A review of the value of MRI signs in low back pain.

Low back pain is a common symptom that can lead to disability and major socio-professional repercussions. Despite advances in imaging, the etiology of the pain often remains unknown. Morphological changes related to normal ageing of the disc appear on MR imaging without any symptoms. The potential impact of changes seen on imaging, especially MRI, also warrants discussion. The purpose of this work is to review the state-of-the-art of this subject, underlining relevant key features for routine radiological practice. We will first discuss anterior and posterior segments of the spine with a focus on anatomical, physiopathological and semiological findings. Secondly we will discuss the diagnostic value of each sign.

Applications in spinal imbalance.

The pelvis may be seen as a single vertebra, between the spine and the femurs. The anatomy of this pelvic vertebra has changed with the evolution of species, notably with the transition to bipedalism, with the consequent appearance of lumbar lordosis. The lumbosacral angle, almost non-existent in other mammals, is at its greatest in humans. Pelvic and spinal radiological parameters reflect the sagittal balance of the spine in bipedal humanity. Applications in the management of spinal imbalance are numerous. Arthrogenic or degenerative kyphosis is the stereotypic example of spinal aging. Postoperative flat back following spine surgery is hard to prevent. Scoliosis surgery in adults should now take greater account of the patient's individual sagittal balance, by analyzing the pelvic and spinal parameters. The extent of arthrodeses performed during adolescence to manage idiopathic scoliosis may also induce problems of balance in adulthood if these elements are not taken into account.

Applications in hip pathology.

Everyday clinical practice frequently leads us to suspect a close relationship between the lumbar spine and the hip-joints. Sagittal balance fundamentally expresses a postural strategy mobilizing the dynamic structure of the lumbar-pelvic-femoral complex in an authentic balance by which obligatory coupled movements transmit stresses in a single structure, the spine, to the two-part structure of the lower limbs, and vice-versa. Flexion contracture is a frequent hip pathology, but congenital dislocation and ankylosis of the hip have the greatest impact on the spine, due to excessive mechanical strain and/or spinal malalignment, which is initially supple but becomes fixed. Clinical analysis, backed up if necessary by infiltration tests and imaging, guides indications for surgical management. These considerations suggest a general attitude that considers not just the hip itself, for which the patient is consulting, but the lumbar-pelvic-femoral complex as a whole (and also the knee) before undertaking total hip replacement. Femoro-acetabular impingement is a recently described pathology associating morphological hip-joint abnormality and labral and joint cartilage lesions, leading to early osteoarthritis of the hip. Abnormal spinal or pelvic parameters have not been found associated with femoro-acetabular impingement. Congenital pelvic tilt is a benign and often overlooked pathology in children. Supra- and infra-pelvic pelvic tilt in childhood palsy raises the difficult strategic issue of how to get these children in their wheelchair with a well-balanced spine over a straight pelvis and frontally and sagittally balanced hips.

Reconstruction of extensive posterior mid-thoracic soft-tissue defects after spinal surgery on irradiated skin.

A 56-year-old patient presented with neurological disorders resulting from an extrinsic medullary compression extending from T3 to T5 associated with a T4 corporeal invasion by a high-grade non-Hodgkin's malignant lymphoma. Treatment consisted in a laminectomy without spinal stabilization followed immediately by chemotherapy (VCAD) and locoregional radiotherapy (20 cycles of 50 Gy between T3 and T7 followed by nine sequences of 18 Gy). The evolution revealed unfavourable with reappearance of a compressive syndrome thus requiring surgical decompression combined with spinal stabilization. The immediate postoperative period was simple but a secondary wound dehiscence was observed surrounded by an inflammatory area of 15 cm on 12 cm. The authors describe the reconstruction by means of a trapezius musculocutaneous island flap. The results were satisfactory and corroborated those previously reported by various authors after use of this flap in similar situations.

Local anaesthetic use for the iliac crest-donor site: pharmacokinetic and pharmacodynamic evaluations.

During orthopaedic surgery of the limb, we performed a prospective, double blind controlled study on three parallel groups in 30 patients to evaluate the pharmacokinetic and pharmacodynamic effect of infiltration of the iliac crest bone graft harvest site with 20 ml of bupivacaine (100 mg), ropivacaine (150 mg) or saline as control group (n = 10 in each group). Then, in a sheep model of iliac crest infiltration, we compared the pharmacokinetics of single administration of plain bupivacaine (100 mg) and bupivacaine (500 mg)-loaded microspheres. In the clinical control group, pain from the iliac crest was worse than pain from the primary surgical site. Pain from the iliac crest was significantly reduced during the first 12 postoperative hours in local anaesthetic groups compared to the control group. However, during this period, pain from the primary surgical site was increased compared to the control group. Finally, there was no difference between the three groups in the average intake of PCA morphine. There was no significant pharmacokinetic and pharmacodynamic difference between plain bupivacaine and ropivacaine. The maximal plasma concentration (Cmax) of ropivacaine and bupivacaine were 964 (282) ng ml(-1) and 638 (366) ng ml(-1), respectively. In the sheep model, it was clearly shown that the release of bupivacaine from microspheres was controlled and prolonged despite the largest dose of bupivacaine used (500 mg; n = 4). Wound infiltration of iliac crest harvest site with local anaesthetic is an easy technique for postoperative analgesia. However, this effect lasts only 12 hours without reducing the morphine consumption due to an increase of pain from the primary surgical site. The local anaesthetic infiltration produced a significant peak of plasma level, which could be dangerous if another infiltration or regional anaesthetic technique was associated with it. Experimentally, as a drug delivery system, the use of local anaesthetic-loaded microspheres could be an interesting alternative.

[Association of Wolff-Parkinson-White syndrome with isolated non-compaction of the left ventricle: a case report]. / Association du syndrome de Wolff-Parkinson-White a une non-compaction isolée du ventricule gauche. A propos d'un cas.

The Wolff-Parkinson-White syndrome (WPW) may be associated with a number of cardiac pathologies, especially congenital disease, in 7.5 to 17% of cases. The authors report a rare association of the WPW syndrome with two Kent bundles, right and left septal, with non-compaction of the left ventricle in a 52 year old man. This was a chance finding during systematic echocardiography after ablation, and confirmed by cardiac MRI. The patient was asymptomatic.

[Cost-benefit evaluation of spinal cord stimulation treatment for failed-back surgery syndrome patients]. / Evaluation coût/bénéfice du traitement des lombosciatalgies post-operatoires par stimulation médullaire.

BACKGROUND AND PURPOSE: Spinal cord stimulation is a well-known treatment of rigorously selected failed-back surgery syndrome patients. Efficacy levels over 50% of pain relief have been reported in long-term studies. The objective of this multicenter prospective evaluation was to analyze the cost to benefit ratio of spinal cord stimulation treatment for failed back surgery syndrome patients. METHODS: Nine hospitals (pain evaluation and treatment centers) were involved in the study. Forty-three patients were selected and implanted between January 1999 and January 2000. For each patient, pre- and post-operative evaluations (6, 12 and 24 months after implantation) were performed to assess pain relief and economical impact on pain treatment costs. RESULTS: After 24 months, mean 60% pain relief was achieved as assessed with the neuropathic pain score using a Visual Analog Scale (success rate=70%), whereas low-back pain was moderately reduced (29%). The Oswestry Disability questionnaire score was improved by a mean 39%. Costs of pain treatment (medication, consultation, other) are reduced by a mean 64% (1705 Euro) per patient per year. CONCLUSIONS: This study confirms a clear analgesic effect on neuropathic sciatalgia, and moderate attenuation of low-back pain. One particular interest of this study is the medico-economic prospective evaluation showing that the initial cost of the implanted device is compensated by a significant, early, and stable reduction in the cost of associated pain therapies.

A memory coiling spiral as nucleus pulposus prosthesis: concept, specifications, bench testing, and first clinical results.

The intradiscal cavity left after a discectomy can be filled by a new nucleus prosthesis made of polycarbonate urethane in the form of a "memory coiling spiral." Biomechanical tests have demonstrated that this device compensates for the loss of disc height, decreases the compression of the facet joints, and restores the kinematics of the spinal segment, without deformation of the vertebral endplates or migration. The device is currently under clinical investigation. Inclusion and exclusion criteria of the pilot study are presented, and preliminary results of the first five patients supplied with the spiral are reported after an average follow-up time of 24 months. No migration of the device has been observed so far. With its easy application due to the standardized approach and the memory coiling mechanism, this device represents an advance within the nonfusion techniques.

A spiral implant as nucleus prosthesis in the lumbar spine.

Microdiscectomy represents the gold standard in disc surgery on the lumbar spine. The remaining defect in the intervertebral disc space can be filled with a newly developed nucleus prosthesis presented in this paper. This prosthesis consists of polycarbonate urethane (Sulene PCU), and takes the form of a memory coiling spiral. It can be easily implanted using the standard microdiscectomy approach with no further tissue damage. Biomechanical tests have shown that anatomical distances can be restored by the spiral for both the facet joints and the endplates. Endplate deformations are not statistically different when compared to intact conditions. Inclusion and exclusion criteria of an in vivo pilot study are presented. The paper describes the insertion setup for the spiral and the technique of implantation. Five patients have been supplied with the implant to date. The first results on postoperative magnetic resonance images are presented.

Hypercapnia during transperitoneal and retroperitoneal endoscopic spinal surgery: a prospective study.

STUDY OBJECTIVE: To evaluate the effect of carbon dioxide (CO(2)) pneumoperitoneum and retropneumoperitoneum insufflation on CO(2) excretion. DESIGN: Prospective study. SETTING: Operating room and recovery room in a teaching hospital. PATIENTS: 29 patients scheduled for orthopedic spine fusion surgery. INTERVENTIONS: Patients received either transperitoneal insufflation (n = 12) or retroperitoneal insufflation (n = 17). MEASUREMENTS AND MAIN RESULTS: Increases in the partial pressure of end-tidal CO(2) (PetCO(2)) and arterial CO(2) tension (PaCO(2)) during retropneumoperitoneum exceeded those obtained during pneumoperitoneum. Furthermore, PetCO(2) increased faster during retroperitoneum and did not reach a plateau. Finally, 76% of the patients in this group required ventilatory adjustment due to high PetCO(2) levels. CONCLUSIONS: This study may focus attention on the need for continuous ventilatory adjustments during transperitoneal endoscopic surgery.

Use of tissue expansion in revision of unhealed below-knee amputation stumps.

When local tissue is insufficient for the revision of unhealed below-knee stumps tissue expansion offers an interesting alternative for local coverage. We used this method in seven patients (five men, two women; mean age 30 years) who had had below-knee amputations, six of them after injury to a healthy limb and one for purpura fulminans. Ten tissue expanders were inflated slowly and intermittently either weekly or twice weekly depending on the patients. The mean expansion period was 92 days. Mean hospital stay for the two operations was 5.8 (range 4-9) and 7.6 (range 6-10) days, respectively. Using subjective and objective criteria, functional outcome was excellent in five patients and good in one. Expansion failed in one because of infection. Expanded skin flaps allow good cover with a minimal scar area in appropriate cases, while preserving the skin sensitivity and length of the tibial shaft.

[Treatment results of fractures of the patella using pre-patellar tension wiring. Analysis of a series of 203 cases]. / Résultats du traitement des fractures de la rotule par haubanage pré-rotulien. Analyse d'une série de 203 cas.

Two hundred three fractures of the patella in 200 patients were treated by tension band wire fixation using one or several wire loops and 2 longitudinally directed Kirschner wires. They were reviewed with a mean follow-up of six years (range 1 to 10 years). There were 143 men and 57 women. Age at operation averaged 36 years (range 18 to 83 years). The most frequent etiology was a road traffic accident. The fractures were simple in 35.5%, slightly comminuted in 37%, and very comminuted in 27.5% of cases. Thirty-four fractures were open, and there were other associated fractures in 35 cases (17%); 12 fractures (6%) were seen in polytrauma patients. The operation was performed on the first day in 63 cases (31.5%), between 2 and 8 days following trauma in 112 cases (56%), and after the 8th day in 25 cases (12.5%). The authors used 2 Kirschner wires in 81 cases (40%), 3 in 73 cases (36%), and more than 3 in 49 cases (24%). A single wire loop was used in 99 cases and a modified tension band wiring in 104 cases; passive mobilisation of the knee was started on the second day after operation, and weight bearing was allowed after five days, except when there were associated lesions. The complications were sepsis in 11 cases (5%), loosening of material in 20 cases (10%), malunion in 9 cases (4.5%), nonunion in 8 cases (4%), femoropatellar osteoarthritis in 17 cases (8.5%). The results were excellent or good in 169 cases (83%), and fair or poor in 34 cases (17%). The authors recommend this operative technique which allows good anatomic reconstruction of the patella, early mobilisation of the knee and early weight-bearing with a high rate of consolidation.

[Interbody arthrodesis of the lumbar vertebrae using retroperitoneal videoendoscopy. A preliminary study of 38 cases]. / Arthrodèse intersomatique du rachis lombaire par vidéoendoscopie rétropéritonéale. Etude préliminaire de 38 cas.

AIM OF THE STUDY: To report a series of 38 patients presenting retroperitoneoscopic inter-body fusion of the lumbar spine from L2 to L5, performed between 1995 and 1998. PATIENTS AND METHODS: This series included 25 women and 13 men aged from 16 to 74 years (mean age: 48.5 years). Surgery was performed in 32 patients for primary degenerative or post-operative instability of the lumbar spine, in five patients for painful sequels of burst fracture, and in one patient for sequels of disc infection. The main complaint was lumbar pain but a real sciatic pain was present in nine patients and was not a contraindication for this surgery. Standard X-rays were performed for each patient, and MRI performed in 30 patients confirmed the diagnosis and was also useful in determining vascular abnormalities. A cast immobilisation of the lumbar spine was done as a preoperative test in every patient. RESULTS: Forty-two levels were fused: 31 with a cage filled with cancellus bone and screwed between the end plates, and 11 with cancellus bone alone or in association with bone substitute, such as beta TCP. Post-operative complications included only a transient paresthesia of the thigh in two cases and a chyloretroperitoneum spontaneously resolutive. After 2.3 months of plaster immobilisation with a follow-up of 11.4 months, patient satisfaction rate was 84.5%, with 68.5% reporting no further back pain. The improvement was estimated by Prolo score. Fusion was considered effective by X-ray examination in all patients with an increase in the intervertebral space of 35% and a recovery of the local lordosis of 15%. CONCLUSION: Retroperitoneoscopic surgery is an elegant and secure method for lumbar interbody fusion of L2 to L5 with very few postoperative complications.

[Extensive pseudotumoral lumbar spine lesions of vascular origin]. / Lésions extensives rachidiennes lombaires pseudo-tumorales d'origine vasculaire.

Extensive remodeling of the anterior aspect of the lumbar spine was observed in two patients with a ruptured aneurysm of the abdominal aorta. Both patients survived as the rupture was contained in the first case and involved a false anastomotic aneurysm in the second. The patients presented with a clinical picture compatible with advanced stage cancer and a radiologic aspect showing anterior erosion of the vertebral bodies, suggestive of very advanced spondylodiscitis. The diagnosis was made on the basis of ultrasound and CT-scan evidence. There was no parallel relationship between the size of the ectasia and the spinal remodelling. A hypothetical pathogenic mechanism involving the intermittent pulsation of the aneurysm and ischaemia of the vertebral bone is proposed.

[Study of the correlation between magnetic resonance imaging and surgery in the diagnosis of chronic Achilles tendinopathies]. / Etude de la corrélation entre l'examen par résonance magnétique et la chirurgie dans le diagnostic des tendinopathies chroniques d'Achille.

Eighteen cases of chronic lesions of the heel cord were evaluated by MRI and operated. The sensitivity of MRI is high in detecting intratendinous lesions (positive predictive value of 0.94); this sensitivity is linked with an unsurpassed anatomical precision. The specificity in the diagnosis of intratendinous lesions is limited as regards partial rupture versus chronic inflammation. This technique can be improved by systematically making fine cuts in the transverse plane, absolutely perpendicular to the heel cord.

[Iliac eventration after posterior iliac bone removal. An original technique of reconstruction]. / Eventration iliaque après prélèvement osseux iliaque postériur. Une technique originale de reconstruction.

A tricortical bone graft removal from the iliac crest causes a parietal defect that may be complicated by iliac or iliolumbar eventration, according to the extent of the bone loss. On the basis of their experience with a particularly characteristic clinical case, the authors describe an original reconstruction technique. The surgical techniques aimed at parietal restoration described in the literature include either the use of foreign materials or of those provided by the patient (skin, fascia lata, etc.), or the use of the surrounding anatomical elements to reconstruct a solid wall. Most of these procedures may be difficult to implement if the loss of substance is extensive, or in a posterior site. Thus, in order to prevent possible recurrence in case of major bone defects, we propose to combine the cure of the eventration with a restoration of bone continuity with a cold-conserved allograft and the reconstruction of the musculoaponeurotic curtain by the translation of the lumbosacral fascia. This procedure allowed obtaining a very satisfactory result, which was stable after 18 months both as regards parietal reconstruction and as regards pain, owing to the restoration of balance in the paraspinal muscular support.