Ankle arthrodesis is effective, reliable, and technically straightforward. It affords substantial pain relief and restoration of function in patients with arthritis of the ankle. In one recent clinical series of forty-eight patients undergoing ankle arthrodesis, the fusion rate was 96% with significant improvement in the average AOFAS (American Orthopaedic Foot and Ankle Society) ankle-hindfoot score (p < 0.0005)1.
Nevertheless, the decreased sagittal-plane motion that results from ankle arthrodesis adversely impacts function. Moreover, this procedure is associated with the development of degenerative change in the ipsilateral hindfoot. In one long-term review, moderate or severe ipsilateral subtalar arthritis developed in 91% of patients who underwent ankle arthrodesis2. As a result of these long-term consequences, many orthopaedic surgeons now consider total ankle replacement to be a viable alternative to arthrodesis and are more frequently offering this operation to their patients3. This trend is likely to continue as advances are made in implant design and as new prostheses are developed. Further, the indications for total ankle replacement are expanding beyond only ideal candidates with good bone stock and minimal deformity.
In the present study, SooHoo and colleagues used the California inpatient discharge database to review more than 5000 patients who underwent total ankle replacement and ankle arthrodesis from 1995 through 2004. Long and short-term outcomes, including the rates of infection, revision surgery, and subtalar joint fusion, were analyzed. Logistic and proportional hazard regression models were also used.
The authors confirmed the longstanding notion that patients who have had total ankle replacement are more likely to need major revision surgery than are patients who have had ankle arthrodesis (23% compared with 11%, respectively, at five years postoperatively). With total ankle replacement, there was also a higher risk of readmission for an infection that was related to the implanted device. Meanwhile, in patients who underwent ankle arthrodesis, there was an increased risk of the development of ipsilateral subtalar arthritis (2.8% in patients who had ankle arthrodesis compared with 0.7% in patients who had ankle replacement).
For orthopaedists who treat ankle arthritis, these findings represent straightforward and useful data that should prove helpful when counseling patients who are considering ankle replacement and/or arthrodesis. The important yet abstract concept of "risk tolerance" becomes pertinent and can be more readily factored into the clinical decision-making process.
Of course, the current study is not without limitations. As the authors acknowledge, patients who undergo ankle arthroplasty may not be comparable with patients who undergo arthrodesis. Indeed, patients who underwent arthrodesis in this study were more likely to have uncontrolled diabetes and osteonecrosis. Furthermore, some may consider subtalar arthritis to be a contraindication to ankle replacement, thereby falsely decreasing the rate of subtalar arthritis in patients who undergo total ankle replacement.
Nevertheless, SooHoo and colleagues are to be commended for conducting a well-structured population-based investigation and presenting concise and useful data that should be shared with all patients who are considering total ankle replacement and ankle arthrodesis.
*The author did not receive any outside funding or grants in support of his research for or preparation of this work. Neither he nor a member of his immediate family received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the author, or a member of his immediate family, is affiliated or associated.
1. Colman AB, Pomeroy GC. Transfibular ankle arthrodesis with rigid internal fixation: an assessment of outcome. Foot Ankle Int. 2007;28:303-7.
2. Coester LM, Saltzman CL, Leupold J, Pontarelli W. Long-term results following ankle arthrodesis for post-traumatic arthritis. J Bone Joint Surg Am. 2001;83:219-28.
3. Easley ME, Vertullo CJ, Urban WC, Nunley JA. Total ankle arthroplasty. J Am Acad Orthop Surg. 2002;10:157-67.