Clinical genetics / edited by Arnold Sorsby.

Date:
1953
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Clinical genetics / edited by Arnold Sorsby. Source: Wellcome Collection.

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    THE LOWER EXTREMITIES As aetiological factors : (1) congenital skeletal anomalies; (2) dystrophic muscular aberrations usually secondary to (3) neurogenic anomalies of the central nervous system have been suggested. Pes cavus.—This presents a deformity of the foot in which clawing of the toes is combined with a high, long arch of the foot. When it is congenital the defect may not be apparent until the child reaches the age of 6-7 years. Other developmental anomalies and even degeneration of the central nervous system or muscular diseases may be associated with or may be the causative agents of pes cavus (spina bifida occulta, myelodysplasia, Friedreich's ataxia, and peroneal atrophy). Tarsal synostoses.—Many congenital synostoses of the various tarsal bones have been reported. Cleft foot.—Cleft foot, or spht foot, closely parallels and is associated with cleft hand. Long bones Congenital defects of fibula.—A primary aplasia of the fibula may be congenital. There may be an absence or a deficiency of the lower half of the bone. A fibrous strand or even a pre-formed cartilaginous anlage may exist. Associated congenital malformations of other parts of the body are not infrequently present. The lower limb is usually shorter than normal and the tibia may present anterior bowing. A dimple in the skin frequently overlies the bony defect. The foot is usually in an equino-valgus position. There may or may not be a reduction in the tarsus and a reduction or absence in the fourth and fifth digital rays. Associated muscular defects are frequently encountered. Congenital defect of tibia.—Congenital defects of the tibia are rather rare. The degree of aplasia varies considerably from complete absence to only partial absence of the distal end of the tibia. The distal end of the femur and the foot may be involved on occasion. The metatarsal and first and second digits may be absent. Anomalies of the related musculature may be associated. Total absence of the tibia is not too uncommon and is frequently unilateral. Congenital angulation and pseudarthrosis of tibia.—Congenital angulation of the tibia is regarded by some as a specific entity distinct from pseudarthrosis of the tibia. It may be unilateral or bilateral. It is frequently associated with other congenital skeletal anomalies. Posterior as well as medial bowing has been reported. The bowing usually occurs at the junction of the middle and lower one-third of the diaphyses. Pseudoarthrosis—a rare affection—may be associated with neurofibromatosis. Congenital deformity of the femur.—Congenital aplasia of the femur is not a very rare anomaly. The partial defect may vary greatly in extent and character. A short femur is frequent in coxa vara. There may be a rudimentary development of the head, neck and upper portion of the shaft, with a fairly intact femur. The femur is not infrequently synostosed with the tibia. The entire limb is shortened and there are often associated other deformities of the lower limb and foot. Phocomelia of lower extremities A peripheral rudiment, digits or a thick skin pad may be attached to the remaining portion of the affected extremity. 277