Pathophysiology of Spondylolisthesis.pptx

A detailed presentation on the pathophysiology of spondylolisthesis

1. Pathophysiology of Spondylolisthesis Dr. Aju Bosco MS(Ortho), DNB, FNB(Spine) Assistant Professor in Orthopaedics & Spine Surgery Institute of Orthopaedics Madras Medical College Chennai-3.

2. Definition Spondylolisthesis refers to the anterior displacement(translation) of a vertebra with respect to the vertebra caudal to it.

3. History A Belgian obstetrician, Herbiniaux noted a bony prominence in front of the sacrum that caused problems in delivery The term spondylolisthesis was used by Kilian in 1854 spondylos - vertebra, Olisthesis - to slip or slide down Ptosis - to fall ( spondyloptosis) lysis -loosening.

4. Spondylolysis Spondylolysis refers to a defect in the pars interarticularis –No displacement most commonly at the L5 to S1 level found in about 5% of the general population Spondylolysis is an acquired condition 20 % is unilateral

5. Spondylolysis The defect develops in 75% of the cases by 5 to 6 years of age. Of these, 75% present with spondylolisthesis

6. SPONDYLOLISTHESIS CLASSIFICATION

7. Wiltse-McNab-Newman classification Type1 :Dysplastic /Developmental Type 11 :Isthmic Type 111 :Degenerative Type 1V :Post traumatic Type V :Pathological 11a Fracture in pars interarticularis (stress fracture) 11b Elongated intact pars interarticularis 11c Acute fracture

8. Marchetti and Bartolozzi(etiology) Developmental A.High dysplastic > with lysis > with elongation B.Low dysplastic >with lysis >with elongation Acquired A.Traumatic >Acute Fracture >Stress fracture B.Post surgery >direct-removal of facet >indirect- above an arthrodesis C.Pathologic (local/Systemic) D.Degenerative

9. 1.Developmental primary congenital dysplasia of the L5-S1 facet joints only at the L5-S1 level associated with spina bifida occulta of L5, of the sacrum more common in females increased pelvic incidence and sacral slope Type I slips are generally limited to 25 to 30%

10. Developmental more common in females increased pelvic incidence and sacral slope Type I slips are generally limited to 25 to 30%

11. trapezoidal shape of L-5, rounding of the superoanterior aspect of the sacrum, (Dome) vertical orientation of the sacrum kyphosis at the involved segments compensatory hyperlordosis at adjacent levels.

12. 2.Isthmic Type

13. Incidence absent in newborns 8% by age 18 years not been reported in nonambulatory patients Men > women Gymnastics, Wt lifting ,Volley ball L5 - 89% , L4 - 11%, L3-3% usually less than 50%

14. Defect pars region is the weakest area of the neural arch The Defect

15. The mechanism inadequate sliding during extension of L4-5 and L5-S1 L5 pars is pinched - limited excursion of the two facet joints fatigue fracture -(Stress fracture) ( “ nutcracker” mechanism ) – in extension relatively low pelvic incidence and sacral slope

16. Lower upper The hard cortical bone of the pars predisposes it to fatigue fracture, as well as nonunion Even If healing occurs, the pars often heals in an elongated position

17. callus formation occurs at the pars, superior articular facet overgrowth occurs - narrow the neural foramen . Fibrocartilaginous tissue in the area of the pars fracture from failed attempts to heal the stress fracture. This pathoanatomy usually affects the L5 nerve root in patients with L5-S1 spondylolisthesis. slipping mechanically stretches the nerve over the sacrum, contributing to radiculopathy.

18. 11a Fracture in pars interarticularis (stress fracture) 11b Elongated intact pars interarticularis 11c Acute fracture

19. shear stresses are placed across the disc, with 100% of the body weight creating an anteriorly directed force, compared with approximately 80% of the body weight when the intact facets share the load. This increased stress exacerbates disc space degeneration in adults and may contribute to the formation of foraminal stenosis and subsequent radiculopathy

20. 3.Degenerative Spondylolisthesis Junghanns first described degenerative (1930)-pseudospondylolisthesis more commonly at the L4-L5 level because the L5-S1 level is protected by the strong transverse-alar ligaments degeneration at the disk and facet joint. the hypertrophied facets and the ligamentum flavum can result in spinal stenosis No pars defect Do not progress beyond 30%

21. 4 High-energy trauma can cause translational deformity Acute fracture other than pars

22. 5.Pathological Pathologic spondylolisthesis is an attenuation of the pedicle caused by weakness of bone general - osteogenesis imperfecta -osteomalacia Local -secondaries

23. 6.Post Surgical a laminectomy that removes an entire articular process or more than half of each articular process . Segments adjacent to previously fused segments are also at risk for development of degenerative spondylolisthesis subluxation is likely due to resection of the capsular, interspinous, or supraspinous ligaments at the adjacent level. the loss of motion of the fused segment may contribute by increasing the motion demands at the next open level.

24. Radiology 80% of the pars defect will be seen on the lateral radiograph. oblique views will pick up an additional 15% of the cases.

25. Lateral view single standing spot lateral radiograph of the lumbosacral junction Displacement and true angulation of lumbosacral junction

26. Supine Flexion/Extension views To maximize motion –lat decubitus flexion-extension lateral views to detect instability

27. Oblique views (R/L) When defect not seen on lat view 20% of pars defect unilateral

28. The scottish terrier sign

29. Napoleon`s Hat sign – AP view lumbosacral kyphosis, superimposition of L5,S1

30. Ferguson`s view Eliminate superimposition Evaluate for spina bifida occulta Evaluate post operative fusion 25 deg Caudocephalic view (outlet view)

31. GRADING OF SPONDYLOLISTHESIS

32. Ant. Displacement Percentage slip/Olisthesis/ant. Translation 1.A line is extended upward from the posterior surface of the first sacral vertebral body . 2. second line is drawn downward from the posterior surface of the fifth lumbar vertebral Body 3. measurement is expressed as a percentage of the AP dimension of the fifth lumbar vertebral body

33. Meyerding Grade1 :0-25% Grade 11 :25-50% Grade 111 :50-75% Grade 1V :75- 100% Grade V : Spondyloptosis

34. Modified Newman Grading system The dome and the anterior surface of thesacrum are divided into 10 equal parts. 1.position of the posterior inferior corner of the body of the fifth lumbar vertebra with respect to the dome of the sacrum 2. 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

35. Sagittal Rotation/Slip Angle 1. the degree of forward tilting of the fifth lumbar vertebral body over the first sacral vertebral body 2. line drawn perpendicular to the posterior aspect of the first sacral body 3. parallel to the inferior aspect of the fifth lumbar vertebral body. the degree of instability and potential for progress

36. Pelvic Morphology measures Pelvic incidence pelvic tilt sacral slope spinal balance measures slip angle L5 incidence lumbar lordosis

37. Pelvic incidence 1.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. 2. normal -around 50 to 55 degrees spondylolisthesis - 70 to 79 degrees 3. describes pelvic morphology and ultimately lumbar lordosis

38. 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. orientation of the pelvis in the sagittal plane and vary according to human posture

39. Sacral slope measurement of the verticalization of the sacrum normal- 30 degrees With increased slippage, the sacrum becomes more vertically orientated

40. L5 Incidence A line from the midpoint of the upper end-plate of L5 is connected to the center of the femoral heads. A second line perpendicular to the upper L5 end-plate is drawn from the midpoint of the end-plate.

41. Sagittal Rotation/Slip Angle 1. the degree of forward tilting of the fifth lumbar vertebral body over the first sacral vertebral body 2. line drawn perpendicular to the posterior aspect of the first sacral body 3. parallel to the inferior aspect of the fifth lumbar vertebral body. the degree of instability and potential for progress

42. As pelvic incidence increases, sacral slope increases and lumbar lordosis increases to maintain sagittal balance. patients with spondylolisthesis have a greater pelvic incidence than controls increased pelvic incidence - predispose to spondylolisthesis.

43. slip percentage , Meyerding grade, and slip angle have been shown to be predictive of progression Measurement of L5 incidence has been shown to correlate with the outcome of spondylolisthesis treatment Pelvic Morphology measures(Pelvic incidence, pelvic tilt, and sacral slope )may not be affected by surgical treatment spinal balance measures (slip angle, L5 incidence, lumbar lordosis) seem to improve and correlate with outcome

44. Lumbar Index decreased lumbar index is secondary to increased slipping the degree of trapezoidal deformation of the L5. when associated with adolescent growth spurt, domeshaped first sacral vertebra, female gender - risk for progression of slipping

45. CT necessary to diagnose occult pars lesions that cannot be visualized on plain films three-dimensional reconstruction is useful in the preoperative evaluation of patients with severe dysplastic spondylolisthesis to characterize the pathologic anatomy more precisely.

46. MRI Disc prolapse in seen in 25% of patients at the next level above the slip 15% at the level of the listhesis itself. in a patient with radicular symptoms not correlating with the level of the slippage useful to rule out other causes of pain, such as tumor or infection

47. Bone Scan Acute conditions, such as a recent injury producing back pain, a bone scan single-photon emission computed tomography (SPECT) scan may be “hot” and confirm an acute fracture of pars

48. SPECT imaging technique using gamma rays

49. Myelogram

50. Risk Factors in Spondylolisthesis for Pain, Progression, and Deformity Younger age Female patient Recurrent symptoms Hamstring tightness, if associated with gait abnormalities or postural deformity RADIOGRAPHIC RISK FACTORS Type I greater risk than type II Greater than 50% slip Increased risk with increased slip angle L5-S1 instability with rounded sacral dome and vertical sacrum