Life Is Under the Knife: The Rest is Just Conversation

Your name has been changed and we no longer recognize your existence. Your mission, should you choose to accept it, is to gather intelligence from the PearlDiver database on posterior lumbar fusion. Your top-secret passwords will be ICD-9 code 81.08 and DRG codes 497 and 498. The following data are for your eyes only!  

Mission Objective 1: Background
Incognito, gather information on posterior lumbar fusion. Maintain your anonymity at all costs! 

Lumbar spine surgery can be broadly grouped into two areas. The first area is comprised of decompression procedures such as a microdiscectomy or laminectomy. These are less invasive than fusion and often provide relief without some of the drawbacks seen in fusion, such as partial loss of motion. Decompression procedures are also often performed along with fusion. According to Dr. Peter Ullrich, Jr., of Spine-health.com, “decompression is a surgical procedure that is performed to alleviate pain caused by pinched nerves.” Dr. Ullrich reports that microdiscectomy surgery success rates range between 90 and 95%, while laminectomy success rates range from 70 to 80%.

Lumbar spine fusion could be the next step in the continuum of care if no improvement is seen after more conservative treatments. The most common approach, and the one that is the subject of this article, is posterior lumbar fusion. The anterior approach is also used, and the lateral approach is gaining popularity.

Posterolateral gutter spine fusion is the most popular method among surgeons who perform lumbar fusion. The method involves placing a bone graft on the posterolateral portion of the spine to achieve fusion. There are also several interbody fusion methods, including posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), and anterior lumbar interbody fusion (ALIF). Interbody fusion involves placing the bone graft directly in the disc space.

Mission Objective 2: Obtain Patient Records
You’re at the point of no return. Its time for some espionage-time to obtain actual patient records. Enter the PearlDiver database, and analyze what procedures are commonly performed with anterior lumbar fusion. The following tables are classified!

Posterior lumbar fusion is often performed with other procedures, as evidenced by the patient records displayed in Table 1. The first four records represent an additional method of lumbar fusion where the spine is fused from the anterior and posterior approaches. Fusion rates can be greater than 95% as a result of this method. This is also one of the more expensive methods in lumbar fusion. The next four records show the bone graft procedure, in which graft material is obtained from the pelvis, and is denoted by ICD-9 code 77.79. Also seen are instances of discectomies (ICD-9 80.51) and decompression procedures (ICD-9 03.09) being done along with posterior lumbar fusion.

Table 1: Lumbar Fusion Patient Records (Associated Procedures)

Table 2 presents the associated diagnoses seen with the patient’s procedure. The patient groups are color coded and the diagnoses that lead to the procedures can be seen. Diagnoses include degenerative disc disease, herniated discs, spondylolisthesis, and lumbar spinal stenosis. Evidence of hypertension and diabetes can also be seen in these patients. 

Table 2: Lumbar Fusion Patient Records (Associated Diagnoses)

According to PearlDiver data, discectomies are the most common procedures performed with posterior lumbar fusion, followed by bone grafts, anterior lumbar fusion, and decompression procedures. As can be seen in Table 3, discectomies increasingly accompany lumbar fusion, on a percentage basis. Chart 1 shows the same data graphically.

Table 3:  Procedures Performed With Lumbar Fusion, 2004 –2006

Chart 1: Procedures Performed With Lumbar Fusion, 2004 – 2006 Combined

Mission Objective 3: Identify Demographics
Attain positive ID of patients on whom the procedure is commonly performed.

Posterior lumbar fusion is performed on women more often than on men: 56% to 43%, respectively. As can be seen from Chart 2, it is most commonly performed between the ages of 40 and 60 years. A drop-off can be seen at 65 years of age, which reflects the fact that the PearlDiver database contains actual patient reocords from a consortium of insurance companies. Hence, the 65 and under population is represented.

Chart 2: Posterior Lumbar Fusion in Females, 2004 – 2006

Mission Objective 4: Ascertain and Analyze Critical Charges
With patient records in hand, infiltrate the PearlDiver database and find relationships among the charges.

Charges for lumbar fusion vary due to factors such as whether the patient was admitted with complications and comorbidities (CC), any accompanying procedures, and the method employed. The most expensive method of lumbar fusion is combined anterior/posterior spinal fusion (DRG code 496). Charges are often over $100,000. This can be observed in Table 1. For this mission, we are going to focus on ICD-9 code 81.08 (posterior lumbar fusion) as it relates to DRG codes 497 (spinal fusion except cervical with CC) and 498 (spinal fusion except cervical with CC).

Patients admitted with CC tend to use more hospital resources than those without them. The charges are applied accordingly. Chart 3 shows average charges for patients admitted without CC (DRG 498). An interesting observation can be made with respect to average charge behavior in the chart. Average charges increase between the 35 – 39 age group and peak in the 40 – 49 age group. They then decline somewhat in later age groups. This is in contrast to what we have seen with respect to anterior cervical fusion, where charges tend to increase with age. This behavior is not seen when comparing charges by age group when patients are admitted with CC, as seen in Chart 4. In fact, the average charges remain relatively flat over the age groups. However, when compared on an annual basis, charges increase.  

Chart 3: Posterior Lumbar Fusion Charges by Gender-DRG Code 498 (Without CC)

Chart 4: Posterior Lumbar Fusion Charges by Gender-DRG Code 497 (With CC)

Mission Objective 5: Complications—Get the numbers!
Like the mission objective says: Numbers, Numbers and more Numbers!

Based on an analysis of 2004 and 2005 data, two areas of interest arise. The first and most obvious is the fact that admittance with CC rise as age increases. This trend is evident in both genders. The second is the variability in younger age groups as seen in the square on Chart 5. For example, it can be seen in Chart 5 that about 30% of patients who undergo posterior lumbar fusion between the ages of 40 and 44 can expect to be admitted with CC. On average, just over 33% of males were admitted with CC over the 2004 – 2006 time frame while the rate for females was slightly higher at just over 35%.

Chart 5: Percent of Lumbar Fusion Patients by Group Admitted With CC

Tables 4 and 5 show average charge comparisons by gender. The tables compare average charges for patients who underwent posterior lumbar fusion (ICD-9 81.08) with CC, to those who had the surgery without CC. Effectively, patients admitted with CC could be charged up to 20% more than if admitted without CC. Patients admitted with CC represent a substantial market for medical device companies. Technology that has the potential to lower charges for those admitted with complications would be welcomed by hospitals.

Table 4: Average Fusion Charges for Males

Table 5: Average Fusion Charges for Females

A patients’ time in the hospital, or length of stay, often correlates with the amount of charges. Table 6 below shows average lengths of stay for patients admitted with and without complications and comorbidities. As one would expect, patients admitted with CC exhibit longer lengths of stay. Also, it is encouraging that the trend is lower with respect to length of stay on an annual basis. As can be seen in the charge trends over the 2004 – 2006 time period, inflation has continued with respect to posterior lumbar fusion even as lengths of stay have declined.  

Table 6: Average Length of Stay (Posterior Lumbar Fusion)

The rise of minimally invasive surgery and surgeon acceptance of it should augment not only declining trends in lengths of stay, but the leveling out, if not decline, of charges. Exciting innovations such as disc arthroplasty, facet joint repair, and nucleus replacement could contribute not only to the well being of patients, but hopefully to more cost effective procedures as well.

Mission in Review

Based on the data presented above, several conclusions can be drawn.

• Common diagnoses seen with posterior lumbar fusion include DDD, disc herniation, spondylolisthesis, spondylosis, and stenosis
• Discectomies are increasingly being performed with posterior lumbar fusion
• Lumbar fusion is accompanied by another procedure roughly 80% of the time
• Lengths of stay declined on an annual basis between 2004 and 2006
• Charges with respect to patients admitted without CC seem to peak between the ages of 40 and 49
• Male patients admitted with CC are charged 15 – 23% more on average
• Female patients admitted with CC are charged 15 – 20% more on average

Mission Accomplished!