The salvage of complex hindfoot problems with use of a custom talar total ankle prosthesis.

BACKGROUND

There has been recent interest in the use of a custom long-stemmed talar component for salvage of failed total ankle replacement or for management of combined ankle and hindfoot pathology. The purpose of this study was to retrospectively review prospective data on patients who underwent total ankle arthroplasty with a custom long-stemmed talar prosthesis.

METHODS

From November 2004 to February 2006, thirty-three custom total ankle arthroplasties were performed in thirty-two patients. The indication for this prosthesis was stage-IV adult-acquired flatfoot deformity in six patients (19%), failure of a prior total ankle replacement because of severe subsidence and loosening of the talar component in thirteen (41%), and combined arthritis of the ankle and hindfoot joints in thirteen patients (41%; fourteen ankles). Patients were assessed for range of motion, radiographic results, and functional outcomes with use of the Short Form-36 (SF-36) subscale scores, American Orthopaedic Foot & Ankle (AOFAS) hindfoot score, and the Maryland Foot Score (MFS) at a minimum of four years.

RESULTS

All patients were followed for an average of 58.6 months (minimum, fifty-two months) There was an overall increase in the total arc of motion following surgery from an average (and standard deviation) of 21.3° ± 14° preoperatively to 32.2° ± 11° postoperatively (p < 0.05). Subsidence (<3 mm) was noted in three patients. One patient had asymptomatic osteolysis around the talar stem. The mean Physical Component Summary score on the SF-36 was 28.2 ± 5.6 preoperatively and increased to 39.7 ± 6.5 postoperatively (p < 0.05). The mean SF-36 Mental Component Summary value increased from 42.2 ± 13.8 preoperatively to 50.8 ± 12.6 postoperatively (p < 0.05). The mean MFS was 47 ± 13 preoperatively and increased to 75 ± 10 postoperatively (p < 0.05). The average AOFAS hindfoot score increased from 41 ± 16 preoperatively to 68 ± 12 postoperatively (p < 0.05). There were three failures at greater than thirty-six months after surgery.

CONCLUSIONS

Our data indicate that the use of a custom long-stemmed talar component, either placed primarily in patients with ankle and hindfoot arthritis or used as a revision prosthesis in patients with a failed total ankle replacement, is promising.