Is there increased intervertebral mobility in isthmic adult spondylolisthesis? A matched comparative study using roentgen stereophotogrammetry

STUDY DESIGN

By roentgen stereophotogrammetric technique, the intervertebral mobility of the spondylolytic segment in eight patients was measured and compared with the mobility of eight nonspondylolytic patients matched according to sex, afflicted segment, and grade of disc degeneration.

OBJECTIVES

To compare the intervertebral mobility of a spondylolytic segment with the mobility of a segment without spondylolysis in adult patients with back pain.

SUMMARY OF BACKGROUND DATA

Evidenced by the resulting olisthetic deformity and supported by the outcome from prior investigations, spondylolysis is assumed to induce spinal segmental instability/hypermobility.

METHODS

After percutaneous application of tantalum indicators for roentgen stereophotogrammetric technique, the intervertebral translations of the spondylolytic fifth lumbar vertebra were measured in eight adult patients with low back pain and low-grade olisthesis. Eight other patients without spondylolysis but with low back pain presumably on degenerative basis were chosen for comparison and had an identical measuring procedure using roentgen stereophotogrammetric technique. The two groups were matched in pairs according to sex, afflicted segment, and grade of disc degeneration.

RESULTS

No significant difference was registered considering the intervertebral mobility for matched pairs in the two groups neither along the sagittal nor the vertical axis. The transverse translations were mostly negligible in both groups.

CONCLUSION

The spondylolytic defect in pars interarticularis does not cause permanent instability/hypermobility detectable in the adult patient with low back pain and low-grade olisthesis.

ACC and back injuries: the relevance of pre-existing asymptomatic conditions

The purpose of the ARCI (1992) and AI (198) Acts is to cover those who suffered from personal injury by accident. This purpose should not be distorted. This review does not aim to suggest that cover be extended to victims of disease. Equally it is inappropriate that imaging be used to detect asymptomatic, age-related change--or reveal asymptomatic abnormalities that do not place the patient at increased risk of symptoms over the general population--so as to unfairly deny coverage to the victims of accidents. This is particularly important to those who suffer personal injury to the lumbar spine where the cause is wholly or substantially an accident, and in whom, without the specified accident having occurred, personal injury (symptoms and disability) would have not been likely to occur. Physicians managing spinal disorders must correlate clinical findings with imaging studies when planning treatment. Those considering entitlement for cover under third party/ACC provisions must pay close attention to the history and clinical evaluation, correlating these with the investigation findings, and not assume that the abnormalities found on sensitive investigations are the cause of the symptoms.

Spondylolysis of the upper lumbar spine. Radiological features

To elucidate the radiological features of spondylolysis of the three upper lumbar vertebrae, review of radiology reports during an 8-year period was performed. Among 17 levels of defects in 14 patients, nine were unilateral. Among 25 defects, nine had an atypical course. In eight of nine atypical defects, the direction was vertical at the inferolateral aspect, and horizontal at the superomedial aspect. The spondylolysis of the upper lumbar spine is often unilateral and the course of the defect is frequently atypical.

Diagnostic value of cervical somatosensory evoked potentials recorded from the intervertebral discs after median and ulnar nerve stimulation in cervical spondylotic myelopathy

We have studied the cervical somatosensory evoked potentials (CSEPs) recorded referentially from serial intervertebral discs after stimulation of the median nerve or the ulnar nerve at the wrist in cervical spondylosis. In seven unilateral radiculopathies, the CSEPs evoked by stimulation on the asymptomatic side normally consisted of the P1-N1 and the P2-N2 components, which represented the potentials arising from the white matter and the gray matter, respectively. Of 21 myelopathies, the CSEPs revealed the white matter involvement with conduction block identified by abrupt P1-N1 amplitude reduction in 7, the gray matter involvement identified by P2-N2 amplitude reduction in 3, or a combination of both in 11. The CSEPs were useful not only for determining the level responsible for myelopathy but also for localizing the lesion in the transverse plane of the spinal cord.

Evaluation of specific stabilizing exercise in the treatment of chronic low back pain with radiologic diagnosis of spondylolysis or spondylolisthesis

STUDY DESIGN

A randomized, controlled trial, test--retest design, with a 3-, 6-, and 30-month postal questionnaire follow-up.

OBJECTIVE

To determine the efficacy of a specific exercise intervention in the treatment of patients with chronic low back pain and a radiologic diagnosis of spondylolysis or spondylolisthesis.

SUMMARY OF BACKGROUND DATA

A recent focus in the physiotherapy management of patients with back pain has been the specific training of muscles surrounding the spine (deep abdominal muscles and lumbar multifidus), considered to provide dynamic stability and fine control to the lumbar spine. In no study have researchers evaluated the efficacy of this intervention in a population with chronic low back pain where the anatomic stability of the spine was compromised.

METHODS

Forty-four patients with this condition were assigned randomly to two treatment groups. The first group underwent a 10-week specific exercise treatment program involving the specific training of the deep abdominal muscles, with co-activation of the lumbar multifidus proximal to the pars defects. The activation of these muscles was incorporated into previously aggravating static postures and functional tasks. The control group underwent treatment as directed by their treating practitioner.

RESULTS

After intervention, the specific exercise group showed a statistically significant reduction in pain intensity and functional disability levels, which was maintained at a 30-month follow-up. The control group showed no significant change in these parameters after intervention or at follow-up.

SUMMARY

A "specific exercise" treatment approach appears more effective than other commonly prescribed conservative treatment programs in patients with chronically symptomatic spondylolysis or spondylolisthesis.

Bone scintigraphy in sports medicine: a review

Bone scintigraphy is of growing interest to the sports physicians in the evaluation of benign disorders of the musculoskeletal system. It is atraumatic and easily applied, and being very sensitive a normal scintigram excludes pathophysiological conditions or mechanical disorders of the bones and joints. The indication is mainly suspicion of stress fractures, where a graduation is possible allowing prognostic interpretation. The finding of stress fractures in female athletes with long-lasting amenorrhea may warrant further interest in the bone mineral content of the skeleton. In the diagnostic evaluation of particularly longer-lasting joint-related pain in younger subjects without obvious degenerative disease, bone scintigraphy is very sensitive to exclude joint affection, but not very specific to reveal an exact diagnosis. In athletes with back pain and radiographically demonstrated spondylolysis, tomography of bone scintigrams (SPECT) may discern between an actively healing process, probably eliciting the pain, and an inactive, healed process not responsible for the back pain. Bone tumors always show increased uptake in bone scintigraphy, but the method does not allow a reliable differentiation between benign and malign etiology.

[Occupational disease 2108. Degeneration pattern in magnetic resonance tomography of the lumbar spine in patient with differential weight-bearing activity]

The addition of vertebral disc degeneration to the job-related disease register raises the question of vertebral disc degeneration patterns according to loading strain. The readings of the lumbar vertebra of construction workers and nurses were compared with those of a group without workload. In the groups examined, aged 35 to 50, monosegmental damage was found in only 17% of the patients with high workload, as opposed to 29% of those with no workload, mostly with monosegmental damage at level L5/S1. Damage to the upper segments of the lumbar spine with intact discs in between was found exclusively in patients with high workload. Multiple segment damage in the age range examined was found in subjects with activities that add to the load of the spinal column. The value of MRI in assessing and evaluating illness originating from the vertebral discs is currently being discussed.

Pathogenesis of cervical spondylotic myelopathy

OBJECTIVE

To determine whether either of two mechanical theories predicts the topographic pattern of neuropathology in cervical spondylotic myelopathy (CSM). The compression theory states that the spinal cord is compressed between a spondylotic bar anteriorly and the ligamenta flava posteriorly. The dentate tension theory states that the spinal cord is pulled laterally by the dentate ligaments, which are tensed by an anterior spondylotic bar.

METHODS

The spinal cord cross section, at the level of a spondylotic bar, is modelled as a circular disc subject to forces applied at its circumference. These forces differ for the two theories. From the pattern of forces at the circumference the distribution of shear stresses in the interior of the disc-that is, over the transverse section of the spinal cord-is calculated. With the assumption that highly stressed areas are most subject to damage, the stress pattern predicted by each theory can be compared to the topographic neuropathology of CSM.

RESULTS

The predicted stress pattern of the dentate tension theory corresponds to the reported neuropathology, whereas the predicted stress pattern of the compression theory does not.

CONCLUSIONS

The results strongly favour the theory that CSM is caused by tensile stresses transmitted to the spinal cord from the dura via the dentate ligaments. A spondylotic bar can increase dentate tension by displacing the spinal cord dorsally, while the dural attachments of the dentate, anchored by the dural root sleeves and dural ligaments, are displaced less. The spondylotic bar may also increase dentate tension by interfering locally with dural stretch during neck flexion, the resultant increase in dural stress being transmitted to the spinal cord via the dentate ligaments. Flexion of the neck increases dural tension and should be avoided in the conservative treatment of CSM. Both anterior and posterior extradural surgical operations can diminish dentate tension, which may explain their usefulness in CSM. The generality of these results must be tempered by the simplifying assumptions required for the mathematical model.

The spondylolytic vertebra and its adjacent segment. Mobility measured before and after posterolateral fusion

STUDY DESIGN

By using roentgen stereophotogrammetric analysis in six patients having tantalum indicators implanted at a preoperative external fixation test, the mobility in the spondylolytic lumbosacral level and its adjacent segment could be studied before fusion and during the course of postoperative fusion consolidation.

OBJECTIVE

To study the mobility effects on the segment adjacent to a lumbar fusion over time from the preoperative situation until fusion healing as defined by roentgen stereophotogrammetric analysis.

SUMMARY OF BACKGROUND DATA

In vitro studies indicate that the altered biomechanical situation after lumbar fusion increases the intradiscal pressure and changes the kinematics in the juxtafused segment.

METHODS

Six patients with low grade spondylolysisolisthesis were scheduled for fusion of the spondylolytic lumbosacral segment after a preoperative external fixation test. The latter procedure also included implantation of tantalum markers for spinal roentgen stereophotogrammetric analysis. Each patient was examined by roentgen stereophotogrammetric analysis at four separate occasions: before fusion (2 months after removal of the external frame) and 3, 6, and 12 months after surgery. The translatory movements of the L5 vertebra in relation to sacrum and of the L4 vertebra in relation to the L5 vertebra were calculated at each examination.

RESULTS

For the juxtafused L4-L5 level, increased and decreased mobility patterns could be identified. Transformation of the preoperative mobility in the lumbosacral segment to the adjacent segment during fusion consolidation was verified in two patients but was not a general phenomenon.

CONCLUSION

Fusion of the lumbosacral segment can alter the kinematics of the adjacent segment, redistributing the mobility toward relative hypermobility in the juxtafused segment.

[Landing after jumps--wrong technique promotes spondylolysis]

The double-S-shape of the vertebral column usually is explained to be an adaptation to the functional requirements of axial shock absorption. We investigated the effects of axial impacts on the coupled motions of the pelvic girdle and the vertebral column. In contrast to the predictions of the bending spring model, in the first few miliseconds after impact induction the vertebral column shows a tendency of lumbal straightening. This effect may be one reason for high stresses in the vertebral arches, promoting spondylolysis and spondylolisthesis. In sports, high axial impact loads, especially provoked by wrong landing techniques after jumps, should be avoided.

Competitive sports and the progression of spondylolisthesis

To consider the effects of several years of competitive sports training on children and adolescents with spondylolisthesis, we carried out a retrospective radiologic and clinical study of 86 young athletes with spondylolysis or spondylolisthesis (24 girls and 62 boys between the ages of 6 and 20 years). The mean degree of displacement was 10.1% at the beginning of the observation. The radiologic tests showed an increase in displacement over time in 33 athletes. The average progression of spondylolisthesis in this group was 10.5%. For 36 athletes, spondylolisthesis did not progress during the period of athletic training. In seven athletes, a decrease in the displacement was observed, from 17.9 to 8.9% on average. For 10 athletes, the course of spondylolisthesis could not be determined, because only one lateral radiograph was available. In spite of intensive daily training, the athletes had no symptoms during the entire period of observation, which lasted an average of 4.8 years. In light of our experiments, there is no justification for generally advising children and adolescents with limited spondylolytic spondylolisthesis not to take part in competitive sports.

Bone SPET of symptomatic lumbar spondylolysis

The aim of this study was to clarify the clinical role of bone single photon emission tomography (SPET) of the lumbar spine in young persons with persistent lumbar pain which might be due to spondylolysis. Thirty-one bone SPET studies were performed on 25 patients (19 males, 6 females) aged 7-26 years (average 15.6 years) who had suffered lumbar pain associated with physical activity, and who were suspected of having spondylolysis. Planar and SPET images of the lumbar spine were obtained 2-3 h following the injection of 99Tc(m)-methylene diphosphonate using a single-head rotating gamma camera. The findings on the bone scintigram were compared with those on the radiograph. Bone scintigraphy at presentation was positive in only 7 of 15 sites of the pars interarticularis defects demonstrated on plain radiographs. On the other hand, seven sites of the pars interarticularis which were normal on the radiograph were positive on bone SPET. As clinical symptoms improved after immobilization using a lumbar corset, bone SPET tended to revert towards normal. The planar image was abnormal in only 8 (42%) of the 19 abnormal sites on the SPET image. A bone SPET study is indicated in patients who are negative on radiological tests and who are still suspected of having spondylolysis. If SPET is positive in these patients, the increased bone uptake is most likely suggestive of a state of 'stress reaction', and may be a good indicator for patient management. If negative, further radiological examinations will be required for proper assessment of the origin of lumbar pain.

Spondylolysis. Bending of the inferior articular processes of lumbar vertebrae during simulated spinal movements

STUDY DESIGN

This was a cadaveric lumbar motion segment experiment.

OBJECTIVES

To measure bending about the pars interarticularis during simulated flexion and extension movements, with and without high compressive forces. This was designed to indicate which activities are most likely to cause spondylolysis.

SUMMARY OF BACKGROUND DATA

The mechanical etiology of spondylolysis is controversial.

METHODS

Motion segments were loaded to simulate: A, full flexion; B, full extension; C, high compression in flexed posture, and D, high compression in lordotic posture. Bending of the inferior articular processes about the pars was measured in the sagittal plane, using a two-dimensional "MacReflex" infrared motion analysis system.

RESULTS

In full flexion, tension in the intervertebral ligaments bent the processes forward and down (by 3.25 degrees +/- 3.07 degrees), whereas in the loading conditions B, C, and D, inter-facet compressive forces caused the processes to bend backward and upward, by 2.24 +/- 2.48 degrees, 0.40 +/- 0.23 degrees, and 0.74 +/- 0.56 degrees respectively.

CONCLUSIONS

Activities that involve alternating flexion and extension movements cause large stress reversals in the pars and pose the greatest threat of spondylolysis. Compressive loading has little effect.

[Natural course in spondylolysis and spondylolisthesis]

The incidence of spondylolysis is approximately 5-6% in the white population. Males and females are equally affected. In about one third of the cases spondylolysis is associated with spondylolisthesis. For the etiology mechanical and genetic factors are important. At the L4 level mechanical factors play the dominant role, while at the L5 level genetic factors are equally important (size and orientation of the facet joints, dysplasia of the vertebral arch). Increased risk for low back pain is found in the presence of the following factors: spondylolisthesis exceeding 10 mm, a low lumbar index, increased lumbar lordosis, spondylolysis at the L4 level and early beginning of symptoms. In the absence of one of these factors the risk for low back pain in adulthood is not greater than in the normal population. This statement is supported by the fact that in a low back clinic with more than 2000 patients with low back pain, the incidence of patients with spondylolysis was not higher than in the normal population. In our own study we followed up 31 patients. The majority of them were symptomatic during adolescence. After a follow-up time of 28 years on average 20 of them stated that they had no pain since adolescence, 8 had only occasional pain and only 2 had undergone operative treatment because of significant low back pain.

Surgical treatment of spondylolysis and spondylolisthesis with a hook screw

Seventeen patients with spondylolysis and minimal spondylolisthesis were treated with a Morscher hook screw and bone grafting. At follow up, 82% had no symptoms and radiographs confirmed fusion of the isthmic defect. One patient had occasional pain, and two had an unsatisfactory result. They were both over 25 years of age and had a moderate displacement of 3-4 mm.

[Traumatic spondylolysis in the hedgehog. A contribution to the problem of isthmus dysplasia]

Traumatic spondylolysis in a hedgehog is reported. On the basis of that rare observation the "dysplastic" thinning of the vertebral isthmus frequently associated with spondylolysis in man is claimed to be related to the "neuroenveloping" function of the spine shared with that of the neurocranium. Dysplasia of the isthmus results from abnormal ganglio-foraminal interrelation in the embryo rather than from any primary derangement of the vertebral bone growth proper.

The R-zero line: a new kinematic concept of the lumbar spine

A new kinematic concept is described that relates to the notion that the lumbar spine behaves as a complete structure. This concept is called the "R-zero line" and represents kinematically the neutral position of the lumbar spine between anteflexion and retroflexion. The clinical significance of this parameter is evaluated in normal individuals and in patients with a symptomatic herniated disc at L4-5, with a symptomatic herniated disc at L5-S1, and with spondylolysis/spondylolisthesis. The results of this study show that the R-zero line has a characteristic configuration in all four test groups.

Spondylolysis and spondylolisthesis in the athlete

Spondylolysis and spondylolisthesis are common causes of back and leg pain in the athletic population. Spondylolysis originates most often in children between 5 and 10 years of age. Many types of athletic activities requiring lumbar extension and rotation place the immature spine at risk for developing these lesions.

Intersegmental sagittal motion in the lower cervical spine and discogenic spondylosis: a preliminary study

OBJECTIVE

The object of this investigation was to identify any correlation between discogenic spondylosis and the type of motion (normal, hypomobility, hypermobility, paradoxical motion) found in the sagittal plane of the intervertebral motion units of the lower cervical spine.

DESIGN AND SETTING

A case control study was performed from the files of 100 patients (ages 15-73) with cervical spine-related symptomatology at the Anglo-European College of Chiropractic Clinic.

PATIENTS

The cases were randomly selected from a cohort of patients with normal radiographic anatomy who attended the clinic from 1987-1990 and were known to have cervical spine neutral, flexion and extension lateral radiographs taken.

MAIN OUTCOME MEASURES

Extended chi 2 was used to test the observed data.

RESULTS

The findings from both the flexion and extension films suggested that intervertebral motion units with and without varying severities of discogenic spondylosis did differ with respect to the type of motion exhibited there (flexion: chi 2 = 39.399, p < .001; extension: chi 2 = 45.7424, p < .001). Intervertebral motion units which had discogenic spondylosis had a greater likelihood of exhibiting motion abnormalities (flexion: chi 2 = 5.665, p < .01; extension: chi 2 = 6.178, p < .01), and all types of motion seemed to be dependent on its severity (flexion: chi 2 = 16.464, p < .01; extension: chi 2 = 15.954, p < .02). In general, normal motion occurred approximately 60% of the time when there was absent or mild discogenic spondylosis and decreased precipitously as moderate and severe amounts of discogenic spondylosis appeared. In global cervical flexion, when there was either little or no discogenic spondylosis and abnormal motion was present, intersegmental hypermobility was predominant. Hypomobility became predominant overall as moderate and severe discogenic spondylosis was found. In global cervical extension, for all severities of discogenic spondylosis when there was abnormal motion, intersegmental hypomobility was predominant. Also of note was the presence of paradoxical motion, which occurred in 11% of the intervertebral motion units without discogenic spondylosis [usually at the C7-T1 intervertebral motion unit (86%)].

CONCLUSIONS

From the data it can be concluded that there are trends which occur with differing amounts of discogenic spondylosis when considering intersegmental cervical sagittal motion. However, additional detailed study is required to corroborate the findings and determine what their clinical significance is.

Pain of musculoskeletal origin in children

Pain in infants and children may be manifest by deformity, altered function, or discomfort. These manifestations are highly age related. Pseudoparalysis may be the only manifestation of septic arthritis of the hip in the neonate; a limp is often the presenting complaint in Perthes' disease, and scoliosis may be the primary manifestation of a herniated disc in an adolescent. New imaging methods aid in diagnosis. Ultrasound is helpful in assessing joint effusions; bone scans localize the cause of a limp; and magnetic resonance imaging shows spinal cord and root lesions. The traditional methods of assessment have not been replaced. History and physical examination are most essential to provide a rational basis on which to select the appropriate imaging study.

[Rotational instability of the lumbar spine--a three-dimensional motion study using bi-plane X-ray analysis system]

The purpose of this study is to investigate the rotational instability of the lumbar spine using bi-plane X-ray analysis system and to clarify mechanical etiology of the lumbar instability. The following results were obtained. (1) The range of rotational motion was about 2 to 3 degrees at each motion segment in the normal lumbar spine. The rotational motion was significantly large in spondylolysis, spondylolisthesis, and degenerative spondylolisthesis. (2) The rotational instability and the flexion-extension instability correlated to each other in spondylolysis and spondylolisthesis. However, in degenerative spondylolisthesis, the rotational instability and the antero-posterior instability were correlated to each other. (3) Instantaneous axis of rotation (IAR) was located at the posterior part of the intervertebral disc in the normal L4 vertebra, and more posteriorly in the L5 vertebra, while the IAR was located anteriorly in spondylolysis, and posteriorly in degenerative spondylolisthesis. (4) When the trunk was twisted, the lumbar lordotic angle was generally decreased, and the lumbar spine showed scoliotic curvature convex to the twisted direction. The apex was located at the L4/5 intervertebral level. Highly significant increases in flexion motion associated with rotation were observed at the pathological levels of spondylolysis and degenerative spondylolisthesis.

[Microtraumatic pathology of the lumbar isthmus: isthmic lysis or spondylolysis]

The authors report the study of a series of 23 partial isthmic lyses which occurred in a young population (15 cases) and in an adult one (8 cases) between 1983 and 1988, in the form of persistent lumbosacral pains. The initial radiological signs, the key to an early diagnosis, are defined: cortical notches more often regarding the lower cortex than the upper one, incomplete fissures reaching the two cortical poles, gradual narrowing of the isthmus. The value of standard radiography is underlined, with the oblique incidences close to the profile regularly ensuring the diagnosis, with the exception of 4 cases out of 23 for which tomography was required. As regards the evolution, the value of the diagnosis of the initial lesions is recalled, giving the hope of a restoration of the posterior inter-articular fractures by a rigid setting (4 months on average). This ability to reconstruct the lumbar isthmus is observed in the young subjects (10 out of 13 immobilizations) but also in the adult subjects (3 reconstructions for 5 immobilizations carried out). These results enable the early detection of prelytic states, in order to administer an suitable treatment resting on the rigid setting of the lumbosacral region, re-education and the control of the risk factors.

Postoperative radiographic evidence for fatigue fracture as the etiology in spondylolysis

The postoperative radiographs of 48 patients who underwent posterolateral in situ fusion for spondylolysis and Grade 1 or less spondylolisthesis over an 11-year period showed healing of the pars defects in 90% of the cases. The patients who showed healing had an average preoperative duration of symptoms of 17 months (mean, 12 months). The five patients whose radiographs showed persistent defects postoperatively were found to have had preoperative symptoms for an average of 47 months (mean, 48 months). This significantly greater (P 0.05) duration of symptoms prior to stabilization was the only variable that proved to be statistically significant. Controversy continues to exist as to the etiology of spondylolysis; however, the ability to heal the defect with lumbar spinal stability certainly supports the theory that the defect is a result of fatigue stresses, which finally manifest as a fracture seen on radiographs as the spondylolytic defect. Posterior spinal stabilization in those patients with symptoms for a period of less than 2 years who have failed conservative management can be expected to heal the pars defects.

The evolution of spondylolysis into spondylolisthesis during adult age

Over a period of two and a half years 7 cases of isthmic spondylolisthesis in adults were observed. Radiographs which had been taken from 7 to 28 years previously, when the patients were aged 27 to 44 years, revealed a spondylolysis in which slipping was either absent or almost imperceptible. In 5 cases the radiographs revealed a gradual increase of vertebral slipping over the years and in all these cases the onset and progression of the listhesis was associated with a decrease in the height of the underlying disc. These observations do not support the widely held view that spondylolysis gradually evolves into spondylolisthesis only during childhood or adolescence. On the contrary, they indicate that it may be initiated and become progressive during adult age.