Endochondral vs. intramembranous demineralized bone matrices as implants for osseous defects.

This study focuses on the difference in regenerative capacity between endochondral and intramembranous demineralized bone matrices (DBMs) when implanted into bony defects. It also focuses on the possible influence of the type of skeletal recipient site (orthotopic or heterotopic). Of 34 Wistar rats, 10 served as a source of DBM, and 24 were divided into two groups of 12 animals. In group A identical defects were produced in the parietal bones, whereas in group B the defects were produced in each radius. The right defects were implanted with endochondral DBM and the left defects were implanted with intramembranous DBM. Descriptive and/or histomorphometric analyses were performed by means of light and polarized microscopy, and radiography (group B). Right and left data were compared to disclose differences in bone-healing capacity. The quantitative results demonstrated that endochondral DBM displays a greater regenerative capacity than intramembranous DBM when implanted heterotopically. The different clinical performances of endochondral and intramembranous bone grafts might be explained on the basis of the mechanical rather than the osteoinductive principle. The qualitative results suggest that the type of bone deposition induced by the DBMs is not related to the type of implanted DBM. Recipient site characteristics and/or environmental factors seem decisive in the occurrence of either types of ossification.

[Severely traumatized patients admitted to Aarhus Community Hospital 1994-1995]. / Svaert tilskadekomne patienter indbragt til Arhus Kommunehospital 1994-1995.

In Denmark, only few studies have addressed the problem of severe trauma. In relation to establishing a trauma manual at our hospital we studied trauma patients requiring immediate anaesthesiological assistance. Patients from the preceeding years, 1994-1995 were identified. The injuries were scored according to the Abbreviated Injury Scale (AIS), and Injury Severity Scores (ISS) were calculated. Two hundred and fifty-eight trauma patients were identified, 132 of these were severely injured, defined as having ISS > or = 15. Of these, 75 patients were multitraumatised, defined as AIS > or = 3 in at least two regions. None of the patients with ISS < or = 15 died. Mortality was 49% among severely injured but not multitraumatised patients, while mortality was 56% among the multitraumatised patients. Head injuries were the most frequently found severe injury (AIS > or = 3), followed by injuries to the thorax and extremities. The anaesthesiologist and the orthopaedic surgeon were involved in initial diagnosis and treatment in all patients, and beyond these a variety of medical specialties were involved. In the light of this study we have revised our procedures and registration concerning severe trauma patients.

Influence of indomethacin on bone turnover related to orthodontic tooth movement in miniature pigs.

The purpose was to evaluate the influence of a prostaglandin inhibitor, indomethacin, on the tissue reaction related to orthodontic tooth movement. Sixteen miniature pigs were chosen for the study, eight of which received indomethacin perorally every day of the 39-day observation period. Sentalloy expansion springs (GAC, Central Islip, N.Y.) delivering 100 cN were inserted on a segmented arch between the central lower incisors. Intravital labeling with tetracycline was used for the evaluation of the rate of bone formation. After the pigs were killed, the bone turnover was evaluated on undecalcified methacrylate embedded sections and on microradiographs. The histomorphometric analysis of bone turnover revealed that the relative extent of resorption surfaces was decreased significantly in the indomethacin treated animals. Formation surfaces were also decreased although not significantly. The bone turnover, but not the mineralization rate, was influenced. The results corroborate the recommendation that prostaglandin inhibitors should be avoided during orthodontic treatments.

Dentin formation in miniature pigs with special reference to indomethacin and orthodontic treatment.

The rate of dentin mineralization and the influence of indomethacin on the dentin mineralization rate during orthodontic treatment was determined in miniature pigs by intravital labeling with tetracycline. The results demonstrated that the dentin mineralization rate in the control animals was 3.8 microns/day, a rate corresponding to that of human teeth. Both indomethacin and orthodontics had an effect on the dentin mineralization rate, indomethacin reducing and orthodontic forces increasing it. In combination, the two factors neutralized each other.

The influence of sex and pre-traumatic headache on the incidence and severity of headache after head injury.

Pre- and post-traumatic headache of 168 individuals aged 18-60 years was registered 9-12 months after a head trauma. Headache before the trauma was reported by 39.9%, women being in the majority. After the trauma 64.3% were suffering from headache. Post-traumatic headache was reported by 64 patients (38.1%), of whom 22 patients experienced an increase of already existing headache and 42 patients complained of new headache. Patients suffering from headache before the trauma were not more at risk of having post-traumatic headache than patients who did not suffer from headache before the trauma. Patients who experienced an increase of already-existing pre-traumatic headache used more analgesics than patients first suffering from headache after the trauma. Post-traumatic headache was reported by more women than men (p less than 0.02), the corresponding relative risk being 1.6. Both the use of analgesics and the frequency of headache showed a significant increase for patients with post-traumatic headache when compared with a "control group" of 41 patients with unchanged headache and when compared with all patients with headache before the trauma. There was no significant difference in the location of pain between the groups analysed.

Functional radiographic examination of the cervical spine in patients with post-traumatic headache.

The segmental extension-flexion motion of the cervical spine and the overall C1-C7 motion were measured on functional X-rays in 19 patients with post-traumatic headache and 19 age- and sex-matched controls. The extension-flexion C1-C7 motion was reduced in patients with post-traumatic headache due to reduced motion in three segments: C2-C3, C5-C6 (p less than 0.05), and C6-C7 (p less than 0.01). In both groups a negative correlation between the C1-C7 motion and age was found, but the regression coefficients were different. Only in the control group could a negative correlation between segmental motion and age be demonstrated. In the patients with post-traumatic headache a statistically significant negative correlation between the log (pain index) and the age-corrected C1-C7 motion was found (p less than 0.04). On the segmental level a negative correlation between the log (pain index) and the age-corrected C1-C2 and C5-C6 motion could be demonstrated (p less than 0.05). Regarding C6-C7 there was a tendency to negative correlation. Furthermore, a negative correlation between the frequency of associated symptoms (dizziness, visual disturbances and ear symptoms) and the age-corrected C5-C6 motion was found. Consequently the decrement of motion primarily affected C2-C3, C5-C6, and C6-C7, whereas the analysis of correlation with pain index indicated C1-C2 and C5-C6 (C6-C7) as the most important segments involved.

An open study comparing manual therapy with the use of cold packs in the treatment of post-traumatic headache.

One year after head trauma, 23 patients with post-traumatic headache entered a prospective clinical controlled trial to find out if specific manual therapy on the neck could reduce the headache. The study was completed by 19 patients (83%). Ten patients were treated twice with manual therapy and nine patients were treated twice with cold packs on the neck. The pain index was calculated blindly. Two weeks after the last treatment the mean pain index was significantly reduced to 43% in the group treated with manual therapy compared with the pretreatment level. At follow-up five weeks later, the pain index was still lower in this group compared with the group treated with cold packs, but this difference was not statistically significant. The pain index for all 19 patients was significantly correlated to the use of analgesics as well as to the frequency of associated symptoms (number of days per week with dizziness, visual disturbances and ear symptoms). It is concluded that the type of manual therapy used in this study seems to have a specific effect in reducing post-traumatic headache. The result supports the hypothesis of a cervical mechanism causing post-traumatic headache and suggests that post-traumatic dizziness, visual disturbances and ear symptoms could be part of a cervical syndrome.