I Walk Like a Monster, Mom!

Patient Presentation
A 4-year-old male came to clinic for a new onset painful limp. He awoke cranky and over the morning he complained of pain in his left leg, possibly in his knee.
His mother looked at his legs twice in the morning and could not find any problems. He was otherwise playful and only complained when he walked. Over the morning she noticed that he began to limp. Around noon, he said, “I walk like a monster!” His mother said he could not run and had a significant left sided limp.
After his afternoon nap, he refused to walk and complained of any motion of his left leg and was brought to the clinic.
The past medical history and family history are negative.
The review of systems revealed no fevers, concurrent or significant illnesses. He is in daycare. He had not received any pain medication. The night before he did slip onto a hardwood floor, but his mother said it was a “normal fall.”The pertinent physical exam revealed an afebrile boy who did not want his left leg moved. He could not pinpoint the pain. His skin, abdomen, back and genitourinary systems were normal. He had shoddy anterior cervical and inguinal adenopathy.
He held his left leg slightly abducted at the hip and flexed at the knee. He had decreased internal rotation and flexion at the left hip. His left knee, ankle and foot and right lower extremity were normal.
The laboratory evaluation included a complete blood count which was normal with a white blood cell count of 8.4 X 1000/mm2and normal differential. His erythrocyte sedimentation rate was 8 mm/hr and his C-reactive protein was < 0.5 mg/dl.
The radiologic evaluation included AP and frog-leg plain radiographs of the pelvis and upper extremity which were normal.
The diagnosis of transient synovitis was made. The patient was sent home with recommendations to receive scheduled ibuprofen for 5 days and to monitor his symptoms. The patient’s clinical course showed slow improvement with no pain on day 2, no limp with walking on day 4, and no limp with running on day 5.


Figure 37 – AP and frog-leg radiographs of the pelvis show no evidence of fracture, avascular necrosis, or slipped capital femoral epiphysis. The only remarkable finding is a subtle one – the left femoral head on both views is slightly more displaced laterally than the right femoral head, suggesting the presence of a left hip effusion. Note that radiographs are extremely insensitive for detecting hip effusions, and a hip effusion cannot be excluded on a normal radiograph. The proper radiology test to evaluate for a hip effusion is a hip ultrasound.

Discussion
Transient synovitis of the hip (i.e. toxic synovitis) is a non-specific inflammation of the hip of unknown cause, although it frequently occurs after a previous bacterial or viral infection. It is self-limited and generally resolves in 1 week.
It often presents with pain and limp. The pain can be referred to the knee and/or thigh and the child may refuse to bear weight. Transient synovitis is a diagnosis of exclusion, particularly of higher morbidity diagnoses such as septic arthritis, osteomyelitis, Legg-Calvé-Perthes disease, juvenile rheumatoid arthritis, slipped capital femoral epiphysis and malignancies.
On physical examination the child often does not like to have the hip and/or knee moved. There is resistance/restriction to internal rotation of the hip and abduction. The laboratory tests are generally normal with the erythrocyte sedimentation rate sometimes being slightly elevated.
Treatment includes rest and non-steroidal, anti-inflammatory medication. Sometimes aspiration of the joint is necessary to rule out a septic arthritis and to relieve pain. If the child fails to improve then other diagnoses must be re-considered and appropriately evaluated.

Learning Point
Limps in children are a common complaint. The potential causes can be narrowed down based upon a good history: acute vs. chronic, painful vs. painless, and age.
Acute and painful limps are more likely due to trauma or infection; chronic limps are likely to be juvenile rheumatoid arthritis or due to causes of painless limps. The younger the child, generally the more cause for concern and the earlier the patient should be evaluated.
In younger children, soft tissue injuries, fractures and transient synovitis are some of the most common causes of limp.
As children get older, Legg-Calvé-Perthes disease and slipped capital femoral epiphysis also are added to the causes.
Pinpointing the location of the problem sometimes is difficult and a good physical examination can be very helpful and also can narrow the differential diagnosis. It is important to remember that pain can be referred from other areas of the body causing a limp (e.g. adenitis, genitourinary system).
Evaluation depends on the differential but often a complete blood count, erythrocyte sedimentation rate and/or C-reactive protein, and plain radiographs begin the evaluation.

Important historical information includes:

  • Patient age
  • Acute or chronic onset
  • Constant or intermittant limp – occurs at various times of the day
  • Affects the child’s daily activities
  • Painful or painless limp
  • Other associated symptoms
  • Loss of developmental milestones
  • History of trauma
  • History of previous or concurrent illnesses

Common Causes of Painful and Painless Limp

  • Painful

    • Infection – transient synovitis, septic arthritis, diskitis, osteomyelitis, adenitis, myositis, bursitis
    • Juvenile rheumatoid arthritis
    • Malignancy – leukemia, primary bone or soft tissue tumor, metastatic disease
    • Osteochondritis – Legg-Calvé-Perthes disease (acute), Osgood-Schlatter, osteochondritis dissecans, etc.
    • Referred pain – back, abdomen, genitourinary system
    • Trauma – fracture, e.g. toddler’s fracture, soft tissue injury, child abuse, slipped capital femoral epiphysis
    • Other – e.g. Caffey’s disease, sickle cell pain crisis, scurvy, porphyria
  • Painless

    • Developmental dysplasia of hip
    • Leg length discrepency
    • Legg-Calvé-Perthes disease (chronic)
    • Neuromuscular problems – e.g. cerebral palsy, muscular dystrophy, poliomyelitis
    • Rickets

Common Causes of Painful Limp by Age

  • Age 1-3 Years
    • Transient synovitis
    • Septic arthritis
    • Trauma – fracture, soft tissue injury
    • Diskitis
    • Juvenile rheumatoid arthritis
  • Age 4-10 years
    • Transient synovitis
    • Septic arthritis
    • Trauma – fracture, soft tissue injury
    • Diskitis
    • Osteomyelitis
    • Juvenile rheumatoid arthritis
    • Legg-Calvé-Perthes disease (acute)
    • Malignancy
    • Sickle cell pain crisis
  • Age 11+ Years
    • Transient synovitis
    • Septic arthritis
    • Trauma – fracture, soft tissue injury
    • Osgood-Schlatter
    • Osteomyelitis
    • Juvenile rheumatoid arthritis
    • Malignancy
    • Slipped capital femoral epiphysis
    • Sickle cell pain crisis

Questions for Further Discussion
1. What are the indications for nuclear medicine or magnetic resonance imaging for possible septic arthritis or osteomyelitis?
2. What organisms commonly cause septic arthritis or osteomyelitis?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Information prescriptions for patients can be found at MEDLINEplus for this topic: Hip Injuries and Disorders

To view current news articles on this topic check Google News.

Rudolph CD, et.al. Rudolph’s Pediatrics. 21st edit. McGraw-Hill, New York, NY. 2003:2436-7.

Grover G. Evaluation of Limp, in Pediatrics A Primary Care Approach, Berkowitz CD. ed. W.B. Saunders Co. Philadelphia PA. 1996:320-324.

Illingworth RS. Common Symptoms of Disease in Children. Blackwell Scientific Publications: Oxford. 1998:273.

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effecively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    8. Health care services aimed at preventing health problems or maintaining health are provided.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

    Author
    Donna M. D’Alessandro, MD
    Associate Professor of Pediatrics, Children’s Hospital of Iowa

    Date
    April 24, 2006