The Limping Child

1. The Limping Child Wendalyn King MD, MPH

2. Walking • 2 phases • Stance • Swing • Both feet in contact with ground only 20% of gait cycle • Developmental process • Toddlers – short, rapid steps • Adult gait pattern present around age 3

3. Limp • Antalgic gait • Pain leads to shortened stance phase on affected side • Most common acute presentation of limp • Trendelenberg • Underlying proximal muscle weakness or hip instability • Equal stance phase, but trunk shifts over affected extremity • Usually non-painful • “waddling” gait if bilateral process

4. Trauma Acute Repetitive SCFE, AVN Infectious/inflammatory Septic arthritis Inflammatory arthritis Osteomyelitis Diskitis Neoplastic Leukemia Primary and metastatic bone lesions Differential Diagnosis

5. Toddler (1-3yr) Infection Occult trauma Neoplasia Child (4-10) Infection Transient synovitis LCPD / AVN Rheumatologic disorder Trauma Neoplasm Adolescent (11+) SCFE Rheumatologic disorder Trauma By Age

6. Evaluation • History • Onset of symptoms • Fever, systemic symptoms • History of trauma • Often present, may be misleading • Physical examination • Inspection • Observe gait • Range of motion (feet, knees, hips)

7. Evaluation • Xray • Labs • CBC, ESR, CRP may be helpful in some instances • Other imaging • Ultrasound (hips) • CT /MRI • Bone scan

8. Case #1 • 18 month old with acute onset limp • Afebrile, otherwise no complaints • Happy and playful until stands up • Fussing, resists weight bearing on R • Normal examination

10. Toddler Fracture • Spiral fracture of distal 1/3 of tibia • Usually simple fall while running or stepping on object • May occur up to 6 yr age (peak 2-4yr) • May not be visible on normal AP/Lat film • Oblique film • Repeat films • Callous formation within 1-2 week • Splint/cast • Healing within 3-4 weeks

11. Case #2 • 2yo male with 1 week of progressive limp and leg pain • Xray at beginning of symptoms negative • Splinted for presumptive fracture • Low grade fever, increasing fussiness, now “dragging leg” and refusing to walk • Exam • Fussy, ?tender to palpation distal L leg • CRP, ESR elevated

15. Osteomyelitis • Most common in children <10 • Usually hematogenous seeding of bone • Trauma (even minor) may predispose • Usually begins in metaphaseal region of long bone • Inflammatory exudate collects in marrow, cortex, subperiosteal space • Ischemia leads to infarction and pain • Form area of necrotic bone called sequestrum • Eventually separates to form free body or may be reabsorbed

16. Osteomyelitis • Common organisms • Staph aureus most common • Group B strep in neonates • H. flu, Strep pyogenes, Salmonella, Pseudomonas, Kingella kingae • May be difficult to localize • Neonates • Spine, pelvis

17. Osteomyelitis • Diagnosis • Radiographs • May be normal or nonspecific for 10-14 days • Bone scan, CT, MRI may be needed • Acute phase reactants • WBC normal initially in 60% cases • CRP rises in 8 hours, peaks 2 days, normalizes over 1 week • ESR normal in 25% new onset cases, may be useful for monitoring therapy • Blood culture positive 50-60% cases • Bone aspiration or biopsy • Treatment is 3-6 weeks of antibiotic therapy

18. Case #3 • 4 year old female with worsening limp and leg pain. Tactile fever at home • Recent URI, otherwise healthy • Exam • Uncomfortable, lying in bed, cries when approached

21. Septic Arthritis • Usually hematogenous seeding • Extension of osteomyelitis • Direct inoculation into joint from penetrating trauma • Etiology • Staph aureus • (H. flu historically) • Kingella kingae • Neonates: E. coli, Candida, GBS • Adolescents: N. Gonorrhea

22. Septic Arthritis • Presentation • Acute joint inflammation • Swelling, redness, pain • “Pseudoparalysis” • Joint held in position to maximize intra-articular space and minimize pressure and pain • Hip – flexion, abduction, external rotation • Knee - partial flexion • Shoulder – adduction and internal rotation • Elbow – midflexion • Often have fever and ill appearance

23. Septic Arthritis • Diagnosis • Blood culture positive 30-40% • Elevated CRP, ESR • Arthrocentesis • Imaging • Widening of joint space, soft tissue swelling • Ultrasound useful for hip effusion • Treatment • Antibiotic • Irrigation and drainage • Prompt surgical drainage of hip (and often shoulder) needed to reduce intra-articular pressure and avoid avascular necrosis of femoral head

24. Diagnostic Dilemmas • Transient synovitis of hip (“toxic synovitis”) • Non-infectious, inflammatory condition • Usually children 3 – 8yrs • May follow viral URI • Mild fever, limp, fussiness • Minimal limitation of range of motion • ESR, CRP, WBC usually normal • Managed with rest, NSAIDs, close follow up

25. Diagnostic Dilemmas • Overlying cellulitis vs Septic Arthritis • Other causes of acute arthritis • HSP • Serum sickness • JRA, lupus • Tick borne illness

26. Case #4 • 4 yo male with 3d h/o limp and thigh pain • No fever • Some improvement with ibuprofen • Active and playful • Uncomfortable with rotation of hip

28. Avascular Necrosis • Legg-Calve-Perthes Disease • Usually occurs 2 – 12 yrs (avg 7) • Males > female • May be secondary to repeated micro-trauma • Recurrent episodes of hip irritability common

29. AVN • Risk of later degenerative arthritis • Worse prognosis with older age (>10) and extensive femoral head deformity • Very good prognosis in children <5 • Treatment • Symptomatic – rest, pain meds • Observation for children <6 • Surgery for older children with severe involvement

30. Case #5 • 5yo female with several days of leg and back pain, decreased appetite and activity and ?weight loss • Xrays pelvis at outside facility negative 2 d before • Pt alert, thin, ill and uncomfortable appearing. Cries with manipulation of hips/legs. ? Firmness to palpation in upper abdomen • CBC, chemistry normal

32. Neoplastic • Leukemia • Neuroblastoma • Primary bone tumors • Benign • Unicameral bone cyst • Osteoid osteoma • Malignant • Ewing and osteogenic sarcomas • Spinal tumors

35. Case #6 • 12yo male with chief complaint of knee pain • Present for a couple weeks, acutely worsened after playing basketball • No fever, no other symptoms • Exam: walks with limp • Knee – no swelling, no tenderness, normal range of motion

38. Slipped Capital Femoral Epiphysis(SCFE) • Most common adolescent hip disorder • Type of epiphyseal fracture • Common in obese adolescents (also in tall, thin kids after growth spurt) • May present with chronic limp, acute pain or combination • Hold leg in slight external rotation and have limited internal rotation

39. SCFE • Xray • Need both hips for comparison • Need frog-leg radiograph • Earliest sign is widening of epiphysis • “pre-slip” condition • Line drawn along outer aspect of femoral neck should intersect the femoral capital epiphysis

43. Case #7 • 15 yo male brought in by EMS for sudden onset severe hip and leg pain • Was running 40 yard dash for football tryouts when developed severe pain and difficulty ambulating • Exam: very uncomfortable, pelvis stable but painful to palpation, pain with hip movement, especially hip flexion

45. Avulsion • Probably secondary to repetitive stress/microfracture • 3 common sites (at major muscle insertions) • Anterior inferior iliac spine • Superior iliac crest • Ischial tuberosity • Initial therapy is rest, crutches, pain meds • Outpatient orthopedic follow up

46. Summary • Many causes of acute limp • Range from trivial (new shoes) to life threatening • Thorough history and physical important • Liberal use of imaging studies • Keep in mind common conditions for each age group • Close follow up if diagnosis in doubt