[Multiple cartilaginous exostoses]

Multiple cartilaginous exostosis (MKE) is an autosomally dominant hereditary disease with great individual expression. The disease becomes apparent most frequently at the age of 2-5 years and approximately 80% of the cases have been diagnosed before the age of ten years. The exostoses continue to grow until shortly after puberty. The exostoses may give rise to severe deformation of the skeleton particularly around the knee, ankle and wrist joints. Reduction of joint mobility is frequently observed either on account of the size of the exostoses and their localization or on account of the joint deformity. Treatment of MKE is surgical and corrective surgery with removal of symptom-producing exostoses is the commonest intervention. Osteotomies or introduction of joint-prostheses may prove necessary in cases with the severest joint deformities. The exostoses may undergo malignant transformation, most frequently to chondrosarcomata which grow relatively slowly and metastasize late. Treatment of these must be undertaken in a tumour centre where limb-saving tumour surgery is available in cooperation between the orthopaedic surgeon and the oncologist. Families with MKE should be given patho-genetic advice.