Effects of medializing calcaneal osteotomy and lateral column lengthening osteotomy variations on foot alignment: A three dimensional anatomical model study.

BACKGROUND: This study quantified the isolated effects of medializing calcaneal osteotomy (MCO) and lateral column lengthening osteotomy (LCLO) on three-dimensional alignment in progressive collapsing foot deformity. METHODS: Weight-bearing CT-based models from six patients underwent virtual MCO and LCLO corrections of 5, 10, and 15 mm, generating 36 models. RESULTS: LCLO corrected forefoot abduction. Anteroposterior talus-first metatarsal angle improved by 4.1°, 9.3°, and 13.9°, with talonavicular coverage changes of -4.6°, -10.7°, and -14.5°. MCO corrected hindfoot valgus, reducing hindfoot moment arm by 5.3, 10.0, and 15.1 mm and improving hindfoot angle by 4.49°, 9.19°, and 13.74° and AP talocalcaneal angle by 3.5°, 7.3°, and 10.9°, respectively. Changes were approximately linear. CONCLUSION: These relationships provide a bone-based framework for deformity-guided planning. They reflect intrinsic osseous correction and may be most applicable to rigid deformities, whereas outcomes in flexible PCFD may depend on soft-tissue and biological factors.