Proximal tibial osteotomy and Taylor Spatial Frame application for correction of tibia vara in morbidly obese adolescents.

BACKGROUND: Four percent of children and adolescents in the United States are morbidly obese. Treatment for tibia vara includes proximal tibial osteotomy and correction with a Taylor Spatial Frame (TSF). There are no reports that specifically examine the success of this technique in morbidly obese adolescents.

METHODS: A retrospective review was conducted of patients between 12 and 18 years of age with a body mass index for age at or above the 99th percentile who had undergone gradual correction of tibia vara with proximal tibial osteotomy and application of a TSF at our institution between 2005 and 2009. Deformity analysis was performed on full-length standing anteroposterior radiographs of both lower extremities and lateral radiographs of the involved tibia obtained preoperatively and at latest follow-up. All complications were recorded.

RESULTS: Fourteen patients met the inclusion criteria. The mean age was 13 years. The average body mass index was 45 kg/m. Preoperative deformity analysis demonstrated a mean mechanical axis deviation of 90 mm, mean mechanical medial proximal tibial angle of 66 degrees, and mean posterior proximal tibial angle of 80 degrees. Analysis at an average follow-up of 14 months demonstrated a mean mechanical axis deviation of 10 mm, mean mechanical medial proximal tibial angle of 88 degrees, and mean posterior proximal tibial angle of 81 degrees. Complications specifically related to the TSF occurred in 2 patients. Both experienced strut disengagement and loss of osteotomy position. This was treated with refastening of the strut and a new program of deformity correction. Complications related to the deformity correction occurred in 3 patients. One had premature fibular consolidation requiring repeat osteotomy, 1 developed a transient partial deep peroneal nerve palsy, and 1 experienced thigh soft tissue irritation from the proximal ring necessitating early TSF removal. One patient had a residual leg-length discrepancy that required tibial lengthening.

CONCLUSIONS: Correction of tibia vara with proximal tibial osteotomy and application of a TSF is an effective treatment option in morbidly obese adolescents. Associated complications are minimal.

LEVEL OF EVIDENCE: Level IV-therapeutic study.