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Notes: Abstract The diagnostic interindividual variance of 91 German and Dutch arthroscopists has been assessed by the Kappa Cohen interobserver variation analysis using a videotape with three complete knee arthroscopies with different pathologies. Non-pathological conditions show a moderate to excellent interobserver correlation, whereas pathological changes often show very little correlation, especially the synovial membrane of the suprapatellar recess, the cartilage of the femuropatellar groove, and the posterior cruciate ligament. The patella alignment also shows a high interobserver variability. There are no apparent differences between German and Dutch arthroscopists. When comparing arthroscopic findings with other imaging techniques the above results should be taken into account because the use of arthroscopy as golden standard is challenged. Furthermore, these results will influence the meaningfulness of medical expert witness based only on pictures. Also the medical cost balance based on arthroscopic findings has to take into account that a wrong diagnosis is possible and therefore charged wrong.

Notes: Abstract A study was conducted to find out whether in a rear-impact motor vehicle accident, velocity changes in the impact vehicle of between 10 and 15 km/h can cause so-called “whiplash injuries”. An assessment of the actual injury mechanism of such whiplash injuries and comparison of vehicle rear-end collisions with amusement park bumper car collisions was also carried out. The study was based on experimental biochemical, kinematic, and clinical analysis with volunteers. In Europe between DM 10 and 20 billion each year is paid out by insurance companies alone for whiplash injuries, although various studies show that the biodynamic stresses arising in the case of slight to moderate vehicle damage may not be high enough to cause such injuries. Most of these experimental studies with cadavers, dummies, and some with volunteers were performed with velocity changes below 10 km/h. About 65% of the insurance claims, however, take place in cases with velocity changes of up to 15 km/h. Fourteen male volunteers (aged 28–47 years; average 33.2 years) and five female volunteers (aged 26–37 years; average 32.8 years) participated in 17 vehicle rear-end collisions and 3 bumper car collisions. All cars were fitted with normal European bumper systems. Before, 1 day after and 4–5 weeks after each vehicle crash test and in two of the three bumper car crash tests a clinical examination, a computerized motion analysis, and an MRI examination with Gd-DTPA of the cervical spine of the test persons were performed. During each crash test, in which the test persons were completely screened-off visually and acoustically, the muscle tension of various neck muscles was recorded by surface eletromyography (EMG). The kinematic responses of the test persons and the forces occurring were measured by accelerometers. The kinematic analyses were performed with movement markers and a screening frequency of 700 Hz. To record the acceleration effects of the target vehicle and the bullet vehicle, vehicle accident data recorders were installed in both. The contact phase of the vehicle structures and the kinematics of the test persons were also recorded using high-speed cameras. The results showed that the range of velocity change (vehicle collisions) was 8.7–14.2 km/h (average 11.4 km/h) and the range of mean acceleration of the target vehicle was 2.1–3.6 g (average 2.7 g). The range of velocity change (bumper car collisions) was 8.3–10.6 km/h (average 9.9 km/h) and the range of mean acceleration of the target bumper car was 1.8–2.6 g (average 2.2 g). No injury signs were found at the physical examinations, computerized motion analyses, or at the MRI examinations. Only one of the male volunteers suffered a reduction of rotation of the cervical spine to the left of 10° for 10 weeks. The kinematic analysis very clearly showed that the whiplash mechanism consists of translation/extension (high energy) of the cervical spine with consecutive flexion (low energy) of the cervical spine: hyperextension of the cervical spine during the vehicle crashes was not observed. All the tests showed that the EMG signal of the neck muscles starts before the head movement takes place. The stresses recorded in the vehicle collisions were in the same range as those recorded in the bumper car crashes. From the extent of the damage to the vehicles after a collision it is possible to determine the level of the velocity change. The study concluded that, the “limit of harmlessness” for stresses arising from rear-end impacts with regard to the velocity changes lies between 10 and 15 km/h. For everyday practice, photographs of the damage to cars involved in a rear-end impact are essential to determine this velocity change. The stress occurring in vehicle rear-end collisions can be compared to the stress in bumper car collisions.

Notes: Summary Dysphagia can be caused by disorders of the cervical spine. Very seldomly, prominent osteophytes of the ventral spine are responsible. The case of a 63-year-old patient with large anterior osteophytes from C3 to C7 is presented. The successful ablation of these spondylophytes relieved the patient of his swallowing difficulties. Up to now there have been many different opinions about the etiology of this disease. In this special case, a diffuse idiopathic skeletal hyperostosis, also known as Forestier's disease or diffuse idiopathic skeletal hyperostosis, seems to be the most likely cause.

Notes: Résumé Quarante segments mobiles lombairs humains ont été préparés et soumis à des essais sur un appareil électromécanique afin d'étudier les modifications biomécaniques, à savoir la pression intradiscale, l'étalement transversal et la hauteur des disques intervertébraux après nucléotomie percutanée. Dans un premier groupe de 20 disques (groupe A), le matériel nucléaire a été retiré en utilisant la technique de nucléotomie percutanée non-automatisée (NAPLD). Dans le second groupe de 20 disques (groupe B), le matériel discal a été ôté par la méthode de nucléotomie percutanée automatisée (APLD). Les résultats des deux groupes ont été statistiquement analysés et comparés entre eux. Dans le premier groupe (NAPLD) l'ablation de 0,1 gramme de substance nucléaire cryoprécipitée a réduit la hauteur du disque de 0,32 mm en moyenne, contre 0,47 mm dans le groupe APLD. De bombement de la périphérie discale s'est accentué dans les deux groupes après l'ablation de 0,1 gramme de matériel nucléaire cryoprécipité: cette accentuation a été de 0,10 mm en moyenne dans le groupe NAPLD contre 0,15 mm dans le groupe APLD. La pression intradiscale a diminué également dans les deux groupes après l'ablation de 0,1 gramme de nucléus cryoprécipité, de 0,94 bar en moyenne dans le groupe NAPLD contre 1,88 bar dans le groupe APLD. Les différences entre les données biomécaniques des deux groupes se sont montrées statistiquement significatives pour les trois paramètres (p〈0,05). Nos résultats montrent que le mécanisme pouvant expliquer l'amélioration de la douleur radiculaire chez les patients avec hernie discale après nucléotomie percutanée reste encore problématique. Nous postulons que la perte de hauteur du disque, et par conséquent, la réduction de tension au niveau de la racine affectée, joue un rôle majeur dans cette amélioration.

Notes: Summary After treatment of a symptomatic herniated disc with chymopapain, 14 patients were re-examined by magnetic resonance imaging (MRI) at a mean follow-up of 72 months. Well-defined MRI findings before chemonucleolysis were compared with those after the procedure by an independent observer. Five MRI parameters were assessed. No significant change was noted in the signal intensity of the affected disc, the extent of osteochondrosis and endplate reaction of the affected segment. The height of the affected disc as well as the size of the disc herniation were reduced significantly. The loss of the height is seen as a direct result of chymopapain activity, whereas the alteration of the size of the herniation seems to depend on the natural history of a disc herniation and is probably not a simple result of the treatment.

Notes: Summary To determine the reliability of lumbar nerve root sheath infiltration, a prospective study was performed. Ninety-four patients were randomized into three groups. In the first group of 33 patients, 0.5 cc of dye (Telebrix N, 30 g) was applied at nerve root L4, in the second group of 30 patients, 1.0 cc, and in the third group of 31 patients, 2.0 cc. The infiltration was quided by computer tomography. The diffusion of the dye was documented with computed tomography of the affected segment L4-5. The images were evaluated by an unbiased observer. The results showed that in the first group the dye diffused to the adjacent ipsilateral nerve roots L3 and/or L5 in nine patients. In the second and third groups this diffusion was seen in 9 and 11 patients, respectively. A diffusion into the psoas muscle was documented in 4, 10 and 22 patients, respectively. These latter differences were statistically significant (P 〈 0.01). Diffusion into the psoas muscle is especially important because the nerve roots converge in this muscle to become a plexus, and they are no longer surrounded by their dural sheaths. Diagnostic lumbar nerve root sheath infiltration should be performed by an experienced examiner. To guarantee high reliability, the tip of the needle should be placed as near as possible to the affected nerve root. The amount of local anaesthetic should be as small as possible, 0.5 cc or preferably less.

Notes: Summary A prospective MRI study was carried out to assess the secondary changes in patients with stenosis and/or herniated disc of the lumbar spinal canal. The study covered 100 patients who had low back and leg pain due to such processes. Of these, 60 patients (group A) had a monoradicular pain pattern, average duration 2 months, due to a herniated lumbar disc. The remaining 40 patients (group B) had acute exacerbation of their chronic low back and leg pain, due to stenosis and herniated disc. As a control group, 5 asymptomatic volunteers with neither stenosis nor herniated disc on MRI were examined. All the patients and volunteers were examined by MRI with several sequences: partial saturation recovery with phase contrast PS (500/10), spin echo SE (500/20), short TI inversion recovery STIR (1900/135/30) and, for the dynamic study, field-gradient echo sequences FAST (50/15): 10 frames in 200 s. In all participants, Gd-DTPA was administered intravenously. In 8 of the patients of group B capillarisation in the protruded nucleus tissue was demonstrated on the PS sequence after Gd-DTPA administration. This tissue also showed decreased signal intensity on the STIR sequence. The capillarisation extended into the centre of the disc. Venous stasis could be verified in all of the 100 patients. An oedema could be verified in all patients of group A; in 20%, its size exceeded that of the herniated disc. In group B, an oedema was seen in only 12 patients. In the control group, no haemodynamic changes were seen. Using MRI, it is possible to define the border between herniated disc tissue and perifocal oedema. In consequence, in cases of acute pain syndromes in patients with herniated discs where oedema is predominant, taking immediate measures to decrease the oedema could be justified. In cases of stenosis, MRI can demonstrate its extent and any associated secondary changes. In patients with multi-level narrowing processes and atypical symptoms, haemodynamic MRI studies may be an important diagnostic tool for finding the symptomatic level.

Notes: Summary Severe fracture-dislocation of the thoracic spine without neurological deficit is rare. Both translational and rotational deformity of the midthoracic spine makes transection of the cord almost inevitable due to the confined dimensions of the cord and spinal canal. Even though associated fractures of posterior elements are frequently seen, they seldom result in neural sparing. The case of a 24-year-old man who sustained a severe rotational fracture-dislocation of T9/T10 with considerable anterolateral displacement is reported. Due to a fractured left pedicle and a right-sided vertical fracture through the posterior aspect of the vertebral body, alignment of the posterior elements in the spinal canal was maintained and there was no neurological deficit. The patient was operatively treated with posterior segmental instrumentation, and was completely asymptomatic at follow-up 5 years later.

Notes: Summary We assessed the interindividual diagnostic variance of 39 experienced arthroscopists by the Kappa Cohen interobserver variation analysis using videotapes of eight different patients with different diagnoses. Arthroscopically normal findings showed a relatively acceptable interobserver correlation. Pathological changes, in contrast, often showed very little correlation, especially in the synovial membrane of the suprapatellar recess, in the cartilage of the femoropatellar groove and the posterior cruciate ligament. In patellar alignment there was also great interobserver variation. Clinical relevance: When comparing arthroscopic findings with other imaging techniques the above results should be taken into account. Furthermore, these results will affect the significance of medical expertise based only on pictures. In addition, medical cost billing, which is based on arthroscopic findings, has to take into account that a wrong diagnosis is possible and therefore charges will be wrong.

Notes: Summary Referring to a case of a glomangioma at the elbow, several aspects of this tumor are illustrated. Since the related hemangiopericytoma can be distinguished from the glomangioma by its biological behavior, the morphological differential diagnosis of both tumors is discussed in detail. Therapeutic consequences of one or the other diagnosis are also indicated.