Triple arthrodesis is the most effective treatment resource for restoring shape and stability to the hind-foot. It is used in order to achieve a plantigrade foot, aligned, stable and painless, in the treatment of various pathologies. However, it has the effect of changing the dynamic mobility of the foot and diminishes the adapting ability to uneven ground, influencing the outcome. Opinions differ on the necessity of internal fixation to maintain the proper alignment of the hind-foot and improve consolidation, influencing the results.

The authors reviewed the patients who underwent triple arthrodesis between 01/01/1998 and 31/12/2008. Of a total of 46 patients 28 were reviewed, corresponding to 29 feet that underwent 36 interventions (7 recurrences).

Patients were divided into two groups according to whether or not the placement of internal fixation. They were evaluated according to the AOFAS ankle and hindfoot score and correlated with the radiologic result.

The most frequent indications for surgery were osteoarthrosis of the tarsus and sequelae of fractures of the calcaneus.

In the group without fixation 68% had radiological signs of consolidation. 24% required revision for non consolidation. In the group with internal fixation there was 72.7% consolidation and 9.1% required revision surgery. Bone graft was more often used in internal fixation group (72.7% vs 40%).

Group without fixation vs group with internal fixation:

AOFAS mean score: 74.5% vs 61.6%, patients without pain: 50% vs 20%; plantigrade foot with good alignment: 66.7% vs 40% without pain: 50% vs 20%; tibiotarsal arthritis: 48% vs 63.6%; Lisfranc arthrosis: 44% vs 63.6%.

There is a higher rate of consolidation in the group setting. However, the functional outcome seems to be better in the group without fixation.

Fixation seems to be associated with better consolidation. The functional outcome is related to a plantigrade and well aligned foot.