Spondylolysis in Active Adolescents
Expediting Return to Play
James L. Moeller, MD; Sami F. Rifat, MD
THE PHYSICIAN AND SPORTSMEDICINE - VOL 29 - NO.12 - DECEMBER 2021
In Brief: Spondylolysis is the most common identifiable cause of back pain in active adolescents, who often cope with the condition by hoping it will just go away. If the pain is prolonged or severe enough to bring them to a physician, an aggressive work-up for a specific diagnosis should be initiated. History and physical exam findings are suggestive but not diagnostic. Radiographs provide a first look, but other tests (eg, bone scans, CT, and MRI) are necessary to determine the metabolic activity and full extent of any lesions. Conservative therapy, including activity modification, physical therapy, and sometimes bracing, provides pain relief and focuses on return to full activity and prevention of recurrence.
Back pain is a common presenting complaint for athletes and other active individuals. In adults, pain is often the result of muscle strains in the lower back or is discogenic (1). In many cases of acute low-back pain in adults, treatment can be initiated based on history and physical examination alone (2), with further diagnostic work-up deferred unless patients don't improve in 2 to 6 weeks.
The epidemiology of low-back pain in active adolescents is vastly different. In many cases, the pain will dissipate on its own, and the athlete continues sports participation without any missed time. When the pain is severe or present long enough to cause an adolescent to seek medical attention, a specific diagnosis should be aggressively sought so that appropriate management techniques can be instituted without delay. Adolescents have a higher incidence of nonmuscular causes for back pain, including tumor, that add urgency to the treatment scenario.
Posterior element injuries of the bony spine may account for up to three-quarters of the cases (1). These injuries can be divided into spondylolysis (stress fractures of the pars interarticularis) and other stress lesions of the posterior elements, sometimes referred to as hyperlordotic mechanical back pain. Fractures of the pars interarticularis region have been identified in the skeletal remains of people from civilizations dating back to 6000 BC, and prevalence rates based on samples from archeological excavations range from 1.42% to 20% (3,4). Currently, the prevalence of spondylolysis in the general population is around 5% to 6% (5). Spondylolysis is the most common cause of low-back pain in active adolescents who seek medical attention; it may account for nearly half of the cases (1). The lesion most commonly occurs at L-5 (6-11), followed by L-4, then L-3.
Spondylolysis is, in part, a product of the ability to ambulate. Rosenberg et al (12) studied people who had never been ambulatory and found no cases of spondylolysis. In adolescents, boys are affected 2 to 3 times more often than girls (5); however, girls have spondylolisthesis (the forward slippage of a superior vertebral body on the one immediately inferior) more frequently. The presence of spina bifida occulta (SBO) (5,13) and a family history of spondylolysis are also risk factors (5).
Certain sports activities also increase the risk of spondylolysis. Sports that involve repetitive hyperextension and extension with rotation, such as gymnastics (11,14), wrestling (15), and weight lifting (11,15), and those that involve torsion against resistance, such as rowing, are associated with a high prevalence of spondylolysis. Some studies (11,16), however, have found no difference between the prevalence of spondylolysis in athletes and in the general population.
History and Physical Exam
Important questions in the medical history focus on the onset of pain, duration of symptoms, and location of the discomfort, with special attention to pain radiation. The clinician should note what provokes or lessens the pain, any past or recent trauma to the back, and if the patient or anyone in the family has ever had this type of problem before, especially during adolescence. Spondylolysis pain is often unilateral but may be bilateral and tends to localize in the lower back. It worsens with sport activities, especially extension and hyperextension, and is relieved by rest.
A history of radicular symptoms may be present in patients who have spondylolysis but is more common when intervertebral disk problems cause pain. Fever, sweats, and chills should raise a red flag for infection. Night pain, sweats, and weight loss are symptoms often associated with malignancy. Saddle numbness and bowel and/or bladder control issues may indicate a cord compression syndrome and should be treated as a surgical emergency.
When an adequate history has been obtained, the focus turns toward the physical exam. Physicians should look for gross abnormalities such as a step-off deformity or scoliosis. SBO may be associated with skin changes such as dimpling and hypertrichosis (17). Most patients who have spondylolysis appear normal.
Palpation may cause discomfort in the paravertebral areas, usually around L-5. Full range of motion is often maintained, although pain with lumbar hyperextension may be present when the patient is seated. The single-leg standing hyperextension test (figure 1), commonly called the stork test, is more sensitive and specific for posterior element injury (18). Pain is typically worse when the patient stands on the ipsilateral leg. Straight-leg raise tests and other tests for discogenic causes of back pain are typically negative. Strength and neurovascular status are typically intact.
In adolescents who have back pain, early use of diagnostic studies is essential. Plain radiographs of the lumbosacral spine should be obtained first. Historically, the x-ray series has included the anteroposterior (AP), lateral, and oblique views. The AP view may detect an unrecognized scoliosis, but, more important, it identifies SBO (figure 2). A well-trained eye may discern a transverse radiolucency consistent with a spondylolytic lesion (figure 3). The lateral view helps identify spondylolisthesis or lytic lesions in patients who have spondylolysis.
Bilateral oblique positioning allows for easier visualization of the pars interarticularis. The classic "scottie dog" is seen on this view, with the pars corresponding to the neck of the dog. Images that resemble a collared dog or a dog with a broken or elongated neck are diagnostic of a stress lesion or fracture through the pars (figure 4). Unfortunately, the presence of a pars lesion on plain radiographs is not diagnostic of an active lesion. In fact, many asymptomatic people have pars defects on screening radiographs. For this reason, many practitioners obtain only AP and lateral radiographs in their initial work-up, knowing that additional tests to determine the metabolic activity of the bony spine will be needed to confirm the diagnosis.
In many instances, the next step is to obtain a nuclear medicine scan. Bone scans, though not very specific, are highly sensitive for detecting increased bony metabolism and may be the most sensitive tool for diagnosing pars lesions (19). The addition of single-photon emission computed tomography (SPECT) increases the sensitivity for detecting activity in the pars region (6,20).
Several clinical scenarios are summarized in table 1. In a patient who has clinically suspected spondylolysis and normal x-rays, a positive SPECT finding at the pars interarticularis (figure 5) may represent a stress fracture (8,21). For many clinicians, this is enough information to initiate treatment. Congeni et al (6), however, demonstrated a 15% false-positive rate for nuclear medicine studies when using computed tomography (CT) for diagnosis. For this reason, thin-slice CT scan through the affected area should be considered before initiating the significant activity restrictions and extensive rehabilitation required to treat these lesions.
Udeshi and Reeves (22) showed that thin-slice magnetic resonance imaging (MRI) can show the pars interarticularis. Unfortunately, this study did not look at the use of MRI for detecting or staging pars injuries.
In adolescents who have low-back pain, normal x-rays, and negative SPECT, other causes of back pain should be investigated (8). MRI is often ordered to look for discogenic or other soft-tissue causes of pain. Thin-slice CT may be more sensitive and specific for viewing bony pathology, but the nuclear study in this case points to a nonbony cause for the pain. Another important consideration in adolescents is that, unlike CT, MRI imparts no ionizing radiation to the patient.
When the symptoms suggest spondylolysis and the x-ray is positive, many clinicians feel that a nuclear study is not needed to confirm the diagnosis; however, we feel that SPECT should be strongly considered. Many patients with radiographically apparent lesions will have negative SPECT scans (53% to 71%) (8,21). Adolescents who have back pain, positive x-rays, and negative SPECT warrant further investigation into the cause of the pain; MRI is the test of choice in this case.
With a positive clinical evaluation, positive x-rays, and positive SPECT, the diagnosis is secure and treatment can be initiated. CT may help determine the stage of injury or healing and the prognosis for complete radiographic healing. Advanced injuries have a decreased likelihood of complete radiographic healing (9). Whether this relates to poor outcome (eventual spondylolisthesis, chronic pain, or inability to return to normal activities) is not well documented.
Treatment of spondylolysis should be individualized and usually starts with conservative measures. Treatment choices should focus on three main outcomes: elimination of pain, preparation for return to full activities, and prevention of recurrence.
Pain. Eliminating pain is a primary concern and is the main reason why patients see a physician. Pain control measures can be initiated before final diagnosis and may include ice, heat, nonsteroidal anti-inflammatory drugs, or even narcotic analgesics. Pain is an important indicator for activity restriction, and pain medication should be used only to allow for activities of daily living, not as a means for earlier return to play. Athletes should refrain from inciting activities, such as running, jumping, and sport-specific activities that cause pain for a minimum of 4 to 6 weeks. Contact and collision sports should be avoided, and other hyperextension activities should also be eliminated during that time.
In most cases, we start with activity modification, elimination of hyperextension activities, and initiation of physical therapy focused on hamstring flexibility exercises and training the deep abdominal muscles by coactivation of the lumbar multifidus proximal to the defect. A study by O'Sullivan et al (10) on training the deep abdominal muscles compared patients who engaged in a specific exercise program directed by physical therapists with those whose treatment was directed by their primary care provider. The specific exercise group showed a statistically significant reduction in pain intensity and functional disability levels after a 10-week regimen and throughout a 30-month follow-up.
Bracing. If our patients show no progress with the above program, or if their pain worsens during therapy, we initiate bracing with thoracolumbosacral orthoses. Many authors advocate immediate bracing of some type (6,7,9), while others believe that bracing should be reserved for patients who continue to have pain despite removal from inciting athletic activities (23). The main advantage of a brace may be in reminding the patient to maintain good posture. Standaert and Herring (24) state that decisions on bracing need to be made on an individual basis with a full understanding of both the intended goals and the consequences of brace application. Routine, prolonged bracing of all patients with symptomatic spondylolysis is probably not necessary and may pose undue burdens on the patients.
Morita et al (9) classified lesions as early, progressive, or terminal, based on radiographic findings. All their patients wore lumbar corsets for 3 to 6 months. Conservative management produced radiographic healing (determined by CT) in 73% of the early, 38.5% of the progressive, and 0% of the terminal defects. Clinical outcomes were not reported.
Daniel et al (7) detected only a 6.8% healing rate after 3 months of full-time bracing (healing was defined as radiographic union coupled with pain-free activities of daily living). In patients who had spondylolysis, Steiner and Micheli (25) reported radiographic union in 37% after use of a modified Boston brace. Despite the low rate of healing from a radiographic standpoint, 96% of these patients had excellent or good clinical results. Some patients who do not have clinical evidence of union report few problems with pain and do not curtail their activities.
Other measures. Surgical intervention may be required in a low percentage of patients (25), typically when conservative treatment fails. There are case reports of bony healing by external electrical stimulation after failed conservative treatment of spondylolysis (26), but this modality has not been studied in depth.
Preparation for return. Many young patients respond quickly to conservative treatment without bracing and return to low-level sport activities after the 4- to 6-week follow-up visit. They are then allowed to increase the intensity of their activities as tolerated under the guidance of the physician and physical therapist. If bracing is used, monthly follow-up is performed, and brace use is discontinued when pain is controlled during daily activities and the examination no longer elicits discomfort. At this stage, the athlete is re-enrolled in therapy to work on spine stabilization and strengthening; sport-specific activities, such as extension, are reintroduced as tolerated.
Whether bracing allows for earlier return to sport is difficult to know based on the current literature. While an aggressive, specific exercise program significantly decreases pain and functional disability (10), return to high-level athletics after such a program has not been studied. Nonrigid bracing coupled with physical therapy (6) may allow for return to a very active or moderately active lifestyle in 95% of patients, but timing is variable (generally 8 weeks or longer).
Precautionary measures. Preventing recurrence may be difficult for young athletes who wish to return to high-level competitive sports. A maintenance training program to preserve spine stabilization should be incorporated into athletes' workout regimens. Patients should avoid repetitive hyperextension activities. Patients should be counseled to quickly report any recurrence of low-back pain, pain that is worsened with extension or twisting, and pain that is worsened by activity and relieved with rest. If precautionary measures can be instituted early, a long course of rest and rehabilitation may be avoided.
A Thorough Strategy
Suspicion of spondylolysis is raised by history, physical examination, and plain radiographs; however, further diagnostic studies are needed for definitive diagnosis. Scintigraphy with SPECT can assess metabolic activity and locate lesions. Thin-slice CT may be useful for staging of injury or healing, and MRI helps diagnose soft-tissue pathology. Return-to-play decisions should be made on a case-by-case basis.
Dr Moeller and Dr Rifat are physicians at Sports Medicine Associates, PLC in Auburn Hills, Michigan. Dr Moeller is chairman of the Division of Sports Medicine at William Beaumont Hospital in Troy, Michigan, and an editorial board member of The Physician and Sportsmedicine. Dr Rifat is head team physician at Oakland University in Rochester, Michigan. Address correspondence to James L. Moeller, MD, Sports Medicine Associates, PLC, 3100 Cross Creek Pkwy, Suite 200, Auburn Hills, MI 48326; e-mail to [email protected].