Limp is an abnormal gait and can result from congenital, infectious, inflammatory, traumatic, neoplastic or congenital causes. It can primarily involve the spine, hips/pelvis, abdomen, or musculoskeletal and soft tissues.
Certainly you should start with an appropriately thorough H&P. Make sure to ask about:
- Fever and other symptoms associated with infections
- Trauma
- Systemic symptoms (pale skin, fatigue, easy/abnormal bruising and/or bleeding, rashes, weight loss)
- Previous episodes of recurrent bone/joint pain
- Location and character of pain. remember that pathology in the hip can lead to referred pain lower in the leg
Causes of Limp by Age
Ill-fitting shoes (more common than you think since kids grow so fast at this age!)
Foreign body in the foot
Transient synovitis
Septic arthritis
Osteomyelitis
Discitis (fever and back pain)
Malignancy (leukemia, neuroblastoma)
Congenital disorders (muscular dystrophy, developmental hip dysplasia)[/tab_item] [tab_item title=”School Age”]Fracture
Sprain/strain
Transient synovitis
Avascular necrosis
Malignancy (leukemia, lymphoma, Ewing’s, osteosarcoma)
Septic arthritis
Osteomyelitis
Rheumatologic disorder (Juvenile idiopathic arthritis)
Leg length discrepancy
Intra-abdominal abscess[/tab_item] [tab_item title=”Adolescent”]Fracture
Sprain/strain
Slipped capital femoral epiphysis
Osgood-Schlatter disease
Rheumatologic disorder (JIA)
Septic joint/osteomyelitis
Malignancy (osteosarcoma, Ewing sarcoma, lymphoma)
Spondylolisthesis
Intra-abdominal abscess[/tab_item] [/fusion_old_tab] [divider scroll_text=””] The evaluation of most cases of limp includes imaging studies – plain films make a lot of sense if there is a history of trauma, but also for recurrent fevers (osteo, tumors). You can get an ultrasound to evaluate for joint effusion. If infectious, inflammatory, or neoplastic causes are in your differential get a CBC w/ diff, blood culture if you suspect osteo or septic arthritis, ESR and CRP.
Many of you have already used the following eponymous criteria, whether or not you’ve actually read the study. Kocher et al developed a clinical evaluation tool to determine the likelihood of septic arthritis after retrospectively evaluating approximately 300 kids. Via multivariable logistic regression they identified four predictors associated with septic hip:
- Fever
- Elevated WBC (>12,000)
- Elevated ESR >40
- Inability to bear weight
The likelihood of septic arthritis based on number of predictors was:
- 0 – <0.2%
- 1 – 3%
- 2 – 40%
- 3 – 93.1%
- 4 – 99.6%
I consult for any patient with 3+ predictors. Those with 2/4 I use a careful H&P and do not consult if my pretest probability for transient synovitis is high. If studies are normal and the patient can bear weight, discharge with PMD follow-up is appropriate. I would recommend that you consider hospitalizing the patient who still cannot bear weight after administration of appropriate pain meds – which in most cases include tylenol/ibuprofen.
Here are some further resources:
Tse SML, Laxer SM. Approach to acute limb pain in childhood.Pediatr Rev. 2006;27:170-180.
