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Radiology of Pediatric Fractures Jean-Marc Gauguet, HMS Year IV Gillian Lieberman, MD 9/14/06 Jean-Marc Gauguet, HMS IV Gillian Lieberman, MD

Radiology of Pediatric Fractureseradiology.bidmc.harvard.edu/LearningLab/musculo/Gauguet.pdf · Radiology of Pediatric Fractures Jean-Marc Gauguet, HMS Year IV Gillian Lieberman,

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Radiology of Pediatric Fractures

Jean-Marc Gauguet, HMS Year IVGillian Lieberman, MD

9/14/06

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Overview

• Osteology

• Salter-Harris Fractures

• Greenstick Fractures

• Torus Fractures

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Longitudinal Bone Growth

• The physis is divided into metaphyseal and epiphyseal sections.• Mitosis of chondrocytes in the epiphyseal section and growth in the

metaphyseal section leads to longitudinal growth.• The resting and proliferating zones contain high amounts of chondoitin

sulfate, which imparts strength.• The hypertrophing zone lacks chondroitin sulfate or calcium and is the

weakest layer - this is the site of physeal fractures .

Pediatric Fractures and Dislocations

Resting

Proliferating

Hypertrophing

Provisional Calcification

Modified from:http://www.unu.edu/Unupress/food2/UID06E/uid06e0u.htm

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Kids bones are special

• Epiphyseal growth plates in children have not completely ossified.

• The periostium in children is thicker, more metabolically active, less easily torn, and more easily stripped from the bone.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Endplate Closure• Prior to endplate closure

there is a balance between chondrocyte proliferation and bone mineralization.

• Once proliferation slows and ceases mineralization can be completed.

• Endplate closure occurs when mineralization crossed into the epiphysis.

Pediatric Fractures and Dislocations

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Salter-Harris (SH) Overview

• Developed 5 level classification system in 1963.

• Fracture involving injury to the physis of long bones before complete closure occurs.

• 35% of all skeletal injuries in children.• 75% of cases occur in kids between 10-15

years.• Most common sites: wrist 50%, ankle 30%.• The growth plate is 2-5 times weaker than

joint capsule or ligaments.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Type I

• Line of cleavage confined to the physis.

• Accounts for 6% of cases.• Most commonly occurs in the

phalanges.• Growth disturbance uncommon

because germinal layer and vessels not disturbed.

• Excellent prognosis, treat with closed reduction and immobilization.

• Patients often treated if no overt signs of fracture, but there is soft tissue swelling or patient is symptomatic. www.emedicine.com

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Type I continued• Best identified by comparing to normal

joint and looking for widening of the physis.

SH I Normal•Swischuk, L.E., et al., Frequently missed fractures in children (value of comparative views). Emergency Radiology. (2004) 11: 22-28.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Swischuk, L.E., et al.

Type II

• Fracture line through the physis and extends through margin of metaphysis - “corner sign”

• Most common type (75% of cases)• Distal radius most common site• Minimal shortening, good outcomes.• Treat with closed reduction and immobilization.

www.emedicine.comBoston Children’s Hospital

SH Type II

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

www.emedicine.com

Type III

• Fracture runs through epiphysis then horizontally through physis.• Accounts for 8% of cases.• Typically seen after partial epiphyseal plate closure in tibia and distal femur. • Some deformity, but most problems arise from fracture entry into joint space.• Treat with closed reduction and immobilization, occasional ORIF.

Boston Children’s Hospital

SH Type III

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

www.emedicine.com

Type IV

• Vertically oriented fracture through epiphysis, physis, and metaphysis.• 10% of injuries.• Most commonly in distal femur and distial tibia.• Requires surgical repair, and often causes disability and joint deformity

from damage to germinal layer and epiphyseal blood supply.

www.emedicine.com

SH Type IV

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Type V

• Crush injury of physis typically from axial loading, no injury to epiphysis or metaphysis.• Accounts for <1% of cases.• Immediate radiographs show no abnormality other than soft tissue swelling, later studies

demonstrate abnormal bone growth.• Associated with growth arrest and formation of bone bridges requiring surgical repair.

www.emedicine.com

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

SH Type V

Rare Types

• VI - Injury to perichondrial structures• VII - Isolated injury to epiphyseal plate• VIII - Isolated injury to metaphysis• IX - Injury to periosteum

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Role of Imaging• Plain films - Standard of care, may not

adequately assess SH-I, SH-V.• CT - 3D reformatting useful in surgical planning.

Can assess bone bar formation. Allows for evaluation of complex triplane fractures1.

• US - Limited use in assessing fractures near joints2.

• MRI - Sensitive detection of fractures when plain films equivocal and evaluation of physis damage.

1Brown, SD, et al., Analysis of 51 tibial triplane fractures using CT with multiplanar reconstruction. AJR (2004) 183: 1489-952 Hubner, U., et al., Ultrasound in the diagnosis of fractures in children. J Bone Joint Surg Br. (2000) 82: 1170-1173.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Case I

• 15 year old male presents to the ED after falling onto his right ankle while wrestling.

• He is unable to bear weight on his right ankle, denies any loss of sensation, and has normal peripheral pulses.

• Differential Diagnosis Includes:– Ankle sprain– Fracture

• Best first evaluated with plain film including AP and lateral spanning the joint above and below the expected fracture.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Case I: Plain Film Radiography

Minimally laterally displaced distal tibia fracture in a Salter- Harris IV fashion

Boston Children’s HospitalBoston Children’s Hospital

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Case I Evaluation

• Salter-Harris IV fractures often require surgical fixation.

• In this patient, a decision to perform a CT was made to better evaluate the extent of the fracture and plan possible surgical repair.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Case I: Sagital CT Reconstruction

Since tibial fragment displaced >2mm and fragment could not reduced closed, decision made to surgically repair

Boston Children’s Hospital

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Confirmed SH-IV fracture through metaphysis, physis, and epiphysis.

Case I: Treatment

A screw was placed through displaced fragment and the patient was casted.

Boston Children’s Hospital

3 months later, cast removed, good fracture healing. Patient did well.

Boston Children’s Hospital

Plain Film Plain Film

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Complications of SH Fractures: Case Ia

12 year old boy with a triplane fracture:

- SH-II of medial tibial- SH-III of lateral epiphysis

Patient still has occasional pain 7 months after injury.

Boston Children’s Hospital

Orthopedic surgeons requested a CT to evaluate patient for epiphyseal plate damage.

Plain Film

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Case Ia: Bone Bridge Formation

• When area of growth arrest less than 50%, then outcomes are good with surgical intervention1.

1 Williamson, R.V., Partial physeal growth arrest: treatment by bridge resection and fat interposition. J Pediatric Orthopaedics (1990) 10: 769-776.

Boston Children’s Hospital

Bone bridge spanning from metaphysis to epiphysis.

Coronal CT

Patient currently has no signs of growth arrest, he will be closely followed. No surgery planned at this time.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Use of MRI in Salter Harris Evaluation

• Not widely used, however, powerful when plain films equivocal as in one study, radiographs detected 9/14 cases while MRI detected 14/14 cases, this improved sensitivity led to a change in management in 5/14 patients.1

• Also used to evaluate damage to physis.

1 Carey, J. et al. MRI of pediatric growth plate injury: correlation with plain film radiographs and clinical outcome. Skeletal Radiology. (1998) 27: 250-255.

SH IVFracture

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Carey, et al.

Spin Echo T1

Normal knee?

No!

Case II

• A 13 year old male presents to the ED with wrist pain after falling off bicycle onto outstretched hand.

• PE reveals deformity of forearm proximal to right wrist, normal distal pulses.

• Radiographs were taken to evaluate patient.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Case II: Plain Flims

AP Lat Boston Children’s Hospital

Incomplete Greenstick fracture of distal radius with palmar angulation.Patient was casted and recovered well.

Boston Children’s Hospital

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Greenstick Fracture• Derived from “green” tree branches that

bend, but do not completely break.• Commonly results from a twisting

motion on an outstretched hand.• The genuine greenstick fracture

involves disruption of cortex and periostium on covex side of fracture.

• Due to the strength of the periostium and incomplete mineralization of bone.

Pediatric Fractures and Dislocations

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Treatment/Prognosis

• Often very easy to reduce and immobilize in a cast.

• Some fractures require completion of the fracture prior to reduction and immobilization.

• The prognosis is also very good for these types of fractures.

• May be complicated by recurrent deformity while casted.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Case III

• 14 year old male presents to the ED after falling onto his left forearm while snowboarding.

• Pain is localized to the forearm, denies any loss of sensation.

• Plain films were ordered.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Case III: Plain Films

Boston Children’s Hospital

Non-displaced torus fracture through distal metaphysis of L radius

Patient was casted and recovered well.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Torus Fracture

• Torus derived from Latin (tori), which means a swelling or protuberance.

• A buckling of the cortex on the compression side, typically 2-3cm from physis.

• Stable, non-displaced fracture, treat with casting.

• Important radiologic distinction between torus and greenstick since risk of recurrent deformation in cast higher in patients with greenstick fractures.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Summary• Pediatric bones are immature with incomplete

growth plate closure and a strong periosteum.• Salter-Harris fractures are common fractures

in children and classification of the type of fracture has important implications on treatment and outcome.

• Plain films are the standard of care for SH fractures, while CT and MRI may be necessary in more complicated cases.

• Torus and Greenstick fractures are “incomplete” fractures unique to children.

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

Acknowledgements

• Dr. Josh Nagler - Boston Children’s Hospital• Dr. Stefanie Koch - Boston Children’s Hospital• Dr. Jim Wu - BIDMC• Pamela Lepkwoski - BIDMC• Dr. Gillian Lieberman - BIDMC

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD

References• Brown, J.H., Growth plate injuries: Salter-Harris classification. Am Fam Physicians. (1992)

46: 1180-1184• Brown, SD, et al., Analysis of 51 tibial triplane fractures using CT with multiplanar

reconstruction. AJR (2004) 183: 1489-95• Carey, J. et al. MRI of pediatric growth plate injury: correlation with plain film radiographs

and clinical outcome. Skeletal Radiology. (1998) 27: 250-255.• Close, B.J., Strouse, P.J. MR of physeal fractures of the adolescent knee. Pediatric

Radiology. (2000) 30: 756-762. • eMedicine, Salter-Harris Fractures• Hubner, U., et al., Ultrasound in the diagnosis of fractures in children. J Bone Joint Surg Br.

(2000) 82: 1170-1173.• Rodriguez-Merchán, E.C., et al., Pediatric skeletal trauma: A review and historical

perspective. Clin Orthop Relat Res. (2006) 432: 8-13. • Rogers, L.F., Poznanski, A.K., Imaging of Epiphyseal Injuries. Radiology. (1994) 191: 297-

308.• Sailhan, F., et al., Three-dimensional MR imaging in the assessment of physeal growth

arrest. Eur Radiol. (2004) 14: 1600-1608.• Swischuk, L.E., et al., Frequently missed fractures in children (value of comparative views).

Emergency Radiology. (2004) 11: 22-28.• von Laer, L., Pediatric Fractures and Dislocations, New York, NY, 2004• www.wheelessonline.com (Wheeless’ Textbook of Orthopedics Online)• http://www.unu.edu/Unupress/food2/UID06E/uid06e0u.htm

Jean-Marc Gauguet, HMS IVGillian Lieberman, MD