ADOLESCENT BLOUNT’S DISEASE: IS FIBULAR OSTEOTOMY NECESSARY?

Abstract

Introduction: The standard treatment of adolescent Blount’s disease includes proximal tibial valgus osteotomy and osteotomy of the fibula. Some believe that the fibula should also be fixed to prevent migration and subluxation. We performed correction of deformities in eight patients (10 tibiae) with adolescent Blount’s disease using the Taylor Spatial Frame (TSF). In all patients, the origin (virtual hinge) was placed at the level of the proximal tibial fibular joint. The purpose of this study was to review treatment outcome of proximal tibial osteotomy without osteotomy of the fibula in patients with adolescent Blount disease.

Methods: Eight patients (10 tibiae) were treated by proximal tibial osteotomies and gradual correction by TSF without fibular osteotomy over a period of three years. All patients were males with a mean age of 14.6 years (range, 14–17 years). All patients had severe proximal tibial varus, four had significant proximal tibial procurvatum, and six had internal tibial torsion. The fibula was not fixed in five patients, and fixed distally in three.

Results: Frames were removed at an average of 12.8 weeks (range, 12–15 weeks). The mean preoperative proximal tibial varus was 16.2^o (range, 12–19^o), corrected to normal values in all patients. The mean preoperative MPTA was 71.4^o (range, 67–77^o) and corrected to a mean MPTA 87.1^o (range, 85–89^o). In four patients (5 tibiae) with proximal tibial procurvatum, the PPTA was corrected to normal range.

Mean correction of internal tibial torsion was 10^o (range, 5–15^o), performed in six patients (8 tibias). Pre-operative MAD was 55.8 mm medial to center of the knee (range, 44–77 mm), corrected to a mean MAD of 4.9 mm medial to center of the knee (range, 2–11 mm).

Complications included superficial pin tract infections in seven patients.

No complications related to the fibula were observed during/after correction.

Conclusion: Based on our initial experience, we believe that most patients with adolescent Blount disease could have successful and predictable correction of tibial deformities without a need for osteotomy and fixation of the fibula.