Musculoskeletal conditions in children — overview

Musculoskeletal (MSK) conditions are common in children and represent a significant proportion of primary care presentations. However, the approach to paediatric MSK disorders differs substantially from adult presentations, as children have unique anatomical features including growth plates (physes), apophyses, and ongoing skeletal development. The challenge for Australian GPs is distinguishing normal developmental variation and self-limiting conditions (such as growing pains) from serious pathology including septic arthritis, leukaemia, bone tumours, and inflammatory arthritis.

Paediatric MSK conditions span mechanical causes (trauma, overuse, growth-related), inflammatory causes (juvenile idiopathic arthritis [JIA], viral arthritis, rheumatic fever), developmental causes (developmental dysplasia of hip, slipped upper femoral epiphysis), and malignant causes (leukaemia, bone or soft tissue tumours). Children may present differently from adults with the same condition — infection presents atypically, pain is poorly localised, and systemic features may be subtle. Limp is a key presenting symptom in young children who cannot articulate pain.

This guideline outlines the Australian primary care approach to paediatric MSK conditions, with emphasis on age-appropriate assessment, early identification of serious pathology via red-flag recognition, appropriate investigations, and timely specialist referral.

Understanding paediatric skeletal anatomy is essential for appropriate diagnosis and management. Key differences from adult anatomy include:

Growth plates (physes) are cartilaginous structures at the ends of long bones where longitudinal bone growth occurs. Physes are mechanically weaker than adjacent bone and ligaments — fractures preferentially occur through the physis rather than ligament rupture. Physis closure occurs progressively during adolescence (femur closes 16–18 years; humerus 19–22 years). Epiphyseal fractures can disrupt growth and cause limb length discrepancy or angular deformity.

Apophyses are secondary ossification centres where muscles and tendons attach. Apophysitis is common in adolescents during growth acceleration periods, presenting as localised tenderness and pain with activity (e.g., Osgood-Schlatter disease at the tibial tuberosity, sever disease at the calcaneal apophysis). Apophyseal injuries are mechanical overuse injuries.

Bone marrow in children is highly cellular and metabolically active, making paediatric bone susceptible to infection (osteomyelitis) and infiltration by malignancy (leukaemia). Haematogenous spread preferentially sequesters in areas of increased blood flow, particularly the metaphyseal regions of long bones.

Inflammatory arthritis in children (JIA) presents with synovial inflammation but may spare systemic features compared to adult rheumatoid arthritis. JIA is the most common chronic arthritis in children.

Growing pains are benign musculoskeletal pain in children aged 3–12 years, typically bilateral, occurring in thighs or lower legs, worse at night, resolving by morning. No joint swelling, systemic features, or impact on function. Pathophysiology remains unclear but is presumed due to rapid bone growth or myofascial tightness.

Paediatric MSK presentations vary markedly by age. Limp is the key presenting symptom in younger children; older children can localise pain. Always enquire about fever, weight loss, night pain, and systemic features, which are red flags for serious pathology.

Distinguishing growing pains from pathology: Growing pains are bilateral, intermittent, occur at night, resolve by morning, associated with periods of rapid growth, no joint swelling or functional limitation. Pathological pain is typically unilateral, persistent, associated with limp or functional limitation, may have swelling, and often accompanied by systemic features.

Investigations in paediatric MSK conditions should be judiciously employed, particularly imaging, as children are more radiosensitive than adults. Clinical assessment guided by red-flag recognition should drive investigation selection.

In paediatric MSK conditions, severity assessment focuses on likelihood of serious underlying pathology rather than pain intensity. The priority is early identification and referral of serious conditions (septic arthritis, malignancy, inflammatory arthritis) while reassuring families about benign conditions.

Management of paediatric MSK conditions is individualised based on diagnosis. Core principles include appropriate analgesia, activity modification (not prolonged immobilisation for benign conditions), physiotherapy referral for structural issues, and specialist referral when serious pathology is suspected or diagnosis uncertain.

• Analgesia: Paracetamol or ibuprofen (age and weight-appropriate dosing) for pain control. NSAIDs preferred for inflammatory conditions and mechanical pain. Simple analgesia often sufficient for benign conditions. Avoid prolonged opioid use.
• Rest and activity modification: For benign conditions and mild injury: continue age-appropriate activity as tolerated, avoiding provocative activities. Prolonged bed rest may worsen outcomes. For serious conditions (septic arthritis, fractures): immobilisation/splinting as indicated.
• Physiotherapy: Referral indicated for persistent monoarthritis (joint mobility, strength, function), structural injuries (post-fracture, ligamentous injury), or overuse injuries (apophysitis, stress fractures). Early physiotherapy facilitates return to activity and prevents deconditioning.
• Orthopaedic referral: Indicated for suspected growth-plate injuries, slipped upper femoral epiphysis, developmental dysplasia of hip, and structural injuries requiring specialist management.
• Rheumatology referral: Persistent monoarthritis or polyarthritis; suspected JIA; systemic features suggesting inflammatory arthritis. Early referral optimises JIA outcomes.
• General paediatric referral: If serious systemic pathology suspected (leukaemia, malignancy); failure to diagnose despite appropriate investigation; requirement for admission (septic arthritis).

Pharmacotherapy in paediatric MSK conditions focuses on analgesia and management of inflammatory conditions. Dosing must be age and weight-appropriate. Disease-modifying therapy (for JIA) is the domain of specialist rheumatology.

Acute presentations of paediatric MSK conditions require rapid assessment to exclude life-threatening or limb-threatening pathology. The limping child with fever is septic arthritis until proven otherwise.

• Acute febrile limp or refusal to weight-bear: Assess for septic arthritis. Examine hip (abduction, internal rotation limitation suggests joint effusion), temperature, WBC, CRP. Perform hip ultrasound if available — measure capsular distance. If high suspicion: admit, image, aspirate, blood culture, commence antibiotics. Do not delay referral awaiting imaging.
• Trauma with severe pain or deformity: Immobilise; X-ray to exclude fracture; analgesia. Refer to ED or orthopaedics if fracture confirmed or clinical concern high.
• Acute severe joint swelling without trauma or fever: Consider crystal arthritis (rare in children), haemarthrosis (bleeding disorder, trauma), acute leukaemia (bleeding, bruising). Aspirate if indicated. FBC to screen for coagulopathy or leukaemia.
• Limp with no fever, normal inflammatory markers, normal imaging: Presumed transient synovitis or benign mechanical cause. Analgesia, activity modification, reassurance. Safety-net advice: return if fever develops, pain worsens, or limp persists >2 weeks.

Appropriate follow-up ensures diagnosis is not missed and therapeutic efficacy is confirmed. Duration and interval of follow-up depend on initial diagnosis, severity, and risk of progression.

Unique considerations apply to specific age groups and special populations within the paediatric population.

Aboriginal and Torres Strait Islander children experience disproportionately high rates of MSK infections, particularly septic arthritis and osteomyelitis, due to higher rates of skin infections, crowded housing, and limited access to early primary care. Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) remain significant problems in remote and regional communities.

Stewardship in paediatric MSK management focuses on appropriate, judicious use of investigations (minimising unnecessary radiation), judicious use of antibiotics (septic arthritis recognised early and appropriately treated), and avoiding prolonged inappropriate medication use.

• Imaging stewardship: Children are more radiosensitive than adults. Avoid routine X-ray of growing pains or uncomplicated viral arthritis. Use clinical assessment and ultrasound (for hip effusion) to guide decision-making. When X-ray indicated: ensure appropriate views and minimal repeats. MRI reserved for when diagnosis unclear after clinical and radiographic assessment.
• Antibiotic stewardship: Septic arthritis requires IV antibiotics but empiric antibiotics are not indicated for presumed viral arthritis or transient synovitis. Joint aspiration with culture guides organism-directed therapy. Use appropriate duration of IV antibiotics (typically 4–6 weeks IV, then oral transition, total 6–8 weeks). Blood culture mandatory before antibiotics if bacteraemia suspected.
• Corticosteroid use: Avoid systemic corticosteroids in JIA management without rheumatology guidance. Intra-articular corticosteroid injection is specialist domain. Short-term low-dose systemic corticosteroids may be used as bridge therapy while DMARDs initiated, but this is rheumatology decision.
• Analgesia: Paracetamol and ibuprofen (at appropriate doses) are first-line. Avoid opioids in acute and chronic MSK conditions. For severe acute pain (fracture, septic arthritis): adequate analgesia facilitates examination and function. Escalate analgesia appropriately rather than providing inadequate pain relief.
• NSAID use in varicella: Individualise decision regarding NSAID use during acute varicella. Risk of invasive secondary infection (IGAS) exists but is rare; benefit for pain relief often justifies use. Avoid if clinical signs of invasive infection develop.

Appropriate referral ensures timely specialist input and optimises outcomes. GPs should maintain low threshold for referral when serious pathology suspected or diagnosis uncertain.

• RACGP — Guidelines for assessment of the limping child (adapted from international guidelines)
• Therapeutic Guidelines: Paediatrics — Musculoskeletal infections, arthritis, and rheumatic conditions; available via eTG complete
• American Academy of Pediatrics — The Pediatric Manual of Physical Diagnosis and Clinical Reasoning in Pediatrics
• Paediatric Rheumatology International Trials Organisation (PRINTO) — Juvenile Idiopathic Arthritis classification and management guidelines
• Caird MS — Osteomyelitis and septic arthritis in children; Clin Infect Dis 2019
• Cawley P, Ahuja V, et al. — The limping child: a practical approach; Paediatr Child Health 2020
• Australian Centre for Posttraumatic Mental Health (ACPMH) — Trauma-informed care in primary health care for Aboriginal and Torres Strait Islander populations
• National Heart Foundation of Australia — Acute Rheumatic Fever and Rheumatic Heart Disease guidelines for remote Aboriginal communities