Evaluation of the Child with Acute Limp

Bruce Minnes MD, FRCPCStaff Physician and Assistant Professor,

Division of Paediatric Emergency MedicineChief Medical Editor, AboutKidsHealth

SickKids and The University of Toronto

bruce.minnes@sickkids.ca@AesklepianBruce

Disclosure

I have no conflicts of interest to disclose in giving this talk.

Bruce Minnes

Objectives

After this talk, participants will be able to:

• Identify common causes of acute limp in children

• Develop appropriate differential diagnoses based on age, clinical findings and circumstance

• Develop an approach to investigating patients with an acute limp

Limp

Abnormal gait pattern:• Pain• Weakness• Deformity

Antalgic: pain shortened stance phase on affected side

Development of gait: mature, rhythmic, reproducible gait cycle after age 7

Assessment - Age

History

• Age• Interactions child/family• Consistency (? Non-accidental injury)• Mechanism (acute or remote)• Associated symptoms: fever, rash, pallor,

bruising, weight loss• Limp: apparent site (referred pain), duration,

severity, effect on activity, painful or painless

Examination - pGALS

paediatric “Gait, Arms, Legs, Spine” examination

• Screening questions: Pain or stiffness? Location?• Gait/general: temperature, walking pattern regular,

on toes, on heels, standing and bending• Arms: not applicable• Legs: swelling, tenderness, deformities, effusions,

entry points, active/passice ROM, laxity, hip IR/ER• Spine: position, ROM, tenderness, overlying

abnormalities

Examination: Look, Feel, Move

• Look: fever, habitus, colour/rashes, entry points, stand, gait, positions (spine, limb), swelling, deformities, muscle bulk

• Feel: focal/general tenderness, can patient localize pain, warmth, effusions

• Move: walk, jump, hop, gait pattern, joint ROMs, back/hips/knees/ankles/feet

• Other: abdomen, scrotum/testes, back

Hips: Internal Rotation

Limp – Key Diagnoses

• Toddler’s fracture• Non-accidental injury (NAI)• Transient synovitis• Septic arthritis/Osteomyelitis• Slipped Capital Femoral Epiphysis (SCFE)• Legg Perthes’ Disease

Toddler’s Fracture

• Subtle undisplaced spiral fracture of tibia• Preschoolers• Sudden twist• History of injury may be absent• Tenderness over tibial shaft• Radiographs: may be subtle, absent, require

oblique views or nuclear medicine scan• Immobilize and arrange follow-up

Toddler’sfracture

Non-Accidental Injury

• Injury pattern vague or inconsistent with history of mechanism or developmental stage

• Recurrent minor fractures• Other unrelated fractures• Variable stages of healing• Fracture pattern: Metaphyseal (bucket-

handle) fracures in long bones

NAI

Non Accidental Injury

Non-Accidental Injury

Transient Synovitis

• Most common cause of atraumatic limp in children

• Boys• Ages 4 – 8 years• Self limiting• ? Post viral• Hip effusion and exclusion of more important

causes

Septic Arthritis

• Infection of synovium and joint space• May originate from haematogenous spread

(Staphylococcus aureus), osteomylelitis of metaphysis or epiphysis

• Hip, shoulder, ankle, elbow, knee• Requires urgent surgical washout and

intravenous antibiotics to prevent/minimize joint destruction and growth arrest

Septic Arthritis: Kocher’s criteria

Predictive factors:

•Fever > 38.5 degrees•Inability to bear weight•ESR > 40 mm/hr•WBC > 12x109 /l

Probability of septic arthritis:•None: <0.2%•One: 3%•Two: 40%•Three: 93.1%•Four: 99.6%

Kocher, MS et al. J Bone Joint Surg Am. 1999. 81:1662-70

Septic Arthritis in Children• Most common organisms: S. aureus and Group A

streptococcus• Typical signs/symptoms may be absent,

particularly in neonates and infants• CRP, ESR added to Kocher’s criteria useful• Recommend early initiation of antibiotics• Length of treatment based on clinical and

serologic response• Arthrotomy, arthroscopy usually recommended• Multidisciplinary approach

Kang, S-N et al. J Bone Joint Surg (Br) 2009. 91B:1127-33

Osteomyelitis:

Lucency in right femoral neck

Cor T2 fs Cor T1

Osteo and septic hip seen on MRI

Slipped Capital Femoral Epiphysis

• Children over 10 years• More common in boys and overweight

patients, hypothyroid, GH deficiency• Displacement of epiphysis relative to

metaphysis (Kline’s Line)• Knee pain• Early fixation improves outcome• Xrays: Hips AP and frog-leg (lateral)

SCFE

SCFE: Frog-leg lateral view

Kline’s Line

Legg Perthe’s Disease

• Idiopathic avascular necrosis of the femoral head

• Ages 4 – 8 years, usually boys• Xray: Hips AP. Lateral sometimes helps.• Sclerosis, fragmentation, irregularity,

flattening of femoral epiphysis• Persistent limp (contrast to transient

synovitis)

Rt AVN: plain film shows sclerosis and irregularity

ASIS Avulsion

• Larger forces – MVC or sport-related• Inability to bear weight from pain• Extremely tender over ASIS, reduced active

hip flexion and pain on passive extension• Non-weight bearing and analgesics with

orthopaedic follow up

Rt ASIS avulsion

Limp – Red Flags

• Age under 3 years• Inability to bear weight• Fever• Systemic illness• Older child with painful or restricted hip

movement

Acute Limp - Summary• Non-traumatic limp is a common presenting

problem in children and adolescents• Age is key in identifying differential

considerations• Hip is most common site of pathology• Delayed diagnosis may worsen outcome

(osteomyelitis, septic joint, SCFE)• Transient synovitis & septic

arthritis/osteomyelitis may be hard to differentiate