Results of medial open reduction of the hip in infants with developmental dislocation of the hip

Thirty-two patients who had medial open reduction of 40 hips were reviewed at an average of 10.3 years follow-up (range 2.5-18.6 y). Center-edge angles and acetabular indices were measured on preoperative, postoperative, and final radiographs. The presence of AVN was noted. The final radiograph was assigned a Severin grade. One hip redislocated. Eight (20%) have required subsequent pelvic osteotomies. AVN developed in 11 hips (27.5%). Of the 11, five were classified as type 1, defined as temporary irregular ossification of the femoral head. Bilateral dislocations and age older than 1 year at surgery correlated with greater likelihood of AVN (p < 0.05), whereas absence of the ossific nucleus did not. Thirty hips were classified as Severin 1 or 2, six were rated Severin 3, and three were Severin 4. Nineteen patients completed gait analysis. Normal motion was documented in 12 of 14 unilateral patients. Significant hip flexor and extensor iso-kinetic weakness was seen. In conclusion, medial open reduction yielded satisfactory results in 75% of hips. Although iliopsoas weakness is common, gait is usually normal.