Acute medial tibial plateau elevation with gradual metaphyseal correction using an Ilizarov fixator for late-presenting infantile Langenskiold stage V and VI Blount's disease. Short-term results.

Abstract

Correcting severe deformities associated with advanced stages of Blount's disease in adolescents varies in the literature between acute and gradual corrections. We aimed to report the early results (radiological and complications) of performing acute medial tibial plateau elevation combined with gradually correcting the metaphyseal deformity using an Illizarov external fixator in adolescents with late-presenting infantile Langenskiold stage V and VI Blount's disease. A prospective case series of 24 patients (24 limbs) with Langenskiold stage V and VI Blount's disease having a mean age of 11.63 ± 1.74 years were included. The radiological outcomes included hip-knee-ankle (HKA) angle, medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), Posterior proximal tibial angle (PPTA), and medial tibial plateau depression angle (MTPDA). Complications at any time point were reported. The Illizarov frame was removed after a mean of 14 ± 2.04 weeks postoperatively. After a mean follow up of 23.33 ± 9.43 months, all the radiological outcomes improved significantly (< 0.001) compared to preoperative values, HKA: 182.17 ± 1.97 vs. 148.29 ± 9.88, MPTA:88.0 (87.0-90.0) vs. 75.5 (70.0-80.0), PPTA 82.0 ± 1.82 vs. 67.67 ± 5.02, JLCA: 2.46 ± 1.77 vs. 19.92 ± 2.75, and MTPDA: 1.96 ± 2.07 vs. 50.08 ± 7.19. No cases of neurovascular complications. The pin tract infection rate was 62.5%, and all were treated conservatively. Varus deformity recurred in 5 (20.8%) patients, all at the metaphyseal level, with no collapse at the elevated medial tibial plateau. Significant Leg length discrepancy (> 2 cm) was encountered in 6 (25%) patients (five were patients with recurrent varus deformities, where the LLD was compensated after deformity correction). The management protocol we adopted, which entailed acute elevation of the medial tibial plateau depression combined with gradual correction of the proximal tibial deformity assisted by the Illizarov external fixator, provided promising results regarding its safety, ability of full deformity correction, and acceptable recurrence incidence. Not applicable.