Percutaneous Spine Procedures: Just Setting the Stage for Fusion?

Welcome to the Orthopedic Theatre! Where all the world is an operating room, the operating table is center stage, the spine surgeon has the lead role, and everyone hopes for a good outcome. Let’s set the stage and open the playbill for the show. Today’s performance will focus on surgical decompression procedures. We will look at selective nerve root blocks, laminectomies, and percutaneous discectomies using the PearlDiver Patient Records Database to longitudinally track patients in order to find out how often these procedures lead to spine fusion. Quiet! The play is about to begin and the ending may be different than what you think!

Act 1: Common Spine Diagnoses Decompressive Treatments

Degenerative disc disease and herniated discs are the most common spine diagnoses in the non-Medicare population, according to the PearlDiver Patient Records Database. When taken together, degenerative disc disease accounts for 21% of the spine diagnoses in this population while herniated discs account for 20%. These diagnoses are most common in the lumbar region, followed by the cervical region.

Back pain is treated along a continuum of care, ranging from conservative therapies to invasive surgical procedures such as spine fusion. Conservative treatments traditionally include exercise regimes, NSAIDs, physical therapy, and steroidal injections. Conservative treatment focuses on pain management, and is generally recommended for at least six months prior to surgical intervention.

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When surgical intervention is necessary, minimally invasive decompression procedures are often the starting point. The basic goal in decompression procedures is to reduce or stop the pain by taking pressure off pinched nerves. Discectomies are the most common procedure performed in the PearlDiver Patient Records Database. A discectomy is performed to remove part of or the entire disc in order to relieve pressure on the nerve. A laminectomy is also a commonly performed decompression procedure where the lamina is removed, whereas during a laminotomy only part is removed. A relatively new technology known as plasma disc decompression (PDD), or nucleoplasty, involves using the ArthroCare’s Coblation® technology to remove tissue from the nucleus of the disc in order to relieve pressure on the nerve created by the bulging disc.

We analyzed primary diagnoses for over 8,400 primary inpatient decompression procedures in the PearlDiver database as defined by ICD-9 procedure code 03.09. It should be noted that this code covers laminectomy, laminotomy, foraminotomy, and spinal canal exploration. As can be seen in Chart 1, the most common primary diagnosis associated with inpatient decompression procedures is spinal stenosis, followed by lumbar disc displacement. Also shown, is a relatively uncommon cause of spinal stenosis that can lead to a decompression procedure, which is the development of a synovial cyst in the lumbar spine. These generally develop at the L4-L5 level. The cyst often develops due to degeneration and is most common in patients older than 45.

Chart 1: Common Primary Diagnoses Associated With Decompression Procedures (Inpatient) Chart 1 Source: PearlDiver Patient Record Database (2004-June 2007)

We also analyzed primary diagnoses for over 21,500 non-fusion related inpatient primary discectomy procedures as defined by ICD-9 procedure code 80.51. It should be noted that if a decompressive laminectomy is performed in conjunction with a discectomy it is covered under this code. Based on PearlDiver inpatient procedure data from 2004–June 2007, over 87% of primary procedures associated with the discectomy are lumbar vertebral disc herniations.

Act 2: The Framework for Our Outcomes Analysis

Outcomes with respect to spine procedures are often measured by pain scales such as the Oswestry Disability Index (ODI) or the Visual Analog Scale (VAS). Using longitudinal patient tracking in the PearlDiver Patient Records Database, we focus in on various decompression procedures and how often patients return subsequently for spine fusion. While pain reduction is the primary focus of most treatments and can be captured in the pain scales mentioned, we believe it is also important to see which procedures lead to more invasive treatments over a given time period such as fusion. In this study, we will examine patients who underwent facet nerve root blocks, inpatient stand-alone discectomy, inpatient laminectomy/laminotomy, and percutaneous disc decompression.

Act 3: Results of the PearlDiver Analysis of Inpatient Decompression Procedures and Selective Nerve Root Blocks

Inpatient Discectomy
Our first analysis focuses on patients who had a non-fusion related, inpatient discectomy as defined by ICD-9 procedure code 80.51 as primary procedure. There were 5,664 patients in this study comprised of 3,157 males (55.7%) and 2,507 females (44.3%). The maximum follow-up period was 3.5 years, as all the surgeries took place in 2004, and patient records were tracked through June 2007. We found that overall 4.4% of the patients returned and underwent a spine fusion. By gender, 3.7% of males and 5.4% of females returned.

Inpatient Decompression Procedure
In this analysis, we looked at patients who had a primary inpatient spinal decompression procedure (laminectomy, laminotomy) using ICD-9 code 03.09. It should be noted that this code excludes a laminectomy performed with a disc excision, as this procedure is covered under ICD-9 code 80.51. We analyzed 2,010 patients in this study comprised of 1,095 males (54.4%) and 915 females (45.6%). We found that overall 3.9% of patients subsequently returned for a spine fusion. By gender, 3.2% of males and 4.8% of females returned during the period analyzed.

Discectomy and Laminectomy Procedure at Different Vertebral Levels
Continuing with our focus on decompression-related procedures, we analyzed 546 patients who were coded with ICD-9 procedure codes 80.51 and 03.09 the same day in 2004. In our prior two analyses, we have isolated these codes on a stand-alone basis where they were coded as the primary inpatient procedure in order to be as specific as possible. If these two codes appear during the same operative session, this implies that a discectomy and a laminectomy/laminotomy were performed, but at different vertebral levels. We analyzed 546 patients who underwent this procedure scenario. By gender, there were 342 males (62.6%) and 204 females (37.4%). We found that overall 8.4% of these patients returned for a subsequent spine fusion. By gender, 7% of males and 10.8% of females returned for spine fusion. These results displayed in a higher percentage of patients returning for fusion than when the procedures were analyzed as stand-alone. Reasons for this may include the severity of the condition, the fact that two procedures were performed, or because the operation was performed over more than one vertebral level, as defined by the coding.

Selective Nerve Root Block
For this analysis, we have chosen patients who underwent a single-level lumbar or sacral selective nerve root nerve root block as defined by CPT code 64483. This injection is performed with fluoroscopic guidance and employs a transforaminal approach. We analyzed 15,933 patients who underwent this procedure in 2004. Overall, 1,420 patients, or 8.9% returned for a subsequent spine fusion. By gender, 7.8% of males and 10.0% of females returned for fusion during the period analyzed.

Act 4: Percutaneous Discectomy/Nucleoplasty

Percutaneous technologies to correct disorders involving herniated discs are gaining popularity. Currently, they are coded under CPT code 62287. We analyzed 319 patients who underwent a percutaneous discectomy in 2004. There were 153 males (48%) and 166 females (52%). Overall, 8.2% of these patients returned for a spine fusion during the period analyzed. By gender, 6% of females and 10.5% of males returned for fusion.

We also analyzed outcomes with respect to the site of care at which the procedure was performed. As can be seen in Chart 2, 60.1% of the procedures were performed in the outpatient hospital setting, while 38.2% were performed in ambulatory surgical centers. Based on our analysis, there was no difference in the chances of returning for fusion based on the site of care at which the procedure was performed.

Chart 2: Percutaneous Discectomy Procedures by Site of Care chart Source: PearlDiver Patient Record Database

Encore: NASS 2007 Electronic Posters 5

Below we are highlighting a paper presented at NASS 2007 that compares plasma disc decompression to selective nerve root block. It should be noted that this is an interim analysis of an ongoing multi-center, prospective, randomized, controlled clinical study and the data presented is based on patients who have reached six-months follow-up. Based on this paper, outcomes after receiving PDD were encouraging.

Plasma Disc Decompression Compared to Selective Nerve Root Block for Treating Symptoms Associated with Contained Disc Protrusion: Interim Results from a Randomized, Controlled Clinical Trial

By Dr. Peter Gerszten, Dr. Sarjoo Bhagia, Dr. Carl Covey, Dr. William Ford, Dr. Christopher Huston, Dr. Jack Kabazie, Dr. Christopher Mocek, Dr. J. Rathmell, Dr. Peter Reusswig, Dr. David Schultz, Dr. T. Simopoulos, Dr. Matthew Smuck, Dr. Jerry Tarver.

According to the abstract, the purpose of the study is “to compare PDD to selective nerve root injection (SNRI) for treating patients with radicular pain originating from a disc protrusion by evaluating treatment efficacy and rate of improvement in symptoms through the first 6 months post-treatment.” According to the authors, the primary aim was to assess VAS scores.

In conclusion, the authors stated that “PDD was associated with greater pain reduction, improved functional scores, and higher proportion of satisfied patients than continued injection series.”

Standing Ovation!

Summary Table: Spine Fusion Following Non-fusion Procedures chart Source: PearlDiver Patient Record Database

In the continuum of spine care, invasive, motion limiting surgeries such as fusion are the last stop when it comes to treating back pain. Our focus has been on procedures that are generally performed earlier in the continuum of care in an effort to see how often they lead to fusion. Based on our analysis, we found that patients who underwent selective nerve root blocks, the most conservative treatment out of the group of procedures we analyzed, returned most often for fusion (8.9%). Patients who had an inpatient laminectomy/laminotomy returned the least often during the period analyzed (3.9%).

The comparison between patients who had an outpatient percutaneous discectomy (defined by CPT code 62287) versus an inpatient discectomy were of interest. Patients who had a primary, non-fusion related inpatient discectomy returned for fusion 4.4% of the time, while patients undergoing a percutaneous discectomy returned for fusion 8.2% of the time.

And the curtain closes! However, PearlDiver analysts will continue to investigate behind the scenes, so stay tuned for your backstage pass!

Written by Matt Menze, PearlDiver Spine Analyst