Does Total Knee Arthroplasty Affect Ankle and Hindfoot Alignment? A Prospective Study on Functional and Radiological...

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Radiology

Background:

• Knee deformities often lead to compensatory hindfoot deformities to maintain a plantigrade foot.
• Total knee arthroplasty (TKA) aims to realign the knee by correcting the hip-knee angle (HKA).
• The impact of severe varus knee deformity on ankle and foot alignment post-TKA is not well-documented.

Purpose of the Study:

• To investigate the effect of TKA on hindfoot alignment in patients with severe varus knee deformity.
• To assess radiological and functional changes in the ankle and foot following TKA.
• To determine the correlation between knee realignment and hindfoot alignment correction.

Main Methods:

• Retrospective analysis of 66 patients (87 knees) who underwent TKA.
• Radiological assessment of hip-knee angle (HKA), tibial plafond inclination angle (TPIA), tibio-talar tilt angle (TTTA), and talar inclination angle (TIA).
• Functional assessment using the American Orthopaedic Foot and Ankle Society (AOFAS) score pre-operatively and at 2-year follow-up.

Main Results:

• TKA demonstrated statistically significant correction in hindfoot alignment parameters (HFA, TPI, TTT, TIA) (p < 0.001).
• Significant improvement in AOFAS scores was observed post-TKA (mean increase from 72.0 to 88.9, p < 0.001).
• While TKA corrects hindfoot alignment, the correlation between HKA correction and ankle alignment correction (TPI, TTT, TIA) was not statistically significant.

Conclusions:

• TKA effectively improves both radiological and functional hindfoot alignment.
• Persistent ankle and hindfoot malalignment post-TKA can be a source of patient dissatisfaction.
• Further research may be needed to address residual malalignment for optimal patient outcomes.