• Make an oblique incision. Avoid peroneal tendons and the sural nerve.
• Avoid aggressive dissection at the calcaneocuboid joint.
• Place the osteotomy 11 to 15 mm proximal to the calcaneocuboid joint.
• Execute the osteotomy perpendicular to the weightbearing surface and parallel to the calcaneocuboid joint.
• Use allogeneic, tricortical iliac crest bone graft fashioned individually.
• No fixation is needed if the osteotomy is stable.
• Perform additional procedures as warranted.
Maximizing The Effectiveness Of The Evans Calcaneal Osteotomy
The Evans calcaneal osteotomy, first described in 1975, is a lateral column lengthening procedure that preserves the calcaneocuboid joint.1 This laterally based opening wedge osteotomy is historically known to provide transverse plane correction for pes planovalgus deformities.
In reality, the Evans calcaneal osteotomy provides multi-planal correction and foot and ankle surgeons routinely utilize it to correct both pediatric and adult pes planovalgus deformities.2-7 In addition to lengthening the lateral column and reducing forefoot abduction, the Evans calcaneal osteotomy realigns the midtarsal joint and reduces calcaneal eversion. This procedure also places tension on the long plantar ligaments and provides significant arch elevation and stabilization. It is because of this powerful, tri-planal correction that the Evans calcaneal osteotomy has become the cornerstone of flexible flatfoot correction for me.
Although this osteotomy provides great correction, surgeons typically perform adjunctive procedures in the medial column and a posterior lengthening to gain full reduction of the pes planovalgus deformity. There is a small learning curve but few complications result when one technically performs the Evans calcaneal osteotomy correctly. Accordingly, I would like to offer some surgical pearls to ensure predictable, successful results.
What You Should Know About Incision Placement And Dissection
The surgeon usually performs the Evans calcaneal osteotomy with the patient under general anesthesia in a supine position. Bump the leg over in a lateral position using an inflatable beanbag. Then one can deflate the beanbag at the completion of the procedure to access other areas of the foot and lower extremity for additional procedures. A thigh tourniquet ensures good visualization and provides access for a gastrocnemius recession or Achilles tendon lengthening, which surgeons routinely perform concomitantly with the Evans osteotomy.
Place an oblique incision over the anterior lateral calcaneus. Start the incision just dorsal to the most superior aspect of the anterior process of the calcaneus and continue proximally and plantarly in line with the relaxed skin tension lines. The midline of the incision is usually about 1 to 1.5 cm proximal to the calcaneocuboid joint where one will make the osteotomy. The incision should end just plantar to the inferior edge of the calcaneus. This landmark is typically more superior than expected and it is common to continue the incision too far plantarly. I recommend drawing anatomic landmarks and drawing the incision itself for accuracy.
This incision is advantageous because it is within the relaxed skin tension lines, minimizing scar formation. This incision also provides good visualization of the surgical site but one should be aware of the surrounding vital structures. Surgeons will sometimes encounter the intermediate dorsal cutaneous nerve in the superior aspect of the incision and the peroneal tendons and sural nerve are in the inferior aspect. Also, the surgeon may occasionally encounter a communicating branch from the intermediate dorsal cutaneous nerve.