Corrective osteotomy for 111.4-degree tibial procurvatum in osteogenesis imperfecta type III patient: a rare case report with multistage interventions.

Osteogenesis imperfecta (OI) is a rare genetic disorder marked by bone fragility and progressive deformity. Type III OI represents a severe form characterized by recurrent fractures, bowing, and significant functional impairment. We report a 17-year-old with type III OI and an extreme 111.4° tibial procurvatum deformity alongside recurrent femoral fractures. His history included multiple intramedullary nailing procedures and revision surgeries. The most recent treatment involved a two-level tibial osteotomy with subsequent cast immobilization, resulting in marked improvement. The Lower Extremity Functional Scale increased from 38/80 preoperatively to 70/80 at follow-up, surpassing the minimal clinically important difference. Severe long bone deformities exceeding 60-90° in OI are uncommon and require individualized, multidisciplinary care. Multilevel osteotomies with intramedullary fixation remain central to correction, though complications persist. This case highlights the complexity of managing extreme tibial deformities in OI and supports multistage reconstruction to restore alignment and function.