أسئلة السادسة جراحة رابعة دمياط (نيورو)

• Surgery covers lumbar disc diseases, lumbosacral radiculopathy, including: definition, causes, symptoms, and treatments; costing 10 LE at Level 4.

Lumbosacral Radiculopathy

• A disorder of the spinal nerve roots from L1-S4
• Caused by compression, irritation, or stretching of the nerve roots which exit the spine
• Can result in radiating pain, tingling, numbness, paraesthesia, occasional shooting pain, motor weakness, and reflex changes
• Radiculopathy is a complex of symptoms from nerve root pathology, including pain, anesthesia, paresthesia, hypoesthesia, motor, and/or reflex changes
• Radicular pain can arise from one or more spinal nerve roots

Common Causes of Lumbosacral Radiculopathy

• Lesions of the intervertebral discs
• Degenerative disease of the spine

Causes of Radicular Symptoms

• Any process that irritates, compresses, or stretches the spinal nerves

Degenerative Conditions of the Spine

• Spondylosis
• Spondylolisthesis
• Spinal canal stenosis
• Lumbar disc herniation

Trauma

• Motor vehicle accident
• Falling from a height
• Pathological fracture
• Osteoporosis

Tumors

• Benign or malignant tumors (primary spinal tumors like Schwannoma, Neurofibroma, Lymphoma, Osteoblastoma, Meningioma)
• Secondary metastatic tumors are more common

Inflammatory Conditions

• Spondylodiscitis
• Epidural abscess
• Fungal infections
• Tuberculosis (TB)

Vascular Conditions

• Arteriovenous malformations (AVM)

History and Symptoms

• History and physical exams are crucial in diagnosing lumbosacral radiculopathy
• Pain is the most common symptom
• Radicular pain presents as electrical shocks or shooting pains that radiate from the buttock to the foot
• Numbness or weakness along the distribution supplied by the respective nerve root(s) are often noted

Red Flag Symptoms

• Could indicate an urgent clinical condition
• Age over 55 years
• Fever or unexplained weight loss and night sweats
• History of significant trauma
• Bowel or bladder dysfunction and saddle anesthesia
• Malignancy (previous surgeries, chemo or radiation therapy, or a history of metastatic disease)
• Significant medical comorbidities
• Progressive neurologic deficit on serial exam

Physical Examination

• General examination includes vital signs, color signs, red flag signs, and other system exams
• Neurological examination includes sensory, motor, and gait exam with assessment for upper motor neuron findings (Babinski sign, Clonus, Spasticity)

Nerve Root Examination

• L1 affects the inguinal region and hip flexors
• L2 affects the anterior mid-thigh and hip flexors
• L3 affects the distal anterior thigh, impacts hip flexors and knee extensors
• L4 affects the medial lower leg and foot, knee extensors, ankle dorsiflexors and patellar reflex
• L5 affects the lateral leg and foot, hallux extension, ankle plantar flexors and Achilles reflex, and diminished or absent Achilles reflex
• S1 affects the lateral side of the foot, ankle plantar flexors, evertors and Achilles reflex

Nerve Root Stretch Signs

• Sciatic nerve stretch test, (Lasègue test/straight leg raising test) where passively raising one leg increases tension on the sciatic nerve between 30 to 60 degrees
• Reproduction of symptoms between 30°-60° suggests lower lumbar nerve root involvement between L4 to S1
• Femoral nerve stretch test, reverse straight leg or Ely test–Slump test is where extending the hip and flexing the knee with patient prone reproduces pain by stretching the femoral nerve and the L2-L4 nerve roots.
• Slump test can reproduce radicular symptoms by placing the patient seated with neck in full flexion and knees in full extension

Investigations

• Lumbosacral Plain X-ray
• CAT scan lumbosacral
• Lumbosacral MRI
• Dexa Bone scan isotopes bone scan
• Laboratory tests in red flag signs
• EMG & NCV (nerve conduction velocity)

Surgical Treatment

• In refractory cases, surgical decompression of the nerve root from offending pathology
• Fusion and instrumentation can be used if there are signs of instability

Surgical Treatments for Specific Conditions

• Lumbar disc herniation is treated with lumbar discectomy
• Lumbar canal stenosis is treated with decompressive laminectomy
• Lumbar spondylolisthesis is treated with lumbar fixation
• Spinal tumors and metastasis are treated with tumor excision
• Spondylodiscitis is treated with evacuation of abscess and debridement

Lumbar Disc Herniation

• Displacement of the nucleus pulposus of the intervertebral disc, which may compress traversing nerve roots or exiting nerve roots within the spinal canal

Anatomical Considerations

• Vertical anatomy of the lumbar nerve root where paracentral and foraminal disc issues will affect different nerve roots, unlike horizontal anatomy of the cervical nerve root
• In the lumbar spine, nerve roots exit below the corresponding pedicle
• A posterolateral lumbar disc herniation (L4-L5) compresses the traversing nerve root (L5)
• Foraminal lumbar disc prolapse (L4-5) compresses (L4)

Key Difference Between Cervical and Lumbar Spine Nerve Root

• Cervical spine C6 nerve root travels under C5 pedicle (mismatch)
• Lumbar spine L5 nerve root travels under L5 pedicle (match)
• C8 nerve root (NO C8 pedicle) allows transition

Horizontal (Cervical) vs. Vertical (Lumbar) Anatomy of Nerve Roots

• Vertical anatomy of lumbar nerve root where a paracentral and foraminal disc will affect different nerve roots
• Because of horizontal anatomy of cervical nerve root where central and foraminal discs will affect the same nerve root
• Exception: Lumbarized or sacralized vertebrae, conjoined lumbar nerve roots, far lateral disc herniation

Intervertebral disc

• Consists of 1) inner nucleus pulposus (NP), 2) outer annulus fibrosus (AF) which maintains the NP within the center of the disc, and 3) cartilaginous endplate

The Central NP

• A site of collagen secretion
• Contains numerous proteoglycans (PG), which facilitate water retention, creating hydrostatic pressure to resist axial compression of the spine
• Primarily composed of type II collagen, which accounts for 20% of its overall dry weight

Epidemiology

• Lumbar Disc Herniation is a very common cause of low back pain and radicular leg pain,
• Incidence rate of 80% of the population sustaining an episode of low back pain (LBP) once during their lifetime
• 80% will improve in short period without cost of imaging or surgery
• Lifetime prevalence of 10%

Age and Sex

• Peak incidence is 4th and 5th decades with a 3:1 male to female ratio

Level

• Commonly affects the L4-L5 & L5-S1 levels

Pathophysiology of Disc Herniation

• Changes in the biology of the intervertebral disc are thought to contribute
• Involves recurrent torsional strain and tears of the outer annulus, leading to herniation of the nucleus pulposus
• Includes reduced water retention in the NP and increased percent of type I collagen within the NP & inner AF
• Herniation is usually unilateral due to the lack of support by the posterior longitudinal ligament

Herniation Zones

• Central prolapse
• Paracentral
• Foraminal
• Extraforaminal

Classification

• Location: central prolapse, paracentral, foraminal, extraforaminal
• Anatomic: protrusion, extrusion, sequestered fragment (free)
• Onset: acute disc herniation, chronic disc herniation

Location Classification Details

• Central prolapse involves back pain and cauda equina syndrome
• Posterolateral (paracentral) is most common, where PLL is weakest, affecting the traversing/descending/lower nerve root, specifically L4/5 affects L5 nerve root
• Foraminal location affects the exiting nerve root
• Extraforaminal is less common (5-10%), where L4/5 affects L4 nerve root and herniated disc material directly compresses dorsal root ganglion
• Axillary which may affect both exiting and descending nerves

Anatomic Classification Details

• Protrusion is eccentric bulging with an intact annulus
• Extrusion is disc material herniates through annulus but remains continuous with disc space
• Sequestered fragment (free) herniates through annulus and is not continuous with disc space

Symptoms of Injury in the Clinical Picture

• Axial back pain (low back pain) may be discogenic or mechanical in nature
• Radicular pain (buttock and leg pain) symptoms worsen with sitting, coughing, Valsalva, sneezing, and improve with standing
• Weakness in the affected myotomes may occur
• Cauda equina syndrome (present in 1-10%)
• Bilateral leg pain, LE weakness, saddle anesthesia, bowel and bladder symptoms are emergent

Cauda Equina Syndrome

• Dysfunction of multiple lumbar & sacral nerve roots within the lumbar canal due to massive lumbar disc herniation, infection tumor or trauma
• Its an urgent neurological condition
• Low back pain and severe sciatica are usually bilateral
• Urine retention or incontinence, saddle anesthesia, significant motor weakness, and sexual dysfunction

Physical Examination for Radiculopathy

• L2 radiculopathy is associated with hip flexor weakness
• L3 radiculopathy is associated with hip adduction and knee extension weakness
• L4 radiculopathy involves ankle dorsiflexion weakness where L4 is greater than L5, and decreased patellar reflex
• L5 radiculopathy involves EHL weakness and manual testing ankle dorsiflexion weakness; test patient by having them walk on heels ankle inversion weakness
• S1 radiculopathy is associated with ankle plantar flexion weakness and decreased Achilles tendon reflex

Provocative Tests- Straight Leg Raise (SLR)

• Tension sign for L5 and S1 nerve root
• Technique can be performed sitting or supine while hip flexion is the identifying factor
• Contralateral SLR is less sensitive but more specific
• Lasègue' sign and SLR aggravated by forced ankle dorsiflexion
• Bow string sign and SLR aggravated by compression on popliteal fossa
• Kernig test involves pain reproduced with neck flexion, hip flexion, and leg extension
• Naffziger test involves pain reproduced by coughing
• Milgram Test involves pain reproduced with straight leg elevation for 30 seconds
• Trendelenburg Test which involves gluteus Medius weakness
• FABER test is Flexion, Abduction, external rotation that is markedly positive in presence of hip joint disease, trochanteric bursitis, and Sacroiliitis

Investigation

• Radiographs of A-P, Lateral, Dynamic and Oblique
• Findings: loss of normal lumbar lordosis (spasm), loss of disc height, lumbar spondylosis (degenerative changes), Lumbar spondylolisthesis
• Lumbosacral CAT scan provides more details about bony anatomy

Indications

• Plain x-ray lumbar sacral spine and pain lasting over a month
• Pain not responding to nonoperative management
• Red flag signs are present
• Highly sensitive and specific and helpful for preoperative planning
• MRI with gadolinium: Useful for revision surgery that allows to distinguish between post- surgical fibrosus (enhances with gadolinium) vs. recurrent herniated disc (does not enhance with gadolinium)

Nonoperative Treatment

• First line of treatment for most patients with disc lumbar herniation
• 80% improve in symptoms within 3 months with nonoperative care
• Size of herniation decreases over time and will reabsorbed sequestered disc herniations show the greatest degree of spontaneous reabsorption.

Non Operative Treament Elements

• Bedrest: Bedrest followed by progressive activity as tolerated
• Medication: Includes NSAIDs, muscle relaxants, Steroidal anti-inflammatory medications, Opioid analgesics
• Physical therapy: Involves Traction & extension exercises extremely beneficial
• Intervention procedures: Involves Steroid injection or Radiofrequency

Selective Nerve Root Corticosteroid Injections

• Second line of treatment if medications fail, use epidural, selective nerve block which leads to long lasting improvement in ~ 50% (compared to ~90% with surgery)

Operative Treatment

• Indicated for Progressive disabling pain that has failed nonoperative management, Progressive neurological deficits, or Cauda equina syndrome

Surgical Options

• Open Lumbar Laminectomy and discectomy
• Lumbar Microdiscectomy, fenestration and foraminotomy
• Lumbar Endoscopic discectomy
• Lumbar Discectomy with fusion and instrumentations
• Lumbar Far lateral microdiscectomy
• Lumbar Disc replacement surgery
• Varied depending on what causes the lumbar radiculopathy
• The treatments involve either decompressing the nerve or stabilizing the spine

Techniques of Lumbar Discectomy

• Varied elements
• Position: Prone position under general or spinal anesthesia
• Incision of the skin, lumbar fascia & separation of paravertebral muscles

Outcome

• 70%-90% Success rate
• Depends on degenerative factors, stenotic factors and instability factors

Complication of Lumbar Discectomy

• Dural tear (1%)
• Nerve root injury
• Incomplete decompression & residual HLD
• Missed level
• Discitis (1%)
• Lumbar instability
• Chronic low back pain & arachnoiditis
• Vascular catastrophe: injury to the vena cava, iliac arteries or aorta
• Endoscopic Lumbar Discectomy

Lumbar Spine Fusion & Instrumentation Types

• Posterior Lumbar Interbody Fusion (PLIF)
• Transforaminal Lumbar Interbody Fusion (TLIF)
• Anterior lumbar interbody fusion (ALIF), involves pedicle screws and Lumbar Cage Implantation

Lumbar Canal Stenosis

• Narrowing of the lumbar canal diameter
• Compression of lumbar nerve roots, resulting in nerve root ischemia.
• Clinical presentation with Neurogenic claudication pain and Decompressive laminectomy with or without fusion and instrumentations as a type of Treatment

Lumbar Spondylolisthesis

• Forward displacement of one vertebra over the other.
• Causes include degenerative spondylosis, spinal trauma, congenital defects, spondylodiscitis, and iatrogenic (previous lumbar laminectomy)
• Causes Instability of the spinal segment which leads to chronic Low back pain and radiculopathy
• Treated with surgical fixation & fusion of the spine