Arthroscopic evaluation of the synovial lining before and after open synovectomy of the knee joint in patients with chronic inflammatory joint diseases.

Twenty-eight patients with chronic inflammatory joint diseases had arthroscopy immediately before synovectomy of the knee joint and 6 and 12 months postoperatively. In patients with moderate and/or severe synovitis of the knee joint all of the synovial membrane is involved in the disease process. Resynovitis (synovitis of the regenerated synovial membrane after synovectomy), however, is patchy and if biopsy should be indicated, arthroscopic guidance is advocated. Following synovectomy there is a recurrence of mild synovitis of varying degree in some cases with an increase in resynovitis between 6 and 12 months. The level of synovitis at 12 months was, however, markedly less than at synovectomy (p less than 0.01). Similar development was found both in histopathology and immunohistopathology after synovectomy. Arthroscopic examination of the synovial membrane in chronic inflammatory disease of the knee joints gives valuable information of the severity and the longitudinal changes of synovitis. A simple method of scoring is described and is imperative when comparing patients or groups of patients and when doing longitudinal arthroscopic studies. The method was used both at arthroscopy and at subsequent synovectomy giving a highly significant correlation (p less than 0.001).