What Is MIS?
Fellowship Trained Surgeons
Who is Texas MIS?
Slide 4

MINIMALLY INVASIVE SPINE SURGERY

TEXAS NEUROSURGICAL INSTITUTE

The Texas Neurosurgical Institute is a fellowship trained minimally invasive spine surgery group. It uses minimally invasive spine surgery techniques, approaches resulting in micro incisions (16 – 22 mm), anatomically safe small surgical corridors and approaches, surgical protocols, surgical technology, spinal equipment, spinal instrumentation, and spinal biologics, to treat surgical disorders and pathologies of all kinds.

TEXAS NEUROSURGICAL INSTITUTE, DR. CHRISTOPHER DUNTSCH, & MINIMALLY INVASIVE SPINE SURGERY DALLAS

The fundamental thought process behind minimally invasive spine surgery is over 60 years old, and has been driven by the greatest neurosurgical minds of the last century.

The technical aspects of these surgical procedures (protocols, surgical anatomy, exposures, access equipment, guidance, instruments and instrumentation, etc.) were established in the late 90s, and have gone through dozens of next generation improvements.

Minimally invasive spine surgery has been proven effective and safe over the last two decades using evidence based medicine.

Minimally invasive spine surgery as a comprehensive medical technology in the present, combined with fellowship trained spine surgeons, allows for nearly all types of spine pathology to be addressed.

Minimally Invasive Spine Surgery, as viewed within a skilled MIS surgeon’s operational paradigm, requires less OR time, less blood loss, less need for a hospital stay, more cases done as same day surgery (>60%), less pain, quicker recoveries, less risk for iatrogenic causes of surgical pathology months to years later that could require additional surgeries, faster return to work for the patient, better VAS and OSWESTRY patient outcome scores.

Minimally Invasive Spine Surgery is the future of spinal surgery, costs the medical system substantially less in socioeconomic expense, is substantially better for the patient in all aspects, and will be the most sought after paradigm / approach for surgical spine fixation within the next decade.

A BRIEF HISTORY FROM AN INSIDE TRACK

Many surgeons have collaborated to bring minimally invasive spine surgery to its current level of efficacy.  However, Dr. Christopher Duntsch, Clinical Director of the Texas Neurosurgical Institute, has an inside vantage point to its history and Dr. Kevin Foley’s  role going back > two decades.  Dr. Kevin Foley began to crystallize the concepts of minimally invasive spine surgery in the mid-90′s.  By the end of the 1990s, minimally invasive spine surgery approaches were taking form, and soon thereafter, several key MIS concepts were becoming a reality.  Dr. Foley spent years in the lab working with engineers and his neurosurgical fellows to create minimally invasive spine surgery access equipment, instruments, guidance systems, lateral approaches, and posterior (sextant) percutaneous pedicle screw – rod systems.  He has accomplished much since, an he earned the right to be named a pioneer in the field of minimally invasive spine surgery many years ago.  Dr. Christopher Duntsch, had the honor in 2009 of spending a year with Dr. Kevin Foley in a Fellowship for minimally invasive spine surgery, one on one, case by case.  During this time, Dr. Duntsch developed further his approaches to the spine using minimally invasive spine surgery in > 99% of his cases in his fellowship year with Dr. Foley, and since then, by using minimally invasive spine surgery in > 95% his surgical cases up until the present. In addition, the fellowship year was a time in which Dr. Duntsch accellerated his knowledge base of spinal instrumentation and biomechanics of the spine.  After recieving a PhD in Cell and Molecular Biology from St Jude Children’s research hospital in 2001, completing two post-doctoral fellowships in cell and molecular biology, serving as an Assistant Professor at the University of Tennessee’s Molecular Neursurgery Program, and founding two stem cell based biotechnology companies for spine and cancer in which he served as the chief science officer, Dr. Duntsch’s has the added knowledge base of bone fusion biologics at the cell and molecular level, and with respect to stem cell biology and bone fusion.  Thus, Dr. Duntsch is one of the few fellowship trained minimally invasive spine surgeons in Dallas / Forth Worth, and has education, training, and expertise in neurosurgery, MIS spine subspecialization, spinal instrumentation, spinal biomechanics, and spinal biologics.  Dr. Christopher Duntsch’s comprehensive background sets him apart in Dallas / Forth Worth, and Texas, and will be used to provide his patients with the best level of care possible in the current day.

Selected references from Dr. Kevin Foley’s Minimally Invasive Inventive Spine Surgery, and Pioneering work of the Last Two Decades (SEE END OF TEXT)

Texas Neurosurgical Institute Neurosurgeons are Fellowship Trained in Minimally Invasive Spine Surgery, and thus are among the most experienced spine surgeons in the Dallas and Central Texas area in using microsurgical approaches and technology to treat diseases of the spine. 

Minimally invasive spine surgery can be utilized to effectively treat chronic back and neck pain, and pain in the arms and legs associated with degenerative disc disease and structural pathology.

Compared to traditional open spine surgery, minimally invasive spine surgery utilizes anatomical aspects of the spine and surrounding tissue structures to create micro incisions and surgical corridors of access.

These approaches enter off the midline, and follow a path between large paraspinal muscles with minimal residual damage. Avoiding the midline of the back where muscles and tendons attach to the spine, and using small paraspinal surface areas for the surgical procedure, results in minimal scaring. Thus the risk of chronic scarring is greatly reduced, as is the risk of chronic degenerative disease and pain that is associated with traditional open surgical procedures.

When indicated, computer-assisted technology (such as computer navigation and nerve monitoring), and highly specialized tools and instrumentation are used resulting in a safe and effective surgical fixation of spine disease.

What is Minimally Invasive Spine Surgery?

Minimally Invasive Spine Surgery does not refer specifically to one type of therapy or a certain surgical approach. Minimally invasive spine surgery is different from traditional, open spine surgery in that the open approach involves making a long incision down the back, stripping large bands of muscle away from the spine and then retracting, or pulling to each side, the surrounding muscles so the surgeon can get a clear view of the vertebrae of the spine to be treated. Minimally invasive spine surgery requires a small incision, muscle dilation and the use of microsurgical and image guided technologies to access, view and repair spinal deterioration or damage. Muscle dilation involves gently and gradually separating, rather than cutting and stripping the muscles that surround the spine.

Minimally Invasive Characteristics:

Smaller incisions.

A constant effort to minimize tissue damage during the exposure, the procedure, and the closure.

Approaches to the spine through nontraditional starting points and trajectories that avoid damage to the midline ligments, muscles and bone, and cause minimal tissue trauma.

Specialized instruments, tubes and dilators, and devices that allow adequate surgical fixation through small surgical corridors possible.

The use of operating microscopes that allow for high magnification and three dimensional binocular views of the tissues, bone, disc, and descending / exiting nerve roots.

Microsurgical Technique.

When is minimally invasive spine surgery indicated?

Minimally invasive spine surgery is indicated whenever the spinal pathology can be treated effectively using minimally invasive techniques, surgical approaches, and instrumentation. Most spine conditions can be treated with minimally invasive approaches. As always, there are exceptions, and a good surgeon will always act in the patient’s best interest. Minimally Invasive Surgery is an excellent alternative to traditional open surgeries for decompressive procedures, stabilization procedures, and the placement of biomedical devices.

Chronic Spine Pain Nonsurgical Conditions Treated

Percutaneous Discectomy

Peripheral Nerve Stimulation

Radiofrequency Ablation

Sacroiliac Pain Treatments

Spinal Cord Stimulator (SCS)

Sphenopalatine Ganglion Block

Stellate Ganglion Block

Superior Hypogastric Plexus Block

Sympathetic Block

Vertebroplasty & Kyphoplasty

Adhesiolysis

Caudal Steroid Injection

Celiac Plexus Block

Cervical Steroid Injection

Continuous Catheter Nerve Blocks

Disc Denervation

Discography

Epidural Steroid Injection

Facet Injections

Ganglion Impar Block

IntraDiscal Electrothermal Therapy

Intrathecal Pumps (ITPs)

Medial Branch Blocks

Occipital Nerve Block

 

 

CONDITIONS TREATED WITH MINIMALLY INVASIVE SPINE SURGERY

Whiplash Syndrome

Traumatic Spinal Injury of the Cervical, Thoracic, or Lumbar Spine

Axial Neck and Spine Pain

Cervical, Thoracic, and Spinal Stenosis

Myelopathy

Facet Degenerative Arthropathy

Posterior Spondylosis of the Cervical, Thoracic, or Lumbar Spine

Axial Mechanical Back Pain

Degenerative Disc Disease of the Cervical, Thoracic, or Lumbar Spine

Neuroforaminal Stenosis of the Cervical, Thoracic, or Lumbar Spine

Ruptured Discs of the Cervical, Thoracic, or Lumbar Spine

Far Lateral Disc Herniations

Radiculopathy – Upper Extremities (Nerve / Nerve Root Compression)

Radiculopathy – Lower Extremities (Nerve / Nerve Root Compression)

Pain in the Neck, Arms, or Legs of Neurologic Origin

Neurologic Deficits of the Cervical, Thoracic, or Lumbar Spine

Neuralgic Deficits of the Upper or Lower Extremities

Symptomatic Spondylothesis

Symptomatic Anterolithesis

Symptomatic Kyphosis

Symptomatic Degenerative Scoliotic Deformities

Occipital and Subocciptal Neuralgia

Clinically Significant Spinal Instability

(pars defects, degenerative congenital, pathologic)

Metastatic Spine Cancer

Primary Bone Cancers

Post-laminectomy Pain

Failed Back Syndrome

Removal of Hardware

Adhesions and Scar Nerve Compression

Spinal Stenosis with Neurogenic Claudication

Conus Medullaris Syndrome

Cauda Equina Syndrome

Neuromodulation

Vertobroplasty

Kyphoplasty

Removal of Foreign Bodies Compressing Neural Tissues

 

Minimally Invasive Techniques and Concepts:

Minimize tissue damage with smaller incisions, smaller exposures.
To minimize deep tissue exposure and tissue damage the surgical procedure.
To minimize tissue damage during the closure of the surgical incision.
The use of surgical approaches that avoid the midline and the critical midline structures.
To avoid damage to central spinal anatomy ~ ligaments, muscles, and bone.
Specialized instruments, tubes, dilators, and surgical devices to gain exposure.
Instruments and techniques for surgical fixation through small surgical corridors.
The use of neuromonitoring of vital nerve plexuses and nerves near the surgical to field.
Operating microscopes for high mag / 3-D binocular views of the tissues, bone, disc, and desc / exit nerve roots.
Microsurgical technique / direct neural decompression,  surgical fixation under direct vision.
Indirect neural decompression of the neural elements with the need for more invasive approaches.

Minimally Invasive Spine Surgery Goals

SPINAL CANAL DECOMPRESSION, DIRECT

SPINAL DISCECTOMY, DIRECT

NEUROFORAMINAL DECOMPRESSION, DIRECT

NEUROFORAMINAL DECOMPRESSION, INDIRECT

DECOMPRESSION, INDIRECT

TUMOR OR FOREIGN BODY REMOVAL

TRAUMATIC INJURIES AMENABLE TO MIS

ANTERIOR INTERBODY DISCECTOMY AND FUSION

IN SITU AND PERCUTANEOUS INSTRUMENTATION

ADJUVANT FACET FUSION AND INSTRUMENTATION

INTERSPINOUS FIXATION AND INSTRUMENTATION

PERCUTANEOUS PEDICAL SCREW / ROD FIXATION

REDUCTION AND STABLIZATION OF SPONDYLOTHESIS

CORRECTION OF DEGENERATIVE SCOLIOTIC DEFORMITY

Advantages Of Minimally Invasive Spine Surgery Include:

Significant Reduction in Post-operative Pain
Less soft tissue damage, Less Scarring, and Improved Cosmesis
Avoidance of normal anatomy above and below the surgical field
Significant Reduction of Post-surgical Axial Back Pain
Decreased Incidence of Adjacent Segment Disease
Shorter hospital stays if needed (usually same day surgery)
Quicker return to a functional level and return to work
Decreased Need for Further Surgery in the Future
Small Incisions (Typically 16 – 23 mm)
Reduced blood loss and Quicker Recovery From Surgery
Avoidance of the midline

 

MINIMALLY INVASIVE SPINE SURGERY – EXAMPLES OF TECHNIQUES, APPROACHES, TECHNOLOGY

POSTERIOR SURGICAL SPINE – CERVICAL, THORACIC, LUMBAR

Interbody Discectomy

Far Lateral Discectomy

Laminotomy, Facetectomy, Neuroforaminotomy

Laminotomy, Facetectomy, Neuroforaminotomy

Interspinous/Facet Instrumentation / Fixation

(posterior-lateral fusion)

Minimally Invasive Thoracic Discectomy with Lateral Approach and MIS System

Intervertebral Discectomy and PEEK Graft Cage Fusion

1 Lateral Lumbar Interbody Fusion (XLIF)

(+/- In Situ Lateral Vertebral Column Instrumentation; +/-Posterior Pedicle / Screw Rod Fixation)

2 Transforaminal Lumbar Interbody Fusion (TLIF)

(Posterior Pedicle / Screw Rod Instrumentation / Fixation)

3 Posterior Pedicle Screw / Rod Instrumentation / Fixation

(posterior-lateral fusion, +/- lumbar / neuroforaminal decompression)

Instrumentation / Fixation and Fusion of Deformities, 360 degree Surgical Fixation

Symptomatic Spondylothesis

Symptomatic Anterolithesis

Symptomatic Kyphosis

Symptomatic Degenerative Scoliotic Deformities

Traumatic Spinal Injury of the Cervical, Thoracic, or Lumbar Spine

Clinically Significant Spinal Instability

(pars defects, degenerative congenital, pathologic)

ANTERIOR SURGICAL SPINE – CERVICAL AND LUMBAR

Anterior Cervical Discectomy with Fusion and Instrumentation / Fixation

Anterior Cervical Corpectomy with Fusion and Instrumentation / Fixation

Anterior Intervertebral Lumbar Discectomy and PEEK Graft Cage Interbody Fusion and Anterior Instrumentation / Fixation (ALIF)

Placement of Thoracic and Occipital/Cervical Spinal Cord Stimulators

Vertebroplasty, Kyphoplasty

Instrumentation / Fixation and Fusion of Deformities, 360 degree Surgical Fixation

Symptomatic Spondylothesis

Symptomatic Anterolithesis

Symptomatic Kyphosis

Symptomatic Degenerative Scoliotic Deformities

Traumatic Spinal Injury of the Cervical, Thoracic, or Lumbar Spine

Clinically Significant Spinal Instability

(pars defects, degenerative congenital, pathologic

 

Common Minimally Invasive Systems / Instrumentation and Hardware – Examples

METRx Minimally Invasive Spinal Access System (Medtronic)

XLIF Extreme Lateral Approach for Discectomy, Fusion, Interbody Graft, and Instrumentation (Nuvasive)

Sextant Percutaneous Minimally Invsasvie Sextant Posterior Cortical Screw / Rod Fixation (Medtronic)

MASS-PLIF with Cortical Screws (Nuvasive)

MIS TLIF with Window and Retracting Pedicle Screws (Nuvasive)

(MEDTRONIC)

Minimally Invasive Placed Posterior Spine Facet Screws and Interspinous Instrumentation / Fixation / Fusion (Nuvasive, Osteom

 

Use Of Biologics and Biotechnology In Spine Surgery

To Accelerate / Enhance Bone Fusion:

Solid Fusion parallels decreased pain, decreased time to recovery, decreased time to return to work, and prevention of pseudoarthrosis, nonunion, or failure of fusion (can requires a difficult more complicated redo surgery)

For Example:

Concentrated Bone Marrow Aspirate from the PSIS to deliver high dose Marrow Stem Cells

Bone Morphogenic Protein-2 Bone Morphorgen / Growth Factor

Demineralized Bone Matrix as a bone fusion catalyst and biocompatible scaffold

Peripheral Bone Growth Stimulators

To Protect the Spinal Cord and Reduce Nerve Root Inflammation:

Dexamethasone (as an anti-inflammatory) – especially when working on the spinal cord.
Duraseal (as a barrier) – when using BMP2 close to the cord and nerve roots

To Reduce Post-surgical Scarring Around Nerve Roots:

Amniotic Graft Overlay and Injectable

To Maintain Excellent Hemostasis When Indicated:

Gel Foam with Thrombin
Floseal

To Repair Dural Tears:

Duraseal

To Protect Neural Structures from BMP-2:

Duraseal

 

EXAMPLES OF SPINAL PATHOLOGIES AND TREATMENT APPROACHES

LUMBAR MINIMALLY INVASIVE DISCECTOMY

A microdiscectomy is performed for sciatica or lumbar radiculopathy due to a lumbar disc prolapse. In general a period of conservative management consisting of oral pain killers, physiotherapy and hydrotherapy and/or an epidural steroid injection is the treatment of choice for sciatica. If symptoms persist and are not tolerable after 6-8 weeks of conservative management, a microdiscectomy may be considered. This is performed under a general anaesthetic. A small 2-2.5cm cut is made in the lower spine directly over the disc prolapse. Using the operative microscope for magnification and illumination, the compressed nerve and disc prolapse are identified and the offending disc fragment removed. The rest of the disc is left in-situ to prevent delayed back pain. Surgery of this manner has an 80-90% chance of success in well chosen surgical cases. The in-hospital stay following a micro-discectomy ranges from 1 to 2 days. Some microdiscectomies are performed on a day-stay basis. Risks of a Lumbar Microdiscectomy: Rare but major risks ( less than 0.5%; case dependent), Nerve injury resulting in weakness, numbness, paralysis, bowel or bladder dysfunction, sexual dysfunction, More common and treatable risks (5-10%), Bleeding, Infection, CSF leak, Recurrent disc prolapse, Delayed instability, Other medical complications (respiratory, cardiovascular, DVT/PE etc),

LUMBAR MICROLAMINECTOMY

A microlaminectomy is performed for neurogenic claudication due to lumbar canal stenosis. In general a period of conservative management consisting of oral pain killers, physiotherapy and hydrotherapy and/or an epidural steroid injection is the treatment of choice for sciatica. If symptoms persist and are not tolerable after 6-8 weeks of conservative management, a microlaminectomy may be considered. This is performed under a general anaesthesia. For microlaminectomies up to 3 spinal levels, a 2.5 to 3cm skin incision will be made over the appropriate levels. Using the operative microscope for magnification and illumination, the lower lumbar nerve roots (cauda equina) are decompressed by drilling off the bony compression and removing the offending thickened ligamentum allowing restoration of the normal dimensions of the central canal. Both ipsilateral and contralateral nerve roots are visualised and completely freed up in this manner. Surgery of this manner has an 80-90% chance of improving claudication (leg) symptoms. This surgery is not targeting back pain. The in-hospital stay following a microlaminectomy ranges from 1 to 3 days. For elderly or deconditioned patients undergoing this surgery, a short period of in-hospital rehabilitation may be arranged for them after their stay in the acute hospital. Risks of a Lumbar Laminotomy: Rare but major risks ( less than 0.5%; case dependent), Nerve injury resulting in weakness, numbness, paralysis, bowel or bladder dysfunction, sexual dysfunction, More common and treatable risks (5-10%), Bleeding, Infection, CSF leak, Recurrent disc prolapse, Delayed instability, Other medical complications (respiratory, cardiovascular, DVT/PE etc)

MINIMALLY INVASIVE LUMBAR FUSIONS

A lumbar fusion may be performed for degenerative (wear and tear), traumatic or neoplastic conditions. The basis of a lumbar fusion is the realignment of the spine and prevention of movement at a certain spine segment, thus attempting to achieve improvements in back pain, mobility and quality of life. A lumbar fusion may be performed in conjunction with a microlaminectomy, and may be performed over several spinal levels. In certain cases of severe spinal deformities, this may involve a staged operation over two sittings. Lumbar fusions involve the substantial removal of the intervertebral disc and placement of an interbody spacer (cage made of reinforced PEEK) prefilled with bone substitute. This is supplemented by the placement of percutaneous pedicle screws through numerous small stab incisions in the back. The long-term goal of surgery is to allow bony growth between the vertebrae, thus preventing movement at the operated spinal level and relieving symptoms of discogenic or facet associated back pain. Intra-operative neuro-monitoring is used in all cases of minimally invasive spinal fusions to maximise safety and prevent the rare risks of inadvertent neural injury. Intra-operative neuro-navigation may also be used for minimally invasive spinal fusions to maximise safety and prevent the rare risks of inadvertent neural injury.  Risks of a Lumbar Laminotomy: Rare but major risks ( less than 0.5%; case dependent), Nerve injury resulting in weakness, numbness, paralysis, bowel or bladder dysfunction, sexual dysfunction, More common and treatable risks (5-10%), Bleeding, Infection, CSF leak, Recurrent disc prolapse, Delayed instability, Other medical complications (respiratory, cardiovascular, DVT/PE etc).

There are three main options in minimally invasive lumbar fusions.

1) TRANS-FORAMINAL LUMBAR INTERBODY FUSION (TLIF – MIS):This is performed under a general anaesthetic. A 2.5 to 3cm skin incision is made about 4cm off the midline of the lower lumbar spine over the appropriate spinal level. The surgical approach utilises the natural planes of the spinal muscles and bluntly splits the muscle fibres rather than cutting them from one side only. Using tubular retractors and the operative microscope, the entire facet joint is removed and the disc approached in this manner. A complete discectomy is performed and an interbody cage placed at an angle across the disc. This interbody fusion is supplemented with percutaneous pedicle screws placed bilaterally through the same incision on the side ipsilateral to the TLIF, and small stab incisions on the contralateral side.

2) EXTREME LATERAL  LUMBAR APPROACH (XLIF/DLIF – MIS):

This is performed under a general anaesthetic. A 2.5 to 3cm skin incision is made on the side with the spinal approach made through the side trunk muscles rather than the back muscles. These trunk muscles are bluntly split and entry into a fat-filled space called the retro-peritoneal space is achieved with minimal approach trauma. The psoas muscle lies on the sides of the lumbar spine and it is through this muscle that the intervertebral discs are reached. Under direct vision, a complete discectomy is performed and a large interbody cage placed across the entire width of the disc. This interbody fusion is supplemented with percutaneous pedicle screws placed bilaterally through small stab incisions on the back. This approach is not appropriate for all levels of the spine, particularly the L5/S1 level.

3) ANTERIOR LUMBAR INTERBODY FUSION (ALIF)

This is performed under a general anaesthetic. A transverse 3 to 4cm skin incision is made low down in the midline of the lower abdominal wall. A retroperitoneal approach is taken to the lower lumber spine and exposure of the relevant discs is made with gentle protection of adjacent important vascular structures. Under direct vision, a complete discectomy is performed and a large interbody cage placed into the disc space. This interbody fusion may then be supplemented with an internal plate or by percutaneous pedicle screws placed bilaterally through small stab incisions on the back.

 

SURGICAL VIDEO GRAPHICS / CLIPS OF EACH TYPE OF SURGERYAnterior Cervical Disectomy with

Fusionhttp://neurosurgic.com/index.phpoption=com_videogals&task=videos&view=single&videoid=557&Itemid=692&redirect=self&id=56The Metrx System for Tubular Minimally Invasive Spine Access System

http://www.lessinvasivespine.com/metrx-system.html

Lumbar Discectomy with METRx Access

http://www.lessinvasivespine.com/mis-lumbar-discectomy.html

Foraminotomy with METRx Access

http://www.lessinvasivespine.com/mis-foraminotomy.html

Laminectomy for Decompression with METRx Access

http://www.lessinvasivespine.com/mis-lumbar-laminectomy.html

Sextant Pedicle Screw / Rod Fixation

http://www.lessinvasivespine.com/sextant-system.html

Trans Foraminal Interbody Fusion

http://www.lessinvasivespine.com/mis-interbody-fusion.html

Extreme Lateral Lumbar Interbody Fusion

http://www.lessinvasivespine.com/mis-direct-lateral-fusion.html

Interspinous Instrumentation

http://www.lessinvasivespine.com/spire-system.html

Selected references from Dr. Kevin Foley’s Pioneering Work in Developing Minimally Invasive Spine Surgery Rationale, technology, Equipment, Hardware, and Proof of Concept to Launch a Paradigm Change

1: Park P, Foley KT, Cowan JA, Marca FL. Minimally invasive pedicle screw
fixation utilizing O-arm fluoroscopy with computer-assisted navigation:
Feasibility, technique, and preliminary results. Surg Neurol Int. 2010 Aug
25;1:44. PubMed PMID: 20975974; PubMed Central PMCID: PMC2958329.

2: Park P, Upadhyaya C, Garton HJ, Foley KT. The impact of minimally invasive
spine surgery on perioperative complications in overweight or obese patients.
Neurosurgery. 2008 Mar;62(3):693-9; discussion 693-9. PubMed PMID: 18425016.

3: Park P, Foley KT. Minimally invasive transforaminal lumbar interbody fusion
with reduction of spondylolisthesis: technique and outcomes after a minimum of 2
years’ follow-up. Neurosurg Focus. 2008;25(2):E16. PubMed PMID: 18673045.

4: Holly LT, Foley KT. Image guidance in spine surgery. Orthop Clin North Am.
2007 Jul;38(3):451-61; abstract viii. Review. PubMed PMID: 17629992.

5: Holly LT, Schwender JD, Rouben DP, Foley KT. Minimally invasive transforaminal
lumbar interbody fusion: indications, technique, and complications. Neurosurg
Focus. 2006 Mar 15;20(3):E6. Review. PubMed PMID: 16599422.

6: Holly LT, Foley KT. Percutaneous placement of posterior cervical screws using
three-dimensional fluoroscopy. Spine (Phila Pa 1976). 2006 Mar 1;31(5):536-40;
discussion 541. PubMed PMID: 16508547.

7: German JW, Foley KT. Disc arthroplasty in the management of the painful lumbar
motion segment. Spine (Phila Pa 1976). 2005 Aug 15;30(16 Suppl):S60-7. Review.
PubMed PMID: 16103835.

8: German JW, Foley KT. Minimal access surgical techniques in the management of
the painful lumbar motion segment. Spine (Phila Pa 1976). 2005 Aug 15;30(16
Suppl):S52-9. Review. PubMed PMID: 16103834.

9: Schwender JD, Holly LT, Rouben DP, Foley KT. Minimally invasive transforaminal
lumbar interbody fusion (TLIF): technical feasibility and initial results. J
Spinal Disord Tech. 2005 Feb;18 Suppl:S1-6. PubMed PMID: 15699793.

10: DiAngelo DJ, Foley KT, Morrow BR, Schwab JS, Song J, German JW, Blair E. In
vitro biomechanics of cervical disc arthroplasty with the ProDisc-C total disc
implant. Neurosurg Focus. 2004 Sep 15;17(3):E7. PubMed PMID: 15636563.

11: DiAngelo DJ, Foley KT. An improved biomechanical testing protocol for
evaluating spinal arthroplasty and motion preservation devices in a multilevel
human cadaveric cervical model. Neurosurg Focus. 2004 Sep 15;17(3):E4. PubMed
PMID: 15636560.

12: Holly LT, Foley KT. Three-dimensional fluoroscopy-guided percutaneous
thoracolumbar pedicle screw placement. Technical note. J Neurosurg. 2003 Oct;99(3
Suppl):324-9. PubMed PMID: 14563154.

13: Holly LT, Foley KT. Intraoperative spinal navigation. Spine (Phila Pa 1976).
2003 Aug 1;28(15 Suppl):S54-61. Review. PubMed PMID: 12897475.

14: Guyer RD, Foley KT, Phillips FM, Ball PA. Minimally invasive fusion: summary
statement. Spine (Phila Pa 1976). 2003 Aug 1;28(15 Suppl):S44. Review. PubMed
PMID: 12897473.

15: Foley KT, Holly LT, Schwender JD. Minimally invasive lumbar fusion. Spine
(Phila Pa 1976). 2003 Aug 1;28(15 Suppl):S26-35. Review. PubMed PMID: 12897471.

16: Perez-Cruet MJ, Foley KT, Isaacs RE, Rice-Wyllie L, Wellington R, Smith MM,
Fessler RG. Microendoscopic lumbar discectomy: technical note. Neurosurgery. 2002
Nov;51(5 Suppl):S129-36. PubMed PMID: 12234440.

17: Foley KT, Gupta SK. Percutaneous pedicle screw fixation of the lumbar spine:
preliminary clinical results. J Neurosurg. 2002 Jul;97(1 Suppl):7-12. PubMed
PMID: 12120655.

18: Haid RW, Foley KT, Rodts GE, Barnes B. The Cervical Spine Study Group
anterior cervical plate nomenclature. Neurosurg Focus. 2002 Jan 15;12(1):E15.
Review. PubMed PMID: 16212328.

19: Foley KT, Lefkowitz MA. Advances in minimally invasive spine surgery. Clin
Neurosurg. 2002;49:499-517. PubMed PMID: 12506566.

20: Foley KT, Gupta SK, Justis JR, Sherman MC. Percutaneous pedicle screw
fixation of the lumbar spine. Neurosurg Focus. 2001 Apr 15;10(4):E10. PubMed
PMID: 16732626.

21: Rampersaud YR, Simon DA, Foley KT. Accuracy requirements for image-guided
spinal pedicle screw placement. Spine (Phila Pa 1976). 2001 Feb 15;26(4):352-9.
PubMed PMID: 11224881.

22: Foley KT, Simon DA, Rampersaud YR. Virtual fluoroscopy: computer-assisted
fluoroscopic navigation. Spine (Phila Pa 1976). 2001 Feb 15;26(4):347-51. PubMed
PMID: 11224880.

23: Rampersaud YR, Foley KT, Shen AC, Williams S, Solomito M. Radiation exposure
to the spine surgeon during fluoroscopically assisted pedicle screw insertion.
Spine (Phila Pa 1976). 2000 Oct 15;25(20):2637-45. PubMed PMID: 11034650.

24: Foley KT, Smith MM, Rampersaud YR. Microendoscopic approach to far-lateral
lumbar disc herniation. Neurosurg Focus. 1999 Nov 15;7(5):e5. PubMed PMID:
16918212.

25: Foley KT, Smith MM. Image-guided spine surgery. Neurosurg Clin N Am. 1996
Apr;7(2):171-86. Review. PubMed PMID: 8726434.

26: Dickman CA, Foley KT, Sonntag VK, Smith MM. Cannulated screws for odontoid
screw fixation and atlantoaxial transarticular screw fixation. Technical note. J
Neurosurg. 1995 Dec;83(6):1095-100. PubMed PMID: 7490629.