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Sample records for internal plate fixation

  1. Processing and evaluation of long fiber thermoplastic composite plates for internal fixation

    NASA Astrophysics Data System (ADS)

    Warren, Paul B.

    The metallic plates used in internal fracture fixation may have up to ten times the elastic modulus of normal bone tissue, causing stress shielding-induced osteopenia in healed bone that can lead to re-fracture after plate removal and prolonged and painful recovery. Thermoplastic polymer matrix composites reinforced with long carbon fiber are promising alternative materials for internal fixation plates because they may be produced with relative ease and be tailored to have specific mechanical properties, alleviating the stress shielding problem. Long carbon fiber-reinforced polyetheretherketone (LCF PEEK) plates were produced using the extrusion / compression molding process. Static flexural testing determined that LCF PEEK plates with rectangular cross-section had an average flexural modulus of 12 GPa, or 23% of the flexural modulus of a stainless steel plate. The LCF PEEK plates also experienced negligible (14.7%, 14.5%, and 16.7%) reductions in modulus after fatigue testing at applied moments of 2.5, 3.0, and 3.5 N•m, respectively, over 106 load cycles. Aging the plates in 0.9% NaCl solution for four and eight weeks caused 0.34% and 0.28% increases in plate mass, respectively. No significant decrease of flexural properties due to aging was detected. Differential scanning calorimetry (DSC) revealed the PEEK matrix of the plates to be 24.5% crystalline, which is lower than typical PEEK crystallinity values of 30-35%. Scanning electron microscopy (SEM) revealed three times as many fiber pullout areas in LCF PEEK fracture surfaces as in fracture surfaces of long carbon fiber-reinforced polyphenylenesulfide (LCF PPS), another plate material tested. DSC and SEM data suggest that improvements in processing conditions and fiber/matrix bonding, along with higher carbon fiber fractions, would enhance LCF PEEK plate performance. LCF PEEK remains a promising alternative to stainless steel for internal fixation plates.

  2. Evidence based postoperative treatment of distal radius fractures following internal locking plate fixation.

    PubMed

    Klein, S M; Prantl, L; Koller, M; Vykoukal, J; Dolderer, J H; Graf, S; Nerlich, M; Loibl, M; Geis, S

    2015-01-01

    Originally, the treatment method of choice for distal radial fractures (DRF) has been a non-operative approach with six to eight weeks of plaster casting. The introduction of volar locking plate systems at the beginning of the 21 st century has pushed trends towards open reduction and internal fixation (ORIF). While the introduction of fixed angle locking plates together with the increasing knowledge on wrist function and related variable outcomes has led to consensus that operative fixation in instable DRF is the treatment method of choice, there is no agreement on a postoperative care of these injuries. The authors will discuss the available evidence for current concepts of postoperative treatment of DRFs following fixed angle fixation under socioeconomical, biomechanical and burden of disease aspects. Further, relevant randomized controlled trials are evaluated with regard to applied postoperative treatment regimes and related risks for complications.

  3. Callus Formation and Mineralization after Fracture with Different Fixation Techniques: Minimally Invasive Plate Osteosynthesis versus Open Reduction Internal Fixation.

    PubMed

    Xu, Haitao; Xue, Zichao; Ding, Haoliang; Qin, Hui; An, Zhiquan

    2015-01-01

    Minimally invasive plate osteosynthesis(MIPO) has been considered as an alternative for fracture treatment. Previous study has demonstrated that MIPO technique has the advantage of less soft tissue injury compared with open reduction internal fixation (ORIF). However, the comparison of callus formation and mineralization between two plate osteosynthesis methods remains unknown. In this experiment, ulna fracture model was established in 42 beagle dogs. The fractures underwent reduction and internal fixation with MIPO or ORIF. Sequential fluorescent labeling and radiographs were applied to determine new callus formation and mineralization in two groups after operation. At 4, 8 and 12 weeks postoperatively, the animals were selected to be sacrificed and the ulna specimens were analyzed by Micro-CT. The sections were also treated with Masson staining for histological evaluation. More callus formation was observed in MIPO group in early stage of fracture healing. The fracture union rate has no significant difference between two groups. The results indicate that excessive soft tissue stripping may impact early callus formation. As MIPO technique can effectively reduce soft tissue injury with little incision, it is considered to be a promising alternative for fracture fixation.

  4. Callus Formation and Mineralization after Fracture with Different Fixation Techniques: Minimally Invasive Plate Osteosynthesis versus Open Reduction Internal Fixation

    PubMed Central

    Ding, Haoliang; Qin, Hui; An, Zhiquan

    2015-01-01

    Minimally invasive plate osteosynthesis(MIPO) has been considered as an alternative for fracture treatment. Previous study has demonstrated that MIPO technique has the advantage of less soft tissue injury compared with open reduction internal fixation (ORIF). However, the comparison of callus formation and mineralization between two plate osteosynthesis methods remains unknown. In this experiment, ulna fracture model was established in 42 beagle dogs. The fractures underwent reduction and internal fixation with MIPO or ORIF. Sequential fluorescent labeling and radiographs were applied to determine new callus formation and mineralization in two groups after operation. At 4, 8 and 12 weeks postoperatively, the animals were selected to be sacrificed and the ulna specimens were analyzed by Micro-CT. The sections were also treated with Masson staining for histological evaluation. More callus formation was observed in MIPO group in early stage of fracture healing. The fracture union rate has no significant difference between two groups. The results indicate that excessive soft tissue stripping may impact early callus formation. As MIPO technique can effectively reduce soft tissue injury with little incision, it is considered to be a promising alternative for fracture fixation. PMID:26444295

  5. Open reduction and internal fixation of posterior pilon fractures with buttress plate

    PubMed Central

    Chen, Da-wei; Li, Bing; Aubeeluck, Ashwin; Yang, Yun-feng; Zhou, Jia-qian; Yu, Guang-rong

    2014-01-01

    Objective: Posterior pilon fractures are rare injuries and have not yet gained well recognition. The purpose of this study was to present the treatment outcome for patients with posterior pilon fractures treated with buttress plate. Method: In this retrospective study we identified patients with posterior pilon fractures of the distal tibia who had undergone open reduction and internal fixation at our institute. Between January 2007 and December 2009, 10 patients (mean age, 46.5 years) who had undergone buttress plating via either a posterolateral approach or a dual posterolateral-posteromedial approach, were selected. All 10 patients were available for follow-up. The clinical outcome was evaluated with the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and the visual analogue scale (VAS). The radiological evaluation was performed using the osteoarthritis-score (OA-score). Results: Satisfactory reduction and stable fixation were accomplished in all patients. At a mean follow-up of 36.2 months, all patients had good radiological results and showed satisfactory clinical recovery. The mean AOFAS sore was 87.8, the mean OA-score was 0.6, and the mean VAS scores during rest, active motion, and weight-bearing walking were 0.6, 0.8, and 1.4, respectively. Conclusion: Buttress plating for posterior pilon fractures gave satisfactory clinical outcomes. It also ensured rigid fixation which in turn enabled earlier postoperative mobilization. Level of Evidence IV, Retrospective Study. PMID:24644421

  6. Treatment of Humeral Shaft Fractures: Minimally Invasive Plate Osteosynthesis Versus Open Reduction and Internal Fixation

    PubMed Central

    Esmailiejah, Ali Akbar; Abbasian, Mohammad Reza; Safdari, Farshad; Ashoori, Keyqobad

    2015-01-01

    Background: The optimal technique for operative fixation of humeral shaft fractures remains controversial and warrants research. Objectives: The purpose of the current study was to compare the functional and clinical outcomes of conventional open reduction and internal fixation (ORIF) with minimally invasive plate osteosynthesis (MIPO) in patients with fractures in two-third distal humeral shaft. Patients and Methods: In the current prospective case-control study, 65 patients with humeral shaft fractures were treated using ORIF (33 patients) or MIPO (32 patients). Time of surgery, time of union, incidence of varus deformity and complications were compared between the two groups. Also, the university of California-Los Angeles (UCLA) shoulder rating scale and Mayo Elbow performance score (MEPS) were used to compare the functional outcomes between the two groups. Results: The median of union time was shorter in the MIPO group (4 months versus 5 months). The time of surgery and functional outcomes based on the UCLA and MEPS scores were the same. The incidence of varus deformity was more than 5° and was higher and the incidence of nonunion, infection and iatrogenic radial nerve injury were lower in the MIPO group; however, the differences were not significant. Conclusions: Due to the shorter union time, to some extent less complication rate and comparable functional and clinical results, the authors recommend to use the MIPO technique in treating the mid-distal humeral shaft fracture. PMID:26543844

  7. Clinical results of using the proximal humeral internal locking system plate for internal fixation of displaced proximal humeral fractures.

    PubMed

    Norouzi, Masoud; Naderi, Mohammad Nasir; Komasi, Mehdi Hemmati; Sharifzadeh, Seyyed Reza; Shahrezaei, Mostafa; Eajazi, Alireza

    2012-05-01

    Proximal humerus fractures are accounting for 4-5% of all fractures with increasing incidence. Proximal Humeral Internal Locking System (PHILOS) plate is a new plate which permits early mobility and lowers the risk of complications. The aim of this study was to evaluate the functional outcome and the complication rate after using this plate. Between 2006-2008, 37 patients with displaced 2-, 3-, and 4-part fractures of the proximal humerus underwent surgery using PHILOS plate. The mean range of follow-up was 12 months. Twenty patients were aged 60 years and younger, and 17 were aged older than 60 years. The average American Shoulder and Elbow Surgeons (ASES) score at the final follow-up was 77.62. According to Michener and colleagues classification, 5.4% of patients had an excellent outcome, 72.9% were minimally functionally limited, 16.2% were moderately functionally limited, and 5.4% were maximally functionally limited. The average ASES score between patients 60 years and older and those 60 years and younger was not different significantly. One patient developed avascular necrosis of the humeral head, 2 patients developed an infection, and no patients developed a nonunion. Fixation with PHILOS plate can be considered a good method with high union rates for this kind of fracture, especially in the older population with osteoporotic bone.

  8. Biomechanical study in polyurethane mandibles of different metal plates and internal fixation techniques, employed in mandibular angle fractures.

    PubMed

    Semeghini Guastaldi, Fernando Pozzi; Hochuli-Vieira, Eduardo; Guastaldi, Antonio Carlos

    2014-11-01

    The aim of this study was to perform a physicochemical and morphological characterization and compare the mechanical behavior of an experimental Ti-Mo alloy to the analogous metallic Ti-based fixation system, for mandibular angle fractures. Twenty-eight polyurethane mandibles were uniformly sectioned on the left angle. These were divided into 4 groups: group Eng 1P, one 2.0-mm plate and 4 screws 6 mm long; group Eng 2P, two 2.0-mm plates, the first fixed with 4 screws 6 mm long and the second with 4 screws 12 mm long. The same groups were created for the Ti-15Mo alloy. Each group was subjected to linear vertical loading at the first molar on the plated side in a mechanical testing unit. Means and standard deviations were compared with respect to statistical significance using ANOVA. The chemical composition of the Ti-15Mo alloy was close to the nominal value. The mapping of Mo and Ti showed a homogeneous distribution. SEM of the screw revealed machining debris. For the plates, only the cpTi plate undergoes a surface treatment. The metallographic analysis reveals granular microstructure, from the thermomechanical trials. A statistically significant difference was found (P < 0.05) when the comparison between both internal fixation techniques was performed. The 2P technique showed better mechanical behavior than 1P. PMID:25340696

  9. Outcome of proximal humerus fractures treated by PHILOS plate internal fixation. Experience of a district general hospital.

    PubMed

    Shahid, Rizwan; Mushtaq, Abid; Northover, Julian; Maqsood, Mohammad

    2008-10-01

    Proximal humerus fractures have been a challenge to achieve stable fixation. PHILOS (Proximal Humerus internal locking system) is part of the latest generation of locking compression plates for proximal humeral fracture fixation. We aim to assess the clinical and functional outcome of proximal humeral fractures (2-part, 3-part and 4-part) treated with the PHILOS plate. We prospectively reviewed 50 patients who had a proximal humeral fracture treated with the PHILOS plate from September 2002 to September 2006 in our institution. Clinical outcome was measured using the patient-based Oxford shoulder and DASH scoring systems. Five patients died and four were lost to follow-up. Eleven patients had 2-part, eleven 3-part and eighteen 4-part fractures. Mean follow-up time was 21.7 months (range: 6-44 months). Radiological union was achieved within 8 weeks in 40/41 fractures; complications were noted in four cases. Better results were achieved in younger than in older patients, and in male than in female patients. The number of fracture fragments did not appear to affect the results, but associated dislocation of the humeral head was a pejorative factor. Our study has shown that the PHILOS plate is a reliable implant. A direct correlation was observed between Oxford shoulder and DASH scores.

  10. Bilateral traumatic proximal humerus fractures managed by open reduction and internal fixation with locked plates.

    PubMed

    Jaiswal, Atin; Kachchhap, Naiman Deepak; Chaterjee, Rupak; Tanwar, Yashwant Singh; Habib, Masood; Singh, Satya Prakash

    2013-01-01

    Fractures of the proximal humerus are uncommon in young patients. Although bilateral fracture of proximal humerus itself is rare, association with epilepsy and electrocution is frequent. Only one case of traumatic bilateral proximal humerus fracture has been reported in the literature. We report a rare case of bilateral traumatic displaced proximal humerus fractures in a 40 years old male patient, which was treated by means of open reduction and internal fixation with proximal humerus locked pates on both sides and obtained a good functional outcome.

  11. Internal fixation of fractures of the shaft of the humerus by dynamic compression plate or intramedullary nail: A prospective study

    PubMed Central

    Raghavendra, S; Bhalodiya, Haresh P

    2007-01-01

    Background: The indications for surgical management of fractures of the shaft of the humerus are clear, but selecting the right implant for internal fixation of humeral fractures has been a dilemma. Materials and Methods: Thirty-six patients (mean age 40.53 years) with fractures of the shaft of the humerus were followed for 12 to 24 months in a prospective study. Eighteen patients each underwent open reduction and internal fixation with compression plating and ante grade interlock nailing. Clinical and radiographic outcome measures included fracture healing, shoulder and elbow functions, need for additional procedures and any complication such as infection and recovery of radial nerve palsy. The results were analyzed statistically using the SPSS 11.5 software, with parametric and nonparametric tests. Results: Nine of the fractures treated with compression plating and seven of those treated with interlock nailing achieved union within six months. Though there was no significant difference in union time between the treatment groups, patients operated with interlock nailing underwent more number of secondary bone grafting procedures to obtain union (six against two). There were 12 patients (66.6%) with excellent and good results in the plating group compared to four patients (25%) in the nailing group. Interlock nailing was associated with significant reduction in shoulder function (P=0.03) and in overall results (P=0.02). Conclusion: Though there was no significant difference between plating or nailing in terms of time to union, compression plating is the preferred method in the majority of fractures of the shaft of the humerus with better preservation of joint function and lesser need for secondary bone grafting for union. PMID:21139747

  12. Combining of small fragment screws and large fragment plates for open reduction and internal fixation of periprosthetic humeral fractures.

    PubMed

    Seybold, Dominik; Citak, Mustafa; Königshausen, Matthias; Gessmann, Jan; Schildhauer, Thomas A

    2011-10-01

    Operative treatment of periprosthetic humeral fractures in elderly patients with osteoporotic bone requires a stable fixations technique. The combination of 3.5 cortical screws with washers in a 4.5 Arbeitsgemeinschaft für Osteosynthesefragen, Limited-contact dynamic compression plate or Locking plate, allows a stable periprosthetic fixation with the small 3.5 screws and 4.5 screws above and below the prosthesis, respectively. This combination is a cost-effective technique to treat periprosthetic humeral fractures.

  13. Complications of rigid internal fixation.

    PubMed

    Campbell, Chris A; Lin, Kant Y

    2009-03-01

    Over the past 20 years, there have been many advances in the development of bone fixation systems used in the practice of craniomaxillofacial surgery. As surgical practices have evolved, the complications of each technologic advance have changed accordingly. Interfragmentary instability of interosseous wiring has been replaced by the risk of exposure, infection, and palpability of plate and screw fixation systems. The improved rigidity of plate fixation requires anatomic alignment of fracture fragments. Failure to obtain proper alignment has led to the phenomenon known as "open internal fixation" of fracture fragments without proper reduction. The size of the plates has decreased to minimize palpability and exposure. However limitations in their application have been encountered due to the physiologic forces of the muscles of mastication and bone healing. In the pediatric population, the long-standing presence of plates in the cranial vault resulted in reports of transcranial migration and growth restriction. These findings led to the development of resorbable plating systems, which are associated with self-limited plate palpability and soft tissue inflammatory reactions. Any rigid system including these produces growth restriction in varying amounts. In this discussion, we review the reported complication rates of miniplating and microplating systems as well as absorptive plating systems in elective and traumatic craniofacial surgery.

  14. Mechanical Comparison of Headless Screw Fixation and Locking Plate Fixation for Talar Neck Fractures.

    PubMed

    Karakasli, Ahmet; Hapa, Onur; Erduran, Mehmet; Dincer, Cemal; Cecen, Berivan; Havitcioglu, Hasan

    2015-01-01

    For talar neck fractures, open reduction and internal fixation have been thought to facilitate revascularization and prevent osteonecrosis. Newer screw systems allow for placement of cannulated headless screws, which provide compression by virtue of a variable pitch thread. The present study compared the biomechanical fixation strength of cannulated headless variable-pitch screw fixation and locking plate fixation. A reproducible talar neck fracture was created in 14 fresh cadaver talar necks. Talar head fixation was then performed using 2 cannulated headless variable-pitch 4-mm/5-mm diameter (4/5) screws (Acutrak; Acumed, Hillsboro, OR) and locking plate fixation. Headless variable-pitch screw fixation had lower failure displacement than did locking plate fixation. No statistically significant differences were found in failure stiffness, yield stiffness (p = .655), yield load (p = .142), or ultimate load between the 2 fixation techniques. Cannulated headless variable-pitch screw fixation resulted in better failure displacement than locking plate fixation in a cadaveric talus model and could be considered a viable option for talus fracture fixation. Headless, fully threaded, variable-pitch screw fixation has inherent advantages compared with locking plate fixation, because it might cause less damage to the articular surface and can compress the fracture for improved reduction. Additionally, plate fixation can increase the risk of avascular necrosis owing to the wider incision and dissection of soft tissues.

  15. The use of a T-shaped contoured unilocking titanium radial plate for prophylactic internal fixation of the radial osteocutaneous donor site.

    PubMed

    Avery, C M E; Parmar, S; Martin, Tim

    2010-12-01

    The radial osteocutaneous flap retains a limited role in reconstructive maxillofacial surgery The application of prophylactic internal fixation, using straight 3.5 mm plates, has become established to substantially reduce the incidence of fracture at the radial donor site. New lower profile T-shaped 2.4 mm plates and anatomically contoured 3.5 mm plates are now available, both with unilocking screw fixation systems. These plates are easy to apply and allow the removal of up to 50% of the circumference of the radial bone, including the maximum amount of good quality bone from the distal radius. Although there have been no reports of complications as a result of a stress shielding effect with larger plates these refinements in plate design should lessen any remaining concerns.

  16. Radial shaft stress fracture after internal fixation using a titanium plate.

    PubMed

    Nagoshi, Narihito; Yamanaka, Kazuyoshi; Sasaki, Takashi

    2015-05-20

    A 22-year-old man, a boxer, presented with acute right forearm pain after striking a punch mitt. The patient had sustained a diaphyseal fracture of the right radius 19 months previously and was treated by minimally invasive plate osteosynthesis using a titanium reconstruction plate. Radiography revealed stress fractures beneath a proximal screw hole of the plate. The forearm was protected in a splint for 6 weeks and the fracture healed. Titanium plates are superior to stainless steel plates, due to various properties of titanium including corrosion resistance and biocompatibility. Removal of such plates is not routinely performed in our hospital, but plate removal may be warranted for patients who actively participate in certain sports.

  17. Combining of small fragment screws and large fragment plates for open reduction and internal fixation of periprosthetic humeral fractures

    PubMed Central

    Seybold, Dominik; Citak, Mustafa; Königshausen, Matthias; Gessmann, Jan; Schildhauer, Thomas A.

    2011-01-01

    Operative treatment of periprosthetic humeral fractures in elderly patients with osteoporotic bone requires a stable fixations technique. The combination of 3.5 cortical screws with washers in a 4.5 Arbeitsgemeinschaft für Osteosynthesefragen, Limited-contact dynamic compression plate or Locking plate, allows a stable periprosthetic fixation with the small 3.5 screws and 4.5 screws above and below the prosthesis, respectively. This combination is a cost-effective technique to treat periprosthetic humeral fractures. PMID:22223961

  18. Variation of plate fixation for mandibular advancement with intraoral vertical ramus osteotomy using endoscopically assisted intraoral rigid or semi-rigid internal fixation: Case series study: Postoperative condylar seating control for mandibular advancement.

    PubMed

    Hara, Shingo; Mitsugi, Masaharu; Tatemoto, Yukihiro

    2015-12-01

    The purpose of the present study was to evaluate the safety and efficacy associated with mandibular advancement by intraoral vertical ramus osteotomy (IVRO) with endoscopically assisted intraoral rigid or semi-rigid internal fixation. The study sample included all patients who had undergone an mandibular advancement by IVRO procedure with endoscopically assisted intraoral plate fixation from September 2008 to May 2012. An mandibular advancement by IVRO with endoscopically assisted intraoral rigid or semi-rigid internal fixation was used for mandibular advancement. The patients were analyzed prospectively, with more than 2 years of follow-up, and were evaluated in terms of functional results, postoperative complications, and skeletal stability. A total of 14 patients (bilateral, 7 patients with class II; unilateral, 7 patients with asymmetry) were included in the present study. The average degree of mandibular advancement was 5.5 ± 1.9 mm (range, 3-9 mm). Both the occlusal relationship and facial appearance in all patients were significantly improved by the surgical-orthodontic treatment, with no major harmful clinical symptoms. In addition, one-screw semi-rigid fixation could control postoperative passive condylar seating. This study showed that mandibular advancement by IVRO with endoscopically assisted, intraoral semi-rigid internal fixation offers a promising treatment alternative for patients with skeletal class II malocclusion or facial asymmetry. PMID:26610634

  19. Open reduction and internal fixation of osteoporotic acetabular fractures through the ilio-inguinal approach: use of buttress plates to control medial displacement of the quadrilateral surface.

    PubMed

    Peter, Robin E

    2015-01-01

    The number of acetabular fractures in the geriatric population requiring open reduction and internal fixation is increasing. Fractures with medial or anterior displacement are the most frequent types, and via the ilio-inguinal approach buttress plates have proved helpful to maintain the quadrilateral surface or medial acetabular wall. Seven to ten hole 3.5 mm reconstruction plates may be used as buttress plates, placed underneath the usual pelvic brim plate. This retrospective study presents our results with this technique in 13 patients at a minimum follow-up of 12 months (average, 31 months). 85% of the patients had a good result. The early onset of post-traumatic osteoarthritis necessitated total hip arthroplasty in two patients (15%) at 12 and 18 months follow-up, respectively. This treatment option should be considered in the surgeon's armamentarium when fixing these challenging cases.

  20. Bicondylar tibial fractures: Internal or external fixation?

    PubMed

    Kumar, Gunasekaran; Peterson, Nicholas; Narayan, Badri

    2011-03-01

    Bicondylar fractures of the tibia, representing the Schatzker V and VI fractures represent a challenging problem. Any treatment protocol should aim at restoring articular congruity and the metaphyseo-diaphsyeal dissociation (MDD)-both of these are equally important to long-term outcome. Both internal and external fixations have their proponents, and each method of treatment is associated with its unique features and complications. We review the initial and definitive management of these injuries, and the advantages and disadvantages of each method of definitive fixation. We suggest the use of a protocol for definitive management, using either internal or external fixation as deemed appropriate. This protocol is based on the fracture configuration, local soft tissue status and patient condition. In a nutshell, if the fracture pattern and soft tissue status are amenable plate fixation (single or double) is performed, otherwise limited open reduction and articular surface reconstruction with screws and circular frame is performed. PMID:21430865

  1. Treatment of Midshaft Clavicle Fractures: Application of Local Autograft With Concurrent Plate Fixation.

    PubMed

    Slette, Erik L; Mikula, Jacob D; Turnbull, Travis Lee; Hackett, Thomas R

    2016-06-01

    Currently, open reduction-internal fixation using contoured plates or intramedullary nails is considered the standard operative treatment for midshaft clavicle fractures because of the immediate rigid stability provided by the fixation device. In addition, autologous iliac crest bone graft has proved to augment osteosynthesis during internal fixation of nonunion fractures through the release of osteogenic factors. The purpose of this article is to describe a surgical technique developed to reduce donor-site morbidity and improve functional and objective outcomes after open reduction-internal fixation with autologous bone graft placement through local autograft harvesting and concurrent plate fixation. PMID:27656378

  2. Internal fixation: a historical review.

    PubMed

    Greenhagen, Robert M; Johnson, Adam R; Joseph, Alison

    2011-08-01

    Internal fixation has become a pillar of surgical specialties, yet the evolution of these devices has been relatively short. The first known description of medical management of a fracture was found in the Edwin Smith Papyrus of Ancient Egypt (circa 2600 bc). The first description of internal fixation in the medical literature was in the 18th century. The advancement of techniques and technology over the last 150 years has helped to preserve both life and function. The pace of advancement continues to accelerate as surgeons continue to seek new technology for osseous fixation. The authors present a thorough review of the history of internal fixation and the transformation into a multibillion dollar industry. PMID:21944395

  3. [Theoretical analysis and numerical simulation of effect of steel plate positions on steel plate rigidity in internal fixation of bone surgery].

    PubMed

    Chen, Bingzhi; Gu, Yuanxian; Lü, Decheng; Lü, Xuemin

    2003-09-01

    In this study we calculate theoretically and use FEM to simulate the effect of plate position relative to bending direction on the overall bending stiffness of the composite system plate-bone. The results show that for different bending directions the effect of the modulus of elasticity of the plate is negligible. Changing the position of a plate will often alter the stress obviously. During the operation, the steel plate should be assigned onto the tension side of the bone. PMID:14565005

  4. Outcome Analysis of Locking Plate Fixation in Proximal Humerus Fracture

    PubMed Central

    Pathak, Abhishek; Gaur, Sanjiv

    2016-01-01

    Introduction Proximal humerus fractures account for approximately 5% of all fractures. Stable minimally displaced fractures can be treated nonoperatively but the management of displaced fractures remain controversial with various modalities of treatment available. Locking plates provide stable fixation and enable early postoperative mobilization specially in osteoporotic proximal humerus fracture. Aim To evaluate the functional outcome of locking plate fixation and to compare the results of two approaches used for fixation. Materials and Methods This prospective study was conducted at a tertiary level hospital between September 2011 to December 2013. PHILOS plates were used for internal fixation of displaced proximal humerus fractures Neer’s type 2 part, 3 part and 4 part fractures on 26 patients (M/F ratio 1.36:1; mean age 46 years). According to Neer classification, 5,12 and 9 patients had displaced 2, 3 and 4 part fractures respectively. Deltopectoral and deltoid splitting approaches were used for fixation on 13 patients each. Functional outcome was assessed using Constant-Murley shoulder score. Graphpad software version 6.0 was used with Chi-square test and Fisher-exact test are used to compare data. The p-value< 0.05 is considered significant. Results Of the 26 patients, all fractures united radiologically and clinically and average constant score at final follow-up was 72.5. At the final follow-up 8 patients had good score, 10 patients had moderate score, 6 patients had excellent outcome and 2 patients had poor outcome according to Constant score. Mean time to union was 12.3 weeks (9 –15 weeks). Four complications (15.4%) were encountered, 2 cases of varus malunion, 1 case of wound infection which required wound debridement and 1 case of screw cut-out in which screw removal was done. Mean constant score in delto splitting approach was 70.9 and 74 in deltopectoral group (p-value= 0.54). No significant difference existed in constant score in 2 approaches

  5. [Angle-fixed plate fixation or double-plate osteosynthesis in fractures of the proximal humerus: a biomechanical study].

    PubMed

    Hessmann, Martin H; Korner, Jan; Hofmann, Alexander; Sternstein, Werner; Rommens, Pol M

    2008-06-01

    Internal fixation of fractures of the proximal humerus needs a high stability of fixation to avoid secondary loss of fixation. This is especially important in osteoporotic bone. In an experimental study, the biomechanical properties of the angle-fixed Philos plate (internal fixator) and a double-plate osteosynthesis using two one-third tubular plates were assessed. The fracture model was an unstable three-part fracture (AO type B2). Eight pairs of human cadaveric humeri were submitted to axial load and torque. In the first part of the study, it was assessed to which degree the original stiffness of the humeri could be restored after the osteotomy by the osteosynthesis procedure. Subsequently, subsidence during 200 cycles of axial loading and torque was analysed. During axial loading, the Philos plate was significantly stiffer and showed less irreversible deformation. Two double-plate fixations, but none of the Philos plate osteosynthesis, failed. During torsion, there were no significant differences between the two implants. From the biomechanical point of view, the angle-fixed Philos plate represents the implant of choice for the surgical fixation of highly unstable three-part fractures of the proximal humerus, as the internal fixator system is characterised by superior biomechanical properties.

  6. Eighth international congress on nitrogen fixation

    SciTech Connect

    Not Available

    1990-01-01

    This volume contains the proceedings of the Eighth International Congress on Nitrogen Fixation held May 20--26, 1990 in Knoxville, Tennessee. The volume contains abstracts of individual presentations. Sessions were entitled Recent Advances in the Chemistry of Nitrogen Fixation, Plant-microbe Interactions, Limiting Factors of Nitrogen Fixation, Nitrogen Fixation and the Environment, Bacterial Systems, Nitrogen Fixation in Agriculture and Industry, Plant Function, and Nitrogen Fixation and Evolution.

  7. Unicortical versus bicortical locked plate fixation in midshaft clavicle fractures.

    PubMed

    Bravman, Jonathan T; Taylor, Michal L; Baldini, Todd; Vidal, Armando F

    2015-05-01

    Higher rates of poor outcomes in displaced midshaft clavicle fractures treated nonoperatively have recently been reported. Along with expanding indications for operative fixation and increasing application of locked plate constructs, it is unknown whether complications related to bicortical penetration of the clavicle can be avoided using unicortical fixation. The purpose of this study is to compare the biomechanical properties of unicortical and bicortical fixation in precontoured vs manually contoured locking clavicle plates. Forty-eight Sawbone composite human clavicle specimens (item #3408; Pacific Research Laboratories, Vashon, Washington) with a midshaft clavicle osteotomy were reduced and plated in 8 specimens each using a bicortical and unicortical fixation for each of 3 locked plate constructs (3.5-mm LCP Reconstruction Plate; 3.5-mm LCP Superior Clavicle Plate; 3.5-mm LCP Superior Anterior Clavicle Plate; Synthes, Inc, West Chester, Pennsylvania). Specimens were tested for stiffness in axial torsion and cantilever bending and then loaded to failure in 3-point bending. Data were analyzed using 2-way analysis of variance and Tukey's test (P<.05). No significant differences were found between unicortical and bicortical fixation in failure load, cantilever bending, and cross body stiffness. Bicortical fixation was significantly stiffer than unicortical fixation in torsion only for the same plates. Significant differences also existed between plates in torsion. Unicortical locked plate fixation may be a reasonable option in the treatment of displaced midshaft clavicle fracture fixation to avoid complications associated with posteroinferior hardware penetration following clavicle fracture fixation based on the biomechanical performance of these constructs. However, it remains unclear whether these differences will be clinically significant. PMID:25970369

  8. Treatment of Palatal Fractures by Osteosynthesis with 2.0-mm Locking Plates as External Fixator

    PubMed Central

    Cienfuegos, Ricardo; Sierra, Eduardo; Ortiz, Benjamin; Fernández, Gerardo

    2010-01-01

    Treatment options for palatal fractures range from orthodontic braces, acrylic bars, and arch bars for maxillomandibular fixation to internal fixation, with plates and screws placed under the palate mucosa and periosteum, together with pyriform aperture or alveolar plating plus buttress reconstruction. Forty-five patients, ages 4 to 56, were treated using medium- or high-profile locking plates placed over the palatal mucosa as an external fixator for palatal fractures, together with treatment for other associated facial fractures. In open fractures, plates were placed after approximating the edges of the mucosal wounds. Plates and screws for palate fixation were removed at 12 weeks, when computed tomography scans provided evidence of fracture healing. All palatal fractures healed by 12 weeks, with no cases of mucosal necrosis, bone exposure, fistulae, or infections. This approach achieves adequate stability, reduces the risk of bone and mucosal necrosis, and promotes healing of mucosal wounds in case of open fractures. PMID:22132261

  9. Management of Postoperative Spondylodiscitis with and without Internal Fixation.

    PubMed

    Wang, Xiang; Tao, Hairong; Zhu, Yanhui; Lu, Xiongwei; Hu, Xiaopeng

    2015-01-01

    Postoperative spondylodiscitis is relatively uncommon. This complication is associated with increased cost, and long-term of inability to work, and even morbidity. Although the majority of postoperative spondylodiscitis cases can be well managed by conservative treatment, postoperative spondylodiscitis after internal fixation and those cases that are unresponsive to the conservative treatment present challenges to the surgeon. Here, a review was done to analyze the treatment of postoperative spondylodiscitis with/without internal fixation. This review article suggested that majority of postoperative spondylodiscitis without internal fixation could be cured by conservative treatment. Either posterior or anterior debridement can be used to treat postoperative spondylodiscitis without internal fixation when conservative treatment fails. In addition, minimally invasive debridement and drainage may also be an alternative treatment. In case of postoperative spondylodiscitis after internal fixation, surgical treatment was required. In the cervical spine, it can be well managed by anterior debridement, removal of internal fixation, and reconstruction of the spinal stability by using bone grafting/cage/anterior plate. Postoperative spondylodiscitis after internal fixation is successfully managed by combined anterior debridement, fusion with posterior approach and removal of pedicle screw or extension of pedicle screw beyond the lesion site, in the thoracic and lumbar spine. PMID:26242325

  10. Retrospective comparison of percutaneous fixation and volar internal fixation of distal radius fractures.

    PubMed

    Lozano-Calderón, Santiago A; Doornberg, Job N; Ring, David

    2008-06-01

    A change in the practice of a single surgeon provided an opportunity for retrospective comparison of comparable cohorts treated with percutaneous fixation (17 patients) or a volar plate and screws (23 patients) an average of 30 months after surgery. The final evaluation was performed according to the Gartland and Werley and Mayo rating systems and the DASH questionnaire. There were no significant differences on the average scores for the percutaneous and volar plating groups, respectively: Gartland and Werley, 4 vs 5; Mayo, 82 vs 83; and DASH score 13 for both cohorts. Motion, grip, and radiographical parameters were likewise comparable. Volar internal plate and screw fixation can achieve results comparable to percutaneous fixation techniques in the treatment of fractures of the distal radius.

  11. Biomechanical evaluation of maxillary Lefort Ι fracture with bioabsorbable osteosynthesis internal fixation.

    PubMed

    Wu, Wei; Zhou, Jiang; Xu, Chong-Tao; Zhang, Jie; Jin, Yan-Jiao; Sun, Geng-Lin

    2014-12-01

    The aim of this study was to apply biomechanical analysis model to evaluate the effects of bioabsorbable internal fixation devices on maxillary Lefort Ι fracture. CT scan technology and the finite element software (ansys) were used to establish three-dimensional finite element models of five resorbable internal fixation devices in maxillary Lefort Ι fractures. We used the model to calculate the stress of the upper jaw and internal fixation. We further analyzed the stability of fixation under four occlusions. The fixation using two bioabsorbable plates was not stable. The zygomaticomaxillary pillars fixation is more stable than other fixations. The stability of fracture fixation was influenced with the molar occlusion. The current study developed a functional three-dimensional finite element model of bioabsorbable internal fixation and compared the stability of five fixation methods for maxillary Lefort Ι fractures. The results would facilitate the application of bioabsorbable materials in dental clinic.

  12. Femoral locking plate failure salvaged with hexapod circular external fixation: a report of two cases.

    PubMed

    Ferreira, N; Marais, L C

    2016-08-01

    Femoral non-unions are difficult to treat even for the experienced orthopaedic trauma surgeon. If the non-union follows failure of modern stable internal fixation, the complexity of the management is further increased. We report two cases of stiff hypertrophic femoral non-unions after failed locking plate fixation that were successfully treated with a new hexapod circular external fixator. In addition to providing the necessary stability for functional rehabilitation and union, the hexapod circular fixator software allows gradual correction of deformities in order to restore the normal mechanical alignment of the limb. PMID:27234444

  13. The Role of Minimally Invasive Plate Osteosynthesis in Rib Fixation: A Review.

    PubMed

    Bemelman, Michael; van Baal, Mark; Yuan, Jian Zhang; Leenen, Luke

    2016-02-01

    More than a century ago, the first scientific report was published about fracture fixation with plates. During the 1950's, open reduction and plate fixation for fractures were standardized by the founders of Arbeitsgemeinschaft für osteosynthesefragen/Association for the Study of Internal Fixation. Since the introduction of plate fixation for fractures, several plates and screws have been developed, all with their own characteristics. To accomplice more fracture stability, it was thought the bigger the plate, the better. The counter side was a compromised blood supply of the bone, often resulting in bone necrosis and ultimately delayed or non-union. With the search and development of new materials and techniques for fracture fixation, less invasive procedures have become increasingly popular. This resulted in the minimally invasive plate osteosynthesis (MIPO) technique for fracture fixation. With the MIPO technique, procedures could be performed with smaller incisions and thus with less soft tissue damage and a better preserved blood supply. The last 5 years rib fixation has become increasingly popular, rising evidence has become available suggesting that surgical rib fixation improves outcome of patients with a flail chest or isolated rib fractures. Many surgical approaches for rib fixation have been described in the old literature, however, most of these techniques are obscure nowadays. Currently mostly large incisions with considerable surgical insult are used to stabilize rib fractures. We think that MIPO deserves a place in the surgical treatment of rib fractures. We present the aspects of diagnosis, preoperative planning and operative techniques in regard to MIPO rib fixation.

  14. The Role of Minimally Invasive Plate Osteosynthesis in Rib Fixation: A Review

    PubMed Central

    Bemelman, Michael; van Baal, Mark; Yuan, Jian Zhang; Leenen, Luke

    2016-01-01

    More than a century ago, the first scientific report was published about fracture fixation with plates. During the 1950’s, open reduction and plate fixation for fractures were standardized by the founders of Arbeitsgemeinschaft für osteosynthesefragen/Association for the Study of Internal Fixation. Since the introduction of plate fixation for fractures, several plates and screws have been developed, all with their own characteristics. To accomplice more fracture stability, it was thought the bigger the plate, the better. The counter side was a compromised blood supply of the bone, often resulting in bone necrosis and ultimately delayed or non-union. With the search and development of new materials and techniques for fracture fixation, less invasive procedures have become increasingly popular. This resulted in the minimally invasive plate osteosynthesis (MIPO) technique for fracture fixation. With the MIPO technique, procedures could be performed with smaller incisions and thus with less soft tissue damage and a better preserved blood supply. The last 5 years rib fixation has become increasingly popular, rising evidence has become available suggesting that surgical rib fixation improves outcome of patients with a flail chest or isolated rib fractures. Many surgical approaches for rib fixation have been described in the old literature, however, most of these techniques are obscure nowadays. Currently mostly large incisions with considerable surgical insult are used to stabilize rib fractures. We think that MIPO deserves a place in the surgical treatment of rib fractures. We present the aspects of diagnosis, preoperative planning and operative techniques in regard to MIPO rib fixation. PMID:26889439

  15. Management of extra-articular fractures of the distal tibia: intramedullary nailing versus plate fixation.

    PubMed

    Casstevens, Chris; Le, Toan; Archdeacon, Michael T; Wyrick, John D

    2012-11-01

    Intramedullary nailing and plate fixation represent two viable approaches to internal fixation of extra-articular fractures of the distal tibia. Although both techniques have demonstrated success in maintaining reduction and promoting stable union, they possess distinct advantages and disadvantages that require careful consideration during surgical planning. Differences in soft-tissue health and construct stability must be considered when choosing between intramedullary nailing and plating of the distal tibia. Recent advances in intramedullary nail design and plate-and-screw fixation systems have further increased the options for management of these fractures. Current evidence supports careful consideration of the risk of soft-tissue complications, residual knee pain, and fracture malalignment in the context of patient and injury characteristics in the selection of the optimal method of fixation.

  16. Internal fixation in a combat theater hospital.

    PubMed

    Large, Thomas M; Bonds, Cale; Howard, Michael

    2013-08-01

    Limited data are available on the use of internal fixation in combat zone hospitals. The authors performed a retrospective review of 713 surgical cases during 2 Operation Enduring Freedom deployments to a Level III theater hospital in 2007 and 2009 to 2010. The epidemiology and short- to intermediate-term outcomes of patients treated with internal fixation devices were studied. The authors found that, with judicious use, internal fixation under a damage control protocol in a combat theater hospital can be performed with acceptable complication rates. PMID:23937739

  17. Comparison of treatment of unstable intra articular fractures of distal radius with locking plate versus non-locking plate fixation

    PubMed Central

    Kumar, Sunil; Chopra, R.K.; Sehrawat, Sunil; Lakra, Akshay

    2014-01-01

    Introduction Unstable intra articular fractures of distal radius are frequently being managed with open reduction and internal fixation. Of late in some biomechanical studies locking plates have been shown to be better in terms of maintenance of radiological parameters in comparison to non-locking plates. We conducted this study to know whether this biomechanical superiority of locking plates is converted in to better clinical outcomes. Materials and methods A study was conducted in 60 patients (30 in each group) with unstable intra articular fractures of distal radius who were treated by open reduction and internal fixation with locking plates and non-locking plates. Patients were evaluated for radiological parameters (intra articular step off, radial height, radial tilt, volar tilt) and functional parameters (flexion, extension, radial deviation, ulnar deviation, pronation, supination grip strength) at two year follow up. Overall outcome was evaluated by scoring systems of Gartland and Werley and modified Green O' Brien. Results The change in radiological parameters from immediate post op to latest at two year in locking plate group was not significant for radial height, radial tilt, volar tilt, but ulnar variance whereas in non-locking plate there was significant change in radial height, volar tilt, ulnar variance but no significant change in radial inclination. In clinical and functional outcome no significant difference was found at two year follow up. Conclusions Locking plates maintain the radiological parameters better than non-locking plates but functional outcome are same for both plates at two year after surgery. PMID:25983474

  18. Distal Humerus Fractures: Open Reduction Internal Fixation.

    PubMed

    Mighell, Mark A; Stephens, Brent; Stone, Geoffrey P; Cottrell, Benjamin J

    2015-11-01

    Distal humerus fractures are challenging injuries for the upper extremity surgeon. However, recent techniques in open reduction internal fixation have been powerful tools in getting positive outcomes. To get such results, the surgeon must be aware of how to properly use these techniques in their respective practices. The method of fixation depends on the fracture, taking the degree of comminution and the restoration of the columns and articular surface into account. This article helps surgeons understand the concepts behind open reduction internal fixation of the distal humerus and makes them aware of pitfalls that may lead to negative results.

  19. Assessment of carbon fibre composite fracture fixation plate using finite element analysis.

    PubMed

    Saidpour, Seyed H

    2006-07-01

    In the internal fixation of fractured bone by means of bone-plates fastened to the bone on its tensile surface, an on-going concern has been the excessive stress shielding of the bone by the excessively-stiff stainless-steel plate. The compressive stress shielding at the fracture-interface immediately after fracture-fixation delays callus formation and bone healing. Likewise, the tensile stress shielding in the layer of bone underneath the plate can cause osteoporosis and decrease in tensile strength of this layer. In this study a novel forearm internal fracture fixation plate made from short carbon fibre reinforced plastic (CFRP) was used in an attempt to address the problem. Accordingly, it has been possible to analyse the stress distribution in the composite plates using finite-element modelling. A three-dimensional, quarter-symmetric finite element model was generated for the plate system. The stress state in the underlying bone was examined for several loading conditions. Based on the analytical results the composite plate system is likely to reduce stress-shielding effects at the fracture site when subjected to bending and torsional loads. The design of the plate was further optimised by reducing the width around the innermost holes.

  20. The use of rigid internal fixation in the surgical management of cervical spondylosis.

    PubMed

    Kwon, Brian K; Vaccaro, Alexander R; Grauer, Jonathan N; Beiner, John M

    2007-01-01

    In the surgical management of cervical spondylosis, the application of rigid internal fixation can enhance the immediate stability of the cervical spine. The sophistication of such internal fixation systems and the indications for their use are continuously evolving. A sound understanding of regional anatomy, biomechanics, and kinematics within the cervical spine is essential for the safe and effective application of internal fixation. Numerous options currently exist for anterior cervical plating systems; some lock the screws to the plate rigidly (constrained), whereas others allow for some rotational or translational motion between the screw and plate (semiconstrained). The role of anterior fixation in single and multilevel fusions is still the subject of some controversy. Long anterior cervical reconstructions may require additional posterior fixation to reliably promote fusion. Rigid fixation in the posterior cervical spine can be achieved with lateral mass screws or pedicle screws. Although lateral mass screws provide excellent fixation within the subaxial cervical spine, the regional anatomy of C2 and C7 often make it difficult to place such screws, and pedicle screws at these levels are advocated. Pedicle screws achieve fixation into both the anterior and posterior column and are arguably the most stable form of rigid internal fixation within the cervical spine. Familiarity with these internal fixation techniques can be an extremely valuable tool for the spine surgeon managing these degenerative disorders of the cervical spine.

  1. Displaced avulsion fractures of the posterior cruciate ligament: Treated by stellate steel plate fixation

    PubMed Central

    Li, Lijun; Tian, Wei

    2015-01-01

    Background: The open reduction with internal fixation is an effective approach for treatment of avulsion fracture of posterior cruciate ligament. The previously used internal fixation materials including hollow screws, absorbable screw, tension bands and sutures have great defects such as insufficient fixation strength, susceptibility to re-fracture, etc. Stellate steel plate is novel material for internal fixation which has unique gear-like structure design. We used stellate steel plate for treatment of displaced avulsion fractures of posterior cruciate ligament in this study. Materials and Methods: 14 patients (9 men, 5 women; aged, 19–35 years; mean age, 28 years) with displaced avulsion fractures of the tibial insertion of the posterior cruciate ligament were retrospectively analyzed between June 2009 and June 2011. The mean duration from injury to the operation was 8.3 days (range 6–15 days). All the patients were treated with open reduction and internal fixation of a stellate steel plate (DePuy, Raynham, MA 02767, USA). The Lysholm-Tegner knee function score criteria were used to analyze results. Results: The mean followup was 24.6 months (range 18–32 months). After 6 months, all the fractures healed and knee joint activity was normal, with no knee stiffness or instability. The Lysholm-Tegner scores were 97.1 ± 1.7 points at the final followup. Conclusion: Owing to its unique gear structure, the stellate steel plate design can effectively fix an avulsion fracture block and it is a simple operation with short postoperative rehabilitation time and firm fixation. PMID:26015605

  2. [Internal fixation of radial shaft fractures: Anatomical and biomechanical principles].

    PubMed

    Bartoníček, J; Naňka, O; Tuček, M

    2015-10-01

    overhang the bone laterally. In a locking plate with a fixed determined trajectory of screws, the locking screws in the central holes of the plate pass off the shaft centre only through a thin interosseous border (medial position), or screws at the ends of the plate are inserted eccentrically (lateral position). Both these techniques reduce stability of internal fixation. Where the plate overlaps the interosseous border, it is difficult to control the mutual rotation of the two main fragments. A shorter LCP plate increases rigidity of fixation, suppresses bone healing and often leads to non-union.Placement of the plate on the lateral surface of the radius is more beneficial from the viewpoint of the bending and torsion stress. Lateral surface of the radius is a tension site, its distal half is not covered by muscles which eliminates the necessity to release them, the interosseous border is not obscured by plate and all this allows a safe control of rotational position of fragments. A properly pre-bent plate follows the physiological curvature of the lateral surface of the radius. Full tightening of standard screws will fix both main fragments firmly to the apex of plate concavity and increase stability of the internal fixation. Due to the shape of the cross-section of the radial shaft, the trajectory of screws is the longest in case of lateral placement of the plate, which increases rotational stability.We place the plate always in a minimal three-hole length on each main fragment. Transverse two-fragment fractures may be fixed with a 2+2 configuration, i.e. with two screws on each main fragment. Fractures with an inter-fragment or comminuted zone are fixed in the 3+3 mode. More extensive comminutions, defects or segmental fractures require 4 plate holes on each fragment, but not more. When drilling screw holes the drill must be directed into the interosseous border. As a result, the screw has the longest trajectory and the best fixation in the bone. Perforation of the

  3. Fractured facial bone reduction and resorbable plate fixation using tapper.

    PubMed

    Kim, Chang Yeon; Kim, Kee Woong

    2011-07-01

    A resorbable fixation system has many advantages, but there are complicated procedures to be accomplished to fix a resorbable plate. The complicated procedures in the fixation of a resorbable plate make the operation for facial fractures more difficult and can result in extended operation time and incomplete reduction or fixation. For these reasons, we suggest a new way of using a tapper that can make the surgery more simple and accurate than before. After the resorbable plate is properly located above the fractured site, a hole on the fracture fragment is made by drill, and the tapper is inserted into the hole. When the tapper is inserted at the proper depth, the fracture fragment can be reduced to right place by handling the inserted tapper. Then, the tapper is inserted to the end, and the handle is split. While the inserted tapper acting as a temporary metal screw is placed, another hole is made at nearby site and the screw is inserted. Next, the inserted tapper acting as a temporary metal screw is removed, and another screw is inserted into the hole from which the tapper was removed. From October 2006 to April 2008, we applied this procedure to 106 facial bone fractures in 68 patients, and no major complications were noted. In conclusion, we tried to make the operation more simple and accurate by using the tapper as an instrument for reduction and fixation of fracture fragment.

  4. A Novel Fixation System for Acetabular Quadrilateral Plate Fracture: A Comparative Biomechanical Study

    PubMed Central

    Zha, Guo-Chun; Sun, Jun-Ying; Dong, Sheng-Jie; Zhang, Wen; Luo, Zong-Ping

    2015-01-01

    This study aims to assess the biomechanical properties of a novel fixation system (named AFRIF) and to compare it with other five different fixation techniques for quadrilateral plate fractures. This in vitro biomechanical experiment has shown that the multidirectional titanium fixation (MTF) and pelvic brim long screws fixation (PBSF) provided the strongest fixation for quadrilateral plate fracture; the better biomechanical performance of the AFRIF compared with the T-shaped plate fixation (TPF), L-shaped plate fixation (LPF), and H-shaped plate fixation (HPF); AFRIF gives reasonable stability of treatment for quadrilateral plate fracture and may offer a better solution for comminuted quadrilateral plate fractures or free floating medial wall fracture and be reliable in preventing protrusion of femoral head. PMID:25802849

  5. Fixation of zygomatic and mandibular fractures with biodegradable plates

    PubMed Central

    Degala, Saikrishna; Shetty, Sujeeth; Ramya, S

    2013-01-01

    Context: In this prospective study, 13 randomly selected patients underwent treatment for zygomatic–complex fractures (2 site fractures) and mandibular fractures using 1.5 / 2 / 2.5-mm INION CPS biodegradable plates and screws. Aims: To assess the fixation of zygomatic-complex and mandibular fractures with biodegradable copolymer osteosynthesis system. Materials and Methods: In randomly selected 13 patients, zygomatic-complex and mandibular fractures were plated using resorbable plates and screws using Champy's principle. All the cases were evaluated clinically and radiologically for the type of fracture, need for the intermaxillary fixation (IMF) and its duration, duration of surgery, fixation at operation, state of reduction at operation, state of bone union after operation, anatomic reduction, paresthesia, occlusal discrepancies, soft tissue infection, immediate and late inflammatory reactions related to biodegradation process, and any need for the removal of the plates. Statistical Analysis Used: Descriptives, Frequencies, and Chi-square test were used. Results: In our study, the age group range was 5 to 55 years. Road traffic accidents accounted for the majority of patients six, (46.2%). Postoperative occlusal discrepancies were found in seven patients as mild to moderate, which resolved with IMF for 1-8 weeks. There were minimal complications seen and only as soft tissue infection. Conclusions: Use of biodegradable osteosynthesis system is a reliable alternative method for the fixation of zygomatic-complex and mandibular fractures. The biodegradable system still needs to be refined in material quality and handling to match the stability achieved with metal system. Biodegradable plates and screws is an ideal system for pediatric fractures with favorable outcome. PMID:23662255

  6. Eighth international congress on nitrogen fixation. Final program

    SciTech Connect

    Not Available

    1990-12-31

    This volume contains the proceedings of the Eighth International Congress on Nitrogen Fixation held May 20--26, 1990 in Knoxville, Tennessee. The volume contains abstracts of individual presentations. Sessions were entitled Recent Advances in the Chemistry of Nitrogen Fixation, Plant-microbe Interactions, Limiting Factors of Nitrogen Fixation, Nitrogen Fixation and the Environment, Bacterial Systems, Nitrogen Fixation in Agriculture and Industry, Plant Function, and Nitrogen Fixation and Evolution.

  7. Comparison of Internal Fixations for Distal Clavicular Fractures Based on Loading Tests and Finite Element Analyses

    PubMed Central

    Sakai, Rina; Matsuura, Terumasa; Tanaka, Kensei; Nakao, Masaki

    2014-01-01

    It is difficult to apply strong and stable internal fixation to a fracture of the distal end of the clavicle because it is unstable, the distal clavicle fragment is small, and the fractured region is near the acromioclavicular joint. In this study, to identify a superior internal fixation method for unstable distal clavicular fracture, we compared three types of internal fixation (tension band wiring, scorpion, and LCP clavicle hook plate). Firstly, loading tests were performed, in which fixations were evaluated using bending stiffness and torsional stiffness as indices, followed by finite element analysis to evaluate fixability using the stress and strain as indices. The bending and torsional stiffness were significantly higher in the artificial clavicles fixed with the two types of plate than in that fixed by tension band wiring (P < 0.05). No marked stress concentration on the clavicle was noted in the scorpion because the arm plate did not interfere with the acromioclavicular joint, suggesting that favorable shoulder joint function can be achieved. The stability of fixation with the LCP clavicle hook plate and the scorpion was similar, and plate fixations were stronger than fixation by tension band wiring. PMID:25136691

  8. Analysis of Sternal Fixation Results According to Plate Type in Sternal Fracture

    PubMed Central

    Byun, Chun Sung; Park, Il Hwan; Hwang, Wan Jin; Lee, Yeiwon; Cho, Hyun Min

    2016-01-01

    Background Sternal fractures are relatively rare, and caused mainly by blunt anterior chest wall trauma. In most cases, sternal fractures are treated conservatively. However, if the patient exhibits problematic symptoms such as intractable chest wall pain or bony crepitus due to sternal instability, surgical correction is indicated. But no consensus exists regarding the most appropriate surgical method. We analyzed the results of surgical fixation in cases of sternal fracture in order to identify which surgical method led to the best outcomes. Methods We retrospectively reviewed the medical records of patients with sternal fractures from December 2008 to December 2011, and found 19 patients who underwent open reduction and internal fixation of the sternum with a longitudinal plate (L-group) or a T-shaped plate (T-group). We investigated patients’ characteristics, clinical details regarding each case of chest trauma, the presence of other associated injuries, the type of open reduction and fixation, whether a combined operation was performed, and postoperative complications. Results Of the 19 patients, 10 patients (52.6%) were male, and their average age was 56.8 years (range, 32 to 82 years). Seven patients (36.8%) had isolated sternal fractures, while 12 (63.2%) had other associated injuries. Seven patients (36.8%) were in the L-group and 12 patients (63.2%) were in the T-group. Three patients in the L-group (42.9%) showed a loosening of the fixation. In all patients in the T-group, the fracture exhibited stable alignment. Conclusion Open reduction and internal fixation with a T-shaped plate in sternal fractures is a safer and more efficient treatment method than treatment with a longitudinal plate, especially in patients with a severely displaced sternum or anterior flail chest, than a longitudinal plate. PMID:27733996

  9. Late extensor pollicis longus rupture following plate fixation in Galeazzi fracture dislocation.

    PubMed

    Sabat, Dhananjaya; Dabas, Vineet; Dhal, Anil

    2014-07-01

    Late rupture of extensor pollicis longus (EPL) tendon after Galeazzi fracture dislocation fixation is an unknown entity though it is a well-established complication following distal radius fractures. We report the case of a 55-year old male who presented with late EPL tendon rupture 4 months following internal fixation of Galeazzi fracture dislocation with a Locking Compression Plate (LCP). He was managed with extensor indicis proprius (EIP) transfer to restore thumb extension. At 4 years followup, functional result of the transfer was good. We identify possible pitfalls with this particular patient and discuss how to avoid them in future.

  10. Fracture biology, biomechanics, and internal fixation.

    PubMed

    Trostle, S S; Markel, M D

    1996-03-01

    The success of orthopedic surgery in ruminants is directly related to the surgeon's knowledge and understanding of bone physiology and mechanics. The relationship of the macro and micro structure and function of bone as it relates to fracture physiology and repair is discussed. A basic review of the biomechanical principles of bone, bone fracture, and fracture repair are presented. The clinical and biomechanical principles of internal fixation are described for fracture repair in ruminants.

  11. Early outcomes of proximal humerus fracture fixation with locking plate and intramedullary fibular strut graft.

    PubMed

    Tan, Edwin; Lie, Denny; Wong, M K

    2014-09-01

    Proximal humerus fractures are commonly encountered in elderly patients. Surgical treatment demonstrates high complication rates, including varus construct collapse and screw cutout. In this study, the authors evaluate the clinical outcome of locking plate fixation with intramedullary fibular strut graft augmentation as a primary surgical treatment in the prevention of early collapse and screw cutout. A total of 9 patients were evaluated. Surgery was performed for displaced proximal humerus fractures between April and December 2011. Patients were either class 2, 3, or 4, according to Neer classification. Mean patient age was 75.4 years. Preoperative and immediate, 6-week, and 3-month postoperative radiographs were evaluated. Head-shaft angles were measured to assess for varus collapse and displacement. Range of motion, complication rates, and functional recovery were also evaluated. Patients underwent open reduction and internal fixation with placement of an intramedullary fibular strut graft. Fixation was achieved with a Philos plate (Synthes, Oberdorf, Switzerland). Reduction and fixation were evaluated with radiographs. Passive exercises and range of motion were allowed immediately postoperatively, and all patients achieved active abduction and forward flexion 6 weeks postoperatively. Shoulder radiographs taken 12 weeks postoperatively revealed no loss of reduction or screw cutout. The introduction of the locking plate has improved outcomes. The addition of an intramedullary strut graft has shown improved preliminary results. Maintained reduction was observed in all 9 patients in the early postoperative period, and good functional motion was achieved. No incidence of screw cutout was recorded.

  12. The use of short carbon fibre reinforced thermoplastic plates for fracture fixation.

    PubMed

    Gillett, N; Brown, S A; Dumbleton, J H; Pool, R P

    1985-03-01

    Thermoplastic plates of Nylon 6-10 and Polybutylene terephthalate reinforced with 30% short randomly oriented carbon fibres were tested for internal fixation of canine femoral transverse midshaft fractures. The elastic modulus of the plates was one-half that of bone: however, ultimate strength and strain in bending were comparable to bone. The fractures healed with moderate callus formation which was completely remodelled by 8 to 12 wk post surgery. Although a moderate inflammatory reaction to occasional particulate debris was noted, the materials appeared to possess the proper elastic moduli to allow sufficient support for the healing fracture without protecting the remodelling process.

  13. Biomechanics of bone-fracture fixation by stiffness-graded plates in comparison with stainless-steel plates

    PubMed Central

    Ganesh, VK; Ramakrishna, K; Ghista, Dhanjoo N

    2005-01-01

    Background In the internal fixation of fractured bone by means of bone-plates fastened to the bone on its tensile surface, an on-going concern has been the excessive stress-shielding of the bone by the excessively-stiff stainless-steel plate. The compressive stress-shielding at the fracture-interface immediately after fracture-fixation delays callus formation and bone healing. Likewise, the tensile stress-shielding of the layer of the bone underneath the plate can cause osteoporosis and decrease in tensile strength of this layer. Method In order to address this problem, we propose to use stiffness-graded plates. Accordingly, we have computed (by finite-element analysis) the stress distribution in the fractured bone fixed by composite plates, whose stiffness is graded both longitudinally and transversely. Results It can be seen that the stiffness-graded composite-plates cause less stress-shielding (as an example: at 50% of the healing stage, stress at the fracture interface is compressive in nature i.e. 0.002 GPa for stainless steel plate whereas stiffness graded plates provides tensile stress of 0.002 GPa. This means that stiffness graded plate is allowing the 50% healed bone to participate in loadings). Stiffness-graded plates are more flexible, and hence permit more bending of the fractured bone. This results in higher compressive stresses induced at the fractured faces accelerate bone-healing. On the other hand, away from the fracture interface the reduced stiffness and elastic modulus of the plate causes the neutral axis of the composite structure to be lowered into the bone resulting in the higher tensile stress in the bone-layer underneath the plate, wherein is conducive to the bone preserving its tensile strength. Conclusion Stiffness graded plates (with in-built variable stiffness) are deemed to offer less stress-shielding to the bone, providing higher compressive stress at the fractured interface (to induce accelerated healing) as well as higher tensile

  14. The Utility of the Fluoroscopic Skyline View During Volar Locking Plate Fixation of Distal Radius Fractures

    PubMed Central

    Vaiss, Lucile; Ichihara, Satoshi; Hendriks, Sarah; Taleb, Chihab; Liverneaux, Philippe; Facca, Sybille

    2014-01-01

    Background Open reduction and internal fixation (ORIF) using a volar locking plate is a common method for treating displaced distal radius fractures. There is, however, the risk of extensor tendon rupture due to protrusion of the screw tips past the dorsal cortex, which cannot always be adequately seen on a lateral fluoroscopic view. We therefore wished to compare the sensitivity of an intraoperative fluoroscopic skyline view to a lateral fluorosocopic view in detecting past pointing of these screws. Material and Methods Our series included 75 patients with an average age of 59 years who underwent volar locked plate fixation of a displaced distal radius fracture. Intraoperative anteroposterior (AP), lateral, and skyline fluoroscopic views were performed in each case. The number of screws that were seen to protrude past the dorsal cortex of the distal fracture fragment were recorded for both the lateral and skyline views. The number of screws that required exchange was also documented. Results No screws were seen to protrude past the dorsal cortical bone on the lateral fluroscopic views. 15 of 300 screws (5%) were seen to protrude past the dorsal cortex by an average of 0.8 mm (range, 0.5 to 2 mm) and were exchanged for shorter screws in 11/75 patients. Conclusion Our results demonstrate that the skyline is more sensitive than a lateral fluoroscopic view at demonstrating protrusion of the screws in the distal fracture fragment following volar locked plate fixation. Level of Evidence IV PMID:25364637

  15. Conceptual finite element study for comparison among superior, anterior, and spiral clavicle plate fixations for midshaft clavicle fracture.

    PubMed

    Huang, Teng-Le; Chen, Wen-Chuan; Lin, Kun-Jhih; Tsai, Cheng-Lun; Lin, Kang-Ping; Wei, Hung-Wen

    2016-10-01

    Open reduction internal fixation technique has been generally accepted for treatment of midshaft clavicle fractures. Both superior and anterior clavicle plates have been reported in clinical or biomechanical researches, while presently the spiral clavicle plate design has been introduced improved biomechanical behavior over conventional designs. In order to objectively realize the multi-directional biomechanical performances among the three geometries for clavicle plate designs, a current conceptual finite element study has been conducted with identical cross-sectional features for clavicle plates. The conceptual superior, anterior, and spiral clavicle plate models were constructed for virtual reduction and fixation to an OTA 15-B1.3 midshaft transverse fracture of clavicle. Mechanical load cases including cantilever bending, axial compression, inferior bending, and axial torsion have been applied for confirming the multi-directional structural stability and implant safety in biomechanical perspective. Results revealed that the anterior clavicle plate model represented lowest plate stress under all loading cases. The superior clavicle plate model showed greater axial compressive stiffness, while the anterior clavicle plate model performed greater rigidity under cantilever bending load. Three model represented similar structural stiffness under axial torsion. Played as a transition structure between superior and anterior clavicle plate, the spiral clavicle plate model revealed comparable results with acceptable multi-directional biomechanical behavior. The concept of spiral clavicle plate design is worth considering in practical application in clinics. Implant safety should be further investigated by evidences in future mechanical tests and clinical observations. PMID:27423702

  16. Locking compression plate distal ulna hook plate as alternative fixation for fifth metatarsal base fracture.

    PubMed

    Lee, Sang Ki; Park, Ju Sang; Choy, Won Sik

    2014-01-01

    Intramedullary screw fixation has been the most common treatment for fifth metatarsal base fractures. However, screw application will not achieve accurate reduction in fractures with small fragments, osteoporotic bone, or Lawrence zone 1 fractures. Because of the similar anatomic architecture between the distal ulna and the fifth metatarsal base, the purpose of the present study was to assess the results of a locking compression plate distal ulna hook plate in stabilizing displaced zone 1 or 2 fifth metatarsal base fractures. A total of 19 patients with Lawrence zone 1 (n = 12) or 2 (n = 7) fractures of the fifth metatarsal base were treated surgically with a locking compression plate distal ulna hook plate. The patients were evaluated clinically and radiographically, and the functional outcomes were graded using the American Orthopaedic Foot and Ankle Society midfoot scoring system. Radiographic bony union was obtained in all patients, at an average of 7.4 weeks. The mean American Orthopaedic Foot and Ankle Society midfoot score improved from 26 (range 0 to 45) points preoperatively to 94 (range 72 to 100) points at the final follow-up visit. Three patients developed post-traumatic cubometatarsal arthrosis, and 1 patient developed sural nerve neurapraxia. In our experience, the distal ulna hook plate achieved a high rate of bony consolidation and anatomically suitable fixation in zone 1 or 2 fifth metatarsal base fractures. We suggest that the locking compression plate distal ulna hook plate should be considered as an alternative treatment of multifragmentary, osteoporotic, and tuberosity avulsion (zone 1) fifth metatarsal base fractures.

  17. Plate selection for fixation of extra-articular distal humerus fractures: a biomechanical comparison of three different implants.

    PubMed

    Scolaro, John A; Hsu, Jason E; Svach, David J; Mehta, Samir

    2014-12-01

    Operative fixation of extra-articular distal humerus using a single posterolateral column plate has been described but the biomechanical properties or limits of this technique is undefined. The purpose of this study was to evaluate the mechanical properties of distal humerus fracture fixation using three standard fixation constructs. Two equal groups were created from forty sawbones humeri. Osteotomies were created at 80mm or 50mm from the tip of the trochlea. In the proximal osteotomy group, sawbones were fixed with an 8-hole 3.5mm LCP or with a 6-hole posterolateral plate. In the distal group, sawbones were fixed with 9-hole medial and lateral 3.5mm distal humerus plates and ten sawbones were fixed with a 6-hole posterolateral plate. Biomechanical testing was performed using a servohydraulic testing machine. Testing in extension as well as internal and external rotation was performed. Destructive testing was also performed with failure being defined as hardware pullout, sawbone failure or cortical contact at the osteotomy. In the proximal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than with the 3.5mm LCP. In the distal osteotomy group, the average bending stiffness and torsional stiffness was significantly greater with the posterolateral plate than the 3.5mm LCP. In extension testing, the yield strength was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens. The yield strength of specimens in axial torsion was significantly greater with the posterolateral plate in the proximal osteotomy specimens, and the dual plating construct in the distal osteotomy specimens. Limited biomechanical data to support the use of a pre-contoured posterolateral distal humerus LCP for fixation of extra-articular distal humerus exists. We have found that this implant provided significantly greater

  18. Intermittent internal fixation with a locking plate to preserve epiphyseal growth function during limb-salvage surgery in a child with osteosarcoma of the distal femur: a case report.

    PubMed

    Mei, Jiong; Ni, Ming; Jia, Guang-Yao; Chen, Yan-Xi; Zhu, Xiao-Zhong

    2015-05-01

    Limb shortening is a problem associated with surgery for osteosarcoma of the lower extremity in adolescents, as the tumors frequently occur near the epiphysis. Herein we report the use of a less invasive stabilization system (LISS) and an intermittent fixation method to preserve the growth function of epiphysis in an 11-year-old patient with an osteosarcoma of the distal femur.The 11-year-old male presented with left knee enlargement and pain for 2 weeks, and magnetic resonance imaging (MRI) and biopsy were consistent with osteosarcoma of the left distal femur. After preoperative chemotherapy, en bloc tumor resection was performed with margins based on MRI findings preserving the epiphyseal growth plate, the tumor cavity was filled with inactivated bone and bone cement, and a LISS was used to stabilize the femur. Aggressive postoperative chemotherapy was given. Approximately 105 weeks after surgery radiography showed that the distal end of the plate had moved superior to the epiphysis along with bone growth. Locking screws were placed in the distal part of the LISS plate to stabilize the re-implanted bone, and external fixation was not needed.The patient was able to walk with the crutches 1 week postoperatively, and bear weight on the extremity 6 weeks postoperatively. At 6 years after surgery, the patient's height had increased 52 cm, shortening of the affected limb was only 1 cm, and the circumference of the affected limb was 2 cm smaller than that of the contralateral limb. There was no significant discomfort in the affected limb, and there was no gait abnormality. The patient could jump and run, and could participate in sports including basketball and badminton to the same degree as his peers.In summary, the novel method of bone reconstruction and fixation provided good results in a child with an osteosarcoma of the distal femur. This fixation method preserves the osteogenic function of the epiphysis and restored bone integrity simultaneously, and

  19. Intermittent internal fixation with a locking plate to preserve epiphyseal growth function during limb-salvage surgery in a child with osteosarcoma of the distal femur: a case report.

    PubMed

    Mei, Jiong; Ni, Ming; Jia, Guang-Yao; Chen, Yan-Xi; Zhu, Xiao-Zhong

    2015-05-01

    Limb shortening is a problem associated with surgery for osteosarcoma of the lower extremity in adolescents, as the tumors frequently occur near the epiphysis. Herein we report the use of a less invasive stabilization system (LISS) and an intermittent fixation method to preserve the growth function of epiphysis in an 11-year-old patient with an osteosarcoma of the distal femur.The 11-year-old male presented with left knee enlargement and pain for 2 weeks, and magnetic resonance imaging (MRI) and biopsy were consistent with osteosarcoma of the left distal femur. After preoperative chemotherapy, en bloc tumor resection was performed with margins based on MRI findings preserving the epiphyseal growth plate, the tumor cavity was filled with inactivated bone and bone cement, and a LISS was used to stabilize the femur. Aggressive postoperative chemotherapy was given. Approximately 105 weeks after surgery radiography showed that the distal end of the plate had moved superior to the epiphysis along with bone growth. Locking screws were placed in the distal part of the LISS plate to stabilize the re-implanted bone, and external fixation was not needed.The patient was able to walk with the crutches 1 week postoperatively, and bear weight on the extremity 6 weeks postoperatively. At 6 years after surgery, the patient's height had increased 52 cm, shortening of the affected limb was only 1 cm, and the circumference of the affected limb was 2 cm smaller than that of the contralateral limb. There was no significant discomfort in the affected limb, and there was no gait abnormality. The patient could jump and run, and could participate in sports including basketball and badminton to the same degree as his peers.In summary, the novel method of bone reconstruction and fixation provided good results in a child with an osteosarcoma of the distal femur. This fixation method preserves the osteogenic function of the epiphysis and restored bone integrity simultaneously, and

  20. Fixation of Intertrochanteric Valgus Osteotomy with T Plate in Treatment of Developmental Coxa Vara

    PubMed Central

    Khairy, Hosam Mohamed

    2016-01-01

    Background Although the valgus subtrochanteric osteotomy is considered as a standard surgical treatment for coxa vara, there is no consensus on the optimal method of fixation and osteotomy technique. Fixation of the osteotomy has been achieved by various methods including external fixation and internal fixation with pins and cerclage and a variety of plates. The aim of this study is the evaluation of the results of developmental coxa treated by Y intertrochanteric valgus osteotomy fixed with a T-buttress plate compared with other methods of fixation in the literature. Methods Eighteen corrective valgus intertrochanteric femoral osteotomies were performed in 18 patients (18 hips) for treatment of unilateral developmental coxa vara deformity and fixed with a T plate. There were 12 males and 6 females. The right hip was affected in 10 patients and the left hip in 8 patients. Clinically, patients were evaluated by Larson hip score. Radiographically, anteroposterior view of the pelvis and frog leg lateral views of the affected hip were taken preoperatively and compared with the findings at the final follow-up. Results The average follow-up was 29 months (range, 24 to 36 months). Clinical results showed improvement of the mean Larson hip score from 57.8 to 97.0 (p < 0.001). Radiological results showed that all osteotomies were completely united in 2.4 months (range, 2 to 3 months) with the achievement of the planned correction angle. The average correction of Hilgenreiner's epiphyseal angle improved from 78.2° to 27.8° (p < 0.001) at the final follow-up. The femoral neck shaft angle was improved from 93.7° to 129.9° (p < 0.001) at the final follow-up. Shortening of the affected limb was corrected from 2.8 cm to 1.3 cm (p < 0.001) at the last follow-up. No major serious complications were recorded in the present study. Conclusions Intertrochanteric valgus osteotomy of the proximal femur fixed with a T plate may be efficient for treatment of developmental coxa vara

  1. Comparison of open reduction internal fixation and conservative treatment plus open reduction internal fixation for calcaneal fractures

    PubMed Central

    Pan, Yongmiao; Yuan, Linyi; Ye, Chengfeng

    2014-01-01

    To compare the effect of open reduction internal fixation and conservative treatment combined with open reduction internal fixation for subjects with calcaneal fractures, 130 patients with calcaneal fractures were divided into observation group and control group. Observation group were treated with open reduction internal fixation and conservative treatment, control group treated as open reduction internal fixation. The healing related indicators, daily life activities ability score of observation group after treatment 6 months were significantly higher than that of the control group, there was no significant difference for the healing rate of excellent and good rate, the daily life activities ability score after one and three year between two groups. Open reduction internal fixation combined with conservative treatment in treatment of calcaneal fractures can clear anatomic structure and have fast function recovery. Thus, it should be as the preferred method for the treatment of calcaneal fractures. PMID:25550973

  2. PERPENDICULAR DOUBLE-PLATE FIXATION WITH LOCKING SYSTEM FOR ACROMION PEDICLE FRACTURE

    PubMed Central

    Zhu, Junkun; Pan, Zhijun; Zheng, Rongzong; Lan, Shuhua

    2016-01-01

    Objective : To describe the surgical technique and preliminary clinical outcomes in a series of open reduction internal fixation of basal acromion process fractures applying a double-plating technique. Methods : Nine consecutive patients, mean age 33.4 years old (range, 23-61 years old) with unilateral acromion fracture (Type 3 AO/OTA) with more than 1cm displacement who underwent fixation utilizing a locked double-plating technique, were evaluated on average at 7.8 months (range, 3-15 months) for outcomes related to pain, shoulder function, and surgical complications. Results : Eight patients recovered with complete radiographic union and favorable shoulder function. One case failed to be fully evaluated for more than 3 months follow-up. The overall scores of Constant, Shoulder Pain and Disability Index (SPADI) and DASH for the eight patients reviewed were 91.9± 6.31, 3.11± 3.79 and 5.2± 6.35, respectively. No post-operative infection or surgical hardware irritation was identified at final follow-up of these eight patients. Conclusion : While more evidence is needed to justify its advantages over traditional implants, perpendicular double-plate with a locking system may be indicated for acromion pedicle fracture treatment, since it performed well for fracture healing and joint function rehabilitation. Level of Evidence IV, Therapeutic Study. PMID:26981047

  3. Comparison between cast immobilization versus volar locking plate fixation of distal radius fractures in active elderly patients, the Asian perspective.

    PubMed

    Chan, Ying-Ho; Foo, Tun-Lin; Yeo, Chong-Jin; Chew, Winston Yoon-Chong

    2014-01-01

    Displaced distal radius fractures in active elderly patients with high functional demand present a clinical dilemma because current evidence is equivocal in the recommendation of treatment. Internal fixation is an increasingly popular option with proposed superior results. Our study aims to evaluate the results among a population of active elderly patients with displaced fractures managed with either cast immobilization or internal fixation with volar locking plate. Seventy-five patients (35 cast immobilization and 40 internal fixation) with mean age of 74 ± 7.5 years with minimum of 12 months follow-up were studied. The radiological and clinical parameters were assessed at three, six, and 12 months. Functional outcomes (DASH, Green-O'Brien) were assessed at 12 months. Patients who underwent surgery regain wrist motion and grip strength earlier, but this was not statistically significant after six months.

  4. Proximal Periprosthetic Femur Fractures: Strategies for Internal Fixation.

    PubMed

    Moloney, Gele B; Toro, Jose B; Helfet, David L; Wellman, David S

    2016-01-01

    As the number of patients living with total hip arthroplasty continues to rise, there will be an increase in periprosthetic fractures requiring surgical treatment. Treatment of periprosthetic femur fractures below a well-fixed hip arthroplasty stem presents a unique set of challenges. A review of the existing literature on surgical technique, including plate selection and configuration, proximal fixation options, and use of allograft, can serve to guide treatment of these challenging injuries. While not conclusive, the literature supports using soft tissue preserving techniques, bicortical proximal fixation, and fixation spanning the length of the femur. PMID:27327912

  5. Clinical Results of Internal Fixation of Subcapital Femoral Neck Fractures

    PubMed Central

    Moon, Kyoung Ho; Shin, Joong Sup; Shin, Eun Ho; Ahn, Chi Hoon; Choi, Geon Hong

    2016-01-01

    Background Subcapital femoral neck is known to cause many complications, such as avascular necrosis (AVN) of the femoral head or nonunion, compared with other femoral neck fractures. The purpose of this study was to analyze the incidence of AVN and fixation failures in patients treated with internal fixation using cannulated screws for the subcapital femoral neck fractures. Methods This study targeted a total of 84 cases of subcapital femoral neck fractures that underwent internal fixation using cannulated screws. The average follow-up time after surgery was 36.8 months (range, 24 to 148 months). Results Nine hips (10.7%) showing AVN of the femoral head and 6 hips (7.1%) showing fixation failures were observed. The factors affecting the incidence of AVN of the femoral head after sustaining fractures correlated well with fracture types in the Garden classification (p = 0.030). The factors affecting fixation failure were the degree of reduction (p = 0.001) measured by the Garden alignment index and firm fixation (p = 0.009) assessed using the technique of 3-point fixation through the inferomedial cortical bone of the femoral neck. Conclusions The complication rates for subcapital femoral neck fractures were lower than those previously reported; hence, internal fixation could be a primary treatment option for these fractures. PMID:27247738

  6. Comparison of Results between Hook Plate Fixation and Ligament Reconstruction for Acute Unstable Acromioclavicular Joint Dislocation

    PubMed Central

    Yoon, Jong Pil; Lee, Byoung-Joo; Nam, Sang Jin; Chung, Seok Won; Jeong, Won-Ju; Min, Woo-Kie

    2015-01-01

    Background In the present study, we aimed to compare clinical and radiographic outcomes between hook plate fixation and coracoclavicular (CC) ligament reconstruction for the treatment of acute unstable acromioclavicular (AC) joint dislocation. Methods Forty-two patients who underwent surgery for an unstable acute dislocation of the AC joint were included. We divided them into two groups according to the treatment modality: internal fixation with a hook plate (group I, 24 cases) or CC ligament reconstruction (group II, 18 cases). We evaluated the clinical outcomes using a visual analog scale (VAS) for pain and Constant-Murley score, and assessed the radiographic outcomes based on the reduction and loss of CC distance on preoperative, postoperative, and final follow-up plain radiographs. Results The mean VAS scores at the final follow-up were 1.6 ± 1.5 and 1.3 ± 1.3 in groups I and II, respectively, which were not significantly different. The mean Constant-Murley scores were 90.2 ± 9.9 and 89.2 ± 3.5 in groups I and II, respectively, which were also not significantly different. The AC joints were well reduced in both groups, whereas CC distance improved from a mean of 215.7% ± 50.9% preoperatively to 106.1% ± 10.2% at the final follow-up in group I, and from 239.9% ± 59.2% preoperatively to 133.6% ± 36.7% at the final follow-up in group II. The improvement in group I was significantly superior to that in group II (p < 0.001). Furthermore, subluxation was not observed in any case in group I, but was noted in six cases (33%) in group II. Erosions of the acromion undersurface were observed in 9 cases in group I. Conclusions In cases of acute unstable AC joint dislocation, hook plate fixation and CC ligament reconstruction yield comparable satisfactory clinical outcomes. However, radiographic outcomes based on the maintenance of reduction indicate that hook plate fixation is a better treatment option. PMID:25729525

  7. Internal fixation at ECWA Hospital, Egbe, Kogi State, Nigeria.

    PubMed

    Agaja, S B

    2002-01-01

    Forty two (42) cases of fractures treated by internal fixation at Egbe Hospital ECWA, Kogi State, Nigeria were analysed retrospectively. Most of the patients requiring internal fixation were young male patients in their reproductive years 26 patients were under 50 years of age out of which 22 patients were males (84.6%) whilst only 4 patients (15.4%) were females. Internal fixation was found to be commoner in males: 31 patients (73.8%) than in females: 11 patients (26.2%). Fractures requiring internal fixation are commoner in the lower limbs than in the upper limbs (Ratio 6:1). The femur is the commonest site of internal fixation, 22 cases (54.2%) followed by the tibia, 6 cases (14.3%). Majority of the patients, 28 cases (67%) left the hospital under 50 days whereas when treated conservatively most will be in the hospital for up to 100 days. Only about 60% of the cases require blood transfusion and even a more cautious approach could reduce this percentage. 13 (31%) of the cases had fever post-operatively which was not necessarily due to infection. Based on its advantages, internal fixation is therefore encouraged and should only be performed by a surgeon who has adequate experience, equipment, instruments and a good operating theatre setting.

  8. Complex fractures of the proximal humerus in the elderly--outcome and complications after locking plate fixation.

    PubMed

    Schliemann, B; Siemoneit, J; Theisen, Ch; Kösters, C; Weimann, A; Raschke, M J

    2012-05-01

    Open reduction and internal fixation (ORIF) with locking plates or primary arthroplasty remains a controversial issue in the management of complex proximal humerus fractures. Aim of this study was to evaluate the surgeon- and patient-based outcome of patients older than 65 years who underwent ORIF using locking plate fixation of a 3- or 4-part fracture of the proximal humerus. Twenty-seven patients older than 65 years were treated with locking plate fixation (PHILOS, Fa. Synthes, Umkirch, Germany). At an average follow-up of 44 months, the clinical and the subjective outcome were evaluated, and complications were analyzed. The mean age- and gender-related Constant score was 70% (30–100%) compared with 92% (47–108%) of the contralateral non-injured shoulder. The mean DASH score was 29 points (0–71). Five patients (18.5%) showed clinical signs of an impingement, which was related to malpositioning of the plate in 3 cases. Screw cutout was seen in 22.2% (6 patients). Avascular necrosis of the head or the tubercula was found in 8 patients (29.6%). The revision rate was 29.6%. However, the patients considered the functional status of their shoulder as “good” or “satisfactory.” The functional and patient-orientated results of the locking plate fixation of complex displaced proximal humerus fractures in the elderly are comparable to those of primary arthroplasty and minimally invasive treatment. Proper surgical technique (screw length, plate position) is mandatory for reducing the revision rate.

  9. Biomechanical Study of the Fixation Strength of Anteromedial Plating for Humeral Shaft Fractures

    PubMed Central

    Zheng, Yin-Feng; Zhou, Jun-Lin; Wang, Xiao-Hong; Shan, Lei; Liu, Yang

    2016-01-01

    Background: Open reduction and internal fixation with plate and screws are the gold standard for the surgical treatment of humeral shaft fractures, this study was to compare the mechanical properties of anteromedial, anterolateral, and posterior plating for humeral shaft fractures. Methods: A distal third humeral shaft fracture model was constructed using fourth-generation sawbones (#3404, composite bone). A total of 24 sawbones with a distal third humeral shaft fracture was randomly divided into three Groups: A, B, and C (n = 8 in each group) for anteromedial, anterolateral, and posterior plating, respectively. All sawbones were subjected to horizontal torsional fatigue tests, horizontal torsional and axial compressive fatigue tests, four-point bending fatigue tests in anteroposterior (AP) and mediolateral (ML) directions and horizontal torsional destructive tests. Results: In the horizontal torsional fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 6.12°, 6.53°, and 6.81°. In horizontal torsional and axial compressive fatigue tests, the mean torsional angle amplitude in Groups A, B, and C were 5.66°, 5.67°, and 6.36°. The mean plate displacement amplitude was 0.05 mm, 0.08 mm, and 0.10 mm. Group A was smaller than Group C (P < 0.05). In AP four-point bending fatigue tests, the mean plate displacement amplitude was 0.16 mm, 0.13 mm, and 0.20 mm. Group B was smaller than Group C (P < 0.05). In ML four-point bending fatigue tests, the mean plate displacement amplitude were 0.16 mm, 0.19 mm, and 0.17 mm. In horizontal torsional destructive tests, the mean torsional rigidity in Groups A, B, and C was 0.82, 0.75, and 0.76 N·m/deg. The yielding torsional angle was 24.50°, 25.70°, and 23.86°. The mean yielding torque was 18.46, 18.05, and 16.83 N·m, respectively. Conclusions: Anteromedial plating was superior to anterolateral or posterior plating in all mechanical tests except in AP four-point bending fatigue tests compared to the

  10. Extraperiosteal Dual Plate Fixation of Acute Mid-Shaft Clavicle Fractures: A Technical Trick.

    PubMed

    Shannon, Steven F; Chen, Xiaobin; Torchia, Michael; Schoch, Bradley

    2016-10-01

    Historically, surgical treatment of acute mid-shaft clavicle fractures has excellent outcomes with low rates of nonunion. More complex fracture patterns with significant comminution may limit the fixation that can be obtained with a single plate. The authors describe the surgical technique and case series of patients treated with extraperiosteal dual plating for acute mid-shaft clavicle fractures.

  11. A survey of current practices and preferences for internal fixation of displaced olecranon fractures

    PubMed Central

    Wood, Thomas; Thomas, Katie; Farrokhyar, Forough; Ristevski, Bill; Bhandari, Mohit; Petrisor, Bradley

    2015-01-01

    Background Olecranon fractures represent 10% of upper extremity fractures. There is a growing body of literature to support the use of plate fixation for displaced olecranon fractures. The purpose of this survey was to gauge Canadian surgeons’ practices and preferences for internal fixation methods for displaced olecranon fractures. Methods Using an online survey tool, we administered a cross-sectional survey to examine current practice for fixation of displaced olecranon fractures. Results We received 256 completed surveys for a response rate of 31% (95% confidence interval [CI] 30.5–37.5%). The preferred treatment was tension band wiring (78.5%, 95% CI 73–83%) for simple displaced olecranon fractures (Mayo IIA) and plating (81%, 95% CI 75.5–85%) for displaced comminuted olecranon fractures (Mayo IIB). Fracture morphology with a mean impact of 3.31 (95% CI 3.17–3.45) and comminution with a mean impact of 3.34 (95% CI 3.21–3.46) were the 2 factors influencing surgeons’ choice of fixation method the most. The major deterrent to using tension band wiring for displaced comminuted fractures (Mayo IIB) was increased stability obtained with other methods described by 75% (95% CI 69–80%) of respondents. The major deterrent for using plating constructs for simple displaced fractures (Mayo IIA) was better outcomes with other methods. Hardware prominence was the most commonly perceived complication using either method of fixation: 77% (95% CI 71.4–81.7%) and 76.2% (95% CI 70.6–81.0%) for tension band wiring and plating, respectively. Conclusion Divergence exists with current literature and surgeon preference for fixation of displaced olecranon fractures. PMID:26204363

  12. Design and Optimization of Resorbable Silk Internal Fixation Devices

    NASA Astrophysics Data System (ADS)

    Haas, Dylan S.

    Limitations of current material options for internal fracture fixation devices have resulted in a large gap between user needs and hardware function. Metal systems offer robust mechanical strength and ease of implantation but require secondary surgery for removal and/or result in long-term complications (infection, palpability, sensitivity, etc.). Current resorbable devices eliminate the need for second surgery and long-term complications but are still associated with negative host response as well as limited functionality and more difficult implantation. There is a definitive need for orthopedic hardware that is mechanically capable of immediate fracture stabilization and fracture fixation during healing, can safely biodegrade while allowing complete bone remodeling, can be resterilized for reuse, and is easily implantable (self-tapping). Previous work investigated the use of silk protein to produce resorbable orthopedic hardware for non- load bearing fracture fixation. In this study, silk orthopedic hardware was further investigated and optimized in order to better understand the ability of silk as a fracture fixation system and more closely meet the unfulfilled market needs. Solvent-based and aqueous-based silk processing formulations were cross-linked with methanol to induce beta sheet structure, dried, autoclaved and then machined to the desired device/geometry. Silk hardware was evaluated for dry, hydrated and fatigued (cyclic) mechanical properties, in vitro degradation, resterilization, functionalization with osteoinductive molecules and implantation technique for fracture fixation. Mechanical strength showed minor improvements from previous results, but remains comparable to current resorbable fixation systems with the advantages of self-tapping ability for ease of implantation, full degradation in 10 months, ability to be resterilized and reused, and ability to release molecules for osteoinudction. In vivo assessment confirmed biocompatibility, showed

  13. Pathophysiology of infections after internal fixation of fractures.

    PubMed

    Schmidt, A H; Swiontkowski, M F

    2000-01-01

    Infection complicating internal fixation of fractures is a serious complication that is difficult to treat. Whenever metallic devices are implanted in vivo, successful biointegration requires that host cells colonize the highly reactive implant surface. Bacteria such as staphylococci can also become adherent to metallic or polymeric implants and will compete with host cells for colonization of the implant surface. Once adherent, these bacteria form a biofilm and undergo phenotypic changes that make them resistant to the normal host immune response as well as to antibiotics. Furthermore, metallic implants themselves cause specific deficits in the function of the local immune system that may render the host response to infection inadequate. Any associated soft-tissue injury causes even greater impairment of local immune function. Despite the potentially detrimental impact of internal fixation, fracture stability is of paramount importance in achieving fracture union and in preventing infection. It has been demonstrated in animal models that contaminated fractures without internal fixation develop clinical infection more commonly than similar fractures treated with internal fixation at the time of colonization. Because of the potential for infection whenever internal fixation is utilized, appropriate prophylactic antibiotic coverage for staphylococci and Gram-negative organisms should be provided. Open wounds and severely damaged soft tissues require aggressive management so that a viable soft-tissue envelope is maintained around the implant. Host factors such as smoking and malnourishment should be corrected. Early diagnosis and aggressive treatment of implant-related infection with antibiotics, debridement, and maintenance of stable internal fixation are essential to successful treatment.

  14. Biomechanical Evaluation of Plate Versus Lag Screw Only Fixation of Distal Fibula Fractures.

    PubMed

    Misaghi, Amirhossein; Doan, Josh; Bastrom, Tracey; Pennock, Andrew T

    2015-01-01

    Traditional fixation of unstable Orthopaedic Trauma Association type B/C ankle fractures consists of a lag screw and a lateral or posterolateral neutralization plate. Several studies have demonstrated the clinical success of lag screw only fixation; however, to date no biomechanical comparison of the different constructs has been performed. The purpose of the present study was to evaluate the biomechanical strength of these different constructs. Osteotomies were created in 40 Sawbones(®) distal fibulas and reduced using 1 bicortical 3.5-mm stainless steel lag screw, 2 bicortical 3.5-mm lag screws, 3 bicortical 3.5-mm lag screws, or a single 3.5-mm lag screw coupled with a stainless steel neutralization plate with 3 proximal cortical and 3 distal cancellous screws. The constructs were tested to determine the stiffness in lateral bending and rotation and failure torque. No significant differences in lateral bending or rotational stiffness were detected between the osteotomies fixed with 3 lag screws and a plate. Constructs fixed with 1 lag screw were weaker for both lateral bending and rotational stiffness. Osteotomies fixed with 2 lag screws were weaker in lateral bending only. No significant differences were found in the failure torque. Compared with lag screw only fixation, plate fixation requires larger incisions and increased costs and is more likely to require follow-up surgery. Despite the published clinical success of treating simple Orthopaedic Trauma Association B/C fractures with lag screw only fixation, many surgeons still have concerns about stability. For noncomminuted, long oblique distal fibula fractures, lag screw only fixation techniques offer construct stiffness similar to that of traditional plate and lag screw fixation. PMID:25990534

  15. Biomechanical Evaluation of Plate Versus Lag Screw Only Fixation of Distal Fibula Fractures.

    PubMed

    Misaghi, Amirhossein; Doan, Josh; Bastrom, Tracey; Pennock, Andrew T

    2015-01-01

    Traditional fixation of unstable Orthopaedic Trauma Association type B/C ankle fractures consists of a lag screw and a lateral or posterolateral neutralization plate. Several studies have demonstrated the clinical success of lag screw only fixation; however, to date no biomechanical comparison of the different constructs has been performed. The purpose of the present study was to evaluate the biomechanical strength of these different constructs. Osteotomies were created in 40 Sawbones(®) distal fibulas and reduced using 1 bicortical 3.5-mm stainless steel lag screw, 2 bicortical 3.5-mm lag screws, 3 bicortical 3.5-mm lag screws, or a single 3.5-mm lag screw coupled with a stainless steel neutralization plate with 3 proximal cortical and 3 distal cancellous screws. The constructs were tested to determine the stiffness in lateral bending and rotation and failure torque. No significant differences in lateral bending or rotational stiffness were detected between the osteotomies fixed with 3 lag screws and a plate. Constructs fixed with 1 lag screw were weaker for both lateral bending and rotational stiffness. Osteotomies fixed with 2 lag screws were weaker in lateral bending only. No significant differences were found in the failure torque. Compared with lag screw only fixation, plate fixation requires larger incisions and increased costs and is more likely to require follow-up surgery. Despite the published clinical success of treating simple Orthopaedic Trauma Association B/C fractures with lag screw only fixation, many surgeons still have concerns about stability. For noncomminuted, long oblique distal fibula fractures, lag screw only fixation techniques offer construct stiffness similar to that of traditional plate and lag screw fixation.

  16. A Meta-Analysis for Postoperative Complications in Tibial Plafond Fracture: Open Reduction and Internal Fixation Versus Limited Internal Fixation Combined With External Fixator.

    PubMed

    Wang, Dong; Xiang, Jian-Ping; Chen, Xiao-Hu; Zhu, Qing-Tang

    2015-01-01

    The treatment of tibial plafond fractures is challenging to foot and ankle surgeons. Open reduction and internal fixation and limited internal fixation combined with an external fixator are 2 of the most commonly used methods of tibial plafond fracture repair. However, conclusions regarding the superior choice remain controversial. The present meta-analysis aimed to quantitatively compare the postoperative complications between open reduction and internal fixation and limited internal fixation combined with an external fixator for tibial plafond fractures. Nine studies with 498 fractures in 494 patients were included in the present study. The meta-analysis found no significant differences in bone healing complications (risk ratio [RR] 1.17, 95% confidence interval [CI] 0.68 to 2.01, p = .58], nonunion (RR 1.09, 95% CI 0.51 to 2.36, p = .82), malunion or delayed union (RR 1.24, 95% CI 0.57 to 2.69, p = .59), superficial (RR 1.56, 95% CI 0.43 to 5.61, p = .50) and deep (RR 1.89, 95% CI 0.62 to 5.80) infections, arthritis symptoms (RR 1.20, 95% CI 0.92 to 1.58, p = .18), or chronic osteomyelitis (RR 0.31, 95% CI 0.05 to 1.84, p = .20) between the 2 groups.

  17. Rigid internal fixation with titanium versus bioresorbable miniplates in the repair of mandibular fractures in rabbits.

    PubMed

    Hochuli-Vieira, E; Cabrini Gabrielli, M A; Pereira-Filho, V A; Gabrielli, M F R; Padilha, J G

    2005-03-01

    The purpose of this study was to compare by qualitative histology the efficacy of rigid internal fixation with titanium system and the Lacto Sorb system in mandibular fractures in rabbits. Thirty male adult rabbits Oryctolagus cuniculus were used. Unilateral mandibular osteotomies were performed between the canine and first premolar. The animals were divided into two groups: for Group I-rigid internal fixation was performed with titanium system 1.5 mm (Synthes, Oberdorf, Switzerland), with two screws of 6 mm (bicortical) on each side of the osteotomy. For Group II-rigid internal fixation was performed with PLLA/PGA system 1.5 mm (Lacto Sorb, WLorenz, Jacksonville, FL, USA). The histological analysis evaluated the presence of inflammatory reaction, degree of bone healing and degree of resorption of the Lacto Sorb screws. The results of both fixation systems were similar, only with a small difference after 15 and 30 days. In Group I a faster bony healing was noted. But after 60 days, bony healing was similar in both groups. It is concluded that both PLLA/PGA and titanium plates and screws provide sufficient strength to permit mandibular bone healing. The resorption process of PLLA/PGA osteosynthesis material did not cause acute or chronic inflammatory reaction or foreign body reaction during the studied period.

  18. [Implant materials for the internal fixation of midfacial fractures].

    PubMed

    Stuck, B A; Heller, T

    2011-11-01

    The material used for osteosynthesis plays a crucial role in the management of facial fractures. Plates need to be flexible enough to be bent and should not be palpable through the skin, while ensuring stable fixation und adequate biocompatibility. Although stainless steel was initially the material of choice, titanium has become the standard material due to its superior biocompatibility. While the explantation of titanium plates and screws appears unnecessary in general, it should be considered in cases of dislocation, cosmetic concerns, pain and infection. Due to their limited initial stability and a potential increase in local complications, resorbable materials based on polymeric lactose are used with caution in midfacial fractures in adults. Our own retrospective study comparing the postoperative complications after fixation of lateral midfacial fractures with titanium and resorbable systems demonstrated a low complication rate for both systems (7-8%) and no statistically significant difference between the two. The appropriate material for fixation should be selected based on the localization and severity of the fracture, the experience of the surgeon as well as on the age and overall condition of the patient.

  19. Perspectives of patients about bioabsorbable internal fixation for maxillofacial fractures

    PubMed Central

    Landes, Constantin; Hoefer, Sebastian H.; Richards, Tereza; Walcher, Felix; Sader, Robert

    2015-01-01

    Purpose: Resorbable/bioabsorbable internal fixation provides effective treatment for maxillofacial fractures and avoids the need for metal hardware removal. We evaluated the initial knowledge, attitudes, subjective demand, and treatment satisfaction of patients concerning bioabsorbable osteofixation for maxillofacial trauma. Materials and Methods: From May 2007 to October 2009, there were 71 patients (63 males and 8 females; mean age: 35 ± 15 years) included in this prospective study. The patients completed preoperative and postoperative (4–6 weeks and 1 year) questionnaires. Results: After receiving information, 70 patients (99%) preferred resorbable/bioabsorbable bone fixation, usually because they preferred to avoid a second operation to remove metal hardware (67 patients [94%]). The higher cost of resorbable/bioabsorbable bone fixation was believed and justified by 41 patients (58%) and not justified by 30 patients (42%). No adverse events were reported by 27 of 34 patients (79%) at 4–6 weeks and by 14 of 21 patients (67%) at 1 year after surgery. Most patients were very satisfied with the outcome of surgery. Conclusion: Patients who have maxillofacial trauma have a high frequency of preference and high satisfaction with resorbable/bioabsorbable than metal osteofixation. Literature review showed increased activity in research and publication worldwide about resorbable bone fixation, suggesting that there may be increased patient demand for resorbable bone fixation in the future. PMID:26981468

  20. Fixation of Radiological Contamination; International Collaborative Development

    SciTech Connect

    Rick Demmer

    2013-03-01

    A cooperative international project was conducted by the Idaho National Laboratory (INL) and the United Kingdom’s National Nuclear Laboratory (NNL) to integrate a capture coating with a high performance atomizing process. The initial results were promising, and lead to further trials. The somewhat longer testing and optimization process has resulted in a product that could be demonstrated in the field to reduce airborne radiological dust and contamination.

  1. Satellite Doppler Fixation and International Boundaries

    NASA Astrophysics Data System (ADS)

    Leppard, N. A. G.

    1980-01-01

    International boundaries have seldom been completely defined in geodetic terms. The existence of natural resources, which ignore the arbitrary boundaries of man, assume considerable importance when division of those resources becomes a point of issue between potential owners. This is particularly so when the boundary is illdefined in a geodetic sense. World-wide satellite reference systems, like natural resources, also have little regard for the internally less precise national or international systems. When the one is used to define the location of the other, great care must be taken to ensure equitable division, for financial gain and loss can be considerable. The definition of position is complicated by the existence of the two ephemerides for the N.N.S.S. satellites and the number of alternative reduction procedures available. The definition of the position of the Frigg Gas Field in the North Sea is an example of how the United Kingdom and Norway resolved the geodetic problem of reconciling geodetic and Doppler data.

  2. An electronically instrumented internal fixator for the assessment of bone healing

    PubMed Central

    Kowald, B.; Seide, K.; Aljudaibi, M.; Faschingbauer, M.; Juergens, C.; Gille, J.

    2016-01-01

    Objectives The monitoring of fracture healing is a complex process. Typically, successive radiographs are performed and an emerging calcification of the fracture area is evaluated. The aim of this study was to investigate whether different bone healing patterns can be distinguished using a telemetric instrumented femoral internal plate fixator. Materials and Methods An electronic telemetric system was developed to assess bone healing mechanically. The system consists of a telemetry module which is applied to an internal locking plate fixator, an external reader device, a sensor for measuring externally applied load and a laptop computer with processing software. By correlation between externally applied load and load measured in the implant, the elasticity of the osteosynthesis is calculated. The elasticity decreases with ongoing consolidation of a fracture or nonunion and is an appropriate parameter for the course of bone healing. At our centre, clinical application has been performed in 56 patients suffering nonunion or fracture of the femur. Results A total of 39 cases of clinical application were reviewed for this study. In total, four different types of healing curves were observed: fast healing; slow healing; plateau followed by healing; and non-healing. Conclusion The electronically instrumented internal fixator proved to be valuable for the assessment of bone healing in difficult healing situations. Cost-effective manufacturing is possible because the used electronic components are derived from large-scale production. The incorporation of microelectronics into orthopaedic implants will be an important innovation in future clinical care. Cite this article: B. Kienast, B. Kowald, K. Seide, M. Aljudaibi, M. Faschingbauer, C. Juergens, J. Gille. An electronically instrumented internal fixator for the assessment of bone healing. Bone Joint Res 2016;5:191–197. DOI: 10.1302/2046-3758.55.2000611. PMID:27226357

  3. Effect of in vitro aging on the stiffness of bioabsorbable fixation plates.

    PubMed

    Zinelis, Spiros; Venetis, Gregory; Eliades, Theodoros; Dimitrakopoulos, Ioannis; Eliades, Georgios

    2011-01-01

    The purpose of this study was to investigate the effect of in vitro aging on the stiffness of bioabsorbable fixation plates. Twenty-four polylactic/polyglycolic acid plates (LactoSorb; Lorenz, Jacksonville, FL) were divided in 3 groups of 8 specimens each. Group A served as control, and groups B and C were immersed in 0.1 M lactic acid for 15 and 30 days, respectively. All specimens were subjected to a 3-point bending test, using a universal testing machine, and the stiffness of each specimen was estimated. When analyzed with one-way analysis of variance, no difference was observed for the control and in vitro-aged specimens with regard to stiffness. Long-term (30 d) in vitro aging of poly-L-lactic acid bioabsorbable fixation plates does not seem to significantly affect the stiffness of the material as derived from a 3-point bending test.

  4. Novel Longitudinal Plate-Fixation Technique after Gross Resection of the Sternum

    PubMed Central

    Tasoglu, Irfan; Lafci, Gokhan

    2012-01-01

    Herein, we describe a plate-fixation technique as an alternative method to close a fragile or fractured sternum. A 69-year-old obese woman with diabetes mellitus and chronic obstructive pulmonary disease underwent coronary artery bypass grafting. One week postoperatively, sternal instability was detected, and traditional rewiring was performed. A week later, because of multiple sternal fractures, we performed sternal resection, with use of longitudinally affixed titanium plates and figure-8 steel wires for the anterior chest wall. The procedure was uneventful, and, on short-term follow-up, the anterior chest wall was stable. This longitudinal plate-fixation technique can be tailored to each patient. We think that the technique is safe, effective, economical, and easy to implement, and it is readily reproducible. To evaluate any associated risks, long-term follow-up in additional patients is warranted. PMID:22740734

  5. Open reduction and internal fixation of proximal humerus fractures.

    PubMed

    Drosdowech, Darren S; Faber, Kenneth J; Athwal, George S

    2008-10-01

    Open reduction of proximal humeral fractures has the advantage of providing direct control over each fracture fragment and permitting anatomic reduction and fixation with advanced devices. Modern fixed-angle locking plates designed specifically for proximal humerus fractures have allowed the expansion of surgical indications permitting surgeons to address more complicated fractures. Advanced preoperative imaging and fluoroscopy allow a better understanding of fracture patterns and permit the surgeon to use this knowledge intraoperatively. Research is required to further validate fracture classification systems, to develop surgical guidelines for decision making, and to compare the outcomes of the various treatments options for proximal humerus fractures.

  6. Internal fixators: a safe option for managing distal femur fractures?

    PubMed Central

    Batista, Bruno Bellaguarda; Salim, Rodrigo; Paccola, Cleber Antonio Jansen; Kfuri, Mauricio

    2014-01-01

    OBJECTIVE: Evaluate safety and reliability of internal fixator for the treatment of intra-articular and periarticular distal femur fractures. METHODS: Retrospective data evaluation of 28 patients with 29 fractures fixed with internal fixator was performed. There was a predominance of male patients (53.5%), with 52% of open wound fractures, 76% of AO33C type fractures, and a mean follow up of 21.3 months. Time of fracture healing, mechanical axis deviation, rate of infection and postoperative complications were registered. RESULTS: Healing rate was 93% in this sample, with an average time of 5.5 months. Twenty-seven percent of patients ended up with mechanical axis deviation, mostly resulting from poor primary intra-operative reduction. There were two cases of implant loosening; two implant breakage, and three patients presented stiff knee. No case of infection was observed. Healing rate in this study was comparable with current literature; there was a high degree of angular deviation, especially in the coronal plane. CONCLUSION: Internal fixators are a breakthrough in the treatment of knee fractures, but its use does not preclude application of principles of anatomical articular reduction and mechanical axis restoration. Level of Evidence II, Retrospective Study. PMID:25061424

  7. In vivo biomechanical evaluation of nail-plate fixation of femoral neck fractures of rehabilitated patients.

    PubMed

    Mizrahi, J; Kantarovski, A; Najenson, T; Susak, Z

    1985-01-01

    A major advantage of internal fixation of intertrochanteric fractures is that it can normally be followed by early and fast rehabilitation of the patient, finding expression in weight bearing and locomotion abilities of the patients. Complications which nevertheless occur, are mostly of mechanical origin. The purpose of our study was to evaluate the biomechanical performance of rehabilitated patients treated with four different types of nail-plates. Forty nine patients (12 men and 37 women) with walking ability, and with an average age of 70.5 years, were tested on a 10 m walkway, instrumented for the monitoring of the time distance parameters of the stride. This method of evaluation is especially suitable for pathological gait, free or supported, as it does not impose any constraints on the natural and individual walking trend of the patient. The average time elapsed between the actual fracture and the locomotor test was 764 days, implying that the investigated patients formed a homogeneous, well-rehabilitated group. The main average stride results were as follows: contact time 1.25 sec, double contact time 0.41 sec, stride length 68.2 cm, velocity 51.39 cm/sec and symmetry 0.51. No significant differences were found in these parameters between the subgroups of patients using different nail-plates. These results show that while the biomechanical performance of the patients with their implants was satisfactory (good walking symmetry) this group can be characterized by its smaller stride and slower gait, compared to those of a healthy population of the same age.

  8. Medial Closing-Wedge Distal Femoral Osteotomy: Fixation With Proximal Tibial Locking Plate

    PubMed Central

    Tírico, Luís Eduardo Passarelli; Demange, Marco Kawamura; Bonadio, Marcelo Batista; Helito, Camilo Partezani; Gobbi, Riccardo Gomes; Pécora, José Ricardo

    2015-01-01

    Distal femoral varus osteotomy is a well-established procedure for the treatment of lateral compartment cartilage lesions and degenerative disease, correcting limb alignment and decreasing the progression of the pathology. Surgical techniques can be performed with a lateral opening-wedge or medial closing-wedge correction of the deformity. Fixation methods for lateral opening-wedge osteotomies are widely available, and there are various types of implants that can be used for fixation. However, there are currently only a few options of implants for fixation of a medial closing-wedge osteotomy on the market. This report describes a medial, supracondylar, V-shaped, closing-wedge distal femoral osteotomy using a locked anterolateral proximal tibial locking plate that fits anatomically to the medial side of the distal femur. This is a great option as a stable implant for a medial closing-wedge distal femoral osteotomy. PMID:26870647

  9. Fixation of 3- and 4-part proximal humerus fractures using the PHILOS plate: mid-term results.

    PubMed

    Gaheer, Rajinder Singh; Hawkins, Amanda

    2010-09-07

    Treatment of unstable, displaced, and comminuted fractures of the proximal humerus remains challenging, and optimal treatment continues to be controversial. Fifty-six patients with displaced 3- and 4-part fractures of the proximal humerus had open reduction and internal fixation using the proximal humeral internal locking system (PHILOS) plate (Synthes, Stratec Medical Ltd, Mezzovico, Switzerland). Data were collected retrospectively, and clinical and radiological outcomes were assessed. Mean follow-up was 40 months (range, 18-62 months). The study shows that the PHILOS plate gives good results in the treatment of displaced 3- and 4-part fractures of the proximal humerus. Good fracture stability can be achieved early, allowing early mobilization without compromising fracture union. Most importantly, it requires minimal soft tissue dissection, does not need contouring, and gives good stability. No differences were observed in the functional outcomes of patients younger and older than 65 years. Few complications were associated with the plate, and the number of ≥2 surgeries was minimal. The complications noted were 1 case each of superficial wound infection, failure of the plate, and persistent stiffness. One patient had screw perforation of the humeral head articular surface, and 1 had subacromial impingement. Of the 32 patients who had been in active employment before the injury, 28 returned to their previous occupation.

  10. Plating versus intramedullary fixation for mid-shaft clavicle fractures: a systemic review and meta-analysis.

    PubMed

    Gao, Yan; Chen, Wei; Liu, Yue-Jv; Li, Xu; Wang, Hai-Li; Chen, Zhao-Yu

    2016-01-01

    Background. Plate fixation and intramedullary fixation are the most commonly used surgical treatment options for mid-shaft clavicle fractures; the latter method has demonstrated better performance in some studies. Objectives. Our aim was to critically review and summarize the literature comparing the outcomes of mid-shaft clavicle fracture treatment with plate fixation or intramedullary fixation to identify the better approach. Search Methods. Potential academic articles were identified from the Cochrane Library, MEDLINE (1966-2015.5), PubMed (1966-2015.5), EMBASE (1980-2015.5) and ScienceDirect (1966-2015.5). Gray studies were identified from the references of the included literature. Selection Criteria. Randomized controlled trials (RCTs) and non-RCTs comparing plate fixation and intramedullary fixation for mid-shaft clavicle fracture were included. Data Collection and Analysis. Two reviewers performed independent data abstraction. The I (2) statistic was used to assess heterogeneity. A fixed- or random-effects model was used for the meta-analysis. Results. Six RCTs and nine non-RCTs were retrieved, including 513 patients in the intramedullary fixation group and 521 patients in the plating group. No significant differences in terms of the union rate and shoulder function were found between the groups. Patients in the intramedullary fixation group had a shorter operative time, less blood loss, smaller wound size, and shorter union time than those in the plating group. With respect to complications, significant differences were identified for all complications and major complications (wound infection, nonunion, implant failures, transient brachial plexopathy, and pain after 6 months). Similar secondary complications (symptomatic hardware, hardware irritation, prominence, numbness, hypertrophic callus) were observed in both groups. Conclusions. Intramedullary fixation may be superior to plate fixation in the treatment of mid-shaft clavicle fractures, with similar

  11. Stoppa Approach for Anterior Plate Fixation in Unstable Pelvic Ring Injury

    PubMed Central

    Choo, Suk Kyu; Kim, Jung-Jae; Lee, Mark

    2016-01-01

    Background The Stoppa (intrapelvic) approach has been introduced for the treatment of pelvic-acetabular fractures; it allows easy exposure of the pelvic brim, where the bone quality is optimal for screw fixation. The purpose of our study was to investigate the surgical outcomes of unstable pelvic ring injuries treated using the Stoppa approach for stable anterior ring fixation. Methods We analyzed 22 cases of unstable pelvic ring injury treated with plate fixation of the anterior ring with the Stoppa approach. We excluded cases of nondisplaced rami fracture, simple symphyseal diastasis, and parasymphyseal fractures, which can be easily treated with other techniques. The average age of the study patients was 41 years (range, 23 to 61 years). There were 10 males and 12 females. According to the Young and Burgess classification, there were 12 lateral compression, 4 anteroposterior compression, and 6 vertical shear fracture patterns. The fracture location on the anterior ring was near the iliopectineal eminence in all cases and exposure of the pelvic brim was required for plate fixation. All patients were placed in the supine position. For anterior plate fixation, all screws were applied to the anterior ramus distally and directed above the hip joint proximally. Radiologic outcomes were assessed by union time and quality of reduction by Matta method. The Merle d'Aubigne-Postel score was used to evaluate the functional results. Results The average radiologic follow-up period was 16 months (range, 10 to 51 months). All fractures united at an average of 3.5 months (range, 3 to 5 months). According to the Matta method, the quality of reduction was classified as follows: 16 anatomical (73%) and 6 nearly anatomical (27%) reductions. There were no cases of screw or implant loosening before bone healing. The functional results were classified as 7 excellent (32%), 12 good (55%), and 3 fair (13%) by the Merle d'Aubigne-Postel score. There were no wound complications

  12. Comparison of palmar fixed-angle plate fixation with K-wire fixation of distal radius fractures (AO A2, A3, C1) in elderly patients.

    PubMed

    Goehre, F; Otto, W; Schwan, S; Mendel, T; Vergroesen, P P; Lindemann-Sperfeld, L

    2014-03-01

    The objective of this prospective, randomized, controlled trial was to compare the results of two operative techniques used for the treatment of unstable distal radius fractures in elderly patients classified as AO types A2, A3, and C1. Patients were treated with either fixed-angle volar plates or K-wires using a combined Kapandji and Willenegger technique. The functional results were determined after 3, 6, and 12 months. We included 40 patients aged over 65 years. Twenty-one patients were treated with plate fixation and 19 with K-wire fixation. The functional results, after 1 year, were nearly the same in both treatment groups, suggesting that either method is suitable for the treatment of unstable distal radius fractures of AO types A2, A3, and C1 in elderly patients. Sixteen of 21 patients with plate fixation and 17 of 19 patients with K-wire fixation present good results as assessed by the Castaing score. The median DASH score was three in both groups after 1 year. The patients with plate fixation were able to resume activities of daily living 4 weeks earlier. The most common complication was an intermediate post-traumatic median nerve irritation. Both methods are suitable for the treatment of elderly patients with unstable distal radius fractures of AO types A2, A3, and C1. If early functional post-operative care is important, palmar fixed-angle plate fixation is an ideal treatment approach. Otherwise, K-wire fixation is an effective, minimally invasive method with comparable clinical results.

  13. The calcar screw in angular stable plate fixation of proximal humeral fractures - a case study

    PubMed Central

    2011-01-01

    Background With new minimally-invasive approaches for angular stable plate fixation of proximal humeral fractures, the need for the placement of oblique inferomedial screws ('calcar screw') has increasingly been discussed. The purpose of this study was to investigate the influence of calcar screws on secondary loss of reduction and on the occurrence of complications. Methods Patients with a proximal humeral fracture who underwent angular stable plate fixation between 01/2007 and 07/2009 were included. On AP views of the shoulder, the difference in height between humeral head and the proximal end of the plate were determined postoperatively and at follow-up. Additionally, the occurrence of complications was documented. Patients with calcar screws were assigned to group C+, patients without to group C-. Results Follow-up was possible in 60 patients (C+ 6.7 ± 5.6 M/C- 5.0 ± 2.8 M). Humeral head necrosis occurred in 6 (C+, 15.4%) and 3 (C-, 14.3%) cases. Cut-out of the proximal screws was observed in 3 (C+, 7.7%) and 1 (C-, 4.8%) cases. In each group, 1 patient showed delayed union. Implant failure or lesions of the axillary nerve were not observed. In 44 patients, true AP and Neer views were available to measure the head-plate distance. There was a significant loss of reduction in group C- (2.56 ± 2.65 mm) compared to C+ (0.77 ± 1.44 mm; p = 0.01). Conclusions The placement of calcar screws in the angular stable plate fixation of proximal humeral fractures is associated with less secondary loss of reduction by providing inferomedial support. An increased risk for complications could not be shown. PMID:21943090

  14. Biomechanical comparison of locking plate and crossing metallic and absorbable screws fixations for intra-articular calcaneal fractures.

    PubMed

    Ni, Ming; Wong, Duo Wai-Chi; Mei, Jiong; Niu, Wenxin; Zhang, Ming

    2016-09-01

    The locking plate and percutaneous crossing metallic screws and crossing absorbable screws have been used clinically to treat intra-articular calcaneal fractures, but little is known about the biomechanical differences between them. This study compared the biomechanical stability of calcaneal fractures fixed using a locking plate and crossing screws. Three-dimensional finite-element models of intact and fractured calcanei were developed based on the CT images of a cadaveric sample. Surgeries were simulated on models of Sanders type III calcaneal fractures to produce accurate postoperative models fixed by the three implants. A vertical force was applied to the superior surface of the subtalar joint to simulate the stance phase of a walking gait. This model was validated by an in vitro experiment using the same calcaneal sample. The intact calcaneus showed greater stiffness than the fixation models. Of the three fixations, the locking plate produced the greatest stiffness and the highest von Mises stress peak. The micromotion of the fracture fixated with the locking plate was similar to that of the fracture fixated with the metallic screws but smaller than that fixated with the absorbable screws. Fixation with both plate and crossing screws can be used to treat intra-articular calcaneal fractures. In general, fixation with crossing metallic screws is preferable because it provides sufficient stability with less stress shielding.

  15. Parallel analysis of finite element model controlled trial and retrospective case control study on percutaneous internal fixation for vertical sacral fractures

    PubMed Central

    2013-01-01

    Background Although percutaneous posterior-ring tension-band metallic plate and percutaneous iliosacral screws are used to fix unstable posterior pelvic ring fractures, the biomechanical stability and compatibility of both internal fixation techniques for the treatment of Denis I, II and III type vertical sacral fractures remain unclear. Methods Using CT and MR images of the second generation of Chinese Digitized Human “male No. 23”, two groups of finite element models were developed for Denis I, II and III type vertical sacral fractures with ipsilateral superior and inferior pubic ramus fractures treated with either a percutaneous metallic plate or a percutaneous screw. Accordingly, two groups of clinical cases that were fixed using the above-mentioned two internal fixation techniques were retrospectively evaluated to compare postoperative effect and function. Parallel analysis was performed with a finite element model controlled trial and a case control study. Results The difference of the postoperative Majeed standards and outcome rates between two case groups was no statistically significant (P > 0.05). Accordingly, the high values of the maximum displacements/stresses of the plate-fixation model group approximated those of the screw-fixation model group. However, further simulation of Denis I, II and III type fractures in each group of models found that the biomechanics of the plate-fixation models became increasingly stable and compatible, whereas the biomechanics of the screw-fixation models maintained tiny fluctuations. When treating Denis III fractures, the biomechanical effects of the pelvic ring of the plate-fixation model were better than the screw-fixation model. Conclusions Percutaneous plate and screw fixations are both appropriate for the treatment of Denis I and II type vertical sacral fractures; whereas percutaneous plate fixation appears be superior to percutaneous screw fixation for Denis III type vertical sacral fracture. Biomechanical

  16. Clinical Use of 3D Printing Guide Plate in Posterior Lumbar Pedicle Screw Fixation.

    PubMed

    Chen, Hongliang; Wu, Dongying; Yang, Huilin; Guo, Kaijin

    2015-01-01

    BACKGROUND This study aimed to evaluate the clinical efficacy of use of a 3D printing guide plate in posterior lumbar pedicle screw fixation. MATERIAL AND METHODS We enrolled 43 patients receiving posterior lumbar pedicle screw fixation. The experimental group underwent 3D printing guide plate-assisted posterior lumbar pedicle screw fixation, while the control group underwent traditional x-ray-assisted posterior lumbar pedicle screw fixation. After surgery, CT scanning was done to evaluate the accuracy of screw placement according to the Richter standard. RESULTS All patients were followed up for 1 month. The mean time of placement for each screw and the amount of hemorrhage was 4.9±2.1 min and 8.0±11.1 mL in the experimental group while 6.5±2.2 min and 59.9±13.0 mL in the control group, respectively, with significant differences (p<0.05). The fluoroscopy times of each screw placement was 0.5±0.4 in the experimental group, which was significantly lower than that in the control group 1.2±0.7 (p<0.05). The excellent and good screw placement rate was 100% in the experimental group and 98.4% in the control group, without any statistical difference (P>0.05). No obvious complications were reported in either group. CONCLUSIONS Compared with the traditional treatment methods, the intra-operative application of 3D printing guide plate can shorten the operation time and reduce the amount of hemorrhage. It can also reduce the fluoroscopy times compared with the traditional fluoroscopy, which cannot improve the accuracy rate of screw placement. PMID:26681388

  17. Clinical Use of 3D Printing Guide Plate in Posterior Lumbar Pedicle Screw Fixation

    PubMed Central

    Chen, Hongliang; Wu, Dongying; Yang, Huilin; Guo, Kaijin

    2015-01-01

    Background This study aimed to evaluate the clinical efficacy of use of a 3D printing guide plate in posterior lumbar pedicle screw fixation. Material/Methods We enrolled 43 patients receiving posterior lumbar pedicle screw fixation. The experimental group underwent 3D printing guide plate-assisted posterior lumbar pedicle screw fixation, while the control group underwent traditional x-ray-assisted posterior lumbar pedicle screw fixation. After surgery, CT scanning was done to evaluate the accuracy of screw placement according to the Richter standard. Results All patients were followed up for 1 month. The mean time of placement for each screw and the amount of hemorrhage was 4.9±2.1 min and 8.0±11.1 mL in the experimental group while 6.5±2.2 min and 59.9±13.0 mL in the control group, respectively, with significant differences (p<0.05). The fluoroscopy times of each screw placement was 0.5±0.4 in the experimental group, which was significantly lower than that in the control group 1.2±0.7 (p<0.05). The excellent and good screw placement rate was 100% in the experimental group and 98.4% in the control group, without any statistical difference (P>0.05). No obvious complications were reported in either group. Conclusions Compared with the traditional treatment methods, the intra-operative application of 3D printing guide plate can shorten the operation time and reduce the amount of hemorrhage. It can also reduce the fluoroscopy times compared with the traditional fluoroscopy, which cannot improve the accuracy rate of screw placement. PMID:26681388

  18. Clinical Use of 3D Printing Guide Plate in Posterior Lumbar Pedicle Screw Fixation.

    PubMed

    Chen, Hongliang; Wu, Dongying; Yang, Huilin; Guo, Kaijin

    2015-12-18

    BACKGROUND This study aimed to evaluate the clinical efficacy of use of a 3D printing guide plate in posterior lumbar pedicle screw fixation. MATERIAL AND METHODS We enrolled 43 patients receiving posterior lumbar pedicle screw fixation. The experimental group underwent 3D printing guide plate-assisted posterior lumbar pedicle screw fixation, while the control group underwent traditional x-ray-assisted posterior lumbar pedicle screw fixation. After surgery, CT scanning was done to evaluate the accuracy of screw placement according to the Richter standard. RESULTS All patients were followed up for 1 month. The mean time of placement for each screw and the amount of hemorrhage was 4.9±2.1 min and 8.0±11.1 mL in the experimental group while 6.5±2.2 min and 59.9±13.0 mL in the control group, respectively, with significant differences (p<0.05). The fluoroscopy times of each screw placement was 0.5±0.4 in the experimental group, which was significantly lower than that in the control group 1.2±0.7 (p<0.05). The excellent and good screw placement rate was 100% in the experimental group and 98.4% in the control group, without any statistical difference (P>0.05). No obvious complications were reported in either group. CONCLUSIONS Compared with the traditional treatment methods, the intra-operative application of 3D printing guide plate can shorten the operation time and reduce the amount of hemorrhage. It can also reduce the fluoroscopy times compared with the traditional fluoroscopy, which cannot improve the accuracy rate of screw placement.

  19. Comparison of outcome of tibial plafond fractures managed by hybrid external fixation versus two-stage management with final plate fixation

    PubMed Central

    Cisneros, Luis Natera; Gómez, Mireia; Alvarez, Carlos; Millán, Angélica; De Caso, Julio; Soria, Laura

    2016-01-01

    Background: Tibial platfond fractures are usually associated with massive swelling of the foot and ankle, as well as with open wounds. This swelling may cause significant decrease of the blood flow, so the state of the soft tissue is determinant for the surgical indication and the type of implant. This retrospective study compares the union times in cases of tibial plafond fractures managed with a hybrid external fixation as a definitive procedure versus those managed with a two stage strategy with final plate fixation. Materials and Methods: A retrospective study in a polytrauma referral hospital was performed between 2005 and 2011. Patients with a tibial plafond fracture, managed with a hybrid external fixation as a definitive procedure or managed with a two stage strategy with the final plate fixation were included in the study. Postoperative radiographs were evaluated by two senior surgeons. Fracture healing was defined as callus bridging of one cortex, seen on both lateral and anteroposterior X-ray. The clinical outcome was evaluated by means of 11 points Numerical Rating Scale for pain and The American Orthopedic Foot and Ankle Society ankle score, assessed at the last followup visit. Thirteen patients had been managed with a hybrid external fixation and 18 with a two-stage strategy with the final plate fixation. There were 14 males and 17 females with a mean age of 48 years (range 19–82 years). The mean followup was 24 months (range 24–70 months). Results: The mean time from surgery to weight bearing was 7 ± 6.36 days for the hybrid fixation group and 57.43 ± 15.46 days for the plate fixation group (P < 0.0001); and the mean time from fracture to radiological union was 133.82 ± 37.83) and 152.8 ± 72.33 days respectively (P = 0.560). Conclusion: Besides the differences between groups regarding the baseline characteristics of patients, the results of this study suggest that in cases of tibial plafond fractures, the management with a hybrid external

  20. A Pitfall in Fixation of Distal Humeral Fractures with Pre-Contoured Locking Compression Plate

    PubMed Central

    Jayakumar, Prakash; Ring, David

    2015-01-01

    Anatomically precontoured locking plates are intended to facilitate the fixation of articular fractures and particularly those associated with osteoporosis. Fractures of the distal humerus are relatively uncommon injuries where operative intervention can be exceptionally challenging. The distal humeral trochlea provides a very narrow anatomical window through which to pass a fixed-angle locking screw, which must also avoid the olecranon, coronoid, and radial fossae. We describe 3 patients (ages 27, 49, and 73 years) with a bicolumnar fracture of the distal humerus where very short distal locking screws were used. Intra-articular screw placement was avoided but loss of fixation occurred in two patients and a third was treated with a prolonged period of immobilization. We postulate that fixed-angle screw trajectories may make it difficult for the surgeon to place screws of adequate length in this anatomically confined region, and may lead to insufficient distal fixation. Surgical tactics should include placement of as many screws as possible into the distal fragment, as long as possible and that each screw passes through a plate without necessarily locking in. PMID:26110181

  1. Locking plate fixation of distal femoral fractures is a challenging technique: a retrospective review

    PubMed Central

    Toro, Giuseppe; Calabrò, Giampiero; Toro, Antonio; de Sire, Alessandro; Iolascon, Giovanni

    2015-01-01

    Summary Distal femoral fractures have typically a bimodal occurrence: in young people due to a high-energy trauma and in older people related to a low-energy trauma. These fractures are associated to a very high morbidity and mortality in elderly. Distal femoral fractures might be treated with plates, intramedullary nails, external fixations, and prosthesis. However, difficulties in fracture healing and the rate of complications are important clinical issues. The purpose of this retrospective review was to present our experience in treatment of distal femoral fracture in a sample of older people in order to evaluate the technical pitfalls and strategies used to face up the fractures unsuccessfully treated with locking plates. We included people aged more than 65 years, with a diagnosis of distal femoral fracture, treated with locking plates. We considered ‘unsuccessfully treated’ the cases with healing problems or hardware failures. Of the 12 patients (9 females and 3 males; mean aged 68.75 ± 3.31 years) included, we observed 3 ‘unsuccessfully cases’, 2 due to nonunions and 1 due to an early hardware failure, all treated using a condylar blade plate with a bone graft. One patient obtained a complete fracture healing after 1 year and in the other cases there was a nonunion. We observed as most common technical pitfalls: inadequate plate lengthening, fracture bridging, and number of locking screws. The use of locking plates is an emerging technique to treat these fractures but it seems more challenging than expected. In literature there is a lack of evidences about the surgical management of distal femoral fractures that is still an important challenge for the orthopaedic surgeon that has to be able to use all the fixation devices available. PMID:27134634

  2. Mechanical testing of a device for subcutaneous internal anterior pelvic ring fixation versus external pelvic ring fixation

    PubMed Central

    2014-01-01

    Background Although useful in the emergency treatment of pelvic ring injuries, external fixation is associated with pin tract infections, the patient’s limited mobility and a restricted surgical accessibility to the lower abdomen. In this study, the mechanical stability of a subcutaneous internal anterior fixation (SIAF) system is investigated. Methods A standard external fixation and a SIAF system were tested on pairs of Polyoxymethylene testing cylinders using a universal testing machine. Each specimen was subjected to a total of 2000 consecutive cyclic loadings at 1 Hz with sinusoidal lateral compression/distraction (+/−50 N) and torque (+/− 0.5 Nm) loading alternating every 200 cycles. Translational and rotational stiffness were determined at 100, 300, 500, 700 and 900 cycles. Results There was no significant difference in translational stiffness between the SIAF and the standard external fixation when compared at 500 (p = .089), 700 (p = .081), and 900 (p = .266) cycles. Rotational stiffness observed for the SIAF was about 50 percent higher than the standard external fixation at 300 (p = .005), 500 (p = .020), and 900 (p = .005) cycles. No loosening or failure of the rod-pin/rod-screw interfaces was seen. Conclusions In comparison with the standard external fixation system, the tested device for subcutaneous internal anterior fixation (SIAF) in vitro has similar translational and superior rotational stiffness. PMID:24684828

  3. Biomechanical comparison of straight and helical compression plates for fixation of transverse and oblique bone fractures: Modeling and experiments.

    PubMed

    Sezek, Sinan; Aksakal, Bunyamin; Gürger, Murat; Malkoc, Melih; Say, Y

    2016-08-12

    Total deformation and stability of straight and helical compression plates were studied by means of the finite element method (FEM) and in vitro biomechanical experiments. Fixations of transverse (TF) and oblique (45°) bone (OF) fractures have been analyzed on sheep tibias by designing the straight compression (SP) and Helical Compression Plate (HP) models. The effects of axial compression, bending and torsion loads on both plating systems were analyzed in terms of total displacements. Numerical models and experimental models suggested that under compression loadings, bone fracture gap closures for both fracture types were found to be in the favor of helical plate designs. The helical plate (HP) fixations provided maximum torsional resistance compared to the (SP) fixations. The fracture gap closure and stability of helical plate fixation for transverse fractures was determined to be higher than that found for the oblique fractures. The comparison of average compression stress, bending and torsion moments showed that the FEM and experimental results are in good agreement and such designs are likely to have a positive impact in future bone fracture fixation designs.

  4. Biomechanical comparison of straight and helical compression plates for fixation of transverse and oblique bone fractures: Modeling and experiments.

    PubMed

    Sezek, Sinan; Aksakal, Bunyamin; Gürger, Murat; Malkoc, Melih; Say, Y

    2016-08-12

    Total deformation and stability of straight and helical compression plates were studied by means of the finite element method (FEM) and in vitro biomechanical experiments. Fixations of transverse (TF) and oblique (45°) bone (OF) fractures have been analyzed on sheep tibias by designing the straight compression (SP) and Helical Compression Plate (HP) models. The effects of axial compression, bending and torsion loads on both plating systems were analyzed in terms of total displacements. Numerical models and experimental models suggested that under compression loadings, bone fracture gap closures for both fracture types were found to be in the favor of helical plate designs. The helical plate (HP) fixations provided maximum torsional resistance compared to the (SP) fixations. The fracture gap closure and stability of helical plate fixation for transverse fractures was determined to be higher than that found for the oblique fractures. The comparison of average compression stress, bending and torsion moments showed that the FEM and experimental results are in good agreement and such designs are likely to have a positive impact in future bone fracture fixation designs. PMID:27567775

  5. LCP distal ulna hook plate as alternative fixation for fifth metatarsal base fracture.

    PubMed

    Lee, Sang Ki; Park, Ju Sang; Choy, Won Sik

    2013-08-01

    Intramedullary screw fixation is the most common treatment for fifth metatarsal base fractures. Screw application does not achieve accurate reduction in fracture with small fragments, osteoporotic bone, or Lawrence zone 1 fractures, however. On the basis of similar anatomical architectures between the distal ulna and the fifth metatarsal base, the purpose of this study was to assess the results of a locking compression plate (LCP) distal ulna hook plate in stabilizing displaced zone 1 or 2 fifth metatarsal base fractures. Nineteen patients with Lawrence zone 1 (n = 12) or 2 (n = 7) fractures of the fifth metatarsal base were treated surgically with an LCP distal ulna hook plate. The patients were evaluated clinically and radiographically, and functional outcomes were graded by using the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot scoring system. Radiographic bony union was obtained in all patients, at an average of 7.4 weeks. The mean AOFAS midfoot score improved from 26 (range, 0-45) preoperatively to 94 (range, 72-100) points at the final follow-up. There were three patients with post-traumatic cubometatarsal arthrosis and one patient with sural nerve neuropraxia. In our experience, the distal ulna hook plate achieves a high rate of bony consolidation and anatomically suitable fixation in zone 1 or 2 fifth metatarsal base fractures. We also suggest that the LCP distal ulna hook plate should be considered as an alternative treatment in multifragmentary, osteoporotic, and tuberosity avulsion (zone 1) fifth metatarsal base fractures.

  6. Managing Vancouver B1 fractures by cerclage system compared to locking plate fixation - a biomechanical study.

    PubMed

    Gordon, Katharina; Winkler, Martin; Hofstädter, Thomas; Dorn, Ulrich; Augat, Peter

    2016-06-01

    With increasing life expectancy and number of total hip arthroplasties (THA), the need for revision surgery is increasing too. The aim of this study was to evaluate the optimal fracture treatment for a clinically characteristic Vancouver B1 fracture. We hypothesized that locking plate fixation has biomechanical advantages over fixation with a simple cerclage system. Additionally, we hypothesized that removal of the primary short stem and revision with a long stem would show biomechanical benefit. The biomechanical testing was performed with a static and a dynamic loading protocol on twenty 4th Generation sawbones. These were divided into four different groups (n = 5 each). In group 1, the primary uncemented short stem remained and the fracture was stabilized with a locking plate. In group 2, the primary stem remained and the fracture was stabilized with a cerclage stabilization system containing two stabilizers and four cerclages. In group 3, the primary stem was replaced by an uncemented long revision stem and the fracture was fixed with a locking plate. In group 4, the short stem was replaced by a long revision stem and the fracture was fixed with the cerclage system. Static testing revealed that the revision of the short stem with the long stem caused a 2-fold (p < 0.001, ANOVA) increase of axial stiffness. In dynamic testing, the number of cycles to failure was 4 times (p < 0.001, ANOVA) higher with the long revision stem. Compared to locked plating cerclage wiring demonstrated a 26% more cycles to failure (p = 0.031, ANOVA). The load to failure was 91% larger (p < 0.001, ANOVA) with the long revision stem and 11% smaller with locked plating (p < 0.001, ANOVA). In conclusion, the present biomechanical study indicates that periprosthetic Vancouver B1 fractures can be sufficiently fixed by simple cerclage systems. Revision with a long replacement stem provides a superior mechanical stability regardless of type of osteosynthesis fixation and is therefore a viable

  7. Biomechanical testing of the LCP--how can stability in locked internal fixators be controlled?

    PubMed

    Stoffel, Karl; Dieter, Ulrich; Stachowiak, Gwidon; Gächter, André; Kuster, Markus S

    2003-11-01

    New plating techniques, such as non-contact plates, have been introduced in acknowledgment of the importance of biological factors in internal fixation. Knowledge of the fixation stability provided by these new plates is very limited and clarification is still necessary to determine how the mechanical stability, e.g. fracture motion, and the risk of implant failure can best be controlled. The results of a study based on in vitro experiments with composite bone cylinders and finite element analysis using the Locking Compression Plate (LCP) for diaphyseal fractures are presented and recommendations for clinical practice are given. Several factors were shown to influence stability both in compression and torsion. Axial stiffness and torsional rigidity was mainly influenced by the working length, e.g. the distance of the first screw to the fracture site. By omitting one screw hole on either side of the fracture, the construct became almost twice as flexible in both compression and torsion. The number of screws also significantly affected the stability, however, more than three screws per fragment did little to increase axial stiffness; nor did four screws increase torsional rigidity. The position of the third screw in the fragment significantly affected axial stiffness, but not torsional rigidity. The closer an additional screw is positioned towards the fracture gap, the stiffer the construct becomes under compression. The rigidity under torsional load was determined by the number of screws only. Another factor affecting construct stability was the distance of the plate to the bone. Increasing this distance resulted in decreased construct stability. Finally, a shorter plate with an equal number of screws caused a reduction in axial stiffness but not in torsional rigidity. Static compression tests showed that increasing the working length, e.g. omitting the screws immediately adjacent to the fracture on both sides, significantly diminished the load causing plastic

  8. Influence of internal fixation systems on radiation therapy for spinal tumor.

    PubMed

    Li, Jingfeng; Yan, Lei; Wang, Jianping; Cai, Lin; Hu, Dongcai

    2015-07-08

    In this study, the influence of internal fixation systems on radiation therapy for spinal tumor was investigated in order to derive a theoretical basis for adjustment of radiation dose for patients with spinal tumor and internal fixation. Based on a common method of internal fixation after resection of spinal tumor, different models of spinal internal fixation were constructed using the lumbar vertebra of fresh domestic pigs and titanium alloy as the internal fixation system. Variations in radiation dose in the vertebral body and partial spinal cord in different types of internal fixation were studied under the same radiation condition (6 MV and 600 mGy) in different fixation models and compared with those irradiated based on the treatment planning system (TPS). Our results showed that spinal internal fixation materials have great impact on the radiation dose absorbed by spinal tumors. Under the same radiation condition, the influence of anterior internal fixation material or combined anterior and posterior approach on radiation dose at the anterior border of the vertebral body was the greatest. Regardless of the kinds of internal fixation method employed, radiation dose at the anterior border of the vertebral body was significantly different from that at other positions. Notably, the influence of posterior internal fixation material on the anterior wall of the vertebral canal was the greatest. X-ray attenuation and scattering should be taken into consideration for most patients with bone metastasis that receive fixation of metal implants. Further evaluation should then be conducted with modified TPS in order to minimize the potentially harmful effects of inappropriate radiation dose.

  9. Mechanical analysis of a rodent segmental bone defect model: the effects of internal fixation and implant stiffness on load transfer.

    PubMed

    Yavari, S Amin; van der Stok, J; Ahmadi, S M; Wauthle, R; Schrooten, J; Weinans, H; Zadpoor, A A

    2014-08-22

    Segmental bone defect animal models are often used for evaluating the bone regeneration performance of bone substituting biomaterials. Since bone regeneration is dependent on mechanical loading, it is important to determine mechanical load transfer after stabilization of the defect and to study the effects of biomaterial stiffness on the transmitted load. In this study, we assess the mechanical load transmitted over a 6mm femur defect that is stabilized with an internal PEEK fixation plate. Subsequently, three types of selective laser melted porous titanium implants with different stiffness values were used to graft the defect (five specimens per group). In one additional group, the defect was left empty. Micro strain gauges were used to measure strain values at four different locations of the fixation plate during external loading on the femoral head. The load sharing between the fixation plate and titanium implant was highly variable with standard deviations of measured strain values between 31 and 93% of the mean values. As a consequence, no significant differences were measured between the forces transmitted through the titanium implants with different elastic moduli. Only some non-significant trends were observed in the mean strain values that, consistent with the results of a previous finite element study, implied the force transmitted through the implant increases with the implant stiffness. The applied internal fixation method does not standardize mechanical loading over the defect to enable detecting small differences in bone regeneration performances of bone substituting biomaterials. In conclusion, the fixation method requires further optimization to reduce the effects of the operative procedure and make the mechanical loading more consistent and improve the overall sensitivity of this rat femur defect model.

  10. Opening wedge osteotomies for correction of hallux valgus: a review of wedge plate fixation.

    PubMed

    Smith, W Bret; Hyer, Christopher F; DeCarbo, William T; Berlet, Gregory C; Lee, Thomas H

    2009-12-01

    Osteotomy of the proximal metatarsal for the correction of moderate to severe hallux valgus deformity is commonly performed. The purpose of this study is to review the early results of a technique for the correction of hallux valgus, an opening wedge osteotomy of the proximal first metatarsal with opening wedge plate fixation. A review was performed of the results of 47 patients (49 feet) who underwent correction of hallux valgus with proximal metatarsal opening wedge osteotomy. All osteotomies were secured with plate fixation on the medial side. Evaluation consisted of preoperative and postoperative radiographic as well as clinical evaluations. Mean corrections of 7 degrees were achieved for the 1-2 intermetatarsal angles. Fourteen complications occurred, 6 of which involved mild hardware irritation and did not affect outcome. Four nonunions or delayed unions were identified. The authors find the opening wedge osteotomy of the proximal first metatarsal to be a technically straightforward procedure for correcting moderate to severe hallux valgus. The correction obtained is comparable to other described techniques. PMID:20400425

  11. Medial Calcar Support and Radiographic Outcomes of Plate Fixation for Proximal Humeral Fractures

    PubMed Central

    Lin, Shih-Jie; Tsai, Yao-Hung; Yang, Tien-Yu; Shen, Shih-Hsun; Huang, Kuo-Chin; Lee, Mel S.

    2015-01-01

    Plate fixation remains one of the most popular surgical procedures for treating proximal humeral fractures (PHFx); however, substantial rates of complications have been reported in the literature. The objectives of the study were to examine how medial calcar support (MCS) affects the radiographic outcomes and to determine the prognostic factors predicting treatment failure. We performed a retrospective cohort study of 89 adult patients who had PHFx and were treated with plate fixation at our institution in 2007–2011. The enrolled patients were separated into two groups according to disruption of medial calcar. Our results revealed an increased rate of poor radiographic outcomes in patients with disrupted medial calcar. Osteonecrosis of the humeral head and redisplacement were the two radiographic outcomes which had a positive causality with disruption of medial calcar (P = 0.008 and 0.050, resp.). Deficient medial calcar, inadequate reduction, diabetes mellitus, chronic kidney disease, and chronic liver disease were all significant predictors for the development of osteonecrosis in patients after PHFx surgery. Inadequate reduction was also a predictor for redisplacement. We confirmed that the restoration of medial calcar as well as comorbid conditions plays key roles in treatment of patients having PHFx with disrupted medial calcar. PMID:25692132

  12. Lateral fixation of AO type-B2 ankle fractures in the elderly: the Knowles pin versus the plate

    PubMed Central

    Huang, Hui-Ling; Lo, Ting-Ying; Huang, Chien-Rae

    2006-01-01

    The study was a retrospective evaluation and comparison. Seventy-five elderly patients (>50 years) with AO type-B2 ankle fractures were treated by open reduction and internal fixation. All patients were followed up retrospectively for at least 12 months. The 75 patients were divided into two groups, based on the method of treatment. The Knowles pin (KP) group included 45 patients with an average age of 62.7 years. The tubular plate (TP) group included 30 patients with an average age of 60.0 years. The clinical results were compared between the two groups. Both of the groups were similar in respect to the injury mechanisms, fracture pattern, open fracture grade, compounding medical conditions, and ankle score (all P values <0.28). However, the KP group had significantly smaller wound incisions, shorter surgery time, shorter hospital stay, less meperidine use, less symptomatic hardware, and lower complication rates than the TP group (all P values <0.03). In conclusion, lateral fixation of AO type-B2 ankle fractures in the elderly by the Knowles pin is recommended due to its simplicity, efficacy and low complication rate. PMID:17043861

  13. Use of a Locked Fibular Plate for Fixation of a Vertical Shear Medial Malleolus Fracture: A Case Report.

    PubMed

    Blake, Sean; Yakubek, George; Shaer, James

    2015-01-01

    Vertical shear fractures of the medial malleolus are less common than transverse fractures. These fractures are often treated with lag screws, posteromedial buttress plating, antiglide plates, and neutralization plates with screws. We report on a 37-year-old male who had fractured his ankle after tripping and falling into a ditch. Initially, the patient was treated with closed reduction and a splint for a trimalleolar fracture with a laterally subluxed talus. However, on review of his preoperative radiographs and computed tomography studies, we confirmed a medial malleolus fracture with a vertical shear pattern and communition. Recently, a contoured fibular locking plate has been developed. We considered this plate to be effective for containing the bone in part because of its broader plate design. We present a case in which a fibular locking plate was used successfully as a neutralization plate as an alternative fixation method for a vertical shear medial malleolar fracture. PMID:26253474

  14. Biomechanical analysis of the acetabular buttress-plate: are complex acetabular fractures in the quadrilateral area stable after treatment with anterior construct plate-1/3 tube buttress plate fixation?

    PubMed Central

    Wu, Yong-De; Cai, Xian-Hua; Liu, Xi-Ming; Zhang, Hong-Xi

    2013-01-01

    OBJECTIVE: The acetabular buttress-plate has been widely used in treating difficult cases with satisfying clinical results. However, the biomechanical properties of a postoperative acetabular fracture fixed by the buttress-plate are not clear. The purpose of this study was to evaluate the biomechanical properties of stability after the anterior tube buttress-plate fixation of complex acetabular fractures in the quadrilateral area. METHODS: A construct was proposed based on anterior construct plate - 1/3 tube buttress plate fixation for acetabular both-column fractures. Two groups of six formalin-preserved cadaveric pelvises were analyzed: (1) group A, the normal pelvis and (2) group B, anterior construct plate-1/3 tube buttress plate with quadrilateral area fixation. The displacements were measured, and cyclical loads were applied in both standing and sitting simulations. RESULTS: As the load was added, the displacements were Aplate - 1/3 tube buttress plate fixation provided a better stable construct for early sitting. The standing mode yielded more significant differences between the groups. Placing a 1/3 tube buttress-plate via an anterior approach is a novel method of providing quadrilateral area support in this setting. PMID:23917670

  15. Comminuted olecranon fracture fixation with pre-contoured plate: Comparison of composite and cadaver bones

    PubMed Central

    Hamilton Jr, David A; Reilly, Danielle; Wipf, Felix; Kamineni, Srinath

    2015-01-01

    AIM: To determine whether use of a precontoured olecranon plate provides adequate fixation to withstand supraphysiologic force in a comminuted olecranon fracture model. METHODS: Five samples of fourth generation composite bones and five samples of fresh frozen human cadaveric left ulnae were utilized for this study. The cadaveric specimens underwent dual-energy X-ray absorptiometry (DEXA) scanning to quantify the bone quality. The composite and cadaveric bones were prepared by creating a comminuted olecranon fracture and fixed with a pre-contoured olecranon plate with locking screws. Construct stiffness and failure load were measured by subjecting specimens to cantilever bending moments until failure. Fracture site motion was measured with differential variable resistance transducer spanning the fracture. Statistical analysis was performed with two-tailed Mann-Whitney-U test with Monte Carlo Exact test. RESULTS: There was a significant difference in fixation stiffness and strength between the composite bones and human cadaver bones. Failure modes differed in cadaveric and composite specimens. The load to failure for the composite bones (n = 5) and human cadaver bones (n = 5) specimens were 10.67 nm (range 9.40-11.91 nm) and 13.05 nm (range 12.59-15.38 nm) respectively. This difference was statistically significant (P ˂ 0.007, 97% power). Median stiffness for composite bones and human cadaver bones specimens were 5.69 nm/mm (range 4.69-6.80 nm/mm) and 7.55 nm/mm (range 6.31-7.72 nm/mm). There was a significant difference for stiffness (P ˂ 0.033, 79% power) between composite bones and cadaveric bones. No correlation was found between the DEXA results and stiffness. All cadaveric specimens withstood the physiologic load anticipated postoperatively. Catastrophic failure occurred in all composite specimens. All failures resulted from composite bone failure at the distal screw site and not hardware failure. There were no catastrophic fracture failures in the cadaveric

  16. Locking plate versus retrograde intramedullary nail fixation for tibiotalocalcaneal arthrodesis: A retrospective analysis

    PubMed Central

    Zhang, Chi; Shi, Zhongmin; Mei, Guohua

    2015-01-01

    Background: Tibiotalocalcaneal arthrodesis (TTCA) surgery is indicated for the end-stage disease of the tibiotalar and subtalar joints. Although different fixation technique of TTCA has been proposed to achieve high fusion rate and low complication rate, there is still no consensus upon this point. The purpose of this study is to compare the clinical efficacy of retrograde intramedullary nail fixation (RINF) and locking plate fixation (LPF) for TTCA. Materials and Methods: Fifty four patients who underwent TTCA through the lateral approach with lateral fibular osteotomy using RINF (32 patients, 18 male/14 female, mean age: 48) or LPF (22 patients, 12 male/10 female, mean age: 51) between January 2007 and January 2010 were retrospectively analyzed. Demographic and clinical characteristics, surgery (operation time, blood loss) outcomes (postoperative fusion rates, visual analog scale and foot and ankle surgery score and complications) were compared. Results: The LPF group had a shorter operation time (72.3 ± 9.2 vs. 102.8 ± 11.1 min, P < 0.001), less blood loss (75.9 ± 20.2 vs. 140.0 ± 23.8 ml, P < 0.001) and less intraoperative fluoroscopy sessions (3.6 ± 0.9 vs. 8.4 ± 1.3, P < 0.001) than the RINF group. Patients were followed up for 12–24 months (mean of 16.2 months). Both groups had similar postoperative fusion rates (90.6% and 95.4%) and the LPF group showed a nonsignificant lower complication rate (18.2% vs. 28.1% respectively). Patients at higher risk on nonunion due to rheumatoid diseases may have a lower nonunion rate with LPF than RINF (one out of eight vs. three out of nine, P < 0.001). Conclusions: The LPF for TTCA was simpler to perform compared with RINF, but with similar postoperative outcomes and complication rates. PMID:26015614

  17. Treatment of unstable distal radius fractures: non-invasive dynamic external fixator versus volar locking plate – functional and radiological outcome in a prospective case-controlled series

    PubMed Central

    Bajwa, Ali S.; Rammappa, Manju; Lee, Ling; Nanda, Rajesh

    2015-01-01

    Introduction: Distal radius fracture (DRF) is a common injury and various treatment modalities including open reduction and internal fixation (ORIF) with volar locking plate are available. More recently, a non-invasive external fixator has been used. Aims: To prospectively compare the use of a non-invasive external fixator with early dynamisation for DRF against ORIF with volar locking plate control group. Methods: Consecutive patients with closed DRF were included in a prospective case-controlled study. Patients were assigned to non-invasive external fixator or ORIF. Minimum follow-up was two years. Follow-up was at weeks 2, 4, 6, 8, 12, 26 and at one and two-year post-operatively. The outcome measures included demographic details, injury mechanism, AO fracture type, risk factors, body mass index (BMI), ulnar styloid fracture and dorsal comminution, radiographs, grip strength and DASH score. Results: Consecutive 50 patients were treated either with non-invasive external fixator (25/50) or with ORIF (25/50) and the mean age of the two groups was 53 years (SD 17.1) and 49 years (SD 19.5), respectively. Demographics were matched in two groups. In the non-invasive external fixator group, there were 10 AO Type-A, 5 Type-B and 10 Type-C fractures. The ORIF group included 8 Type-A, 6 Type-B and 11 Type-C fractures. The mean DASH score at three-months and one-year post-injury in non-invasive fixator group was 12.2 (SD 3.1) and 3.5 (SD 0.7), respectively, significantly greater than those of ORIF group 14.5 (SD 5.6) and 11.2 (SD 4.4), respectively (p < 0.05). Conclusion: DRF treated with non-invasive external fixator can give functional results superior to ORIF at three-months and the trend is maintained at one and two-year post-operatively. PMID:27163089

  18. An in vivo evaluation of PLLA/PLLA-gHA nano-composite for internal fixation of mandibular bone fractures.

    PubMed

    Peng, Weihai; Zheng, Wei; Shi, Kai; Wang, Wangshu; Shao, Ying; Zhang, Duo

    2015-11-09

    Internal fixation of bone fractures using biodegradable poly(L-lactic-acid) (PLLA)-based materials has attracted the attention of many researchers. In the present study, 36 male beagle dogs were randomly assigned to two groups: PLLA/PLLA-gHA (PLLA-grafted hydroxyapatite) group and PLLA group. PLLA/PLLA-gHA and PLLA plates were embedded in the muscular bags of the erector spinae and also implanted to fix mandibular bone fractures in respective groups. At 1, 2, 3, 6, 9, and 12 months postoperatively, the PLLA/PLLA-gHA and PLLA plates were evaluated by adsorption and degradation tests, and the mandibles were examined through radiographic analysis, biomechanical testing, and histological analysis. The PLLA/PLLA-gHA plates were non-transparent and showed a creamy white color, and the PLLA plates were transparent and faint yellow in color. At all time points following surgery, adsorption and degradation of the PLLA/PLLA-gHA plates were significantly less than those of the PLLA plates, and the lateral and longitudinal bending strengths of the surgically treated mandibles of the beagle dogs in the PLLA/PLLA-gHA group were significantly greater than those of the PLLA group and reached almost the value of intact mandibles at 12 months postoperatively. Additionally, relatively rapid bone healing was observed in the PLLA/PLLA-gHA group with the formation of new lamellar bone tissues at 12 months after the surgery. The PLLA/PLLA-gHA nano-composite can be employed as a biodegradable material for internal fixation of mandibular bone fractures.

  19. An in vivo evaluation of PLLA/PLLA-gHA nano-composite for internal fixation of mandibular bone fractures.

    PubMed

    Peng, Weihai; Zheng, Wei; Shi, Kai; Wang, Wangshu; Shao, Ying; Zhang, Duo

    2015-12-01

    Internal fixation of bone fractures using biodegradable poly(L-lactic-acid) (PLLA)-based materials has attracted the attention of many researchers. In the present study, 36 male beagle dogs were randomly assigned to two groups: PLLA/PLLA-gHA (PLLA-grafted hydroxyapatite) group and PLLA group. PLLA/PLLA-gHA and PLLA plates were embedded in the muscular bags of the erector spinae and also implanted to fix mandibular bone fractures in respective groups. At 1, 2, 3, 6, 9, and 12 months postoperatively, the PLLA/PLLA-gHA and PLLA plates were evaluated by adsorption and degradation tests, and the mandibles were examined through radiographic analysis, biomechanical testing, and histological analysis. The PLLA/PLLA-gHA plates were non-transparent and showed a creamy white color, and the PLLA plates were transparent and faint yellow in color. At all time points following surgery, adsorption and degradation of the PLLA/PLLA-gHA plates were significantly less than those of the PLLA plates, and the lateral and longitudinal bending strengths of the surgically treated mandibles of the beagle dogs in the PLLA/PLLA-gHA group were significantly greater than those of the PLLA group and reached almost the value of intact mandibles at 12 months postoperatively. Additionally, relatively rapid bone healing was observed in the PLLA/PLLA-gHA group with the formation of new lamellar bone tissues at 12 months after the surgery. The PLLA/PLLA-gHA nano-composite can be employed as a biodegradable material for internal fixation of mandibular bone fractures. PMID:26551378

  20. Diagnosis and rehabilitation of deep wound infection and internal fixation rejection in elbow

    PubMed Central

    Lu, Huiping; Song, Lin; Lin, Ying

    2016-01-01

    Abstract This study aims at diagnosis and rehabilitation of a rare case of deep wound infection and internal fixation rejection in elbow. The patient sustained a distal fracture in the humerus 1 year ago, which was internal fixed. The wound always effused and the elbow had pain and swelling; joint motion was limited. Blood sedimentation rate and C reactive protein level increased, bacterial culture suggested deep wound infection, and ultrasound indicated inflammation. The main diagnoses were deep wound infection and internal fixation rejection. Therapeutics interventions were antibiotic agents, physical therapy, operative debridement, incision, drainage, and exercise and physical therapy. One year later, the internal fixation was taken out. His elbow was fully mobilized and the fracture healed. He got back to his former job. When encountered deep wound infection again and again after internal fixation, rejection should be considered. Except for anti-infection treatment, rehabilitation cannot be neglected, or the healing process may be delayed. PMID:27281079

  1. Bio-Environment-Induced Degradation and Failure of Internal Fixation Implants

    PubMed Central

    Zhou, Yan; Perkins, Luke A.; Wang, Guodong; Zhou, Dongsheng; Liang, Hong

    2015-01-01

    Internal fixations provide fast healing but their failure remains problematic to patients. Here, we report an experimental study in failure of three typical cases of metals: a bent intramedullary stainless steel nail, a broken exterior pure Ti plate, and a broken intramedullary stainless steel nail. Characterization of the bent nail indicates that those metals are vulnerable to corrosion with the evidence of increased surface roughness and embrittlement. Depredated surface of the Ti plate resulted debris particles in the surrounding tissue of 15.2 ± 6.5 μm in size. Nanoparticles were observed in transmission electron microscope. The electron diffraction pattern of the debris indicates a combination of nanocrystalline and amorphous phases. The failure mode of the broken nail made of stainless steel was found to be fatigue initiated from the surface. This study clearly shows the biological-attack induced surface degradation resulting in debris and fatigue. Future design and selection of implant materials should consider such factors for improvement. PMID:26501330

  2. A Novel Internal Fixator Device for Peripheral Nerve Regeneration

    PubMed Central

    Chuang, Ting-Hsien; Wilson, Robin E.; Love, James M.; Fisher, John P.

    2013-01-01

    Recovery from peripheral nerve damage, especially for a transected nerve, is rarely complete, resulting in impaired motor function, sensory loss, and chronic pain with inappropriate autonomic responses that seriously impair quality of life. In consequence, strategies for enhancing peripheral nerve repair are of high clinical importance. Tension is a key determinant of neuronal growth and function. In vitro and in vivo experiments have shown that moderate levels of imposed tension (strain) can encourage axonal outgrowth; however, few strategies of peripheral nerve repair emphasize the mechanical environment of the injured nerve. Toward the development of more effective nerve regeneration strategies, we demonstrate the design, fabrication, and implementation of a novel, modular nerve-lengthening device, which allows the imposition of moderate tensile loads in parallel with existing scaffold-based tissue engineering strategies for nerve repair. This concept would enable nerve regeneration in two superposed regimes of nerve extension—traditional extension through axonal outgrowth into a scaffold and extension in intact regions of the proximal nerve, such as that occurring during growth or limb-lengthening. Self-sizing silicone nerve cuffs were fabricated to grip nerve stumps without slippage, and nerves were deformed by actuating a telescoping internal fixator. Poly(lactic co-glycolic) acid (PLGA) constructs mounted on the telescoping rods were apposed to the nerve stumps to guide axonal outgrowth. Neuronal cells were exposed to PLGA using direct contact and extract methods, and they exhibited no signs of cytotoxic effects in terms of cell morphology and viability. We confirmed the feasibility of implanting and actuating our device within a sciatic nerve gap and observed axonal outgrowth following device implantation. The successful fabrication and implementation of our device provides a novel method for examining mechanical influences on nerve regeneration. PMID

  3. Technique of Open Reduction and Internal Fixation of Comminuted Proximal Humerus Fractures With Allograft Femoral Head Metaphyseal Reconstruction.

    PubMed

    Parada, Stephen A; Makani, Amun; Stadecker, Monica J; Warner, Jon J P

    2015-10-01

    Proximal humerus fractures are common injuries that can require operative treatment. Different operative techniques are available, but the hallmark of fixation for 3- and 4-part fractures is a locking-plate-and-screw construct. Despite advances in this technology, obtaining anatomical reduction and fracture union can be difficult, and complications (eg, need for revision) are not uncommon. These issues can be addressed by augmenting the fixation with an endosteally placed fibular allograft. Although biomechanical and clinical results have been good, the technique can lead to difficulties in future revision to arthroplasty, a common consequence of failed open reduction and internal fixation. The technique described, an alternative to placing a long endosteal bone graft, uses a trapezoidal, individually sized pedestal of allograft femoral head to facilitate the reduction and healing of the humeral head and tuberosity fragments in a displaced 3- or 4-part fracture of the proximal humerus. It can be easily incorporated with any plate-and-screw construct and does not necessitate placing more than 1 cm of bone into the humeral intramedullary canal, limiting the negative effects on any future revision to arthroplasty.

  4. Subchondral insufficiency fracture of the femoral head after internal fixation for femoral neck fracture: histopathological investigation.

    PubMed

    Sonoda, Kazuhiko; Yamamoto, Takuaki; Motomura, Goro; Kido, Hidehiko; Iwamoto, Yukihide

    2014-08-01

    Late segmental collapse after internal fixation for femoral neck fracture is the phenomenon observed in post-traumatic osteonecrosis of the femoral head (ON), which has generally been reported to occur over a year or more after internal fixation. Subchondral insufficiency fracture of the femoral head (SIF) has also been recognized to cause femoral head collapse, however, only two cases of SIF after internal fixation for femoral neck fracture have been reported. We report a case with femoral head collapse observed 5 months after internal fixation for femoral neck fracture, which was histopathologically diagnosed as SIF. Clinically, differentiating SIF from ON is important because some cases of SIF have been reported to heal without surgical treatments. The timing of femoral head collapse after femoral neck fracture may be different between SIF and post-traumatic ON.

  5. A Biomechanical Comparison of Locking Versus Conventional Plate Fixation for Distal Fibula Fractures in Trimalleolar Ankle Injuries.

    PubMed

    Nguyentat, Annie; Camisa, William; Patel, Sandeep; Lagaay, Pieter

    2016-01-01

    Previous biomechanical studies have advocated the use of locking plates for isolated distal fibula fractures in osteoporotic bone. Complex rotational ankle injuries involve an increased number of fractures, which can result in instability, potentially requiring the same fixed angle properties afforded by locking plates. However, the mechanical indication for locking plate technology has not been tested in this fracture model. The purpose of the present study was to compare the biomechanical properties of locking and conventional plate fixation for distal fibula fractures in trimalleolar ankle injuries. Fourteen (7 matched pairs) fresh-frozen cadaver leg specimens were used. The bone mineral density of each was obtained using dual x-ray absorptiometry scans. The fracture model simulated an OTA 44-B3.3 fracture. The syndesmosis was not disrupted. Each fracture was fixated in the same fashion, except for the distal fibula plate construct: locking (n = 7) and one-third tubular (n = 7). The specimens underwent axial and torsional cyclic loading, followed by torsional loading to failure. No statistically significant differences were found between the locking and conventional plate constructs during both fatigue and torque to failure testing (p > .05). Our specimen bone mineral density averages did not represent poor bone quality. The clinical implication of the present study is that distal fibular locking plates do not provide a mechanical advantage for trimalleolar ankle injuries in individuals with normal bone density and in the absence of fracture comminution.

  6. Combined Type II Odontoid Fracture with Jefferson's Fracture Treated with Temporary Internal Fixation.

    PubMed

    Pawar, Abhijit Yuvaraj; O'Leary, Patrick F

    2015-12-01

    An 18-year-old male presented after a motor vehicle rollover accident. Computed tomography (CT) scan confirmed the diagnosis of Type II odontoid fracture. Considering the patient's young age and the limitations of C1-C2 fusion including significant loss of cervical rotation, temporary internal fixation with a lateral mass fixation of C1 and pedicle fixation of C2 without fusion was done. CT scan done at 6-month follow-up visit showed healed odontoid fracture and excellent C1-C2 alignment. At ninth postoperative month, internal fixation was removed. Patient had normal movements of cervical spine at 1-year follow-up. Temporary internal fixation can be an important tool in the armamentarium of the surgeon in treating type II odontoid fractures in young adults and children. This strategy avoids the complications halo fixation and immobilizes the unstable C1-C2 segment without fusion. Removal of the internal fixation after healing allows restoration of the rotational motion. PMID:26713132

  7. Combined Type II Odontoid Fracture with Jefferson's Fracture Treated with Temporary Internal Fixation.

    PubMed

    Pawar, Abhijit Yuvaraj; O'Leary, Patrick F

    2015-12-01

    An 18-year-old male presented after a motor vehicle rollover accident. Computed tomography (CT) scan confirmed the diagnosis of Type II odontoid fracture. Considering the patient's young age and the limitations of C1-C2 fusion including significant loss of cervical rotation, temporary internal fixation with a lateral mass fixation of C1 and pedicle fixation of C2 without fusion was done. CT scan done at 6-month follow-up visit showed healed odontoid fracture and excellent C1-C2 alignment. At ninth postoperative month, internal fixation was removed. Patient had normal movements of cervical spine at 1-year follow-up. Temporary internal fixation can be an important tool in the armamentarium of the surgeon in treating type II odontoid fractures in young adults and children. This strategy avoids the complications halo fixation and immobilizes the unstable C1-C2 segment without fusion. Removal of the internal fixation after healing allows restoration of the rotational motion.

  8. Use of a locking compression plate as an external fixator for repair of a tarsometatarsal fracture in a bald eagle (Haliaeetus leucocephalus).

    PubMed

    Montgomery, Ronald D; Crandall, Elizabeth; Bellah, Jamie R

    2011-06-01

    We describe the successful treatment of a tarsometatarsal fracture in a mature bald eagle (Haliaeetus leucocephalus) using a locking compression plate as an external fixator. The anatomy of the area (inelastic dermis and minimal subcutaneous space) and the high forces placed on a fracture at that site necessitated a unique approach to fixation. The unconventional use of a locking compression plate as an external fixator was minimally invasive, well tolerated by the eagle, and provided adequate stability in opposing fracture forces. This technique may serve as a method of fixation for tarsometatarsal fractures in other large avian species.

  9. Use of a locking compression plate as an external fixator for repair of a tarsometatarsal fracture in a bald eagle (Haliaeetus leucocephalus).

    PubMed

    Montgomery, Ronald D; Crandall, Elizabeth; Bellah, Jamie R

    2011-06-01

    We describe the successful treatment of a tarsometatarsal fracture in a mature bald eagle (Haliaeetus leucocephalus) using a locking compression plate as an external fixator. The anatomy of the area (inelastic dermis and minimal subcutaneous space) and the high forces placed on a fracture at that site necessitated a unique approach to fixation. The unconventional use of a locking compression plate as an external fixator was minimally invasive, well tolerated by the eagle, and provided adequate stability in opposing fracture forces. This technique may serve as a method of fixation for tarsometatarsal fractures in other large avian species. PMID:21877449

  10. Open reduction and internal fixation of two- and three-part displaced surgical neck fractures of the proximal humerus.

    PubMed

    Cuomo, F; Flatow, E L; Maday, M G; Miller, S R; McIlveen, S J; Bigliani, L U

    1992-11-01

    Twenty-two patients aged 20 to 82 years (average 56 years) were followed for 1.1 to 8.9 years (average 3.3 years) after open reduction and internal fixation of two- and three-part displaced surgical neck fractures of the proximal humerus. There were 14 two-part displaced surgical neck fractures, seven three-part displaced greater tuberosity and surgical neck fractures, and one three-part displaced lesser tuberosity and surgical neck fracture. Fixation was achieved with heavy nonabsorbable sutures or wire that incorporated the rotator cuff tendons, tuberosities, and shaft. In cases with significant surgical neck comminution, humeral Enders nails were incorporated in a tension-band construct to provide longitudinal stability. Eighteen (82%) of the 22 patients had good or excellent results. Three (14%) of the 22 had satisfactory results, and one (5%) had an unsatisfactory result. The use of a technique of limited internal fixation for these displaced fractures without the use of plates and screws achieved fracture stability and a high percentage of acceptable results.

  11. Biomechanical stability of a volar locking-screw plate versus fragment-specific fixation in a distal radius fracture model.

    PubMed

    Cooper, Ellis O; Segalman, Keith A; Parks, Brent G; Sharma, Krishna M; Nguyen, Augustine

    2007-04-01

    Eight matched pairs of cadaveric radii were osteotomized by removing a 4-mm dorsal wedge of bone at the level of the sigmoid notch designed to simulate dorsal comminution. They were then fixed with either a volar locking-screw plate or fragment-specific fixation. All constructs underwent biomechanical testing in a custom-designed, custom-fabricated 4-point bending device. No statistically significant difference in stiffness was noted between the groups. Linear displacement and angulation at the osteotomy site were significantly less in the group with fragment-specific fixation at loads expected to be encountered during postoperative rehabilitation. Angulation at the osteotomy site was significantly less in the locking-screw plate group at higher loads.

  12. The biomechanical effect of bone quality and fracture topography on locking plate fixation in periprosthetic femoral fractures.

    PubMed

    Leonidou, Andreas; Moazen, Mehran; Lepetsos, Panagiotis; Graham, Simon M; Macheras, George A; Tsiridis, Eleftherios

    2015-02-01

    Optimal management of periprosthetic femoral fractures (PFF) around a well fixed prosthesis (Vancouver B1) remains controversial as adequate fixation needs to be achieved without compromising the stability of the prosthesis. The aim of this study was to highlight the effect of bone quality i.e. canal thickness ratio (CTR), and fracture topography i.e. fracture angle and its position in relation to the stem, on the biomechanics of a locking plate for a Vancouver B1 fracture. A previously corroborated simplified finite element model of a femur with a cemented total hip replacement stem was used in this study. Canal thickness ratio (CTR) and fracture topography were altered in several models and the effect of these variations on the von Mises stress on the locking plate as well as the fracture displacement was studied. Increasing the CTR led to reduction of the von Mises stress on the locking plate as well as the fracture movement. In respect to the fracture angle with the medial cortex, it was shown that acute angles resulted in lower von Mises stress on the plate as opposed to obtuse angles. Furthermore, acute fracture angles resulted in lower fracture displacement compared to the other fractures considered here. Fractures around the tip of the stem had the same biomechanical effect on the locking plate. However, fractures more distal to the stem led to subsequent increase of stress, strain, and fracture displacement. Results highlight that in good bone quality and acute fracture angles, single locking plate fixation is perhaps an appropriate management method. On the contrary, for poor bone quality and obtuse fracture angles alternative management methods might be required as the fixation might be under higher risk of failure. Clinical studies for the management of PFF are required to further support our findings.

  13. Treatment of Unstable Posterior Pelvic Ring Fracture with Pedicle Screw-Rod Fixator Versus Locking Compression Plate: A Comparative Study

    PubMed Central

    Bi, Chun; Wang, Qiugen; Nagelli, Christopher; Wu, Jianhong; Wang, Qian; Wang, Jiandong

    2016-01-01

    Background The aim of this study was to assess the clinical results of treatment for unstable posterior pelvic fractures using a pedicle screw-rod fixator compared to use of a locking compression plate. Material/Methods A retrospective study was performed between June 2010 and May 2014 and the data were collected from 46 patients with unstable posterior pelvic ring fractures. All patients were treated using either a pedicle screw-rod fixator (study group, 24 patients) or locking compression plate (control group, 22 patients). In these patients, causes of injury included traffic accidents (n=27), fall from height (n=12), and crushing accidents (n=7). The quality of reduction and radiological grading were assessed. Clinical assessments included the operation time, times of X-ray exposures, bleeding volume during operation, incision length, and Majeed postoperative functional evaluation. Results No iatrogenic neurovascular injuries occurred during the operations in these 2 groups. The average follow-up time was 24.5 months. All fractures were healed. The significant differences (P<0.05) between the 2 groups were operation duration, size of incision, and intraoperative bleeding volume. Statistically significant differences in the Majeed postoperative functional evaluation and times of X-ray exposures were not found between the 2 groups. Conclusions Similar clinical effects were achieved in treating the posterior pelvic ring fractures using the pedicle screw-rod fixator and the locking compression plate. However, the pedicle screw-rod fixator has the advantages of smaller incision, shorter duration of the operation, and less bleeding volume compared to using the locking compression plate. PMID:27748355

  14. Polymer cable/grip-plate system with locking screws for stable fixation to promote healing of trochanteric osteotomies or fractures in revision total hip arthroplasty.

    PubMed

    Berend, Keith R; Willen, Jacob L; Morris, Michael J; Adams, Joanne B; Lombardi, Adolph V

    2014-11-01

    Multiple methods have been proposed to establish stable fixation to promote healing of trochanteric osteotomies or fractures in revision total hip arthroplasty (revTHA), from wiring techniques through cable-plate systems with or without supplemental locking screws. The purpose of this study is to report the clinical results of a single cable-plate system with locked screw fixation in revTHA. Between 2009 and 2012, 27 grip-plates (Supercable® System, Kinamed Inc., Camarillo, CA) were used in 26 patients in 27 revTHA procedures. Utilization was 12 1-hole (50 mm) grip-plates, 10 2-hole (135 mm) grip-plates, four 4-hole (190 mm) grip-plates, and one 6-hole (245 mm) grip-plate. There were 14 women and 12 men. Age averaged 63.2 years and BMI averaged 29.4 kg/m2. At average 2.5 year follow-up, grip-plate fixation was considered successful in 22 hips (81%) with five failures. Three failures consisted of 50 mm/short grip-plates used in one trochanteric slide, and two intraoperative trochanteric fractures during revTHA. The two additional failures were related to pre-revision trochanteric avulsion from bony necrosis of the proximal femur. An additional three grip-plates were removed electively for soft-tissue irritation and pain but with successful fixation and bony healing. Thus 70% of hips were free of reoperation related to the grip-plate. All other hips had successful fixation and the grip-plate was not symptomatic. In this study, the cable-grip system and isoelastic Supercables provided reliable fixation for adequate healing of difficult ETO and trochanteric fractures with an 81% rate of mechanical success with radiographic and clinical healing observed.

  15. Functional outcome after successful internal fixation versus salvage arthroplasty of patients with a femoral neck fracture

    PubMed Central

    Zielinski, Stephanie M.; Keijsers, Noël L.; Praet, Stephan F.E.; Heetveld, Martin J.; Bhandari, Mohit; Wilssens, Jean Pierre; Patka, Peter; Van Lieshout, Esther M.M.

    2014-01-01

    Objectives To determine patient independency, health-related and disease-specific quality of life (QOL), gait pattern, and muscle strength in patients after salvage arthroplasty for failed internal fixation of a femoral neck fracture. Design Secondary cohort study to a randomized controlled trial. Setting Multicenter trial in the Netherlands, including 14 academic and non-academic hospitals Patients Patients after salvage arthroplasty for failed internal fixation of a femoral neck fracture were studied. A comparison was made with patients who healed uneventfully after internal fixation. Intervention None (observatory study) Main outcome measurements Patient characteristics, SF-12, and WOMAC scores were collected. Gait parameters were measured using plantar pressure measurement. Maximum isometric forces of the hip muscles were measured using a handheld dynamometer. Differences between the fractured and contralateral leg were calculated. Groups were compared using univariate analysis. Results Of 248 internal fixation patients (median age 72 years), salvage arthroplasty was performed in 68 patients (27%). Salvage arthroplasty patients had a significantly lower WOMAC score (median 73 versus 90, P=0.016) than patients who healed uneventfully after internal fixation. Health-related QOL (SF-12) and patient independency did not differ significantly between the groups. Gait analysis showed a significantly impaired progression of the center of pressure in the salvage surgery patients (median ratio −8.9 versus 0.4, P=0.013) and a significant greater loss of abduction strength (median −25.4 versus −20.4 N, P=0.025). Conclusion Despite a similar level of dependency and QOL, salvage arthroplasty patients have inferior functional outcome than patients who heal after internal fixation of a femoral neck fracture. PMID:24835623

  16. An Overview of Internal Fixation Implant Metallurgy and Galvanic Corrosion Effects.

    PubMed

    Koh, Justin; Berger, Aaron; Benhaim, Prosper

    2015-08-01

    Orthopedic and hand surgery implants for internal fixation of fractures have evolved substantially over the past 50 years. Newer metal compositions have been used, and new standards have been applied to older alloys, resulting in modern implants with unique physical properties and better clinical performances. Conventional wisdom has long dictated that implanting different metals should be avoided, but few guidelines exist regarding the safety of using in proximity implant systems of dissimilar metals. To better characterize the landscape of internal fixation implant metallurgy, we have compiled the recommendations and conclusions of the currently available and pertinent literature.

  17. Possibility of Fixation of a Distal Radius Fracture With a Volar Locking Plate Through a 10 mm Approach.

    PubMed

    Naito, Kiyohito; Zemirline, Ahmed; Sugiyama, Yoichi; Obata, Hiroyuki; Liverneaux, Philippe; Kaneko, Kazuo

    2016-06-01

    The management of distal radius fractures has dramatically improved due to the development of a locking plate system. In addition, mini-invasive surgery has been performed in a lot of surgical fields in recent years. The aim of the present study is to investigate the possibility of fixation of a distal radius fracture with a volar locking plate through a 10 mm approach. Eighteen patients with distal radius fracture (mean age: 66 y; range, 28 to 88 y; 8 males and 10 females) were operated on using a volar locking plate. The incision for plating was always 10 mm long. The clinical, cosmetic, and radiologic outcomes were investigated. At 3 months' follow-up, the range of motion of the wrist joint was 67.5 degrees in flexion, 65.6 degrees in extension, 88.3 degrees in pronation, and 88.3 degrees in supination. The % grip strength compared to the healthy side ranged from 35% to 100%. The VAS, Q-DASH, and modified Mayo scores were 0.7, 8.5, and 93.3, respectively (excellent in all 18 patients). Bone union was achieved on plain x-ray radiography and cosmetic problems were satisfied in all patients. Our results suggest that it is possible to achieve fixation of a distal radius fracture with a volar locking plate through a 10 mm approach. However, its applicability to surgery must be carefully examined. If any difficulties in plate installation or approach occur during this intervention, it will be necessary to consider switching to a conventional approach. We believe that surgeons must not adhere to a mini-invasive approach. PMID:27015408

  18. Regional alterations in long bone 85Sr clearance produced by internal fixation devices. Part II. Histomorphometry.

    PubMed

    Simmons, D J; Daum, W J; Calhoun, J H

    1988-01-01

    The effects of each of the surgical stages involved in compression plating on the development of cortical thinning and porosity were assessed in the intact midshaft, stress-shielded femoral segments of adult mongrel dogs 6 months postoperatively. The data were evaluated in terms of a postsurgical tetracycline-based measure of remodeling and terminal 85Sr clearance (SrC) values for the plated segments of bone. Drilling had no effect on any parameter. Screw application was associated with minimal cortical thinning (p less than 0.05), while plate fixation clearly promoted thinning (p less than 0.01) and porosity (p less than 0.05). The percentage of labeled osteons, a measure of remodeling activity, increased only after plate fixation (p less than 0.05), and the labeling patterns suggested that most osteons had formed during the first 4 postsurgical months. That none of these changes were correlated with the 6-month SrC values suggests that the development of plate-induced osteopenia involves disparate histomorphometric time constants, rather than lack of any association. PMID:3225712

  19. Analytical modeling and vibration analysis of internally cracked rectangular plates

    NASA Astrophysics Data System (ADS)

    Joshi, P. V.; Jain, N. K.; Ramtekkar, G. D.

    2014-10-01

    This study proposes an analytical model for nonlinear vibrations in a cracked rectangular isotropic plate containing a single and two perpendicular internal cracks located at the center of the plate. The two cracks are in the form of continuous line with each parallel to one of the edges of the plate. The equation of motion for isotropic cracked plate, based on classical plate theory is modified to accommodate the effect of internal cracks using the Line Spring Model. Berger's formulation for in-plane forces makes the model nonlinear. Galerkin's method used with three different boundary conditions transforms the equation into time dependent modal functions. The natural frequencies of the cracked plate are calculated for various crack lengths in case of a single crack and for various crack length ratio for the two cracks. The effect of the location of the part through crack(s) along the thickness of the plate on natural frequencies is studied considering appropriate crack compliance coefficients. It is thus deduced that the natural frequencies are maximally affected when the crack(s) are internal crack(s) symmetric about the mid-plane of the plate and are minimally affected when the crack(s) are surface crack(s), for all the three boundary conditions considered. It is also shown that crack parallel to the longer side of the plate affect the vibration characteristics more as compared to crack parallel to the shorter side. Further the application of method of multiple scales gives the nonlinear amplitudes for different aspect ratios of the cracked plate. The analytical results obtained for surface crack(s) are also assessed with FEM results. The FEM formulation is carried out in ANSYS.

  20. COMPARISON OF VOLUMES OCCUPIED BY DIFFERENT INTERNAL FIXATION DEVICES FOR FEMORAL NECK FRACTURES

    PubMed Central

    Lauxen, Daniel; Schwartsmann, Carlos Roberto; Silva, Marcelo Faria; Spinelli, Leandro de Freitas; Strohaecker, Telmo Roberto; Souza, Ralf Wellis de; Zimmer, Cinthia Gabriely; Boschin, Leonardo Carbonera; Gonçalves, Ramiro Zilles; Yépez, Anthony Kerbes

    2015-01-01

    Objective: The objective of this paper is to measure the volume occupied by the most widely used internal fixation devices for treating femoral neck fractures, using the first 30, 40 and 50 mm of insertion of each screw as an approximation. The study aimed to observe which of these implants caused least bone aggression. Methods: Five types of cannulated screws and four types of dynamic hip screws (DHS) available on the Brazilian market were evaluated in terms of volume differences through water displacement. Results: Fixation with two cannulated screws presented significantly less volume than shown by DHS, for insertions of 30, 40 and 50 mm (p=0.01, 0.012 and 0.013, respectively), fixation with three screws did not show any statistically significant difference (p= 0.123, 0.08 and 0.381, respectively) and fixation with four cannulated screws presented larger volumes than shown by DHS (p=0.072, 0.161 and 0.033). Conclusions: Fixation of the femoral neck with two cannulated screws occupied less volume than DHS, with a statistically significant difference. The majority of screw combinations did not reach statistical significance, although fixation with four cannulated screws presented larger volumes on average than those occupied by DHS. PMID:27047886

  1. Open reduction and internal fixation of extracapsular mandibular condyle fractures: a long-term clinical and radiological follow-up of 25 patients

    PubMed Central

    2014-01-01

    Background During the last 2 decades, many studies on the treatment of mandibular condyle fracture have been published. The incidence of mandibular condyle fractures is variable, ranging from 17.5% to 52% of all mandibular fractures. This retrospective study evaluated the long-term clinical and radiological outcomes after surgical treatment of 25 patients with a total of 26 extracapsular condyle fractures. Methods We used 2 types of surgical approaches, the retromandibular retroparotid or preauricular approach. Three kinds of rigid internal fixation plates were used—single plate, double plate, and trapezoidal plate. The following post-operative clinical parameters were evaluated: dental occlusion, facial nerve functionality, skin scarring, and temporomandibular joint functionality. All patients underwent post-operative orthopanoramic radiography and computed tomography. The patients were also monitored for complications such as Frey’s syndrome, infection, salivary fistula, plate fracture, and permanent paralysis of the facial nerve; the patient’s satisfaction was also recorded. Results Of the 25 patients, 80% showed occlusion recovery, 88% had no facial nerve injury, and 88% presented good surgical skin scarring. The patients showed early complete recovery of temporomandibular joint functionality and 72% of them were found to be asymptomatic. The postoperative radiographs of all patients indicated good recovery of the anatomical condylar region, and 80% of them had no postoperative complications. The average degree of patient satisfaction was 8.32 out of 10. Our results confirm that the technique of open reduction and internal fixation in association with postoperative functional rehabilitation therapy should be considered for treating patients with extracapsular condylar fractures. Conclusion The topic of condylar injury has generated more discussion and controversy than any other topic in the field of maxillofacial trauma. We confirm that open reduction and

  2. Coracoid bone graft osteolysis after Latarjet procedure: A comparison study between two screws standard technique vs mini-plate fixation

    PubMed Central

    Giacomo, Giovanni Di; Costantini, Alberto; de Gasperis, Nicola; De Vita, Andrea; Lin, Bernard K. H.; Francone, Marco; Beccaglia, Mario A. Rojas; Mastantuono, Marco

    2013-01-01

    Aims: One of the reason for Latarjet procedure failure may be coracoid graft osteolysis. In this study, we aimed to understand if a better compression between the coracoid process and the glenoid, using a mini-plate fixation during the Latarjet procedure, could reduce the amount of coracoid graft osteolysis. Materials and Methods: A computed tomography scan analysis of 26 prospectively followed-up patients was conducted after modified Latarjet procedure using mini-plate fixation technique to determine both the location and the amount of coracoid graft osteolysis in them. We then compared our current results with results from that of our previous study without using mini-plate fixation to determine if there is any statistical significant difference in terms of corcacoid bone graft osteolysis between the two surgical techniques. Results: The most relevant osteolysis was represented by the superficial part of the proximal coracoid, whereas the deep part of the proximal coracoid graft is least involved in osteolysis and has best bone healing. The current study showed a significant difference only for the deep part of the distal coracoid with our previous study (P < 0.01). Discussion: To our knowledge, there are no studies in literature that show the causes of coracoid bone graft osteolysis after Latarjet procedure. Conclusion: Our study suggests that there is a significant difference only for the deep part of the distal coracoid in terms of osteolysis. At clinical examination, this difference did not correspond with any clinical findings. Level of Evidence: Level 4. Clinical Relevance: Prospective case series, Treatment study. PMID:23858288

  3. Computer-assisted preoperative simulation for positioning of plate fixation in Lefort I osteotomy: A case report.

    PubMed

    Suenaga, Hideyuki; Taniguchi, Asako; Yonenaga, Kazumichi; Hoshi, Kazuto; Takato, Tsuyoshi

    2016-06-01

    Computed tomography images are used for three-dimensional planning in orthognathic surgery. This facilitates the actual surgery by simulating the surgical scenario. We performed a computer-assisted virtual orthognathic surgical procedure using optically scanned three-dimensional (3D) data and real computed tomography data on a personal computer. It helped maxillary bone movement and positioning and the titanium plate temporary fixation and positioning. This simulated the surgical procedure, which made the procedure easy, and we could perform precise actual surgery and could forecast the postsurgery outcome. This simulation method promises great potential in orthognathic surgery to help surgeons plan and perform operative procedures more precisely.

  4. When Should Open Reduction and Internal Fixation Ankle Fractures Begin Weight Bearing? A Systematic Review.

    PubMed

    Smith, Toby O; Davies, Leigh

    2008-02-01

    The objective of this paper was to review the literature to assess when open reduction and internal fixation ankle fractures should commence weight bearing for the best outcome. An electronic search was undertaken of the databases AMED, Cinahl, Embase, Medline (via Ovid), Pedro and Pubmed, from their inception to November 2005. References lists were scrutinised and a hand search was also performed. We included all English language, human subject, controlled clinical trials, comparing the effects of early against later weight bearing following open reduction and internal fixation of ankle fractures. Two reviewers independently assessed the methodological quality of the literature using the PEDro (Physiotherapy Evidence Database) scoring system. Five papers comprising of 366 ankle fractures were reviewed. Overall, there was no significant difference between commencing early, compared to later weight bearing in subjects following open reduction and internal fixation, when evaluated against function, pain, range of movement, radiological assessment, complications, and return to work. The evidence reviewed was generally poor, with numerous methodological design limitations. The literature suggested that were was little difference between encouraging early or delayed weight bearing after open reduction and internal fixation of ankle fractures. Neither early nor later weight bearing significantly improves or jeopardises outcomes. However, due to the plethora of methodological limitations and limited evidence, it is not possible to reference this conclusion with conviction. Further large, well-designed randomized controlled trials are required to evaluate this area. PMID:26815494

  5. Internal fixation treatments for intertrochanteric fracture: a systematic review and meta-analysis of randomized evidence.

    PubMed

    Yu, Jiajie; Zhang, Chao; Li, Ling; Kwong, Joey S W; Xue, Li; Zeng, Xiantao; Tang, Li; Li, Youping; Sun, Xin

    2015-12-11

    The relative effects of internal fixation strategies for intertrochanteric fracture after operation remain uncertain. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to address this important issue. We searched PubMed, EMBASE and CENTRAL for RCTs that compared different internal fixation implants in patients with intertrochanteric fracture at 6-month follow-up or longer. We ultimately included 43 trials enrolling 6911 patients; most trials were small in sample sizes and events. Their risk of bias was generally unclear due to insufficient reporting. Because of these, no statistically significant differences were present from most of the comparisons across all the outcomes, and no definitive conclusions can be made. However, a number of trials compared two commonly used internal fixation strategies, gamma nail (GN) and sliding hip screw (SHS). There is good evidence suggesting that, compared to SHS, GN may increase the risk of cut out (OR = 1.87, 95% CI, 1.08 to 3.21), re-operation (OR = 1.61, 95% CI, 1.02 to 2.53), intra-operative (OR = 3.14, 95% CI, 1.34 to 7.35) and later fractures (OR = 3.67, 95% CI, 1.37 to 9.83). Future randomized trials or observational studies that are carefully designed and conducted are warranted to establish the effects of alternative internal fixation strategies for intertrochanteric fracture.

  6. Serological diagnosis of brucellosis in water buffaloes (Bubalus bubalis): comparison among complement fixation, serum agglutination and rose bengal plate test.

    PubMed

    Mathias, L A; Pinto, A A

    1983-12-01

    The results of a comparative study among complement fixation (CFT), plate agglutination (PAT), tube agglutination (TAT) and Rose Bengal plate tests ( RBPT ) to the serodiagnosis of brucellosis in Indian buffaloes are reported. Sera from 212 buffaloes unvaccinated against brucellosis were examined and the CFT was able to reveal significant titres in sera with low agglutinating titres. From 109 sera which did not show agglutination titres in the PAT, four showed complement fixing titre greater than 1 in 200. All the positive sera to the RBPT gave complement fixing titre equal to or greater than 1 in 20. In sera that showed negative result to the RBPT the CFT was able to reveal relatively high titres. From 131 sera negative to the RBPT five showed complement fixing titres greater than 1 in 60.

  7. Intramedullary Nailing Versus Plate Fixation for the Treatment Displaced Midshaft Clavicular Fractures: A Systematic Review and Meta-Analysis

    PubMed Central

    Hussain, Nasir; Sermer, Corey; Prusick, Parker J.; Banfield, Laura; Atrey, Amit; Bhandari, Mohit

    2016-01-01

    The two commonly performed surgical techniques used to repair displaced midshaft clavicle fractures are plate fixation or intramedullary nailing; however, despite recent evidence, the optimal method to treat such fractures remains a continued topic of debate. A meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate long term function, complications, and operative duration in adult patients receiving intramedullary nailing in comparison to plating. Seven RCTs and three quasi-randomized trials were included. No significant difference was found in long-term function between the two groups (MD: −0.66, 95% CI: −2.03 to 0.71, I2 = 62%, p = 0.34). Patients who received plating had a 2.19 times increased risk of treatment failure, but this failed to reach significance (95% CI: 0.93 to 5.15, I2 = 0%, p = 0.07). The risk of non-operative complications was 2.11 times higher in patients who received plating and this reached statistical significance (95% CI: 1.38 to 3.23, I2 = 53%, p = 0.0006). Finally, plating significantly prolonged operative duration by 20.16 minutes (95% CI: 16.87 to 23.44, I2 = 56%, p < 0.00001). Our results suggest that intramedullary nailing and plating provide equivalent long-term functional outcomes; however, plating may lead to a higher risk of treatment failure and non-operative complications. PMID:27762393

  8. Three-dimensional stabilization provided by the external spinal fixator compared to two internal fixation devices: a biomechanical in vitro flexibility study.

    PubMed

    Lund, Teija; Nydegger, Thomas; Rathonyi, Gabor; Nolte, Lutz-Peter; Schlenzka, Dietrich; Oxland, Thomas R

    2003-10-01

    We performed an in vitro study to investigate the stabilization (i.e. motion reduction) provided by the external spinal fixator (ESF), and to compare the three configurations of the ESF with two internal fixation techniques. Six human cadaveric lumbar spine specimens (L3-S1) were subjected to multidirectional flexibility testing in six configurations: (1) intact, (2) ESF in neutral, (3) ESF in distraction, (4) ESF in compression, (5) translaminar facet screw fixation, and (6) internal transpedicular fixation. Both the ESF and the internal fixation systems stabilized the specimens from L4 to S1. In each testing configuration, pure bending moments of flexion-extension, bilateral axial rotation, and bilateral lateral bending were applied to the uppermost vertebra stepwise to a maximum of 10 Nm. The rigid body motion between the vertebrae was measured using an optoelectronic camera system, and custom software was used to calculate the intervertebral rotations. For each applied motion in all testing configurations, the total range of motion (ROM) of L4-S1 is reported. All three ESF configurations stabilized the spine significantly when compared to the intact specimen. The ESF in compression provided significantly more stabilization in flexion-extension than the two other ESF configurations, but no other significant differences were found between the three ESF modes. In flexion-extension the ESF stabilized the spine significantly when compared with the two internal fixation devices. Only in bilateral lateral bending was the ESF inferior to internal transpedicular fixation in providing stabilization. The results of the present study suggest that the ESF provides a high degree of stabilization for preoperative assessment of selected low back pain patients. Whether other non-mechanical factors affect the pain relief experienced by the patients remains unknown.

  9. Evaluation of three-dimensional printing for internal fixation of unstable pelvic fracture from minimal invasive para-rectus abdominis approach: a preliminary report

    PubMed Central

    Zeng, Canjun; Xiao, Jidong; Wu, Zhanglin; Huang, Wenhua

    2015-01-01

    Objective: The aim of this study is to evaluate the efficacy and feasibility of three-dimensional printing (3D printing) assisted internal fixation of unstable pelvic fracture from minimal invasive para-rectus abdominis approach. Methods: A total of 38 patients with unstable pelvic fractures were analyzed retrospectively from August 2012 to February 2014. All cases were treated operatively with internal fixation assisted by three-dimensional printing from minimal invasive para-rectus abdominis approach. Both preoperative CT and three-dimensional reconstruction were performed. Pelvic model was created by 3D printing. Data including the best entry points, plate position and direction and length of screw were obtained from simulated operation based on 3D printing pelvic model. The diaplasis and internal fixation were performed by minimal invasive para-rectus abdominis approach according to the optimized dada in real surgical procedure. Matta and Majeed score were used to evaluate currative effects after operation. Results: According to the Matta standard, the outcome of the diaplasis achieved 97.37% with excellent and good. Majeed assessment showed 94.4% with excellent and good. The imageological examination showed consistency of internal fixation and simulated operation. The mean operation time was 110 minutes, mean intraoperative blood loss 320 ml, and mean incision length 6.5 cm. All patients have achieved clinical healing, with mean healing time of 8 weeks. Conclusion: Three-dimensional printing assisted internal fixation of unstable pelvic fracture from minimal invasive para-rectus abdominis approach is feasible and effective. This method has the advantages of trauma minimally, bleeding less, healing rapidly and satisfactory reduction, and worthwhile for spreading in clinical practice. PMID:26550226

  10. Concurrent Minimally Invasive Carpal Tunnel Release Techniques in Distal Radius Open Reduction Internal Fixation.

    PubMed

    Low, O-Wern; Cheah, Andre E J

    2016-02-01

    Carpal tunnel syndrome is a common complication associated with distal radius fractures. Open carpal tunnel release in the same setting as open reduction and internal fixation of distal radius fractures is widely accepted. In this paper, we describe the technical details of a minimally invasive carpal tunnel release in the same setting as the fixation of a distal radius fracture via the same incision. Two options of minimally invasive techniques are described: The Knifelight® (Stryker, Kalamazoo, Michigan, USA) instrument and the single portal carpal tunnel release system (Agee, 3M Healthcare, St Paul, Minnesota, USA). Being well known and accepted techniques of carpal tunnel release, we believe that the techniques described in this paper provide a viable alternative for carpal tunnel release in the setting of distal radius fracture fixation; with the added advantages of the original minimally invasive techniques. PMID:27454517

  11. A Novel Shape Memory Plate Osteosynthesis for Noninvasive Modulation of Fixation Stiffness in a Rabbit Tibia Osteotomy Model

    PubMed Central

    Müller, Christian W.; Pfeifer, Ronny; Meier, Karen; Decker, Sebastian; Reifenrath, Janin; Gösling, Thomas; Wesling, Volker; Krettek, Christian; Hurschler, Christof; Krämer, Manuel

    2015-01-01

    Nickel-titanium shape memory alloy (NiTi-SMA) implants might allow modulating fracture healing, changing their stiffness through alteration of both elastic modulus and cross-sectional shape by employing the shape memory effect (SME). Hypotheses: a novel NiTi-SMA plate stabilizes tibia osteotomies in rabbits. After noninvasive electromagnetic induction heating the alloy exhibits the SME and the plate changes towards higher stiffness (inverse dynamization) resulting in increased fixation stiffness and equal or better bony healing. In 14 rabbits, 1.0 mm tibia osteotomies were fixed with our experimental plate. Animals were randomised for control or induction heating at three weeks postoperatively. Repetitive X-ray imaging and in vivo measurements of bending stiffness were performed. After sacrifice at 8 weeks, macroscopic evaluation, µCT, and post mortem bending tests of the tibiae were carried out. One death and one early implant dislocation occurred. Following electromagnetic induction heating, radiographic and macroscopic changes of the implant proved successful SME activation. All osteotomies healed. In the treatment group, bending stiffness increased over time. Differences between groups were not significant. In conclusion, we demonstrated successful healing of rabbit tibia osteotomies using our novel NiTi-SMA plate. We demonstrated shape-changing SME in-vivo through transcutaneous electromagnetic induction heating. Thus, future orthopaedic implants could be modified without additional surgery. PMID:26167493

  12. Influence of internal fixator flexibility on murine fracture healing as characterized by mechanical testing and microCT imaging.

    PubMed

    Steck, Roland; Ueno, Masaki; Gregory, Laura; Rijken, Noortje; Wullschleger, Martin E; Itoman, Moritoshi; Schuetz, Michael A

    2011-08-01

    Mechanically well-defined stabilization systems have only recently become available, providing standardized conditions for studying the role of the mechanical environment on mouse bone fracture healing. The aim of this study was to characterize the time course of strength recovery and callus development of mouse femoral osteotomies stabilized with either low or high flexibility (in bending and torsion) internal fixation plates. Animals were euthanized and femora excised at 14, 21, and 28 days post-osteotomy for microCT analysis and torsional strength testing. While a larger mineralized callus was observed in osteotomies under more flexible conditions at all time points, the earlier bridging of the mineralized callus under less flexible conditions by 1 week resulted in an earlier recovery of torsional strength in mice stabilized with low flexibility fixation. Ultimate torque values for these bones were significantly higher at 14 and 21 days post-osteotomy compared to bones with the more flexible stabilization. Our study confirms the high reproducibility of the results that are achieved with this new implant system, therefore making it ideal for studying the influence of the mechanical environment on murine fracture healing under highly standardized conditions.

  13. Clinical outcome of internal fixation of unstable juvenile osteochondritis dissecans lesions of the knee.

    PubMed

    Webb, Jonathan E; Lewallen, Laura W; Christophersen, Christy; Krych, Aaron J; McIntosh, Amy L

    2013-11-01

    Juvenile osteochondritis dissecans (OCD) lesions of the knee are a common cause of knee pain in skeletally immature patients.The authors sought to determine lesion healing rates, the risk factors associated with failure to heal, and the clinical outcomes for patients who underwent internal fixation for unstable OCD lesions. A retrospective review was conducted of all patients who underwent internal fixation of OCD lesions from 1999 to 2009. Using validated scoring systems, clinical outcome and functional activity were evaluated at the follow-up. The study group comprised 19 patients (20 knees). Mean patient age was 14.5 years (range, 12-17 years). Mean clinical follow-up was 7 years (range, 2-13 years). Mean radiographic follow-up was 2.5 years (range, 0.5-9 years). Fourteen (70%) lesions were grade 3 and 6 (30%) were grade 4. Eleven knees had lateral condyle lesions and 9 had medial lesions. Bioabsorbable fixation was used in 13 knees, metal fixation was used in 5 knees, and 2 knees were fixed with a combination of methods. Osseous integration was evident in 15 (75%) of 20 knees at final follow-up. The 5 unhealed lesions were lateral condylar lesions. Mean Tegner activity scores improved from 3.3 preoperatively to 5.6 at final follow-up. Mean Lysholm and International Knee Documentation Committee scores were 86.8 and 88.7, respectively, at final follow-up. Further operative intervention was required in 11 knees, with 50% of patients undergoing removal of hardware and 15% requiring subsequent osteochondral allograft transplantation. The authors recommend bioabsorbable fixation for symptomatic stable lesions and metal compression screws with staged removal for unstable lesions.

  14. Comparison of functional outcomes of total elbow arthroplasty vs plate fixation for distal humerus fractures in osteoporotic elbows.

    PubMed

    Egol, Kenneth A; Tsai, Peter; Vazques, Oscar; Tejwani, Nirmal C

    2011-02-01

    Treating intra-articular fractures about the osteoporotic distal humerus poses a significant challenge. The purpose of this retrospective study was to evaluate functional outcomes for distal humeral fractures treated with total elbow arthroplasty (TEA) or open reduction and internal fixation (ORIF) in a nonarthritic elderly population with osteoporosis. We reviewed the records of all women older than age 60 who had undergone surgical treatment for intraarticular distal humerus fractures (Orthopaedic Trauma Association types 13B and 13C) by 1 of 2 surgeons. Demographic and operative data were obtained, charts were reviewed, and patients were asked to have their outcomes evaluated with the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and the Mayo Elbow Performance Index (MEPI). Twenty-two patients (23 elbows) were identified, and 2 of these (3 elbows) were excluded. Of the remaining 20 patients, 9 had undergone cemented, semiconstrained TEA as initial treatment, and 11 had undergone ORIF. These 2 groups were compared. Mean follow-up was 14.8 months (range, 6-38 months). There were no significant differences between the TEA and ORIF groups with respect to demographic factors. Final elbow range of motion was 92° flexion-extension arc (arthroplasty group) and 98° (fixation group). Two patients in the arthroplasty group and 2 in the fixation group died. For the remaining patients, mean DASH scores were 30.2 (arthroplasty) and 32.1 (fixation), and mean MEPI scores were 79 (arthroplasty) and 85 (fixation). These differences were not statistically significant. Four TEAs developed radiographic loosening by a mean of 15 months, and 1 of these underwent revision with good outcome. Ten of the 11 fractures in the fixation group healed radiographically; the 1 nonunion with collapse continued to be asymptomatic. Two patients in the fixation group underwent contracture release after union for limited elbow range of motion. Many factors come into play in the

  15. Comparison of functional outcomes of total elbow arthroplasty vs plate fixation for distal humerus fractures in osteoporotic elbows.

    PubMed

    Egol, Kenneth A; Tsai, Peter; Vazques, Oscar; Tejwani, Nirmal C

    2011-02-01

    Treating intra-articular fractures about the osteoporotic distal humerus poses a significant challenge. The purpose of this retrospective study was to evaluate functional outcomes for distal humeral fractures treated with total elbow arthroplasty (TEA) or open reduction and internal fixation (ORIF) in a nonarthritic elderly population with osteoporosis. We reviewed the records of all women older than age 60 who had undergone surgical treatment for intraarticular distal humerus fractures (Orthopaedic Trauma Association types 13B and 13C) by 1 of 2 surgeons. Demographic and operative data were obtained, charts were reviewed, and patients were asked to have their outcomes evaluated with the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and the Mayo Elbow Performance Index (MEPI). Twenty-two patients (23 elbows) were identified, and 2 of these (3 elbows) were excluded. Of the remaining 20 patients, 9 had undergone cemented, semiconstrained TEA as initial treatment, and 11 had undergone ORIF. These 2 groups were compared. Mean follow-up was 14.8 months (range, 6-38 months). There were no significant differences between the TEA and ORIF groups with respect to demographic factors. Final elbow range of motion was 92° flexion-extension arc (arthroplasty group) and 98° (fixation group). Two patients in the arthroplasty group and 2 in the fixation group died. For the remaining patients, mean DASH scores were 30.2 (arthroplasty) and 32.1 (fixation), and mean MEPI scores were 79 (arthroplasty) and 85 (fixation). These differences were not statistically significant. Four TEAs developed radiographic loosening by a mean of 15 months, and 1 of these underwent revision with good outcome. Ten of the 11 fractures in the fixation group healed radiographically; the 1 nonunion with collapse continued to be asymptomatic. Two patients in the fixation group underwent contracture release after union for limited elbow range of motion. Many factors come into play in the

  16. UK Fixation of Distal Tibia Fractures (UK FixDT): protocol for a randomised controlled trial of ‘locking’ plate fixation versus intramedullary nail fixation in the treatment of adult patients with a displaced fracture of the distal tibia

    PubMed Central

    Achten, Juul; Parsons, Nicholas R; McGuinness, Katie R; Petrou, Stavros; Lamb, Sarah E; Costa, Matthew L

    2015-01-01

    Introduction The treatment of displaced, extra-articular fractures of the distal tibia remains controversial. These injuries are difficult to manage due to limited soft tissue cover, poor vascularity of the area and proximity to the ankle joint. Surgical treatment options are expanding and include locked intramedullary nails, plate and screw fixation and external fixator systems. The nail and plate options are most commonly used in the UK, but controversy exists over which treatment is most clinically and cost-effective. In this multicentre randomised controlled trial we aim to assess ratings of disability 6 months postinjury in patients who have sustained a distal tibia fracture treated with either an intramedullary nail or plate and locking screw fixation. Methods and analysis Adult patients presenting at trial centres with an acute fracture of the distal tibia will be considered for inclusion. A total of 320 patients will provide 90% power to detect a difference of 8 points in Disability Rating Index (DRI) score at 6 months at the 5% level. The randomisation sequence is stratified by trial centre and age, and administered via web-based service with 1:1 treatment allocation. Baseline demographic and pre-injury functional data and radiographs will be collected using the DRI, Olerud and Molander, and EuroQol EQ-5D questionnaire. Clinical assessment, early complications and radiographs will be recorded at 6–8 weeks. Functional outcome, health-related quality of life and resource use will be collected at 3, 6 and 12 months postoperatively. The main analysis will investigate differences in DRI 6 months postsurgery, between the two treatment groups, on an intention-to-treat basis. Tests will be two-sided and considered to provide evidence for a significant difference if p values are <0.05. Ethics and dissemination NRES Committee West-Midlands, 6/11/2012 (ref:12/WM/0340). The results of the trial will be disseminated via peer-reviewed publications and

  17. Enhancement of Apoptosis by Titanium Alloy Internal Fixations during Microwave Treatments for Fractures: An Animal Study

    PubMed Central

    Zhang, Lina; Ye, Dongmei; Feng, Xianxuan; Fu, Tengfei; Bai, Yuehong

    2015-01-01

    Objective Microwaves are used in one method of physical therapy and can increase muscle tissue temperature which is useful for improving muscle, tendon and bone injuries. In the study, we sought to determine whether titanium alloy internal fixations influence apoptosis in tissues subjected to microwave treatments at 2,450 MHz and 40 W during the healing of fractures because this issue is not yet fully understood. Methods In this study, titanium alloy internal fixations were used to treat 3.0-mm transverse osteotomies in the middle of New Zealand rabbits’ femurs. After the operation, 30-day microwave treatments were applied to the 3.0 mm transverse osteotomies 3 days after the operation. The changes in the temperatures of the muscle tissues in front of the implants or the 3.0 mm transverse osteotomies were measured during the microwave treatments. To characterize the effects of titanium alloy internal fixations on apoptosis in the muscles after microwave treatment, we performed TUNEL assays, fluorescent real-time (quantitative) PCR, western blotting analyses, reactive oxygen species (ROS) detection and transmission electron microscopy examinations. Results The temperatures were markedly increased in the animals with the titanium alloy implants. Apoptosis in the muscle cells of the implanted group was significantly more extensive than that in the non-implanted control group at different time points. Transmission electron microscopy examinations of the skeletal muscles of the implanted groups revealed muscular mitochondrial swelling, vacuolization. ROS, Bax and Hsp70 were up-regulated, and Bcl-2 was down-regulated in the implanted group. Conclusion Our results suggest that titanium alloy internal fixations caused greater muscular tissue cell apoptosis following 2,450 MHz, 40 W microwave treatments in this rabbit femur fracture models. PMID:26132082

  18. Displaced Intra-Articular Fractures of the Distal Radius: Open Reduction With Internal Fixation Versus Bridging External Fixation

    PubMed Central

    Fakoor, Mohammad; Fakoor, Morteza; Mohammadhoseini, Payam

    2015-01-01

    Background: Distal radius fracture is common in all ages. Mobility and wrist function is important. The choice of treatment should aim for optimal function with minimal complications. Objectives: In this study we compared two surgical approaches, open reduction and internal fixation (ORIF) and closed reduction with external fixation (CR + EF), for treatment of intra-articular distal radius fractures. Patients and Methods: Ninety-four patients with distal radius fracture (type 3, 4 and 5 Fernandez classification) were treated with two surgical methods (ORIF and CR + EF); 55 were treated with CR + EF and 39 were treated with ORIF by different surgeons. All patients were assessed at the end of the first, third and sixth week; and then after the third, sixth and 12th month. At the end of the follow-up, all patients completed the Michigan hand outcome questionnaire (MHOQ). We compared radiological parameters of distal radius, range of motion (ROM) of the wrist, duration of rehabilitation, complication and patient satisfaction of the methods. Results: In our study, radiological findings for the ORIF group were radial inclination (RI): 19.35, radial length (RL): 10.35, radial tilt (RT): 8.92, and ulnar variance (UV): 1.64, while for the CR + EF group these were RI: 15.13, RL: 8, RT: 4.78, and UV: 0.27. The ROM for ORIF were flexion/extension (F/E): 137, Radial/Ulnar deviation (R/U): 52, and Supination/Pronation (S/P): 141, while for the CR + EF group these were F/E: 117, R/U: 40 and S/P: 116. Michigan hand outcome score for ORIF was 75% and for Ext. fix was 60%. The rate of complication with the ORIF method was 58% and in Ext. fix this was 69%. The patients in CR + EF had more than the ORIF course of physiotherapy and rehabilitation. Conclusions: In comparison of ORIF and CR + EF, all results including functional score, clinical and radiologic criteria were in favor of the ORIF method while there were less complications with this method. We believe that ORIF is a better

  19. Wire internal fixation: an obsolete, yet valuable method for surgical management of facial fractures

    PubMed Central

    Bouletreau, Pierre; Konsem, Tarcissus; Traoré, Ibraïma; Coulibaly, Antoine Toua; Ouédraogo, Dieudonné

    2014-01-01

    In some developing countries wire is still widely used in facial fractures internal fixation. This study presents the effectiveness and complications of wire osteosynthesis in a university teaching hospital in Burkina Faso and discusses some of its other benefits and disadvantages. Notes of 227 patients with facial fractures treated by wire internal fixation at department of stomatology and maxillofacial surgery of CHU Souro Sanou, Burkina Faso between 2006 and 2010 are reviewed retrospectively. A satisfactory treatment outcome was recorded in 91.2% of the 227 patients. Complications occurred in 8.8% of the patients who had operative site infection (3.1%), malocclusion (1.8%), sensory disturbance (1.8), facial asymmetry (1.3%), delayed bone union (0.9%) or enophtalmos (0.4%). The overall complications rate was 7.4% after mandibular osteosynthesis, 6.9% after Le Fort osteosynthesis and 6.5% after zygoma osteosynthesis. Post operative infections occurred irrespective to the surgical site. The other complications were more specific to the surgical site. Wire internal fixation may be a reasonable alternative for the surgical treatment of non-comminuted facial fractures and those without bone substance loss, in the setting of limited resources. PMID:25237416

  20. Clinical Evaluation of an Unsintered Hydroxyapatite/Poly-L-Lactide Osteoconductive Composite Device for the Internal Fixation of Maxillofacial Fractures

    PubMed Central

    Sukegawa, Shintaro; Kanno, Takahiro; Katase, Naoki; Shibata, Akane; Takahashi, Yuka; Furuki, Yoshihiko

    2016-01-01

    Introduction: OSTEOTRANS MX (Takiron Co, Ltd, Osaka, Japan) is a resorbable osteosynthetic material composed of an unsintered hydroxyapatite/poly-l-lactide composite, and its osteoconductive capacity has been documented. The authors here report their clinical experience using OSTEOTRANS MX. Methods: The authors treated 35 patients (19 men, 16 women; age, 14–88 years; mean ± standard deviation, 38.4 ± 19.9 years) with maxillofacial fractures. The authors used standard surgery to stabilize fractures in all patients, fitting resorbable plates (thickness, 1.0 or 1.4 mm) and screws (diameter, 2 mm) according to Arbeitsgemeinschaft für Osteosynthesefragen/Association (AO) for the Study of Internal Fixation guidelines. Results: All patients eventually achieved satisfactory healing with favorable restoration of form and function without foreign body reaction. Complications occurred in 3 patients—plate exposure in 2 and discomfort in 1. However, fracture sites healed in all patients. Scanning electron microscopy revealed that the devices bonded directly to the bone without interposition of nonmineralized tissue. Conclusion: OSTEOTRANS MX is a useful material with few complications. Its osteoconductive bioactivity is advantageous for the early functional improvement of maxillofacial fractures. PMID:27428913

  1. Biomechanical in vitro evaluation of three stable internal fixation techniques used in sagittal osteotomy of the mandibular ramus: a study in sheep mandibles

    PubMed Central

    de OLIVERA, Leandro Benetti; SANT'ANA, Eduardo; MANZATO, Antonio José; GUERRA, Fábio Luis Bunemer; ARNETT, G. William

    2012-01-01

    Among the osteotomies performed in orthognathic surgery, the sagittal osteotomy of the mandibular ramus (SOMR) is the most common, allowing a great range of movements and stable internal fixation (SIF), therefore eliminating the need of maxillomandibular block in the postoperative period. Objectives: The purpose of this study was to evaluate the biomechanical resistance of three national systems used for SIF in SOMR in sheep mandibles. Material and methods: The study was performed in 30 sheep hemi-mandibles randomly divided into 3 experimental groups, each containing 10 hemi-mandibles. The samples were measured to avoid discrepancies and then subjected to SOMR with 5-mm advancement. In group I, 2.0x12 mm screws were used for fixation, inserted in an inverted "L" pattern (inverted "L" group). In group II, fixation was performed with two 2.0x12 mm screws, positioned in a linear pattern and a 4-hole straight miniplate and four 2.0x6.0 mm monocortical screws (hybrid group). In group III, fixation was performed with two 4-hole straight miniplates and eight 2.0x6.0 mm monocortical screws (mini plate group). All materials used for SIF were supplied by Osteosin - SIN. The hemimandibles were subjected to vertical linear load test by Kratos K2000MP mechanical testing unit for loading registration and displacement. Results: All groups showed similar resistance during mechanical test for loading and displacement, with no statistically significant differences between groups according to analysis of variance. Conclusion: These results indicate that the three techniques of fixation are equally effective for clinical fixation of SOMR. PMID:23032203

  2. Is Loss of Fixation Following Locked Plating of Proximal Humeral Fractures Related to the Number of Screws and Their Positions in the Humeral Head?

    PubMed Central

    Maddah, Mohammad; Prall, Wolf C.; Geyer, Lucas; Wirth, Stefan; Mutschler, Wolf; Ockert, Ben

    2014-01-01

    The aim of the study was to examine the correlation between the chosen position of screws and the complications observed in patients who underwent locked plating of proximal humeral fractures. We evaluated radiographs of 367 patients treated by locked-plating for proximal humeral fractures. Radiographs were taken at one day, 6 weeks, 3 months and 6 months after surgery, and were analyzed for secondary fracture displacement, loss of fixation, cutting out of screws and necrosis of the humeral head. Secondary loss of fixation occurred in 58 cases (15.8%) and among those cutting out of screws was observed in 25 cases (6.8%). In cases of secondary loss of fixation a mean of 6.7 screws were used to fix the fracture (vs 6.6, P=0.425). There was neither significant correlation between position of screws and the occurrence of postoperative loss of fixation in Spearman correlation nor relationship from backward logistic regression analysis. Loss of fixation following locked plating of proximal humeral fractures does not relate to the number of screws and their positions in the humeral head. In consequence, anatomic fracture reduction and restoration of the humeral head-shaft angle are still important factors and should not be disregarded. PMID:25002940

  3. Compression-plate fixation of femoral shaft fractures in children aged 8 to 12 years.

    PubMed

    Fyodorov, I; Sturm, P F; Robertson, W W

    1999-01-01

    Twenty-one patients between the ages of 8 and 12 years with 23 femoral-shaft fractures underwent dynamic compression plating (DCP) between August 1993 and February 1996. Eleven patients had isolated femoral-shaft fractures, five had associated long-bone injuries, and five had multiple organ injuries. A 4.5-mm DCP plate was used in each case. Patients were kept non-weight bearing with crutches for an average of 8 weeks. Hardware failure occurred in two patients at 6 weeks. One was treated with revision plating, and the other, with spica casting. Both healed uneventfully. No other complications occurred. All patients were radiographically and clinically healed at last follow-up.

  4. Comparison of nail-plate fixation and Ender's nailing for intertrochanteric fractures.

    PubMed

    Hall, G; Ainscow, D A

    1981-02-01

    Two comparable groups of patients with fractures of the trochanteric region of the femur were studied. One hundred and sixty-five fractures had been fixed with conventional nail-plates and 132 with Ender's nails. Ender's nails gave superior results in the treatment of trochanteric fractures. The operation was quicker and less traumatic than that using conventional nail-plates and both the mortality rate and the time in hospital were reduced. More patients in the group with Ender's nails who were initially independent returned to an independent existence.

  5. Internal fixation after fracture or osteotomy of the femur in young children with polyostotic fibrous dysplasia.

    PubMed

    Benedetti Valentini, Matteo; Ippolito, Ernesto; Catellani, Francesco; Farsetti, Pasquale

    2015-07-01

    Children from 4 to 7 years of age with polyostotic fibrous dysplasia (PFD) may need internal fixation of the femur for either fracture or osteotomy. At that age, the small size of the femur allows only the use of small intramedullary nails. However, titanium elastic nails and rigid intramedullary pediatric interlocking femoral nails - good for fracture or osteotomy fixation in the normal femur - are not indicated in PFD. From 2009 to 2011, we treated eight cases of PFD femoral fracture and deformity by internal fixation with a custom-modified adult humeral nail to which a spiral blade was connected. The 7-mm thick nail fit properly into the small femoral shaft and the spiral blade conferred ideal mechanical support to the femoral neck. Three cases had replacement of the humeral nail with a more appropriate adult femoral nail 3 years after the index procedure when the femur had reached an adequate size. In the maximum follow-up period of 4 years, few complications were observed.

  6. Early open reduction and internal fixation of the disrupted pelvic ring.

    PubMed

    Goldstein, A; Phillips, T; Sclafani, S J; Scalea, T; Duncan, A; Goldstein, J; Panetta, T; Shaftan, G

    1986-04-01

    Early open reduction and internal fixation (ORIF) of extremity fractures in patients with multiple injuries has been demonstrated to be safe, improve survival, and decrease the incidence of respiratory failure. Complications leading to abandonment of planned operative fixation and death in several patients with pelvic fractures led us to initiate a policy of early ORIF of the disrupted pelvic ring. Early ORIF of the pelvis was performed in 15 multiply injured patients between May 1984 and August 1985. Patients ranged in age from 13 to 79 years, their Hospital Trauma Index-ISS scores ranged from 14 to 68, and number of preoperative transfusions ranged from 0 to 42. Types of fractures were A-P compression, two, lateral compression, one, vertical shear, seven, complex, two, and acetabulum with ring disruption, three. All patients were resuscitated, transported in pneumatic antishock garments, and evaluated by abdominal and pelvic CT scan (in two patients following celiotomy). Preoperative angiograms to assess retroperitoneal hemorrhage in eight patients resulted in identification and control of significant bleeding in five. The mean time from injury to pelvic stabilization was 38 hours. Seven patients underwent ORIF within the first 24 hours. In most cases simultaneous anterior and posterior internal fixation was performed with the patient in the lateral decubitus position. Excluding associated procedures, operative time averaged 5.1 hours. Intra-operative transfusions averaged 4 units (range, 0-11). Rigid fixation was achieved in all patients. Most patients were out of bed by the third postoperative day. No patient developed respiratory failure. Two patients developed wound infections. Modification of our technique has avoided this complication in the latter part of this series.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Effects of Low-Dose Microwave on Healing of Fractures with Titanium Alloy Internal Fixation: An Experimental Study in a Rabbit Model

    PubMed Central

    Zhang, Han; Fu, Tengfei; Jiang, Lan; Bai, Yuehong

    2013-01-01

    Background Microwave is a method for improving fracture repair. However, one of the contraindications for microwave treatment listed in the literature is surgically implanted metal plates in the treatment field. The reason is that the reflection of electromagnetic waves and the eddy current stimulated by microwave would increase the temperature of magnetic implants and cause heat damage in tissues. Comparing with traditional medical stainless steel, titanium alloy is a kind of medical implants with low magnetic permeability and electric conductivity. But the effects of microwave treatment on fracture with titanium alloy internal fixation in vivo were not reported. The aim of this article was to evaluate the security and effects of microwave on healing of a fracture with titanium alloy internal fixation. Methods Titanium alloy internal fixation systems were implanted in New Zealand rabbits with a 3.0 mm bone defect in the middle of femur. We applied a 30-day microwave treatment (2,450MHz, 25W, 10 min per day) to the fracture 3 days after operation. Temperature changes of muscle tissues around implants were measured during the irradiation. Normalized radiographic density of the fracture gap was measured on the 10th day and 30th day of the microwave treatment. All of the animals were killed after 10 and 30 days microwave treatment with histologic and histomorphometric examinations performed on the harvested tissues. Findings The temperatures did not increase significantly in animals with titanium alloy implants. The security of microwave treatment was also supported by histology of muscles, nerve and bone around the implants. Radiographic assessment, histologic and histomorphometric examinations revealed significant improvement in the healing bone. Conclusion Our results suggest that, in the healing of fracture with titanium alloy internal fixation, a low dose of microwave treatment may be a promising method. PMID:24086626

  8. Distal Radius Volar Rim Fracture Fixation Using DePuy-Synthes Volar Rim Plate.

    PubMed

    Kachooei, Amir Reza; Tarabochia, Matthew; Jupiter, Jesse B

    2016-03-01

    Background To assess the results of distal radius fractures with the involvement of the volar rim fixed with the DePuy-Synthes Volar Rim Plate. Case Description We searched for the patients with volar rim fracture and/or volar rim fractures as part of a complex fracture fixed with a volar rim plate. Ten patients met the inclusion criteria: three patients with type 23B3, six patients with type 23C, and one patient with very distal type 23A. The mean follow-up was 14 months (range: 2-26). Fractures healed in all patients. Of the three patients with isolated volar rim fractures (type 23B3), two patients had no detectable deficits in motion. These patients had an average Gartland and Werley score of 9 (range: 2-14). Of the other seven patients (six with type 23C and one with type 23A fracture), three patients healed with full range of motion and four had some deficits in range of motion. Two patients had excellent results, three had good results, and two had fair results using the Gartland and Werley categorical rating. One patient healed with a shortened radius and ulnar impingement requiring a second surgery for ulnar head resection arthroplasty. Literature Review Results after nonoperative treatment of volar rim fractures are not satisfactory and often require subsequent corrective osteotomy. Satisfactory outcomes are achieved when the fragments are well reduced and secured regardless of the device type. Clinical Relevance Volar rim plates give an adequate buttress of the volar radius distal to volar projection of the lunate facet and do not interfere with wrist mobility. Furthermore, the dorsal fragments can be fixed securely through the volar approach eliminating the need for a secondary posterior incision. However, patients should be informed of the potential problems and the need to remove the plate if symptoms develop.

  9. Fixation of sternal fracture using absorbable plating system, three years follow-up

    PubMed Central

    Katballe, Niels; Pilegaard, Hans

    2015-01-01

    Sternal fractures occur due to severe chest wall trauma in a small number of patients. They are often conservatively treated. The surgical intervention, although controversial, is indicated in case of deformity, severe pain, and ventilatory complications. We report the first case where absorbable plate has been used to fix a traumatic fracture in a 42-year-old female. After 3 years, the patient is still free of symptoms and CT scanning reveals intact sternal bone structure. PMID:26101659

  10. Reconstruction of multiplanar deformity of the hindfoot and midfoot with internal fixation techniques.

    PubMed

    Dreher, Thomas; Hagmann, Sebastién; Wenz, Wolfram

    2009-09-01

    Reconstruction surgery of the midand hindfoot is a demanding challenge for foot surgeons. Satisfactory results depend not only on surgical technique and skills but also on the knowledge of underlying disorders, pathomechanics, and indication criteria. The cavovarus foot, the planovalgus foot, and Charcot's foot are some of the most challenging foot deformities, requiring different surgical strategies for their correction. Most of the osteotomies and fusions in children and adults can be fixed with transcutaneous Kirschner wires, which are inexpensive and easy to use and remove. The use of alternative fixation systems such as cannulated screws, compression screws, or angle-stable locking plates depends on patient age, vascular situation, risk for nonunion, and underlying pathology.

  11. Treatment of Spinal Tuberculosis by Debridement, Interbody Fusion and Internal Fixation via Posterior Approach Only.

    PubMed

    Tang, Ming-xing; Zhang, Hong-qi; Wang, Yu-xiang; Guo, Chao-feng; Liu, Jin-yang

    2016-02-01

    Surgical treatment for spinal tuberculosis includes focal tuberculosis debridement, segmental stability reconstruction, neural decompression and kyphotic deformity correction. For the lesions mainly involved anterior and middle column of the spine, anterior operation of debridement and fusion with internal fixation has been becoming the most frequently used surgical technique for the spinal tuberculosis. However, high risk of structural damage might relate with anterior surgery, such as damage in lungs, heart, kidney, ureter and bowel, and the deformity correction is also limited. Due to the organs are in the front of spine, there are less complications in posterior approach. Spinal pedicle screw passes through the spinal three-column structure, which provides more powerful orthopedic forces compared with the vertebral body screw, and the kyphotic deformity correction effect is better in posterior approach. In this paper, we report a 68-year-old male patient with thoracic tuberculosis who underwent surgical treatment by debridement, interbody fusion and internal fixation via posterior approach only. The patient was placed in prone position under general anesthesia. Posterior midline incision was performed, and the posterior spinal construction was exposed. Then place pedicle screw, and fix one side rod temporarily. Make the side of more bone destruction and larger abscess as lesion debridement side. Resect the unilateral facet joint, and retain contralateral structure integrity. Protect the spinal cord, nerve root. Clear sequestrum, necrotic tissue, abscess of paravertebral and intervertebral space. Specially designed titanium mesh cages or bone blocks were implanted into interbody. Fix both side rods and compress both sides to make the mesh cages and bone blocks tight. Reconstruct posterior column structure with allogeneic bone and autologous bone. Using this technique, the procedures of debridement, spinal cord decompression, deformity correction, bone grafting

  12. Treatment of Spinal Tuberculosis by Debridement, Interbody Fusion and Internal Fixation via Posterior Approach Only.

    PubMed

    Tang, Ming-xing; Zhang, Hong-qi; Wang, Yu-xiang; Guo, Chao-feng; Liu, Jin-yang

    2016-02-01

    Surgical treatment for spinal tuberculosis includes focal tuberculosis debridement, segmental stability reconstruction, neural decompression and kyphotic deformity correction. For the lesions mainly involved anterior and middle column of the spine, anterior operation of debridement and fusion with internal fixation has been becoming the most frequently used surgical technique for the spinal tuberculosis. However, high risk of structural damage might relate with anterior surgery, such as damage in lungs, heart, kidney, ureter and bowel, and the deformity correction is also limited. Due to the organs are in the front of spine, there are less complications in posterior approach. Spinal pedicle screw passes through the spinal three-column structure, which provides more powerful orthopedic forces compared with the vertebral body screw, and the kyphotic deformity correction effect is better in posterior approach. In this paper, we report a 68-year-old male patient with thoracic tuberculosis who underwent surgical treatment by debridement, interbody fusion and internal fixation via posterior approach only. The patient was placed in prone position under general anesthesia. Posterior midline incision was performed, and the posterior spinal construction was exposed. Then place pedicle screw, and fix one side rod temporarily. Make the side of more bone destruction and larger abscess as lesion debridement side. Resect the unilateral facet joint, and retain contralateral structure integrity. Protect the spinal cord, nerve root. Clear sequestrum, necrotic tissue, abscess of paravertebral and intervertebral space. Specially designed titanium mesh cages or bone blocks were implanted into interbody. Fix both side rods and compress both sides to make the mesh cages and bone blocks tight. Reconstruct posterior column structure with allogeneic bone and autologous bone. Using this technique, the procedures of debridement, spinal cord decompression, deformity correction, bone grafting

  13. Treatment of Spinal Tuberculosis by Debridement, Interbody Fusion and Internal Fixation via Posterior Approach Only

    PubMed Central

    Tang, Ming‐xing; Wang, Yu‐xiang; Guo, Chao‐feng; Liu, Jin‐yang

    2016-01-01

    Surgical treatment for spinal tuberculosis includes focal tuberculosis debridement, segmental stability reconstruction, neural decompression and kyphotic deformity correction. For the lesions mainly involved anterior and middle column of the spine, anterior operation of debridement and fusion with internal fixation has been becoming the most frequently used surgical technique for the spinal tuberculosis. However, high risk of structural damage might relate with anterior surgery, such as damage in lungs, heart, kidney, ureter and bowel, and the deformity correction is also limited. Due to the organs are in the front of spine, there are less complications in posterior approach. Spinal pedicle screw passes through the spinal three‐column structure, which provides more powerful orthopedic forces compared with the vertebral body screw, and the kyphotic deformity correction effect is better in posterior approach. In this paper, we report a 68‐year‐old male patient with thoracic tuberculosis who underwent surgical treatment by debridement, interbody fusion and internal fixation via posterior approach only. The patient was placed in prone position under general anesthesia. Posterior midline incision was performed, and the posterior spinal construction was exposed. Then place pedicle screw, and fix one side rod temporarily. Make the side of more bone destruction and larger abscess as lesion debridement side. Resect the unilateral facet joint, and retain contralateral structure integrity. Protect the spinal cord, nerve root. Clear sequestrum, necrotic tissue, abscess of paravertebral and intervertebral space. Specially designed titanium mesh cages or bone blocks were implanted into interbody. Fix both side rods and compress both sides to make the mesh cages and bone blocks tight. Reconstruct posterior column structure with allogeneic bone and autologous bone. Using this technique, the procedures of debridement, spinal cord decompression, deformity correction, bone

  14. [Humerus varus: correction by proximal valgus osteotomy with precontourned plate fixation in children].

    PubMed

    Tallón-López, J; Domínguez-Amador, J J; Andrés-García, J A

    2014-01-01

    Varus deformity of the proximal humerus in children is a little known pathology due to its low incidence of presentation. Progress has been made in recent years in understanding the possible etiology and pathophysiological causes. Radiological criteria for diagnosis and functional impairment that occurs have also been defined. However, there are few reports in the literature about the surgical treatment of this deformity in children. In this paper we present a case of surgical treatment of this deformity by corrective osteotomy fixed with precontoured external maleolar plate osteosynthesis.

  15. New tool for applying traction during open reduction and internal fixation of acetabular fractures.

    PubMed

    Lien, Fang-Chieh

    2012-04-01

    Open reduction and internal fixation is used to treat complex acetabular fractures. Traction on the femur is necessary to reduce the acetabulum and is accomplished by surgical assistants or with mechanical devices. To overcome the disadvantages of various traction methods, the author designed a simple, novel traction device that can be used on an ordinary orthopedic or radiolucent operating table and has advantages over manual traction and commercial traction tables. The device consists of a horizontal cross-bar supported over the patient by 2 free-standing legs and is constructed from commercially available parts.

  16. A new material (single crystal sapphire screw) for internal fixation of the mandibular ramus.

    PubMed

    Iizuka, T; Fujimoto, H; Ono, T

    1987-02-01

    A new single crystal sapphire bone screw which has favourable properties such as chemical stability, mechanical strength and biocompatibility, was applied for rigid internal fixation of the sagittal split osteotomies in 86 cases since 1982. Radiographic findings supported the excellent biocompatibility of the material; there was no noticeable bone loss around the screw and the excellent bone adaptation to the threaded portion was observed. The screws can mechanically support the split mandibular rami until bone union occurs. Complications due to the screw were not encountered in follow-up periods of 0.5-3.5 years.

  17. Double plate fixation for correction of the malunited distal ulna fracture: a case report.

    PubMed

    Bessho, Yuki; Okazaki, Masato; Nakamura, Toshiyasu

    2011-01-01

    A 62-year-old woman visited our hospital one year after a motor vehicle accident complaining of ulnar wrist pain and restricted pronation and supination. Radiographs showed a 35° angular deformity at the ulnar neck. Closing wedge osteotomy was performed using two plates for stabilization. Twenty-four months postoperatively, the osteotomy site united without correction loss and the patient gained adequate pronation and supination. To the best of our knowledge, this represents the first report of corrective osteotomy for the treatment of malunited ulnar neck fracture. Although salvage operations such as ulnar head resection and the Sauvé-Kapandji procedure may provide reasonable results, anatomical repair can be considered as an option. PMID:22072470

  18. Combined Internal and External Fixation for Diabetic Charcot Reconstruction: A Retrospective Case Series.

    PubMed

    Hegewald, Kenneth W; Wilder, Megan L; Chappell, Todd M; Hutchinson, Byron L

    2016-01-01

    Diabetic Charcot neuroarthropathy is a complex, limb-threatening disease process with major lifestyle-altering repercussions for patients. When Charcot neuroarthropathy leads to unstable deformity, ulceration, and potential infection despite conservative therapies, foot and ankle surgeons often consider reconstructive limb salvage procedures to restore function. The purpose of the present study was to evaluate the clinical and radiographic outcomes of diabetic Charcot reconstruction using combined internal and external fixation. A total of 22 patients were reviewed; 16 (72.73%) midfoot and 6 (27.27%) tibiotalocalcaneal arthrodesis procedures were consecutively performed from March 2009 to May 2013. All surgical procedures were performed in nonacute phases of the Charcot process in patients with diagnosed diabetes mellitus and documented peripheral neuropathy. Patients were excluded from the study if they were not diabetic despite having undergone Charcot reconstruction, regardless of the fixation method, or if they did not complete radiographic imaging. During a mean follow-up period of 58.60 ± 42.37 (range 16 to 164) weeks, limb salvage was achieved in 20 patients (90.91%), and 2 (9.09%) required below-the-knee amputation at a mean of 42 ± 14.14 weeks. Wound dehiscence occurred in 8 (36.36%), pin tract infection in 10 (45.45%), and superficial wound infection in 9 (40.91%) and peaked in bimodal fashion at 4 and 8 weeks postoperatively. Radiographic analysis of the pre- versus postoperative alignment showed statistically significant changes in the lateral talo-first metatarsal angle (p = .02) and lateral talar declination angle (p = .01). The limb salvage rates with diabetic Charcot reconstruction are improving in part because of the continued development of increasingly superior modalities for both internal and external fixation.

  19. Combined Internal and External Fixation for Diabetic Charcot Reconstruction: A Retrospective Case Series.

    PubMed

    Hegewald, Kenneth W; Wilder, Megan L; Chappell, Todd M; Hutchinson, Byron L

    2016-01-01

    Diabetic Charcot neuroarthropathy is a complex, limb-threatening disease process with major lifestyle-altering repercussions for patients. When Charcot neuroarthropathy leads to unstable deformity, ulceration, and potential infection despite conservative therapies, foot and ankle surgeons often consider reconstructive limb salvage procedures to restore function. The purpose of the present study was to evaluate the clinical and radiographic outcomes of diabetic Charcot reconstruction using combined internal and external fixation. A total of 22 patients were reviewed; 16 (72.73%) midfoot and 6 (27.27%) tibiotalocalcaneal arthrodesis procedures were consecutively performed from March 2009 to May 2013. All surgical procedures were performed in nonacute phases of the Charcot process in patients with diagnosed diabetes mellitus and documented peripheral neuropathy. Patients were excluded from the study if they were not diabetic despite having undergone Charcot reconstruction, regardless of the fixation method, or if they did not complete radiographic imaging. During a mean follow-up period of 58.60 ± 42.37 (range 16 to 164) weeks, limb salvage was achieved in 20 patients (90.91%), and 2 (9.09%) required below-the-knee amputation at a mean of 42 ± 14.14 weeks. Wound dehiscence occurred in 8 (36.36%), pin tract infection in 10 (45.45%), and superficial wound infection in 9 (40.91%) and peaked in bimodal fashion at 4 and 8 weeks postoperatively. Radiographic analysis of the pre- versus postoperative alignment showed statistically significant changes in the lateral talo-first metatarsal angle (p = .02) and lateral talar declination angle (p = .01). The limb salvage rates with diabetic Charcot reconstruction are improving in part because of the continued development of increasingly superior modalities for both internal and external fixation. PMID:26188625

  20. Analysis of risk factors for femoral head necrosis after internal fixation in femoral neck fractures.

    PubMed

    Wang, Tao; Sun, Jun-Ying; Zha, Guo-Chun; Jiang, Tao; You, Zhen-Jun; Yuan, De-Jing

    2014-12-01

    Femoral head necrosis is a rare but devastating complication following femoral neck fracture. The reported incidence of avascular necrosis after femoral neck fracture fixation varies widely, and there is no consensus regarding its risk factors. The aim of this study was to analyze the risk factors for femoral head necrosis after internal fixation in femoral neck fracture. This retrospective study included 166 patients with femoral neck fractures treated with surgical reduction and internal fixation at the authors' institution from January 2004 to December 2008. Eight patients died for reasons unrelated to the surgery, and 12 patients were lost to follow-up. The remaining 146 patients (146 fractures) were followed until union or until conversion to total hip arthroplasty. The patients included 61 males and 85 females with an average age of 47.5 years (range, 18-68 years). The authors analyzed the following factors: age, sex, Garden classification, reduction quality, surgical methods, injury-to-surgery interval, preoperative traction, weight-bearing time, and implant removal. All patients were followed for a mean of 52 months (range, 6-90 months). The incidence of femoral head necrosis was 14.4% (21/146). Garden classification (P=.012), reduction quality (P=.008), implant removal (P=.020), and preoperative traction (P=.003) were significantly associated with femoral head necrosis. Patient age (P=.990), sex (P=.287), injury-to-surgery interval (P=.360), weight-bearing time (P=.868), and surgical methods (P=.987) were not significantly associated with femoral head necrosis. In multivariate logistic regression analysis, implant removal was not a significant risk factor for femoral head necrosis development (P=.498). Garden classification, reduction quality, and preoperative traction had a significant effect on femoral head necrosis development. PMID:25437087

  1. Femoral neck shortening after internal fixation of a femoral neck fracture.

    PubMed

    Zielinski, Stephanie M; Keijsers, Noël L; Praet, Stephan F E; Heetveld, Martin J; Bhandari, Mohit; Wilssens, Jean Pierre; Patka, Peter; Van Lieshout, Esther M M

    2013-07-01

    This study assesses femoral neck shortening and its effect on gait pattern and muscle strength in patients with femoral neck fractures treated with internal fixation. Seventy-six patients from a multicenter randomized controlled trial participated. Patient characteristics and Short Form 12 and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were collected. Femoral neck shortening, gait parameters, and maximum isometric forces of the hip muscles were measured and differences between the fractured and contralateral leg were calculated. Variables of patients with little or no shortening, moderate shortening, and severe shortening were compared using univariate and multivariate analyses. Median femoral neck shortening was 1.1 cm. Subtle changes in gait pattern, reduced gait velocity, and reduced abductor muscle strength were observed. Age, weight, and Pauwels classification were risk factors for femoral neck shortening. Femoral neck shortening decreased gait velocity and seemed to impair gait symmetry and physical functioning. In conclusion, internal fixation of femoral neck fractures results in permanent physical limitations. The relatively young and healthy patients in our study seem capable of compensating. Attention should be paid to femoral neck shortening and proper correction with a heel lift, as inadequate correction may cause physical complaints and influence outcome. PMID:23823040

  2. A Comparison of Internal Fixation and Bipolar Hemiarthroplasty for the Treatment of Reverse Oblique Intertrochanteric Femoral Fractures in Elderly Patients

    PubMed Central

    Park, Bong-Ju; Min, Woong-Bae

    2015-01-01

    Purpose To compare the clinical and radiological results between internal fixation using the proximal femoral nail system and bipolar hemiarthroplasty (BHA) in reverse oblique intertrochanteric hip fractures in elderly patients. Materials and Methods From January 2005 to July 2012, we reviewed the medical records of 53 patients who had been treated surgically for reverse oblique intertrochanteric fracture and had been followed-up on for a minimum of two years. All patients were ≥70 years of age, and divided into two groups for retrospective evaluation. One group was treated with internal fixation using the proximal femoral nail system (31 cases), and the other group was treated with BHA (22 cases). Results Early ambulation postoperatively and less pain at postoperative three month were significantly superior in the BHA group. However, by 24 months postoperatively, the internal fixation group exhibited higher Harris scores and correspondingly less pain than the BHA group. There were no significant differences in union rate, duration of hospitalization or lateral wall fracture healing between the two groups. Four patients in the internal fixation group underwent reoperation. Conclusion In the treatment of intertrochanteric fracture of the reverse oblique type, open reduction and internal fixation should be considered to be the better choice for patients with good health and bone quality. However, in cases of severe comminition of fracture and poor bone quality, BHA is an alternative offering advantages including early ambulation, less pain at early stages, and a lower risk of reoperation. PMID:27536619

  3. Biomechanical Comparison of Two Kinds of Internal Fixation in a Type C Zone II Pelvic Fracture Model

    PubMed Central

    Wu, Tao; Chen, Wei; Zhang, Qi; Zheng, Zhan-Le; Lyu, Hong-Zhi; Cui, Yun-Wei; Cheng, Xiao-Dong; Zhang, Ying-Ze; Yang, Yan-Jiang

    2015-01-01

    Background: Unstable pelvic fractures are complex and serious injuries. Selection of a fixation method for these fractures remains a challenging problem for orthopedic surgeons. This study aimed to compare the stability of Tile C pelvic fractures fixed with two iliosacral (IS) screws and minimally invasive adjustable plate (MIAP) combined with one IS screw. Methods: This study was a biomechanical experiment. Six embalmed specimens of the adult pelvis were used. The soft tissue was removed from the specimens, and the spines from the fourth lumbar vertebra to the proximal one-third of both femurs were retained. The pubic symphysis, bilateral sacroiliac joints and ligaments, bilateral hip joints, bilateral sacrotuberous ligaments, and bilateral sacrospinous ligaments were intact. Tile C pelvic fractures were made on the specimens. The symphysis pubis was fixed with a plate, and the fracture on the posterior pelvic ring was fixed with two kinds of internal fixation in turn. The specimens were placed in a biomechanical machine at a standing neutral posture. A cyclic vertical load of up to 500 N was applied, and displacement was recorded. Shifts in the fracture gap were measured by a grating displacement sensor. Statistical analysis used: Paired-samples t-test. Results: Under the vertical load of 100, 200, 300, 400, and 500 N, the average displacement of the specimens fixed with MIAP combined with one IS screw was 0.46, 0.735, 1.377, 1.823, and 2.215 mm, respectively, which was significantly lower than that of specimens fixed with two IS screws under corresponding load (P < 0.05). Under the vertical load of 500 N, the shift in the fracture gap of specimens fixed with MIAP combined with one IS screw was 0.261 ± 0.095 mm, and that of specimens fixed with two IS screws was 0.809 ± 0.170 mm. The difference was significant (P < 0.05). Conclusion: The stability of Tile C pelvic fractures fixed with MIAP combined with one IS screw was better than that fixed with two IS screws

  4. Factors affecting the functional results of open reduction and internal fixation for fracture-dislocations of the proximal interphalangeal joint.

    PubMed

    Watanabe, Kentaro; Kino, Yoshitake; Yajima, Hiroki

    2015-01-01

    To clarify the factors affecting functional results of fracture-dislocations of the proximal interphalangeal (PIP) joint treated by open reduction and internal fixation (ORIF), 60 patients, including 38 patients with a dorsal fracture-dislocation and 22 with a pilon fracture, were analysed. The mean ratio of articular surface involvement was 48.5% and a depressed central fragment existed in 75.3% of the cases. ORIF was performed in 47 patients through a lateral approach using Kirschner wires and in 13 through a palmar approach using a plate or screws. The mean flexion, extension and range of motion (ROM) of the PIP joint was 89.5°, 11.5° and 78.0°, respectively. Stepwise regression analysis revealed that a delayed start of active motion exercise after surgery, elderly age and ulnar ray digit were factors affecting functional outcomes. Although ORIF allows accurate restoration of the articular surfaces, an early start of motion exercise is essential for good results.

  5. Biomechanics of humerus fracture fixation by locking, cortical, and hybrid plating systems in a cadaver model.

    PubMed

    Sutherland, George B; Creekmore, Tina; Mukherjee, Debi P; Ogden, Alan L; Anissian, Lucas; Marymont, John V

    2010-08-11

    The goal of this study was to discover how locking or cortical screws or a hybrid of both would perform in stabilizing a simulated humerus fracture. We simulated stripping of screw threads or poor bone quality by overdrilling the screw hole, and also studied a control group with no overdrilling. A total of 38 fresh frozen cadaver humeri were divided into 2 groups: 16 undergoing overdrilling with a drill bit 0.3 mm less than the diameter of the screw and 22 undergoing no overdrilling. A 4-point bending test followed torsional fatigue of 1000 cycles with an amplitude of +/-10 degrees. The post-fatigued samples were retested in the same way after tightening the loose screws if necessary. Finally, each fatigued specimen was tested for failure in torsion at 0.5 Hz by applying a maximum rotational displacement of 60 degrees .The bending stiffness values (Nm/mm) of cortical and locking screws, with the exception of the hybrid system, were significantly higher for the overdrilled group than the non-overdrilled (cortical, 6.9 vs 5.6; locking, 9.1 vs 6.3; hybrid, 8.4 vs 6.8). Fatigue had no effect on the bending stiffness of all the screw/plate systems (cortical, 6.9 vs 7.4; locking, 9.1 vs 8.8; hybrid, 8.5 vs 8.1). The overdrilling had no effect on the failure loads and displacements for all the screws except cortical screws, where the failure displacement was significantly higher for the overdrilling group. The torsional stiffness retentions after 1000 cycles were significantly different for overdrilled specimens in the cortical screws group only.Overdrilling had a minimal effect on bending and torsional properties. The results of the locking and hybrid were close, and the cortical screw had only slightly lower bending stiffness.

  6. Total Hip Arthroplasty Using Non-Modular Cementless Long-Stem Distal Fixation for Salvage of Failed Internal Fixation of Intertrochanteric Fracture.

    PubMed

    Shi, Xiaojun; Zhou, Zongke; Yang, Jing; Shen, Bin; Kang, Pengde; Pei, Fuxing

    2015-11-01

    Thirty one patients were treated with salvage total hip arthroplasty (THA) for failed internal fixation of intertrochanteric fracture. After a mean follow-up of 47.5 months, all patients reported remarkable pain relief and return to ambulation. Twenty five patients had no pain, and 6 patients complained of residual trochanteric low-grade pain without compromise of activities. The Harris Hip score increased from a preoperative average of 28.4 points to a postoperative average of 85.6 points. All patients demonstrated successful bony union and five had Brooker I or II heterotopic ossification. Seven patients had intraoperative or early complications and were treated successfully. There was no infection, re-fracture, loosening, or revision for any reason. Salvage THA using non-modular cementless long-stem prosthesis represents an effective procedure after failed intertrochanteric fixation.

  7. Use of the trochanteric flip osteotomy to facilitate internal fixation of a femoral head fracture

    PubMed Central

    Gillespie, James A.; Marsh, Andrew G.; Patil, Sanjeev R.

    2016-01-01

    We report the case of a 42-year-old male who suffered a fracture–dislocation of the femoral head. After a closed reduction of the hip, this proceeded to an open reduction with internal fixation of the fractured femoral head, in addition to labral repair and micro-fracture of an articular cartilage defect. After considering the risks to the femoral head blood supply, the trochanteric flip osteotomy was used. This provided ample and safe exposure. At 14 months follow-up, the patient-reported outcome measures are favourable: modified Harris Hip Score (81/100), the non-arthritic hip score (92.5/100) and SF-12 (41/48). PMID:27470013

  8. Use of the trochanteric flip osteotomy to facilitate internal fixation of a femoral head fracture.

    PubMed

    Gillespie, James A; Marsh, Andrew G; Patil, Sanjeev R

    2016-01-01

    We report the case of a 42-year-old male who suffered a fracture-dislocation of the femoral head. After a closed reduction of the hip, this proceeded to an open reduction with internal fixation of the fractured femoral head, in addition to labral repair and micro-fracture of an articular cartilage defect. After considering the risks to the femoral head blood supply, the trochanteric flip osteotomy was used. This provided ample and safe exposure. At 14 months follow-up, the patient-reported outcome measures are favourable: modified Harris Hip Score (81/100), the non-arthritic hip score (92.5/100) and SF-12 (41/48). PMID:27470013

  9. Bioabsorbable bone fixation plates for X-ray imaging diagnosis by a radiopaque layer of barium sulfate and poly(lactic-co-glycolic acid).

    PubMed

    Choi, Sung Yoon; Hur, Woojune; Kim, Byeung Kyu; Shasteen, Catherine; Kim, Myung Hun; Choi, La Mee; Lee, Seung Ho; Park, Chun Gwon; Park, Min; Min, Hye Sook; Kim, Sukwha; Choi, Tae Hyun; Choy, Young Bin

    2015-04-01

    Bone fixation systems made of biodegradable polymers are radiolucent, making post-operative diagnosis with X-ray imaging a challenge. In this study, to allow X-ray visibility, we separately prepared a radiopaque layer and attached it to a bioabsorbable bone plate approved for clinical use (Inion, Finland). We employed barium sulfate as a radiopaque material due to the high X-ray attenuation coefficient of barium (2.196 cm(2) /g). The radiopaque layer was composed of a fine powder of barium sulfate bound to a biodegradable material, poly(lactic-co-glycolic acid) (PLGA), to allow layer degradation similar to the original Inion bone plate. In this study, we varied the mass ratio of barium sulfate and PLGA in the layer between 3:1 w/w and 10:1 w/w to modulate the degree and longevity of X-ray visibility. All radiopaque plates herein were visible via X-ray, both in vitro and in vivo, for up to 40 days. For all layer types, the radio-opacity decreased with time due to the swelling and degradation of PLGA, and the change in the layer shape was more apparent for layers with a higher PLGA content. The radiopaque plates released, at most, 0.5 mg of barium sulfate every 2 days in a simulated in vitro environment, which did not appear to affect the cytotoxicity. The radiopaque plates also exhibited good biocompatibility, similar to that of the Inion plate. Therefore, we concluded that the barium sulfate-based, biodegradable plate prepared in this work has the potential to be used as a fixation device with both X-ray visibility and biocompatibility. PMID:24964903

  10. Bioabsorbable bone fixation plates for X-ray imaging diagnosis by a radiopaque layer of barium sulfate and poly(lactic-co-glycolic acid).

    PubMed

    Choi, Sung Yoon; Hur, Woojune; Kim, Byeung Kyu; Shasteen, Catherine; Kim, Myung Hun; Choi, La Mee; Lee, Seung Ho; Park, Chun Gwon; Park, Min; Min, Hye Sook; Kim, Sukwha; Choi, Tae Hyun; Choy, Young Bin

    2015-04-01

    Bone fixation systems made of biodegradable polymers are radiolucent, making post-operative diagnosis with X-ray imaging a challenge. In this study, to allow X-ray visibility, we separately prepared a radiopaque layer and attached it to a bioabsorbable bone plate approved for clinical use (Inion, Finland). We employed barium sulfate as a radiopaque material due to the high X-ray attenuation coefficient of barium (2.196 cm(2) /g). The radiopaque layer was composed of a fine powder of barium sulfate bound to a biodegradable material, poly(lactic-co-glycolic acid) (PLGA), to allow layer degradation similar to the original Inion bone plate. In this study, we varied the mass ratio of barium sulfate and PLGA in the layer between 3:1 w/w and 10:1 w/w to modulate the degree and longevity of X-ray visibility. All radiopaque plates herein were visible via X-ray, both in vitro and in vivo, for up to 40 days. For all layer types, the radio-opacity decreased with time due to the swelling and degradation of PLGA, and the change in the layer shape was more apparent for layers with a higher PLGA content. The radiopaque plates released, at most, 0.5 mg of barium sulfate every 2 days in a simulated in vitro environment, which did not appear to affect the cytotoxicity. The radiopaque plates also exhibited good biocompatibility, similar to that of the Inion plate. Therefore, we concluded that the barium sulfate-based, biodegradable plate prepared in this work has the potential to be used as a fixation device with both X-ray visibility and biocompatibility.

  11. Temporomandibular joint morphology changes with mandibular advancement surgery and rigid internal fixation: a systematic literature review.

    PubMed

    Kersey, Michael L; Nebbe, Brian; Major, Paul W

    2003-02-01

    The purpose of this systematic review was to evaluate the effect of bilateral sagittal split mandibular osteotomy (BSSO) with rigid internal fixation (RIF) on temporomandibular joint (TMJ) morphology. Controlled trials of BSSO with RIF treatment of Class II patients using transcranial radiographs, submental vertex (SMV) radiographs, tomographic radiography, computed tomography (CT) scan, or magnetic resonance imaging (MRI) to assess TMJ morphology were identified by Medline (1966-2001) and PubMed. Case reports were excluded. On the basis of our search only six studies were included in this review. All studies used internal controls with pre- and posttreatment imaging. Two studies used SMV, one used transcranial radiographs, one used tomography, two used CT scan and one used MRI. Methodological deficiencies prevent major conclusions regarding osseous remodeling and disk status. There was a wide range of individual variability in condyle position change. The reviewed studies have highlighted the importance of further research. Prospective controlled studies using serial MRI and tomography or CT scan are required to establish effect of BSSO with RIF on TMJ morphology.

  12. On the free flexural vibration of rectangular plates with straight or curved internal line supports

    NASA Astrophysics Data System (ADS)

    Young, P. G.; Dickinson, S. M.

    1993-03-01

    The Rayleigh-Ritz method is used, with simple polynomials as admissible functions, to obtain the eigenvalue equation for the free vibration of a rectangular plate which has an internal line support lying along a line describable in terms of a general polynomial. Numerical and graphical results are presented for plates with internal supports lying along straight lines, for which comparison results also exist, and for plates with the supports lying along different types of curves, including a central circular support.

  13. Arthroscopically Assisted Open Reduction-Internal Fixation of Ankle Fractures: Significance of the Arthroscopic Ankle Drive-through Sign.

    PubMed

    Schairer, William W; Nwachukwu, Benedict U; Dare, David M; Drakos, Mark C

    2016-04-01

    Standalone open reduction-internal fixation (ORIF) of unstable ankle fractures is the current standard of care. Intraoperative stress radiographs are useful for assessing the extent of ligamentous disruption, but arthroscopic visualization has been shown to be more accurate. Concomitant arthroscopy at the time of ankle fracture ORIF is useful for accurately diagnosing and managing syndesmotic and deltoid ligament injuries. The arthroscopic ankle drive-through sign is characterized by the ability to pass a 2.9-mm shaver (Smith & Nephew, Andover, MA) easily through the medial ankle gutter during arthroscopy, which is not usually possible with both an intact deltoid ligament and syndesmosis. This arthroscopic maneuver indicates instability after ankle reduction and fixation and is predictive of the need for further stabilization. Furthermore, when this sign remains positive after fracture fixation, it may guide the surgeon to further evaluate the adequacy of fixation for the possible need for further fixation of the syndesmosis or deltoid. We present the case of an ankle fracture managed with arthroscopy-assisted ORIF and describe the clinical utility of the arthroscopic ankle drive-through sign. PMID:27462542

  14. Proximal tibial fractures with impending compartment syndrome managed by fasciotomy and internal fixation: A retrospective analysis of 15 cases

    PubMed Central

    Sharma, Naveen; Singh, Varun; Agrawal, Ashish; Bhargava, Rakesh

    2015-01-01

    Background: Proximal tibia fractures with compartment syndrome present a challenge for orthopedic surgeons. More often than not these patients are subjected to multiple surgeries and are complicated by infection osteomyelitis and poor rehabilitation. There is no consensus in the management of these fractures. Most common mode is to do early fasciotomy with external fixation, followed by second stage definitive fixation. We performed a retrospective study of proximal tibia fractures with impending compartment syndrome treated by single stage fasciotomy and internal fixation. Results in terms of early fracture union, minimum complications and early patient mobilization were very good. Materials and Methods: Fifteen patients who were operated between July 2011 and June 2012 were selected for the study. All documents from their admission until the last followup in December 2013 were reviewed, data regarding complications collected and results were evaluated using Oxford Knee scoring system. Results: At the final outcome, there was anatomical or near anatomical alignment with no postoperative problems with range of motion of near complete flexion (>120) in all patients within 3 months. 13 patients started full weight bearing walking at 3 months. Delayed union in two patients and skin necrosis in one patient was observed. Conclusions: Since the results are encouraging and the rehabilitation time is much less when compared to conventional approaches, it is recommended using this protocol to perform early fasciotomy with the definitive internal fixation as single stage surgery to obtain excellent followup results and to reduce rehabilitation time, secondary trauma, expense of treatment and infection rate. PMID:26538755

  15. Percutaneous Reduction and Fixation with Kirschner Wires versus Open Reduction Internal Fixation for the Management of Calcaneal Fractures: A Meta-Analysis.

    PubMed

    Wu, Jianbin; Zhou, Feiya; Yang, Lei; Tan, Jun

    2016-01-01

    The aim of our meta-analysis was to compare outcomes for two surgical treatments of calcaneal fractures, percutaneous reduction and fixation with Kirschner wires (PRFK) and open reduction internal fixation (ORIF), with the intent of evaluating the quality of evidence to inform practice. Search of MEDLINE, Cochrane and CNKI databases to identify randomized controlled trials (RCTs) comparing PRKF and ORIF on the following outcomes: post-operative function, complications and quality of the reduction. Odd ratios (OR) and weighted mean differences were pooled using either a fixed-effects or random-effects model, depending on the heterogeneity of the trials included in the analysis. Eighteen RCTs provided the data from 1407 patients. PRFK was associated with a lower risk of surgical wound complications, and ORIF with better post-operative function, angle of Gissane, calcaneal height, and calcaneal width. There were no statistically significant differences between the techniques with regards to post-operative Böhler's angle. PRFK does not provide a substantive advantage over ORIF for the treatment of calcaneal fractures in adults. PRFK may, however, yield comparable functional outcomes to ORIF for closed Sanders type II calcaneal fractures but with less complication related to surgical wound healing. PMID:27457262

  16. Percutaneous Reduction and Fixation with Kirschner Wires versus Open Reduction Internal Fixation for the Management of Calcaneal Fractures: A Meta-Analysis

    PubMed Central

    Wu, Jianbin; Zhou, Feiya; Yang, Lei; Tan, Jun

    2016-01-01

    The aim of our meta-analysis was to compare outcomes for two surgical treatments of calcaneal fractures, percutaneous reduction and fixation with Kirschner wires (PRFK) and open reduction internal fixation (ORIF), with the intent of evaluating the quality of evidence to inform practice. Search of MEDLINE, Cochrane and CNKI databases to identify randomized controlled trials (RCTs) comparing PRKF and ORIF on the following outcomes: post-operative function, complications and quality of the reduction. Odd ratios (OR) and weighted mean differences were pooled using either a fixed-effects or random-effects model, depending on the heterogeneity of the trials included in the analysis. Eighteen RCTs provided the data from 1407 patients. PRFK was associated with a lower risk of surgical wound complications, and ORIF with better post-operative function, angle of Gissane, calcaneal height, and calcaneal width. There were no statistically significant differences between the techniques with regards to post-operative Böhler’s angle. PRFK does not provide a substantive advantage over ORIF for the treatment of calcaneal fractures in adults. PRFK may, however, yield comparable functional outcomes to ORIF for closed Sanders type II calcaneal fractures but with less complication related to surgical wound healing. PMID:27457262

  17. Kirschner wire migration causing spinal cord injury one year after internal fixation of a clavicle fracture.

    PubMed

    Fransen, Patrick; Bourgeois, Sylvie; Rommens, Jacques

    2007-06-01

    K-wire migration after internal fixation of the clavicle has rarely been reported to cause spinal cord injuries. A 30-year-old man presented with progressive paraparesis, hypaesthesia under a Th4 level and electric pain in the neck and arms. CT of the spine revealed a migrated K-wire from a one-year-old clavicle osteosynthesis, penetrating the spinal canal through the Th2 nerve root foramen, and perforating the spinal cord with a transversal trajectory. Surgical removal of the K-wire was performed after exposing both ends. Laminectomy allowed visual control of the entry point and correction of cerebrospinal fluid leakage. The pain disappeared and the patient recovered a normal gait after 6 weeks. The use of two incisions is advocated in such cases: one lateral to allow wire removal, and one medial for dural repair and early intradural bleeding control. Regular follow ups, K-wire removal after fracture healing as well as bending the wire end in a walking stick shape should minimise the risk of migration. PMID:17715732

  18. Flexural Vibration Of Skew Mindlin Plates With Oblique Internal Line Supports

    NASA Astrophysics Data System (ADS)

    Xiang, Y.; Kitipornchai, S.; Liew, K. M.; Wang, C. M.

    1994-12-01

    A free vibration analysis of moderately thick skew plates with oblique internal line supports is presented. Mindlin's plate theory is employed and the pb -2 Rayleigh-Ritz method is applied to obtain the governing eigenvalue equation for internally supported skew plates. A set of natural frequencies for skew Mindlin plates with oblique internal line supports having different combinations of boundary conditions has been determined for various aspect ratios a/b, relative thickness ratios t/b and skew angles α. The validity of the approach is illustrated by comparing the results with other established values. From literature searches, it appears that no work has previously been done on the free vibration of moderately thick skew plates with oblique internal line supports. Thus this paper may provide some important information to designers and engineers for use in practical applications.

  19. [Acetabular fractures in the elderly. Outcome of open reduction and internal fixation].

    PubMed

    Tosounidis, G; Culemann, U; Bauer, M; Holstein, J H; Garcia, P; Kurowski, R; Pizanis, A; Aghayev, E; Pohlemann, T

    2011-08-01

    The aim of this study was to analyze the clinical outcome and incidence of hip arthritis in elderly patients with acetabular fractures. Because of poor bone quality in the elderly, even a low-energy trauma may lead to an acetabular fracture. An anatomical reconstruction of the acetabulum is necessary to achieve sufficient stability also for a potential hip arthroplasty. So far, there is very limited information on the outcome of acetabular fractures in the elderly. During a period of 6 years (2001-2006), 48 patients older than 60 years were admitted to our department with an acetabular fracture. Thirty-nine patients were treated operatively and nine patients non-operatively. Twenty-nine operatively treated patients were followed up. Nineteen of them were assessed using EQ-5D, SF-12 and Merle d'Aubigné questionnaires in addition to their clinical examination. Ten other surgical patients were only examined using the questionnaires. Of the 29 patients that were followed up, 5 underwent total hip arthroplasty due to secondary post-traumatic hip arthritis after open reduction and internal fixation (ORIF). The range of motion of the operated hip was comparable to that of the non-operated contralateral side. However, the internal rotation was found to be slightly decreased at the operated side when compared to the non-operated contralateral side. Merle d'Aubigné score and physical and mental SF-12 score components as well as quality of life were better in patients treated with ORIF compared to those patients that were treated by secondary hip arthroplasty. Regarding the different treatment strategies (ORIF vs primary hip arthroplasty vs non-operative treatment) of acetabular fractures in the elderly, data from the literature are conflicting. Our results indicate that ORIF represents a good treatment option for acetabular fractures in the elderly. In patients that did not develop secondary hip arthritis, a good clinical outcome and quality of life was documented. PMID

  20. Ankle fusion stability: a biomechanical comparison of external versus internal fixation.

    PubMed

    Hoover, Justin R; Santrock, Robert D; James, William C

    2011-04-11

    This biomechanical study compares bimalleolar external fixation to conventional crossed-screw construct in terms of stability and compression for ankle arthrodesis. The goals of the study were to determine which construct is more stable with bending and torsional forces, and to determine which construct achieves more compression.Fourth-generation bone composite tibia and talocalcaneal models were made to 50th percentile anatomic specifications. Fourteen ankle fusion constructs were created with bimalleolar external fixators and 14 with crossed-screw constructs. Ultimate bend, torque, and compression testing were completed on the external fixator and crossed-screw constructs using a multidirectional Materials Testing Machine (MTS Systems Corp, Eden Prairie, Minnesota). Ultimate bend testing revealed a statistically significant difference (P=.0022) with the mean peak load to failure for the external fixator constructs of 973.2 N compared to 612.5 N for the crossed-screw constructs. Ultimate torque testing revealed the mean peak torque to failure for the external fixator construct was 80.2 Nm and 28.1 Nm for the crossed-screw construct, also a statistically significant difference (P=.0001). The compression testing yielded no statistically significant difference (P=.9268) between the average failure force of the external fixator construct (81.6 kg) and the crossed-screw construct (81.2 kg).With increased stiffness in both bending and torsion and comparable compressive strengths, bimalleolar external fixation is an excellent option for tibiotalar ankle arthrodesis.

  1. Simulation-based particle swarm optimization and mechanical validation of screw position and number for the fixation stability of a femoral locking compression plate.

    PubMed

    Lee, Chian-Her; Shih, Kao-Shang; Hsu, Ching-Chi; Cho, Tomas

    2014-01-01

    Locking compression plates (LCPs) have been used to fix femoral shaft fractures. Previous studies have attempted to identify the best LCP screw positions and numbers to achieve the fixation stability. However, the determined screw positions and numbers were mainly based on the surgeons' experiences. The aim of this study was to discover the best number and positions of LCP screws to achieve acceptable fixation stability. Three-dimensional numerical models of a fractured femur with the LCP were first developed. Then, the best screw position and number of LCPs were determined by using a simulation-based particle swarm optimization algorithm. Finally, the results of the numerical study were validated by conducting biomechanical tests. The results showed that the LCP with six locking screws resulted in the necessary fixation stability, and the best combination of positions of locking screws inserted into the LCP was 1-5-6-7-8-12 (three locking screws on either side of the bone fragment with two locking screws as close as practicable to the fracture site). In addition, the numerical models and algorithms developed in this study were validated by the biomechanical tests. Both the numerical and experimental results can provide clinical suggestions to surgeons and help them to understand the biomechanics of LCP systems.

  2. Corrective osteotomy through fracture site and internal fixation with headless screws for type I (Hahn-Steinthal) capitellar malunion

    PubMed Central

    Jeevannavar, Santosh Somayya; Shenoy, Keshav Someshwar; Daddimani, Ravi M

    2013-01-01

    A 20-year-old woman presented 6 months after an initial injury to her left elbow with pain and restricted movements. She was diagnosed with a type I malunited (Hahn-Steinthal) type of capitellum fracture through radiographic studies. Classically, the treatment has been excision of the fragment, which carries a risk of valgus instability of the elbow and late osteoarthrosis. We report a case of malunited type I capitellum fracture, for which corrective osteotomy through fracture site, open reduction and internal fixation was done 6 months following missed trauma. At 24 months follow-up the capitellum fracture had united and the patient has a stable elbow and excellent range of motion. Our case demonstrates that for type I malunited capitellum fractures corrective osteotomy through fracture site and internal fixation rather than excision of the fragment in young can result in successful union and stable elbow. PMID:23709538

  3. Treatment of stress fracture of the olecranon in throwing athletes with internal fixation through a small incision.

    PubMed

    Fujioka, Hiroyuki; Tsunemi, Kenjiro; Takagi, Yohei; Tanaka, Juichi

    2012-01-01

    The present study is a report of retrospective case series of stress fracture of the olecranon. Six patients presented posterior elbow pain in throwing in baseball and softball, but fracture was not diagnosed in radiographs. We detected stress fracture of the olecranon using computed tomographic (CT) scan and treated the patient with internal fixation with a headless cannulated double threaded screw through a small skin incision. All patients returned to competitive level without elbow complaints after the operation.When throwing athletes present with unusual posterior elbow pain and no significant findings on radiographs, a CT scan examination should be performed. We recommend surgical treatment of internal fixation with a screw through a small skin incision, as a good option for stress fracture of the olecranon in order to allow early return to sports activity in competitive athletes.

  4. Review of techniques for monitoring the healing fracture of bones for implementation in an internally fixated pelvis.

    PubMed

    Wong, Lydia Chwang Yuh; Chiu, Wing Kong; Russ, Matthias; Liew, Susan

    2012-03-01

    Sacral fractures from high-impact trauma often cause instability in the pelvic ring structure. Treatment is by internal fixation which clamps the fractured edges together to promote healing. Healing could take up to 12 weeks whereby patients are bedridden to avoid hindrances to the fracture from movement or weight bearing activities. Immobility can lead to muscle degradation and longer periods of rehabilitation. The ability to determine the time at which the fracture is stable enough to allow partial weight-bearing is important to reduce hospitalisation time. This review looks into different techniques used for monitoring the fracture healing of bones which could lead to possible methods for in situ and non-invasive assessment of healing fracture in a fixated pelvis. Traditional techniques being used include radiology and CT scans but were found to be unreliable at times and very subjective in addition to being non in situ. Strain gauges have proven to be very effective for accurate assessment of fracture healing as well as stability for long bones with external fixators but may not be suitable for an internally fixated pelvis. Ultrasound provides in situ monitoring of stiffness recovery but only assesses local fracture sites close to the skin surface and has only been tested on long bones. Vibration analysis can detect non-uniform healing due to its assessment of the overall structure but may suffer from low signal-to-noise ratio due to damping. Impedance techniques have been used to assess properties of non-long bones but recent studies have only been conducted on non-biological materials and more research needs to be done before it can be applicable for monitoring healing in the fixated pelvis.

  5. Trimalleolar fracture with a double fragment of the posterior malleolus: a case report and modified operative approach to internal fixation.

    PubMed

    Karachalios, T; Roidis, N; Karoutis, D; Bargiotas, K; Karachalios, G G

    2001-02-01

    Fractures of the medial and lateral malleoli are frequently associated with fractures of the posterior malleolus, comprising trimalleolar fractures. The posterior fragment may be posteromedial or posterolateral and its size determines the necessity for surgical or non-surgical treatment. The authors describe a case of trimalleolar fracture with double involvement of the posterior malleolus, both a posteromedial and posterolateral fragment. A modified transmalleolar operative approach for internal fixation is recommended when dealing with such complex trimalleolar fractures of the ankle.

  6. Open Reduction and Internal Fixation Versus Hemiarthroplasty in the Management of Proximal Humerus Fractures

    PubMed Central

    Thorsness, Robert; Iannuzzi, James; Noyes, Katia; Voloshin, Ilya

    2014-01-01

    Objectives: The purpose of this study was to use a nationally representative database to determine the differences in 30-day outcomes based on procedure type for management of proximal humerus fractures including complications, readmission, operative time, and length of stay. Further, we sought to determine patient characteristics and perioperative factors associated with poor outcomes. Design/Setting: This was a retrospective study of the National Surgical Quality Improvement Program (NSQIP) database. The NSQIP comprises a clinical database with systematic patient tracking at multiple hospitals across the United States. Patients: A total of 413 patients with proximal humerus fractures managed surgically were included. Intervention: Of 413 patients, 330 underwent open reduction and internal fixation (ORIF) and 83 underwent hemiarthroplasty. Main Outcomes/Measurements: The primary end points included major and minor complications, operative time, rate of return to the operating room, and length of stay. Results: Compared to the hemiarthroplasty cohort, patients in the ORIF cohort were significantly younger (64.2; 17-90 and 69.3; 20-90, respectively, P = .007) and were significantly less likely to be of functionally dependent status (17.5% and 27.7%, P = .036). Compared to the hemiarthroplasty cohort, the ORIF cohort demonstrated fewer postoperative bleeding complications (2.4% and 8.4%, respectively, P = .016) and shorter operative times (115 vs 131 minutes, P = .017). There were no significant differences between the groups with respect to complications, reoperation rates, or length of hospital stay. On multivariable analysis, hemiarthroplasty demonstrated increased risk of postoperative bleeding compared to ORIF (odds ratio = 7.06, confidence interval: 2.06-24.24; P = .002) as well as increased operative time (P = .01). Conclusions: Patients who undergo hemiarthroplasty for management of proximal humerus fractures are significantly older and often functionally

  7. Fibular Strut Graft Augmentation for Open Reduction and Internal Fixation of Proximal Humerus Fractures

    PubMed Central

    Saltzman, Bryan M.; Erickson, Brandon J.; Harris, Joshua D.; Gupta, Anil K.; Mighell, Mark; Romeo, Anthony A.

    2016-01-01

    Background: Proximal humerus fractures are common problems plaguing the elderly population. Purpose: The purposes of this study were to determine the outcomes of fibular strut allografts in treatment of proximal humerus fractures with open reduction internal fixation (ORIF) and to present the authors’ preferred surgical technique. The hypothesis was that the use of fibular strut allografts in treating proximal humerus fractures with ORIF will provide low reoperation rates with acceptable outcomes. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review was registered with PROSPERO and performed with PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines using 3 publicly available free databases. Therapeutic clinical outcome investigations reporting arthroscopic elbow outcomes with levels of evidence 1 through 4 were eligible for inclusion. All study, subject, and surgical technique demographics were analyzed and compared between continents and countries. Statistics were calculated using Student t tests, 1-way analysis of variance, chi-square tests, and 2-proportion Z tests. Results: Four studies met the inclusion criteria. While there is great heterogeneity existing in the literature surrounding use of a fibular strut allograft as an adjunct to ORIF of proximal humerus fractures, current evidence shows a humeral head screw penetration rate of 3.7% with acceptable functional outcome scores, with a reoperation rate of 4.4% at a weighted mean 80.78 weeks (1.55 years) of postoperative follow-up. Conclusion: There is great heterogeneity that exists in the literature surrounding the use of a fibular strut allograft as an adjunct to ORIF of proximal humerus fractures. Current evidence shows a screw penetration rate of 3.7% with acceptable functional outcome scores, demonstrating fibular strut allograft is a viable option for treating proximal humerus fractures. PMID:27504463

  8. The biomechanics of plate fixation of periprosthetic femoral fractures near the tip of a total hip implant: cables, screws, or both?

    PubMed

    Shah, S; Kim, S Y R; Dubov, A; Schemitsch, E H; Bougherara, H; Zdero, R

    2011-09-01

    Femoral shaft fractures after total hip arthroplasty (THA) remain a serious problem, since there is no optimal surgical repair method. Virtually all studies that examined surgical repair methods have done so clinically or experimentally. The present study assessed injury patterns computationally by developing three-dimensional (3D) finite element (FE) models that were validated experimentally. The investigation evaluated three different constructs for the fixation of Vancouver B1 periprosthetic femoral shaft fractures following THA. Experimentally, three bone plate repair methods were applied to a synthetic femur with a 5 mm fracture gap near the tip of a total hip implant. Repair methods were identical distal to the fracture gap, but used cables only (construct A), screws only (construct B), or cables plus screws (construct C) proximal to the fracture gap. Specimens were oriented in 15 degrees adduction to simulate the single-legged stance phase of walking, subjected to 1000 N of axial force, and instrumented with strain gauges. Computationally, a linearly elastic and isotropic 3D FE model was developed to mimic experiments. Results showed excellent agreement between experimental and FE strains, yielding a Pearson linearity coefficient, R2, of 0.92 and a slope for the line of best data fit of 1.06. FE-computed axial stiffnesses were 768 N/mm (construct A), 1023 N/mm (construct B), and 1102 N/mm (construct C). FE surfaces stress maps for cortical bone showed Von Mises stresses, excluding peaks, of 0-8 MPa (construct A), 0-15 MPa (construct B), and 0-20 MPa (construct C). Cables absorbed the majority of load, followed by the plates and then the screws. Construct A yielded peak stress at one of the empty holes in the plate. Constructs B and C had similar bone stress patterns, and can achieve optimal fixation. PMID:22070022

  9. Wedgeless 'V' shaped distal femoral osteotomy with internal fixation for genu valgum in adolescents and young adults.

    PubMed

    Gupta, Vikas; Kamra, Gaurav; Singh, Davinder; Pandey, Ketan; Arora, Sumit

    2014-06-01

    The treatment of angular malalignment includes restoration of normal mechanical axis alignment and joint orientation.The supracondylar wedgeless distal femoral 'V' osteotomy, as a treatment modality, is sparsely explored in the literature. This study was conducted at a tertiary level teaching referral hospital from October 2010 to September 2012. Forty six lower limbs (in 30 patients) were operated with a wedgeless 'V' osteotomy that was fixed with a buttress 'L' plate. The pre-operative deformity, post-operative correction and knee range of movement were noted. Mobilisation was started at 3 weeks after surgery and full weight-bearing was allowed at 3 months. The knee score by Bostman et al. was used for functional outcome. The mean age of the patients in our study was 16.9 years (range: 15 years to 23 years). The patients were followed up for a mean period of 19.8 months (range, 15 months to 29 months). The mean radiological tibiofemoral angle was 22.2 degrees (range, 16 degrees to 29 degrees) before surgery, that improved to a mean postoperative value of 5.1 degrees (range, 0 degrees to 10 degrees) (p < 0.001). The mean preoperative lateral distal femoral angle was 79.23 degrees that improved to a mean value of 89.13 degrees after surgery (p < 0.001). The mean mechanical axis deviation was 19.56 mm before surgery that improved to a mean postoperative value of 3.7 mm (p < 0.001). All patients reached a correction of the deformity and 44 cases out of a total of 46 had an excellent functional outcome, 2 patients had a good functional outcome. None had an unsatisfactory outcome. Two cases had a deep wound infection that subsided after implant removal. None of the cases had other complications. The distal femoral 'V' shaped osteotomy is a simple procedure for the correction of genu valgum in individuals nearing skeletal maturity and is easy to perform. It has the advantage of being wedgeless as it does not cause limb length discrepancy. Internal fixation helps in

  10. Dynamic Hip Screw with Trochanteric Stablization Plate Fixation of Unstable Inter-Trochanteric Fractures: A Prospective Study of Functional and Radiological Outcomes

    PubMed Central

    Shetty, Ashwin; Sadasivan, Anand Kumar; Hegde, Anoop

    2016-01-01

    Introduction Management of unstable intertrochanteric fractures have posed a unique challenge to orthopaedicians over years. Several surgical techniques and implants have been developed for the same. Fractures of the lateral wall have been considered as the major cause of femoral medialization after fixation by Dynamic Hip Screw (DHS). Studies have shown that supplementation of trochanteric stabilization plate reduces the incidence of femoral medialization. Aim To assess the radiological union and hip function after fixation of unstable intertrochanteric fractures with DHS and Trochanteric Stabilization Plate (TSP). Materials and Methods A prospective study was conducted with a total of 32 patients between age groups of 30-70 years with Evan Jensen unstable and very unstable type of intertrochanteric fractures, between August 2013 to March 2015 in the Department of Orthopaedics ARS Hospital, Tirupur, Tamil Nadu, India. They underwent open reduction and DHS and TSP fixation. They were started on full weight bearing mobilization on post op day three. They were reviewed at post-op weeks 3,6,12 and 24. Hip mobilization and rehabilitation exercises were instituted during course of reviews. Radiographs were taken to assess fracture union and hip function was evaluated during follow-ups. At the end of 24 weeks, degree of radiographic union was scored as per Radiological Union Score for Hip (RUSH). Hip function was scored with Harris hip score. Analyses were done using frequency and proportions. Chi-square tests were used to assess the test of association. Results Fifteen patients had RUSH scores between 10-20 and 17 patients had scores between 20-30 points. RUSH score had mean of 21.03+/- 2.132 points. 9 of 32 patients had excellent results as per Harris hip score, 10 had good, nine had fair and four had poor. On comparison of Harris hip score with RUSH score: Interval between 10-20 points, of 15 patients; two had excellent results, five had good, five had fair and three

  11. Vibration of triangular plates: Point supports, mixed edges and partial internal curved supports

    NASA Astrophysics Data System (ADS)

    Liew, K. M.; Wang, C. M.

    1994-05-01

    A numerical method, which is a hybrid form of the Rayleigh-Ritz method and the Lagrangian multiplier method, is presented in this paper for the vibration analysis of general triangular plates with complicated supported conditions. These support conditions include internal clamped or simple point supports, mixed periphery boundary conditions and partial internal curved supports. Several plate examples are used to illustrate the method. Apart from the limiting cases of some of these triangular plates with point supports where existing results are available for comparison, the frequency parameters presented in this paper are new. They should be valuable to designers in some industrial applications.

  12. Retrospective study of two fixation methods for 4-corner fusion: Shape-memory staple vs. dorsal circular plate.

    PubMed

    Le Corre, A; Ardouin, L; Loubersac, T; Gaisne, E; Bellemère, P

    2015-12-01

    The purpose of this study was to compare the results of two groups of patients with four-corner fusion, one group fixed with shape-memory staples and the other with locked circular plates. This retrospective study compared 52 wrists operated for scaphoid excision and four-corner fusion between 2005 and 2011. The arthrodesis was ensured by a shape-memory quadripodal staple (4Fusion(®), Memometal™) in 37 cases and a locking dorsal circular plate (Xpode(®), Biotech Ortho™) in 15 cases. In the staple group, the mean age was 58.5 years and the average follow-up was 4.3 years. In the circular plate group, the mean age was 58.6 years and the average follow-up was 3.1 years. Pain, range of motion, grip strength, functional scores (QuickDASH and PWRE), fusion of the midcarpal joint, complications (implant fracture and reoperation) and patients' satisfaction were used as outcome measures. There was no pain in 43% of patients in the staple group and 40% of patients in the circular plate group at the follow-up; range of motion and functional scores were similar in both groups. Seventy-five percent of patients in the staple group were satisfied or very satisfied versus 60% in the circular plate group. The implant broke in 24.3% of cases in the staple group and 60% in the circular plate group. Reoperation was needed in 18% of the staple cases and 14% of the plate cases. There was no difference between the implants in terms of pain, range of motion, functional scores and patient satisfactory. The implant fracture rate in the plate group was high. This study brings into question implant reliability for the four-corner fusion procedure.

  13. In vitro biomechanical evaluation of internal fixation techniques on the canine lumbosacral junction

    PubMed Central

    Dillard, Stacy; Roe, Simon

    2015-01-01

    Few biomechanical studies have evaluated the effect of internal stabilization techniques after decompressive surgery on the stability of the canine lumbosacral junction. The purpose of this canine cadaver study is to evaluate the stability of the canine lumbosacral (LS) spine in flexion and extension following laminectomy and discectomy and then stabilization with each of the three techniques: pins and polymethylmethacrylate (P/PMMA), two dorsal locking plates (SOP) or bilateral transarticular facet screws (FACET).Using a cantilever biomechanical system, bending moments were applied to the LS and range of motion (ROM) was recorded via a rotational potentiometer. With 3 Nm, the ROM (n = 4 in each group) for P/PMMA, SOP and FACET were 1.92 ± 0.96°, 2.56 ± 0.55°and 3.18 ± 1.14°, respectively. With moments up to 35 Nm, the P/PMMA specimens appeared stable. Sacroiliac motion in the SOP and FACET groups invalidated further comparisons. Each of the stabilization techniques (P/PMMA, SOP, and FACET) significantly decreased the range of motion in flexion and extension for low bending moments. PMID:26312169

  14. [Comparative serology in typhoid fever in children. II. Comparison of a microhemagglutination plate technic with Ruiz-Castañeda surface fixation].

    PubMed

    Alvarado-Alemán, F; González-Quijano, M; Rodríguez-Solis, B; Ramírez-Vidals, A; Isibasi, A; Kumate, J

    1989-02-01

    Two lipopolysaccharide antigens that differ by the technique of preparation from S. typhi, one named crude is easily extracted, the other one is water-phenol extracted. Both were adsorbed by papain and cysteine to lamb erythrocyte surfaces, fixed then by glutaraldehyde and used in a plate microhemagglutination test (MHA). The MHA test was done with 30 sera from children with S. typhi blood isolates. The same number of control sera were tested for comparison. The crude LPS antigen showed better sensitivity: 73% versus 53% of the water-phenol extracted one despite a high index correlation (r = 0.88). The latest one was evaluated in a prospective study, using it during a six-month period in an emergency room with S. typhi blood isolated sera. The MHA test was compared with the surface fixation test. Both assays showed similar sensitivity and a specificity of 91 and 100%, respectively.

  15. International Space Station Internal Thermal Control System Cold Plate/Fluid-Stability Test: Two Year Update

    NASA Technical Reports Server (NTRS)

    Wieland, Paul; Holt, Mike; Roman, Monsi; Cole, Harold; Daugherty, Steve

    2003-01-01

    Operation of the Internal Thermal Control System (ITCS) Cold Plate/Fluid-Stability Test Facility commenced on September 5, 2000. The facility was intended to provide advance indication of potential problems on board the International Space Station (ISS) and was designed: 1) To be materially similar to the flight ITCS. 2) To allow for monitoring during operation. 3) To run continuously for three years. During the first two years of operation the conditions of the coolant and components were remarkably stable. During this same period of time, the conditions of the ISS ITCS significantly diverged from the desired state. Due to this divergence, the test facility has not been providing information useful for predicting the flight ITCS condition. Results of the first two years are compared with flight conditions over the same time period, showing the similarities and divergences. To address the divergences, the test facility was modified incrementally to more closely match the flight conditions, and to gain insight into the reasons for the divergence. Results of these incremental changes are discussed and provide insight into the development of the conditions on orbit.

  16. Internal fixation of the spine using a braided titanium cable: clinical results and postoperative magnetic resonance imaging.

    PubMed

    Doran, S E; Papadopoulos, S M; Miller, L D

    1996-03-01

    Segmental spinal fixation using sublaminar or interspinous stainless steel wire has been successfully used for many years. Stainless steel cables have been developed that are stronger and more flexible, allowing for shorter operative time and decreased risk of neurological deficit. However, stainless steel implants create significant artifact on magnetic resonance imaging (MRI), reducing the postoperative usefulness of this imaging modality. Titanium instrumentation has the advantage of producing minimal MRI artifact. Recently, a braided titanium cable has been developed that has the advantages of strength and flexibility as well as minimal production of MRI artifact. We present a series of 50 patients who underwent internal fixation of the spine using a braided titanium cable either alone or in combination with supplementary titanium instrumentation. No instrument failures have occurred to date. Postoperative MRI scans have revealed minimal implant-related artifact, allowing for high-resolution, noninvasive postoperative imaging of the neuraxis. We conclude that braided titanium cable has significant advantages over stainless steel cable or monofilament wire and is a valuable instrument for segmental spine fixation.

  17. The use of fibrin and gelatin fixation to repair a kinked internal carotid artery in carotid endarterectomy

    PubMed Central

    Kubota, Hisashi; Sanada, Yasuhiro; Tanikawa, Rokuya; Kato, Amami

    2016-01-01

    Background: The kinking of the internal carotid artery (ICA) after final closure in carotid endarterectomy (CEA) is thought to be uncommon. When it occurs, it is mandatory to reconstruct ICA to preserve normal blood flow. We herein present a case in which a fixation technique was applied to repair an ICA that became kinked during CEA. Case Description: A 68-year-old man presented with cerebral infarction due to an artery-to-artery embolism from the right cervical ICA stenosis. CEA was performed 12 days after admission. After final closure, a distal portion of ICA was found to have been kinked following plaque resection in CEA procedure. Fixation with fibrin glue and gelatin was used to reinforce the arterial wall and repair the kink. Postoperative magnetic resonance angiography demonstrated the release of the kink in ICA. Conclusion: Fixation with fibrin and gelatin is a salvage armamentarium that can be considered in CEA for the repair of kinked or tortuous ICA. PMID:27308092

  18. Surgical Fixation of Sternal Fractures: Preoperative Planning and a Safe Surgical Technique Using Locked Titanium Plates and Depth Limited Drilling

    PubMed Central

    Schulz-Drost, Stefan; Oppel, Pascal; Grupp, Sina; Schmitt, Sonja; Carbon, Roman Th.; Mauerer, Andreas; Hennig, Friedrich F.; Buder, Thomas

    2015-01-01

    Different ways to stabilize a sternal fracture are described in literature. Respecting different mechanisms of trauma such as the direct impact to the anterior chest wall or the flexion-compression injury of the trunk, there is a need to retain each sternal fragment in the correct position while neutralizing shearing forces to the sternum. Anterior sternal plating provides the best stability and is therefore increasingly used in most cases. However, many surgeons are reluctant to perform sternal osteosynthesis due to possible complications such as difficulties in preoperative planning, severe injuries to mediastinal organs, or failure of the performed method. This manuscript describes one possible safe way to stabilize different types of sternal fractures in a step by step guidance for anterior sternal plating using low profile locking titanium plates. Before surgical treatment, a detailed survey of the patient and a three dimensional reconstructed computed tomography is taken out to get detailed information of the fracture’s morphology. The surgical approach is usually a midline incision. Its position can be described by measuring the distance from upper sternal edge to the fracture and its length can be approximated by the summation of 60 mm for the basis incision, the thickness of presternal soft tissue and the greatest distance between the fragments in case of multiple fractures. Performing subperiosteal dissection along the sternum while reducing the fracture, using depth limited drilling, and fixing the plates prevents injuries to mediastinal organs and vessels. Transverse fractures and oblique fractures at the corpus sterni are plated longitudinally, whereas oblique fractures of manubrium, sternocostal separation and any longitudinally fracture needs to be stabilized by a transverse plate from rib to sternum to rib. Usually the high convenience of a patient is seen during follow up as well as a precise reconstruction of the sternal morphology. PMID

  19. Healing of fractures with freeze-dried cortical bone plates. Comparison with compression plating.

    PubMed

    Malinin, T; Latta, L L; Wagner, J L; Brown, M D

    1984-11-01

    The healing of fractures of the radius with internal fixation by stainless-steel compression plates was compared with fractures fixed with freeze-dried bone-plate allografts. Fractures fixed with metallic plates gained slightly less than half the biomechanical strength of the contralateral control bone and healed without noticeable external callus formation. Bone-plated fractures regained three-fourths of the biomechanical strength of controls and healed by forming an external callus. Bone-plate allografts were eventually incorporated in the host bone. Allograft plates were vascularized and remodeled into cancellous bone in the process of incorporation in the host bones.

  20. Comparison of the ilioinguinal approach and the anterior intrapelvic approaches for open reduction and internal fixation of the acetabulum.

    PubMed

    Archdeacon, Michael T

    2015-02-01

    The ilioinguinal and anterior intrapelvic approaches to the acetabulum often involve different strategies for the treatment of acetabular fractures. The ilioinguinal approach allows access to the entire internal iliac fossa and pelvic brim, including indirect access to the quadrilateral surface. In contrast, the anterior intrapelvic approach allows access to the anterior elements from inside the pelvis with the surgeon standing opposite the fracture pathology. Therefore, the goal of this article is to clarify the advantages and disadvantages for each approach with respect to exposure, reduction, and fixation.

  1. Triplane fractures of the distal tibia requiring open reduction and internal fixation. Pre-operative planning using computed tomography.

    PubMed

    Jones, S; Phillips, N; Ali, F; Fernandes, J A; Flowers, M J; Smith, T W D

    2003-05-01

    Computed tomography (CT) of triplane fractures provides useful information not available on conventional radiographs. Knowledge of the size and position of displaced fragments, the location of the intra-articular fracture and any associated articular incongruency is useful when undertaking pre-operative planning.A postal survey of surgeons revealed only 38% always requested CT scans before undertaking open reduction and internal fixation of displaced triplane fractures. Examples of the usefulness of CT scans in pre-operative planning is presented in two cases.

  2. A Novel Murine Model of Established Staphylococcal Bone Infection in the Presence of a Fracture Fixation Plate to Study Therapies Utilizing Antibiotic-laden Spacers after Revision Surgery

    PubMed Central

    Inzana, Jason A.; Schwarz, Edward M.; Kates, Stephen L.; Awad, Hani A.

    2014-01-01

    Mice are the small animal model of choice in biomedical research due to the low cost and availability of genetically engineered lines. However, the devices utilized in current mouse models of implant-associated bone infection have been limited to intramedullary or trans-cortical pins, which are not amenable to treatments involving extensive debridement of a full-thickness bone loss and placement of a segmental antibiotic spacer. To overcome these limitations, we developed a clinically faithful model that utilizes a locking fracture fixation plate to enable debridement of an infected segmental bone defect (full-thickness osteotomy) during a revision surgery, and investigated the therapeutic effects of placing an antibiotic-laden spacer in the segmental bone defect. To first determine the ideal time point for revision following infection, a 0.7 mm osteotomy in the femoral mid-shaft was stabilized with a radiolucent PEEK fixation plate. The defect was inoculated with bioluminescent Staphylococcus aureus, and the infection was monitored over 14 days by bioluminescent imaging (BLI). Osteolysis and reactive bone formation were assessed by X-ray and micro-computed tomography (micro-CT). The active bacterial infection peaked by 5 days post-inoculation, however the stability of the implant fixation became compromised by 10–14 days post-inoculation due to osteolysis around the screws. Thus, day 7 was defined as the ideal time point to perform the revision surgery. During the revision surgery, the infected tissue was debrided and the osteotomy was widened to 3 mm to place a poly-methyl methacrylate spacer, with or without vancomycin. Half of the groups also received systemic vancomycin for the remaining 21 days of the study. The viable bacteria remaining at the end of the study were measured using colony forming unit assays. Volumetric bone changes (osteolysis and reactive bone formation) were directly measured using micro-CT image analysis. Mice that were treated with

  3. Functional outcomes and cost estimation for extra-articular and simple intra-articular distal radius fractures treated with open reduction and internal fixation versus closed reduction and percutaneous Kirschner wire fixation

    PubMed Central

    Dzaja, Ivan; MacDermid, Joy C.; Roth, James; Grewal, Ruby

    2013-01-01

    Background We sought to compare direct costs and clinical and radiographic outcomes for distal radius fractures (DRF) treated with open reduction internal fixation with volar locking plates (VLP) versus closed reduction and percutaneous pinning (CRPP). Methods We identified patients with AO-type A and C1 DRFs from a prospective database. Outcomes were assessed at 6 weeks and at 3, 6 and 12 months, and surgical care costs were estimated. Results Twenty patients were treated with CRPP and 24 with VLP. There were no significant differences in patient-rated wrist evaluation (PRWE) scores between the 2 groups at any time point (mean 16.2 ± 23.1 in the CRPP group v. 21.5 ± 23.6 in the VLP group, p = 0.91). Overall alignment was maintained in both groups; however, there was a greater loss of radial height over time with CRPP than VLP (0.97 mm v. 0.25 mm, p = 0.018). The mean duration of surgery was longer for VLP than CRPP (113.9 ± 39.5 min v. 86.5 ± 7.8 min, p = 0.029), but there were fewer clinic visits (5.2 ± 1.4 v. 7.8 ± 1.3, p < 0.001) and fewer radiographs (7.4 ± 2.7 v. 9 ± 2.4, p = 0.031). The total cost per case was greater for VLP than CRPP ($1637.27 v. $733.91). Conclusion Based on PRWE scores, VLPs did not offer any significant advantage over CRPP in patients with simple fracture types between 3 and 12 months, but they were much more costly. Whether VLP offers any functional advantage earlier in recovery, thereby justifying their expense, requires further investigation in the form of a prospective randomized trial with a detailed cost analysis. PMID:24284144

  4. Regional alterations in long bone produced by internal fixation devices. Part I. /sup 85/Sr clearance

    SciTech Connect

    Daum, W.J.; Simmons, D.J.; Calhoun, J.H.; Benedetto, A.R.

    1988-01-01

    We examined the effect of rigid plate application on the radiostrontium clearance of the intact canine femur at 6 months. We examined each of the component surgical steps. We calculated the clearance both for the whole bone and for each of the five transverse sections of the whole bone. Screw application, but not drilling, increased the clearance in the segment about the screw holes. Plate application produced an increase in the segment beneath the plate as well as around the screws and in the whole bone. These changes are accomplished not only by an absolute increase in clearance to the middle three segments, but by a relative diminution in clearance by the most proximal and distal segments. The histomorphometric changes in long bones following rigid plating may be accompanied by regional increases in bone blood flow.

  5. Reducing chromium losses from a chromium plating bath. 1987 summer intern report. Project conducted at New Dimension Plating, Hutchinson, Minnesota

    SciTech Connect

    Achman, D.

    1987-12-31

    The company employs about forty people and operates for one or two eight hour shifts with an average of 315 racks of chrome plating per eight hour day. They plate a variety of metals including copper, nickel, gold, brass and chromium. Chromium is the major metal plated and is usually the last step in plating cycle. Most parts are copper plated and then nickel plated in preparation for chrome plating. The main difference between New Dimension Plating and other plating shops is the variety of parts plated. As New Dimension Plating is a job shop, a wide range of parts such as motorcycle accessories, stove parts, and custom items are metal finished. The plating lines are manual, meaning employees dip the racks into the tanks by hand. This fact along with the fact that parts vary greatly in size and shape accounts for the significant drag-out on the chromium plating line.

  6. The effect of internal heating on plate dynamics in planetary mantle convection

    NASA Astrophysics Data System (ADS)

    Stein, C.; Hansen, U.; Lowman, J. P.

    2009-12-01

    Plate dynamics on terrestrial planets such as Mars, Venus and Earth strongly differs in temporal variability and thermal evolution. Stagnant-lid convection is characterized by a hot convecting interior and subduction events leading to a cooling of the interior. Moreover it has been shown that the heating mode of mantle convection affects the time-dependence of plate-like surface behavior. Flow reversals have been observed as a result of a heat build-up close to a subduction zone. We investigate the effect of strong internal heating on plate dynamics which is of particular importance for the Super-Earth, a recently discovered class of exosolar planets. In particular, in numerical mantle convection models we consider different modes of internal heating such as purely internal heating and mixed-mode heating. In our study we apply different model approaches in which the viscosity depends on temperature and pressure to allow for high viscosity plates. Plate mobilisation is obtained by additionally employing either a stress dependence of the viscosity or utilizing the force-balance method. The latter approach requires that the stress at the base of each high viscosity plate sums to zero so that the plates neither drive nor resist mantle flow. We find differences between the two modes of heating which has implications for the thermal history. Systems with an insulating bottom are characterized by a cooler interior than systems which are additionally heated from below. This leads to great differences in the plate dynamics, as it is more difficult to sustain stagnant-lid convection in cooler systems.

  7. EVALUATION OF PATIENTS UNDERGOING FIXATION OF DIAPHYSEAL HUMERAL FRACTURES USING THE MINIMALLY INVASIVE BRIDGE-PLATE TECHNIQUE

    PubMed Central

    Superti, Mauro José; Martynetz, Fábio; Falavinha, Ricardo Sprenger; Fávaro, Rodrigo Caldonazzo; Boas, Luis Felipe Villas; Filho, Salim Mussi; Martynetz, Juliano; Ribas, Bruno

    2015-01-01

    Objective: The aim was to describe the experience of our group in treating humeral shaft fractures using the bridge–plate technique via an anterior approach. Methods: Seventeen patients with acute diaphyseal humeral fractures with an indication for surgical treatment who were operated in 2006–2010 were evaluated. The AO and Gustilo & Anderson classifications were used. All the patients were operated using the anterior bridge-plate technique and completed a follow–up period of at least twelve months. Results: Sixteen men and one woman were treated. Their mean age was 31.8 years (18–52). Among the injury mechanisms found were: five motorcycle accidents, four car accidents, three fractures due to firearm projectiles, two falls to the ground and finally, with one case each, assault, crushing and being run over. Eight patients had open fractures: two grade I, one grade II, four grade IIIa and one grade IIIb, according to the Gustilo-Anderson classification. In relation to the AO classification, we found: one 12A1, three 12A2, four 12A3, one 12B1, four 12 B2, three 12B3 and one 12C2. The mean postoperative follow-up was 25 months (12–48). As complications, two patients had pain in the elbow and a ROM deficit and one had deep infection. The mean time taken to achieve consolidation was 17.5 weeks. There was no loss of reduction, pseudarthrosis or malunion in this series of patients. Conclusion: The authors believe that the technique described has low rates of complications and morbidity, with good initial results, although the series is limited by the small sample. PMID:27042639

  8. Biomechanical Study of Acetabular Tridimensional Memoryalloy Fixation System

    NASA Astrophysics Data System (ADS)

    Liu, Xin-Wei; Xu, Shuo-Gui; Zhang, Yun-Tong; Zhang, Chun-Cai

    2011-07-01

    We developed the acetabular tridimensional memoryalloy fixation system (ATMFS), which is made of NiTi shape memory alloy, according to the specific mechanical properties of biological memory material, NiTi shape memory alloy and measured distribution of contact area and pressure between the acetabulum and the femoral head of cadaveric pelvis. Seven formalin-preserved cadaveric pelves were used for this investigation. Pressure-sensitive film was used to measure contact area and pressure within the anterior, superior, and posterior regions of the acetabulum. The pelves were loaded under the following four conditions: (1) intact; (2) following a creation posterior wall fracture defect; (3) following reduction and standard internal fixation with reconstruction plate; and (4) following reduction and internal fixation with a new shape memory alloy device named ATMFS. A posterior wall fracture was created along an arc of 40° to 90° about the acetabulur rim. Creation of a posterior wall defect resulted in increased load in the superior acetabulum (1485 N) as compared to the intact condition (748 N, P = 0.009). Following reduction and internal fixation, the load distributed to the superior acetabulum (1545 N) was not statistically different from the defect condition. Following the fixation with ATMFS, the load seen at the superior region of the actabulum (964 N) was familiar with fixation with reconstruction plate and was not different from intact state ( P = 0.45). These data indicate that the use of ATMFS as a fracture internal fixation device resulted a partial restoration of joint loading parameters toward the intact state. ATMFS fixation may result in a clinical benefit.

  9. Internal and edge cracks in a plate of finite width under bending

    NASA Technical Reports Server (NTRS)

    Boduroglu, H.; Erdogan, F.

    1983-01-01

    Internal and edge cracks were studied by using Reissner's transverse shear theory. The effect of stress-free boundaries on the stress intensity factors in plates under bending were investigated. Among the results found, particularly interesting are those relating to the limiting cases of the crack geometries. The numerical results are given for a single internal crack, two collinear cracks, and two edge cracks. The effect of Poisson's ratio on the stress intensity factors was studied.

  10. Flexural vibration of in-plane loaded plates with straight line/curved internal supports

    NASA Astrophysics Data System (ADS)

    Liew, K. M.; Wang, C. M.

    1993-10-01

    An investigation into the vibration analysis of a class of in-plane loaded rectangular plates with internal supports of arbitrary contour is conducted. Solutions to this vibration problem are obtained based on the pb-2 Rayleigh-Ritz method. The Ritz function for this method is defined as the product of (1) a two-dimensional polynomial function expanded in a new manner, (2) equations of the internal support and (3) equations of the boundary supports each raised to the power of either 0, 1, or 2 corresponding to a free, simply supported or clamped edge, respectively. A comparison study on the convergence between the proposed set of polynomials and mathematically complete set of polynomials is conducted. The simplicity and accuracy of the method are demonstrated by analyzing square plates with either two intersecting internal line supports or a central ring support. The influence of the in-plane loads on the natural frequencies will be studied. Note that this paper presents some first known solutions to in-plane loaded rectangular plates with internal supports of arbitrary contour. The mode shapes for these plates are also presented in contour plots.

  11. Hamate hook nonunion treated with a hook plate: case report and surgical technique.

    PubMed

    Taleb, Chihab; Murachowsky, Joel; Ruggiero, Gustavo M

    2012-12-01

    Despite of its rarity, hamate hook nonunion can cause several complications like tendon rupture or loss of grip strength. Admitted treatments in the literature are excision of the bone fragment or its open reduction and internal fixation. We report a clinical case of a high-level baseball player with hamate hook nonunion treated with an original technique of fixation using a hook plate.

  12. An internal state variable mapping approach for Li-Plating diagnosis

    NASA Astrophysics Data System (ADS)

    Bai, Guangxing; Wang, Pingfeng

    2016-08-01

    Li-ion battery failure becomes one of major challenges for reliable battery applications, as it could cause catastrophic consequences. Compared with capacity fading resulted from calendar effects, Li-plating induced battery failures are more difficult to identify, as they causes sudden capacity loss leaving limited time for failure diagnosis. This paper presents a new internal state variable (ISV) mapping approach to identify values of immeasurable battery ISVs considering changes of inherent parameters of battery system dynamics for Li-plating diagnosis. Employing the developed ISV mapping approach, an explicit functional relationship model between measurable battery signals and immeasurable battery ISVs can be developed. The developed model can then be used to identify ISVs from an online battery system for the occurrence identification of Li-plating. Employing multiphysics based simulation of Li-plating using COMSOL, the proposed Li-plating diagnosis approach is implemented under different conditions in the case studies to demonstrate its efficacy in diagnosis of Li-plating onset timings.

  13. Osteosynthesis of ununited femoral neck fracture by internal fixation combined with iliac crest bone chips and muscle pedicle bone grafting

    PubMed Central

    Baksi, D D; Pal, A K; Baksi, D P

    2016-01-01

    Background: Ununited femoral neck fracture is seen commonly in developing countries due to delayed presentation or failure of primary internal fixation. Such fractures, commonly present with partial or total absorption of femoral neck, osteonecrosis of femoral head in 8–30% cases with upward migration of trochanter posing problem for osteosynthesis, especially in younger individuals. Several techniques for treatment of such conditions are described like osteotomies or nonvascularied cortical or cancellous bone grafting provided varying degrees of success in terms of fracture union but unsatisfactory long term results occurred due to varying incidence of avascular necrosis (AVN) of femoral head. Moreover, in presence of AVN of femoral head neither free fibular graft nor cancellous bone graft is satisfactory. The vascularied bone grafting by deep circumflex iliac artery based on iliac crest bone grafting, free vascularied fibular grafting and muscle pedicle periosteal grafting showed high incidence of success rate. Osteosynthesis is the preferred treatment of choice in ununited femoral neck fracture in younger individuals. Materials and Methods: Of the 293 patients operated during the period from June 1977 to June 2009, 42 were lost to followup. Seven patients with gluteus medius muscle pedicle bone grafting (MPBG) were excluded. Thus, out of 244 patients, 208 (85.3%) untreated nonunion and 36 (14.7%) following failure of primary internal fixation were available for studies. Time interval between the date of injury and operation in untreated nonunion cases was mean 6.5 months and in failed internal fixation cases was mean 11.2 months. Ages of the patients varied from 16 to 55 years. Seventy patients had partial and 174 had subtotal absorption of the femoral neck. Evidence of avascular necrosis (AVN) femoral head was found histologically in 135 (54.3%) and radiologically in 48 (19.7%) patients. The patients were operated by open reduction of fracture, cannulated hip

  14. Shaft Fractures of Both Forearm Bones: The Outcomes of Surgical Treatment with Plating Only and Combined Plating and Intramedullary Nailing

    PubMed Central

    Kim, Sang Bum; Yi, Jin Woong; Lee, Jung Bum; Lim, Byoung Gu

    2015-01-01

    Background Plate fixation is the most commonly used technique for the treatment of shaft fractures of both forearm bones (SFBFBs). However, all fractures are difficult to treat with plate fixation because of soft tissue injuries, fracture patterns, or the patient's condition. The purpose of this study is to compare the functional results of plate fixation only and combined plate and intramedullary (IM) nail fixation in SFBFBs. Methods Fifty-nine cases of SFBFBs that were surgically treated from June 2007 to July 2012 were retrospectively reviewed. In this study, 47 cases that were followed up for more than 12 months were included. All SFBFBs were divided into two groups according to the methods used for internal fixation: plate fixation only (group A) and combined plate and IM nail fixation (group B). The fixation methods were determined intraoperatively. Plate fixation was considered as the first option in all cases, but combined plate and IM nail fixation was selected as the second option if it was difficult to be fixed with plate only. Groups A and B comprised of 31 and 16 cases, respectively. The functional results were evaluated by the Grace and Eversmann rating system and the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. Results In groups A and B, a radiologic union was achieved in 30/31 and 14/16 cases and average union time was 11.1 and 17.8 weeks, respectively. According to the Grace and Eversmann rating system, group A had excellent results in 15 cases, good in 14, acceptable in one, and unacceptable in one. Group B had excellent results in three cases, good in nine, acceptable in two, and unacceptable in two. The average DASH score was 7.1 points (range, 0 to 19.2 points) in group A and 15.1 points (range, 0 to 29.6 points) in group B. Three cases of nonunion with unacceptable results achieved a bony union by additional procedures and the functional results of these cases improved to good or excellent. Conclusions The functional

  15. The curative effect comparison between prolonged third generation of gamma nail and prolonged dynamic hip screw internal fixation in treating femoral intertrochanteric fracture and the effect on infection.

    PubMed

    He, Wenye; Zhang, Wei

    2015-03-01

    The objective was to explore the curative effect of prolonged third generation of gamma nail (pTGN) and prolonged dynamic hip screw (pDHS) internal fixation in treating femoral intertrochanteric fracture, and analyze the incidence rate of infection for better clinical diagnosis and treatment. Sixty five patients with femoral intertrochanteric fracture during February, 2011-February, 2013 were selected and divided into two groups, with one receiving pTGN (control group) and the other one receiving pDHS internal fixation (observation group). The clinical effects of two groups were compared. In control group, the excellent and good rate was 78.13 %, the total effective rate was 87.5 %, and the total complication rate was 6.24 %; in observation group, the excellent and good rate was 78.79 %, the total effective rate was 90.91 %, the total complication rate was 6.06 %; there was no statistical difference between two groups (p > 0.05). The operation time, the intraoperative fluoroscopy time, and the total blood loss had statistically significant difference between two groups (p < 0.05); however, the differences of the total length of incision, the length of preoperative hospitalization, postoperative ambulatory episode, and the length of stay between two groups were not statistically significant (p > 0.05). Both pTGN and pDHS internal fixation were effective on femoral intertrochanteric fracture, with pDHS internal fixation having better overall efficiency.

  16. Open Reduction and Internal Fixation of the Posteromedial Tibial Plateau via the Lobenhoffer Approach.

    PubMed

    Hake, Mark E; Goulet, James A

    2016-08-01

    Posteromedial fractures of the tibial plateau are often encountered after high-energy injuries. They can be seen in isolation or in combination with lateral column fractures. These fractures must be recognized and stabilized independently of any lateral sided fracture to ensure the stability of the final construct. First described in 1997, the Lobenhoffer approach provides access to the posteromedial and posterior aspects of the proximal tibia, allowing for reduction and stabilization of fractures in this location with a posteromedial plate. We present our technique for this approach for the treatment of an isolated posteromedial tibial plateau fracture. The procedure is performed in the prone position. An interval between the gastrocnemius and pes anserine is developed and the fracture apex visualized. The reduction maneuver involves extension and valgus of the knee along with direct manipulation of the fracture fragment. A small fragment antiglide plate is then placed to stabilize the fracture. This relatively straightforward approach is of great use when treating complex tibial plateau fractures involving the medial and posterior columns. PMID:27441936

  17. Natural convection on a vertical plate in a saturated porous medium with internal heat generation

    NASA Astrophysics Data System (ADS)

    Guedda, M.; Sriti, M.; Achemlal, D.

    2014-08-01

    The main goal of this paper is to re-exam a class of exact solutions for the two-dimensional free convection boundary layers induced by a heated vertical plate embedded in a saturated porous medium with an exponential decaying heat generation. The temperature distribution of the plate has been assumed to vary as a power of the axial coordinate measured from the leading edge of the plate and subjected to an applied lateral mass flux. The boundary layer equations are solved analytically and numerically using a fifth-order Runge-Kutta scheme coupled with the shooting iteration method. As for the classical problem without internal heat generation, it is proved that multiple (unbounded) solutions arise for any and for any suction/injection parameter. For such solutions, the asymptotic behavior as the similarity variable approaches infinity is determined.

  18. Free Vibrations of a Trapezoidal Plate with an Internal Line Hinge

    PubMed Central

    Quintana, María Virginia; Grossi, Ricardo Oscar

    2014-01-01

    This paper deals with a general variational formulation for the determination of natural frequencies and mode shapes of free vibrations of laminated thin plates of trapezoidal shape with an internal line hinge restrained against rotation. The analysis was carried out by using the kinematics corresponding to the classical laminated plate theory (CLPT). The eigenvalue problem is obtained by employing a combination of the Ritz method and the Lagrange multipliers method. The domain of the plate is transformed into a rectangular domain in the computational space by using nonorthogonal triangular coordinates and the transverse displacements are approximated with a set of simple polynomials automatically generated and expressed in the triangular coordinates. The developed algorithm allows obtaining approximate analytical solutions for mentioned plate with different geometries, aspect ratio, position of the line hinge, and boundary conditions including translational and rotational elastically restrained edges. It allows studying the influence of the mentioned line on the vibration frequencies and respective mode shapes. The algorithm can easily be programmed and it is numerically stable. Additionally, as a particular case, the results of triangular plates can be easily generated. PMID:24723796

  19. Internal (Annular) and Compressible External (Flat Plate) Turbulent Flow Heat Transfer Correlations.

    SciTech Connect

    Dechant, Lawrence; Smith, Justin

    2016-01-01

    Here we provide a discussion regarding the applicability of a family of traditional heat transfer correlation based models for several (unit level) heat transfer problems associated with flight heat transfer estimates and internal flow heat transfer associated with an experimental simulation design (Dobranich 2014). Variability between semi-empirical free-flight models suggests relative differences for heat transfer coefficients on the order of 10%, while the internal annular flow behavior is larger with differences on the order of 20%. We emphasize that these expressions are strictly valid only for the geometries they have been derived for e.g. the fully developed annular flow or simple external flow problems. Though, the application of flat plate skin friction estimate to cylindrical bodies is a traditional procedure to estimate skin friction and heat transfer, an over-prediction bias is often observed using these approximations for missile type bodies. As a correction for this over-estimate trend, we discuss a simple scaling reduction factor for flat plate turbulent skin friction and heat transfer solutions (correlations) applied to blunt bodies of revolution at zero angle of attack. The method estimates the ratio between axisymmetric and 2-d stagnation point heat transfer skin friction and Stanton number solution expressions for sub-turbulent Reynolds numbers %3C1x10 4 . This factor is assumed to also directly influence the flat plate results applied to the cylindrical portion of the flow and the flat plate correlations are modified by

  20. Does Extraction or Retention of the Wisdom Tooth at the Time of Surgery for Open Reduction and Internal Fixation of the Mandible Alter the Patient Outcome?

    PubMed

    Hammond, Douglas; Parmar, Sat; Whitty, Justin; Pigadas, Nick

    2015-12-01

    Whether to extract or retain wisdom teeth present in a fracture line is a controversial topic. This study reviewed the records of all patients who had mandibular wisdom teeth at the time of the injury, and had an open reduction and internal fixation procedure between January 2009 and January 2012. The cohort of patients who concomitantly had their wisdom tooth extracted at the time of fixation had a greater complication rate (24.3%) compared with patients who did not (14.9%). This suggests that if third molars in the line of a fracture have caries, are fractured, show signs of pericoronitis, are periodontally involved, or are interfering with the occlusion are extracted at the time of fixation, this will increase the incidence of complications.

  1. Open Reduction and Internal Fixation of the Tibial Plateau Through the Anterolateral Approach.

    PubMed

    Hake, Mark E; Goulet, James A

    2016-08-01

    Fractures of the tibial plateau are challenging injuries to treat. The lateral tibial plateau is fractured more commonly than the medial plateau and the workhorse approach for these fractures is the anterolateral approach. This approach allows visualization of the lateral joint, metaphysis, and can be extensile if there is shaft extension. We present our technique for performing the anterolateral approach while treating a Schatzker III tibial plateau fracture. Special attention is given to performing a submeniscal arthrotomy to view the joint surface and judge the reduction. A femoral distractor is placed to assist with elevation the joint surface and visualization of the lateral plateau. A cortical window is created using a triple reamer from the sliding hip screw set. The reduction is performed and supported with cancellous bone chips. Finally, a lateral locking plate with rafting screws is placed. Knowledge of this approach and the strategies needed to address lateral and some bicondlar tibial plateau fractures are crucial to good patient outcomes. PMID:27441932

  2. A laboratory investigation to assess the influence of cement augmentation of screw and plate fixation in a simulation of distal femoral fracture of osteoporotic and non-osteoporotic bone.

    PubMed

    Wähnert, D; Lange, J H; Schulze, M; Gehweiler, D; Kösters, C; Raschke, M J

    2013-10-01

    The augmentation of fixation with bone cement is increasingly being used in the treatment of severe osteoporotic fractures. We investigated the influence of bone quality on the mechanics of augmentation of plate fixation in a distal femoral fracture model (AO 33 A3 type). Eight osteoporotic and eight non-osteoporotic femoral models were randomly assigned to either an augmented or a non-augmented group. Fixation was performed using a locking compression plate. In the augmented group additionally 1 ml of bone cement was injected into the screw hole before insertion of the screw. Biomechanical testing was performed in axial sinusoidal loading. Augmentation significantly reduced the cut-out distance in the osteoporotic models by about 67% (non-augmented mean 0.30 mm (sd 0.08) vs augmented 0.13 mm (sd 0.06); p = 0.017). There was no statistical reduction in this distance following augmentation in the non-osteoporotic models (non-augmented mean 0.15 mm (sd 0.02) vs augmented 0.15 mm (sd 0.07); p = 0.915). In the osteoporotic models, augmentation significantly increased stability (p = 0.017). PMID:24078541

  3. Antimicrobial prophylaxis in open reduction and internal fixation of compound mandibular fractures: a collaborative regional audit of outcome.

    PubMed

    Singh, Rabindra P; Carter, Lachlan M; Whitfield, Paul H

    2013-07-01

    We conducted a regional 2-stage prospective audit involving 5 different maxillofacial units in the Yorkshire region of the UK to evaluate the effectiveness of perioperative antimicrobial prophylaxis in the treatment of mandibular fractures. In the first stage (145 patients) we surveyed current practice concerning antimicrobial prophylaxis and found out the current infection rate after open reduction and internal fixation (ORIF) of mandibular fractures. In the second stage (157 patients) we implemented a common antimicrobial protocol in all units and recorded the infection rates using the new regimen. In the first stage a wide range of antimicrobial prophylaxis was used in different units. The agreed perioperative antimicrobial protocol in the second stage was to begin amoxicillin or clarithromycin and metronidazole intravenously on admission and include 2 postoperative doses. The infection rates were 10.3% and 8.9%, respectively, and the difference between the two groups was not significant (χ(2)=0.051, df=1, p=0.83). The infection rate in the Yorkshire region was similar to results from other centres. We recommend short perioperative antimicrobial prophylaxis with a maximum of 2 postoperative doses after ORIF of mandibular fractures.

  4. The incidence and consequences of early wound infection after internal fixation for trauma in HIV-positive patients.

    PubMed

    Bates, J; Mkandawire, N; Harrison, W J

    2012-09-01

    We report a prospective single-blind controlled study of the incidence of early wound infection after internal fixation for trauma in 609 patients, of whom 132 were HIV-positive. Wounds were assessed for healing using the ASEPSIS score. There was no significant difference in the rate of infection between HIV-positive and HIV-negative patients undergoing clean surgery (4.2% vs 6%, respectively; p = 0.65). HIV-positive patients did not receive additional antibiotic prophylaxis or antiretroviral therapy as part of their management. The difference in the rate of infection between HIV-positive and HIV-negative patients with an open fracture or other contamination was not significant (33% vs 15%, respectively; p = 0.064). There was no relationship between CD4 count and infection rate. HIV status did not significantly influence the number of secondary surgical procedures (p = 0.183) or the likelihood of developing chronic osteomyelitis (p = 0.131). Although previous contamination from the time of injury was a risk factor for infection in mal- and nonunions, it was not significantly increased in HIV-positive patients (p = 0.144). We conclude that clean implant surgery in HIV-positive patients is safe, with no need for additional prophylaxis.

  5. Post-traumatic distal humerus non-union : Open reduction and internal fixation: long-term results.

    PubMed

    Allende, Christian; Allende, Bartolomé T

    2009-10-01

    The objective of this paper is to evaluate the long-term functional results achieved after open reduction and internal fixation of 24 distal humerus non-unions. Non-unions were extra-articular-extracapsular (11 cases), extra-articular-intracapsular (8 cases) and intra-articular (5 cases). Preoperative elbow range of motion averaged 45 degrees. Time between original trauma and revision surgery averaged 14 months. Stabilisation methods varied according to type and location of the non-union. Follow-up averaged 46 months (range: 18-108). Elbow range of motion at last examination averaged 98 degrees . Flexion averaged 110 degrees and extension loss averaged 17 degrees . The disabilities of the arm, shoulder and hand (DASH) score averaged 16 points. Secondary transposition of the ulnar nerve was necessary in three cases. Sixteen patients reported no pain at last examination, seven had mild pain and one had moderate pain. Distal humerus non-unions present different characteristics; consequently, surgical treatment must be individualised for each patient. Even though they are demanding procedures, bony union and good long-term functional results were achieved.

  6. A comparative study of internal fixation and prosthesis replacement for radial head fractures of Mason type III.

    PubMed

    Ruan, Hong-Jiang; Fan, Cun-Yi; Liu, Jun-Jian; Zeng, Bing-Fang

    2009-02-01

    Although several treatment options for radial head fractures are available, no clear solutions exist. In this study we therefore compare open reduction and internal fixation (ORIF) with bipolar radial head prosthesis replacement in treatment of radial head fractures of Mason type III. Cement stem and bipolar radial prosthesis were used to treat 12 fresh cases and two old cases of Mason type III radial head fracture. As a control group, another eight cases of radial head type III fracture were treated with ORIF with cannulated screws and Kirschner (K) wires. The 14 patients who received radial head prosthesis replacement were followed-up for 15.9 months (range 10-27 months). According to elbow functional evaluation criteria by Broberg and Morrey, we found excellent results in nine cases, good in four, and fair in one. Mean follow-up of the eight cases in the ORIF group was 14 months (range 10-21 months), with good results in one case, fair in four, and poor in three. The result was good or excellent in 92.9% of prosthesis replacement patients and in 12.5% of ORIF patients. This difference is statistically significant (P = 0.0004; Fisher's exact test). We concluded that bipolar radial head prosthesis replacement is better than ORIF in treatment of Mason type III radial head fracture. PMID:17938924

  7. Single Oblique Posterolateral Approach for Open Reduction and Internal Fixation of Posterior Malleolar Fractures With an Associated Lateral Malleolar Fracture.

    PubMed

    Choi, Jun Young; Kim, Ji Hoon; Ko, Hyeong Tak; Suh, Jin Soo

    2015-01-01

    The purpose of the present retrospective study was to describe the single oblique posterolateral approach for open reduction and internal fixation of large, displaced, posterior malleolar fractures with an associated lateral malleolar fracture. A single oblique posterolateral approach was used for osteosynthesis of the posterior and lateral malleolus in 50 consecutive patients (23 females [46%], 27 males [54%]; mean age, 47.44 ± 16.13 years; mean follow-up duration, 26.32 ± 5.15 months). The mean interval to surgery was 4.3 ± 1.9 days after the inciting trauma. During the follow-up period, the surgery was complicated by skin necrosis around the incision in 2 (4%) patients and sural nerve damage in 2 (4%) patients. We found that the single oblique posterolateral approach to large, displaced, posterior malleolar fractures with an associated lateral malleolar fracture provided easy exposure of the posterior and lateral malleoli and had the potential to decrease the incidence of sural nerve injury because of the smaller incision size.

  8. Occult internal iliac arterial injury identified during open reduction internal fixation of an acetabular fracture: a report of two cases.

    PubMed

    Chaus, George W; Heng, Marilyn; Smith, Raymond M

    2015-07-01

    We present two cases of occult internal iliac arterial injury identified during operative reduction of a widely displaced posterior column posterior wall acetabular fracture. This complication was not recognised until reduction of the column fracture. There were no preoperative signs or symptoms indicative of a vascular injury. These cases emphasise the heightened awareness one must have when treating widely displaced posterior column fractures of the acetabulum, especially those fractures with extension into the greater sciatic notch, as previously formed clot can become dislodged and hemostasis lost. We also present management options when this complication occurs. We believe any surgeon treating acetabular fractures should be aware of this serious and potentially fatal complication.

  9. Heterotopic Ossification around the Knee after Internal Fixation of a Complex Tibial Plateau Fracture Combined with the Use of Demineralized Bone Matrix (DBM): A Case Report

    PubMed Central

    Nota, Sjoerd P.F.T.; Kloen, Peter

    2014-01-01

    Demineralized bone matrix has been successfully commercialized as an alternative bone graft material that not only can function as filler but also as an osteoinductive graft. Numerous studies have confirmed its beneficial use in clinical practice. Heterotopic ossification after internal fixation combined with the use of demineralized bone matrix has not been widely reported. In this paper we describe a 39 year old male who sustained a complex articular fracture that developed clinically significant heterotopic ossification after internal fixation with added demineralized bone matrix. Although we cannot be sure that there is a cause-and-effect relation between demineralized bone matrix and the excessive heterotopic ossification seen in our patient, it seems that some caution in using demineralised bone matrix in similar cases is warranted. Also, given the known inter- and intraproduct variability, the risks and benefits of these products should be carefully weighed. PMID:25692153

  10. Total Hip Arthroplasty for Failed Internal Fixation After Femoral Neck Fracture Versus That for Acute Displaced Femoral Neck Fracture: A Comparative Study.

    PubMed

    Yang, Zhouyuan; Liu, Huifang; Xie, Xiaowei; Tan, Zhen; Qin, Tianqiang; Kang, Pengde

    2015-08-01

    The outcome of total hip arthroplasty (THA) for failed internal fixation after femoral neck fracture (FNF) versus that for acute displaced femoral neck fracture is still controversial. This study retrospectively analyzed a consecutive series of 130 THAs for acute displaced FNF (64, group I) and for failed internal fixation (66, group II). Results showed THAs in group II were more technically demanding procedures with longer operative time and larger amounts of drainage compared to that in group I. Furthermore, multivariate analysis revealed that the associations between THAs (group II) and hip complications were notable (OR=4.15, P=0.017). These increased risks should be paid much attention to, not only for choosing the appropriate treatment option, but also for providing effective perioperative care.

  11. Open reduction and internal fixation of two-part displaced fractures of the greater tuberosity of the proximal part of the humerus.

    PubMed

    Flatow, E L; Cuomo, F; Maday, M G; Miller, S R; McIlveen, S J; Bigliani, L U

    1991-09-01

    Twelve patients, ranging in age from thirty-four to seventy-two years (average, fifty-three years), were evaluated an average of five years (range, two to eight years) after open reduction and internal fixation of a two-part displaced fracture of the greater tuberosity of the proximal part of the humerus. The indication for operative reduction was one centimeter or more of displacement of the fracture as seen on the diagnostic radiographs. The anterosuperior deltoid-splitting approach, combined with rotation of the humerus, allowed adequate exposure of the retracted tuberosity. Internal fixation of the greater tuberosity with heavy, non-absorbable sutures and careful repair of the rotator cuff permitted early passive motion. All fractures healed without postoperative displacement. Six patients had an excellent result and six had a good result; active elevation averaged 170 degrees. There was one partial, transient palsy of the axillary nerve.

  12. Prophylactic radiotherapy against heterotopic ossification following internal fixation of acetabular fractures: a comparative estimate of risk

    PubMed Central

    Nasr, P; Yip, G; Scaife, J E; House, T; Thomas, S J; Harris, F; Owen, P J; Hull, P

    2014-01-01

    Objective: Radiotherapy (RT) is effective in preventing heterotopic ossification (HO) around acetabular fractures requiring surgical reconstruction. We audited outcomes and estimated risks from RT prophylaxis, and alternatives of indometacin or no prophylaxis. Methods: 34 patients underwent reconstruction of acetabular fractures through a posterior approach, followed by a 8-Gy single fraction. The mean age was 44 years. The mean time from surgery to RT was 1.1 days. The major RT risk is radiation-induced fatal cancer. The International Commission on Radiological Protection (ICRP) method was used to estimate risk, and compared with a method (Trott and Kemprad) specifically for estimating RT risk for benign disease. These were compared with risks associated with indometacin and no prophylaxis. Results: 28 patients (82%) developed no HO; 6 developed Brooker Class I; and none developed Class II–IV HO. The ICRP method suggests a risk of fatal cancer in the range of 1 in 1000 to 1 in 10,000; the Trott and Kemprad method suggests 1 in 3000. For younger patients, this may rise to 1 in 2000; and for elderly patients, it may fall to 1 in 6000. The risk of death from gastric bleeding or perforation from indometacin is 1 in 180 to 1 in 900 in older patients. Without prophylaxis risk of death from reoperation to remove HO is 1 in 4000 to 1 in 30,000. Conclusion: These results are encouraging, consistent with much larger series and endorse our multidisciplinary management. Risk estimates can be used in discussion with patients. Advances in knowledge: The risk from RT prophylaxis is small, it is safer than indometacin and substantially overlaps with the range for no prophylaxis. PMID:25089852

  13. Tips of the trade #38. The Herbert screw in closed reduction and internal fixation of the Jones fracture.

    PubMed

    Traina, S M; McElhinney, J P

    1991-08-01

    A technique of using a cannulated Herbert screw is presented for addressing the troublesome Jones fracture. This closed intramedullary fixation technique allows early healing without many of the screw head problems encountered in the more traditional AO screw techniques.

  14. The Correlation between the Fracture Types and the Complications after Internal Fixation of the Femoral Neck Fractures

    PubMed Central

    Jo, Suenghwan; Lee, Hyeon Jun

    2016-01-01

    Purpose This study aims to determine the correlation between the fracture patterns and the complications in patients with femoral neck fracture treated with internal fixation. Materials and Methods The study comprises 45 patients with femoral neck fracture treated with multiple screws or compression hip screw between May 2008 and April 2012. The mean age was 48 years at the time of the surgery and the mean duration from initial injury to surgery was 20 hours. The fracture patterns were identified according to the anatomical location, the Garden classification and the Pauwels classification. The occurrence of nonunion and avascular necrosis were reviewed with clinical results including Harris hip score and Lunceford hip function test. The correlation between the fracture pattern and occurrence of complications were analyzed. Results Fracture site union was achieved in 40 hips with the average union time of 17 weeks. Five nonunions occurred which showed high likelihood to occur in subcapital type, displaced (Garden stage III or IV) and Pauwels type III fractures (P<0.05). Avascular necrosis was developed in 10 hips which was mostly in subcapital type and Pauwels type III fracture but no statistical significance was found (P>0.05). The mean Harris hip score was 91 points, and Lunceford functional results were excellent in 15 hips, good in 24, fair in 4 and poor in 2. Conclusion There was high risk of nonunion in subcapital type fracture, displaced fracture (Garden stage III and IV) and vertically oriented fracture (Pauwels type III). Careful attention is needed in these fracture types. PMID:27536642

  15. On selection of primary modes for generation of strong internally resonant second harmonics in plate

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Chillara, Vamshi Krishna; Lissenden, Cliff J.

    2013-09-01

    The selection of primary shear-horizontal (SH) and Rayleigh-Lamb (RL) ultrasonic wave modes that generate cumulative second harmonics in homogeneous isotropic plates is analyzed by theoretical modeling. Selection criteria include: internal resonance (synchronism and nonzero power flux), group velocity matching, and excitability/receivability. The power flux, group velocity matching, and excitability are tabulated for the SH and RL internal resonance points. The analysis indicates that SH waves can generate cumulative symmetric RL secondary wave fields. Laboratory experiments on aluminum plates demonstrate that excitation of the SH3 primary mode generates the s4 secondary RL mode and that the secondary wave field amplitude increases linearly with propagation distance. Simple magnetostrictive transducers were used to excite the primary SH wave and to receive the SH and RL wave signals. Reception of these wave modes having orthogonal polarizations was achieved by simply reorienting the electrical coil. The experiment was complicated by the presence of a nonplanar primary wavefront, however finite element simulations were able to clarify the experimental results.

  16. Prospects of implant with locking plate in fixation of subtrochanteric fracture: experimental demonstration of its potential benefits on synthetic femur model with supportive hierarchical nonlinear hyperelastic finite element analysis

    PubMed Central

    2012-01-01

    Background Effective fixation of fracture requires careful selection of a suitable implant to provide stability and durability. Implant with a feature of locking plate (LP) has been used widely for treating distal fractures in femur because of its favourable clinical outcome, but its potential in fixing proximal fractures in the subtrochancteric region has yet to be explored. Therefore, this comparative study was undertaken to demonstrate the merits of the LP implant in treating the subtrochancteric fracture by comparing its performance limits against those obtained with the more traditional implants; angle blade plate (ABP) and dynamic condylar screw plate (DCSP). Materials and Methods Nine standard composite femurs were acquired, divided into three groups and fixed with LP (n = 3), ABP (n = 3) and DCSP (n = 3). The fracture was modeled by a 20 mm gap created at the subtrochanteric region to experimentally study the biomechanical response of each implant under both static and dynamic axial loading paradigms. To confirm the experimental findings and to understand the critical interactions at the boundaries, the synthetic femur/implant systems were numerically analyzed by constructing hierarchical finite element models with nonlinear hyperelastic properties. The predictions from the analyses were then compared against the experimental measurements to demonstrate the validity of each numeric model, and to characterize the internal load distribution in the femur and load bearing properties of each implant. Results The average measurements indicated that the constructs with ABP, DCPS and LP respectively had overall stiffness values of 70.9, 110.2 and 131.4 N/mm, and exhibited reversible deformations of 12.4, 4.9 and 4.1 mm when the applied dynamic load was 400 N and plastic deformations of 11.3, 2.4 and 1.4 mm when the load was 1000 N. The corresponding peak cyclic loads to failure were 1100, 1167 and 1600 N. The errors between the

  17. Analytical modeling for vibration analysis of thin rectangular orthotropic/functionally graded plates with an internal crack

    NASA Astrophysics Data System (ADS)

    Joshi, P. V.; Jain, N. K.; Ramtekkar, G. D.

    2015-05-01

    An analytical model is presented for vibration analysis of a thin orthotropic and general functionally graded rectangular plate containing an internal crack located at the center. The continuous line crack is parallel to one of the edges of the plate. The equation of motion of the orthotropic plate is derived using the equilibrium principle. The crack terms are formulated using Line Spring Model. The effect of location of crack along the thickness of the plate on natural frequencies is analyzed using appropriate crack compliance coefficients in the Line Spring Model. By using the Berger formulation for in-plane forces, the derived equation of motion of the cracked plate is transformed into a cubic nonlinear system. Applying the Galerkin's method, the equation is converted into well known Duffing equation. The peak amplitude is obtained by employing Multiple Scales perturbation method. The effect of nonlinearity is also established by deriving frequency response equation for the cracked plate using method of multiple scales. The influence of crack length, boundary conditions and crack location along the thickness, on the natural frequencies of a square and rectangular plate is demonstrated. It is found that the vibration characteristics are affected by the length and location of crack along the thickness of the plate. It is thus deduced that the natural frequencies are minimum when crack is internal and its depth is symmetric about the mid-plane of the plate for all the three boundary conditions considered. Further, it is concluded that the presence of crack across the fibers decreases the frequency more as compared to crack along the fibers. The Effect of varying elasticity ratio on the fundamental frequencies of the cracked plate is also established.

  18. Long-term growth and alignment after occipitocervical and atlantoaxial fusion with rigid internal fixation in young children.

    PubMed

    Kennedy, Benjamin C; D'Amico, Randy S; Youngerman, Brett E; McDowell, Michael M; Hooten, Kristopher G; Couture, Daniel; Jea, Andrew; Leonard, Jeffrey; Lew, Sean M; Pincus, David W; Rodriguez, Luis; Tuite, Gerald F; Diluna, Michael L; Brockmeyer, Douglas L; Anderson, Richard C E

    2016-01-01

    of these growth patterns or alignment were evident. CONCLUSIONS These results demonstrate that most young children undergoing AA and OC fusion with rigid internal fixation continue to have good cervical alignment and continued growth within the fused levels during a prolonged follow-up period. However, some variability in vertical growth and alignment exists, highlighting the need to continue close long-term follow-up.

  19. Long-term growth and alignment after occipitocervical and atlantoaxial fusion with rigid internal fixation in young children.

    PubMed

    Kennedy, Benjamin C; D'Amico, Randy S; Youngerman, Brett E; McDowell, Michael M; Hooten, Kristopher G; Couture, Daniel; Jea, Andrew; Leonard, Jeffrey; Lew, Sean M; Pincus, David W; Rodriguez, Luis; Tuite, Gerald F; Diluna, Michael L; Brockmeyer, Douglas L; Anderson, Richard C E

    2016-01-01

    of these growth patterns or alignment were evident. CONCLUSIONS These results demonstrate that most young children undergoing AA and OC fusion with rigid internal fixation continue to have good cervical alignment and continued growth within the fused levels during a prolonged follow-up period. However, some variability in vertical growth and alignment exists, highlighting the need to continue close long-term follow-up. PMID:26451720

  20. Plating of proximal humeral fractures.

    PubMed

    Martetschläger, Frank; Siebenlist, Sebastian; Weier, Michael; Sandmann, Gunther; Ahrens, Philipp; Braun, Karl; Elser, Florian; Stöckle, Ulrich; Freude, Thomas

    2012-11-01

    The optimal treatment for proximal humeral fractures is controversial. Few data exist concerning the influence of the surgical approach on the outcome. The purpose of this study was to evaluate the clinical and radiological outcomes of proximal humeral fractures treated with locking plate fixation through a deltopectoral vs an anterolateral deltoid-splitting approach. Of 86 patients who met the inclusion criteria, 70 were available for follow-up examination. Thirty-three patients were treated through a deltopectoral approach and 37 through an anterolateral deltoid-splitting approach. In all cases, open reduction and internal fixation with a PHILOS locking plate (Synthes, Umkirch, Germany) was performed. Clinical follow-up included evaluation of pain, shoulder mobility, and strength. Constant score and Disabilities of the Arm, Shoulder and Hand (DASH) score were assessed. A clinical neurological examination of the axillary nerve was also performed. Consolidation, reduction, and appearance of head necrosis were evaluated radiographically. After a mean follow-up of 33 months, Constant scores, DASH scores, and American Shoulder and Elbow Surgeons scores showed no significant differences between the groups. Clinical neurologic examination of the axillary nerve revealed no obvious damage to the nerve in either group. Deltopectoral and anterolateral detoid-splitting approaches for plate fixation of proximal humeral fractures are safe and provide similar clinical outcomes. The results of this study suggest that the approach can be chosen according to surgeon preference.

  1. Plate tectonics and offshore boundary delimitation: Tunisia-Libya case at the International Court of Justice

    NASA Astrophysics Data System (ADS)

    Stanley, Daniel Jean

    1982-03-01

    The first major offshore boundary dispute where plate tectonics constituted a significant argument was recently brought before the International Court of Justice by Libya and Tunisia concerning the delimitation of their continental shelves. Libya placed emphasis on this concept to determine natural prolongation of its land territory under the sea. Tunisia contested use of the entire African continental landmass as a reference unit and views geography, geomorphology and bathymetry as relevant as geology. The Court pronounced that “It is the outcome, not the evolution in the long-distant past, which is of importance.” Moreover, it is the present-day configuration of coasts and seabed that are the main factors, not geology.

  2. Homogeneous plate based antibody internalization assay using pH sensor fluorescent dye.

    PubMed

    Nath, Nidhi; Godat, Becky; Zimprich, Chad; Dwight, Stephen J; Corona, Cesear; McDougall, Mark; Urh, Marjeta

    2016-04-01

    Receptor-mediated antibody internalization is a key mechanism underlying several anti-cancer antibody therapeutics. Delivering highly toxic drugs to cancer cells, as in the case of antibody drug conjugates (ADCs), efficient removal of surface receptors from cancer cells and changing the pharmacokinetics profile of the antibody drugs are some of key ways that internalization impacts the therapeutic efficacy of the antibodies. Over the years, several techniques have been used to study antibody internalization including radiolabels, fluorescent microscopy, flow cytometry and cellular toxicity assays. While these methods allow analysis of internalization, they have limitations including a multistep process and limited throughput and are generally endpoint assays. Here, we present a new homogeneous method that enables time and concentration dependent measurements of antibody internalization. The method uses a new hydrophilic and bright pH sensor dye (pHAb dye), which is not fluorescent at neutral pH but becomes highly fluorescent at acidic pH. For receptor mediated antibody internalization studies, antibodies against receptors are conjugated with the pHAb dye and incubated with the cells expressing the receptors. Upon binding to the receptor, the dyes conjugated to the antibody are not fluorescent because of the neutral pH of the media, but upon internalization and trafficking into endosomal and lysosomal vesicles the pH drops and dyes become fluorescent. The enabling attributes of the pHAb dyes are the hydrophilic nature to minimize antibody aggregation and bright fluorescence at acidic pH which allows development of simple plate based assays using a fluorescent reader. Using two different therapeutic antibodies--Trastuzumab (anti-HER2) and Cetuximab (anti-EGFR)--we show labeling with pHAb dye using amine and thiol chemistries and impact of chemistry and dye to antibody ration on internalization. We finally present two new approaches using the pHAb dye, which will be

  3. Biomechanical Concepts for Fracture Fixation.

    PubMed

    Bottlang, Michael; Schemitsch, Christine E; Nauth, Aaron; Routt, Milton; Egol, Kenneth A; Cook, Gillian E; Schemitsch, Emil H

    2015-12-01

    Application of the correct fixation construct is critical for fracture healing and long-term stability; however, it is a complex issue with numerous significant factors. This review describes a number of common fracture types and evaluates their currently available fracture fixation constructs. In the setting of complex elbow instability, stable fixation or radial head replacement with an appropriately sized implant in conjunction with ligamentous repair is required to restore stability. For unstable sacral fractures with vertical or multiplanar instabilities, "standard" iliosacral screw fixation is not sufficient. Periprosthetic femur fractures, in particular Vancouver B1 fractures, have increased stability when using 90/90 fixation versus a single locking plate. Far cortical locking combines the concept of dynamization with locked plating to achieve superior healing of a distal femur fracture. Finally, there is no ideal construct for syndesmotic fracture stabilization; however, these fractures should be fixed using a device that allows for sufficient motion in the syndesmosis. In general, orthopaedic surgeons should select a fracture fixation construct that restores stability and promotes healing at the fracture site, while reducing the potential for fixation failure.

  4. Combined medial column primary arthrodesis, middle column open reduction internal fixation, and lateral column pinning for treatment of Lisfranc fracture-dislocation injuries.

    PubMed

    Boffeli, Troy J; Pfannenstein, Ryan R; Thompson, Jonathan C

    2014-01-01

    Lisfranc fracture-dislocation can be a devastating injury with significant long-term sequelae, including degenerative joint disease, progressive arch collapse, and chronic pain that can be potentiated if not effectively treated. We present a case to demonstrate our preferred surgical approach, consisting of combined medial column primary arthrodesis, middle column open reduction internal fixation, and lateral column pinning, with the primary goal of minimizing common long-term complications associated with Lisfranc injuries. We present the case of a typical patient treated according to this combined surgical approach to highlight our patient selection criteria, rationale, surgical technique, and operative pearls. A 36-year-old male who had sustained a homolateral Lisfranc fracture-dislocation injury after falling from a height initially underwent fasciotomy for foot compartment syndrome. The subsequent repair 16 days later involved primary first tarsometatarsal joint fusion, open reduction internal fixation of the second and third tarsometatarsal joints, and temporary pinning of the fourth and fifth tarsometatarsal joints. He progressed well postoperatively, exhibiting an American College of Foot and Ankle Surgeons forefoot score of 90 of 100 at 1 year after surgery with no need for subsequent treatment. Lisfranc fracture-dislocations often exhibit primary dislocation to the medial column and are conducive to arthrodesis to stabilize the tarsometatarsal complex. The middle column frequently involves comminuted intra-articular fractures and will often benefit from less dissection required for open reduction internal fixation instead of primary fusion. We propose that this surgical approach is a viable alternative technique for primary treatment of Lisfranc fracture-dislocation injuries.

  5. Internal Fixation Versus Nonoperative Treatment for Displaced 3-Part or 4-Part Proximal Humeral Fractures in Elderly Patients: A Meta-Analysis of Randomized Controlled Trials

    PubMed Central

    Li, Jing; Chen, Aimin

    2013-01-01

    Background A few studies focused on open reduction and internal fixation (ORIF) or nonoperative treatment of displaced 3-part or 4-part proximal humeral fractures in elderly patients have been published, all of whom had a low number of patients. In this meta-analysis of randomized controlled trials (RCTs), we aimed to assess the effect of ORIF or nonoperative treatment of displaced 3-part or 4-part proximal humeral fractures in elderly patients on the clinical outcomes and re-evaluate of the potential benefits of conservative treatment. Methods We searched PubMed and the Cochrane Central Register of Controlled Trials databases for randomized controlled trials comparing ORIF and nonoperative treatment of displaced 3-part or 4-part proximal humeral fractures in elderly patients. Our outcome measures were the Constant scores. Results: Three randomized controlled trials with a total of 130 patients were identified and analyzed. The overall results based on fixed-effect model did not support the treatment of open reduction and internal fixation to improve the functional outcome when compared with nonoperative treatment for treating elderly patients with displaced 3-part or 4-part proximal humeral fractures (WMD −0.51, 95% CI: −7.25 to 6.22, P = 0.88, I2 = 0%). Conclusions Although our meta-analysis did not support the treatment of open reduction and internal fixation to improve the functional outcome when compared with nonoperative treatment for treating elderly patients with displaced 3-part or 4-part proximal humeral fractures, this result must be considered in the context of variable patient demographics. Only a limited recommendation can be made based on current data. Considering the limitations of included studies, a large, well designed trial that incorporates the evaluation of clinically relevant outcomes in participants with different underlying risks of shoulder function is required to more adequately assess the role for ORIF or nonoperative

  6. Periprosthetic femoral fracture--a biomechanical comparison between Vancouver type B1 and B2 fixation methods.

    PubMed

    Moazen, Mehran; Mak, Jonathan H; Etchels, Lee W; Jin, Zhongmin; Wilcox, Ruth K; Jones, Alison C; Tsiridis, Eleftherios

    2014-03-01

    Current clinical data suggest a higher failure rate for internal fixation in Vancouver type B1 periprosthetic femoral fracture (PFF) fixations compared to long stem revision in B2 fractures. The aim of this study was to compare the biomechanical performance of several fixations in the aforementioned fractures. Finite element models of B1 and B2 fixations, previously corroborated against in vitro experimental models, were compared. The results indicated that in treatment of B1 fractures, a single locking plate can be without complications provided partial weight bearing is followed. In case of B2 fractures, long stem revision and bypassing the fracture gap by two femoral diameters are recommended. Considering the risk of single plate failure, long stem revision could be considered in all comminuted B1 and B2 fractures. PMID:24035619

  7. Torsional moment to failure for carbon fibre polysulphone expandable rivets as compared with stainless steel screws for carbon fibre-reinforced epoxy fracture plate fixation.

    PubMed

    Sell, P J; Prakash, R; Hastings, G W

    1989-04-01

    A method of securing carbon fibre-reinforced epoxy bone plates with carbon fibre polysulphone expanding rivets was investigated. Six carbon fibre-reinforced epoxy bone plates were secured to rods with carbon fibre polysulphone rivets and six were secured with standard cortical stainless steel screws. These constructions were then subjected to pure torsional load to failure. The carbon fibre expandable rivets failed at a greater torsional moment.

  8. Finite element analysis of a bone healing model: 1-year follow-up after internal fixation surgery for femoral fracture

    PubMed Central

    Jiang-jun, Zhou; Min, Zhao; Ya-bo, Yan; Wei, Lei; Ren-fa, Lv; Zhi-yu, Zhu; Rong-jian, Chen; Wei-tao, Yu; Cheng-fei, Du

    2014-01-01

    Objective: Finite element analysis was used to compare preoperative and postoperative stress distribution of a bone healing model of femur fracture, to identify whether broken ends of fractured bone would break or not after fixation dislodgement one year after intramedullary nailing. Method s: Using fast, personalized imaging, bone healing models of femur fracture were constructed based on data from multi-slice spiral computed tomography using Mimics, Geomagic Studio, and Abaqus software packages. The intramedullary pin was removed by Boolean operations before fixation was dislodged. Loads were applied on each model to simulate a person standing on one leg. The von Mises stress distribution, maximum stress, and its location was observed. Results : According to 10 kinds of display groups based on material assignment, the nodes of maximum and minimum von Mises stress were the same before and after dislodgement, and all nodes of maximum von Mises stress were outside the fracture line. The maximum von Mises stress node was situated at the bottom quarter of the femur. The von Mises stress distribution was identical before and after surgery. Conclusion : Fast, personalized model establishment can simulate fixation dislodgement before operation, and personalized finite element analysis was performed to successfully predict whether nail dislodgement would disrupt femur fracture or not. PMID:24772140

  9. Staged Columnar Fixation of Bicondylar Tibial Plateaus: A Cheaper Alternative to External Fixation.

    PubMed

    Perdue, Aaron; Greenberg, Sarah E; Sathiyakumar, Vasanth; Thakore, Rachel V; Mir, Hassan R; Obremskey, William T; Sethi, Manish K

    2016-01-01

    The objective of this study was to compare complication rates and costs of staged columnar fixation (SCF) to external fixation for bicondylar tibial plateau fractures. Patients who received SCF or temporary external fixation across a 3-year period at a major level I trauma center underwent a retrospective chart review for associated complications. Fisher's exact analysis was used to determine any statistical difference in complication rates between both groups. However, there was no significant difference in complication rates between the SCF and external fixator groups. Average medial plate costs for SCF were $2131 compared with an average external fixator cost of $4070 (p < .0001). Given that all patients with external fixation undergo eventual medial and lateral plating, savings with SCF include $4070 plus operative costs for removing the fixator. As our health care system focuses on cost-cutting efforts, orthopaedic trauma surgeons must explore cheaper and equally effective treatment alternatives. PMID:27082883

  10. Reverse shoulder prosthesis as revision surgery after fractures of the proximal humerus, treated initially by internal fixation or hemiarthroplasty.

    PubMed

    Lollino, Nicola; Paladini, Paolo; Campi, Fabrizio; Merolla, Giovanni; Rossi, Paolo; Porcellini, Giuseppe

    2009-04-01

    Complex (3-4 fragments) fractures of the proximal humerus often have a bad outcome, whatever treatment is performed. When revision surgery is required, reverse shoulder prosthesis can improve function and reduce pain in these patients. We analysed whether the choice of the first treatment (hemiarthroplasty vs. reduction and fixation) can influence the outcome of revision surgery. Our data demonstrate that results are not significantly dependent on the choice of the first implant, even though there is a tendency for patients with previous hemiarthroplasty to have a worse outcome. PMID:19711168

  11. Biologic Fixation through Bridge Plating for Comminuted Shaft Fracture of the Clavicle: Technical Aspects and Prospective Clinical Experience with a Minimum of 12-Month Follow-up

    PubMed Central

    Park, Chang-Min; Kim, Jae-Do

    2013-01-01

    For comminuted shaft fracture of clavicle, the operative goal, aside from sound bone healing without complications of direct reduction, is maintenance of the original length in order to maintain the normal biomechanics of adjacent joint. Our bridge plating technique utilizing distraction through a lumbar spreader was expected to be effective for restoring clavicular length with soft tissue preservation. However, there are two disadvantages. First, there is more exposure to radiation compared to conventional plating; and second, it is difficult to control the rotational alignment. Despite these disadvantages, our technique has important benefits, in particular, the ability to preserve clavicular length without soft tissue injury around the fracture site. PMID:24340154

  12. A 4-GHz frequency-domain fluorometer with internal microchannel plate photomultiplier cross-correlation.

    PubMed

    Berndt, K W; Gryczynski, I; Lakowicz, J R

    1991-01-01

    We have developed and tested a multifrequency phase/modulation fluorometer based on the Hamamatsu Model R2024U gatable microchannel plate photomultiplier (MCP-PMT), using internal MCP-PMT cross-correlation. This internal mixing is accomplished by biasing and modulating the gating mesh which is located 0.2 mm behind the photocathode. Near the photocathode center, no high-frequency photocurrent modulation was achieved. Within a circular area near the photocathode edge, however, the R2024U allows accurate phase shift and demodulation measurements up to at least 4.5 GHz, the frequency limit of our PMT-modulation amplifier. By mixing immediately after the photocathode, there is no decrease in the time resolution due to transit time spread, and the MCP has to process only low-frequency signals. This means no low-level high-frequency signal voltages have to be handled in this fluorometer, and the problems of RF shielding become much less critical. Also, the effective output impedance of the PMT has been increased, resulting in a 43-dB increase in the PMT output signal power. In principle, more MCPs could be built into the PMT, allowing an improved fluorescence detection limit. We have used the method of reference fluorophores in order to compensate for pronounced PMT color effects, a wavelength-dependent modulation, and a wavelength-dependent time shift. No color correction is required in the case of time-dependent depolarization. The performance of the instrument was verified by measurements of the intensity decay of perylene, which showed a single-exponential decay, and by measurements of the decay of tryptophan in water, which showed a double-exponential decay, as expected.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2048714

  13. Plate tectonics and offshore boundary delimitation: Tunisia-Libya case at the International Court of Justice

    SciTech Connect

    Stanley, D.J.

    1983-03-01

    Advances in the technology for exploiting resources of the oceans, particularly recovery of hydrocarbons and minerals in deep water, is benefiting a growing number of nations. At the same time, however, economic and political pressures have induced concern and there is now a much increased emphasis on jurisdiction to divide the offshore areas between the 132 coastal nations. Negotiations affect research operations at sea and, in consequence, marine scientists have been made aware of offshore problems as highlighted by the Law of the Sea Treaty (UNCLOS III) and complications arising from the legal versus scientific definitions of continental shelves and margins. The first major offshore boundary case of international scope where plate tectonics has constituted a significant argument is the one recently brought before the International Court of Justice by Libya and Tunisia concerning the delimitation of their continental shelves. Of the two parties, Libya placed the greatest emphasis on this concept as a means to determine natural prolongation of its land territory into and under the sea. Tunisia contested Libya's use of the whole of the African continental landmass as a reference unit; in Tunisia's view, considerations of geography, geomorphology, and bathymetry are at least as relevant as are those of geology. In its landmark judgment (February 1982) - which almost certainly will have far-reaching consequences in future such boundary delimitation cases - the court pronounced that It is the outcome, not the evolution in the long-distant past, which is of importance, and that it is the present-day configuration of the coasts and sea bed which are the main factors to be considered, not geology.

  14. Preoperative Planning of Virtual Osteotomies Followed by Fabrication of Patient Specific Reconstruction Plate for Secondary Correction and Fixation of Displaced Bilateral Mandibular Body Fracture.

    PubMed

    Thor, Andreas

    2016-06-01

    This paper describes the course of treatment of a severely diplaced bilateral mandibular body fracture, where the first osteosynthesis failed. The subject developed an open bite due to a posterior rotation of the distal part of the mandible and anterior rotation of the proximal parts of the mandible. This situation was evaluated with CBCT and the facial skeleton was segmented using computer software. Correct occlusion was virtually established by bilateral virtual osteotomies in the fracture areas of the mandible. After segmentation, the mandible was virtually rotated back into position and the open bite was closed. A patient specific mandibular reconstruction plate was outlined and fabricated from the new virtual situation and the plate was thereafter installed utilizing the preoperative plan. Osteotomy- and drill-guides was used and thus simplified the surgery resulting in uneventful healing. Virtual planning and patient specific implants and guides were valuable in this case of secondary reconstructive trauma surgery. PMID:27162581

  15. A consistent geodynamic model for predicting the velocity and plate-internal deformation of Eurasia

    NASA Astrophysics Data System (ADS)

    Govers, Rob; Garcia-Sancho, Candela; Warners-Ruckstuhl, Karin; van der Burgt, Janneke; Wortel, Rinus

    2015-04-01

    The motion and deformation of tectonic plates is driven by gravity and resisted by frictional forces. In principle it should thus be possible to build mechanical models that reproduce plate velocities and surface deformation. Here we present a new approach that overcomes many of the previous obstacles to achieving this goal. Our approach to quantify the forces is based on mechanical equilibrium of the whole Eurasian plate, meaning that an increase in, for instance collision, forces must be matched by other plate tectonic forces. We first focus on present-day Eurasia. We include basal tractions from a global convection model, lithospheric body forces, and edge forces resulting from the interaction of the Eurasian plate with neighboring plates. The resulting force distribution is constrained by observed plate motion and by stress observations. Eurasia's stress field turns out to be most sensitive to the distribution of collision forces on the plate's southern margin and, to a lesser extent, to lithospheric density structure and normal pressure from mantle flow. Stress observations require collision forces on the India-Eurasia boundary of 7.0 - 10.5 TN/m. A similar analysis is performed for Eurasia at 20 Ma and 40 Ma. Plate geometry is taken from the global Lausanne (Stampfli) reconstruction, as are plate velocities and oceanic ages. Lithospheric body forces are accounted for in a simplified way because we lack detailed enough information on the plate scale topography. For the Miocene, we find ˜1.2 TN/m for the collision force on the India-Eurasia boundary. In the Eocene, the collision force we find is ˜0.4 TN/m. We conclude that the magnitude of the collision force on Tibet increased significantly after 20 Ma: from 40-20 Ma, the plate contact force on the India/Tibet plate boundary segment was of the same order of magnitude as resistive forces on subduction plate boundaries elsewhere. Our timing of the collision force on Eurasia, is substantially younger than the

  16. Plate convergence, transcurrent faults and internal deformation adjacent to Southeast Asia and the western Pacific

    NASA Technical Reports Server (NTRS)

    Fitch, T. J.

    1971-01-01

    A model for oblique convergence between plates of lithosphere is proposed in which at least a fraction of slip parallel to the plate margin results in transcurrent movements on a nearly vertical fault which is located on the continental side of a zone of plate consumption. In an extreme case of complete decoupling only the component of slip normal to the plate margin can be inferred from underthrusting. Recent movements in the western Sunda region provide the most convincing evidence for decoupling of slip, which in this region is thought to be oblique to the plate margin. A speculative model for convergence along the margins of the Philippine Sea is constructed from an inferred direction of oblique slip in the Philippine region. This model requires that the triple point formed by the junction of the Japanese and Izu-Bonin trenches and the Nankai trough migrate along the Sagami trough.

  17. Analysis of residual stress and hardness in regions of pre-manufactured and manual bends in fixation plates for maxillary advancement.

    PubMed

    Araújo, Marcelo Marotta; Lauria, Andrezza; Mendes, Marcelo Breno Meneses; Claro, Ana Paula Rosifini Alves; Claro, Cristiane Aparecida de Assis; Moreira, Roger William Fernandes

    2015-12-01

    The aim of this study was to analyze, through Vickers hardness test and photoelasticity analysis, pre-bent areas, manually bent areas, and areas without bends of 10-mm advancement pre-bent titanium plates (Leibinger system). The work was divided into three groups: group I-region without bend, group II-region of 90° manual bend, and group III-region of 90° pre-fabricated bends. All the materials were evaluated through hardness analysis by the Vickers hardness test, stress analysis by residual images obtained in a polariscope, and photoelastic analysis by reflection during the manual bending. The data obtained from the hardness tests were statistically analyzed using ANOVA and Tukey's tests at a significance level of 5 %. The pre-bent plate (group III) showed hardness means statistically significantly higher (P < 0.05) than those of the other groups (I-region without bends, II-90° manually bent region). Through the study of photoelastic reflection, it was possible to identify that the stress gradually increased, reaching a pink color (1.81 δ / λ), as the bending was performed. A general analysis of the results showed that the bent plate region of pre-bent titanium presented the best results.

  18. Evaluation of colon cancer histomorphology: a comparison between formalin and PAXgene tissue fixation by an international ring trial.

    PubMed

    Gündisch, Sibylle; Slotta-Huspenina, Julia; Verderio, Paolo; Ciniselli, Chiara Maura; Pizzamiglio, Sara; Schott, Christina; Drecoll, Enken; Viertler, Christian; Zatloukal, Kurt; Kap, Marcel; Riegman, Peter; Esposito, Irene; Specht, Katja; Babaryka, Gregor; Asslaber, Martin; Bodó, Koppany; den Bakker, Michael; den Hollander, Jan; Fend, Falko; Neumann, Jens; Reu, Simone; Perren, Aurel; Langer, Rupert; Lugli, Alessandro; Becker, Ingrid; Richter, Thomas; Kayser, Gian; May, Annette M; Carneiro, Fatima; Lopes, José Manuel; Sobin, Leslie; Höfler, Heinz; Becker, Karl-Friedrich

    2014-11-01

    The aim of our study was to evaluate the quality of histo- and cytomorphological features of PAXgene-fixed specimens and their suitability for histomorphological classification in comparison to standard formalin fixation. Fifteen colon cancer tissues were collected, divided into two mirrored samples and either formalin fixed (FFPE) or PAXgene fixed (PFPE) before paraffin embedding. HE- and PAS-stained sections were scanned and evaluated in a blinded, randomised ring trial by 20 pathologists from Europe and the USA using virtual microscopy. The pathologists evaluated histological grading, histological subtype, presence of adenoma, presence of lymphovascular invasion, quality of histomorphology and quality of nuclear features. Statistical analysis revealed that the reproducibility with regard to grading between both fixation methods was rather satisfactory (weighted kappa statistic (k w) = 0.73 (95 % confidence interval (CI), 0.41-0.94)), with a higher agreement between the reference evaluation and the PFPE samples (k w = 0.86 (95 % CI, 0.67-1.00)). Independent from preservation method, inter-observer reproducibility was not completely satisfactory (k w = 0.60). Histomorphological quality parameters were scored equal or better for PFPE than for FFPE samples. For example, overall quality and nuclear features, especially the detection of mitosis, were judged significantly better for PFPE cases. By contrast, significant retraction artefacts were observed more frequently in PFPE samples. In conclusion, our findings suggest that the PAXgene Tissue System leads to excellent preservation of histomorphology and nuclear features of colon cancer tissue and allows routine morphological diagnosis.

  19. Hinged external fixation for complex fracture-dislocation of the elbow in elderly people.

    PubMed

    Maniscalco, P; Pizzoli, A L; Renzi Brivio, L; Caforio, M

    2014-12-01

    The authors report their experience of treating complex elbow fracture-dislocations in elderly people, using a minimally-invasive approach with a new articulated external fixator that is associated with minimal internal fixation. The clinical results for 19 patients are presented according to outcome factors, such as range of motion, pain and function, rate and type of complications, and reoperation rate. The results indicate that this treatment strategy should be considered as a good alternative to other treatment options reported in the literature, including conservative treatment, ORIF with angular stable plates and total elbow arthroplasty. PMID:25457320

  20. Open reduction and fixation of proximal humeral fractures and fracture-dislocations.

    PubMed

    Moda, S K; Chadha, N S; Sangwan, S S; Khurana, D K; Dahiya, A S; Siwach, R C

    1990-11-01

    Open reduction and internal fixation was employed in the treatment of 25 severely displaced fractures and fracture-dislocations of the proximal humerus. Our aims were accurate reduction and stable fixation to allow early mobilisation and to achieve full functional recovery. In 15 fractures an AO T-plate was used and in 10 a bent semitubular plate was employed as a blade plate. Excellent or satisfactory results were obtained in all six patients with two-part fractures involving the surgical neck; in four of the five patients with three-part fractures involving the surgical neck and tuberosities; in nine of the 11 patients with fracture-dislocation; and in two of the three patients with split fractures of the humeral head. Overall results were good or satisfactory in 21 of the 25 cases. Unsatisfactory results were associated with rotator cuff damage.

  1. External fixation is more suitable for intra-articular fractures of the distal radius in elderly patients.

    PubMed

    Ma, Chuang; Deng, Qiang; Pu, Hongwei; Cheng, Xinchun; Kan, Yuhua; Yang, Jing; Yusufu, Aihemaitijiang; Cao, Li

    2016-01-01

    The purpose of this study was to compare the functional outcomes, psychological impact, and complication rates associated with external fixation and volar or dorsal plating in relation to the functional parameters following treatment of intra-articular fractures of the distal radius (IFDR) in patients older than 65 years. We hypothesized that using volar or dorsal plating would improve functional outcomes, but that it would be associated with more complications and equivalent functional outcomes when compared with the external fixation group. A total of 123 consecutive patients suffering from IFDR were recruited into the study. The patients were measured for clinical, radiological, and psychosocial functioning outcomes and were followed up after 1 week and 3, 6 and 12 months. After 3 months, the plating group had better pronation (P=0.001), supination, (P=0.047) and extension (P=0.043) scores. These differences were somewhat attenuated by 6 months and disappeared at 1 year. The plating group had a greater occurrence of wound infection (P=0.043), tendonitis, (P=0.024) and additional surgery compared with the external fixation group. The only TNO-AZL Adult Quality of Life scores in the plating group that were lower than those in the external fixation group were in the "gross motor" category (walking upstairs, bending over, walking 500 yards; P=0.023). Internal fixation was more advantageous than external fixation in the early rehabilitation period; after 1 year the outcomes were similar. The plating group showed significantly higher levels of wound infection and tendonitis and had a greater need for additional surgeries. PMID:27408765

  2. External fixation is more suitable for intra-articular fractures of the distal radius in elderly patients

    PubMed Central

    Ma, Chuang; Deng, Qiang; Pu, Hongwei; Cheng, Xinchun; Kan, Yuhua; Yang, Jing; Yusufu, Aihemaitijiang; Cao, Li

    2016-01-01

    The purpose of this study was to compare the functional outcomes, psychological impact, and complication rates associated with external fixation and volar or dorsal plating in relation to the functional parameters following treatment of intra-articular fractures of the distal radius (IFDR) in patients older than 65 years. We hypothesized that using volar or dorsal plating would improve functional outcomes, but that it would be associated with more complications and equivalent functional outcomes when compared with the external fixation group. A total of 123 consecutive patients suffering from IFDR were recruited into the study. The patients were measured for clinical, radiological, and psychosocial functioning outcomes and were followed up after 1 week and 3, 6 and 12 months. After 3 months, the plating group had better pronation (P=0.001), supination, (P=0.047) and extension (P=0.043) scores. These differences were somewhat attenuated by 6 months and disappeared at 1 year. The plating group had a greater occurrence of wound infection (P=0.043), tendonitis, (P=0.024) and additional surgery compared with the external fixation group. The only TNO-AZL Adult Quality of Life scores in the plating group that were lower than those in the external fixation group were in the “gross motor” category (walking upstairs, bending over, walking 500 yards; P=0.023). Internal fixation was more advantageous than external fixation in the early rehabilitation period; after 1 year the outcomes were similar. The plating group showed significantly higher levels of wound infection and tendonitis and had a greater need for additional surgeries. PMID:27408765

  3. EVALUATION OF SURGICAL TREATMENT OF FRACTURES OF THORACOLUMBAR SPINE WITH THIRD-GENERATION MATERIAL FOR INTERNAL FIXATION

    PubMed Central

    Bortoletto, Adalberto; Rodrigues, Luiz Cláudio Lacerda; Matsumoto, Marcelo Hide

    2015-01-01

    Objective: To evaluate the functional results from patients with surgical fractures in the thoracolumbar spine. Method: A prospective study including 100 patients with spinal fractures in the thoracic and lumbar segments was conducted. The lesions were classified in accordance with the AO system, and the patients were treated surgically. The presence of early kyphosis and its evolution after the surgical intervention, and the presence of postoperative pain and its evolution up to the 24th week after the surgery, were evaluated. We compared our data with the literature. Results: One hundred surgical patients were analyzed, of which 37 were type A, 46 were type B and 17 were Type C. Patients who presented Frankel A kept their clinical status, but patients with Frankel B or higher evolved with some improvement. The average improvement in pain based on a visual analog scale was more than four points. All the patients were able to return to their daily routine activities, although we did not take the return to work to be an assessment criterion. Conclusion: Despite controversy regarding the indications for surgery in cases of fractured spine, we believe that the method that we used was satisfactory because of the good results and low complication rate. However, more randomized prospective studies with longer follow-up are needed in order to evaluate this type of fixation. PMID:27047822

  4. Bicolumnar 90-90 Plating of Low-Energy Distal Humeral Fractures in the Elderly Patient

    PubMed Central

    Leigey, Daniel F.; Farrell, Dana J.; Siska, Peter A.

    2014-01-01

    Fragility fractures of the distal humerus in elderly patients, especially the low transcondylar fracture pattern, can be difficult to optimally manage. Although the fractures are typically low energy resulting in either extra-articular or simple intra-articular patterns, gaining fixation into the distal fragments can be difficult with open reduction internal fixation (ORIF) using traditional 90-90 or parallel plating techniques. Anatomy preserving reconstruction with ORIF is preferred over total elbow arthroplasty (TEA) if possible. In this study, 15 patients were managed with a bicolumnar 90-90 plating construct as a novel method of enhancing distal fixation in these fractures. Fourteen patients went on to radiographic union at an average of 77 days after surgery with an average arc of motion of 105°. One patient was lost to follow-up. Bicolumnar 90-90 plating of distal humerus fractures in elderly patients may represent a viable alternative to traditional ORIF or TEA. PMID:25360342

  5. Bicolumnar 90-90 plating of low-energy distal humeral fractures in the elderly patient.

    PubMed

    Leigey, Daniel F; Farrell, Dana J; Siska, Peter A; Tarkin, Ivan S

    2014-09-01

    Fragility fractures of the distal humerus in elderly patients, especially the low transcondylar fracture pattern, can be difficult to optimally manage. Although the fractures are typically low energy resulting in either extra-articular or simple intra-articular patterns, gaining fixation into the distal fragments can be difficult with open reduction internal fixation (ORIF) using traditional 90-90 or parallel plating techniques. Anatomy preserving reconstruction with ORIF is preferred over total elbow arthroplasty (TEA) if possible. In this study, 15 patients were managed with a bicolumnar 90-90 plating construct as a novel method of enhancing distal fixation in these fractures. Fourteen patients went on to radiographic union at an average of 77 days after surgery with an average arc of motion of 105°. One patient was lost to follow-up. Bicolumnar 90-90 plating of distal humerus fractures in elderly patients may represent a viable alternative to traditional ORIF or TEA.

  6. Bicolumnar 90-90 plating of low-energy distal humeral fractures in the elderly patient.

    PubMed

    Leigey, Daniel F; Farrell, Dana J; Siska, Peter A; Tarkin, Ivan S

    2014-09-01

    Fragility fractures of the distal humerus in elderly patients, especially the low transcondylar fracture pattern, can be difficult to optimally manage. Although the fractures are typically low energy resulting in either extra-articular or simple intra-articular patterns, gaining fixation into the distal fragments can be difficult with open reduction internal fixation (ORIF) using traditional 90-90 or parallel plating techniques. Anatomy preserving reconstruction with ORIF is preferred over total elbow arthroplasty (TEA) if possible. In this study, 15 patients were managed with a bicolumnar 90-90 plating construct as a novel method of enhancing distal fixation in these fractures. Fourteen patients went on to radiographic union at an average of 77 days after surgery with an average arc of motion of 105°. One patient was lost to follow-up. Bicolumnar 90-90 plating of distal humerus fractures in elderly patients may represent a viable alternative to traditional ORIF or TEA. PMID:25360342

  7. A multicenter, prospective, randomized, controlled trial of open reduction--internal fixation versus total elbow arthroplasty for displaced intra-articular distal humeral fractures in elderly patients.

    PubMed

    McKee, Michael D; Veillette, Christian J H; Hall, Jeremy A; Schemitsch, Emil H; Wild, Lisa M; McCormack, Robert; Perey, Bertrand; Goetz, Thomas; Zomar, Mauri; Moon, Karyn; Mandel, Scott; Petit, Shirlet; Guy, Pierre; Leung, Irene

    2009-01-01

    We conducted a prospective, randomized, controlled trial to compare functional outcomes, complications, and reoperation rates in elderly patients with displaced intra-articular, distal humeral fractures treated with open reduction-internal fixation (ORIF) or primary semiconstrained total elbow arthroplasty (TEA). Forty-two patients were randomized by sealed envelope. Inclusion criteria were age greater than 65 years; displaced, comminuted, intra-articular fractures of the distal humerus (Orthopaedic Trauma Association type 13C); and closed or Gustilo grade I open fractures treated within 12 hours of injury. Both ORIF and TEA were performed following a standardized protocol. The Mayo Elbow Performance Score (MEPS) and Disabilities of the Arm, Shoulder and Hand (DASH) score were determined at 6 weeks, 3 months, 6 months, 12 months, and 2 years. Complication type, duration, management, and treatment requiring reoperation were recorded. An intention-to-treat analysis and an on-treatment analysis were conducted to address patients randomized to ORIF but converted to TEA intraoperatively. Twenty-one patients were randomized to each treatment group. Two died before follow-up and were excluded from the study. Five patients randomized to ORIF were converted to TEA intraoperatively because of extensive comminution and inability to obtain fixation stable enough to allow early range of motion. This resulted in 15 patients (3 men and 12 women) with a mean age of 77 years in the ORIF group and 25 patients (2 men and 23 women) with a mean age of 78 years in the TEA group. Baseline demographics for mechanism, classification, comorbidities, fracture type, activity level, and ipsilateral injuries were similar between the 2 groups. Operative time averaged 32 minutes less in the TEA group (P = .001). Patients who underwent TEA had significantly better MEPSs at 3 months (83 vs 65, P = .01), 6 months (86 vs 68, P = .003), 12 months (88 vs 72, P = .007), and 2 years (86 vs 73, P = .015

  8. WRIST ARTHRODESIS WITH MINIMAL FIXATION PRESERVING THE CARPOMETACARPAL JOINTS

    PubMed Central

    Pardini, Arlindo Gomes; Pádua Gonçalves, Rodolfo Fonseca; Freitas, Afrânio Donato; Chaves, Antonio Barbosa

    2015-01-01

    Objective: Wrist arthrodesis is a surgical procedure that should always be considered in cases of pathological conditions in which anatomical and functional structures are altered. In general, the results are very satisfactory, particularly for pain relief, and in the majority of cases, there is considerable functional improvement. Various techniques have been described, with different methods of internal fixation, most of which include the carpometacarpal joints in the fusion. The objective of this study was to evaluate the results from wrist arthrodesis using a technique that is simpler, more biological, less expensive, and does not involve the carpometacarpal joints. Methods: Fifteen patients with wrist arthrodesis were evaluated (six with sequelae from trauma, four with rheumatoid arthritis, three with Kienbock grade IV, one with Preiser and one with panarthrosis). The technique consisted of using an iliac bone plate and internal fixation with Kirschner wires, avoiding the carpometacarpal joints. Results: The evaluation was based on consolidation time (93% in seven weeks); movements of the fingers and pronosupination; pinch and grasp strength; functional evaluation through the DASH, pain and patient satisfaction questionnaires. In general, the results were similar to those of other, more aggressive techniques, and the non-inclusion of the carpometacarpal joints did not affect the final result. Conclusion: Wrist arthrodesis with fixation using Kirschner wires and an iliac bone plate, preserving the carpometacarpal joints, gives good or excellent results that are not inferior to those of other techniques that have been described. However, it presents major advantages over other methods: it is less aggressive and cheaper, and does not have the inconvenience and complications associated with the use of plates and screws. PMID:27022522

  9. Optimizing Stability in Femoral Neck Fracture Fixation.

    PubMed

    Ye, Ye; Hao, Jiandong; Mauffrey, Cyril; Hammerberg, E Mark; Stahel, Philip F; Hak, David J

    2015-10-01

    Optimizing stability of femoral neck fracture fixation is important in obtaining a successful outcome. The mechanical problems and strategies for achieving optimal stability differ depending on patients' age and degree of osteoporosis. Femoral neck fractures in younger adults usually result from high-energy trauma and have a vertical fracture pattern. Strategies for optimizing fixation stability in this group include placing additional screws at right angles to the fracture plane and medial buttress plate augmentation. In elderly patients, screw position relative to the intact cortical femoral neck bone is of critical importance. Additional strategies for optimizing fixation stability in this group include the concept of length stable fixation, use of adjunctive calcium phosphate cement, and use of novel fixed angle fixation implants. PMID:26488776

  10. Comparison of Primary Radial Head Replacement and ORIF (Open Reduction and Internal Fixation) in Mason Type III Fractures: A Retrospective Evaluation in 72 Elderly Patients

    PubMed Central

    Liu, Run; Liu, Pengcheng; Shu, Hexi; Gong, Jinpeng; Sun, Qi; Wu, Jiezhou; Nie, Xiaoyang; Yang, Yong; Cai, Ming

    2015-01-01

    Background The aim of this study was to compare radial head prosthesis replacement with open reduction and internal fixation (ORIF) in the surgical treatment of Mason type III radial head fractures in 72 elderly patients. Material/Methods Seventy-two elderly patients (mean age, 67.1±1.25 years, range, 62–81 years) with Mason type III radial head fractures were treated from January 2001 to June 2012. Of these, 37 cases received radial prosthesis and 35 cases were treated with ORIF. All patients were followed up for 10 to 15.6 months. Results Based on the elbow functional evaluation criteria score by Broberg and Morrey, 29 cases achieved excellent results, 7 were good, and 1 was fair in the replacement group. In the ORIF group, excellent results were seen in 24 cases, good in 9, and fair in 2. The rates of good or excellent results were 78.4% and 68.6% for prosthesis replacement patients and ORIF patients, respectively (P<0.05). The Visual Analogue Scores (VAS) for replacement and ORIF groups were 2.25 and 1.67, respectively (P<0.05). Conclusions The radial head prosthesis replacement method is a relatively better surgical approach than ORIF in the treatment of elderly patients with Mason type III radial head fractures. PMID:25567738

  11. Lithospheric flexure under the Hawaiian volcanic load: Internal stresses and a broken plate revealed by earthquakes

    NASA Astrophysics Data System (ADS)

    Klein, Fred W.

    2016-04-01

    Several lines of earthquake evidence indicate that the lithospheric plate is broken under the load of the island of Hawai`i, where the geometry of the lithosphere is circular with a central depression. The plate bends concave downward surrounding a stress-free hole, rather than bending concave upward as with past assumptions. Earthquake focal mechanisms show that the center of load stress and the weak hole is between the summits of Mauna Loa and Mauna Kea where the load is greatest. The earthquake gap at 21 km depth coincides with the predicted neutral plane of flexure where horizontal stress changes sign. Focal mechanism P axes below the neutral plane display a striking radial pattern pointing to the stress center. Earthquakes above the neutral plane in the north part of the island have opposite stress patterns; T axes tend to be radial. The M6.2 Honomu and M6.7 Kiholo main shocks (both at 39 km depth) are below the neutral plane and show radial compression, and the M6.0 Kiholo aftershock above the neutral plane has tangential compression. Earthquakes deeper than 20 km define a donut of seismicity around the stress center where flexural bending is a maximum. The hole is interpreted as the soft center where the lithospheric plate is broken. Kilauea's deep conduit is seismically active because it is in the ring of maximum bending. A simplified two-dimensional stress model for a bending slab with a load at one end yields stress orientations that agree with earthquake stress axes and radial P axes below the neutral plane. A previous inversion of deep Hawaiian focal mechanisms found a circular solution around the stress center that agrees with the model. For horizontal faults, the shear stress within the bending slab matches the slip in the deep Kilauea seismic zone and enhances outward slip of active flanks.

  12. Strength analysis of clavicle fracture fixation devices and fixation techniques using finite element analysis with musculoskeletal force input.

    PubMed

    Marie, Cronskär

    2015-08-01

    In the cases, when clavicle fractures are treated with a fixation plate, opinions are divided about the best position of the plate, type of plate and type of screw units. Results from biomechanical studies of clavicle fixation devices are contradictory, probably partly because of simplified and varying load cases used in different studies. The anatomy of the shoulder region is complex, which makes it difficult and expensive to perform realistic experimental tests; hence, reliable simulation is an important complement to experimental tests. In this study, a method for finite element simulations of stresses in the clavicle plate and bone is used, in which muscle and ligament force data are imported from a multibody musculoskeletal model. The stress distribution in two different commercial plates, superior and anterior plating position and fixation including using a lag screw in the fracture gap or not, was compared. Looking at the clavicle fixation from a mechanical point of view, the results indicate that it is a major benefit to use a lag screw to fixate the fracture. The anterior plating position resulted in lower stresses in the plate, and the anatomically shaped plate is more stress resistant and stable than a regular reconstruction plate.

  13. Lithospheric flexure under the Hawaiian volcanic load: Internal stresses and a broken plate revealed by earthquakes

    USGS Publications Warehouse

    Klein, Fred W.

    2016-01-01

    Several lines of earthquake evidence indicate that the lithospheric plate is broken under the load of the island of Hawai`i, where the geometry of the lithosphere is circular with a central depression. The plate bends concave downward surrounding a stress-free hole, rather than bending concave upward as with past assumptions. Earthquake focal mechanisms show that the center of load stress and the weak hole is between the summits of Mauna Loa and Mauna Kea where the load is greatest. The earthquake gap at 21 km depth coincides with the predicted neutral plane of flexure where horizontal stress changes sign. Focal mechanism P axes below the neutral plane display a striking radial pattern pointing to the stress center. Earthquakes above the neutral plane in the north part of the island have opposite stress patterns; T axes tend to be radial. The M6.2 Honomu and M6.7 Kiholo main shocks (both at 39 km depth) are below the neutral plane and show radial compression, and the M6.0 Kiholo aftershock above the neutral plane has tangential compression. Earthquakes deeper than 20 km define a donut of seismicity around the stress center where flexural bending is a maximum. The hole is interpreted as the soft center where the lithospheric plate is broken. Kilauea's deep conduit is seismically active because it is in the ring of maximum bending. A simplified two-dimensional stress model for a bending slab with a load at one end yields stress orientations that agree with earthquake stress axes and radial P axes below the neutral plane. A previous inversion of deep Hawaiian focal mechanisms found a circular solution around the stress center that agrees with the model. For horizontal faults, the shear stress within the bending slab matches the slip in the deep Kilauea seismic zone and enhances outward slip of active flanks.

  14. Bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber composite: biomechanical properties and biocompatibility

    PubMed Central

    Qiao, Bo; Li, Jidong; Zhu, Qingmao; Guo, Shuquan; Qi, Xiaotong; Li, Weichao; Wu, Jun; Liu, Yang; Jiang, Dianming

    2014-01-01

    An ideal bone plate for internal fixation of bone fractures should have good biomechanical properties and biocompatibility. In this study, we prepared a new nondegradable bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber (n-HA/PA66/GF) composite. A breakage area on the n-HA/PA66/GF plate surface was characterized by scanning electron microscopy. Its mechanical properties were investigated using bone-plate constructs and biocompatibility was evaluated in vitro using bone marrow-derived mesenchymal stem cells. The results confirmed that adhesion between the n-HA/PA66 matrix and the glass fibers was strong, with only a few fibers pulled out at the site of breakage. Fractures fixed by the n-HA/PA66/GF plate showed lower stiffness and had satisfactory strength compared with rigid fixation using a titanium plate. Moreover, the results with regard to mesenchymal stem cell morphology, MTT assay, Alizarin Red S staining, enzyme-linked immunosorbent assay, and reverse transcription polymerase chain reaction for alkaline phosphatase and osteocalcin showed that the n-HA/PA66/GF composite was suitable for attachment and proliferation of mesenchymal stem cells, and did not have a negative influence on matrix mineralization or osteogenic differentiation of mesenchymal stem cells. These observations indicate that the n-HA/PA66/GF plate has good biomechanical properties and biocompatibility, and may be considered a new option for internal fixation in orthopedic surgery. PMID:24669191

  15. Bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber composite: biomechanical properties and biocompatibility.

    PubMed

    Qiao, Bo; Li, Jidong; Zhu, Qingmao; Guo, Shuquan; Qi, Xiaotong; Li, Weichao; Wu, Jun; Liu, Yang; Jiang, Dianming

    2014-01-01

    An ideal bone plate for internal fixation of bone fractures should have good biomechanical properties and biocompatibility. In this study, we prepared a new nondegradable bone plate composed of a ternary nano-hydroxyapatite/polyamide 66/glass fiber (n-HA/PA66/GF) composite. A breakage area on the n-HA/PA66/GF plate surface was characterized by scanning electron microscopy. Its mechanical properties were investigated using bone-plate constructs and biocompatibility was evaluated in vitro using bone marrow-derived mesenchymal stem cells. The results confirmed that adhesion between the n-HA/PA66 matrix and the glass fibers was strong, with only a few fibers pulled out at the site of breakage. Fractures fixed by the n-HA/PA66/GF plate showed lower stiffness and had satisfactory strength compared with rigid fixation using a titanium plate. Moreover, the results with regard to mesenchymal stem cell morphology, MTT assay, Alizarin Red S staining, enzyme-linked immunosorbent assay, and reverse transcription polymerase chain reaction for alkaline phosphatase and osteocalcin showed that the n-HA/PA66/GF composite was suitable for attachment and proliferation of mesenchymal stem cells, and did not have a negative influence on matrix mineralization or osteogenic differentiation of mesenchymal stem cells. These observations indicate that the n-HA/PA66/GF plate has good biomechanical properties and biocompatibility, and may be considered a new option for internal fixation in orthopedic surgery. PMID:24669191

  16. Quantitative histological evaluation of early fracture healing of cortical bones immobilized by stainless steel and composite plates.

    PubMed

    Akeson, W H; Woo, S L; Coutts, R D; Matthews, J V; Gonsalves, M; Amiel, D

    1975-11-24

    Internal fixation devices of less bending stiffness than conventional plates made of stainless steel or vitallium were compared with conventional plates in a study of fracture healing. The material for this investigation was a fine graphite fiber reinforced methyl methacrylate resin composite with a modulus of elasticity approximately ten times less than that of stainless steel. Osteotomies were performed on canine radii. Internal fixation was accomplished by means of a composite plate on the left side, and a stainless steel plate on the right. Clinical assessment, as well as biomechanical and quantitative histological techniques, were used to compare osteotomy healing of the two sides. At four months, all osteotomies had healed and the bioengineering tests showed radii from the two sides had equivalent strength. However, significantly less cortical porosity was found in the side with the composite plate (6.8 per cent), as compared to that of the stainless steel plated side (14 per cent). These results suggest that a less stiff fixation plate may have some advantage in the treatment of long bone fracture if there is no implant failure, and if union rates are equivalent.

  17. Scattering of flexural waves from a hole in a thin plate with an internal beam.

    PubMed

    Climente, A; Norris, Andrew N; Sánchez-Dehesa, José

    2015-01-01

    The scattering of flexural waves by a hole in a thin plate traversed by a beam is modeled here by coupling the Kirchhoff-Love and the Euler-Bernoulli theories. A closed form expression is obtained for the transfer matrix (T-matrix) relating the incident wave to the scattered cylindrical waves. For this purpose, a general method has been developed, based on an analogous impedance method for acoustic waves, for calculating the T-matrix for flexural wave scattering problems. The T-matrix for the problem considered displays a simple structure, composed of distinct sub-matrices which decouple the inside and the outside fields. The conservation of energy principle and numerical comparisons with a commercial finite element simulator have been used to prove the theory.

  18. Cheek drooping in 2 patients with maxillary fractures after rigid fixation with bioabsorbable mesh.

    PubMed

    Oh, Seung Hyun; Kim, Chung Hun; Choi, Hyun Gon; Hwang, Euna

    2014-03-01

    Bioabsorbable plate-screw systems are commonly used for the internal fixation of facial bone fractures. The anterior maxilla has a unique curved shape, and fractured bony fragments tend to be small and fragile; therefore, more effective rigid fixation can be achieved using a molded bioabsorbable mesh rather than a bioabsorbable plate. Herein, we describe 2 patients with cheek drooping after a rigid fixation of comminuted maxillary fracture using bioabsorbable meshes and screws.The postoperative courses were uneventful, but both showed soft tissue bulging in the cheek area of the operation site for 12 to 13 months after the operation. No other symptom or sign related to inflammation or foreign body reaction was noted.In comminuted maxillary fractures, bone fragments are more conveniently fixed with a 1-piece molded bioabsorbable mesh. However, it is believed that a single large mesh may interfere with adhesion between the maxillary surface and the overlying soft tissue. Therefore, we recommend using the least amount of mesh to fixate maxillary bone fragments.

  19. Latarjet Fixation

    PubMed Central

    Alvi, Hasham M.; Monroe, Emily J.; Muriuki, Muturi; Verma, Rajat N.; Marra, Guido; Saltzman, Matthew D.

    2016-01-01

    Background: Attritional bone loss in patients with recurrent anterior instability has successfully been treated with a bone block procedure such as the Latarjet. It has not been previously demonstrated whether cortical or cancellous screws are superior when used for this procedure. Purpose: To assess the strength of stainless steel cortical screws versus stainless steel cannulated cancellous screws in the Latarjet procedure. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen matched-pair shoulder specimens were randomized into 2 separate fixation groups: (1) 3.5-mm stainless steel cortical screws and (2) 4.0-mm stainless steel partially threaded cannulated cancellous screws. Shoulder specimens were dissected free of all soft tissue and a 25% glenoid defect was created. The coracoid process was osteomized, placed at the site of the glenoid defect, and fixed in place with 2 parallel screws. Results: All 10 specimens failed by screw cutout. Nine of 10 specimens failed by progressive displacement with an increased number of cycles. One specimen in the 4.0-mm screw group failed by catastrophic failure on initiation of the testing protocol. The 3.5-mm screws had a mean of 274 cycles (SD, ±171 cycles; range, 10-443 cycles) to failure. The 4.0-mm screws had a mean of 135 cycles (SD, ±141 cycles; range, 0-284 cycles) to failure. There was no statistically significant difference between the 2 types of screws for cycles required to cause failure (P = .144). Conclusion: There was no statistically significant difference in energy or cycles to failure when comparing the stainless steel cortical screws versus partially threaded cannulated cancellous screws. Clinical Relevance: Latarjet may be performed using cortical or cancellous screws without a clear advantage of either option. PMID:27158630

  20. External Fixation of Open Humerus Factures

    PubMed Central

    Marsh, JL; Mahoney, Craig R; Steinbronn, Dave

    1999-01-01

    Fifteen patients with open shaft of humerus fractures were treated with a monolateral external fixator. Nine patients presented with nerve palsies. Two radial nerves were disrupted and required grafting. Of the seven others, six spontaneously recovered and one brachial plexus partially improved. All fractures healed. The average duration of external fixation was 21 weeks. Four patients required additional procedures prior to healing (external fixator reapplication - 2, plating and bone grafting - 2). Two of these four experienced breakage of 4.5 mm external fixation pins. Eight patients developed pin tract infections, which all resolved with local care and antibiotics. Thirteen patients were contacted at an average of 63 months after injury. Eleven reported they were satisfied with their result, nine had no functional limits, and eight reported no pain. PMID:10847515

  1. What is new in distal femur periprosthetic fracture fixation?

    PubMed

    Tosounidis, Theodoros H; Giannoudis, Peter V

    2015-12-01

    Distal femoral periprosthetic fractures are on the rise. Increased mortality of these injuries is also evident from recent data. Their incidence and risk factors have been extensively reported in the past but new data are being available that merit attention. The increased incidence and the even higher projected incidence should direct the focus of future strategies to the education of surgeons, relevant capacity of hospital and reconfiguration of health care resources. New and potentially modifiable risk factors should be taken into consideration to the informed consent process and new studies should be developed to clarify the causative relationship of the new risk factors such as the peptic ulcer disease and the COPD. The main internal fixation techniques remain the lateral locking plating and the retrograde intramedullary nailing. New techniques in plating are the supplementary medial plate in selected cases and the far cortical locking. Nailing is considered a valid option especially in fractures located well above the anterior flange of the femoral component of the arthroplasty. Results and outcomes from good quality studies are still sparse regarding the comparison between plating and nailing. Interprosthetic fractures constitute an entity that is lately gaining considerable attention. The best method of management of these injuries is still evolving with considerable amount of work being done in the clinical and biomechanical level.

  2. Secondary Radial Nerve Palsy after Minimally Invasive Plate Osteosynthesis of a Distal Humeral Shaft Fracture

    PubMed Central

    Bichsel, Ursina; Nyffeler, Richard Walter

    2015-01-01

    Minimally invasive plate osteosynthesis is a widely used procedure for the treatment of fractures of the femur and the tibia. For a short time it is also used for the treatment of humeral shaft fractures. Among other advantages, the ambassadors of this technique emphasize the lower risk of nerve injuries when compared to open reduction and internal fixation. We report the case of secondary radial nerve palsy caused by percutaneous fixation of a plate above the antecubital fold. The nerve did not recover and the patient needed a tendon transfer to regain active extension of the fingers. This case points to the importance of adequate exposure of the bone and plate if a humeral shaft fracture extends far distally. PMID:26558125

  3. Biomechanical Analysis of the Fixation System for T-Shaped Acetabular Fracture.

    PubMed

    Fan, Yanping; Lei, Jianyin; Zhu, Feng; Li, Zhiqiang; Chen, Weiyi; Liu, Ximing

    2015-01-01

    This study aims to evaluate the biomechanical mechanism of fixation systems in the most frequent T-shaped acetabular fracture using finite element method. The treatment of acetabular fractures was based on extensive clinical experience. Three commonly accepted rigid fixation methods (double column reconstruction plates (P × 2), anterior column plate combined with posterior column screws (P + PS), and anterior column plate combined with quadrilateral area screws (P + QS)) were chosen for evaluation. On the basis of the finite element model, the biomechanics of these fixation systems were assessed through effective stiffness levels, stress distributions, force transfers, and displacements along the fracture lines. All three fixation systems can be used to obtain effective functional outcomes. The third fixation system (P + QS) was the optimal method for T-shaped acetabular fracture. This fixation system may reduce many of the risks and limitations associated with other fixation systems.

  4. Functional outcome of Schatzker type V and VI tibial plateau fractures treated with dual plates

    PubMed Central

    Prasad, G Thiruvengita; Kumar, T Suresh; Kumar, R Krishna; Murthy, Ganapathy K; Sundaram, Nandkumar

    2013-01-01

    Background: Dual plate fixation in comminuted bicondylar tibial plateau fractures remains controversial. Open reduction and internal fixation, specifically through compromised soft tissues, has historically been associated with major wound complications. Alternate methods of treatment have been described, each with its own merits and demerits. We performed a retrospective study to evaluate the functional outcome of lateral and medial plate fixation of Schatzker type V and VI fractures through an anterolateral approach, and a medial minimally invasive approach or a posteromedial approach. Materials and Methods: We treated 46 tibial plateau fractures Schatzker type V and VI with lateral and medial plates through an anterolateral approach and a medial minimal invasive approach over an 8 years period. Six patients were lost to followup. Radiographs in two planes were taken in all cases. Immediate postoperative radiographs were assessed for quality of reduction and fixation. The functional outcome was evaluated according to the Oxford Knee Score criteria on followup. Results: Forty patients (33 men and 7 women) who completed the followup were included in the study. There were 20 Schatzker type V fractures and 20 Schatzker type VI fractures. The mean duration of followup was 4 years (range 1-8 years). All patients had a satisfactory articular reduction defined as ≤2 mm step-off or gap as assessed on followup. All patients had a good coronal and sagittal plane alignment, and articular width as assessed on supine X-rays of the knee in the anteroposterior (AP) and lateral views. The functional outcome, as assessed by the Oxford Knee Score, was excellent in 30 patients and good in 10 patients. All patients returned to their pre-injury level of activity and employment. There were no instances of deep infection. Conclusions: Dual plate fixation of severe bicondylar tibial plateau fractures is an excellent treatment option as it provides rigid fixation and allows early knee

  5. Structural-acoustic model of a rectangular plate-cavity system with an attached distributed mass and internal sound source: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Pirnat, Miha; Čepon, Gregor; Boltežar, Miha

    2014-03-01

    In this paper three approaches are combined to develop a structural-acoustic model of a rectangular plate-cavity system with an attached distributed mass and internal sound source. The first approach results from a recently presented analysis based on the Rayleigh-Ritz method and is used to circumvent the difficulties in obtaining the natural frequencies and mode shapes of a plate with an attached, distributed mass. Furthermore, different plate boundary conditions can be accommodated. The resulting mode shapes are defined as continuous functions; this is advantageous as they can be directly used in the second approach, i.e., the classic modal-interaction approach in order to obtain the coupled equations of the system. Finally, in the third approach a group of point sources emitting a pressure pulse in the time domain is used to model an internal sound source. For the validation of the developed model an experiment was conducted in two configurations using a simply supported aluminium plate and a clamped plate coupled with a plexiglas box containing a loudspeaker. Good agreement was found between the analytical and experimental data.

  6. Finite element analysis of patient-specific condyle fracture plates: a preliminary study.

    PubMed

    Aquilina, Peter; Parr, William C H; Chamoli, Uphar; Wroe, Stephen

    2015-06-01

    Various patterns of internal fixation of mandibular condyle fractures have been proposed in the literature. This study investigates the stability of two patient-specific implants (PSIs) for the open reduction and internal fixation of a subcondylar fracture of the mandible. A subcondylar fracture of a mandible was simulated by a series of finite element models. These models contained approximately 1.2 million elements, were heterogeneous in bone material properties, and also modeled the muscles of mastication. Models were run assuming linear elasticity and isotropic material properties for bone. The stability and von Mises stresses of the simulated condylar fracture reduced with each of the PSIs were compared. The most stable of the plate configurations examined was PSI 1, which had comparable mechanical performance to a single 2.0 mm straight four-hole plate. PMID:26000081

  7. Early motion protocol for select Galeazzi fractures after radial shaft fixation.

    PubMed

    Gwinn, David E; O'Toole, Robert V; Eglseder, W Andrew

    2010-01-01

    Galeazzi fractures traditionally are treated in long arm casts with the wrist fully supinated for 6 weeks after open reduction and internal fixation. Recent literature suggests that early motion can be permitted for a subset of Galeazzi fractures. Defining a safe postoperative protocol that allows immediate elbow motion, immediate platform weight bearing, and early wrist motion might decrease elbow morbidity, increase range of motion, and improve outcomes. A retrospective review of a prospectively collected database of 26 patients at a level I trauma center was conducted. Early motion protocol was assigned to patients who were radiographically and clinically stable after plate and screw fixation. Elbow flexion and platform weight bearing were allowed immediately; increased wrist rotation was allowed at 2-week intervals. Early motion of elbow and wrist seems to be safe during postoperative rehabilitation of repaired Galeazzi fractures. The postoperative protocol might maximize elbow and wrist range of motion.

  8. Effect of Hall Current and Chemical Reaction on MHD Flow Along an Accelerated Porous Flat Plate with Internal Heat Absorption/Generation

    NASA Astrophysics Data System (ADS)

    Kar, M.; Sahoo, S. N.; Dash, G. C.

    2014-05-01

    The effect of the Hall current on unsteady free convection of an electrically conducting incompressible viscous fluid past an accelerated vertical porous plate with internal heat absorption/generation in the presence of various species (H2, CO2, H2O, and NH3) undergoing a first-order chemical reaction in a uniform transverse magnetic field is studied. The role of pertinent parameters characterizing the flow field is discussed. The governing equations are solved using the Hhn(x) functions. It is revealed that heat generation coupled with injection results in a backflow rise. A linearly varying velocity of the plate causes a sudden rise or fall of the velocity in the vicinity of the plate, whereas an asymptotically varying velocity leads to a uniform fall. The presence of chemical reaction increases the secondary velocity by 40%.

  9. Early results for treatment of three- and four-part fractures of the proximal humerus using the PHILOS plate system.

    PubMed

    Moonot, P; Ashwood, N; Hamlet, M

    2007-09-01

    Secure fixation of displaced proximal fractures of the humerus is a challenging problem. A total of 32 patients with acutely displaced three- or four-part proximal fractures of the humerus were treated by open reduction and internal fixation using the proximal humeral internal locking system (PHILOS) plate. There were 23 women and nine men with a mean age of 59.9 years (18 to 87). Data were collected prospectively and the outcomes were assessed using the Constant score. The mean follow-up was for 11 months (3 to 24). In 31 patients (97%) the fracture united clinically and radiologically at a mean of 10 weeks (8 to 24). The mean Constant score at final review was 66.5 (30 to 92). There was no significant difference in outcome when comparing patients aged more than 60 years (18 patients) with those aged less than 60 years (14 patients) (t-test, p = 0.8443). There was one case each of nonunion, malunion and a broken screw in the elderly population. This plate provides an alternative method of fixation for fractures of the proximal humerus. It provides a stable fixation in young patients with good-quality bone sufficient to permit early mobilisation. Failure of the screws to maintain fixation in the elderly remains a problem.

  10. Kennedy Space Center Fixation Tube (KFT)

    NASA Technical Reports Server (NTRS)

    Richards, Stephanie E.; Levine, Howard G.; Romero, Vergel

    2016-01-01

    Experiments performed on the International Space Station (ISS) frequently require the experimental organisms to be preserved until they can be returned to earth for analysis in the appropriate laboratory facility. The Kennedy Fixation Tube (KFT) was developed to allow astronauts to apply fixative, chemical compounds that are often toxic, to biological samples without the use of a glovebox while maintaining three levels of containment (Fig. 1). KFTs have been used over 200 times on-orbit with no leaks of chemical fixative. The KFT is composed of the following elements: a polycarbonate main tube where the fixative is loaded preflight, the sample tube where the plant or other biological specimens is placed during operations, the expansion plug, actuator, and base plug that provides fixative containment (Fig. 2). The main tube is pre-filled with 25 mL of fixative solution prior to flight. When actuated, the specimen contained within the sample tube is immersed with approximately 22 mL (+/- 2 mL) of the fixative solution. The KFT has been demonstrated to maintain its containment at ambient temperatures, 4degC refrigeration and -100 C freezing conditions.

  11. Thermal protection system gap heating rates of the Rockwell International flat plate heat transfer model (OH2A/OH2B)

    NASA Technical Reports Server (NTRS)

    Foster, T. F.; Lockman, W. K.; Grifall, W. J.

    1973-01-01

    Heat transfer data for the Rockwell International Flat Plate Thermocouple Model are presented. The model simulated the Space Shuttle Vehicle Thermal Protection System. Data were recorded for locations in and around various size gaps for various gap orientation configurations. The test was conducted at Mach 5.1 for free-stream Reynolds number per foot values from 500,000 to 1,500,000.

  12. Cost of external fixation vs external fixation then nailing in bone infection

    PubMed Central

    Emara, Khaled Mohamed; Diab, Ramy Ahmed; Ghafar, Khaled Abd EL

    2015-01-01

    AIM: To study the cost benefit of external fixation vs external fixation then nailing in treatment of bone infection by segment transfer. METHODS: Out of 71 patients with infected nonunion tibia treated between 2003 and 2006, 50 patients fitted the inclusion criteria (26 patients were treated by external fixation only, and 24 patients were treated by external fixation early removal after segment transfer and replacement by internal fixation). Cost of inpatient treatment, total cost of inpatient and outpatient treatment till full healing, and the weeks of absence from school or work were calculated and compared between both groups. RESULTS: The cost of hospital stay and surgery in the group of external fixation only was 22.6 ± 3.3 while the cost of hospital stay and surgery in the group of early external fixation removal and replacement by intramedullary nail was 26.0 ± 3.2. The difference was statistically significant regarding the cost of hospital stay and surgery in favor of the group of external fixation only. The total cost of medical care (surgery, hospital stay, treatment outside the hospital including medications, dressing, physical therapy, outpatient laboratory work, etc.) in group of external fixation only was 63.3 ± 15.1, and total absence from work was 38.6 ± 6.6 wk. While the group of early removal of external fixation and replacement by IM nail, total cost of medical care was 38.3 ± 6.4 and total absence from work or school was 22.7 ± 4.1. The difference was statistically significant regarding the total cost and absence from work in favor of the group of early removal and replacement by IM nail. CONCLUSION: Early removal of external fixation and replacement by intramedullary nail in treatment of infected nonunion showed more cost effectiveness. Orthopaedic society needs to show the cost effectiveness of different procedures to the community, insurance, and health authorities. PMID:25621219

  13. Fixation systems of greater trochanteric osteotomies: biomechanical and clinical outcomes.

    PubMed

    Jarit, Gregg J; Sathappan, Sathappan S; Panchal, Anand; Strauss, Eric; Di Cesare, Paul E

    2007-10-01

    The development of cerclage systems for fixation of greater trochanteric osteotomies has progressed from monofilament wires to multifilament cables to cable grip and cable plate systems. Cerclage wires and cables have various clinical indications, including fixation for fractures and for trochanteric osteotomy in hip arthroplasty. To achieve stable fixation and eventual union of the trochanteric osteotomy, the implant must counteract the destabilizing forces associated with pull of the peritrochanteric musculature. The material properties of cables and cable grip systems are superior to those of monofilament wires; however, potential complications with the use of cables include debris generation and third-body polyethylene wear. Nevertheless, the cable grip system provides the strongest fixation and results in lower rates of nonunion and trochanteric migration. Cable plate constructs show promise but require further clinical studies to validate their efficacy and safety.

  14. Comparison of Biomechanical Characteristics and Pelvic Ring Stability Using Different Fixation Methods to Treat Pubic Symphysis Diastasis

    PubMed Central

    Yao, Feng; He, Yu; Qian, Hebu; Zhou, Dongsheng; Li, Qinghu

    2015-01-01

    Abstract The intention of this study was to compare the biomechanical characteristics using 5 internal fixation methods used clinically to stabilize a pubic symphysis diastasis (PSD, Tile type B1). A 3-dimensional finite element model of PSD was simulated using 5 implants, including single superior plate (Single-Plate), superior and anterior plate (Dual-Plate), single cannulated screw (Single-Screw), crossed dual cannulated screws (Cross-Screw), and parallel dual cannulated screws (Para-Screw). Three loads were distributed in all models, including dual-leg standing, single-leg stance, and rotation. To evaluate the biomechanical properties, the construct stiffness, the stress distribution, and the von Misses stress were recorded and analyzed. To evaluate pelvic ring stability, the micromotion of the pubic symphysis and iliosacral joint was analyzed. Disruption of pubic symphysis dramatically decreased the pelvic ring stability. Cross-screw and Para-Screw showed higher stiffness than other methods. All implants endured the maximum von Misses stress under single-leg stance. For Plate-Screw system, the maximum stress occurred at a place where it strides over pubic symphysis and adjacent Plate-Screw interface. The single implant and Para-Screw had a tendency to fail. Para-Screw showed the best fixation effect under dual-leg conditions. Cross-screw showed superior antishearing force capacity under single-leg stance. Dual-Plate provided maximum antihorizontal rotation. Para-Screw provided the maximum stabilization for the posterior pelvic ring. This study showed the biomechanical advantages of dual-implant for PSD only from the finite element view. The Para-Screw provided high construct stiffness under 3 load conditions. The single implant and Para-Screw had a tendency to fail. The better anterior and posterior pelvic stabilization were obtained by the dual-implant fixation than other methods. Therefore, the Cross-Screw and Dual-Plate fixation methods should be preferred

  15. Lengthening over nails using the double plate system ONAS-DPS

    PubMed Central

    Antolič, Vane

    2016-01-01

    Stable insertion of large Schanz screws behind an intramedullary (IM) nail when lengthening over nails (LON) may be difficult due to the limited bone stock. Additionally, the highly probable contact between the screws and IM nail (which is difficult to avoid) increases the likelihood of infection spreading from the skin via Schanz screws directly to the IM nail. A new device for LON has been developed. Instead of inserting Schanz screws from the external fixator beside the IM nail (as in standard LON), a system of two overlaying plates was constructed. Schanz screws can be fixed to the plates without entering the bone. The plates are fixed to the bone using four angle stability screws. The holes in the plates offer stabile fixation for a chosen angle under which the screw is positioned through the cortical bone. Using the new system there is no need to place Schanz screws behind the IM nail. Instead, Schanz screws pass to the plate and not through the bone. The new system for elongation over IM nail is called “Over Nail Angle Stability-Double Plate System” (ONAS-DPS) [Antolič V (2013) Modular side device with an intramedullary nail for guiding a bone during its lengthening. World Intellectual Property Organization. International Publication number: WO 2013/176632 A1]. PMID:27163094

  16. On the use of pb-2 Rayleigh-Ritz method for free flexural vibration of triangular plates with curved internal supports

    NASA Astrophysics Data System (ADS)

    Liew, K. M.

    1993-08-01

    This paper presents a set of comprehensive and accurate results for the free-flexural vibration of triangular plates of arbitrary boundary conditions with/without curved internal supports. These results are presented for ten distinct cases involving the combinations of free, simply supported, or clamped edge conditions. In the present study, a simple and straightforward pb-2 Rayleigh-Ritz method is employed to determine the first few natural frequencies for the triangular plates with a wide range of aspect ratios; i.e., a/b = 2/5, 1/2, 2/square root of 3, and 2. A set of pb-2 Ritz functions consisting of the product of a two-dimensional polynomial function and a basic function is used. The basic function is defined by the product of (1) equations of the prescribed continuous piecewise boundary each raised to the power of 0, 1, or 2, corresponding to a free, simply supported, or clamped edge, and (2) equations of the internal supports. The members of the generated set of functions satisfy automatically all the kinematic boundary conditions of the plate at the outset. The present results for some cases are compared with available published values from the open literature.

  17. Present-Day Kinematics of the Dead Sea Transform and Internal Deformation within the Sinai and Arabian Plates

    NASA Astrophysics Data System (ADS)

    Gomez, F. G.; Yassminh, R.; Cochran, W. J.; Reilinger, R. E.; Barazangi, M.

    2015-12-01

    An updated GPS velocity field along the Dead Sea Fault (DSF) provides a basis for assessing off-transform strain within the Sinai and Arabian plates along entire length of this left-lateral, continental transform. As one of the main tectonic elements in the eastern Mediterranean region, an improved kinematic view of the DSF elucidates the broader understanding of the regional tectonic framework, as well as contributes to refining the earthquake hazard assessment. Reconciling short-term (geodetic) measurements of crustal strain with neotectonic data on fault movements can yield insight into the mechanical and rheological properties of crustal deformation associated with transform tectonics. In addition to regional continuous GPS stations, this study assembles results from campaign GPS networks in Syria, Lebanon, and Jordan spanning more than a decade. 1-sigma uncertainties on velocities range from less than 0.4 mm/yr (continuous stations and older GPS survey sites) to about 1.0 mm/yr (newer survey sites). Analyses using elastic block models suggest slip rates of 4.0 - 5.0 mm/yr along the southern and central DSF and slip rates of 2.0 - 3.0 mm/yr along the northern DSF, and fault locking depths also vary along strike of the transform. Furthermore, the spatial distribution of GPS observations permits analyzing residual strains within the adjacent plates, after plate boundary strain is removed. A key observation is horizontal stretching within the Sinai plate, which may be related to pull by the subducted slab of the Sinai plate. Within the Arabian plate, areas of horizontal stretching generally correlate with locations of Quaternary volcanism.

  18. Titanium plate artefact mimicking popliteal artery dissection on digital subtraction CT angiography.

    PubMed

    Woodacre, Timothy; Wienand-Barnett, Sophie

    2013-04-05

    Titanium plates used for the internal fixation of long bone fractures cause significant artefact on CT scans but have not been reported to affect digital subtraction CT angiography. We present a patient with clinical suspicion of popliteal artery injury following a high tibial osteotomy. The osteotomy was stabilised with a titanium locking plate. During the digital subtraction process used to produce reconstruction CT angiography, removal of artefact caused by the titanium plate produced CT images mimicking the appearance of a popliteal artery dissection. The imaging inaccuracy was realised prior to the patient undergoing further intervention. We highlight the potential error caused by titanium plates on digital subtraction CT angiography and recommend careful analysis of such images prior to further treatment.

  19. Arthroscopic Fixation of Tibial Spine Avulsion Fracture in Open Physis

    PubMed Central

    Chouhan, Varun

    2016-01-01

    Introduction: Arthroscopic fixation of tibial spine fracture in patients with open physis without damaging the growth plate is very important. We have described a very simple and effective technique for the first time in this article. Case report: A 16-year-old boy sustained avulsion fractures of tibial spine while playing. He was treated arthroscopically with excellent results. Conclusion: Arthroscopic fixation of tibial spine fracture in patients with open physis with two cannulated screws perpendicular to each other is a very simple technique providing strong construct, and allowing early mobilization without risk of damage to the growth plate. PMID:27703945

  20. An Isolated Displaced Fracture of the Coracoid Process Treated with Open reduction and internal fixation - A Case Report and Review of Literature

    PubMed Central

    Archik, Shreedhar; Nanda, Saurav Narayan; Tripathi, Sanjay; Choudhari, Ashlesh; Rajadhyaksha, Harshada

    2016-01-01

    Introduction: Isolated coracoid fractures are rare and few scattered cases are reported in literature. Coracoid fractures can be missed and the treatment for coracoid process fractures is still controversial. The case presented here is of an isolated coracoid process fracture which was treated surgically. Case Report: A 15-years old male presented after 4 days of injury complaining of persistent pain in the right shoulder following a jerk during bowling. Physical examination revealed tenderness in the left shoulder. There was pain on abduction and external rotation. The neurovascular examination was normal. Osseous avulsion of the distal tip of the coracoid process was confirmed by CT and MRI. The short head of the biceps and coracobrachialis was attached to the avulsed tip, while the pectoralis minor was attached to the coracoid base. The case was managed by open reduction and fixation with a 3.5mm cannulated screw and washer. Conclusion: Isolated coracoid fracture is a rare entity causing impairment of upper limb movement. It can be diagnosed more accurately by MRI scan and CT scan. In case of young highly demanding individuals like athletes surgical management may be a better option as compared to conservative treatment to achieve early use of the extremity, good radiological union and clinical function.

  1. Difficulties encountered removing locked plates

    PubMed Central

    Raja, S; Imbuldeniya, AM; S, Garg; Groom, G

    2012-01-01

    INTRODUCTION Locked plates are commonly used to obtain fixation in periarticular and comminuted fractures. Their use has also gained popularity in repairing fractures in osteoporotic bone. These plates provide stable fixation and promote biological healing. Over the last 3 years, we have used over 150 locked plates with varying success to fix periarticular fractures involving mainly the knee and ankle. In this study, we report our clinical experience and the difficulties encountered when removing locked plates in adult patients with a variety of indications including implant failure, infection, non-union and a palpable symptomatic implant. METHODS A retrospective analysis was performed of patients enrolled prospectively into a database. Included in the study were 36 consecutive adult patients who each underwent the procedure of locked plate removal in a single inner city level 1 trauma centre. Data collected included primary indication for fixation, indication for implant removal, time of the implant in situ, grade of operating surgeon and difficulties encountered during the procedure. RESULTS Implant removal was associated with a complication rate of 47%. The major problems encountered were difficulty in removing the locked screws and the implant itself. A total of ten cold welded screws were found in eight cases. Removal was facilitated by high speed metal cutting burrs and screw removal sets in all but one case, where a decision was made to leave the plate in situ. CONCLUSIONS The majority of studies investigating implant removal and problems encountered in doing so report a relatively high complication rate. With the advent of locking plates and their growing popularity, difficulties are now being seen intra-operatively when removing them. There is a paucity of data, however, specifically directed at locking plate removal. We recommend that surgeons should be aware of the potential complications while removing locked plates. Fluoroscopic control and all

  2. Photographic fixative poisoning

    MedlinePlus

    Photographic developer poisoning; Hydroquinone poisoning; Quinone poisoning; Sulfite poisoning ... Hydroquinones Quinones Sodium thiosulfate Sodium sulfite/bisulfite Boric acid Photographic fixative can also break down (decompose) to form sulfur dioxide gas.

  3. Temporary intra-operative reduction techniques for tibial fracture fixation: A review of the literature.

    PubMed

    Beazley, J C; Hull, P

    2010-12-01

    Accurate intra-operative reduction and maintenance of reduction is essential for successful fixation of tibial fractures. Although many tibial fractures can be reduced with minimal manipulation, numerous techniques have been described to facilitate fixation of more difficult fractures. These include use of a traction table, manual traction techniques, temporary distracters, reduction clamps and temporary unicortical plating. This article reviews the literature and assesses the options available for the temporary reduction and maintenance of reduction of tibial fractures prior to definitive fixation.

  4. Assessment of the influence of Laser phototherapy on the bone repair process of complete fractures in tibiae of rabbits stabilized with semi-rigid internal fixation treated with or without MTA graft: a histological study

    NASA Astrophysics Data System (ADS)

    Soares, Luiz G. P.; Silva, Aline C. P.; Silva, Anna Paula L. T.; Neves, Bruno Luiz R. C.; Santos, Nicole R. S.; dos Santos, Jean N.; Pinheiro, Antonio L. B.

    2016-03-01

    Beside biomaterials, Laser phototherapy has shown positive effects as auxiliary therapy in bone repair process, especially when involving large bone losses. The aim of this histological study was to evaluate, by light microscopy, the influence of laser phototherapy on the repair of complete tibial fractures in rabbits treated or not with semi-rigid internal fixation and Mineral Trioxide Aggregate - MTA graft. Twelve Rabbits were randomly divided into four groups with three animals each. After general anesthesia, complete fractures were created in one tibia with a carborundum disk. All animals (groups I-IV) had the fracture stabilized with semi-rigid fixation (wire osteosynthesis - WO). Group I was routinely fixed with WO; groups II and IV fracture was filled by blood clot and MTA implant. In Groups III and IV fracture was filled by blood clot and further irradiated with laser (λ780 nm, 70 mW, CW, Φ = 0.04 cm2, 20.4 J/cm2, per session, t = 300s, 142.8 J/cm2 per treatment). The phototherapy protocol was applied immediately after the surgery and repeated each 48 hours during 15 days. Animal death occurred on the 30th postoperative day. After removal of the specimens, the samples were routinely processed, stained with HE and evaluated by light microscopy. Histologically, the group treated with MTA graft and irradiated with laser showed the fracture filled by a more organized and mature trabecular bone, when compared with all other groups. From the results of the present study, it may be concluded that the association of Laser phototherapy + MTA graft in fractures treated with WO improved bone repair when compared with fractures treated only with WO.

  5. The presence of nodules on legume root systems can alter phenotypic plasticity in response to internal nitrogen independent of nitrogen fixation.

    PubMed

    Goh, Chooi-Hua; Nicotra, Adrienne B; Mathesius, Ulrike

    2016-04-01

    All higher plants show developmental plasticity in response to the availability of nitrogen (N) in the soil. In legumes, N starvation causes the formation of root nodules, where symbiotic rhizobacteria fix atmospheric N2 for the host in exchange for fixed carbon (C) from the shoot. Here, we tested whether plastic responses to internal [N] of legumes are altered by their symbionts. Glasshouse experiments compared root phenotypes of three legumes, Medicago truncatula, Medicago sativa and Trifolium subterraneum, inoculated with their compatible symbiont partners and grown under four nitrate levels. In addition, six strains of rhizobia, differing in their ability to fix N2 in M. truncatula, were compared to test if plastic responses to internal [N] were dependent on the rhizobia or N2 -fixing capability of the nodules. We found that the presence of rhizobia affected phenotypic plasticity of the legumes to internal [N], particularly in root length and root mass ratio (RMR), in a plant species-dependent way. While root length responses of M. truncatula to internal [N] were dependent on the ability of rhizobial symbionts to fix N2 , RMR response to internal [N] was dependent only on initiation of nodules, irrespective of N2 -fixing ability of the rhizobia strains.

  6. Delayed Union of a Sacral Fracture: Percutaneous Navigated Autologous Cancellous Bone Grafting and Screw Fixation

    SciTech Connect

    Huegli, R. W. Messmer, P.; Jacob, A. L.; Regazzoni, P.; Styger, S.; Gross, T.

    2003-09-15

    Delayed or non-union of a sacral fracture is a serious clinical condition that may include chronic pain, sitting discomfort, gait disturbances, neurological problems, and inability to work. It is also a difficult reconstruction problem. Late correction of the deformity is technically more demanding than the primary treatment of acute pelvic injuries. Open reduction, internal fixation (ORIF), excision of scar tissue, and bone grafting often in a multi-step approach are considered to be the treatment of choice in delayed unions of the pelvic ring. This procedure implies the risk of neurological and vascular injuries, infection, repeated failure of union, incomplete correction of the deformity, and incomplete pain relief as the most important complications. We report a new approach for minimally invasive treatment of a delayed union of the sacrum without vertical displacement. A patient who suffered a Malgaigne fracture (Tile C1.3) was initially treated with closed reduction and percutaneous screw fixation (CRPF) of the posterior pelvic ring under CT navigation and plating of the anterior pelvic ring. Three months after surgery he presented with increasing hip pain caused by a delayed union of the sacral fracture. The lesion was successfully treated percutaneously in a single step procedure using CT navigation for drilling of the delayed union, autologous bone grafting, and screw fixation.

  7. [Multifunctional external fixator compatible with the Zespol system and Schanz pins].

    PubMed

    Molski, K; Molski, K

    1995-01-01

    The construction and use of new external fixator broadening the use and increasing efficacy of Zespol system is presented. The apparatus may be used primarily or may replace Zespol plate. It enables controlled interfragmental compression, limb elongation, correction of angular and translational dislocations. After bony union occurs the fixator may be replaced with Zespol plate and reapplied to another patient. It is also compatible with Schanz pins. PMID:8620776

  8. Surgical Management of Tibial Plateau Fractures With 3.5 mm Simple Plates

    PubMed Central

    Bagherifard, Abolfazl; Jabalameli, Mahmoud; Hadi, Hosseinali; Rahbar, Mohammad; Minator Sajjadi, Mohammadreza; Jahansouz, Ali; Karimi Heris, Hossein

    2016-01-01

    Background Tibial plateau fractures can be successfully fixed utilizing 3.5 mm locking plates. However, there are some disadvantages to using these plates. Objectives In the current prospective study, we investigated the outcome of treating different types of tibial plateau fractures with 3.5 mm simple plates which, to our knowledge, has not been evaluated in previous studies. Materials and Methods Between 2011 and 2013, 32 patients aged 40 ± 0.2 years underwent open reduction and internal fixation for tibial plateau fractures with 3.5 mm simple plates. The patients were followed for 16.14 ± 2.1 months. At each patient’s final visit, the articular surface depression, medial proximal tibial angle, and slope angle were measured and compared with measurements taken early after the operation. The functional outcomes were measured with the WOMAC and Lysholm knee scores. Results The mean union time was 13 ± 1.2 weeks. The mean knee range of motion was 116.8° ± 3.3°. The mean WOMAC and Lysholm scores were 83.5 ± 1.8 and 76.8 ± 1.6, respectively. On the early postoperative and final X-rays, 87.5% and 84% of patients, respectively, had acceptable reduction. Medial proximal tibial and slope angles did not change significantly by the last visit. No patient was found to have complications related to the type of plate. Conclusions In this case series study, the fixation of different types of tibial plateau fractures with 3.5 mm simple non-locking and non-precontoured plates was associated with acceptable clinical, functional, and radiographic outcomes. Based on the advantages and costs of these plates, the authors recommend using 3.5 mm simple plates for different types of tibial plateau fractures. PMID:27626010

  9. Management of infectious fractures with "Non-Contact Plate" (NCP) method.

    PubMed

    Alemdar, Celil; Azboy, Ibrahim; Atiç, Ramazan; Özkul, Emin; Gem, Mehmet; Kapukaya, Ahmet

    2015-09-01

    The aim of this study was to evaluate the outcomes of internal fixation with Non-Contact Plating (NCP) after deep infection caused by previous surgeries of the tibia or femur fractures. The study included 15 patients (4 female and 11 male). The mean age patients was 36.6 years (range, 21-64 years). There were 6 femur and 9 tibia fractures. The mean follow-up period was 25.7 months (range, 15-45 months). The study comprised 11 open and 4 closed fractures. External fixator was used in 3, plate in 4, and intramedullary nail in 8 patients for index surgery. Deep infection was diagnosed via clinical findings, laboratory parameters, and microbiological evaulation. Deep infection was diagnosed within a mean period of 5.5 weeks (range, 2-10 weeks). The infecting organism was methicillin-resistant staphylococcus aureus (MRSA) in 5, methicillin-sensitive staphylococcus aureus (MSSA) in 6, pseudomonas auroginosa in 2, and enterobacteriacea in 2 patients. Union achieved in all patients. Mean time to union was 17 (range, 11-38) weeks. Delayed union was observed in 3 patients who required additional surgeries. Of these one patient developed osteomyelitis. The NCP is an effective alternative method in the treatment of deep infection encountered after internal or external fixation for the tibia, or femur fractures.

  10. Management of infectious fractures with "Non-Contact Plate" (NCP) method.

    PubMed

    Alemdar, Celil; Azboy, Ibrahim; Atiç, Ramazan; Özkul, Emin; Gem, Mehmet; Kapukaya, Ahmet

    2015-09-01

    The aim of this study was to evaluate the outcomes of internal fixation with Non-Contact Plating (NCP) after deep infection caused by previous surgeries of the tibia or femur fractures. The study included 15 patients (4 female and 11 male). The mean age patients was 36.6 years (range, 21-64 years). There were 6 femur and 9 tibia fractures. The mean follow-up period was 25.7 months (range, 15-45 months). The study comprised 11 open and 4 closed fractures. External fixator was used in 3, plate in 4, and intramedullary nail in 8 patients for index surgery. Deep infection was diagnosed via clinical findings, laboratory parameters, and microbiological evaulation. Deep infection was diagnosed within a mean period of 5.5 weeks (range, 2-10 weeks). The infecting organism was methicillin-resistant staphylococcus aureus (MRSA) in 5, methicillin-sensitive staphylococcus aureus (MSSA) in 6, pseudomonas auroginosa in 2, and enterobacteriacea in 2 patients. Union achieved in all patients. Mean time to union was 17 (range, 11-38) weeks. Delayed union was observed in 3 patients who required additional surgeries. Of these one patient developed osteomyelitis. The NCP is an effective alternative method in the treatment of deep infection encountered after internal or external fixation for the tibia, or femur fractures. PMID:26435249

  11. Improving carbon fixation pathways

    SciTech Connect

    Ducat, DC; Silver, PA

    2012-08-01

    A recent resurgence in basic and applied research on photosynthesis has been driven in part by recognition that fulfilling future food and energy requirements will necessitate improvements in crop carbon-fixation efficiencies. Photosynthesis in traditional terrestrial crops is being reexamined in light of molecular strategies employed by photosynthetic microbes to enhance the activity of the Calvin cycle. Synthetic biology is well-situated to provide original approaches for compartmentalizing and enhancing photosynthetic reactions in a species independent manner. Furthermore, the elucidation of alternative carbon-fixation routes distinct from the Calvin cycle raises possibilities that novel pathways and organisms can be utilized to fix atmospheric carbon dioxide into useful materials.

  12. Plate motion

    SciTech Connect

    Gordon, R.G. )

    1991-01-01

    The motion of tectonic plates on the earth is characterized in a critical review of U.S. research from the period 1987-1990. Topics addressed include the NUVEL-1 global model of current plate motions, diffuse plate boundaries and the oceanic lithosphere, the relation between plate motions and distributed deformations, accelerations and the steadiness of plate motions, the distribution of current Pacific-North America motion across western North America and its margin, plate reconstructions and their uncertainties, hotspots, and plate dynamics. A comprehensive bibliography is provided. 126 refs.

  13. First metatarsophalangeal arthrodesis: a biomechanical comparison of three fixation constructs.

    PubMed

    Foote, Kristopher M; Teasdall, Robert D; Tanaka, Martin L; Scott, Aaron T

    2012-01-01

    First metatarsophalangeal joint arthrodesis is utilized in the treatment of severe arthritis and hallux valgus. Successful fusion relies on limiting motion at the fusion site and may be achieved through numerous methods. Use of locking plates has recently generated considerable interest, but whether they provide any biomechanical advantage over other available constructs is unclear. Utilizing cyclic loading intended to mimic early weight bearing, the stiffness of three fixation methods for first metatarsophalangeal arthrodesis was compared using Sawbones. The one-third tubular plate completed 1.8 and 2.4 times more cycles before failure than the X-type locking plate or crossed screws, respectively. No difference was detected in cycles to failure between the X-type locking plate and crossed screws. One-third tubular plate mean stiffness was 49% greater than crossed screws at all cycles and greater than X-type locking plate by an average of 25%, beginning at cycle 50.

  14. Comparison of Biomechanical Characteristics and Pelvic Ring Stability Using Different Fixation Methods to Treat Pubic Symphysis Diastasis: A Finite Element Study.

    PubMed

    Yao, Feng; He, Yu; Qian, Hebu; Zhou, Dongsheng; Li, Qinghu

    2015-12-01

    The intention of this study was to compare the biomechanical characteristics using 5 internal fixation methods used clinically to stabilize a pubic symphysis diastasis (PSD, Tile type B1).A 3-dimensional finite element model of PSD was simulated using 5 implants, including single superior plate (Single-Plate), superior and anterior plate (Dual-Plate), single cannulated screw (Single-Screw), crossed dual cannulated screws (Cross-Screw), and parallel dual cannulated screws (Para-Screw). Three loads were distributed in all models, including dual-leg standing, single-leg stance, and rotation. To evaluate the biomechanical properties, the construct stiffness, the stress distribution, and the von Misses stress were recorded and analyzed. To evaluate pelvic ring stability, the micromotion of the pubic symphysis and iliosacral joint was analyzed.Disruption of pubic symphysis dramatically decreased the pelvic ring stability. Cross-screw and Para-Screw showed higher stiffness than other methods. All implants endured the maximum von Misses stress under single-leg stance. For Plate-Screw system, the maximum stress occurred at a place where it strides over pubic symphysis and adjacent Plate-Screw interface. The single implant and Para-Screw had a tendency to fail. Para-Screw showed the best fixation effect under dual-leg conditions. Cross-screw showed superior antishearing force capacity under single-leg stance. Dual-Plate provided maximum antihorizontal rotation. Para-Screw provided the maximum stabilization for the posterior pelvic ring.This study showed the biomechanical advantages of dual-implant for PSD only from the finite element view. The Para-Screw provided high construct stiffness under 3 load conditions. The single implant and Para-Screw had a tendency to fail. The better anterior and posterior pelvic stabilization were obtained by the dual-implant fixation than other methods. Therefore, the Cross-Screw and Dual-Plate fixation methods should be preferred in the

  15. Carbon-fibre reinforced plates for problem fractures.

    PubMed

    Pemberton, D J; McKibbin, B; Savage, R; Tayton, K; Stuart, D

    1992-01-01

    We report our experience with carbon-fibre reinforced plastic (CFRP) plates in the management of 19 problem fractures complicated by either infection, nonunion, comminution or contamination. The combination offers secure fixation without inhibition of callus formation.

  16. Biomechanical comparison of three fixation techniques used for four-corner arthrodesis.

    PubMed

    Kraisarin, J; Dennison, D G; Berglund, L J; An, K N; Shin, A Y

    2011-09-01

    Clinical results following four-corner arthrodesis vary and suggest that nonunion may be related to certain fixation techniques. The purpose of our study was to examine the displacement between the lunate and capitate following a simulated four-corner arthrodesis with the hypothesis that three types of fixation (Kirschner wires, dorsal circular plate, and a locked dorsal circular plate) would allow different amounts of displacement during simulated wrist flexion and extension. Cadaver wrists with simulated four-corner arthrodeses were loaded cyclically either to implant failure or until the lunocapitate displacement exceeded 1 mm. The locked dorsal circular plate group was significantly more stable than the dorsal circular plate and K-wire groups (p = 0.018 and p = 0.006). While these locked dorsal circular plates appear to be very stable our results are limited only to the biomechanical behavior of these fixation techniques within a cadaver model. PMID:21636620

  17. A new fixation technique for the Lapidus bunionectomy.

    PubMed

    Wang, James C; Riley, Brendan M

    2005-01-01

    Presented here is a preliminary report of 102 patients who underwent first metatarsocuneiform joint arthrodeses performed with external fixation for the correction of hallux valgus. The advantages of using external fixation are the ability to initiate early weightbearing, predictable fusion, and removal of all of the hardware postoperatively. In the 102 patients reported here, the average time to initiation of unassisted full weightbearing was 13.1 days. The average time to fusion was 5.3 weeks, with removal of the external fixator at an average of 5.5 weeks postoperatively. There was no incidence of delayed union or nonunion. There was one case of pin-tract irritation, which resolved with appropriate pin care and a short course of oral antibiotics. External fixation is an effective alternative to traditional internal fixation techniques in metatarsocuneiform joint arthrodesis.

  18. Fixation produced by conflict.

    PubMed

    Karsh, E B

    1970-05-15

    All rats given a choice between a rewarded alternative and a conflict alternative (rewarded and punished) developed position fixations when the position of the alternatives was reversed. In contrast, all animals given one rewarded alternative and another nonrewarded (or punished and nonrewarded) alternative learned to choose the rewarded side during 25 successive reversals.

  19. The Fixation of Nitrogen.

    ERIC Educational Resources Information Center

    Andrew, S. P. S.

    1978-01-01

    Discusses the fixation of atmospheric nitrogen in the form of ammonia as one of the foundations of modern chemical industry. The article describes ammonia production and synthesis, purifying the hydrogen-nitrogen mix, nitric acid production, and its commericial plant. (HM)

  20. Update: Biological Nitrogen Fixation.

    ERIC Educational Resources Information Center

    Wiseman, Alan; And Others

    1985-01-01

    Updates knowledge on nitrogen fixation, indicating that investigation of free-living nitrogen-fixing organisms is proving useful in understanding bacterial partners and is expected to lead to development of more effective symbioses. Specific areas considered include biochemistry/genetics, synthesis control, proteins and enzymes, symbiotic systems,…

  1. Fixation produced by conflict.

    PubMed

    Karsh, E B

    1970-05-15

    All rats given a choice between a rewarded alternative and a conflict alternative (rewarded and punished) developed position fixations when the position of the alternatives was reversed. In contrast, all animals given one rewarded alternative and another nonrewarded (or punished and nonrewarded) alternative learned to choose the rewarded side during 25 successive reversals. PMID:5444066

  2. Fiber-matrix interface studies on bioabsorbable composite materials for internal fixation of bone fractures. I. Raw material evaluation and measurement of fiber-matrix interfacial adhesion.

    PubMed

    Slivka, M A; Chu, C C; Adisaputro, I A

    1997-09-15

    bone fractures, but likely had insufficient stiffness for applications such as bone plates for fixing cortical bone fractures.

  3. Arthroscopic Removal of Symptomatic Proximal Humerus Locking Plates With Bone-Void Filler Augmentation.

    PubMed

    Voleti, Pramod B; Camp, Christopher L; Sinatro, Alec L; Dines, Joshua S

    2016-04-01

    Open reduction internal fixation of proximal humerus fractures is often accomplished with proximal humerus locking plates. While these plates have a good track record, they can become symptomatic and require removal once the fracture has healed. Open hardware removal is associated with a number of additional risks to the patient, including infection, scarring, nerve damage, and blood loss. In addition, the recovery time after open hardware removal may be prolonged, thereby predisposing the patient to postoperative stiffness. The purpose of this article is to describe a technique for removing proximal humerus locking plates arthroscopically. Although technically demanding, the benefits of this technique include smaller incisions, quicker recovery time, decreased risk of infection, and reduced blood loss. Arthroscopy also provides the surgeon with the ability to address concomitant intra-articular pathology at the time of surgery. Additionally, we use a bone-void filler to reduce the risk of fracture through stress caused by previous screw holes. PMID:27462532

  4. The Therapeutic Effect of Tibia Counter Rotator With Toe-Out Gait Plate in the Treatment of Tibial Internal Torsion in Children

    PubMed Central

    Son, Su Min; Ahn, Sang Ho; Jung, Gil Su; Seo, Sang Wan; Park, In Sik; Song, Jun Chan; Jang, Sung Ho

    2014-01-01

    Objective To evaluate the therapeutic effect of a Tibia Counter Rotator (TCR) with toe-out gait plate (GP) upon tibial internal torsion by a comparative analysis of transmalleolar angle (TMA) and gait analysis with GP alone. Methods Twenty participants with tibial internal torsion were recruited for this study. Each 10 participants were included in group A with TCR and GP application and in group B with GP application only. The TMA and the kinematic results were used for the evaluation of the therapeutic effects of orthoses. Results Within each group, TMA showed a significant increase after treatment. Group A showed a continuous improvement up to six months, however, group B showed an improvement up to five months only. Group A showed a significantly higher correction effect than group B after treatment. Regarding kinematic data, both groups showed a significantly decreased mean ankle adduction angle after treatment. However, group A showed a significantly lower mean ankle adduction angle than group B after six months. Conclusion The group with TCR and GP showed a significantly better outcome and continued correction force compared to the group with GP only. Our results suggest that TCR with GP may be useful therapeutic orthoses for children with tibial internal torsion. PMID:24855616

  5. The concept of locking plates.

    PubMed

    Cronier, P; Pietu, G; Dujardin, C; Bigorre, N; Ducellier, F; Gerard, R

    2010-05-01

    After a short historical review of locking bone plates since their inception more than a century ago to the success of the concept less than 15 years ago with today's plates, the authors present the main locking mechanisms in use. In the two broad categories - plates with fixed angulation and those with variable angulation - the screw head is locked in the plate with a locknut by screwing in a threaded chamber on the plate or by screwing through an adapted ring. The authors then provide a concrete explanation, based on simple mechanical models, of the fundamental differences between conventional bone plates and locking plates and why a locking screw system presents greater resistance at disassembly, detailing the role played by the position and number of screws. The advantages of epiphyseal fixation are then discussed, including in cases of mediocre-quality bone. For teaching purposes, the authors also present assembly with an apple fixed with five locking screws withstanding a 47-kg axial load with no resulting disassembly. The principles of plate placement are detailed for both the epiphysis and diaphysis, including the number and position of screws and respect of the soft tissues, with the greatest success assured by the minimally invasive and even percutaneous techniques. The authors then present the advantages of locking plates in fixation of periprosthetic fractures where conventional osteosynthesis often encounters limited success. Based on simplified theoretical cases, the economic impact in France of this type of implant is discussed, showing that on average it accounts for less than 10% of the overall cost of this pathology to society. Finally, the possible problems of material ablation are discussed as well as the means to remediate these problems.

  6. Experimental study in order to assess the effects of limited periosteum stripping on the fracture healing and to compare osteosynthesis using plates and screws with intramedullary Kirschner wire fixation.

    PubMed

    Neagu, Tiberiu Paul; Enache, Valentin; Cocoloş, Ion; Ţigliş, Mirela; Cobilinschi, Cristian; Ţincu, Radu

    2016-01-01

    There are many studies that investigate indirect and direct fracture healing but few mention the effect of periosteum stripping on consolidation of fractures. Most of these studies use only one method of osteosynthesis for each group. Therefore, we reported a new developed murine model in order to assess if limited periosteum stripping influence significantly the quality of the fracture healing process by comparing two different osteosynthesis methods to reduce simultaneously bilateral femur fractures. We applied the experimental protocol for a number of 12 rats. We used plates and screws to reduce femoral osteotomy for the right hind limb and intramedullary Kirschner wire for the left hind limb. Clinical, radiological and histological assessments were made for a period of eight weeks. The absence of a healthy hind limb led to a slower healing process based on the histological findings and to implant failure based on radiological findings. In summary, complete fracture healing was not achieved during this experimental study. Therefore, we consider that future studies are needed for a better understanding of the effects of periosteum removal on the fracture healing process. PMID:27516016

  7. Nuclear reactor alignment plate configuration

    DOEpatents

    Altman, David A; Forsyth, David R; Smith, Richard E; Singleton, Norman R

    2014-01-28

    An alignment plate that is attached to a core barrel of a pressurized water reactor and fits within slots within a top plate of a lower core shroud and upper core plate to maintain lateral alignment of the reactor internals. The alignment plate is connected to the core barrel through two vertically-spaced dowel pins that extend from the outside surface of the core barrel through a reinforcement pad and into corresponding holes in the alignment plate. Additionally, threaded fasteners are inserted around the perimeter of the reinforcement pad and into the alignment plate to further secure the alignment plate to the core barrel. A fillet weld also is deposited around the perimeter of the reinforcement pad. To accomodate thermal growth between the alignment plate and the core barrel, a gap is left above, below and at both sides of one of the dowel pins in the alignment plate holes through with the dowel pins pass.

  8. External Fixation: Principles and Applications.

    PubMed

    Bible, Jesse E; Mir, Hassan R

    2015-11-01

    The modularity and ease of application of modern external fixation has expanded its potential use in the management of fractures and other musculoskeletal conditions. In fracture care, it can be used for provisional and definitive fixation. Short-term provisional applications include "damage control" and periarticular fracture fixation. The risk:benefit ratio of added stability needs to be assessed with each fixator. Soft-tissue management is critical during pin insertion to lessen the risk of loosening and infection. Although provisional fixation is safe for early conversion to definitive fixation, several factors affect the timing of definitive surgery, including the initial injury, external fixator stability, infection, and the physiologic state of the patient. PMID:26306568

  9. The Mechanics of External Fixation

    PubMed Central

    Rozbruch, S. Robert

    2006-01-01

    External fixation has evolved from being used primarily as a last resort fixation method to becoming a main stream technique used to treat a myriad of bone and soft tissue pathologies. Techniques in limb reconstruction continue to advance largely as a result of the use of these external devices. A thorough understanding of the biomechanical principles of external fixation is useful for all orthopedic surgeons as most will have to occasionally mount a fixator throughout their career. In this review, various types of external fixators and their common clinical applications are described with a focus on unilateral and circular frames. The biomechanical principles that govern bony and fixator stability are reviewed as well as the recommended techniques for applying external fixators to maximize stability. Additionally, we have illustrated methods for managing patients while they are in the external frames to facilitate function and shorten treatment duration. PMID:18751766

  10. Development of a Titanium Plate for Mandibular Angle Fractures with a Bone Defect in the Lower Border: Finite Element Analysis and Mechanical Test

    PubMed Central

    Goulart, Douglas Rangel; Kemmoku, Daniel Takanori; Noritomi, Pedro Yoshito

    2015-01-01

    ABSTRACT Objectives The aim of the present study was to develop a plate to treat mandibular angle fractures using the finite element method and mechanical testing. Material and Methods A three-dimensional model of a fractured mandible was generated using Rhinoceros 4.0 software. The models were exported to ANSYS®, in which a static application of displacement (3 mm) was performed in the first molar region. Three groups were assessed according to the method of internal fixation (2 mm system): two non-locking plates; two locking plates and a new design locking plate. The computational model was transferred to an in vitro experiment with polyurethane mandibles. Each group contained five samples and was subjected to a linear loading test in a universal testing machine. Results A balanced distribution of stress was associated with the new plate design. This plate modified the mechanical behavior of the fractured region, with less displacement between the fractured segments. In the mechanical test, the group with two locking plates exhibited greater resistance to the 3 mm displacement, with a statistically significant difference when compared with the new plate group (ANOVA, P = 0.016). Conclusions The new plate exhibited a more balanced distribution of stress. However, the group with two locking plates exhibited greater mechanical resistance. PMID:26539287

  11. Femoral Aperture Fixation Improves Anterior Cruciate Ligament Graft Function When Added to Cortical Suspensory Fixation

    PubMed Central

    Porter, Mark D.; Shadbolt, Bruce

    2016-01-01

    Background: Recommendations for bone tunnel placement during anterior cruciate ligament (ACL) reconstruction have become more precise. However, these recommendations differ neither with the choice of graft nor with the method of fixation used. The influence of the method of femoral fixation used on the biomechanical function of a soft tissue ACL graft remains unknown. Hypothesis: Our null hypothesis was that adding femoral aperture fixation to femoral cortical fixation, using the same bone tunnels, will not alter the control of anterior translation (AT) and internal rotation (IR) during ACL reconstruction using a hamstring graft. Study Design: Controlled laboratory study. Methods: A total of 22 patients with an acute isolated ACL rupture underwent reconstruction using a single-bundle autologous hamstring graft. Computer navigation was used intraoperatively to plot the AT and IR during the pivot-shift test before reconstruction, after ACL reconstruction using cortical suspensory fixation, and after the addition of femoral aperture fixation. Statistical analysis (analysis of variance) was used to compare the AT and IR during the pivot shift at each stage in the procedure. Results: Before ACL reconstruction, the mean (±SD) AT was 14.2 ± 7.3 mm and mean IR was 17.2° ± 5.5°. After reconstruction using femoral cortical suspension, these figures were significantly reduced to 6.2 ± 3.5 mm and 12.5° ± 3.20°, respectively (P < .001). The addition of the aperture fixation was associated with a further significant reduction to 4.6 ± 3.2 mm and 10.4° ± 2.7°, respectively (P < .001). Conclusion: The addition of femoral aperture fixation to suspensory fixation results in a significant reduction in both the AT and IR that occurs during the pivot-shift assessment immediately after ACL reconstruction using autologous hamstring graft. Clinical Relevance: The most precise positioning of bone tunnels during soft tissue ACL reconstruction needs to take into consideration

  12. Femoral Aperture Fixation Improves Anterior Cruciate Ligament Graft Function When Added to Cortical Suspensory Fixation

    PubMed Central

    Porter, Mark D.; Shadbolt, Bruce

    2016-01-01

    Background: Recommendations for bone tunnel placement during anterior cruciate ligament (ACL) reconstruction have become more precise. However, these recommendations differ neither with the choice of graft nor with the method of fixation used. The influence of the method of femoral fixation used on the biomechanical function of a soft tissue ACL graft remains unknown. Hypothesis: Our null hypothesis was that adding femoral aperture fixation to femoral cortical fixation, using the same bone tunnels, will not alter the control of anterior translation (AT) and internal rotation (IR) during ACL reconstruction using a hamstring graft. Study Design: Controlled laboratory study. Methods: A total of 22 patients with an acute isolated ACL rupture underwent reconstruction using a single-bundle autologous hamstring graft. Computer navigation was used intraoperatively to plot the AT and IR during the pivot-shift test before reconstruction, after ACL reconstruction using cortical suspensory fixation, and after the addition of femoral aperture fixation. Statistical analysis (analysis of variance) was used to compare the AT and IR during the pivot shift at each stage in the procedure. Results: Before ACL reconstruction, the mean (±SD) AT was 14.2 ± 7.3 mm and mean IR was 17.2° ± 5.5°. After reconstruction using femoral cortical suspension, these figures were significantly reduced to 6.2 ± 3.5 mm and 12.5° ± 3.20°, respectively (P < .001). The addition of the aperture fixation was associated with a further significant reduction to 4.6 ± 3.2 mm and 10.4° ± 2.7°, respectively (P < .001). Conclusion: The addition of femoral aperture fixation to suspensory fixation results in a significant reduction in both the AT and IR that occurs during the pivot-shift assessment immediately after ACL reconstruction using autologous hamstring graft. Clinical Relevance: The most precise positioning of bone tunnels during soft tissue ACL reconstruction needs to take into consideration

  13. A randomized controlled trial of nonoperative treatment versus open reduction and internal fixation for stable, displaced, partial articular fractures of the radial head: the RAMBO trial

    PubMed Central

    2014-01-01

    Background The choice between operative or nonoperative treatment is questioned for partial articular fractures of the radial head that have at least 2 millimeters of articular step-off on at least one radiograph (defined as displaced), but less than 2 millimeter of gap between the fragments (defined as stable) and that are not associated with an elbow dislocation, interosseous ligament injury, or other fractures. These kinds of fractures are often classified as Mason type-2 fractures. Retrospective comparative studies suggest that operative treatment might be better than nonoperative treatment, but the long-term results of nonoperative treatment are very good. Most experts agree that problems like reduced range of motion, painful crepitation, nonunion or bony ankylosis are infrequent with both nonoperative and operative treatment of an isolated displaced partial articular fracture of the radial head, but determining which patients will have problems is difficult. A prospective, randomized comparison would help minimize bias and determine the balance between operative and nonoperative risks and benefits. Methods/Design The RAMBO trial (Radial Head – Amsterdam – Amphia – Boston - Others) is an international prospective, randomized, multicenter trial. The primary objective of this study is to compare patient related outcome defined by the ‘Disabilities of Arm, Shoulder and Hand (DASH) score’ twelve months after injury between operative and nonoperative treated patients. Adult patients with partial articular fractures of the radial head that comprise at least 1/3rd of the articular surface, have ≥ 2 millimeters of articular step-off but less than 2 millimeter of gap between the fragments will be enrolled. Secondary outcome measures will be the Mayo Elbow Performance Index (MEPI), the Oxford Elbow Score (OES), pain intensity through the ‘Numeric Rating Scale’, range of motion (flexion arc and rotational arc), radiographic appearance of the fracture

  14. Novel posterior fixation keratoprosthesis

    NASA Astrophysics Data System (ADS)

    Lacombe, Emmanuel

    1992-08-01

    The keratoprosthesis is the last solution for corneally blind patients that cannot benefit from corneal transplants. Keratoprostheses that have been designed to be affixed anteriorly usually necessitate multi-step surgical procedures and are continuously subjected to the extrusion forces generated by the positive intraocular pressure; therefore, clinical results in patients prove inconsistent. We proposed a novel keratoprosthesis concept that utilizes posterior corneal fixation which `a priori' minimizes the risk of aqueous leakage and expulsion. This prosthesis is implanted in a single procedure thereby reducing the number of surgical complications normally associated with anterior fixation devices. In addition, its novel design makes this keratoprosthesis implantable in phakic eyes. With an average follow-up of 13 months (range 3 to 25 months), our results on 21 cases are encouraging. Half of the keratoprostheses were implanted in severe burn cases, with the remainder in cases of pseudo- pemphigus. Good visual results and cosmetic appearance were obtained in 14 of 21 eyes.

  15. CARBON DIOXIDE FIXATION.

    SciTech Connect

    FUJITA,E.

    2000-01-12

    Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

  16. Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity.

    PubMed

    Schroth, Volkhard; Joos, Roland; Jaschinski, Wolfgang

    2015-01-01

    In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptability of the binocular vergence system may diminish effects of the prisms over time. This study investigates effects of wearing prisms constantly for about 5 weeks in daily life. Two groups of 12 participants received eyeglasses with prisms having either a base-in direction or a base-out direction with an amount up to 8 prism diopters. Prisms were prescribed based on clinical fixation disparity test plates at 6 m. Two dependent variables were used: (1) subjective fixation disparity was indicated by a perceived offset of dichoptic nonius lines that were superimposed on the fusion stimuli and (2) objective fixation disparity was measured with a video based eye tracker relative to monocular calibration. Stimuli were presented at 6 m and included either central or more peripheral fusion stimuli. Repeated measurements were made without the prisms and with the prisms after about 5 weeks of wearing these prisms. Objective and subjective fixation disparity were correlated, but the type of fusion stimulus and the direction of the required prism may play a role. The prisms did not reduce the fixation disparity to zero, but induced significant changes in fixation disparity with large effect sizes. Participants receiving base-out prisms showed hypothesized effects, which were concurrent in both types of fixation disparity. In participants receiving base-in prisms, the individual effects of subjective and objective effects were negatively correlated: the larger the subjective (sensory) effect, the smaller the objective (motor) effect. This response pattern was related to the vergence adaptability, i.e. the individual fusional vergence reserves.

  17. Effects of Prism Eyeglasses on Objective and Subjective Fixation Disparity.

    PubMed

    Schroth, Volkhard; Joos, Roland; Jaschinski, Wolfgang

    2015-01-01

    In optometry of binocular vision, the question may arise whether prisms should be included in eyeglasses to compensate an oculomotor and/or sensory imbalance between the two eyes. The corresponding measures of objective and subjective fixation disparity may be reduced by the prisms, or the adaptability of the binocular vergence system may diminish effects of the prisms over time. This study investigates effects of wearing prisms constantly for about 5 weeks in daily life. Two groups of 12 participants received eyeglasses with prisms having either a base-in direction or a base-out direction with an amount up to 8 prism diopters. Prisms were prescribed based on clinical fixation disparity test plates at 6 m. Two dependent variables were used: (1) subjective fixation disparity was indicated by a perceived offset of dichoptic nonius lines that were superimposed on the fusion stimuli and (2) objective fixation disparity was measured with a video based eye tracker relative to monocular calibration. Stimuli were presented at 6 m and included either central or more peripheral fusion stimuli. Repeated measurements were made without the prisms and with the prisms after about 5 weeks of wearing these prisms. Objective and subjective fixation disparity were correlated, but the type of fusion stimulus and the direction of the required prism may play a role. The prisms did not reduce the fixation disparity to zero, but induced significant changes in fixation disparity with large effect sizes. Participants receiving base-out prisms showed hypothesized effects, which were concurrent in both types of fixation disparity. In participants receiving base-in prisms, the individual effects of subjective and objective effects were negatively correlated: the larger the subjective (sensory) effect, the smaller the objective (motor) effect. This response pattern was related to the vergence adaptability, i.e. the individual fusional vergence reserves. PMID:26431525

  18. No Higher Risk of CRPS After External Fixation of Distal Radial Fractures – Subgroup Analysis Under Randomised Vitamin C Prophylaxis§

    PubMed Central

    Zollinger, Paul E.; Kreis, Robert W.; van der Meulen, Hub G.; van der Elst, Maarten; Breederveld, Roelf S.; Tuinebreijer, Wim E.

    2010-01-01

    Operative and conservative treatment of wrist fractures might lead to complex regional pain syndrome (CRPS) type I. In our multicenter dose response study in which patients with distal radial fractures were randomly allocated to placebo or vitamin C in a daily dose of 200mg, 500mg or 1500mg during 50 days, an operated subgroup was analyzed. 48 (of 427) fractures) were operated (11.2%). Twenty-nine patients (60%) were treated with external fixation, 14 patients (29%) with K-wiring according to Kapandji and five patients (10%) with internal plate fixation. The 379 remaining patients were treated with a plaster. In the operated group of patients who received vitamin C no CRPS (0/37) was seen in comparison with one case of CRPS (Kapandji technique) in the operated group who received placebo (1/11 = 9%, p=.23). There was no CRPS after external fixation. In the conservatively treated group 17 cases of CRPS (17/379 = 4.5%) occurred in comparison with one in case of CRPS in the operated group (1/48 = 2.1%, p=.71). External fixation doesn’t necessarily lead to a higher incidence of CRPS in distal radial fractures. Vitamin C may also play a role in this. This subgroup analysis in operated distal radial fractures showed no CRPS occurrence with vitamin C prophylaxis. PMID:20309405

  19. Bacterial alternative nitrogen fixation systems.

    PubMed

    Joerger, R D; Bishop, P E

    1988-01-01

    The introduction briefly reviews some of the salient features of the well-characterized conventional molybdo-enzyme system for N2 fixation. This is followed by a brief account of the discovery of an alternative N2 fixation system that does not require molybdenum in the N2-fixing bacterum Azotobacter vinelandii. The next section cites observations from the early literature on N2 fixation suggesting may not always require molybdenum. Next, recent evidence for an alternative N2 fixation system in A. vinelandii is discussed. A brief description of our discovery of an alternative nitrogenase which is not a molybdenum or vanadium enzyme is presented, followed by a summary of recent papers describing an alternative vanadium-containing nitrogenase. Available information on the genetics and regulation of alternative N2 fixation systems is discussed. Finally, the possible/probable presence of alternative N2 fixation systems in bacteria other than Azotobacter species is covered.

  20. Retrospective study of mandibular angle fractures treated with three different fixation systems

    PubMed Central

    Bhatt, Krushna; Arya, Satyavrat; Bhutia, Ongkila; Pandey, Sandeep; Roychoudhury, Ajoy

    2015-01-01

    Aim: To evaluate the outcomes of mandibular angle fractures treated with metal 2.0 mm locking, metal 2.0 mm nonlocking, and 2.5 mm resorbable systems. Study Design: Retrospective cohort study. Materials and Methods: Trauma records were screened for linear angle fractures treated with open-reduction and internal semi-rigid fixation with single metal/bioresorbable plates, and baseline variables were tabulated. The outcome variable was the presence or absence of any complication. Statistical Analysis Used: The Fisher's exact test and analysis of covariance (ANCOVA) using STATA 11. Results: A total of 60 case records of over four years were included. The mean age of the patients was 27.4 (SD 9.7) years. Fifty-five were male and five female. There were 20 nonlocking and 16 locking metal miniplates and 24 bioresorbable plates. In 55 (91.6%) cases there was a third molar in the fracture line. In 51/55 (92.7%) cases the third molar was retained. In seven patients postoperative complications were seen. There was no difference between the complication rates of the three treatment groups. Infection was the most common complication followed by delayed union and hardware failure. Conclusions: This retrospective study found no difference in the complication rate when fractures of the mandibular angle were treated with locking or nonlocking miniplates or bioresorbable plates. PMID:26668450

  1. Nitrogen fixation apparatus

    DOEpatents

    Chen, Hao-Lin

    1984-01-01

    A method and apparatus for achieving nitrogen fixation includes a volumetric electric discharge chamber. The volumetric discharge chamber provides an even distribution of an electron beam, and enables the chamber to be maintained at a controlled energy to pressure (E/p) ratio. An E/p ratio of from 5 to 15 kV/atm of O.sub.2 /cm promotes the formation of vibrationally excited N.sub.2. Atomic oxygen interacts with vibrationally excited N.sub.2 at a much quicker rate than unexcited N.sub.2, greatly improving the rate at which NO is formed.

  2. Precambrian and Mesozoic plate margins: Montana, Idaho and Wyoming with field guides for the 8th international conference on basement tectonics

    SciTech Connect

    Lewis, S.E.; Berg, R.B.

    1988-07-01

    Two field trips held in conjunction with the 8th International Conference on Basement Tectonics are the raison d'etre for this volume, which would perhaps otherwise seem an eclectic association. The unifying theme is an investigation of the nature of plate margins in time and space, consonant with the main theme of the conference, Characterization and Comparison of Precambrian Through Mesozoic Continental Margins. Papers presented at the conference will be published in a separate volume by the International Basement Tectonics Association, Inc. The first field trip is at least a preliminary attempt at an overview of the Precambrian (predominantly Archean) crystalline basement of southwestern Montana. A number of interesting investigations have been focused on this region in recent years. Thus, papers in the first part of this volume take the reader from the Stillwater Complex across the Beartooth Plateau, to the northern borders of Yellowstone National Park on to the southern Madison Range, and finally to some of the western-most (probable) Archean exposures in the Highland Mountains south of Butte. Moving considerably forward on the geologic time scale, the other broad topic dealt with in a second field trip and complementary articles is a relatively recent collisional terrane in central Idaho and eastern Oregon. Examined are portions of the Idaho batholith and its enigmatic and fascinating marginal rocks, and to the west, the heart of the suture zone itself in the Wallowa-Seven Devils terrane with its group of exotic intrusive, metavolcanic, and metasedimentary rocks. Individual papers are processed separately for the data base.

  3. Triangular Fixation Technique for Bicolumn Restoration in Treatment of Distal Humerus Intercondylar Fracture

    PubMed Central

    Kang, Seung-Hoon; Jeong, Min; Lim, Hae-Seong

    2016-01-01

    Background Distal humerus intercondylar fractures are intra-articular and comminuted fractures involving soft tissue injury. As distal humerus is triangle-shaped, parallel plating coupled with articular fixation would be suitable for bicolumn restoration in treatment of distal humerus intercondylar fracture. Methods This study included 38 patients (15 males and 23 females) who underwent olecranon osteotomy, open reduction and internal fixation with the triangle-shaped cannulated screw and parallel locking plates (triangular fixation technique). Functional results were assessed with the visual analog scale (VAS) scores, Mayo elbow performance (MEP) scores and Disabilities of the Arm, Shoulder and Hand (DASH) questionnaires. Anteroposterior and lateral elbow radiographs were assessed for reduction, alignment, fracture union, posttraumatic arthrosis, and heterotopic ossification, and computed tomography (CT) scans were used to obtain more accurate measurements of articular discrepancy. Results All fractures healed primarily with no loss of reduction. The mean VAS, MEP, and DASH scores of the affected elbow were not significantly different from those of the unaffected elbow (p = 0.140, p = 0.090, and p = 0.262, respectively). The mean degree of flexion was significantly lower in the affected elbow than in the unaffected elbow, but was still considered as functional (p = 0.001, > 100° in 33 of 38 patients). Two cases of articular step-offs (> 2 mm) were seen on follow-up CT scans, but not significantly higher in the affected elbow than in the unaffected elbow (p = 0.657). Binary logistic regression analysis revealed that only Association for Osteosynthesis (AO) type C3 fractures correlated with good/excellent functional outcome (p = 0.012). Complications occurred in 12 of the 38 patients, and the overall reoperation rate for complications was 10.5% (4 of 38 patients). Conclusions Triangular fixation technique for bicolumn restoration was an effective and reliable

  4. [An experimental study of the effects of stress-relaxation plate on bone remodeling].

    PubMed

    Dai, M; Dai, K; Qui, S

    1995-11-01

    An ideal bone plate would provide rigid fixation to ensure stabilization of bone fragments at the early stage after fracture, while at the late stage osteoporosis induced by stress shielding effect of the plate should be prevented. However, there is no report of such a plate that could meet with all these requirements. Twenty-eight adult New Zealand rabbits were used in this experiment. Ordinary stainless-steel plate (no washer plate) and similar plate padded with ultrahigh molecular polyethylene washers in its screw holes (washer plate) were fixed respectively on mid-shelf of each side of tibiae. The animals were killed at 2, 4, 8, 12, 16, 20 and 24 weeks after operation, and the fixed bone segments of both tibiae were removed for light microscopy, polarized light microscopy and fluoroscopy. The results showed that the tibiae fixed with plate fixation both appeared bone resorption, but there was more severe resorption in bone with no washer plate fixation than that with washer plate fixation. Cancelization of cortical bone was seen in the former but not in the latter at 12 weeks postopertively. This demonstrated that the washer might creep and damage with fixation time, resulting in gradual decrease in the rigidity of the plate-screw system and thus reducing bone resorption as caused by stress shielding. PMID:8731919

  5. Treatment of nonunion and malunion of trauma of the foot and ankle using external fixation.

    PubMed

    Molloy, Andrew Peter; Roche, Andy; Narayan, Badri

    2009-09-01

    Salvage of nonunion and malunion of trauma of the foot and ankle is often challenging surgery. Internal fixation provides the mainstay of most orthopedic surgeons' treatment of these conditions. Patient systemic factors, local factors, and the complex nature of these often multiplanar deformities may make external fixation a more viable option. This article provides an overview of the principles and results of the use of external fixation. PMID:19712890

  6. Central acetabular fracture with dislocation treated by minimally invasive plate osteosynthesis.

    PubMed

    2015-06-01

    Central acetabular fractures with dislocation are usually the result of high-energy trauma, resulting in joint incongruity, and are frequently associated with other injuries. Open reduction and internal fixation has been the standard treatment for acetabular fractures, but it is associated with extensive surgical trauma, and complications such as haematoma formation, iatrogenic nerve injury, and heterotopic ossification. We present the case of a 63-year-old female who sustained a central acetabular fracture of the hip with dislocation as a result of an automobile collision. Closed reduction of the dislocation was performed, and the fracture was managed by minimally invasive plate osteosynthesis using a specially prepared plate. At 01 year postoperatively, radiographs showed the fracture to have been well-healed with good congruity of the joint. However, heterotopic ossification of the joint was noted. The technique allowed reduction of the fracture with minimal surgical trauma.

  7. Central acetabular fracture with dislocation treated by minimally invasive plate osteosynthesis.

    PubMed

    2015-06-01

    Central acetabular fractures with dislocation are usually the result of high-energy trauma, resulting in joint incongruity, and are frequently associated with other injuries. Open reduction and internal fixation has been the standard treatment for acetabular fractures, but it is associated with extensive surgical trauma, and complications such as haematoma formation, iatrogenic nerve injury, and heterotopic ossification. We present the case of a 63-year-old female who sustained a central acetabular fracture of the hip with dislocation as a result of an automobile collision. Closed reduction of the dislocation was performed, and the fracture was managed by minimally invasive plate osteosynthesis using a specially prepared plate. At 01 year postoperatively, radiographs showed the fracture to have been well-healed with good congruity of the joint. However, heterotopic ossification of the joint was noted. The technique allowed reduction of the fracture with minimal surgical trauma. PMID:26060171

  8. Modeling and minimizing interference from corneal birefringence in retinal birefringence scanning for foveal fixation detection

    PubMed Central

    Irsch, Kristina; Gramatikov, Boris; Wu, Yi-Kai; Guyton, David

    2011-01-01

    Utilizing the measured corneal birefringence from a data set of 150 eyes of 75 human subjects, an algorithm and related computer program, based on Müller-Stokes matrix calculus, were developed in MATLAB for assessing the influence of corneal birefringence on retinal birefringence scanning (RBS) and for converging upon an optical/mechanical design using wave plates (“wave-plate-enhanced RBS”) that allows foveal fixation detection essentially independently of corneal birefringence. The RBS computer model, and in particular the optimization algorithm, were verified with experimental human data using an available monocular RBS-based eye fixation monitor. Fixation detection using wave-plate-enhanced RBS is adaptable to less cooperative subjects, including young children at risk for developing amblyopia. PMID:21750772

  9. Modeling and minimizing interference from corneal birefringence in retinal birefringence scanning for foveal fixation detection.

    PubMed

    Irsch, Kristina; Gramatikov, Boris; Wu, Yi-Kai; Guyton, David

    2011-07-01

    Utilizing the measured corneal birefringence from a data set of 150 eyes of 75 human subjects, an algorithm and related computer program, based on Müller-Stokes matrix calculus, were developed in MATLAB for assessing the influence of corneal birefringence on retinal birefringence scanning (RBS) and for converging upon an optical/mechanical design using wave plates ("wave-plate-enhanced RBS") that allows foveal fixation detection essentially independently of corneal birefringence. The RBS computer model, and in particular the optimization algorithm, were verified with experimental human data using an available monocular RBS-based eye fixation monitor. Fixation detection using wave-plate-enhanced RBS is adaptable to less cooperative subjects, including young children at risk for developing amblyopia.

  10. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fixation device. 886.1290 Section 886.1290 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A fixation device is an AC-powered device intended for use as a fixation target for the patient...

  11. Stereotactic atlantoaxial transarticular screw fixation.

    PubMed

    Laherty, R W; Kahler, R J; Walker, D G; Tomlinson, F H

    2005-01-01

    Atlantoaxial stabilisation can be performed using a variety of surgical techniques. Developments in spinal instrumentation and stereotactic technology have been incorporated into these procedures. We have recently adopted frameless stereotaxy to assist in such operations. A retrospective study of patients treated by the authors and using frameless stereotaxy from 2001 to 2002 was performed. Each patient underwent pre-operative fine-cut CT in the position of fixation. Using these images, screw trajectory was planned. Stereotaxis and fluoroscopy was utilised during fixation. A post-operative CT was performed. There were nine patients. Bilateral screw placement was achieved in eight. In the remaining case stereotactic planning predicted the single screw fixation. There were no post-operative complications. Post-operative CT showed screw placement corresponding to the planned trajectory in all 17 screws. Stabilisation was achieved in all. Stereotactic atlantoaxial screw fixation is an accessible, safe and accurate method for the management of C1-2 instability. PMID:15639416

  12. Molecular Biology of Nitrogen Fixation

    ERIC Educational Resources Information Center

    Shanmugam, K. T.; Valentine, Raymond C.

    1975-01-01

    Reports that as a result of our increasing knowledge of the molecular biology of nitrogen fixation it might eventually be possible to increase the biological production of nitrogenous fertilizer from atmospheric nitrogen. (GS)

  13. Intramedullary versus extramedullary fixation in the management of subtrochanteric femur fractures: a meta-analysis

    PubMed Central

    Liu, Pengcheng; Wu, Xing; Shi, Hui; Liu, Run; Shu, Hexi; Gong, JinPeng; Yang, Yong; Sun, Qi; Wu, Jiezhou; Nie, Xiaoyang; Cai, Ming

    2015-01-01

    Background Intramedullary and extramedullary fixation methods are used in the management of subtrochanteric femur fractures. However, whether intramedullary or extramedullary fixation is the primary treatment for subtrochanteric femur fractures in adults remains debatable. Level of evidence Meta-analyses of prospective studies, level I. Materials and methods The Cochrane library, Embase, Google Scholar, and PubMed databases were searched separately for all relevant studies published before January 1, 2015. No language restriction was applied. Prospective randomized controlled trials that compared intramedullary or extramedullary internal fixation to repair subtrochanteric femur fractures in adults were included. We determined intraoperative data, postoperative complications, fracture fixation complications, wound infection, hospital stay days, and final outcome measures to assess the relative effects of different internal fixation methods for the treatment of subtrochanteric femur fractures in adults. Results Six studies were included in our meta-analysis. The relative risks (RRs) of revision rate was 83% lower (RR, 0.17, 95% confidence interval [CI], 0.05 to 0.60; P=0.006), fixation failure rate was 64% lower (RR, 0.36, 95% CI, 0.12 to 1.08; P=0.07), non-union rate was 77% lower (RR, 0.23, 95% CI, 0.07 to 0.81; P=0.02) in the intramedullary group compared with the extramedullary group. No significant differences were found between the intramedullary group and extramedullary group for intraoperative data, postoperative complications, wound infection, hospital stay days or final outcome measures. Conclusion In conclusion, our meta-analysis suggests that there was no significant difference in intraoperative data, postoperative complications, wound infection, hospital stay days or final outcome measures between intramedullary and extramedullary internal fixation. However, a significant decrease occurred in the rate of fracture fixation complications for patients

  14. Biomechanical analysis and clinical effects of bridge combined fixation system for femoral fractures.

    PubMed

    Wang, Da-xing; Xiong, Ying; Deng, Hong; Jia, Fu; Gu, Shao; Liu, Bai-lian; Li, Qun-hui; Pu, Qi; Zhang, Zhong-Zi

    2014-09-01

    This work aimed to compare the stress distribution and mechanical properties of our bridge combined fixation system and commonly used metal locking plate screw system by finite element analysis and by using the Zwick/Z100 testing machine. In addition, we also investigated the clinical outcome of our bridge combined fixation system for femoral fractures in 59 patients from June 2005 to January 2013. As a result, the stress distribution in the bone plate and screws of metal locking plate screw system during walking and climbing stairs was significantly lower than that of metal locking plate screw system. No significant difference in the displacement was observed between two systems. The equivalent bending stiffness of bridge combined fixation system was significantly lower than that of metal locking plate screw system. There were no significant differences in the bending strength, yield load, and maximum force between two systems. All the cases were followed up for 12-24 months (average 18 months). The X-ray showed bone callus was formed in most patients after 3 months, and the fracture line was faint and disappeared at 6-9 months postoperatively. No serious complications, such as implant breakage and wound infection, occurred postoperatively. According to self-developed standard for bone healing, clinical outcomes were rated as excellent or good in 55 out of 59 patients (success rate: 93.2%). Therefore, our findings suggest that our bridge combined fixation system may be a promising approach for treatment of long-bone fractures.

  15. PHILOS humerus plate for a distal tibial fracture.

    PubMed

    Twaij, Haider; Damany, Dev

    2013-01-04

    This report discusses the use of an alternative implant in the emergency fixation of a distal tibial fracture. We planned to fix the shear-type medial malleolar fracture in a closed, tri-malleolar fracture with a locking distal tibial plate. Intra-operatively, it was noted that the required plate was unavailable. A PHILOS humeral plate seemed to fit the contours of the distal tibia. The broad end of the PHILOS, when placed distally, gave options to place locking screws in the medial malleolar fragment. The fracture was stable after fixation. The patient made a full post-operative recovery and follow-up at 4 months was satisfactory. Despite adequate planning, there will be instances where one has to improvise. An understanding of the principles of fracture management can aid in finding solutions. PHILOS humeral plate may be used to stabilize a distal tibial fracture if an appropriate distal tibial locking plate is not available.

  16. [Intra-articular fracture of the distal radius: results following osteosynthesis with a support plate].

    PubMed

    Ferguson, G A; Leutenegger, A; Mark, G; Breiter, H; Rüedi, T

    1989-01-01

    The treatment of comminuted intra-articular fractures of the distal radius often requires an operative fixation. Beside the recently recommended external fixator, the support plate fixation offers a helpful alternative to treatment. Between 1980 and 1986, 30 wrists in 29 patients with intra-articular fractures of the distal radius were stabilized with a buttress plate an the Kantonsspital Chur, Switzerland. The mean follow-up-time was 15 months. These follow-ups showed that the buttress plate in treatment of complicated intra-articular fractures allows a satisfactory reduction and stabilization with restoration of the articular congruity and the possibility for early active assisted motion. Buttress plate fixation still remains a demanding technique, which in complicated cases, should be reserved for the experienced surgeon. PMID:2500786

  17. Fixation orientation in ankle fractures with syndesmosis injury.

    PubMed

    Nimick, Craig J; Collman, David R; Lagaay, Pieter

    2013-01-01

    Accurate reduction of the syndesmosis has been shown to be an important prognostic factor for functional outcome in ankle injuries that disrupt the syndesmosis. The purpose of the present case series was to assess the fixation orientation and the position of the fibula within the tibial incisura after open reduction and internal fixation of ankle fractures with syndesmosis injury. Computed tomography was used to assess the accuracy of the reduction. Twelve patients were included in the present case series. A ratio representing the relationship between the tibia and fibula and the orientation of the syndesmotic fixation was measured preoperatively and postoperatively and compared with the uninjured contralateral ankle, representing the patient's normal anatomy. The measurements were accomplished electronically to one tenth of 1 mm using Stentor Intelligent Informatics, I-site, version 3.3.1 (Phillips Electronics; Andover, MA). Posteriorly oriented syndesmotic fixation caused posterior translation of the fibula with respect to the tibia and anteriorly oriented syndesmotic fixation caused anterior translation. PMID:23540759

  18. Functional and Radiological Outcome of Schatzker type V and VI Tibial Plateau Fracture Treatment with Dual Plates with Minimum 3 years follow-up: A Prospective Study

    PubMed Central

    Suri, Harpreet Singh; Gangrade, Kewal

    2016-01-01

    Introduction High energy intra-articular fractures involving the tibial plateau causes various problems related to management like wound dehiscence, severe comminution leading to malalignment and delayed complications like varus collapse, implant failure and arthritis of knee joint. Aim This study was done to determine functional, radiological outcome and the complications of Schatzker V and VI tibial plateau fractures treated with bipillar plating with dual plates with a regular follow-up of atleast 3 years. Materials and Methods Total 34 cases of tibial plateau fracture type V and VI treated with dual plating were studied from January 2011 to December 2013 in KIMS Hospital were followed for minimum of 3 years. The patients were operated through an anterolateral approach for lateral plate and a medial column plate was put through a minimally invasive medial approach or an open posteromedial approach. Results Total 34 patients were evaluated postoperatively thoroughly for functional outcome using The Knee Society Score and radiological outcomes by Modified Rasmussen Assessment criteria which showed 29 patients (85.29%) had excellent and 5 patients (14.71%) had good objective knee society score. 24 patients (70.59%) had excellent, 8 patients (23.53%) had good and 1patient (2.94%) were each of poor and fair functional knee society score. Eleven patients (32.35%) had excellent, 21patients (61.76%) had good and 2 patients (5.88%) had fair radiological outcome. Conclusion We conclude that open reduction and internal fixation of high-energy tibial plateau fractures with dual plates via 2 incisions gives excellent to good functional outcome with minimal soft tissue complications. Thus, a minimally invasive approach should be used which helps in preventing soft tissue problems and helps in early wound healing. Fixation done by bipillar plating is important for early mobilization of knee joint. Early mobilization leads to better range of movements and thereby better

  19. Distal femoral derotational osteotomy with external fixation for correction of excessive femoral anteversion in patients with cerebral palsy.

    PubMed

    Skiak, Eyad; Karakasli, Ahmet; Basci, Onur; Satoglu, Ismail S; Ertem, Fatih; Havitcioglu, Hasan

    2015-09-01

    Patients with cerebral palsy (CP) disorder often develop rotational hip deformity. Increasing deformities impair already diminished walking abilities; femoral osteotomies are often performed to maintain and improve walking abilities. Fixation of osteotomies with condylar plates has been used successfully, but does not often enable immediate postoperative full weight-bearing. To avoid considerable postoperative rehabilitation deficit and additional bone loss because of inactivity, a postoperative treatment with full weight-bearing, is therefore, desirable. Self-tapping Schanz screws with a unilateral external fixator crossing the knee joint providing stronger anchoring in osteopenic bone might fulfill these demands. A retrospective study was carried out on 27 ambulatory CP patients, mean age 17.5 years (range 9-22 years); 11 patients with bilateral severe intoeing deformities underwent a supracondylar femoral osteotomy between September 2008 and April 2012. All patients were allowed to bear their full weight postoperatively. The aim of this study was to describe the technique, the results of this technique, to evaluate the time required for bone healing, and the type of complications associated with a distal derotational femoral osteotomy fixed with a uniaxial external fixator crossing the knee joint. A total of 27 patients were studied [mean weight 48.8 kg (range 29.8-75 kg)]. The mean preoperative rotation included internal rotation of 69° and external rotation of 17°. All patients were evaluated clinically and radiographically for a minimum of 1 year after surgery. There was a significant decrease in the mean medial rotation from 69° to 32° (P=0.00034). The lateral rotation increased significantly from preoperative 17° to postoperative 45° (P=0.0011). The femoral anteversion decreased significantly from a mean of 55° preoperatively to a mean 17° postoperatively (P=0.030). All patients, except one, achieved solid fusion uneventfully. One patient was a

  20. Intraocular lens fixation with dacron.

    PubMed

    Peyman, G A; Koziol, J E

    1978-10-01

    To overcome the problem of postoperative lens dislocation, we evaluated a new means of lens fixation. Our experimental studies in rabbits and primates demonstrated that Dacron polyethylene terephtalate induced a cellular reaction from either the anterior or posterior iris surface when placed in contact with the iris, thereby establishing a bond between the Dacron fibers and the iris. Dacron mesh can be attached to the distal portion of either the anterior or posterior loops of a Binkhorst iris clip (4-loop) lens. In the rabbit eye, lens fixation occurred within five days; in the primate eye, 30 days. When combined with silk, Dacron produced tissue ingrowth in the primate eye within 14 days. No unwanted reaction occurred in any animal with the Dacron and silk combination. Being biodegradable, the silk induced faster cellular ingrowth than the Dacron. However, Dacron, which is not biodegradable, provided a permanent means of fixation. PMID:155053

  1. Plate on plate osteosynthesis for the treatment of nonhealed periplate fractures.

    PubMed

    Arealis, Georgios; Nikolaou, Vassilios S; Lacon, Andrew; Ashwood, Neil; Hamlet, Mark

    2014-01-01

    Purpose. The purpose of this paper is to present our technique for the treatment of periplate fractures. Methods. From 2009 to 2012 we treated three patients. In all cases the existing plate was left and the new one placed over the existing. Locking screws were placed through both plates. The other screws in the new plate were used as best suited the fracture. Results. In all cases less than 6 months had passed between fractures. None of the original fractures had healed. Mean followup was 2 years. All fractures proceeded to union within 7 months. No complications were recorded. All the patients returned to their normal activities and were satisfied with the results of their treatment. Conclusion. Our plate on plate technique is effective for the treatment of periplate fractures. A solid fusion can be achieved at the new fracture site without disturbing the previous fixation.

  2. Plate on Plate Osteosynthesis for the Treatment of Nonhealed Periplate Fractures

    PubMed Central

    Nikolaou, Vassilios S.; Lacon, Andrew; Ashwood, Neil; Hamlet, Mark

    2014-01-01

    Purpose. The purpose of this paper is to present our technique for the treatment of periplate fractures. Methods. From 2009 to 2012 we treated three patients. In all cases the existing plate was left and the new one placed over the existing. Locking screws were placed through both plates. The other screws in the new plate were used as best suited the fracture. Results. In all cases less than 6 months had passed between fractures. None of the original fractures had healed. Mean followup was 2 years. All fractures proceeded to union within 7 months. No complications were recorded. All the patients returned to their normal activities and were satisfied with the results of their treatment. Conclusion. Our plate on plate technique is effective for the treatment of periplate fractures. A solid fusion can be achieved at the new fracture site without disturbing the previous fixation. PMID:24967127

  3. Mechanical properties of Indonesian-made narrow dynamic compression plate.

    PubMed

    Dewo, P; van der Houwen, E B; Sharma, P K; Magetsari, R; Bor, T C; Vargas-Llona, L D; van Horn, J R; Busscher, H J; Verkerke, G J

    2012-09-01

    Osteosynthesis plates are clinically used to fixate and position a fractured bone. They should have the ability to withstand cyclic loads produced by muscle contractions and total body weight. The very high demand for osteosynthesis plates in developing countries in general and in Indonesia in particular necessitates the utilisation of local products. In this paper, we investigated the mechanical properties, i.e. proportional limit and fatigue strength of Indonesian-made Narrow Dynamic Compression Plates (Narrow DCP) as one of the most frequently used osteosynthesis plates, in comparison to the European AO standard plate, and its relationship to geometry, micro structural features and surface defects of the plates. All Indonesian-made plates appeared to be weaker than the standard Narrow DCP because they consistently failed at lower stresses. Surface defects did not play a major role in this, although the polishing of the Indonesian Narrow DCP was found to be poor. The standard plate showed indications of cold deformation from the production process in contrast to the Indonesian plates, which might be the first reason for the differences in strength. This is confirmed by hardness measurements. A second reason could be the use of an inferior version of stainless steel. The Indonesian plates showed lower mechanical behaviour compared to the AO-plates. These findings could initiate the development of improved Indonesian manufactured DCP-plates with properties comparable to commonly used plates, such as the standard European AO-plates.

  4. The Ankle Injury Management (AIM) trial: a pragmatic, multicentre, equivalence randomised controlled trial and economic evaluation comparing close contact casting with open surgical reduction and internal fixation in the treatment of unstable ankle fractures in patients aged over 60 years.

    PubMed Central

    Keene, David J; Mistry, Dipesh; Nam, Julian; Tutton, Elizabeth; Handley, Robert; Morgan, Lesley; Roberts, Emma; Gray, Bridget; Briggs, Andrew; Lall, Ranjit; Chesser, Tim Js; Pallister, Ian; Lamb, Sarah E; Willett, Keith

    2016-01-01

    BACKGROUND Close contact casting (CCC) may offer an alternative to open reduction and internal fixation (ORIF) surgery for unstable ankle fractures in older adults. OBJECTIVES We aimed to (1) determine if CCC for unstable ankle fractures in adults aged over 60 years resulted in equivalent clinical outcome compared with ORIF, (2) estimate cost-effectiveness to the NHS and society and (3) explore participant experiences. DESIGN A pragmatic, multicentre, equivalence randomised controlled trial incorporating health economic evaluation and qualitative study. SETTING Trauma and orthopaedic departments of 24 NHS hospitals. PARTICIPANTS Adults aged over 60 years with unstable ankle fracture. Those with serious limb or concomitant disease or substantial cognitive impairment were excluded. INTERVENTIONS CCC was conducted under anaesthetic in theatre by surgeons who attended training. ORIF was as per local practice. Participants were randomised in 1 : 1 allocation via remote telephone randomisation. Sequence generation was by random block size, with stratification by centre and fracture pattern. MAIN OUTCOME MEASURES Follow-up was conducted at 6 weeks and, by blinded outcome assessors, at 6 months after randomisation. The primary outcome was the Olerud-Molander Ankle Score (OMAS), a patient-reported assessment of ankle function, at 6 months. Secondary outcomes were quality of life (as measured by the European Quality of Life 5-Dimensions, Short Form questionnaire-12 items), pain, ankle range of motion and mobility (as measured by the timed up and go test), patient satisfaction and radiological measures. In accordance with equivalence trial US Food and Drug Administration guidance, primary analysis was per protocol. RESULTS We recruited 620 participants, 95 from the pilot and 525 from the multicentre phase, between June 2010 and November 2013. The majority of participants, 579 out of 620 (93%), received the allocated treatment; 52 out of 275 (19%) who received CCC later

  5. Present-day plate motions

    NASA Technical Reports Server (NTRS)

    Minster, J. B.; Jordan, T. H.

    1977-01-01

    A data set comprising 110 spreading rates, 78 transform fault azimuths and 142 earthquake slip vectors was inverted to yield a new instantaneous plate motion model, designated RM2. The mean averaging interval for the relative motion data was reduced to less than 3 My. A detailed comparison of RM2 with angular velocity vectors which best fit the data along individual plate boundaries indicates that RM2 performs close to optimally in most regions, with several notable exceptions. On the other hand, a previous estimate (RM1) failed to satisfy an extensive set of new data collected in the South Atlantic Ocean. It is shown that RM1 incorrectly predicts the plate kinematics in the South Atlantic because the presently available data are inconsistent with the plate geometry assumed in deriving RM1. It is demonstrated that this inconsistency can be remedied by postulating the existence of internal deformation with the Indian plate, although alternate explanations are possible.

  6. Surgical Treatment of Sternoclavicular Joint Dislocation Using a T-plate

    PubMed Central

    Hwang, Wan Jin; Lee, Yeiwon; Yoon, Yoo Sang; Kim, Young Jin; Ryu, Han Young

    2016-01-01

    A 22-year-old man was hospitalized with a sternoclavicular joint (SCJ) dislocation caused by a traffic accident. Surgical reduction and fixation of the SCJ were performed using a T-plate. SCJ dislocation is rare, accounting for less than 1% of all dislocations, and is usually treated conservatively, although severe cases may require surgery. Surgery typically involves joint reduction and fixation using an autologous tendon graft, but this has disadvantages such as the requirement for additional surgery to obtain autologous tissue and an extended operative time. To overcome these issues, here, we performed a simple SCJ reduction and fixation using a T-plate and achieved good results. PMID:27298805

  7. Missing nitrogen fixation in the Benguela region

    NASA Astrophysics Data System (ADS)

    Wasmund, Norbert; Struck, Ulrich; Hansen, Anja; Flohr, Anita; Nausch, Günther; Grüttmüller, Annett; Voss, Maren

    2015-12-01

    Opposing opinions on the importance of nitrogen fixation in the northern Benguela upwelling region provoked us to investigate the magnitude of nitrogen fixation in front of northern Namibia and southern Angola. Measurements of nitrogen fixation rates using the 15N method at 66 stations during seven cruises from 2008 to 2014 showed that, in general, the 15N content in the biomass did not increase after tracer incubation with 15N2, indicating that no nitrogen fixation occurred. Correspondingly, the filamentous nitrogen-fixing cyanobacterium Trichodesmium was almost not present. The abundant picocyanobacteria did obviously not perform nitrogen fixation to a significant degree. The artificial improvement of conditions for nitrogen fixation in mesocosm experiments, including phosphate and iron additions and a warmer temperature, failed to induce nitrogen fixation. A plausible explanation of these findings is a lack of conditioned cells for nitrogen fixation in the Benguela region.

  8. First metatarsophalangeal joint arthrodesis: current fixation options.

    PubMed

    Moon, Jared L; McGlamry, Michael C

    2011-04-01

    This article reviews the current literature on first metatarsophalangeal joint arthrodesis rates using various forms of fixation, as well as reviewing biomechanical studies comparing the strengths of the different fixation options that are available.

  9. Understanding Nitrogen Fixation

    SciTech Connect

    Paul J. Chirik

    2012-05-25

    synthesis of ammonia, NH{sub 3}, from its elements, H{sub 2} and N{sub 2}, via the venerable Haber-Bosch process is one of the most significant technological achievements of the past century. Our research program seeks to discover new transition metal reagents and catalysts to disrupt the strong N {triple_bond} N bond in N{sub 2} and create new, fundamental chemical linkages for the construction of molecules with application as fuels, fertilizers and fine chemicals. With DOE support, our group has discovered a mild method for ammonia synthesis in solution as well as new methods for the construction of nitrogen-carbon bonds directly from N{sub 2}. Ideally these achievements will evolve into more efficient nitrogen fixation schemes that circumvent the high energy demands of industrial ammonia synthesis. Industrially, atmospheric nitrogen enters the synthetic cycle by the well-established Haber-Bosch process whereby N{sub 2} is hydrogenated to ammonia at high temperature and pressure. The commercialization of this reaction represents one of the greatest technological achievements of the 20th century as Haber-Bosch ammonia is responsible for supporting approximately 50% of the world's population and serves as the source of half of the nitrogen in the human body. The extreme reaction conditions required for an economical process have significant energy consequences, consuming 1% of the world's energy supply mostly in the form of pollution-intensive coal. Moreover, industrial H{sub 2} synthesis via the water gas shift reaction and the steam reforming of methane is fossil fuel intensive and produces CO{sub 2} as a byproduct. New synthetic methods that promote this thermodynamically favored transformation ({Delta}G{sup o} = -4.1 kcal/mol) under milder conditions or completely obviate it are therefore desirable. Most nitrogen-containing organic molecules are derived from ammonia (and hence rely on the Haber-Bosch and H{sub 2} synthesis processes) and direct synthesis from

  10. Options for acetabular fixation surfaces.

    PubMed

    Klika, Alison K; Murray, Trevor G; Darwiche, Hussein; Barsoum, Wael K

    2007-01-01

    Aseptic loosening is the most common cause for revision total hip arthroplasty (THA). Due to poor long-term results with cemented acetabular components, cementless implants that rely on biologic fixation became popular in the United States for both primary and revision procedures in the early 1980s. Cementless acetabular components used in THA have been reported to have superior radiographic performance compared with cemented fixation, although the optimal method of acetabular fixation remains controversial. Cementless acetabular components require initial implant stability to allow for bone ingrowth and remodeling into the acetabular shell, providing long-term durability of the prosthesis. Many improved implant materials are available to facilitate bone growth and remodeling, including the 3 most common surface treatments; fibermesh, sintered beads, and plasma spray coatings. Recently added to these are porous metal surfaces, which have increased porosity and optimal pore sizes when compared with titanium fibermesh. The most studied of these materials is the titanium fibermesh fixation surface, which has demonstrated a mechanical failure rate of 1% at 10 to 15 years. This technology utilizes the diffusion bonding process to attach fiber metal pads to a titanium substrate using heat and pressure. The sintered bead fixation surface offers a porous coating of various sizes of spherical beads, achieved by the sintering process, and has been shown to provide long-term fixation. While there are less long-term published data regarding the titanium plasma spray surface, its early results have provided evidence of its durability, even in the face of significant osteolysis. The most recently added alternative fixation surface is porous tantalum metal, which offers potentially greater bone ingrowth and bone graft incorporation due to its high porosity (80%) and low modulus of elasticity (3 MPa). Porous tantalum implants have shown early favorable clinical results and have

  11. Binocular Fixation Disparity in Single Word Displays

    ERIC Educational Resources Information Center

    Paterson, Kevin B.; Jordan, Timothy R.; Kurtev, Stoyan

    2009-01-01

    It has been claimed that the recognition of words displayed in isolation is affected by the precise location at which they are fixated. However, this putative role for fixation location has yet to be reconciled with the finding from reading research that binocular fixations are often misaligned and, therefore, more than 1 location in a word is…

  12. Nonbridging external fixation of distal radius fractures.

    PubMed

    Eichenbaum, Matthew D; Shin, Eon K

    2010-08-01

    Surgical management of distal radius fractures continues to evolve because of their high incidence in an increasingly active elderly population. Traditional radiocarpal external fixation relies on ligamentotaxis for fracture reduction but has several drawbacks. Nonbridging external fixation has evolved to provide early wrist mobility in the setting of anatomic fracture reduction. Several studies of the nonbridging technique have demonstrated satisfactory results in isolated nonbridging external fixation series and in comparison with traditional spanning external fixation. Nonbridging external fixation for surgical treatment of distal radius fractures can be technically demanding and requires at least 1 cm of intact volar cortex in the distal fracture fragment for successful implementation.

  13. Plate tectonics conserves angular momentum

    NASA Astrophysics Data System (ADS)

    Bowin, C.

    2010-03-01

    A new combined understanding of plate tectonics, Earth internal structure, and the role of impulse in deformation of the Earth's crust is presented. Plate accelerations and decelerations have been revealed by iterative filtering of the quaternion history for the Euler poles that define absolute plate motion history for the past 68 million years, and provide an unprecedented precision for plate angular rotation variations with time at 2-million year intervals. Stage poles represent the angular rotation of a plate's motion between adjacent Euler poles, and from which the maximum velocity vector for a plate can be determined. The consistent maximum velocity variations, in turn, yield consistent estimates of plate accelerations and decelerations. The fact that the Pacific plate was shown to accelerate and decelerate, implied that conservation of plate tectonic angular momentum must be globally conserved, and that is confirmed by the results shown here (total angular momentum ~1.4+27 kg m2 s-1). Accordingly, if a plate decelerates, other plates must increase their angular momentums to compensate. In addition, the azimuth of the maximum velocity vectors yields clues as to why the "bend" in the Emperor-Hawaiian seamount trend occurred near 46 Myr. This report summarizes processing results for 12 of the 14 major tectonic plates of the Earth (except for the Juan de Fuca and Philippine plates). Plate accelerations support the contention that plate tectonics is a product of torques that most likely are sustained by the sinking of positive density anomalies revealed by geoid anomalies of the degree 4-10 packet of the Earth's spherical harmonic coefficients. These linear positive geoid anomalies underlie plate subduction zones and are presumed due to phase changes in subducted gabbroic lithosphere at depth in the upper lower mantle (above 1200 km depth). The tectonic plates are pulled along by the sinking of these positive mass anomalies, rather than moving at near constant

  14. Standards of external fixation in prolonged applications to allow safe conversion to definitive extremity surgery: the Aachen algorithm for acute ex fix conversion.

    PubMed

    Horst, Klemens; Andruszkow, Hagen; Weber, Christian; Dienstknecht, Thomas; Hildebrand, Frank; Tarkin, Ivan; Pape, Hans-Christoph

    2015-09-01

    External fixation has become an important tool in orthopedic surgery. Technology has improved the design and material as well as the construct of the fixator. As most patients are converted from external fixation to definite stabilization during later clinical course, prevention of complications such as infection is of high importance. Based on the current literature, principles of temporary external fixation were summarized. We focused on minimizing the risk of infection and introduce a standardized algorithm how to proceed when converting from external to internal fixation, which also was examined for effectiveness.

  15. Standards of external fixation in prolonged applications to allow safe conversion to definitive extremity surgery: the Aachen algorithm for acute ex fix conversion.

    PubMed

    Horst, Klemens; Andruszkow, Hagen; Weber, Christian; Dienstknecht, Thomas; Hildebrand, Frank; Tarkin, Ivan; Pape, Hans-Christoph

    2015-09-01

    External fixation has become an important tool in orthopedic surgery. Technology has improved the design and material as well as the construct of the fixator. As most patients are converted from external fixation to definite stabilization during later clinical course, prevention of complications such as infection is of high importance. Based on the current literature, principles of temporary external fixation were summarized. We focused on minimizing the risk of infection and introduce a standardized algorithm how to proceed when converting from external to internal fixation, which also was examined for effectiveness. PMID:26458293

  16. Optical microscopy of Arabidopsis seedlings fixed in non-fresh FAA using Kennedy Fixation Tubes.

    PubMed

    Honma, Yoshihiro; Nakabayashi, Izumi; Tamaoki, Daisuke; Kasahara, Haruo; Ishioka, Noriaki; Shimazu, Toru; Kasahara, Hirokazu; Yamada, Mitsuhiro; Karahara, Ichirou; Kamisaka, Seiichiro

    2003-12-01

    Samples will be kept in non-fresh fixative for longer period than usual in Kennedy Space Center Fixation Tubes (KFT) when they will be fixed for microscopy in the International Space Station (ISS). It is necessary to examine characteristics of samples prepared under such conditions and to improve preservation of the samples. In this study, morphology of Arabidopsis tissues prepared under such conditions was examined under a light microscope. Deformation of cell shape was observed in tissues with well-developed intercellular spaces when they were fixed in non-fresh fixative for longer period in KFTs.

  17. Evolution of the Hoffmann Fixators.

    PubMed

    Seligson, David

    2015-09-01

    Dr. Raoul Hoffmann of Geneva, Switzerland with the collaboration of Henri Jaquet developed the original Hoffmann external fixateur as a system for treating broken bones without necessarily opening a fracture site to reposition the bone ends. This system has evolved to a more flexible, modular concept with input from surgeons and engineers. In this chapter the modifications of the Hoffmann family of fixators are traced and the important steps in the development of the concept and the instrumentation emphasized. PMID:26458297

  18. Local versus basin-scale limitation of marine nitrogen fixation.

    PubMed

    Weber, Thomas; Deutsch, Curtis

    2014-06-17

    Nitrogen (N) fixation by diazotrophic plankton is the primary source of this crucial nutrient to the ocean, but the factors limiting its rate and distribution are controversial. According to one view, the ecological niche of diazotrophs is primarily controlled by the ocean through internally generated N deficits that suppress the growth of their competitors. A second view posits an overriding limit from the atmosphere, which restricts diazotrophs to regions where dust deposition satisfies their high iron (Fe) requirement, thus separating N sources from sinks at a global scale. Here we use multiple geochemical signatures of N2 fixation to show that the Fe limitation of diazotrophs is strong enough to modulate the regional distribution of N2 fixation within ocean basins--particularly the Fe-poor Pacific--but not strong enough to influence its partition between basins, which is instead governed by rates of N loss. This scale-dependent limitation of N2 fixation reconciles local observations of Fe stress in diazotroph communities with an inferred spatial coupling of N sources and sinks. Within this regime of intermediate Fe control, the oceanic N reservoir would respond only weakly to enhanced dust fluxes during glacial climates, but strongly to the reduced fluxes hypothesized under anthropogenic climate warming. PMID:24889607

  19. Local versus basin-scale limitation of marine nitrogen fixation.

    PubMed

    Weber, Thomas; Deutsch, Curtis

    2014-06-17

    Nitrogen (N) fixation by diazotrophic plankton is the primary source of this crucial nutrient to the ocean, but the factors limiting its rate and distribution are controversial. According to one view, the ecological niche of diazotrophs is primarily controlled by the ocean through internally generated N deficits that suppress the growth of their competitors. A second view posits an overriding limit from the atmosphere, which restricts diazotrophs to regions where dust deposition satisfies their high iron (Fe) requirement, thus separating N sources from sinks at a global scale. Here we use multiple geochemical signatures of N2 fixation to show that the Fe limitation of diazotrophs is strong enough to modulate the regional distribution of N2 fixation within ocean basins--particularly the Fe-poor Pacific--but not strong enough to influence its partition between basins, which is instead governed by rates of N loss. This scale-dependent limitation of N2 fixation reconciles local observations of Fe stress in diazotroph communities with an inferred spatial coupling of N sources and sinks. Within this regime of intermediate Fe control, the oceanic N reservoir would respond only weakly to enhanced dust fluxes during glacial climates, but strongly to the reduced fluxes hypothesized under anthropogenic climate warming.

  20. Fixation strategies for retinal immunohistochemistry.

    PubMed

    Stradleigh, Tyler W; Ishida, Andrew T

    2015-09-01

    Immunohistochemical and ex vivo anatomical studies have provided many glimpses of the variety, distribution, and signaling components of vertebrate retinal neurons. The beauty of numerous images published to date, and the qualitative and quantitative information they provide, indicate that these approaches are fundamentally useful. However, obtaining these images entailed tissue handling and exposure to chemical solutions that differ from normal extracellular fluid in composition, temperature, and osmolarity. Because the differences are large enough to alter intercellular and intracellular signaling in neurons, and because retinae are susceptible to crush, shear, and fray, it is natural to wonder if immunohistochemical and anatomical methods disturb or damage the cells they are designed to examine. Tissue fixation is typically incorporated to guard against this damage and is therefore critically important to the quality and significance of the harvested data. Here, we describe mechanisms of fixation; advantages and disadvantages of using formaldehyde and glutaraldehyde as fixatives during immunohistochemistry; and modifications of widely used protocols that have recently been found to improve cell shape preservation and immunostaining patterns, especially in proximal retinal neurons. PMID:25892361

  1. Fixation Strategies For Retinal Immunohistochemistry

    PubMed Central

    Stradleigh, Tyler W.; Ishida, Andrew T.

    2015-01-01

    Immunohistochemical and ex vivo anatomical studies have provided many glimpses of the variety, distribution, and signaling components of vertebrate retinal neurons. The beauty of numerous images published to date, and the qualitative and quantitative information they provide, indicate that these approaches are fundamentally useful. However, obtaining these images entailed tissue handling and exposure to chemical solutions that differ from normal extracellular fluid in composition, temperature, and osmolarity. Because the differences are large enough to alter intercellular and intracellular signaling in neurons, and because retinae are susceptible to crush, shear, and fray, it is natural to wonder if immunohistochemical and anatomical methods disturb or damage the cells they are designed to examine. Tissue fixation is typically incorporated to guard against this damage and is therefore critically important to the quality and significance of the harvested data. Here, we describe mechanisms of fixation; advantages and disadvantages of using formaldehyde and glutaraldehyde as fixatives during immunohistochemistry; and modifications of widely used protocols that have recently been found to improve cell shape preservation and immunostaining patterns, especially in proximal retinal neurons. PMID:25892361

  2. The effectiveness of standard povidone iodine surgical preparation in decontaminating external fixator components.

    PubMed

    Hak, David J; Wiater, Patrick J; Williams, Robert M; Pierson, Carl L

    2005-12-01

    The purpose of this study was to evaluate the effectiveness of standard iodine surgical scrubs to remove bacteria from external fixator components. Sterile adjustable external fixation clamps, Schanz pins, and carbon fibre rods were coated with a sterile protein solution and immersed in solution of coagulase negative Staphylococcus (10(3)organisms/ml). They were then decontaminated in standard fashion using a povidone iodine scrub and paint solution. After neutralisation the components were sonicated, serially diluted, plated on blood agar, and incubated for 24h. Unassembled external fixation components were examined individually, and as assembled pin-rod-clamp constructs with and without manipulation of the clamp. Of the three external fixation components (pins, rods, clamps) the highest number of bacterial colony forming units was seen on the external fixation clamps. Manipulation of the assembled construct significantly increased the mean bacterial colony counts compared to the assembled non-manipulated construct (p=0.0007). Standard surgical preparation does not remove all bacteria from external fixators during subsequent operative procedures.

  3. Finite Element Analysis of a New Pedicle Screw-Plate System for Minimally Invasive Transforaminal Lumbar Interbody Fusion

    PubMed Central

    Zhou, Yue; Li, Changqing; Liu, Huan

    2015-01-01

    Purpose Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is increasingly popular for the surgical treatment of degenerative lumbar disc diseases. The constructs intended for segmental stability are varied in MI-TLIF. We adopted finite element (FE) analysis to compare the stability after different construct fixations using interbody cage with posterior pedicle screw-rod or pedicle screw-plate instrumentation system. Methods A L3–S1 FE model was modified to simulate decompression and fusion at L4–L5 segment. Fixation modes included unilateral plate (UP), unilateral rod (UR), bilateral plate (BP), bilateral rod (BR) and UP+UR fixation. The inferior surface of the S1 vertebra remained immobilized throughout the load simulation, and a bending moment of 7.5 Nm with 400N pre-load was applied on the L3 vertebra to recreate flexion, extension, lateral bending, and axial rotation. Range of motion (ROM) and Von Mises stress were evaluated for intact and instrumentation models in all loading planes. Results All reconstructive conditions displayed decreased motion at L4–L5. The pedicle screw-plate system offered equal ROM to pedicle screw-rod system in unilateral or bilateral fixation modes respectively. Pedicle screw stresses for plate system were 2.2 times greater than those for rod system in left lateral bending under unilateral fixation. Stresses for plate were 3.1 times greater than those for rod in right axial rotation under bilateral fixation. Stresses on intervertebral graft for plate system were similar to rod system in unilateral and bilateral fixation modes respectively. Increased ROM and posterior instrumentation stresses were observed in all loading modes with unilateral fixation compared with bilateral fixation in both systems. Conclusions Transforaminal lumbar interbody fusion augmentation with pedicle screw-plate system fixation increases fusion construct stability equally to the pedicle screw-rod system. Increased posterior

  4. Pearls and Pitfalls of the Volar Locking Plating for Distal Radius Fractures.

    PubMed

    Im, Jin-Hyung; Lee, Joo-Yup

    2016-06-01

    Volar locking plate fixation has been widely accepted method for the treatment of unstable distal radius fractures. Although the results of volar locking plate fixation are encouraging, it may cause implant-related complications such as flexor or extensor tendon injuries. In depth understanding of anatomy of the distal radius is mandatory in order to obtain adequate fixation of the fracture fragments and to avoid these complications. This article will review the anatomic characteristics of the distal radius because selecting proper implant and positioning of the plate is closely related to the volar surface anatomy of the distal radius. The number and the length of distal locking screws are also important to provide adequate fixation strength to maintain fracture fixation. We will discuss the pros and cons of the variable-angle locking plate, which was introduced in an effort to provide surgeons with more freedom for fixation. Finally, we will discuss about correcting radial length and volar tilt by using eccentric drill holes and distal locking first technique.

  5. Pearls and Pitfalls of the Volar Locking Plating for Distal Radius Fractures.

    PubMed

    Im, Jin-Hyung; Lee, Joo-Yup

    2016-06-01

    Volar locking plate fixation has been widely accepted method for the treatment of unstable distal radius fractures. Although the results of volar locking plate fixation are encouraging, it may cause implant-related complications such as flexor or extensor tendon injuries. In depth understanding of anatomy of the distal radius is mandatory in order to obtain adequate fixation of the fracture fragments and to avoid these complications. This article will review the anatomic characteristics of the distal radius because selecting proper implant and positioning of the plate is closely related to the volar surface anatomy of the distal radius. The number and the length of distal locking screws are also important to provide adequate fixation strength to maintain fracture fixation. We will discuss the pros and cons of the variable-angle locking plate, which was introduced in an effort to provide surgeons with more freedom for fixation. Finally, we will discuss about correcting radial length and volar tilt by using eccentric drill holes and distal locking first technique. PMID:27454625

  6. Overcoming fixation with repeated memory suppression.

    PubMed

    Angello, Genna; Storm, Benjamin C; Smith, Steven M

    2015-01-01

    Fixation (blocks to memories or ideas) can be alleviated not only by encouraging productive work towards a solution, but, as the present experiments show, by reducing counterproductive work. Two experiments examined relief from fixation in a word-fragment completion task. Blockers, orthographically similar negative primes (e.g., ANALOGY), blocked solutions to word fragments (e.g., A_L_ _GY) in both experiments. After priming, but before the fragment completion test, participants repeatedly suppressed half of the blockers using the Think/No-Think paradigm, which results in memory inhibition. Inhibiting blockers did not alleviate fixation in Experiment 1 when conscious recollection of negative primes was not encouraged on the fragment completion test. In Experiment 2, however, when participants were encouraged to remember negative primes at fragment completion, relief from fixation was observed. Repeated suppression may nullify fixation effects, and promote creative thinking, particularly when fixation is caused by conscious recollection of counterproductive information.

  7. Corrugated cover plate for flat plate collector

    DOEpatents

    Hollands, K. G. Terry; Sibbitt, Bruce

    1978-01-01

    A flat plate radiant energy collector is providing having a transparent cover. The cover has a V-corrugated shape which reduces the amount of energy reflected by the cover away from the flat plate absorber of the collector.

  8. Proposed Use of the Computer as a Tool to Aid Analysis of Properties of Materials in Fixators of Spine

    PubMed Central

    Santos, Antonio; Moreira, Fernando

    2014-01-01

    With objective of analyzing the mechanical behavior of the internal fixators of spine and of the bony structure, the pieces and the group were made (it structures bony x internal fixator) with the aid a software of solid modeling. The materials used in the rehearsals had been the titanium, now in the market and a castor oil polyurethane destined to the development of you implant bony. PMID:24825938

  9. Modeling fixation locations using spatial point processes.

    PubMed

    Barthelmé, Simon; Trukenbrod, Hans; Engbert, Ralf; Wichmann, Felix

    2013-10-01

    Whenever eye movements are measured, a central part of the analysis has to do with where subjects fixate and why they fixated where they fixated. To a first approximation, a set of fixations can be viewed as a set of points in space; this implies that fixations are spatial data and that the analysis of fixation locations can be beneficially thought of as a spatial statistics problem. We argue that thinking of fixation locations as arising from point processes is a very fruitful framework for eye-movement data, helping turn qualitative questions into quantitative ones. We provide a tutorial introduction to some of the main ideas of the field of spatial statistics, focusing especially on spatial Poisson processes. We show how point processes help relate image properties to fixation locations. In particular we show how point processes naturally express the idea that image features' predictability for fixations may vary from one image to another. We review other methods of analysis used in the literature, show how they relate to point process theory, and argue that thinking in terms of point processes substantially extends the range of analyses that can be performed and clarify their interpretation.

  10. Nitrogen fixation method and apparatus

    DOEpatents

    Chen, H.L.

    1983-08-16

    A method and apparatus for achieving nitrogen fixation includes a volumetric electric discharge chamber. The volumetric discharge chamber provides an even distribution of an electron beam, and enables the chamber to be maintained at a controlled energy to pressure (E/p) ratio. An E/p ratio of from 5 to 15 kV/atm of O[sub 2]/cm promotes the formation of vibrationally excited N[sub 2]. Atomic oxygen interacts with vibrationally excited N[sub 2] at a much quicker rate than unexcited N[sub 2], greatly improving the rate at which NO is formed. 1 fig.

  11. Nitrogen fixation method and apparatus

    DOEpatents

    Chen, Hao-Lin

    1983-01-01

    A method and apparatus for achieving nitrogen fixation includes a volumetric electric discharge chamber. The volumetric discharge chamber provides an even distribution of an electron beam, and enables the chamber to be maintained at a controlled energy to pressure (E/p) ratio. An E/p ratio of from 5 to 15 kV/atm of O.sub.2 /cm promotes the formation of vibrationally excited N.sub.2. Atomic oxygen interacts with vibrationally excited N.sub.2 at a much quicker rate than unexcited N.sub.2, greatly improving the rate at which NO is formed.

  12. Cortical bone screw fixation in ionically modified apatite cements.

    PubMed

    Barralet, J E; Duncan, C O; Dover, M S; Bassett, D C; Nishikawa, H; Monaghan, A; Gbureck, U

    2005-05-01

    Hydroxyapatite cements are used in reconstruction of the face; usually in well-defined cavities where the cement can be stabilized without the need for internal fixation. A hydroxyapatite cement that could enable screw fixation and some loading therefore has considerable potential in maxillofacial reconstruction. It has been demonstrated recently that water demand of calcium phosphate cements can be reduced by ionically modifying the liquid component. This study investigated the capacity of an ionically modified precompacted apatite cement to retain self-tapping cortical bone screws. Screw pullout forces were determined in the direction of the screw long axis and perpendicular to it, using cortical bone and polymethylmethacrylate cement as a control. In bending pullout tests, measured forces to remove screws from ionically modified precompacted cement were insignificantly different from cortical bone. However, pullout forces of bone screws from hydroxyapatite cement decreased with aging time in vitro.

  13. Proximal Humerus Fracture Plating Through the Extended Anterolateral Approach.

    PubMed

    Gardner, Michael J

    2016-08-01

    Several approaches to the proximal humerus for fracture fixation are possible. The traditional utilitarian approach to the shoulder, the deltopectoral, has distinct disadvantages when performing fracture reduction and locked plating. The anterolateral acromial approach exploits the intermuscular plane between the anterior and middle heads of the deltoid. After identifying the position of the axillary nerve as it crosses this interval, fracture reduction and fixation is performed. Direct access to both the greater and the lesser tuberosities is facilitated. The cancellous surface of the humeral head fragment provides an excellent surface for direct manipulation without further endangering the extraosseous soft tissue attachments. PMID:27441923

  14. Arthroscopic 4-Point Suture Fixation of Anterior Cruciate Ligament Tibial Avulsion Fractures

    PubMed Central

    Boutsiadis, Achilleas; Karataglis, Dimitrios; Agathangelidis, Filon; Ditsios, Konstantinos; Papadopoulos, Pericles

    2014-01-01

    Tibial eminence avulsion fractures are rare injuries occurring mainly in adolescents and young adults. When necessary, regardless of patient age, anatomic reduction and stable internal fixation are mandatory for fracture healing and accurate restoration of normal knee biomechanics. Various arthroscopically assisted fixation methods with sutures, anchors, wires, or screws have been described but can be technically demanding, thus elongating operative times. The purpose of this article is to present a technical variation of arthroscopic suture fixation of anterior cruciate ligament avulsion fractures. Using thoracic drain needles over 2.4-mm anterior cruciate ligament tibial guidewires, we recommend the safe and easy creation of four 2.9-mm tibial tunnels at different angles and at specific points. This technique uses thoracic drain needles as suture passage cannulas and offers 4-point fixation stability, avoiding potential complications of bony bridge fracture and tunnel connection. PMID:25685674

  15. Acetabular liner fixation by cement.

    PubMed

    Jiranek, William A

    2003-12-01

    Many situations in revision THA require the exchange of a PE liner in the setting of a well-fixed cementless acetabular shell. Unfortunately, a replacement liner is not always available, the locking mechanism of the metal shell may be damaged or incompatible with the desired liner, or the shell is malpositioned. Revision of a well-fixed cementless acetabular shell has been associated with considerable morbidity. This raises several questions: can a new PE liner be fixed in the existing shell using bone cement, and if so, which techniques can improve the end result, and in which patients should they be used? Biomechanical testing of cemented PE liners has shown initial fixation strengths that exceed conventional locking mechanisms. It is not known during what period this initial fixation will fail, but clinical reports with followup of as many as 6 years have shown survival in approximately 90% of cases. These studies have shown the importance of proper patient selection, accurate sizing of the PE liner, careful preparation of the substrate of the liner and the shell, and good cement technique. The potential advantages of this technique are less surgical morbidity, more rapid surgery and patient recovery, the ability to incorporate antibiotics in the cement, and more liner options.

  16. Comparative study of bone repair in mandibular body osteotomy between metallic and absorbable 2.0 mm internal fixation systems. Histological and histometric analysis in dogs: a pilot study.

    PubMed

    Sverzut, C E; Kato, R B; Rosa, A L; Trivellato, A E; Sverzut, A T; da Silveira, K M; de Oliveira, P T

    2012-11-01

    The objective of this study was to compare the bone repair along a mandibular body osteotomy stabilized with 2.0 mm absorbable and metallic systems. 12 male, adult mongrel dogs were divided into two groups (metallic and absorbable) and subjected to unilateral osteotomy between the mandibular third and fourth premolars, which was stabilized by applying two 4-hole plates. At 2 and 18 weeks, three dogs from each group were killed and the osteotomy sites were removed and divided equally into three parts: the upper part was labelled the tension third (TT), the lower part the compression third (CT), and the part between the TT and CT the intermediary third (IT). Regardless of the treatment system, union between the fragments was observed at 18 weeks and the CT showed more advanced stages of bone repair than the TT. Histometric analysis did not reveal any significant differences among the 3 parts or systems in the distance between bone fragments at 2 weeks. Although at 18 weeks the proportions of newly formed bone did not differ among TT, IT and CT, significantly enhanced bone formation was observed in all sections for the metallic group. The patterns of repair were distinct between treatments.

  17. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Fixation device. 886.1290 Section 886.1290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A...

  18. 21 CFR 886.1290 - Fixation device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Fixation device. 886.1290 Section 886.1290 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1290 Fixation device. (a) Identification. A...

  19. Biochemical Approaches to Improved Nitrogen Fixation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improving symbiotic nitrogen fixation by legumes has emerged again as an important topic on the world scene due to the energy crisis and lack of access to nitrogen fertilizer in developing countries. We have taken a biochemical genomics approach to improving symbiotic nitrogen fixation in legumes. L...

  20. Delayed Foreign Body Reaction Caused by Bioabsorbable Plates Used for Maxillofacial Fractures

    PubMed Central

    Jeon, Hong Bae; Gu, Ja Hea; Oh, Sang Ah

    2016-01-01

    Background Bioabsorbable plates and screws are commonly used to reduce maxillofacial bones, particularly in pediatric patients because they degrade completely without complications after bone healing. In this study, we encountered eight cases of a delayed foreign body reaction after surgical fixation with bioabsorbable plates and screws. Methods A total of 234 patients with a maxillofacial fracture underwent surgical treatment from March 2006 to October 2013, in which rigid fixation was achieved with the Inion CPS (Inion, Tampere, Finland) plating system in 173 patients and Rapidsorb (Synthes, West Chester, PA, USA) in 61 patients. Their mean age was 35.2 years (range, 15-84 years). Most patients were stabilized with two- or three-point fixation at the frontozygomatic suture, infraorbital rim, and anterior wall of the maxilla. Results Complications occurred in eight (3.4%) of 234 patients, including palpable, fixed masses in six patients and focal swelling in two patients. The period from surgical fixation to the onset of symptoms was 9-23 months. Six patients with a mass underwent secondary surgery for mass removal. The masses contained fibrous tissue with a yellow, grainy, cloudy fluid and remnants of an incompletely degraded bioabsorbable plate and screws. Their histological findings demonstrated a foreign body reaction. Conclusions Inadequate degradation of bioabsorbable plates caused a delayed inflammatory foreign body reaction requiring secondary surgery. Therefore, it is prudent to consider the possibility of delayed complications when using bioabsorbable plates and surgeons must conduct longer and closer follow-up observations. PMID:26848444

  1. Microsaccades counteract visual fading during fixation.

    PubMed

    Martinez-Conde, Susana; Macknik, Stephen L; Troncoso, Xoana G; Dyar, Thomas A

    2006-01-19

    Our eyes move continually, even while we fixate our gaze on an object. If fixational eye movements are counteracted, our perception of stationary objects fades completely, due to neural adaptation. Some studies have suggested that fixational microsaccades refresh retinal images, thereby preventing adaptation and fading. However, other studies disagree, and so the role of microsaccades remains unclear. Here, we correlate visibility during fixation to the occurrence of microsaccades. We asked subjects to indicate when Troxler fading of a peripheral target occurs, while simultaneously recording their eye movements with high precision. We found that before a fading period, the probability, rate, and magnitude of microsaccades decreased. Before transitions toward visibility, the probability, rate, and magnitude of microsaccades increased. These results reveal a direct link between suppression of microsaccades and fading and suggest a causal relationship between microsaccade production and target visibility during fixation.

  2. A comparison of reversed locking compression-distal femoral plates and blade plates in osteotomies for young adult hip pathology.

    PubMed

    MacLean, Simon B M; Evans, Scott; O'Hara, John N

    2013-01-01

    The aim of this study was to compare fixation of proximal femoral osteotomies using reverse contralateral LCP-Distal Femoral Plates (LCP-DF) with the more traditional blade plate technique. This was a retrospective review over six years of a single surgeon's practice within a tertiary orthopaedic unit. Patient demographics were collected, along with indication for surgery. Radiological outcomes, fixation failures and the need for revision surgery were recorded. Forty-six patients were identified; 23 patients in the LCP-DF plate group (7 females, 16 males. Mean age 18.3 years old) and 23 patients in the blade plate group (6 females, 17 males. Mean age 19.1 years old). The patients' presenting conditions were; 26 Perthes'; eight hip dysplasia; 11 slipped capital femoral epiphysis; one fibrous dysplasia. Osteotomy type included; 13 Double osteotomy, 11 Imhauser; 13 pure valgus; eight valgus + rotation; There was one revision for implant failure in the LCP-DF group. In the blade plate group, there were four implant failures--three requiring revision operations (p = 0.155). In the LCP-DF group the mean neck-shaft angle difference compared to the contralateral side (if normal) or 135 degrees (if abnormal) was 0.58°. In the condylar plate group the mean difference was 4.37°. The use of a contralateral LCP-DF plate in the reverse contralateral position to stabilise proximal femoral osteotomies in our cohort confers advantages over blade plate technology. We have found that the plate is stiffer, is easier to use and provides increased screw placement options over standard proximal femoral locking plates.

  3. Sputtering and ion plating

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The proceedings of a conference on sputtering and ion plating are presented. Subjects discussed are: (1) concepts and applications of ion plating, (2) sputtering for deposition of solid film lubricants, (3) commercial ion plating equipment, (4) industrial potential for ion plating and sputtering, and (5) fundamentals of RF and DC sputtering.

  4. Arthroscopic coracoclavicular ligament reconstruction using biologic and suture fixation.

    PubMed

    Pennington, William T; Hergan, David J; Bartz, Brian A

    2007-07-01

    Presented in this report is a modified arthroscopic approach to acromioclavicular joint reconstruction via suture and allograft fixation. An arthroscopic approach is used to expose the base of the coracoid by use of electrocautery. After an open distal clavicle excision is performed, clavicular and coracoid tunnels are created under arthroscopic visualization as previously described by Wolf and Pennington. The myotendinous end of a semitendinosus allograft is sutured to a Spider plate (Kinetikos Medical, San Diego, CA). The tendinous end of the graft is prepared with a running baseball stitch. A Nitinol wire with a loop end (Arthrex, Naples, FL) is used to pass 2 free FiberTape sutures (Arthrex) and the leading sutures from the tendinous end of the graft through the clavicular and coracoid tunnels, exiting out the anterior portal. One of the FiberTape sutures is retrieved with a grasper and passed over the anterior aspect of the distal clavicle. The second FiberTape suture and the allograft are passed over the distal end of the resected clavicle. While the acromioclavicular joint is held reduced, the FiberTape sutures are tied to the plate and the allograft is tensioned medially until the plate is embedded against the superior surface of the clavicle. The tendinous end of the graft is secured to the superior surface of the clavicle with a Bio-tenodesis screw (Arthrex) medial to the clavicular tunnel.

  5. Reducing Postoperative Fracture Displacement After Locked Plating of Proximal Humerus Fractures: Current Concepts.

    PubMed

    Newman, Jared; Kahn, Mani; Gruson, Konrad I

    2015-07-01

    The incidence of proximal humerus fractures in the elderly has been rising. Concomitantly, operative fixation with use of locking plates has been increasing. Postoperative complications of locking plate fixation, particularly in the setting of osteoporotic bone, include screw penetration of the articular surface, progressive fracture displacement, and avascular necrosis. Intraoperative techniques to enhance the fixation construct and reduce complications include use of rotator cuff sutures, bone void fillers (fibular strut allograft, cancellous allograft, autograft, bone cement), appropriate placement of divergent and shorter locking screws, and medial calcar reduction and support. More recent clinical and biomechanical studies suggest that use of these strategies may reduce complications after locked plating of osteoporotic proximal humerus fractures. Furthermore, a multidisciplinary approach to the evaluation and treatment of osteoporosis may be beneficial in these patients.

  6. Reducing Postoperative Fracture Displacement After Locked Plating of Proximal Humerus Fractures: Current Concepts.

    PubMed

    Newman, Jared; Kahn, Mani; Gruson, Konrad I

    2015-07-01

    The incidence of proximal humerus fractures in the elderly has been rising. Concomitantly, operative fixation with use of locking plates has been increasing. Postoperative complications of locking plate fixation, particularly in the setting of osteoporotic bone, include screw penetration of the articular surface, progressive fracture displacement, and avascular necrosis. Intraoperative techniques to enhance the fixation construct and reduce complications include use of rotator cuff sutures, bone void fillers (fibular strut allograft, cancellous allograft, autograft, bone cement), appropriate placement of divergent and shorter locking screws, and medial calcar reduction and support. More recent clinical and biomechanical studies suggest that use of these strategies may reduce complications after locked plating of osteoporotic proximal humerus fractures. Furthermore, a multidisciplinary approach to the evaluation and treatment of osteoporosis may be beneficial in these patients. PMID:26161759

  7. Complement fixation by rheumatoid factor.

    PubMed Central

    Tanimoto, K; Cooper, N R; Johnson, J S; Vaughan, J H

    1975-01-01

    The capacity for fixation and activation of hemolytic complement by polyclonal IgM rheumatoid factors (RF) isolated from sera of patients with rheumatoid arthritis and monoclonal IgM-RF isolated from the cryoprecipitates of patients with IgM-IgG mixed cryoglobulinemia was examined. RF mixed with aggregated, reduced, and alkylated human IgG (Agg-R/A-IgG) in the fluid phase failed to significantly reduce the level of total hemolytic complement, CH50, or of individual complement components, C1, C2, C3, and C5. However, sheep erythrocytes (SRC) coated with Agg-R/A-IgG or with reduced and alkylated rabbit IgG anti-SRC antibody were hemolyzed by complement in the presence of polyclonal IgM-RF. Human and guinea pig complement worked equally well. The degree of hemolysis was in direct proportion to the hemagglutination titer of the RF against the same coated cells. Monoclonal IgM-RF, normal human IgM, and purified Waldenström macroglobulins without antiglobulin activity were all inert. Hemolysis of coated SRC by RF and complement was inhibited by prior treatment of the complement source with chelating agents, hydrazine, cobra venom factor, specific antisera to C1q, CR, C5, C6, or C8, or by heating at 56 degrees C for 30 min. Purified radiolabeled C4, C3, and C8 included in the complement source were bound to hemolysed SRC in direct proportion to the degree of hemolysis. These data indicate that polyclonal IgM-RF fix and activate complement via the classic pathway. The system described for assessing complement fixation by isolated RF is readily adaptable to use with whole human serum. PMID:1078825

  8. Dinitrogen fixation in aphotic oxygenated marine environments

    PubMed Central

    Rahav, Eyal; Bar-Zeev, Edo; Ohayon, Sarah; Elifantz, Hila; Belkin, Natalia; Herut, Barak; Mulholland, Margaret R.; Berman-Frank, Ilana

    2013-01-01

    We measured N2 fixation rates from oceanic zones that have traditionally been ignored as sources of biological N2 fixation; the aphotic, fully oxygenated, nitrate (NO−3)-rich, waters of the oligotrophic Levantine Basin (LB) and the Gulf of Aqaba (GA). N2 fixation rates measured from pelagic aphotic waters to depths up to 720 m, during the mixed and stratified periods, ranged from 0.01 nmol N L−1 d−1 to 0.38 nmol N L−1 d−1. N2 fixation rates correlated significantly with bacterial productivity and heterotrophic diazotrophs were identified from aphotic as well as photic depths. Dissolved free amino acid amendments to whole water from the GA enhanced bacterial productivity by 2–3.5 fold and N2 fixation rates by ~2-fold in samples collected from aphotic depths while in amendments to water from photic depths bacterial productivity increased 2–6 fold while N2 fixation rates increased by a factor of 2 to 4 illustrating that both BP and heterotrophic N2 fixation were carbon limited. Experimental manipulations of aphotic waters from the LB demonstrated a significant positive correlation between transparent exopolymeric particle (TEP) concentrations and N2 fixation rates. This suggests that sinking organic material and high carbon (C): nitrogen (N) micro-environments (such as TEP-based aggregates or marine snow) could support high heterotrophic N2 fixation rates in oxygenated surface waters and in the aphotic zones. Indeed, our calculations show that aphotic N2 fixation accounted for 37 to 75% of the total daily integrated N2 fixation rates at both locations in the Mediterranean and Red Seas with rates equal or greater to those measured from the photic layers. Moreover, our results indicate that that while N2 fixation may be limited in the surface waters, aphotic, pelagic N2 fixation may contribute significantly to new N inputs in other oligotrophic basins, yet it is currently not included in regional or global N budgets. PMID:23986748

  9. Osteoporotic hip fractures: the burden of fixation failure.

    PubMed

    Broderick, J M; Bruce-Brand, R; Stanley, E; Mulhall, K J

    2013-01-01

    Osteoporotic hip fractures are a major cause of morbidity and mortality in the elderly. Furthermore, reduced implant anchorage in osteoporotic bone predisposes towards fixation failure and with an ageing population, even low failure rates represent a significant challenge to healthcare systems. Fixation failure in fragility fractures of the hip ranges from 5% in peritrochanteric fractures through to 15% and 41% in undisplaced and displaced fractures of the femoral neck, respectively. Our findings, in general, support the view that failed internal fixation of these fragility fractures carries a poor prognosis: it leads to a twofold increase in the length of hospital stay and a doubling of healthcare costs. Patients are more likely to suffer a downgrade in their residential status upon discharge with a consequent increase in social dependency. Furthermore, the marked disability and reduction in quality of life evident before salvage procedures may persist at long-term followup. The risk, of course, for the elderly patient with a prolonged period of decreased functioning is that the disability becomes permanent. Despite this, however, no clear link between revision surgery and an increase in mortality has been demonstrated in the literature.

  10. Bioabsorbable plates and screws in pediatric craniofacial surgery: a review of 22 cases.

    PubMed

    Kumar, A V; Staffenberg, D A; Petronio, J A; Wood, R J

    1997-03-01

    The purpose of this study was to evaluate the application of bioabsorbable fixation devices in reconstructive craniofacial procedures in the pediatric population. We reviewed 22 cases in which bioabsorbable plates and screws were used in craniofacial surgery for reconstruction. The procedures were performed in a 7-month period. The patients ranged in age from 5 to 228 months at the time of surgery (mean, 76.7 months). The postoperative clinical follow-up ranged from 2 to 16 weeks. The fixation devices were evaluated with regards to satisfactory fixation at the time of procedure. The postoperative follow-up evaluated clinical wound healing, signs of infection or local inflammation, and visibility or palpability of plates through the skin. All patients except one showed satisfactory wound healing with no sign of infection or local inflammation. The plates provided satisfactory fixation and were not visible through the skin. Two patients had plates that were palpable at the 4-month follow-up period. One patient with repair of a blow-out fracture of the orbit with resorbable mesh had redness and swelling over the wound site 2 weeks postoperatively with resolution 4 weeks postoperatively. Our early experience suggests reabsorbable fixation is an attractive option in pediatric plastic and craniofacial surgery. With further experience, this technology may represent the standard of care in reconstruction of the infant calvarium. PMID:10332274

  11. Treatment of posterior cruciate ligament avulsion fractures of the tibia using a toothed plate and hollow lag screw

    PubMed Central

    Chen, Wei; Luo, Wei; Chen, Zhiqing; Jiang, Yi

    2016-01-01

    INTRODUCTION To investigate the feasibility and clinical efficacy of using a toothed plate and hollow lag screw in the surgical treatment of posterior cruciate ligament (PCL) avulsion fractures of the tibia. METHODS A total of 21 patients were treated with open reduction and internal fixation using a toothed plate and hollow lag screw, through a posteromedial approach using an inverted L-shaped incision. The patients were allowed appropriate functional exercises, including knee flexion and extension, after removal of the plaster at postoperative weeks 3–6. The follow-up period was between six months and two years. RESULTS This was a retrospective study of patients with PCL avulsion fractures of the tibia caused by road traffic accidents (n = 9), sports-related injuries (n = 6), falls (n = 5) and machinery-related injuries (n = 1). 20 patients presented with fresh fractures and one with an old fracture. The patients (13 men, eight women) had a mean age of 41.5 (range 19–72) years. Anatomical reduction of the fracture and satisfactory fixation were achieved in all 21 patients. Bony union was achieved in all patients at 8–12 weeks after surgery. Six months after surgery, knee flexion was 121.9° ± 10.4° and extension was 0°. According to the Lysholm Knee Scoring Scale, 19 patients were rated as ‘excellent’ and two as ‘good’. CONCLUSION The use of a toothed plate and hollow lag screw could be a simple and reliable approach for PCL avulsion fractures of the tibia. Patients achieved good knee function after surgery. PMID:26831316

  12. Relationship Between Final Performance and Block Times with the Traditional and the New Starting Platforms with A Back Plate in International Swimming Championship 50-M and 100-M Freestyle Events

    PubMed Central

    Garcia-Hermoso, Antonio; Escalante, Yolanda; Arellano, Raul; Navarro, Fernando; Domínguez, Ana M.; Saavedra, Jose M.

    2013-01-01

    The purpose of this study was to investigate the association between block time and final performance for each sex in 50-m and 100-m individual freestyle, distinguishing between classification (1st to 3rd, 4th to 8th, 9th to 16th) and type of starting platform (old and new) in international competitions. Twenty-six international competitions covering a 13-year period (2000-2012) were analysed retrospectively. The data corresponded to a total of 1657 swimmers’ competition histories. A two-way ANOVA (sex x classification) was performed for each event and starting platform with the Bonferroni post-hoc test, and another two-way ANOVA for sex and starting platform (sex x starting platform). Pearson’s simple correlation coefficient was used to determine correlations between the block time and the final performance. Finally, a simple linear regression analysis was done between the final time and the block time for each sex and platform. The men had shorter starting block times than the women in both events and from both platforms. For 50-m event, medalists had shorter block times than semi- finalists with the old starting platforms. Block times were directly related to performance with the old starting platforms. With the new starting platforms, however, the relationship was inverse, notably in the women’s 50-m event. The block time was related for final performance in the men’s 50- m event with the old starting platform, but with the new platform it was critical only for the women’s 50-m event. Key Points The men had shorter block times than the women in both events and with both platforms. For both distances, the swimmers had shorter block times in their starts from the new starting platform with a back plate than with the old platform. For the 50-m event with the old starting platform, the medalists had shorter block times than the semi-finalists. The new starting platform block time was only determinant in the women’s 50-m event. In order to improve

  13. Salient in space, salient in time: Fixation probability predicts fixation duration during natural scene viewing.

    PubMed

    Einhäuser, Wolfgang; Nuthmann, Antje

    2016-09-01

    During natural scene viewing, humans typically attend and fixate selected locations for about 200-400 ms. Two variables characterize such "overt" attention: the probability of a location being fixated, and the fixation's duration. Both variables have been widely researched, but little is known about their relation. We use a two-step approach to investigate the relation between fixation probability and duration. In the first step, we use a large corpus of fixation data. We demonstrate that fixation probability (empirical salience) predicts fixation duration across different observers and tasks. Linear mixed-effects modeling shows that this relation is explained neither by joint dependencies on simple image features (luminance, contrast, edge density) nor by spatial biases (central bias). In the second step, we experimentally manipulate some of these features. We find that fixation probability from the corpus data still predicts fixation duration for this new set of experimental data. This holds even if stimuli are deprived of low-level images features, as long as higher level scene structure remains intact. Together, this shows a robust relation between fixation duration and probability, which does not depend on simple image features. Moreover, the study exemplifies the combination of empirical research on a large corpus of data with targeted experimental manipulations. PMID:27627736

  14. "False" migration of rigid fixation appliances in pediatric craniofacial surgery.

    PubMed

    Papay, F A; Hardy, S; Morales, L; Walker, M; Enlow, D

    1995-07-01

    Osseous fixation techniques have been widely used to provide rigid stabilization in the craniofacial skeleton. Reported sequelae of its usage has been limited to palpation of the screw-plate system and radiological imaging artifacts. Over the past 3 years we have identified miniplates, microplates, and wire sutures on the inner cranial table of the growing child. The observation of "false" migration of these appliances has provided the impetus to review these patients in more detail. Twenty patients underwent secondary cranial remodeling within a two-year period; 7 of these patients were seen to have "false" migration. There were no untoward sequelae in removal of these appliances, and no adverse neurological symptoms were seen.

  15. Immaturity of Visual Fixations in Dyslexic Children.

    PubMed

    Tiadi, Aimé; Gérard, Christophe-Loïc; Peyre, Hugo; Bui-Quoc, Emmanuel; Bucci, Maria Pia

    2016-01-01

    To our knowledge, behavioral studies recording visual fixations abilities in dyslexic children are scarce. The object of this article is to explore further the visual fixation ability in dyslexics compared to chronological age-matched and reading age-matched non-dyslexic children. Fifty-five dyslexic children from 7 to 14 years old, 55 chronological age-matched non-dyslexic children and 55 reading age-matched non-dyslexic children participated to this study. Eye movements from both eyes were recorded horizontally and vertically by a video-oculography system (EyeBrain(®) T2). The fixation task consisted in fixating a white-filled circle appearing in the center of the screen for 30 s. Results showed that dyslexic children produced a significantly higher number of unwanted saccades than both groups of non-dyslexic children. Moreover, the number of unwanted saccades significantly decreased with age in both groups of non-dyslexic children, but not in dyslexics. Furthermore, dyslexics made more saccades during the last 15 s of fixation period with respect to both groups of non-dyslexic children. Such poor visual fixation capability in dyslexic children could be due to impaired attention abilities, as well as to an immaturity of the cortical areas controlling the fixation system.

  16. Immaturity of Visual Fixations in Dyslexic Children

    PubMed Central

    Tiadi, Aimé; Gérard, Christophe-Loïc; Peyre, Hugo; Bui-Quoc, Emmanuel; Bucci, Maria Pia

    2016-01-01

    To our knowledge, behavioral studies recording visual fixations abilities in dyslexic children are scarce. The object of this article is to explore further the visual fixation ability in dyslexics compared to chronological age-matched and reading age-matched non-dyslexic children. Fifty-five dyslexic children from 7 to 14 years old, 55 chronological age-matched non-dyslexic children and 55 reading age-matched non-dyslexic children participated to this study. Eye movements from both eyes were recorded horizontally and vertically by a video-oculography system (EyeBrain® T2). The fixation task consisted in fixating a white-filled circle appearing in the center of the screen for 30 s. Results showed that dyslexic children produced a significantly higher number of unwanted saccades than both groups of non-dyslexic children. Moreover, the number of unwanted saccades significantly decreased with age in both groups of non-dyslexic children, but not in dyslexics. Furthermore, dyslexics made more saccades during the last 15 s of fixation period with respect to both groups of non-dyslexic children. Such poor visual fixation capability in dyslexic children could be due to impaired attention abilities, as well as to an immaturity of the cortical areas controlling the fixation system. PMID:26924975

  17. A simple method of intramedullary fixation for proximal interphalangeal arthrodesis.

    PubMed

    Canales, Michael B; Razzante, Mark C; Ehredt, Duane J; Clougherty, Coleman O

    2014-01-01

    Lesser digital arthrodesis has become one of the most widely used techniques in foot and ankle surgery. When performing digital arthrodesis, surgeons have an abundance of options for implantable devices. We provide information on a simple method of achieving successful arthrodesis. An intramedullary Kirschner wire is implanted into the proximal phalanx with the intermediate phalanx compressed over the wire for rigid internal fixation to avoid the use of an external device. We have had results similar to those from the published data of more expensive implants. PMID:24846156

  18. A simple method of intramedullary fixation for proximal interphalangeal arthrodesis.

    PubMed

    Canales, Michael B; Razzante, Mark C; Ehredt, Duane J; Clougherty, Coleman O

    2014-01-01

    Lesser digital arthrodesis has become one of the most widely used techniques in foot and ankle surgery. When performing digital arthrodesis, surgeons have an abundance of options for implantable devices. We provide information on a simple method of achieving successful arthrodesis. An intramedullary Kirschner wire is implanted into the proximal phalanx with the intermediate phalanx compressed over the wire for rigid internal fixation to avoid the use of an external device. We have had results similar to those from the published data of more expensive implants.

  19. Fixational eye movements in amblyopia and strabismus.

    PubMed

    Ciuffreda, K J; Kenyon, R V; Stark, L

    1979-11-01

    Horizontal eye position was monitored using a photoelectric method during monocular and binocular fixation in four patients having amblyopia without strabismus, thirteen patients having constant strabismus with amblyopia, and five patients having intermittent strabismus. Four abnormalities of fixation were found: increased drift, saccadic intrusions, manifest nystagmus, and latent nystagmus. Increased drift was related to the presence of amblyopia, while saccadic intrusions and nystagmus were related to the presence of strabismus. Understanding dynamic aspects of oculomotor control can provide insight into clinical assessment of fixation in amblyopia and strabismus.

  20. [The Taylor spatial frame fixator. Soft-tissue distraction for post-traumatic varus deformities of the hindfoot].

    PubMed

    Gessmann, J; Seybold, D; Baecker, H; Muhr, G; Graf, M

    2009-02-01

    Despite adequate primary treatment many ankle fractures result in post-traumatic deformities and arthrosis. Revision mostly requires a multidirectional correction whereas internal fixation procedures are often not applicable due to soft tissue damage and the extent of deformity. The Taylor spatial frame enables simultaneous correction of multidirectional deformities through a virtual hinge using the same ideas of distraction osteogenesis as the Ilizarov fixator. The presented case demonstrates minimally invasive correction of a complex deformity of the ankle with the Taylor spatial frame fixator. Orthogonal alignment was achieved and a stabilizing tibiotalar arthrodesis was performed achieving a good functional and pain-free result.

  1. An arbitrarily shaped inclusion with uniform eigencurvatures in an infinite plate, semi-infinite plate, two bonded semi-infinite plates or a circular plate

    NASA Astrophysics Data System (ADS)

    Wang, Xu; Zhou, Kun

    2015-04-01

    Within the framework of the Kirchhoff-Love isotropic and homogeneous plate theory, we obtain, in a unified manner, the analytic solutions to the Eshelby's problem of an inclusion of arbitrary shape with uniform eigencurvatures in an infinite plate, a semi-infinite plate, one of two bonded semi-infinite plates or a circular plate by means of conformal mapping and analytical continuation. The edge of the semi-infinite plate can be rigidly clamped, free or simply supported, while that of the circular plate can be rigidly clamped, free or perfectly bonded to the surrounding infinite plate. Several examples of practical and theoretical interests are presented to demonstrate the general method. In particular, the elementary expressions of the internal elastic fields of bending moments and deflections within an ( n + 1)-fold rotational symmetric inclusion described by a five-term mapping function, a symmetric airfoil cusp inclusion, a symmetric lip cusp inclusion and an inclusion described by a rational mapping function in an infinite plate are derived.

  2. Neural correlates of fixation duration in natural reading: Evidence from fixation-related fMRI.

    PubMed

    Henderson, John M; Choi, Wonil; Luke, Steven G; Desai, Rutvik H

    2015-10-01

    A key assumption of current theories of natural reading is that fixation duration reflects underlying attentional, language, and cognitive processes associated with text comprehension. The neurocognitive correlates of this relationship are currently unknown. To investigate this relationship, we compared neural activation associated with fixation duration in passage reading and a pseudo-reading control condition. The results showed that fixation duration was associated with activation in oculomotor and language areas during text reading. Fixation duration during pseudo-reading, on the other hand, showed greater involvement of frontal control regions, suggesting flexibility and task dependency of the eye movement network. Consistent with current models, these results provide support for the hypothesis that fixation duration in reading reflects attentional engagement and language processing. The results also demonstrate that fixation-related fMRI provides a method for investigating the neurocognitive bases of natural reading.

  3. Neural correlates of fixation duration in natural reading: Evidence from fixation-related fMRI.

    PubMed

    Henderson, John M; Choi, Wonil; Luke, Steven G; Desai, Rutvik H

    2015-10-01

    A key assumption of current theories of natural reading is that fixation duration reflects underlying attentional, language, and cognitive processes associated with text comprehension. The neurocognitive correlates of this relationship are currently unknown. To investigate this relationship, we compared neural activation associated with fixation duration in passage reading and a pseudo-reading control condition. The results showed that fixation duration was associated with activation in oculomotor and language areas during text reading. Fixation duration during pseudo-reading, on the other hand, showed greater involvement of frontal control regions, suggesting flexibility and task dependency of the eye movement network. Consistent with current models, these results provide support for the hypothesis that fixation duration in reading reflects attentional engagement and language processing. The results also demonstrate that fixation-related fMRI provides a method for investigating the neurocognitive bases of natural reading. PMID:26151101

  4. Ocular Fixation Abnormality in Patients with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Shirama, Aya; Kanai, Chieko; Kato, Nobumasa; Kashino, Makio

    2016-01-01

    We examined the factors that influence ocular fixation control in adults with autism spectrum disorder (ASD) including sensory information, individuals' motor characteristics, and inhibitory control. The ASD group showed difficulty in maintaining fixation especially when there was no fixation target. The fixational eye movement characteristics of…

  5. Protein detection in gels without fixation.

    PubMed

    Joo, Won-A; Speicher, David W

    2007-05-01

    A number of alternative methods are described for detecting proteins in polyacrylamide gels that do not require fixation of the protein either prior to staining or in conjunction with staining. The primary advantage of avoiding fixation is that this makes it easier to remove proteins of interest from the gels for subsequent analysis. In general, the sensitivity of protein detection methods that avoid fixation is lower than for detection methods using fixation. For any given method, sensitivity is dependent on the volume of the protein band within the gel; hence, sensitivity is highest for sharp, narrow bands. Techniques described in this unit include protocols for protein detection in gels by SDS precipitation, preparation of contact blots, staining with imidazole-zinc, and use of the fluorescent labels IAEDANS and fluorescamine. Several additional methods, including the use of tryptophan fluorescence, guide strips, and minimal protein staining, are discussed in the Commentary.

  6. Periprosthetic fracture fixation in osteoporotic bone.

    PubMed

    Lenz, Mark; Lehmann, Wolfgang; Wähnert, Dirk

    2016-06-01

    Fixation techniques of periprosthetic fractures are far from ideal although the number of this entity is rising. The presence of an intramedullary implant generates its own fracture characteristics since stiffness is altered along the bone shaft and certain implant combinations affect load resistance of the bone. Influencing factors are cement fixation of the implant, intramedullary locking and extramedullary or intramedullary localization of the implant and the cortical thickness of the surrounding bone. Cerclage wires are ideally suited to fix radially displaced fragments around an intramedullary implant but they are susceptible to axial and torsional load. Screws should be added if these forces have to be neutralized. Stability of the screw fixation itself can be enhanced by embracement configuration around the intramedullary implant. Poor bone stock quality, often being present in metaphyseal areas limits screw fixation. Cement augmentation is an attractive option in this field to enhance screw purchase. PMID:27338227

  7. Methanotrophy Induces Nitrogen Fixation in Boreal Mosses

    NASA Astrophysics Data System (ADS)

    Tiirola, M. A.

    2014-12-01

    Many methanotrophic bacterial groups fix nitrogen in laboratory conditions. Furthermore, nitrogen (N) is a limiting nutrient in many environments where methane concentrations are highest. Despite these facts, methane-induced N fixation has previously been overlooked, possibly due to methodological problems. To study the possible link between methanotrophy and diazotrophy in terrestrial and aquatic habitats, we measured the co-occurrence of these two processes in boreal forest, peatland and stream mosses using a stable isotope labeling approach (15 N2 and 13 CH4 double labeling) and sequencing of the nifH gene marker. N fixation associated with forest mosses was dependent on the annual N deposition, whereas methane stimulate N fixation neither in high (>3 kg N ha -1 yr -1) nor low deposition areas, which was in accordance with the nifH gene sequencing showing that forest mosses (Pleurozium schreberi and Hylocomium splendens ) carried mainly cyanobacterial N fixers. On the other extreme, in stream mosses (Fontinalis sp.) methane was actively oxidized throughout the year, whereas N fixation showed seasonal fluctuation. The co-occurrence of the two processes in single cell level was proven by co-localizing both N and methane-carbon fixation with the secondary ion mass spectrometry (SIMS) approach. Methanotrophy and diazotrophy was also studied in peatlands of different primary successional stages in the land-uplift coast of Bothnian Bay, in the Siikajoki chronosequence, where N accumulation rates in peat profiles indicate significant N fixation. Based on experimental evidence it was counted that methane-induced N fixation explained over one-third of the new N input in the younger peatland successional stages, where the highest N fixation rates and highest methane oxidation activities co-occurred in the water-submerged Sphagnum moss vegetation. The linkage between methanotrophic carbon cycling and N fixation may therefore constitute an important mechanism in the rapid

  8. Earth's Decelerating Tectonic Plates

    SciTech Connect

    Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

    2008-08-22

    Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

  9. The role of 3D plating system in mandibular fractures: A prospective study

    PubMed Central

    Prasad, Rajendra; Thangavelu, Kavin; John, Reena

    2013-01-01

    Aim: The aim of our study was to evaluate the advantages and disadvantages of 3D plating system in the treatment of mandibular fractures. Patients and Methods: 20 mandibular fractures in 18 patients at various anatomic locations and were treated by open reduction and internal fixation using 3D plates. All patients were followed at regular intervals of 4th, 8th and 12th weeks respectively. Patients were assessed post-operatively for lingual splay and occlusal stability. The incidence of neurosensory deficit, infection, masticatory difficulty, non-union, malunion was also assessed. Results: A significant reduction in lingual splay (72.2%) and occlusal stability (72.2%) was seen. The overall complication rate was (16.6%) which included two patients who developed post-operative paresthesia of lip, three patients had infection and two cases of masticatory difficulty which later subsided by higher antibiotics and 4 weeks of MMF. No evidence of non-union, malunion was noted. Conclusion: A single 3D 2 mm miniplate with 2 mm × 8 mm screws is a reliable and an effective treatment modality for mandibular fracture. PMID:23946559

  10. Tips and Tricks in Mallet Fracture Fixation.

    PubMed

    Chin, Yuin Cheng; Foo, Tun-Lin

    2016-10-01

    We describe three steps to aid fracture assessment and fixation in the extensor block pin technique for mallet fractures. The first step is the use of fluoroscopy in the initial assessment to determine indication for fixation. Next is the use of supplementary extension block pin to control larger dorsal fragments. The third technique described details the steps of open reduction of nascently malunited fractures. PMID:27595969

  11. Nitrogen fixation and CO/sub 2/ metabolism: proceedings

    SciTech Connect

    Ludden, P.W.; Burris, J.E.

    1985-01-01

    Photosynthesis and nitrogen fixation are key metabolic processes which lead to the production of reduced carbon and nitrogen compounds. These compounds are essential for the maintenance and continuation of life on earth. In this volume many recent advances in the study of nitrogen fixation and photosynthetic carbon dioxide fixation are presented. The papers were presented in seven sessions. These sessions were the biochemistry of the legume nodule, genetics and molecular biology of nitrogen fixation, enzymes and cofactors involved in inorganic nitrogen reductions, aspects of nitrogen fixation by associations and symbioses, physiology of free-living nitrogen fixers, interactions between carbon metabolism and nitrogen fixation, photorespiration in plants, and photosynthetic carbon fixation. (DT)

  12. Radioscapholunate arthrodesis using low-profile dorsal pi plate.

    PubMed

    Galvis, Elkin J; Kumar, Kannan K; Özyurekoglu, Tuna

    2013-06-01

    Radioscapholunate arthrodesis is a desirable method to treat isolated radiolunate arthritis or ulnar translocation of the carpal bones. An intact midcarpal joint is a prerequisite for functional range of motion. Previously, high rates of nonunion were observed with these procedures, as rigid fixation was difficult to obtain with simple Kirschner wires and screws. A successful outcome depends on bringing the scaphoid, lunate, and the radius to an anatomic alignment, and rigid fixation of the arthrodesis. We describe a technique for the arthrodesis of the radioscapholunate joint from the dorsal side using a low-profile locking Pi plate. We observed the advantages of an easy approach, better visualization of the joint, and easier manipulation of the carpal bones. The Pi plate fits on the scaphoid, lunate, and the radius with minimal adjustment. It is not necessary to remove the Lister's tubercle. Pi plate allows for rigid fixation and compression between the scaphoid, lunate, and the radius by 1 compression and 1 locking screw in scaphoid and lunate, and by 2 eccentric compression screws in the radius. Rectangular retinacular flaps were used under and over the extensor tendons. We performed these arthrodeses in patients with lunate fossa arthritis after a distal radius fracture, and with ulnar translocation of the carpus. We have observed excellent clinical results with about 50% of wrist motion preserved and no cases of nonunion or delayed union.

  13. Surgical Treatment of Unstable Distal Radius Fractures With a Volar Variable-Angle Locking Plate: Clinical and Radiological Outcomes

    PubMed Central

    Khatri, Kavin; Sharma, Vijay; Farooque, Kamran; Tiwari, Vivek

    2016-01-01

    Background Unstable distal end radius fractures are difficult to manage and so various treatment modalities have been described. The use of variable-angle locking plates is promoted for the management of these fractures. Objectives This study aimed to evaluate the functional and radiological outcomes in unstable distal end radius fractures treated with variable-angle locking plates. Patients and Methods We reviewed 23 unstable distal end radius fractures that were treated at our institution with volar variable-angle locking plates. The mean age of the patients was 32.82 ± 11.81 years (range 19 to 62) and the mean duration of follow-up was 11.04 ± 2.47 months (range 6 to 15). All of the patients underwent open reduction and internal fixation with a variable-angle locking plate. Radiological parameters such as radial inclination, length, tilt, and ulnar variance were measured at six weeks and at the final follow-up. The functional evaluation was conducted by measuring the range of motion at the wrist joint as well as the grip strength. Gartland and Werley’s demerit scoring system was used to assess the final outcome. Results There were two cases of superficial infection that responded to oral antibiotics. One patient had developed a hypertrophic scar, while another had carpal tunnel syndrome that was conservatively managed. There was a significant improvement in the functional indices from six weeks to the final follow-up, while the radiological parameters were maintained. According to Gartland and Werley, excellent results were reported in 65.2% cases, while good results were present in 35% cases. Conclusions The use of variable-angle locking plates in treating unstable distal end radius fractures is associated with excellent to good functional outcomes with minimal complications.

  14. Surgical Treatment of Unstable Distal Radius Fractures With a Volar Variable-Angle Locking Plate: Clinical and Radiological Outcomes

    PubMed Central

    Khatri, Kavin; Sharma, Vijay; Farooque, Kamran; Tiwari, Vivek

    2016-01-01

    Background Unstable distal end radius fractures are difficult to manage and so various treatment modalities have been described. The use of variable-angle locking plates is promoted for the management of these fractures. Objectives This study aimed to evaluate the functional and radiological outcomes in unstable distal end radius fractures treated with variable-angle locking plates. Patients and Methods We reviewed 23 unstable distal end radius fractures that were treated at our institution with volar variable-angle locking plates. The mean age of the patients was 32.82 ± 11.81 years (range 19 to 62) and the mean duration of follow-up was 11.04 ± 2.47 months (range 6 to 15). All of the patients underwent open reduction and internal fixation with a variable-angle locking plate. Radiological parameters such as radial inclination, length, tilt, and ulnar variance were measured at six weeks and at the final follow-up. The functional evaluation was conducted by measuring the range of motion at the wrist joint as well as the grip strength. Gartland and Werley’s demerit scoring system was used to assess the final outcome. Results There were two cases of superficial infection that responded to oral antibiotics. One patient had developed a hypertrophic scar, while another had carpal tunnel syndrome that was conservatively managed. There was a significant improvement in the functional indices from six weeks to the final follow-up, while the radiological parameters were maintained. According to Gartland and Werley, excellent results were reported in 65.2% cases, while good results were present in 35% cases. Conclusions The use of variable-angle locking plates in treating unstable distal end radius fractures is associated with excellent to good functional outcomes with minimal complications. PMID:27679785

  15. ASSEMBLY OF PARALLEL PLATES

    DOEpatents

    Groh, E.F.; Lennox, D.H.

    1963-04-23

    This invention is concerned with a rigid assembly of parallel plates in which keyways are stamped out along the edges of the plates and a self-retaining key is inserted into aligned keyways. Spacers having similar keyways are included between adjacent plates. The entire assembly is locked into a rigid structure by fastening only the outermost plates to the ends of the keys. (AEC)

  16. Accelerated plate tectonics.

    PubMed

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence.

  17. Variable Nitrogen Fixation in Wild Populus

    PubMed Central

    Doty, Sharon L.; Sher, Andrew W.; Fleck, Neil D.; Khorasani, Mahsa; Bumgarner, Roger E.; Khan, Zareen; Ko, Andrew W. K.; Kim, Soo-Hyung; DeLuca, Thomas H.

    2016-01-01

    The microbiome of plants is diverse, and like that of animals, is important for overall health and nutrient acquisition. In legumes and actinorhizal plants, a portion of essential nitrogen (N) is obtained through symbiosis with nodule-inhabiting, N2-fixing microorganisms. However, a variety of non-nodulating plant species can also thrive in natural, low-N settings. Some of these species may rely on endophytes, microorganisms that live within plants, to fix N2 gas into usable forms. Here we report the first direct evidence of N2 fixation in the early successional wild tree, Populus trichocarpa, a non-leguminous tree, from its native riparian habitat. In order to measure N2 fixation, surface-sterilized cuttings of wild poplar were assayed using both 15N2 incorporation and the commonly used acetylene reduction assay. The 15N label was incorporated at high levels in a subset of cuttings, suggesting a high level of N-fixation. Similarly, acetylene was reduced to ethylene in some samples. The microbiota of the cuttings was highly variable, both in numbers of cultured bacteria and in genetic diversity. Our results indicated that associative N2-fixation occurred within wild poplar and that a non-uniformity in the distribution of endophytic bacteria may explain the variability in N-fixation activity. These results point to the need for molecular studies to decipher the required microbial consortia and conditions for effective endophytic N2-fixation in trees. PMID:27196608

  18. Variable Nitrogen Fixation in Wild Populus.

    PubMed

    Doty, Sharon L; Sher, Andrew W; Fleck, Neil D; Khorasani, Mahsa; Bumgarner, Roger E; Khan, Zareen; Ko, Andrew W K; Kim, Soo-Hyung; DeLuca, Thomas H

    2016-01-01

    The microbiome of plants is diverse, and like that of animals, is important for overall health and nutrient acquisition. In legumes and actinorhizal plants, a portion of essential nitrogen (N) is obtained through symbiosis with nodule-inhabiting, N2-fixing microorganisms. However, a variety of non-nodulating plant species can also thrive in natural, low-N settings. Some of these species may rely on endophytes, microorganisms that live within plants, to fix N2 gas into usable forms. Here we report the first direct evidence of N2 fixation in the early successional wild tree, Populus trichocarpa, a non-leguminous tree, from its native riparian habitat. In order to measure N2 fixation, surface-sterilized cuttings of wild poplar were assayed using both 15N2 incorporation and the commonly used acetylene reduction assay. The 15N label was incorporated at high levels in a subset of cuttings, suggesting a high level of N-fixation. Similarly, acetylene was reduced to ethylene in some samples. The microbiota of the cuttings was highly variable, both in numbers of cultured bacteria and in genetic diversity. Our results indicated that associative N2-fixation occurred within wild poplar and that a non-uniformity in the distribution of endophytic bacteria may explain the variability in N-fixation activity. These results point to the need for molecular studies to decipher the required microbial consortia and conditions for effective endophytic N2-fixation in trees. PMID:27196608

  19. Variable Nitrogen Fixation in Wild Populus.

    PubMed

    Doty, Sharon L; Sher, Andrew W; Fleck, Neil D; Khorasani, Mahsa; Bumgarner, Roger E; Khan, Zareen; Ko, Andrew W K; Kim, Soo-Hyung; DeLuca, Thomas H

    2016-01-01

    The microbiome of plants is diverse, and like that of animals, is important for overall health and nutrient acquisition. In legumes and actinorhizal plants, a portion of essential nitrogen (N) is obtained through symbiosis with nodule-inhabiting, N2-fixing microorganisms. However, a variety of non-nodulating plant species can also thrive in natural, low-N settings. Some of these species may rely on endophytes, microorganisms that live within plants, to fix N2 gas into usable forms. Here we report the first direct evidence of N2 fixation in the early successional wild tree, Populus trichocarpa, a non-leguminous tree, from its native riparian habitat. In order to measure N2 fixation, surface-sterilized cuttings of wild poplar were assayed using both 15N2 incorporation and the commonly used acetylene reduction assay. The 15N label was incorporated at high levels in a subset of cuttings, suggesting a high level of N-fixation. Similarly, acetylene was reduced to ethylene in some samples. The microbiota of the cuttings was highly variable, both in numbers of cultured bacteria and in genetic diversity. Our results indicated that associative N2-fixation occurred within wild poplar and that a non-uniformity in the distribution of endophytic bacteria may explain the variability in N-fixation activity. These results point to the need for molecular studies to decipher the required microbial consortia and conditions for effective endophytic N2-fixation in trees.

  20. Maxwellian Eye Fixation during Natural Scene Perception

    PubMed Central

    Duchesne, Jean; Bouvier, Vincent; Guillemé, Julien; Coubard, Olivier A.

    2012-01-01

    When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF) of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell's law for each participant and for each scene condition (normal or scrambled). The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes. PMID:23226987

  1. Maxwellian eye fixation during natural scene perception.

    PubMed

    Duchesne, Jean; Bouvier, Vincent; Guillemé, Julien; Coubard, Olivier A

    2012-01-01

    When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF) of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell's law for each participant and for each scene condition (normal or scrambled). The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes. PMID:23226987

  2. Rotatable shear plate interferometer

    DOEpatents

    Duffus, Richard C.

    1988-01-01

    A rotatable shear plate interferometer comprises a transparent shear plate mounted obliquely in a tubular supporting member at 45.degree. with respect to its horizontal center axis. This tubular supporting member is supported rotatably around its center axis and a collimated laser beam is made incident on the shear plate along this center axis such that defocus in different directions can be easily measured.

  3. Plating Tank Control Software

    1998-03-01

    The Plating Tank Control Software is a graphical user interface that controls and records plating process conditions for plating in high aspect ratio channels that require use of low current and long times. The software is written for a Pentium II PC with an 8 channel data acquisition card, and the necessary shunt resistors for measuring currents in the millampere range.

  4. Screen test for cadmium and nickel plates

    NASA Technical Reports Server (NTRS)

    Phan, Angie H.; Zimmerman, Albert H.

    1994-01-01

    A new procedure is described which was recently developed to quantify loading uniformity of nickel and cadmium plates and to screen finished electrodes prior to cell assembly. The technique utilizes the initial solubility rates of the active material in a standard chemical deloading solution at fixed conditions. The method can provide a reproducible indication of plate loading uniformity in situations where high surface loading limits the free flow of deloading solution into the internal porosity of the sinter plate. A preliminary study indicates that 'good' cell performance is associated with higher deloading rates.

  5. Internal combustion engine noise reduction plate

    SciTech Connect

    Ballheimer, B.; Stratton, M.K.

    1988-09-20

    This patent describes a cylinder block having a pair of elongate, spaced apart sidewalls each defining an outer mounting surface along a lower edge thereof, crankshaft mounting means integral with the block in elevationally upwardly spaced relation to the outer mounting surface and including removable bearing caps the sidewalls further defining inner mounting surfaces elevationally spaced below the bearing caps; a crankshaft rotatable mounted in the crankshaft mounting means and retained therein by the bearing caps; an oil pan sealingly and removable connected to the outer mounting surfaces of the sidewalls; and rigidifying means removable connected to the inner mounting surface. The rigidifying means structurally interconnecting the pair of sidewalls and being free of connection with the bearing caps.

  6. An improved plating process

    NASA Technical Reports Server (NTRS)

    Askew, John C.

    1994-01-01

    An alternative to the immersion process for the electrodeposition of chromium from aqueous solutions on the inside diameter (ID) of long tubes is described. The Vessel Plating Process eliminates the need for deep processing tanks, large volumes of solutions, and associated safety and environmental concerns. Vessel Plating allows the process to be monitored and controlled by computer thus increasing reliability, flexibility and quality. Elimination of the trivalent chromium accumulation normally associated with ID plating is intrinsic to the Vessel Plating Process. The construction and operation of a prototype Vessel Plating Facility with emphasis on materials of construction, engineered and operational safety and a unique system for rinse water recovery are described.

  7. Angular shear plate

    SciTech Connect

    Ruda, Mitchell C.; Greynolds, Alan W.; Stuhlinger, Tilman W.

    2009-07-14

    One or more disc-shaped angular shear plates each include a region thereon having a thickness that varies with a nonlinear function. For the case of two such shear plates, they are positioned in a facing relationship and rotated relative to each other. Light passing through the variable thickness regions in the angular plates is refracted. By properly timing the relative rotation of the plates and by the use of an appropriate polynomial function for the thickness of the shear plate, light passing therethrough can be focused at variable positions.

  8. Superfund record of decision (EPA Region 1): New Hampshire Plating Company, Merrimack, NH, September 28, 1998

    SciTech Connect

    1999-03-01

    This decision document presents the selected remedial action for the New Hampshire Plating Company Superfund Site (Site) located in Merrimack, New Hampshire. This ROD sets forth the selected remedy for the New Hampshire Plating Company Site, which involves in-place treatment of metal-contaminated soil by chemical fixation, natural attenuation of contaminated groundwater in the overburden aquifers, and institutional controls to allow for acceptable re-development and prevent future ingestion of contaminated groundwater.

  9. [Results of treating forearm bone shaft fractures with a 3.5 mm self compressive plate].

    PubMed

    Małecki, P; Kaleta, M; Tokarowski, A; Kusz, D; Wójcik, B

    1997-01-01

    Results of 29 forearm bones shaft fracture treatment with 3.5mm self compressive plate in 26 patients aged 18-64 (mean 33) are presented. Open reduction with 3.5mm self compressive plate fixation has been performed in all cases. Anderson et al criteria were used to assess functional and radiological outcome. Excellent and good functional results were achieved in 25 cases, one was rated fair, no poor results were observed. PMID:9490253

  10. Anatomic Anterolateral Ligament Reconstruction of the Knee Leads to Overconstraint at any Fixation Angle

    PubMed Central

    Schon, Jason; Brady, Alex; Moatshe, Gilbert; Cruz, Raphael; Chahla, Jorge; Dornan, Grant; Turnbull, Travis L.; Engebretsen, Lars

    2016-01-01

    Objectives: Anterior cruciate ligament (ACL) tears are one of the most common injuries among athletes. However, the ability to fully restore rotational stability with ACL reconstruction (ACLR) remains a challenge because up to 25% of patients may present with a residual pivot shift following surgery. Advocacy for reconstruction of the anterolateral ligament (ALL) is rapidly increasing because biomechanical studies have reported that the ALL is a significant contributor to internal rotational stability of the knee. Although several graft fixation angles for the anatomic ALL reconstruction (ALLR) have been reported in literature, none have been biomechanically validated. Therefore, the purpose of this study was to assess the effect of ALLR graft fixation angle on knee joint kinematics in the clinically relevant setting of a concomitant ACLR. The goal was to find the optimal knee flexion angle for fixation of the ALLR graft that would most accurately restore native knee kinematics without introducing overconstraint to the knee. It was hypothesized that all fixation angles would significantly reduce rotational laxity compared to the sectioned ALL state and that fixation at 30° would best reproduce native joint kinematics. Methods: Eight non-paired fresh-frozen human cadaveric knees with no prior injury, surgical history, or gross anatomic abnormality were evaluated with a 6 degree-of-freedom robotic system. Each specimen underwent a full kinematic assessment in each of the following states: 1) intact, 2) anatomic single-bundle (SB) ACLR with intact ALL, 3) anatomic SB ACLR with sectioned ALL, 4) 7 anatomic SB ACLR and ALLR states utilizing ALL graft fixation knee flexion angles of 0°, 15°, 30°, 45°, 60°, 75° and 90°, and 5) sectioned ACL and ALL. Internal rotation during a 5 N-m internal rotation torque and anterior displacement during an 88 N anterior load were recorded at 15° intervals between 0° and 120° of knee flexion. Axial plane displacement and

  11. Multicolor printing plate joining

    NASA Technical Reports Server (NTRS)

    Waters, W. J. (Inventor)

    1984-01-01

    An upper plate having ink flow channels and a lower plate having a multicolored pattern are joined. The joining is accomplished without clogging any ink flow paths. A pattern having different colored parts and apertures is formed in a lower plate. Ink flow channels each having respective ink input ports are formed in an upper plate. The ink flow channels are coated with solder mask and the bottom of the upper plate is then coated with solder. The upper and lower plates are pressed together at from 2 to 5 psi and heated to a temperature of from 295 F to 750 F or enough to melt the solder. After the plates have cooled and the pressure is released, the solder mask is removed from the interior passageways by means of a liquid solvent.

  12. Geologically current plate motions

    NASA Astrophysics Data System (ADS)

    DeMets, Charles; Gordon, Richard G.; Argus, Donald F.

    2010-04-01

    We describe best-fitting angular velocities and MORVEL, a new closure-enforced set of angular velocities for the geologically current motions of 25 tectonic plates that collectively occupy 97 per cent of Earth's surface. Seafloor spreading rates and fault azimuths are used to determine the motions of 19 plates bordered by mid-ocean ridges, including all the major plates. Six smaller plates with little or no connection to the mid-ocean ridges are linked to MORVEL with GPS station velocities and azimuthal data. By design, almost no kinematic information is exchanged between the geologically determined and geodetically constrained subsets of the global circuit-MORVEL thus averages motion over geological intervals for all the major plates. Plate geometry changes relative to NUVEL-1A include the incorporation of Nubia, Lwandle and Somalia plates for the former Africa plate, Capricorn, Australia and Macquarie plates for the former Australia plate, and Sur and South America plates for the former South America plate. MORVEL also includes Amur, Philippine Sea, Sundaland and Yangtze plates, making it more useful than NUVEL-1A for studies of deformation in Asia and the western Pacific. Seafloor spreading rates are estimated over the past 0.78 Myr for intermediate and fast spreading centres and since 3.16 Ma for slow and ultraslow spreading centres. Rates are adjusted downward by 0.6-2.6mmyr-1 to compensate for the several kilometre width of magnetic reversal zones. Nearly all the NUVEL-1A angular velocities differ significantly from the MORVEL angular velocities. The many new data, revised plate geometries, and correction for outward displacement thus significantly modify our knowledge of geologically current plate motions. MORVEL indicates significantly slower 0.78-Myr-average motion across the Nazca-Antarctic and Nazca-Pacific boundaries than does NUVEL-1A, consistent with a progressive slowdown in the eastward component of Nazca plate motion since 3.16 Ma. It also

  13. Interrami intraoral fixation technique for severe mandibular rifle fragmented bullet injury management.

    PubMed

    Shuker, Sabri T

    2013-07-01

    Interrami intraoral Kirschner wire fixation technique is presented for the reduction, stabilization, and immobilization of a pulverized and avulsed lower jaw caused by rifle fragmented bullet injuries. This indirect mandibular war injury fixation technique was tolerated by the patients and tissue more than any indirect external fixation. In addition, it is easier than open reduction using large bone plates for disrupted ballistics mandibular injury defects. An interrami intraoral fixation is appropriate for severely disrupted mandibular hard and soft tissues, and has been adapted in cases of mass casualties and limited resources. Benefits of use include limited hospital beds and fewer follow-up visits. Rifle fragmented bullet injuries need more attention for several reasons: not only because of the higher mortality and devastating nature of the injuries, but also because these injuries are responsible for an unreported type of bullet biomechanism wounding in the craniofacial region. In turn, this necessitates specialized victim management. The survival rates depend on immediate proper execution of airway, breathing, and circulation, which become more complicated as it relates to airway compromise and oropharyngeal hemorrhage resuscitation. Survival is predicated on the implementation of feasible, sensible, life-saving techniques that are applied at the appropriate time.

  14. Design Fixation in the Wild: Design Environments and Their Influence on Fixation

    ERIC Educational Resources Information Center

    Youmans, Robert J.

    2011-01-01

    Many studies of design fixation ask designers to work in controlled laboratory or classroom environments, but innovative design work frequently occurs in dynamic, social environments. The two studies reviewed in this paper investigated how three independent variables likely to be present in many design environments affect design fixation. The…

  15. Fixation location effects on fixation durations during reading: an inverted optimal viewing position effect.

    PubMed

    Vitu, F; McConkie, G W; Kerr, P; O'Regan, J K

    2001-01-01

    Previous research has found that words are identified most quickly when the eyes are near their center (the Optimal Viewing Position effect). A study was conducted to determine whether this same phenomenon is observed during reading, as revealed by a relationship between fixation position in a word and the duration of the fixation. An analysis of three large existing corpora of eye movement data, two from adults and one from children, showed a surprising inverted Optimal Viewing Position curve: mean fixation duration is greatest, rather than lowest, when the eyes were at the centers of words. From this phenomenon, we suggest an alternative explanation to the fixation duration trade-off effect in word refixations [O'Regan & Lévy-Schoen, Attention and performance XII: the psychology of reading (1987)]; the phenomenon also contradicts expectations of both oculomotor and cognitive theories of eye movement control. Attempts to test alternative explanations led to the discovery of another phenomenon, the Saccade Distance effect: mean fixation durations vary with the distance of the prior fixation from the currently-fixated word, being longer with greater distances. The durations of fixations in reading are complexly determined, with influences both from language and perceptual/oculomotor levels.

  16. The Elastic Internal Traction (EIT): an effective method to reduce the displaced facial fractures.

    PubMed

    Taglialatela Scafati, C; Facciuto, E; Aliberti, F

    2004-10-01

    Open reduction and rigid fixation are commonly used to treat displaced fractures of the facial skeleton. Manual reduction can be performed by means of forceps or transosseus wires to close the bone fragments. In order to reduce facial fractures, we used a technique, called Elastic Internal Traction (EIT), based on the elastic action of rubber bands stretched between screws placed on both sides of the fracture line. We have used EIT in 104 patients suffering from mandibular fractures, and 40 cases of patients with orbito-maxillary complex fractures out of the 707 patients treated for trauma between July 2000 and August 2002 at our hospital. In our opinion, this technique provides an effective reduction and a stable primary fixation of the bone before the final fixation. It also has the advantage that the surgical field is clear of the assistant's hands and surgical instruments that are usually used to lock the reduction. The resulting operative time is shortened, and the plating of the bone is simplified.

  17. Autologous grafts of double-strut fibular cortical bone plate to treat the fractures and defects of distal femur: a case report and review of literature.

    PubMed

    Chen, Xu; Li, Jian-Jun; Kong, Zhan; Yang, Dong-Xiang; Yuan, Xiang-Nan

    2011-01-01

    We reported a 23-year-old man who was involved in a high-speed motorcycle accident. He sustained a closed fracture at the right distal femur. The primary fracture happened on February 2008. He underwent open reduction and internal fixation with cloverleaf plate. And one hundred days after the surgery, the proximal screws were pulled-out, but the bone union was not achieved. Treatment consisted of exchanging the cloverleaf plate with a locking compression plate and using an auto-iliac bone graft to fill the nonunion gap. In July 2009, the patient had a sharp pain in the right lower limb. The X-ray revealed that the plate implanted last year was broken, causing a nonunion at the fracture site. Immediately the plate and screws were removed and an intramedullary nail was inserted reversely from the distal femur as well as a 7 cm long bone from the right fibula was extracted and longitudinally split into two pieces to construct cortical bone plates. Then we placed them laterally and medially to fracture site, drilled two holes respectively, and fastened them with suture. We carried on auto-iliac bone grafting with the nonunion bone grafts. The follow-up at 15 months after operation showed that the treatment was successful, X-ray confirmed that there was no rotation and no angular or short deformity. We briefly reviewed the literature regarding such an unusual presentation and discussed in details the possible etiology and the advantages of autologous double-strut fibular grafts to cope with such an intractable situation.

  18. Image-guided percutaneous internal fixation of sacral fracture.

    PubMed

    Kinon, Merritt D; Desai, Rupen; Loriaux, Daniel; Houten, John K

    2016-01-01

    Percutaneous iliosacral screw placement is a technically challenging procedure with a significant complication profile for misplaced screws. The use of stereotactic image guidance has been shown to provide superior accuracy in the placement of spinal instrumentation. Here, the authors describe a novel application of O-arm technology (Medtronic Sofamor Danek, Memphis, TN, USA) to help safely place iliosacral screws for the treatment of a traumatic sacral fracture.

  19. Image-guided percutaneous internal fixation of sacral fracture.

    PubMed

    Kinon, Merritt D; Desai, Rupen; Loriaux, Daniel; Houten, John K

    2016-01-01

    Percutaneous iliosacral screw placement is a technically challenging procedure with a significant complication profile for misplaced screws. The use of stereotactic image guidance has been shown to provide superior accuracy in the placement of spinal instrumentation. Here, the authors describe a novel application of O-arm technology (Medtronic Sofamor Danek, Memphis, TN, USA) to help safely place iliosacral screws for the treatment of a traumatic sacral fracture. PMID:26433323

  20. Posterior Fixation Techniques in the Subaxial Cervical Spine

    PubMed Central

    Ghori, Ahmer; Makanji, Heeren; Cha, Thomas

    2015-01-01

    This article reviews the historical context, indications, techniques, and complications of four posterior fixation techniques to stabilize the subaxial cervical spine. Specifically, posterior wiring, laminar screw fixation, lateral mass fixation, and pedicle screw fixation are among the common methods of operative fixation of the subaxial cervical spine. While wiring and laminar screw fixation are now rarely used, both lateral mass and pedicle screw fixation are technically challenging and present the risk of significant complications if performed incorrectly. With a sound understanding of anatomy and rigorous preoperative evaluation of bony structures, both lateral mass and pedicle screw fixation provide a safe and reliable method for subaxial cervical spine fixation. PMID:26594602

  1. Clinical Effect of Acute Complete Acromioclavicular Joint Dislocation Treated with Micro-Movable and Anatomical Acromioclavicular Plate

    PubMed Central

    Liu, Qingjun; Miao, Jianyun; Lin, Bin; Guo, Zhimin

    2012-01-01

    Objectives: We evaluated the long-term clinical results of acute complete acromioclavicular dislocations treated with micro-movable and anatomical acromioclavicular plate. Methods: Open reduction and internal fixation was performed using the MAAP in 16 patients (10 males, 6 females; mean age 36 years; range16 to 63 years) with acute complete acromioclavicular joint dislocation. Radiographic evaluations were routinely conducted every 3 weeks until 3 months postoperatively. The MAAP were removed under local anesthesia after 3 months postoperatively. We evaluated the functional results by using the constant scoring system and radiological results in the last follow-up time. The mean follow up was 26 months (range 16 to 38 months). Results: The mean Constant score was 94 (range, 78 to 100). The results were excellent in 12 patients (75.0%), good in 3 patients (18.8%) and satisfactory in 1patient (6.2%). Three patients with scores of 80 to 90 had mild pain during activity, but have not affected the shoulder range of motion. One patient has both some pain and limited range of motion of shoulder joint. All patients but one have returned to their preoperative work without any limitations. Compared to the contralateral side, radiography showed anatomical reposition in the vertical plane in 14 cases, slight loss of reduction in 2 older patients. Conclusion: We recommend the MAAP fixation for surgical treatment of acute complete acromioclavicular joint dislocation as it could provide satisfactory shoulder functions and clinical results, with lower complication rate. However, it is necessary to continue to observe the clinical effects of this fixation technique. PMID:23091410

  2. Updated Outcomes of Prophylactic Femoral Fixation.

    PubMed

    Kreul, Sarah M; Sorger, Joel I; Rajamanickam, Victoria P; Heiner, John P

    2016-01-01

    Despite an increasing number of patients with metastatic bone disease (MBD), minimal data exist regarding outcomes of patients undergoing prophylactic femoral fixation for MBD when compared with other frequently performed orthopedic operations, such as hemiarthroplasty of the femur. The authors performed a retrospective database review evaluating these procedures due to similar operative times and patient populations and also reviewed common comorbidities such as body mass index (BMI). The goal was to provide updated results of prophylactic femoral fixation and evaluate whether certain patient risk factors (eg, BMI) altered 30-day survival for patients with MBD. The authors reviewed 1849 patients with and without MBD treated by prophylactic fixation and hemiarthroplasty from 2006 to 2011 identified in the American College of Surgeons National Surgical Quality Improvement Program database. There were no significant differences in complications between patients undergoing surgical treatment for impending or actual femoral fracture. In addition, there were no differences between the 217 patients with MBD in either the hemiarthroplasty or prophylactic fixation groups because the rate of death within 30 days postoperatively was 5.56% and 3.30%, respectively (P=.526). When comparing BMI, obese patients had higher rates of wound infection, and underweight patients were more likely to develop pneumonia or die within 30 days postoperatively. Patients with impending femur fractures benefit from prophylactic fixation and perform as well in the short term as patients undergoing hemiarthroplasty. Certain BMI categories (underweight or obese) contributed to poorer outcomes. These findings provide updated information for discussing risks and benefits with surgical candidates.

  3. High-impact poly(L/D-lactide) for fracture fixation: in vitro degradation and animal pilot study.

    PubMed

    Tams, J; Joziasse, C A; Bos, R R; Rozema, F R; Grijpma, D W; Pennings, A J

    1995-12-01

    The impact strength of amorphous lactide copolymers can be significantly improved by blending with biodegradable rubbers. Rubber toughening of amorphous poly(85L/15D -lactide) with the copolymer poly (50/50-trimethylenecarbonate-co-epsilon-caprolactone) results in a high-impact polymer (PDLLA/P(TMC-CL)). In vitro, the PDLLA/P(TMC-CL) blend retained its tensile and impact strength for a long period of time. Up to 45 weeks, the amount of water absorbed by the blend remained very low and no significant mass loss was observed. To test the suitability for fracture fixation, in a dog study mandibular fractures were fixated with PDLLA/P(TMC-CL) bone plates and screws. Bone healing was uneventful without premature failure of the implants. Although long-term degradation studies have to be carried out, PDLLA/P(TMC-CL) seems to be promising for application in fracture fixation.

  4. A biomechanical comparison of four different fixation methods for midshaft clavicle fractures.

    PubMed

    Chen, Yang; Yang, Yang; Ma, Xinlong; Xu, Weiguo; Ma, Jianxiong; Zhu, Shaowen; Ma, Baoyi; Xing, Dan

    2016-01-01

    Clavicle fractures may occur in all age groups, and 70%-80% of clavicle fractures occur in the midshaft. Many methods for treating midshaft clavicular fractures have been reported and remain controversial. To provide some guidance for clinical treatment, 30 artificial polymethyl methacrylate models of the clavicle were sewn obliquely at the midshaft to simulate the most common type of clavicular fractures, and the fracture models were divided into five groups randomly and were fixed as follows: the reconstruction plates were placed at the superior position of the fracture model (R-S group), the reconstruction plates were placed at the anteroinferior position of the fracture model (R-AI group), the locking plates were placed at the superior position (L-S group), the locking plates were placed at the anteroinferior position (L-AI group); and the control models were unfixed (control group). The strain gauges were attached to the bone surface near the fracture fragments, and then, the biomechanical properties of the specimens were measured using the compression test, torsion test and three-point bending test. The results showed that plate fixation can provide a stable construct to help with fracture healing and is the preferred method in the treatment of clavicle fractures. The locking plate provides the best biomechanical stability when placed at the anteroinferior position, and this surgical method can reduce the operation time and postoperative complications; thus, it would be a better choice in clinical practice.

  5. Distal radius fractures-Design of locking mechanism in plate system and recent surgical procedures.

    PubMed

    Inagaki, Katsunori; Kawasaki, Keikichi

    2016-05-01

    Recently, many studies have emphasized the importance of the comprehension of detailed functional anatomy of the distal forearm and wrist joint, and their biomechanics. A significant contribution which yields good functional outcomes of surgical treatment was the development of the locking plate technology; this technology has facilitated the improvement of the surgical technique for the fixation of fractures. This article reviews the locking mechanism and design of the fixation screws and plate, and the details of the surgical technique including the double-tired subchondral support procedure as it is applied to common fractures. Arthroscopic-assisted surgical procedures can be used to reduce the intra-articular fracture fragments after realignment of the distal radius with the locking plate. This technique is also useful at the time of fixation to assess soft tissue injury. The combination of arthroscopic-assisted reduction and locking plate fixation is now indicated for AO type C2 and C3 intra-articular comminuted fractures. PMID:27006135

  6. Hypervelocity plate acceleration

    SciTech Connect

    Marsh, S.P.; Tan, T.H.

    1991-01-01

    Shock tubes have been used to accelerate 1.5-mm-thick stainless steel plates to high velocity while retaining their integrity. The fast shock tubes are 5.1-cm-diameter, 15.2-cm-long cylinders of PBX-9501 explosive containing a 1.1-cm-diameter cylindrical core of low-density polystyrene foam. The plates have been placed directly in contact with one face of the explosive system. Plane-wave detonation was initiated on the opposite face. A Mach disk was formed in the imploding styrofoam core, which provided the impulse required to accelerate the metal plate to high velocity. Parametric studies were made on this system to find the effect of varying plate metal, plate thickness, foam properties, and addition of a barrel. A maximum plate velocity of 9.0 km/s has been observed. 6 refs., 17 figs.

  7. Determinants of eye-fixation duration.

    PubMed

    Salthouse, T A; Ellis, C L

    1980-06-01

    Four variables that might be presumed to contribute to the duration of an eye fixation were investigated in a series of seven experiments. These variables were stimulus processing time, relative emphasis on speed or accuracy, sequential dependencies across successive fixations, and amplitude of the preceding and following saccades. The pattern of results suggested a two-component model to account for the duration of single eye-fixations. One component is the minimum pause time of the eye, estimated to be about 200 msec without any stimulus processing. The second component involves stimulus processing, estimated to require a minimum of 50 to 100 msec, but subject to a number of influences that can substantially increase or decrease this duration. Although the authors did not generate this model to account for eye movements in complex tasks such as reading, they speculate about how complications could be added.

  8. Control and Functions of Fixational Eye Movements

    PubMed Central

    Rucci, Michele; Poletti, Martina

    2016-01-01

    Humans and other species explore a visual scene by rapidly shifting their gaze 2-3 times every second. Although the eyes may appear immobile in the brief intervals in between saccades, microscopic (fixational) eye movements are always present, even when attending to a single point. These movements occur during the very periods in which visual information is acquired and processed and their functions have long been debated. Recent technical advances in controlling retinal stimulation during normal oculomotor activity have shed new light on the visual contributions of fixational eye movements and their degree of control. The emerging body of evidence, reviewed in this article, indicates that fixational eye movements are important components of the strategy by which the visual system processes fine spatial details, enabling both precise positioning of the stimulus on the retina and encoding of spatial information into the joint space-time domain.

  9. Intermaxillary fixation screws versus Erich arch bars in mandibular fractures: A comparative study and review of literature

    PubMed Central

    Qureshi, Ahtesham Ahmad; Reddy, Umesh K.; Warad, N. M.; Badal, Sheeraz; Jamadar, Amjad Ali; Qurishi, Nilofar

    2016-01-01

    Objective: Various techniques have been employed from time to time to achieve maxillomamdibular fixation. Although arch bars provide an effective and versatile means of maxillomandibular fixation, their use is not without shortcomings. However the introduction of intermaxillary fixation screws (IMF) has eliminated many of these issues of arch bars. The aim of the present study was to compare the advantages and disadvantages of intermaxillary fixation screws over the Erich arch bars in mandibular fractures. Materials and Methods: Sixty dentulous patients who reported to Department of Oral and Maxillofacial Surgery, Al-Ameen Dental College and Hospital, Bijapur with mandibular fractures and required intermaxillary fixation as a part of treatment plan followd by open reduction and internal fixation under GA were selected and randomly divided into 2 groups of 30 patients each that is Group A and Group B. Group A included patients who received intermaxillary fixation with Erich arch bars. Group B includes patients who received intermaxillary fixation with IMF Screws. The parameters compared in both the groups included, surgical time taken, gloves perforation, post-operative occlusion, IMF stability, oral hygiene, patient acceptance and comfort and non-vitality characteristics. Results: The average surgical time taken and gloves perforations were more in Group A,the patient acceptance and oral hygiene was better in Group B, there was not much statistically significant difference in postoperative occlusion and IMF stability in both groups. Accidental root perforation was the only limitation of IMF screws. Conclusion: Intermaxillary fixation with IMF screws is more efficacious compared to Erich arch bars in the treatment of mandibular fractures. PMID:27563602

  10. Plating methods, a survey

    NASA Technical Reports Server (NTRS)

    Berkowitz, J. B.; Emerson, N. H.

    1972-01-01

    Results are presented of a comprehensive search of the literature available, much of which has been generated by the research centers of NASA and its contractors, on plating and coating methods and techniques. Methods covered included: (1) electroplating from aqueous solutions; (2) electroplating from nonaqueous solutions; (3) electroplating from fused-salt baths; (4) electroforming; (5) electroless plating, immersion plating, and mirroring; (6) electroplating from gaseous plasmas; and (7) anodized films and conversion coatings.

  11. GOLD PLATING PROCESS

    DOEpatents

    Seegmiller, R.

    1957-08-01

    An improved bath is reported for plating gold on other metals. The composition of the plating bath is as follows: Gold cyanide from about 15 to about 50 grams, potassium cyanide from about 70 to about 125 grams, and sulfonated castor oil from about 0.1 to about 10 cc. The gold plate produced from this bath is smooth, semi-hard, and nonporous.

  12. Biomechanical optimization of different fixation modes for a proximal femoral L-osteotomy

    PubMed Central

    Tai, Ching-Lung; Chen, Weng-Pin; Chen, Hsih-Hao; Lin, Chien-Yu; Lee, Mel S

    2009-01-01

    Background Numerous proposed surgical techniques have had minimal success in managing greater trochanter overgrowth secondary to retarded growth of the femoral capital epiphysis. For reconstruction of residual hip deformities, a novel type of proximal femur L-osteotomy was performed with satisfactory results. Although the clinical outcome was good, the biomechanical characteristics of the femur after such an osteotomy have not been clearly elucidated. Therefore, this study presents a three dimensional finite element analysis designed to understand the mechanical characteristics of the femur after the L-osteotomy. Methods A patient with left hip dysplasia was recruited as the study model for L-osteotomy. The normal right hip was used as a reference for performing the corrective surgery. Four FEA models were constructed using different numbers of fixation screws but the same osteotomy lengths together with four FEA models with the same number of fixation screws but different osteotomy lengths. The von Mises stress distributions and femoral head displacements were analyzed and compared. Results The results revealed the following: 1). The fixation devices (plate and screws) sustained most of the external loading, and the peak value of von Mises stress on the fixation screws decreased with an increasing number of screws. 2). Additional screws are more beneficial on the proximal segment than on the distal segment for improving the stability of the postoperative femur. 3). The extent of osteotomy should be limited because local stress might be concentrated in the femoral neck region with increasing length of the L-osteotomy. Conclusion Additional screw placement on the proximal segment improves stability in the postoperative femur. The cobra-type plate with additional screw holes in the proximal area might improve the effectiveness of L-osteotomies. PMID:19744345