Effect of the Copenhagen Achilles Rupture Treatment Algorithm (CARTA) on Calf Muscle Volume and Tendon Elongation After Acute Achilles Tendon Rupture: A Predefined Secondary Analysis of the First 60 Patients in a Randomized Controlled Trial

BACKGROUND: Surgical treatment of acute Achilles tendon rupture (ATR) lowers the risk of rerupture and may reduce calf atrophy and elongation of the Achilles tendon. The Copenhagen Achilles Rupture Treatment Algorithm (CARTA) was developed to provide individualized treatment selection based on ultrasonographic evaluation of the rupture. PURPOSE: In a randomized setup, the present study aimed to investigate whether treatment selection using the CARTA could reduce atrophy and tendon elongation compared with (1) patients treated surgically and (2) patients treated nonsurgically. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: A total of 60 patients with an acute ATR were randomly assigned to receive treatment based on the CARTA (intervention), surgical treatment (control), or nonsurgical treatment (control) in a 1 to 1 to 1 ratio. After 1 year, magnetic resonance imaging of both calves was performed, and muscle volume and Achilles tendon length were measured. Results were presented as the ratio between the affected and the unaffected limbs (ie, limb symmetry index; %). RESULTS: A total of 156 patients were assessed for eligibility, 60 patients were randomized, and 54 patients provided data for the study—19 patients received treatment based on the CARTA (intervention group), 17 patients received nonsurgical treatment (control), and 18 patients received surgical treatment (control). No statistically significant differences were found between the intervention group and the 2 control groups regarding muscle volume and tendon length. No statistically significant differences were found between patients treated surgically and patients treated nonsurgically. Comparison between the affected and the unaffected limb showed statistically significant muscle atrophy (24%-30%) and tendon elongation (soleus, 59%-76%; gastrocnemius, 8%-14%) in the affected limb in all 3 groups. CONCLUSION: Individualized treatment of acute ATR using an ultrasonographic selection algorithm did not reduce calf muscle atrophy or tendon elongation when compared with surgical and nonsurgical treatment. Surgical treatment did not reduce calf muscle atrophy or tendon elongation compared with nonsurgical treatment.