Papers by Pr Gilles PERRIN
European journal of orthopaedic surgery & traumatology : orthopedie traumatologie, Jan 7, 2015
Simulating compressive action of muscles, a follower load attends to reproduce a more physiologic... more Simulating compressive action of muscles, a follower load attends to reproduce a more physiological biomechanical behaviour of the cervical spine. Only few experimental studies reported its influence on kinematics and intradiscal pressure in the cervical spine. In vitro human cadaveric and numerical simulating evaluation of a compressive preload in the cervical spine. To analyse the influence of a compressive follower preload on the biomechanical behaviour of the cervical spine. The present study was divided into two parts: part 1: in vitro investigation; part 2: numerical simulating analysis. Part 1: Twelve human cadaveric spines from C2 to T2 were evaluated intact and after application of a 50-N follower load. All tests were performed under load control by applying pure moments loading of 2 Nm in flexion/extension (FE), axial rotation (AR) and lateral bending (LB). Three-dimensional displacements were measured using an optoelectronic system, and intradiscal pressures were measured...
European Journal of Orthopaedic Surgery & Traumatology, 2014
Your article is protected by copyright and all rights are held exclusively by Springer-Verlag Fra... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag France. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
ISRN Orthopedics, 2013
Dynamic systems in the lumbar spine are believed to reduce main fusion drawbacks such as pseudart... more Dynamic systems in the lumbar spine are believed to reduce main fusion drawbacks such as pseudarthrosis, bone rarefaction, and mechanical failure. Compared to fusion achieved with rigid constructs, biomechanical studies underlined some advantages of dynamic instrumentation including increased load sharing between the instrumentation and interbody bone graft and stresses reduction at bone-to-screw interface. These advantages may result in increased fusion rates, limitation of bone rarefaction, and reduction of mechanical complications with the ultimate objective to reduce reoperations rates. However published clinical evidence for dynamic systems remains limited. In addition to providing biomechanical evaluation of a pedicle-screw-based dynamic system, the present study offers a long-term (average 10.2 years) insight view of the clinical outcomes of 18 patients treated by fusion with dynamic systems for degenerative lumbar spine diseases. The findings outline significant and stable s...
Neurochirurgie, 2007
Les résultats et les facteurs influençant le contrôle local et la survie seront discutés.
World Neurosurgery, 2012
Hemivertebra frequently occurs in pediatric patients and is treated with vertebral excision to st... more Hemivertebra frequently occurs in pediatric patients and is treated with vertebral excision to stop the progression of the deformity. A case of L3 hemivertebra associated with lumbar kyphoscoliosis in an adult is reported. A 46-year-old woman presented with severe chronic back pain of 6 years' duration. Radiologic examinations showed that the L3 vertebra had a trapezoidal shape revealing a partially segmented hemivertebra. The patient underwent a two-stage corrective surgery. The first stage consisted of a transpedicular osteotomy (TPO) with posterior instrumentation from L1 to L5 and a bone graft; 1 month later, anterior interbody fusions were performed at L2-3 and L3-4 using interbody cages and bone morphogenetic protein. No postoperative complication was reported after 2 years of follow-up. TPO improved clinical symptoms, corrected the spinal deformity, and reduced the lumbar kyphosis.
La Presse Médicale, 2007
information médicale des hospices civils, Lyon (69) 2. Pôle des spécialités neurologiques, Hôpita... more information médicale des hospices civils, Lyon (69) 2. Pôle des spécialités neurologiques, Hôpital neurologique Pierre Wertheimer, Bron (69) 3. Direction de projet pôles d'activité médicale, Lyon (69)
The overall incidence of bone metastases in patients with cancer of all types is approximately 70... more The overall incidence of bone metastases in patients with cancer of all types is approximately 70%. After lung and liver, the skeletal system is the third most frequent site of metastases. The spine is a very common site of bony metastases. Metastatic disease of the spine is a significant source of morbidity for patients with cancer. Neurological dysfunction also significantly alters a patient's quality of life by disrupting bowel and bladder function and ability to ambulate. If 3% of spinal metastases are from unknown primary tumours, 75% of the vertebral secondary tumours originate from the following primary tumours: breast cancer as the main source of secondary tumours, prostate cancer, renal tumours and thyroid tumours. The mechanical explanations of metastatic distribution and modes of hematogenous spread remain challenged. Spread of metastases from breast and prostate is believed to be delivered by the vertebral venous system. In contrast, metastases from lung cancer are ...
The Spine Journal, 2005
patients, 88% were operated at the L4-L5 level. Mean time of surgery was 74 minutes with 19 minut... more patients, 88% were operated at the L4-L5 level. Mean time of surgery was 74 minutes with 19 minutes for implant time. Average blood loss was 180 cc. At baseline, the mean VAS was 70.9. At three months, VAS was significantly reduced (pϽ.01) to a mean 20.6 with further reductions to 17.8 at 6 months and 10.6 at 12 months. The SF-36 values (baseline/1 year) were as follows: "Physical Component Summary" was 45.1/50.4 and "Mental Component Summary" was 29.9/48.6. Beginning at 3 months postop, SF-36 scores improved in every category over the preoperative values, statistically significant in all categories except general health. At 1 year, the patients reached SF-36 scores very similar to the French general population norms. JOA score (15 point scale) significantly improved from 6.1 at preop to 13.7 at 12 months (pϽ.01) after reaching a plateau at 3 months (12.5). The Odom's results provide good preliminary evidence of efficacy, with 80%, 88% and 89% of subjects categorized as 'excellent' or 'good' at 3 months, 6 months, and 12 months, respectively. Half of the patients in the 'fair' category at 3 months shifted to the 'good' or 'excellent' categories at 12 months. The first results obtained at 2 years are good but statistical analysis will require a greater amount of data. In the overall series of 260 cases, only three implantrelated failures were observed.
Surgical and Radiologic Anatomy, 2003
The purpose of this study was first to assess the feasibility of C7 transpedicular screwing with ... more The purpose of this study was first to assess the feasibility of C7 transpedicular screwing with a morphological study and secondly to evaluate the safety of such a surgical technique when guided only by posterior landmarks. Eighteen C7 vertebrae, harvested from fresh human cadavers, were included in this study. First the morphometry of C7 pedicle was performed on computed tomography with multiplanar reconstructions. Results of this quantitative anatomy were compared with the literature data. Secondly 30 pedicle screws, whose placement was guided only by anatomical features on the posterior face of the dorsal arch, were inserted in 15 C7 vertebrae. A second computed tomographic examination was done after the surgical procedure to check the screw placement in both planes. The average pedicular width was 6±1.2 mm and the average height was
Neurosurgery, 2007
OBJECTIVE The main objectives of this study were to analyze and compare spinopelvic parameters, i... more OBJECTIVE The main objectives of this study were to analyze and compare spinopelvic parameters, including the pelvis shape, in a population of 40 patients with degenerative spondylolisthesis (DSPL) and to compare these patients with a control group of asymptomatic volunteers. METHODS Forty patients with DSPL were included in this study. Spinopelvic parameters were analyzed on preoperative full spine x-rays in a standardized standing position. The following spinopelvic parameters were measured: pelvic incidence (PI), sacral slope, pelvic tilt, lumbar lordosis, thoracic kyphosis, and positioning of the C7 plumb line. The population of patients was compared with a control population of 154 normal and asymptomatic adults who were studied in a recently published study. In order to understand variations of spinopelvic parameters, a control group was matched according to the PI, which is a morphological parameter. RESULTS The PI was significantly greater for patients with DSPL (60.1 ± 10.6...
Journal of Neurosurgery: Spine, 2004
Object. The purpose of this study was to assess human cervical spine pullout force after lateral ... more Object. The purpose of this study was to assess human cervical spine pullout force after lateral mass fixation involving two different techniques: the Roy-Camille and the Magerl techniques. Although such comparisons have been conducted previously, because of the heterogeneity of results and the importance of this procedure in clinical practice, it is essential to have data derived from a prospective and randomized biomechanical study involving a sufficient sample of human cervical spines. The authors also evaluated the influence of the sex, the vertebral level, the bone mineral density (BMD), the length of bone purchase, and the thickness of the anterior cortical purchase. Methods. Twenty-one adult cervical spines were harvested from fresh human cadavers. Computerized tomography was performed before and after placing 3.5-mm titanium lateral mass screws from C-3 to C-6. Pullout forces were evaluated using a material testing machine. The load was applied until the pullout of the screw...
European Spine Journal, 2012
Background The purpose of the study was to report radiological outcomes after total disc replacem... more Background The purpose of the study was to report radiological outcomes after total disc replacement (TDR) in the cervical spine through a 24 months follow-up (FU) prospective study with a special focus on sagittal alignment and kinematics at instrumented and adjacent levels. Materials and methods Thirty-two patients, who sustained one-level TDR with a ball-and-socket arthroplasty (Discocerv TM implant, Scient'x/Alphatec Spine, USA) were consecutively included in the study. Clinical (visual analogical scale and neck disability index) and radiological parameters were measured preoperatively and postoperatively at 3/6 months, 1-year and 2-year FU. Sagittal alignment, ranges of motion (ROM) and center of rotations (CORs) were analyzed using specific motion analysis software (Spineview TM , Paris, France). Patients CORs were compared with those of a control group of 39 normal and asymptomatic subjects. Results Both local and C3-C7 lordosis significantly increased postoperatively (?8°and ?13°at 2 years, respectively). At instrumented level ROM in flexionextension (FE) was measured to 10.2°preoperatively versus 7.5°at 1 year and 6.1°at 2 years. There were no differences in ROM at adjacent levels between pre and postoperative assessments. When compared with control group and preoperative measurements, we noted postoperative cranial shift of the COR at instrumented level for patients group. In contrast, there was no difference in CORs location at adjacent levels. Conclusion Through this prospective study, we observed that cervical lordosis consistently increased after TDR. In addition, although ball-and-socket arthroplasty did not fully restore native segmental kinematics with significant reduction of motion in FE and consistent cranial shift of the COR, no significant changes in terms of ROM and CORs were observed at adjacent levels.
European Spine Journal, 2011
Introduction Aging of the spine is characterized by facet joints arthritis, degenerative disc dis... more Introduction Aging of the spine is characterized by facet joints arthritis, degenerative disc disease and atrophy of extensor muscles resulting in a progressive kyphosis. Recent studies confirmed that patients with lumbar degenerative disease were characterized by an anterior sagittal imbalance, a loss of lumbar lordosis and an increase of pelvis tilt. The aim of this paper was thus to describe the different compensatory mechanisms which are observed in the spine, pelvis and/or lower limbs areas for patients with severe degenerative spine. Methods We reviewed all the compensatory mechanisms of sagittal unbalance described in the literature. Results According to the severity of the imbalance, we could identify three different stages: balanced, balanced with compensatory mechanisms and imbalanced. For the two last stages, the compensatory mechanisms permitted to limit consequences of lumbar kyphosis on the global sagittal alignment. Reduction of thoracic kyphosis, intervertebral hyperextension, retrolisthesis, pelvis backtilt, knee flessum and ankle extension were the main mechanisms described in the literature. The basic concept of these compensatory mechanisms was to extend adjacent segments of the kyphotic spine allowing for compensation of anterior translation of the axis of gravity. Conclusions To avoid underestimate the severity of the degenerative spine disorder, it thus seems important to recognize the different compensatory mechanisms from the upper part of the trunk to the lower limbs. We propose a three steps algorithm to analyse the balance status and determine the presence or not of these compensatory mechanisms: measurement of pelvis incidence, assessment of global sagittal alignment and analysis of compensatory mechanisms successively in the spine, pelvis and lower limbs areas.
Uploads
Papers by Pr Gilles PERRIN