Practice Essentials of Imaging in Early Diagnosis of DDH.

INTRODUCTION

Developmental dysplasia of hip joint (DDH) is a dynamic progressive pathology which can tilt either way. The term strictly applies to primary dysplasia, where etiology is not clearly known. Secondary dysplasia can be due multiple causes, such as neuromuscular disorders, connective tissue disorders or skeletal syndromes.

METHODS

The etiology being multifactorial, it needs a multidisciplinary team to address the issue at hand. The management starts antenatally with a detailed history of any risk factors and a dedicated ultrasound of the foetus, since forewarned is forearmed. At birth, a paediatrician having a keen sense of DDH will perform Barlow's or Ortolani's manoeuvre and can be the first one to sound the alarm in the event of positive findings. How and when a Radiologist needs to step in will depend on inter-departmental discussions between the paediatrician and the orthopedician.

RESULTS

In the presence of positive clinical screening tests, and non-availability of ultrasound, a preliminary X ray pelvis AP view including both hip joints should be the requisitioned in a child of any age, particularly, if belonging to the high-risk group. If ultrasound is available, a screening exam till 6 months of age is recommended to rule out DDH.

DISCUSSIONS

India is known for its vast numbers and little babies with occult diseases are the first to bear the brunt of conditions which have very few symptoms to start with. DDH is one such condition which most unfortunately expresses itself as a symptom only when it's too late, i.e., most often when the child begins to walk. Ultrasound is the modality of choice in neonates; however, since India is a country of modest means, in majority of the regions, radiographs still remain the first line of investigation.