A Prospective, Multicenter Study of Developmental Dysplasia of the Hip: What Can Patients Expect After Open Reduction?

Abstract

Background: Although there are several predominantly single-center case series in the literature, relatively little prospectively collected data exist regarding the outcomes of open hip reduction (OR) for infantile developmental dysplasia of the hip (DDH). The purpose of this prospective, multi-center study was to determine the outcomes after OR in a diverse patient population. Methods: The prospectively collected database of an international multicenter study group was queried for all patients treated with OR for DDH. Minimum follow-up was 1 year. Proximal femoral growth disturbance (PFGD) was defined by consensus review using Salter’s criteria. Persistent acetabular dysplasia was defined as an acetabular index >90th percentile for age. Statistical analyses were performed to compare preoperative and operative characteristics that predicted re-dislocation, PFGD, and residual acetabular dysplasia. Results: A cohort of 232 hips (195 patients) was identified; median age at OR was 19 months (interquartile range 13 to 28) and median follow-up length was 21 months (interquartile range 16 to 32). Re-dislocation occurred in 7% of hips (n=16/228). The majority (81%; n=13/16) occurred in the first year after initial OR. Excluding patients with repeat dislocation, 94.5% of hips were IHDI 1 at most recent follow-up. On the basis of strict radiographic review, some degree of PFGD was present in 44% of hips (n=101/230) at most recent follow-up. Seventy-eight hips (55%) demonstrated residual dysplasia compared with established normative data. Hips that had a pelvic osteotomy at index surgery had about half the rate of residual dysplasia (39%; n=32/82) versus those without a pelvic osteotomy with at least 2 years follow-up (78%; n=46/59). Conclusions: In the largest prospective, multicenter study to date, OR for infantile DDH was associated with a 7% risk of re-dislocation, 44% risk of PFGD, and 55% risk of residual acetabular dysplasia at short term follow-up. The incidence of these adverse outcomes is higher than previous reports. Patients treated with concomitant pelvic osteotomy had lower rates of residual dysplasia. These prospectively collected, multicenter data provide better generalizable information to improve family education and appropriately set expectations. Level of Evidence: Level II, prospective comparative study.

Children’s orthopaedics

“…However, this prospective, multicentre study from a clinical outcomes team in Philadelphia (Pennsylvania, USA) aimed to investigate the outcomes of open reduction (OR) for infantile developmental dysplasia of the hip (DDH). 1 This is an interesting study that provides insights into expectations based on current evidence. The paper is the largest multicentre study to date, with a minimum follow-up of one year.…”

Femoral Head Remodeling After Surgical Reduction of Developmental Hip Dislocations

“…Patients with developmental hip dislocations that fail conservative management or present late often require surgical intervention in the form of closed or open reduction and hip spica casting. 3,4 Magnetic resonance imaging (MRI) is often used postoperatively to confirm the reduction in the spica cast without exposure to ionizing radiation and allows for excellent visualization of the cartilaginous femoral head in patients that have not yet formed an ossific nucleus. 5 In addition to images obtained immediately postoperatively, MRI at subsequent time intervals may be used to confirm maintenance of hip reduction and can also show improvement of the femoral head position within the acetabulum.…”

“…6 Current existing literature describes changes in acetabular morphology in patients with DDH after reduction, but there is a paucity of research on femoral head changes. 4,7,8 This may be due to difficulties in quantitatively measuring femoral head shape in addition to lack of multiplanar imaging at regular time points after reduction. Using hip arthrograms and MRIs, previous studies have demonstrated dysplasia and lack of sphericity of the femoral head in patients with DDH at the time of reduction.…”

“…Treatment is ideally initiated as early as possible with the goal of a congruent and concentrically reduced hip to allow for maximal remodeling and development of the femoral head and acetabulum. Patients with developmental hip dislocations that fail conservative management or present late often require surgical intervention in the form of closed or open reduction and hip spica casting 3,4 . Magnetic resonance imaging (MRI) is often used postoperatively to confirm the reduction in the spica cast without exposure to ionizing radiation and allows for excellent visualization of the cartilaginous femoral head in patients that have not yet formed an ossific nucleus 5 .…”

“…Current existing literature describes changes in acetabular morphology in patients with DDH after reduction, but there is a paucity of research on femoral head changes 4,7,8 . This may be due to difficulties in quantitatively measuring femoral head shape in addition to lack of multiplanar imaging at regular time points after reduction.…”