Background: The diagnosis and prophylaxis of developmental dysplasia of the hip (DDH) is still controversial. In particular the role of the clinical examination and US scan of the hip is discussed in the medical literature.
Aim: The aim of the study is to present our experience with diagnostic problems in DDH, and especially to present the value of the clinical examination in diagnosing patients with DDH requiring orthopedic treatment.
Material and methods: During 36 months clinical and ultrasonographic examination with Graf's method was performed in 972 infants (1944 hips, 511 girls, 461 boys) at the mean age of 9 weeks. The sensitivity, specificity, positive and negative predictive values (PPV, NPV) of clinical examination of the hip in the diagnosis of DDH requiring orthopedic treatment were assessed.
Results: The diagnosis of pathologic dysplasia according to Graf's criteria was made in 5.7% of patients. More than half of them (3.5% of all investigated group) had no obvious clinical signs of dysplasia, even among children with most advanced dysplasia (0.25% of the cohort). Sensitivity of the clinical examination in detecting patients with DDH requiring treatment was 46%, specificity -- 92%, PPV -- 28%, NPV -- 96%.
Conclusions: Clinical examination alone has little value in DDH diagnosis and screening. Large percentage of treated DDH had no obvious pathologic signs in clinical examination -- were clinically 'silent'. We postulate performing US scan screening in all infants with positive risk factors and positive for DDH clinical examination up to the 6th week of life. In all other children US scan of the hips should be advised up to the end of 12th week of life.