HINDFOOT ARTHRODESIS: EFFECT OF EARLY WEIGHT BEARING ON UNION RATE

Abstract

Introduction: Non-union is a potential complication following hindfoot arthrodesis and occurs at a rate of 5–10% as reported in the literature. Following the procedure, patients are usually kept non-weight bearing (NWB) for 6–8 weeks followed by protected full weight bearing (FWB) for further 6 weeks. Based on radiological and clinical evidence of bony union at 12 weeks patients are allowed to mobilise FWB without protection.

Aim: The aim of this study is to evaluate the effect of early post operative weight bearing on the union rate, following hindfoot arthrodesis.

Method: In this retrospective study data was collected on patients who had hindfoot arthrodesis from 2003 to 2008 by a single surgeon. Two post operative mobilisation protocols were used and the union rates were compared.

• Protocol 1: 6 weeks NWB, 3 weeks partial weight bearing (PWB), 3 weeks FWB in plaster.

• Protocol 2: 2 weeks NWB, 4 weeks PWB, 6 weeks FWB in plaster.

Results: 128 hindfoot joint arthrodesis were performed in 73 patients. Non-union rate was 2%(1 in 44) in early weight bearing group and 20% (4 in 16) in late weight bearing group. Union rate following the revision surgery with bone graft was 100% in both groups.

Conclusion: The union rate following hindfoot surgery significantly improves (p=0.01) with early post-operative weight bearing.