Markers of inflammation and fibrinolysis in relation to outcome after surgery for lumbar disc herniation. A prospective study on 177 patients.

PURPOSE: The role of inflammation and fibrinolysis for the development of back pain and sciatica has been discussed. The aim of this study was to assess the relationship between markers of inflammation and fibrinolysis, to predict the outcome after surgery for lumbar disc herniation. METHODS: 177 patients were recruited. High sensitive C-reactive protein (hsCRP), plasminogen activator inhibitor 1 (PAI-1), fibrinogen, and D-dimer were analyzed preoperatively. Visual analogue scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and EuroQol 5 Dimensions (EQ-5D) were assessed preoperatively and at 6 weeks, 6-, 12-, and 24- months postoperatively. Dichotomization was made at the median for the laboratory analyses, and between the worst quartile and the other three quartiles for the outcome variables. Logistic regression was used to determine the odds ratios (OR) and 95 % confidence intervals (CI). RESULTS: The associations between PAI-1 and outcome seemed to be most prominent at the 6 and 12-month follow-up. When being in the upper half of PAI-1, the OR for being in the worst quartile of VAS back pain 12 months postoperatively was 3.33 (1.56-7.10). The corresponding OR for VAS leg pain was 2.46 (1.18-5.10), for ODI 2.83 (1.35-5.94) and for EQ-5D 2.73 (1.30-5.75). The OR for hsCRP was 2.10 (1.03-4.29) for being in the worst quartile of VAS back pain. Fibrinogen or D-dimer was not associated with any outcome variable. CONCLUSIONS: High PAI-1, a marker of fibrinolysis, was fairly consistently associated with poor outcome, while hsCRP, fibrinogen, and D-dimer were not.

Pain-drawing does not predict the outcome of fusion surgery for chronic low-back pain: a report from the Swedish Lumbar Spine Study.

Despite a widespread use of pain drawing in the selection of patients for surgical and non-surgical treatment, its value as a predictor of outcome is still not well documented. In a prospective multicentre randomised controlled trial of surgical and non-surgical treatment for chronic low-back pain (CLBP), two hypotheses were tested: (1). Pain drawing predicts outcome of treatment for CLBP, (2). Pain drawing is associated with psychological characteristics of patients with CLBP. Two hundred and sixty-four patients with severe CLBP of long duration completed pain drawings as part of a battery of questionnaires prior to treatment. They were followed up at 2 years post-treatment, with renewed completion of questionnaires. Outcome was measured in three ways: patient global assessment, change of disability/pain, and work status. The pain drawing was analysed by four different methods. The association between the pain drawings and outcomes was analysed. Personality traits and depressive symptoms were evaluated in the psychological assessment. None of the four methods of interpretation of the pain drawings demonstrated any significant association with outcome, in either the surgical or the non-surgical group. The pain drawing was associated with pre-treatment back pain intensity and depressive symptoms. No predictive value of the pain drawing regarding the outcome of treatment of CLPB was demonstrated. The concept of "organic/non-organic" pain in conjunction with chronic low-back pain is not supported by the results of the present study.

Neurobehavioral and developmental profile of very low birthweight preterm infants in early infancy.

AIM: To describe the neurobehavioral and developmental profile of very low birthweight (VLBW) preterm infants in early infancy. METHODS: Twenty VLBW infants and 10 term control infants were assessed at term, 3 and 6 mo of age. Neurobehavioral assessments included the Neonatal Behavioral Assessment Scale (NBAS) at term; the Infant Behavioral Assessment at term, 3 and 6 mo of age and the Behavioral Rating Scale of the Bayley Scales of Infant Development-II (BSID-II) at 3 and 6 mo of age. Development was evaluated with the Bayley Motor and Mental Scale at 3 and 6 mo. RESULTS: At term age VLBW infants differed from term infants on all the clusters and supplementary items of the NBAS. VLBW infants also showed more stress and less approach behavior at term and 6 mo of age and more problems with self-regulation in all subsystems at 6 mo of age. Moreover, VLBW infants performed lower on the Bayley Motor, Mental and Behavioral Rating Scale: 12 VLBW infants scored questionable or non-optimal on the Psychomotor Development Index and 18 questionable or non-optimal on the Behavioral Rating Scale. These results support the need for neurobehavioral intervention of VLBW infants in the first 6 mo of life. CONCLUSION: Almost all VLBW infants showed non-optimal motor quality behavior at 6 mo and encountered far more problems with self-regulation compared with term infants.

Laminar hook instrumentation in the cervical spine. An experimental study on the relation of hooks to the spinal cord.

Several anterior and posterior methods are today available for stabilization of the cervical spine. Factors such as level and degree of instability, method of decompression, bone quality, length of fixation and safety factors influence the choice of method for a particular patient. The use of laminar hooks in the cervical spine has been restricted by fear of cord compression with the potential of tetraplegia. The aim of the present study was to assess the safety and determine the anatomical relation between hooks inserted in the cervical spinal canal and the dura and spinal cord. Thirteen cadavers from seven women and six men with no evidence of cervical spine disorder were included. The mean age was 81.3 years (range 65-101 years). The cervical spine was instrumented with cervical Compact Cotrel Dubousset hooks and rods. The effect of the hook on the dura was studied by myelography in nine cadavers. The deformation of the dural sac was quantified by measurement of the maximal width of the indentation of the contrast column at each level. A CT myelography scan was obtained in three cadavers. The ratio between the distance of maximal hook intrusion into the spinal canal and the canal diameter in the direction of the hook was calculated. The relation between inserted hooks and the spinal cord and dura was documented in a fresh cadaver studied with CT myelography. A hemilaminectomy was performed at all levels in three cadavers with direct visual inspection and photography of the hook sites before and after excision of the dura. A dural deformation of 2 mm or less, as observed by myelography, was found at four out of 77 (5%) hook sites. The deformation was caused by a supralaminar hook at C3, C6 and C7 and by an infralaminar hook at C6. The mean hook intrusion in the spinal canal, as observed on CT, was 27% (range 8-43) of the canal diameter. On visual inspection, 14 out of 18 hooks were in contact with the dura. After removal of the dura, two out of the 18 hooks in the same cadaver were in contact with the spinal cord. However, no deformation of the cord was observed. To our knowledge this is the first study systematically documenting the relation between hooks and the spinal cord in cadavers. In 95% of the hooks no deformation of the dural sac was observed and there was no evidence of spinal cord deformation. From an anatomical point of view, laminar hook instrumentation can be considered a safe procedure. The study shows, however, that hooks inserted in the cervical spine have a close anatomical relationship with the neuraxis, and at stenotic levels the use of other techniques is therefore recommended.

Intra- and inter-tester reliability and reference values for hand strength.

The intra- and inter-tester reliability for measurement of handgrip strength and indexgrip strength using the Jamar dynamometer was investigated in 32 healthy volunteers, and the intra-tester reliability in 13 patients with cervical radiculopathy. The results from the reliability studies showed that handgrip and indexgrip strength measured with the Jamar dynamometer is a reliable method (ICC values 0.85-0.98) and can be recommended for use in clinical practice. Age- and sex-specific reference values for handgrip strength and indexgrip strength were measured with the Jamar dynamometer in 101 randomly selected healthy volunteers, aged 25-64 years. The results from the reference value study showed that sex is a more important determinant of hand strength than age, height and body weight. The reference values for hand strength improve the potential for objective evaluation of patients with arm/hand disorders caused by cervical radiculopathy.

Is the efficacy of the Cloward procedure overestimated? Technique of evaluation affects the outcome.

The purpose of the present study was to investigate the influence of the evaluation technique on the outcome of the Cloward procedure in cervical radiculopathy. The retrospective study included 94 consecutive patients operated on with anterior decompression and fusion with heterologous bone (Surgibone, Unilab). There were 56 men and 38 women, with a mean age of 48 years (range 27-78 years). Sixty-six patients had a single-level fusion, 26 a two-level fusion and one patient had a three-level fusion. The follow-up rate was 91/94 (97%) and evaluation was performed by an independent observer. Pain was quantified by visual analogue scale (VAS, range 0-100), functional disability by the new functional index Cervical Spine Functional Score (CSFS, range 0-100) and by the Neck Pain Disability Index (NPDI, range 0-100). The overall clinical outcome was assessed as excellent, good, fair or poor by both the patient and by the independent observer using Odom's criteria. At a mean follow-up of 26 months (range 12-56 months) the mean pain index was 39 (range 0-98), the mean CSFS 39 (range 0-85) and the mean NPDI 32 (range 0-76). The classification of the observer was 37% excellent, 40% good, 17% fair and 6% poor, and that of the patient was 53% excellent, 23% good, 20% fair and 4% poor. In the group classified as good by the observer, all scores were above 40, suggesting considerable remaining symptoms, and only 50% had returned to work. The results suggest that previous reports on the Cloward procedure using categorizations into excellent, good, fair or poor have overestimated the efficacy of the procedure. Only an excellent, but not a good, result as classified by the patient or an independent observer reflects a successful outcome. Neither of the variables studied seems independently sufficient for a balanced reflection of the outcome. The results suggest pain (VAS) as the primary outcome measurement, which, combined with the overall evaluation by the independent observer and work status, gives a multidimensional expression of the outcome.

Intra- and inter-tester reliability and reference values for isometric neck strength.

BACKGROUND AND PURPOSE: Age- and sex-specific reference values for neck strength based on reliable measurements in the upright position are lacking. The aim of the present study was to determine intra- and inter-tester reliability and age- and sex-specific reference values for isometric neck strength in extension, flexion and lateral flexion in sitting position measured with the David Back Clinic 140 (DBC 140) equipment. METHOD: The reliability of the DBC 140 equipment was investigated in 30 healthy volunteers and reference values were obtained from 101 healthy men and women. RESULTS: The reliability study showed that neck strength measured with the DBC 140 equipment has almost perfect intra- and inter-tester reliability (ICC values between 0.85 and 0.97). The mean value of the first in a series of three measurements was the highest for all three test leaders and for almost all directions. Results from the reference value study showed that gender is a much more important determinant of neck strength than age, body weight or body mass index (BMI). Neck strength in women was, on average, 55% of that in men, and when adjusted for body weight or BMI, the percentages were 70% and 59%, respectively. In all directions observed, neck strength decreased by approximately 20% from age 25 to 64 years. CONCLUSIONS: Measurements of neck strength taken in upright position with the DBC 140 equipment have almost perfect intra- and inter-tester reliability and justify the use of this test procedure. The use of the first measurement in a test series can be recommended for use in clinical practice since it was shown to be the maximal test value and thus, had a very low intra-tester difference. The use of reference values for neck strength when evaluating patients with neck disorders needs to take gender into account.

Surgery versus conservative management in adult isthmic spondylolisthesis--a prospective randomized study: part 1.

STUDY DESIGN: A prospective randomized study was performed. OBJECTIVE: To determine whether posterolateral fusion in patients with adult isthmic spondylolisthesis results in an improved outcome compared with an exercise program. SUMMARY OF BACKGROUND DATA: In spondylolisthesis, satisfactory results have been reported with both surgical and conservative management. The evidence for treatment efficacy, however, is weak because prospective randomized studies are lacking. METHODS: In this study, 111 patients were randomly allocated to an exercise program (n = 34) or posterolateral fusion with or without transpedicular fixation (n = 77). The inclusion criteria were lumbar isthmic spondylolisthesis of any grade, at least 1 year of low back pain or sciatica, and a severely restricted functional ability in individuals 18 to 55 years of age. Pain and functional disability were quantified before treatment and at 1- and 2-year follow-up assessments by visual analog scales (VAS). RESULTS: The 2-year follow-up rate was 93%. The functional outcome, as assessed by the Disability Rating Index and the pain reduction, was better in the surgically treated group than in the exercise group at both the 1- and 2-year follow-up assessments (P < 0.01). In the longitudinal analysis, the mean Disability Rating Index and pain improved in the surgical group (P < 0.0001). In the exercise group, the Disability Rating Index did not change at all, whereas the pain decreased slightly (P < 0.02). CONCLUSIONS: Surgical management of adult isthmic spondylolisthesis improves function and relieves pain more efficiently than an exercise program.

Instrumented and noninstrumented posterolateral fusion in adult spondylolisthesis--a prospective randomized study: part 2.

STUDY DESIGN: A prospective randomized study was performed. OBJECTIVE: To determine whether transpedicular fixation improves the outcome of posterolateral fusion in patients with adult isthmic spondylolisthesis. SUMMARY OF BACKGROUND DATA: The use of transpedicular fixation remains controversial. Both a positive effect and no effect from additional transpedicular fixation have been reported. METHODS: In this study, 77 patients randomly underwent posterolateral fusion with (n = 37) or without (n = 40) transpedicular fixation. The inclusion criteria were lumbar isthmic spondylolisthesis of any grade, at least 1 year of low back pain or sciatica, and severely restricted functional ability in individuals 18 to 55 years of age. RESULTS: The follow-up rate was 94%. At a 2-year follow-up assessment, the level of pain and functional disability were strikingly similar in the two groups, and there was no significant difference in fusion rate. CONCLUSIONS: Lumbar posterolateral fusion performed in situ for adult isthmic spondylolisthesis relieves pain and improves function. The use of supplementary transpedicular instrumentation does not add to the fusion rate or improve the clinical outcome.

Symptoms, signs, and functional disability in adult spondylolisthesis.

STUDY DESIGN: A cross-sectional clinical study. OBJECTIVES: To determine whether there are specific symptoms, signs, and functional disability associated with adult spondylolisthesis. SUMMARY OF BACKGROUND DATA: In spite of the common occurrence of adult spondylolisthesis, the symptoms, signs, and disability associated with it have not been analyzed in a large, well-defined group of patients. METHODS: The symptoms, signs, and disability of 111 consecutive patients with adult spondylolisthesis, before randomized treatment with fusion or physiotherapy, were compared with those of 39 patients with nonspecific low back pain before lumbar fusion. The patients completed a questionnaire covering clinical history and symptoms and submitted a pain drawing. The signs were documented. Functional disability and pain were quantified by 12-function and 2-pain visual analog scales, respectively. RESULTS: Sixty-two percent of the patients reported low back pain as well as sciatica, 7% sciatica only, and 31% low back pain only. Specific signs were infrequent. A positive straight leg raising test result in 12% and an L5 sensory disturbance in 13% were the most common. The symptoms were similar in patients with spondylolisthesis and chronic low back pain, but the chronic low back pain group reported more functional disability. Patients with a nonorganic pain drawing (widespread, nonspecific pain) were more often blue collar workers; were more often and longer on sick leave; and reported reduced mental condition, sexual function, functional ability, and more pain than patients with an organic pain drawing (localized, specific pain). CONCLUSIONS: The clinical pattern and functional disability in adult spondylolisthesis and in low back pain of nonspecific origin are similar. Sciatica in adult spondylolisthesis is typically not associated with a positive straight leg raising test result.

Degenerative changes following anterior cervical discectomy and fusion evaluated by fast spin-echo MR imaging.

PURPOSE: To review pre- and postoperative fast spin-echo (FSE) MR images of disc herniation and spondylosis in patients after spinal cervical surgery. MATERIAL AND METHODS: Data were reviewed of 68 patients after anterior discectomy and fusion (ADF) operations using the Cloward technique with solid single level (C5-C6 or C6-C7) or 2-level fusions (C5-C7). The average interval from surgery to review was 37 months. Age- and sex-matched controls without neck problems were examined. RESULTS: Preoperatively, the fusion groups had a higher incidence of protruded disc, and anterior and posterior osteophytes at the levels to be fused than the controls. Post-operatively, there was a significantly higher incidence of posterior osteophytes at the fused levels compared with the controls. Furthermore, the disc herniations and anterior osteophytes at the levels above and below the operated segments were more frequent in the fusion group. CONCLUSION: ADF causes acceleration of the degenerative changes at the fused level and at the levels below and above the fused segments.

Fast spin-echo MR assessment of patients with poor outcome following spinal cervical surgery.

PURPOSE: The aim of the investigation was to evaluate poor outcome following spinal and cervical surgery. MATERIAL AND METHODS: A total of 146 consecutive patients operated with anterior discectomy and fusion (ADF) with the Cloward technique were investigated. Clinical notes, plain radiography, CT, and fast spin-echo (FSE) images were retrospectively evaluated. RESULTS: Some 30% of the patients had unsatisfactory clinical results within 12 months after surgery; 13% had initial improvement followed by deterioration of the preoperative symptoms, while 14.4% were not improved or worsened. Disc herniation and bony stenosis above, below, or at the fused level were the most common findings. In 45% of patients, surgery failed to decompress the spinal canal. In only 4 patients was no cause of remaining myelopathy and/or radiculopathy found. FSE demonstrated a large variety of pathological findings in the patients with poor clinical outcome after ADF. Postoperatively, patients with good clinical outcome had a lower incidence of pathological changes. CONCLUSION: FSE is considered the primary imaging modality for the cervical spine. However, CT is a useful complement in the axial projection to visualize bone changes.

The segmental effect of Cotrel-Dubousset instrumentation on vertebral rotation, rib hump and the thoracic cage in idiopathic scoliosis.

The segmental effect of Cotrel-Dubousset instrumentation (CDI) on the spine and thoracic cage was investigated in 38 patients with adolescent idiopathic scoliosis by preoperative and postoperative postero-anterior and lateral radiographs and computed tomography from T1 to S1. Mean Cobb angle decreased by 67%. The T5-T12 kyphosis in the hypokyphotic patients increased on average by 8.4 degrees (P < 0.001). Average preoperative as well as postoperative maximal vertebral rotation was located at the apex level, and was reduced from 19.0 degrees to 14.3 degrees (P < 0.001). All vertebrae between the upper and lower instrumented vertebrae were significantly derotated. Average derotation for the apical zone was 4.8 degrees (P < 0.001), for the upper instrumented zone it was 2.5 degrees (P < 0.01), and for the lower instrumented zone it was 2.6 degrees (P < 0.01). Vertebral derotation was significantly higher in the apical zone than in the upper and lower instrumented zones. The apical rib hump index (RHi) decreased by 38% (P < 0.001) and the cumulative RHi for the five apical levels decreased by 34% (P < 0.001). The RHi for the two levels above and below the instrumentation each decreased by 20% (n.s.). No significant increase in sagittal or transverse rib cage diameter at any level was observed. The translation in the coronal plane of the apical vertebra of major right thoracic curves improved significantly (P < 0.001). The preoperative flexibility index of the major curve correlated positively (r = 0.47) with derotation at the apex level (P < 0.01). However, no correlation was found between flexibility index and reduction of RHi at the apex level. Vertebral derotation did not correlate with reduction in RHi at any level. The study shows that CDI results in a postoperative three-dimensional improvement of the spine and a limited improvement of the thoracic cage, with no tendency towards a worsened deformity at any level within or outside the instrumentation.

The position of the aorta in relation to the vertebra in patients with idiopathic thoracic scoliosis.

One CT-scan at the central part of the vertebral body of the apical vertebra of 32 patients with right convex thoracic idiopathic scoliosis and one CT-scan of either T8 or T9 of 22 normal subjects are included in this study. The position of the aorta in relation to the apical vertebra of the scoliotic patients and the corresponding vertebra of the normal subjects was determined at the horizontal plane. The mean lateral translation of the aorta in relation to the mid axis of the vertebral body increased from 19.7 +/- 4.3 mm in the normal group to 26.4 +/- 4.1 mm in the scoliotic group (p = 0.0001). In the normal group the aorta was located 41.7 +/- 8.6 mm in front of a perpendicular line to the mid axis of the vertebral body and in the scoliotic group this distance was reduced to 30.0 +/- 9.0 mm making the position of the aorta more posterior in the scoliotic group (p = 0.0001). This was in accordance with a decreased mean kyphosis-lordosis index from 0.53 +/- 0.06 in the normal group to 0.46 +/- 0.07 in the scoliotic group (p = 0.01). The position of the aorta, also expressed as the angle formed between the aorta and the vertebral body, the "aorto-vertebral angle", was increased from 24.4 degrees +/- 6.9 degrees in the normal group to 41.4 degrees +/- 8.4 degrees the scoliotic patients, (p = 0.0001). The aorto-vertebral angle did not change significantly with increasing Cobb angle (p = 0.26) but was positively correlated to the vertebral rotation (p = 0.0001). An estimation of the length of the intercostal arteries revealed a significantly greater R (right)/L (left) index in the scoliotic patients 1.18 +/- 0.11 than in the normal subjects 1.08 +/- 0.06 (p = 0.0003). It is concluded that the rotation and the anterior displacement of the vertebral body in scoliosis result in a deviation of the aorta along the left (concave) side of the vertebral body to a more posterior position relative to the vertebral body with a possible increased length of the intercostal artery on the right (convex) side.

Electrical muscle stimulation on the spine. Three-dimensional effects in rabbits.

We investigated the 3-dimensional effect of electrostimulation of the latissimus dorsi, the erector spinae and the intercostal muscles on spinal configuration in 16 New Zealand white rabbits. Electrostimulation on the right side of the spine resulted in a left convex, hypokyphotic curve and vertebral body rotation towards the convexity of the curve in all rabbits. The Cobb angle in the coronal plane increased with stimulation of each of the muscles examined. The kyphosis decreased with stimulation of the latissimus dorsi and the erector spinae. The vertebral rotation increased with stimulation of all muscles. Stimulation of the tested muscles resulted in the simultaneous occurrence of a 3-dimensional spinal deformity with the characteristics of idiopathic scoliosis.

Structural vertebral changes in the horizontal plane in idiopathic scoliosis and the long-term corrective effect of spine instrumentation.

The rotation and structural changes of the apex vertebra in the horizontal plane as well as of the thoracic cage deformity were quantified by measurements on computed tomography (CT) scans from patients with right convex thoracic idiopathic scoliosis (IS). The CT scans were obtained from 12 patients with moderate scoliosis (mean Cobb angle 25.8 degrees, r 13 degrees-30 degrees) and from 33 with severe scoliosis (mean Cobb angle 46.2 degrees, r 35 degrees-71 degrees). In addition, CT scans of thoracic vertebrae from 15 patients without scoliosis were used as reference material. Ten of the scoliotic cases had had Cotrel-Dubousset instrumentation (CDI) and posterior fusion and had entered a longitudinal study on the effect of operative correction on the re-modelling of the apical vertebra. An increasingly asymmetrical vertebral body, transverse process angle, pedicle width and canal width were found in the groups with scoliosis as compared with the reference material. Vertebral rotation and rib hump index were significantly larger in patients with early and advanced scoliosis than in normal subjects. The modelling angle of the vertebral body, the transverse process angle index and the vertebral rotation in relation to the middle axis of the thoracic cage were significantly greater in patients with severe than with moderate scoliosis. The results of this longitudinal study suggest that the structural changes of the apical vertebra regress 2 years or more after CD instrumentation.

Horizontal plane morphometry of normal and scoliotic vertebrae. A methodological study.

Computed tomography (CT) scans are widely used for quantification of the morphology of the vertebral body and of the changes of the thoracic cage in the horizontal plane in scoliosis. So far, however, no method exists for precise quantification of the parameters of the posterior elements. We present a method for quantification on the basis of CT scans of different parameters of the morphology of both the vertebral body and posterior elements in the horizontal plane. The precision and accuracy of the method were estimated in a model study by CT scanning of a normal and a scoliotic vertebra in different, controlled, tilted positions. Moreover, in a clinical study CT scans of 19 thoracic vertebrae from non-scoliotic subjects and the apex vertebra from 40 scoliotic subjects were selected to test the applicability of the method to clinical studies. The intra- and interobserver variation of the measurements was analysed. The angle between the longitudinal axis of the vertebral body and that of the whole vertebra was used to evaluate the asymmetry of the vertebral body. The right to left pedicle width index, the right to left hemi-canal width index and the index of transverse process angles related to the axis of the vertebra were used to quantify the asymmetry of the posterior elements. The results indicate that, except for the pedicle width index, the variables under study were not significantly influenced by a 5 degrees or 10 degrees tilt ventrally, dorsally, or laterally of either the normal or the scoliotic vertebra. Hence, the method can be satisfactorily applied to longitudinal group comparisons.(ABSTRACT TRUNCATED AT 250 WORDS)

Vertebral rotation and pedicle length asymmetry in the normal adult spine.

Rotation in the horizontal plane of vertebra T8, T9 or T10 was determined on CT scans of 25 male and 25 female patients with normal spines. The pedicle length was measured using a new method, and the right/left pedicle length index was calculated. In 38 (76%) of the patients there was vertebral rotation to the right with a mean Cobb angle of 3.0 degrees, and in 4 (8%) rotation to the left, mean Cobb angle 2.2 degrees (P < 0.01). In 8 (16%) there was no measurable rotation. The pedicle length index was greater than 1.05 in 9 subjects, between 0.95 and 1.05 in 16 and less than 0.95 in 25, indicating a predominance of longer pedicles on the left side. In 21 out of the 38 patients with vertebral rotation to the right, the left pedicle was longer than the right one (P < 0.01). The results indicate that the normal spine is afflicted with a vertebral rotation to the right in association with a longer pedicle on the left. The significance of these observations for the pathogenesis of idiopathic scoliosis remain uncertain.

Accuracy and applicability of measurement of the scoliotic angle at the frontal plane by Cobb's method, by Ferguson's method and by a new method.

A new method for the measurement of scoliotic curves in antero-posterior (AP) radiographs is presented, in which the centre of the surface image of the vertebral bodies of the apical and two end vertebrae of the curvature are defined on the basis of geometric principles. Measurements using the Cobb, the Ferguson, and the new method were performed on ten AP radiographs from each of three groups of young patients with right convex thoracic idiopathic scoliosis with Cobb angles of between 7 and 15 degrees, 16 and 45 degrees and 46 and 80 degrees, respectively. Measurements using the Cobb method yielded significantly higher values than measurements using either the Ferguson method or the new method. In curves with Cobb angles of between 7 and 15 degrees, the values using Ferguson's method were significantly lower than those using the new method; the difference increased significantly in curves with a Cobb angle of 16 degrees or more. The level of significance of the intra- and interobserver differences between the new, the Cobb and the Ferguson methods was significantly higher in curves with a Cobb angle of 16 degrees or more. It is argued that measures of the scoliotic angle obtained by the new method are of greater clinical relevance than those obtained by the two other methods. Unlike the Cobb method, the new method takes into consideration the translation of the apical vertebra in relation to the end vertebrae and not only the tilt of the end vertebrae of the curve. As compared to the Ferguson method, the new method is based on standardised geometric principles, and is not influenced by changes in the shape of the vertebral body. Moreover, the repeatability of the new method is greater than that of both the Cobb method and the Ferguson method. Therefore, it is believed that the new method provides a more accurate measure of the scoliotic curve than do the two other methods, and it is to be preferred over the other two methods in longitudinal evaluation of the development of the curve.

Sagittal configuration of the spine and growth of the posterior elements in early scoliosis.

The early changes of the sagittal alignment of the spine and the asymmetry between the posterior and anterior elements were determined on the basis of 134 lateral and 167 anteroposterior radiographs obtained from a control group and from patients with early scoliosis. The radiographs were allocated into four groups according to the degree of the Cobb angle. In thoracic curves with a Cobb angle of more than 8 degrees, the kyphosis and the vertebral sagittal wedge angle decreased in comparison with the control group. The sagittal-wedge angle of the disc did not change significantly with increasing Cobb angle. The pedicle height in relation to the vertebral height, considered to represent the growth of the posterior element in relation to the growth of the anterior element, was not significantly different in the scoliotic groups as compared with the control group. The results indicate that changes of the sagittal configuration of the spine occur early in idiopathic scoliosis and that they are associated with disturbed growth of the vertebral body but not of the posterior elements. These findings seem to reflect a simultaneous deformation in the coronal and sagittal planes rather than a single growth disturbance in any specific plane.