Lumbar spinal stenosis

An illustrated presentation on lumbar spinal stenosis

1. LUMBAR SPINAL STENOSIS Dr A. E. Bassey

2. Outline Introduction Anatomy Classification Pathophysiology Differential diagnoses Clinical features Investigation Treatment Post-operative care Outcome factors Complications Current trends Conclusion References

3. Introduction Lumbar spinal stenosis is a clinical syndrome of buttock or lower extremity pain, with or without low back pain, resulting from diminished space for neurovascular elements in the spinal canal It is one the commonest conditions for which patients see a physician, or lose days from work, causing a heavy burden to the healthcare system as the economy by way of productivity losses Prompt diagnosis and appropriate treatment are essential to obtaining outcomes that are satisfactory to both patient and attending surgeon

4. Introduction Age-associated condition Population-based study in Japan: 40-49yrs – 1.7-2.2% 70-79yrs – 10.3-11.2% Commonest indication for spine surgery in >65yrs Commoner in women

5. Anatomy Five lumbar vertebrae Consecutive vertebrae articulate anteriorly via a primary cartilaginous joint, and posteriorly via 2 synovial joints (facet joints) Each vertebra has broadly, a vertebral body and vertebral arch

6. Anatomy Supporting ligaments: Supraspinous ligament Interspinous ligament Ligamentum flavum

7. Anatomy IV disc Has central gel-like nucleus pulposus 85% water Mostly Type II collagen Surrounded by concentric rings of fibrocartilage

8. Classification

9. Classification Anatomically, classified into: Central stenosis Lateral recess stenosis Foraminal stenosis

10. Pathophysiology Intervertebral disc changes Changes in nucleus pulposus Dehydration Reduced chondroitin sulfate:Keratin sulfate ratio Changes in Annulus fibrosus Facet joint changes Degeneration, capsular hypertrophy, osteophyte formation Intervertebral foramen changes Ligamentum flavum changes Spinal instability

11. Pathophysiology Factors causing symptoms are Neural compression Vascular compromise Inflammatory mediators ? Demyelination

12. Differential diagnosis Mechanical low back pain Lower limb arthritis Vascular claudication Peripheral neuropathy

13. Clinical features History Neurogenic claudication is the hallmark feature of LSS – present in 90% of those with symptomatic LSS Low back pain Severe neurologic deficits are uncommon Medical co-morbidities Examination Observation – sit, stand, ambulate with trunk flexed forward Lumbar extension provokes symptoms Neurologic exam is most times normal – mostly due to recess stenosis Assymetric DTRs Sensorimotor deficits in L5 Nerve root tension signs are usually not present Remember to Screen hip and knee Check for stocking-type hypoaesthesia Check for vascular insufficiency

14. Investigation Xray MRI CT myelogram EMG, SSEPs, NCS

15. MRI

16. MRI

17. Treatment Non-operative Operative

18. Treatment Rationale for non-operative treatment In terms of natural history, most cases of LSS run a benign course with rapid or catastrophic neurologic deterioration occurring rarely Non-operative gives acceptable outcomes in the long term – measuring walking distance, pain control etc Early vs delayed surgery yielded similar outcomes Findings from the SPORT Trial Largest Level I study comparing non-operative therapy and decompressive laminectomy for LSS Outcome measures - bodily pain and physical function on the SF-36 health status questionnaire and the modified Oswestry Disability Index At 2yrs, surgical treatment had significantly better outcomes that non-op At 5yrs, the surgery group still had better parameters, but the difference was no longer statistically significant, except for indices such as SF-36 bodily pain and physical function, ODI

19. Treatment Based on these, some experts recommend attempting non-operative treatment first, for mild to moderate stenosis. Despite all of these, open decompressive laminectomy is currently considered the GOLD standard treatment modality for lumbar spinal stenosis The factors guiding treatment choice should include Severity of pain Patient’s functional status Presence of co-morbidities Patient’s preference

20. Treatment Non-operative treatment Drug therapy PCM is ineffective compared to placebo (Williams et al – 2014, Machado et al - 2015) NSAID use should be discouraged due to Inflammation is not core pathophysiology Age-related comorbidities can be aggravated Pure analgesics, eg opioids, are useful (remember sedation and risk of falls) Gabapentin has been shown to be useful – improved walking distance, decreased pain scores, recovery of sensory deficits ( Yaksi et al – 2007, Kaye et al - 2014) Other drugs – pregabalin, TCAs, duloxetine – have not been studied in LSS Recommendation – Start gabapentin. If low back pain is present add opioid

21. Treatment Physical therapy Aim of PT Reduce lordosis Reduce extension forces on spine Increase abdominal core strength Other benefits – improve mood, mutual support, weight control Flexion-based lumbar stabilization exercises Stationary cycle Elliptical trainers Aquatic exercises Use of lumbar corset in slight flexion also beneficial

22. Treatment Epidural corticosteroid injection This is presumed to quell the inflammatory reaction resulting from stenosis It may be caudal, interlaminar or transforaminal Evidence in support of benefits of single injection is lacking, Multiple reports abound extolling the benefits of a multiple injection regimen, with effects lasting up to 2 years ( Hoogmartens et al – 1987, Botwin et al – 2002, Delport et al – 2004)

23. Surgical treatment Ultimately, the main indications for surgical therapy are the patient’s desire and failed non-operative management. Surgical treatment being current gold standard is reinforced by A recent Cochrane review stating “moderate and high quality evidence for non-operative treatment is lacking and thus prohibits recommendations for guiding clinical practice.” ( Ammendolia et al – 2013) Non-operative treatment is therefore currently based on experience and training guided by limited clinical outcome data Proper patient selection is critical to achieving a good outcome. The ideal patient has features of neurogenic claudication, which are relieved by lumbar flexion activities. This was echoed by Deen and colleagues Surgical decompression is usually done on an elective basis, except there’s rapidly progressing neurologic deficit

24. Surgical treatment Techniques of surgical decompression Laminectomy +/- Arthrodesis Laminotomy Fenestration Laminoplasty MicroEndoscopic Decompressive Laminotomy InterSpinous Process devices Even though open Decompressive laminectomy is considered to gold standard for treatment of LSS, current evidence is still insufficient to decide which technique is most effective (Cochrane reviews – Gibson et al – 2005, Overdevest et al - 2015).

25. Surgical treatment Open decompressive laminectomy Involves removal of posterior osseoligamentous structures Where symptoms are predominantly radicular, laminectomy alone is done Indications for laminectomy and fusion are: Neurogenic claudication with significant LBP component Neurogenic claudication + instability/spondylolisthesis LSS with degenerative scoliosis Revision decompressive laminectomy

26. Surgical treatment Open laminotomy Done in those with primarily lateral recess stenosis Aims to preserve much of the posterior structures with advocates claiming improved stability and lower complication rates Approaches Unilateral laminotomy Bilateral laminotomy Unilateral laminotomy for bilateral decompression Thome & colleagues (2005) prospectively compared unilateral laminotomy for bilateral decompression, bilateral laminotomy and open laminectomy Walking distance, pain control, pt satisfaction all similar Dural tear commonest complication BL had lowest complication rate

27. Surgical treatment Celik & colleagues (2010) went further to compare bilateral laminotomy and open laminectomy Adequate decompression achieved in both groups on CT/MRI BL – much lower complication rate BL – nonsignificant trend to superior walking distance, pain control, ODI Fenestration Decompression is done through a 5mm hole in subjacent pars No outcome reports yet

28. Surgical treatment Laminoplasty Distraction laminoplasty – used to decompress central and lateral recess stenosis Expansive lumbar laminoplasty – Sangwan & colleagues (2008) reviewed 25 patients who had ELL. There was an average of 124% increase in AP spinal canal diameter. Some experts however feel it fails to properly address lateral recess stenosis

29. Surgical treatment MicroEndoscopic Decompressive Laminotomy Minimally invasive approach to decompressive laminotomy Unilateral approach permits bilateral decompression Yagi et al (2009) & Mobbs et al (2014) prospectively compared MEDL and open laminectomy Similar outcomes MEDL had significantly lower perioperative morbidity – intraop blood loss, muscle damage, opioid requirement for pain, time to mobilization, length of stay MEDL had lower complication rate

30. Post-operative care Ambulate all patients ASAP, if possible on same day as surgery. If there was a dural tear that was repaired then ambulate after 48hrs If fusion done apply LS orthotic for 6wks. If fusion involves sacrum and bone quality is questionable, apply LS orthotic with thigh extension The patient should avoid bending and twisting movements, and lifting heavy objects for 6-12 weeks First post op visit is at 2-3 weeks, if decom alone was done, subsequent visits would be at 3 moths and 1 year If fusion was done subsequent visits are at 6wks, 3 months, 6 months, 1 year and annually till 5 years

31. Outcome factors Good outcome factors Predominant leg pain Higher disability Neuroforaminal stenosis Neurologic deficit Poor outcome factors Smoking Occupational lifting Symptoms lasting >12 months

32. Complications Lumbar spinal stenosis LL muscle weakness Bladder/dysfunction Depression Decompressive surgery Dural tear Infection Instability DVT/PE

33. Current trends Use Interspinous Process spacers Principle – they are inserted into interspinous space and used to distract adjacent interspinous processes, thus increasing spinal canal and foraminal capacity. The patient likely to benefit is one who has neurologic claudication that is relieved within 5 minutes of sitting down, and no more than grade I spondylolisthesis It should not be used in poor bone due to risk of fractures Wu et al (2014) & Hong et al (2015) in their metanalyses compared ISP and open decompression – outcomes were similar, but the ISP group had significantly higher reoperation rates

34. Conclusion As populations age, incidence of LSS is likely to rise. Our healthcare system needs to be empowered via capacity-building and infrastructural development to care for victims of this ubiquitous, disabling and costly disease. Surgical decompression still remains the gold standard of care. A thorough history and physical examination, as well as use of appropriate imaging are indispensable to determining those who stand to benefit from invasive procedures.

35. THANK YOU

36. References Apley’s System of Orthopaedics and Fractures, 10 th Ed (2018), pp524 – 527 Rothman-Simeone and Herkowitz The Spine, 7 th Ed (2018), pp1019 – 1057 Weinstein JN, Tosteson TD et al Surgical versus nonsurgical therapy for lumbar spinal stenosis. N Engl J Med. 2008 Feb 21;358(8):794-810. Watters WC, Baisden J, Gilbert TJ, et al. Degenerative lumbar spinal stenosis: an evidence-based clinical guideline for the diagnosis and treatment of degenerative spinal stenosis. Spine J. 2008;8:305-310. Williams CM, Maher CG, Latimer J, et al. Efficacy of paracetamol for acute low-back pain: a double-blind, randomized controlled trial. Lancet. 2014;384:1586-1596. Machado GC, Maher CG, Ferreira PH, et al. Eicacy and safety of paracetamol for spinal pain and osteoarthritis: systematic review and meta-analysis of randomized placebo controlled trials. BMJ. 2015;350h:1225. Thomé C, Zevgaridis D, Leheta O, et al. Outcome after less-invasive decompression of lumbar spinal stenosis: a randomized comparison of unilateral laminotomy, bilateral laminotomy, and laminectomy. J Neurosurg Spine. 2005;3(2):129-141.

37. References Yaksi A, Ozgonenel L, Ozgonenel B. he eicacy of gabapentin therapy in patients with lumbar canal stenosis. Spine. 2007;32:939-942. Kaye AD, Rivera Bueno F, Katalenich B, et al. The effects of gastroretentive gabapentin ( Gralise ) on spinal stenosis patients with radicular pain. Pain Physician. 2014;17:169-178. Hoogmartens M, Morelle P. Epidural injection in the treatment of spinal stenosis. Acta Orthop Belg. 1987;53:409-411. Delport EG, Cucuzzella AR, Marley JK, et al. Treatment of lumbar spinal stenosis with epidural steroid injections: a retrospective outcome study. Arch Phys Med Rehabil . 2004;85:479-484. Ammendolia C, Sturber KJ, Rok E, et al. Nonoperative treatment for lumbar spinal stenosis with neurogenic claudication. Cochrane Database Syst Rev . 2013;(8):CD010712. Gibson JN, Waddell G. Surgery for degenerative lumbar spondylosis: updated Cochrane Review. Spine. 2005;30:2312-2320. Overdevest GM, Jacobs W, Vleggeert-Lankamp C, et al. Effectiveness of posterior decompression techniques compared with conventional laminectomy for lumbar stenosis. Cochrane Database Syst Rev. 2015;(3):CD010036.

38. References Celik SE, Celik S, Göksu K, Kara A, Ince I. Microdecompressive laminotomy with a 5-year follow-up period for severe lumbar spinal stenosis. J Spinal Disord Tech. 2010;23(4):229-235. Sangwan SS, Kundu ZS, Walecha P, et al. Degenerative lumbar spinal stenosis—results of expansive laminoplasty. Int Orthop . 2008;32(6):805-808 Yagi M, Okada E, Ninomiya K, Kihara M. Postoperative outcome after modified unilateral-approach microendoscopic midline decompression for degenerative spinal stenosis. J Neurosurg Spine. 2009;10(4):293-299. Mobbs RJ, Li J, Sivabalan P, Raley D, Rao PJ. Outcomes after decompressive laminectomy for lumbar spinal stenosis: comparison between minimally invasive unilateral laminectomy for bilateral decompression and open laminectomy. J Neurosurg Spine. 2014;21(2):179-186 Wu AM, Zhou Y, Li QL, et al. Interspinous spacer versus traditional decompressive surgery for lumbar spinal stenosis: a systematic review and meta-analysis. PLoS One. 2014;9(5):e97142. Hong P, Liu Y, Li H. Comparison of the eicacy and safety between interspinous process distraction device and open decompression surgery in treating lumbar spinal stenosis: a meta-analysis. J Invest Surg. 2015;28(1):40-49.