Pathologic Fracturesin Children

Joshua Klatt, MD

Original Author: Steven Frick, MD; March 20041st Revision: Steven Frick, MD; August 20062nd Revision: Joshua Klatt, MD; January 2010

Pathologic Fracture =

Fracture through abnormal bone

Pathologic Fractures

• Abnormal bone lacks normal biomechanic and viscoelastic properties– Intrinsic processes

• Localized - Bone cyst, neoplasm, etc.• Systemic - OI, osteopenia, osteopetrosis,

rickets, etc.

– Extrinsic processes• Radiation, biopsy, defects after plate removal,

etc.

Osteopetrosis - failed fixation of femoral neck fracture.

No osteoclasts = No remodeling.

With every fracture:

Ask the question -

Is this fracture through NORMAL bone?

•The orthopaedic surgeon may be the first to have opportunity to make the diagnosis. (malignancy, metabolic disease, etc.)

Often Need to Do More than Treat the Fracture

• Differ from fractures in normal bone in that one must take into account…– Etiology– Natural history– Treatment of underlying abnormality

• Must treat both fracture and underlying cause!

Often Need to Do More than Treat the Fracture

• Minor or no trauma?– Less than anticipated for fracture pattern

• Any antecedent pain?– Only with activity vs. night pain

• Recent illness?

• Weight loss?

• Fevers?

History

History

• Ask about growth and development• Dietary habits• Kidney disease

– May suggest rickets or renal osteodystrophy, etc.

• Thyroid disease• Family history

– Dysplasias, metabolic disorders, osteoporosis, neuromuscular disorders, etc.

• AskAsk about prior malignancies, even in the child!

• Families will not always volunteer this information

History

• Look for soft tissue mass vs. fracture hematoma

• Other systems- skin, lymphatics, solid organs

• Height - weight percentiles

Physical Exam

11 yo - Osteosarcoma

• CBC with differential

• ESR

• Calcium (ionized), Phosphorus, Alkaline phosphatase

• Bun/Cr

Lab Tests

• Osteopenia

• Physeal width (rickets)

• Soft tissue calcifications

• Presence of mass

• Any periosteal reaction

RadiographsBe suspicious!

• Is pathology… – Localized and isolated?– Polyostotic?– Generalized to entire skeletal system?– A generalized condition with skeletal

manifestations?

Radiographs

• Where is lesion located?

• What is lesion doing to bone?

• What is bone doing to lesion?

• Are there clues to type of lesion?

Enneking’s 4 Questions

Enneking, et al. The surgical staging of MSK sarcoma. JBJS 62-A:1027-1030, 1980.Enneking. A System of Staging MSK Neoplasms. CORR 204:9-24, 1986.

•Size

•Margination

•Cortex

•Soft tissue mass

Benign vs. MalignantMankin’s Criteria

Gebhardt, Ready & Mankin. Tumors about the knee in children. Clin Orthop 255:86-110, 1980.

• Benign bone lesion• Malignant bone

lesion• Infection• Metabolic bone

disease

Categorize/Make Diagnosis

• Skeletal dysplasia • Neuropathic • Osteopenia-disuse• Overuse

Treatment

• Union best achieved by correcting biomechanical and biological environment

• While chemo & radiation slow healing, they provide a beneficial response in presence of rapidly dividing malignant cells

• Not true neoplasms, etiology unknown• Often loculated and not truly “unicameral”• Most frequently contain serous fluid• Usually metaphyseal• Proximal humeral & femoral lesions account

for 94% of all lesions• Most in patients 3-14 years old, average age

9• Males > females (2:1)

Simple Bone Cyst(Unicameral Bone Cyst)

Baig & Eady. Unicameral (Simple) Bone Cysts. South Med J. 99(9):966-76, 2006.

• Fallen leaf sign (or fragment) is virtually pathognomonic

• Treatment– Fracture heals; cyst persist in 50-90%– Humerus - treat fracture, address lesion after

fracture is healed, if felt to be necessary– Displaced proximal femur #s - Open reduction,

grafting and rigid fixation, unless very young– Posterior facet #s of the calcaneus - Open

reduction, if necessary with grafting and fixation

SBC Pathologic Fracture

• Controversial!– Open Management

• Curettage/graft• Bone graft substitutes

– Minimally invasive techniques (injections)• Steroid injections• Bone marrow injections

– All seem to work with similar frequency (~90%)• But can be recurrence with any of them!

• Disrupt hydraulics- puncture, screw, wires, rods, etc.

SBC Treatment

• 18 ga spinal needle• C-arm• Serous fluid, straw colored• 2nd needle- vent• Depo-Medrol 160 mg• Watch for immediate drainage from large

outflow veins• May need multiple injections

SBC Injection

LJ, 8 yo with arm pain when throwing, injected once with methylprednisolone (multiple sites), healing at 3 months

SBC - Risk Factors for Recurrence

• Only reliable predictor of treatment success is age of the patient– > 10 yrs heal ~ 90% of time– < 10 yrs heal ~ 60% of time

• Most cysts tend to heal after skeletal maturity

Baig & Eady. Unicameral (Simple) Bone Cysts. South Med J. 99(9):966-76, 2006.Spence et al. Solitary unicameral bone cyst: treatment with freeze-dried crushed cortical-bone allograft. JBJS-A 58:636-41, 1976

SBC

• Expansile

• Often wider than physis

• Eccentric

• Aggressive at margins

Aneurysmal Bone Cyst(ABC)

Cottalorda & Bourelle, Current treatments of primary ABCs. J Pediatr Orthop B 15:155-67, 2006.

• Symptoms usually present for < 6 months• Lesion may attain considerable size before

recognized• Can exist as…

– primary bone lesion (70%) – secondary lesion in other osseous conditions (30%)

• Pelvic lesions account for 50% of all flat bone lesions (~10% total)– Treatment is difficult due to inaccessibility and

integrity of acetabulum

Aneurysmal Bone Cyst(ABC)

Cottalorda et al. Aneurysmal Bone Cysts of the Pelvis in Children. J Pediatr Orthop. 25:471-5, 2005.

ABC

ABC

ABC

Bur, et al. Fluid-fluid levels in a unicameral bone cyst: CT and MR findings. J Comput Assist Tomogr 17:134-6, 1993.Papagelopoulos, et al. Treatment of aneurysmal bone cysts of the pelvis and sacrum. JBJS-A 83:1674-81, 2001.

Look for fluid-fluid levels on MRI (however, not especially specific)

5 yo female with 1 year of hip pain and 4 prior steroid injections, progressive coxa vara. Biopsy = ABC

Curettage, biopsy consistent with aneurysmal bone cyst

1 month after curettage, bone grafting, valgus/internal fixation, spica immobilization

• Curettage and bone graft

• +/- internal fixation

• ? Injection of fibrosing agent (Ethibloc, Ethicon, etc.) is controversial

• High recurrence

ABC

Cottalorda & Bourelle, Current treatments of primary ABCs. J Pediatr Orthop B 15:155-67, 2006.Adamsbaum et al. Intralesional Ethibloc injection in primary ABCs. Skeltal Radiol. 32:559-66, 2003.Varshney et al. Is Sclerotherapy Better than Intralesional Excision for treating ABCs. CORR epib 2009.

Nonossifying Fibroma(NOF)

• Benign, nonosteoid-producing lesion• Usually found in metaphyses of long bones• Prediliction for lower extremities• Usually asymptomatic• Often incidental radiographic finding

– It is speculated that up to a 1/3 of children may have at least a minor NOF/fibrous cortical defect

• Almost always regress by early 20’s

Betsy et al. Metphyseal fibrous defects. J Am Acad Orthop Surg. 12:89-95, 2004.

Nonossifying Fibroma(NOF)

• Most treated non-op!• Let fracture heal, excellent healing potential• Most NOF’s persist after #, but heal by

skeletal maturity• If fractures once with minimal trauma,

potential risk to fracture again unless bone changes with healing

• If necessary, treat with curettage/bone graft

Betsy et al. Metphyseal fibrous defects. J Am Acad Orthop Surg. 12:89-95, 2004.

10 yo male - running during soccer.

NOF fracture - at 4 weeks underwent allograft DBM / cancellous bone graft.

Healed at 9 mos.

NOF - Prophylactic Bone Graft?

• Are size parameters predictable?– Arata and Peterson, JBJS 1981

• Review of 23 fractures over 50 years• Suggest tx if greater than 50% diameter, >33 mm length

– Easley and Kneisl, JPO 1997• Review of 22 lesions, many without #s, over 25 years• Only included large lesions (above criteria)• Only 41% had fractures, no refractures• Suggest prophylactic surgery not necessary in many• Criteria for surgery still not well defined

Arata et al. Pathological fxs through NOFs. JBJS-A. 63:980-8, 1981.Easley & Kneisl. Pathologic fxs through NOFs: is prophylactic treatment warranted? J Pediatr Orthop 17:808-13, 1997.

Fibrous Dysplasia

• Developmental disorder of bone, etiology unclear– May be mutation leading to activation of c-fos oncogene

• Can be associated with endocrine disorders (McCune-Albright syndrome)

• Can be mono- or polyostotic• Usually affects adolescents and young adults• Many solitary asymp lesions found incidentally

– Most do not require intervention– If increased fracture risk, treat with curettage, bone grafting

and sometimes internal fixation

Parekh et al. Fibrous Dysplasia. J Am Acad Orthop Surg. 12:303-13, 2004.

Fibrous Dysplasia

• Surgical treatment for:– Progressive lesions– Large lesions with pain

• Pain & deformity suggest microfractures

– Failure of conservative treatment– Less successful in:

• Younger patients• Larger and proximal femoral lesions• Polyostotic disease, esp McCune-Albright syndrome

Enneking & Gearen. Fibrous dysplasia of the femoral neck: Treatment by cortical bone-grafting. JBJS-A 68:1415-22, 1986

Fibrous Dysplasia

• Lesions are never eradicated, even with grafting• All grafts are eventually absorbed into dysplastic

bone• Cortical grafts at a much slower rate and therefore

recommended for weight-bearing bones• Enneking suggested cortical struts alone for femoral

neck• Fixation in WB bones seems to improve outcome in

children

Enneking & Gearen. Fibrous dysplasia of the femoral neck: Treatment by cortical bone-grafting. JBJS-A 68:1415-22, 1986.Stephenson et al. Fibrous dysplasia: An analysis of options for treatment. JBJS-A 69:400-9, 1987.

14 yo female - fell walking across front yard

3 months of left hip pain - Motrin

Referred for “path fx through Ewing’s sarcoma”

Dx -polyostotic fibrous dysplasia

3 Years Postop

Notice resorption of graft and recurrence of cystic changes in femoral neck. Can have secondary ABC develop within fibrous dysplasia.

Fibrous Dysplasia

• Consider other sites (polyostotic disease)• Bone scan to help identify other lesions

– Although lesions usually revealed on scan, a ‘cold’ bone scan does not rule out lesions

• For extensive involvement (McCune-Albright) consider intramedullary fixation/splinting

11 yo male – fem neck path fx, nondisplaced. Fibular allograft (neck) and titanium elastic nails (subtroch and shaft)

13 yrs old – 2 years postop. lesions in Rt. femur and tibia. No pain in hip, in karate.

Fibular graft gone. Treat painful tibia? Nail? Pamidronate?

5 yo - Albright’s polyostotic fibrous dysplasia

Prophylactic Treatment of Fibrous Lesions (NOF /FD)

• Any mechanical pain?• Location and size - relative issues• Supracondylar femur, proximal femur more

worrisome• Pharmacologic approach (bisphosphonates)

for painful fibrous dysplasia – some reported successes

Parekh et al. Fibrous Dysplasia. J Am Acad Orthop Surg. 12:303-13, 2004.DiCaprio & Enneking. Fibrous dysplasia. Pathophysiology, evaluation and treatment. JBJS-A87:1848-64, 2005.

• Abnormal type I collagen – COL1A and COL2A defects– Location and type of mutation in collagen molecule

determine phenotype (Sillence)

• Severe types (II-IV)- multiple fractures prior to skeletal maturity– Also find joint laxity, gray-blue sclera,

dentogenesis imperfecta, premature deafness, kyphoscoliosis & basilar invagination

• Lower extremity > upper extremity

Osteogenesis Imperfecta(OI)

Sillence et al. Genetic heterogeneity in osteogenesis imperfecta. J Med Gen. 16:101-16, 1979.Van Dijk et atl. Classification of Osteogenesis Imperfecta revisited. Eur J Med Genet 53:1-5, 2010.

• Early onset (fxs prior to walking)- more fractures (2x)– Direct relationship between increased bone

turnover and severity of disease

• Closed tx- limit immobilization time to reduce further osteopenia

• IM fixation often needed– Also used for realignment surgery and to decrease

fracture risk

OI

D’Astous & Carroll: Connective Tissue Diseases, in Vaccaro (ed): OKU 8. Rosemont, IL, AAOS, 2005.

3 yr old OI - multiple fxs Lt femur

OI

OI – Olecranon Fx

OI- New Methods

• Minimize disuse osteoporosis

• Early IM fixation• New design

– Expandable nails

• Bisphosphonates– Increase bone density

• Osteoclast inhibitors

– Decrease fracture rate– Oral and IV effective

Phillipi et al. Bisphosphonate therapy for OI. Cochrane Database Syst Rev 8(4), 2008Panigrahi et al. Response to zolendronic acid in children with type 3 OI. J Bone Biner Metab, Feb 4, 2010. [Epub ahead of print]

Ollier’s Disease (Multiple Enchondromas)

• Linear masses of cartilage in metaphyseal and diaphyseal regions of long bones

• Asymmetric, often unilateral• Usually sporadic occurrence • Pathologic fx may occur

Lewis et al. Benign and malignant cartilage tumors. Instr Course Lect 36:87-114, 1987.

7 yo male - femur fracture jumping on bed

Enchondromatosis Rt. femur/tibia/pelvis

• Infection should always be in differential of pathologic fractures

• However, pathologic fracture uncommon in osteomyelitis

• Often delayed diagnosis• More common in weight-bearing bones (i.e.

femur, tibia)• Involucrum may be supportive of diagnosis

Osteomyelitis

Taylor et al. Childhood osteomyelitis presenting as a pathologic fracture. Clin Rad 63:348-51, 2008.Gelfand, et al. Path fx in acute osteo of long bones secondary to community Acquired MRSA? Am J Med Sci 332:357-60, 2006.

•Post-Irradiation

•Steroids

•Chemotherapy (MTX)

Iatrogenic Osteoporosis

10 yo female ALL - chemotherapy/steroids

Fx after fall from chair. Tx = immobilization

• Myelomeningocele, paraplegics, sensory neuropathies, etc.

• Exam frequently reveals warm, erythematous, swollen joint

• Often mistaken for infection, DVT, tumor

Neuropathic Fractures

3 yo with spina bifida, swollen leg

Consult = DVT vs. infection?

X-ray - healing fx may look like malignancy

11 yo male - Duchene Muscular Dystrophy

Hip pain for 2 months. Disuse fracture/nonunion

• Usually through normal bone subjected to abnormal stresses

• May be mistaken for more serious pathology (esp. longitudinal stress fxs)

• History of recent increased activity• Proximal tibia, distal fibula, metatarsals most

common• Treat with rest, which can be challenging to

achieve

Stress Fractures

Heyworth & Green. Lower extremity stress fractures in pediatric and adolescent athletes. Curr Opin Pediatr 20:58-61, 2008.

12 yr old male, activity related pain, training for baseball, running 6 miles per day, referred for Ewing’s sarcoma.

Dx: Longitudinal femoral stress fracture

Stress Fractures

• Can occur through pathologic bone

• Congenital abnormalities, metabolic disorders (osteoporosis, osteomalacia)

Congenital Tibial Dysplasia

Presented at age 10 after fracture from minor trauma

Had “bowed leg”her entire life

No other msk abnormalities

Sakamoto et al. Congenital pseudarthrosis of the tibia: analysis of the histology and the NF1 gene. J Orthop Sci 12:361-5, 2007.

• Referral to musculoskeletal oncologist• Requires complete staging• Biopsy needed - follow proper “rules” for

biopsy • Notify pathologist of fracture

– Avoid fracture callus (histology may look malignant)

– Biopsy soft tissue mass

Malignant Appearing Pathologic Fracture

Osteogenic Sarcoma

Malignant Pathologic Fractures

• May need immediate amputation• Osteosarcoma

– some fx may heal during neoadjuvant chemotherapy

• Ewing’s– closed immobilization– chemotherapy

Path fx lesser trochanter

Stage IIB

MRI - soft tissue mass posterior

Ewing’s sarcoma - allograft-prosthesis composite

Pediatric Pathologic Fxs

• Be suspicious - scrutinize every fracture film! • Most frequently a benign process• Make the diagnosis to guide treatment• Appropriate referral / workup for suspected

malignancy• Prophylactic treatment for benign lesions on

an individual basis

Bibliography• Enneking, et al. The surgical staging of MSK sarcoma. JBJS 62-A:1027-1030, 1980.• Enneking. A System of Staging MSK Neoplasms. CORR 204:9-24, 1986.• Gebhardt, Ready & Mankin. Tumors about the knee in children. Clin Orthop 255:86-110, 1980.• Baig & Eady. Unicameral (Simple) Bone Cysts. South Med J. 99(9):966-76, 2006.• Spence et al. Solitary unicameral bone cyst: treatment with freeze-dried crushed cortical-bone allograft. JBJS-A

58:636-41, 1976• Cottalorda & Bourelle, Current treatments of primary ABCs. J Pediatr Orthop B 15:155-67, 2006.• Cottalorda et al. Aneurysmal Bone Cysts of the Pelvis in Children. J Pediatr Orthop. 25:471-5, 2005.• Bur, et al. Fluid-fluid levels in a unicameral bone cyst: CT and MR findings. J Comput Assist Tomogr 17:134-6, 1993.• Papagelopoulos, et al. Treatment of aneurysmal bone cysts of the pelvis and sacrum. JBJS-A 83:1674-81, 2001.• Adamsbaum et al. Intralesional Ethibloc injection in primary ABCs. Skeltal Radiol. 32:559-66, 2003.• Varshney et al. Is Sclerotherapy Better than Intralesional Excision for treating ABCs. CORR epib 2009.• Betsy et al. Metphyseal fibrous defects. J Am Acad Orthop Surg. 12:89-95, 2004.• Arata et al. Pathological fxs through NOFs. JBJS-A. 63:980-8, 1981.• Easley & Kneisl. Pathologic fxs through NOFs: is prophylactic treatement warranted? J Pediatr Orthop 17:808-13,

1997.• Parekh et al. Fibrous Dysplasia. J Am Acad Orthop Surg. 12:303-13, 2004.• Enneking & Gearen. Fibrous dysplasia of the femoral neck: Treatment by cortical bone-grafting. JBJS-A 68:1415-22,

1986• Stephenson et al. Fibrous dysplasia: An analysis of options for treatment. JBJS-A 69:400-9, 1987.• DiCaprio & Enneking. Fibrous dysplasia. Pathophysiology, evaluation and treatment. JBJS-A87:1848-64, 2005.• Sillence et al. Genetic heterogeneity in osteogenesis imperfecta. J Med Gen. 16:101-16, 1979.

Bibliography• Van Dijk et atl. Classification of Osteogenesis Imperfecta revisited. Eur J Med Genet 53:1-5, 2010.• D’Astous & Carroll: Connective Tissue Diseases, in Vaccaro (ed): OKU 8. Rosemont, IL, AAOS, 2005.• Phillipi et al. Bisphosphonate therapy for OI. Cochrane Database Syst Rev 8(4), 2008• Panigrahi et al. Response to zolendronic acid in children with type 3 OI. J Bone Biner Metab, Feb 4, 2010.

[Epub ahead of print]• Lewis et al. Benign and malignant cartilage tumors. Instr Course Lect 36:87-114, 1987.• Taylor et al. Childhood osteomyelitis presenting as a pathologic fracture. Clin Rad 63:348-51, 2008.• Gelfand, et al. Path fx in acute osteo of long bones secondary to communit acquired MRSA? Am J Med Sci

332:357-60, 2006.• Heyworth & Green. Lower extremity stress fractures in pediatric and adolescent athletes. Curr Opin Pediatr

20:58-61, 2008.• Sakamoto et al. Congenital pseudarthrosis of the tibia: analysis of the histology and the NF1 gene. J Orthop

Sci 12:361-5, 2007.

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