Effective Treatment of Insertional Achilles Tendinopathy with Minimally Invasive Zadek Osteotomy, Independent of X/Y Ratio
Authors: Hall Sarah , Schipper Oliver , Johnson A. Holly , Kaplan Jonathan , Jackson J. Benjamin , Vulcano Ettore , Gonzalez Tyler 
Published: December 2024

Category: Hindfoot; Ankle Introduction/Purpose: The Zadek osteotomy (ZO) has been demonstrated to be an effective treatment for patients with Haglund deformity and Insertional Achilles Tendinopathy (IAT). Radiographic measurements are one method of diagnostic criteria that have been utilized to define a more specific patient cohort that is a superior candidate for Zadek intervention. Tourné et al. most recently proposed an X/Y < 2.5 to define candidates that will benefit from the Zadek. However, many clinicians do not consider radiographic measurements to define efficacy of ZO. Additionally, current literature is lacking a direct comparison of ZO efficacy in patients with preoperative X/Y ratios above and below Tourné’s criteria. The current study tested the hypothesis: patients with IAT, regardless of X/Y ratio, would improve in pain and physical function after ZO. Methods: This was a retrospective, multi-center study. Patients underwent ZO at two different institutions, by three different fellowship trained orthopedic foot and ankle surgeons. 48 cases in 46 patients treated with Zadek osteotomy were included in our retrospective analysis. There were 34 cases with preoperative X/Y < 2.5 and 14 cases with preoperative radiographs measuring an X/Y > 2.5. All patients had a minimum of one-year follow-up (mean 23.24±4.82). Pain, function, and mobility PROMIS scores, VAS scores, complications, X/Y ratio measurements, and calcaneal pitch angle measurement were collected preoperatively and at final follow-up appointment. Cases were placed in cohorts based on preoperative X/Y above or below 2.5). T-tests were used to determine statistical differences following ZO. Similarly, chi-squared analysis was used to compare differences in categorical data between our groups. Results: A summary of preoperative and postoperative PROMIS scores, VAS scores, calcaneal pitch measurements, and X/Y ratios can be found in Table 1. Patients with X/Y < 2.5 demonstrated significant improvement in PROMIS pain, function, mobility scores, VAS score, calcaneal pitch angle, and X/Y ratio following ZO intervention (p< 0.05). In comparison, following ZO, patients with X/Y > 2.5 demonstrated significant improvement in PROMIS pain, VAS, and X/Y ratio (p< 0.05). However, in patients with X/Y > 2.5, preoperative VAS scores were higher (p=0.014) and improved to a significantly larger degree (p=0.006). There was one case of minor neuropathy (X/Y > 2.5); there was one patient that required revision to open debridement and repair (X/Y < 2.5). We observed a 98% rate of satisfaction overall following ZO intervention. Conclusion: Zadek osteotomy demonstrated improvement in patients’ pain and excellent patient satisfaction, regardless of their preoperative X/Y ratio on radiograph. However, patients with X/Y ratio < 2.5 did demonstrate significant improvement in patient reported function and mobility scores. Overall, a 98% satisfaction was observed following ZO in all patients. Preoperative X/Y ratio did not seem to determine success of ZO in the treatment of IAT, however, further clinical correlation is needed. to better understand differences if PROMIS physical function and mobility in terms of long-term success of the ZO.