Resection of the Fifth Metatarsal Base in the Severe Rigid Cavovarus Foot

Cavovarus deformity associated with neuromuscular imbalance is a challenging pathology. Most of these deformities lead to pressure symptoms at the lateral border of the foot. This leads to pain, callosity, and commonly fracture of the fifth metatarsal base. This study reports the outcome of a cohort of patients who underwent an adjunctive procedure of resection of the fifth metatarsal, either partial or complete, in conjunction with cavovarus foot reconstruction to offload the lateral border of the foot.

This was a retrospective study looking at the clinical and radiographic outcome of patients with an underlying neuromuscular problem with a cavovarus foot who underwent a resection of the fifth metatarsal. This was used as an adjunctive procedure during reconstruction for lateral foot pressure overload symptoms. Case notes and radiographs were reviewed. The distance on weight-bearing radiographs from the inferior most part of the bony prominence on the lateral border of the foot to the floor was measured and compared between pre- and postoperatively. Eighteen patients met the inclusion criteria. Mean age was 55 years. Mean follow-up was 32 months.

Fourteen patients had a partial base of fifth metatarsal resection, and 4 had a complete fifth ray resection. Radiographic measurements showed a statistically significant improvement in the distance from the inferior most part of the bony prominence on the lateral border of the foot to the floor between pre- and postoperative radiographs. Sixteen patients reported a significant improvement in their symptoms, 2 had some persistent lateral overload symptoms.

The technique described in this study has not been reported previously for this indication. We believe it is a good adjunctive procedure in cavovarus foot reconstruction for patients suffering from lateral pressure overload. We describe strict guidelines and indications for this procedure.

Level IV, case series.