II. Etiology

  1. Idiopathic

III. Epidemiology

  1. Incidence: Common (8x more common than septic hip in children)
    1. Most common cause of limp with Hip Pain under age 10
    2. Peaks ages 3 to 6 years
  2. Boys more commonly affected than girls by a 4:1 ratio
  3. Unilateral involvement in 95% of cases

IV. Pathophysiology

  1. Inflammatory Arthritis of the hip

V. Symptoms

  1. Follows 3-6 days after Upper Respiratory Infection

VI. Signs

  1. Hip Pain
    1. Pain radiates to anteromedial thigh and knee
  2. Reduced Hip Range of Motion
    1. Guarded hip rotation in Transient Synovitis (but will tolerate passive range of motion testing)
    2. Will bear weight on joint enough to demonstrate a limp
    3. Contrast with Septic Arthritis with more pronounced spasm, guarding, and fixed position with a refusal to bear weight
  3. Fever
    1. Low grade fever may be present (under 39 C or 101 F)
    2. Contrast with Septic Arthritis with higher Temperature and associated systemic symptoms (e.g. malaise)

VII. Labs

  1. Acute phase reactants: Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (C-RP)
    1. ESR and C-RP will be normal or only slightly elevated in Transient Synovitis
    2. Contrast with Septic Arthritis in which ESR >25 mm/h (>40 is highly suggestive) and C-RP >20 mg/L
  2. Joint aspirate
    1. Hip Synovial Fluid clear

VIII. Imaging

  1. Hip XRay
    1. Bony landmarks normal
      1. No signs of Fracture or defect
      2. Rules out serious hip disease
        1. Aseptic necrosis
        2. Osteomyelitis
    2. Increased space between acetabulum and femoral head
  2. Hip Ultrasound
    1. Demonstrates joint effusion (>2 mm) in >50% of cases
    2. Joint effusion on Ultrasound requires joint aspirate to differentiate from septic hip

IX. Diagnosis: Kocher's Decision rule - 4 Criteria

  1. Findings suggestive of Septic Arthritis
    1. Fever >38.5 C (101.3 F)
    2. Inability or refusal to bear weight
    3. Erythrocyte Sedimentation Rate >40 mm Hg
    4. White Blood Cell Count >12,000/mm3
  2. Interpretation of 4 critreria rule
    1. All 4 factors absent rules out Septic Arthritis (Test Sensitivity 99.8%)
    2. All 4 factors present strongly suggests infection (60-98% likelihood of septic hip)
  3. Modifications
    1. C-Reactive Protein (C-RP) >20 mg/L (or 2 mg/dl) has been included as a fifth factor criteria
  4. References
    1. Kocher (2004) J Bone Joint Surg 86-A:1629-35 [PubMed]
    2. Sultan (2010) J Bone Joint Surg Br 92(9): 1289-93 [PubMed]

X. Diagnosis: Decision rule - 2 Criteria

  1. Findings suggestive of Septic Arthritis
    1. Inability or refusal to bear weight
    2. C-Reactive Protein (C-RP) >20 mg/L (or 2 mg/dl)
  2. Interpretation
    1. Both factors absent: <1% probability of Septic Arthritis
    2. Both factors present: >74% probability of Septic Arthritis
  3. References
    1. Caird (2006) J Bone Joint Surg Am 88(6): 1251-7 +PMID:16757758 [PubMed]
    2. Singhal (2011) J Bone Joint Surg Br 92(9): 1289-93 [PubMed]

XI. Evaluation: Red Flags suggestive of Septic Arthritis of the hip

  1. Fever (esp. >101.3 F or 38.5 C)
  2. Toxic appearance
  3. Pain with Hip Range of Motion in any direction
  4. Refusal to bear weight
  5. Erythrocyte Sedimentation Rate >40 mm/hour
  6. C-Reactive Protein >20 ml/L

XII. Differential Diagnosis

  1. Septic Arthritis of the hip
    1. Keep high index of suspicion
    2. See Signs and Diagnosis above
  2. Legg-Calve-Perthes Disease

XIII. Management

  1. Non-weight bearing on affected leg
  2. Bed rest for 2 to 3 days
  3. NSAIDs
    1. May speed up recovery time
    2. Also offers Analgesic effect
    3. Failure to improve with NSAIDs should prompt reconsideration of differential diagnosis
    4. Kermond (2002) Ann Emerg Med 40:294-9 [PubMed]

XIV. Course

  1. Usually clears within 7 days

XV. References

  1. Jhun and Raam in Herbert (2016) EM:Rap 16(2):15-6
  2. Claudius and Behar in Majoewsky (2012) EM:RAP-C3 2(8): 1
  3. Sawyer (2009) Am Fam Physician 79(3):215-24 [PubMed]

Images: Related links to external sites (from Bing)

Related Studies (from Trip Database) Open in New Window

Ontology: Transient synovitis of hip (C0149908)

Concepts Disease or Syndrome (T047)
ICD10 M67.35
SnomedCT 301864002
English Transient synovitis, hip, hip synovitis transient, transient synovitis of hip, Transient synovitis of hip, Transient synovitis of hip (disorder)
Spanish sinovitis transitoria de la cadera (trastorno), sinovitis transitoria de la cadera

Ontology: Toxic synovitis (C0302886)

Concepts Disease or Syndrome (T047)
ICD10 M67.3
Dutch toxische synoviitis, synoviitis; toxisch, toxisch; synoviitis
French Synovite toxique
German toxische Synovitis
Italian Sinovite tossica
Portuguese Sínovite tóxica
Spanish Sinovitis tóxica
Japanese 中毒性滑膜炎, チュウドクセイカツマクエン
Czech Toxická synovitida
English toxic synovitis, synovitis toxic, synovitis toxic (diagnosis), synovitis; toxic, toxic; synovitis, Toxic synovitis
Hungarian Toxikus synovitis

Ontology: Transient synovitis (C0343179)

Concepts Disease or Syndrome (T047)
ICD10 M67.3 , M67.30, M67.39
SnomedCT 202924004
German Transitorische Synovitis
Korean 일과성 윤활막염
English Transient synovitis, unspecified site, Transient synovitis, site unspecified, synovitis transient, transient synovitis, Toxic synovitis, Transient synovitis, Transient synovitis (disorder), synovitis; transient, transient; synovitis
Dutch passagère; synoviitis, synoviitis; passagère, Passagre synoviitisa
Spanish sinovitis transitoria (trastorno), sinovitis transitoria

Ontology: Irritable hip (C0410082)

Concepts Pathologic Function (T046)
ICD10 M24.85
SnomedCT 202473003, 202539005, 202007007, 301813003
English irritable hip, Irritable hip, Irritable hip (disorder)
Spanish cadera irritable (trastorno), cadera irritable