of the ACL and its functional bundles during three static knee positions: full extension, 30° of flexion, and a position intended to mimic a valgus collapse position described in the literature. For this study, the valgus collapse position consisted of 30° of knee flexion, internal rotation of the hip, and 10° of external tibial rotation. ACL length decreased significantly from full extension (30.2 ± 2.6 mm) to 30° of flexion (27.1 ± 2.2 mm). ACL length further decreased in the valgus collapse position (25.6 ± 2.4 mm). Both functional bundles of the ACL followed similar trends with regards to decreases in length in each of the three positions. Since strain would follow patterns of ACL length, landing on an extended knee may be a more relevant risk factor for ACL injuries than the valgus collapse position in males. Future studies should evaluate the effects of dynamic motion patterns on in vivo ACL strains. PMID:22855117

  3. The effects of a valgus collapse knee position on in vivo ACL elongation.

    PubMed

    Utturkar, G M; Irribarra, L A; Taylor, K A; Spritzer, C E; Taylor, D C; Garrett, W E; Defrate, Louis E

    2013-01-01

    There are conflicting data regarding what motions increase ACL injury risk. More specifically, the mechanical role of valgus collapse positions during ACL injury remains controversial. Our objective was to evaluate ACL elongation in a model that mimics knee movements thought to occur during ACL injury. Eight healthy male subjects were imaged using MR and biplanar fluoroscopy to measure the in vivo elongation of the ACL and its functional bundles during three static knee positions: full extension, 30° of flexion, and a position intended to mimic a valgus collapse position described in the literature. For this study, the valgus collapse position consisted of 30° of knee flexion, internal rotation of the hip, and 10° of external tibial rotation. ACL length decreased significantly from full extension (30.2 ± 2.6 mm) to 30° of flexion (27.1 ± 2.2 mm). ACL length further decreased in the valgus collapse position (25.6 ± 2.4 mm). Both functional bundles of the ACL followed similar trends with regards to decreases in length in each of the three positions. Since strain would follow patterns of ACL length, landing on an extended knee may be a more relevant risk factor for ACL injuries than the valgus collapse position in males. Future studies should evaluate the effects of dynamic motion patterns on in vivo ACL strains.

  4. Trajectory and atmospheric structure from entry probes: Demonstration of a real-time reconstruction technique using a simple direct-to-Earth radio link

    NASA Astrophysics Data System (ADS)

    Withers, Paul

    2010-12-01

    The reconstruction of the trajectory and atmospheric structure associated with an entry probe has traditionally relied upon onboard accelerometer measurements. Here we outline an equivalent reconstruction technique that uses Doppler-shifted direct-to-Earth transmissions instead. A critical assumption is that the entry probe's angle of attack is zero. The technique is successfully demonstrated on the atmospheric entry of the Mars Exploration Rover Opportunity, terminating at parachute deployment. This technique can be applied in real-time, which supports mission operations and public engagement. It can also be applied to entry probes that fail during their high-risk atmospheric entry.

  5. Trajectory And Atmospheric Structure From Entry Probes: Demonstration Of A Real-time Reconstruction Technique Using A Simple Direct-to-earth Radio Link

    NASA Astrophysics Data System (ADS)

    Withers, Paul

    2010-10-01

    The reconstruction of the trajectory and atmospheric structure associated with an entry probe has traditionally relied upon onboard accelerometer measurements. Here we outline an equivalent reconstruction technique that uses Doppler-shifted direct-to-Earth transmissions instead. A critical assumption is that the entry probe's angle of attack is zero. The technique is successfully demonstrated on the atmospheric entry of the Mars Exploration Rover Opportunity, terminating at parachute deployment. This technique can be applied in real-time, which supports mission operations and public engagement. It can also be applied to entry probes that fail during their high-risk atmospheric entry.

  6. Rectovaginal septal repair: case presentations and introduction of a modified reconstruction technique.

    PubMed

    Walfisch, A; Zilberstein, T; Walfisch, S

    2004-11-01

    Rectovaginal fistula are a relatively rare kind of anorectal fistulas. Spontaneous healing is rare and the rectal advancement flap repair is the most popular procedure with success rates ranging between 60% and 80%. We present a new technique for repairing damage in the rectovaginal septum that consists of placing a folded polyglycolic acid mesh (Dexon) between the levator ani muscle closure area and the vaginal wall. This absorbable mesh separates the suture lines on the vaginal and rectal walls, and induces fibrosis and healing. The technique was performed in four women suffering from a rectovaginal fistula due to different causes. It was successful in all cases.

  7. D Reconstruction and Modeling of Subterranean Landscapes in Collaborative Mining Archeology Projects: Techniques, Applications and Experiences

    NASA Astrophysics Data System (ADS)

    Arles, A.; Clerc, P.; Sarah, G.; Téreygeol, F.; Bonnamour, G.; Heckes, J.; Klein, A.

    2013-07-01

    Mining and underground archaeology are two domains of expertise where three-dimensional data take an important part in the associated researches. Up to now, archaeologists study mines and underground networks from line-plot surveys, cross-section of galleries, and from tool marks surveys. All this kind of information can be clearly recorded back from the field from threedimensional models with a more cautious and extensive approach. Besides, the volumes of the underground structures that are very important data to explain the mining activities are difficult to evaluate from "traditional" hand-made recordings. They can now be calculated more accurately from a 3D model. Finally, reconstructed scenes are a powerful tool as thinking aid to look back again to a structure in the office or in future times. And the recorded models, rendered photo-realistically, can also be used for cultural heritage documentation presenting inaccessible and sometimes dangerous places to the public. Nowadays, thanks to modern computer technologies and highly developed software tools paired with sophisticated digital camera equipment, complex photogrammetric processes are available for moderate costs for research teams. Recognizing these advantages the authors develop and utilize image-based workflows in order to document ancient mining monuments and underground sites as a basis for further historical and archaeological researches, performed in collaborative partnership during recent projects on medieval silver mines and preventive excavations of undergrounds in France.

  8. Failure of Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Samitier, Gonzalo; Marcano, Alejandro I.; Alentorn-Geli, Eduard; Cugat, Ramon; Farmer, Kevin W; Moser, Michael W

    2015-01-01

    The present review classifies and describes the multifactorial causes of anterior cruciate ligament (ACL) surgery failure, concentrating on preventing and resolving such situations. The article particularly focuses on those causes that require ACL revision due to recurrent instability, without neglecting those that affect function or produce persistent pain. Although primary ACL reconstruction has satisfactory outcome rates as high as 97%, it is important to identify the causes of failure, because satisfactory outcomes in revision surgery can drop to as much as 76%. It is often possible to identify a primary or secondary cause of ACL surgery failure; even the most meticulous planning can give rise to unexpected findings during the intervention. The adopted protocol should therefore be sufficiently flexible to adapt to the course of surgery. Preoperative patient counseling is essential. The surgeon should limit the patient’s expectations for the outcome by explaining the complexity of this kind of procedure. With adequate preoperative planning, close attention to details and realistic patient expectations, ACL revision surgery may offer beneficial and satisfactory results for the patient. PMID:26550585

  9. 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

  10. Application of AI techniques to a voice-actuated computer system for reconstructing and displaying magnetic resonance imaging data

    NASA Astrophysics Data System (ADS)

    Sherley, Patrick L.; Pujol, Alfonso, Jr.; Meadow, John S.

    1990-07-01

    To provide a means of rendering complex computer architectures languages and input/output modalities transparent to experienced and inexperienced users research is being conducted to develop a voice driven/voice response computer graphics imaging system. The system will be used for reconstructing and displaying computed tomography and magnetic resonance imaging scan data. In conjunction with this study an artificial intelligence (Al) control strategy was developed to interface the voice components and support software to the computer graphics functions implemented on the Sun Microsystems 4/280 color graphics workstation. Based on generated text and converted renditions of verbal utterances by the user the Al control strategy determines the user''s intent and develops and validates a plan. The program type and parameters within the plan are used as input to the graphics system for reconstructing and displaying medical image data corresponding to that perceived intent. If the plan is not valid the control strategy queries the user for additional information. The control strategy operates in a conversation mode and vocally provides system status reports. A detailed examination of the various AT techniques is presented with major emphasis being placed on their specific roles within the total control strategy structure. 1.

  11. Microcomputer-based technique for 3-D reconstruction and volume measurement of computer tomographic images. Part 1: Phantom studies.

    PubMed

    Albright, R E; Fram, E K

    1988-12-01

    This paper presents a microcomputer-based technique that accurately quantifies volumes from computed tomographic (CT) scans of irregularly shaped objects as well as displaying 3-D reconstructions. The method uses standard CT film, allowing analysis of previous or outside CT studies. The planimetry method showed less than 5% error in measuring irregular 2-D areas larger than 6 mm2. The method is demonstrated to be significantly more accurate than spherical, ellipsoid, or rectangular geometric models in quantifying object volume by CT (P less than .001). With a single gantry angle, planimetry showed a two standard deviation error under 10% in measuring the volume of irregular objects compared with an error over 30% for ellipsoid models. The inaccuracy of the spherical model (80% error) and the rectangular prism model (192% error) renders them impractical to provide quantitative object volume. Microcomputer planimetry provides an accurate and versatile means to measure the volume and produce 3-D reconstructions of objects scanned with CT, and it has potential application in quantifying tumor response with CT and magnetic resonance imaging.

  12. Comparison of Statistical Estimation Techniques for Mars Entry, Descent, and Landing Reconstruction from MEDLI-like Data Sources

    NASA Technical Reports Server (NTRS)

    Dutta, Soumyo; Braun, Robert D.; Russell, Ryan P.; Clark, Ian G.; Striepe, Scott A.

    2012-01-01

    Flight data from an entry, descent, and landing (EDL) sequence can be used to reconstruct the vehicle's trajectory, aerodynamic coefficients and the atmospheric profile experienced by the vehicle. Past Mars missions have contained instruments that do not provide direct measurement of the freestream atmospheric conditions. Thus, the uncertainties in the atmospheric reconstruction and the aerodynamic database knowledge could not be separated. The upcoming Mars Science Laboratory (MSL) will take measurements of the pressure distribution on the aeroshell forebody during entry and will allow freestream atmospheric conditions to be partially observable. This data provides a mean to separate atmospheric and aerodynamic uncertainties and is part of the MSL EDL Instrumentation (MEDLI) project. Methods to estimate the flight performance statistically using on-board measurements are demonstrated here through the use of simulated Mars data. Different statistical estimators are used to demonstrate which estimator best quantifies the uncertainties in the flight parameters. The techniques demonstrated herein are planned for application to the MSL flight dataset after the spacecraft lands on Mars in August 2012.

  13. Lower Limb Kinematics and Dynamic Postural Stability in Anterior Cruciate Ligament-Reconstructed Female Athletes

    PubMed Central

    Delahunt, Eamonn; Chawke, Mark; Kelleher, Judy; Murphy, Katie; Prendiville, Anna; Sweeny, Lauren; Patterson, Matt

    2013-01-01

    Context: Deficits in lower limb kinematics and postural stability are predisposing factors to the development of knee ligamentous injury. The extent to which these deficits are present after anterior cruciate ligament (ACL) reconstruction is still largely unknown. The primary hypothesis of the present study was that female athletes who have undergone ACL reconstruction and who have returned to sport participation would exhibit deficits in dynamic postural stability as well as deficiencies in hip- and knee-joint kinematics when compared with an age-, activity-, and sex-matched uninjured control group. Objective: To investigate dynamic postural stability as quantified by the Star Excursion Balance Test (SEBT) and simultaneous hip- and knee-joint kinematic profiles in female athletes who have undergone ACL reconstruction. Design: Descriptive laboratory study. Setting: University motion-analysis laboratory. Patients or Other Participants: Fourteen female athletes who had previously undergone ACL reconstruction (ACL-R) and 17 age- and sex-matched uninjured controls. Intervention(s): Each participant performed 3 trials of the anterior, posterior-medial, and posterior-lateral directional components of the SEBT. Main Outcome Measure(s): Reach distances for each directional component were quantified and expressed as a percentage of leg length. Simultaneous hip- and knee-joint kinematic profiles were recorded using a motion-analysis system. Results: The ACL-R group had decreased reach distances on the posterior-medial (P < .01) and posterior-lateral (P < .01) directional components of the SEBT. During performance of the directional components of the SEBT, ACL-R participants demonstrated altered hip-joint frontal-, sagittal-, and transverse-plane kinematic profiles (P < .05), as well as altered knee-joint sagittal-plane kinematic profiles (P < .05). Conclusions: Deficits in dynamic postural stability and concomitant altered hip- and knee-joint kinematics are present after ACL

  14. Strength and Functional Performance Recovery After Anterior Cruciate Ligament Reconstruction in Preadolescent Athletes

    PubMed Central

    Greenberg, Elliot M.; Greenberg, Eric T.; Ganley, Theodore J.; Lawrence, J. Todd R.

    2014-01-01

    Background: In the skeletally immature population, the incidence of anterior cruciate ligament (ACL) injuries and ACL reconstructions appears to be increasing. Differences in surgical techniques, physiology, and emotional maturity may alter the rehabilitation progression and impact the outcomes when compared with adults. Reports of objective strength recovery and performance-based outcome measures after pediatric ACL reconstruction (ACLR) are limited. Study Design: Retrospective case series. Level of Evidence: Level 4. Methods: All patients that underwent all-epiphyseal ACLR from January 2008 to August 2010 were identified. Isokinetic peak quadriceps/hamstring torque values and functional performance measures in unilateral hopping tasks were extracted and compared with the noninjured limb. A limb symmetry index (LSI) of ≥90% was considered satisfactory. Results: Complete data were available for 16 patients (mean age, 12.28 years; range, 8.51-14.88 years). By a mean 7 months (range, 3.02-12.56 years) postoperatively, only 9 of 16 (56%) were able to achieve a satisfactory LSI for quadriceps strength. For hamstring strength, 15 of 16 (94%) were able to achieve satisfactory LSI. By a mean of 12 months (range, 5.39-24.39 months) postoperatively, only 6 of 16 subjects (38%) were able to achieve satisfactory performance on all functional hop tests. At a mean 15.42 months (range, 8.58-24.39 months) postsurgery, only 4 of 16 (25%) subjects were able to achieve an LSI of ≥90% on all testing parameters. Conclusion: For some pediatric patients, significant strength and functional deficits may be present at greater than 1 year after ACLR. This population may require more prolonged rehabilitation programs to allow for adequate recovery of strength and function because of unique characteristics of normal growth and development. PMID:24982702

  15. Comparing different assimilation techniques for the ionospheric F2 layer reconstruction

    NASA Astrophysics Data System (ADS)

    Gerzen, Tatjana; Minkwitz, David; Schlueter, Stefan

    2015-08-01

    From the applications perspective the electron density is the major determining parameter of the ionosphere due to its strong impact on the radio signal propagation. As the most ionized ionospheric region, the F2 layer has the most pronounced effect on transionospheric radio wave propagation. The maximum electron density of the F2 layer, NmF2, and its height, hmF2, are of particular interest for radio communication applications as well as for characterizing the ionosphere. Since these ionospheric key parameters decisively shape the vertical electron density profiles, the precise calculation of them is of crucial importance for an accurate 3-D electron density reconstruction. The vertical sounding by ionosondes provides the most reliable source of F2 peak measurements. Within this paper, we compare the following data assimilation methods incorporating ionosonde measurements into a background model: Optimal Interpolation (OI), OI with time forecast (OI FC), the Successive Correction Method (SCM), and a modified SCM (MSCM) working with a daytime-dependent measurement error variance. These approaches are validated with the measurements of nine ionosonde stations for two periods covering quiet and disturbed ionospheric conditions. In particular, for the quiet period, we show that MSCM outperforms the other assimilation methods and allows an accuracy gain up to 75% for NmF2 and 37% for hmF2 compared to the background model. For the disturbed period, OI FC reveals the most promising results with improvements up to 79% for NmF2 and 50% for hmF2 compared to the background and up to 42% for NmF2 and 16% for hmF2 compared to OI.

  16. Stature estimation in ancient Egyptians: a new technique based on anatomical reconstruction of stature.

    PubMed

    Raxter, Michelle H; Ruff, Christopher B; Azab, Ayman; Erfan, Moushira; Soliman, Muhammad; El-Sawaf, Aly

    2008-06-01

    Trotter and Gleser's (Trotter and Gleser: Am J Phys Anthropol 10 (1952) 469-514; Trotter and Gleser: Am J Phys Anthropol 16 (1958) 79-123) long bone formulae for US Blacks or derivations thereof (Robins and Shute: Hum Evol 1 (1986) 313-324) have been previously used to estimate the stature of ancient Egyptians. However, limb length to stature proportions differ between human populations; consequently, the most accurate mathematical stature estimates will be obtained when the population being examined is as similar as possible in proportions to the population used to create the equations. The purpose of this study was to create new stature regression formulae based on direct reconstructions of stature in ancient Egyptians and assess their accuracy in comparison to other stature estimation methods. We also compare Egyptian body proportions to those of modern American Blacks and Whites. Living stature estimates were derived using a revised Fully anatomical method (Raxter et al.: Am J Phys Anthropol 130 (2006) 374-384). Long bone stature regression equations were then derived for each sex. Our results confirm that, although ancient Egyptians are closer in body proportion to modern American Blacks than they are to American Whites, proportions in Blacks and Egyptians are not identical. The newly generated Egyptian-based stature regression formulae have standard errors of estimate of 1.9-4.2 cm. All mean directional differences are less than 0.4% compared to anatomically estimated stature, while results using previous formulae are more variable, with mean directional biases varying between 0.2% and 1.1%, tibial and radial estimates being the most biased. There is no evidence for sig