Evaluation of the Child with Acute Limp Bruce Minnes MD, FRCPC Staff Physician and Assistant Professor, Division of Paediatric Emergency Medicine Chief Medical Editor, AboutKidsHealth SickKids and The University of

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’s fracture

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 > 12x10 9 /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 :

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) B:

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