Non-operative Treatment for Acute Achilles Tendon Rupture: Evaluation of Clinical Results and Tendon Lengthening on Magnetic Resonance Imaging.

BACKGROUND

In previous clinical studies of Achilles tendon (AT) ruptures, there are few reports measuring the AT length after conventional non-operative treatment without early functional rehabilitation. This study reviewed the outcomes of non-operative treatment for AT ruptures and assessed tendon length using magnetic resonance imaging (MRI).

METHODS

Patients with acute AT rupture who underwent non-operative treatment were included in this retrospective study. In our department, conventional non-operative treatment without early functional rehabilitation is used to avoid excessive tendon lengthening in patients with AT rupture. Patients wore a below-the-knee cast and performed non-weight-bearing walking for 4 weeks. Subsequently, the cast was removed, and an ankle-foot orthosis was applied for 4-6 weeks. The mean follow-up period was 28 months. Clinical outcomes were assessed using the Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale and the AT Total Rupture Score (ATRS). The tendon length and morphology were evaluated using MRI.

RESULTS

Sixty-four patients (42 men, 22 women; mean age, 44 years) with acute AT rupture underwent non-operative treatment. The mean JSSF score and ATRS were 97 and 91 points, respectively. Among 43 athletes, 36 (83.7%) returned to their pre-injury level of sports participation. Tendon re-rupture occurred in 2 of 64 patients (3.1%). T2-weighted MRI revealed fusiform-shaped tendon thickening and homogeneous low-signal changes in all patients. The mean AT length measured by MRI after treatment was 66.4 mm.

CONCLUSION

Conventional non-operative treatment without early functional rehabilitation has a low re-rupture rate and favorable clinical outcomes, and MRI findings indicated good tendon healing in all patients. In our non-operative treatment, tendon lengthening increased up to 6 months post-injury. Overall, these results indicate that casting and non-weight-bearing for 4 weeks may represent a safe and effective treatment option associated with limited excessive tendon lengthening and re-rupture.

LEVEL OF EVIDENCE: Level IV, retrospective cohort study.