How To Perform The Double Calcaneal Osteotomy

By Alan R. Catanzariti, DPM, Robert W. Mendicino, DPM, and Brian D. Neerings, DPM

   The double calcaneal osteotomy includes a combination of the posterior calcaneal displacement osteotomy (PCDO) and the Evans anterior opening wedge calcaneal osteotomy. One would consider this combination for symptomatic flexible flatfoot deformity in both the adolescent flexible flatfoot and the adult with late stage II (Johnson and Strom’s classification) posterior tibial tendon dysfunction (PTTD).

   The PCDO consists of a transcortical osteotomy through the posterior tuber of the calcaneus with medial transposition of the tuberosity. The PCDO displaces the insertion of the Achilles tendon medially in relation to the subtalar joint axis, increasing the supinatory action during the midstance phase of gait. In addition, this procedure displaces the ground reactive forces medially in relation to the subtalar joint axis with medial translation of the plantar tubercle resulting in a supinatory moment at heel strike.

   The Evans anterior calcaneal osteotomy is placed approximately 1.0 cm proximal to the calcaneocuboid joint. The surgeon would subsequently place a laterally based wedge of bone into the osteotomy site, effectively lengthening the lateral column and stabilizing the midtarsal joint. The prevailing theory is that lengthening the lateral column creates a “bowstringing” effect that may be responsible for clinical restoration of the longitudinal arch. Lateral column lengthening will reduce inversion demand on the posterior tibial tendon and reduce the posterior muscle group force required to achieve the heel rise position.

   Surgeons may employ the double calcaneal osteotomy when significant calcaneal valgus, forefoot abduction and midtarsal joint instability coexist. The deformity must be flexible with no radiographic signs of tritarsal joint degeneration. The double calcaneal osteotomy is a joint sparing procedure that maintains a supple foot while restoring anatomic alignment, stabilizing the midtarsal joint and improving function.

What You Should Look For During The Physical Examination

   Clinicians should evaluate the foot and ankle with both non-weightbearing and weightbearing exams. The examination should answer several key questions. Is the deformity flexible? What are the primary components of deformity (i.e., soft tissue contractures or muscle/tendon weakness)? What is the function of the tibialis posterior tendon? Does the ankle joint contribute to the valgus deformity?

   During the non-weightbearing exam, one should evaluate the ankle joint for the presence of instability, equinus, deformity or pain. Assess the tritarsal complex for flexibility and instability. Check for midtarsal joint instability by placing the subtalar joint in neutral and maximally loading the lateral column. When evaluating adult patients, one should check the course of the tibialis posterior tendon for tenderness, edema, nodularity or gross attenuation. Keep in mind that the tibialis posterior tendon is often unable to support the medial arch adequately in mid- to late-stage II PTTD and one may need to address this following osseous realignment.

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