Screening and treatment in developmental dysplasia of the hip-where do we go from here?

Abstract

Purpose: Developmental dysplasia of the hip (DDH) is a leading cause of disability in childhood and early adult life. Clinical and sonographic screening programmes have been used to facilitate early detection but the effectiveness of both screening strategies is unproven. This article discusses the role for screening in DDH and provides an evidence-based review for early management of cases detected by such screening programmes.

Methods: We performed a literature review using the key words 'hip dysplasia,' 'screening,' 'ultrasound,' and 'treatment.'

Results: The screening method of choice and its effectiveness in DDH still needs to be established although it seems essential that screening tests are performed by trained and competent examiners. There is no level 1 evidence to advise on the role of abduction splinting in DDH although clinicians feel strongly that hip instability does improve with such a treatment regime. The definition of what constitutes a pathological dysplasia and when this requires treatment is also poorly understood.

Conclusion: Further research needs to establish whether early splintage of clinically stable but sonographically dysplastic hips affects future risk of late-presenting dysplasia/dislocation and osteoarthritis. There is a need for high quality studies in the future if these questions are to be answered.

Fig. 1

Late-presenting developmental dysplasia of the right hip. Galleazi test demonstrates shortening of the right femur. The patient also had limitation of abduction at 90° of hip flexion

Fig. 2

Coronal ultrasound section through the acetabulum. Appearances of the acetabular modelling, cartilaginous roof and bony rim grade hip dysplasia into Graf types 1–4 [28]. The femoral head cover method uses line A (an extension of the iliac wing) to define the percentage of the femoral head covered by the bony acetabulum [32]

Fig. 3

Standard coronal ultrasound section through the acetabulum of a normal hip. The α-angle is a measure of acetabular depth and is the angle formed between the acetabular roof (line 3) and vertical cortex of the ilium (line 1). The normal α-angle is  ≥ 60°. The beta angle is the angle formed between the vertical cortex of the ilium and triangular labral fibrocartilage (line 2). It represents the acetabular cartilaginous roof modelling and is normally <77°

Fig. 4

Coronal ultrasound sections through the acetabulum using a modified Graf technique [26] illustrate the different Graf subtypes. a Graf 1 normal hip, α-angle ≥ 60°. b Graf 2a mildly dysplastic hip, 50° ≤ α-angle  <60°. c Graf 2c severely dysplastic but contained hip with ossification delay and a shallow acetabulum, 43° ≤ α-angle  <50°. d Graf 3 subluxed hip, α-angle <43°, β-angle >77° (see Table 2 for morphological descriptions)