A New Classification To Prognosticate The Collapse Of Atraumatic Osteonecrosis Of The Femoral Head Based On The Shape Of The Viable/necrotic Interface

ObjectiveBecause of the difficulty of recognition, diagnosis, treatment, quick progression of disease and increased morbidity, atraumatic osteonecrosis of the femoral head has increasingly become one of the problem in clinicians. According the research of the progression of disease, about 80% of untreated patients with femoral head necrosis have to suffer the collapse of the invalid femoral head in 1-3 years. Irreversible pain and activity limitation of the hip have serious influence the patient’s life. Therefore, the prognostication of the collapse of the femoral head is the key to the diagnosis and treatment. After reading a large number of atraumatic osteonecrosis of the femoral head imaging data and Long-term clinical experience and generalizations, researchers have found there is a relationship between the shape of the viable/necrotic interface and the collapse of the femoral head. Our research is to discover the relationship between the shape of the viable/necrotic interface and the collapse of the femoral head based on a large number of atraumatic osteonecrosis of the femoral head imaging date, which will make some contribution to the prognostication the collapse of atraumatic osteonecrosis of the femoral head, and attempting to differ treatment based on the shape of differentiation.MethodsWe have collected the X-ray, CT and MRI imaging date along the process of disease of patients who have suffered the atraumatic osteonecrosis of the femoral head and have not accepted surgery, from the first affiliated hospital of GuangZhou University of Traditional Chinese Medicine in January 2012 to March 2015. We have classified the femoral head with different shape of the viable/necrotic interface and recorded time before the collapse of femoral head. To analyse the relationship between the shape of the viable/necrotic interface and the collapse of the femoral head with chi-square test, Kaplan-Meier survival analysis and Cox regression, and attempt to establish a new classification system to prognosticate the collapse of osteonecrosis of the femoral head based on the different shape of the viable/necrotic interface.ResultsOur research have collected 95 patients (111 hips) and imaging date with total process of osteonecrosis of femoral head. We have gotten 75 male and 20 female in group,54 cases in left side,57 cases in right side. Age was ranged from 18 to 73, average for 45.52±13.24. All the case was in the light of diagnosis criteria, and insist in follow-up clinic and conservative medication. All patients have not accept surgical intervention, and can collect the first-visit imaging date and total process of osteonecrosis of femoral head.Observe finished at the time of the collapse of femoral head,60 hips have collapsed compare to the other 51 hips survival. The average follow-up 18.77+12.49 (3-58) months, collapse rate for 53.15%, and the average collapse time is 16.44+12.54(3-58)months. The new classification is four types, as types for:Transverse type, V type, Zigzag type and Closed type. There are 38 hips in transverse type group, collapse for 31 hips (81.58%), and the average collapse time is 13.16±11.10 (4-50) months. Tapered type is for 45 hips, collapsed for 24 hips (53.33%), and the average collapse time is 19.88±13.49 (3-58) months. There are 15 hips in wavy group, collapse for 4 hips (26.67%), and the average collapse time is 21.25±13.35 (10-39) months. Finally, the closed type is for 13 hips, but there is no collapse hip in this group. We analyzed the date with chi-square test, rank test, one-way ANOVA, Kaplan-Meier survival analysis and Cox regression, and the test show that there is a conspicuous different about the collapse time and survival time of hips among the four groups.ConelusionThe establishment of this new classification of the shape of the viable/necrotic interface is based on the fundamental of collapse of osteonecrosis of femoral head. The classification can not only forecast whether the femoral head will collapse or not, but also can estimate the time of the collapse that will happen. Therefore, it’s can make contributions to the treatment we choose and the right time we implement. Furthermore, it can provide more information about the prognostication to clinicians. In conclusion, the classification of the shape of the viable/necrotic interface is differing from other classification for the collapse of ONFH, so it can supplement each other and make contributions together for the prognostication of ONFH.