[Biometric and biomechanic analysis of lumbar posterior facets based on a CT-scan database]. / Analyse biométrique et biomécanique des articulaires lombaires postérieures au sein d'une base de données scanographique.

AIM OF THE STUDY: Our knowledge on anatomy of lumbar spine is based on few cadaver's study with old and few subjects. CT-scan is very precise for lumbar facet's morphology. We have analysed 400 subjects. The aim of this study is to measure different distances, angles and circles to better understand the mechanical function of the lumbar facets. PATIENTS AND METHODS: We have analysed 720 CT-scan. We had 217 men and 183 women with 59 years of mean age. We used native slices of 1.25 mm thick from L1 to S1. We created transversal plan and we put different mark point. We took their coordinates and we have calculated different distances, angles and mechanical circles. We have compared different axis of rotation of the facets. RESULTS: From L1 to S1, the facets goes near to the posterior wall and far from themselves. Moreover, the posterior angle between both facets increase down to the sacrum. The radius of the left side circle and the right one are very closed in 50% of the cases but the three radius are close only in 10% of cases. CONCLUSION: This study based on 400 subjects shows that there is not a unique axis of rotation for both lumbar posterior facets. We have had only 50% of symmetry between both sides whatever the level studied.

[Discoscanner: indications, technique, tips and tricks, interpretation]. / Discoscanner: indications, technique, trucs et astuces, interprétation.

Discography test associated with the scanner (discoscanner) is an exam that has been a renewed interest in recent few years. Thanks to the emergence of new interventions such as disc prosthesis, the procedures require confirmation of the disc level to deal with and the origin of discogenic symptoms. The aim of this paper is to describe the techniques, challenges and tips as well as the interpretation of functional and morphological examination.

Medicoeconomic evaluation of total disc replacement based on French National Health Care System data.

INTRODUCTION: Total disc replacement (TDR) has existed since 1984 but is not covered by the French national healthcare system (Sécurité Sociale). The present study assessed clinical outcomes, and also pre-, peri- and postoperative treatment costs. HYPOTHESIS: Surgical management of low back pain (LBP) provides medical and economic benefit. MATERIALS AND METHODS: A prospective study recruited 19 patients in the Nice University Hospital Center (France); mean age, 41 years; 15 female. Inclusion criteria were: age less than 60 years; chronic low back pain (LBP) with single-segment discopathy; work related injuries and patients not covered under the General provision of the Sécurité Sociale were excluded. VAS, Oswestry and SF36 scores and return to work capability were analyzed. The local national health insurance branch office (Caisse Primaire d'Assurance Maladie [CPAM]) provided detailed coverage data for a 39-month period around the operation. RESULTS: Revision surgery was required for one instance of vertebral fracture. Preoperative follow-up was 14 months, postoperative FU 21 months and the perioperative period 4 months. LBP and quality of life showed improvement. Seventy-nine percent of patients reported satisfaction, 59% returned to work, and 84% had leisure activity. Total CPAM payout (reimbursement) was €399,082. Daily sickness benefit and disability compensation were the main cost items. Mean TDR cost per patient was €6833. Mean reimbursements were 19% lower post- than preoperatively. Pre- and postoperative clinical results did not correlate, while pre- and postoperative reimbursement costs did, as did cost and postoperative clinical status (r=-0.72). Preoperative cost was a predictive factor for postoperative clinical result. DISCUSSION: TDR achieves favorable medicoeconomic results. LEVEL OF EVIDENCE: III: case-control study.

[Posterior percutaneous arthrodesis under CT guidance after surgical anterior arthrodesis: a new technique]. / Arthrodèse percutanée postérieure sous guidage scanner en complément de l'arthrodèse antérieure chirurgicale: une nouvelle technique.

Transfacet screws may be useful for stabilizing segments reconstructed with bone graft or cages, the role of supplementary posterior fixation, particularly minimally invasive techniques such as transfacetar percutaneous screws is relevant. To benefit from a mechanical fixation after anterior arthrodesis without the inconveniences of the open classical posterior surgical intervention, we have developed a new procedure performed under local anesthesia and CT guidance and based on the intra-articular application of screws. This study was designed to demonstrate the feasibility of using a CT-scan to perform posterior arthrodesis of the spine under local anesthesia.

Comparison between single- and multi-level patients: clinical and radiological outcomes 2 years after cervical disc replacement.

In cervical multi-level degenerative pathology, considering the morbidity of the extensive fusion techniques, some authors advocate for the multilevel disc replacement. This study compared the safety and efficacy of disc replacement with an unconstrained prosthesis in multi- versus single-level patients. A total of 231 patients with cervical degenerative disc disease (DDD) who were treated with cervical disc replacement and completed their 24 months follow-up were analyzed prospectively: 175 were treated at one level, 56 at 2 levels or more. Comparison between both groups was based on usual clinical and radiological outcomes [Neck Disability Index (NDI), Visual Analog Scale (VAS), Range of Motion, satisfaction]. Safety assessments, including complication and subsequent surgeries, were also documented and compared. Mean NDI and VAS scores for neck and arm pain were improved in both groups similarly. Improvement of mobility at treated segments was also similar. Nevertheless, in the multi-level group, analgesic use was significantly higher and occurrence of Heterotopic Ossification significantly lower than in the single-level group. Subject satisfaction was nearly equal, as 94.2% of single-level group patients would undergo the surgery again versus 94.5% in the multi-level group. The overall success rate did not differ significantly. Multi-level DDD is a challenging indication in the cervical spine. This study showed no major significant clinical difference between the two groups. We need further studies to know more about the impact of multi-level arthroplasty, especially on the adjacent segments, but these results demonstrate initial safety and effectiveness in this patient sample.

Intermediate clinical and radiological results of cervical TDR (Mobi-C) with up to 2 years of follow-up.

The interest in cervical total disc replacement (TDR) as an alternative to the so-far gold standard in the surgical treatment of degenerative disc disease (DDD), e.g anterior cervical discectomy and fusion (ACDF), is growing very rapidly. Many authors have established the fact that ACDF may result in progressive degeneration in adjacent segments. On the contrary, but still theoretically, preservation of motion with TDR at the surgically treated level may potentially reduce the occurrence of adjacent-level degeneration (ALD). The authors report the intermediate results of an undergoing multicentre prospective study of TDR with Mobi-C prosthesis. The aim of the study was to assess the safety and efficacy of the device in the treatment of DDD and secondary to evaluate the radiological status of adjacent levels and the occurrence of ossifications, at 2-year follow-up (FU). 76 patients have performed their 2-year FU visit and have been analyzed clinically and radiologically. Clinical outcomes (NDI, VAS, SF-36) and ROM measurements were analyzed pre-operatively and at the different post-operative time-points. Complications and re-operations were also assessed. Occurrences of heterotopic ossifications (HOs) and of adjacent disc degeneration radiographic changes have been analyzed from 2-year FU X-rays. The mean NDI and VAS scores for arm and neck are reduced significantly at each post-operative time-point compared to pre-operative condition. Motion is preserved over the time at index levels (mean ROM = 9 degrees at 2 years) and 85.5% of the segments are mobile at 2 years. HOs are responsible for the fusion of 6/76 levels at 2 years. However, presence of HO does not alter the clinical outcomes. The occurrence rate of radiological signs of ALD is very low at 2 years (9.1%). There has been no subsidence, no expulsion and no sub-luxation of the implant. Finally, after 2 years, 91% of the patients assume that they would undergo the procedure again. These intermediate results of TDR with Mobi-C are very encouraging and seem to confirm the efficacy and the safety of the device. Regarding the preservation of the status of the adjacent levels, the results of this unconstrained device are encouraging, but longer FU studies are needed to prove it.

[Extension reserve of the hip in relation to the spine: Comparative study of two radiographic methods]. / Mesure de la réserve d'extension de la hanche en relation avec le rachis. Etude comparative de deux méthodes radiologiques.

SUMMARY: Free-hip movement is necessary for good spinal function. Limitation generally affects extension. The range of hip extension from the standing position can be considered as the hip's "extension reserve". The amplitude of this reserve must be known because any deficit requires a pathological solicitation of the vertebral column. Measurement of the extension reserve of the hip is useful for analyzing spinal disease and for preoperative planning. Physical examination can measure extension, but cannot differentiate movement produced by the hip from that originating in the spine. We have been unable to locate any radiographic method in the literature. The purpose of this study was to evaluate radiographic measurements and to propose a novel method. The study was conducted with 37 patients with spinal disease. Two radiographic methods were compared. Four lateral views, including the lumbar spine, the pelvis and the femur were obtained in each patient: neutral position, retroversion of the pelvis and extension of each hip in lunge position. The X-rays were digitalized for computer processing. The extension reserve of the hip was calculated for each radiographic method. Extension reserve was defined as the difference in the pelvis-femoral angle between the neutral position and extension. There was a positive correlation between the two methods (p<0.0006; p<0.0009). Mean extension using the pelvis retroversion method was 1.8 degrees +/-6.77; with the hip-extension method, it was hip I (side with the superior value): 15.9 degrees +/-6.57; hip II 10.0 degrees +/-7.89. The pelvis-retroversion method gave a lower measurement compared with the lunge position method (p<0.0001). For 13 of 37 subjects (35%), this method gave negative values, that is, failure of the measurement method. The method of hip extension in lunge position was superior to the pelvis-retroversion method, which gave lower measurements that were often incoherent and unable to provide specific information for each hip. The method using the lunge position for hip extension appears to be preferable. We are currently conducting a clinical trial to include extension reserve in the analysis of sagittal balance and for determining curvature corrections. We propose a mathematical formula using extension reserve for determining sagittal correction. Radiographic determination of extension reserve of the hip joint is of major importance for assessing spinal disease in addition to its contribution to the analysis of hip and pelvic disease. The methods presented here enable radiographic measurement of the extension reserve of the hip.

[Percutaneous osteosynthesis of lumbar and thoracolumbar spine fractures without neurological deficit: surgical technique and preliminary results]. / Ostéosynthèse percutanée des fractures lombaires et thoracolombaires non neurologiques: technique chirurgicale et résultats préliminaires.

PURPOSE OF THE STUDY: The aim of this work was to study the technique of percutaneous osteosynthesis of lumbar and thoracolumbar spine fractures without neurological deficit and to report preliminary results. MATERIAL AND METHODS: This retrospective study included 15 patients with lumbar or thoracolumbar spine fractures who were treated between January 2004 and January 2006 by percutaneous osteosynthesis. There were seven men and eight women, mean age 36 years (range 16-58 years). The Magerl classification (AO) was A1 (n=4), A2 (n=1), A3 (n=9), B2 (n=1). Levels were T12 (n=1), L1 (n=10), L2 (n=2), L3 (n=1), L4 (n=1). A specific instrument set was used to insert a short fixation using two pedicular screws on either side of the fractured vertebra and two prebent 5.5mm rods introduced with an aiming device. The operation was performed under fluoroscopy. Ten patients wore a removable corset. The upright position was allowed if there were no other injuries. Computed-tomography scans were obtained preoperatively, postoperatively and at two years follow-up. Function was assessed with the Oswestry score. RESULTS: Mean operative time was 108 minutes (range 40-180 minutes). None of the patients with an isolated spinal injury required blood transfusion. Mean hospital stay was 12 days (range 4-28). Results were expressed for 13 patients whose operations were exclusively percutaneous. Mean follow-up was 17 months (range 6-30). The visual analog scale (VAS) was 1.6/10. The mean Oswestry score was 16. Three quarters of the patients resumed their occupational activities. None of the patients was dissatisfied. Mean vertebral kyphosis (VK) improved from 16 to 8.1 degrees , corrected regional angle (CRA) from 12 to 2.5 degrees at last follow-up. Loss of correction at last follow-up was 1.1 degrees for VK and 2.5 degrees for CRA. The rate of pedicle screw malposition was 3.8%. There were no cases of disassembly nor material failure. There were no infections. None of the implants had to be removed. DISCUSSION: Percutaneous osteosynthesis of the spine is technically feasible, but requires considerable experience. Functional and subjective results have been good. The loss of correction at last follow-up has been comparable to that observed with conventional open surgery. This technique is an intermediary method between orthopaedic treatment and conventional surgery. Exact indications must be established. CONCLUSION: Percutaneous osteosynthesis of lumbar and thoracolumbar spine fractures is an attractive therapeutic option. Our results are encouraging. Indications and limitations of this technique must be carefully identified.

[Can the postoperative pain level be predicted preoperatively?]. / Peut-on prévoir, avant l'intervention, l'intensité de la douleur postopératoire?

PURPOSE OF THE STUDY: We searched for factors present preoperatively which could be used to predict the intensity of postoperative pain. MATERIAL AND METHODS: We undertook a prospective study among all patients aged over 18 years who underwent shoulder surgery from January to September 2004 in our unit. The study included 86 patients for which the following data were noted preoperatively: past history of pain, intensity and duration of prior pain, triggering factors, localization, psychological context. The intensity of the postoperative pain was measured on a visual analog scale (VAS); measurements were noted up to 24 hours postop then at one month. Data processing was performed with Statview5.5. RESULTS: Significant postoperative pain was correlated with a prior history of surgical pain, with duration of prior pain, with intensity of preoperative pain, and with depression. DISCUSSION: Significant sustained preoperative pain can favor memory of pain leading to postoperative sensitivization of nociception neurons. Intense postoperative pain can favor the development of refractory chronic pain. CONCLUSION: Significant postoperative pain can be expected in the following situations: pain after prior surgery, presence of chronic pain sustained for more than six months, intense preoperative pain, state of depression.

[Lumbar videodiscectomy. Results in a prospective consecutive series]. / Vidéo-discectomie lombaire. Résultats d'une série prospective continue.

PURPOSE OF THE STUDY: We report results obtained in a prospective consecutive cohort of patients undergoing videoscopy-guided discectomy using the Destandau technique. MATERIAL AND METHODS: Between June 1998 and August 2000, 40 patients underwent videoscopy-guided discectomy. There were 24 males and 16 females, mean age 43 years (24-78 years). Eleven patients had associated lumbar stenosis. Outcome was reviewed by an independent investigator. Mean follow-up was 19 months (12-67). RESULTS: One patient required reoperation to establish proof of infection. Three patients required revision for open extended decompression which did not reveal any case of remaining hernia fragment or postoperative hematoma. All three of these patients had lumbar stenosis. At last follow-up 36 patients had not required revision surgery. Mean hospital stay was 3.3 days. The Waddel score was excellent or good for 91% of patients and the Prolo score was excellent or good for 84%. Mean improvement compared with the preoperative status was 65%, as assessed by the Oswestry score. DISCUSSION AND CONCLUSIONS: Lumbar videodiscectomy provides satisfactory functional results equivalent to those of microdiscectomy. The advantages of this technique are the precise control of the operation and the good hemostasis made possible by the optical magnification. Low cost is another advantage since the procedure only requires a standard arthroscopic column and standard spinal surgery instruments. Associated stenosis is a relative contraindication for this minimally invasive technique.

[Videoscopic retropleural and retroperitoneal approach to the thoracolumbar junction of the spine]. / Voie rétro séreuse du rachis à l'étage thoraco-lombaire sous contrôle vidéoscopique.

PURPOSE OF THE STUDY: A minimally invasive anterior approach has been developed for the thoracolumbar junction of the spine. The aim of this study was to evaluate the possibilities of videoscopic treatment of fractures and malunions of the thoracolumbar junction and to report the first results obtained with this technique. MATERIAL AND METHODS: Video-assisted surgery was performed in eleven patients using costal resection and a retropleural and retroperitoneal approach. Anterior arthrodesis was performed in all cases, four with anterior instrumentation. The indications were trauma for six patients and malunion for five. RESULTS: Mean follow-up was 17.4 months. For malunion patients, the mean angular gain was 22.4 degrees. Radiological anterior fusion was achieved in all cases except one. The mean angular loss was 5.7 degrees. DISCUSSION: The surgeon can control the procedures by direct vision, while the assistant follows the operation on the video display screen. The upper par of L1 can be reached via a supradiaphragmatic retropleural approach, while a larger exposure is possible if the insertions of the diaphragm are released and the retroperitoneal space is opened. The crus does not have to be sectioned to expose the lateral part of the thoracolumbar vertebrae. Possible complications are similar to those which can be observed with open procedures. CONCLUSION: The videoscopic approach enables the exposure of throacolumbar junction with a smaller parietal lesion than with open procedures. It enables arthrodesis procedures with corporectomay, angular correction and anterior osteosynthesis.

Traumatic rotatory displacement of the lower cervical spine.

The authors describe the classification for traumatic rotary injuries of the cervical spine. The classification is based on a review of 306 severe lower cervical spine injuries observed in 255 patients between 1980 and 1994. Traumatic rotatory displacements (TRD) represented 39% of the 306 severe injuries. Three different lesions were observed: unilateral facet fractures, fracture-separation of the articular pillars, and unilateral facet dislocations.

Five years' experience of the retroperitoneal lumbar and thoracolumbar surgery.

Retroperitoneal videoscopic spine surgery has been developed in our department since 1994. It has been used not only at the lumbar, but also at the thoracolumbar and lumbosacral level. Thirty-eight patients have been operated on. We have performed 12 thoracolumbar approaches, 23 lumbar approaches, and 3 retroperitoneal lumbosacral approaches. In every case, a video-assisted technique has been employed. These techniques have been used for anterior grafting in 18 cases of fracture, for corporectomy and grafting with or without anterior osteosynthesis in 6 cases of malunion, for cage implantation or isolated grafting in 10 cases of degenerative disc disease, and for the treatment of 4 cases of spondylodiscitis. Results were satisfactory for every type of pathology. The complications related to the approach were the same as those seen with open surgery; however, the videoscopic approach seems to us less invasive, with cosmetic benefit, less blood loss, and more rapid recovery. A video-assisted technique appears to be a good compromise between videoscopic technique and open surgery. With the development of these techniques, few indications remain for open anterior surgery on the lumbar spine in our opinion.

Lung nematodes of chamois, Rupicapra rupicapra tatrica, from the Tatra National Park, Slovakia.

A larvoscopic examination of faeces collected from localities inhibited by chamois in the Tatra National Park (TANAP) in 1997 demonstrated the presence of the lung nematodes Muellerius spp. (likely to be M. tenuispiculatus and M. capillaris) and Neostrongylus linearis. The overall prevalence of lung nematodes in chamois herds in TANAP was 48.4% with prevalences of 45.6% and 11.9% for Muellerius spp. and N. linearis, respectively. No significant differences in lung nematode prevalences were observed in the biotopes of TANAP with prevalence values of 44.9% being recorded in the High Tatras and 58.5% in the Belianske Tatras. Individual species were in equal proportion in both biotopes, although N. linearis was significantly less prevalent (11.2-13.8%). The prevalence of lung nematodes in the High Tatras varied from 25.0 to 84.2% within individual localities, while in the Belianske Tatras it was more proportionate (50.0-85.7%). In the High Tatras, the prevalence of lung nematodes in the chamois herds peaked during August, declining to its lowest in October. A similar prevalence was also recorded for Muellerius species, while the minimum prevalence of N. linearis was found in July. In the Belianske Tatras, the prevalence of lung nematodes including both species of Muellerius peaked in July and gradually decreased until October. On the other hand, N. linearis was most prevalent in October. The mean L1 count per gram faeces was low (7.6 +/- 13.2 larvae g-1).

[Retroperitoneoscopic anterior approach to the L2, L3, L4 vertebral bodies]. / Voie d'abord antérieure de L2, L3, L4 par rétropéritonéoscopie.

PURPOSE OF THE STUDY: We present a technique of retroperitoneal video assisted anterior approach of vertebral bodies and adjacent discs on L2-L3-L4 levels without CO2 insufflation. MATERIALS: A videosurgical material is required as well as fluoroscopic control. Ordinary anesthesia methods can be used. The patient is placed in right lateral decubitus. Ay. A3 cm incision is targeted moderately anteriorly at the level of the vertebra. Dissection of the retroperitoneal space is begun by blunt finger dissection and completed by a balloon. A camera is inserted. CO2 insufflation is not used for this open video-assisted technique. METHODS: We have performed 12 arthrodeses with this technique, 11 of them without corporectomy. In one case, a corporectomy with peroneal graft was used. RESULTS: Eleven arthrodesis fused. The possible complications are the same as with a full open procedure. DISCUSSION: Extension of this approach is limited cranially by the 12th rib and caudally by the iliac crest. CONCLUSION: Although this is an easy to perform mini open technique, a learning curve is necessary. Conservation to a full open procedure is possible at any point in the procedure.

New possibilities in L2-L5 lumbar arthrodesis using a lateral retroperitoneal approach assisted by laparoscopy: preliminary results.

Four patients underwent lumbar interbody fusion, performed via a video-assisted retroperitoneal laparoscopic approach, complementary to posterior osteosynthesis at the L2-L3, L3-L4 and/or L4-L5 level. In three cases the interventions were for lumbar fractures, and in one case for microcristalline arthritis. After surgical training on human cadavers and several porcine operative sessions, retroperitoneal lateral approaches on the left side were performed by the authors without CO2 insufflation, assisted by videoscopy. The fusion process was monitored by fluoroscopy. It is possible to perform this technique cranially above L2 or caudally below L5. Minimal blood loss was observed. Average time for these interventions was 127 min. Interbody fusion was achieved in the first, second and fourth cases; the outcome in the third case at the final check-up, 6 months after operation, was uncertain. The first patient had a complication of ureteral wound, which was certainly caused by insufficient experience with the new technique. The authors hope to extend the application of this technique to other procedures as they become more experienced.

Short device fixation and early mobilization for burst fractures of the thoracolumbar junction.

The authors present a retrospective study based on a homogeneous series of 34 patients with burst fractures of the thoracolumbar junction, fixed using Cotrel-Dubousset instrumentation. These patients underwent instrumentation using a short construct of hooks and screws gripping the two vertebrae above the lesion (2HS) and screws and hooks gripping the first vertebra below the lesion (1SH). This construct was therefore called "2HS-1SH". In order to evaluate just the material resistance after getting up, only the patients who were upright on the 4th day without a body cast and with no secondary anterior osteosynthesis were included in this study. Four patients showed some neurological symptoms on admission but recovery was so quick that they could be included in this study. Mean follow-up was 4 years 1 month (range 3 years 1 month and 6 years 2 months). Vertebral and regional kyphosis angles were measured preoperative, postoperatively and at the final follow-up. Functional recovery and complications were analyzed. Mean vertebral kyphosis was 21.2 degrees preoperatively, 3.8 degrees postoperatively and 5.3 degrees at the final follow-up. Regional kyphosis angles were respectively 19.2, 0.2, and 2.7 degrees. We had two cases of deep suppuration, one early and the other late. None of the patients required analgesics for more than 6 months after the operation. Patients returned to work after 5 months on average. The authors concluded that fixation by screw-and-hook constructs is an effective way to stabilize thoracolumbar junction burst fractures.

Role of small mammals in the epidemiology of toxocariasis.

Studies were conducted on the role of small mammals in maintaining toxocariasis foci in urban, rural and montane biotopes. The lowest relative density of small mammals was recorded in the urban locality and the highest in the rural and montane localities. Anti-Toxocara antibodies were most frequently detected in synanthropic and hemisynanthropic species Mus musculus, Apodemus agrarius and Micromys minutus--32.0, 30.4 and 25.0%, respectively. The highest seropositivity was found in small mammals from the urban and rural localities--22.2 and 21.6%, respectively. Toxocara canis was most prevalent in urban stray dogs (75.0%) and least prevalent in foxes from the montane locality (7.0%). The prevalence of Toxocara cati in cats at the urban, rural and montane localities was 66.2, 65.2 and 76.9%, respectively. In clinically healthy human populations, the highest seroprevalence was detected in the rural locality (14.0%). Children of the same area were 3 times more seropositive (12.9%) than those from the urban and montane localities (4.3 and 4.0%). Our studies suggest an important role for small mammals as paratenic hosts--reservoirs of Toxocara larvae--in maintaining toxocariasis foci. In this respect toxocariasis may be classified as an anthropopurgic focal zoonosis.

Motorcycle petrol tanks and their role in severe pelvic injuries.

Between 1985 and 1992, nine patients who sustained severe pelvic lesions as a result of motorcycle accidents were admitted to and treated in the authors' department. In six of these nine cases the petrol tank of the motorcycle was one of the wounding agents, and all six patients had the same kind of motorcycle with an oversized petrol tank. All six patients had unstable pelvic lesions. In addition, four had subperitoneal haematomas which required multiple transfusions; five had perineal and/or genital lesions, and one had a ruptured membranous urethra. Severe pelvic injuries are rare, but can have after-effects which jeopardize the social and family life of the patients. A national epidemiological study would be useful to evaluate the frequency of such injuries and to draw conclusions leading to improved safety for motorcyclists.