Abstract / Summary
For young patients with osteonecrosis of the femoral head (ONFH), early adoption of appropriate hip-preserving surgery may prevent or delay the need for total hip arthroplasty (THA). To reduce soft-tissue and osseous disruption as well as simplify the procedure while maintaining clinical efficacy, we modified the “light bulb” procedure. This study aims to evaluate the clinical efficacy of the modified “light bulb” procedure for treating early-stage ONFH, and to analyze non-disease-related factors influencing femoral head survival, thereby establishing indications for this surgical technique. This retrospective study included 63 patients (70 hips) with early-stage ONFH who underwent the modified “light bulb” procedure at the Department of Orthopedics, Shanghai Sixth People’s Hospital, between September 2021 and June 2024. The cohort comprised 47 males (51 hips) and 16 females (19 hips), with ages ranging from 19 to 49 years. Patients were followed clinically and radiographically preoperatively, at 3 months, 6 months, 1 year postoperatively, and annually thereafter, with a minimum follow-up duration of 2 years. Clinical outcomes were evaluated based on serial assessments of patient demographics, Visual Analog Scale (VAS), and Harris Hip Scores (HHS) obtained preoperatively and at successive postoperative intervals. Radiographic follow-up included serial pelvic X-rays and magnetic resonance imaging (MRI) obtained preoperatively and postoperatively to assess ARCO stage, China-Japan Friendship Hospital (CJFH) classification, collapse of femoral head, necrotic lesion area of femoral head and involvement area of articular surface. Hip preservation failure was defined as a composite endpoint, including HHS-defined functional failure, radiographic failure, or conversion to THA. HHS-defined functional failure was defined as a postoperative HHS below 80 points. Radiographic failure was defined as progressive femoral head collapse or the onset/progression of secondary osteoarthritis. Univariate logistic regression analysis was performed on the follow-up data to identify risk factors associated with clinical outcomes and radiographic progression, and Kaplan–Meier analysis was used to estimate femoral head survival rates. At the final follow-up (mean duration 23.9 ± 9.8 months), the overall hip preservation success rate was 71.4% (50/70 hips). Univariate logistic regression analysis revealed that CJFH L3 classification (OR 22.50, 95% CI 2.11–240.40, P = .010), ARCO IIIA (OR 7.43, 95% CI 2.35–23.48, P < .001), femoral head collapse (OR 7.43, 95% CI 2.35–23.48, P < .001), necrotic area > 30% (OR 7.11, 95% CI 2.06–24.54, P = .002), 15–30% articular surface area involved (OR 9.51, 95% CI 2.44–37.04, P = .001), corticosteroid use (OR 6.14, 95% CI 1.54–24.46, P = .010), high body mass index (BMI, OR 1.96, 95% CI 1.35–2.86, P < .001), and smoking (OR 5.29, 95% CI 1.73–16.12, P = .003) were significantly associated with the failed hip preservation. Kaplan–Meier analysis demonstrated that ARCO stage, CJFH classification, involvement area of articular surface, BMI, necrotic lesion area of femoral head, etiology, and smoking status significantly affected postoperative femoral head survival time. Therefore, involvement of the lateral pillar, ARCO stage IIIA, necrotic area > 30%, higher BMI, smoking, and steroid- or alcohol-induced osteonecrosis are all associated with poorer prognoses. At a mean follow-up of approximately 24 months, the modified “light bulb” procedure was associated with favorable hip-preservation outcomes in patients with early-stage ONFH, particularly in younger patients with lower BMI, earlier ARCO stage, and no lateral pillar involvement. By allowing debridement, decompression, and bone grafting of the necrotic region through a single tunnel, this technique may provide a tissue-sparing option for preserving the native hip. Longer-term follow-up is required to establish the durability of these outcomes and to further define the indications for this procedure.