1	Interspinous Process Decompression System (X-STOP) for Treatment of Lumbar Spinal Stenosis John C. Chiu, M.D., FRCS, D.Sc. Chief Neurospine Surgery California Spine Institute Thousand Oaks, California, USA
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3	Introduction: Lumbar Spinal Stenosis (LSS) is the most common reason for back surgery in people over the age of 50 in the United States 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
4	Introduction: The degenerative process is very slow Symptoms may remain unchanged or even improve in majority of patients However, patients with severe symptoms will tend to deteriorate
5	Introduction: Low back pain Pain and weakness in the legs that limit Standing and walking Self-supporting daily activities Work, social and recreational activities
6	Introduction: Extension provokes symptoms Pain/weakness in the legs
7	Introduction:
8	Introduction:
9	Introduction: Canal narrowing caused by: Disc Bulge Anterior offset of L4 over L5 with Hypertrophy of the ligamentum flavum
10	Introduction: Disc bulge This & enfolded Ligamentum flavum Narrowed Trifoil Canal Narrowed Lateral Recess Hypertrophied Facets Neural Compression
11	Introduction: Narrowing of neural foramen at L4-5 Arrow points to nerve root in the superior aspect of the foramen
12	Introduction:
13	Introduction: Lack of activity may lead to Obesity General physical deterioration Depression/other psychological problems Symptom relief In flexion When sitting
14	LSS Treatment Options Conservative Treatment Mild to Moderate Symptoms Non-operative care: Analgesics and muscle relaxing medications NSAIDs Self-limiting activities of daily living/use of shopping cart and leaning forward at the desk Exercise & weight reduction Physical therapy with flexion exercise Bracing may be helpful Epidural steroid injections
15	LSS Treatment Options Surgical Treatment More Severe Symptoms Decompressive Surgery Foraminotomy Laminotomy Laminectomy May be accompanied by fusion Interspinous process decompression implants IPD (X-STOP) for treatment of LSS as an option
16	Introduction: Traditional open spinal surgery and spinal fusion surgery are associated with significant local morbidity and long-term convalescence, with greater expense Therefore, the search for less invasive and Minimally Invasive Spinal surgery (MISS) began Explosive advances in bio technology, bio computer/digital science and new innovative surgical advances have propelled modern less invasive and minimally invasive surgery in all areas (including less invasive and minimally invasive spine surgery) Less invasive and MISS aims to reduce tissue trauma, preventing iatrogenic problems and preserving spinal segmental motion and improves results
17	Introduction: X-STOP, interspinous process decompression system (IPD) provides a conservative yet effective minimally invasive surgical treatment for 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
18	Interspinous Process Decompression System – IPD - (X-STOP) - for treatment of LSS The surgical indication for Lumbar Spinal Stenosis (LSS) with IPD: Age 50 or older Significant neurogenic intermittent claudication (NIC) with relief in flexion of lumbar spine Evidence of LSS with x-ray, MRI scan and/or CT scan 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
19	Interspinous Process Decompression System – IPD - (X-STOP) - for treatment of LSS Contra-indication: Allergic to titanium or titanium alloy Significant instability of lumbar spine An ankylosed segment in affected level Acute fracture of spinal processes or pars interarticularis Significant scoliosis with Cobb angle greater than 25° With significant cauda equina syndrome defined as neural compression Diagnosed with severe osteoporosis in the spine more than 2.5 SD below the mean Acute systemic infection or infection localized to the site of implant
20	X-STOP Surgical Technique: Right lateral decubitus Permit flexion Enable proper implant sizing Using arm board Using radiolucent table and C-arm
21	Surgical Technique: Prepare the patient with mild IV conscious sedation: Patient can respond to commands Local anesthesia mixture of Xylocaine and Marcaine for the skin fascia and posterior rami structures
22	IPD - X-STOP Implant Device: This implant device consists of a fixed wing spacer implant with adjustable universal wing and tapered expander/dilator device and locking screw 2^nd Locking adjustable wing to complete the device
23	X-STOP Surgical Instruments: Small dilator Large dilator Sizing distractor Implant spacer inserter Wing inserter Hex head driver
24	Surgical Procedure: 5-8 cm. lumbar incision in the midline
25	Surgical Procedure: Identify and confirm the level with 18 ga. spinal needle
26	Surgical Procedure: Incise the fascia along the supraspinous ligament: Preserve the supraspinous ligament leaving 1.5-2 cm. between the lumbar fascia incision along the spinal processes bilaterally
27	Surgical Procedure: Dissection bluntly to the lamina Elevating the paraspinous musculature bilaterally Use a Cobb elevator to dissect along the bone to the lamina laterally Start dissection in the lower right side
28	Surgical Procedure: Insert dilator at 90° along the spinal process and rotate the dilator 90° until it contacts the interspinous ligaments as anteriorly as possible
29	Surgical Procedure: Insert the dilator into interspinous ligament Illustration and x-ray confirmation Trim facet if hypertrophic facet prevents sufficiently anterior positioning of the dilator and instruments Redundant facet tissue, hypertrophic, should be excised Trim facets if necessary
30	Surgical Procedure:
31	Surgical Procedure:
32	Surgical Procedure: Select implants with a fixed wing spacer implant adjustable universal wing tapered expander locking screw, 6 mm. to 14 mm.
33	Surgical Procedure: Pull thumb button of handle for removal of implant from the cassette box Align pins with holes in the main body of the spacer Release button to lock spacer assembly to the handle
34	Surgical Procedure: Position implant properly Align the spacer assembly instrument handle with the interspinous space Orient the tissue expander at 45° to the spinal process to make insertion easy Use the left index finger to guide implant through hole made by the sizer Leave insertion instrument attached during fluoroscopy
35	Surgical Procedure: Remove adjustable wing from cassette Pull the thumb button to open tab Align pin with hole Release the button to lock the wing to the handle
36	Surgical Procedure: Visualize the threaded hole above the spinal process Excessive tissue must be excised to visualize the threaded hole Lifting the spacer insert handle to help exposure the screw hole Align and attach the universal wing onto the spacer assembly Guide the locking screw into the threaded hole
37	Surgical Procedure: The two instrument handles nested and fitted together Once the screw is engaged, turn the end of the wing instrument handle clockwise approximately 3 rotations Release the universal wing by retracting the thumb lever Do not yet disengage the spacer assembly insertion instrument
38	Surgical Procedure: Adjust and tighten the wing with a hex head screwdriver until you hear a click twice
39	Surgical Procedure: Adjust and tighten the wing Adjust the wing assembly to fit snugly against the lateral surface of the spinal process Tighten the locking screw with hex head screwdriver until it clicks twice. Remove the hex head screwdriver leaving the spacer assembly instrument in place until final confirmation of the implant position.
40	Surgical Procedure: Confirm final position with lateral and AP fluoroscopic views
41	Case Illustrations: Case I 62 Year old R.N. for US Naval Base Intraticable increasing progressive LSS symptoms – NIC more than one year with pain and weakness of legs walking 50 feet or more, and is relieved by bending forward or flexion of the spine Sitting tends 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 Unwilling to undergo open invasive spinal surgery XSTOP interspinous process decompression implant L4-L5 gave relief Post op spinal canal, foraminal, alignment and disc height measurement all significantly improved
42	Case I Radiographic evidence of LSS L4-L5 on X-ray and MRI
43	Surgical Procedure:
44	Case II 65 year old male respiratory therapist with progressive increasing NIC, pain and weakness of legs when walking 50 feet or more and is relieved by bending forward and flexion of the spine Sitting tends 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 Unwilling to undergo open invasive spinal surgery XSTOP interspinous process decompression implants and L3-4 and L4-5 gave relief Post op spinal canal, foraminal, alignment and disc height measurement all significantly improved
45	Case II Preoperative Radiographic/MRI evidence of severe LSS L3-L4 and L4-L5 on MRI
46	Surgical Procedure:
47	Discussion and Comment: LSS and NIC have been limited to a choice of treatment of non surgical therapies and traditional more traumatic open decompressive spinal surgery with or without spinal fusion Interspinous process decompression system (IPD) (X-STOP) was developed to provide a minimally invasive decompressive surgical treatment When IPD treatment combined with MISS endoscopic transforaminal lumbar discectomy/foraminoplasty (with laser thermodiskoplasty) can provide further decompression of neural structure and LSS and improves the surgical result
48	Discussion and Comment: The surgical indication of X-STOP surgery for LSS are: Age 50 or older Significant neurogenic intermittent claudication (NIC) with relief in flexion of lumbar spine Evidence of LSS with x-ray, MRI scan and/or CT scan 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
49	Discussion and Comment: Outpatient surgery with less trauma Safe under IV conscious sedation Insignificant blood loss Little or no resection of bone or soft tissue Low incidence of infection, superficial Low incidence of erosion, migration and expulsion or even spinal process fracture Virtually no chance of dural tear or neurological complication Does not create instability Speedier recovery Implant can be removed Does not preclude other treatment options
50	Discussion and Comment:
51	Discussion and Comment: The author’s personal experience with this out patient procedure has been outstanding X-STOP system provides excellent symptomatic relief of pain and NIC related to LSS with much less trauma Satisfaction score (96%) and significant improved clinical outcome with visual analogue pain scale (VAS), Oswestry disability score/index (ODI), were achieved
52	Conclusion: Interspinous process decompression system (IPD) X-STOP, provides a conservative yet effective MISS treatment for patients suffering from significant symptomatic LSS 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
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