Coronal Hindfoot Alignment in Midfoot Charcot Neuroarthropathy

Charcot neuropathy of the ankle and midfoot: a challenging treatment situation

“…While the aetiology of midfoot CN is established, this is not the case for the combined midfoot and ankle CN. It is hypothesized that changes in the coronal plane of the ankle and hindfoot result in abnormal compensatory forces within the midfoot and forefoot ( 6 ). Hindfoot varus deformity induces an external rotation moment of the talus, resulting in breakdown at the tarsometatarsal and naviculo-cuneiform joints.…”

“…Hindfoot varus deformity induces an external rotation moment of the talus, resulting in breakdown at the tarsometatarsal and naviculo-cuneiform joints. While patients with hindfoot valgus results in breakdown at the midtarsal joints ( 6 , 10 ).…”

“…An alternative hypothesis suggests an increased risk of ankle CN in patients with midfoot CN with a hindfoot varus deformity due to recurrent lateral ankle instability ( 6 , 14 ). This implies that coronal hindfoot alignment influences the location of midfoot CN while the later can initiate ankle CN in presence of coronal hindfoot malalignment.…”

“…Repeated micro-trauma in these osteopenic bones results in failure of the midfoot osseo-ligamentous structures. This is further exacerbated by progressive hindfoot equinus deformity from motor neuropathy induced contraction of gastrocnemius-soleus muscle fibres and increased glycosylation of tendo-Achilles collagen fibres ( 5 , 6 ). This results in a short and stiff gastrocnemius-soleus-tendo-Achilles complex.…”

“…This results in a short and stiff gastrocnemius-soleus-tendo-Achilles complex. The resultant hindfoot equinus is considered the major deforming force for the initiation and progression of midfoot CN in the sagittal plane with additional coronal and rotational deformities from the tightness of tibialis anterior, tibialis posterior and peroneal brevis muscles ( 6 ).…”