Concurrent Calcaneal Osteotomy with Hindfoot Arthrodesis for Pes Planovalgus: Outcomes and Alignment

Category: Hindfoot; Other Introduction/Purpose: Severe, rigid deformities of the hindfoot related to pes planovalgus are commonly treated with hindfoot arthrodesis. Deformity recurrence and ankle valgus deformity can occur due to attenuated and often incompetent medial soft tissues. While the addition of a medial displacing calcaneal osteotomy (MDCO) to a hindfoot arthrodesis has been described, the complication profile and the effect on alignment parameters including ankle alignment has not been well elucidated. There is biomechanical data to suggest that the addition of MDCO to a triple arthrodesis will reduce the force on the deltoid ligament by 56% (Okereke et al). The purpose of this study is to evaluate the clinical and radiographic outcomes of combined calcaneal osteotomy with hindfoot arthrodesis, and compare to a group that had hindfoot arthrodesis alone. Methods: We performed an IRB-approved single institution retrospective review of all patients who had undergone double or triple arthrodesis for pes planovalgus over a 6-year period from 1/1/2016 to 12/31/2021, and comparing those who had concurrent MDCO and those with arthrodesis alone, via CPT code. We included those who were >/= age 18 and had undergone double or triple arthrodesis, and had a minimum of 3 months follow up with radiographs. Patients were excluded if they had prior hindfoot arthrodesis surgery, charcot arthropathy, or documented neuropathy. We collected basic demographic data, surgical data including length of surgery, type of implant(s) and grafting used, pre-operative and post-operative radiographic parameters, complications, reoperations and presence of union of any and all arthrodesis and osteotomy sites. The primary outcome variable was successful arthrodesis of the subtalar (ST) joint, with secondary outcomes including successful union of the remaining sites. Results: A total of 22 patients (26 surgeries) had undergone concurrent hindfoot arthrodesis and MDCO versus 145 patients (150 surgeries) for hindfoot arthrodesis alone. Follow up was 10.6 and 10.8 months on average, respectively. The MDCO cohort surgical duration was 27 minutes longer than the control group (p=0.0079). Pre-operative and post-operative talonavicular (TN) coverage, AP and lateral Meary’s angle, cuboid height, calcaneal pitch, and post-operative AP ankle alignment were not significantly different between the groups. There were no failures of the MDCO or wound issues with the MDCO incision. The nonunion rate for the ST joint was 3.8% and 4.7%, respectively with TN nonunion rate of 15.4% and 16.7%, respectively (p>0.99). Reoperation rates were 23.1% and 20.7%, respectively. Conclusion: In conclusion, this study has demonstrated that when deemed appropriate based on intraoperative or preoperative findings, the addition of an MDCO to either a double or triple arthrodesis is a safe and effective adjunct. There is a slightly longer surgical time, without any additional surgical complication risks. Longer term radiographic follow up is needed to determine if this helps to protect against late ankle valgus collapse.