Surgical technique, fusion rates, and planovalgus foot deformity correction with naviculocuneiform fusion.

BACKGROUND: Arthrodesis of the naviculocuneiform (NC) joints is not a common procedure, as it is perceived by many to be less reliable or less predictable than arthrodesis of proximal or distal joints in the medial column. There is a subset of patients with planovalgus feet, cavovarus feet, and degenerative arthritis who also have an apex of deformity at the NC joints in whom fusion is indicated. The surgical technique, fusion rates, and deformity correction data for NC fusion in planovalgus feet are evaluated in this report.

METHODS: Twenty-eight patients (33 feet) who underwent surgery between October 2008 and November 2012 were identified who had NC fusion as their only arthrodesis procedure. Medical records and radiographs were reviewed, and time to union was calculated. Twenty patients from that group underwent NC fusion for symptomatic planovalgus feet, and their preoperative and last postoperative weight-bearing radiographs were reviewed and compared for deformity correction. All patients were operated on by the senior author or a senior foot and ankle trainee during fellowship using the same surgical technique, and all patients followed a standardized postoperative rehabilitation protocol.

RESULTS: Mean time to union for all 33 NC fusions was 21.7 ± 2 weeks (mean ± SEM). One patient underwent revision for nonunion, resulting in an arthrodesis rate of 97%. For NC fusions in those with planovalgus feet, an improvement in mean lateral talus-first metatarsal angle (Meary's line) from 12.3 ± 1.3 degrees to 5.2 ± 1.2 degrees (P < .05) was found. There was also a mean improvement in talonavicular coverage angle from 14.1 ± 1.8 degrees to 7.4 ± 1.3 degrees (P < .05). There were 2 superficial wound infections that were successfully treated with oral antibiotics, there were no cases of deep vein thrombosis or pulmonary embolism, and all patients came out of cast at 6 weeks into a fixed angle boot to commence weight bearing. Patients were happy with 32 of the 33 procedures and required no further treatment for their condition.

CONCLUSIONS: NC fusion was a safe and predictable procedure for any of its indications, with a fusion rate similar to that of other joints in the foot albeit with a longer time to union. For patients with symptomatic and flexible planovalgus feet, NC fusion resulted in deformity correction in multiple planes and good symptomatic relief.

LEVEL OF EVIDENCE: Level IV, retrospective case series.