Congenital deformities about the knee.

Congenital deformities about the knee are the result of abnormalities of all the anatomical structures that make up this joint. In some cases the structural changes observed are due to primary disorders of formation and growth of one or more of the anatomical components of the knee. Disorders are known to occur in the integumentary, muscular, ligamentous supporting, and skeletal systems. Examples of these disorders are seen in the bone dysplasias and joint laxity syndromes. In other cases exaggerated intrauterine positions of the limb seem to bring about certain adaptive changes in the embryological development of this joint. Epiphyseal dysplasias can lead to precocious arthropathy. Subluxation of the patella is often an indicator of a ligamentous laxity syndrome. It can also occur as a result of anatomical abnormalities of the femoral condyles or be due to congenital or acquired quadriceps fibrosis. Hypoplasia of the patella with dislocation is seen in the nail-patella syndrome.