[Joint-preserving correction of Chopart joint malunions].

BACKGROUND

Injuries to the mid-tarsal (Chopart) joint are frequently overlooked or misinterpreted and therefore, not adequately treated at initial presentation. Malunion results in a loss of essential joint function and a three-dimensional malalignment leading to considerable impairment of global foot function and a rapid development of painful posttraumatic arthritis.

METHODS

If no symptomatic arthritis is present, joint displacement or non-union may be subject to secondary anatomical reconstruction and internal fixation. Bone grafting becomes necessary in cases of non-union or partial avascular necrosis (AVN) of the navicular bone. In most cases joint destruction will have lead to manifest posttraumatic arthritis requiring fusion of the affected joint. Arthrodesis is always combined with axial realignment. Rebalancing of the medial and lateral foot columns is of utmost importance.

RESULTS

We have treated 16 patients with joint-preserving correction of the Chopart joint: 6 of the navicular bone, 3 of the talar head, 3 of the anterior calcaneal process, 2 of the cuboid and 2 with combined malunions. Two female patients aged 50 and 67 years developed AVN of the navicular bone and required talonavicular fusion and one patient with a nonunion of the anterior calcaneal process needed a second revision surgery to achieve union. The average American Orthopaedic Foot and Ankle Society (AOFAS) score of 12 patients increased from 37 preoperatively to 77 at follow-up after an average of 2 years.

CONCLUSION

Joint-preserving corrections are generally possible for all four bony components of the Chopart joint in carefully selected cases of malunited fractures and fracture dislocations.