SLR - December 2016 - James Foster
Reference: Stavrakis Al, SooHoo NF. Trends in Complication Rates Following Ankle Arthrodesis and Total Ankle Replacement. J Bone Joint Surg Am. 2016 Sept 7;98(17):1453-8.Scientific Literature Review
Reviewed By: James Foster, DPM
Residency Program: Grant Medical Center
Podiatric Relevance: Ankle arthritis results in substantial pain, disability, and diminished quality of life to the podiatric patient. Once conservative treatment fails, surgical intervention is often necessary. This historically has been treated with primary arthrodesis of the ankle joint, however concern for reoperation including increased risk of developing arthritis in adjacent joints, and multiple revisions has increased interest in total ankle replacement. Total ankle replacement allows the patient to maintain some ankle joint range of motion, potentially decreasing risk of arthritis in adjacent joints, but long-term outcomes comparing these two surgical options is limited. The purpose of this study was to demonstrate increasing utilization and lower complication rates for total ankle replacement using previously published cases from 1995-2004, compared to new data and cases from 2005-2010.
Methods: This study was a retrospective review assessing short and long term outcomes of all patients who underwent either primary ankle arthrodesis or ankle replacement during the 16-year observation period (1995-2010) in the state of California using ICD-9-CM codes from the California Office of Statewide Health Planning and Development (OSHPD) discharge database. Short-term outcomes studied included acute myocardial infarction, pneumonia, sepsis, pulmonary embolism, mechanical complications, surgical site bleeding, peri-prosthetic infection, and wound infection. Long-term outcomes evaluated were overall rate of revision surgery, adjacent joint procedures, total knee replacement, and below-the-knee amputation.
Results: A total of 8,491 patients (86.90%) underwent ankle arthrodesis, and 1,280 (13.10%) underwent total ankle replacement during the 16-year observation period. There was a peak in annual volume of ankle arthrodesis procedures in 2006, followed by a decline in the total number of these cases, which was complemented by an increase in volume of total ankle replacement. Short-term complication results showed decreased rate of readmission and peri-prosthetic joint infection/wound infection for total ankle replacement when compared to ankle arthrodesis. There was no difference in the rate of acute MI, pneumonia, sepsis, pulmonary embolism, mechanical complications, surgical-site bleeding, or death. Long-term complications showed patients with total ankle replacement were at lower risk of requiring subsequent subtalar arthrodesis, requiring ankle arthrodesis as a salvage procedure, or requiring below-knee amputation. The total ankle replacement group was at a higher risk of undergoing revision ankle procedures. There was no difference between the two groups in regards to subsequent triple arthrodesis, tarsometatarsal arthrodesis, or total knee replacement.
Conclusions: Based on this retrospective study, the previous findings from 1995-2004 which included association with increased risk of device related infection, as well as major revision surgery when compared to ankle arthrodesis was no longer the case, suggesting risks associated with total ankle replacement have decreased over time. The risk of subtalar arthrodesis following total ankle replacement remains lower than ankle arthrodesis over the long term, which may be due to the fact that maintaining some ankle joint range of motion may have the advantage of preventing adjacent joint arthritis. However, one of the key weaknesses in this observational study design was selection bias between the groups. There’s no preoperative information of severity of arthritis or other factors that may complicate surgery, and there’s no information on functional outcomes. Ankle arthrodesis may be recommended more often to patients with higher degrees of medical comorbidity, increasing complication risk. Another weakness was the difference in length of observational period for patients depending on their procedure date. Mean follow-up was 6.6 years with a standard deviation of 4.6 years, but the bottom 25% of those cases had an observation period of 2.7 years or less, which likely had an impact on long-term complication rates. Despite the short-comings this study, the new data does suggest there is no longer the same risk of short-term complication after total ankle replacement, and should be considered a safe alternative to ankle arthrodesis. Maintaining some ankle joint range of motion may slow the progression of adjacent joint breakdown, and should be considered on a case to case basis.