THE NATURAL HISTORY OF DEVELOPMENTAL DYSPLASIA OF THE HIP (DDH) FOLLOWING EARLY SUPERVISED TREATMENT IN THE PAVLIK HARNESS: LONG TERM PROSPECTIVE LONGITUDINAL FOLLOW-UP

Abstract

Between June 1988 and December 1997, 332 babies with 546 dysplastic hips were treated in the Pavlik harness for primary Developmental Dysplasia (DDH) as a product of the Southampton selective screening program. Each was managed by a strict protocol including ultrasonic monitoring of treatment within the harness. The group was prospectively studied over a mean duration of 6. 5 years (SD=2. 7y) with 89. 1% follow-up. The Acetabular Index (AI) and Centre-Edge angle of Wiberg (CEA) were measured on annual radiographs to determine the natural history of hip development following treatment in the Pavilik harness. These were compared to published normal values.

We observed a failed reduction rate of 15. 2% of all complete hip dislocations; these required alternative surgical treatment. The development of those hips of infants successfully treated in the harness showed no significant difference from the normal values of Acetabular Index for female left hips, after eighteen months of age. Of those dysplastic hips that were successfully reduced in the harness; 2. 4% exhibited persisting significant late dysplasia (CEA< 20°) and 0.2% demonstrated persistent severe late dysplasia (CEA< 15 °) All such cases could be identified at sixty months. Dysplasia was clinically deemed sufficient to merit innominate osteotomy in 0. 9% dysplastic hips treated. Avascular necrosis was noted in 1% of hips treated in the harness.

We conclude that using our protocol, successful initial treatment of DDH with the Pavlik harness appears to revert the natural history of hip development to that of the normal population. We recommend that regular radiographic surveillance up to 60 months of age constitutes safe and effective practice.