Diagnostic Imaging of Sports-Related Spinal Disorders

Lower Back Pain in the Athlete: Common Conditions and Treatment

Athletes younger than 12 years of age commonly have pathology related to the lower back pain. Spondylolysis is the most common condition in these athletes. Other conditions, including lumbar Scheuermann's disease,scoliosis, disc herniation, fractures, and muscular stains, can occur. Most of the mature general population experiences low back at some time in life. Athletes may be at increased risk, but outcomes are good. The majority of low back pain in mature athletes is mechanical in nature. Herniated discs,spinal stenosis, sacoilitis, and sacral stress fractures can also cause low back pain in these athletes. Low back conditions mentioned above may be treated with rest, specific exercise programs, and medication. Surgery is indicated for severe spinal stenosis, pain with evidence of neurological compromise,and some painful deformities. Newer treatments for back pain are emerging,but few controlled clinical trials are available.

Cervical sprains, disc herniations, minor fractures, and other cervical injuries in the athlete

In today's health-conscious society, more people are participating in athletic endeavors. As participation increases, so does the incidence of cervical injuries. Fortunately, most of the cervical injuries seen in sports are minor and can be treated successfully with minimal morbidity. It is important, however, to accurately assess the patient sustaining a cervical injury to rule out the presence of a more severe cervical injury. When practitioners understand the pathophysiology and treatment of common injuries, including sprains, strains, contusions, disc herniations, and simple fractures, most athletes can be returned to full function.

Magnetic resonance imaging of sports injuries of the spine

Spinal injuries are relatively frequent events in professional athletes. Greater popularity of recreational athletic activities has increased the occurrence of sports-related spinal injuries in the general population. The demand of high-intensity sports places a constant load on the vertebral column. Several studies have demonstrated higher prevalence of spinal abnormalities in athletes than nonathletes. Direct correlation of the number and extent of injuries with the length in years of sports activity has been established. Diagnostic imaging, particularly magnetic resonance imaging (MRI), plays a crucial role in evaluating and detecting sports-related spinal injuries. Subtle bone marrow, soft-tissue, and spinal cord abnormalities, which may not be apparent on other imaging modalities, can be readily detected on MRI. Early detection often leads to prompt accurate diagnosis and expeditious management, in many cases avoiding unnecessary procedures. This article reviews the technical aspects of MRI for evaluation of the spine and the role of MRI in the assessment of sports-related spinal injuries.

Neuromuscular function in athletes following recovery from a recent acute low back injury

STUDY DESIGN

Observational case control design.

OBJECTIVES

To examine muscle response to sudden trunk loading in athletes with and without a recent history of acute low back injury (LBI).

BACKGROUND

Impaired neuromuscular function is associated with chronic low back pain. This study examined whether such impairment persists after recovery from an acute LBI.

METHODS AND MEASURES

Seventeen athletes who had a recent history of acute LBI and 17 matched healthy controls were tested. At the time of testing (mean = 56 days postinjury, range = 7-120 days postinjury), all athletes were symptom free and had returned to regular competition. Subjects performed isometric exertions in trunk flexion, extension, and left and right lateral bending against a trunk restraining cable. Upon reaching the target isometric force, the cable was released to impose sudden loading on the lumbar spine. Surface EMG signals from 12 major trunk muscles were recorded. The shut-off and switch-on latencies and number of muscles responding to sudden loading were compared between the 2 groups.

RESULTS

In all 4 testing directions, the athletes with a recent history of acute LBI shut off significantly fewer muscles and did so with delayed latency. On average, the injured subjects shut off 4.0 out of 6.0 (SD = 1.3) muscles compared to 4.6 out of 6.0 (SD = 1.3) muscles in the control group. The average muscle shut-off latency was 71 (SD = 31) milliseconds for the injured and 50 (SD = 21) milliseconds for the control subjects. No differences were found in number or latency of muscles switching on.

CONCLUSIONS

These objective measures of neuromuscular function indicated an altered muscle response pattern to sudden trunk loading in athletes following their clinical recovery from a recent acute LBI.

Cervical spinal stenosis and sports-related cervical cord neurapraxia in children

STUDY DESIGN

Congenital spinal stenosis has been demonstrated to contribute to cervical cord neurapraxia after cervical spinal cord injury in adult athletes. A sagittal canal diameter <14 mm and/or a Torg ratio (sagittal diameter of the spinal canal: midcervical sagittal vertebral body diameter) of <0.8 are indicative of significant cervical spinal stenosis. Although sports-related cervical spine injuries are common in children, the role of congenital cervical stenosis in the etiology of these injuries remains unclear.

OBJECTIVES

The authors measured the sagittal canal diameter and the Torg ratio in children presenting with cervical cord neurapraxia resulting from sports-related cervical spinal cord injuries to determine the presence of congenital spinal stenosis.

METHODS

A total of 13 children (9 male, 4 female) presented with cervical cord neurapraxia after a sports-related cervical spinal cord injury. Age ranged from 7 to 15 years (mean +/- SD, 11.5 +/- 2.7 years). The sports involved were football (n = 4), wrestling (n = 2), hockey (n = 2), and soccer, gymnastics, baseball, kickball, and pogosticking (n = 1 each). Lateral cervical spine radiographs were used to determine the sagittal canal diameter and the Torg ratio at C4.

RESULTS

The sagittal canal diameter (mean +/- SD, 17.58 +/- 1.63 mm) and the Torg ratio (mean +/- SD, 1.20 +/- 0.24) were normal in all of these children.

CONCLUSION

Using the sagittal canal diameter and the Torg ratio as a measurement of congenital spinal stenosis, the authors did not find evidence of congenital cervical spinal stenosis in a group of children with sports-related cervical spinal cord neurapraxia. The occurrence of cervical cord neurapraxia in pediatric patients can be attributed to the mobility of the pediatric spine rather than to congenital cervical spinal stenosis.

A history of low back injury is a risk factor for recurrent back injuries in varsity athletes

In this prospective study, we investigated whether a history of previous low back injury and dissatisfaction with a coach and teammates could predict future low back injury in varsity athletes during a 1-year follow-up period. Of 679 Yale varsity athletes surveyed in 1999, 18.3% (124) reported that they had sustained a low back injury within the past 5 years, and 6.8% (46) sustained a low back injury in the follow-up season. There were no differences in incidence rates between men and women or between athletes involved in contact or noncontact sports. A history of low back injury was the significant predictor for sustaining low back injury in the following year, and athletes who reported previous low back injury were at three times greater risk. Athletes who still had pain at the time of the survey were six times more likely to sustain a low back injury than were athletes without a history of low back injury. These results suggest that some risk factors associated with a history of low back injury predispose athletes to sustain recurrent injury. They may be congenital or a result of insufficient recovery time after the first low back injury episode.

Routine thin slice MRI effectively demonstrates the lumbar pars interarticularis

AIM

To confirm that routine thin slice sagittal magnetic resonance imaging (MRI) of the lumbar spine effectively demonstrates the lumbar pars interarticularis.

METHOD

A retrospective review of 100 MRI examinations was carried out and the appearance of the pars interarticularis at L4 and L5 bilaterally was assessed and classified as Type 1 - normal, Type 2 - sclerotic pars, Type 3 - not assessable and Type 4 - pars defect. A total of 400 pars were assessed. Those with known or obvious lytic spondylolysis were excluded from the study. All MRI examinations had both sagittal T1- and T2- weighted sequences and both were assessed. Sagittal T1 sequences were carried out with a 3 mm slice thickness and T2 image sequences with a 4 mm slice thickness.

RESULTS

The total number of pars assessed as normal (Type 1) was 299 (75%) of the T1-weighted images; 80 (20%) were classified Type 2. On T2-weighted imaging 290 (72.5%) were Type 1 and 66 (16.5%) were Type 2. Both of these types of appearances correlate well with the finding of a normal pars interarticularis. Thus, 379 (95%) of the pars appeared normal on T1-weighting and 356 (89%) on T2-weighting.

CONCLUSION

Contrary to previous findings with 5 mm thick slices, routine thin slice sagittal T1 and T2 images effectively demonstrate the pars interarticularis, with acceptable data acquisition times and image quality. We believe this is mainly due to the thinner slices obtained in our series.