Medializing Osteotomy

Hazibullah Waizy

Assil-Ramin Alimy

♦ INTRODUCTION

Medializing calcaneal osteotomy is an effective and frequently used technique for the restoration of hindfoot alignment and biomechanics. Calcaneal osteotomies provide correction in multiple planes, while still preserving joint and tendon function.¹ Medializing calcaneal osteotomy was first described by Gleich in 1893 for the correction of pes planovalgus deformities.² Gleich proposed a medial wedge resection. Dwyer popularized calcaneal osteotomy by his description of a lateral closing wedge osteotomy for the correction of cavovarus foot deformities in 1959.³ A variation of an opening wedge calcaneal osteotomy, which provides correction through lengthening the lateral column was proposed in 1975 by Evans.⁴ Koutsogiannis further popularized the medializing calcaneal osteotomy in 1971 by successfully utilizing the approach for correction of flexible pediatric flatfoot.⁵ Osteotomies through the calcaneal body realign the weight-bearing forces to the structural tripod and may further redirect the pull of the Achilles tendon.³ Medializing osteotomies are used for the correction of planovalgus deformities, whereas lateralizing osteotomies are utilized for the treatment of cavovarus deformities.

For the past 20 years, there has been growing interest and demand for minimally invasive procedures in medicine and, particularly, in orthopedic surgery. Complications with open calcaneal osteotomies through the standard lateral approach include wound dehiscence, peroneal tendon irritation, damage to the sural nerve, and delayed union, nonunion, and irritation.⁶,⁷,⁸ Furthermore, medial neurovascular structures are at risk during medializing calcaneal osteotomies through a lateral approach.⁹,¹⁰ Minimally invasive surgery (MIS) offers several advantages that may reduce the risk of these complications. MIS facilitates wound healing and avoids complications by limiting the soft-tissue dissection, decreasing postoperative pain and morbidity.¹¹

♦ INDICATIONS AND CONTRAINDICATIONS

Indications for minimally invasive medializing calcaneal osteotomies (MIMCOs) include symptomatic flexible pes planovalgus deformities and failed previous conservative treatment.⁵,¹²,¹³,¹⁴ Furthermore, MIMCO may be utilized combined with a hindfoot arthrodesis.¹⁵ Additional soft-tissue procedure like tendon reconstructions, tendon transfers, and ligament reconstruction are frequently part of the hindfoot correction.⁶,¹⁶,¹⁷,¹⁸,¹⁹,²⁰

Contraindications for the MIMCO resemble those of open surgery and include symptomatic arthritis of the subtalar, talonavicular, and calcaneocuboid joints.¹² A rigid subtalar joint with limited motion should be treated with a fusion approach.²¹ Furthermore, a large dorsal displacement osteotomy for high calcaneal pitch may be considered as a contraindication for MIS and rather be performed open.²² Further systemic risk factors that should be considered preoperatively include smoking, poor patient compliance, diabetes mellitus, inflammatory arthropathies, and medications like disease-modifying agent medications (DMARD) and glucocorticoids.¹² Moreover, local risk factors like poor vascularity, poor soft-tissue envelope at the operative site, and previous infections need to be cautiously assessed and evaluated before surgery. Although these risk factors represent a significantly higher risk with the open approach than with MIS.¹

♦ PATIENT HISTORY AND PHYSICAL EXAMINATION

The physical examination should involve inspection, palpation, range of motion (ROM), muscle strength testing, and gait assessment. A comparison to the contralateral foot should be made. Also, the physical examination should be performed with and without weight bearing.

Inspection: The flexible flatfoot will have an arch without weight bearing, which will disappear with weight bearing.²³ The patient will be noted to overpronate. Observing the patient from the back will demonstrate the “too many toes” sign.²³,²⁴

Palpation: The physician should palpate various structures, including the deltoid ligament, posterior tibial tendon, lateral rearfoot, ankle joint, subtalar joint, talonavicular joint, and the calcaneocuboid joint.⁴

ROM: Examining ROM allows further differentiation regarding flexible versus rigid pes planus.²³ The Hubscher maneuver (or Jack test) is a test to determine the flexibility of a pes planovalgus in which the examiner dorsiflexes the hallux while the patient is weight bearing.²⁵,²⁶ In flexible pes planovalgus, the arch of the foot increases, as opposed to rigid
planovalgus in which the arch is not present with or without weight bearing.²⁵,²⁶

Muscle strength testing: The physician can evaluate muscle strength by having the patient perform a single limb heel raise.²³ The inversion against resistance may be used to evaluate the posterior tibial tendon muscle strength.²³,²⁷

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