Differential Diagnosis for an 8-month Male with Audible Knee Click
- Single most likely diagnosis
- Developmental Dysplasia of the Hip (DDH): This condition is a common cause of audible knee clicks in infants, resulting from an abnormal formation of the hip joint. The click is often heard as the femoral head moves in and out of the acetabulum.
- Other Likely diagnoses
- Patellofemoral instability: This condition can cause a clicking sound as the patella moves out of its normal track. It's less common in infants but should be considered.
- Ligamentous laxity: Infants with generalized ligamentous laxity may exhibit joint clicks or clunks due to the increased mobility of their joints.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Slipped Capital Femoral Epiphysis (SCFE): Although rare in infants, SCFE is a serious condition that requires prompt diagnosis and treatment to prevent long-term damage. It can present with a click or clunk.
- Septic arthritis: This is an infection within a joint, which is a medical emergency. While it may not typically present with a simple click, any sign of joint instability or abnormal sounds in the context of fever or irritability should prompt consideration of septic arthritis.
- Rare diagnoses
- Synovial chondromatosis: A rare condition characterized by the growth of cartilage in the synovium of the joint, which can cause clicking or locking sensations.
- Meniscal tears: Although more common in older children and adults, meniscal tears can occur in infants, especially with trauma, and might present with a click or snap.