PERCUTANEOUS PERFORATIONS FOR THE TREATMENT OF OSTEONECROSIS OF THE ANKLE

Abstract

Introduction: Core decompression has historically been used during the early stages of osteonecrosis of the ankle as a treatment method to decrease pain and defer the eventual collapse of the joint. Originally, this procedure was described using large diameter trocars. The multiple locations of the lesions (such as the distal tibia and fibula, the talar dome, the calcaneus, and/or the metatarsals) and the relative small affected bones (compared to the femoral head and distal femur) make this procedure technically difficult. The investigators report on the treatment of osteonecrosis of the ankle with a new technique using multiple small percutaneous 3-mm perforations.

Methods: Between September, 2002 and May, 2004, the senior author treated 44 symptomatic ankles affected with osteonecrosis using the multiple perforation technique. The series included 31 patients (23 women, 8 men) who had a mean age at the time of surgery of 42 years (range, 17 to 61 years). All the procedures were performed using a 3-millimeter Steinman pin technique. Radiographic outcome was assessed during post-operative clinical visits using plain x-rays and magnetic resonance imaging. Clinical outcome was assessed postoperatively using the AOFAS (American Orthopaedic Foot and Ankle Society) score. Progression of the disease (defined as evidence of subchondral collapse or AOFAS score < =80 points) was correlated with demographic variables such as associated risk factors, prior surgical procedures, size, and location of the lesions.

Results: Ankle arthrodesis was avoided in 93% of the cases (41 of 44 ankles) at a mean follow-up of 3.6 years (range, 2 to 5 years). Forty of 44 ankles (91%) had a successful clinical outcome (AOFAS score ≥ 80 points). The AOFAS score for the entire series increased from a preoperative mean of 41 points (range, 34 to 55 points) to a postoperative mean of 88 points (range, 51 to 100 points). The AOFAS score for the series excluding the three ankles that required arthrodesis increased from a preoperative mean of 41 points to 91 points postoperatively. The three cases that required ankle arthrodesis presented initially with osteonecrosis of multiple bones about the ankle (talus, calcaneus, distal tibia and fibula) and two of these cases had HIV as an associated risk factor for osteonecrosis. All but 8 patients presented signs and symptoms of osteonecrosis in other joints (hip, knee, shoulder) and this had a negative correlation with outcome. There were no complications from the procedures, which were all performed as outpatient surgeries.

Discussion: The percutaneous perforations technique appears to be a low-morbidity method of relieving symptoms and deferring ankle arthrodesis (or other invasive procedures) in patients with symptomatic osteonecrotic ankles. The authors believe that these results support the need for a multicenter-randomized study comparing minimally invasive treatment options for osteonecrosis.