orthopedic surgery grand round 7 th february 2013 dr. j.w. kinyanjui registrar ward 6d
TRANSCRIPT
Orthopedic Surgery Grand Round7th February 2013Dr. J.W. Kinyanjui
Registrar Ward 6D
OutlineIntroduction
Epidemiology
Pathophysiology
Clinical evaluation
Management
IntroductionFracture through abnormal bone
Minor trauma or during normal activity
5th decade most prevalent
Metastases 2nd most common cause of pathologic fractures
F: breast and lungs – 80%
M: prostate and lungs – 80%
10% - no primary tumor found
Epidemiology – incidence at autopsyPrimary Site % metastasis to
BoneBreast 50-85Lung 30-50Prostate 50-70Hodgkin’s 50-70Kidney 30-50Thyroid 40Melanoma 30-40Bladder 12-25
PathophysiologyMost spread is hematogenous
Few tumors due to contiguous spread
Most common osteolytic via osteoclast stimulation
Prostate – commonly osteoblastic
Breast – mixed
Theories explaining predilection of bone for metastasis
Paget’s fertile soil hypothesis1889
Sites of secondary growths are not a matter of chance
Some organs provide a more fertile environment for the growth of certain metastases
Example: breast cancer to liver, Krukenberg tumor
Prostate cancer to bone
Hart and fielder later proved this using radioactive labelling
Ewing’s circulation theory1928
Metastatic deposits dependent on route of blood and lymph flow
Organs though to be passive receptacles
Organs with prominent venous systems have more secondaries
Baston plexus of spine responsible for prostate secondaries
Red marrow theoryIn descending order of frequency:
SpinePelvisRibsProximal appendicular skeleton
Marrow sinusoids more susceptible to tumor cell penetration
Sudden change from arterioles to sinusoids favours tumor cell entrapment
Ewing’s and Paget’s theories not mutually exclusive
Molecular levelCells from primary enter blood vessels
Attachment and penetration of basement membrane, neovascularisation
Type 1 collagen shown to be chemotactic to tumor cells
RANK ligand produced by tumor cells stimulating osteoclast activity
PTHrP produced by breast and lung cancer cells stimulates osteoclasts
Prostate cancer cells produce BMPs, IGF1, TGFβ2 which stimulate osteoblasts
Clinical evaluation: HistoryPain – most common, preceding fracture, night,
constant, dull, aggravated by activity
Trauma – usually minimal for type of fracture
Constitutional – anorexia, night sweats, weight loss, fatigue
Previous cancer
Carcinogen – smoking, radiation, occupational toxins
Factors suggesting pathologic fractureSpontaneous fracture
Minor trauma
Pain at site preceeding fracture
Multiple recent fractures
Age > 45 yrs
Prior history of malignancy
Associated problemsLowered Quality of life:
Debilitating pain
Immobility
Neurologic deficits – spine mets
Anaemia
Hypercalcemia
HypercalcemiaNeurologic: headache, confusion, irritability,
blurred vision
Gastrointestinal: anorexia, nausea, vomiting, abdominal pain, constipation, weight loss
Musculoskeletal: fatigue, weakness, joint and bone pain, unsteady gait
Urinary: nocturia, polydypsia, polyuria, urinary tract infections
Clinical evaluation: examinationLocal: mass, deformity, tenderness,
contiguous skeleton, neurologic exam
Systemic: cachexia, pallor, lymphadenopathy, entire skeletal system
Primary: breast, thyroid, prostate, lung, pelvic
Clinical evaluation: LaboratoryTBC – anaemia of chronic disease
Calcium – elevated
Alkaline phosphatase – elevated, non specific
Tumor markers – PSA, CEA, CA125, TFTs
N-telopeptide + C-telopeptide – markers of bone destruction, determine extent of skeletal involvement, assess response to bisphosphonates
Imaging: plain radiographsEnneking’s questions:
Location: diaphysis, metaphysis, epiphysis, cortical or medullary
Effect: osteoblastic vs. osteolytic or mixed
Reaction: sclerotic rim, periosteal reaction, codman triangle
Isolated avulsion of lesser trochanter – imminent femoral neck fracture
Osteolytic, diaphyseal medullary, periosteal reaction
Osteoblastic mets to bone
Codman triangle
Osteolytic lesion in lesser trochanter
Radiology: CT scans
Most sensitive for detecting bone destruction
Determines extent of cortical involvement
Also used to search for primary lesion in pelvis, abdomen or chest
Mixed lesion in lung mets
Radiology: MRI
Most sensitive for assessment of the anatomic extent of a lesion
Most adequate for spinal metastases to determine neurologic structure involvement
Can determine extraosseous spread of a mass
Bone scanningTechnetium-99m (99m Tc) bone scanning:
Sensitive for detection of occult lesions
Assessment of the biologic activity of lesions
Identification of other sites
Assessing response to therapy
BiopsyIndicated to rule out primary tumor of bone
Immunohistochemistry can determine primary
Biopsy at fracture site complicated by bleeding and callus formation
Needle vs incisional
Oncological surgical principles adhered to
Cultures to rule out infection
Impending pathologic fracturesProphylactic stabilisation before radiotherapy
can be performed for pain
Radio and chemotherapy without stabilisation also an option
Decision to stabilise difficult
Mirel’s criteria useful to determine which lesions at high risk of fracture
Mirel’s criteriaVARIABLE SCORE
SITE Upper Limb Lower Limb Peritrochanteric
PAIN Mild Moderate Severe
LESION Blastic Mixed Lytic
SIZE <1/3 1/3 – 2/3 >2/3
Size is the diameter of cortex involved on plain radiographsA score of 8 or more is an indication for prophylactic stabilisation
AdvantagesProphylactic stabilisation:
Shorter hospital stay
More immediate pain relief
Faster and less complex surgery
Quicker return to premorbid function
Improved survival
Management objectivesDecrease pain
Restore function
Maintain/restore mobility
Limit surgical procedures
Minimize hospital time
Early return to function (immediate weightbearing)
Non operative managementBisphosphonates – modifies bone resorption by
osteoclasts, shown to reduce risk of skeletal metastasis
Hematologic – correction of anaemia, coagulopathy, DVT prophylaxis
Hypercalcemia – hydration, calcium restriction, bisphosphonates, mithramycin
Analgesia
Radiation – most useful in spinal metastases
RadiotherapyUsed to reduce pain secondary to bone metastases
Partial in 80%. Complete in 50 – 60%
Halts progression of bony destruction
Allows healing of an impending pathologic fracture
Postoperative local tumor control
Bracing
Patients with limited life expectancies, severe comorbidities, small lesions, or radiosensitive tumors
Upper extremity lesions particularly amenable
Adjuvant radiotherapy of suscepible tumors required
Operative: principlesDurable, weight bearing impalnts needed
PPMA augmentation of construct useful incl. prosthesis
Bone graft less useful due to prolonged healing time
Prophylactically stabilise as much bone as possible
Anticipate hemorrhage due to neovascularisation
Thus tourniquet, preoperative embolisation
Upper extremityScapula, clavicle – non operative
Proximal humerus – prosthesis (long stem), intramedullary nail with multiple screws
Humerus Diaphysis – locked IM nail > plating
Distal humerus – prosthesis, retrograde flexible IM nails > bicondylar plating
Forearm – Rare. IM nails or plating
Lower extremityAcetabular – reconstruction with appropriate
prosthesisFemoral neck – hemi- or THR. Cemented. Long
stemIntertrochanteric – recon nail or prosthesis >
DHSSubtrochanteric – locked IM nailFemur shaft – locked IM nail preferably
cephalomedullaryAround the knee – locked plating > retrograde
nailing
Spinal fracturesCommonly present with compression fracture
MRI to differentiate from osteoporosis
Lesion involving body and pedicle sparing disc highly suggestive
Radiotherapy, steroids if no neurodeficits or impending fracture
Spinal fracturesSurgery:
Progression of disease after radiationNeurologic compromiseImpending fractureSpinal instability due to pathologic fractureProgressive deformity due to pathologic
fractureOptions:
Minimally invasive kyphoplasty/vertebroplastyDecompression and instrumentation
Controversies and future trendsOptimal length of femoral component of THRCriteria for impeding fractureWide resection of solitary metastases – RCCRadiofrequency ablationCryotherapyAcetabuloplasty – percutaneous PMMA
injectionRANK L modificationAngiogenesis inhibitors
SummaryDiagnosis 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