Recently, some studies have focused attention on the possibility that anaerobic pathogens of low virulence could constitute an etiological factor in disc herniation. There have been isolated such strains, predominantly Propionibacterium acne, between 7 and 53% of patients undergoing surgery for disc pathology. According to these studies, patients with anaerobic infections of the disc are more likely to develop Modic changes in the adjacent vertebrae. The aim of this work was to test this hypothesis by growing in specific media the disc material extracted in a series of lumbar discectomy and relating this factor with the presence of pre-intervention Modic changes. A total of 22 consecutive patients undergoing primary unisegmental discectomy for lumbar disc herniation (77.2% male, mean age 40.1 ± 9.1 years) were included. All patients were immunocompetent and none had previously received an epidural steroid injection prior surgery. MRI study confirmed the disc herniation. Following strict antiseptic protocols, the extracted disc material was sent for slow-growth anaerobic enriched culture (>10 days).Background
Methods
A new triggered electromyography test for detection of stimulus diffusion to intercostal muscles of the contralateral side during thoracic pedicle screw placement was evaluated. Experimental research was carried out in order to determine if, using this test, neural contact at different aspects of the spinal cord and nerve roots could be discriminated. Nine industrial pigs (60–75 kg) had 108 pedicle screws placed bilaterally in the thoracic spine (T8–T13). Neural structures were stimulated under direct vision at different anatomic locations from T9 to T12. Recording electrodes were placed over the right and left intercostal muscles. Increasing intensity of the stimulus was applied until muscle response was detected at the contralateral side (diffusion phenomenon). After this first experiment, the thoracic spine was instrumented. Screws were placed in the pedicle in two different positions, the anatomic intrapedicular location and with purposeful contact with the neural elements.Introduction
Methods
To determine the limits of spinal displacement before the onset of neurophysiological changes during spinal surgery. Assessing if the type of force applied or the section of the adjacent nerve roots increases the tolerance to displacement. Experimental study in 21 domestic pigs. Three groups were established according to the displacing force applied to the cord: separation (group 1, n=7), root stump pull (group2, n=7) and torque (group3, n=7). Successive records of cord-to-cord motor evoked potential were obtained. The displacing force was removed immediately when neurophysiological changes observed. The experiment was repeated after sectioning the adjacent nerve roots.Objectives
Methods
We have studied the medium- and long-term effects of femoral intramedullary nailing in 34 children. There was a high incidence of abnormality at the proximal end of the femur, including coxa valga, arrest of growth of the greater trochanter and thinning of the neck of the femur, because of damage to the trochanterocervical growth plate. These disorders affected 30% of the patients, mostly under the age of 13 years (p <
0.05), and were seen more frequently when the nail had been introduced through the piriform fossa. Other factors, such as the side, gender, aetiology, proximal or retrograde insertion, the size of nail and removal of the implant did not influence the result. We recommend that in patients under the age of 13 years other methods of management should be used to avoid damage to the growth plate.
