LOW BACK PAIN IN A COMPETITIVE CRICKET ATHLETE

Abstract

Physical therapists treating adolescent and young adult athletes with low back pain complaints should have a high level of clinical suspicion of the possibility for spondylolysis, spondylolisthesis, or developing stress reactions of the pars interarticularis. This case outlines the use of conventional radiography, computerized tomography, and Single photon emission computed tomography (SPECT) in the differential diagnosis for an adolescent cricket athlete with low back pain.

INTRODUCTION

Competitive athletes presenting with low back pain provide multiple decision making challenges for physiotherapists. Criteria are not well defined to direct management regarding initiating care immediately or perhaps delaying treatment until diagnostic imaging is completed. Whether to pursue a course of care focused on mobilization or stabilization is often a key element of the dilemma. This case report highlights the difficulty in initial patient management decisions in athletes presenting with low back pain.

CLINICAL PRESENTATION

A male, age 17, reported for physical therapy consultation for his primary complaint of low back pain upon referral by his primary care physician. His description of symptoms was of dull and intermittent pain with the peak being at 6 of 10 on a visual analog scale. He denied any distal symptoms, including paresthesia.

He reported a history of pain of five days duration with the onset during a college cricket match. He was bowling early in the match in the fifth over when he noticed the onset of the pain. (Figure 1) (Figure 2) An over is a set of six consecutive balls bowled in succession toward a batsman with the side fielding usually bowling 50 overs in total during a match at this level of cricket. He continued to bowl for three additional overs until the pain increased to the level requiring him to withdraw from that session. He awoke the next morning with complaints of stiffness in his low back and attempted to continue participating, although in a different position on the field. Because of worsening left low back pain and he was unable to bowl or train. He subsequently consulted with a physician within one week of this exacerbation and reported to physical therapy one week after seeing the physician. While admitting to intermittent low back pain over the previous two years, the symptoms were described as only minor and were successfully addressed with topical counterirritants, stretching, and allowing continued participation.

Figure 1.

Example of the bowling action by a professional athlete, midrange throughout the movement. Note: This is not the athlete described in this case. (Downloaded from http://icc-cricket.yahoo.net/photogallery.php?gallId=1387).

Figure 2.

Example of the bowling action by a professional athlete, in follow-through phase. (Downloaded from http://icc-cricket.yahoo.net/photogallery.php?gallId=1389).

Notable in this patient's recent history was an increase in the intensity and method of his training program during a college holiday period. He had also been attempting a new bowling technique with more “front on action” or positioning the coronal plane of the trunk directed toward the batsman.

His past history was remarkable for an anterior cruciate ligament rupture and reconstruction two years prior with successful rehabilitation. Recovery from this injury was sufficient to allow his return to competitive 100 and 200 meter sprinting. He denied any other significant health issues.

At this time of his presentation for physical therapy, he reported symptoms in the left low back as being at a level of one of 10 on a numerical pain scale with activities of daily living. The 24-hour behavior of his symptoms included complaints of stiffness before bed, with minimal disturbance of sleep because of pain. A brief interval of subjective stiffness was reported upon waking in the morning, but this was reduced within 20 minutes of rising. His symptoms throughout the day were reported as minimal, but increased with prolonged standing to 2 of 10 on a verbal analog scale.

Once provoked, the patient described his symptoms as remaining irritated for approximately 30 minutes. He reported being able to lessen his back pain with recumbent positioning and taking an over-the-counter analgesic.

EVALUATION

At the time of initial consultation with the physical therapist, the patient presented with normal gait and no obvious antalgic patterns of spontaneous movement. Upon visual observation and palpation, his lumbar lordosis appeared to be increased along with the impression of greater than typical resting tone in the paraspinal musculature while standing. Lumbar flexion was not restricted and the patient displayed only mild pain occurring upon his return to an upright, neutral position. Standing extension was also within normal expectations, but with end of range discomfort. Standing extension also revealed segmental hinging, or the appearance of excessive movement at one level and a reduction of movement at adjacent levels, which was observed by the examining clinician. Lateral flexion movement elicited complaints of feeling “stiff” with pain being reported with left lateral flexion. The one-legged hyperextension test provoked left-sided low back pain when performed on the left side. Passive accessory motions of the lumbar vertebrae provoked pain on the left at L4-5, but with no detectable movement loss. Palpation also revealed generalized tenderness of the left low back and increased firmness of the left paraspinal musculature. Sacroiliac pain provocation tests were negative. Hip range of motion was within normal limits and hip quadrant testing was negative. Hamstring muscle length was asymmetrical with less length present on the left. Trigger points were located in the left gluteal and proximal hamstring musculature. The patient reported that radiographs of his lumbar spine were recently completed at the direction of his primary care physician and these were reported to be negative for fractures. (Figures 3a and 3b).

Figure 3.

Standard radiographs of the lumbar spine of this athlete, a) lateral view, b) lateral oblique view.

Because of suspicion of pars interarticularis injury, the patient was referred back to his primary care physician for additional diagnostic evaluation. The absence of identifiable hypomobility accounting for his low back pain, pain provocation with lumbar extension, and his age placing him in a high risk population for spondylolysis or spondylolisthesis raised the suspicion for pars interarticularis injury during examination and subsequent evaluation by the evaluating physiotherapist.

DIAGNOSTIC IMAGING IN PATIENTS WITH SUSPECTED PARS INTERARTICULARIS LESIONS

Although the patient in this case presented with conventional radiographs of his lumbar spine interpreted as negative (Figures 3a and 3b), unremarkable radiographic results must be considered with caution in individuals with suspected pars interarticularis lesions. The absence of an overt spondylolisthesis on radiography does not rule out more subtle forms of pars interarticularis pathology. As the pars interaricularis lies oblique to all three orthogonal planes, the standard radiological views often do not align with the desired anatomy ideally and, thus, a bony lesion may be missed.^1,2 The defect of spondylolysis in radiography is visualized as a lucent zone in the region of the pars interarticularis, which is classically described as having the appearance of a collar on the “scotty dog” or a broken neck as seen in lateral oblique radiographs.^2,3 Standard three-view radiography has been reported to be insensitive to 20% of spondylolysis with only the lateral oblique view offering diagnostic value.⁴ Other investigators have suggested a collimated lateral view to be slightly more sensitive.⁵ The use of radiography remains controversial in identification of pars interarticularis lesions because of its inability to rule out stress responses and non-displaced fractures and its lack of specificity.⁶ Particularly problematic in the diagnostic process is the common occurrence of asymptomatic pars lesions. Spondylolysis and spondylolisthesis have been found to occur equally as often in those individuals without symptoms as those with complaints of low back pain.^7,8 Thus, low back symptoms in some persons can be inaccurately attributed to the pars lesions, but can be unrelated to the cause(s) of low back pain.^9,10 Beyond basic radiography multiple additional imaging modalities may contribute to diagnosis of pars interarticularis lesions.

Magnetic resonance imaging (MRI) has also been used in the diagnostic challenge of decision making of those with suspected spondylosis or spondylolisthesis. MRI can also demonstrate an on-going process with fluid sensitive and fat-suppressed imaging sequences such as T2-weighted and short tau inversion recovery (STIR) with reverse angle oblique images.^11,12 Greater signal intensity, consistent with edema, may be demonstrated in the pars interarticularis with these sequences.⁹ Additionally, T1-weighted images also offer the best anatomical detail, also with reverse angle oblique images. Incomplete fractures, however, may not be revealed with MRI because of its inability to depict cortical bone integrity.^2,11 The reverse oblique angles may be necessary as standard slices in the cardinal planes may allow lesions to escape detection.^13,14 Three-dimensional MRI imaging, if available, may offer greater sensitivity than standard MRI.¹¹ In the presence of radicular signs or symptoms, MRI is clearly indicated for visualization of the soft tissue, including the neural elements. Another benefit of MRI is the absence of ionizing radiation, which may be a particularly relevant consideration for younger individuals.

Computed tomography (CT) is very sensitive in detecting a compromise in the integrity of cortical bone with its multiplanar reconstructions and is generally considered to be most accurate in identifying a fracture. On CT scan, spondylolysis and spondylolisthesis are well demonstrated as a linear lucidity or defect extending through the pars interarticularis.⁷ CT, however, may not reveal a stress reaction in which there is no overt disruption of the cortical bone.^2,3 As CT technology has advanced, including volume rendering, the ability to detect smaller anatomical defects has commensurately improved. However, CT delivers relatively high levels of ionizing radiation.²

Increased metabolic activity, typical of a stress response, can be revealed by nuclear imaging.¹⁵ Scintigraphy, with increased radioisotope uptake in the region of the pars interarticularis, suggests a metabolically active lesion and, thus, is diagnostically important when correlated with symptoms. Studies directly comparing radiography and scintigraphy suggest that scintigraphy is more sensitive in identifying posterior element pathology.^16,17 The weakness of scintigraphy in suspected pars lesions, as with most of its musculoskeletal applications in first line imaging, is its relatively limited specificity in differential diagnosis.¹⁵ The increased uptake of radio-isotope is often attributable to multiple potential origins or causes.

Single photon emission computed tomography (SPECT) is considered most accurate in identifying an on-going process with greater anatomical specificity when related to current symptoms. Similarly, the on-going activity offers information as to the potential for healing of the lesion. If the increased metabolic activity from the lesion has ceased, there is likely to be no increase of radioisotope uptake. As a result, chronic lesions may not be detected.¹² Thus, SPECT alone may not be an appropriate first order diagnostic procedure.

Perhaps most valuable is the combination of CT and SPECT. Tomography of a scintigram enables localization of the increased radioisotope signal to the ­posterior vertebral elements, specifically the pars interarticularis.^2,13,18 The presence of a normal CT accompanied by significant findings with SPECT suggests no overt fracture, but a stress response present at the pars interarticularis. Such results may point to the potential for a large treatment effect in which the fracture may be prevented with activity management and rehabilitation.⁶ The cricket athlete in this case represents this subgroup of patients. Current American College of Radiology Appropriateness Criteria recommends for suspected spondylolysis or stress fracture in athletes, bone scintigraphy with SPECT followed by limited CT, if the SPECT is positive.¹⁹

In Figures 4a and 4b, axial and sagittal CT reconstructions demonstrate no identifiable pathology. Figure 5, however, reveals increased uptake of the radioisotope at the posterior elements of L4-5. Thus, the CT images indicate no frank fracture being present, but the SPECT study reveals increased metabolic activity, consistent with a stress response.

Figure 4.

Computerized Tomography of the lumbar spine of this athlete, a) axial view, b) sagittal view.

Figure 5.

SPECT Images; note darker areas, indicative of increased uptake of the radioisotope at the posterior elements of L4-5.

PHYSICAL THERAPY MANAGEMENT PROCESS

Once the pars stress reaction was identified, relative rest, including cessation of his sporting activity, was initiated. He was specifically restricted from participating in cricket and bowling for six weeks. He also immediately began a course of physiotherapy focusing on activation and training of the spinal stabilizing musculature, including the transversus abdominis and lumbosacral multifidi. The design of this exercise program was directed at neutral positioning of the lumbar spine with low load, high repetition activities in a Pilates-like program. He was also directed to avoid large excursions of trunk movement, particularly in extension. This exercise program was enhanced by real-time feedback with rehabilitative ultrasound while in the clinical setting and a pressure biofeedback unit for use at home. Once optimally recruited, training of the target musculature for endurance was the objective.

After successfully participating in this phase for approximately two weeks, he demonstrated full, pain-free lumbar motion while lying. His trunk motor control exercise progression was advanced to more challenging positions, including quadruped. Additionally, lower extremity muscle extensibility specific to his sporting demands were addressed, such as ankle dorsiflexion and hip musculature length in all planes. Unilateral declined squats with a focus on neutral spine positioning were also initiated. The arabesque exercise was introduced to train control of the spine with flexion over the forwardly placed lower extremity, similar to the demands of bowling.

At four weeks, more dynamic and loading exercise was introduced, including hopping on various surfaces with the focus on controlled, unilateral landing. Gentle rotatory movements of the trunk were incorporated into his exercise program and motion mimicking bowling activity against light elastic band resistance was also introduced. Re-education regarding his bowling style toward more side-on and ­semi-side-on positions also began. These alignments of the trunk are generally considered to lessen the risk of spinal injury compared to the front-on technique with which he had been experimenting prior to the worsening of his symptoms. The front-on style of bowling may result in greater lumbar compressive and rotational forces during the approach.

At approximately six weeks, he was allowed to bat into the cricket nets, thereby challenging dynamic rotation, as well as begin gentle jogging. Monitoring of his progress continued to include the requirement that each progressive step be achieved without inducing low back symptoms. He soon after began practicing bowling into the nets with activity specific reconditioning.

OUTCOME

At approximately eight weeks following diagnosis and the initiation of his individually designed exercise program, he returned to competition. He was able to participate fully without return of symptoms. Follow-up at six months revealed that he has remained symptom free.

RECOMMENDATIONS FOR THE FUTURE

The challenge for physiotherapists is discriminating those persons who present with simple mechanical low back pain fully within the scope of practice from those who present with a more complex condition, perhaps caused by a disturbance of the structural integrity of the lumbar spine. Adolescent and young adult athletes are particularly at risk for injuries to the pars interarticularis. In a study of over 4200 athletes with low back pain, 590 (13.9%) had radiologically identifiable spondylolysis and among those with identifiable pars lesions 47.5% (280) had spondylolisthesis.²⁰ Among the athletic populations most at risk are cricket players.^21–23 The action of bowling requires movement of the trunk in all three cardinal planes with compressive forces through the lumbar spine exceeding eight times that of body weight.^22,23 Examination features alerting the clinician to potential pars defects have not been well defined. The one-legged standing hyperextension test used in the examination of this patient, although positive, has not withstood scrutiny when studied. This test has been shown to have 55.2% sensitivity, 67.6% specificity, a negative predictive value of 46.9%, and a positive predictive value of 53.8% for detecting active spondylolysis in young, active patients with low back pain. Thus, the one-legged hyperextension test should not be relied upon for diagnosis or exclusion of pars interarticularis lesions.¹³ Other authors⁷ have reported palpable lesions to correlate well with radiological results. These palpable findings, however, assume a relatively large magnitude of displacement with spondylolisthesis and perhaps do not represent the majority of patients in whom the physiotherapist would be attempting to utilize such decision making. Other authors^24–26 have offered anecdotal reports of a shortened stride, flexed hips and knees in stance and during gait, and either flattened or increased lumbar lordosis.

Physiotherapists treating adolescent and young adult athletes with low back pain complaints should have a high level of clinical suspicion of the possibility for spondylolysis, spondylolisthesis, or developing stress reactions of the pars interarticularis. No single algorithm to guide decision making for proceeding with conservative care or referring for diagnostic imaging has been validated. In the predominance of patients presenting with low back pain, diagnostic imaging results do not influence care choices. Among the population represented by this athlete, however, clinician knowledge of imaging selection and interpretations based on patient specific clinical reasoning contributed directly to treatment choices.