Chirogeek has posted some excellent new studies for us all to read, but some may need some explanation of the abbreviations so I thought I would post the definitons here for all to read...again...

Definitions provided below for Charite, PLIF, ALIF, TLIF, discectomy, IDET
PLIF, ALIF and TLIF Procedures

http://www.scoliosisassociates.com/s...-tlif-alif-041

Spinal fusion is a surgical procedure in which two or more vertebrae are joined or fused together. Fusion surgeries typically require the use of bone graft to facilitate fusion. This involves taking small amounts of bone from the patient’s pelvic bone (autograft), or from a donor (allograft), and then packing it between the vertebrae in order to “fuse” them together. This bone graft, along with a biomechanical spacer implant, will take the place of the intervertebral disc, which is entirely removed in the process. Spinal fusion surgery is a common treatment for such spinal disorders as spondylolisthesis, scoliosis, severe disc degeneration, or spinal fractures. Fusion surgery is usually considered only after extensive non-operative therapies have failed. Three common fusion surgeries available at our practice include PLIF, ALIF and TLIF.

PLIF
PLIF stands for Posterior Lumbar Interbody Fusion. In this fusion technique, the vertebrae are reached through an incision in the patient’s back (posterior). The PLIF procedure involves three basic steps:


Pre-operative planning and templating. Before the surgery, the surgeon uses MRI and CAT scans to determine what size implant(s) the patient needs.
Preparing the disc space. Depending on the number of levels to be fused, a 3-6 inch incision is made in the patient’s back and the spinal muscles are retracted (or separated) to allow access to the vertebral disc. The surgeon then carefully removes the lamina (laminectomy) to be able to see and access the nerve roots. The facet joints, which lie directly over the nerve roots, may be trimmed to allow more room for the nerve roots. The surgeon then removes the affected disc and surrounding tissue and prepares bone surfaces of adjacent vertebrae for fusion.
Implants inserted. Once the disc space is prepared, bone graft, allograft or BMP with a cage, is inserted into the disc space to promote fusion between the vertebrae. Additional instrumentation (such as rods or screws) may also be used at this time to further stabilize the spine.

TLIF

TLIF stands for Transforaminal Lumbar Interbody Fusion. This fusion surgery is a refinement of the PLIF procedure and has recently gained popularity as a surgical treatment for conditions affecting the lumbar spine. The TLIF technique involves approaching the spine in a similar manner as the PLIF approach but more from the side of the spinal canal through a midline incision in the patient’s back. This approach greatly reduces the amount of surgical muscle dissection and minimizes the nerve manipulation required to access the vertebrae, discs and nerves. The TLIF approach is the preferred method at our practice for interbody fusion as it is generally less traumatic to the spine, is safer for the nerves, and allows for minimal access and endoscopic techniques to be used for spinal fusion.

As with PLIF and ALIF, disc material is removed from the spine and replaced with bone graft (along with cages, screws, or rods if necessary) inserted into the disc space. The instrumentation helps facilitate fusion while adding strength and stability to the spine. We currently use many state of the art cage technologies including those made of bone, titanium, polymer, and even bioresorbable materials.

ALIF

ALIF stands for Anterior Lumbar Interbody Fusion. This procedure is similar to PLIF, however it is done from the front (anterior) of the body, usually through a 3-5 inch incision in the lower abdominal area or on the side. This incision may involve cutting through, and later repairing, the muscles in the lower abdomen.

At our practice, a mini open ALIF approach is available that preserves the muscles and allows access to the front of the spine through a very small incision. This approach maintains abdominal muscle strength and function and is oftentimes used to fuse the L5-S1 disc space.

Once the incision is made and the vertebrae are accessed, and after the abdominal muscles and blood vessels have been retracted, the disc material is removed. The surgeon then inserts bone graft (and anterior interbody cages, rods, or screws if necessary) to stabilized the spine and facilitate fusion.

Minimal Access
We routinely do several types of spinal procedures utilizing minimal access techniques. The development of these techniques originated with the application of endoscopy during microdiscectomy surgery for herniated lumbar discs. It has now been applied to fusion surgeries. Ask a member of our clinical team to see if this might be right for you.

After Fusion Surgery
Recovery time is different for every patient. However, most patients are up and walking by the end of the first day after surgery. Most patients can expect to stay in the hospital for 3-5 days depending on their condition. Once released from the hospital, patients who have undergone a PLIF, ALIF, or TLIF procedures are given a prescription for pain medications to be taken if needed, as well as a detailed post-operative activity plan to help ease recovery and return to a healthy life.

Case Example of Degenerative Spondylolisthesis treated with TLIF





This 58 year old woman had degenerative spondylolisthesis at the L4/5 level as shown on the x-ray and MRI above. She had difficulty walking distances and back and leg pain. She was treated with laminectomy and fusion with instrumentation.

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Total Disc Replacement—Charite™ Artificial Disc
The Charité Artificial Disc is a total disc replacement technology that uses two metal alloy endplates and its unique sliding core. This offers the theoretical advantage of allowing the spacer to shift dynamically within the disc space during spinal motion, moving posteriorly with flexion and anteriorly in lumbar extension. Some experts feel this may improve the segmental rotation and decrease the possibility of facet impingement at extremes of motion. This has not yet been clinically demonstrated.

Figure 14: Charité artificial disc

Figure 15a and 15b: Charité Artificial Disc design to mimic normal disc motion

The Charité Artificial Disc was designed to restore disc space height, to restore motion segment flexibility, to prevent disc degeneration at adjacent segments, to reduce or eliminate pain from motion or from nerve compression, and to improve the patient's functional activities. It was designed to be biocompatible and durable. It has a life span of 40 years (85 million cycles).

The Charité Artificial Disc has kinematics that mirror the segmental motion of a normal spine. It is designed to allow anatomic alignment in lordosis, and to allow normal facet joint loading and unloading.

Wear debris, a concern with polyethylene implants in the peripheral joints, has been studied in the Charité, given the implant's proximity to the spinal canal and nerve roots. In a long-term laboratory test of cyclical motion simulating >11 years of use, no wear debris particles were identified. There is minimal deformation of the core, with less than 8% height loss expected in 10 years of use.

Meticulous attention to implantation is required to ensure that the articulating surfaces of the endplates are parallel in order to restore normal biomechanics. Angled prosthetic endplates are available and were designed to produce parallel surfaces while accommodating lumbar lordosis. Different size endplates are available to the surgeon, so the largest size possible can be used to minimize the chance of subsidence into the bone. Care must be exercised by the surgeon to place the implant centrally in both the sagittal and antero-posterior planes.

Figure 16: Charité Artificial Disc is centralized, front view

Figure 17: Charité Artificial Disc is centralized, side view

Rotation must be controlled by the surgeon during implantation. The endplates are inserted , and the polyethylene core placed into position as the disc space is distracted. Core dislocation is a rarely reported complication.

The surgical approach is typically through an anterior retro-peritoneal route. Patient positioning is important so that radiographic confirmation of the implant position can be seen easily by the surgical team. Factors critical for a good result using the Charité are proper patient selection, selecting the correct prosthesis size, and proper prosthesis positioning with the CentreLine Instruments

Several clinical studies have been published documenting the European experience with this disc since 1987. Worldwide experience with this unconstrained anatomic disc replacement is now greater than 10,000 cases.

Cinotti reported on 46 Italian patients in 1996, with 2-5 year follow-up. He saw no implant failures, but did report reoperation in 19% for continued pain and one case of implant dislocation due to wrong size selection. Overall patient satisfaction was 63%.

LeMaire reported his French series in 1997, following 105 patients a mean of 51 months with 79% good outcomes and no device failures.

Zeegers reported 50 patients in 1999 in a Dutch series. He showed 70% good results with 2 year follow-up, but he did report 24 reoperations in 12 patients, none due to device failure.

The US FDA study was launched at the Texas Back Institute with the first US implantation in March 2000. Since that time, 294 patients have been enrolled in the FDA multicenter (14) study. The study was completed in December 2001, and the FDA approved the Charite for single-level L4-5 and L5-S1 implantation as of October 2004.

The study protocol called for a 2:1 randomization of Charite:BAK threaded fusion cages with autogenous bone graft. 196 patients received the Charité Artificial Disc as part of the randomization, with another 71 non-randomized patients receiving the disc as part of the experience portion of the protocol, so that a total of 267 discs were implanted.

Inclusion criteria were age 18-60, single-level L4-5 or L5-S1 symptomatic degenerative disc disease confirmed by discography, Oswestry score >30, VAS score >4/10, failed >6 months of nonoperative care, back and/or leg pain without nerve compression, <3 prior abdominal surgeries, and compliance with the follow-up schedule.

Exclusion criteria included previous fusion, multilevel degeneration, prior fracture in the lower lumbar spine, non-contained HNP, osteoporosis or metabolic bone disease, spondylolisthesis >3 mm, positive straight leg raise, scoliosis >11 mm, spinal tumor, infection, facet joint arthrosis, psychological disorder, and morbid obesity.

Additional exclusions were metal allergy, bone growth stimulator elsewhere in the spine, participation in another study, arachnoiditis, pregnancy, chronic steroid use, or presence of an autoimmune disease.

Figure 18: Front view of implanted Charité Artificial Disc

Figure 19: Side view of implanted Charité Artificial Disc

Anterior cervical decompression (discectomy)
A cervical disc herniation can be removed through an anterior approach to relieve spinal cord or nerve root pressure and alleviate corresponding pain, weakness, numbness and tingling. This procedure, called a cervical discectomy, allows the offending disc to be surgically removed.

The anterior approach to the cervical spine (from the front of the neck) can provide exposure from C2 down to the cervico-thoracic junction. Spine surgeons often prefer it because it provides good access to the spine through a relatively uncomplicated pathway. All things being equal, the patient tends to have less wound pain from this approach than from a posterior operation.

After a skin incision is made, only one thin vestigial muscle needs to be cut, after which anatomic planes can be followed right down to the spine. The limited amount of muscle division or dissection helps to limit postoperative pain following the spine surgery. The main trouble that patients have after surgery is a sore throat and difficulty swallowing, which produces a sense of a ‘lump in the throat’ caused by the surgical manipulation of the area.

The general procedure for the decompression surgery includes the following:

1. Surgical approach

The skin incision is one to two inches and horizontal, and can be made on the left or right hand side of the neck.

The thin platysma muscle under the skin is then split in line with the skin incision and the plane between the sternocleidomastoid muscle and the strap muscles is then entered.

Next, a plane between the trachea/esophagus and the carotid sheath can be entered.

A thin fascia (flat layers of fibrous tissue) covers the spine (pre-vertebral fascia) which is dissected away from the disc space.

2. Disc removal

A needle is then inserted into the disc space and an x-ray is done to confirm that the surgeon is at the correct level of the spine.

After the correct disc space has been identified on x-ray, the disc is then removed by first cutting the outer annulus fibrosis (fibrous ring around the disc) and removing the nucleus pulposus (the soft inner core of the disc).

3. Dissection

Dissection is carried out from the front to back to a ligament called the posterior longitudinal ligament. Often this ligament is gently removed to allow access to the spinal canal to remove any osteophytes (bone spurs) or disc material that may have extruded through the ligament.

The dissection is often performed using an operating microscope or magnifying loupes to aid with visualization of the smaller anatomic structures.

Possible risks and complications of anterior cervical discectomy surgery may include:

Inadequate symptom relief

Failure of bone graft healing (a.k.a. non-union or pseudarthrosis)

Persistent swallowing or speech disturbance

Nerve root damage

Damage to the spinal cord (about 1 in 10,000)

Bleeding

Infection

Damage to the trachea/esophagus

Also, the small nerve that supplies innervation to the vocal cords (recurrent laryngeal nerve) will sometimes not function for several months after neck surgery because of retraction during the procedure, which can cause temporary hoarseness. Retraction of the esophagus can also produce difficulty with swallowing, which has usually resolved within a few weeks to months.

There is little chance of a recurrent disc herniation because most of the disc is removed with this type of surgery.

An anterior cervical fusion is usually done as part of a cervical discectomy. The insertion of a bone graft into the evacuated disc space serves to prevent disc space collapse and promote a growing together of the two vertebrae into a single unit. This ‘fusion’ prevents local deformity (kyphosis) and serves to maintain adequate room for the nerve roots and spinal cord.

By: Peter F. Ullrich, Jr., MD

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IDET - IDET (Intradiscal Electrothermal Therapy) back surgery animation
IDET is a minimally invasive outpatient back surgery to treat patients with chronic low back pain that is caused by tears or small herniations of their lumbar discs. This animation walks you through the steps involved in an IDET back surgery.

Click on link to see animation...

http://www.spine-health.com/dir/idet.html

Autograft bone for spinal fusion
Autograft bone (patient’s own bone) is harvested from the iliac crest (hip). This technique has been the gold standard since the 1950’s. Autograft bone usually achieves a fusion in 90%-95% of patients.

The principal disadvantage with using autograft bone is that another incision needs to be made over the hip to harvest the bone graft. Possible complications associated with taking out bone graft include:

Graft site chronic pain (which happens 10% to 25% of the time)

Infection

Bleeding

Damage to the lateral femoral cutaneous nerve (a sensory nerve that supplies sensation to the front of the thigh)

Pelvis bone fracture

The chances of a complication increase with the size of the bone graft and patient obesity. For those who opt to use an autograft, many patients find the bone graft harvest site to be more painful than the cervical surgery site itself.



2. Allograft bone for cervical spinal fusion
Allograft bone (a.k.a. ‘bank’ bone or donor bone from a cadaver) eliminates the need to harvest the patient’s own bone. Basically, the donor graft acts as a bone scaffolding onto which the patient’s own bone grows and eventually replaces over years. There are no living cells in the bone graft, so there is little chance of a graft ‘rejection’ like with an organ transplant. However, bone graft healing remains an issue, as there is a somewhat greater likelihood of bone graft failure with allograft compared to autograft.

With allografts, the speed of healing may be slower than an autograft bone fusion. In addition:

In one-level spinal fusions, it yields nearly equivalent fusion rates as autograft bone.

Anterior cervical instrumentation (plates & screws) are commonly employed with allografts to increase fusion rates.

With increasing numbers of levels to be grafted/fused, the differences in fusion rates between allograft and autograft become more significant.

There is a theoretical risk of transmission of an infection from a donor. The risk of contracting a disease such as HIV or hepatitis from an allograft has been estimated to be between 1 in 200,000 to 1 in 1 million. However, with modern procurement and sterilization methods for bone tissue, the risk is essentially moot.

Potential risks and complications of a spinal fusion surgery include:

The principal risk from a spine fusion is that the graft does not heal. In general, allograft bone does not heal quite as well as autograft bone, but both yield good results when used in the anterior cervical spine.

If a graft is used without instrumentation, there is a small chance (1% to 2%) of a graft dislodgment or extrusion. If this happens, another operation is necessary to reinsert the bone graft, and instrumentation (plates) can then be used to hold it in place.

Controversies about spine fusion surgery
While physicians agree on many things about spine fusion surgery, there are some areas that lack consensus. Two such areas are the type of bone used (autograft vs. allograft) and how many levels should be fused.

Type of bone used with fusion surgery
Whether an autograft or allograft is used is based mostly on a combination of the surgeon’s and patient’s preference. Some surgeons still feel most comfortable with autograft as it yields the best fusion rates. Other surgeons have had good results with allograft bone and wish to avoid the postoperative pain and possible complications associated with harvesting a bone graft.

In some instances, it may be more compelling to use a patient’s own bone. There are some situations where it is more difficult to get a solid fusion and using a better bone graft is reasonable. Factors that may make obtaining a solid fusion difficult include:

Revision surgery (previously failed grafts)

Smokers/smokeless tobacco product users

Multiple level fusions

Disease states which inhibit bone healing or which require medications that do so
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Bone graft for spinal lumbar fusion

Bone graft for spinal fusion surgeries may either be harvested from the patient (autologous bone) or from a cadaver (allograft bone).

Autologous bone is harvested from the patient's pelvic bone (iliac crest) and provides the spinal fusion with a calcium scaffolding for the new bone to grow on (conduction). In addition, autologous bone also contains bone-growing cells (osteoblasts) and bone-growing proteins (bone morphogenic proteins).

Allograft bone simply provides a calcium scaffolding and does not have any bone-growing cells or bone-growing proteins. In the lumbar spine, allograft bone is restricted for use in ALIF or PLIF procedures in which bone graft is placed in compression (the compression aids the healing process for the bone). In a posterolateral gutter spine fusion, in which the bone is placed in tension, allograft bone by itself will not heal well (although allograft chips combined with autograft may be used to extend the harvested bone graft).

Autologous bone, in which the bone is harvested from the patient’s body during spine surgery, has the obvious disadvantage of higher post-operative pain. Most of the pain associated with bone graft harvesting is either from too much muscle stripping or from cutting the small sensory nerves (cluneals) that lie in the fat layer over the pelvis (iliac crest). With careful surgical technique, both of these pitfalls may be avoided.

In posterolateral gutter spine fusion and PLIF procedures, a single incision can be used for the spinal fusion surgery and to harvest the bone from the pelvis (iliac crest). The pelvis can be approached through a plane that has no nerves or blood vessels, and only the top portion of the crest needs to be stripped of its muscles (gluteal muscles). Use of this surgical technique minimizes the blood loss and post-operative pain associated with bone graft harvesting.

Bone harvested for ALIF procedures is done through a separate incision (one inch to two inches long) over the iliac crest. Again, only the very top portion of the iliac crest needs to be removed and the soft cancellous (spongy) bone from in between the cortical (hard) layers of bone is scooped out.

Scooping the bone out of the pelvic bone does not result in a lot of pain because there are no nerve fibers inside the bone. However, care must be taken to avoid the sensory nerve in this region (lateral femoral cutaneous nerve) as damage to this nerve can produce pain and numbness in the front of the thigh (meralgia parasthetica). In general, this approach should be associated with minimal post-operative pain or discomfort because limited soft tissue stripping is needed.

There are currently several products on the market and in development that act either as a bone graft extender or substitute. Demineralized bone matrix (bone that has had the calcium removed) has been available for the past several years. It carries some of the bone morphogenic proteins that the body uses to induce bone formation. There are also calcium hydroxyappetite products or coral, both of which have structures similar to bone and act as scaffolding for new bone.

There has been a lot of excitement among spine surgeons awaiting the new bone morphogenic protein products that are expected to be strong inducers of bone growth (osteoinductive). These new products will be relatively expensive, but will probably be able to grow bone even better than the patient’s own bone and bone graft harvesting may no longer be necessary.




3) My OSS was assisted by a laparascopic surgeon who did the abdominal part. How does that differ from today's minimally invasive approaches??

I am not certain I know how to answer this question, but maybe someone else does and will come along and answer it for you....

4) what's the latest on nucleoplasty? I found this study of nucleoplasty, but I think it is still not popular on the board, but not real certain....best to ask it of others publicly....The results of the study are probably dependent on who is doing the study as well...

Abstract ID: A-38
Abstract Title: The Efficacy of Nucleoplasty™ in the Treatment of Contained Herniated Lumbar Intervertebral Discs
Authors: Provenzano D1, Dellapiazza D2, Gaughan J3, Kabazie A4
Ohio Valley General Hospital1, Ohio Valley General Hospital2, Temple University School of Medicine3, The Western Pennsylvania Hospital4
Poster Type:

ABSTRACT BODY
Introduction: Sixty to 80% of adults will experience low back pain, the leading cause of both time lost from work and permanent disability in North America.(1) Technologies for percutaneous disc procedures have been introduced to treat both low back and radicular pain. Disc nucleoplasty™ utilizing coblation technology™ was FDA cleared in 2001 and to date greater than 35,000 procedures have been performed. Safety and efficacy data published on this technique are relatively scarce. To assess the safety and efficacy profile of nucleoplasty, we performed a retrospective review.

Materials and Methods: Following IRB approval, a retrospective review was performed of perioperative clinical records and procedure notes of all patients who underwent nucleoplasty from 2001 to 2004 by the senior author (AJK). Assessment of long-term safety and efficacy occurred via a prospective telephone follow-up. Previously, some patients received conservative therapy including modalities such as opioid and non-opioid medications, physical therapy and epidural steroids. Patients were divided into three groups based on length of follow-up: less than 6 months, 6 months to 1 year, and greater than 1 year. A clinically important reduction in pain was considered to be ≥30% on a 0 to 10 verbal numerical rating scale.(2)

Results: 121 patients (133 procedure levels) underwent nucleoplasty from 2001 to 2004 with a mean duration of symptoms of 1276 ± 1454 (s.d.) days and a mean follow-up of 511 ± 571 days. The mean age was 40 ± 11 years (64 males & 57 females). Prior to the procedure 75% of patients had constant pain. The primary pain was axial lumbar spine in 91 (75%), radicular in 16 (13%), and both in 14 (12%) patients. No difference in outcome was noted among the areas of primary pain. 43% of patients were associated with workers compensation claims with no statistically significant difference in improvement compared to non-workers compensation patients. 69 patients (57%, 95% CI 48%-66%) had ≥30% pain relief and 53 patients (44%, 95% CI 35%-53%) had ≥50% pain relief. Pain relief achieved did not decrease with time. There was no difference in pain reduction between the three time frame groups. No complications were associated with this procedure including discitis or neurological injury.

Discussion: Over 500,000 percutaneous decompressions for herniated discs have been performed in the last 20 years, often allowing patients to avoid a more invasive technique.(3) The nucleoplasty procedure is a safe technique providing an improvement in verbal numerical rating scales. Future studies on nucleoplasty would benefit from randomized controlled studies with direct comparison to conservative therapy, other percutaneous disc decompression technologies, and microdiscectomy. In addition, defining selection criteria is warranted.

All work was completed at Western Pennsylvania Hospital.

1. Garfin, et al. 1997. Orthopaedic Knowledge Update: Spine. Rosemont: American Academy of Orthopaedic Surgerons.
2. Farrar, et al. Clinical importance of changes in chronic pain intensity measured on an 11-point numerical pain rating scale. Pain. 2001;94:149-158.
3. Reddy, et al. New approach to the management of acute disc herniation. Pain Physician. 2005;8:385-389.

ATTACHED FILES
Reg Anesth Pain Med 2006; 30(3):A-38