The role of internal fixation in the treatment of femoral head necrosis with ipsilateral hip fracture

Whether internal fixation or hip arthroplasty is the most appropriate initial treatment for patients with ipsilateral hip fracture and osteonecrosis of the femoral head remains unknown. In this study, the prognoses of patients who underwent internal fixation or hip arthroplasty were analyzed and compared to explore the role of internal fixation in treating such patients. We retrospectively reviewed 69 patients diagnosed with osteonecrosis of the femoral head and ipsilateral hip fracture from 1999 to 2018. They were divided into the hip arthroplasty or internal fixation group. The visual analog scale and Harris score were used. The incidence of complications and the conversion to arthroplasty were also investigated to further explore the role of internal fixation. Male patients (male/female: 25/31 vs 20/38, P = .015), younger patients (average age: 46.80 ± 13.14 vs 61.07 ± 15.61, P < .001), and patients with femoral neck fractures (fracture type, femoral neck/trochanter: 21/31 vs 12/38, P = .003) were more likely to receive 1-stage hip arthroplasty. Of 38 patients undergoing internal fixation, fracture nonunion was identified in 9, and progression of osteonecrosis was identified in 16. Meanwhile, conversion to secondary hip arthroplasty occurred in 13 patients. Four independent risk factors for conversion to secondary hip arthroplasty were identified: age of ≤60 years (odds ratio [OR] = 9.786, 95% confidence interval [CI] = 2.735–35.015), male sex (OR = 6.790, 95% CI = 1.718–26.831), collapse of the femoral head before injury (OR = 7.170, 95% CI = 2.004–25.651), and femoral neck fracture (OR = 8.072, 95% CI = 2.153–30.261). A new scoring system was constructed for predicting conversion to hip arthroplasty in patients undergoing internal fixation treatment. A cutoff of ≤2 points indicated low risk for conversion, 3 to 4 points indicated moderate risk, and ≥5 points indicated high risk. Patients who underwent internal fixation had worse prognoses than those who underwent 1-stage hip arthroplasty. However, in this study, hip arthroplasty conversion did not occur in most patients who received internal fixation. Using the new scoring system to identify patients who may require conversion to replacement may help make appropriate patient management and clinical decisions.