lumbar interbody fusion 3.pptx clinical features treatment

lumbar interbody fusion
Clinical features and treatment

1. Lumbar Interbody Fusion Procedures By Dr. Shravan V Moderator Dr. Venkateswar Reddy Sir 1

2. Degenerative disc and facet joint disease of the lumbar spine is common in the ageing population. Lumbar spondylosis may result in Mechanical back pain, Radicular and Claudicant symptoms, Reduced mobility, Poor quality of life. 2

3. The indications may include: Degenerative spondylolisthesis Isthmus spondylolisthesis Spinal stenosis Lumbar spondylosis Intervertebral disc herniation Patients with deformity Spinal trauma and ocologic conditions 3

4. Interbody fusion Removal of the intervertebral disc and replacement of bone graft or a device to maintain alignment and disc height. This devices usually contain bone graft material which facilitates fusion. 4

5. There are FIVE Lumbar interbody fusion approaches Anterior lumbar inter body fusion. Posterior lumbar inter body fusion. Oblique lumbar inter body fusion. Lateral lumbar inter body fusion. Transforaminal inter body fusion. 5

6. Anterior Lumbar Interbody Fusion (AILF) Anterior lumbar inter body fusion is one of the best less invasive surgeries for anterior support in the distal part of the lumbar spine. Best approach for the level L5-S1 Can also be used at the levels of L4-L5, L3-L4 But it is technically difficult at this levels as they have close relation ship with the abdominal aorta and Vena cava 6

7. Administer general anaesthesia and place the patient in the Trendeleburg position. The correct level of L5 should be exactly identified and lie on the same line and this is achieved with the help of fluoroscopy and c-arm Spinous process and end plates must be aligned according to the patients lordosis 7

8. Indications Degenerative disc disease with or with out radiculopathy Spondylolisthesis Failed posterior fusion Scolosis 8

9. Rationale for ALIF With ALIF, an inter body device is used to redistribute the weight bearing distribution to the original ratio According to the WOOLF law, the fusion potential increases if the graft are placed under the direct compression that supports the placement of the graft in the anterior column. Radiological outcomes, including the height restoration and focal and lumbar lordosis, were superior in anterior approach. 9

10. Approach ALIF is performed through the Retroperitonal approach 10

11. Skin Incision Incision should be strictly correlated to the level to approach Ideal incision should be minimal, horizontal 6-7 cm long Oriented slightly to the left 11

12. Blunt finger dissection is used to mobilise the skin and Soft tissues of the left anterior rectus sheath. Sheath thus opened longitudinally near the midline using the electrocautery 12

13. The medial boarder of the inferior rectus muscle is mobilised over a cranial to caudal distance of approximately 10 cm Muscle is then mobilised laterally to expose the underlying arcuate line. 13

14. The identification of the Psoas muscle makes it possible to locate and palpate the left great vessels Care must be takes to avoid tears in the peritoneal lining. Ureter must be identified to prevent inadvertent injuries 14

15. Deep self retaining abdominal retractors are placed to maintain a sufficient corridor to the disc space Steinmann pins are used as alternative Retractors should be securely locked to avoid unexpected mobilisation that can injurie the surrounding structures. 15

16. At the level of L5-S1 the disc is typically located below the bifurcation of the great vessels. The middle sacral artery and vein must be ligated or coagulated by using a bipolar electrocautery. 16

17. Identify the lateral boarder of the L5-S1 disc Then incise the anterior annulus midline in a vertical fashion and develop a flap on either side. 17

18. At the level of L4-L5 or L3-L4 the aorta and vena cava must be retracted to the right. Segmental arteries and veins must be ligated 18

19. Proceed to remove the disc down to the subcentral bone. Care must be taken not to enter the epidural space Use of lamina spreaders will facilitate the disc removal. 19

20. Meticulously remove the entire nucleus pulposus and all the cartilage from the endplates. Pieces of cartilage may inhibit fusion if present either on the endplates or in the bony material used for the fusion. 20

21. The ideal cage size should cover approximately 90% of the end plate Should be firmly seated over the end plate Cage must be filled with bone or bone substitute. 21

22. The cage is then inserted, and the cage inserter is struck properly until the desired position is reached. This procedure is controlled by the C-arm in AP and lateral positions. After the final positioning of the cage is achieved, the lordosis is reduced by returning the table to the initial position 22

23. A set of anchors or screws can be attached, ensuring sound fixation and stabilization. Additional fixatorn is recommended is stand alone cages are used Open or percutaneous screws can be used according to preoperative planning 23

24. After careful visualisation of all the anatomical structures that have been passed through during the approach, the fascia can be closed. Closure should be done usually without using a drain 24

25. Post operative care Nasogastric suction may be necessary for gastric decompression for about 36 hours. Mobilisation of lower limb to avoid pooling of blood. Intermittent compression boots, and low-molecular weight heparin all are used for deep vein thrombosis prophylaxis. In-bed exercises with straight leg raising are started on the first postoperative day and continued indefinitely. 25

26. Postoperative radiographs are made before discharge from the hospital . Three months later, side bending and flexion and extension radiographs are made in the standing position to provide information about the success of arthrodesis. Radiographs are then repeated at 6 and 12 months after surgery, with the solid fusion not confirmed until 1 year after surgery. Tomograms may be useful in evaluating suspected pseudarthrosis. 26

27. Advantages and disadvantages Advantage: avoidance cutting muscles of the back. Disadvantages : risk of injury to the structures mainly in the abdomen. 27

28. Posterior Lumbar Interbody Fusion Managing spondylolisthesis requires good knowledge of lumbosacral anatomy. G oals of the surgical management are: Solid fusion across L5-S1 Failed back surgery syndrome Spondylolisthesis Bilateral midline disc herniation Segmental instability Degenerative disc disease 28

29. Contraindication for PLIF Osteoporosis Discitis Subchondral sclerosis Adhesive arachnoiditis 29

30. The classical PLIF technique consists of three surgical steps Laminectomy or laminotomy with partial or complete facetectomy Removal of the intervertebral disc Fusion 30

31. Preparation The patient is placed in the prone position, on a radiolucent table. The skin and subcutaneous tissue is infiltrated with a 1:500,000 epinephrine solution to achieve hemostasis. Two parallel skin incisions are made proximally 2.5 cm lateral to the midline at the level of L4-S1. 31

32. Alternatively, a vertical incision is made midline over the spinus processes of L4-S1 Intramuscular plane must be developed between the multifidus and the longissimus using blunt dissection 32

33. Plane is developed, palpate medially the facets while continuing to dissect lateral to them all the way down to the transverse process. Self-retaining retractors are placed allowing visualization of the part articularis medially and the transverse process laterally. 33

34. Distally, dissection is taken down onto the sacral ala. At the S1 level the iliac crest tends to be on the superficial lateral aspect of the approach, allowing for bone graft harvesting if required. 34

35. Pedicle screw insertion in L5 and S1 is performed in a standard fashion, ensuring that the proximal facet is not breached by the pedicle screw. 35

36. Pedicle screw insertion L5 The entry point of the pedicle screw is defined as the confluence of any of the four lines. Pars interarticularis Maxillary process Lateral border of the superior articular facet Mid transverse process 36

37. Open the superficial cortex of the entry point with a burr or a wronger A pedicle probe is used to navigate down the isthmus of the pedicle in to the vertebral body The pedicle probe should be inserted in a trajectory superimposed on the transverse process and parallel to the superior endplate 37

38. Transverse plane inclination It is important to avoid medial penetration of the spinal canal superficially or lateral or anterior penetration of the vertebral body cortex at the depth of insertion. 38

39. Screw insertion Once the pedicle track has been created, conformation of complete intraosseous trajectory by pedicle. And body palpation using a pedicle probe. At any point in the process, radiographic confirmation can be obtained. 39

40. A screw of the appropriate diameter and length is carefully inserted in to the prepared track. 40

41. Pedicle screw is defined by the inferior border of the superior facet of S1 Once the superficial cortex of the entry point with a burr or a rongeur The trajectory of the screw is 30 degree medially 41

42. Cranial caudal angulation A pedicle probe is used to navigate down the isthmus of the pedicle in to the vertebral body The appropriate trajectory of the pedicle probe in the cranial caudal direction occurs by aiming towards the promontory 42

43. Classically these screws are large in diameter, however, shorter in length than the L5 screws. If screws are too long and breach the anterior cortex, L5 nerve root and great vessels are at risk of injury. 43

44. Pedicle Screw Insertion at S1 The entry point of the pedicle screw is defined by the inferior border of the superior facet of S1 Open the superficial cortex of the entry point with a burr or a rongeur. The trajectory of the screw is 30° medially. 44

45. A pedicle probe is used to navigate down the isthmus of the pedicle into the vertebral body. The appropriate trajectory of the pedicle probe in the cranial caudal direction occurs by aiming towards the promontory. It is important to confirm a complete intraosseous trajectory by pedicle and body palpation using a pedicle sounding device. 45

46. Interbody fusion is performed via a transforaminal approach. Due to the anterior listhesis the course and location of the L5 nerve root places it at risk. Facet removal may be performed if wide decompression is needed. Inferior facet of L5 and a part of S1 superior facet is removed bilaterally. Care is taken to protect the nerve root before the facet and disc removal. 46

47. The disc is removed by incising the anulus fibrosis. Care is taken not to disrupt the anterior anulus. The endplates are cleared for all traces of cartilaginous material to ensure fusion. 47

48. Once the intervertebral disc have mobilised , the disc space is filled with Cancellous bone Structural bone graft is impacted providing anterior structural support. A cage can be used instead of the structural bone. 48

49. For these deformities a reduction maneuver is not necessary. The rods are contoured to accommodate both the S1 and L5 pedicle screws. The rods must respect the L5-S1 lordosis Posterior lateral fusion should be carried out across the transverse process of L5 to the sacral ala. 49

50. Post Operative Care Detailed post operative neural assessment must be conducted to look integrity of L5 nerve root as well as scaral nerves the controls bowel and bladder High grade spondylolisthesis that have been reduced are at higher risk of postoperative foot drop To minimise such injuries post operative on bed knee and hips are flexed Patients are made to sit up in the bed on the first day of surgery. Bracing is optional 50

51. Patient with intact neurological status are made to stand and walk on the second day after surgery Patients are generally followed with periodical X-ray at 6weeks, 3 months, 6 months, and 1year looking for spinal fusion. 51

52. Transforaminal Lumbar Interbody Fusion This is minimally invasive procedure. Goal of this surgery is to directly decompress the nerve root, decompress the thecal sac when indicated. Insert an Hinterbody cage and stabilise the segment with percutaneous pedicle screw instrumentation Most of the patients have grade 1 and grade 2 spondylolisthesis 52

53. The patient is positioned prone with a free hanging belly. The hips and chest are padded. The position should promote lordosis of the lumbar spine. 53

54. Palpate the spinous processes and mark the midline and the iliac crests bilaterally Based on the laterality of the facet resection and inter body placement, k-wire and AP fluroscopy are used to mark the cranial and caudal pedicles of the intended level horizontally and vertically Mark a vertical incision line 1–2 cm lateral to the ipsilateral lateral borders of the cranial and caudal pedicle on the side of the approach. 54

55. 4–5 cm skin incision at the location planned in the previous step. This incision can ultimately also be used for percutaneous pedicle screw insertion on the same side. Dissect down to the fascia. A 2.5 cm fascial incision is made medial to the skin incision. Insert the first dilator, angle slightly medially, and “feel” for the base of the spinous process and lamina. 55

56. Ipsilateral decompression Resection of the inferior articular process Resect the inferior articular processes by using a drill or a osteotome Main bony surgical landmarks are Inferior boarder of lamina Para interarticilaris An L shaped or curved course is taken from point A to Point B Use a large pituitary rongeur to harvest the inferior articular process. 56

57. Resection of superior articular process Identify the superior wall of the caudal pedicle and then use a burr or an osteotome to disconnect and harvest the superior articular process 57

58. Resection of ligaments flavum Release the ligamentum flavum from the underlying dura with a ball tip hook. Resect the ligamentum flavum from lateral to medial to expose the disc within the foramen. 58

59. Discectomy After removing the ligamentum flavum, the disc will be visible. The exiting nerve root passes under the remaining pars interarticularis at the cranial margin of the visible field, and the traversing nerve root may be visualized medially. Bipolar coagulation with irrigation can be used to control epidural bleeding from vessels overlying the disc. Ensure that the disc material is freed from the dura using a ball tip hook 59

60. Perform a peace meal discectomy using a pitutary rongeurs and curettes Decorticates the end plate using a rasp. Completely remove the cartilage from the vertebral endplates 60

61. Insert a disc shaver into the disc space and rotate, progressively distracting the disc space. Remove the remaining disc material and continue using larger disc shavers until maximal distraction without endplate damage is achieved. A trial can be used to further confirm the optimal implant size. 61

62. Pack the bone graft into anterior portion of the discectomy space. A structural implant of appropriate size, filled with additional bone graft, aimed medially towards the anterior third of the disc. 62

63. Ap and later x-rays are taken to confirm the appropriate positioning of the cage with in the disc space To achieve the maximum lordosis, the cage should be positioned as anteriorly as possible If necessary additional decompression can be performed with the table tilted to treat more central stenosis. 63

64. Hemostasis is achieved with hemostatic agents or bipolar cautery. Packing the tube with gauze for five minutes will usually allow coagulation to take place. Topical steroids are not recommended so as not to interfere with the fusion process. The tube is slowly removed. Any muscular bleeding should be identified and cauterized. The fascia is typically closed using interrupted sutures. Infiltration of the muscle with local anesthetics is optional. Standard multilayer closure of subcutaneous layers and skin is performed. 64

65. Post Operative Care The patient can usually be discharged on the following day with a short course of pain medication. Lumbar immobilization is typically not required for one-level procedures. For high-risk patients or multilevel fusion, lumbar immobilization is at the surgeon’s discretion. Patients may feel incisional or muscular pain that usually subsides within a few days. 65

66. Lateral Lumbar Interbody Fusion The disc is approached from an extreme lateral incision (retro peritoneal ) on the patient’s side The advantage is the avoidance of the back muscle and abdominal structures required in traditional fusion procedures The disadvantage is that L5-S1 is not accessible with this procedure 66

67. A transpsoas approach is performed. The best position should be the middle third of the disc space, depending on the distance from the lumbar plexus. Ap and Lat views are conformed. K wire is positioned inside the tube, it lock the tube in correct position. A self-retaining retractor system is highly recommended to lock the retractor in the correct position during the procedure. 67

68. The length of the blades is adjusted according to the patient's size. The opening of the blades should not exceed the size of the instruments that are used for the disc preparation. This can protect the patient from bleeding and neurological issues. The annulus is opened in a small square using a sharp blade, avoiding injury to the anterior longitudinal ligament (ALL) and the posterior longitudinal ligament (PLL) 68

69. The size of the incision should not exceed the size of the planned cage. The most commonly used width is 22 mm. The height and shape of the implant depend on Previous height of disc space Osteophytes Condition of facet Deformities 69

70. The cage must be securely attached to the cage inserter to avoid misplacement. The cage is then inserted, and a press-fit is achieved. Different types of additional fixation can be used according to the preoperative planning 70

71. Indication and contraindication for LLIF Indication: LLIF is most suitable for interbody access from L2-L4 for degenerative disc disease with or without instability Adjacent segmental disease Grade 1 or Grade 2 degenerative spondylolisthesis Complex degenerative scoliotic deformity 71

72. Contraindication LLIF at L5-S1 is generally contraindicated due to obstruction by the iliac wing Other relative contraindications include grade 3 or greater degenerative spondylolisthesis Greater than 30 deg lumbar deformities Bilateral retroperitoneal scarring LLIF is generally not used alone when direct posterior decompression is necessary, such as with lumbar stenosis or disc rupture. 72

73. Oblique Lumbar Inter Body Fusion The disc is approached from the lateral side of the patients side. The procedure is done obliquely (infront of the iliac crest ) which gives access to L5-S1 Anterior to psoas muscle- avoids injury to psoas muscle and lumbar plexus that leads to less incidence of cruralgia Away from peritoneum and vasculature Preserve sympathetic plexus decreased incidence of retrograde ejaculation. 73

74. Advantages of OLIF Direct visualisation and discectomy, easy to do end plate preparation Can be performed L2-L3 to L4-L5 Upto 3 level fusion can be done using 4cm incision by sliding window technique Less incidence of hernia and ileus Decreased blood loss Increased surface area of the OLIF cage which is three times more than TLIF cage gives better and strong arthrodesis 74