Minimum 24-Month Outcomes of Minimally Invasive Paratenon Protection Repair vs Open Giftbox Repair of Ruptured Achilles Tendon

Background: The paratenon has been shown to promote Achilles tendon healing, but the evidence supporting the role of paratenon protection technique in Achilles tendon repair is sparse. We retrospectively assessed the results of a paratenon-sparing repair technique vs an open giftbox repair of Achilles tendon ruptures. Methods: Patients with Achilles tendon rupture who underwent surgical treatment at our hospital between January 2015 and August 2021 were retrospectively reviewed. Among them, 61 patients underwent surgical repair using the minimally invasive paratenon protection technique (MI group) and 67 patients using the open repair giftbox technique (OR group). The postoperative rehabilitation protocol was identical in both groups. The operation time, complication rate, length and cross-sectional area (CSA) of Achilles tendon, shear wave elastography (SWE), CSA of the calf triceps muscle, isokinetic strength, Achilles tendon Total Rupture Score (ATRS), and the Victorian Institute of Sports Assessment–Achilles (VISA-A) score were compared between the 2 groups. Results: The average follow-up time was 40.0 ± 10.2 months. The operation time and complication rate in the MI group were significantly lower than in the OR group ( P < .001, P = .031). The ATRS score ( P = .015), VISA-A score ( P = .002), isokinetic strength (60 degrees/second: P = .006; 180 degrees/second: P = .036), SWE values ( P = .007), and CSA of Achilles tendon ( P = .043) in the MI group were significantly higher than the OR group. SWE values were significantly positively correlated with the ATRS score ( r = 0.294, P < .001) and the VISA-A score ( r = 0.304, P < .001). And a significant negative correlation was found between Achilles tendon extension length and peak torque (60 degrees/second: r = −0.309, P < .001; 180 degrees/second: r = −0.218, P = .013). Conclusion: Compared with the open repair giftbox technique, the minimally invasive paratenon protection technique was associated with likely marginally clinically significant improved clinical outcome scores, greater isokinetic strength, and better mechanical properties of the Achilles tendon.