Lumbar disc prolapse Nearly 75% of the lumbar flexion–extension occursat the lumbosacral junction, 20% at the L4/5 leveland the remaining 5% is at the upper lumbar levels. So it is not surprising that 90% of lumbar discprolapses occur at the lower two lumbar levels; themost frequently affected disc is at the L5/S1 level. The lumbar disc consists of an internal soft nucleuspulposus surrounded by an external laminar fibrouscontainer, the annulus fibrosus.
Degrees of disc diseaseDegrees of disc disease Disc bulgeDisc bulge symmetrical extension of disc beyond thesymmetrical extension of disc beyond theendplates.endplates. Disc protrusionDisc protrusion focal area of extension still attached to thefocal area of extension still attached to thedisc.disc. Disc extrusionDisc extrusion fragment which lost its connection to the disc.fragment which lost its connection to the disc. Disc sequestrationDisc sequestration fragment is contained within the PLLfragment is contained within the PLL Disc migrationDisc migration fragment which travel caudal or rostral tofragment which travel caudal or rostral toendplateendplate
Clinical Picture1- Low back pain: About 90% of the population suffer from low backpain at some time. 30% of these will develop leg pain due to lumbarspine pathology. The pain is worse on movement, coughing, sneezingor straining. Pain is relieved with rest.
2- Sciatica: Pain in the leg due to lumbosacral nerve rootcompression in the distribution of the sciatic nerveCauses Lumbar disc prolapse causing nerve root compression. Bony compression of the nerve root, usually by anosteophyte, Narrowing of the ‘lateral recess’ of the spinal canal Tumours of the cauda equina or by pelvic tumours.3- Sensory & motor manifestations4- Sphencteric manifestations
Examination Localized tenderness over the lower back. Scoliosis may be seen, usually concave to the side of theaffected leg. Straight leg raising (Lasegue’s test): will be restricted on theaffected side and, in severe cases, pain in the affected legwill be reproduced when the opposite leg is raised. Wasting of certain muscle groups. Muscle weakness according to root compressed. Sensory affection according to root compressed. Deep tendon reflexes should be carefully tested.
L5/S1 diSc proLapSe•Pain along the posterior thigh with radiationto the heel•Weakness of plantar flexion (on occasion(•Sensory loss in the lateral foot•Absent ankle jerk.
L4/5 diSc proLapSe•Pain along the posterior or posterolateral thighwith radiation to the dorsum of the foot and greattoe•Weakness of dorsiflexion of the toe or foot•Paraesthesia and numbness of the dorsum ofthe foot and great toe•Reflex changes unlikely.
L3/4 diSc proLapSe•Pain in the anterior thigh•Wasting of the quadriceps muscle•Weakness of the quadriceps function and dorsiflexion of foot•Diminished sensation over anterior thigh, knee and medial aspectof lower leg•Reduced knee jerk.
InvestigationsX ray LSS: Which may reveal Straight lumbar curve Narrowing of disc spaces Osteoarthritic changes Associated spondylolisthesis °enerative changes.Lumbar myelography was the time honored investigation for lumbar discprolapse. Its invasive technique & invention of CT & MRI limited itsuse.
High-quality computerized tomography scanningand magnetic resonance imaging have largely supersededmyelography for the diagnosis of lumbar disc prolapse. The MRI is especially helpful in showing the size,configuration and position of the disc prolapse, as well asany associated nerve root or thecal compression. In addition the MRI will also demonstrate pathology at otherdiscs, such as degenerative changes as evidenced bydecreased signal in the disc on the T2-weighted scans.
Treatment Most patients with sciatica achieve good pain relief withsimple conservative treatment and less than 20% willrequire surgery. The likelihood of symptomatic relief without surgery isrelated to the pathology of the disc prolapse. A‘bulging’ disc is likely to settle with simple conservativemeasures. But sciatica due to a nucleus pulposus that has herniatedout of the disc space and ‘sequestrated’ outside theannulus will probably need surgery for satisfactory reliefof symptoms.
Conservative treatment Bed rest for a period of about 1-3 days` Although traction is sometimes recommended it probablyhas only limited benefit and may result in lower legcomplications. Simple analgesic agents and non-steroidal antiinflammatory medication. High-dose corticosteroids. Vitamin B complex. Muscle relaxant.
Surgical treatmentIndicationsIndications a) Pain: especially Incapacitating pain notresponding to conservative measures and recurrentepisodes of pain b) Neurological deficits c) Motor or sphincteric.Aim of surgery:Aim of surgery: Excision of the disc prolapse with decompression ofthe affected nerve root.
In the past the operation usually entailed a completeor partial laminectomy, identification of thecompressed nerve root, its mobilization off the discprolapse and excision of the herniated disc. Recently disc prolapses can be excised with minimaldisturbance to the normal bony anatomy and withthe removal of only a small amount of bone. A full laminectomy may occasionally be necessaryprior to the disc excision of a large central discprolapse causing cauda equina compression. A percutaneous endoscopic lumbar discectomy canbe done.
The cervical disc consists of an internal nucleuspulposus surrounded by the external fibrous lamina,the annulus fibrosus. The CDP is usually in the postero-lateral direction,because the strong posterior longitudinal ligamentprevents direct posterior herniation. Unlike the lumbar region, the nerves pass directlylaterally from the cervical cord to their neural foramen,so that the herniation compresses the nerve at thatlevel. So aC5/6 disc prolapse will cause compression of theC6 nerve root, a C6/7 prolapse causes compressionof the C7 nerve root.
Clinical presentation: The characteristic presenting features of these patients are neckand arm pain and the neurological manifestations of cervical nerveroot compression. Cord compression (myelopathy).Examination: Restricted cervical spine movements. The head is often moderately flexed, and tilted towards the side ofthe pain in some patients but occasionally away from it in others. If the disc herniation is longstanding there may be weakness&wasting in the appropriate muscle group. Sensation should be tested & the sensory loss will becharacteristic for the nerve root involved although there may besome overlap.
The deep tendon reflexes provide objective evidenceof nerve root compression in the following distribution:•• Biceps reflex C5Biceps reflex C5•• Brachioradialis (supinator) reflex C6Brachioradialis (supinator) reflex C6•• Triceps reflex C7Triceps reflex C7 A full neurological examination must be performed andparticular care taken to assess the lower limbs forhypertonia, hyperreflexia and +ve babinski.
C6/C7 prolapsed intervertebral disc (C7 nerve root):• Weakness of elbow extension.• Absent triceps jerk.• Numbness or tingling in the middle or index finger.C5/6 prolapsed intervertebral disc (C6 nerve root):• Depressed supinator reflex.• Numbness or tingling in the thumb or index finger.• Occasionally mild weakness of elbow flexion.
C7/T1 prolapsed intervertebral disc (C8 nerve root):• Weakness may involve long flexor muscles, triceps,finger extensors and intrinsic muscles.• Diminished sensation in ring and little finger and onthe medial border of the hand and forearm• Triceps jerk may be depressed.
Investigations MRI cervical spine: is now the investigation of choiceand has almost completely replaced both myelographyand CT. The cervical myelogram using water-based non-ioniciodine contrast material was a most useful investigation fordetermining the presence and site of the disc herniation. CT scanning by itself is frequently not helpful, but ifperformed following intrathecal iodine contrast it willdemonstrate a disc herniation, and smaller volumes ofintrathecal contrast are necessary than with myelography.
TreatmentConservative treatment: Most patients with cervical disc herniationachieve good pain relief with conservativetreatment. Bed rest, cervical collar, simple analgesicmedication, non-steroidal anti-inflammatorymedication and muscle relaxants.
Surgical treatment:Surgical treatment: The most commonly performed operations forcervical disc prolapse are: Cervical foraminotomy with excision of the discprolapse. Anterior cervical discectomy, with subsequent fusion.