Soleus Atrophy is Common after the Nonsurgical Treatment of Acute Achilles Tendon Ruptures: A Randomized Clinical Trial Comparing Surgical and Nonsurgical Functional Treatments

SLR - November 2017 - Raffaella R. Pascarella

Reference: Heikkinen J, Lantto I, Flinkkila T, Ohtonen P, Niimaki J, Siira P, Laine V, Leppilahti J. Soleus Atrophy is Common after Non-Surgical Treatment Of Acute Achilles Tendon Ruptures: A Randomized Clinical Trial Comparing Surgical And Non-Surgical Functional Treatments. American Journal of Sports Medicine 2017;45(6):1395–1404.

Scientific Literature Review

Reviewed By: Raffaella R. Pascarella DPM
Residency Program: Cambridge Health Alliance, Cambridge, MA

Podiatric Relevance: Both surgical and nonsurgical treatment of acute Achilles tendon ruptures have been shown to produce satisfactory clinical outcomes. More recent randomized control trials have shown that surgical repair allowed for earlier rehabilitation with faster and more complete recovery of calf muscle strength. This is of particular interest as regaining maximum strength and function following injury are of high importance, especially in an active patient population. Residual weakness may result in rerupture or reinjury, gait abnormalities, decreased physical activity and decreased long-term patient satisfaction. The aim of this study was to assess structural changes, fatty degeneration and lengthening of the Achilles tendon and whether these findings could be correlated to calf muscle strength in surgical vs. nonsurgical treatment.

Methods: A prospective, randomized control trial of 60 patients (55 men, five women) with complete Achilles tendon ruptures was performed. Patients were randomly allocated to the two groups: surgical (32 patients) and nonsurgical (28 patients) with no significant differences in sex, age, activity level, BMI or height between the two groups. Surgical treatment was performed within seven days of injury, and the tendon was repaired directly using a Krackow technique with nonabsorbable suture. Nonsurgical treatment involved placing the patient in a cast for one week and afterward a dynamic vacuum orthosis with varying degrees of plantarflexion. Both groups were allowed to bear weight in the dynamic orthosis after one week, and active plantarflexion was encouraged and had identical rehabilitation protocols. Outcome measures at three and 18 months included calf volume, fatty degeneration of muscle, Achilles tendon length and isokinetic strength. MRI was performed of the affected leg at three and 18 months, and the Goutallier method was used to classify fatty degeneration, calf volume and FHL, deep flexor muscle volumes were measured and the length of the Achilles tendon was determined using the Silbernagel method for MRI.

Results: There were no statistically significant differences in calf muscle volume and fatty degeneration between the two groups at three and 18 months. FHL and deep flexor muscle volume increased similarly in both groups. At 18 months, the Achilles tendons treated conservatively were, on average, 19 mm longer than when compared to their surgically treated counterparts. At 18 months, patients treated surgically demonstrated 10 to 18 percent greater isokinetic strength, which was correlated with soleus atrophy (P<.001).

Conclusions: Nonsurgical treatment of acute Achilles tendon rupture resulted in greater soleus muscle atrophy compared to surgical treatment, which resulted in greater atrophy of the soleus muscle. Surgical treatment resulted in 10 to 18 percent more isokinetic strength than nonsurgical treatment after 18 months. Limitations of the study include the lack of MRI imaging of the contralateral limb, using an invalidated method for measuring Achilles tendon length and the study was underpowered. Both surgical and nonsurgical treatment of acute Achilles tendon ruptures are accepted treatment methods. Areas of future interest could include whether hypertrophy of the FHL has any long-term effects on biomechanics or whether a more intensive rehabilitation protocol during the first six months would reduce volume loss and strength deficits.