Purpose of the study

The aim of this work was to study the influence of the slice orientation of T2 axial images in numerical measurements of DSCA and study the effect that this change of slice angle would have on the morphological grading assessment.

Introduction: Several studies have looked at accuracy of thoracic pedicle screw placement, both in vivo and on cadavers, using fluoroscopy, image guidance, and anatomical landmarks. To our knowledge the upper thoracic spine (T1-T6) has not been specifically studied in the context of screw insertion and placement accuracy without the use of either image guidance or fluoroscopy. Our objective was to study the accuracy of placement of upper thoracic screws without the use of fluoroscopy, and report on implant related complications.

Methods: A single surgeon inserted a total of 60 screws in 13 consecutive non-scoliotic spine patients. These 60 screws were the first to be placed in the high thoracic spine in our institution. All previous surgeries used only a hook or wire technique for the upper thoracic spine. The most common diagnosis in our patient population was trauma. All screws were inserted using a modified Roy-Camille technique. Post operative axial computed tomography (CT) images were obtained for each patient and analyzed by an independent senior radiologist for placement accuracy. Furthermore we reviewed the operative records of each patient to record any implant related complications.

Results: No pedicle screw misplacements were found in 61.5% of the patients. Fifty three out of the 60 screws were placed correctly within all the pedicle margins. The overall pedicle screw placement accuracy was 88.3% using our modified Roy-Camille technique. Five medial and 2 lateral violations were noted in the 7 misplaced screws. One of the 7 misplaced screws was considered to be a marginal violation. No implant related complications were noted. Furthermore, no learning curve effect was noted as far as misplacement pattern was concerned.

Conclusion: We found that inserting pedicle screws in the upper thoracic spine based solely on anatomical landmarks was safe with an accuracy comparable to that of published studies on image guided surgery at the thoracic level.

Background: Low back pain due to disc degeneration is a major problem in industrialized countries. So far surgical treatment has consisted of either fusing the involved segments or replacing them with a prosthetic disc. Both techniques yield unpredictable results.

Objective: Looking at a biological solution we have been exploring the possibilities of harvesting and culturing adult and fetal human intervertebral disc cells in vitro.

Methods: Nucleus pulposus tissue has been surgically removed in cases of scoliosis, lumbar disc degeneration and cervical disc herniation after obtaining patient’s consent. Fetal disc tissue was also obtained following approval by the hospital ethics committee. Tissue was put in culture with and without prior collagenase II digestion. No antibiotics or growth factors were used. Cells were kept in culture until confluence and preserved in liquid nitrogen for further study.

Results: We found that it was possible to obtain homogenous populations of cells macroscopically identifiable as chondrocytes from the adult donnors. Collagenase II treatment provided the best results in adult cells whereas digestion was not necessary for the fetal tissue. The latter showed rapid growth compared to adult cells. Further characterization is underway.

Conclusions: It is possible to obtain cultures of nucleus pulposus human cells from a variety of donors, including adolescent patients with little degeneration as well as from patients showing symptoms and signs of lumbar and cervical disc degeneration.. Fetal tissue could also be cultured without growth factor use. Fetal cells in particular multiplied faster than adult cells and could possibly be used as a cell bank in view of tissue engineering projects.

Aims: The aim of this study was to compare the results of Micro Endoscopic Discectomy (MED) toMicro Surgical Discectomy (MSD). Methods: 12 Patients were reviewed by an independent observer. This included the þrst 6 patients who underwent MED and 6 patients who underwent MSD selected randomly. There was no signiþcant difference between the two groups concerning age and sex distribution, occupation, preoper-ative time of work and clinical symptomatology. The disc herniations were located at L4-5 in 6 patients and L5-S1 in 6 patients. Patients were followed up for an average of 9 months (Range 2–22 months). They were assessed using the following questionnaires Oswestry low back pain and disability, Modiþed Gre-enough and Fraser and Mc Nab. Results: Both groups faired equally according to Mc Nab. The MED group appeared to require less postoperative analgesia especially opioid based preparations and were discharged earlier. The only complication was one patient in the MED requiring conversion to MSD. Conclusion: Our results indicate that MED is at least as effective as MSD, although it initially takes longer to perform due to the learning curve. However, the decrease in postoperative analgesia requirements and earlier discharge is beneþcial. In addition, we feel it has advantages over the percutaneous posterolateral discectomy for nerve root compression, which cannot treat sequestrated discs, or patients with disc herniations associated with recess stenosis.