Posterior Tibial Tendon Excision and Postoperative Pain in Adult Flatfoot Reconstruction: A Preliminary Report

Background: Posterior tibial tendon insufficiency plays a large role in the pathogenesis of adult acquired flatfoot deformity (AAFD) in select patients. Transfer of the flexor digitorum longus is indicated to compensate for the loss of posterior tibial tendon function; however the role of resection of the degenerated posterior tibial tendon remains unclear. The aim of this study was to determine the effect of posterior tibial tendon resection on pain relief following surgical treatment of stage II AAFD. Methods: All patients who underwent surgical treatment for stage II AAFD and posterior tibial tendon insufficiency were retrospectively reviewed. Patients were divided into two groups based on whether the degenerated posterior tibial tendon was resected or left in situ. Twenty-seven patients with a mean follow-up of 13.3 months were included in the study. A visual analog scale (VAS) score for pain was recorded for each patient pre-operatively and at final follow-up. Concomitant surgical procedures and the incidence of postoperative medial arch pain were also reported. Preoperative deformity and postoperative deformity correction were assessed by measuring the anteroposterior talar-first metatarsal angle, the talonavicular (TN) coverage angle, the lateral talar-first metatarsal angle, and the calcaneal pitch onstandard weight bearing radiographs. Results: Eleven patients underwent FDL transfer and resection of the posterior tibial tendon (PTT resection group), and 16 patients underwent FDL transfer without resection of the posterior tibial tendon (PTT in situ group). A greater percentage of patients in the PTT resection group underwent lateral column lengthening (100 vs 18.8%, p < 0.001), and a greater percentage of patients in the PTT in situ group had a medial displacement calcaneal osteotomy performed (93.8 vs 18.2%, p < 0.001). There was no difference in preoperative VAS pain scores between groups, and all patients demonstrated excellent pain relief postoperatively. No patient in either group reported medial arch pain postoperatively. Radiographic assessment revealed similar deformity preoperatively in both groups, and patients in the PTT resection group demonstrated a greater correction of the TN coverage angle (9.8 ± 4.6 vs 6.0 ± 4.1 degrees, p = 0.041). Conclusion: Resection of the PTT did not significantly affect postoperative VAS scores at final follow-up. It did however, correlate with a slightly greater correction of the TN coverage angle. There were no instances of pain along the medial ankle or medial arch of the foot in either group postoperatively. Future prospective studies are needed to determine whether resection of the PTT is necessary at the time of surgery for stage II AAFD.