Introduction

Children present to the ED with a wide spectrum of possible causes for a limp ranging from benign conditions to serious underlying pathology. Common conditions are discussed within this guideline, including an approach to initial assessment and management. A broader range of conditions may need to be considered, especially if the limp has persisted for more than one week.

Broader range of diagnostic differentials for acute and persistent limp

Category	Conditions
Infection	septic arthritis osteomyelitis subperiosteal abscess myositis acute rheumatic fever
Post-infection	transient synovitis (post-viral) post- streptococcal infection (including rheumatic fever) serum sickness myositis
Trauma (accidental or non-accidental)	toddler’s fracture non accidental injuries (corner fractures) sprains haemophilia
Primary bone disease	slipped upper femoral epiphysis (SUFE) Perthes disease apophysitis developmental dysplasia of the hip (DDH)
Referred pain	appendicitis psoas abscess discitis testicular torsion (refer to Acute scrotal pain guideline)
Other	Neoplastic, inflammatory, non-inflammatory (mechanical or anatomical) conditions, haemophilia (can be atraumatic), chronic pain syndrome or psychogenic disorders.

Septic arthritis commonly occurs in children aged less than three years but can occur at any age.

Consider septic arthritis in any child with joint pain and fever.

Common causes of acute limp by age and order of incidence

Frequency	Less than 1 year	1- 4 years	5 -10 years	Over 10 years
Most common Least common	trauma including non-accidental injury (NAI) septic arthritis/ DDH Haemophilia Acute Rheumatic fever	transient synovitis trauma including NAI and toddler’s fracture septic arthritis/ osteomyelitis DDH Perthes disease Haemophilia Acute Rheumatic fever	trauma transient synovitis septic arthritis/ osteomyelitis Perthes disease psychogenic pain Haemophilia Acute Rheumatic fever	trauma septic arthritis/ osteomyelitis SUFE (3:1 male to female) inflammatory arthritis psychogenic pain Haemophilia

Common ED presentation

Transient synovitis
History	recent report of upper respiratory or gastrointestinal viral infection is common¹ males to females 2:1
Examination	normal temperature or low-grade pyrexia (less than 38.5°C) related to viral infection usually able to walk and weight bear with mild pain or discomfort
Diagnosis	usually by exclusion, with a careful history and examination (blood tests not routinely required though may be needed to exclude other diagnoses). Blood tests may be useful to reduce the pre-test probability of septic arthritis. careful clinical assessment is needed to differentiate transient synovitis from an early presentation of septic arthritis in the younger age group²
Management	most recover with rest and anti-inflammatory medication within weeks, though usually shorter

Less common but serious ED presentations

Septic arthritis
History	usually acute onset of fever (greater than or equal to 38.5° C) and toxaemia
Examination	severe pain may occur with passive motion child reluctant/unable to move the joint or weight bear
Diagnosis	urgent blood and synovial cultures are required to confirm diagnosis synovial fluid aspiration in children must always occur in a sterile environment in the operating theatre if suspected and greater than four hour delay for synovial fluid aspiration in OT, antibiotics IV must be given in consultation with orthopaedic staff (see Paediatric Bone and Joint Infection Management Guideline) synovial fluid isolates are commonly S. aureus or Streptococcus sp.
Management	an orthopaedic emergency – urgent antibiotics IV (after obtaining samples for culture) is required to avoid joint destruction. If the child is septic, start IV antibiotics prior to obtaining operative samples.

Osteomyelitis
History	subtle onset of symptoms including limp, reluctance to weight bear or reduced movement can affect any bone but more commonly the femur is affected commonly in the metaphyseal area can have concomittent septic arthritis if metaphysis is intra-articular (hip, ankle)
Examination	pain may be localised with tenderness redness and swelling are usually late signs
Diagnosis	requires index of clinical suspicion bloods usually show raised inflammatory markers and the blood culture may be positive Imaging can show changes on plain film if symptoms present > than 1 week and can be useful for progression. MRI is as sensitive but more specific than bone scan.
Management	guided by orthopaedic surgeons – IV antibiotics +/- operative management

Perthes disease
History	hip discomfort and limp that may fluctuate. Males to females 5:1
Examination	loss of hip internal rotation and abduction
Diagnosis	X-rays can be normal in the early stages, with later changes of joint effusion, epiphyseal fragmentation or loss of femoral head height maintain a high index of suspicion and consider orthopaedic referral in males aged 3-10 years with persistent limp, even if X-rays are normal can often be a painless limp MRI may be a useful diagnostic tool if readily available.
Management	supportive and/or surgical referral to orthopaedic service early

Slipped upper femoral epiphysis (SUFE)
History	limp often present for weeks or months, and may have been preceded by minor trauma
Examination	may present with groin/ anterior thigh/ knee pain, abnormal gait, weakness and/or thigh atrophy. Leg held in externally rotated position.
Diagnosis	demonstrated on X-ray of pelvis (including frog leg view) X-ray may be normal or only minor slip in early stages Can be easily missed. Look at both the AP and Lateral films. Follow Kleins line to see if it intersect the epiphysis, maintain a high index of suspicion in overweight adolescents with persistent limp
Management	Non weight bare and prompt operative treatment required

Assessment

The aim of the assessment is to differentiate the children who have serious underlying pathology from the larger group of children who do not have a serious cause for their limp.

History

History taking should include specific information on:

onset and course of limp
history of trauma
pain history – including localisation, magnitude, pain migration, number of joints involved, exacerbating/ relieving factors
constitutional symptoms such as fevers, malaise, anorexia, weight loss, night sweats
bleeding history- excess bruising/bleeding, prolonged/frequent epistaxis, prolonged bleeding after invasive procedures
preceding illness including sore throat or skin infections
previous or recurrent injuries (haemophilia, or should raise suspicion of NAI especially in infants and younger children)
social history
developmental delay

Examination

Clinical examination should include:

general examination with attention to vital signs and appearance, bruising and lymphadenopathy
neurological examination – symmetry of limbs, muscle atrophy, power, tone, reflexes and coordination, including ataxia
joint examination (including joint above and below) assessing swelling, tenderness, warmth, active and passive mobility
point bony tenderness (may indicate osteomyelitis)
abdomen, scrotum and spine examination to exclude referred pain from other possible causes

Considerations in children

physical examination can be challenging in younger children – observation of how they move, weight bear, crawl, walk, run, jump and squat will be very helpful in terms of localising potential pathology
neurological weakness can present as a limp.

Alert

Septic arthritis is an orthopaedic emergency. Delay in diagnosis increases the risk of joint destruction.

Red flags to suggest serious pathology for a child with a limp

fever greater than or equal to 38.5°C
recent throat or skin infection
inability to weight bear or severe, localised joint pain
bony pain
systemic symptoms such as weight loss, night sweats
possible unwitnessed trauma/NAI
overweight adolescent

Suspect septic arthritis in child with a fever greater than 38.5°C, acute onset of severe, localised joint pain and difficulty weight bearing.

Seek urgent senior emergency/orthopaedic advice as per local practice if septic arthritis is suspected.

Investigations

Investigations required will depend on the assessment. Children presenting within a few days of onset of the limp and with no red flags may not require any investigations. Clinicians must ascertain the benefits before ordering tests and clarify what a specific test will add to the evaluation of the limping child.

Investigations for a child with a limp

Investigation type	Utility
Plain X-rays	identify fractures Perthes disease, SUFE, DDH and bony lesions a normal X-ray does NOT exclude early septic arthritis or osteomyelitis
Full blood count	exclude malignancy assist in assessing the risk of septic arthritis or osteomyelitis
C reactive protein	assist in assessing the risk of septic arthritis or osteomyelitis
Erythrocyte sedimentation rate	assist in assessing the risk of septic arthritis, osteomyelitis or other inflammatory causes of limp
Coagulation	assist in identifying haemophilia
ASOT/Anti DNase	may be positive in septic arthritis and useful to risk stratify for acute rheumatic fever
ECG	useful to risk stratify for acute rheumatic fever
Throat/wound swab M/C/S	Testing for Group A Streptococcus (GAS) for risk of acute Rheumatic Fever. Note high carriage rate does not always indicate infection.
Blood cultures	essential if suspect septic arthritis or osteomyelitis
Joint ultrasound	identify effusion but does not discriminate between exudate and transudate absence of effusion on formal USS can be used to exclude septic arthritis negative bedside ultrasound should always be confirmed by formal radiology especially if high index of suspicion for septic arthritis⁵
Specialised imaging	imaging including CT scan, MRI and bone scan should only be requested on specialist advice

Diagnosing septic arthritis

Definitive diagnosis is confirmed on positive joint aspirate by orthopaedic surgeons in theatre. In the ED, Kocher’s criteria^6-8 can assist in determining the likelihood of septic arthritis.

Predictors	Probability of septic arthritis
fever greater than 38.5 °C non-weight bearing leukocytosis greater than 12,000/mm³ ESR greater than 40 mm/hr	Number of predictors	Probability of septic arthritis
	0	0.2%
	1	3%
	2	40.0%
	3	93.1%
	4	99.6%

There is a modified Kocher which also uses a CRP of >20.

Management

Refer to the flowchart [PDF 486.63 KB] for a summary of the recommended assessment and investigation for a child presenting to ED with an unexplained limp.

The appropriate management will be guided by the outcome of the assessment.

Urgent referral to orthopaedic team as per local practice is required for all children with suspected septic arthritis.

If suspected septic arthritis and unwell or septic, give urgent empiric antibiotics after blood cultures obtained. Do not delay whilst waiting for operative intervention. This management should be as per statewide sepsis protocols.

Prompt referral to orthopaedic service as per local practice is required for all children with concerns of serious underlying pathology.

Consider seeking orthopaedic advice as per local practice for a child with a persistent limp (greater than one week) and a normal X-ray.

Escalation and advice outside of ED

Clinicians can contact the services below if escalation of care outside of senior clinicians within the ED is needed, as per local practices. Transfer is recommended if the child requires a higher level of care.

Alert

Septic arthritis is an orthopaedic emergency. Suspect in any limping child with severe, localised joint pain and fever.

Child with septic arthritis (requires time-critical care)

Reason for contact	Who to contact
For urgent advice and referral of child with suspected septic arthritis	Contact the onsite/local orthopaedic service. The onsite/local paediatric service may assist with emergency management.

Reason for contact

Who to contact

For urgent advice and referral of child with suspected septic arthritis

Contact the onsite/local orthopaedic service.

The onsite/local paediatric service may assist with emergency management.

Non-critical child

May include children with
serious pathology identified on X-ray X-ray NAD but persistent limp unable to walk due to inability to weight bear

Reason for contact	Who to contact
Advice (including management, disposition or follow-up)	Follow local practices. Options: onsite/local orthopaedic service Queensland Children’s Hospital experts via Children’s Advice and Transport Coordination Hub (CATCH) on 13 CATCH (13 22 82) (24-hour service) local and regional paediatric videoconference support via Telehealth Emergency Management Support Unit TEMSU (access via QH intranet) on 1800 11 44 14 (24-hour service)
Referral	First point of call is the onsite/local orthopaedic service

Inter-hospital transfers

Do I need a critical transfer?	discuss with onsite/local orthopaedic service view Queensland Paediatric Transport Triage Tool
Request a non-critical inter-hospital transfer	contact onsite/local orthopaedic service contact RSQ on 1300 799 127 for aeromedical transfers contact Children’s Advice and Transport Coordination Hub (CATCH) on 13 CATCH (13 22 82) for transfers to Queensland Children’s Hospital
Non-critical transfer forms	QH Inter-hospital transfer request form (access via QH intranet) aeromedical stepdown [PDF] (access via QH intranet) commercial aeromedical transfers: Qantas Virgin Jetstar

Disposition

When to consider discharge from ED

Most children who do not have serious underlying pathology can be managed supportively at home, with appropriate advice around when to represent for review at either their GP or the ED.

Parents should be advised to represent for medical review (GP or ED) if the child develops a fever or symptoms persist or worsen.

Follow-up

Recommended follow-up is based on the outcome of the assessment. Follow-up is not routinely required for children for whom no serious underlying pathology is suspected.

When to consider admission

As per advice for children requiring specialist referral.

Consider admission for any child who cannot weight bear and is no longer mobile.

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Key points

Purpose