Objective:To establish a classification system for the repair band in the subchondral bone origination point in MRI for traumatic osteonecrosis of the femoral head (ONFH) and preliminarily explore the correlation between this classification and the progression of femoral head collapse.Methods:A retrospective analysis was conducted on 73 cases of traumatic ON-FH treated at the Quanzhou Orthopedic-traumatological hospital from January 2000 to December 2019. Among them, there were 46 males and 27 females with an average age of 34.9±8.3 years (range 19-55 years). Clinical and radiological data such as age, gender, side, fracture classification, reduction quality, JIC classification, and bone repair band (BRB) classification were recorded. The progression of traumatic ONFH was assessed using the ARCO staging system, with stages IIIA and IIIB defined as mild collapse and progressive collapse, respectively. The BRB classification was established based on MRI findings, and the inter- and intra-observer consistency of the BRB classification was analyzed using Kappa test. The correlation between the BRB classification and progressive femoral head collapse was analyzed using the Kaplan-Meier survival curve and binary variable Cox regression analysis.Results:According to the BRB classification, 73 cases were divided into type 1 with superficial lesion in 38.4%, type 2 with uncertain lesion in 21.9%, and type 3 with extensive lesion in 39.7%. The inter-observer consistency Kappa value for the BRB classification was 0.798, and the intra-observer consistency Kappa value was 0.896, indicating a high level of consistency. A follow-up of 73 cases (54.8±34.9 months, range 24-165 months) showed a significant correlation between the BRB classification and ARCO staging at the last follow-up (χ 2=37.556, P<0.001), with progression to stages IIIA and IIIB as follows: type 1 had 3 and 1 cases, type 2 had 4 and 1 cases, and type 3 had 14 and 12 cases, respectively. Using the occurrence of progressive collapse (stage IIIB) as the endpoint, the risk of progression to stage IIIB for type 2 was not statistically different from type 1 [ HR=1.766, 95% CI (0.465, 6.702), P=0.403]; the risk of progression to stage IIIB for type 3 was significantly higher than for type 1 [ HR=15.126, 95% CI (4.708, 48.592), P<0.001]. Conclusion:The BRB classification is closely related to the progression of traumatic ONFH and is an independent risk factor for predicting the occurrence of progressive collapse; this classification is helpful for early diagnosis and predicting the progression of collapse and treatment plan decision-making.