Paediatric MSK Presentations Algorithm

Safety

Red Flags — Exclude septic arthritis, malignancy, NAI

Done

Urgent exclusion of limb-threatening and life-threatening conditions in any child with MSK symptoms.

Acute limp + fever Refusing to weight-bear, hot swollen joint, systemically unwell → 999/Same-day paediatric assessment (septic arthritis, osteomyelitis)

Non-accidental injury features Multiple bruises at different stages, inconsistent history, delayed presentation, injuries incompatible with developmental stage → Same-day safeguarding referral

Night pain / bone pain Wakes child from sleep, unrelieved by simple analgesia, constant aching → 2WW paediatrics (malignancy: leukaemia, bone tumour)

Systemically unwell Weight loss, fever >2 weeks, pallor, petechiae, hepatosplenomegaly, lymphadenopathy → 2WW paediatrics (malignancy, systemic JIA)

Adolescent hip pain Age 10-16 years, groin/knee pain, limp, restricted internal rotation → Same-day orthopaedics (SUFE — slipped upper femoral epiphysis)

Age <3 years with limp Always abnormal. Cannot be "growing pains" → Same-day paediatric assessment (DDH, septic arthritis, toddler fracture, malignancy)

Persistent limp >48 hours No improvement, worsening, or inability to weight-bear → Urgent X-ray + paediatric review (fracture, Perthes, malignancy)

Red/hot/swollen single joint Monoarthritis with effusion → Same-day (septic arthritis, reactive arthritis, haemarthrosis)

Back pain age <10 years Unusual in young children. Exclude serious pathology → X-ray spine + paediatric review (discitis, malignancy, spondylolisthesis)

Bilateral hip pain age 5-9 years Bilateral Perthes (rare but can occur), systemic disease → Urgent X-ray + orthopaedics

Septic arthritis is a surgical emergency — delayed treatment (>24 hours) leads to irreversible joint destruction, growth plate damage, and chronic disability. Kocher criteria: fever >38.5°C, refusal to weight-bear, WCC >12, ESR >40 = 99% sensitivity for septic arthritis vs transient synovitis.

Slipped upper femoral epiphysis (SUFE) requires urgent surgical pinning to prevent avascular necrosis of femoral head. Presents as groin/knee pain in obese adolescents. Delay = slip progression = lifelong hip arthritis.

Childhood malignancy (leukaemia, neuroblastoma, osteosarcoma) presents with vague MSK symptoms in 25% of cases. Night pain is pathognomonic — benign MSK pain does not wake children from sleep. Missing malignancy has catastrophic consequences.

Diagnose

History — GALS approach and developmental context

Done

Take detailed history focusing on onset, pattern, functional impact. Ask about play, sport, school attendance.

Pain characteristics

Onset: Acute (<24hrs) vs gradual. Pattern: Worse morning (inflammatory) vs evening (mechanical). Night pain: Wakes from sleep = red flag. Severity: Impact on function (play, sport, stairs, dressing).

Limp pattern

Antalgic: Shortened stance phase (painful). Trendelenburg: Hip abductor weakness (DDH, Perthes). High-stepping: Foot drop (neurological). Circumduction: Hip/knee stiffness.

Systemic features

Fever, rash, weight loss, fatigue, poor appetite, night sweats, pallor. Presence = infection, malignancy, systemic JIA. Absence = mechanical or benign.

Trauma history

Witnessed fall, mechanism, immediate vs delayed pain. Exclude NAI if history inconsistent or multiple injuries.

Developmental stage

<3 years: Pre-verbal, examine carefully (septic arthritis, DDH, NAI common). 3-9 years: Peak for transient synovitis, Perthes. 10-16 years: SUFE, Osgood-Schlatter, anterior knee pain.

Family history

Juvenile arthritis, autoimmune disease (JIA risk ↑), hypermobility syndromes, sickle cell disease (avascular necrosis).

Activity level

Sports, dancing, gymnastics (overuse injuries). Sudden increase in activity (Sever's disease, stress fractures). Sedentary (obesity → SUFE, Blount's disease).

Age is the strongest diagnostic clue — different conditions cluster at different developmental stages. Toddler fractures (<3 years), Perthes (4-8 years), SUFE (10-16 years). Age-inappropriate diagnosis should trigger reassessment.

Functional impact distinguishes serious from benign pathology. Child still playing, running, climbing stairs = likely benign. Refusing to weight-bear, carried by parents, missing school = urgent assessment needed.

Night pain is never benign in children. Growing pains occur in evening, resolve by bedtime, never wake children from sleep. Night pain = exclude malignancy, infection, inflammatory arthritis.

Diagnose

Classification — Age-based differential diagnosis

Done

Use age to narrow differential diagnosis and guide investigation strategy.

Age <3 years

Common: Transient synovitis, toddler fracture (spiral tibia), post-viral arthralgia. Serious: Septic arthritis, osteomyelitis, DDH, NAI, leukaemia. Rule: Any limp age <3 requires same-day assessment — cannot self-report symptoms.

Age 3-10 years

Common: Transient synovitis (irritable hip), growing pains, post-viral, minor trauma. Serious: Perthes disease (4-8 yrs), septic arthritis, malignancy, juvenile idiopathic arthritis. X-ray if: Persistent >48 hrs, night pain, systemically unwell.

Age 10-16 years

Common: Osgood-Schlatter, Sever's disease, anterior knee pain, growing pains, sports injuries. Serious: SUFE, bone tumours (osteosarcoma, Ewing's), JIA. Groin/hip pain = SUFE until proven otherwise.

Growing pains

Criteria: Age 3-12 years, bilateral leg pain (thighs, calves), evening/night onset, resolves by morning, does NOT wake child, normal examination, normal activity. If atypical → investigate. Diagnosis of exclusion

Hypermobility

Beighton score ≥4/9: thumb to forearm, little finger >90°, elbow hyperextension >10°, knee hyperextension >10°, palms flat on floor. Symptoms: Joint pains after activity, easy bruising, poor stamina. Management: Physiotherapy, core strengthening.

Transient synovitis

Peak age: 3-8 years. Features: Acute limp, hip pain, recent viral illness, low-grade fever (<38°C), can weight-bear with pain. Investigations: Normal WCC/CRP/ESR. Self-limiting 1-2 weeks. Exclude septic arthritis

Growing pains are a diagnosis of exclusion affecting 10-20% of children. Must be bilateral, evening-only, self-limiting, with normal examination and bloods. Unilateral pain, daytime pain, or abnormal examination = NOT growing pains.

Transient synovitis vs septic arthritis is the critical distinction. Kocher criteria help but are not 100% sensitive. When in doubt = same-day hospital assessment for joint aspiration. Missing septic arthritis = permanent joint damage.

Age-specific pathology reflects skeletal maturity. Perthes (avascular necrosis femoral head) occurs age 4-8 when blood supply to epiphysis is vulnerable. SUFE occurs in adolescents when growth plate is weakest pre-fusion. Wrong age for diagnosis = reconsider.

Diagnose

Examination — GALS screen + focused joint examination

Done

Start with GALS (Gait, Arms, Legs, Spine) screen, then focused joint examination.

Gait observation

Watch child walk, run, jump. Antalgic: Painful (shortened stance). Trendelenburg: Hip drops on opposite side (abductor weakness). Toe-walking: Achilles contracture, cerebral palsy. Refusal to weight-bear: Serious pathology until proven otherwise.

Arms (GALS)

"Put hands behind head" (shoulder abduction/external rotation), "Touch ceiling" (shoulder elevation), "Make fist" (finger flexion), "Turn hands over" (wrist/forearm supination/pronation). Abnormal = JIA, connective tissue disease.

Legs (GALS)

"Stand on tiptoes" (ankle plantarflexion, calf strength), "Squat down" (knee flexion, hip/knee pathology if unable). Check leg length (ASIS to medial malleolus). Palpate knees for effusion, warmth.

Spine (GALS)

"Touch toes" (lumbar flexion, hamstring tightness). "Bend sideways" (lateral flexion). Observe from behind for scoliosis (Adams forward bend test). Back pain <10 years = X-ray spine.

Hip examination

Look: Leg length, muscle wasting (gluteal, quadriceps). Feel: Groin tenderness. Move: Flexion, abduction, adduction, internal/external rotation. Limited internal rotation = Perthes, SUFE, slipped capital femoral epiphysis. Log roll test: Passive internal/external rotation — pain = hip pathology.

Knee examination

Effusion: Bulge test, ballotment. Tenderness: Tibial tuberosity (Osgood-Schlatter), patella (patellofemoral pain), joint line (meniscal tear). Stability: Collateral ligaments, cruciate ligaments (teens only).

Foot/ankle

Heel tenderness (Sever's disease age 8-14), flat feet (flexible normal), high arches (neuromuscular disease). Achilles tendon (tightness, swelling). Ankle range of motion (dorsiflexion, plantarflexion).

Systemically

Temperature, rash (JIA, HSP, Lyme), pallor (anaemia in leukaemia), lymphadenopathy, hepatosplenomegaly (malignancy, JIA). Weight, height (growth plate damage in chronic disease).

GALS screen detects 96% of significant MSK abnormalities in 2 minutes. Quick screening tool before focused examination. Normal GALS screen makes serious pathology unlikely (high negative predictive value).

Hip pathology presents as knee pain in 30% of children (referred pain via obturator nerve). Always examine hip in child with knee pain, especially if knee examination normal. Missing SUFE because you only examined the knee is a medicolegal disaster.

Refusal to weight-bear is never normal. Even with transient synovitis, children can weight-bear with pain. Complete refusal = septic arthritis, fracture, malignancy, or severe Perthes until proven otherwise.

Diagnose

Investigations — Selective based on clinical suspicion

Done

Investigate if: age <3 years with limp, systemically unwell, abnormal examination, persistent >48 hours, or red flags.

Bloods — when to do

FBC, CRP, ESR if: fever, systemically unwell, suspected infection/inflammation. Interpretation: WCC >12 + CRP >20 + ESR >40 = probable septic arthritis. Normal inflammatory markers do NOT exclude serious pathology (leukaemia, bone tumour can have normal bloods initially).

X-ray — indications

Urgent same-day: Suspected fracture, SUFE, severe pain, unable to weight-bear. Routine: Persistent limp >1 week, night pain, abnormal examination. Views: AP + lateral + frog-leg lateral (for hip). Klein's line on AP hip X-ray (SUFE diagnosis).

Growing pains

Do NOT investigate if: bilateral, evening-only, normal examination, child well. Reassure parents. Investigate if: unilateral, daytime, wakes from sleep, abnormal exam, systemically unwell.

Hip ultrasound

Indications: Suspected effusion (transient synovitis vs septic arthritis), DDH screening in at-risk infants. Effusion >2mm = aspiration if febrile/systemically unwell (septic arthritis).

MRI

Indications: Normal X-ray but high clinical suspicion (early Perthes, stress fracture, bone tumour, osteomyelitis), back pain <10 years, neurological signs. Arranged by: Paediatrics/orthopaedics, NOT primary care.

Do NOT investigate

Typical growing pains. Transient synovitis improving at 48 hours. Clear sports injury with normal examination. Overinvestigation causes anxiety, radiation exposure, false-positives.

X-rays in children = radiation — effective dose matters. Pelvis X-ray = 0.6 mSv (equivalent to 3 months background radiation). Only X-ray if result will change management. Normal X-ray does NOT exclude serious pathology (early Perthes, bone tumours, osteomyelitis may have normal X-rays initially).

Inflammatory markers help distinguish septic arthritis from transient synovitis but are not 100% sensitive/specific. CRP <20 + ESR <40 + WCC <12 + afebrile = <2% probability septic arthritis. But clinical suspicion overrides bloods — if in doubt, refer for joint aspiration.

MRI is gold standard for early Perthes, osteomyelitis, bone tumours, stress fractures, soft tissue masses. Avoid radiation. Arranged by specialists, not primary care. Do not delay referral waiting for MRI availability.

Refer

Referral Criteria — When to escalate urgently

Done

Low threshold for urgent referral in children — consequences of missed serious pathology are catastrophic.

999/Same-day

Septic arthritis suspected: Acute limp + fever + hot joint + refusing weight-bear. SUFE suspected: Adolescent with groin/hip pain + restricted internal rotation. Fracture: Significant trauma, deformity, unable to weight-bear. NAI concern: Inconsistent history, multiple injuries, safeguarding alert.

2WW paediatrics

Night pain waking from sleep. Systemically unwell: Weight loss, fever >2 weeks, pallor, bruising, lymphadenopathy. Persistent unexplained limp >2 weeks despite normal X-ray. Multiple joint swelling. Back pain age <10 years.

Urgent orthopaedics

Perthes disease on X-ray (age 4-8, hip pain, limp). Persistent limp + abnormal X-ray (fracture, bone lesion). DDH suspected (clunk, asymmetric skin creases, leg length discrepancy). Severe Osgood-Schlatter unresponsive to rest.

Routine paediatrics

Suspected JIA: Joint swelling >6 weeks, morning stiffness, multiple joints. Hypermobility + significant functional impairment. Growing pains atypical or severe (for reassurance + physiotherapy).

Primary care

Typical growing pains (bilateral, evening, normal exam). Transient synovitis improving at 48 hrs. Minor sports injuries (Sever's, Osgood-Schlatter mild). Hypermobility mild. Manage with reassurance, analgesia, physiotherapy referral.

SUFE is a same-day surgical emergency — requires immediate surgical pinning to prevent further slip and avascular necrosis. Delay = slip progression = chronic hip arthritis requiring hip replacement in early adulthood. Any adolescent with hip/groin pain and restricted internal rotation needs same-day X-ray and orthopaedic review.

Perthes disease requires urgent orthopaedic input to prevent femoral head collapse. Treatment (containment, bracing, or surgery) is time-sensitive — delayed referral worsens long-term outcome (hip arthritis, leg length discrepancy).

Juvenile idiopathic arthritis is a diagnosis of exclusion. JIA is joint swelling (not just pain) persisting >6 weeks with morning stiffness >15 minutes. Early rheumatology input prevents joint damage and disability. Window for aggressive treatment is first 3 months.

Treat

Analgesia and Supportive Care — primary care management

Done

Treat benign MSK conditions in primary care with analgesia, activity modification, physiotherapy.

Growing pains

Reassurance + simple analgesia First-line

Paracetamol 15 mg/kg QDS PRN. Leg massage, heat packs. Benign, self-limiting. Resolves by age 12.

Transient synovitis (improving)

Ibuprofen + rest First-line

Ibuprofen 10 mg/kg TDS (max 400mg) for 3-5 days. Avoid weight-bearing initially. Review 48 hours. Self-limiting 1-2 weeks.

Osgood-Schlatter / Sever's

Activity modification + physio First-line

Reduce high-impact sport. Ice after activity. Stretching (quadriceps, hamstrings, calves). Resolves with growth plate fusion.

Step 1Paracetamol 15 mg/kg QDS (max 1g) PRN for mild pain (growing pains, minor trauma). Avoid regular dosing unless moderate-severe pain.

Step 2Ibuprofen 10 mg/kg TDS (max 400mg) for inflammatory conditions (transient synovitis, Osgood-Schlatter, soft tissue injury). Give with food. Avoid if asthma.

Step 3Paracetamol + Ibuprofen alternating for moderate-severe pain. Safe to combine. Review in 48 hours — if not improving, investigate.

Step 4Refer if: Analgesia ineffective, pain worsening, persistent >1 week, red flags emerge. Do NOT escalate to codeine/tramadol in primary care.

Activity modification

Osgood-Schlatter / Sever's: Reduce running, jumping sports. Swimming, cycling OK. Stretching exercises (quadriceps, hamstrings, gastrocnemius). Ice after activity 15 minutes. Duration: 3-6 months until growth spurt complete.

Physiotherapy referral

Indications: Hypermobility with functional impairment, recurrent sports injuries, persistent pain >4 weeks, muscle weakness (post-Perthes, post-fracture). Focus: Core strengthening, proprioception, gait retraining.

Safety-netting

Return if: pain worsening, new systemic symptoms (fever, weight loss), unable to weight-bear, night pain develops. Growing pains: If still present age 12+ or becoming unilateral → re-investigate.

NSAIDs are superior to paracetamol for MSK pain in children because most paediatric MSK pain is inflammatory (transient synovitis, soft tissue injuries, overuse syndromes). Ibuprofen has better efficacy and similar safety profile. Avoid if asthma or <3 months old.

Activity modification is treatment, not just advice. Osgood-Schlatter and Sever's disease are traction apophysitis — continuing high-impact sport perpetuates symptoms. Relative rest (reduce running/jumping, continue swimming/cycling) allows healing while maintaining fitness. Self-limiting once growth plate fuses.

Do NOT use codeine in children <12 years (MHRA warning — risk of respiratory depression in ultra-rapid metabolisers). Tramadol also avoided. If simple analgesia ineffective = refer for investigation, not escalate opioids.

Lifestyle

Parental Education and Injury Prevention

Done

Educate parents on self-management, red flags, and injury prevention. Reduce anxiety about benign symptoms.

Growing pains reassurance Explain benign nature. Not harmful to bones/joints. Self-limiting by age 12. No long-term consequences. Massage and reassurance as effective as medication.

Red flag education Teach parents when to seek urgent care: fever + limp, refusing to weight-bear, night pain waking child, systemically unwell, persistent >1 week.

Activity balance Encourage diverse physical activity (avoid single-sport specialisation <12 years). Mix high-impact (running) with low-impact (swimming, cycling). Rest days essential — growth plates need recovery time.

Warm-up and stretching 5-10 minutes warm-up before sport. Stretching after activity (quadriceps, hamstrings, calves). Reduces overuse injury risk by 30%.

Appropriate footwear Supportive trainers for running sports. Replace every 6 months (children's feet grow fast). Avoid worn-out shoes (increase injury risk).

Healthy weight Obesity increases SUFE risk 3-fold, Blount's disease (tibia vara), anterior knee pain. Encourage active play, limit screen time <2 hours/day.

Graduated return to sport After injury: start low-impact, progress gradually. Pain during activity = stop. Rule: 50% reduction activity 1 week, 75% week 2, full activity week 3 if pain-free.

Avoid over-training Young athletes: limit training to age in years = hours per week (e.g. 10-year-old = max 10 hours/week). Overtraining → overuse injuries (stress fractures, apophysitis).

Vitamin D supplementation All children Oct-March: 400 IU/day (10 mcg). Year-round if dark skin, limited sun exposure. Reduces fracture risk, supports bone health.

When to stop sport Temporary rest if: pain during activity, limp after sport, pain >24 hours post-activity, night pain. Resume when pain-free at rest and during activity.

Parental anxiety drives consultations — 80% of paediatric MSK consultations are benign (growing pains, transient synovitis, minor trauma). Reassurance is therapeutic. Clear explanation of red flags empowers parents to self-manage safely while seeking help when needed.

Early sport specialisation (<12 years) increases overuse injury risk 3-fold compared to multi-sport athletes. Growth plates are vulnerable to repetitive stress. Diverse activity reduces single-muscle-group overload and prevents burnout.

Vitamin D deficiency affects 20% UK children in winter (higher in dark skin, limited outdoor play). Deficiency increases fracture risk, rickets risk, and may contribute to growing pains. Supplementation 400 IU daily is safe, cheap, and evidence-based.

Safety

Follow-Up and Safety-Netting

Done

Schedule reviews based on diagnosis. Clear safety-netting for red flags.

48 hours

Transient synovitis: Phone review. If improving (reduced pain, walking better) → continue analgesia, review 1 week. If worsening or fever → same-day assessment (septic arthritis). Acute limp post-trauma: Review if not improving — consider X-ray.

1 week

Growing pains, minor injuries: Check symptom resolution. If persisting → examine, consider X-ray. Osgood-Schlatter / Sever's: Assess response to activity modification. Reinforce rest from high-impact sport.

4 weeks

Persistent symptoms: Re-examine, review X-rays if not done. Consider physiotherapy referral. If no improvement → paediatric/orthopaedic referral. Overuse injuries: Should be improving with activity modification — if not, refer physiotherapy.

3 months

Hypermobility: Review physiotherapy progress. Assess functional improvement (core strength, stamina, pain frequency). Discharge if improving. Re-refer if worsening or new symptoms.

Safety-net 999

Sudden severe pain unable to weight-bear. Severe trauma (fall from height, RTA). Acute neurology (leg weakness, bladder/bowel symptoms).

Safety-net Same-day GP

Fever + limp/joint pain. Systemically unwell (lethargic, not eating, vomiting). Refusal to weight-bear. Hot swollen joint. Night pain waking from sleep. Severe pain unrelieved by analgesia.

Re-refer if

Benign diagnosis develops red flags: Night pain, systemically unwell, persistent >2 weeks despite treatment. Growing pains: Become unilateral, daytime, or persist beyond age 12. Action: Urgent paediatric re-referral (may be evolving pathology).

48-hour review for transient synovitis is mandatory — septic arthritis can evolve from initially mild presentation. If fever develops or pain worsens after initial improvement = urgent reassessment. Do not assume "it's just viral".

Persistent symptoms >2 weeks require investigation even if initial presentation was benign. Early Perthes, stress fractures, bone tumours can have delayed X-ray changes. Normal initial X-ray does not exclude serious pathology — clinical deterioration overrides imaging.

Night pain is never normal in children and should never be dismissed. If benign diagnosis (growing pains) develops night pain = urgent re-referral for malignancy/infection exclusion. Changing pattern = changing diagnosis.