[Arthrolysis of the knee joint].

This publication consists of two parts, the first of which is concerned with the definition of arthrolysis as a mere soft tissue procedure. This is delineated from arthroplasty. In the second part, arthrolysis results are presented. Three different means of treatment are possible for knee joint stiffness: manual joint mobilization under anaesthesia, arthroscopic operation, and "open" arthrolysis. The authors concentrate on the third type of treatment because of the great amount of long-term experience they have made. In the majority of cases knee joint stiffness is caused by immobilization and posttraumatic and postoperative effects on the joint itself or in the area of the joint. Morphological findings are intraarticular adhesions in the recessus, as well as between the joint surfaces, retraction of the capsular-ligament system, and extra-articularly located impediments caused by shrinkage and scars in the muscles, tendons, and sliding laminas of the soft tissue. Open arthrolysis is indicated after failure of conservative treatment and in cases of severe stiffness of the knee joint. For operative arthrolysis many requirements must be met, which are specified in detail. The preoperative information about the treatment given to the patient is of particular interest. The operative methods, including postoperative management, are described only briefly, because the presentation of the results is the main purpose of this paper. Eighty-five patients (94%) who underwent open arthrolysis were personally examined. Information about the other patients was obtained from medical records such as the examination at discharge or the last presentation in the outpatient clinic. The average follow-up time was 5 years and 4 months ranging from 6 months to 14.25 years. The results are differentiated in many respects whereas the so-called relative improvement of joint mobility following an operation is of main interest. Well-defined criteria have been published and were applied. The results are listed according to the severity of joint stiffness. Four grades of joint stiffness are created, ranging from grade IV, the most severe form with a preoperative maximum of joint mobility of 30 degrees, to grade I with a maximum of 90 degrees joint mobility. In all, operative procedures led to an improvement in nearly 100% compared to the preoperative findings. The results are presented in relation to age, operative methods, previous operations, and different stages during the follow-up.