Anterolateral Necrotic Lesion Serves as an Early Warning Sign of Developing Collapse in Osteonecrosis of the Femoral Head

Abstract

Objective: Load bearing capacity of the bone structure of anterolateral weight-bearing area plays an important role in the progressive collapse in osteonecrosis of the femoral head (ONFH). The purpose of this study is to assess the efficacy of combined evaluation of anteroposterior (AP) and frog-leg lateral (FLL) view to diagnose collapse.Methods: Between December 2016 to August 2018, a total of 478 hips from 372 patients with ONFH (268 men, 104 women; mean age 37.9±11.4 years) were retrospectively evaluated. All patients received standard AP and FLL views of hip joints. Japanese Investigation Committee (JIC) classification system was used to classified necrotic lesion in AP view. Anterior necrotic lesion was evaluated by FLL view. All patients with precollapse ONFH underwent non-operative hip preserving therapy. The collapse rate was calculated and compared with Kaplan–Meier survival analysis with radiological collapse as endpoints.Results: Forty-four (44/478, 9.2%) hips were classified as type A, 65 (65/478, 13.6%) as type B, 232 (232/478, 48.5%) as type C1, and 137 (137/478, 28.7%) as type C2. Three hundred cases (300/478, 62.5%) were collapsed at the initial time point. Two hundred and twenty six (226/300, 75.3%) hips and 298 (298/300, 99.3%) hips collapse were identified with AP view and FLL view, respectively. An average follow-up of 37.0±32.0 months was conducted to evaluate the occurence of collapse in 178 precollapse hips. During follow-up period, collapse occurred in 89 hips (50.0%). Seventy-seven (77/89, 86.5%) hips was determined with AP view alone and 85 (85/89, 95.5%) hips were determined with combination of AP and FLL views. The collapse rate at five years were reported as 0% and 0%, 16.2% and 24.3%, 58.3% and 68.1%, and 100% and 100% according to combination of AP and FLL views or AP view alone for types A, B, C1, and C2, respectively.Conclusion: The collapse can be diagnosed more accurately by combination of AP and FLL views. Besides, JIC type A and type B ONFH can be treated with conservative hip preservation, but precollapse type C2 ONFH should be treated with joint-preserving surgery. Type C1 needs further study to determine which subtype has potential risk of collapse.

Less sclerotic microarchitecture pattern with increased bone resorption in glucocorticoid-associated osteonecrosis of femoral head as compared to alcohol-associated osteonecrosis of femoral head

“…According to Kim et al's histological investigation, patients with AONFH or idiopathic ONFH had normal or almost normal cancellous bone in the acetabulum and proximal femur, whereas GONFH may be linked to more extensive osteonecrosis (17). In a study by Wei et al, GONFH was characterized by multiple "osteolytic bone destruction", while AONFH was manifested by some kinds of "coagulative destruction" (18,19). When compared to age-matched controls, patients with ONFH brought on by glucocorticoid usage or sickle-cell illness have been observed to have worse THA outcomes in clinical settings (20)(21)(22).…”