Functional outcome after modified Blair tibiotalar arthrodesis for talar osteonecrosis.

BACKGROUND: Osteonecrosis of the talar body is a challenging problem for both patient and surgeon. One reconstruction option is an arthrodesis of the tibia to the talar neck, as described by Blair, which has the theoretical advantages of salvaging some hindfoot height and motion of the subtalar joint. A few case series have been published describing outcome after modified Blair fusions, none with validated functional outcomes. The purpose of this article is to describe a modification of Blair's original technique, and report the functional outcomes in a series of patients undergoing this procedure.

METHOD: A retrospective review of seven patients with talar osteonecrosis undergoing modified Blair tibiotalar arthrodesis was performed. The median patient age was 51 (range, 39-78). Median follow-up was 20 months (range, 12-112). Two patients required a repeat procedure for delayed/nonunion, with subsequent uneventful union. In all patients the procedure included compression screw fixation of the talar head to the anterior distal tibia, with the two repeat procedures and the most recent patient having an additional anterior compression plate and bone graft. Functional outcome measures using both the AOFAS ankle-hindfoot score and the SF-36 global health outcome measure were obtained at latest follow-up. In addition, radiographic assessment of bone union and time to union was determined.

RESULTS: Median SF-36 physical and mental component scores were 46 and 61, respectively. The median AOFAS ankle-hindfoot score was 67 out of 100. Median visual analog scales for postoperative pain and function were 7.1 and 6.0 respectively, out of a best possible score of 10.

CONCLUSION: Functional outcome scores after modified Blair arthrodesis are lower than similar scores after conventional tibiotalar fusion, and much lower than "normal" values; however, the procedure has similar, if not lower, complication rates to alternative complex hindfoot reconstructions, and this procedure is a valuable alternative in the management of talar osteonecrosis with arthrosis.