Rune Hedlund

Predictive factors for the outcome of anterior cervical decompression and fusion.

In a prospective study, 103 patients were randomised to anterior cervical decompression and fusion (ACDF) with a cervical carbon-fibre intervertebral fusion cage or the Cloward procedure. Preoperative background variables, active range of neck motion, handgrip strength, radiological evaluation and subjective variables were used in a multiple regression model to find the strongest predictors of postoperative outcome as measured by current pain intensity and the Neck Disability Index (NDI). Male sex, greater kyphosis at the level operated on, non-smoking, a greater neck mobility in right rotation, low disability on NDI, and older age were predictors of pain reduction and explained 30% of current pain intensity at follow-up. Higher educational level, non-smoking, greater kyphosis at the level operated on, a greater flexion mobility, greater right handgrip strength and lower current pain intensity were predictors of improvement, and explained 28% of the postoperative outcome on NDI. The most important predictor for postoperative pain intensity was the magnitude of the preoperative kyphosis. Preoperative pain intensity was the most important predictor for improved NDI. At follow-up about 70% of the patients still had deficit based on current pain intensity and NDI, and 44% had remaining dysfunction based on Odoms criteria. In conclusion, the multivariate analysis shows that male sex, non-smoking, greater segmental kyphosis and a low pain and disability level are preoperative predictors of a good outcome in ACDF. In addition, the study suggests the importance of other predictive variables than those studied for the outcome of ACDF.

The incidence of femoral shaft fractures in children and adolescents.

We report the incidence of fractures by sex and age based on 851 femoral shaft fractures from specific types of trauma. The maximum incidence occurred between 2 and 3 years of age, and the total incidence was 2.6 times higher in boys than in girls. In 438 cases the fractures were caused by falls and in 413 cases by traffic accidents. Fractures reported to be caused by falls were most common in children 2 and 3 years of age. Because child abuse has been shown to be involved in the majority of such fractures in early infancy, the data demonstrate the possible magnitude of this problem. Traffic accidents were most common in the oldest age groups, reaching 3.7 cases/10,000 population/year in boys 16 and 17 years of age. Although all fractures were more common during the periods of the fastest skeletal growth, the difference in incidence between different causes indicated that environmental factors are more important than endogenous factors for the risk of fracture.

Hip fracture incidence in Stockholm 1972-1981

We studied the incidence of cervical and trochanteric hip fractures in Stockholm, Sweden from 1972 through 1981. The material, selected from a computerized medical information register, consisted of 11 812 cervical fractures and 8094 trochanteric fractures. The incidence did not change in the age group 50-74 years. In males 75 years of age and older, the incidence of both fracture types caused by moderate trauma increased annually by 5-6 per cent. In females 75 years and older, the incidence of trochanteric fractures caused by moderate trauma increased annually by 6 per cent, whereas the incidence of cervical fractures increased only marginally.

Age- and sex-specific incidence of femoral neck and trochanteric fractures. An analysis based on 20,538 fractures in Stockholm County, Sweden, 1972-1981

The risk of fracturing the proximal femur is high for individuals with metabolic bone disease or with low bone mass associated with advanced age. Incidences of 20,538 trochanteric and femoral neck fractures in adult Swedish men and women, from a computerized medical information register for all hospitals in Stockholm County, were analyzed for age- and sex-dependence. The rate of increase in the occurrence of fracture was nearly constant for both sexes, exponentially increasing with age for men over 20 years old and for women over 30 years old. The incidence of trochanteric and femoral neck fracture for men doubled every 7.8 and 7.0 years, respectively. The doubling rate of fracture incidence for premenopausal women, aged 30 to 49 years, did not significantly differ from that for postmenopausal women, aged 50 to 69 years. These findings suggest that age-associated factors common to both sexes provide the main risk for fracturing the proximal femur. Menopause does not pose a major risk.

Epidemiology of diaphyseal femoral fracture

The incidence of diaphyseal femoral fracture in adults, aged 20 years and older, was determined in Stockholm County using hospital admission rates. The validity of the data was investigated by a study of the medical records of a sample of 277 cases and also by determining the incidence in a subpopulation of 139 cases using an alternative method. The incidence decreased from age 20 to middle age after which it increased into old age. The age-related increase was more pronounced in women and in fractures caused by moderate trauma. From 1972 to 1981, the incidence of diaphyseal femoral fracture caused by moderate trauma increased annually by 10 per cent in women aged 75 years and older.

Long-term randomised comparison between a carbon fibre cage and the Cloward procedure in the cervical spine

A prospective randomised study. To compare the long-term outcome of anterior cervical decompression and fusion (ACDF) with a cervical intervertebral fusion cage (CIFC) and the Cloward procedure (CP). We have previously shown that the 2xa0year outcome of ACDF with the CIFC is the same as for the CP. The fusion rate in CIFC group was, however, only 55%, compared to 85% in CP group. The long-term outcome of CIFC is poorly documented. Ninety-five patients with at least 6xa0months duration of neck pain and radicular arm pain were randomly allocated for ACDF with the CIFC or the CP. Radiographs were obtained at 2xa0years. Questionnaires about pain, disability (Neck Disability Index, NDI), distress, quality of life and global outcome were obtained from 83 patients (87%) (43 CIFC, 40 CP) at a mean follow-up time of 6xa0years (range 56–94xa0months). There were no significant differences in any outcome variable between the two treatments. For both CP and CIFC the pain intensity improved (P<0.0001) whereas the NDI was unchanged at long-term follow-up compared to preoperatively. In the CIFC group patients with a healed fusion had significantly less mean pain (24xa0mm) and NDI (26%) than patients with pseudarthrosis (42 and 41, respectively). Furthermore, the mean pain and NDI reported by CIFC patients with a healed fusion was significantly less than in healed CP patients (37 and 38, respectively). The long-term outcome is the same for the CIFC and the CP, with similar improvements of pain but with considerable remaining functional disability. However, in the subgroup of patients with healed CIFC the outcome was clearly better than for the non-healed CIFC group, and also clearly better than for the healed CP group. Thus, if the healing problem associated with the CIFC can be solved the results indicate that a better outcome can be expected with the cage than with the CP.

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

SummaryA 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°, 16 and 45° and 46 and 80°, 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°, the values using Fergusons method were significantly lower than those using the new method; the difference increased significantly in curves with a Cobb angle of 16° 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° 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.

Vertebral rotation and pedicle length asymmetry in the normal adult spine

SummaryRotation 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°, and in 4 (8%) rotation to the left, mean Cobb angle 2.2° (P0.01). 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 (P0.01). 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.

Prediction of fusion and importance of radiological variables for the outcome of anterior cervical decompression and fusion

In a prospective randomised study with a 2-year follow-up, 103 patients were randomised to anterior cervical decompression and fusion (ACDF) with a cervical carbon-fibre intervertebral fusion cage (CIFC) or the Cloward procedure (CP). The purpose of the present study was to report predictors for fusion and also to investigate the importance of radiological variables for the clinical outcome. Gender, age, smoking habits, disc height, segmental kyphosis and type of surgical procedure were used as independent (before surgery) variables in a multiple regression model. Male gender, one-level surgery and CP treatment were significant predictors of fusion and explained 14% of the variability of fusion status at follow-up. Number of levels operated on, however, did not influence the clinical outcome. Fifty-two per cent of the women and 17% of the men in the CIFC group, and 25% of the women and 8% of the men in the CP group, had pseudarthrosis. Although patients with a healed fusion had significantly less pain intensity than patients with pseudarthrosis, radiological variables explained only 4% of the variability of pain at follow-up. Apart from a significant correlation between preoperative kyphosis and neck disability index at follow-up, no significant correlation between either postoperative kyphosis or preoperative or postoperative disc height and clinical outcome was found. Neither degree of segmental kyphosis nor disc height was different between patients with healed fusion and pseudarthrosis. One can conclude that male gender and type of surgery were significant predictors for a healed fusion and that pseudarthrosis affected outcome. In contrast to the commonly held view based mainly on theoretical considerations, no effect on clinical outcome could be demonstrated for segmental kyphosis and disc height at follow-up. Overall, the study shows that the importance of radiological factors as predictors for fusion as well as clinical outcome is limited.

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

SummaryOne 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°±6.9° in the normal group to 41.4°±8.4° 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.RésuméLa coupe tomodensitométrique passant par le milieu du corps de la vertèbre du sommet de courbure chez 32 patients porteurs d’une scoliose thoracique idiopathique à convexité droite et une coupe en T8 ou T9 chez 22 sujets normaux ont été inclues dans cette étude. Les rapports de l’aorte avec la vertèbre apicale chez les patients scoliotiques, et avec la vertèbre correspondante chez les sujets normaux, ont été établis dans un plan axial. Le positionnement latéral moyen de l’aorte par rapport à l’axe médian du corps vertébral passait de 19,7±4,3 mm dans le groupe normal à 26,4±4,1 mm dans le groupe avec scoliose (p = 0,0001). Dans le groupe normal le plan frontal de l’aorte perpendiculaire à Taxe médian du corps vertébral était situé à 41,7±8,6 mm. et dans le groupe avec scoliose cette distance était réduite à 30,0±9,0 mm, traduisant une position plus dorsale, de l’aorte (p = 0,0001). Ceci était corrélé avec une diminution de l’index moyen de cypholordose, de 0.53±0,06 dans le groupe normal à 0,46± 0,07 dans le groupe avec scoliose (p = 0,01). La position de l’aorte était également exprimée par l’angle entre l’aorte et le corps vertébral, angle aorto-vertébral. lequel passait de 24,4°±6,9° dans le groupe normal à 41,1°±8,4° chez les patients scoliotiques (p = 0.0001). L’angle aorto-vertébral n’était pas significativement modifié par l’augmentation de l’angle de Cobb (p = 0,26) mais était corrélé à la rotation vertébrale (p = 0,0001). L’estimation de la longueur des artères intercostales révélait chez les patients scoliotiques une augmentation significative de l’index R (droite) / L (gauche) à 1,18 ±0.1 1 contre 1,08±0,06 chez les sujets normaux (p = 0,0003). Nous concluons que la rotation et l’avancée du corps vertébral dans la scoliose provoque un déplacement dorsal de l’aorte le long du bord gauche du corps vertébral avec une probable augmentation delongueur de l’artère intercostale du côté droit (convexe).