Essential Insights On Treating End-Stage Ankle Arthritis

John F. Grady, DPM, FASPS, Sarah Mahowald, DPM, and Donald Graves, DPM

   Despite these complications, 92 out of the first 100 patients reported good or excellent results, and would have chosen to have the procedure again. We removed the implant in four patients who went on to ankle arthrodesis. One patient lost her leg. Out of the first seven implants, there was a 71 percent complication rate with 7.43 degrees of dorsiflexion. The subsequent 93 implants had a 16 percent complication rate with 13.14 degrees of dorsiflexion. This demonstrates the learning curve.

   In addition, the earlier implants used an older model Agility design and the later implants were with more recent models. The next 100 implants had a 6 percent complication rate, further demonstrating the learning curve. Indeed, the learning curve is even more reason to view with skepticism the results of people publishing their first 100 cases after a short period of time.

Comparing One Surgeon’s Ankle Arthroplasty Results With Ankle Arthrodesis Outcomes

In the same period of time of his first 100 ankle implants, the lead author assessed his ankle arthrodesis rate and complications, looking at 26 patients from 1998 to 2002 with a follow-up of two years. For these patients, etiologies included post-traumatic osteoarthritis (22), rheumatoid arthritis (3) and psoriatic arthritis (1). The average pre-op range of motion was 12.5 degrees of plantarflexion and -3 degrees of dorsiflexion. The average post-op range of motion was 3 degrees of plantarflexion and 1.3 degrees of dorsiflexion. The average pre-op pain was 8.2/10 and the average post-op pain was 2.1/10 or a 74 percent reduction in pain.

   There was an 8 percent complication rate. The complications were a non-union that the lead author was able to successfully revise and a dehiscence, which closed with conservative care in two months. Despite the apparent success, 7 out of 26 patients (27 percent) considered the results less than good and would not have chosen this procedure again. Four out of six satisfied patients had a subsequent knee replacement and one hip replacement.

   This suggests that the arthrodesis of the ankle puts more pressure on the hip and knee although these are people with arthritis in general so one cannot interpret too much from that result.

Final Notes

We should not compare data from a surgeon with good ankle arthrodesis experience to data from a surgeon who is inexperienced with ankle arthroplasty. Rather, we should compare the data of a surgeon who has decent experience with ankle arthrodesis to the data of a surgeon who has decent experience with ankle arthroplasty. In addition, techniques have changed so much that early studies on ankle replacement are not as relevant as more recent studies.

   We believe more patients would prefer ankle replacement over arthrodesis, particularly in most young patients, even though several reports have suggested that the survivorship of implants and outcomes is less favorable in younger patients.23,24 It is the lead author’s experience, however, that younger patients actually do better and are even more satisfied with the results over the course of time even though there is the risk of early wearing out or implant failure. Obviously, there are circumstances (such as severe deformity or neuropathy) in which ankle arthrodesis would be favorable to ankle arthroplasty.

   In conclusion, the question no longer is, “Which is the better procedure: ankle arthrodesis or ankle joint replacement?” Rather, the question is, “Who is the ideal candidate for ankle replacement and who has to settle for arthrodesis as a solution to end-stage ankle arthritis?”

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