Winter 2019 Issue
Volume 11 | Number 1
Zac Taylor, OMS III1, Max Jiganti, OMS III1, Rajeev Herekar, OMS II2, Jonathon Minor, MD1,3
1Burrell College of Osteopathic Medicine, Las Cruces, NM
2Nova Southeastern University College of Osteopathic Medicine, Ft. Lauderdale, FL
3SPARCC Sports Medicine, Tucson, AZ
Spondylolysis, the fracture of vertebrae at the pars interarticularis, and the progression to spondylolisthesis, which involves 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, presented with chronic (2+ years) histories of low back pain which were aggravated by dancing. Both patients had pain/tenderness in the lumbar/sacroiliac region. Despite arriving at largely the same diagnosis initially, the 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 range of motion/special maneuver tests (hyperextension, Kemp test, etc) and had pain upon palpation of the spinous processes while the latter 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 suspicion 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 and suggests the need for increased reliance on imaging in cases of low back pain with similar presentations.
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, while spondylolisthesis refers to the same fracture in addition to anterior slippage of the inferior vertebrae. Dancers in particular, 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-L5.3,4 Hypermobility is a common cause for the low back pain in adolescent dancers, and the consistent rotation and hyperextension of the lumbar spine leads to microtrauma building up over time, taking a toll on the human body with 100% of retired dancers reporting one or more injuries during their career.5,6
Spondylolysis is typically asymptomatic, but may progress to symptomatic lesions in certain cases. Affected dancers often develop chronic back pain with insidious onset, presenting at the age of 15 on average. The pain is more often unilateral, while bilateral lesions at the same vertebral level can lead to the slippage seen in spondylolisthesis.2
Adolescent dancers have a four-fold increased risk in spondylolysis compared to the general population, and youth sport-related low back pain has shown to have a 50% chance of spondylolysis. Needless to say, 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 along with a motion test showing hypermobility between vertebrae.7 High specificity and moderate sensitivity in diagnosing spondylolisthesis has been observed with palpation of the lumbar spinous process in a systematic review.8 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, which is often attributed to wear and tear degeneration and/or inflammatory arthritis. Dancers may be at risk because of the repetitive single leg jumps and long strides that place stress on the joint. Sacroiliitis can result from hypo or hypermobility due to the unique anatomical nature of the joint allowing for only minimal motion.
It is important to distinguish sacroiliitis from spondylolisthesis as the clinical presentations can be similar. Sacroiliitis, like spondylolisthesis, typically presents as lower back pain. Sacroiliitis may involve the buttocks with extension into to the pelvis and down the leg.9 Diagnosis is made with by physical exam involving point tenderness of the joint, hips, and buttocks along with passive leg movements to elicit pain, although provocative tests do not provide a powerful positive predictive value.10 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, and MRI, used if inflammatory causes, such as ankylosing spondylitis (common comorbidity) are suspected.11
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 two 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 two-year history of lower back pain. The patient had no other medical conditions or past surgical history. The patient is a dancer and experienced the pain most extremely when she danced, in particular any movement that requires back extension. Upon presentation, the pain was localized to the lower back, just lateral to the spine at the level of L5.
|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.|
Upon physical examination, the physician was able to elicit pain upon palpation of the L4 and L5 spinous process. Along with pain upon palpation along the left sacroiliac joint. She also experienced pain in her back and gluteal muscles upon full forward flexion. All other additional movements and special maneuvers were negative. This included 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, but no frank pain with piriformis stretch test.
A lumbar spine X-ray was ordered which showed a distinct step off at the L5-S1 junction. A follow-up MRI was also performed that showed previous spondylolisthesis at the L4-L5 and L5-S1 levels with an associated L4-L5 disc bulge. The 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.
A 17-year-old female presented to the clinic with a three-year history of lower back pain. Patient experienced the pain upon completion of a dance jump, in which she felt the pain immediately upon impact with the floor. The patient was able to continue dancing, but eventually had to stop due to the back pain. Upon presentation, the patient localized to the lumbar spine around the L3L5 levels bilaterally.
|Figure 2: Sagittal lumbar MRI revealing no structural defects or bony abnormalities that would indicate a spondylolisthesis.|
Physical examination of the low back and hips showed 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 for the patient. Upon evaluation of the imaging, no fractures or vertebral slippage were present, thus eliminating the diagnosis of spondylolisthesis. After follow up in office examination, the diagnosis of sacroiliitis was made and being treated.
As previously discussed, accurately diagnosing lower back pain can be very difficult. Nonspecific pain localization and non-specific testing can be challenging for the clinician to make an accurate diagnosis without imaging.12 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 the motion testing has shown them to be unreliable (and nonspecific).13,14 This has also been consistent with our experience. 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, it was found that the Stork test (also known as the one-legged hyperextension test) is generally not useful in detecting spondylosis or spondylolisthesis.15 They found that it is not sensitive or specific for active spondylolysis and has a poor negative predictive value. That study concluded that the diagnosis cannot be made without the proper imaging. Additionally, in a systematic review conducted in 2014, it was found that Kemp’s test is a poor diagnostic accuracy.16 A positive Kemp’s test often is elicited on any facet joint pain and other lower back pathologies such as sacroiliitis as seen in the second case.
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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