Extracorporeal Shock Wave Therapy Combined with Subtalar Arthroereisis and Medial Column Stabilisation in the Treatment of PCFD: A Retrospective Study

Abstract Objective Both the stability of the subtalar joint and the support of the medial column serve as crucial stabilising structures in progressive collapsing foot deformity (PCFD). Effective restoration of these stabilising components—often involving gastrocnemius or Achilles tendon recession—is essential for the treatment of PCFD. Therefore, this study aims to evaluate the clinical outcomes of extracorporeal shock wave therapy (ESWT) combined with subtalar arthroereisis and medial column stabilisation for PCFD. Methods Sixty-eight patients (68 feet) with PCFD treated at our hospital between February 2023 and April 2024 were retrospectively analysed. The patients were divided into two groups based on treatment regimen: the intervention group (IG, n = 36), which received ESWT combined with subtalar arthroereisis (HyProCure) and medial column stabilisation [hereinafter referred to as ‘dual stabilisation procedures (DSP)’], and the control group (CG, n = 32), which underwent DSP alone. The groups underwent preoperative and postoperative assessments of clinical function and imaging parameters. Clinical function assessments included the Visual Analogue Scale (VAS) for pain, American Orthopaedic Foot and Ankle Society (AOFAS) ankle–hindfoot score, and Tegner activity scale score. Conversely, imaging assessments encompassed weight-bearing anteroposterior talo-first metatarsal angle (T1-MT), talonavicular coverage angle (TNCA), lateral calcaneal pitch angle (pitch angle), lateral talo-first metatarsal angle (Meary’s angle), calcaneal valgus angle (CVA), and elastic modulus of the Achilles tendon or gastrocnemius muscle. Complications, including flatfoot recurrence, internal fixation implant rejection, and wound infection, were also documented. Results Postoperative follow-up lasted at least 12 months, with a mean duration of (13.66 ± 1.65) months. At the last follow-up, analyses revealed that both groups exhibited significant improvements in weight-bearing X-ray parameters (T1-MT, TNCA, pitch angle, Meary’s angle and CVA) compared with their preoperative values ( P < 0.05). The intervention group demonstrated superior outcomes for CVA and elastic modulus of the Achilles tendon and gastrocnemius muscle compared to the control group ( P < 0.05). Postoperatively, in both groups, the AOFAS and Tegner activity scores were higher than the preoperative values within the same group, whereas the VAS scores were lower relative to the preoperative measurements. Notably, the intervention group showed higher AOFAS and Tegner activity scores than the control group at 2 and 6 months postoperatively and at the last follow-up ( P < 0.05) and a lower VAS score at 2 months postoperatively ( P < 0.05). During follow-up, 59 patients (86.76%) from both groups met the criteria for returning to athletic activity. The intervention group achieved a shorter time to return to athletic activity [(6.26 ± 1.26) months; 33 cases, 91.67%] compared with the control group [(8.24 ± 2.06) months; 26 cases, 81.25%], with a significant difference ( P < 0.05). Postoperatively, one patient in the intervention group developed recurrence of flatfoot deformity after removal of the subtalar joint stabiliser, and one patient in the control group had poor healing of an infected medial foot wound. No other severe adverse complications were observed in either group. Conclusion ESWT combined with DSP effectively ameliorates PCFD, restores ankle–foot function and lower limb alignment and facilitates earlier return to athletic activity postoperatively.