Abstract
Category:
Ankle Arthritis; Ankle
Introduction/Purpose:
Predictors of intra operative and early complications following total ankle replacement (TAR) become more important as the incidence and indications for TAR continue to expand. Talar bone loss whether from avascular necrosis, osteoarthritis, or post traumatic arthritis can be a challenging problem to deal with in TAR. The aim of this study is to report predictors of complications in TAR with talar bone loss.
Methods:
A retrospective review using CPT codes for four surgeons over a three-year period at an academic institution was performed. A single surgeon reviewed the immediate preoperative plain radiographs for 200 consecutive patients for talar bone loss. The mortise and lateral views were used to calculate talar bone loss and then averaged (Fig 1). 37 patients were identified as having talar bone defects of greater than 20 percent when the two measurements were averaged. Our preoperative variables we looked at were size of talar defect, location, and cause of talar defect and postoperatively, the implant choice. Our primary outcomes were intraoperative fracture, reoperation, subsidence, and revision surgery.
Results:
The average follow up was 23 months. The average defect size was 54 percent with a range of 20 to 100 percent. Mann U Whitney tests were performed that showed a relationship between the lateral and overall percentage of talar bone loss being predictive of subsidence of the talar component. A Fischer exact test showed a that a chamfered talus cut was protective against subsidence. The mean of the talar bone loss for the chamfered components were 40% versus 58% in flat cut. There were no other significant differences when comparing complications, fracture, reoperation, or wound complications.
Conclusion:
While TAR for patients with talar bone loss can be a good option for the patient and surgeon it does have a higher complication rate than standard TARs. Careful attention should be given to the percentage of talar bone loss. Flat cut and revision style components were more likely to be used in worse situations, so it is not the authors belief that they are more prone to subsidence. All patients over 20% bone loss need extensive discussion regarding potential complications and additional procedures. Talar bone loss is a difficult problem to deal with but TAR is a viable option.
