On the nature and etiology of chronic achilles tendinopathy

Abstract: The present studies included 362 consecutive patients and 147 healthy controls and were conducted to provide a rational basis for treatment and future research. The major lesion was a focal non-inflammatory tendon degeneration (tendinosis). Twenty per cent of the cases were complicated by a secondary partial rupture. The paratenon was normal. A study of tendon blood flow using laser Doppler flowmetry, refuted the popular theory of the mid-tendon hypovascular zone as a cause of ruptures and chronic lesions. Symptomatic tendons had an increased blood flow of uncertain origin corresponding to the lesion. There was little difference between patients and controls with regard to alignment and joint motion in the foot. Biomechanical abnormalities, often incriminated in overuse injuries, are not important in chronic achilles tendinopathy and the virtue of orthotics is questionable. Previous steroid injections were associated with a doubled rate of partial ruptures in surgical cases and have no logical place in the treatment of a degenerative lesion. Abnormal imaging with ultrasonography and MRI was associated with more severe histopathology and could indicate a poor prognosis but neither method afforded any advantages over clinical evaluation in preoperative assessment and decision making. Men prevailed and had an increased rate of abnormal biopsies and an increased risk of acquiring a partial rupture which is mainly due to a higher participation in sports as compared with women. Old age was related to severe histopathology and a decrease in physical activity, blood flow and flexibility of the muscle-tendon unit. Most patients were athletes but physical activity was not correlated to histopathology and could be more important in provoking symptoms than in the evolution of the actual lesion.