Transient Synovitis of the Hip

Transient synovitis is a common childhood condition involving pain and limited motion of the hip. It is called transient because the problem resolves gradually on its own. It usually improves after a few days, but it can last up to a couple of weeks. It is also called toxic synovitis.

CAUSES

The exact cause of transient synovitis is unknown. It may be due to a viral infection. Many children with transient synovitis had an upper respiratory infection or other infection shortly before developing hip symptoms. Injury to the hip area might also trigger the condition.

SYMPTOMS

Symptoms are usually mild. Aside from hip pain and a limp, the child is not usually ill. Symptoms may include:

  • Hip or groin pain (on one side only).

  • Limp with or without pain.

  • Thigh pain (on one side).

  • Knee pain (on one side).

  • Low-grade fever, less than 100.4° F (38° C) taken by mouth.

  • Crying at night (younger children).

DIAGNOSIS

Your caregiver will want to rule out more serious causes of hip pain, limp, or not being able to walk. To do this your caregiver may do the following tests:

  • Blood tests.

  • Urine tests.

  • X-rays of the hip.

  • Ultrasound of the hip.

  • Needle aspiration of the hip if fluid is seen in the joint.

  • MRI scan.

TREATMENT

Treatment of transient synovitis is usually done at home. In some cases, hospitalization is needed to rule out a more serious cause. Activity can be resumed as tolerated when the pain begins to go away. Pain usually resolves in 1 to 2 weeks but can last 1 month in some patients.

HOME CARE INSTRUCTIONS

  • Heat and massage of the area may be suggested.

  • Avoid putting weight on the affected leg.

  • Avoid full activity until the limp and pain have gone away almost completely.

  • Rest is important. Children can usually walk comfortably 1 to 2 days after beginning treatment. Restrict full activity (like running or sports) until fully recovered.

  • Only take over-the-counter or prescription medicines for pain, discomfort, or fever as directed by your caregiver.

SEEK MEDICAL CARE IF:

  • Your child has pain in other joints.

  • Your child has new, unexplained symptoms.

  • Your child has pain not controlled with the medicines prescribed.

  • Your child has pain that gets gradually worse or fails to improve.

  • Your child has pain that returns after a period of time with no pain.

  • Your child has a joint that becomes red or swollen.

SEEK IMMEDIATE MEDICAL CARE IF:

  • Your child has severe pain.

  • Your child has a fever.

  • Your child refuses to walk.