Return to Sport and Functional Outcomes After Minimally Invasive Zadek Osteotomy for Insertional Achilles Tendinopathy in Young Athletes: A Retrospective Case Series

Background: Insertional Achilles tendinopathy (IAT) is a common cause of posterior heel pain in active individuals and athletes. Traditional open surgical techniques are effective but associated with notable morbidity and prolonged rehabilitation. Minimally invasive Zadek osteotomy (MIS Zadek) has emerged as a tendon-preserving alternative aimed at reducing soft tissue disruption and facilitating early recovery. This study evaluated clinical and functional outcomes of MIS Zadek in young, athletic patients with IAT. Methods: This retrospective single-centre case series included patients younger than 55 years who underwent MIS Zadek for symptomatic IAT between 2022 and 2024, with a minimum follow-up of 18 months. All patients were physically active before symptom onset. Procedures were performed according to the technique described by Kaplan et al. Primary outcomes included return-to-sport time, Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF), and PROMIS Pain Interference (PI). Secondary outcomes included visual analogue scale (VAS) pain scores, radiographic union, and complications. PROMIS outcomes were evaluated against established minimal clinically important difference thresholds. Results: Fifteen athletic patients (mean age, 37.2 ± 9.1 years; 10 males, 5 females) with no relevant comorbidities were included with a minimum 18-month follow-up. All patients returned to their preinjury level of sport at a mean of 4.2 ± 1.1 months. Radiographic union was achieved in all cases at a mean of 10.2 ± 2.1 weeks. PROMIS Physical Function improved from 39.6 ± 5.8 preoperatively to 52.4 ± 6.1 at 3 months and 59.1 ± 5.0 at final follow-up ( P < .001), whereas PROMIS Pain Interference decreased from 63.9 ± 6.4 to 51.2 ± 6.0 and 45.1 ± 5.0, respectively ( P < .001). VAS pain scores improved from 7.1 ± 1.2 to 1.8 ± 1.1 at final follow-up (mean change −5.3, 95% CI −6.0 to −4.6; P < .001). Two minor complications (13%) were observed. Conclusion: MIS Zadek was associated with meaningful pain relief, functional improvement, and return to sport in athletic patients with IAT in this cohort. These findings suggest that it may represent a viable tendon-preserving surgical option. Prospective comparative studies are needed to further evaluate its role relative to alternative treatments. Level of Evidence: Level IV, therapeutic case series.