PELVIC INSUFFICIENCY FRACTURE[PIF]-A UNDER/MISDIAGNOSED ENTITY

M.D,D.N.B[RT],FAROI[USA],MBA[ICFAI],PDCR,CEPC

DR KANHU CHARAN PATRORADIATION ONCOLOGIST

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Case

• 52 year female• Known case of cancer cervix of >2years• Treated with radiation• Regular f/up with clinically controlled disease• p/w-chronic Lumbosacral pain of 6months

duration• Locoregional exam-N• Clinically controlled disease• USG/CT PELVIS-N• Planned for –bone scan

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Background • Cancer cervix is the most common malignancy in

underdeveloped and developing country.

• It is the most curable malignancy with long f-up alsonoted.

• Some patients presenting with chronic lowbackache, which is overlooked and under managed

• Most of the these due to PIF.

• These fractures are often confused with bothclinically and radiographically with metastaticdisease.

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Definition

• The term "stress fracture" refers to the failure of the skeleton to withstand sub maximal forces over time

– Insufficiency fracture results when normal stress is applied to abnormal bone (such as bone with osteoporosis.

• It is a type of osteoporotic fracture also.

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Radiation therapy to pelvis

• Cervix-most common

• Rectum

• Bladder

• Prostate

• Anal canal

• Others

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Etiology

• Renal failure

• Rheumatoid arthritis

• Extended corticosteroid use

• History of radiation therapy to pelvis

• Mechanical changes after hip arthroplasty

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Pathophysiology

• Series of pathological changes• Ranging from mild inflammation to neoplasia• Either may be delayed or acute• Radiation has been shown to directly affect

osteoblasts, osteoclasts, and osteocytes, resulting in a net reduction in bone matrix production.

• In addition, radiation to the vascular supply of bone has been reported to cause microcirculation occlusion and further compromise of osteoblast function.

• Radiation osteitis• Artificial menopause-ovarian irradiation-osteoprosis

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Pathophysiology -Contd.

• Usually they do not develop seriouscomplications associated with the fractures.

• How-ever, in the general population, apersonal history of a # is the most significantrisk factor for developing another fracture

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Incidence

• Analysis of the data showed that the cumulative incidence of pelvic fractures within the first five years of the study period was statistically significantly greater in the irradiated group than in the non-irradiated group for all three types of cancer:

– For anal cancer, 14.0% of women in the irradiated group had a pelvic fracture, compared with 7.5% in the non-irradiated group.

– For cervical cancer, the rates were 8.2% and 5.9%, respectively.

– For rectal cancer, the rates were 11.2% in the irradiated group versus 8.7% in the non-irradiated group.

Baxter NN et al. Risk of Pelvic Fractures in Older Women Following Pelvic Irradiation. JAMA.2005; 294:2587-2593

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Nancy N. Baxter, MD, PhD; Elizabeth B. Habermann, BS; Joel E. Tepper, MD; Sara B. Durham, MSc; Beth A. Virnig, MPH, PhDJAMA. 2005;294(20):2587-2593. doi:10.1001/jama.294.20.2587.3/4/2015 11

Nancy N. Baxter, MD, PhD; Elizabeth B. Habermann, BS; Joel E. Tepper, MD; Sara B. Durham, MSc; Beth A. Virnig, MPH, PhDJAMA. 2005;294(20):2587-2593. doi:10.1001/jama.294.20.2587.3/4/2015 12

Age

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Radiotherapy dose relationship

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Time to start

H Abe, M Nakamura, S TakahashiAJR 158:599-602, March 1992

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Risk factor association

• Body weight 49 kg or below (P=0.044)

• More than three deliveries (P=0.021)

Ichiro Oginoa, Radiotherapy and OncologyVolume 68, Issue 1, July 2003, Pages 61–67

Potential risk factors (age, weight, type II diabetes, delivery,menopause, total external dose, total brachytherapy dose) wereassessed

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Sign & symptom

• Minor trauma and insidious onset • Low backache• Groin pain• Buttock pain• Severe pain in the buttocks, back, hip, groin and/or pelvis• Halting, painful walking• Tenderness in the back or pelvic area• Limited range of motion in the low back• In rare cases, disturbed bowel or bladder function with

decreased leg strength and sensation

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Location

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Diagnosis

• Plain film- typically occult on plain film unless secondary remodeling has begun.

• MRI

• Scintigraphic

• CT scan- is a relatively insensitive method of detection

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X-ray-pelvis

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X-ray

Degree of confidence

• The degree of confidence is low. Sacral fractures are difficult to detect because of osteoporosis, overlying bowel gas, and calcified vessels.

False positives/negatives

• Parasymphyseal and pubic ramus fractures often are mistaken for malignant lesions. Sacral, iliac, and supra-acetabular fractures often are difficult to detect.

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CT SCAN

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CT SCAN-# SACRAL ALA

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CT SCAN-FRACTURE LINE

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CT SCAN-TARLOV CYST

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CT

Degree of confidence

• CT findings may be definitive for the diagnosis ofinsufficiency fractures of the pelvis. CT is specific andis useful as an alternative to MRI or bonescintigraphy when radiographs are inconclusive.

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MRI-T1

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MRI-T2

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MRI

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MRI

Degree of confidence

• MRI is highly sensitive and highly specific. However, it cannot be used in patients with Pacemakers, which is a significant limitation in the elderly population.

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BONE SCAN

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BONE SCAN

Degree of confidence• The degree of confidence may be high. Nuclear

studies are highly sensitive and highly specific when a typical pattern of sacral uptake or concomitant sacral and pubic uptake is observed. If a typical pattern of abnormality is not present, the bone scan is much less specific.False positives/negatives

• For variant or incomplete patterns of uptake, the findings may be mistaken as signifying malignancy or other diseases. CT or MRI is useful in such cases.

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AWARE

• Be aware that these patients may presentwith pelvic pain which may be misdiagnosedas metastatic bone disease.

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D/D

PIF

• Soft tissue mass is absent,

• Bone destruction is lacking,

• Adjacent fascial planes are preserved

MET.

• Soft tissue mass is present,

• Bone destruction

• Loss of Adjacent fascial planes

In women who present with pelvic pain after radiotherapy for cervical cancer, bony destruction and fractures may be indicative of a late radiation effect rather than osseous metastasis

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Prevention

• The prevention of osteoporosis and pelvicfractures may result in improved survivorshipin women undergoing radiotherapy.

• Atleast extra dietary calcium daily

• Calcium supplementation

• Role of bispohosphonates

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Treatment

• Conservative treatment

• No extra stress on bone

• Analgesic –WHO ladder

• Calcium/vitamin D3supplementation

• Lumbosacral belt

• Antiresorptive therapies. – Bisphosphonates

– Calcitonin

– Hormonal replacement therapy

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Pain control• There are reasons of concern about the use of

peripherally acting analgesics (NSAIDs) in fracturehealing, because they block the activity ofprostaglandins, especially PGE2, which plays asignificant role in bone healing

• NSAIDs are associated with a high risk of delayed union or non-union of long bone fractures, even after surgical treatment

• For this reason NSAIDs are not recommended for the therapy of sacral stress fractures.

– Mehallo CJ, Drezner JA, Bytomski JR. Practical management: nonsteroidal antiinflammatory drug (NSAID) use in athletic injuries. Clin J Sport Med 2006; 16: 170-174.

– Dimmen S, Nordsletten L, Engebretsen L, Steen H and Madsen JE. Negative effect of parecoxib on bone mineral during fracture healing in rats. Acta Orthopaedica 2008; 79 (3): 438-444

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Hormonal replacement therapy

• Raloxifene is a selective estrogen receptor modulator (SERM) adopted for the prevention and treatment of post-menopausal osteoporosis.

• Together with bisphosphonates and calcitonin, it belongs to the antiresorptive therapies.

• Treatment with raloxifene reduces vertebral fractures risk relative to placebo in post-menopausal women, while its efficacy has not been demonstrated on non-vertebral fractures.

• Raloxifene may not be considered the first line therapy for osteoporosis due to the increasing risk of thromboembolic events.

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Physical therapy

• Physical therapy,

• Heat

• Massage

• TENS (Transcutaneous Electrical Nerve Stimulation)

• Bed rest

• Lumbosacral belt

• Physiotherapy

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Take home massage

• Please recognize this clinical entity .

• Mostly in postmenopausal woman

• Starts with 1-2 year of treatment

• Do not misdiagnose with metastasis

• Bone scan is highly sensitive.

• Pattern ‘H’ ,butterfly are Characteristic of bone scan

• Simple conservative management with calcium supplementation is sufficient

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Bottomline

• Knowledge of pelvic insufficiency fractures isessential in order to rule out metastaticdisease, and thus avoid inaccurate treatment

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Radiotherapist prospective

• Can we consider reducing the dosecontribution to the sacrum and sacroiliacjoints, without underdosing the tumor,especially in

– Postmenopausal women

– With many deliveries

– Low body weight.

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Thanks

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