Disc Height Reduction Research Articles

THE PREVALENCE OF DISC AGING AND BACK PAIN AFTER FUSION EXTENDING INTO THE LOWER LUMBAR SPINE. A matched MR study twenty-five years after surgery for adolescent idiopathic scoliosis

Purpose: To determine the long-term outcome after fusion for adolescent idiopathic scoliosis in terms of degenerative disc findings diagnosed using MR imaging and to elucidate the clinical consequences. Material and Methods: Thirty-two patients with adolescent idiopathic scoliosis, who had undergone spinal fusion using Harrington rods to the lower lumbar spine with one or two unfused discs below the fusion, were re-examined 25 years after the fusion. The re-examinations included validated questionnaires, clinical examination, full standing frontal and lateral radiographs and MR examination of the lower lumbar region. Curve size and degenerative findings on MR images were evaluated by two unbiased radiologists, blinded to the clinical findings. A matched control group of 32 persons without scoliosis was subjected to the same examinations. Results and Conclusion: There were significantly more degenerative disc changes (p<0.0001), disc height reduction (p=0.0010) and end-plate changes (p<0.0001 for both upper and lower end-plates) in the lowest unfused disc in the patient group compared with the control group. The MR findings in the lowest unfused disc, but not the one above, in the patient group correlated to lumbar pain intensity as well as to the diminished lumbar lordosis.

The long-term effects of rally driving on spinal pathology

Objectives. To investigate the consequences of rally driving on lumbar degenerative changes. Background. Vehicular driving is suspected to accelerate disc degeneration through whole-body vibration, leading to back problems. However, in an earlier well-controlled study of lumbar MRI findings in monozygotic twins, significant effects of lifetime driving on disc degeneration were not demonstrated. Another study of machine operators found only long-term exposure to vibration on unsprung seats led to a reduction in disc height. Design. Case-control study comparing rally drivers with population sample. Methods. Eighteen top rally drivers and co-drivers, mean age 43 yrs (SD, 10), volunteered for the study. The subjects were interviewed and imaged with a MR scanning and lumbar images were analyzed for degenerative findings using a standard scoring protocol previously published. The reference group was composed of 14 men, mean age 55 yrs (SD, 10), selected from a population sample. Results. Overall results showed no significant differences in lumbar degenerative findings as assessed from MR images between the rally drivers and the reference group; age-adjusted differences were not statistically significant for disc heights, bulges, herniations, end-plate irregularities, or osteophytes. Conclusion. Even extreme vehicular vibration as experienced in rally driving does not appear to have significant effects on disc generation. Relevance The study results do not support driving, and its associated whole body vibration, as a significant cause of disc degeneration and question the theory that the higher incidence of back pain among drivers is due to accelerated disc degeneration. Other driving-related factors, such as postural stress, may deserve more attention.

Intervertebral disc reconstitution after chemonucleolysis with chymopapain is dependent on dosage.

The current report describes a study in beagles in which the effects of intradiscal injection of three doses of chymopapain were evaluated with respect to the reduction of disc width and reconstitution of the nucleus pulposus. To establish an intradiscal dose of chymopapain that would achieve optimal reduction in disc height followed by maximum reconstitution of the nucleus pulposus. Earlier reports of the efficacy of high and low doses of chymopapain for chemonucleolysis have provided conflicting data, and a scientific basis for an appropriate dose is lacking. Four mature, female beagles were subjected to chemonucleolysis using three doses of chymopapain as Chymodiactin (31, 63 and 125 picokatals/disc) injected into the L2-L3, L1-L2, and L3-L4 discs. Disc widths were monitored radiographically over 32 weeks. Proteoglycans were radiolabeled by intravenous injection with Na2 35SO4 (1 mCi/kg) 24 hours before sacrifice, and their specific activities (disintegrations per minute/mg proteoglycan), hydrodynamic size, and ability to aggregate determined. Sixty-three picokatals of Chymodiactin produced optimal disc reconstitution after chemonucleolysis. A reduction in disc height of approximately 35% was evident within 1 month and this slowly returned to approximately 90% of the preinjection value after 32 weeks. The nucleus pulposus contained approximately 75% of the proteoglycan content of control tissues, and most of these formed aggregates with hyaluronan. Disc collagen levels remained relatively unaffected by treatment. This study demonstrates that an effective reduction in disc width compatible with later reconstitution of the nucleus pulposus can be achieved experimentally with an appropriate dose of chymopapain. These data clearly indicate that an optimal dose of chymopapain for chemonucleolysis in humans needs to be established.

Radiological features during and following treatment of spinal tuberculosis.

A retrospective study was performed in order to document the sequence and time scale of radiological changes occurring during the healing of spinal tuberculosis. 28 episodes occurred in 26 patients, of whom only two were Caucasian. All demonstrated good response to conventional chemotherapy. Soft-tissue masses increased in size for up to 1.5 months and took about 12 months to resolve. Bone destruction was seen in all cases and progressed in 70% of patients, whilst on treatment. There was loss of vertebral body height in 79%, which progressed for up to 14 months; any recovery of height was a very late feature. Sclerosis was seen at presentation in 52% and developed in most of the remaining patients within 5 months of instigating treatment. It progressed for up to 14 months and took, on average, 31 months to return to normal. Reduction in disc height was commonly seen and the vertebrae fused in three-quarters of those affected, the time of onset of fusion being very variable. To manage patients with spinal tuberculosis, an appreciation of the variability of radiological changes that can occur during treatment is necessary.

The thoracolumbar spine in young elite athletes. Current concepts on the effects of physical training.

Due to the increased interest in physical fitness and to the fact that athletes start their training at younger ages the risk for injuries to the growing individual has increased. The spine, as with the rest of the skeleton, is at greater risk of injury during growth, especially during the adolescent growth spurt. Back pain is more common among athletes participating in sports with high demands on the back than other athletes and nonathletes. Disc degeneration, defined as disc height reduction on conventional radiographs and reduced disc signal intensity on MRI, has been found in a higher frequency among wrestlers and gymnasts than nonathletes. Abnormalities of the vertebral bodies including abnormal configuration, Schmorl's nodes and apophyseal changes are common among athletes. These abnormalities are similar to those found in Scheuermann's disease. Athletes with these types of abnormalities have more back pain than those without. Spondylolysis has been found in higher frequencies than expected among athletes representing many different sports. Spondylolysis has been reported in up to 50% of athletes with back pain. Scoliosis has been found in up to 80% of athletes with an asymmetric load on the trunk and shoulders, such as javelin throwers and tennis players. The scoliosis, however, is a small curvature and does not cause back pain.