Abstract
Research Type:
Level 2 - Prospective comparative study, Meta-analysis of Level 2 studies or Level 1 studies with inconsistent results
Introduction/Purpose:
***This is an ongoing study. 21 of 40 patients have completed the protocol and were included in this preliminary data. This will be completed before the 2025 Annual AOFAS Conference. *** The gold standard for surgical treatment of insertional Achilles tendinopathy (IAT) is the open midline Achilles tendon splitting, Haglund’s resection. However, the percutaneous Zadek osteotomy (ZO) is a safe and effective alternative surgical treatment, with recent studies demonstrating a high rate of patient satisfaction and minimal complications.
Retrospective studies have compared patient-reported outcomes and radiographic findings between the percutaneous ZO and open Haglund’s resection; however, data on post-operative strength remain limited. Accordingly, this study assesses the postoperative push-off and gait strength following open Haglund’s resection or percutaneous ZO for IAT.
Methods:
Patients ≥ 18 years of age who underwent a unilateral percutaneous ZO or open Haglund’s resection for treatment of IAT with ≥ 1-year follow-up met the inclusion criteria for this prospective study. Exclusion criteria included a history of other midfoot or hindfoot surgery, recent (< 6 months) lower extremity surgery, or established neuromuscular conditions. Static plantarflexion and dorsiflexion strength were assessed on each patient in seated (knee at 90°) and supine (knee at 180°) positions. Standing strength was evaluated by unilateral and bilateral calf raises performed on pressure plates. Finally, patients ambulated at a self-selected pace, and vertical and anterior ground reaction forces at toe-off were captured, the latter depicting forward propulsion. Each assessment was performed bilaterally, so the patients’ non-operative limb provided a control for comparison. All study personnel were blinded to patients’ operative side and surgical procedure.
Results:
Twenty-one patients were included in the current study (8 ZO, 13 open Haglund’s resection). For each measurement, the mean difference between operative and non-operative limbs was calculated within each cohort. Strength measurements were reported in pounds of force (lbf) and a percentage of body weight (%BW); ground reaction forces were presented as %BW. In patients who underwent open Haglund’s resection, there was a statistically significant decrease in the vertical ground reaction force (VGRF) of the operative limb during unilateral calf raises when compared to the non-operative limb (p=0.03). No loss of strength was found during gait for either cohort.
Conclusion:
A statistically significant decrease in operative leg strength during unilateral calf raise (compared to non-operative) was observed following open Haglund’s resection. Meanwhile, no such loss of strength was observed following the percutaneous ZO. No loss of strength was found during gait for either cohort. While both procedures are safe and effective surgical options for managing IAT, these preliminary findings suggest the percutaneous ZO may allow for preserved post-operative strength relative to the open Haglund’s resection. Additional investigation is required to expand upon these findings.
Table 1A. Summary of Patient Demographics (n=21). B.Paired differences (non-operative side & operative side), represented as mean +/‒ SD. Data are stratified by surgery. Bold indicates a statistically significant difference. Negative values indicate that, on average, the operative side performed better than the non-operative side.