Outcomes of open versus minimally invasive Zadek osteotomy in treatment of insertional Achilles tendinopathy.

BACKGROUND Insertional Achilles tendinopathy (IAT) often necessitates surgery when conservative measures fail. In recent years, minimally invasive (MIS) Zadek osteotomy has emerged as a favourable alternative to open surgeries such as calcaneoplasty and tendon reattachment. This study evaluates our experience with MIS Zadek osteotomy and compares its clinical outcomes with those of open calcaneoplasty and Achilles tendon reattachment in the treatment of recalcitrant IAT.

METHODS A retrospective comparative study was conducted on thirty patients treated surgically for IAT between January 2023 and December 2024. Patients were divided into two groups: Open calcaneoplasty with Achilles tendon reattachment (n = 15), and MIS Zadek osteotomy (n = 15). Inclusion criteria comprised of patients with symptomatic IAT refractory to nonoperative treatment while patients with concomitant foot deformity or inflammatory conditions, and those who have undergone prior surgery to the same ankle were excluded. All patients had a minimum follow-up of twelve months. Primary clinical outcomes analysed include time taken to unrestricted independent ambulation, Visual Analogue Scale (VAS) scores, European Foot and Ankle Society (EFAS) scores, ability to perform unassisted single-legged heel raise (SLHR), satisfaction, and post-operative complications.

RESULTS Time to unrestricted independent ambulation and ability was significantly shorter in the MIS group (mean=7.1 weeks) versus the open group (mean=13.2 weeks; p < 0.001). More patients who underwent MIS Zadek were able to perform unassisted SLHR at 3 months (46.67 % in the open group vs 86.7 % in the MIS group; p = 0.019). Both groups had significant pain reduction at 12 months (VAS 0.67 vs. 0.20; p = 0.176). EFAS scores improved in both groups, with no significant intergroup differences at six or twelve months. Wound complications occurred in 26.7 % (n = 4) of patients in the open group, including one deep infection requiring readmission and multiple debridement. No wound-related complications were reported in the MIS group (p = 0.032).

CONCLUSION MIS Zadek osteotomy is a viable surgical alternative for IAT, offering comparable pain relief and functional improvement while significantly shortening the time to independent ambulation and risk of wound complications. Comparative studies with larger sample sizes and longer term follow-up are warranted to validate these findings.

LEVEL OF EVIDENCE III.