The Role of Taylor Spatial Frame in the Treatment of Blount Disease

Abstract

Background: Alteration of the posteromedial part of the proximal tibia is the main characteristic of Blount's disease and if left untreated, leg alignment and normal development of the lower limbs may be compromised.

Aim: To report treatment outcomes in children with Blount's disease using the Taylor Spatial Frame (TSF).

Materials and methods: From January 2007 to December 2014, 16 young children (24 tibia) with a mean age of 7.5 years (range of 3-14 yrs) and severe Blount's disease were treated using TSF. Preoperative long standing radiographs were performed and anatomic medial proximal tibial angle (MPTA), diaphyseal-metaphyseal tibial angle (Drennan), femoro-tibial angle and leg length discrepancy (LLD) were measured.

Results: Post-operative improvement of all measurements was observed. MPTA increased from a mean of 71.8° (58° - 79°) to 92.5° (90° - 95°), the Drennan decreased from 16.6° (14° - 18°) to 3.6° (0° - 6°), the F-T angle changed from 15.4° (10° - 25°) of varus to 5.9° (2° - 10°) of valgus and the LLD decreased from 208 mm (150-320) to 69 mm (0- +120). Mean follow-up was 45.6 months. According to Paley's criteria pin track infection was present in 6 tibiae, while in 5 patients software changes were necessary. Recurrence was observed in 3 patients (triplets). Complete restoration of the mechanical axis was obtained at the end of the treatment.

Conclusions: In the last decades, different surgical treatments have been proposed for Blount's disease (tension band plate, staples, osteotomies using external or internal fixation). External fixation using the TSF allows gradual safe correction of multiplanar deformities and is a well-tolerated technique by patients with Blount's disease.

Keywords: Blount’s disease; children; external fixation; multiplanar deformity; tibial osteotomy.