Acute Lumbar Disk Injuries in Active Patients
Making Optimal Management Decisions
Mathew W. Lively, DO; Julian E. Bailes, Jr, MD
THE PHYSICIAN AND SPORTSMEDICINE - VOL 33 - NO. 4 - APRIL 2022
For CME accreditation information, instructions and learning objectives, click here.
In Brief: Managing acute lumbar disk herniations in active patients can be challenging for physicians, especially when controversies surrounding treatment options make choosing the right care more difficult. The prognosis for lumbar disk herniations is generally favorable, and most patients will improve with conservative measures, such as early activity and avoiding bed rest. Minimally invasive techniques, such as percutaneous diskectomy, laser diskectomy, and epidural corticosteroid injection, may help control sciatic pain. Athletes who sustain late-season disk injuries should receive conservative treatment before considering surgery. Those who have early-season injuries may be able to return to competition sooner by having a microdiskectomy before a full course of conservative therapy is completed, but data supporting this approach are currently lacking.
The incidence of low-back pain in college athletes ranges from 6.9% to 64.8%,1-6 and, similar to findings in the general population, most back injuries do not involve herniated intervertebral disks.3,7,8 One 10-year study3 of college athletes reported that only 7.2% of back pain complaints were related to a disk injury.3 Although disk herniation is not a frequent cause of sports-related back pain, its treatment is often difficult because of the controversies surrounding nonoperative management versus surgery, particularly if the injury occurs during the competitive season. Current data on the management of lumbar disk herniations can help formulate a treatment plan for athletes who experience an acute disk herniation and, often, sciatica.
Disk herniation is commonly defined as a focal or asymmetric extension of disk material beyond the intervertebral interspace (figure 1: not shown), including subclassifications of protrusion and extrusion types.9 By contrast, a disk bulge is a circumferential, symmetric extension beyond the interspace.9
Disk herniations, like bulges, can exist without any clinical symptoms, but patients who have an acute herniation of a lower-back disk typically have back and sciatic leg pain. Sciatica is described as a sharp or burning pain that radiates down the posterolateral aspect of the leg. The pain is usually distal to the knee and may be associated with numbness or paresthesia.10 Sciatica with disk herniation has a dermatomic pattern, and pain often extends to the heel or foot of one leg. The leg pain is so severe that it usually overshadows the back pain.10,11 Sciatica has a high sensitivity (95%) for disk herniation, and, without sciatica, the diagnosis of a significant herniation is less likely.10,11 Magnetic resonance imaging is generally accepted as the most sensitive test to detect herniations.
The classic physical exam finding of a disk herniation is a positive straight-leg-raise test. Since first described and attributed to Laségue in 1881, various authors have modified the straight-leg-raise test. Over time, these modifications have caused confusion about the proper interpretation of the maneuver.11 In the strictest sense, the test is performed with the patient supine, and the clinician passively raises the extended leg on the sciatic side without modifying foot dorsiflexion, knee flexion, or popliteal pressure. With this maneuver, tension on the L5 and S1 spinal nerve roots occurs between 30° and 70° of hip flexion.10,11 No noticeable tension is placed on the nerve roots prior to 30° of flexion, and no increased tension occurs above maximum when past 70° of hip flexion.10,11 Therefore, reproduction of the sciatic pain distal to the knee with passive flexion between 30° and 70° constitutes a positive test. When compared with operative findings of a herniated disk, the straight-leg- raise test shows a sensitivity of 72% to 97% and a specificity of 11% to 66%.10,11
In contrast, the crossed straight-leg-raise test (sciatic pain in the symptomatic leg when performing a straight-leg-raise test on the unaffected side) carries a low sensitivity but a high specificity of 85% to 100% for a lower lumbar disk herniation.10,11 Motor testing of the lower leg in patients who have significant lumbar disk herniation will often reveal weakness with ankle dorsiflexion and/or great toe extension.7
Approximately two thirds of disk herniations occur posterolaterally, with the remainder occurring centrally.12 Both posterolateral and central herniations can cause sciatica, and 95% of herniations occur at the L4-5 or L5-S1 levels.12,13 Although lifting is a mechanism of injury often associated with acute disk rupture, athletic weight lifting has not been shown to increase the risk of herniation.14
Lumbar disk herniations generally carry a favorable prognosis. Although surgery is commonly believed necessary for successful recovery, more than 90% of patients who have disk herniation will improve with nonoperative treatment.7,15 Those who respond to conservative care will typically report reduced pain and sciatica within 4 to 6 weeks of the initial injury.16,17
Progressive neurologic deficits are uncommon, but, when present, they often occur within the first 2 to 3 weeks of radicular pain onset.16 Partial or complete resorption of herniated material may occur several months after injury. Interestingly, the likelihood of resorption increases with the size of herniation, and large extrusions show the highest rate of total resorption.16,18,19 Clinical improvement, however, usually occurs before a morphologic change in disk size can be seen on radiographs.19 The most favorable prognosis for recovery from a disk herniation occurs in patients who have a good baseline fitness level and are motivated to return to function.16 Fortunately, athletes often possess these favorable characteristics.
The traditional treatment for patients who had sciatica caused by disk herniation was bed rest for 2 days to 2 weeks. A study20 comparing bed rest to early activity in patients with both acute and chronic nonspecific low-back pain showed that bed rest of any duration is not effective and is probably detrimental to recovery. Although less abundant, the existing data on sciatica caused by disk compression also show bed rest to be an ineffective treatment.21 Therefore, the initial nonoperative measure for an athlete who has a disk herniation is to discourage bed rest and encourage early activity, usually a progressive walking program as tolerated.20
Physical therapy for sciatica often focuses on lumbar extension exercises, even though clinical studies of these exercises in patients with low-back pain have failed to show an advantage over other treatments.22 Applicability of these results in the herniation-induced sciatica population, however, is questionable, because these trials either excluded patients with sciatica or applied extension exercises to all patients with low-back pain. Cadaver studies23 demonstrate that extension of the lumbar spine relieves nerve root tension and decreases the compressive forces on a nerve root at the site of a herniation. One study by Nwuga and Nwuga24 showed a significant decrease in pain for patients with disk herniations who were given extension exercises compared with patients given flexion exercises.
A recent meta-analysis25 in patients who had sciatica showed that spinal manipulation was more beneficial in treating pain and improving function compared with placebo and compared with treatments that are considered ineffective or harmful. Spinal manipulation was not any more or less effective than other conventional treatments, such as physical therapy, exercise, or analgesics (table 1).
Minimally Invasive Techniques
To avoid open diskectomy if conservative treatment fails, injections and numerous minimally invasive techniques have been and continue to be developed for treating lumbar disk disease. Not all of these techniques are indicated in the treatment of disk herniations, and some of those that are indicated have questionable efficacy.
Epidural corticosteroid injections have been controversial in the treatment of lumbar disk herniations, because controlled studies of their effectiveness have produced mixed results.26-30 Although methodologic protocols vary, most studies26,28 show that epidural injections do not provide long-term benefits in symptom reduction or functional improvement, nor do they reduce the need for surgery on a herniated disk.28 Their role in the management of disk herniations appears to be in the treatment of acute sciatic pain. Patients who received the most benefits from epidurals had a shorter duration (less than 1 year) of symptoms prior to injection.27,29 Jackson et al30 tested the effectiveness of epidural corticosteroids in competitive athletes who had sciatica for an average of 3.6 months and reported positive results in only 44% of those treated.
Chemonucleolysis with chymopapain is another injection technique used for herniated lumbar disks. This treatment is infrequently performed today, because complications of neurotoxicity and anaphylaxis were reported in earlier studies. More recent evaluations of chemonucleolysis31,32 have shown it is a safe and effective technique in properly selected patients. One large study32 reported a success rate of 88% in patients with an acute disk herniation and sciatica. Patients in their teens and 20s whose symptom onset was less than 6 months earlier received the greatest benefit. A critical review of chemonucleolysis31 concluded that it is a beneficial therapy for some patients, but individuals receiving the technique are likely to need a repeat procedure; and diskectomy results are poorer in patients who have previously received the injection than in those who have not.
Intravenous infusion with infliximab has been tested on patients who had severe sciatica caused by a herniated disk. In a study by Karppinen et al,33 a single 2-hour infusion of a tumor necrosis factor-alpha antagonist was compared with a placebo infusion. The results showed that a significant number of treated patients were pain-free 2 weeks, 1 month, and 3 months after infusion. Although this study was not a prospective randomized trial and involved only 10 patients, the results are impressive enough to warrant further investigation of monoclonal antibodies as a treatment for sciatica.
Percutaneous diskectomy or nucleotomy is a minimally invasive technique for removing herniated disk material. Studies34-37 of this procedure in athletes, however, show no decided advantage over open diskectomy. Matsunaga et al35 reported worse long-term outcomes in athletes receiving percutaneous diskectomy compared with manual laborers. No significant difference was found in the number of athletes who were able to return to sports after percutaneous versus open diskectomy.
In a study of elite athletes by Mochida et al,36 only half the athletes who received percutaneous diskectomy were able to return to sport. Those who returned earlier than 3 months postprocedure showed the poorest response.
Another study37 of percutaneous diskectomy in athletes similarly reported an average return to sports in 2 months following the procedure; however, only 38% were able to resume their preoperative activity level. By comparison, athletes who undergo a microdiskectomy may be able to return to sports in as little as 4 to 6 weeks.38 Percutaneous diskectomy is also limited by the fact that it is indicated only for protrusion-type herniations and is not useful in larger, extruded disks.
Laser diskectomy has been used to treat herniated disks since 1986. Nonprospective, nonrandomized studies39,40 reported successful outcomes of 50% to 89%. However, true efficacy is questionable because of the lack of quality-controlled trials comparing laser decompression to standard diskectomy. Laser disk decompression, like percutaneous nucleotomy, is considered a blind technique, because the herniation and amount of material being removed is not directly visualized during the procedure. Patients with large herniations (occupying >50% of the spinal canal) and/or patients with migration or sequestration of free fragments are not candidates for blind, minimally invasive techniques.39
Intradiskal electrothermal therapy (IDET) is a minimally invasive procedure used to treat low-back pain caused by internal disk disruption or anular tears. IDET is not indicated in individuals who have disk herniation or sciatica. It is primarily used as an alternative to spinal fusion in patients who have chronic discogenic pain that is unresponsive to conservative care.41
Surgery continues to be a treatment alternative for sciatica caused by lumbar disk herniation; however, similar to other management options, timing and careful patient selection play major roles in its effectiveness.
Lumbar diskectomy provides good to excellent outcomes for sciatica in 65% to 90% of treated patients.29,31,42 Outcome is better in patients who receive surgery within a year of symptom onset. After 1 year of symptoms, positive surgical outcomes drop precipitously to around 25%.29 Compared with nonoperative care, diskectomy provides faster relief from sciatica during an acute attack,31,43 but long-term outcomes between patients treated surgically and those treated nonoperatively are often no different.13,31,42,43 Thus, the primary benefit of nonemergent diskectomy is to provide relief from sciatic pain when initial nonoperative care does not.31 The type of diskectomy performed may play a role in surgical outcomes.
Microdiskectomy is often proposed for athletes, because it is less invasive than standard diskectomy with a laminectomy.38 Although general population studies show no difference in outcomes between patients treated by microdiskectomy compared with standard diskectomy,31 no studies in athletes directly compare the two techniques. Among studies of diskectomy in athletes, the highest rate of return to sport was found by Wang et al.44 They reported that 90% of Division 1 college athletes who underwent a single-level microdiskectomy were able to return to their sport at the varsity level.
Complications of microdiskectomy (eg, bleeding, infection, thromboembolism) are not common, but they are potential risks.45 The most common late complication is a recurrent disk herniation at the same level, which occurs in approximately 5% of patients. Reherniation may necessitate a second surgery,46 and patients who choose to undergo microdiskectomy should be informed of this possibility.
Artificial replacement of a lumbar disk or its nucleus is an open technique that is still in the developmental phases in the United States. Currently, the indications for disk replacement are the same as for spinal fusion (ie, patients who have discogenic pain caused by degeneration or internal disruption that is unrelieved by other therapies). Patients with significant disk herniations or facet abnormalities should not be considered candidates for disk replacement.47
Rehabilitation is a pivotal factor in the speed of recovery following diskectomy. In the past, postoperative exercise was restricted until 6 weeks after surgery. Now, studies48-51 using early and more aggressive exercise after diskectomy report better outcomes than traditional postsurgical care.
Manniche et al51 removed all restrictions for postsurgical activity and lifting, and they advised diskectomy patients to return to full occupational, domestic, and recreational activities as soon as they felt able. The mean time for postoperative return to work in all patients was 1.2 weeks, and a subgroup of patients in heavy-work occupations returned to full activity in 3.4 weeks. Two-year follow-up data showed that an early return to work was not correlated with recurrent sciatica or operation for reherniation.
A recent critical review52 of rehabilitation after lumbar disk surgery also found no evidence that patients need to have their activities limited after first-time lumbar disk surgery. Although we are not aware of studies that measure accelerated activity in athletes, it seems reasonable to assume that they would also be candidates for aggressive rehabilitation following surgery.
The most appropriate surgical outcome measure for athletes is a return to their previous level of participation. Using this criterion, 33% to 90% of those undergoing all types of diskectomy are able to return to their activity following surgery.34,36,37,44 Surprisingly, athletes often cite lumbar muscle fatigue as the reason for their inability to return to sports following diskectomy.35,36
Special Considerations for Athletes
Because various conservative and surgical treatment options are available for managing disk herniations, the care of athletes who have an acute disk abnormality can be a difficult and controversial process, especially if the injury occurs during the competitive season. Some basic conclusions can be made that may help guide health professionals in treating athletes who have lumbar disk herniations and sciatica.
Because the symptoms of an acute herniation often resolve without surgical intervention, an operative procedure is not immediately necessary, unless evidence of cauda equina syndrome or significant neurologic deficit (eg, foot drop) is seen. Choosing a management path depends on the timing of the injury, the wishes of a well-informed athlete, and the access to appropriate medical professionals and facilities.
Initially, an acute disk herniation should be treated with early, low-level aerobic activity to avoid the debilitating effects of bed rest. When the patient is treated conservatively with analgesic medication, early activity, and a comprehensive physical therapy program, symptomatic improvement typically begins within 4 to 6 weeks postinjury, allowing a gradual return to normal functional abilities. Because sciatic pain is often the limiting step in the recovery process, an epidural steroid injection during this time may enable the rehabilitation process to progress at a faster rate.
With adequate pain control, either through oral medication or epidural injections, the exercise therapy program progresses based on frequent reassessments of the athlete's functional ability. Following this approach, athletes in lower-static sports (eg, tennis, swimming, running) may be able to return to full activity within a relatively short time. More physically demanding sports (eg, football) may require a longer rehabilitation because of the increased spinal loads that occur during activity.
Because a rapid return to activity after microdiskectomy typically takes 4 to 6 weeks,38 treating a late-season herniation surgically is probably not warranted. If the herniation does not respond to nonoperative treatment, surgery is indicated before the start of the next season, because surgical outcomes are more favorable with herniations of less than 1-year duration.29
Managing early-season disk herniations is more challenging because of the uncertainty of treatment responses. Because surgery has been shown to provide faster relief from sciatica than conservative care,31,43 and some athletes return to competition in as little as 4 to 6 weeks postsurgery,38 the argument can be made that an athlete receiving early diskectomy stands a better chance of return to play during the season than one who is treated conservatively. However, no studies support this argument. An athlete who chooses to have a diskectomy prior to a complete course of conservative care should understand that surgery is intended to provide only the chance of a more rapid recovery. The long-term benefits of diskectomy, at least in the general population, are no different than conservative care.13,31,42,43
Rapid return to sports is not a standard indication for diskectomy. This decision is a serious one, and both the athlete and physician need to thoughtfully consider the risks vs the potential benefits. Some insurance providers may be unlikely to authorize payment under such circumstances. Although anecdotal reports40 of athletes returning to sport soon after a microdiskectomy exist, no outcome studies are available that examine the short- or long-term consequences of this decision.
If an athlete undergoes diskectomy, postoperative rehabilitation is vital to a full and safe return to participation. Few activity restrictions are necessary following surgery, so rehabilitation can begin early and progress rapidly. Because athletes often report muscle fatigue as a limiting factor in return to sports,35,36 rehabilitation should focus on lumbar strength and endurance.
Dr Lively is an associate professor of internal medicine and pediatrics and medical director of intercollegiate athletics at West Virginia University in Morgantown. Dr Bailes is a professor and chairman of the department of neurosurgery at West Virginia University. Address correspondence to Mathew W. Lively, DO, Dept of Internal Medicine, West Virginia University, Box 9167, Morgantown, WV 26506; e-mail to [email protected].
Disclosure information: Drs Lively and Bailes disclose no significant relationship with any manufacturer of any commercial product mentioned in this article. No drug is mentioned in this article for an unlabeled use.