Talocalcaneal Tarsal Coalitions and the Calcaneal Lengthening Osteotomy: the Role of Deformity Correction

SLR - November 2012 - Eoin Gorman

Reference: Mosca VS, Bevan WP. Talocalcaneal Tarsal Coalitions and the Calcaneal Lengthening Osteotomy: the Role of Deformity Correction. J Bone Joint Surg Am. 2012; 94: 1584-94.

Scientific Literature Review

Reviewed by: Eoin Gorman, DPM
Residency Program: Columbia – St. Mary’s Milwaukee, WI

Podiatric Relevance: 
Historically, tarsal coalitions have a prevalence of 1-2 percent with subtalar joint middle facet coalitions accounting for approximately 45 percent of cases. Surgical treatment is indicated in painful coalitions that fail conservative care. Hindfoot valgus is often found associated with tarsal coalitions and may require additional surgical correction to achieve full pain relief and functionality. Correction of valgus deformity with a calcaneal lengthening osteotomy (Evans) may alleviate pain and help to avoid subtalar or triple arthrodesis even in cases with coalitions greater than 50 percent of the subtalar joint. 

Methods: 
This study retrospectively examined three groups of patients with middle facet subtalar joint coalitions and hindfoot valgus corrected surgically. The three groups consisted of patients treated with calcaneal lengthening osteotomy (Evans) and no coalition resection (group one, 10 feet), patients treated with simultaneous coalition resection and calcaneal lengthening osteotomy (group two, two feet), and patients treated with calcaneal lengthening osteotomy sometime after coalition resection (group three, four feet). CT was used to estimate the size of the coalition as well as the degree of hindfoot valgus. Resection was indicated with coalition less than 50 percent of the subtalar joint and calcaneal lengthening osteotomy was performed in cases of hindfoot valgus greater than 16 degrees. Multiple other additional surgical procedures were also performed. The AOFAS ankle-hindfoot score was used to measure patient outcomes.

Results: 
Eight total patients (13 feet) were followed for more than two years with three patients (three feet) lost to follow up. Group one was found to have an improved AOFAS score from an average of 61.3 to 90.7, group two improved from 64 to 92, and group three improved from 71.5 to 92.

Conclusions: 
Successful treatment of painful subtalar coalitions can be accomplished with correction of hindfoot valgus with a calcaneal lengthening osteotomy (Evans) with or without resection of subtalar joint coalitions. The calcaneal lengthening osteotomy was shown to correct all planes of deformity even in cases of rigid flatfoot. This shows that triple or subtalar joint arthrodesis may not be necessary, and potential development of secondary ankle or chopart joint arthritis may be avoided.