🔍 Key Findings

• A lateral surgical approach can successfully implant a canine total ankle replacement (cTAR) prosthesis with accurate implant orientation and stable joint mechanics.
• Post-implantation angular laxity was greater after the lateral approach (15.5°) than the medial approach (9.5°, p = 0.044), though joints remained within acceptable stability limits.
• External rotational laxity increased after implantation with both approaches (lateral +5.4°, medial +6.7°), suggesting mild postoperative rotational laxity likely related to soft-tissue dissection.
• Implant alignment differed minimally between approaches, with most alignment differences <4°, indicating comparable surgical accuracy.
• Bone–implant interface gaps were small and similar between approaches, with ~96% of gaps <1 mm, indicating excellent implant seating.
• Damage to the short lateral collateral ligament occurred in 4/5 lateral-approach limbs, likely due to its insertion near the talar articular surface.
• Technical challenges with the lateral approach included COR post placement and fibular fragment retraction, sometimes leading to slightly proximal implant milling.
• Clinical implication: A lateral approach is a viable alternative when medial exposure is difficult (e.g., medial implants, fibrosis, or abnormal medial malleolus), though ligament injury risk must be considered.