Impact factors and clinical outcomes of the treatment for osteonecrosis of femoral head by using impacting bone graft: a long and mid-term study

Abstract

Objective To investigate the long and mid-term clinical outcomes of the impacting bone graft and impact factors in treating osteonecrosis of femoral head (ONFH). Methods Impacting bone graft was utilized to treat 54 patients (64 hips) with ONFH. There were 44 cases male and 10 female with an average age of 35.44±8.86 (range, 20-55) years. There were 5 hips caused by trauma, 23 hips by glucocorticoid administration, 28 hips by intake of alcohol, 4 hips by alcohol and glucocorticoid induced, and 4 hips by idiopathic factors. There were 14 hips at ARCO (Association Research Circulation Osseous) stage Ⅱ, 50 hips at stage Ⅲ and 6 hips at JIC (Japanese Osteonecrosis Investigation Committee) type B, 23 hips at type C1, 35 hips at C2 type. Harris hip score (HHS) was used to evaluate the clinical effects. Potential factors, including age, etiologies, pain duration, ARCO stage and JIC type, were evaluated to investigate their impacts on clinical outcomes. Surgery failure was defined as diverting to other surgeries, or poor HHS score evaluation (<70 points). The survival time of femoral head was defined as the interval between time of impacting bone graft and the failure of surgery. Results The mean follow-up duration was 8.61±1.45 (range, 5.13-10.84) years. The proportion of patients with excellent or good Harris score was 81.3% (52/64). The excellent or good rate was 76.0% (38/50) at 8 years follow-up. Furthermore, the total survival rate of femoral head was 92% at 8 years follow-up. The number of surgical failure was 10 (12 hips) and the failure rate was 18.8% (12/64). There were no significant differences in ages, etiologies, pain duration, ARCO stage and JIC type among these patients before surgery (P 0.05). When considering the duration after the initial pain, there were significant differences among 6 months group, 7-12 months group and over 12 months group (P<0.05). There were significant differences between the Ⅲa stage and Ⅲc stage (P<0.05), and between the C1 type and C2 type (P<0.05). Multifactor Logistic regression showed that there was closely relationship between the Harris score (excellent or good rate) after surgery and pain duration, ARCO stage, JIC type (P<0.05). Conclusion Impacting bone graft for ONFH is satisfy in the long and mid-term follow up duration. Impacting bone graft would be more suitable for patients with the collapse less than 2 mm, the lateral wall preservation and interval after the initial pain less than 12 months. Key words: Femur head necrosis; Bone transplantation; Root cause analysis; Follow-up studies