Calcaneal Osteotomy Types 2026: Evans, Dwyer & Koutsogian | DPM

Medically reviewed by Dr. Tom Biernacki, DPM — Board-Certified Podiatric Surgeon — Balance Foot & Ankle, Howell & Bloomfield Township, MI. Last updated April 2026.

Calcaneal osteotomies are among the most powerful tools in reconstructive foot surgery — they allow the surgeon to fundamentally alter hindfoot alignment by repositioning the calcaneal body relative to the talus and the rest of the foot. The four most commonly performed calcaneal osteotomies — Evans, Dwyer, Koutsogiannis (medial displacement calcaneal osteotomy, MDCO), and the Z-cut (also called the combined osteotomy) — each address different deformity planes and are selected based on the specific biomechanical problem being corrected.

Evans Osteotomy (Lateral Column Lengthening)

The Evans osteotomy is a lateral column lengthening procedure performed through an oblique cut in the anterior calcaneus, typically 1.5 cm posterior to the calcaneocuboid joint. A structural bone graft (typically tricortical iliac crest or allograft) is impacted into the osteotomy site to lengthen the lateral column. The biomechanical effect is to reduce forefoot abduction and restore the talar head coverage that is lost in flexible flatfoot deformity — essentially by pushing the forefoot laterally relative to the hindfoot, recreating the lateral arch and reducing the valgus hindfoot moment. The Evans osteotomy is the primary procedure for correcting significant forefoot abduction in symptomatic flexible flatfoot reconstruction. Potential complications include calcaneocuboid joint impingement if placed too far anterior, and lateral column overload producing lateral midfoot pain if overcorrected.

Dwyer Osteotomy (Lateral Closing Wedge)

The Dwyer osteotomy is a lateral closing wedge calcaneal osteotomy that removes a laterally-based wedge from the calcaneal body, allowing the posterior fragment to shift medially and correct varus hindfoot alignment. It is the primary procedure for correcting hindfoot varus in cavovarus foot reconstruction — often combined with plantar fascia release and peroneal tendon procedures for comprehensive cavovarus correction. The degree of wedge removal directly determines the degree of varus correction; careful pre-operative planning with weight-bearing hindfoot alignment radiographs guides wedge sizing. The Dwyer osteotomy is the opposite of the MDCO — it corrects varus rather than valgus.

Koutsogiannis / Medial Displacement Calcaneal Osteotomy (MDCO)

The MDCO — also called the Koutsogiannis or Gleich osteotomy — is a transverse oblique cut through the calcaneal body that allows the entire posterior tuberosity to slide medially, typically 8–12mm. This medial shift reduces the valgus moment on the hindfoot, decreasing subtalar joint stress and offloading the failing posterior tibial tendon in Stage II PTTD (posterior tibial tendon dysfunction / adult acquired flatfoot deformity). The MDCO is the most commonly performed hindfoot osteotomy in adult flatfoot reconstruction — it is reliable, technically reproducible, and provides consistent reduction of hindfoot valgus when combined with soft tissue procedures (FDL tendon transfer, spring ligament repair).

Z-Cut / Combined Osteotomy

The Z-cut osteotomy combines elements of lateral column lengthening and medial displacement into a single calcaneal cut shaped like a Z or step-cut configuration. This allows simultaneous correction of forefoot abduction (through lateral column lengthening) and hindfoot valgus (through medial displacement of the tuberosity) without requiring two separate osteotomy sites. The Z-cut is particularly valuable in moderate-to-severe flexible flatfoot with both significant forefoot abduction and hindfoot valgus requiring correction in both planes. Dr. Biernacki at Balance Foot & Ankle performs comprehensive hindfoot reconstruction including calcaneal osteotomy selection and surgical planning. Call (810) 206-1402 for a surgical consultation at our Bloomfield Township or Howell office.

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If home care isn’t resolving your your foot or ankle concern, a visit with a board-certified podiatrist is the fastest path to accurate diagnosis and a personalized plan. At Balance Foot & Ankle Specialists, Dr. Tom Biernacki, Dr. Carl Jay, and Dr. Daria Gutkin offer appointments at both our Howell and Bloomfield Township offices. We perform on-site diagnostic ultrasound, digital X-ray, conservative care, advanced regenerative treatments, and minimally invasive surgery when indicated.

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