Avascular necrosis of the head of the femur, stage III, surgical management by drilling and bone grafting, clinical follow-up and magnetic resonance imaging results

ABSTRACT

This study was designed to elucidate the clinical, radiological and magnetic resonance imaging [MRI] results of management of atraumatic, aseptic, avascular necrosis of the head of the femur [AVN] in adults, stage III, by a new technique of drilling and autogenous bone grafting. 10 cases of AVN stage III were managed by drilling and bone grafting. There were 7 cases of corticosteroid therapy induced [AVN-CS] and 3 cases of idiopathic necrosis [AN-I]. The drilling was perofrmed by a 7mm reamer under image intensifier control. The cortical graft was obtained from the lateral cortex of the femur, and the cancellous bone grafts were obtained from the proximal femoral metaphysis, utilizing a single incision. Patients were evaluated prior to surgery and at 3, 6, 12, 18, and 24 month after surgery. Clinical evaluation, X-rays and MRI were all revised. Data were collected on all six appointments. Complaints and clinical examinations were summeriied by the Harris hip score. The aim of radiological examinations was to classify the stage of AVN before surgery and after 2 years follow-up and to assess the condition of AVN of the femoral head by detection of further collapse and osteoarthritic changes. MRI was performed for diagnosis and to demonstrate the extent of involvement of the head, to investigate the signal intensity and characteristics of the area of AVN during various stages of necrosis and healing, and to assess the viability of the graft and new bone formation. Clinically significant improvement of the hip score [pain, activity, gait, range of motion, and deformity] was noted in all cases. The hip score improved from an avarage of 27 points prior to surgery, to an average of 72 points after 24 month follow-up. 2 cases showed roentgenographic and MRI evidence of progression to stage IV. Plain radiography was useful in staging and follow-up of collapse and detection of the development of osteoarthritic changes. MRI proved to be a useful tool for diagnosis, staging, evaluation, and follow-up of reparative changes. MRI was useful in assessing marrow changes and graft incorporation and new bone formation after treatment of AVN of the femoral head by drilling and autogenous bone grafting. Drilling and bone grafting proved to be a useful method for treatment of AVN stage III as regarding pain and disability. This method is more suitable for the younger age group to defer early joint replacement. Radiography was usefeul for staging, detection of collapse, detecting progression of collapse, and detection of development of osteoarthritic changes. MRI proved to be an adequate tool for diagnosis, evaluation of the pathologic process, staging and classification of the disease, and for monitoring the incorporation of the graft, revasularization, healing and new bone formation in the necrotic femoral head