Knee osteotomies significantly influence coronal ankle alignment: A radiographic analysis

Area of Science:

• Orthopedic surgery
• Biomechanics
• Radiographic analysis

Background:

• Knee osteotomies are performed to correct alignment and reduce joint load.
• The impact of these procedures on distal lower limb alignment, specifically the ankle, is not fully understood.

Purpose of the Study:

• To evaluate the effect of lateral closing-wedge high tibial osteotomy (LCW-HTO) and medial closing-wedge distal femoral osteotomy (MCW-DFO) on ankle coronal alignment.
• To assess changes in tibio-talar inclination (TTI) and Mikulicz lateral distal tibial angle (M-LDTA) post-osteotomy.

Main Methods:

• Retrospective analysis of 60 knees (37 LCW-HTO, 23 MCW-DFO) with pre- and post-operative full-length weight-bearing radiographs.
• Measured radiographic parameters included LDTA, hip-knee-ankle angle, M-LDTA, and TTI.
• Ankle realignment was quantified by changes in LDTA-M-LDTA difference and TTI.

Main Results:

• Both MCW-DFO and LCW-HTO significantly improved LDTA-M-LDTA and TTI.
• MCW-DFO demonstrated a greater correction in both parameters compared to LCW-HTO.
• Post-operative TTI and M-LDTA showed convergence, indicating improved alignment.

Conclusions:

• Knee osteotomies significantly influence ankle coronal alignment, altering TTI and M-LDTA.
• Higher-level osteotomies (MCW-DFO) have a more pronounced effect on ankle alignment than LCW-HTO.
• Preoperative assessment of knee deformities is crucial to anticipate and prevent post-operative ankle imbalance.