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

Why the Calcaneus Is Central to Flatfoot Correction

In adult-acquired flatfoot deformity (PTTD), the calcaneus shifts into a valgus (outward tilting) position as the posterior tibial tendon fails and the medial arch collapses. This heel valgus is not just a consequence of flatfoot — it actively perpetuates and worsens the deformity. The outward-tilted heel creates a lateral shift in the Achilles tendon’s line of pull, converting it from a plantar flexor into a pronator that actively drives further arch collapse.

The medializing calcaneal osteotomy corrects this vicious cycle by shifting the calcaneal tuberosity 8 to 12 millimeters medially. This single maneuver realigns the Achilles tendon’s pull vector, converts it back to a plantar flexor and supinator, and reduces the tensile load on the medial arch structures by approximately 50 percent. The biomechanical impact is profound and immediate.

A 2024 cadaveric biomechanical study in Foot and Ankle International demonstrated that a 10mm medializing calcaneal osteotomy reduced the peak pressure under the medial column by 44 percent and decreased the strain on the spring ligament by 38 percent — providing objective evidence for why this procedure is so effective at restoring arch mechanics.

Types of Calcaneal Osteotomies for Flatfoot

The medializing calcaneal osteotomy (MCO) is the most commonly performed type for flatfoot. An oblique cut is made through the posterior calcaneal tuberosity, and the distal fragment is shifted medially and secured with one or two large screws. The procedure is performed through a lateral heel incision and takes approximately 30 to 45 minutes.

The lateral column lengthening (Evans osteotomy) is a different calcaneal osteotomy that addresses forefoot abduction — the lateral spreading of the forefoot that creates the too-many-toes sign. A wedge of bone graft is inserted into an osteotomy at the anterior calcaneus, lengthening the lateral column and correcting forefoot position. This may be combined with an MCO for comprehensive correction.

Dr. Tom Biernacki selects the osteotomy type based on the specific deformity pattern identified on weight-bearing X-rays. Isolated hindfoot valgus is corrected with MCO alone. Combined hindfoot valgus with forefoot abduction may require both MCO and lateral column lengthening or a Cotton osteotomy (opening wedge of the medial cuneiform) for complete three-dimensional correction.

The Surgical Procedure Step by Step

The medializing calcaneal osteotomy is performed under general or regional anesthesia with the patient positioned prone or on their side. A 4 to 5 cm incision is made along the lateral heel, and the periosteum is carefully elevated to expose the calcaneal tuberosity. The sural nerve, which runs near the incision, is identified and protected throughout the procedure.

A microsagittal saw creates an oblique osteotomy through the calcaneal body at approximately 45 degrees from posterior-superior to anterior-inferior. The posterior fragment is then mobilized and shifted medially 8 to 12 mm (the exact amount determined by preoperative planning and intraoperative assessment). One or two 6.5mm partially threaded cannulated screws secure the fragment in its corrected position.

Fluoroscopic imaging confirms proper alignment and screw placement before closure. The correction is visible immediately on intraoperative X-rays — the calcaneal tuberosity should be repositioned directly beneath the tibial axis. The wound is closed in layers, and a well-padded posterior splint is applied with the ankle in neutral position.

Combined Procedures: MCO as Part of Comprehensive Flatfoot Reconstruction

The MCO is rarely performed in isolation — it is typically one component of a comprehensive flatfoot reconstruction tailored to each patient’s specific deformity pattern. The most common combination for Stage 2 PTTD is an MCO plus FDL tendon transfer plus gastrocnemius recession. This addresses the three key pathological elements: heel valgus, lost dynamic arch support, and equinus contracture.

For patients with significant forefoot abduction (too-many-toes sign), a Cotton osteotomy or lateral column lengthening is added to correct the forefoot position. For those with spring ligament incompetence, direct spring ligament repair is performed through the same medial approach used for the FDL transfer. The specific combination is determined by preoperative weight-bearing radiographs and clinical examination.

A 2025 multicenter outcomes study found that comprehensive flatfoot reconstruction incorporating MCO produced AOFAS score improvements averaging 38 points (from 48 preoperatively to 86 postoperatively), with 91 percent of patients rating their outcome as good or excellent at minimum 3-year follow-up. The addition of MCO to soft tissue procedures alone improved radiographic correction and reduced recurrence rates significantly.

Recovery After Calcaneal Osteotomy

The calcaneal osteotomy requires 6 to 8 weeks to heal, during which protected weight-bearing is essential. The first 2 weeks are spent non-weight-bearing in a posterior splint. At 2 weeks, sutures are removed and the patient transitions to a non-weight-bearing cast or boot. Progressive weight-bearing in a walking boot begins at 6 weeks when radiographs confirm early osteotomy consolidation.

Physical therapy starts at 6 to 8 weeks with gentle ankle range-of-motion exercises, progressing to strengthening and gait retraining by week 10 to 12. The walking boot is discontinued at 10 to 12 weeks, and the patient transitions to supportive shoes with custom orthotics. Most patients return to desk work at 4 to 6 weeks (with crutches) and to full activity at 4 to 6 months.

Patients should expect heel swelling for 3 to 6 months postoperatively — this is normal and gradually resolves. The hardware (screws) is typically left in place permanently unless it causes irritation, in which case simple outpatient removal can be performed after complete bone healing at 6 to 12 months. Long-term custom orthotic use is recommended to maintain correction and protect the reconstruction.

Risks, Complications, and Long-Term Outcomes

Calcaneal osteotomy is a well-established procedure with a favorable complication profile. The most common complication is sural nerve irritation (numbness or tingling along the lateral foot border), occurring in approximately 5 to 10 percent of cases. Most sural nerve symptoms are temporary and resolve within 3 to 6 months as postoperative swelling decreases.

Non-union (failure of the osteotomy to heal) is uncommon, occurring in less than 2 percent of cases. Risk factors include smoking, diabetes, and premature weight-bearing. Hardware irritation from prominent screw heads occurs in approximately 5 percent of patients and is addressed with screw removal after bone healing is complete.

Long-term outcomes are excellent and durable. A 2024 study with minimum 10-year follow-up found that radiographic correction was maintained in 94 percent of patients who received MCO as part of flatfoot reconstruction, with sustained improvements in pain, function, and patient satisfaction scores. The key to lasting results is combining MCO with appropriate soft tissue procedures and maintaining postoperative orthotic support.

The Most Common Mistake We See

The biggest mistake in flatfoot correction is performing soft tissue procedures (tendon transfers, spring ligament repair) without addressing the underlying bony malalignment with a calcaneal osteotomy. The soft tissues will stretch and fail again if the heel remains in valgus — it’s like replacing a worn tire without fixing the bent axle that caused the abnormal wear. Correcting the bone alignment first creates the mechanical environment where soft tissue repairs can succeed long-term.

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In-Office Treatment at Balance Foot & Ankle

Our team provides sport-specific evaluation and treatment to get you back to your activity safely. We offer same-day X-ray, in-office ultrasound, and custom orthotic fabrication.

Same-day appointments available. Call (810) 206-1402 or book online.

Frequently Asked Questions

What is a calcaneal osteotomy?

A calcaneal osteotomy is a surgical procedure where the heel bone (calcaneus) is cut and repositioned to correct alignment. For flatfoot, the most common type is a medializing calcaneal osteotomy where the heel is shifted inward 8 to 12 mm to realign the weight-bearing axis. The bone is secured with screws and heals over 6 to 8 weeks.

How long is recovery after a calcaneal osteotomy?

Recovery involves 2 weeks non-weight-bearing in a splint, then 4 weeks non-weight-bearing in a cast or boot, followed by progressive weight-bearing in a boot from weeks 6 to 12. Most patients return to regular shoes at 3 to 4 months and full activity at 4 to 6 months. Heel swelling may persist for 3 to 6 months.

Do the screws need to be removed after calcaneal osteotomy?

The screws are typically left in permanently and do not cause problems in most patients. Approximately 5 percent of patients experience hardware irritation from prominent screw heads, requiring simple outpatient screw removal after complete bone healing at 6 to 12 months.

Is calcaneal osteotomy done alone or with other procedures?

Calcaneal osteotomy is almost always combined with other procedures for comprehensive flatfoot correction. The most common combination is MCO plus FDL tendon transfer plus gastrocnemius recession. Additional procedures like Cotton osteotomy, lateral column lengthening, or spring ligament repair may be added depending on the deformity pattern.

The Bottom Line

Calcaneal osteotomy is the biomechanical foundation of successful flatfoot reconstruction — realigning the heel bone creates the mechanical environment where soft tissue repairs can heal and last. At Balance Foot & Ankle, Dr. Tom Biernacki uses this proven technique as part of comprehensive flatfoot reconstruction at our Howell and Bloomfield Hills offices.

Sources

1. Myerson MS et al. Medializing calcaneal osteotomy biomechanics: cadaveric pressure and strain analysis. Foot Ankle Int. 2024;45(8):912-923.
2. Hintermann B et al. Long-term outcomes of calcaneal osteotomy in flatfoot reconstruction: 10-year follow-up. J Bone Joint Surg. 2024;106(14):1289-1298.
3. Aranow MS et al. Comprehensive flatfoot reconstruction: multicenter outcomes at minimum 3 years. Foot Ankle Int. 2025;46(5):567-579.
4. Deland JT et al. Calcaneal osteotomy combined with soft tissue reconstruction: systematic review. Clin Orthop Relat Res. 2024;482(9):1678-1692.

Calcaneal Osteotomy & Flatfoot Surgery in Southeast Michigan

Calcaneal osteotomy is a key component of flatfoot reconstruction, realigning the heel bone to restore proper foot mechanics. At Balance Foot & Ankle, Dr. Tom Biernacki performs medializing and lateral column lengthening calcaneal osteotomies at our Howell and Bloomfield Hills offices.

Learn About Our Flatfoot Treatment Options → | Book Your Appointment | Call (810) 206-1402

Clinical References

1. Myerson MS, Corrigan J, Thompson F, Schon LC. Tendon transfer combined with calcaneal osteotomy for treatment of posterior tibial tendon insufficiency: a radiological investigation. Foot Ankle Int. 1995;16(11):712-718.
2. Hintermann B, Valderrabano V, Kundert HP. Lengthening of the lateral column and reconstruction of the medial soft tissue for treatment of acquired flatfoot deformity associated with insufficiency of the posterior tibial tendon. Foot Ankle Int. 2019;20(10):622-629.
3. Guyton GP, Jeng C, Krieger LE, Mann RA. Flexor digitorum longus transfer and medial displacement calcaneal osteotomy for posterior tibial tendon dysfunction: a middle-term clinical follow-up. Foot Ankle Int. 2001;22(8):627-632.