Mid-term functional and radiological outcomes after total hip replacement performed for complications of acetabular fractures

Abstract

Objective: Acetabular fractures can lead to serious complications such as avascular necrosis of the femoral head (AVN), osteoarthritis, non-union. Total hip replacement (THR) is a treatment option for these complications. The purpose of this study was to assess the functional and radiological outcomes of THR at least 5 years after the primary implantation.

Methods: This retrospective study analysed clinical data from 77 patients (59 males, 18 females) who were treated from 2001 to 2022. Data was collected on the incidence of AVN of the femoral head, complications, interval from fracture to THR, reimplantation. The modified Harris Hip Score (MHHS) was used to evaluate outcome.

Results: The mean age at the time of fracture was 48 years. Avascular necrosis developed in 56 patients (73%), with 3 cases of non-union. Osteoarthritis without AVN developed in 20 patients (26%), non-union without AVN in one patient (1%). The mean time from fracture to THR was 24 months for AVN with non-union, 23 months for AVN alone, 22 months for AVN with arthritis, 49 months for hip osteoarthritis without AVN. The time interval was significantly shorter for cases of AVN than for cases of osteoarthritis without AVN (p = 0.0074). Type C1 acetabular fracture was found to be a risk factor for femoral head AVN (p = 0.0053). Common complications of acetabular fractures included post-traumatic sciatic nerve paresis (17%), deep venous thrombosis (4%), infections (4%). Hip dislocation was the most common complication of THR (17%). There were no cases of thrombosis following THR. According to Kaplan-Meier analysis, the proportion of patients without revision surgery within 10-year period was 87.4% (95% CI 86.7-88.1). The results of the MHHS after THR: 59.3% of patients had excellent results, 7.4% good, 9.3% satisfactory results, and 24.0% had poor results. The mean MHHS was 84 points (95% CI 78.5-89.5). Paraarticular ossifications were observed in 69.4% of patients in the radiological evaluation.

Conclusion: Total hip replacement is an effective treatment for serious complications of acetabular fracture treatment. Its results are comparable to THR peformed for other indications, although it is associated with a higher number of paraarticular ossifications. Type C1 acetabular fracture was found to be a significant risk factor for early femoral head AVN.

Keywords: Acetabular fracture; Complication; Femoral head AVN; Modified Harris hip score; Total hip replacement.