Winter 2021 Issue
Volume 13 | Number 1
Zac Taylor, OMS III1; Max Jiganti, OMS III1; Rajeev Herekar, OMS II2; Jonathon Minor, MD1,3
Spondylolysis, the fracture of vertebrae at the pars interarticularis, and the progression to spondylolisthesis, involving fracture in addition to anterior slippage of the vertebra, are very common causes of low back pain in adolescent athletes. Dancers are among the most prevalent athletes to suffer, possibly due to repetitive impact and trunk contortions. Two such patients, 16- and 17-year-old female dancers are reviewed. Each presented with chronic (2+ years) histories of low back pain aggravated by dancing. Both patients had pain/tenderness in the lumbar/sacroiliac region. Differences between cases were notable and required further imaging to accurately make the diagnosis. Imaging revealed that the former did indeed have a spondylolisthesis, while the second was eventually diagnosed with sacroiliitis. The former was found to be negative on many ranges of motion/special maneuver tests (hyperextension, Kemp test, etc.) and had pain upon palpation of the spinous processes. The latter patient was positive on a large number of motion tests and had tenderness of the paraspinal muscles. The variability in presentation between adolescent dancers with low back pain warrants increased surveillance among clinicians who treat this population. Furthermore, the lack of specificity and sensitivity for certain physical exam tests should elicit caution when ruling out differentials. Lack of sensitivity also suggests the need for increased reliance on imaging to further differentiate cases of low back pain of similar presentation.
Keywords: Spondylosis, spondylolisthesis, low back pain, sacroiliitis
Spondylolysis and spondylolisthesis are common low back injuries of active adolescents, most notably, those involved in rotational sports. Spondylolysis refers to fracture of the pars interarticularis, either unilateral or bilateral. Spondylolisthesis refers to fracture, in addition to anterior slippage of the inferior vertebrae. Dancers have repetitive axial loading combined with consistent rotation, which has been shown to be the most common athletic mechanism leading to pars fracture1,2. Over 90% of these injuries occur at the junction of L5-S1; second most commonly at L4-L534. Hypermobility is a common cause for low back pain in adolescent dancers. Consistent rotation and hyperextension of the lumbar spine leads to microtrauma building up over time. Reportedly, 100% of retired dancers report one or more injuries during their career5,6.
Spondylolysis is typically asymptomatic but may progress to symptomatic lesions in certain cases. Affected dancers often develop chronic back pain with insidious onset. Average age of presentation is 15. Pain is often unilateral, while bilateral lesions at the same vertebral level can lead to the slippage seen in spondylolisthesis2.
Adolescent dancers have a four-fold increased risk in spondylolysis compared to the general population. Youth sport-related low back pain has a 50% chance of spondylolysis. Spondylolysis and spondylolisthesis should be high on the differential diagnosis in young dancers presenting with low back pain.
Clinical diagnosis of spondylolisthesis is supported with positive findings in palpation or inspection of intervertebral slip. Diagnosis requires a motion test revealing hypermobility between vertebrae7. High specificity and moderate sensitivity in diagnosing spondylolisthesis has been observed with palpation of the lumbar spinous process in a systematic review8. Clinical tests have varying results in patients with spondylolysis and spondylolisthesis, making CT scans, MRI, or X-ray necessary to confirm the diagnosis.
Another cause of low back pain in young athletes, sacroiliitis, is characterized by inflammation of unilateral or bilateral sacroiliac joints. This is often attributed to wear and tear degeneration and/or inflammatory arthritis. Dancers may be at risk resulting from repetitive single leg jumps and long strides placing stress on the joint. Sacroiliitis may result from hypo- or hypermobility due to the unique anatomical nature of the joint allowing for only minimal motion.
It is important to distinguish similar presentations of sacroiliitis from spondylolisthesis. Sacroiliitis, like spondylolisthesis, typically presents as lower back pain. Sacroiliitis may involve the buttocks with extension into the pelvis and down the leg9. Diagnosis is made based on physical examination. Pertinent findings include point tenderness of the joint, hips, and buttocks along with passive leg movements to elicit pain. Provocative tests do not provide a powerful positive predictive value10. Special tests include Distraction (posterior pressure on the ASIS, most sensitive to inflammation of sacroiliac joint), Thigh Thrust (pressure through femur with flexed hip), FABER (flexion, abduction, external rotation), side lying compression, and Gaenslen’s test (torsional stress). Imaging modalities include X-ray, used to visualize joint alterations. Magnetic Resonance Imaging (MRI) is utilized if inflammatory causes, such as ankylosing spondylitis (common comorbidity) are suspected11.
In this report we examine two separate cases of adolescent dancers, both presenting with low back pain but with differences in their clinical presentations. Through physical exam, proper imaging, and special tests, two unique diagnoses were made demonstrating the importance of thorough work up in youth back pain patients. While low back pain in active adolescents in the context of positive clinical exam findings strongly supports the diagnosis of spondylolisthesis, there are other diagnoses that must be considered. The following cases indicate the wide variability of presentation in low back pain and the need for thorough physical exam with appropriate spine imaging.
A 16-year-old female presented to the clinic with a 2-year history of lower back pain. The patient had no other medical conditions or past surgical history. The patient is a dancer and experienced pain most extremely when she danced. Movement that requires back extension results in pain was localized to the lower back, just lateral to the spine at the level of L5.
Physical examination elicits pain at L4 and L5 spinous processes. Likewise, pain upon palpation was noted along the left sacroiliac joint. She also experienced pain in her back and gluteal muscles upon full forward flexion. Additional movements and special maneuvers did not elicit pain including trunk extension, trunk rotation, Kemp test, stork test, straight leg raise test, lateral pelvic compression, sacroiliac torque test, anterior pelvic distraction test, axial loaded thigh thrust, and sacral compression test. She also experienced stretching without pain with piriformis stretch test.
A lumbar spine X-ray revealed a distinct step off at the L5-S1 junction. Follow up MRI was performed showing previous spondylolisthesis at the L4-L5 and L5-S1 levels with an associated L4-L5 disc bulge. MRI was absent of any bone marrow edema or other indicators of acute trauma to the vertebra.
Patient was diagnosed with a spondylolisthesis with an associated disc bulge and prescribed a two-week hiatus from dance or exercise, a soft lumbar brace to be used as needed when returning to dance, and physical therapy. Patient has returned to dance and is not experiencing significant pain or any limitations.
Figure 1: A) Sagittal lumbar X-ray of the patient. Fracture of the pars articularis and slippage of the vertebral body can be clearly seen at the L5/S1 junction. B) Sagittal MRI of the lumbar spine confirming the X-ray findings. In addition, the herniation.
A 17-year-old female presented with a 3-year history of lower back pain. Patient experienced pain upon completion of a dance jump. She felt the pain immediately upon impact with the floor. The patient was able to continue dancing, but eventually stopped secondary to pain. Upon presentation, pain localized to the lumbar spine around the L3-L5 levels bilaterally.
Physical examination of the low back and hips revealed significant tenderness to palpation along the lumbar paraspinal muscles bilaterally with additional pain along the right sacroiliac joint. Patient was positive in the following special maneuvers: hyperextension in the prone position, Kemp test, stork test, FABER, FADIR, piriformis crossover test, sacroiliac joint compression, and cross-leg test for sacroiliac pain. Hip range of motion was intact but was painful at end-range motion.
An initial diagnosis of spondylolisthesis was suspected, but MRI imaging was ordered. No fractures or vertebral slippage were present, thus eliminating the diagnosis of spondylolisthesis. At follow up, the diagnosis of sacroiliitis was rendered and treatment begun.
Figure 2: Sagittal lumbar MRI revealing no structural defects or bony abnormalities that would indicate a spondylolisthesis.
Accurately diagnosing lower back pain can be very difficult. Non-specific pain localization and non-specific testing can be challenging for the clinician to make an accurate diagnosis without imaging12. Currently, motion testing such as trunk extension, stork test, and Kemp’s test (also referred to as the Quadrant test and the extension-rotation test) are used to diagnose spondylosis/spondylolisthesis in addition to history, palpation, and observation,
Previous study of motion testing has determined them to be unreliable (and non-specific)13,14. Our experience confirms this finding. Extension of the lumbar spine will generally elicit pain in the patient with spondylosis or spondylolisthesis. However, other pathologies will produce a positive extension test. In one study conducted in 2006, the Stork test (also known as the one-legged hyperextension test) was generally not useful in detecting spondylosis or spondylolisthesis15. It lacked sensitivity or specificity for active spondylolysis and had a poor negative predictive value. It concluded that the diagnosis cannot be made without the proper imaging. Additionally, in a systematic review conducted in 2014, Kemp test was discovered to possess poor diagnostic accuracy16. A positive Kemp test often is elicited on any facet joint pain and other lower back pathologies such as sacroiliitis as seen in the second case.
While motion tests in series aid in diagnostic confidence, none of the exams stand alone as reliable or accurate exams. All tests load the lumbar spine with force that could elicit pain with lumbar disc disease or facet joint arthropathy. Our findings in these cases are consistent with previous studies and highlight both needs for diagnostic imaging and careful consideration of the clinician in diagnosing lower back pain secondary to poorly predictive tests and variable pain presentations.
Although the diagnosis of a pars interarticularis fracture is not uncommon, especially amongst certain populations, the presentation can be variable making the clinical diagnosis difficult. Clinicians should be thorough in their diagnostic workup and be mindful of the limitations that exist for the low back physical examination tests.
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