Abstract
We conducted a follow-up study in patients with DDH in whom triradiate cartilages closed after bones previously treated at our department reached adult bone age. Examinations were performed after the patients were divided into 2 groups, one group involving patients with Conservative Therapy and the other group receiving Invasive Therapy. The conservative group included 62 joints in 56 patients (males: 7, females: 49), with a mean age of 19.2 years, and involving of 3 kinds of therapy According to the Severin classification at the final examination, 43 patients belonged to Group I and the remaining 19 patients with some residual subluxation, Group II. Of these, 6 patients underwent manual reduction under general anesthesia, 3 of whom developed inverted limbus. Invasive therapy included 17 joints in 17 patients (males: 2, females: 15) . Initial operations involved 13 patients with Ludloff s method and 4 patients undergoing femoral varus-derotation osteotomy. As for 5 patients with Ludloffs method, the remaining residual subluxation led to additional surgery for correction in adolescence. The CE angles showed an improved course in patients without femoral head deformities such as coxa magna. The results of this follow-up study demonstrated that most patients undergoing reduction by RB without apparent intervening substances yielded almost normal growth even with a slightly thickening of the floor of the acetabulum, as indicated on a plain radiograph, at the time of closed triradiate cartilage following adult bone age. In contrast, the cases with onset of some residual subluxation were often observed in patients in whom reduction was inhibited by failed acquisition of the afferent femoral head due to an inverted limbus or a thickening of the limbus, resulting in manual reduction under general anesthesia or open reduction.
