SLR - May 2015 - Abigail Smith

The Impact of Diabetes on the Short- to Mid-Term Outcome of Total Ankle Replacement

Reference: Choi WJ, Lee JS, Lee M, Park JH, Lee JW. The Impact of Diabetes on Short- to Mid-term Outcome of Total Ankle Replacement. Bone Joint J. 2014 Dec;96-B(12):1674-80.

Scientific Literature Review

Reviewed By: Abigail Smith, DPM
Residency Program: North Colorado Medical Center, Greeley, CO

Podiatric Relevance: Total ankle replacement (TAR) technology has advanced over recent years, and as such, these types of procedures are becoming relatively more common within the podiatric and orthopaedic communities.  Proper patient selection is also important when performing TAR surgery. Diabetes has been associated with poorer outcomes in other joint replacement and ankle fracture surgeries. Given the prevalence of diabetes in the podiatric patient population it is important to realize the impact of this medical comorbidity on TAR outcomes.

Methods: Data was collected from 173 patients that underwent TAR (HINTEGRA prosthesis) between January 2004 and December 2011 using similar operative technique. There were 130 non-diabetic subjects and 43 diabetic subjects. The diabetic group was further subdivided into controlled (n = 25) and uncontrolled (n = 18). Follow-up was at least 24 months. Pre-operative and post-operative evaluation consisted of the Ankle Osteoarthritis Scale (AOS), and final follow-up evaluation included determining AOFAS ankle-hindfoot scores. Radiological progress was also assessed at each follow-up visit, looking for radiolucency at the implant-bone interface and osteolysis.

Results: Significant improvement in AOS and AOFAS scores was observed in both the diabetic and non-diabetic groups, however, the post-operative AOS disability scores were significantly higher in the diabetic group compared to the non-diabetic group. More specifically, the uncontrolled diabetic group experienced higher AOS disability scores versus the controlled diabetic group. Continued post-operative improvement was also better in the non-diabetic group. Clinical failure rate was higher in the diabetic group (21 percent) compared to the non-diabetic group (11.6 percent). The diabetic group experienced a higher rate of early-onset osteolysis (25.5 percent) compared with the non-diabetic group (10.7 percent). In terms of survival, Kaplan-Meier survival analysis revealed similar survival between diabetics and non-diabetics up to 36 months, after which the diabetic group had decreased survival. Survival rates were similar in the non-diabetic group and controlled diabetic group, but both of these groups had significantly better survival rates compared to the uncontrolled diabetic group.

Conclusions: The results of this study show that patients with diabetes experience increased rates of certain complications associated with TAR. Poor glycemic control contributes to diabetic complications (vasculopathy, neuropathy, dermopathy, nephropathy, etc.) that may affect the post-operative course and ultimate survival of the implant. Specifically, uncontrolled diabetics had more complications related to wound healing. The higher rate of early-onset osteolysis in the diabetic patients is hypothesized to be attributed to insulin deficiency affecting osteoblast function in the early post-operative stages. The results of this study seem to suggest a negative impact of diabetes on short- to mid-term outcomes of TAR. These findings re-inforce the need for a thorough discussion between physician and the diabetic (and non-diabetic) patient when considering TAR surgery.

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