Patient outcomes in lumbar discectomy for lumbar disc herniation

Marc Darrow, MD, JD.

A lumbar discectomy describes a surgical procedure that removes the discs of the spine that are causing you pain and functional difficulties. The surgery can be performed as minimally invasive, smaller incision or as “open” back surgery. No surgery is “easier.” Less invasive simply means the surgical wound is not as large, the surgical procedure itself, whether open or minimally invasive is still the same. Part of the vertebrae, the lamina has to be cut away so the surgeon can access the bulging, herniated disc. Once there, nerves have to be gently set aside. Then the disc or discs in a multi-level procedure can be cut away. Your surgeon may decide to perform a lumbar spinal fusion as well if he/she feels that spine will become too unstable because of the surgery. Then plates, screws and bone graft will be introduced to fuse two vertebrae together.

This type of surgery is usually considered after a long bout of conservative care treatments and in patients who do physically demanding work or have spinal hypermobility and significant instability. The patients may have displayed symptoms of:

• Severe back pain
• Weakness or numbness in leg or foot
• A leg pain that is worse than the back pain or leg pain where no back pain is present.

Typically however, surgery is usually delayed as long as possible, except in situations where the patient has lost bladder control or there are other significant neurological defects.

Residual back pain following spinal surgery may still occur in many patients despite appropriate management

A November 2023 study (1) while suggesting “surgical management of lumbar disc herniation in the form of discectomy is superior to conservative management in terms of better recovery and pain relief, there was still a problem with recurrence, residual back pain, and disability.” These are “common expected complications following surgery.”

In this study of 201 patients, 59% male, ages ranging from 41 to 60 years, most patients underwent one surgery (83.6%) in the form of discectomy alone (90.5%) at L3-L4 (58.7%), for which the intervertebral disc was the most common degenerative indication for surgery.

• All patients (100%) had low back pain preoperatively, and most patients (50.7%) had no back pain six months postoperatively.
• The level of disability six months postoperatively was moderate in 40.4% of the patients.
• Preoperatively, 58.2% had diminished neurological status, while only 29.9% showed a deficit postoperatively.

Postoperative low back pain was significantly associated with office-based jobs (60.5%) and a high number of surgeries. The following factors were observed to be risk factors for having lower back pain: six months postoperatively, being unemployed, having an office-based job, and the underlying cause of the problem being degenerative disc disease.

The researchers conclusions: “Lumbar discectomy is a successful procedure for relieving low back pain among patients with degenerative spine disease, with an improvement that involves neurological status. However, residual back pain may still occur in less than half of the patients despite appropriate management, such as being unemployed or office-based employees and having multiple spine surgeries. However, low back pain-related disability is often moderate, with increasing severity seen with increased age, being female, and being unemployed.”

The factors associated with the recurrence of lumbar disk herniation following lumbar discectomy

A March 2022 paper (2) examined the factors associated with the recurrence of lumbar disc herniation following lumbar discectomy. In this study the researchers looked to understand what would make some patients be at risk for recurrence of lumbar disc herniation.

To do this, the medical records of  816 consecutive patients with lumbar disc herniation who underwent lumbar discectomy were examined. Patients were followed up postoperatively for more than 5 years. Patients were divided into 3 groups;

• group 1 included patients who experienced symptomatic recurrence of lumbar disc herniation within the first postoperative 24 months 
• group 2 included patients with symptomatic recurrence of lumbar disc herniation after 24 months,
• and group 3 included the patients who hadn’t experienced symptomatic recurrence of lumbar disc herniation. 

What the researchers found was patients who had traumatic spinal injury before surgery, were overweight, or suffered a traumatic spinal injury after surgery (such as those that can occur during workout, sports, or physically demanding lines of work) were at higher risk for recurrence of lumbar disc herniation. The doctors here suggested that “to reduce the risk of recurrence of lumbar disc herniation, patients with these risk factors should receive more attention during surgical interventions. The patients should avoid gaining weight and potential traumatic accidents.”

Weight loss can help avoid back surgery

Another March 2022 study (3) assessed risk factors for poor outcomes following minimally invasive discectomy. In this study, patients were divided into satisfied and dissatisfied subgroups based on function, back and leg pain scores.

• A total of 222 patients (92.1%) completed 2-year follow-up, and the postoperative function, back and leg pain scores were significantly improved after surgery as compared to preoperatively. The risk factors for  poor short-term functional improvement:
  • older age
  • lateral recess stenosis
  • and lower pre-surgery functionality. 

The risk factors for  poor short-term pain improvement:

• Higher levels of back pain pre-surgery was associated with poor short-term relief of back pain, while absence of decreased sensation, and far-lateral disc herniation, were associated with poorer short-term relief of leg pain. Lumbar facet joint osteoarthritis was identified as a risk factor for poor functional improvement and relief of back pain.

The question is then why did 38% of patients not get good improvement?

A July 2023 study (4) examined improvements in pain following decompressive spinal surgery, in the form of laminectomy or discectomy. This was a large study of 25,349 patients of whom 92.2% reported significant back pain at baseline. Sixty-two percent of patients attained the minimal clinically important difference (a 30% reduction) in their back pain, with 51% reporting a substantial improvement (more than 50% pain reduction). This improvement was observed by 6 weeks post-surgery and was mostly maintained at 2 years.

Patients suffering with predominantly back pain faired slightly better than patients with predominantly leg pain. (63.6% vs 60.1% achieved minimal clinically important difference.)

In the end, low back pain improved in approximately 62% of patients who undergo lumbar decompressive surgery, with 51% experiencing substantial improvement. The question is then why did 38% of patients not get good improvement?

Exploring the research: Is minimally invasive surgery better than open surgery?

A September 2021 study (5) suggests that “Although minimally invasive techniques have some advantages over the open techniques in the peri-operative factors  (hospital admission, anesthesia, surgical prep), all the techniques are effective and provide similar pain relief and functional outcomes at the end of two years. There were minor differences in incidence of complications between techniques.”

• The overall complication rate was 10.1%.
• The most common complication was recurrence (6.86%), followed by re-operation (4.3%), Cerebrospinal fluid (CSF) leak (2.24%), wrong level surgery (0.74%), superficial infection (0.62%) and deep infection (0.37%).

A November 2022 study (6) compared percutaneous transforaminal discectomy, microendoscopic discectomy and traditional open surgery through surgical indicators and postoperative outcomes. In a review of 6467 cases, the therapeutic effect and safety of percutaneous transforaminal discectomy, microendoscopic discectomy and open surgery in the treatment of lumbar disc herniation were comparable. Percutaneous transforaminal discectomy had obvious advantages in that it is minimally invasive, with rapid recovery after surgery, but its recurrence rates and revision rates were higher than microendoscopic discectomy and open surgery. The authors concluded by suggesting: ” it is not possible to blindly consider replacing microendoscopic discectomy and open surgery with percutaneous transforaminal discectomy.” The research of differing types of surgery is discussed below.

Returning to work after surgery

A September 2021 study (7) examine the length of time it took patients who underwent elective lumbar surgery to return to work. The study authors noted: “Time to return to work after elective lumbar spine surgery is variable and dependent on many factors including patient, work-related, and surgical factors.” To assess results the researchers examined data of patient outcomes for the following procedures:

• Elective 1- or 2-level discectomy, laminectomy, and/or fusion procedures

Then they assessed the percentage of patients who returned to work and the time to return to work postoperatively.

Results:

• Of the 1805 employed patients included in this analysis:
  • 71% returned to work at an average of 61 days.
  • The average return to work after:
    • a discectomy was 51 days
    • a laminectomy was 46 days
    • a fusion procedure was 90 days
• Predictors of early return to work included:
  • Being male
  • Having a higher education level (high school or above),
  • Higher preoperative Physical Component Summary score, (better function, less pain)
  • Working preoperatively,
  • NOT having a fusion

Those who did not return to work:

• Having symptoms lasting more than 2 years
• An increased number of comorbidities
• An education level below high school,
• and an active workers’ compensation claim.

82% eventually get back to work

An August 2021 study (8) focused on the fusion aspect of surgery and the longer delay to get back to work. There research in over 5000 patient outcomes suggested:

• The need for fusion in lumbar disc herniation cases is unusual, seen in only 10% of cases in this study.
• The addition of fusion to the surgical procedure decreased the returned to work rate from 85 to 66% at 3 months and from 93 to 82% at 12 months post-op.

77% for patient with a heavy-very heavy workload

A March 2024 study (9) examined the rate and time to return to work based on workload intensity after elective degenerative lumbar spine surgery. In this study, 1290 patients working pre-operatively who underwent a primary one- or two-level elective lumbar spine surgery for degenerative conditions were evaluated. The percentage of patients who returned to work at 1 year and the time to return to work post-operatively were analyzed based on workload intensity.

Of the 1290 patients included in the analysis, the overall rate of return to work was 82% at one year. Based on workload there was no significant difference in time to return to work after a fusion procedure, with average time to return to work being 10 weeks. For non-fusion procedure, the sedentary group had a statistically significantly quicker time to return to work than the light-moderate and heavy-very heavy groups. The rate of return to work ranged between:

• 84% for patients with sedentary work to
• 77% for patient with a heavy-very heavy workload.

The author’s concluded: Average time to resumption of work was about 10 weeks following a fusion regardless of work intensity. There was more variability following non-fusion surgeries such as laminectomy and discectomy reflecting the patient’s job demands.

Return to Sport in the NFL, NBA, MLB, and NHL

A February 2022 paper (10) described the idea that athletes make a full recovery and return to previously to sport after discectomy debatable. In this paper the researchers wrote: “The treatment of Lumbar Disc Herniation in elite athletes is a debated topic that lacks consensus in the literature due to varying outcome reporting methods. The objective of this study was to quantify the overall performance of a sample of professional athletes before and after receiving a lumbar discectomy or microdiscectomy in a cohort of players in the National Football League (NFL), National Basketball Association (NBA), National Hockey League (NHL) and Major League Baseball (MLB).”

A total of 38 professional players met study inclusion criteria. NFL players had the lowest return-to-play (RTP) at nine of 14 (64%). The return-to-play for NBA, NHL and MLB players were comparable with 6/7 (86%) vs 8/9 (89%) vs 7/8 (88%). NFL players had the lowest average career length after surgery at 34.8 months, while NBA players had the longest average career length at 48 months. MLB players on average required the longest time to return to pre-surgical level of performance (24 months) and required the longest average recovery time at 12 months.

“Based on these results, the average performance of most elite athletes are likely to decrease after undergoing a lumbar discectomy. Although it appears that performance peaks in the initial years after the operation for some players, there was an overall long-term decline in this sample of elite athletes.”

Why the microdiscectomy fails

In February 2022 (11) researchers suggested that discectomy decreases facet joint distance (the segment is collapsing) and increases the instability of the spine. This is what they wrote: “Although the surgical gold standard (discectomy) for treating Lumbar disc herniation is well established, consequences from this surgery on the biomechanics of the spine are still a matter of discussion. Using a finite element model (a computer model)  of the L4-L5 spinal segment, this researchers aimed

• to determine the changes in facet joint distance during physiological motions of a lumbar spine in a healthy-normal condition, after conservative and aggressive percutaneous transforaminal endoscopic discectomy (PTED) to correct lumbar disc herniation, and during mild and severe (disk degeneration);
• to determine spine instability and endplate stresses under various physiological motions.

The results they suggest based on the computer model: “Aggressive-percutaneous transforaminal endoscopic discectomy in a healthy disc decreased facet distances in axial rotation, lateral bending, and flexion. Mild and severe disc degeneration increased the stiffness of the spine, resulting in a decrease in the range of motion (ROM) for all conditions. Severe disc degeneration decreased ROM as high as 57% for lateral bending, while a 13% decrease was observed for mild degeneration. High and abnormal endplate stress distributions were observed due to percutaneous transforaminal endoscopic discectomy and (disk degeneration).”

Microendoscopic discectomy, higher revision rates

A July 2022 paper (12) compared Microendoscopic (a very small incision) discectomy with conventional open lumbar discectomy. The researchers write: “Microendoscopic discectomy for lumbar disc herniation has been shown to be as effective as traditional microdiscectomy or open discectomy in terms of clinical outcomes such as pain relief, and it is less invasive. . . Given the higher reoperation risk with microendoscopic discectomy compared with microdiscectomy or open discectomy at an average of 4 years of follow-up, surgeons should select microdiscectomy or open discectomy, despite the current popularity of microendoscopic discectomy. The revision risk of microendoscopic discectomy compared with microdiscectomy or open discectomy in the long term remains unclear.”

Predicting Lumbar Herniation Recurrence following Surgical Repair

A July 2022 paper (13) attempted to suggest a standard criteria for evaluating the risk of recurrent disk herniation following surgical repair. To do this, researchers investigated the predictive values of five pre-surgical imaging parameters.

• 188 patients(89 female, 99 male, median age 50) receiving first corrective surgery for lumbar disk herniation were enrolled.
• Microdiscectomy was performed in 161 of these patients and endoscopic translaminar discectomy approach was performed in 27 patients.
• Recurrent disk herniation was observed in 21 of 188 patients.
  • 17 of the recurrences disc herniations were seen in those who underwent microdiscectomy and 4 in those who underwent endoscopic translaminar discectomy.
  • There were significant differences in pain, function and disability scores at four, twelve, and 24 months between patients with recurrence and the 167 no-recurrence patients. Patients with poor clinical scores and recurrence exhibited additional radiological abnormalities prior to surgery such as poor paraspinal muscle quality, longer annular tears, higher Modic change type, higher modified Phirrmann disk degeneration grade ( grading system to assess disc degenerative disease severity), and sacralization or fusion. This risk evaluation protocol may prove valuable for patient selection, surgical planning, and choice of postoperative recovery regimen. 

Study questions microdiscectomy for sciatica pain

A February 2022 study (14) questioned microdiscectomy for sciatica pain and assessed the long-term surgical treatment effects, suggesting that previously reported outcomes may not accurately represent true outcomes and patient complications may be more prevalent. What the researchers wrote: “It remains unclear whether the long-term results of (random control trials) regarding the outcome of microdiscectomy for lumbosacral radicular syndrome (LSRS) are generalizable (meaning accurate for all sciatic pain sufferers). The purpose of this study was to determine the external validity of the outcome presented in random control trials after microdiscectomy for lumbosacral radicular syndrome (LSRS) in a patient group from a high-volume spine center.

• 246 patients had  a single level microdiscectomy for MRI disk-related lumbosacral radicular syndrome (LSRS).
• Patient responses from questionnaires for back and leg pain and function were examined.

Re-operation occurred in 64 (26%) patients. Unfavorable perceived recovery was noted in 85 (35%) patients, and they had worse leg and back pain than the 161 (65%) patients with a favorable recovery. Conclusion: “In this cohort study, the long-term results after microdiscectomy for LSRS were less favorable than those obtained in random control trials, possibly caused by less strict patient selection than in random control trials. Our findings emphasize that patients, who do not meet the same inclusion criteria for surgery as in random control trials, should be informed about the chances of a less favorable result.”

Radicular pain improves but not the back pain

A January 2022 paper (15) wrote: “Most postoperative patients with herniated lumbar disc complained of lower leg radiating pain (LRP), referred buttock pain (RBP), and low back pain (LBP). When discectomy is performed, improvement in lower leg radiating pain (LRP) is observed due to spinal nerve irritation. However, long-term lower leg radiating pain (LRP) due to degenerative changes in the disc may occur postoperatively. In addition, limited research has been reported on the short-term (within 1 year) improvement in low back pain (LBP) after discectomy.”

• Low back pain showed both statistical and clinical improvement within the first 3 months postoperatively, but the improvement was not observed until 12 months postoperatively.
• Referred buttock pain (RBP) and
• Leg radiating pain (LRP) showed both statistical and clinical improvement within the first 3 months and further consistently showed statistical improvement.
• Low back pain (LBP) improved clinically only until 3 months postoperatively regardless of the type of herniation.
• Low back pain showed improvement within the first 3 months postoperatively and plateaued afterward, and Referred buttock pain and radiculopathy showed consistent improvement until 12 months postoperatively. This may explain why patients from 12-month follow-up showed improvement in referred buttock pain and radiculopathy but not low back pain.

Lumbar sacralization

A March 2024 study (16) assessed outcomes in patients who underwent L4-L5 microdiscectomy who also suffered with lumbar sacralization (the abnormal fusion of the L5-S1 vertebrae). In this study of two hundred and forty patients, those with lumbar sacralization suffered from higher risk of postoperative radicular and back pain , higher recurrence rates, and worse disability

Surgery versus conservative care

Research (17) suggests that “evidence comparing the effectiveness of surgical and conservative treatment of symptomatic lumbar disc herniation is controversial. (While) surgical treatment patients reported less back pain at six weeks than those receiving conservative therapy, were more likely to report more than a 50% decrease in back pain symptoms from baseline to 6 weeks and reported less physical function disability at 52 weeks. The other assessments showed minimal between-group differences with conservative care group, including the null effect (that surgery was not better than conservative care was not an expected result).