Focal lesions of the Achilles tendon: real-time variation of lesion grading during ultrasound-guided platelet-concentrate injection.

INTRODUCTION: Achillodynia (Achilles tendon pain) is a significant source of disability for many sport people. Achilles tendon (AT) tear is the third most frequent major tendon disruption after those of the rotator cuff and knee extensor mechanism. The incidence of the AT tears is 11–18% overall. Unlike acute AT tear, chronic tear diagnosis is more difficult to make particularly when the chronic tear involves the AT only partially. Over the last 10 years, real time ultrasound has been used increasingly to diagnose Achilles tendon tears, thanks to its ability to perform dynamic study, in passive and active muscle contraction. Furthermore, ultrasound-guided procedures are increasingly used for local delivering of drugs as platelet-concentrate, in order to stimulate tendon regeneration and healing. REPORT/DISCUSSION: A 36-year-old woman presented with right achillodynia for 9 months without history of trauma. Radiography of the right ankle was normal. An ultrasound exam was then performed by an expert radiologist, with the use of a 12 MHz linear-array transducer. Perpendicular transverse and longitudinal images of the Achilles tendon were obtained, as well as of the contralateral tendon which served as control. Right tendon was minimally thickened with normal echotexture and two millimetric hypoechogenic areas of tendon fibers discontinuity without communication between them; power-Doppler technique revealed an increased vascularization, so it was made diagnosis of two focal AT partial tears in acute tendinitis; a retrocalcaneal bursitis was also noted; the contralateral tendon was normal. The patient was then treated with ultrasound-guided injection of platelet-concentrate after informed consent. Using a 20-G needle, platelet concentrate was injected directly into tendon substance. During injection it was noted that gel-solution passed from Achilles tendon into the retrocalcaneal bursa, showing a complete lesion which linked the two partial tears seen previously. In our case, platelet-concentrate injection was able to show a complete lesion acting as a contrast medium, changing the lesion grading from two partial tears into a complete tear of AT. Based on our case, it is possible to affirm that focal partial tears may be indeed an occult complete tear and further studies are to be taken in order to evaluate partial tears during ultrasound-guided platelet-concentrate injections..