Background: The Dega osteotomy is a versatile procedure that is widely used to treat neuromuscular hip dysplasia. There is a paucity of the English language literature on its use in acetabular dysplasia seen in developmental dysplasia of the hip (DDH).
Methods: A retrospective radiographic and chart review was performed for all patients diagnosed with DDH who underwent a modified Dega osteotomy between March 1995 and December 2008 at the Shriners Hospital for Children or the Montreal Children's Hospital (Montréal, Canada) by 2 orthopaedic surgeons. Radiographic parameters were measured at the preoperative, immediate postoperative, and final follow-up time points. These parameters included the acetabular index, center edge angle, Reimer's extrusion index, Shenton line, and grading by the Severin classification.
Results: A total of 20 patients (21 hips), of which 18 were female, underwent a modified Dega osteotomy at an average age of 55.6 months (range, 20 to 100 mo). Of the 21 hips (1 bilateral and 19 single cases), 9 hips involved the right side and 12 hips involved the left side. Before surgery, 9 patients had a subluxated hip, 7 patients had a dislocated hip, and 5 patients had a dysplastic hip. Ten hips underwent concomitant procedures including 10 open reductions with capsulorraphy. The acetabular index improved from 37 degrees (SD 8) preoperatively to 19 degrees (SD 8) on the date of last visit. The center edge angle improved from 2 (SD 17) to 25 degrees (SD 12).
Conclusions: The results of this study demonstrate that the modified Dega osteotomy produces near-normal lateral coverage parameters in children with DDH.
Level of evidence: Therapeutic study, clinical case series: level IV.