Non-operative treatment of tendo-achilles rupture: is “gap size” important in determining suitability for functional rehabilitation?

S.C. Roberts, P. Francis, N. Hughes, G. Boyd, M.A. Glazebrook

Introduction: The treatment of acute rupture of the tendo-achilles remains controversial. There is good evidence to suggest that outcomes are the same for both operative and non-operative treatment when a functional rehabilitation program is utilised. However, debate continues as to whether the radiological gap-size between the proximal and distal remnants of the tendon has an influence on the suitability for non-operative management.

Methods: All adult patients who attended the emergency department with a clinically suspected tendo-achilles rupture were place in a plantarflexed cast, and underwent MRI scanning to confirm the diagnosis. They were then counselled on the risks and benefits of operative versus non-operative treatment. Patients opting for non-operative treatment were asked to take part in the study and treated using a functional rehabilitation programme. Gap sizes were determined using a standardised protocol by a single musculoskeletal radiologist blinded to the clinical outcomes.

Results: A total of 69 patients have been recruited into the study, 40 have complete their one year review. There were two re-ruptures. The average age was 42.4 years (range 19-70). The average gap size recorded by MRI was 40.4mm (range 6-110). The average ATRS score was 80 (range 17-100) and the single limb heel raise percentage of contralateral side was 64.8% (range 4-115). The Spearman rank correlation coefficient comparing gap size and ATRS score was 0.272 (p=0.045) and for gap size and strength was 0.158 (p=0.165).

Conclusion: This study shows a weak positive correlation between MRI measured gap size of the ruptured tendo-achilles and the Achilles tendon Total Rupture Score at one year. No correlation could be demonstrated between gap size and strength at one year. These results suggest that the MRI measured gap size is unimportant in predicting outcome and hence suitability for non-operative treatment of tendo-achilles rupture using functional rehabilitation.