Two-Stage Surgical Treatment of Complex Femoral Deformities with Severe Coxa Vara in Polyostotic Fibrous Dysplasia

Background: In patients with polyostotic fibrous dysplasia with extensive femoral involvement, severe coxa vara may cause complex femoral deformities that are difficult to treat with a single-stage surgical procedure. We evaluated the results of treatment of such patients with a two-stage procedure. Methods: Eleven patients with polyostotic fibrous dysplasia and severe coxa vara (including one who required bilateral treatment and one who required repeat treatment) were treated surgically at a mean age of fourteen years and four months. A two-stage surgical procedure was planned to correct the deformity. The first stage involved correction of the coxa vara and fixation with a hip plate. The second stage involved correction of a shepherd's crook deformity if present and definitive fixation with an interlocking cervicodiaphyseal nail. All patients were evaluated clinically and radiographically at a mean of four years and seven months after the second-stage procedure. Results: The femoral neck-shaft angle averaged 83 degrees before surgery and was corrected to a mean of 130 degrees after the first-stage procedure. In two patients, cutout of the hip screw-plate caused acute postoperative loss of correction (by 40 degrees in one patient and 20 degrees in the other). After the second-stage procedure, the neck-shaft angle was either fully corrected or improved and the shepherd's crook deformity was fully corrected in all patients. At the time of the latest follow-up, the mean neckshaft angle was 124 degrees, with a mean loss of correction of 5 degrees relative to the angle measured at the end of the second-stage procedure. The mean estimated blood loss was 625 mL in the first stage and 979 mL in the second. Conclusions: The two-stage surgical procedure designed to treat patients with polyostotic fibrous dysplasia with complex femoral deformity and severe coxa vara restored a nearly normal femoral alignment that was maintained at a mean of four years and seven months of follow-up. The clinical benefits were pain relief in all of the patients and gait normalization or improvement in most. The estimated blood loss was substantial in both stages.