A. Definition

1. Uneven, jerky or laborious gait
2. Common presentation of lower extremity musculosketetal disease in children
3. Caused by either pain, weakness or deformity of involved extremity
4. Limited verbal skills makes etiologic determination difficult
5. Children have difficulty localizing pain

B. History

1. Major or minor trauma including sports activity
2. Fever, weight loss or anorexia
3. Change in pain with activity
4. Recent illnesses or antibiotic use
5. Awakening from sleep at night in pain
6. Morning stiffness
7. Recent vaccinations or other intramuscular injections
8. New or poorly fitting shoes
9. Migratory arthralgias
10. Associated back pain
11. Endocrinopathies
12. Family history of connective tissue disease

C. Physical Examination

1. Careful observation of the child's actions
2. Muscle strength
3. Joint tenderness (physeal and joint line)
4. Bony tenderness or deformity
5. Joint effusion
6. Range of motion (active and passive)
7. Inflammation of joints, tendons, or muscles
8. Leg length: distance from anterior superior iliac spine to medial malleolus of ankle
9. Skin rashes
10. Soles of feet for calluses or foreign bodies
11. Gait Evaluation
    1. Infant should: sit at 6 months
    2. Crawl at 9 months
    3. Walk with assistance at 12 months
    4. Walk independently at 15 months
    5. Run at 18 months
12. Normal Gait Variants
    1. Genu varum (bow legs) normal up to 2 years
    2. Genu valgum (knock knees) normal up to 3 years
    3. Toddlers spend a less time in single stance than older children

D. Types of Gaits

1. Antalgic Gait
   1. Most common
   2. Short stance phase
   3. Caused by pain in weight bearing extremity
   4. Suggests fracture, septic arthritis, transient synovitis
2. Trendelenberg Gait
   1. Downward pelvic tilt during the swing phase
   2. Caused by weakness or spasm in contralateral gluteus muscle
   3. Legg-Calve-Perthes, slipped capital femoral epiphysis, congenital hip dislocation
3. Steppage Gait
   1. Seen with foot drops
   2. Exaggerated hip / knee flexion during swing phase to clear the dropped foot from floor
   3. Suggests neurologic diseases that cause loss of dorsiflexion of the ankle
4. Toe-walking Gait
   1. Stepping primarily on toes
   2. Suggests mild cerebral palsy, heel foreign body, toddler's fracture of the calcaneus
5. Stooped Gait
   1. Bilaterally increased hip flexion
   2. Suggests inter-abdominal or pelvic pathology

E. Laboratory Evaluation

1. Radiographs of involved extremity (other extremity comparison films rarely helpful)
2. White blood cell count with differential
3. Erythrocyte sedimentation rate
4. Ultrasound can be used for joint effusions
5. Bone scan often diagnostic in otherwise ambiguous cases

F. Differential Diagnosis

1. Transient Synovitis
   1. Most common non-traumatic hip pain in children
   2. Peak incidence at 6 years but seen from 9 months to adolescence
   3. Affects 3% of all children
   4. Unknown etiology but believed to be a post-viral illness sequelae
   5. Presents with unilateral hip pain
2. Antalgic gait
   1. Restricted hip motion (preferentially held in abduction and external rotation)
   2. Hip radiograph sometimes shows slight widening of joint space
   3. Ultrasound can confirm presence of hip effusion
   4. Treat with bed rest and non-steroidal anti-inflammatory drugs
   5. Two thirds of patients have resolution of their symptoms with 2 weeks
3. Toddler's Fractures
   1. Occur in children 1 to 4 years of age.
   2. Caused by relatively minor trauma
   3. Presents with localized tenderness and swelling but no bruising or deformity
   4. Twisting of distal extremity will produce severe pain if fracture present
   5. Fracture seen most clearly on oblique radiographic view
   6. Always consider possibility of non-accidental trauma
   7. This is especially important with proximal injuries
4. Slipped Capital Femoral Epiphysis
   1. Occurs during late childhood and adolescence
   2. Presents with insidious onset of dull pain and antalgic gait
   3. Slow chronic lateral displacement of the upper femoral neck with stationary capital femoral epiphysis
   4. Increased risk for obese or rapidly growing children
   5. Associated with endocrinopathies (most commonly hypothyroidism),
   6. Also associated with delayed skeletal maturation or family history of SCFE
   7. Bilateral involvement seen in more than 25% of cases
   8. Athletic activity exacerbates the injury
   9. Radiographs often normal or show a widening of the proximal physis
   10. Surgical stabilization of epiphysis with metallic fixation devices often required
5. Legg-Calve-Perthes Disease (see below)
6. Septic Arthritis (see below)
7. Discitis and Osteomyelitis (see below)
8. Reflex Sympathetic Dystrophy (RSD)
   1. Peripheral nerve dysfunction results in sympathetic nerve hyperactivity
   2. Typically involves the hand or foot
   3. Symptoms proceeded by relatively minor trauma
   4. Causes a continuous burning pain of affected extremity
   5. Associated with vasomotor instability of affected area
   6. Increased skin temperature, erythema and edema observed
   7. Immobilization provides some relief
   8. Persistent and severe pain may require sympathectomy or chronic pain medications
   9. Relatively uncommon in children
9. Osgood-Schlatter Disease
   1. Commonly affects athletic and actively growing adolescents
   2. Traction injury at site of patellar tendon insertion to the proximal tibial tuberosity
   3. Caused by repetitive microtrauma causing a partial avulsion
   4. Pain relieved with rest
   5. Examination shows prominence of tibial tuberosity with soft tissue swelling and occasionally a palpable bony mass
   6. Knee radiography may show irregularity of tibial tuberosity
   7. Treatment consists of rest, activity restriction and rarely a knee immobilizer
10. Stress Fractures
    1. Most common in adolescents
    2. Results from repetitive loading that causes fatigue with eventual fracture
    3. Bone remodelling occurs in response to stress
    4. If continuous stress during period of bone resorption, then a stress fracture can occur
    5. Radiographic changes seen 1-2 weeks after the onset of symptoms
    6. Periosteal reaction with new bone formation
    7. Thin lucency of the bone
    8. Bone scan will be abnormal within 3 days after onset of pain
11. Child Abuse
    1. Always maintain a high index of suspicion
    2. Half of cases occur in children under 1 year of age
    3. Suggestive findings
    4. Metaphyseal-epiphyseal injuries
    5. Vertebral fractures
    6. Finger fractures in ambulatory fractures
    7. Avulsion fractures of clavicle or acromium
    8. Fractures inconsistent with age of child or story provided
    9. Multiple fractures involving more than one skeletal focus
    10. Inappropriate delay in seeking medical attention
    11. Fractures at various stages of healing
    12. Fully investigate any concerning findings for the welfare of the child
12. Neoplasms
    1. Extremely rare in children
    2. Typically antecedent trauma history
    3. Often present with persist bony pain or swelling which can be nocturnal
    4. Most commonly involves distal femur of proximal tibia
    5. Radiograph of affected extremity showing bony lesions
    6. Rapidly growing malignant tumor will have no defined margins
    7. Slowly growing benign tumors typically have distinct borders
    8. Surgical resection, radiation or chemotherapy required if neoplasm identified

G. Septic Arthritis

1. Most commonly affects the knee and hip joints
2. Ninety percent of cases are monarticular
3. Early diagnosis and treatment are essential for good outcomes (minimal residua)
4. Examination
   1. Joint effusion
   2. Severe pain on joint motion
   3. Tenderness and warmth over the joint
5. Laboratory studies
   1. ESR elevated in 90% of cases, but is not specific
   2. WBC elevated in 30-60% of cases
   3. Arthrocentesis gold standard - WBC counts in joint fluid may be >25K/µL
6. Radiography
   1. Joint widening
   2. Soft tissue swelling,
   3. Obliteration of normal fat planes
   4. Osteomyelitis
   5. Bone scan is positive in area of arthritis and/or osteomyelitis
   6. MRI scan can assess soft tissue involvement
7. Treatment
   1. Prompt pus evacuation - multiple evacuations usually required
   2. Continue evacuations until fluid no longer accumulates in joint
   3. Joint fluid analysis with therapy should show falling WBC
   4. Intravenous antibiotics in high doses are required

H. Osteomyelitis

1. Most common in first 5 years of life (hematogenous spread most common)
2. Typically affects a single long bone (femur, humerus, and fibula)
3. Presents with local tenderness and fever
4. ESR and CRP elevated in 85-90% of cases
5. Blood cultures positive in 50% of cases
6. Radiographic changes
   1. Initially loss of soft tissue planes adjacent to bone
   2. Bony destructive changes 10-14 days after onset of infection
7. Bone scan (three phase) is usually considered the gold standard for diagnosis
8. However, MRI scan may help differentiate soft tissue from bone problems

I. Discitis

1. Inflammatory condition primarily involving the intervertebral disc
2. Rare condition occurring primarily in children under 5 years of age
3. Thought to be a low grade infection of the disk
4. Organisms
   1. Majority caused by Staphylococcus aureus
   2. Staph. epidermidis not uncommon
   3. Salmonella
   4. Kingella
5. Causes gradual onset of limp and refusal to sit, stand or walk
6. Examination reveals diffuse spinal tenderness with muscle spasm
7. Radiography
   1. Narrowing of joint space and irregular erosion of adjacent vertebral surfaces
   2. Both bone scan and MRI useful for early diagnosis
8. Treatment
   1. Rest
   2. Immobilization
   3. Antistaphylococcal antibiotics (oral or intravenous)

J. Legg-Calve-Perthe Disease

1. Onset occurs from 3 to 12 years with peak incidence between 5 to 7 years
2. Boys are affected 3-5 times more frequently than girls
3. Pathogenesis
   1. Idiopathic ischemic necrosis of capital femoral epiphysis
   2. Probably due to increased intracapsular pressure due to developmental anomalies
   3. Increased intracapsular pressure leads to repetitive re-infarction of femoral epiphysis
   4. Normal physiologic response is attempt at revascularization (angiogenic factors)
4. Associated with increased incidence of coagulopathies
5. Symptoms occur when necrotic subchondral bone fractures and collapses
   1. Presents with insidious onset of lip progressing to Trendelenberg gait
   2. Causes loss of internal rotation and abduction of the hip
6. Radiographic changes
   1. Initially epiphysis smaller with widening of medial joint space
   2. Physeal plate and metaphysis become blurry and radiolucent
   3. Subcondral fractures seen (Crescent sign)
   4. Later reossification of radiolucent areas
   5. Finally remodelling of proximal femur
7. Treatment
   1. Reduced activity
   2. Non-steroidal anti-inflammatory drugs (NSAIDs)
   3. Surgical containment of femoral head within acetabulum
8. Prognosis
   1. Determined by age on onset: children under 6 years have better outcomes
   2. Limp often persists for 2 to 4 years

References

1. Clark MC. 1997. Pediat Emerg Med. 2(12)123
2. Renshwa TS. 1995. Pediat in Rev. 16 (12) 458
3. Koop S and Qaunbeck D. 1996. Pediat Clin of North Amer. 43(5)1053