A Salter-Harris (SH) type I fracture is a fracture through the growth plate (physis) without involvement of the metaphysis or epiphysis, unique to skeletally immature children. [1-2] It is the most commonly clinically diagnosed physeal fracture in the ED setting, particularly at the distal fibula (ankle), though it can occur at any physis. Notably, the diagnosis is often clinical and presumptive — radiographs are typically normal, and MRI studies have shown that many clinically diagnosed SH-I injuries of the distal fibula are actually ligament sprains. [2-3]
The following figure illustrates the Salter-Harris classification system:
1. History
- Mechanism: Inversion/twisting injury (ankle), hyperextension (knee), fall on outstretched hand (wrist), or direct trauma [2][4]
- Symptom characterization: Acute onset of pain localized over the growth plate region; inability or limited ability to bear weight or use the affected extremity
- Timing: Acute traumatic event, typically during sports or play
- Severity/progression: Pain worsens with weight-bearing or movement; swelling develops rapidly
- Associated symptoms: Swelling, limping, refusal to use the extremity
- Important negatives: No fever, no night pain, no systemic symptoms (helps exclude infection/malignancy); no history of prior injury to the same site within 3 months [3]
2. Alarm Features
- Displaced SH-I fractures (especially distal femur or proximal tibia) — risk of neurovascular compromise involving the popliteal artery and peroneal nerve [4]
- Inability to ambulate with joint effusion and negative radiographs — suspect occult SH-I of the distal femur, which carries a 36% rate of growth disruption [4]
- Pallor, pulselessness, paresthesias, or compartment syndrome signs — emergent orthopedic consultation
- Mechanism inconsistent with injury or injury in a pre-ambulatory child — consider non-accidental trauma [5]
- Open fracture or significant deformity
- Physeal gapping >3 mm after reduction raises suspicion for entrapped periosteum and increased risk of premature physeal closure [6]
3. Medications
- Acute pain management:
- Ibuprofen 10 mg/kg PO q6-8h (first-line NSAID for pediatric musculoskeletal pain)
- Acetaminophen 15 mg/kg PO q4-6h (adjunct or alternative)
- Avoid: Aspirin in children (Reye syndrome risk); opioids rarely needed for nondisplaced SH-I fractures
- Caution: NSAIDs are safe for short-term use in fracture healing; no strong evidence that short courses impair pediatric fracture healing
- Procedural sedation may be required for displaced fractures requiring reduction in the ED [7]
4. Diet
- No specific acute dietary modifications required
- Ensure adequate calcium and vitamin D intake for optimal bone healing, particularly in children with dietary deficiencies
- Maintain adequate hydration, especially if immobilized
5. Review of Systems
- MSK: Pain with weight-bearing, range of motion limitation, joint stiffness
- Neuro: Numbness, tingling, weakness distal to injury (peroneal nerve at knee; sural/superficial peroneal at ankle)
- Vascular: Skin color changes, temperature differences, capillary refill
- Constitutional: Fever, weight loss, night sweats (red flags for infection or malignancy) [8]
- GI/GU: If pelvic physis involved, assess for associated injuries
6. Collateral History and Family History
- Obtain a detailed account of the mechanism from witnesses (coaches, parents, teachers)
- Inconsistent or changing stories raise concern for non-accidental trauma — particularly in children <2 years or pre-ambulatory [5]
- Family history of bone disorders (osteogenesis imperfecta, rickets) or connective tissue disease
- Social context: sports participation level, prior injuries, access to follow-up care
7. Risk Factors
- Age: Peak incidence in adolescents (average ~10-11 years); physes are weakest during periods of rapid growth [9-10]
- Sex: Males > females (~58% male) [2]
- Sports participation: Football, basketball, running, gymnastics — twisting and high-impact activities [2]
- Skeletal immaturity: Open physes are mechanically weaker than adjacent ligaments; the physis will fail before the ligament tears [4]
- Prior physeal injury increases risk of growth disturbance with re-injury
- Location-specific risk: Distal femoral SH-I fractures carry the highest risk of growth arrest (36%) among SH-I injuries [4]
8. Differential Diagnosis
- Ankle sprain/ligament injury — MRI studies show the majority of clinically presumed SH-I distal fibula fractures are actually ligament injuries (80% in one study) [2-3]
- Avulsion fracture (distal fibula, lateral talus) — may be radiographically occult; detected on MRI [2]
- Bone contusion/bruise — common MRI finding in radiograph-negative ankle injuries [2]
- SH type II fracture — most common physeal fracture overall; involves metaphysis (Thurston-Holland fragment visible on X-ray) [10]
- Toddler fracture (spiral tibial fracture) — in younger children with limp and tibial tenderness [5]
- Apophysitis (Sever disease, Osgood-Schlatter) — overuse, insidious onset, no acute trauma [11]
- Osteomyelitis/septic arthritis — fever, elevated inflammatory markers, refusal to bear weight [12]
- Malignancy (leukemia, osteosarcoma) — night pain, constitutional symptoms, persistent pain at rest [5]
- Non-accidental trauma — inconsistent mechanism, multiple injuries, pre-ambulatory child [5]
9. Past Medical History
- Prior fractures or physeal injuries (increased risk of growth disturbance)
- Previous injury to the same extremity within 3 months [3]
- Pre-existing musculoskeletal disease, skeletal dysplasia, or metabolic bone disease (rickets, osteogenesis imperfecta)
- Coagulopathies
- Developmental delay (may alter history reliability)
- Chronic conditions affecting bone health (renal disease, endocrine disorders)
10. Physical Exam
- Vital signs: Generally normal; tachycardia may indicate pain or occult vascular injury
- Inspection: Swelling, ecchymosis, deformity over the physis; compare with contralateral side
- Palpation: Point tenderness directly over the physis is the hallmark finding — this distinguishes physeal injury from ligamentous injury (tenderness over ligament attachments) [3][9]
- Range of motion: Pain with active and passive motion of the adjacent joint
- Weight-bearing assessment: Limited or inability to bear weight [3]
- Neurovascular exam: Mandatory — assess distal pulses, capillary refill, sensation, and motor function; particularly critical for distal femur and proximal tibia injuries (popliteal artery, peroneal nerve) [4]
- Joint effusion: Presence of effusion with inability to ambulate despite negative radiographs suggests occult SH-I fracture [4]
- Squeeze test (ankle): Compression of the calcaneus reproduces pain at the physis
11. Lab Studies
- Routine labs are not indicated for straightforward traumatic SH-I fractures
- If infection is suspected: CBC, CRP, ESR, blood cultures [12]
- If malignancy is a concern: CBC with differential, LDH, peripheral smear [5]
- If metabolic bone disease suspected: calcium, phosphorus, alkaline phosphatase, 25-OH vitamin D [13]
12. Imaging
- First-line: Plain radiographs (AP, lateral, and oblique/mortise views of the affected joint)
- SH-I fractures are typically radiograph-negative because the fracture line runs entirely through unossified cartilage [1][3]
- May show soft-tissue swelling over the physis; widening of the physis if displaced
- Comparison views of the contralateral extremity can be helpful but are not routinely required
- MRI: Most sensitive modality for confirming SH-I fractures and detecting ligament injuries, bone contusions, and physeal bar formation [4][14]
- Not routinely needed for low-risk injuries (e.g., nondisplaced distal fibula) — many orthopedists treat empirically [3-4]
- Indicated when diagnosis is uncertain, symptoms are not improving, or high-risk location (distal femur)
- Ultrasound: Can detect subperiosteal hematoma as evidence of physeal injury [2]
- CT: Rarely needed for SH-I; more useful for SH-III/IV to assess articular displacement [9]
- Serial radiographs: May show periosteal new bone formation at 10-14 days, confirming fracture retrospectively
13. Special Tests
- Ottawa Ankle Rules — validated in children >5 years; can help determine need for radiographs in ankle injuries, though physeal tenderness in a child generally warrants imaging
- Salter-Harris classification (SALTR mnemonic):
- Type I: Straight across (through physis only)
- Type II: Above (metaphysis + physis)
- Type III: Lower (epiphysis + physis)
- Type IV: Through (metaphysis + physis + epiphysis)
- Type V: Rammed/crushed (compression of physis)
- Point-of-care ultrasound: Can identify joint effusion and soft-tissue swelling to support clinical diagnosis
- Clinical diagnostic criteria for presumed SH-I distal fibula: (1) limited weight-bearing, (2) tenderness and swelling over the distal fibular physis, (3) normal radiographs with open physes [2-3]
14. ECG
- Not routinely indicated
- Consider if procedural sedation is planned for fracture reduction
15. Assessment
Severity stratification by location
- Low-risk SH-I: Distal fibula — most common; excellent prognosis; many are actually sprains on MRI. Treated as a low-risk injury. [2-3]
- Moderate-risk SH-I: Distal radius, distal tibia — nondisplaced fractures generally do well with immobilization [6]
- High-risk SH-I: Distal femur, proximal tibia — significant risk of growth arrest (36% for SH-I at distal femur), angular deformity, and neurovascular compromise [4]
Most nondisplaced SH-I fractures heal without permanent deformity. [1] However, displaced fractures carry a 4-fold increased risk of growth arrest compared with nondisplaced fractures. [4] Complications include premature physeal closure, angular deformity (valgus, varus, procurvatum, recurvatum), leg-length discrepancy, joint stiffness, and posttraumatic arthritis. [4]
16. Treatment Plan
Low-risk (distal fibula) — nondisplaced
- Removable ankle brace or air-stirrup is at least as effective as casting, with faster functional recovery [2-3][15]
- Weight-bearing as tolerated
- Immobilization for approximately 2-3 weeks, then mobilize as symptoms allow [2]
- RCT evidence supports removable splint over rigid cast for these injuries [2]
Moderate-risk (distal radius, distal tibia) — nondisplaced
- Short-arm or short-leg cast for 3-4 weeks
- Non-weight-bearing or weight-bearing as tolerated depending on location [6]
High-risk (distal femur, proximal tibia) — nondisplaced
- Long-leg cast, non-weight-bearing [4][16]
- Close orthopedic follow-up mandatory
- Some orthopedists treat empirically with casting even without MRI confirmation [4]
Displaced SH-I fractures (any location)
- Gentle closed reduction under appropriate analgesia/sedation; avoid multiple reduction attempts (risk of further physeal damage) [6-7]
- Percutaneous pinning often recommended for distal femur fractures, as casts alone have a high failure rate in maintaining alignment [17]
- Open reduction if closed reduction fails or periosteal entrapment is suspected (physeal gap >3 mm) [6]
Pain management
- Ibuprofen + acetaminophen alternating schedule
- Ice, elevation, rest
17. Disposition
Discharge criteria (low-risk, nondisplaced)
- Distal fibula SH-I: Removable brace, weight-bear as tolerated, follow-up with PCP or orthopedics in 1-2 weeks [3][15]
- Adequate pain control, intact neurovascular exam, reliable family for follow-up
Orthopedic consultation in ED
- Displaced SH-I fractures requiring reduction
- Distal femur or proximal tibia SH-I fractures (high-risk locations) [4][17]
- Neurovascular compromise
- Open fractures
- Failed reduction or suspected periosteal entrapment
Admission criteria
- Neurovascular compromise requiring monitoring or intervention
- Displaced distal femoral fractures requiring operative fixation [17]
- Compartment syndrome concern
- Non-accidental trauma requiring child protective evaluation
18. Follow-Up / Return Precautions
- Low-risk (distal fibula): Follow-up in 1-2 weeks; orthopedic referral not routinely necessary — reserve for patients not recovering as expected. PCP follow-up is appropriate for many of these injuries. [3][15]
- Moderate/high-risk locations: Orthopedic follow-up within 1 week; serial radiographs to monitor alignment
- Long-term monitoring: SH fractures should be monitored for 6-12 months to detect growth arrest and angular deformity. MRI is the most sensitive tool for early detection of physeal bar formation. [4][14]
- Expected recovery: Low-risk distal fibula injuries — most children return to normal activity within 4-6 weeks; mild disability scores at 1 month are common. High-risk locations may require longer recovery. [3]
Return precautions (counsel families)
- Return immediately for increasing pain, numbness/tingling, color change in fingers/toes, worsening swelling, or inability to move digits
- Cast/splint care instructions (keep dry, do not insert objects)
- No return to sports until cleared by treating physician
- Emphasize the importance of follow-up appointments to monitor for growth disturbance, especially for knee injuries
References
1. Growth Plate Injuries: Salter-Harris Classification. — Brown JH, DeLuca SA. American Family Physician. 1992.
2. Interventions for Treating Ankle Fractures in Children. — Yeung DE, Jia X, Miller CA, Barker SL. The Cochrane Database of Systematic Reviews. 2016.
3. Radiograph-Negative Lateral Ankle Injuries in Children: Occult Growth Plate Fracture or Sprain?. — Boutis K, Plint A, Stimec J, et al. JAMA Pediatrics. 2016.
4. Acute Knee Injuries in Children and Adolescents: A Review. — MacDonald J, Rodenberg R, Sweeney E. JAMA Pediatrics. 2021.
5. Evaluating the Child With a Limp. — Morancie NA, Helton MR. American Family Physician. 2023.
6. Physeal Fractures of the Distal Tibia and Fibula (Salter-Harris Type I, II, III, and IV Fractures). — Podeszwa DA, Mubarak SJ. Journal of Pediatric Orthopedics. 2012.
7. Pediatric Fracture Reduction in the Emergency Department. — Bin K, Rony L, Henric N, Moukoko D. Orthopaedics & Traumatology, Surgery & Research : OTSR. 2022.
8. The Child With Joint Pain in Primary Care. — Sen ES, Clarke SL, Ramanan AV. Best Practice & Research. Clinical Rheumatology. 2014.
9. Pediatric Physeal Ankle Fracture. — Wuerz TH, Gurd DP. The Journal of the American Academy of Orthopaedic Surgeons. 2013.
10. Clinical Characteristics of 1124 Children With Epiphyseal Fractures. — Deng H, Zhao Z, Xiong Z, et al. BMC Musculoskeletal Disorders. 2023.
11. Apophysitis and Osteochondrosis: Common Causes of Pain in Growing Bones. — Achar S, Yamanaka J. American Family Physician. 2019.
12. Acute Bacterial Arthritis in Children: Guidelines From the Pediatric Infectious Diseases Society and Infectious Diseases Society of America. — Jobi-Odeneye AO. American Family Physician. 2024.
13. Vitamin D, Calcium or a Combination of Vitamin D and Calcium for the Treatment of Nutritional Rickets in Children. — Chibuzor MT, Graham-Kalio D, Osaji JO, Meremikwu MM. The Cochrane Database of Systematic Reviews. 2020.
14. Imaging of Pediatric Growth Plate Disturbances. — Nguyen JC, Markhardt BK, Merrow AC, Dwek JR. Radiographics : A Review Publication of the Radiological Society of North America, Inc. 2017.
15. Evidence Into Practice: Emergency Physician Management of Common Pediatric Fractures. — Boutis K, Howard A, Constantine E, Cuomo A, Narayanan U. Pediatric Emergency Care. 2014.
16. Growth Plate Fractures of the Distal Femur. — Wall EJ, May MM. Journal of Pediatric Orthopedics. 2012.
17. An Uncommon Salter-Harris I Fracture of the Distal Femoral Physis With Marked Epiphyseal Dislocation. — Hale C, Forstater A, O'Malley G. Pediatric Emergency Care. 2013.