Pathologic Fractures in Children

Steven Frick, MD

Pathologic Fracture =

Fracture through Abnormal Bone

Osteopetrosis - failed fixation of femoral neck fracture. No osteoclasts - No remodeling.

With every fracture

Ask the question -

Is this fracture through NORMAL bone?

•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

•Minor Or No Trauma•Any Antecedent Pain?•Night pain?•Recent Illness?•Weight loss?•Fevers?

History

History

• Ask about growth and development• Dietary habits• kidney disease• thyroid disease• Family history

•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 - OGS

•CBC with differential•ESR•Calcium, Phosphorus, Alkaline phosphatase•Bun/Cr

Lab Tests

•Osteopenia•Physeal width (rickets)•Soft tissue calcifications•Presence of mass•Any periosteal reaction

RadiographsBe Suspicious

•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

•Size•Margination•Cortex•Soft tissue mass

Benign vs. MalignantMankin’s Criteria

•Benign Bone Lesion•Malignant Bone Lesion•Infection•Metabolic Bone Disease•Skeletal Dysplasia •Neuropathic •Osteopenia- Disuse•Overuse

Make Diagnosis/Categorize

•Metaphyseal•Proximal humerus, femur•3-14 years old•Males > females

Unicameral Bone CystUBC

•Fallen leaf sign (or fragment)•Active= adjacent to physis•tx= immobilize•fx heals; cyst persist in 85%

UBC Pathologic Fracture

•Steroid injections•Bone marrow injections•Bone graft substitutes•Open currettage/graft•disrupt hydraulics- puncture, screw, wires, rods

UBC Persistent

•18 ga spinal needle•C-arm•Serous fluid, straw colored•2nd needle- vent•Depomedrol 160 mg•may need multiple injections

UBC Injection

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

UBC - Risk Factors for Recurrence

• Age < 10• male • “active” lesions• large size• multiloculated• cyst index (Kaelin)

UBC

•Expansile•Often wider than physis•Eccentric•Aggressive at margins

Aneurysmal Bone CystABC

ABC

ABC

ABC

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

•Currettage and bone graft•+/- internal fixation•high recurrence

ABC

Currettage, biopsy consistent with aneurysmal bone cyst

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

Nonossifying Fibroma(NOF)

• Let fracture heal• most NOF’s persist• assume if fractures once with minimal

trauma, high risk to fracture again unless bone changes with healing

• currettage/bone graft

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?

• Controversial• Arata and Peterson, JBJS 1981 - >50%

diameter, >33 mm length• Easley and Kneisl, JPO 1996 - prophylactic

surgery not necessary in many

Fibrous Dysplasia

• Weightbearing bones - ORIF or structural graft

• Enneking - cortical struts alone for femoral neck

• cancellous bone graft will remodel into fibrous dysplasia, therefore cortical grafts recommended

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

Fibrous Dysplasia

• Consider other sites• Bone scan, MRI• 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. FD 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 (pamidronate) for

painful fibrous dysplasia – role?

•Abnormal type I collagen •Severe type - multiple fractures prior to skeletal maturity•Lower extremity > upper extremity•Femur, tibia, humerus

Osteogenesis Imperfecta(OI)

•Early onset (fxs prior to walking)- more fractures (2x)•Closed tx- limit immobilization time•IM fixation often needed

OI

3 yo OI - multiple fxs Lt femur

OI

OI – Olecranon Fx

•Minimize disuse osteoporosis•Early IM fixation•Alendronate, pamidronate, other bisphosphonates / osteoclast inhibitors

OI- New Methods

Ollier’s Disease Enchondromatosis

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

• asymmetric, often unilateral• usually sporadic occurrence • pathologic fx may occur

7 yo male - femur fracture jumping on bed

Enchondromatosis femur/tibia/ pelvis Rt LE

•Infection always in differential•Pathologic fracture uncommon•Delayed diagnosis•Femur, tibia•Involucrum may be supportive

Osteomyelitis

•Post-Irradiation•Steroids•Chemotherapy (MTX)

Iatrogenic Osteoporosis

10 yo female ALL - chemotherapy/steroids

fx after fall from chair. Tx = immobilization

•Myelomeningocele, paraplegics, sensory neuropathies•Often mistaken for infection, DVT, tumor

Neuropathic Fractures

3 yo MMC - swollen leg Consult = DVT vs infection?

Take an xray - healing fx may look like malignancy

11 yo male - Duchenne 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•femur, tibia, fibula

Stress Fractures

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

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

•Referral to musculoskeletal oncologist•Requires complete staging•Biopsy needed - follow proper “rules” for biopsy • Avoid fracture callus, notify pathologist of fx - biopsy soft tissue mass

Malignant Appearing Pathologic Fracture

Osteogenic sarcoma

Malignant Pathologic Fractures

• May need immediate amputation• OGS - some fx may heal during

neoadjuvant chemotherapy• Ewing’s - closed immobilization,

chemotherapy

Path fx lesser trochanter

Stage IIB

MRI - soft tissue mass posterior

Ewings sarcoma - allograft-prosthesis composite

Pediatric Pathologic Fxs

• Be suspicious - scrutinize every fracture film

• Usually benign process• Make the diagnosis to guide treatment• Appropriate referral / workup for suspected

malignancy• prophylactic treatment for benign lesions on

an individual basis

•Unicameral Bone Cysts (UBC)•Nonossifying Fibromas•Aneurysmal Bone Cyst (ABC)

Benign Bone Lesions

•Rickets•Renal Osteodystrophy•Hyperparathyroidism•Cushing’s

Metabolic Bone Disease

Malignant Bone Lesions

• Osteogenic Sarcoma• Ewing’s Sarcoma• Leukemia/Lymphoma

•Fibrous Dysplasia•Osteogenesis Imperfecta•Ollier’s Disease•Osteopetrosis

Skeletal Dysplasias

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