Early Complications of a Novel Retrograde Intramedullary Femoral Nail in the Treatment of Femur Fractures.

OBJECTIVES: To determine the early implant failure rate of a novel retrograde intramedullary femoral nail. DESIGN: Retrospective cohort study. SETTING: Academic level 1 trauma center. PATIENTS SELECTION CRITERIA: Patients aged 18 years and older with an acute OTA/AO 32-A, 32-B, 32-C, and 33-A fractures or periprosthetic distal femur fracture from April 2018 to April 2022 were included in the study. The 2 interventions compared were the Synthes Expert retrograde/antegrade femoral nail (or control implant) versus the next-generation retrograde femoral nail (RFN)-advanced retrograde femoral nail (RFNA or experimental implant) (Synthes, West Chester, PA). OUTCOME MEASURES AND COMPARISONS: Early implant-related complications between the experimental and control implants were assessed including locking screw back out, screw breakage, intramedullary nail failure, need for secondary surgery, and loss of fracture reduction. RESULTS: Three hundred fourteen patients were identified with a mean age of 31.0 years, and 62.4% of the patients being male. Open fractures occurred in 32.5% of patients with 3.8% of injuries being distal femur periprosthetic fractures. Fifty-six patients were in the experimental group and 258 patients in the control group. Mean follow-up was 46.8 weeks for the control cohort and 21.0 weeks for the experimental cohort. Distal interlocking screw back out occurred in 23.2% (13 of 56) of the experimental group patients and 1.9% (5 of 258) of the control group patients ( P < 0.0001). Initial diagnosis of interlocking screw back out occurred at an average of 3.2 weeks postoperatively (range, 2-12 weeks). Fifty-four percent of patients who sustained screw back out underwent a secondary operation to remove the symptomatic screws (12.5% of all patients treated with the experimental implant required an unplanned secondary operation due to screw back out). A logistic regression model was used to predict screw back out and found the experimental implant group was 4.3 times as likely to experience distal locking screw back out compared with the control group ( P = 0.01). CONCLUSIONS: The retrograde femoral nail-advanced implant was associated with a significantly higher rate of screw back out with a substantial number of unplanned secondary surgeries compared with the previous generation of this implant. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Obturator dislocations of the hip associated with pelvic ring injuries: Case report and review of the literature.

Case: An obturator hip dislocation with an associated open book pelvic ring injury is an extremely rare injury pattern. This case report will discuss challenges to closed reduction, acute management strategies and review the literature on combined hip dislocations and open book pelvic ring injuries. Conclusion: This injury pattern presents unique reduction challenges that should be recognized early in order to provide effective resuscitation and preserve the femoral head blood supply. Failing to close reduce the hip delays reducing the pelvic ring volume because sheets and binders are precluded from working effectively.

Predicting five-year mortality in soft-tissue sarcoma patients.

Aims: The aim of this study was to identify factors associated with five-year cancer-related mortality in patients with limb and trunk soft-tissue sarcoma (STS) and develop and validate machine learning algorithms in order to predict five-year cancer-related mortality in these patients. Methods: Demographic, clinicopathological, and treatment variables of limb and trunk STS patients in the Surveillance, Epidemiology, and End Results Program (SEER) database from 2004 to 2017 were analyzed. Multivariable logistic regression was used to determine factors significantly associated with five-year cancer-related mortality. Various machine learning models were developed and compared using area under the curve (AUC), calibration, and decision curve analysis. The model that performed best on the SEER testing data was further assessed to determine the variables most important in its predictive capacity. This model was externally validated using our institutional dataset. Results: A total of 13,646 patients with STS from the SEER database were included, of whom 35.9% experienced five-year cancer-related mortality. The random forest model performed the best overall and identified tumour size as the most important variable when predicting mortality in patients with STS, followed by M stage, histological subtype, age, and surgical excision. Each variable was significant in logistic regression. External validation yielded an AUC of 0.752. Conclusion: This study identified clinically important variables associated with five-year cancer-related mortality in patients with limb and trunk STS, and developed a predictive model that demonstrated good accuracy and predictability. Orthopaedic oncologists may use these findings to further risk-stratify their patients and recommend an optimal course of treatment.

Cerebral fat embolism syndrome (FES): similar cases with different outcomes.

Fat embolism syndrome (FES) is a rare multisystem, clinical syndrome occurring in 0.9%-2.2% of long-bone fractures. The severity of FES can vary from subclinical with mild respiratory changes and haematological aberrations to a fulminant state characterised by sudden onset of severe respiratory and neurological impairment. Here we present two patients with cerebral FES secondary to femur fracture. Both patients exhibited profound neurological impairment with varied outcomes. Our cases highlight the importance of a high clinical suspicion of FES in patients with long-bone fractures and neurological deterioration. We recommend early plate osteosynthesis to prevent additional emboli in patients with FES and situational placement of intracranial pressure monitoring. Finally, cerebral FES has low mortality even in a patient with tentorial herniation and fixed, dilated pupils.

Biomechanical Evaluation of Osteoporotic Proximal Periprosthetic Femur Fractures With Proximal Bicortical Fixation and Allograft Struts.

OBJECTIVES: To evaluate the strength of proximal bicortical fixation using a novel osteoporotic synthetic bone model of Vancouver B1 periprosthetic proximal periprosthetic femur fractures (PFFs) and to assess the influence of strut allograft augmentation with regard to allowing early assisted weight bearing. The secondary aim was to evaluate whether the strut position, either medial or anterior, influenced the strength of the construct. METHODS: Thirty synthetic osteoporotic femurs were implanted with cemented stems. A segmental defect made distal to the stem simulated a fracture and was repaired with a stainless steel locking compression plate and 2 stainless steel proximal locking attachment plates. Specimens were then divided into 3 groups: no-strut, medial strut, and anterior strut. Cadaveric femoral struts were wired to the specimens. Cyclic axial compression simulated assisted weight bearing and was followed by loading to failure. RESULTS: Medial struts required higher failure load than no-strut (P = 0.008) and more energy to failure than anterior (P = 0.018) or no-strut (P < 0.001). The higher load to failure, however, would not be advantageous in clinical practice because estimates for assisted weight bearing after fractures in average-weight patients are well below these failure loads. Furthermore, all specimens tolerated cyclical loading. All failures occurred distal to the plate originating at the last screw hole. CONCLUSIONS: Failure loads for all groups were above what would be expected for low-demand activities of assisted weight bearing. Therefore, proximal bicortical fixation should allow for early, assisted weight bearing without allograft strut augmentation even with lower density bone.