Spondylolisthesis

a comprehensive review of spondylolisthesis

1. Spondylolisthesis Dr.Sairamakrishnan S

2. In 1782, Herbiniaux , a Belgian obstetrician, noted a bone prominence in front of the sacrum that caused problems in delivery . In 1854, Kilian coined the term spondylolisthesis, derived from the Greek spondylos , meaning “vertebra,” and olisthenein , meaning “to slip.”

3. Spondylolisthesis is defined as the forward slippage of one vertebra on its adjacent caudal segment . Spondylolysis is a defect in pars interarticularis (the part of neural arch just caudal to the confluence of the pedicle, the superior articular process and the most cephalad part of the lamina ) Spondyloptosis : used to describe as fall of L5 vertebra into the pelvis and lie anterior to sacrum .

4. HOOK AND CATCH CONCEPT Hook: Pedicle Pars inter- articularis Inferior process of the cephalad level Catch: Superior process of the caudal level

5. Classification Wiltse , Newman and Macnab Based on a mixture of etiological and topographical criteria Meyerding Classification B ased on percentage of slip in lateral radiograph Marchetti and Bartolozzi Emphasizes the developmental and dysplastic aspects

6. Epidemiology Incidence: 6% in general population Male:female ratio: 2:1, slippage more in females. Incidence in children <6years: 2.6% Ethnicity: more common in Caucasians than Blacks; eskimos of Alaska reported incidence upto 50%. Exact etiology: obscure

7. Degenerative spondylolisthesis (>40years) more common in females. Genetic and familial assosciation : 26% of patients with isthmic spondylolisthesis had first degree relatives with same disease

8. Etiology: Developmental Spondylolisthesis With Lysis Wiltse et al: normal flexon contracture of the hip in childhood causes increased lumbar lordosis leading to increased force at Pars interarticularis . Lett et al: shear stress greater at pars when lumbar spine is extended . Cryon and Hutton: Pars is thinner and vertebral disc is less resistant to shear in children and adolescents than in adults

9. Etiology : Isthmic spondylolisthesis Due to upright walking and wt . bearing. M=F: 2:1 Risk factors: Gymnastics / Football/wt. lifting, dancing and others with excessive lordosis or hyperflexion of the lumbar spine.

10. Etiology:Degenerative spondylolisthesis Sagital facet theory: Facet oriented in such a way that it doesn’t resist Intratranslation forces over time leading to degenaration and Spondylolisthesis Disc degeneration theory: Disc narrows first leading to overloading of facets, Accelerated arthritic changes , Secondary remodelling , Anterolisthesis

11. TRAUMATIC PATHWAY Sup. and inf. articular process impingement creates a bending moment that is resisted by the Pars. Repetitive impingement- fatigue In Erect posture-Center of Gravity is anterior to LS joint. Lumbar spine-forward force and rotate anteriorly into flexion about the sacral dome. Initiated by the repetitive cyclic loading

12. Stress fracture of Pars and post. neural arc separates from body Gap occupied by the fibrous tissue - Non union Increased shear load to disc though axial load remains unchanged Premature disc degeneration Vertebral subluxation

13. DYSPLASTIC PATHWAY Initiated by the cong. defect (dysplasia) in the bony hook or its catch. Repeated loading unopposed by bony constraints Plastic deformation of soft tissue restrains: IV Disc, Antr and Postr Ligament complex Subluxation of vertebra

14. DYSPLASTIC PATHWAY With continuous growth Slippage and abnormal growth in the involved vertebral bodies or sacrum Changes seen: -Trapezoid shape of L5 Rounding of supero anterior aspect of sacrum Vertical orientation of the sacrum Junctional kyphosis at involved segments - Compensatory hyperlordosis at the adjacent levels

15. DEGENERATIVE SPONDYLOLISTHESIS Sagital facets degeneration No resistance for anterior translation force Predilection for slippage Anterolisthesis

16. DEGENERATIVE SPONDYLOLISTHESIS Disc degeneration Disc narrowing and subsequent overloading of facets Accelerated arthritic changes Secondary remodelling Anterolisthesis

17. TRAUMATIC SPONDYLOLISTHESIS High energy trauma Translational deformity Fracture of bony hook other than Pars ie: Pedicle, Superior and Inferior articular facets Associated multiple bony and STI Subluxation

18. POST SURGICAL Laminectomy Removal of >1/2 or entire articular process Destabilize the spine subluxation

19. POST SURGICAL Fusion of segments Resection of capsular, Supraspinous and Interspinous ligaments Increasing motion demand subluxation

20. Natural history Dysplastic spondylolisthesis : Early age; usually asymptomatic Severe slip(9-15,seldom after 20) Risk of neurological complications Higher risk of slip progression-cauda equina syndrome as the neural arc is intact .

21. Degenerative Spondylolisthesis Rare before 50. Matsunaga et al 10 yrs prospective study--34% showed progression of the slippage-though no significant effect in the clinical outcome F urther disc space narrowing continued in those without slip However back pain improved ( Autostabilisation ) 83 % of the pts with neurological signs and symptoms deteriorated

22. Clinical evaluation Inspection Buttocks: Flat, Heart shaped in high grade slip due to sacral prominence. Sacrum : more vertical, appears to extend to the waist Lumbar hyperlordosis above the level of the slip to compensate for the displacement. Transverse loin crease Peculiar spastic gait -due to hamstring tightness and lumbosacral kyphosis.

23. Flat buttocks Lumbar hyperlardosis Transverse loin crease

24. Causes of pain L5 compression / traction Abnormal motion Facet joint arthrosis Pars scar

25. Radiographs AP view Standing Lateral view including the hips.(15% of deformities spontaneously reduce on supine imaging.) Oblique view: help in viewing pars interarticularis defect (decapitated scotty dog ) Lateral flexion and extension views: determination of translational instability

26. Flexion-extension lateral views may reveal instability, which is considered to be present when 4 mm of translation or 10 degrees of sagittal rotation greater than the adjacent level is identified Fegurson view depicts the L5 pedicles, transverse processes and sacral ala more clearly

27. Ferguson view

28. Flexion Extension views

29. Oblique view

30. CT myelography Used as indicated for the evaluation of spinal stenosis and may show facet overgrowth, hypertrophy of the ligamentum flavum , and, rarely, disc herniation, tumors, etc .

31. SPECT A Single-photon Emission Computed Tomography bone scan is necessary to show whether uptake is increased in the pars. A SPECT scan is helpful in determining whether the process is acute or chronic . If increased uptake is confirmed, a CT scan can be obtained to evaluate whether there are thickened cortices consistent with a stress reaction or whether there is an acute stress fracture

32. MRI Allows for additional visualization of soft tissue and neural structures and is recommended in all cases associated with neurologic findings. In the early course of the disease, MRI helps in identifying the stress reaction at the pars interarticularis before the end-stage bony defect. MRI may show the degree of impingement of neural elements by fibrous scar tissue at the spondylolytic defect. Status of disc.

33. IMPORTANT RAD I O L OG IC A L PARAMETERS Slip Angle The slip angle is measured from the superior border of L5 and a perpendicular line from the posterior edge of the sacrum Angle greater than 45* degrees associated with greater risk of slip progression, instability, and development of postoperative pseudarthrosis .

34. Pelvic incidence: A line perpendicular to the midpoint of the sacral end plate is drawn. A second line connecting the same sacral midpoint and the center of the femoral heads is drawn. The angle subtended by these lines is the pelvic incidence Pelvic incidence: Pelvic tilt + sacral slope Normal: 50 degrees Unaffected by posture Increased PI may predispose to spondylolisthesis .

35. Pelvic tilt : A line from the midpoint of the sacral end plate is drawn to the center of the femoral heads. The angle subtended between this line and the vertical reference line is the pelvic tilt. Higher pelvic tilt predisposes to spondylolisthesis.

36. DE WALD MODIFIED NEWMAN SPONDYLOLISTHESIS GRADING SYSTEM Better define the amount of anterior roll of L5. The dome and the anterior surface of the sacrum is divided into 10 equal parts. The scoring is based on the position of the posterior inferior corner of the body of the L5 with respect to the dome of the sacrum. The second number indicates the position of the anterior inferior corner of the body of the L5 vertebra with respect to the anterior surface of the first sacral segment

37. Clinical Growth yrs (9 – 15) Girls > Boys symptomatic Postural or gait abnormality Radiographic Type 1 (dysplastic) Vertical sacrum >50 % slip Increasing slip angle Instability on flex/ ext views RISK FACTORS FOR SLIP PROGRESSION IN SPONDYOLISTHESIS

38. Management Conservative Operative

39. Conservative Includes complete cessation of activity, rehabilitation with strengthening of the abdominal and paraspinal musculature, minimization of pelvic tilt, and antilordotic bracing. The brace is worn for throught the day for minimum of 3 to 6 months. If clinical symptoms improve, the brace can be gradually weaned through a period of part-time wear .

40. If the SPECT scan reveals metabolic activity and a CT scan shows thickening of the pars, avoidance of aggravating activity and core strengthening exercises are recommended. If the SPECT scan is metabolically active and CT indicates an acute stress fracture, a 3-month trial of orthotic treatment is warranted. If the defect has not healed in 3 months, continued orthotic wear is not indicated. The CT scan is the most helpful radiographic technique to determine the presence or absence of healing .

41. Have excellent relief of symptoms or only minimal discomfort at long-term follow-up. If a patient does not respond to conservative measures, other causes of back pain should be ruled out. Special attention should be paid to those whose symptoms do not respond to bed rest or who have objective neurological findings. A very small percentage of patients with spondylolysis who do not respond to conservative measures and in whom the other possible causes of back pain have been eliminated may require operative treatment.

42. Operative treatment Indications Persistent symptoms despite 9 months to 1 year of conservative treatment, Persistent tight hamstrings, abnormal gait, and pelvic-trunk deformity. Development of a neurological deficit . In a skeletally immature patient with slippage greater than 50% or a mature adolescent with a slip greater than 75%, even if the patient is asymptomatic

43. Surgical Goals Address the pars defect & the rattler Decompress the foraminal stenosis Address the degenerate discs Address the dynamic instability

44. Options Direct repair of pars defect Decompression and fusion without fixation Decompression and fusion with pedicle screw fixation Posterolateral insitu fixation Partial reduction and fixation Complete reduction, fusion and fixation Posterolateral interbody fusion and fixation/PLIF Trans foraminal interbody fusion/TLIF Anterior interbody fusion/ALIF

45. REPAIR OF SPONDYLOLYTIC DEFECT Procedures : Buck technique Scott wiring Modified Scott Technique Kakiuchi procedure (repair with an ipsilateral pedicle screw and hook).

46. Bucks

47. Scott

48. Modified S cott

49. Kakiuchi

50. Insitu fixation

51. Grob’s technique

52. Interbody Fusion In cases with more than 50% slippage

53. KELLOG SPEED ANTERIOR FUSION USING FIBULAR GRAFT

54. Most authors agree that slippage of more than 50% requires fusion. The reduction of spondylolisthesis with instrumentation improves the chance of fusion, but these procedures have many risks and potential complications/neurological injury fusion in situ should be considered a method of choice in severe L5 isthmic spondylolisthesis. I n severe spondylolisthesis, the sacral roots are stretched over the back of the body of S1 and are sensitive to any movement of L5 on S1

55. Treatment of spondyloptosis