SPONDYLOLISTHESIS

SPONDYLOLISTHESIS Mouli Edward

SpondylolisthesisThe word spondylolisthesis is derived from the Greek words spondylo meaning spine and listhesis meaning to slip or slide. Spondylolisthesis is a descriptive term referring to slippage (usually forward) of a vertebra and the spine above it relative to the vertebra below.

Classification

Type I: Congenital spondylolisthesis Type II: Isthmic spondylolisthesis Type III: Degenerative spondylolisthesis Type IV: Traumatic spondylolisthesis Type V: Pathologic spondylolisthesis

Pathomechanic

Body central gravity lies anterior to lumbosacral joint and the disc in this region lies obliquely; hence the shear forces created quite remarkably.This shear force compensated by orientation of facet joint, integrity of the pars interarticularis, posterior musculature and integrity of intervertebral disc. Failure one of these mechanisms can lead to increase shear force and anterior translation.

PathomechanicAn anterior translation would alter normal lever arm and further increase the shear force. These would leads to progressive disc degeneration and lumbosacral kyphosis.In high percentage slip (> 50%), the posterior portion of L5 rested an anterior portion of S1. Due to high concentration load these region would remodeled and resulted in trapezoidal L5 and rounded S1 dome. These will further accelerates the slip and rotation of L5 on S1.

Classification and PathomechanicWiltse et al (1976)Congenital

Dysplastic posterior element and articular processesDysplastic articular processes with sagittal orientation of facets jointsOther congenital anomalies

Classification and PathomechanicWiltse et al (1976)2. IsthmicLytic- stress fracture of parsElongated pars- healed type IIA.

Classification and PathomechanicWiltse et al (1976)3. Degenerative spondylolisthesis commonly caused by intersegmental instability produced by facet arthropathy.This variation usually occurs in the adult population and, in most cases, does not progress beyond a grade I spondylolisthesis

Classification and PathomechanicWiltse et al (1976)4. Traumatic spondylolisthesis in rare instances, result from acute stresses (trauma) to the facet or pars

Classification and PathomechanicWiltse et al (1976)5. Phathologic spondylolisthesisAny bone disorder may destabilize the facet mechanism producing pathologic spondylolisthesis. Iatrogenic spondylolisthesis, lastly, may occur if an overzealous surgeon performs too great of a facetectomy

Grading System Meyerding in 1947The degree of slippage is measured as the percentage of distance the anteriorly translated vertebral body has moved forward relative to the superior end plate of the vertebra below. Classifications use the following grading system: Grade 1: 1- 25% slippage Grade 2: 26-50% slippage Grade 3: 51-75% slippage Grade 4: 76-100% slippage Grade 5: Greater than 100% slippage

EpidemiologyFrequency In the US: Wiltse as well as Beutler

incidence of 6-7% for isthmic spondylolysis. Up to 5% of children aged 5-7 years have been found to have spondylolysis, many of whom are asymptomatic. The incidence increases up to the 7% by age 18. Approximately 82% of cases of isthmic spondylolisthesis occur at L5-S1.Another 11.3% occur at L4-L5.

EpidemiologyRace: The most commonly affected group is the white male with an incidence of 6.4%.Degenerative spondylolisthesis affects black females more commonly than white females (and females are more commonly affected than men).

EpidemiologySex: Beutler et al

Congenital spondylolisthesis (dysplastic type) occurs with a 2:1 female-to-male

Degenerative spondylolisthesis occurs more commonly in females with a 5:1 female-to-male ratio.

EpidemiologyAge:

Congenital/dysplastic spondylolisthesis has been documented in children as young as 3.5 months. Degenerative spondylolisthesis occurs most commonly after age 40 years.

Symptoms and signsDepend on the severity of the condition. Pain is the most common symptom of spondylolisthesis. Pain may originate in the area of lysis or may arise from other structures that have been affected by secondary changes of lysis or spondylolisthesis, such as degenerative change in the disk, facet-joint arthropathy, and ligamentous sprain or strain.

Symptoms and signsIn addition, pain may arise from neural involvement, which may be from the spinal canal stenosis that can occur in high grades of spondylolisthesis. In this situation, an intact neural arch slides forward, narrowing the spinal canal and compressing the cauda equina. Clinical features of spinal claudication may ensue.

Symptoms and signsAlternatively, as the neural arch slides forward, the inferior articular process of the slipping vertebra can impinge on the nerve roots in the lateral recess of the spinal canal and cause clinical findings of radiculopathy. Typically, this may involve the L5 or S1 nerve roots.Flattening of the back Spinous process step-off

ExaminationLateral and anteroposterior plain radiographs of the lumbar spine The lateral view is useful in detecting spondylolisthesis.

ExaminationThe lateral view may demonstrate the pars defect, and show Slip angle

ExaminationBilateral oblique views are especially useful to visualize the pars interarticularis defect, which has the appearance of a Scottie dog with a collar . An elongated pars also may be seen.

ExaminationMRI evaluates disc but can see a pseudodisc herniation due to rotatory element of slip

TreatmentNon-operative:ExercisesActivity modificationBracing : if symptom persist in spite the above treatmentadolescents - x-rays every 6 months until maturity

Risk factors for Slip progression:young age at presentation females slip angle > -10 degrees high grade slip dome shaped sacrum inclined sacrum (>30deg. beyond vertical)

TreatmentSurgeryIndication : Failed conservative treatment (after at least 6 months of orthosis application)Various technique of direct repair

Surgical Procedures Posterior decompression with pedicle screw fixation and posterolateral fusion. This operative plan is reserved for patients with mild to moderate slips with marked disc space narrowing .

Surgical Procedures2. Posterior decompression and pedicle screw fixation with the addition of lumbar interbody fusion (PLIF or TLIF). This operative strategy is reserved for slips with a relatively preserved disc space and in cases where slip reduction is performed

Surgical Procedures3. Decompression and fixation with sacral transdiscal screw fixation ending in the L5 body. This operative plan is performed in patients with advanced slip accompanied by advanced disc space narrowing