A Simpler, More Limited Approach

January/February 2005 • Vol 95 • No 1 • Journal of the American Podiatric Medical Association Equinus deformity is defined as a limitation of dorsiflexion motion of the ankle joint. Although many authors have attempted to specify the necessary degrees of ankle dorsiflexion, normative values have been limited.1, 2 Biomechanically, the maximum amount of dorsiflexion in the stance phase of normal gait occurs just before heel lift with the knee extended.1 The minimum amount of ankle range of motion necessary for normal gait is 10° of dorsiflexion and 20° of plantarflexion.1-3 DiGiovanni et al2 differentiated gastrocnemius equinus from gastrocnemius soleus equinus. Gastrocnemius equinus is defined as 5° or less of ankle dorsiflexion with the knee in full extension, and gastrocnemius soleus equinus is defined as 10° or less of ankle dorsiflexion with the knee in full extension or in 90° of flexion. Equinus imparts a major deforming force on the foot and is a causative factor in many foot and ankle pathologic entities, including plantar fasciitis, pes planus, hallux abducto valgus, Achilles tendinosis, Charcot’s midfoot collapse, and diabetic ulcerations.3 DiGiovanni et al2 found either gastrocnemius or gastrocnemius soleus equinus in patients with a symptomatic foot and ankle. In asymptomatic patients, gastrocnemius and gastrocnemius soleus equinus are not uncommon (33% and 17%, respectively).4 Many types of equinus have been described: osseous equinus, pseudoequinus (plantarflexed forefoot without ankle equinus), gastrocnemius equinus, gastrocnemius soleus equinus, and a combination of types.3 In addition, an ankle joint capsule contracture can produce or contribute to any type of equinus.5 We present a review of the anatomy, biomechanics, and clinical assessment of equinus. A detailed surgical technique for gastrocnemius soleus recession is outlined, and an anatomical guide for surgical treatment is presented.