Original Article

Treatment Of Lumbar Spinal Stenosis With Interspinous Process Decompression System (IPD) (X-Stop®)

J Chiu

Citation

J Chiu. Treatment Of Lumbar Spinal Stenosis With Interspinous Process Decompression System (IPD) (X-Stop®). The Internet Journal of Minimally Invasive Spinal Technology. 2006 Volume 1 Number 1.

Abstract

Lumbar spinal stenosis is most common reason for back surgery in patients over the age of 50 in America. With increased life expectancy, and the aging of baby boomers, many patients suffering from progressive lumbar spinal stenosis with symptomatic intermittent neurogenic claudication (NIC) have been limited to a choice between non-surgical therapies and more traumatic decompressive surgical procedure, with or without lumbar fusion. The interspinous process decompression system (IPD) (X-STOP®) implant was developed to provide a minimally invasive alternative therapeutic treatment of lumbar spinal stenosis.


The X-STOP® interspinous process decompression system, surgical indications, operative techniques, case illustrations, outcome and the potential complications and their avoidance are described and discussed herein.

 

Introduction

With increase in life expectancy and the aging of Baby Boomers, more people are living to an age when Lumbar Spinal Stenosis (LSS) condition becomes symptomatic. LSS is one of the most common causes for spinal surgery in the elderly population over the age of 50 in the United States, and is a frequent manifestation of pathophysiological process of spinal degeneration that occurs with aging and often becomes symptomatic in the fifth and sixth decades of life (1,2,3,4,5,6,7,8,9,10,11,12) (Table 1). Approximately 2 million physician's offices visits were related to symptoms of LSS. It is estimated that more that 125,000 laminectomy procedures were performed for LSS. The financial impact of LSS in terms of health care dollars and lost work hours reaches billions of dollars each year in the US (1, 3, 5,6,7,8,9).

LSS presenting as disabling neurogenic intermittent claudication (NIC) and requiring surgical intervention, if not successful with conservative treatment of medication and exercise program. The pathophysiology of LSS is complex and multifactorial of progressive neural compression, as the result of spinal degeneration with narrowing of the spinal canal and neural foramina, secondary to the degeneration of the intervertebral disc, a loss of disc height, causing the effected spinal segment to adopt a position of hyperextension, leading to a bulging of annulus, hypertrophy of the facet, spondylolisthesis, and a thickening of interspinous ligament, in particular the ligamentum flavum (8,9,10,11,12,13,14,15,16,17,18) (Figure 1a-1d). The narrowing of the spinal canal and neural foramen leads to nerve root compression and ischemia, and neurogenic intermittent claudication (NIC) (17,18,19,20,21,22,23,24).

Figure 1
Figure 1a: Normal spinal canal on the left; degenerative lumbar spondylosis and stenosis on the right

Figure 2
Figure 1b: MRI T2 Sagital image: spinal canal narrowing caused by degenerative disc bulge, disc space collapse, spondylolisthesis L4 on L5 and hypertrophy of ligamentum flavum

Figure 3
Figure 1c: MRI T2 axial images: lumbar stenosis of canal on the left secondary to disc bulge, facet hypertrophy, hypertrophic lig. Flavum causing neural compression; on the right normal

Figure 4
Figure 1d: MRI T2 images: sagital view on the left with severe lumbar spondylosis, spondylolisthesis L4 on L5 and marked foraminal stenosis; axial view of spinal stenosis on right

Figure 5
Table 1: Pathophysiology of lumbar stenosis

Typically the posture of the LSS patient is kyphotic while walking. Of course, extension of the spine often provokes symptoms while flexion relieves them (12,13,14,15). Typically, x-rays are taken to evaluate the alignment of the spine and extent of the degenerative bony changes. MRI scanning is helpful in defining and confirming nerve root impingement, disc bulging, ligamentum flavum hypertrophy, disc degeneration, and other soft tissue condition. Radiographic evidence of stenosis must be correlated with the patient's symptoms before diagnosis can be confirmed (4, 20, 23, 25,26,27).

The treatment of LSS begins with a regimen of non-surgical medical management (10,11,12, 16). While some patients respond to this treatment well, many do not and become candidates for the surgical intervention. More traumatic decompressive lumbar laminectomy is the most common surgical procedure with (for spinal instability) or without fusion (14, 19, 28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46).

Interspinous process decompression (IPD) (X-STOP®) is a minimally invasive spinal surgery (MISS) in which an implant is placed between the adjacent spinal processes of the symptomatic disc level. The intraspinal process decompression system was developed for patients who have LSS with disabling neurogenic intermittent claudication, and who are able to relieve their symptoms when they bend forward or flex their spine. The IPD (X-STOP®) is designed (47,48,49,50,51,52,53,54) to limit pathological extension of the spinal segments and to maintain them in a neutral or slightly flexed position which may allow patients to resume their normal posture rather than flex the entire spine to gain symptomatic relief.

The reputation of fusion technology causes adverse consequence of fusion with loss of mobility, stiffness, and junctional disc (55,56) degeneration. The unique design of X-STOP® (IPD) allows it to be implanted with a straight forward approach without fixation to the bone or ligament, provides a physiologic spinal motion preservation system, as in other minimally invasive spinal surgery(57,58,59,60,61,61,62,63,64,65,66).

Advantages

The advantages of using IPD or X-STOP® procedure over decompressive lumbar laminectomy are:

  • This minimally invasive spine surgery (MISS) usually can be performed on an outpatient basis

  • The procedure can usually be performed by using local anesthetics and IV conscious sedation. Patients with higher medical risks, which prohibit the use of general anesthesia, can be treated.

  • It usually requires little or no tissue or bone resection.

  • No significant blood loss

  • Most patients experience faster recover, ambulation and rapid relief of LSS symptoms.

  • The spinal canal is not compromised.

  • OR time is usually less than 60 minutes.

  • Much lower complication rate.

  • Implant can be removed easily.

Surgical Technique (,)

Meticulous and proper patient selection and proper surgical indication for X-STOP® (IPD) technique are of paramount importance in achieving good clinical results and in avoiding potential complications.

On physical examination, the patient should undergo a complete physical examination to rule out other disease processes with similar symptoms as LSS, especially vascular claudication of the legs. Radiological imaging studies should correlate with the patient's clinical signs to confirm the diagnosis of LSS.

The X-STOP® is contraindicated in patients with severe osteoporosis. It is manufactured from a titanium alloy and is MRI safe.

Surgical Indications

X-STOP® (IPD) procedure is indicated for patients (8,9):

  • Age 50 or older

  • Significant neurogenic intermittent claudication (NIC) with relief in flexion of lumbar spine

  • Secondary to evidence of LSS with x-ray, MRI scan and/or CT scan of thickened ligamentum flavum narrowed lateral recess and all central canal narrowing.

  • Not responding to at least six months of conservative treatment

  • No more than two levels of lumbar stenosis

  • Patient does not desire traditional lumbar surgery

Contraindications in the following situation

  • Spinal anatomy or disease that would prevent implantation of the device or cause the device to be unstable.

  • Known allergy to titanium or titanium alloy.

  • Significant scoliosis (greater than 25° of Cobb angle).

  • Active systemic infection or infection localized to site of the implantation.

  • Severe osteoporosis is more than 2.5 SD below the mean value of normal adult.

  • Cauda equina syndrome.

The X-STOP® System

The implant (IPD) (X-STOP®) (Figure 2a) is comprised of two components: A spacer implant assembly and a locking wing assembly with a fixed wing on the oval spacer, and a locking assembly of a wing and a locking screw.

The surgical instruments (Figure 2b):

  • Small curved dilator

  • Large curved dilator

  • Sizing distractor

  • Spacer insertion instrument

  • Wing insertion instrument

  • Hex head screwdriver

Figure 6
Figure 2a: X-STOP implant device consisting of fixed wing, spacer implant, and adjustable universal wing

Figure 7
Figure 2b: X-STOP surgical instruments - Small dilator, Large dilator, Sizing distractor, Implant spacer inserter ,Wing inserter and Hex head driver

Anesthesia

The surgeon may typically use monitored IV conscious mild sedation combined with local anesthesia, allowing a greater selection of higher anesthesia risk patients for this IPD procedure. In this manner, the anesthesiologist or the anesthetist can administer 2 g of Ancef and 8 mg dexamethasone IV at the start of the procedure. Local anesthesia of 1% Xylocaine mixed with 0.25% Marcaine is injected into subcutaneous tissue and paraspinal tissue. The patient should be sedated but remain awake and responsive to verbal commands (conscious sedation). Patients should not be disoriented.

The use of surface EEG monitoring provides added precision of anesthesia delivery, and offers an additional safeguard for patients undergoing this IPD procedure.

Operating Room Setup

Patient positioning (,)

Most of the time the patient is placed on a radiolucent table in the right lateral decubitus position (Figure 3) to allow flexion of the lumbar spine to have patient flex the spine to achieve spinal distraction, which is to be monitored radiographically with the digital C-arm fluoroscopy and image intensifier intraoperatively.

Figure 8
Figure 3: Patient positioning – right lateral decubitus

Operative Technique (,)

Skin incision and localization

After the surgical field is prepped and draped, a 4-8 cm. vertical midline lumbar incision (Figure 4a) is made over the proper spinal processes, under fluoroscopic guidance.

Using an 18 gauge spinal needle, the intraspinal process space for IPD insertion can be identified fluoroscopically (Figure 4b).

Of course, the skin and fascia are infiltrated on both sides of the supraspinous ligament, leaving 1.5 cm. of ligament width intact (Figure 4c). Also posterior rami nerves along the posterior aspect of facets joints and pars are infiltrated. A retractor is placed in after subperiosteal dissection of the tissue.

Figure 9
Figure 4a

Figure 10
Figure 4b:Fluoroscopic view of 18guage spinal needle in between L4 and L5 spinal processes

Figure 11
Figure 4c: Incision of lumbar fascia paraspinally leaving 1.5 cm width of supra spinous ligament

Creating the pilot hole

After incision of the lumbar fascia on either side of the spinal processes and supraspinous ligament, the dissection of the paraspinal muscle is performed, separating the bony spinal processes and lamina. The supraspinous ligament is preserved. With flexion position of the lumbar spine, the interspinous ligament is entered with a small curved dilator by paralleling the dilator to the spinous process until the facet is encountered, then rotating the instrument 90° and interspinous ligament with the tip of dilator into the lowest point of the interspinous ligament (Fig 5a, 5b). Fluoroscopy is used to confirm the position of the dilator (Figure 5c). A larger sized dilator is to follow to dilate the ligamentous opening further.

Figure 12
Figure 5a: Dilator to create a pilot hole anteriorly at interspinous ligament

Figure 13
Figure 5b: Dilator to create a pilot hole anteriorly at interspinous ligament

Figure 14
Figure 5c: Fluoroscopic confirmation of the dilator in the pilot hole anteriorly at interspinous ligament

Application of the sizing distractor (Fig 6a-6c)

The sizing distractor is to be placed in the same opening as far anteriorly toward the lumbar lamina as possible for advancing of the distractor. A finger on the contralateral margin of the interspinous ligament to find the tip of the distractor as it passes through the opening. Once the distractor is in place, squeeze its handle gently and slowly until the resistance is encountered. As the handles are squeezed more and more, resistance should increase. When the supraspinous ligament becomes taut, optimal sizing has been achieved. Fluoroscopy is utilized for confirmation.

Figure 15
Figure 6a: The sizing distractor: closed on left and open on the right

Figure 16
Figure 6b: The sizing distractor opened

Figure 17
Figure 6c: Fluoroscopic confirmation of the sizing distractor: closed on top image and open on the bottom image

Selection of X-STOP® implant

With the handles open, the tip of the sizing distractor is shaping the opening of the spacer of X-STOP® implant. The measurement of the opening for the distractor ranges from 6 mm. to 14 mm. corresponding to the size of the X-STOP® implants available (Figure 7a – 7c). A locking nut at the base of the handle can be adjusted to fix the tips at specific size (Fig 7d).

Figure 18
Figure 7a: X-STOP implants: 6mm – 14mm sizes

Figure 19
Figure 7b: X-STOP implants with a locking universal wing in place

Figure 20
Figure 7c: An implant in the storage cassette

Figure 21
Figure 7d: X-STOP spacer component of the implant is engaged to the handle for insertion

Insertion and securing of X-STOP® implant

The X-STOP® assembly is then removed from the sterilization container with a spacer insertion instrument as instructed for proper insertion into the opening of the interspinous process created. The X-STOP® implant must be placed in the cavity between the spinal processes as anteriorly as possible (Fig 8a-8d).

Figure 22
Figure 8a: Insertion of the X-STOP spacer through the pilot hole at the interspinous ligament

Figure 23
Figure 8b: Side view of insertion of the X-STOP spacer through the pilot hole at the interspinous ligament

Figure 24
Figure 8c: Fluoroscopic confirmations of insertion of the X-STOP spacer through the pilot hole at the interspinous ligament

Posterior position of the implant is incorrect. Once the spacer assembly is secured in place, do not disengage the insertion instrument. Then attachment of the wing assembly is to be performed as instructed on the other side of the spinal processes. Do not disengage the spacer insertion instrument yet. The wing assembly should be adjusted to fit snugly against the lateral surface of the spinous processes. The hex head screwdriver is utilized to lock the screw of the wing with the wing adjusted as medially as possible (Fig 9a-9d). Once the locking screw is tightened to its pre-set torque, it clicks once followed by a second click. Fluoroscopy is used to confirm the position (Fig 10a, 10b). Then remove the hex head screwdriver first followed by removal of the spacer insertion instruments.

Figure 25
Figure 9a: Universal locking wing to be engaged to the handle for application

Figure 26
Figure 9b: Universal locking wing engaged to the handle for attachment onto the spacer

Figure 27
Figure 9c: Universal locking wing engaged to the handle for attachment onto the spacer, closer view

Figure 28
Figure 9d: Universal locking wing engaged to the handle for attachment onto the spacer, and is tightened and locked in place with the hex head screw driver

Figure 29
Figure 10a: Lateral view of fluoroscopic confirmation of the X-STOP implant at L4 – L5 in proper position

Figure 30
Figure 10b: AP view of fluoroscopic confirmation of the X-STOP implant at L4 – L5 in proper position

If necessary hemostasis is accomplished with bi-polar coagulation. The lumbar fascia and skin edges are closed with simple sutures.

Double Level X-STOP® implant surgery

Again, after separation of the soft tissue from the spinal process and lamina, the first X-STOP® should always be inserted at the caudal level and the second X-STOP® should be inserted at the upper level after the first insertion, with the same surgical technique described previously.

When two X-STOP® implants are placed at adjacent levels, usually there is a slight overlap of the superior and inferior implant wing with the shorter wing of the superior implant positioned posteriorly to the long tapered wing of the inferior implant. Rotation of the inferior implant wing would be effectively prevented. Again, fluoroscopy confirms the correct placement of the X-STOP's ® (Fig 11a, 11b).

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Postoperative Care

Postoperative ambulation begins immediately after recovery and the patient is usually discharged one to two hours after the procedure. They may shower and drive a car the following day. Applying an ice pack is helpful. Non steroidal anti-inflammatory drugs (ANSAIDs) are prescribed and mild analgesics and muscle relaxants as needed. Patient returns to usual activities in 10 days to 2 weeks, provided heavy labor and prolonged sitting are not involved. Mild progressive exercise program can begin the day after the surgery.

Physiotherapy is recommended for the first several weeks following surgery to condition the patient and to allow the patient's spine to adjust to the presence of the X-STOP®. Gradual physical activity and build up are recommended for the first six weeks. Avoidance of hyperextension of the spine, no heavy lifting, no stair climbing, no sports such as swimming, golfing, tennis, racquetball, running or jogging. This will avoid damage to the spinal processes. Walking is appropriate as tolerated but not to exceed one hour in duration.

After two weeks, cycling as tolerated. Strenuous activities and swimming may be added at six months. Again, a stress fracture of the spinal process may occur if strenuous physical activity is resumed too soon postoperatively.

Case Illustrations and Outcome

Case 1 –Lumbar stenosis L4-L5 (central and lateral)- single level (Fig 12a-12d): 62 Year old female R.N. for a U.S. Naval Base, with intractable increasing progressive LSS symptoms of neurogenic intermittent claudication (NIC) for more than one year, had pain and weakness of legs after walking 50 feet or more, and was relieved by bending forward or flexion of her spine. Sitting tended to relieve her symptoms by leaning forward. More than 6 months of conservative treatment gave no relief, including physical therapy, medication, injectional therapy and exercise. She was unwilling to undergo open invasive spinal surgery. X-STOP interspinous process decompression implant L4-L5 gave her immediate relief of symptoms. Post operatively, her spinal canal, foraminal, alignment and disc height measurement all significantly improved on imaging studies.

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Case 2 - Lumbar stenosis L3-L4 and L4-L5 (central and lateral) - double level (Fig 13a-13e): 65 year old male respiratory therapist had progressive increasing NIC, pain and weakness of legs when walking 50 feet or more and was relieved by bending forward and flexion of the spine. Sitting tended to relieve his symptoms by leaning forward. More than 6 months of conservative treatment gave no relief, including physical therapy, medication, injectional therapy and exercise. He was unwilling to undergo open invasive spinal surgery. X-STOP interspinous process decompression implants at L3-L4 and L4-L5 gave him immediate relief of symptoms. Post operatively his spinal canal, foraminal, alignment and disc height measurement all significantly improved on imaging studies.

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Discussion

X-STOP®, interspinous process decompression system (IPD) provides a conservative yet effective minimally invasive surgical treatment for the elderly patients suffering from lumbar spinal stenosis with neurogenic intermittent claudication (NIC). X-STOP® treatment is an outpatient surgical procedure, and offers an attractive alternative to both conservative care and more traumatic traditional decompressive lumbar spinal surgery with or without fusion. Patient's clinical outcome and satisfaction are achieved with this minimally invasive X-STOP® system.

The unique design of X-STOP® (IPD) allows it to be implanted with a straight forward approach without fixation to the bone or ligament, and preserves physiological spinal motion (7,8, 47,48,49,50,51,52,53,54). This procedure of X-STOP®/IPD for the treatment of lumbar spinal stenosis combined with transforaminal endoscopic lumbar discectomy/foraminoplasty with laser thermodiskoplasty (55,56,57,58,59,60,61,62,63,64,65,66), can provide further decompression of neural structure and lumbar nerve, and improves the decompressive surgical result(7,8).

Conclusion

Interspinous process decompression system (IPD) X-STOP® procedure for decompression of lumbar spinal stenosis is a minimally invasive, safe and effective treatment alternative to traditional more traumatic lumbar laminectomy and laminotomy procedures with or without fusion. It leads to excellent results, speedier recovery, and significant economic savings. When it is combined with endoscopic lumbar transforaminal discectomy/foraminoplasty (with laser thermodiskoplasty), it can provide further decompression of neural structure and lumbar nerve, and improves the spinal decompressive result. In addition, it also preserves the lumbar spinal motion.

Correspondence to

John C. Chiu, M.D., D.Sc, F.R.C.S Department of Neurospine Surgery California Center for Minimally Invasive Spine Surgery California Spine Institute Medical Center 1001 Newbury Road Newbury Park, CA 91320 Telephone: (805) 375-7900 Fax: (805) 499-4137 Email: chiu@spinecenter.com

References

1. Agency for Healthcare Research and Quality 2001:1-265.
2. Long DM, BenDebba M, Torgerson WS, et al. Persistent back pain and sciatica in the United States: patient characteristics. J Spinal Disord 1996;9:40-58.
3. Fanuele JC, Birkmeyer NJ, Abdu WA, et al. The impact of spinal problems on the health status of patients: have we underestimated the effect? Spine 2000; 25:1509-14.
4. Boden SD, Davis DO, Dina TS, et al. Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation. J Bone Joint Surg Am 1990;72:403-8.
5. Hart LG, Deyo RA, Cherkin DC. Physician office visits for low back pain. Frequency, clinical evaluation, and treatment patterns from a U.S. national survey. Spine 1995;20 1-9.
6. Grazier KL, Holbrook TL, Kelsey JL, et al. The Frequency of Occurrence, Impact, and Cost of Musculoskeletal Conditions in the United States. Chicago, IL: American Academy of Orthopaedic Surgeons, 1984.
7. Deyo RA. Promises and limitations of the Patient Outcome Research Teams: the low-back pain example. Proc Assoc Am Physicians 1995;107:324-8.
8. Chiu J. Interspinous Process Decompression System (X-STOP) for Treatment of Lumbar Spinal Stenosis, AAMISMS 14th Course for New Innovations and Advances in Endoscopic Minimally Invasive Spine Surgery, Thousand Oaks, California, USA 2/14-16/2006, Proceedings: pp. 6-7.
9. Chiu J, Interspinous Process Decompression System (X-STOP) for Treatment of Lumbar Spinal Stenosis, 2006 Annual Meeting of Taiwan Spine Society, National Defense Medical Center - Taipei, Taiwan, Republic of China, 4/15/2006, Proceedings; pp. 17
10. Arbit E, Pannullo S. Lumbar stenosis a clinical review. Clin Orthop 2001; 384:1 37-43.
11. Blau JN, Logue V. The natural history of intermittent claudication of the cauda equina. A long term follow-up study. Brain 1978;101:211-22.
12. Dyck P. The stoop-test in lumbar entrapment radiculopathy. Spine 1 979;4: 89-92.
13. Hurri H, Slatis P, Soini J, eta1. Lumbar spinal stenosis: assessment of long- term outcome 12 years after operative and conservative treatment. Spinal Disord 1998;11:110-5.
14. Iguchi T, Kurihara A, Nakayama J, et al. Minimum 10-year outcome of decompressive laminectomy for degenerative lumbar spinal stenosis. Spine 2000;25
15. Inufusa A, An HS, Lim TH, et al. Anatomic changes of the spinal canal and intervertebral foramen associated with flexion-extension movement. Spine 1996;2 1:24 12-20.
16. Simotas AC. Nonoperative treatment for lumbar spinal stenosis. Clin Orthrop 2001;384:153-61.
17. Jenis LG, An US. Spine update. Lumbar foraminal stenosis. Spine 2000;25: 389-94.
18. Johnsson KE, Rosen I, Uden A. The natural course of lumbar spinal stenosis. Clin Orthop 1992;279:82-6.
19. Jonsson B, Annertz M, Sjoberg C, et al. A prospective and consecutive study of surgically treated lumbar spinal stenosis. Part I: clinical features related to radiographic findings. Spine 1997;22:2932-7.
20. Schonstrom N, Willen J. Imaging lumbar spinal stenosis (review). Radiol Clin North Am 200 1;39:3 1-53.
21. Verbiest H. A radicular syndrome from developmental narrowing of the lumbar vertebral canal. J Bone Joint Surg 1954;36B:230-7.
22. Verbiest U. Fallacies of the present definition, nomenclature, and classification of the stenosis of the lumbar vertebral canal. Spine 1976;1:217-25.
23. Penning L, Wilmink JT. Posture-dependent bilateral compression of L4 or L5 nerve roots in facet hypertrophy. A dynamic CT-myelographic study. Spine 1987;12:488-500.
24. Porter RW. Spinal stenosis and neurogenic claudication. Spine 1996;21: 2046-52.
25. Willen J, Danielson B, Gaulitz A, et al. Dynamic effects on the lumbar spinal canal: axially loaded CT-myelography and MRI in patients with sciatica and/or neurogenic claudication. Spine I 997;22:2968-76.
26. Sortland O, Magnaes B, Hauge T. Functional myelography with metrizamide in the diagnosis of lumbar spinal stenosis. Acta Radiol Suppl 1977; 3 55:42-54.
27. Chung SS, Lee CS, Kim SH, et al. Effect of low back posture on the morphology of the spinal canal. Skeletal Radiol 2000;29:2 17-23.
28. Dong G, Porter RW. Walking and cycling tests in neurogenic and intermittent claudication. Spine 1989;14:965-9.
29. Schonstrom N, Lindah 5, Willen J, et al. Dynamic changes in the dimensions of the lumbar spinal canal: an experimental study in vitro. J Orthop Res 198 9; 7: 115-2 1.
30. Amundsen T, Weber H, Lilleas F, eta1. Lumbar spinal stenosis. Clinical and radiologic features. Spine 1 995;20: 1178-86.
31. Ciol MA, Deyo RA, Howell E, et al. An assessment of surgery for spinal stenosis: time trends, geographic variations, complications, and reoperations. JAm Geriatr Soc 1996;44:285-90.
32. Deyo RA, Cherkin DC, LoeserJD, etal. Morbidity and mortality in association with operations on the lumbar spine. The influence of age, diagnosis, and procedure. J Bone Joint Surg Am 1992;74:536-43.
33. Markwalder TM. Surgical management of neurogenic claudication in 100 patients with lumbar spinal stenosis due to degenerative spondylolisthesis. Acta Neurochir (Wien) 1993;120:136-42.
34. Stucki G, Daltroy L, Liang MH, et al. Measurement properties of a self- administered outcome measure in lumbar spinal stenosis. Spine 1996;21: 796-803.
35. Neumann P, Wang Y, Karrholm J, et al. Determination of inter-spinous process distance in the lumbar spine. Evaluation of reference population to facilitate detection of severe trauma. Fur Spine J 1999;8:272-8.
36. KatzJN. Spinal Stenosis Data. Boston: Harvard Medical School, 2003:1-33.
37. Gunzburg R, Keller TS, Szpalski M, et al. Clinical and psychofunctional measures of conservative decompression surgery for lumbar spinal stenosis: a prospective cohort study. Fur SpineJ 2003;12:197-204.
38. Johnsson KE, Uden A, Rosen I. The effect of decompression on the natural course of spinal stenosis. A comparison of surgically treated and untreated patients. Spine 1991;16:615-9.
39. Atlas SJ, Keller RB, Robson D, et al. Surgical and nonsurgical management of lumbar spinal stenosis: foui-year outcomes from the Nlaine lumbar spine study. Spine 2000;25:556-62.
40. Benz RJ, Ibrahim ZG, Afshar P, et al. Predicting complications in elderly patients undergoing lumbardecompression. C Orthop 2001;384: 116-21.
41. Khoo LT, Fessler RG. Microendoscopic decompressive laminotomy for the treatment of lumbar stenosis. Neurosurgery 2002;51(Supplement 2):146-54.
42. Reindl R, Steffen T, Cohen L, eta1. Elective lumbar spinal decompression in the elderly: is it a high-risk operation? Can J Surg 2003;46:43-6.
43. Postacchini F, Cinotti G, Perugia D, et al. The surgical treatment of central lumbar stenosis. Multiple larninotomy compared with total laminectomy. J Bone Joint Surg Br 1993;75:386-92.
44. Fox MW, Onofrio BM, Hanssen AD. Clinical outcomes and radiological instability following decompressive lumbar laminectomy for degenerative spinal stenosis: a comparison of patients undergoing concomitant arthrode sis versus decompression alone. J Neurosurg 1996;85P93-802.
45. Kalbarczyk A, Lukes A, Seiler RW. Surgical treatment of lumbar spinal stenosis in the elderly. Acta Neurochir (Wien) 1998;140:637-41.
46. Katz JN, Lipson SJ, Chang LC, et al. Seven-to 10-year outcome of decompressive surgery for degenerative lumbar spinal stenosis. Spine 1996;21: 92-8.
47. Siddiqui M, Nicol M, Karadimas E, Smith F, Wardlaw D. The Positional Magnetic Resonance Imaging Changes in the Lumbar Spine Following Insertion of a Novel Interspinous Process Distraction Device. Spine 2005;30;23: pp 2677-2682
48. Richards J, Majumdar S, Lindsey D, Beaupré G, Yerby S. The Treatment Mechanism of an interspinous Process Implant for Lumbar Neurogenic Intermittent Claudication. Spine 2005;30;7: pp. 744 -749
49. Tatwar V, Lindsey D, Fredrick A, Hsu K, Zucherman J, Yerby S.. Insertion loads of the X STOP interspinous process distraction system designed to treat neurogenic intermittent claudication. European Spine Journal © Springer-Verlag 2005 10.1 007/s00586-005-0891 -9
50. Zucherman JF, Hsu KY, Hartjen CA, Mehalic TF, et al. A Multicenter, Prospective, Randomized Trial Evaluating the X STOP Interspinous Process Decompression System for the Treatment of Neurogenic Intermittent Claudication - Two-Year Follow-Up Results. Spine 2005;30:12 pp 1351-1358
51. Fuchs P, Lindsey D, Hsu K, MD, Zucherman J, Yerby S. The Use of an Interspinous Implant in Conjunction With a Graded Facetectomy Procedure. Spine 2005;30:11, pp 1266-1272
52. Lindsey D, Swanson K, Fuchs P, Hsu K, Zucherman J, Yerby S. The Effects of an Interspinous Implant on the Kinematics of the Instrumented and Adjacent Levels in the Lumbar Spine. Spine 2003;28;19: pp 2192 - 2197
53. Swanson K, Lindsey D, Hsu K, Zucherman J, Yerby S. The Effects of an Interspinous Implant on Intervertebral Disc Pressures. Spine 2003;28;1: pp 26-32
54. Wiseman C, Lindsey D, Fredrick A, Yerby S. The Effect of an Interspinous Process Implant on Facet Loading During Extension. Spine 2005:30;8: pp 903-907
55. Chiu J, Clifford T, Princenthal R, Junctional Disc Herniation in Post Spinal Fusion Treated with Endoscopic Spine Surgery: In, Szabo Z, Coburg AJ, Savalgi R, Reich H, Yamamotto M, eds. Surgical Technology International XIV, UMP, San Francisco, CA 2005: p.305-315
56. Chiu J, Digital Technology Assisted Minimally Invasive Spinal Surgery (MISS) for Spinal Motion Preservation. In: Lemke H.U, Vannier MN, Invamura RD, eds. Computer Assisted Radiology and Surgery. Amsterdam, San Diego, Oxford, London: Elsevier Medical Publisher; 2004, pp 461-466.
57. Chiu J. Endoscopic Lumbar Foraminoplasty In: Kim D, Fessler R, Regan J, eds. Endoscopic Spine Surgery and Instrumentation. New York: Thieme Medical Publisher; 2004: Chapter 19, pp 212-229.
58. Chiu, J., Savitz, MH. Use of Laser in Minimally Invasive Spinal Surgery and Pain Management. In: Kambin P, ed. Arthroscopic and Endoscopic Spinal Surgery - Text and Atlas. Second Edition. New Jersey: Humana Press; 2005: Chapter 13, pp 259-269.
59. Chiu J, Clifford T. Transforaminal Endoscopic Decompression: In: Savitz M, Chiu J, Rauschning W, Yeung A, eds. The Practice of Minimally Invasive Spinal Technique: 2005 Edition, AAMISS Press, New City, New York, 2005: 60:p 435-441
60. Chiu J, Stechison M, Percutaneous Vertebral Augmentation and Reconstruction with an Intervertebral Mesh and Morecelized Bone Graft: In, Szabo Z, Coburg AJ, Savalgi R, Reich H, Yamamotto M, eds. Surgical Technology International XIV, UMP, San Francisco, CA 2005: p.287-296
61. Chiu J, Transforaminal Endoscopic Laser Microdecompression for Herniated Lumbar Discs and Spinal Stenosis: In; Khamlichi A, eds. Reprinted from 13th World Congress of Neurological Surgery, Marrakesh, 6/19-24/2005, International Proceedings, Medimond, Bologna, Italy, pp. 77-82
62. Chiu J, Posterolateral Endoscopic Thoracic Microdiscectomy, World Spine III: The Third Interdisciplinary Congress on Spine Care, Rio de Janeiro, Brazil, 7/31-8/3/2005, Proceedings: pp. 2
63. Chiu J, Clifford T, Greenspan M. Percutaneous microdecompressive endoscopic cervical discectomy with laser thermodiskoplasty. Mt Sinai J. of Med 2000;67:278-282.
64. Chiu, J, Endoscopic Assisted Lumbar Microdecompressive Spinal Surgery With A New SMART Endoscopic Spine System, 5th Global Congress and Hands-on Course on Minimally Invasive Spinal Techniques, Hasbrouck Heights Hilton, New Jersey/New York City, USA 12/15-18/2005, Proceedings; pp.12-13.
65. Chiu J, Yeung A, Lekht Z. Monitoring During Percutaneous Endoscopic Discectomy: In: Savitz M, Chiu J, Rauschning W, Yeung A, eds. The Practice of Minimally Invasive Spinal Technique: 2005 Edition, AAMISS Press, New City, New York, 2005: 90:p597-602
66. Chiu J, Savitz M. Operating Room of the Future for Spinal Procedures In: Savitz M, Chiu J, Rauschning W, Yeung A, eds. The Practice of Minimally Invasive Spinal Technique: 2005 Edition, AAMISS Press, New City, New York, 2005: 98:p645-648

Author Information

John C. Chiu, M.D., F.R.C.S., DSc
Director, Department Neurospine Surgery, Department of Neurospine Surgery, California Center for Minimally Invasive Spine Surgery, California Spine Institute Medical Center

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