Change of Tibio-Talar Motion After Total Ankle Replacement

족관절 인공관절 치환술 후 족관절 운동범위의 변화

Purpose: Ankle fusion that is operated on severe ankle arthritis has its weakness in that normal walking is impossible, even though the result is pretty good. As a alternative choice, total ankle replacement pursues the longer survivorship with material improvement. However, it is not yet known how much range of motion is possible after the replacement, or how it has changed overtime. Therefore, we need an analyzation for that. Materials and Methods: A retrospective review of sixty-seven patients undergoing STAR total ankle replacement at our institution between 1998 and 2002 was conducted. Of those, twenty-six (39%) had complete sets of full dorsiflexion and plantar flexion lateral radiographs both between "immediate" postop and at a minimum of 2-years follow-up and no revision procedure during that time. The mean age of these patients was 63.2 years when the surgery was done; the etiology of arthrosis was 21(81%) post-traumatic/degenerative, 4 rheumatoid and 1 psoriatic. Results: Average "immediate" ankle range of motion was $15.9^{\circ}$, and total foot (non-ankle) motion was $20.6^{\circ}$. At one, two, and three years the average ankle and total foot ranges of motion were $17.4^{\circ}$, $17.6^{\circ}$, $15.6^{\circ}$ and $21.0^{\circ}$, $22.0^{\circ}$, $21.2^{\circ}$ respectively. Statistically there was no significant difference between "immediate" postop motion and one to three years postop (all p>0.05). Conclusion: The range of motion after the STAR total ankle replacement is maintained from the "immediate" postoperative range of motion, but not increased, in the 1-3 year post replacement period.