SLR - January 2022 - Alex Barnett

Effect of Muscle Atrophy and Fatty Infiltration on Mid-Term Clinical, and Functional Outcomes After Achilles Tendon Repair

Reference: Eken, G, Misir A, Tangay, C, Atici, T, Demirhan, N, Sener, N. Effect Of Muscle Atrophy and Fatty Infiltration on Mid-Term Clinical, and Functional Outcomes After Achilles Tendon Repair. Foot Ankle Surg. 2021 Oct;27(7):730-735.

Level of Evidence: IV

Scientific Literature Review

Reviewed By: Alex Barnett, DPM
Residency Program: John Peter Smith Hospital – Fort Worth, TX

Podiatric Relevance: Muscle atrophy is a very common problem after Achilles tendon repair. This article presents how much muscle atrophy truly happens in the post-operative course. If we can decrease the amount of muscle loss in the post-operative period, patient satisfaction scores will be higher as will functionality.

Methods: This is a retrospective study from January 2006 to December 2018 of 46 patients. Patients included were between 18-65 years of age, with Achilles tendon injury but without a history of trauma to contralateral extremity. Exclusion criteria was any reoperation of the Achilles tendon. All Achilles tendons were repaired in an open fashion. In order to evaluate atrophy, ipsilateral and contralateral calf circumference (CC) was measured 10 centimeters distal to the tibial tuberculum; maximum heel raise and ankle range of measurement measurements were also recorded in each patient. MRI assessment was performed on both legs to assess fat infiltration, muscle volume and cross-sectional area of the calf. The healthy contralateral leg served as a normal comparison. Functional outcomes were evaluated using the Achilles tendon Total Rupture Score (ATRS), the American Orthopedic Foot and Ankle Society (AOFAS), ankle-hind foot score and the Leppilahti score

Results: Median follow up was 89.1 months. Overall, patients had reported excellent outcomes. There was however, a significant difference in ankle joint dorsiflexion degrees compared to the operative limb. There was significant negative correlations between cross sectional area and Muscle volume loss between all three functional outcome scores. MRI finding of fatty infiltration was negatively correlated with only the AOFAS score. Operated leg Calf Circumference was not significantly correlated with operated leg fatty infiltration. Operated legs had higher fatty infiltration then non-operative legs. A superficial infection was developed in two legs and treated with oral antibiotics. Muscle Volume, cross sectional area, and fatty infiltrate was found worst compared to the non-operative extremity. Average mean volume loss 8.8%, with a cross sectional loss of 10.6 percent after a mean follow-up of 7.4 years was found. That is significant amount of calf atrophy compared to the contralateral extremity. Fatty infiltration was found to be highly present in the operative leg compared to the nonoperative extremity on MRI. Midterm results did indicate good-excellent clinical outcomes on the three scores.

Conclusions: Muscle atrophy is negatively correlated with functional outcome scores and this is valuable information for clinicians treating Achilles tendon rupture. A hindrance of this study is a lack of a control group that included minimally invasive repair patients and non-surgical treatment patients. Smoking and increased age are two factors that may increase fatty infiltration Podiatric surgeons need to be aware of the potential for muscle atrophy following Achilles tendon repair so that they may properly educate their patients.

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