Risk of Postoperative Sciatic Nerve Palsy After Posterior Acetabular Fracture Fixation: Does Patient Position Matter?

OBJECTIVES: To determine whether the prone or lateral position is associated with postoperative sciatic nerve palsy in posterior acetabular fracture fixation. DESIGN: Retrospective cohort study. SETTING: Three Level I trauma centers. PATIENTS: Patients with acetabular fractures treated with a posterior approach (n = 1045). INTERVENTION: Posterior acetabular fixation in the prone or lateral positions. OUTCOME MEASUREMENTS: The primary outcome was the prevalence of postoperative sciatic nerve palsy by position. Secondary outcomes were risk factors for nerve palsy, using multiple regression analysis and propensity scoring. RESULTS: The rate of postoperative sciatic nerve palsy was 9.5% (43/455) in the prone position and 1.5% (9/590) in the lateral position ( P < 0.001). Intraoperative blood loss and surgical duration were significantly higher for patients who developed a postoperative sciatic nerve palsy. Subgroup analysis showed that position did not influence palsy prevalence in posterior wall fractures. For other fracture patterns, propensity score analysis demonstrated a significantly increased odds ratio of palsy in the prone position [aOR 7.14 (2.22-23.00); P = 0.001]. CONCLUSIONS: With the exception of posterior wall fracture patterns, the results of this study suggest that factors associated with increased risk for postoperative sciatic nerve palsy after a posterior approach are fractures treated in the prone position, increased blood loss, and prolonged operative duration. These risks should be considered alongside the other goals (eg, reduction quality) of acetabular fracture surgery when choosing surgical positioning. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The use of a triflange salvage system for catastrophic pelvic osteolysis after failed total hip arthroplasty.

INTRODUCTION: The custom triflange acetabular implant (CTAI) has been described to address catastrophic pelvic osteolysis, but long-term outcome data is scarce. METHODS: Revision-free survivorship after revision THA with a CTAI was retrospectively reviewed in seven patients. RESULTS: Mean and median follow-up time were 7.39 (1.61-16.8) years and 7.50 years, respectively. Revision-free survivorship was 85.7% (6/7). One patient underwent revision for recurrent dislocations. All patients were able to ambulate at recent follow-up- 2/7 without assistance. CONCLUSIONS: The CTAI is a viable option for patients with catastrophic pelvic osteolysis. There is a high complication rate, but the incidence of revision is low.

Hysteresis and Instability Predicted in Moisture Degradation of Perovskite Solar Cells.

The degradation of the perovskite solar cell structure was expected recently to be reversible, which opened a new gate to the enhancement of the device lifetime by reversing the process. However, the kinetic details of the structural collapse and recovery are still missing, without which the perovskite reversibility cannot be further explored. Due to the experimental difficulty, a purposeful numerical model was conducted in this report, to simulate the water diffusion process in the perovskite structure in both directions. It was found that the moisture diffusion needs to be initiated by a certain level of structural imperfection and is non-Fickian, as assisted by the collapse of the perovskite into the 1D chains. The reversibility was verified by the back diffusion, but accompanied by hysteresis, stagnancy, and even surprising instability, which initiated the water flow under initial equilibrium, due possibly to the imbalance during the reconstruction of the perovskite lattice. These observations offer new insights to form strategies of improvement, for example, via the possible self-healing perovskite devices.

Proximal Femoral Bone Cyst After Single Screw Fixation for Slipped Capital Femoral Epiphysis: A Case Report.

CASE: An 11-year-old female patient underwent bilateral in situ fixation for slipped capital femoral epiphyses using single, cannulated, stainless steel screws. She presented 12 years later with a large osteolytic lesion of the proximal femur, which only involved 1 side. Histological evaluation showed a foreign-body reaction and synovial lining. Infection was ruled out and dynamic hip screw stabilization, and bone grafting were performed. The bone graft healed, and the hardware was removed to prevent a similar reaction. In retrospect, postoperative radiographs at 7 weeks showed subtle osteolysis along the screw. CONCLUSION: Intra-articular drilling, vertical screw placement into the posterior epiphysis, and the prominent screw head may have led to this unexpected complication.

Characterization of ossification of the posterior rim of acetabulum in the developing hip and its impact on the assessment of femoroacetabular impingement.

BACKGROUND: Many radiographic indices that are used to assess adolescents for femoroacetabular impingement rely on an ossified posterior acetabular wall. A recent study identified a secondary ossification center in the posterior rim of the acetabulum, the ossification of which may affect perceived acetabular coverage. The purpose of this study was to characterize ossification of the posterior rim of the acetabulum with use of a longitudinal radiographic study and quantify its impact on the radiographic assessment of femoroacetabular impingement. METHODS: In this study, we utilized a historical collection of annual radiographs made in a population of healthy adolescents. Six hundred and twelve anteroposterior radiographs of the left hip of ninety-eight patients were reviewed to identify the appearance, duration, and fusion of the secondary ossification center in the posterior rim of the acetabulum. The center-edge angle was then measured before appearance and after fusion of the secondary ossification center in a subset of ten patients who had <5° of rotation on all radiographs. RESULTS: The secondary ossification center in the posterior rim was identified in seventy-three of the ninety-eight subjects, with no significant difference between the sexes. The mean patient age at the time of radiographic appearance of this secondary ossification center was fourteen years for males and twelve years for females. The mean duration of radiographic appearance was ten months for both sexes. Serial center-edge angles were measured in a subset of ten patients, and they increased during posterior rim ossification by a mean of 4.1°. CONCLUSIONS: The secondary ossification center in the posterior rim of the acetabulum (the posterior rim sign) is a common radiographic finding that reliably appears for ten months around the time of triradiate closure. Posterior rim ossification led to a mean increase of 4° of perceived acetabular coverage through the center-edge angle. Given the narrow margin between normal coverage (33° to 36°) and acetabular overcoverage (>40°), the use of radiographs in adolescents with incompletely ossified hips may lead to misinterpretation of acetabular coverage. In patients with open triradiate cartilage, magnetic resonance imaging may be considered for the assessment of femoroacetabular impingement. CLINICAL RELEVANCE: The posterior rim ossification sign is a normal finding in adolescent hip development and has important implications for the proper evaluation of femoroacetabular impingement.

The effect of antiestrogen agents on risk of autoimmune disorders in patients with breast cancer.

OBJECTIVE: To investigate the relationship between antiestrogen therapy in women with breast cancer and risk of autoimmune disease. METHODS: We used a national database to assess the incidence of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) following treatment with selective estrogen receptor modulators (SERM) or aromatase inhibitors (AI) in women with breast cancer. The total number of patients in our study was 190,620. RESULTS: We observed highly significant, cumulative dose-dependent increased OR of incidence of both SLE and RA following treatment with SERM (p < 0.0001). The odds of developing RA were also increased following AI therapy (p < 0.001), but there was a trend for reduced odds of SLE, though this trend did not attain statistical significance (p = 0.070 for 2-11 months of treatment and p = 0.254 for 12+ months of treatment). CONCLUSION: Antiestrogen agents may have an important effect on risk of autoimmune disease.