[Osteochondrosis dissecans of the knee and sports]

Osteochondritis dissecans (O.d.) of the knee is a common disease, but the aetiological factors are still controversial. With a follow-up examination of 97 surgically treated patients (109 lesions) we looked for the influence of preoperative sports activities as a possible aetiological factor. Most of the patients complained first symptoms at puberty age between 10 and 15 years, girls with a mean age of 12.4 years and boys with a mean age of 15 years. Because of that, humoral factors are supposed to have influence on the onset of this lesion. Also patients with O.d. of the knee demonstrated a high rate of sports activities and/or trauma prior to the onset of symptoms. There was also a good correlation between lesions at the medial condyle with varus malalignment. Additionally, in most of the patients a high grade of general ligament laxity could be observed at the follow-up examination. It seems that biomechanical factors have an important aetiological influence on the initiation of O.d. at the knee. At the date of follow-up examination all patients reported on a minor sports activity in comparison to sports activities prior to the onset of symptoms. The amount of postoperative sports activities depends on the level of the resulting Lysholm score and on the grade of osteoarthritis.