Outcomes of late-stages infantile Blount's disease managed by acute single stage: medial hemi-plateau elevation and metaphyseal osteotomy. Eight case series.

This study aimed to evaluate the clinical and radiological outcomes of surgical intervention involving acute medial hemi-plateau elevation and metaphyseal osteotomy with internal fixation and growth modulation for late-stages Blount's disease. A retrospective analysis was conducted on consecutive patients with late-stages infantile tibia vara between 2014 and 2020. Inclusion criteria consisted of children aged 8 years and older with Blount's disease with Langenskiold stage IV, V or VI, tibia vara more than 30*, medial plateau depression angle (MPDA) exceeding 25* and knee instability with a minimum follow-up period of 3 years. Patients with Limb length discrepancy greater than 5 cm were excluded. Data collection included assessments of age, weight, disease stage, clinical tibiofemoral angle (TFA), mechanical medial proximal tibial angle (mMPTA), MPDA, tibial torsion and knee instability. Functional outcomes were evaluated using modified Pediatric Outcome Data Collection Instruments (PODCI) scores. The study included 5 children with 8 affected limbs. Among them, three children with five limbs had recurrent deformities after previous surgeries. All cases showed significant improvements in TFAs, mMPTA, tibial torsion, knee instability and modified PODCI scores. Complications included 4 cases of superficial infections, 1 intra-articular fracture, 2 minor screw breakage and 2 on-table under correction. Surgical intervention involving acute Single-stage medial hemi-plateau elevation and metaphyseal osteotomy leads to satisfactory outcomes in late-stages Blount's disease among older children. It is crucial to achieve proper correction of all deformity components during surgery, with epiphysiodesis on the lateral side to prevent further recurrence. Continuous follow-up until skeletal maturity is essential for optimal results.