Reliability of radiographical measurements of spondylolisthesis and extension-flexion radiographs of the lumbar spine.

We studied the reliability of extension-flexion radiography by analysing intra-observer and inter-observer variations in measurements of 30 patients with established L5-S1 spondylolisthesis. The highest intra-observer angular variations among three radiologists were found at the L5-S1 level (mean 1.6 degrees, S.D. 1.6 degrees, max. 9 degrees) and the highest sagittal translation also at the L5-S1 level (mean 0.6 mm, S.D. 0.8 mm, max. 4 mm). The highest angular inter-observer variation was found at the L5-S1 level (mean 2.6 degrees, S.D. 2.3 degrees, max. 11 degrees) while the highest variation in sagittal translatory movement was found at the L4-L5 level (mean 1.4 mm, S.D. 1.2 mm, max. 6 mm). The mean intra-observer variation for L5 olisthesis was 1.0 mm (S.D. 0.9 mm, max. 5 mm) and the corresponding inter-observer variation 1.3 mm (S.D. 1.1 mm, max. 6 mm). Thus, in general, the overall consistency and concordance were good. The variations in intra-observer and inter-observer readings were similar. Variability in readings did not depend on the magnitude or abnormality of the readings. On the other hand, variability may occur because of difficulty in defining the exact landmarks used for the measurements. We point out that in certain cases the diagnostic value of one single reading of an extension-flexion radiography examination may be questionable.

Lumbar isthmic spondylolisthesis in children and adolescents. Radiologic evaluation and results of operative treatment.

A clinical and radiologic follow-up study of a group of 75 children and adolescents, comprised of both boys and girls, who underwent spondylodesis for spondylolisthesis between the years 1979 and 1984 is reported. Sagittal rotation, lumbosacral joint angle, lumbar lordosis, wedging of olisthetic vertebrae, and the rounding of the upper sacrum showed considerable statistical correlation to the amount of slipping and accordingly should be noted when estimating the risk of progression of the spondylolisthesis. When the spondylolisthesis was accompanied by scoliosis, it was noted that seriousness of the former was closely correlated to that of the latter. Most patients profited by the operation, and solid fusion was achieved in almost all cases. The posterolateral spondylolysis performed using graft from the iliac crest, the interbody fusion technique, or their combination turned out to be the most reliable surgical methods. The combined technique was especially required in cases with a high degree of slipping.

Surgical treatment of severe isthmic spondylolisthesis in adolescents. Reduction or fusion in situ.

Twenty-two adolescent patients with severe (more than 50%) slip were surgically treated. Eleven were reduced with Magerl/Dick transpedicular screw devices and fused posteriorly from L4 to S1, and 2 weeks later anteriorly L5-S1; the other 11 were fused in situ L4-S1 (6 patients) or L5-S1 (5 patients) using a circumferential (6 patients), anterior (4 patients) or posterolateral (1 patient) technique without instrumentation. The two groups were comparable as to age at operation, age at follow-up, follow-up time, and preoperative radiologic measurement of the slip, lumbosacral kyphosis, and clinical findings. The mean follow-up times were 56.5 and 59.8 months, respectively. In the reduction group an improvement in the slip of 36.1 percentage points was achieved as compared with 7.7 percentage points in the in situ-fusion group. The sagittal rotation angle improved by 11 in the reduction group and worsened by 2.8 in the in situ-fusion group. There were no differences between the groups in the functional tests or clinical findings concerning pain. Subjective assessment was good in both groups at follow-up; that is, the pain had disappeared. Mean operation time and intraoperative blood loss were significantly higher in the reduction group. Reduction procedures were also associated with a higher number of complications and reoperations. No neurologic complications, however, occurred in the reduction group. Based on this study, in situ fusions are to be preferred in adolescents with severe spondylolisthesis.

Prolonged exposure to gunfire noise among professional soldiers.

OBJECTIVES: The aim of the study was a retrospective assessment of the exposure of professional soldiers to impulse noise from gunfire. METHODS: A questionnaire on noise exposure and use of hearing protectors was administered to a stratified random sample of 699 army officers (mean age 39.8 years) with an average of 18 years of exposure to shooting noise. For a comparison of the number of shots from different weapons, the peak sound pressure levels of shots were adjusted in relation to one pistol shot according to the equal energy principle. Total exposure time was estimated with the equal energy principle, the number of shots from different weapons, the energy levels of different shots, the effectiveness of hearing protection, and the distance from the noise source being taken into account. RESULTS: Rifles, shotguns, and pistols were the predominant exposure sources. Impulse noise exposure averaged 164,183 shots from different weapons. After adjustment to the energy level of one pistol shot, the average was 78,000 personally fired shots. The total shooting noise exposure averaged 218,000 adjusted shots. Translated into exposure to steady noise of 85 dB(A) for 40 h a week, the exposure to noise from personally fired shots equaled an exposure time of 22.0 years and the total exposure averaged 61.0 years. The heaviest exposure occurred during the first 10-15 years of the men's careers. CONCLUSIONS: Exposure to gunfire noise among professional soldiers is high enough to cause severe hearing deterioration already at early career stages if effective hearing protectors are not worn at all times on shooting occasions.

Hearing loss and handicap of professional soldiers exposed to gunfire noise.

OBJECTIVES: The aim of the study was to investigate the prevalence and degree of hearing loss and other disabling consequences of noise among professional soldiers. METHODS: A cross-sectional audiometric survey was combined with a questionnaire study on disabilities in a stratified random sample of 699 army officers (mean age 39.8 years) with long-term exposure to gunfire noise. RESULTS: In 224 (32%) officers, the hearing threshold was found to be 20 dB or less at all of the frequencies measured (0.5, 1, 2, 3, 4, 6, and 8 kHz). Most of the 475 (68%) subjects with hearing loss belonged to older age categories, but more than one-fourth (26%) of the officers under 30 years of age had a hearing loss. Low frequencies were deteriorated in 110 (16%) subjects. The average of the hearing threshold levels of the frequencies 2 and 4 kHz exceeded 20 dB in 229 (33%) officers. For 347 (49.6%) subjects hearing was normal for their age. The degree of age-corrected hearing loss, especially at low frequencies, correlated highly significantly with exposure. Altogether 220 (32%) men experienced tinnitus, 118 (17%) of them continuously. Tinnitus was the most common among the men with severe or disabling hearing loss. Twenty-four (3.4%) of 699 officers needed sound amplification in noisy environments. CONCLUSIONS: The prevalence of hearing loss in the Finnish Defence Forces seems to have decreased, but a fairly large number of younger men still suffer considerable hearing loss and disabling tinnitus, although the use of hearing protectors has substantially increased during the past 15 years. Most of the subjects experienced communication difficulties in noisy environments.

Long-term results of the Evans procedure for lateral instability of the ankle.

We studied the late outcome of 40 ankles (from a consecutive series of 42) treated by a modified Evans procedure. The peroneus brevis tendon was used to fashion a static tenodesis. All the patients had suffered from persistent lateral instability following an ankle sprain. The follow-up period was between nine and 12 years. Excellent or good results were achieved in 33 ankles (82.5%), three had a fair result, and four were poor. The clinical results were matched by the radiographic results which showed significant talar tilt or anterior talar translation in only three ankles. The functional result showed no positive correlation with the stress-radiographic analysis. We concluded that this modification of the Evans operation gives satisfactory long-term results, which show little change from the good results at 24 to 35 months reported in an earlier paper from our department.

Impaction bone grafting in revision hip surgery. A high incidence of complications.

We have reviewed retrospectively 68 revisions of the femoral component in arthroplasties of the hip in 65 patients, using impaction bone grafting, at a median of three years (1 month to 6 years). We employed the cemented Exeter X-Change technique in 36 patients and the uncemented Bi-Metric allografting method in 32. The 37 bone defects were grade 3 or grade 4 on the Endo-Klinik classification. The Mayo hip score improved from a mean of 32 (SD +/- 18) to 62 (SD +/- 15). Most (25) of the 34 complications occurred in grade-3 and grade-4 defects; nine were intraoperative diaphyseal fractures and eight fractures of the greater trochanter. All the fractures united. The risk of intraoperative fracture was prevented by supporting the bone with wires in 16 hips, with reinforcement mesh in 18 and by a plate in six. Early migration of the stem of more than 10 mm during the first year indicated rotational instability; it occurred in three cases. In difficult revision cases with large defects of the femoral bone, bone-impaction techniques carry a high risk of complications.

Subclinical vestibular pathology in patients with noise-induced hearing loss from intense impulse noise.

Sixty patients with varying degrees of noise-induced hearing loss (NIHL) after long-term exposure to intense impulse noise from firearms, but without manifest clinical symptoms of vestibular pathology, were tested for body sway using a stable platform. The results were compared with those from 115 healthy referents examined in the same way. Subjects with NIHL showed significantly more body sway, estimated as movement of the centre of gravity in the horizontal plane, than did the referents. Subjects with more severe NIHL showed more sway than subjects with milder acoustic trauma. The results show that body sway is increased in patients with NIHL from exposure to impulse noise of high intensity in a way suggesting an exposure-effect relationship. This suggests subclinical disturbances of the vestibular system in these patients. The underlying mechanism may be simultaneous mechanical damage to both the cochlear and vestibular partitions by intense impulse noise.

Self-reported elevated blood pressure in army officers with hearing loss and gunfire noise exposure.

The association of noise-induced hearing loss from gunfire noise with the occurrence of elevated blood pressure was investigated with screening audiometric measurement results and a questionnaire in a randomly selected group of 699 army officers. After age correction, hearing was found to be deteriorated (i.e., more than 20 dB at all of the measured frequencies) in 352 (50.4%) subjects. Of the 699 officers, 535 (76.5%) reported normal and 164 (23.5%) reported elevated blood pressure. In 122 (17.5%), elevation was permanent and verified by a physician. The occurrence of elevated blood pressure showed a highly significant correlation with severity of hearing loss (chi-square = 25.4; p < 0.001), but not with exposure to gunfire noise. Self-reported hypertension seemed to be associated with severity of impulse noise-induced hearing loss, but not with the amount of gunfire noise exposure. Thus, the present study does not support the suggestion that there exists a simultaneous correlation between impulse noise exposure, noise-induced hearing loss, and self-reported elevated blood pressure.

Inclination of the acetabular cup in erect posture radiographs.

Inclination of the acetabular component was measured in a series of 100 patients who underwent total hip replacement. The radiographs were taken with the patients in erect posture. Two different reference lines were used in the measurements: the ischial reference line, and the true horizontal line perpendicular to a plumb-line used as a vertical reference line. The values measured using these two reference lines correlated well with each other, though there were important differences caused by pelvic tilt. Often an inclination that was within the normal range when measured, using the ischial tuberosity line as a reference, shifted excessively to horizontal or vertical when control measurements were performed using the true horizontal line as the reference. We conclude that inclination of the acetabular cup should be measured in erect posture radiographs, because pelvic tilt increases the degree of inclination on the side of pelvic adduction.

Preoperative leg-length inequality and hip osteoarthrosis: a radiographic study of 100 consecutive arthroplasty patients.

OBJECTIVE: To assess the leg-length inequality in patients with hip osteoarthrosis (OA) and to evaluate a possible association between the length disparity and side of OA. DESIGN AND PATIENTS: Weight-bearing radiographs of 100 consecutive patients undergoing arthroplasty for primary OA were examined and measured for inequality of leg length, pelvic tilt and severity of OA. RESULTS: The radiographic results showed that preoperatively OA occurred more frequently in the hip of the longer (84%) than the shorter (16%) leg. However, the development of OA did not show a linear relationship with the magnitude of leg-length inequality. CONCLUSION: As hip OA occurred more frequently in the longer leg the authors speculate whether leg-length inequality might predispose to OA in the hip of the longer leg.

Spinal growth and progression of adolescent idiopathic scoliosis.

The spinal growth in scoliotic segments (T4-L4) of 110 girls with untreated idiopathic scoliosis was measured from two successive radiographs taken at a mean interval of 1.1 years. At the first visit the mean age of the patients was 14 years (range 11-16 years), the mean magnitude of the major curves 24 degrees (range 9 degrees-38 degrees) and that of the minor curves 14 degrees (range 2 degrees-38 degrees). Spinal growth was most rapid at the age of 11-12 years. The progression of the curves (major plus minor) correlated with the spinal growth (r = 0.384). The greater the initial curves were, the stronger the correlation was between the spinal growth and the progression of the curves (r = 0.046-0.639), and the correlation was more significant in thoracic scoliosis (r = 0.560) than in thoracolumbar and lumbar scoliosis (r = 0.152).

Measurement variations in scoliotic angle, vertebral rotation, vertebral body height, and intervertebral disc space height.

Thirty consecutive posteroanterior and lateral radiographs of patients with adolescent idiopathic scoliosis with a mean Cobb angle of 24.4 degrees were read. In measuring the scoliotic angle, the interobserver error (SD) was 2.8 degrees and the intraobserver, 1.8 degrees. Rotation of the apical vertebra was estimated by measuring the translation of the pedicle on posteroanterior radiographs. For vertebral rotation, the interobserver measurement error (SD) was 3.4 and the intraobserver, 1.8%. The height of the apical vertebral body and the intervertebral disc space next inferior to it were measured on lateral radiographs as the anterior angles of the diagonals of the respective body or disc space. In measuring the vertebral body height, the interobserver error (SD) was 3.2 and the intraobserver, 2.6 degrees, and in measuring the intervertebral disc space height, the interobserver error was 2.4 and the intraobserver, 1.8 degrees. The angles can be transformed to a corresponding height/length ratio by a simple trigonometrical formula.

Three-year results of bracing in scoliosis.

We treated 107 patients with idiopathic scoliosis with the Boston brace. The primary correction was good in all the curve patterns. The follow-up time after weaning averaged 3 years. The best final result was achieved in thoracic and lumbar curves (mean 2 degrees). The final correction was worse in patients with an initial curve less than 30 degrees when compared with the patients with larger curves. Except the double major curves, there was a positive correlation between the primary correction, duration of the treatment, and the final result. The results in 14 patients with bracing for 12 hours daily did not differ from the remainder. Progression of the initial curve more than 5 degrees after the treatment was noted in 24 patients. Three patients were operated on later because of progression. We conclude that bracing can prevent progress of scoliosis.

Biological factors and predictability of bracing in adolescent idiopathic scoliosis.

Biological factors that could have a predictive value in treating idiopathic scoliosis by brace were studied in 107 patients (102 girls and 5 boys). The mean age of the patients was 14 years 6 months, and the mean Cobb angle of the curves was 36 degrees at start of treatment. The Boston brace was used for an average of 1 year 6 months, and mean follow-up time after weaning was 3 years. Scoliosis with an apex of Th 10-12 proved to be the most favorable for the final result, with a mean correction of 2 degrees. All other curves remained unchanged. Patients who had a period of rapid growth just before or during treatment had a better final result than the others. The final result was also better when treatment was started before menarche.

Leg-length inequality has poor correlation with lumbar scoliosis. A radiological study of 100 patients with chronic low-back pain.

Leg-length inequality and its hypothetical consequences, pelvic tilt and lumbar scoliosis, were measured in 100 young or middle-aged adults suffering from chronic low-back pain. Leg-length inequality had a good correlation with the pelvic tilt assessed from the iliac crests, a moderate correlation with the sacral tilt, but a poor correlation with the lumbar scoliosis. The sacral tilt correlated well with the lumbar scoliosis when the tilt was more than 3 degrees but poorly when it was smaller. Thus, there is a gradually decreasing correlation between the posture parameters when moving from the hips up to the lumbar spine. We conclude that before a radiologically observed leg-length inequality be considered as the cause of low-back pain, an erect-posture radiograph of the whole pelvis and lumbar spine is essential, in order to assess an existing pelvic tilt and scoliosis.

Sonographic measurement of vertebral dislocation in spondylolisthesis.

The vertebral dislocation in spondylolisthesis was measured by both sonography and roentgenography in 20 patients with spondylolysis and 6-28 mm of spondylolisthesis. The two methods were applied independently of each other. The difference between the sonographic and roentgenographic measure of vertebral dislocation was 0-3 mm (mean 1.3 mm). The accuracy of sonography is sufficient for clinical work. The advantage of sonography is that the radiation burden of patients with spondylolysis can be decreased by replacing roentgenographic follow-up with sonography.

[Experiences with lateral electric surface stimulation in the treatment of idiopathic scoliosis]. / Erfahrungen mit der lateralen elektrischen Oberflächenstimulation zur Behandlung idiopathischer Skoliosen.

Lateral electrical surface stimulation (LESS) was used for treatment of idiopathic scoliosis in 20 children and adolescents (mean age 10.9 years, mean Cobb angle 26 drs.). Six patients were treated until skeletal maturity showing a mean curve progression of 8 degrees at follow-up. In 14 patients treatment failed due to skin irritation, sleeping disturbances or progression. Five patients had to be operated on. Twenty patients of a control group treated with Boston brace (mean age 11.9 years, mean Cobb angle 34 drs.) showed mean curve improvement of 2 degrees at follow-up. Only one patient of the control group had to be operated on. Brace treatment was superior to stimulation in this small patient group presented.

Trunk asymmetry and screening for scoliosis: a longitudinal cohort study of pubertal schoolchildren.

A cohort of children was followed-up annually from an average age of 10.8-13.8 years to assess various measures of trunk asymmetry for their predictive value in the screening of scoliosis. Of 1060 children, 855 (80.7%) participated in the final examination. Trunk asymmetry was measured by the forward bending test and moiré topography. A posteroanterior standing radiograph of the spine was taken of those 250 (29.2%) children who had a trunk hump > or = 8 mm. Only 8.3% of the children were found to be symmetric (hump 0-2 mm) in the forward bending test: 65.5% had a hump of 3-7 mm and 26.2% had a hump > or = 8 mm at 13.8 years. Also, moiré fringe asymmetry proved to be common (prevalence of asymmetry > 1 fringe 47.3%), but its correlations with rib hump (r = 0.16) and Cobb angle (r = 0.12) were low. At the final examination, the prevalence of scoliosis (Cobb angle > or = 10 degrees) was 9.2%. Two girls (0.2%) needed brace treatment. The forward bending test is preferable to moiré topography in screening for scoliosis, and a hump size of 6 mm at an average age of 10.8 years is the nearest to optimal as a screening threshold.