The Ruptured Achilles Tendon Elongates for Six Months After Surgical Repair Regardless of Early or Late Weightbearing in Combination with Ankle Mobilization: A Randomized Control Trial

SLR - May 2019 - Kelsey J. Millonig

Reference: Eliasson P, Agergaard A, Couppe C, Svensson R, Hoeffner R, Warming S, Warming N, Holm C, Jensen M, Krogsgaard M, Kjaer M, Magnusson P. The Ruptured Achilles Tendon Elongates for Six Months After Surgical Repair Regardless of Early or Late Weightbearing in Combination with Ankle Mobilization. The American Journal of Sports Medicine. 2018:46(10):2492–2502. doi: 10.1177/0363546518781826

Scientific Literature Review

Reviewed By: Kelsey J. Millonig, DPM
Residency Program: CHI Franciscan Foot and Ankle Institute, Federal Way, WA

Podiatric Relevance: Treatment and rehabilitation protocols of acute Achilles tendon ruptures (AATRs) is widely debated in the literature and may affect clinical outcomes. Short episodes of loading have been shown to be beneficial for healing tendon without inducing tendon lengthening; however, no data is available to identify how early repaired tendon can withstand loading without sustaining permanent structural changes. The aim of this study is to determine if tendon elongation, mechanical properties and functional outcomes are affected by different rehabilitation.

Methods: A randomized control trial was completed of 75 consecutive patients between ages 18 to 65 with AATR. All patients underwent direct surgical repair with Kessler technique with vicryl suture. Tantalum beads were placed in both the distal and proximal parts of the tendon rupture site. The patients were randomized into three groups: restricted weightbearing until week 7 followed by full weightbearing at week 8 (LWB+IMMOB), ankle range of motion exercises were performed but weightbearing was restricted until week 7 followed by full weightbearing at week 8 (LWB+MOB), and lastly, immediate partial weightbearing postoperatively and full weightbearing by week 5 (EWB+MOB). The primary outcome measured was blinded and was tendon elongation. Secondary outcomes were not blinded but included mechanical properties, such as isometric plantar flexion, ankle joint range of motion, maximal plantar flexion muscle strength, tendon cross-sectional area, muscle cross-sectional area, heel-rise test and patient-reported outcomes.

Results: There was no significant difference between groups demographically with sex, age, body mass index and days from rupture to surgery. There was no difference between rehabilitation groups in regard to tendon elongation. All groups demonstrated increased elongation with approximately 50 percent of elongation taking place in the initial three months and the remaining 50 percent occurring in the subsequent three months. There was no difference between groups with secondary outcomes. Tendon cross-sectional area increased in size in all groups in the postoperative period. The medial and lateral gastrocnemius muscle cross-section increased in size from six to 26 weeks. The soleus muscle cross section declined from weeks six to 26 weeks and did not recover at 52 weeks. With heel rise index representing overall triceps surae endurance, capacity only recovered 63 percent to 70 percent compared to the uninjured side at one year. Patient-reported outcomes and time to return to activity had no meaningful improvements beyond one year. Seven complications were reported of the 75 patients with no group effect.
 
Conclusions: The authors concluded that the results of this study suggest increased tendon elongation and stiffness for at least six months postoperatively. However, there were no differences in the primary or secondary outcomes with various rehabilitation loading patterns in the initial eight weeks after surgical repair. Achilles tendon elongation continued for up to six months after surgery, and muscle strength, muscle endurance and patient-reported outcomes did not reach normal values, collectively demonstrating that the time to recover full function after rupture is at least one year. It is unknown if a controlled loading paradigm may be important beyond the initial two to three months after repair.