Title : Nine years too late: A rare case of very late diagnosed bilateral Developmental Dysplasia of the Hip (DDH)
Abstract:
Introduction: Developmental Dysplasia of the Hip (DDH) is typically diagnosed in infancy, with late presentations being uncommon in a healthcare system with routine neonatal screening. This report presents the case of a 9-year-old girl with previously undiagnosed bilateral DDH, first identified when she presented with acute left knee pain. The patient was a first-born child, born at 42 weeks, with no perinatal complications or developmental delays. She walked at 14 months, met all developmental milestones, and was an active swimmer. Her parents had only noticed subtle signs, such as circumduction of the leg when stepping onto a high surface and reluctance to be carried in a piggyback position.
Method: The patient initially presented to a district general hospital with atraumatic left knee pain. Pelvic radiographs unexpectedly revealed bilateral dislocated hips, prompting referral to a tertiary children’s hospital for further assessment. Clinical examination at the children’s hospital revealed tenderness over the medial aspect of the left knee. She held her left leg in a FABER position, and tenderness was elicited in both groins on palpation. An elective Examination Under Anaesthesia (EUA) and left hip arthrogram were planned and performed.
Results: Intraoperative findings demonstrated slight shortening of the left leg and an external rotation deformity. Assessment of range of movement showed bilateral hip flexion of 120°, internal rotation of 90°, and abduction of 20°; external rotation was 90° on the right and 80° on the left. An anterolateral arthrogram using Omnipaque confirmed the femoral head was intracapsular. Subsequently, 40 mg of Kenalog and local anaesthetic were administered. Postoperatively, the patient was monitored and discharged with a plan for reassessment in two weeks. Radiographs confirmed longstanding bilateral hip dislocations with dysplastic acetabulae.
Conclusion: This case highlights the importance of considering hip pathology as a differential diagnosis in paediatric knee pain, especially in older children where signs may be subtle. Late-diagnosed DDH remains a significant clinical challenge and is often associated with the need for complex surgical reconstruction. Early diagnosis and timely intervention are essential to improve long-term functional outcomes.
