High lumbar stenosis (thoracolumbar junction)


Introduction

Stenosis of the lumbar spine can occur at different areas of the lumbar spine. Stenosis of the lumbar spine is most common at L4-5 level but can also occur at L3-4, L2-3, L5-S1, and L1-2 in decreasing frequency. Stenosis can result from a number of causes such as hypertrophy of the ligamentum flavum. Ossification of the ligamentum flavum can also result in stenosis. Additionally, broad-based disc or rarely calcification of the posterior longitudinal ligament can also contribute to stenosis. Other factors that may lead to stenosis are congenital stenosis of the spine combined with degenerative changes and facet hypertrophy. These changes may be the result of degenerative changes or can be attributed to microinstability at the location of the stenosis. This can be especially true for stenosis due to adjacent segment disease from a prior surgical fusion. Symptoms vary significantly for those with stenosis and can include symptoms of neurogenic claudication, radiculopathy, sensation loss, weakness, and even incontinence.

The management consideration becomes more complex when the stenosis is in the high lumbar spine region. This is especially so when there is a prior instrumentation at this location, which can be further destabilized from further bony removal. Further consideration for destabilization is when the stenosis is in thoracolumbar junction, as the combination of decompression with the high mobility in this location can also lead to destabilization. In this case we review the important factors to consider in thoracolumbar stenosis.

Example Case

  • Chief complaint: back pain and leg pain

  • History of present illness: A 66-year-old male with a history of motor vehicle accident 1 year prior. Since that time, he has had progressively worsening gait issues as well as back pain. His gait instability has progressively worsened over the last 6 to 8 weeks. He states that he has gone from ambulating freely to using a cane and now using a walker. He also reports some issues with urgency but denies incontinence. Imaging was done and there was concern for stenosis ( Figs. 13.1–13.3 ).

    Fig. 13.1, Preoperative magnetic resonance images. (A) T2 sagittal and (B) T2 axial images demonstrating T11-12 ligamentum hypertrophy with cord compression and T2 cord signal change at this location.

    Fig. 13.2, Preoperative computed tomography scans. (A) Sagittal, (B) coronal, and (C) axial images demonstrating previous instrumentation at L2-5 with solid bony fusion.

    Fig. 13.3, Preoperative x-rays. (A) Lateral and (B) AP x-rays demonstrating L5-S1 interbody fusion with spinous process device.

  • Medications: lisinopril-hydrochlorothiazide

  • Allergies: no known drug allergies

  • Past medical and surgical history: hepatitis C, hypertension, cervical fusion, lumbar laminectomy, appendectomy

  • Family history: noncontributory

  • Social history: no smoking history, occasional alcohol

  • Physical examination: awake, alert, and oriented to person, place, and time; cranial nerves II–XII intact; bilateral deltoids/biceps/triceps 5/5; interossei 5/5; iliopsoas/knee flexion/knee extension/dorsi, and plantar flexion 5/5

  • Reflexes: 2+ in bilateral biceps/triceps/brachioradialis; 3+ in bilateral patella/ankle; no clonus, positive Babinski on the left, negative Hoffman; sensation decreased in bilateral lower extremities

  • Jeff D. Golan, MD

  • Neurosurgery

  • McGill University

  • Montreal, Quebec, Canada

  • Patrick C. Hsieh, MD

  • Neurosurgery

  • University of Southern California

  • Los Angeles, California, United States

  • Paul M. Huddleston, III, MD

  • Orthopaedic Surgery

  • Mayo Clinic

  • Rochester, Minnesota, United States

  • Peter Jarzem, MD

  • Orthopaedic Surgery

  • McGill University

  • Montreal General Hospital

  • Montreal, Canada

Preoperative
Additional tests requested None Hepatology evaluation
  • DEXA

  • L-spine flexion-extension x-rays

  • CT myelogram

  • Complete spine MRI

  • DEXA

  • Hepatology evaluation

Surgical approach selected T11-12 MIS laminectomy T11-12 laminectomy and facetectomy and excision of synovial cyst and T11-12 posterior fusion T11-12 laminectomy T11-12 laminectomy with interbody and fascectomy and domino to previous fusion with vertebroplasty
Goal of surgery Decompress cord Decompress cord, spinal stability, and fusion to prevent facet arthropathy Decompress cord Decompress cord, stabilization of scoliotic deformity, prevent kyphosis
Perioperative
Positioning Prone on Jackson table, no pins Prone on Jackson table, no pins Prone on Jackson table, with Mayfield pins Prone on Jackson table, no pins
Surgical equipment
  • IOM

  • Fluoroscopy

  • Surgical microscope

  • IOM (MEP/SSEP)

  • Fluoroscopy

  • O-arm

  • Ultrasound

  • Ultrasonic bone scalpel

  • IOM (MEP/SSEP/EMG)

  • Surgical microscope

  • Cell saver

  • IOM (MEP)

  • Fluoroscopy

Medications None Steroids, maintain MAP >85, liposomal bupivacaine Tranexamic acid, liposomal bupivacaine Steroids, tranexamic acid
Anatomical considerations T11-12 facets Spinal cord, T12 nerve roots, pedicle orientation, sagittal alignment Spinal cord, T11-12 facets Spinal cord, nerve roots
Complications feared with approach chosen Inadequate decompression, spinal cord injury, nerve root injury, mechanical back pain from overaggressive facetectomy Wrong level surgery, CSF leak, spinal cord injury, screw or cage malposition Instability, infection CSF leak, spinal cord injury, nerve root irritation
Intraoperative
Anesthesia General General General General
Exposure T11-12 T11-12 T10-L3 T11-L3
Levels decompressed T11-12 T11-12 T10-L2 T11-12
Levels fused None T11-12 None T11-L3
Surgical narrative Position prone, confirm level, 3 cm incision 1 cm off midline on left side (left facet appears more horizontal than right), incise through skin and thoracolumbar fascia, finger dissect through muscle onto base of T11 spinous process and medial lamina, x-ray to confirm level, sequentially dilate to 19 mm tube and dock with final tube, use microscope to define anatomy and dissect residual muscle and periosteum with Bovie to expose base of T11-12 spinous process and caudal portion of T11 and rostral T12 lamina, drill ipsilateral T11 lamina until yellow ligament is freed, drill on underside of spinous process and inner portion of contralateral lamina leaving yellow ligament for now, drill until T12 superior face identified and move laterally until flush with medial portion of pedicle, free yellow ligament and decompress underlying thecal sac, remove ligament on ipsilateral side and in midline using curettes and micro rongeurs, assure adequate bony decompression on contralateral side using curette to feel subarticular space, drill more lamina if needed, identify and recognize contralateral T11 and T12 roots, cord should be free of bony contact and roots well visualized, withdraw tube, close thoracolumbar and Scarpa’s fascia, standard closure Preposition MEP/SSEP, position prone and postflip MEP/SSEP, expose T11-12 level and confirm with x-ray or O-arm, prep pedicle screws T11-12, T11-12 laminectomy and facetectomy with at least 50% facet joint removal to decompress spinal cord, excise synovial cyst, decompress from pedicle to pedicle, completely remove all ligamentum flavum at T11-12, check adequacy of decompression with ultrasound, complete facetectomy and costotransversectomy for discectomy if there is still ventral compression, place T11-12 pedicle screws and rods, check implant with O-arm, arthrodesis and placement of bone graft at T11-12, vancomycin and tobramycin in cavity, closure in layers with drain Position prone after preflip IOM, postflip IOM, x-ray to guide incision, midline incision, subperiosteal dissection, confirm level with biplanar x-ray and compare with preoperative x-rays to confirm level as well as long x-ray to count from lumbosacral junction, microscope brought into the field hemilaminectomy removing inferior third of T10, central lamina of T11-L1, remove central ligamentum flavum/epidural fat/overgrown facet capsules/lateral recess until flush with medial wall of L2 pedicles, identify L1 nerve roots, foraminotomy of bilateral L1 roots, irrigate with saline and dilute betadine, layered wound closure without a drain, liposomal bupivacaine throughout Position prone, posterior approach through midline, expose previous hardware, remove topmost screws, add fenestrated screws above compression, complete facet osteotomy at all compressed levels, perform TLIF, check position of hardware with fluoroscopy, place vertebroplasty cannula at level above screws, cement fenestrated screws at vertebral level above the screws under fluoroscopy, domino to previous hardware, close wound over drain
Complication avoidance MIS, tubular-assisted left-sided approach, limit pressure on dura and underlying cord when using Kerrison rongeur, decompress ipsilateral side to provide contralateral working corridor Preflip IOM, remove facet to allow access, wide decompression, complete facetectomy and costotransversectomy for discectomy if residual compression on ultrasound Preflip IOM, confirm level by comparing with preoperative x-ray Use fenestrated screws above compression, facetectomy at compressed levels, vertebroplasty
Postoperative
Admission Floor Floor Floor Floor
Postoperative complications feared Inadequate decompression, spinal cord injury, nerve root injury, mechanical back pain from overaggressive facetectomy Pain, hematoma, implant malposition, adjacent segment disease, kyphosis Instability, infection Spinal cord injury, CSF leak, wound infection, hardware malplacement
Anticipated length of stay 1 day 2–3 days 1–2 days 3–4 days
Follow-up testing
  • L-spine standing x-rays before discharge

  • MRI L-spine 3–6 months after surgery

L-spine AP and lateral standing x-rays before discharge and 3 months, 6 months, 1 year, 2 years after surgery
  • Upright scoliosis x-rays 3 months after surgery

  • T-L spine flexion-extension 3 months after surgery

T-L spine x-ray after surgery
Bracing None None TLSO brace for 6 weeks None
Follow-up visits 2–4 weeks, 3–4 months, 9–12 months after surgery 2–3 weeks, 6 weeks, 3 months, 6 months, 12 months, annually after surgery 2 weeks, 3 months after surgery 2 weeks after surgery
AP, Anteroposterior; CSF , cerebrospinal fluid; DEXA , dual-energy x-ray absorptiometry; IOM , intraoperative monitoring; MAP , mean arterial pressure; MEP , motor evoked potential; MIS , minimally invasive surgery; MRI , magnetic resonance imaging; SSEP , somatosensory evoked potential; TLSO, thoracic lumbar sacral orthosis.

Differential diagnosis

  • Spinal stenosis

  • Facet hypertrophy

  • Ligamentum flavum hypertrophy

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