The Internet Journal of Spine Surgery ISPUB.COM Volume 2 Number 1

Percutaneous and Reconstruction with an Intravertebral Mesh and Morcelized Graft J Chiu, M Stechison

Citation J Chiu, M Stechison. Percutaneous Vertebral Augmentation and Reconstruction with an Intravertebral Mesh and Morcelized Bone Graft. The Internet Journal of Spine Surgery. 2004 Volume 2 Number 1.

Abstract This presentation is to discuss the percutaneous outpatient vertebral augmentation (VA) and reconstruction with a polyethylene intravertebral mesh (OptiMesh® Spineology, Inc., Stillwater, MN, USA) and biologic morcelized bone graft, the surgical indications, operating technique, case illustrations and clinical outcome. In the past vertebroplasty and kyphoplasty have provided excellent pain relief for vertebral compression fracture (VCF), but with a high incidence of complication; i.e., leakage of Polymethylmethacrylate (PMMA) into spinal canal or vasculature, cardiopulmonary complication, and adjacent vertebral fracture.

This percutaneous VA system, is designed, developed, and used for VCF treatment without above complications, and is a true biologic vertebral reconstruction. An OptiMesh® consists of, multi-strand polyester mesh or sac to be packed with specially ground bone chips or morcelized bone chips inside the mesh device to create a hyperdensed graft pack for restoring height resulting in pain relief.

This minimally invasive outpatient percutaneous OptiMesh® VA provides an efficacious and controlled delivery mechanism to stabilize and treat painful osteoporotic, traumatic and neoplastic VCF. In addition it can easily be used as an excellent intravertebral spacer and for intravertebral /fixation.

INTRODUCTION patients. 4 In greater than 50% of osteoporotic patients with Approximately 700,000 patients per year, in the United more than one VCF, activities of daily living cannot be States, are afflicted with vertebral compression fracture performed without assistance.5 The resulting spinal deformity from VCF is the increased risk factor for hip (VCF) secondary to . 1,2,3,4 The lifetime risks of symptomatic vertebral compression fracture (VCF) fracture, cardio pulmonary complication, and physical secondary to osteoporosis is 16% for females, and 5% for debilitation from inactivity.1,2,3, 6,7,8,9,10 males. Osteoporotic VCF survival rate, five years after Many other potential consequences are obvious with chronic diagnosis made, is 61%. VCF affects 25% of females over severe pain, decreased lung function, inactivity, severe the age of 50 and 40% of females over the age of 80 , , , . 1 2 3 4 anxiety, and depression with 23% increase in mortality rate. VCF is defined as the reduction of vertebral body (VB) , , , , height by 15% or greater and can be classified by the degree 1 2 3 10 14 and type of deformity, which includes wedge, biconcavity, The goals of vertebral augmentation are; correction of VB and compression fractures. 3 The most commonly deformity, significant reduction of pain, improvement of compressed VB levels are lower thoracic vertebrae, L1 and quality of life, to improve ability to perform daily living

L4. 3Of course, there is also post-traumatic type of VCF and activities and to lower complication rate, e.g., hip fracture, other types of pathology causing VCF. Traditional cardio pulmonary complication and physical debilitation conservative treatment of vertebral body compression from inactivity, subsequent adjacent VCF and reduced fracture includes analgesics, immobilization, muscle mortality rate. 1,2,3, 10 relaxant, physiotherapy, and external bracing, if indicated. 3 The resulting painful collapse and leads to the Historically, vertebroplasty and kyphoplasty have provided development of chronic pain syndrome in one-third of these excellent pain relief for VCF, but with very high incidence

1 of 9 Percutaneous Vertebral Augmentation and Reconstruction with an Intravertebral Mesh and Morcelized Bone Graft of complication, i.e., leakage of Polymethylmethacrylate ABSOLUTE CONTRA-INDICATION IN THE (PMMA) into spinal canal or vasculature, cardiopulmonary FOLLOWING SITUATIONS complication, and adjacent vertebral fracture. Therefore, 1. Patient with painless asymptomatic stable VCF vertebral augmentation (VA) is indicated for painful VCF. 2. Massive “burst” osteoporotic or non osteoporotic 1,2,3 fractures A percutaneous vertebral augmentation system with a polyethylene mesh sac (OptiMesh® Spineology, Inc., 3. Patient with fracture that is clearly responding to Stillwater, MN) and morcelized bone graft, is designed, medical therapy developed and used for VCF treatment without above 4. Osteomyelitis of target complications, and is a true biologic vertebral reconstruction. This provides excellent pain relief and fewer 5. Prophylactic treatment with no evidence of fracture technological risks and is osteoconductive and osteoinductive. 6. Uncorrected coagulation disorder or bleeding disorder With accumulated surgical experience in percutaneous endoscopic minimally invasive spinal surgery, this vertebral RELATIVE CONTRA-INDICATION IN THE augmentation procedure can be easily performed FOLLOWING SITUATIONS percutaneously with minimal or no blood loss, for vertebral 1. Medically high risk patient or unstable patient body reconstruction, for excellent pain relief, and to improve quality of life. 11,12,13 2. Patient with retropulsed fragment causing spinal canal compromise of greater than 20% INDICATIONS Treatment criteria for this polyethylene mesh sac and 3. Restless patient, unable to lie prone for the entire morcelized bone graft (OptiMesh®) percutaneous vertebral procedure under IV conscious sedations augmentation system are: 4. Patient with pain due to herniated spinal disc, facet 1. Treatment of painful osteoporotic or post-traumatic arthropathy, spinal stenosis or degenerative change vertebral compression fracture and secondary and not due to VCF kyphosis 5. Pathological fracture with tumor significantly 2. Intractable pain in a focal band like radiation that is extending into the spinal canal worse with weight bearing and is relieved with rest or in a recumbent position OPERATING ROOM SET UP

3. Intractable pain unrelieved by analgesics and Both local anesthesia (under IV conscious sedation) and narcotics general anesthesia can be used. It is Author's preference to use local anesthesia with IV conscious sedation for a single 4. Painful compression fracture of vertebra due to level, and general anesthesia for multiple levels. osteoporosis, aggressive hemangioma, 15 metastatic disease, osteogenic imperfecta, trauma PATIENT POSITIONING (FIG. 1A, B, C): or vertebral osteonecrosis In prone as for thoracic or lumbar surgery on a radiolucent Jackson table or a Kambin frame. Digital C-arm 5. Chronic trauma fracture with non-union of fracture with image intensifier is to be utilized for monitoring of the fragments procedure for radiographic visualization of the position and surgical instrumentation. The patient is prepped and draped 6. Internal stabilization of unstable post-traumatic in the usual sterile fashion. vertebral compression fracture

7. Patient with multiple compression fractures with risk of pulmonary compromise

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Figure 1 para-pedicularly (Fig. 3a), approximately 45° angle to Figure 1: Patient positioning contact the superior lateral quadrant of the pedicle and vertebral body junction. The portal of entry is extrapedicular approach (Fig. 3 b,c), with stylette inserted just lateral and superior to the pedicle on the lateral view, centered within the pedicle although anatomically it would be lateral to it. On the PA view the needle should appear to enter the bone at SURGICAL TECHNIQUE the superior lateral aspect of the vertebral body with a trajectory aiming inferomedially, approximately 20 degrees IMPLANT DEVICE (FIG. 2): towards the spine process, and toward the desired target A polyethylene mesh sac (OptiMesh®) consists of three position as “50/50 image” on AP view (Fig. 4a). On the dimension multi-strand polyester mesh or sac to be packed lateral view, the trajectory is directed toward the anterior with bony allograft inside the polyethylene mesh with inferior aspect of the vertebral body and toward the desired specially ground bone chips or morcelized bone chips inside target position as “50/50 image” on lateral view (Fig. 4b). the mesh sac device creating a hyperdensed graft pack for The spinal cord is less at risk with a more lateral starting restoring height resulting in pain relief. position than the transpedicle approach, especially at the thoracic spine region. Lateral deviation risks pneumothorax. Figure 2 Also lateral vertebral body violation can injure the segmental Figure 2: Polyethylene mesh sac (OptiMesh™) and 2 sac packed with bone chips artery, great vessels or lungs. Figure 3 Figure 3: Portal of entry and trajectory for the guide pin for desired position “50/50 image”

Figure 4 Figure 4: Guide pin trajectory toward and beyond desired target position of “50/50 image” (red dot) under fluoroscopy GRANULAR MECHANICS Granules flow like liquid when uncontained but act like solid when contained. The granular packs are known to be porous even in their most rigid state.

SURGICAL PROCEDURES INSTRUMENTS AND PREPARATION: SURGICAL INSTRUMENTS ARE DEMONSTRATED IN THE ILLUSTRATIONS. The procedure is performed under fluoroscopic guidance with a guide pin to the desired target position as “50/50 image” on AP and lateral view of the spinal vertebra. A dilator is inserted over the guide pin and impacted into the Usually, the stylette or the guide pin starts approximately vertebra (Fig. 5 a,b). Then a working channel or cannula 5-10cm from mid-line (thoracic 5-7cm and lumbar 8-10cm) (access portal) is placed over the dilator and secured to the

3 of 9 Percutaneous Vertebral Augmentation and Reconstruction with an Intravertebral Mesh and Morcelized Bone Graft metal frame connected to the operating table (Fig. 6a,b,c). Figure 8 Figure 8: Shaper Figure 5 Figure 5: Dilator of the guide pin impacted onto the vertebra

The polyethylene mesh sac is inserted through the working Figure 6 channel (access portal) into the vertebral cavity (Fig. 9 a, b). Figure 6: Working cannula placed over the dilator Then the mesh is filled with morcelized bone graft from diverted fill tubes (Fig. 10 a, b, c, d, e).

Figure 9 Figure 9: Mesh sac is inserted through the working channel (access portal) into the vertebral cavity

After removal of the guide pin and dilator, a drill was utilized to create a cavity in the vertebra (Fig. 7a,b,c).

Figure 7 Figure 7: Drilling the vertebra

The polyethylene mesh sac (OptiMesh®) size is based on the anticipated height, drill depth, and the cavity created by the shaper (Fig. 8a), after drilling to insure good fit for the cavity created and mesh pore distension (Fig. 8b).

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Figure 10 Figure 12 Figure 10: Filling the OptiMesh® with morcelized bone Figure 12: Vertebral augmentation procedure – illustrations graft (implant) step by step

Step 1 (Fig. 12a) Insert the guide pinDilator placed over the guide pin

Step 2 (Fig. 12b) Access portal over dilatorDilator and guide pin are removedDrill initiates cavity creation

Step 3 (Fig. 12c) Cavity is enlarged with shaper

Step 4 (Fig. 12d) Insert OptiMesh® implant or mesh sac After compacting the mesh with the bone chips, the neck of the mesh sac is crimped (Fig. 11 a,b). The instruments are Step 5 (Fig. 12e) OptiMesh® filled with morcelized bone removed and the wound is closed. graft

Figure 11 Step 6 (Fig. 12f) OptiMesh® is detachedInstruments Figure 11: The mesh sac is crimped at the neck and is removed detached, before the instruments are removed. CASE ILLUSTRATIONS Case 1 (Fig. 13a-e) is a 70 year old male with severe thoracolumbar pain on activity from T10 post-traumatic osteoporotic vertebral compression fracture. Under conscious sedation and local anesthesia, OptiMesh® vertebral augmentation was performed as an outpatient. The patient had immediate excellent postoperative pain relief (VAS scores) and was discharged from the surgical unit in two hours. ILLUSTRATIONS STEP-BY-STEP (FIG. 12A-F)

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Figure 13 days. Seven weeks after surgery her CT scan demonstrated Figure 13: 70 year old male with severe thoracolumbar pain the evidence of osteointegration of the bone graft at T7 on activity from T10 osteoporotic post-traumatic vertebral vertebra. compression fracture (VCF). Figure 15 Figure 15: 70 year old female manager with painful post- traumatic osteoporotic wedge T7 vertebral compression fracture (VCF)

Case 2 (Fig. 14a-d) is a 72 year old female with severe thoracolumbar pain from T12 post-traumatic osteoporotic vertebral compression fracture. IV conscious sedation and local anesthesia were utilized for OptiMesh® vertebral augmentation with immediate significant postoperative pain relief right after the outpatient surgery and was discharged from the surgical unit in one hour.

Figure 14 Figure 14: 72 year old female with severe thoracolumbar pain from T12 post traumatic osteoporotic vertebral compression fracture (VCF).

DISCUSSION Painful osteoporotic fractures significantly reduce quality of life and are a significant risk factor for hip fracture, for secondary pulmonary insufficiency, physical disability from

inactivity and increased mortality among the VCF patients.8,

10The economic burden related to management of the osteoporotic VCF has been estimated to be $700 million per

year. 9 While success in producing pain relief has been reported by many authors using PMMA techniques, numerous problems have developed. There is a risk of leakage into the disc or paraspinal region, into spinal neural foramen and spinal canal causing secondary significant Case 3 (Fig. 15a-e) is a 71 year old female manager with neurological complications necessitating immediate surgery. painful post-traumatic osteoporotic compressive T7 fracture. 16 Some have resulted in permanent neurological deficit in As an outpatient under IV conscious sedation and local spite of immediate evacuation of PMMA. Interestingly, the anesthesia, OptiMesh® vertebral augmentation was incidence of compressive complication from cement leakage performed. She had immediate postoperative almost is higher with kyphoplasty than vertebroplasty, perhaps complete pain relief (VAS) and returned to work in three related to higher incidence of surgical pedicle fracture. Also, hypotension may be produced by absorption of PMMA

6 of 9 Percutaneous Vertebral Augmentation and Reconstruction with an Intravertebral Mesh and Morcelized Bone Graft occasionally from its cardiotoxic and arrhythmogenic 2. Due to the osteoconductive and osteoinductive properties. Deaths have been documented from these properties, it can be used to create biologic procedures23 pulmonary embolism and fat embolism have vertebral reconstruction. This mesh containment also been reported.23,24 eliminates complications of intra-vascular embolism, spinal canal encroachment, from Of course, incidence of adjacent level fracture from VCF is PMMA application in Vertebroplasty and as high as 52% after vertebroplasty, 29% for kyphoplasty are Kyphoplasty, and subsequent adjacent VCF. The significant. 7,8,9,10, 14,15,16,17,18,19,20,21,22,23,24 adjacent vertebra integrity should be more protected by the construct with a similar elasticity Minimally invasive percutaneous vertebral augmentation and physical characteristics of the morcelized with intravertebral polyethylene mesh sac (OptiMesh®) is a bone, more matched to that of adjacent bone than new fill material containment technology for use in the PMMA. minimally invasive vertebral biologic reconstruction procedure. It consists of a polyethylene mesh sac that is 3. Patient satisfaction and excellent clinical outcome introduced into the vertebral body and filled with morcelized are achieved with this minimally invasive vertebral bone allograft. Compaction of the allograft bone inside the augmentation technique. OptiMesh® device creates a hyperdense graft pack capable of reducing the fracture and restoring height by realigning References fracture fragments resulting in pain relief and functional 1. Garfin S, Reiley M, Wong W, et al., Vertebroplasty and improvement. Kyphoplasty. In: Savitz MH, Chiu JC, Yeung AD, eds. The Practice of Minimally Invasive Spinal Technique. Obvious advantages of percutaneous vertebral augmentation Richmond, VA: AAMISMS Education, LLC; 2000: pp with an intravertebral polyethylene mesh sac (OptiMesh®) 249-260 2. Bono C, Garfin S, Kyphoplasty. In Kim D, Fessler R, filled with morcelized bone graft, over vertebroplasty and Regan J, eds. New York: Thieme Medical Publisher; kyphoplasty are numerous. It includes no risk of leakage of December 2004: Chapter 30, pp 328-337. PMMA into the spinal canal causing neurological 3. Do HM, Kim B, Percutaneous Vertebroplasty for Painful Vertebral Body Compression Fractures Endoscopic Spine complication or into the vasculature system, with cardio- Surgery and Instrumentation. In Kim D, Fessler R, Regan J, pulmonary complications including cardio-toxicity, eds. New York: Thieme Medical Publisher; December 2004: Chapter 29, pp 315-327 arrhythmia, and pulmonary embolism, and even lower risk 4. Riggs BL, Melton U III. The worldwide problem of of fatty embolism, indication for broader spectrum of osteoporosis. Insights afforded by epidemiology. Bone pathology and the prospect of bone fusion and integration of 17:505S - 511S 5. Leidig-Bruckner G, Minne HW, Schlaich C, et al. Clinical the prosthesis over time by using bone rather than PMMA. grading of spinal osteoporosis: quality of life components The physical properties of the bone graft more closely and spinal deformity in women with chronic low and women with vertebral osteoporosis. J Bone Miner Res approximate those to the adjacent vertebral segment in 12:663-675, 1997 density tend to avoid subsequent adjacent vertebral fracture. 6. Yuan H, Brown C, Phillips F, Osteoporotic Spinal The bony construct is also osteo-conductive and osteo- Deformity: A Biomechanical Rationale for the Clinical Consequences and Treatment of Vertebral Body inductive to accomplish biologic vertebral reconstruction. It Compression Fractures, J Spinal Disord Tech 17:236-242, can be used to treat painful spinal hemangioma, other 2004 7. Leech JA, Dulberg C, Kellie S et al. Relationship of lung osteolytic vertebral lesions and other types of VCFs. function to severity of osteoporosis in women. Am Rev Respir Dis 141:68-71, 1990 CONCLUSION 8. Schlaich C, Minne HW, Bruckner T et al. Vertebral fractures and mortality in older women; a prospective study. 1. Minimally invasive percutaneous vertebral Study of Osteoporotic Fractures Research Group. Arch augmentation with intravertebral mesh Intern Med 159:1215-1220, 1998 (OptiMesh®) and bone graft provides an 9. Mefton LJ, III. Epidemiology of spinal osteoporosis. Spine 22:2S-11S, 1997 efficacious and controlled delivery mechanism to 10. Fribourg D, Tang C, Sra P, et al. Incidence of subsequent stabilize and treat painful osteoporotic, traumatic vertebral fracture after kyphoplasty- Spine 29:2270-2276. 2004 and neoplastic VCF, and also avoids serious 11. Chiu J, Digital Technology Assisted Minimally Invasive complications from PMMA. Spinal Surgery (MISS) for Spinal Motion Preservation. In: Lemke H.U, Vannier MN, Invamura RD, eds. Computer Assisted Radiology and Surgery. Amsterdam, San Diego,

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Oxford, London; Elsevier Medical Publisher; 2004, pp compression fractures after kyphoplasty. Spine 461-466. 29:2120-2125, 2004 12. Chiu, J., Posterolateral Endoscopic Thoracic 19. Grados F, Depriester C, Cayrolle G, et al. Long-term . In Kim D, Fessler R, Regan J, eds. Endoscopic observations of vertebral osteoporotic fractures treated by Spine Surgery and Instrumentation. New York: Thieme percutaneous vertebroplasty. Rheumatology 39:1410- 1414, Medical Publisher; December 2004: Chapter 11 pp 125-136. 2000 13. Chiu, J., Endoscopic Lumbar Foraminoplasty In Kim D, 20. Silverman SL, Minshall ME, Harper KD et al. The Fessler R, Regan J, eds. Endoscopic Spine Surgery and relationship of health-related quality of life to prevalent and Instrumentation. New York: Thieme Medical Publisher; incident vertebral fractures in post-menopausal women with December 2004: Chapter 19, pp 212-229. osteoporosis. Arthrisit Rheurn 44:2611-2619, 2001 14. Lindsay R, Silverman SL, Cooper C, et al. Risk of new 21. Hyde JA, Feinberg J. Secondary osteoporotic vertebral fracture in the year following a fracture, JAMA compression fractures after kyphoplasty. Paper presented at 285:319-323, 2001 70th Annual Meeting of the American Academy of 15. Gailbert P. Deramond H, Rosat P et al. Note preliminaire Orthopedic Surgeons; February 5-9,2003 New Orleans, LA sur le traitment des angiomes vertebraux par vertebroplastie 22. Phillips H, Cole PV, Lenin AW. Cardiovascular effects percutanee. Neurochinirgie 33: 166-168, 1987 of implanted acrylic . Br Med 33:460-471, 1971 16. Peters K, Guiot B, Martin P, et al. Vertebroplasty for 23. Nussbaum DA, Gailloud P, Kieeran M. A review of osteoporotic compression fractures: current practice and complications associated with vertebroplasty and evolving techniques. Neurosurgery 51: S2-96-S2-103, 2002 kyphoplasty as reported to the Food and Drug 17. Convery F, Gunn D, Hugues D, et al. The relative safety Administration Medical Device Related Website. J Vasc of polymethylmethacrylate, J Bone Surg Am Interv Radiol 15:1185-1192,2004 57A:57-64, 1975 24. Aebli N, Krebs J, Davis G, et al. Fat embolism and acute 18. Hasrop J, Prpa B, Reinhardt MK et al. Primary and hypotension during vertebroplasty. An experimental study in secondary osteoporosis' incidence of subsequent vertebral sheep. Spine 27:460-466, 2002

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Author Information John C. Chiu, M.D., D.Sc., F.R.C.S., Director, Neurospine Surgery, California Spine Institute

Michael T. Stechison, M.D., Ph.D., F.R.C.S., Greater Atlanta Neurosurgery, P.C.

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