Predicting Collapse in Osteonecrosis of the Femoral Head Using a New Method: Preserved Angles of Anterior and Lateral Femoral Head.

BACKGROUND: Femoral head collapse (FHC) is associated with a poor prognosis in osteonecrosis of the femoral head (ONFH). Preserved angles (PAs), including the lateral preserved angle (LPA), the anterior preserved angle (APA) and the combined preserved angle (CPA), can be used to quantify the extent of femoral head necrosis and predict the risk of femoral head collapse. The purpose of this retrospective cohort study was to assess the efficacy of these preserved angles in the prediction of femoral head collapse using plain radiographs. METHODS: Patients with ONFH treated conservatively between January 2010 and January 2019 were analyzed retrospectively to assess the risk of FHC. A logistic regression model was used to evaluate the independent prognostic factors associated with FHC, including age, sex, etiology, onset of symptom, The Japanese Investigation Committee classification, and PAs (LPA, APA, and CPA). RESULTS: A total of 137 patients, with 180 hips, had follow-up of at least two years and were included. During the follow-up period, FHC occurred in 89 hips (49.44%) after the initial diagnosis. Multivariable analysis indicated that CPA (odds ratio [OR] = 0.95; 95%CI = 0.93-0.97; P < 0.01) was a stronger predictor of femoral head collapse compared with the Japanese Investigation Committee classification (OR = 2.40, 95%CI = 0.92-6.25; P > 0.01). The receiver operating characteristic and survival curve analyses revealed that the predictive cutoff point for the CPA was 118.7° (sensitivity = 96.70%, specificity = 79.78%, log-rank test: P < 0.01). CONCLUSIONS: Assessment of preserved angles on plain radiographs is a simple method to quantify the extent of lateral and anterior necrosis of the femoral head. Specifically, CPA has a potential value in predicting femoral head collapse.

Huo Xue Tong Luo capsule, a vasoactive herbal formula prevents progression of asymptomatic osteonecrosis of femoral head: A prospective study.

BACKGROUND/OBJECTIVE: A prospective cohort study aimed to evaluate the clinical efficacy of a specific vasoactive herbal formula, Huo Xue Tong Luo capsule (HXTL capsule), for the treatment of patients with asymptomatic osteonecrosis of femoral head (ONFH). METHODS: We evaluated a clinical trial of 55 patients (59 hips) with asymptomatic ONFH (no joint collapse) evaluated by Steinberg staging system and necrosis range classification criteria. Then, they were given HXTL capsule under specific protocol. Among them, 39 males and 16 females with an average age of 36.4 ± 10.1 years were followed up for an average of 4.38 years during treatment. The aggravation of clinical and imaging results was assessed by initial pain and joint collapse. The clinical and imaging outcomes of these patients were compared with those of a historical control group from the literature under critical inclusion criteria. RESULTS: At the latest follow-up, initial pain occurred in five of 59 (8.5%) hips of patients taking HXTL capsule compared with 31 of 81 (38.3%) controls (p < 0.001), and joint collapse occurred in 13 of 59 (22.0%) hips of patients taking HXTL capsule compared with 26 of 81 (32.1%) controls (p < 0.001). There was no association between joint collapse and multiple key factors of ONFH. Only the location of type C2 necrotic lesions (hazard ratio, 4.12; 95% confidence interval, 2.64-18.91) and the extent of large necrotic lesions (hazard ratio, 3.39; 95% confidence interval, 1.43-16.21) predicted joint collapse. CONCLUSION: As an agent formulated by vasoactive herbals, HXTL capsule with specific protocol is an effective medicine for relieving hip pain and preventing joint collapse in patients with asymptomatic ONFH. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: The translation potential of this prospective cohort study is that the initially officially approved clinical indication for HXTL capsule for treatment of ONFH is due to its possible effect of revascularization on angiogenesis of necrosis. It is has been now proven to be effective for a new clinical application.