Long Term Follow-up of Free Vascularized Fibular Grafting in the Osteonecrosis of the Femoral Head
MC Yoo, YJ Cho, KI Kim, YS Chun, JW Yi
Department of Orthopaedic Surgery, School of Medicine, Kyung Hee University, Seoul, Korea

Purpose: To evaluate the clinical and radiographic long term follow-up results of vascularized fibular grafting (VFG) as a joint preserving procedure of the osteonecrosis of the femoral head (ONFH).

Materials and Methods: Between October 1979 and December 1992, 97 hips of 89 patients with ONFH that could follow up for at least 10 years were evaluated. The mean age at the time of operation was 34 years. There were 49 hips of Ficat stage II, 48 hips of stage III. The disease was associated with consumption of alcohol in 19 hips, trauma in 17, use of steroid in 7, in the remaining 54, the condition was idiopathic.

Results: The overall satisfactory results, including excellent, good or improved by 10 points, were seen in 78 hips(80.4%) clinically, and 63 hips(64.9%) showed radiographic improvement or no change . Radiographically, new bone formation and remodeling in 32 hips and no more progression of necrosis in 31 hips and collapse in 34 hips. There were only 9 conversions to THA until the last follow-up. By Kaplan-Meier survivorship analyses, there was a significant lower rate of conversion to total hip arthroplasty (THA) in younger patients who were less than 35 years. The probability of conversion to THA was not significantly related with etiology, radiologic stage, or location and involvement of the necrosis.

Conclusion: VFG not only has an excellent new bone formation and remodeling capacity but also is one of the highly recommendable joint preserving procedures in symptomatic ONFH in younger patients with early collapsed stages. Furthermore, the femoral head replacement would be avoided or at least postponed in advanced stage of young patients.