Pathologic Fractures

H.T. Temple, MD

Pathologic Fractures

• Tumors– primary– secondary (metastatic) (most common)

• Metabolic– osteoporosis (most common)– Paget’s disease– hyperparathyroidism

Pathologic Fractures Benign Tumors

• Fractures more common in benign tumors (vs malignant tumors)– most asymptomatic prior to fracture– antecedent nocturnal symptoms rare– most common in children

• humerus• femur

– unicameral bone cyst, fibroxanthoma, fibrous dysplasia, eosinophilic granuloma

Unicameral Bone Cyst

• Fractures observed more often in males than females

• May be active or latent• Almost always solitary• First two decades• Humerus and femur most

common sites

Unicameral Bone Cyst

• Treatment - impending fractures– observation – aspiration and injection methylprednisolone or

bone graft material– curetting and bone graft (+/-) internal fixation

• Treatment - fractures– allow fracture to heal and reassess– ORIF for femoral neck fractures

Fibroxanthoma• Most common benign tumor• Femur, distal tibia, humerus• Multiple in 8% of patients

(especially patients with neurofibromatosis)

• Increased risk of pathologic fracture in lesions >50% diameter of bone and >22mm length

Fibroxanthoma

• Treatment– observation– curetting and bone graft for impending

fractures– immobilization and reassess after healing for

patients with fracture

Fibrous Dysplasia

• Solitary vs. multifocal (solitary most common)

• Femur and humerus • First and second decades • May be associated with

café au lait spots and endocrinopathy (Albright’s syndrome)

Fibrous Dysplasia

• Treatment– observation– curetting and bone graft (cortical allograft) to

prevent deformity and fracture (+/-) internal fixation

– expect resorption of graft and recurrence– pharmacologic—bisphosphonates

Pathologic FracturesPrimary Malignant Tumors

• Relatively rare• May occur prior to or during treatment• May occur later in patients with radiation

osteonecrosis (Ewing’s, lymphoma)• Osteosarcoma, Ewing’s, malignant fibrous

histiocytoma, fibrosarcoma

Pathologic FracturesPrimary Malignant Tumors

• Suspect primary tumor in younger patients with aggressive appearing lesions– poorly defined margins (wide zone of

transition)– matrix production– periosteal reaction

• Patients usually have antecedent pain before fracture, especially night pain

Pathologic FracturesPrimary Malignant Tumors

• Pathologic fracture complicates but does not mitigate against limb salvage

• Local recurrence is higher• Survival is not compromised• Patients with fractures and underlying suspicious

lesions or history should be referred for biopsy

A

B

A. Pathologic fracture through MFHarising in antecedent infarct

B. (H&E 100x) Pleomorphic spindledcells with storiform growth pattern

Pathologic FracturesPrimary Malignant Tumors

• Always biopsy solitary destructive bone lesions even with a history of primary carcinoma

• Case:A 62 year-old woman with a history of breast carcinoma presented with a pathologic fracture through a solitary proximal femoral lesion

Pre-op Post-

Intermediate grade chondrosarcoma

*fixation of primary bone tumors is not done without other tumor treatment due to potential for spread of tumor

Pathologic FracturesPrimary Malignant Tumors

• Treatment– immobilization– staging– biopsy– adjuvant treatment (chemotherapy)– resection/amputation

Metabolic Bone Disease

• Osteoporosis– insufficiency fractures

• Paget’s disease– early and late stages; most fractures occur in the

late stage of disease• Hyperparathyroidism

– dissecting osteitis– fractures through brown tumors

Paget’s Disease• Radiographic appearance

– Thickened cortices– Purposeful trabeculae– Bowing deformities– Joint arthrosis

• Fracture – delayed healing– malignant transformation

• Treatment– Osteotomy to correct alignment– Excessive bleeding– Joint arthroplasty vs. ORIF

Hyperparathyroidism

• Adenoma• Polyostotic disease• Mental status changes• Abdominal pain• Nephrolithiasis• Polyostotic disease

– mixed radiolucent/radiodense

Mixedradiodense

andradiolucent

lesions

Hyperparathyroidism

• May be secondary to renal failure

– secondary– tertiary

• Treatment – parathyroid adenectomy– ORIF for fracture– correct calcium Pathologic fracture

through brown tumor

Metastatic Disease and Myeloma

• Aside from osteoporosis, most common causes of pathologic fracture

• Fifth decade and beyond• Appendicular sites: femur and humerus

most common• All metastatic tumors are not treated the

same

Overall Incidence of Metastases to Bone at Autopsy

• 70% Jaffe, 1958• 12% Clain, 1965• 32% Johnson, 1970• 21% Dominok, 1982

Incidence of Metastases at Autopsy by Primary Tumor Site

Primary Site % metastasis to BoneBreast 50-85Lung 30-50Prostate 50-70Hodgkin’s 50-70Kidney 30-50Thyroid 40Melanoma 30-40Bladder 12-25

Incidence of Metastases

• 60% of patients with early identified cancer may already have metastases

• 10-15% of all patients with primary carcinoma will have radiologic evidence of bone metastases during course of disease

Route of Metastases

• Contiguous

• Hematogenous– most common

Mechanism of Metastases

• Release of cells from the primary tumor

• Invasion of efferent lymphatic or vascular channels

• Dissemination of cells• Endothelial attachment and

invasion at distant site• Angiogenesis and tumor growth at

distant site

Bone Destruction

• Early– most important– osteoclast mediated

• Late– malignant cells may be

directly responsible

Metastases of Unknown Origin

• 3-4% of all carcinomas have no known primary site

• 10-15% of these patients have bone metastases

Diagnostic Strategy for Patients with Unknown Primary

% Primary Tumor Identified

History and Physical 8%Chest X-Ray 43%Chest CT 15%Abdominal CT 13%Biopsy 8%

Rougraff, 1993

Defects

• Cortical defects weaken bone especially in torsion

• Two types– stress riser - smaller than the diameter of bone– open section defect - larger than the diameter of

bone…. causes a 90% reduction in load to failure and demand augmentation and fixation

Impending Pathologic Fracture

• 61% of all pathologic fractures occur in the femur

• 80% are peritrochanteric• fracture in this area results

in significant morbidity• historic data on impending

pathologic fracture involves the proximal femur

Impending Pathologic Fracture• Parrish and Murray, 1970

– increasing pain with advancing cortical destruction of lesions involving >50% of the shaft diameter

• Beals, 1971– lesions >2.5 cm are at increased risk to fracture

• Murray, 1974– increased fracture with destruction of > one-

third of the cortex, pain after radiotherapy

Impending Pathologic Fracture• Fidler, 1981% shaft destroyed Incidence Fx (%)0-25% 0%25-50% 3.7%50-75% 61%>75% 79%

• Conclusion: Patients with tumors destroying >50% of the diameter of bone require prophylactic internal fixation

Indication for Prophylactic Internal Fixation

• “Harrington criteria”– >50% of diameter of bone– >2.5 cm– pain after radiation– fracture of the lesser trochanter

• Limitations– only for proximal femur– doesn’t account for tumor biology

Harrington, K.D.: Clin. Orthop. 192: 222, 1985

Mirels Scoring System

Score 1 2 3

Site upper limb lower limb peritrochanteric

Pain mild moderate functional

Lesion blastic mixed lytic

Size <1/3 1/3-2/3 >2/3

Score < 7 – no surgeryScore > 7 – prophylactic fixation

Mirels, H.: Clin. Orthop. 249: 256, 1989.

AA

BB

A.A. Impending pathologic Impending pathologicfracture femoral neckfracture femoral neck

B.B. Quantitative CT Quantitative CT

AA

Quantitative CT is a more sensitive study to assess the degree Quantitative CT is a more sensitive study to assess the degree of bone destructionof bone destruction

Radiotherapy

• All tumor defects that meet the criteria for internal fixation do not require surgery– >50% of diameter of bone– >2.5 cm– pain after radiation– fracture of the lesser trochanter

• Tumor biology is variable - some lesions are very sensitive to radiotherapy

RadiotherapyPre XRTProstate

CA

Post XRTProstate

CA

Goals of Surgery in Treating Patients with Pathologic Fractures

• Relieve pain• Restore function• Facilitate nursing care

Pathologic FractureSurvival

• 75% of patients with a pathologic fracture will be alive after one year

• the average survival is ~ 21 months

Pathologic Fracture Treatment

• Biopsy especially for solitary lesions• Nails versus plates versus arthroplasty

– plates, screws and cement superior for torsional loads

– interlocked nails stabilize entire bone• Cement augmentation• Radiation/chemotherapy• Aggressive rehabilitation

pre-op pre-op post-op

Renal Cell Carcinoma

*pre operative embolization of renal cell mets should be done

Pathologic Fracture Treatment

• Periarticular fractures, especially around the hip are more appropriately treated with arthroplasty

• Periacetabular fractures– protrusio shell, cement, arthroplasty– saddle prosthesis– Structural allograft-prosthesis composite

Fracture Healing

• 129 patients• overall rate = 35%• 74% for patients surviving > 6 months• radiotherapy <30 GY did not adversely

affect fracture healing

Gainor, B.J.: CORR 178: 297, 1983

Cement

PMMA no PMMAPain relief 97% 83%

Ambulation 95% 75%

Fixation failure 2 cases 6 cases

Haberman, E.T: CORR, 169: 70, 1982

Pre-opPre-oprenal cellrenal cellcarcinomacarcinoma

Post-oprenal cellcarcinoma

Resection for Pathologic and Impending Pathologic Fractures

• Radiation and chemotherapy resistant tumors– renal– thyroid– melanoma– occasionally lung

• Solitary metastases (controversial)

Solitary adenocarcinoma

• Post-op intercalary allograft

Complications

• Infection– malnutrition– hematomyelopoetic suppression

• Hemorrhage– vascular tumors ( renal and thyroid)

• Tumor recurrence• Failure of fixation• Thromboembolic disease

Post embolizationPre embolization

Pre-operative embolization can preventhemorrhage with intra-lesional surgery

Summary

• Diagnosis and treatment requires a multidisciplinary approach

• Aggressive surgical treatment relieves pain, restores function, and facilitates nursing care

• Biopsy all solitary lesions or refer appropriately• Understand tumor biology and tailor treatment

Thank You

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