Degenerative Spine Disease

Shikher ShresthaNINAS

Problem Statement

2002 survey

26% americans – low back pain and 14% - neck pain

890 million office visits due to back pain

2005 -

JAMA - $86 billion health expenditures in spine related problems

Anatomy and Physiology of Spine Degeneration

Kirkaldy- Willis three-joint complex Theory

spine – at each level composed of three joints complex that are affected in degenerative process

This comprise of intervertebral disc and two zygapophyseal joints (dorsal articulating joints)

Degeneration of any one joint leads to degeneration of the other two, initiating a casacade that leads to spinal degenerative disease

Pathology.. Disc Degeneration..

Components of disc

nucleus pulposussemigelatinous structure situated near the

centerremnant of notochord; composed of

mucopolysaccharide + salt + water

annulus fibrosismultilayered circular structures that

surrounds the pulposuscomposed of fibrocartilaginous lamellae;

stiffer than nucleus

cartilagenous end plates

Mechanism of disc degeneration

Part of natural aging process

Repetitive loading results in forces that foster degeneration

Aging dessication collagen and proteoglycans are replaced with fibrous tissue

Continued Axial pressure

less compliant annulus develops circumferential tears most frequently in dorsolateral aspect

tears enlarge and develop into radial tears

herniation of nucleus pulposus

Relative dorsal location of nucleus pulposus and presence of posterior longitudinal ligament lead to classical dorsolateral disc herniation

Circumferential bulge of annulus due to annular tear loss of disc height and osteophyte formation at the attachment of the annulus to vertebral body narrowing of central canal and neural foramen

Dorsal joint degeneration

Articulating facets from superior and inferior vertebral segments

Joints – composed of cartilage, synovial membrane and capsule

Aging synovial reaction, fibrillation of articular cartilage, osteophyte formation laxity of joint capsule

Leads to subluxation of joint

Osteophyte spinal canal and lateral recess stenosis

Combine Three-joint complex Degeneration

Individual aging process of disc and dorsal facet joints are interlaced to contribute to the clinical manifestation of spondylosis

Disc degeneration loss of disc height subluxation of dorsal joints

This compounds to natural process of facet joint degeneration

Subluxation of rostral vertebral body ventrally with respect to the caudal vertebral body (spondylolisthesis)

This results in further narrowing of neural foramina lateral nerve root entrapment

Three stages of Degenerative Spine Disease

Dysfunction stage

Destabilization stage

Restabilization stage

Dysfunction stage..

Characterized by synovial reaction in dorsal joint and small tears in the intervertebral discs

Minor or absent clinical symptoms that are best treated conservatively

Destabilization Stage..

Kirkaldy-Willis defines this stage as

greater degeneration in the three-joint complex, manifesting as laxity and subluxation in the dorsal joints and progressive disc degeneration

Abnormal spinal motion

Natural mobility of the spine lost

Compounded by advanced disc degeneration and disc height reduction lead to spondylolisthesis

Rx – core strengthening and flexibility program to stabilize and normalize dysfunctional motion segment

Restabilization Stage

Instability is reduced via osteophyte formation secondary to a prior increased joint laxity and loss of disc interspace height

Resolution of symptoms can occur due to gradually decreased spinal motion

There may be radiculopathy from spinal nerve entrapment or claudication symptoms from central canal and lateral recess stenosis

CT Myelographyeffective alternative to MRI for assessing neural

elements, central or foraminal stenosis

MRIgold standard for evaluation spinal canal stenosissoft tissue surrounding spinal canal, discs,

ligamentum flavum and facet joints visualizedhypertrophy of PLL, ligamentum flavum and facet

hypertrophy can be localized specifically

Discographymore invasive diagnostic strategycan be done if clinical presentation does not match the

findings in other imaging modalityuseful to identify and characterize diseaseinvolves injecting contrast material into the disc in question

normal cervical disc tolerates 0.2-0.5 ml fluid whereas a degenerated disc can accept 0.5-1.5 ml fluid

if the pain produced following contrast injection is concordant with the typical pain experienced by the patient pathological

Treatment Options

Non operative management

natural course of spinal stenosis – 47% patients with neurogenic claudication and radiculopathy symptomatic improvement without intervention

Reason – progressive disc dehydration shrinking of disk decrease in root compression

Medical

symptomatic relief to reduction in inflammation

NSAIDsNarcotics to supplement masks

degenerative process until it progresses and improves spontaneously

muscle relaxants – shows some benefitSystemic oral steroids – anti inflammatory

effects may reduce nerve root irritation

Physical reconditioning via physical therapist – strengthen core musclesFlexibility exercise to help preserve normal motion

Epidural steroid injections – short term benefit

Facet joint injection (long acting anesthetic and steroids)33% patients reported >50% pain relief – result

consistent with placebo also; hence controversial

key to efficacy is proper selection of patients with facet syndrome

Facet syndrome defined as pain in the hips and buttocks area, cramping thigh pain, and back stiffness that is worse in the morning, without lower extremity paresthesia

Spinal Manipulative Therapy (SMT) by chiropractors, physical therapists and osteopathic physicians

3 main types of manipulations – therapeutic massage, mobilization and manipulative procedures

Hypothesis – neck or back pain is caused by either a limited range of motion or abnormal dorsal intervertebral joint motion

SMT “resets” the joint by extending the joint beyond the passive range of motion, into the “paraphysiologic range of motion”

Operative Treatment

May correlate with the extent of disease progression

Discectomy

ventral or dorsal approachCervical Spine:

ventral approach often utilized in cervical spine

Ventral – performed through a paramedian incisionrequires little muscle splitting low amount of postoperative

pain and morbiditycomplicationsdysphagia secondary to retraction of esophagus (1-79%

cases)damage to recurrent laryngeal n. vocal cord palsy improves with time

Dorsal approach in cervical spineeffective in eliminating unilateral n. root

compressionforaminotomies with or without discectomyrequires muscle splitting variable post

operative pain

simple foraminotomies and discectomies do not require fusion

minimally invasive techniques to reduce amount of muscle dissection shown to have up to 97% success rate alleviating radiculopathy symptoms

Lumbar spine

categorized as anterior and posterior approachposterior approach more often utilized

involves unilateral muscle dissection exposing the lamina hemilaminectomy removal of herniated disc

The Spine Patient Outcomes Research Trial (SPORT) – prospective, randomized trial evaluating lumbar discectomies against nonoperative treatment

conclusion – patients undergoing lumbar discectomies enjoyed reduction of pain, improvements in physical functioning, and a greater improvement in their disability index than conservative mgmt grp.

Laminectomy

Decompress spine via the removal of lamina and spinous process

Applied for multilevel reduction of spinal canal stenosis

Effective in cervical canal stenosis with spondolytic myelopathy and ossification of posterior longitudinal ligament

Development of postoperative kyphosis in 14-47% cases

This led to use of cervical laminectomy combined with fusion and laminoplasty decreased incidence of postoperative kyphosis

Laminectomy in lumbar spine involves removal of lamina and medial facetectomy to eliminate lateral recess stenosis

Laminoplasty

Detachment of lamina on only one side by creating a trough, and thinning the lamina on the contralateral side to allow for “hinging” at the attached lamina site

Detached lamina elevated and secured using small bone graft to maintain the decompressed state

Preservation of posterior element effectively decompress the spinal canal without the consequences of fusion such as loss of range of motion and adjacent segment degeneration

Laminoplasty – 27% improvement in preventing the incidence of postoperative kyphosis

Fusion

Debated topic

None of the study provides class I evidence to indicate clear benefit

Consideration to perform fusion is based on the need to create stability in an unstable region of the spine

A review of 13 class II and III studies comparing outcome of anterior cervical discectomies with or without fusion performed by Matz et. Al. Demonstrated no clinically significant advantage of including fusion

Although no class I or II evidence to support the use of cervical laminectomy with fusion, there is class III evidence that fusion reduces postoperative kyphosis

A great deal controversy regarding fusion in lumbar spine

Indicated typically in Kirkaldy-Willis second stage, where maximum destabilization is present

Lumbar fusion can be used to augment the transition of the second to third stage of restabilization.

Autograft bone is used either in the dorsolateral spaces or the interspaces to facilitate bony fusion while the construct immobilizes the spinal segment.

There are no clear data to support the presumption that fusion results in better outcomes compared to simple laminectomy alone.

Oswestry disability Index (ODI)

Modic change – vertebral body marrow change

Thank you!!!