Understanding And Managing Equinus Deformities
Equinus often lies at the root of a wide variety of foot and ankle conditions although the prevalence of the deformity is not universally recognized. This author details the incidence of equinus and shares his perspectives on its impact, pertinent surgical considerations and the benefits of endoscopic gastrocnemius recession.
Hallux valgus, hallux rigidus, metatarsalgia, capsulitis, adductovarus contracture of the fifth digit, pes valgo planus, hypermobility of the first ray, hammer digit syndrome, clinodactyly, lateral column syndrome, sesamoiditis and plantar fasciosis are all common conditions of the foot. What do they all have in common? Most often, there is an accompanying limitation of ankle joint dorsiflexion: equinus.1,2
It is universally accepted that equinus can be due to several different etiologies. These etiologies include:
• bony block between the talus and distal tibia (osseous equinus);
• contracture or tightness of the soleus muscle (soleal equinus);
• contracture or tightness of the soleus and gastrocnemius muscles (gastroc-soleal equinus);
• isolated tightness of the gastrocnemius muscles (gastrocnemius equinus); and
• compensatory loss of ankle joint range of motion for some other condition such as pes cavus (pseudoequinus).
In my clinical experience, gastrocnemius tightness accounts for approximately 85 percent of all equinus. However, it is not universally accepted in orthopedic and podiatric surgery that gastrocnemius equinus is primarily causal in many of the aforementioned common pedal conditions.
In their 2002 Journal of Bone and Joint Surgery article, DiGiovanni and colleagues eloquently state the following:1
“Except for a few still controversial examples of plantar fasciitis, forefoot ulceration in diabetics, or progressive hallux valgus or flatfoot, the relationship between tightness of the superficial posterior compartment and progressive pathological changes in the foot in non-spastic individuals has been overlooked entirely by the orthopaedic community. In contradistinction, more attention has been paid to this phenomenon in the podiatric literature over the past three decades …”
However, it is my contention that even in podiatric surgery, equinus accounts for the overwhelming majority of pedal pathology and is largely ignored even when one appreciates it via an accurate diagnosis and thorough biomechanical understanding.
Foundational treatment of equinus with a minimally invasive, endoscopic gastrocnemius recession (EGR) technique can effectively treat global pathology. The endoscopic gastrocnemius recession obviates the frequently devastating sequelae one sees with extensive forefoot reconstruction and reduces the postoperative morbidity associated with these more extensive surgeries. In addition, the procedure eliminates the deforming causative force, which is likely to contribute to ongoing pathology.