01OverviewDefinition, clinical context and the essential points that orientate the chapter.
Record the exact mechanism, energy, time, hand or foot dominance, sport and previous pain. Determine age and remaining growth from puberty and growth trajectory, not date alone. Ask about previous fracture, infection, metabolic disease and treatment. In repetitive injury, quantify training and recovery. Reconstruct whether the account fits developmental ability and involve safeguarding services for inconsistency, multiple injuries or concerning delay without allowing this to postpone analgesia and splintage.
Inspect skin, swelling, bruising, deformity and joint position and palpate gently to localise maximal tenderness to the physis. Examine the joint above and below. Document named peripheral nerve motor and sensory functions, pulse, capillary refill and temperature before and after any intervention. Repeatedly reassess pain and compartments. Do not force stress views or range across a displaced injury. Photograph an open wound according to local policy and cover it once with a sterile dressing.
Obtain AP and lateral radiographs centred to include the adjacent joint; add oblique or specialised views only when they answer a specific question. Type I can show only soft-tissue swelling or physeal widening. Type II includes a metaphyseal Thurston-Holland fragment. Types III and IV enter the joint. Type V may be invisible until growth disturbance. Comparison films are not routine but can help when normal variants remain genuinely uncertain after expert review.
CT defines articular gap, step, comminution and three-dimensional anatomy in transitional ankle, distal humeral and other complex patterns. MRI detects occult physeal and trabecular injury and later maps the size and position of a physeal bridge. Ultrasound has selected use in unossified anatomy and guided reduction but is operator dependent. Do not let advanced imaging delay urgent reduction for threatened skin or perfusion.
Provide age-appropriate analgesia and splint in the safest position. Urgently reduce gross displacement under adequate sedation or anaesthesia when neurovascular function or skin is threatened. Use one controlled manoeuvre by an experienced clinician and confirm neurovascular status and radiographs afterwards. Repeated forceful attempts, levering across the physis or accepting rotation increases harm. Open injury follows BOAST open-fracture antibiotic, tetanus, debridement and fixation principles.
Stable, acceptably aligned type I and II injuries often receive cast or brace treatment with early fracture-clinic review. Acceptable angulation depends on site, plane, age and remodelling potential; rotation remodels poorly. Unstable displacement requires percutaneous wire, screw or other fixation. Smooth wires can cross a physis temporarily when necessary, but minimise passes, size and duration. Avoid threaded implants across a healthy open growth plate when another safe trajectory exists.
Intra-articular type III and IV injury requires accurate reduction, often assessed by CT and achieved closed or open according to pattern. Transitional distal-tibial Tillaux and triplane fractures occur during asymmetric closure and demand joint-surface restoration while less growth remains. Distal-femoral and proximal-tibial physes contribute heavily to limb length and remain high risk even after apparently good reduction, so follow-up intensity reflects anatomy rather than only Salter number.
Growth surveillance compares serial standing alignment, limb length and Harris growth-arrest lines. MRI maps a suspected bar. A small bar with substantial growth remaining may be resected with interposition; thresholds depend on site, percentage and expertise. Other options include contralateral or ipsilateral epiphysiodesis, guided growth, corrective osteotomy and lengthening. Calculate predicted discrepancy and time intervention around remaining growth, updating the plan as the child matures.
Key points
- Salter-Harris I stays within the physis, II exits through metaphysis, III through epiphysis, IV crosses metaphysis to epiphysis and V is compression injury.
- First-line assessment includes mechanism, remaining growth, skin, deformity, adjacent joint and documented distal pulse, perfusion, motor and sensation before and after splintage.
- First-line imaging is orthogonal radiography including the adjacent joint; normal films do not exclude a type-I injury with focal physeal tenderness.
- CT is the reference structural study for complex intra-articular step and operative planning, while MRI detects occult physeal injury and maps a later growth bar without radiation.
- Restore alignment gently and early; avoid repeated reduction attempts because each pass can further damage the germinal physis.
- Salter-Harris III and IV fractures usually require anatomical joint reduction and stable fixation, placed to minimise additional physeal injury.
- Do not assume type predicts outcome alone: site, displacement, energy, age, reduction trauma and blood supply change arrest risk.
- Arrange growth surveillance for high-risk sites and injuries, comparing alignment, limb length and Harris growth-arrest lines until risk has passed.
02AetiologyUnderlying causes, associations and risk factors, with why each one matters.
Acute shear and compression
Falls, sport and road trauma transmit tension, shear or crushing force through the mechanically weaker growth plate.
Repetitive physeal stress
Gymnastics, throwing and running can widen and injure an open physis through repeated submaximal load before an acute fracture occurs.
Iatrogenic physeal injury
Repeated reduction, drilling, threaded implants, radiation or surgery can damage germinal cells and create a growth bar.
Pathological vulnerability
Infection, tumour and metabolic bone disease can weaken or bridge the physis and change fracture and arrest risk.
03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.
- 1Physeal zone failure
Trauma commonly separates the hypertrophic zone, while injury to the reserve and proliferative cells determines later growth disturbance.
- 2Salter-Harris propagation
The fracture can remain within physis or exit through metaphysis, epiphysis or both, defining types I to IV; compression defines type V.
- 3Bony bridge formation
Damaged opposing metaphyseal and epiphyseal surfaces unite across the physis, tethering further longitudinal growth locally or completely.
- 4Angular versus length effect
A peripheral bar creates asymmetric growth and angulation, while a central or complete bar predominantly shortens the bone.
- 5Joint-surface consequence
Epiphyseal fracture extension creates articular step and cartilage damage, adding post-traumatic arthritis risk independent of growth arrest.
04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.
Point tenderness directly over an open growth plate after trauma supports occult type-I injury despite normal films.
A triangular metaphyseal fragment attached to the displaced epiphysis defines a Salter-Harris II pattern.
An epiphyseal fracture line in type III or metaphyseal-to-epiphyseal line in type IV threatens joint congruity.
Salter-Harris V can be initially occult and later presents through physeal closure, angular change or shortening.
A Harris line that is non-parallel to the physis suggests uneven resumption of growth and a developing tether.
Localised bridging arrests one side while the opposite physis grows, progressively angulating the limb.
05InvestigationsWhat to request, why it matters and how to interpret it.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
First-line orthogonal fracture radiographsFirst stepFirst line - Why
- Define physis, displacement, metaphyseal and epiphyseal extension, joint alignment and associated injury.
- Interpretation and limitations
- A normal result does not exclude type I when tenderness is focal; immobilise and arrange clinical review if suspicion remains.
- 02
CT for intra-articular anatomy - Why
- Measure joint gap and step and define transitional or complex fracture geometry for reduction planning.
- Interpretation and limitations
- CT is the reference bony detail study when articular accuracy changes surgery, balanced against paediatric radiation.
- 03
MRI for occult injury or physeal bar - Why
- Show cartilage, marrow oedema, unossified fracture and the location and percentage of growth-plate bridging.
- Interpretation and limitations
- MRI is preferred for bar mapping and occult injury without radiation but usually follows urgent stabilisation.
- 04
Serial standing alignment and length imaging - Why
- Detect partial or complete arrest and quantify mechanical-axis and limb-length effects during growth.
- Interpretation and limitations
- Compare Harris lines, joint orientation and predicted discrepancy over time rather than relying on one film.
- 05
Bone-age and growth prediction - Why
- Estimate remaining growth and the likely final discrepancy before bar resection, epiphysiodesis or lengthening.
- Interpretation and limitations
- Combine skeletal maturity with serial measured growth; prediction carries uncertainty and must be updated.
06Differential diagnosisRealistic alternatives and the features that help distinguish them.
Ligament sprain
In a child, focal physeal tenderness can be more important than apparent ligament pain because the physis may fail first.
Apophyseal avulsion
Traction separates a tendon apophysis such as tibial tubercle or pelvis rather than the longitudinal growth plate.
Occult metaphyseal fracture
Trabecular injury adjacent to the physis can be radiographically subtle and has a different growth-arrest profile.
Infection or tumour
Fever, night pain, destructive change or atraumatic widening requires non-traumatic investigation and specialist biopsy or culture planning.
Normal physeal appearance
Open physes and accessory ossification centres can mimic fracture, making anatomy, tenderness and age-specific comparison important.
07ManagementImmediate care, first-line treatment, alternatives and escalation.
01ImmediateProtect physis and limbFirst stepTrauma produces focal physeal pain, deformity, open wound or neurovascular concern.+
- 1Use trauma assessment, give analgesia and document skin, compartments and named distal neurovascular findings.
- 2Cover an open wound, give indicated antibiotics and tetanus care and splint without repeated manipulation.
- 3Obtain orthogonal radiographs, but reduce urgently under trained conditions if perfusion or skin is threatened.
- 4Repeat and document neurovascular and compartment examination after every splint or reduction.
02Stable extra-articularHold an acceptable reductionType I or II injury is stable and aligned within site- and age-specific limits.+
- 1Immobilise in the appropriate cast or brace and provide written elevation, cast and return advice.
- 2Arrange early fracture-clinic imaging to detect loss of position.
- 3Progress motion and loading according to healing and site rather than pain alone.
- 4Select growth follow-up from physis, energy, displacement and age, not from Salter type alone.
03Unstable or articularRestore joint and physeal alignmentDisplacement is unacceptable, unstable or extends through the articular surface.+
- 1Use CT when articular step or complex geometry changes operative planning.
- 2Perform one controlled closed reduction or open reduction when interposition or incongruity persists.
- 3Stabilise with the least physeal trauma, minimising wire passes and avoiding permanent threaded crossing where feasible.
- 4Confirm joint surface, fixation and neurovascular status and monitor for compartment syndrome.
04Growth arrestMap the bar and predict consequenceSerial follow-up shows angular change, shortening or asymmetric growth-arrest lines.+
- 1Obtain standing alignment and length imaging and MRI to map bar location and proportion.
- 2Estimate remaining growth and projected deformity with repeated measurements.
- 3Consider bar resection for a suitably small accessible bridge with useful growth remaining.
- 4Use guided growth, epiphysiodesis, osteotomy or lengthening when bar biology, maturity and predicted discrepancy require them.
Key medicines and prescribing safety3 treatments · regimens, roles and cautions+
Paracetamol for paediatric fracture pain
Prescribe the current BNFC age- and weight-based dose, documenting exact milligrams, formulation volume, interval and maximum daily amount.Check weight, liquid strength, liver disease and other containing products; escalating pain despite treatment requires compartment and cast assessment.
Intravenous morphine for severe displaced-fracture pain
Use the local paediatric IV titration protocol with weight-based small aliquots and continuous respiratory, sedation and oxygen-saturation monitoring during acute care.Ensure resuscitation capability, reduce and titrate cautiously in cardiorespiratory or renal impairment and treat pain without delaying neurovascular reduction.
Open-fracture intravenous antibiotics
Give the locally approved age- and weight-based intravenous regimen as soon as possible for an open physeal fracture, recording administration time and allergy status before operative debridement.Do not delay for imaging or theatre, adapt for immediate allergy, contamination and local resistance and recognise antibiotics do not replace debridement.
08ComplicationsImportant consequences, why they occur and why they matter clinically.
Partial physeal arrest
A peripheral or central bar creates progressive angulation, joint malorientation and altered loading as unaffected physis continues growing.
Complete growth arrest
Premature closure causes limb shortening whose magnitude depends on remaining growth and the contribution of that physis.
Articular incongruity
Residual articular step after type III or IV injury causes stiffness, persistent pain and premature post-traumatic osteoarthritis.
Malunion or instability
Inadequate reduction or fixation permits deformity, recurrent displacement and impaired function even without a physeal bar.
Neurovascular and compartment harm
Displacement and swelling can injure adjacent vessels and nerves or raise compartment pressure, particularly around knee, ankle and forearm.
09Monitoring and follow-upTreatment response, safety checks and longer-term review.
- Repeat pain, compartments, skin, pulse, perfusion, motor and sensation after splinting, reduction and during swelling.
- Check early radiographs for maintained reduction and cast fit as swelling changes.
- After fixation, monitor pin sites, joint motion, infection, hardware position and healing before advancing loading.
- Use site-specific growth surveillance for high-risk injuries even when initial reduction and symptoms are satisfactory.
- Measure limb length, mechanical axis and Harris lines serially and investigate asymmetric change with MRI.
- After corrective growth surgery, continue follow-up for rebound, overcorrection, residual discrepancy and adjacent-joint function.
10Special situationsVariants, exceptions and circumstances that change the usual approach.
Normal films can hide type I
The cartilaginous physis can separate without visible bony fragment, making focal tenderness and protection important.
Type does not equal prognosis
Distal-femoral site, high energy and reduction trauma can make a type-II injury riskier than another site's type IV.
Rotation remodels poorly
Children correct some angular deformity near active physes, but rotational malalignment should not be accepted on that assumption.
Every reduction is another insult
Repeated passes increase germinal-cell and vascular injury, so experienced controlled technique matters.
Harris lines record growth
Symmetrical parallel lines suggest resumed growth, while convergence or asymmetry warns of a partial tether.
Bar treatment needs time
Removing a bridge is useful only when enough healthy physis and remaining growth can produce meaningful correction.
11Common pitfallsFrequent interpretation and management errors.
- 01
Calling focal physeal tenderness a sprain because initial radiographs are normal.
- 02
Performing repeated forceful reduction attempts across the growth plate.
- 03
Accepting rotation because children have remodelling potential.
- 04
Missing articular step in Salter-Harris III or IV by relying on two-dimensional films alone.
- 05
Discharging a high-risk distal-femoral or distal-tibial injury without growth surveillance.
- 06
Waiting for obvious deformity before investigating asymmetric Harris lines or limb-length change.