Idiopathic Coxa Vara in Childhood

Idiopathic coxa vara in children may be seen either as a congenital malformation or a developmental change in the proximal femur. In the literature, these cases are usually discussed under the headings “congenital coxa vara,” “infantile coxa vara,” “cervical coxa vara,” or “developmental coxa vara.” Idiopathic coxa vara in childhood was first described by Hofmeister (1) in 1894 and Kredel (2) in 1896. Reviews of the subject were published by Zadek (3) in 1935 and Babb, Ghormley, and Chatterton (4) in 1949. Many recent case reports and analyses of treatment have appeared in orthopedic and surgical journals (5–11) but few are to be found in the radiologic literature. Heublein, Bernstein, and Hubenet (12) include “congenital coxa vara” in a discussion of Hip Lesions of Infants and Children. Clark and Jacobson (13) consider the clinical and roentgen features of congenital coxa vara as indicative of an osteochondrodysplasia of the femoral neck. Brailsford (14) describes the radiographic features of the condition in full. Coxa vara in children is the result of a diminution in the angle of inclination of the femoral neck and shaft below the normal 120° The classification proposed by Fairbank (15) in 1928, which is most useful from a radiologic point of view, may be modified as follows: Idiopathic: a. Congenital: Mild or severe coxa vara, with associated congenital anomalies such as dislocation of hip, faulty development of thefe mur, craniocleidodysostosis, etc. b. Developmental: Progressive, usually appearing between the ages of two and six years, with characteristic roentgenologic features. Rachitic: Usually associated with active rickets. Adolescent: Secondary to slipped capital femoral epiphysis. Traumatic: Usually following fracture of the femoral neck (rare in children). Inflammatory: Secondary to tuberculosis or other infection. Other Underlying Bone Diseases: Osteogenesis imperfecta, cretinism, dyschondroplasia, Paget's disease, osteoporosis, etc. Capital Coxa Vara: Occasionally seen in severe osteoarthritis and Legg-Perthes' disease. In congenital coxa vara, associated congenital anomalies are characteristically present, particularly in the hip or femur. This type of coxa vara is usually recognized at birth or shortly thereafter. In the developmental type, congenital anomalies are less evident, and the process is not apparent until the age of three or four years. Duncan (16) states unequivocally that coxa vara found after the age of four without associated congenital anomalies is always developmental.