Foot and Ankle International - 2026-03-04 - Journal Article
Total Ankle Arthroplasty Kinematics Using a Symmetric Bicondylar Talar Component Design: A Cadaveric Gait Simulation Short Report.
Palma J, Hoffman JW, Harnroongroj T, Kim S, Henry J, Deland J, Ellis SJ, Steineman B, Demetracopoulos CA
Topics
Key Takeaway
A symmetric bicondylar talar component TAA reduced dorsiflexion by 4.0° and increased transverse-plane ankle ROM by only 1.9° during cadaveric gait simulation, with no significant subtalar kinematic changes.
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Summary
This study quantified ankle and hindfoot kinematics after TAA using a symmetric bicondylar talar component in an 11-specimen cadaveric 6-DOF robotic gait simulation of the stance phase. Post-TAA ankle dorsiflexion decreased 4.0° (P=.041) and inversion increased 1.5° in early stance, while talonavicular eversion increased 3.5° in late stance (P=.016); subtalar kinematics were unchanged. Transverse-plane ankle ROM increased 1.9° (P=.025), which the authors characterize as smaller than previously reported values for asymmetric talar designs under comparable conditions.
Key Limitation
The sample size of 11 specimens is underpowered to detect small but clinically meaningful kinematic differences, and the absence of soft-tissue tensioning protocols may not replicate in vivo ligamentous constraint.
Original Abstract
BACKGROUND
The availability of total ankle arthroplasty (TAA) systems with varying designs of talar condylar geometry has increased. However, it remains unclear how these features influence the motion of the ankle and hindfoot joints. This study assessed the ankle and hindfoot kinematics using a contemporary TAA system with a symmetric bicondylar talar component design.
METHODS
TAA was performed in eleven mid-tibia specimens. A 6-degree-of-freedom robot sequentially simulated the stance phase for the intact and post-TAA conditions. The kinematics and range of motion (ROM) of the ankle, subtalar, and talonavicular joints were calculated and compared between conditions.
RESULTS
The ankle demonstrated decreased dorsiflexion by 4.0 degrees ( P = .041) and increased inversion by 1.5 degrees ( P = .04) during early stance. The talonavicular joint was significantly more everted by 3.5 degrees during a portion of late stance ( P = .016). There were no significant differences between conditions in the subtalar joint. The ankle ROM in the transverse plane increased 1.9 degrees post-TAA ( P = .025), but no significant changes were observed in the subtalar or talonavicular joints.
CONCLUSION
In this cadaveric stance‑phase simulation, ankle and hindfoot kinematics and ROM were modestly altered after TAA. Therefore, a TAA system with a symmetric talar condylar design may closely replicate native ankle and hindfoot joint motion.
CLINICAL RELEVANCE
Implant design may influence joint kinematics; in this cadaveric model, a symmetric bicondylar talar component showed smaller transverse‑plane ROM increases than those previously reported for one asymmetric design tested under similar conditions.