Double Versus Triple Arthrodesis for Adult-Acquired Flatfoot Deformity Due to Stage III Posterior Tibial Tendon Insufficiency: A Prospective Comparative Study of Two Cohorts

SLR - December 2021 - Andrew Ganshirt

Reference: Fadle AA, El-Adly W, Attia AK, Mohamed MM, Mohamadean A, Osman AE. Double Versus Triple Arthrodesis for Adult-Acquired Flatfoot Deformity Due to Stage III Posterior Tibial Tendon Insufficiency: A Prospective Comparative Study of Two Cohorts. Int Orthop. 2021 Sep;45(9):2219-2229.

Level of Evidence: Level II

Scientific Literature Review

Reviewed By: Andrew Ganshirt, DPM
Residency Program: Ascension SE Wisconsin – Milwaukee WI

Podiatric Relevance: Progressive collapsing foot deformity (PCFD) is a common cause of foot pain and disability. While there are many pathologies that can lead to PCFD, posterior tibial tendon dysfunction is the most important contributor to PCFD. When PTTD reaches Stage 3 as classified Myerson et al. surgical treatment options are often limited to hindfoot arthrodesis. Literature is limited in comparative studies for double vs triple arthrodesis for optimal treatment. The purpose of this study was to compare double vs triple arthrodesis in terms of functional outcomes and deformity correction.

Methods: A prospective comparative cohort study was carried out at a level I academic center from May 2017 to May 2019. 23 patients with PCFD Stage III were included and assigned to either the double or triple arthrodesis group based on the presence or absence of calcaneocuboid degeneration on radiographic evaluation and or lateral joint line tenderness. Patient’s age ranged between 15 and 45 and were followed for one year. Primary outcomes were union rates, AOFAS scores, radiological parameters of deformity correction on AP and lateral radiographs. Secondary outcomes were operative time, time to union and complications. The double arthrodesis was done through the medial approach and the triple arthrodesis was performed through the standard medial and lateral approach. Post-operative protocol was standardized for both groups.

Results: A total of 23 patients completed the study, 13 double arthrodesis and 10 triple arthrodesis. All patients in both groups achieved union by four months post-operatively. The AOFAS hindfoot score was improved in both groups, however the triple arthrodesis group did see a greater improvement than the double arthrodesis group.  There was no difference between radiographic parameters postoperatively. The mean operative time was significantly shorter in the double arthrodesis group than the triple arthrodesis. One patient in the triple group developed wound dehiscence that resolved with wound care. No wound complications with the double group.

Conclusions: This study concluded that a double arthrodesis for PTTI stage III is a reliable option for achieving union, improving functional outcomes and deformity correction when compared to triple arthrodesis. Specifically, there is a significantly shorter operative time and lower risk for wound complications. The authors recommend a double arthrodesis if the CC joint is unaffected in severe valgus deformities where there is a concern for the lateral soft tissues. Limitations include a small patient population and short term follow up of one year. This study is in line with previous findings, further supporting the double arthrodesis for PCFD when the CC joint is asymptomatic.