CHRONIC ACHILLES TENDINOPATHY - A SURVEY OF SURGICAL AND HISTOPATHOLOGIC FINDINGS

The surgical findings and the histopathology are reported for 163 pati ents (134 males, 29 females; mean age, 38 years; range, 13-72 years; 7 5% athletes) with chronic Achilles tendinopathy, Biopsy specimens from symptomatic (155 cases) and nonsymptomatic (90 cases) parts of the te ndon and from the paratenon (97 cases) were obtained, Surgical reports were reviewed and histopathology was evaluated according to a standar dized protocol, Eighteen tendons also were analyzed by immunofluoresce nce for fibrinogen, immunoglobulins, and complement, Degenerative chan ges (tendinosis) characterized by abnormal fiber structure, focal hype rcellularity, and vascular proliferation were noted in 90% of biopsy s pecimens from symptomatic parts of the tendons and, to a lesser degree , in 20% from nonsymptomatic parts, Fibrinogen could be identified in most lesion biopsy specimens, Partial tendon ruptures were present in 19% of the patients and always occurred in areas afflicted with tendin osis. The paratenon was mostly normal or revealed only slight changes, Increasing age and male gender were associated with more pronounced h istopathologic changes, Tendinosis, sometimes complicated by partial r upture, appears to be the major lesion in chronic Achilles tendinopath y; the paratenon is rarely involved, Important features are a lack of inflammatory cells and a poor healing response.