Osteotomies of the Foot for Cavus Deformities

Indications

Rigid cavus foot with plantar flexion of the first ray (Fig. 1A and 1B)

Ankle/foot instability symptoms, including pain

Painful metatarsal heads and callosities

Ankle and foot sprains, and/or fractures

Pitfalls

• All cavus foot deformities should be thoroughly worked up for a possible cause for the condition. If the cavus cause is neurologic (Fig. 2), after correcting the bony deformity, later follow-up with tendon transfer to the forefoot or toes is often needed.

Controversies

• If the forefoot is flexible, orthotics and soft tissue procedures should be considered. Multiple plantar releases and tendon transfers can be used in the more supple feet. We prefer orthotics for the flexible feet and bony procedures if the feet are rigid.

Examination/Imaging

All patients are assessed to evaluate the flexibility of the hindfoot varus using the kneeling test (Fig. 3A–C).

• This technique is easier and more reliable than the Coleman block test. It allows the surgeon to tell if a sliding calcaneal osteotomy will be necessary to correct heel varus.

• The patient’s forefoot is hinded to check the calcaneus position relative to the tibia; if valgus, the forefoot only is corrected.

Standing anteroposterior (AP) radiographs of both ankles are obtained.

Standing AP and lateral (Fig. 4) radiographs of both feet are examined, focusing of the apex of the deformity.

Preoperative computed tomography scans with three-dimensional reconstruction may be considered to visualize the deformity.

Treatment Options

• Fusions: McElvenny and Caldwell (1958) described fusion of the first metatarsal, cuneiform, and navicular joints.

• Triple arthrodesis: Saltzman et al. (1999) detailed long-term follow-up at 25 and 40 years after a triple arthrodesis. This study found suboptimal results for triple arthrodesis as time went on and thus demonstrates the need for joint-sparing surgery in younger patients.

• Osteotomies across joints: Japas (1968) described his “V” osteotomy of the midfoot. Wilcox and Weiner presented their “Akron dome osteotomy” in 1985, and recently provided longer term follow-up (Weiner et al., 2008). These are salvage surgical options.