The role of subtalar extrarticular screw arthroereisis (SESA) in surgical treatment of tarsal coalitions.

BACKGROUND: Talocalcaneal (TCC) and calcaneonavicular (CNC) coalitions are the most common cause of rigid symptomatic flatfoot in children. After resection, calcaneal lengthening osteotomy or arthrodesis are usually reported as second step surgery for correction of the most frequent valgus hindfoot deformity. More recently, coalition resection and minimally invasive subtalar extraarticular screw arthroereisis (SESA) for hindfoot valgus correction in one step have been described. We report the functional mid-term results of patients treated in adolescence with resection and valgus correction with SESA. METHODS: Between 2008 and 2024 data were collected from 25 patients (18 M, 7 F) affected by TCC (n = 16, 7R, 9L) and CNC (n = 16, 8R, 8L), all with symptomatic rigid flatfeet (n = 32). Average age at surgery was 12.8 ± 1.4 years (9.8-16.4 years, median 12.8). All patients underwent resection and SESA for correction of residual hindfoot valgus deformity; 31/32 feet had postoperative American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot score. Mann-Whitney test was used for comparison between TCC and CNC outcomes. RESULTS: Average follow-up (FU) was 4.7 ± 3.2 years (6 months-11.9 years, median 3.7) with a mean age at FU of 17.5 ± 3.3 years (13.2-25.4 years, median 16.8). Overall average AOFAS Ankle-Hindfoot score was 95.6 ± 5.7 and 94.3 ± 6.6 for TCC and 96.7 ± 4.6 for CNC, respectively. Subgroup scores for pain, function, and alignment were 37.3 ± 4.6, 48.7 ± 2.4, and 8.3 ± 2.4 for TCC and 38.1 ± 4.0, 48.6 ± 6.2, and 10.0 for CNC, respectively, showing a statistically significant difference between TCC and CNC only for alignment (p = 0.014). No patients had additional surgery for complications or valgus recurrence. CONCLUSIONS: Symptomatic rigid flatfeet affected by TCC and CNC and treated in adolescence with coalition resection and SESA for residual hindfoot valgus correction achieved good to excellent results in all cases. Further surgery to correct malalignment was avoided. LEVEL OF EVIDENCE: Level IV, retrospective study.