SLR - February 2021 - John Shields

The Outcomes of Subtalar Arthroeresis in Pes Planus: A Systemic Review and Meta-Analysis

Reference: Tan JHI, Tan SHS, Lim AKS, Hui JH. The Outcomes of Subtalar Arthroeresis in Pes Planus: A Systemic Review and Meta-Analysis. Arch Orthop Trauma Surg. 2020 May 6. doi: 10.1007/s00402-020-03458-8. Epub ahead of print. PMID: 32377845.

Level of Evidence: 1 systemic review and meta-analysis

Scientific Literature Review

Reviewed By: John Shields, DPM
Residency Program: NYU Langone Hospital – Brooklyn, NY

Podiatric Relevance: Subtalar arthroeresis is a popular surgical intervention for correction and/or treatment of flexible flatfoot deformities. This review stands to condense and organize the results of current literature to offer evaluation of current outcomes so as to offer guidance in the use of this particular intervention.

Methods: This meta-analysis initially compiled 159 studies identified through PubMed, MEDLINE, and CINAHL, based on PRISMA guidelines. One hundred twenty-three articles were excluded based on the following criteria: age inclusion (patients 21 or younger), non-human studies, review articles, case reports, non-english articles, and unsuitable publication type. The remaining 36 citations were then assessed for eligibility. Nineteen articles were excluded based upon no reported clinical outcomes, focus not being exclusive to arthroeresis, inability to isolate outcomes of arthroeresis, and small sample sizes (less than 10 patients). Seventeen full text studies met final inclusion criteria and were reviewed for this meta-analysis. Outcome data such as lateral talo-first metatarsal angle, talocalcaneal angle, anterior–posterior talocalcaneal angle, and calcaneal pitch was initially run through random-effect meta-analysis to compare pre-operative and post-operative outcomes. Observed heterogeneity between studies led the authors of this study to then instead compare unweighted estimates for pre-operative and post-operative outcomes using raw data divided by the total number of surgeries performed.

Results: The lateral talo-first metatarsal angle (Meary’s angle) was reported by seven studies, and all seven reported a decrease demonstrating reduction of the pes planus deformity at the level of the medial longitudinal arch. Calcaneal pitch was reported by five studies, all reporting increased calcaneal pitch post-operatively. The lateral talocalcaneal angle was reported by four studies, showing significant post-operative decreased measurements. The anterior–posterior talocalcaneal angle (Kite’s angle) was reported by three studies, all showing decreased post-operative values. One hundred eighty-seven of 199 feet (94.0 percent) had improvement in their grading of outcomes post-operatively as compared to pre-operatively. Most common complications were incomplete correction of the deformity, which required supplemental conservative treatment. 

Conclusions: The trends in the compiled data suggest that subtalar arthroeresis for the treatment of pes planus in pediatric populations yields repeatable, consistent radiographic reduction of the pes planus deformity, with a high degree of satisfaction among treated patients post-operatively. While this information is valuable as a tool  for procedure selection, the lack of long-term follow-up data available for inclusion and comparison in this meta-analysis suggests that further research in that direction would be fruitful, particularly because long term complications may necessitate revisional surgery and explantation, and a more complete understanding of the pre-operative indications and predisposing factors that may contribute to long-term post-operative complications. The authors of this meta-analysis directly address this concern, stating that it “may be premature to conclude that subtalar arthroeresis is able to maintain the positive clinical outcomes till adulthood”. Collecting and organizing this information in the future would be the next step in evidence-based treatment of pediatric flexible flatfoot deformities and given the high frequency of pediatric clinical visits for complaints of pediatric flatfoot deformities, data-driven and supported intervention planning would be useful to all podiatrists treating the pediatric population.

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