Toxic Synovitis Of The Hip
Last updated: October 30, 2014
ICD-9 Code: Transient synovitis hip 727.09
ICD-10 Code: Right hip M67.351; Left hip M67.352
Synonyms: Transient synovitis of the hip, irritable hip.
Definition: Toxic (transient) synovitis of the hip is a self-limiting inflammatory process that affects young children with acute nontraumatic hip pain.
Etiology: Thought to be postviral, possibly reactive in nature.
Demographics: Peak onset age is 4 to 5 years but ranges from 6 months to 16 years. Males are more affected than females.
Cardinal Features: Acute or gradual onset of hip pain or limp, usually unilateral, with or without of hip, knee, or thigh pain. Bilateral in a minority. The child may be irritable with low-grade fever. There is pain on hip range of motion; hence, the hip is positioned flexed, abducted, or externally rotated to minimize discomfort. Episodes usually last days.
Uncommon Findings: Recurrent attacks in >15%. Chronic synovitis is less common. Rarely, patients with toxic synovitis of the hip will develop Legg- Calvé-Perthes disease.
Laboratory Tests: Modest elevations of WBCs, ESR, and CRP may be seen.
Imaging: Ultrasonography is effective at identifying hip effusions and can also be used for diagnostic aspiration.
Keys to Diagnosis: Limping or hip pain in a child with inflammatory indices, higher ESR, CRP, fevers, and neutrophil percentage (~90%) suggest septic arthritis rather than toxic hip synovitis.
Differential Diagnosis: Septic arthritis, Legg-Calvé-Perthes, juvenile pauciarticular spondylitis.
Treatment: Toxic synovitis of the hip is best managed with rest and antiinflammatory therapy. NSAIDs have been shown to reduce the duration of symptoms. Follow-up examination is also recommended to confirm diagnosis and maintenance of hip range of motion.
Kermond S, Fink M, Graham K, et al. A randomized clinical trial: should the child with transient synovitis of the hip be treated with nonsteroidal anti-inflammatory drugs? Ann Emerg Med 2002;40:294–299. PMID: 12192353
McCarthy JJ, Noonan KJ. Toxic synovitis. Skeletal Radiol. 2008;37:963-5. PMID: 18594806