Intervertebral Disc Prolapse Investigations & Management

Lumbar Intervertebral Disc Prolapse-Clinical Features, Investigations & ManagementDr M AvinashGanga Medical CentreCoimbatore

IntroductionClinical featuresBack painOther symptomssignsDifferential diagnosisInvestigationsManagementNon operativeoperative

IntroductionUnderstanding of disc degeneration- evolved. Treatment is far from satisfactory limited by lack of specific diagnoses Need to improve understanding at a basic science and clinical level.79% men & 89% women-specific cause unknown. Unless pathological process is better described, and reliable criteria for the diagnosis are determined, improvement in treatment outcomes cannot occur, regardless of the technology available

Best ApproachHistory > physical examination > diagnosis supported by diagnostic studies

Wrong approachMatching diagnosis and treatment to the results of diagnostic studies

MRI shows disc herniations in 20% to 36% of normal volunteers76% of asymptomatic controls

Lumbar disc diseaseClinical Features

Clinical FeaturesAGE: 30 40 years

SEX: Male affected more than female

MOST COMMON LEVEL: L4-L5 (next common level is L5-S1)

MOST COMMON TYPE: Posterolateral type

Clinical Features-Back PainMechanical midline, worse with activityInstability midline, gluteal, worse in morning, sinuvertebral nerveRadiculopathy Claudication heaviness of one or both legsInflammatory worse in morning better with activityInfection/Tumorsrest pain and night pain

Clinical features-Radiculopathy Radicle- rootShooting pain distributed along the dermatome of the involved nerve root biochemical mediators(TNF alpha, interleukins) or mechanical compression Pain typically radiates below the kneeLeg pain = or > than back pain Worse on activity or bending forwardsMay have red flags

Clinical features- HistoryMay attribute to episode of traumaProlonged history of repetitive lower back and buttock painrelieved by a short period of rest. suddenly exacerbated, often by a flexion episode, with the appearance of leg pain. increasing with activity, especially sitting, straining sneezing decreased by rest, especially in the semi-Fowler position

Other SymptomsWeaknessCorresponding to level of neurological involvement

ParesthesiaDermatomal distribution

Cauda equina

Cauda EquinaEmergencyAggressive evaluation and managementmost consistent symptoms(Tay & Chacha)saddle anesthesiabilateral ankle areflexia bladder symptomsOther symptoms-numbness and weakness in both legs, rectal pain, numbness in the perineum, bowel disturbances

Clinical Features- SignsAntalgic gaitAffected hip more extended and knee more flexed than normal sideTrendelenberg gait (L5 nerve root)List abrupt planar shiftAxillary disc same sideShoulder disc- opposite sideThigh and calf muscle wastingLoss of lumbar lordosisParaspinal spasm- central furrow sign

Flat back deformity of chronic IVDP

12

Clinical features- Tests

Straight Leg RaisingLasegues testr/o hamstring tightness

Clinical Features- Tests

CONTRALATERAL LEG RAISING TEST (FRAJERSZTAGN TEST)

AFFECTED SIDENORMAL SIDE

Clinical Features -TestsFemoral nerve stretch testL2,3 and 4 nerve roots

Bowstring sign

Clinical features Flip test

NEGATIVEPOSITIVE

Clinical features-Slump test

Clinical features

NAFFZIGER TEST

VALSALVA MANEUVRE

Clinical features- ROMFlexion- Painful and restricted

Lateral bending to the same sidePainful and restricted

Clinical features -NeurologyL1L2

Clinical Features- NeurologyL3

Clinical Features- NeurologyL4

22

Clinical Features- NeurologyL5

Trendelenberg test

Clinical Features- NeurologyS1

Clinical Features- Red FlagsExtremes of age (55yr)Neurological deficitsFeverUnexplained weight loss(10lb in 6months)MalaiseRest pain/ night painSignificant traumaDrug and alcohol abuse

Non Organic Signs Of WaddellDescribed by Waddel in post op patients

Non anatomic tenderness

Simulation sign

Distraction sign

Regional sensory or motor disturbance

Overreaction(most sensitive)

Clinical features-Never forget

Sacroiliac and hip joint examination

Examination of peripheral pulses

Differential Diagnosis- Lumbar Disc DiseaseINTRASPINAL CAUSESProximal to disc: Conus and Cauda equine lesions (eg. Neurofibroma, ependymoma)Disc levelHerniated nucleus pulposusStenosis (Canal or recess)TraumaInfection: Osteomyelitis or discitis ( with nerve root pressure)Inflammation: Arachnoiditis, ankylosing spondylitisNeoplasm: Benign or malignant with nerve root pressure(multiple myeloma, extradural tumors)Other degenerative causes

Differential Diagnosis- Lumbar Disc DiseaseEXTRASPINAL CAUSESPelvis Cardiovascular conditions (eg. Peripheral vascular disease)Gynaecological conditionsOrthopaedic conditions ( osteoarthritis of hip, Muscle related disease, Facet joint arthropathy)Sacroiliac joint diseaseNeoplasmPeripheral nerve lesionsNeuropathy (Diabetic, tumour, alcohol)Local sciatic nerve conditions (Trauma, tumour)Inflammation (herpes zoster)

KEY DIAGNOSTIC POINTSLUMBAR DISC PROLAPSELeg pain greater than back painSLRT +Neurological deficit present ANNULAR TEARSBack pain greater than leg painBilateral SLRT positiveFACET JOINT ARTHROPATHYLocalized tenderness present unilaterally over jointPain occurs immediately on spinal extensionPain exacerbated with ipsilateral side bending

SPINAL STENOSISHeaviness(no pain) develops after walks a limited distance.Flexion relieves symptomsNo neurological deficit SLRT -veMYOGENIC OR MUSCLE RELATEDPain localised to affected musclePain increases on prolonged muscle usePain reproduced with sustained muscle contraction against resistanceContralateral pain with side bending

Investigations

THE CORNERSTONE OF DIAGNOSIS OF LUMBAR DISC DISEASE IS THE HISTORY AND PHYSICAL EXAMINATION NOT THE INVESTIGTION

Investigations- Plain RadiographsSimplest and most readily availableAP and Lateral viewsLoss of lumbar lordosisIndicationsPositive SLR Red FlagsUnresponsive to conservative treatment

Other viewsOblique viewsSpondylolisthesis and lysisHypertrophic changes around foramina in cervical spineLateral flexion/ extension viewsFerguson View20 degrees caudocephalic AP far out syndrome, fifth root compression by a large transverse process of the L5 vertebra against the ala of the sacrum. Angled caudal views facet or laminar pathological conditions.

X ray- Signs of InstabilityIndirect SignsDisc space narrowing, Sclerosis of end plates OsteophytesTraction spur Vacuum Sign Direct signsTranslational abnormalities on dynamic films

Investigations RadiographyFeatures of Instability-Traction spurs

Tensile stresses by ALL or outer annulus fibres on body periosteum

2-3mm from end plate 35

Vacuum signKnuttsons signradiolucent defect presence of nitrogen gas accumulations in annular and nuclear degenerative fissurestypical central vacuum phenomenon gas collection that fills large neo-cavity occupying both the nucleus and annulus indicative of advanced disc degeneration. Other typeGas at outermost part of the annulus fibrosus close to the vertebral cornerrupture of the insertion of Sharpeys fibres

Reduction in Height of Pedicle

REDUCTION IN THE HEIGHT OF THE PEDICLE

Flexion Extension Views Forward translation of one vertebra over the other - anterior sliding instability.Backward translation - posterior sliding instability. Excessive angular movement of a motion segment / rotation - angular instability. Abnormal axial rotation in which posterior margin of the vertebral body has a focal double contour during bending.

Technique of Measuring Translation

Cobb Method

Superimposition method

Investigations- CT

Assessment of fractures spondylolysis preoperative planning,Alternative for assessing a patient with instrumentation

Investigations- CTADVANTAGESExtremely useful, highly accurate & noninvasive tool in the evaluation of spinal disease.provides superior imaging of cortical and trabecular bone compared with MRI.It provides contrast resolution and identify root compressive lesions such as disc herniation.It also helps to differentiate between bony osteophyte from soft disc.It helps to diagnose foraminal encroachment of disc material due to its ability to visualize beyond the limits of the dural sac and root sleeves.

LimitationsIt cannot differentiate between scar tissue and new disc herniationIt does not have sufficient soft tissue resolution to allow differentiation between annulus and nucleusLiteratureEnd plate avulsions in CT scan by Rajasekaran et al

AXIAL LOCATION

SAGITTAL SECTION

Investigations- MRIMost accurate and sensitive modality for the diagnosis of subtle spinal pathology, test of chice It allows direct visualization of herniated disc material and its relationship to neural tissue including intrathecal contents.Advantages over myelographyNo radiationOp procedureNo intrathecal contrast More accurate in far lateral discDisc disease of LS junctionEarly disc disease

Advantages over CTimaging the discdirectly images neural structures. shows the entire region of study (i.e., cervical, thoracic, or lumbar). ability to image the nerve root in the foramenLimitationsShowing abnormal anatomy in asymptomatic patientClinical exam is paramount

which is difficult even with postmyelography CT because the subarachnoid space and the contrast agent do not extend fully through the foramen

47

Rajasekaran et al. found consistent differences dependent on the end plate in the pattern of gadodiamide diffusion into the nucleus pulposus. These pattern differences correlated more with degenerative changes and not with age.

Stages of Disc Prolapse

CONTRAST ENCHANCED MRIHere GADOLINIUM labeled diethylenetriaminepentaacetate (Gd-DTPA) administered intravenously and MRI scan done.ADVANTAGESDisplay the inflammatory reaction critical to the pathophysiology of radicular pain or radiculopathyAllows discrimination of scar from recurrent disc.

MyelographyUnnecessary if clinical and CT or MRI findings are in complete agreement.Indicationssuspicion of an intraspinal lesion, patients with spinal instrumentation, questionable diagnosis resulting from conflicting clinical findings and other studies . previously operated spine marked bony degenerative change that may be underestimated on MRIarachnoiditis

MyelographyDyesAir, oil contrast, water-soluble (absorbable) metrizamide (Amipaque)-higher complication ratesiohexol (Omnipaque)- approved for thoracic and lumbar myelographyiopamidol (Isovue-M). Water-soluble contrast media -standard agents for myelographyAdvantages: absorption by the body, enhanced definition of structures, tolerance, and the ability to vary the dosage for different contrastsDisadvantages : capable of showing the level at which the pathology lies but fails to show the nature of the lesion or its precise location in the anatomic segment Complications: nausea, vomiting, confusion, and seizures. Rare complications include stroke, paralysis, and death.Arachnoiditis- iophendylate(oil contrast). Not noted in water contrast.

PrecautionsClear explanation of the procedureHydration of the patient using the lowest possible dose discontinuation of phenothiazines and tricyclic drugs before, during, and after the procedure30-degree elevation of the patient's head until the contrast material is absorbedProper equipmentSmaller gauge needles (22-gauge or 25-gauge) Whitacre-type needle with a blunter tip and side port opening

, including a fluoroscopic unit with a spot film device, image intensification, tiltable table, and television monitoring59

Air contrast is used rarely -Only in situations in which the patient is extremely allergic to iodized materials

ProcedureDont place the needle cephalad to L2-3 - conus medullaris at riskMidline needle placement minimizes lateral nerve root irritation epidural injection.Tilt patient up - increases intraspinal pressure and minimize the epidural space.dose of iohexol- 10 to 15 mL ,concentration of 170 to 190 mg/mL. Higher concentrations for higher areas A full lumbar examination should include upto level of T7 Cervical myelogram -allow the contrast to proceed cranially. Extend the neck and head maximally to prevent - intracranial migration of contrast blood in initial tap- abort procedure proper needle position confirmed but CSF flow minimal or absent, suspect a neoplastic process.

Electrodiagnostic studies

Applied when clinical examination and imaging fail to provide a clear diagnosis or perhaps conflicting diagnosesMay include needle electromyelography, somatosensory evoked potentials or cervical root stimulationOperator dependedMay help differentiate primary cervical disorders from peripheral nerve entrapments syndromes or pain eminating from the intrinsic shoulder pathology

Electromyographythe identification of

peripheral neuropathy

diffuse neurological involvement

Investigations-Injection studiesEpidural steroidFacet joint injectionsDiscographyFocused and controlled anesthesia of particular anatomic structures to help define loci of pain (excl discography)

Used whendiagnosis is in doubt pathological condition diffuseIdentification of pain generator difficultTherapeutic as well as diagnostic

Injection studies- AgentsContrast diatrizoate meglumine iothalamate meglumine (Conray), iohexol (Omnipaque) safest to use iopamidol, metrizamide (Amipaque)Local AnaestheticsLidocaine Tetracaine bupivacaine- low conc & volume(