Project description:Diaphyseal defects in long bones of extremities following segmental resection are very common in the clinic, and reconstruction remains a great challenge. Although there are many treatments for diaphyseal defects at present, reconstruction with an intercalary endoprosthesis may be an optimal method. We demonstrate a surgical technique for reconstruction of a humeral shaft defect with an intercalary endoprosthesis following tumor resection, and achieve a good clinical outcome. We conclude that in comparison with other methods, reconstruction with an intercalary endoprosthesis is simple, effective, and allows for earlier weight bearing and more rapid restoration of function.
Project description:Medial patellofemoral ligament reconstruction risks patellar fracture with the osseous violation necessary for patellar attachment. Anatomic studies identify an entire medial patellofemoral complex of structures responsible for medial restraint to patellar lateral instability. One specific component of this complex is the medial quadriceps tendon femoral ligament (MQTFL). This note presents the technique, pearls and pitfalls, and critical surgical anatomy necessary for successful MQTFL reconstruction-a treatment strategy for patellar instability with no increased risk for patellar fracture. An autograft hamstring tendon or allograft tendon is fixed to the anatomically identified femoral origin and passed deep to the vastus medialis obliquus to then weave around the distal medial quadriceps tendon. This simulates the native anatomic interdigitation of the MQTFL with the quadriceps tendon and provides a stable restraint to prevent lateral patellar subluxation or dislocation.
Project description:PurposeBone healing in femoral reconstructions using intercalary allografts can be compromised in a tumour context. There is also a high revision rate for non-union, infection, and fractures in this context. The advantages and disadvantages of an associated vascularised fibula graft (VFG) are still a matter of debate.MethodsIn a multicentre study, we retrospectively analysed 46 allograft reconstructions, operated on between 1984 and 2017, of which 18 were associated with a VFG (VFG+) and 28 without (VFG-), with a minimum follow-up of 2 years. We determined the cumulative probability of bone union as well as the mid- and long-term revision risks for both categories by Kaplan-Meier survival analysis and a multivariate Cox model. We also compared the MSTS scores.ResultsSignificant differences in favour of VFG+ reconstruction were observed in the survival analyses for the probability of bone union (log-rank, p = 0.017) and in mid- and long-term revisions (log-rank, p = 0.032). No significant difference was observed for the MSTS, with a mean MSTS of 27.6 in our overall cohort (p = 0.060). The multivariate Cox model confirmed that VFG+ was the main positive factor for bone union, and it identified irradiated allografts as a major risk factor for the occurrence of mid- and long-term revisions.ConclusionBone union was achieved earlier in both survival and Cox model analyses for the VFG+ group. It also reduced the mid- and long-term revision risk, except when an irradiated allograft was used. In case of a tumour, we thus recommend using VFG+ from a fresh-frozen allograft, as it appears to be a more reliable long-term option.
Project description:Background and objectiveThe use of bone allograft reconstructions after tumor resection can introduce significant complications. Stable fixation is required to decrease the incidence of mechanical complications of segmental bone allografts. The purpose of the present study is to compare plating fixation methods of diaphyseal allografts after intercalary resection of the femur.MethodsWe created four defined fixation models using plates and/or intramedullary polymethylmethacrylate (PMMA) to simulate typical bone tumor resection with intercalary allograft reconstruction. One angularly stable plate (DFP) with 13 locking screws and fresh frozen allografts (labeled "I") were used for bone reconstruction. Three modified reconstructions were created: "II" included a supplementary plate (SP) with four locking screws, "III" was augmented with intramedullary PMMA in the allograft, and "IV" combined intramedullary PMMA and both plates. We applied a load model that simulates partial weight bearing on the lower limb to simulate the load during postoperative rehabilitation.ResultsThe highest stress in the DFP occurred at the allograft-bone transition, with variant IV reaching 297 MPa. PMMA augmentation reduced median interfragmentary motion (IFM) and sliding distances, with variant III achieving the lowest distal sliding distance (0.9 μm) in the distal area. Supplementary plate fixation reduced maximal and median proximal IFM distances (86.9 μm in variant II vs. 116.0 μm in variant I) but increased sliding distances (23.7 μm in variant II vs. 0.6 μm in variant I).ConclusionsPMMA augmentation reduces IFM and sliding distances, enhancing rigidity, particularly in the distal area. Supplementary plate fixation decreases IFM distances in the proximal area but increases sliding distances in the same region. Variants III and IV demonstrate lower IFM and sliding distances in the distal area overall. Variant III shows very low sliding distances in both distal and proximal areas. Variant IV combines improved firmness with slightly higher stress levels.
Project description:Restoring femoral rotation alignment and limb length after distal femur resection and endoprosthetic reconstruction is crucial to avoid poor outcomes. This technical note presents a simple and reliable intraoperative technique for restoring femoral rotation and length during distal femur resection and endoprosthetic reconstruction without the need for extensive preoperative planning or complex perioperative modalities. The method utilizes an external fixator frame as a guiding device to assess and restore the native alignment. This approach provides a practical alternative to relying solely on the position of the linea aspera, which has been shown to be an unreliable landmark for rotational alignment. Implementing this technique can contribute to improved functional outcomes in patients undergoing distal femur endoprosthetic reconstruction.
Project description:PurposeThe proximal tibia is a common location for osteosarcoma. Modular endoprosthesis is a popular reconstructive option, yet it has been associated with many complications. Our study aimed to evaluate the functional outcome and complications of proximal tibial osteosarcoma patients treated by limb salvage using modular endoprosthesis.MethodsA retrospective study of a prospective database was performed during the period between January 2000 and July 2017. Fifty-five patients with proximal tibial osteosarcoma underwent resection and modular endoprosthetic reconstruction. The functional outcome was evaluated using the Musculoskeletal tumor society scoring system and knee range of motion. Postoperative complications were classified according to Henderson classification; Type 1 (soft tissue failure), Type 2 (aseptic loosening), Type 3 (structural failure), Type 4 (infection) and Type 5 (local tumor progression).ResultsThe mean follow-up period was 71.69 ± 49.76 months. The mean musculoskeletal tumor society score was 26.5 ± 2.22; the mean range of motion was 72.63 ± 25.07, and the mean extension lag was 15.09 ± 15.38. Type 1, type 2, type 3, type 4, and type 5 complications occurred in 7.3%, 14.5%, 21.8%, 23.6%, and 5.5%, respectively. Chest metastasis developed in 10 patients (18.2%). The estimated 5-year and 10-year survival rates for the treated patients were 83.6% and 79.9%.ConclusionsProximal tibial osteosarcoma reconstruction with a modular endoprosthesis is a reliable treatment option for retaining limb function. Most complications are manageable.
Project description:Detailed anatomic dissections of the deep medial knee retinaculum have shown a consistent prominent anatomic structure extending from the distal deep quadriceps tendon to the adductor tubercle region, forming a distinct medial quadriceps tendon-femoral ligament (MQTFL). Reconstruction of this anatomic structure has yielded consistent medial stabilization of the patellofemoral joint without drilling into the patella over more than 3 years in patients with recurrent patella instability and dislocation. Results are similar to those of MPFL reconstruction but with reduced risk of patella fracture, a known and serious complication of MPFL reconstruction. The reconstruction graft is secured at the anatomic femoral origin of the MQTFL and brought under the vastus medialis such that it may be woven and attached to the deep distal medial quadriceps tendon to provide a secure, reliable reproduction of the MQTFL and excellent stabilization of the patellofemoral joint without risk of patella fracture.
Project description:Introduction: Femur and tibia are the most commonly affected sites for primary malignant bone tumors in children. The wide resection of the tumor frequently requires the physis to be resected. The normal growth of the unaffected limb will result in a significant limb length discrepancy at skeletal maturity. To compensate for this resulting LLD, different generations of extendible endoprostheses have been developed. Non-invasive extendable prostheses eliminate the need for surgical procedures and general anesthesia, enabling gradual and painless lengthening. Currently available non-invasive extendable prostheses focus on joint reconstruction, and no case series analysis of intercalary non-invasive extendable prosthesis has been reported. Therefore, we have designed a novel non-invasive electromagnetic extendable intercalary endoprosthesis. Methods:In vitro mechanical experiments and in vivo animal experiments were conducted. Results:In vitro experiments have confirmed that the prosthetics can extend at a constant rate, increasing by 4.4 mm every 10 min. The average maximum extension force during prosthetic elongation can reach 1306N. In animal in vivo experiments, the extension process is smooth and non-invasive, and the sheep is in a comfortable state. Discussion: The in vitro and in vivo animal studies provide evidence to support the extension reliability, laying the foundation for future large-scale validation experiments.
Project description:ContextFemoral shaft cortical thickening has been mentioned in reports of atypical subtrochanteric and diaphyseal (S/D) femur fractures, but it is unclear whether thickening precedes fracture or results from a preceding stress fracture and what role bisphosphonates might play in cortical thickening.ObjectiveOur objective was to examine the relationship of cortical thickness to S/D fracture risk as well as establish normal reference values for femoral cortical thickness in a large population-based cohort of older women.DesignUsing pelvic radiographs obtained in 1986-1988, we measured femoral shaft cortical thickness 3 cm below the lesser trochanter in women in the Study of Osteoporotic Fractures. We measured this in a random sample and in those with S/D fractures and femoral neck and intertrochanteric fractures. Low-energy S/D fractures were identified from review of radiographic reports obtained between 1986 and 2010. Radiographs to evaluate atypia were not available. Analysis used case-cohort, proportional hazards models.OutcomesCortical thickness as a risk factor for low-energy S/D femur fractures as well as femoral neck and intertrochanteric fractures in the Study of Osteoporotic Fractures, adjusting for age and bone mineral density in proportional hazards models.ResultsAfter age adjustment, women with thinner medial cortices were at a higher risk of S/D femur fracture, with a relative hazard of 3.94 (95% confidence interval = 1.23-12.6) in the lowest vs. highest quartile. Similar hazard ratios were seen for femoral neck and intertrochanteric fractures. Medial or total cortical thickness was more strongly related to fracture risk than lateral cortical thickness.ConclusionsIn primarily bisphosphonate-naive women, we found no evidence that thick femoral cortices placed women at higher risk for low-energy S/D femur fractures; in fact, the opposite was true. Women with thin cortices were also at a higher risk for femoral neck and intertrochanteric fractures. Whether cortical thickness among bisphosphonate users plays a role in atypical S/D fractures remains to be determined.
Project description:BackgroundThe outcome of non-surgical treatment is generally good, but the treatment course can be long and painful with approximately a quarter of the patients acquiring a nonunion. Both surgical and non-surgical treatment can have disabling consequences such as nerve injury, infection, and nonunion. The purpose of the study is to compare patient-reported outcomes after surgical and non-surgical treatment for humeral shaft fractures.MethodsA pragmatic randomized controlled trial (RCT) is planned with two study groups (SHAFT-Young and SHAFT-Elderly). A total of 287 eligible acute humeral shaft fractures are scheduled to be recruited and randomly allocated to surgical or non-surgical treatment with the option of early crossover due to delayed union. The surgical method within the allocation is decided by the surgeon. The primary outcome is the Disability of Arm, Shoulder, and Hand (DASH) score at 52 weeks, and is assessor blinded. The secondary outcomes are DASH score, EQ-5D-5L, pain assessed by visual analog score, Constant-Murley score including elbow range of motion, and anchor questions collected at all timepoints throughout the trial. All complications will be reported including; infection, nerve or vascular injury, surgical revisions (implant malpositioning, hardware failure, aseptic loosening, and peri-implant fracture), major adverse cardiovascular events, and mortality.DiscussionThe SHAFT trial is a pragmatic multicenter RCT, that will compare the effectiveness of the main strategies in humeral shaft fracture treatment. This will include a variety of fracture morphologies, while taking the dilemmas within the population into account by splitting the population by age and providing the orthopedic society with an interval for early crossover surgery.Trial registrationClinicaltrials.gov NCT04574336 . Registered on 5 October 2020.