Partial Achilles Tendon Tear – a figure of our IMAGination?

P. Seyed-Safi, O. Naji, R. Faroug, A. Beer, A. Vijapur, U. Oduoza, K. Johal, S. Mordecai, R. Deol, K. Davda, N. Sivanadarajah, E. Ieong, B. Rudge

Aim: Our collaborative study aims to demonstrate that acute partial Achilles Tendon Tears (ATTs) are not separate diagnostic entities from full ATTs. and should be thought of as a continuum rather than binary partial or full.

Methods: We pooled anonymised data from four hospitals, identifying patients with acute partial ATTs on USS reports from 2019-2021. Patients were only included if they had an acute injury and no previous background Achilles tendinopathy.

Results: 91 patients had acute partial ATTs reported on USS. 74/91 (81%) of patients had clinical findings in keeping with a full ATT (positive Simmonds test, palpable gap). 88/91 (97%) of patients were managed according to local full ATT protocols. 2 patients had MRIs – one showed no tear, the other showed a full rupture. 2 patients underwent surgical repair and both intra-operatively were found to have full ATTs.

Conclusion: Our regional data suggests that a significant proportion (81%) of USS diagnosed partial ATTs may in fact be misdiagnosed full ATTs. All injuries clinically suspicious for an ATT should be managed according to local Achilles Protocol. USS is useful to diagnose the presence or absence of a tear but is not good at differentiating partial vs full tear. There is significant tendon end fibrillation and overlap on USS of an acute full ATT, which can give the impression of a partial ATT. More research is needed into whether any threshold exists to support the current distinction of “partial” and “full” as relates to management and outcomes.