The Association Between a Hindfoot Deformity Assessed by Weightbearing CT and the Full Leg Alignment

Category: Hindfoot Introduction/Purpose: The exact relationship between different types of hindfoot deformities and the full leg alignment is currently unclear. Therefore, our aim is to assess hindfoot alignment on a weight-bearing CT (WBCT) and its association with the full leg radiographic alignment. Methods: A retrospective analysis was performed on a study population of 109 patients (mean age of 53 years ± 14.49) with a varus or valgus hindfoot deformity and the presence or absence of ankle osteoarthritis (OA) based on the Takakura classification. The mechanical hindfoot - (mHA) and subtalar vertical angle (SVA) were determined on WBCT, while the mechanical tiba – (mTA) and mechanical tibiofemoral angle (mTFA) were measured on full leg radiographs. Results: In patients with ankle OA, a hindfoot valgus deformity was associated with a significantly higher mean varus alignment of the knee (mTFA = -1.8°±2.1; mTAx= -4.3°±1.9) compared to a valgus alignment of the knee (mTFA = 0.3°±2.6; mTAx= -1.4°±2.2; P