Intratendinous Distribution Of Achilles tendinosis, A retrospective Study.

BACKGROUND. Achilles tendinopathy is a very common condition. The pathology of overuse tendinopathy has been described as a continuum that comprises 3 stages: reactive tendinopathy, tendon disrepair and degenerative tendinopathy with tendinosis. The precise location of tendinosis in the Achilles tendon tends to vary from patient to patient: musculotendinous, insertional, anteriorly or posteriorly in the tendon. AIM. This study describes the variation in the location of the intratendinous zone of tendinosis in the Achilles tendon. PATIENTS AND METHODS. All ultrasound scans of all patients who presented with pain in the Achilles region were retrospectively analyzed and classified. In this respect, classification occurred into the following three categories: tendinosis, reactive tendinopathy or other (e.g. normal scan, peritendinopathy, bursitis,…).The tendinosis group was subdivided according to the location of the tendinosis zone into proximal or insertional, which were further subdivided into anterior, posterior or both. RESULTS. In total we recorded and examined the ultrasound scans from 395 tendons from 325 patients, meaning 70 patients had bilateral complaints. 209 of them were men and the mean age of this population was 43 years. In 41 patients we found two zones of tendinosis. In 55,5% of the patients with pain in the Achilles region tendinosis was seen, in 18,8% reactive tendinopathy and in 25,7% something else. The results showed that in 68,2% of the sample the tendinosis zone was proximal, whereas in 31,8 % it was insertional. The proximal tendinosis zone was mostly found right across the width of the tendon (57%), but also anteriorly (15,2%) and posteriorly (27,8%).The insertional tendinosis zone, however, was mostly found posteriorly (49,3%), followed by anteriorly (27,3%) and across the width of the tendon (23,4%). CONCLUSIONS. Although we already know that the tendinosis zone in Achilles tendinopathy occurs at different locations, the relative distribution of these zones remained relatively unclear. The distribution described raises concern about the fact that all these patients are often treated with the same protocol. Further research is needed to determine whether a difference in approach according to the location of the tendinosis zone is appropriate.