Biomedical subjects

J Y Lazennec

Publications and source records attributed to J Y Lazennec.

At least 19 recordsLinked to original sources

PubMed2006

Parkinson's disease with camptocormia.

BACKGROUND: Camptocormia is defined as an abnormal flexion of the trunk that appears when standing or walking and disappears in the supine position. The origin of the disorder is unknown, but it is usually attributed either to a primary or a secondary paravertebral muscle myopathy or a motor neurone disorder. Camptocormia is also observed in a minority of patients with parkinsonism. OBJECTIVE: To characterise the clinical and electrophysiological features of camptocormia and parkinsonian symptoms in patients with Parkinson's disease and camptocormia compared with patients with Parkinson's disease without camptocormia. METHODS: Patients with parkinsonism and camptocormia (excluding patients with multiple system atrophy) prospectively underwent a multidisciplinary clinical (neurological, neuropsychological, psychological, rheumatological) and neurophysiological (electromyogram, ocular movement recording) examination and were compared with age-matched patients with Parkinson's disease without camptocormia. RESULTS: The camptocormia developed after 8.5 (SD 5.3) years of parkinsonism, responded poorly to levodopa treatment (20%) and displayed features consistent with axial dystonia. Patients with camptocormia were characterised by prominent levodopa-unresponsive axial symptoms (ie, axial rigidity, gait disorder and postural instability), along with a tendency for greater error in the antisaccade paradigm. CONCLUSION: We suggest that (1) the salient features of parkinsonism observed in patients with camptocormia are likely to represent a specific form of Parkinson's disease and camptocormia is an axial dystonia and (2) both camptocormia and parkinsonism in these patients might result from additional, non-dopaminergic neuronal dysfunction in the basal ganglia.

Aged↗

PubMed2005

The mini-invasive anterior extra peritoneal approach to the pelvis.

Retroperitoneal pelvic tumours are rare and their surgical approach is challenging. Various surgical approaches have been proposed. We present here an original mini-invasive anterior retroperitoneal approach the pelvic retroperitoneum, which was successful in a 26-year-old woman who had a benign schwannoma of the left sacral plexus. This technique presents advantages over other techniques that were considered in this case, as the least invasive and safest procedure.

Abdominal Muscles↗

PubMed2004

Variations of caudal, central, and cranial acetabular anteversion according to the tilt of the pelvis.

Variations of acetabular anteversion measured at the level of the diameter of the acetabulum according to the tilt of the pelvis are known. But the values of this anteversion at other levels of the acetabulum, near the roof or near the obturator foramen, are unknown. Attracted by the very changeable morphology of the acetabular cover, we studied the caudal, central, and cranial acetabular anteversion of 12 pelvises in four positions of dorsal-ventral inclination. The caudal, central, and cranial acetabular anteversion diminished with the ventral tilt of the pelvis. The anteversions also diminished from the caudal part of the acetabulum to the cranial part, whatever the inclination of the pelvis. These notions represent a reference that, once completed with clinical studies of healthy volunteers and patients presenting an anomaly of the acetabulum cover, will enable researchers to define threshold values of normal and pathological conditions.

Acetabulum↗

PubMed2000

Sagittal alignment in lumbosacral fusion: relations between radiological parameters and pain.

The objective of this study was to conduct a radiological analysis of posture before and after lumbosacral fusion to evaluate the influence of spinal alignment on the occurrence and pattern of post surgical pain. The study included 81 patients, of whom 51 had a history of previous low back surgery. We excluded patients with suspected or confirmed nonunion. In the fusion group, the 27 patients who were pain free after the procedure were compared to the 54 patients with residual pain. Thirty patients had pain only or primarily when they were standing immobile, 18 when they were sitting immobile, and six in both positions. Measurements were done on full-length lateral radiographs of the spine, with the patient standing according to Duval Beaupère criteria. The subgroup with postfusion pain was characterized at baseline by a more vertical sacrum with less sacral tilt (ST) (P < 0.0062) and more pelvic tilt (PT) (P < 0.0160). PT at last follow-up (PT fu) correlated with the presence of postfusion pain (NP: P = 0.0003). In the patients with postfusion pain, PT was almost twice the normal value. ST at last follow-up (ST fu) in the standing position was also correlated with the presence of postfusion pain (P < 0.0001) indicating that the sacrum remained abnormally vertical in the subjects with postfusion pain. Using logistic regression, the only prognostic factor for residual pain at last follow-up was ST fu. Both at pre-operative evaluation and at last follow-up, patients with pain in the standing position or in both the standing and sitting positions were characterized at pre-operative status by a more vertical sacrum with less sacral tilt. The results of this study indicate that, achieving a strong fusion should not be the only goal. Appropriate position of the fused vertebrae is also of paramount importance to minimize muscle work during posture maintenance. The main risk is failing to correct or to causing excessive pelvic retroversion with a vertical sacrum leading to a sagittal alignment that replicates the sitting position. This situation is often accompanied by loss of lumbar lordosis and adversely affects stiff or degenerative hips.

Adult↗

PubMed2000

Hangman's fracture: the relationship between asymmetry and instability.

There is ambiguity concerning the nomenclature and classification of fractures of the ring of the second cervical vertebra (C2). Disruption of the pars interarticularis which defines true traumatic spondylolisthesis of C2, is often wrongly called a pedicle fracture. Our aim in this study was to assess the influence of asymmetry on the anatomical and functional outcome and to evaluate the criteria of instability established by Roy-Camille et al. We studied the plain radiographs and CT scans of 24 patients: 13 were judged to be asymmetrical, ten were considered unstable and 14 stable. Treatment was with a Minerva jacket in 15 fractures and by operation in nine. Surgery was undertaken in patients with severe C2 to C3 sprains. One patient with an unstable lesion refused operation and was treated conservatively with a poor radiological result. Our study showed that asymmetry of the fracture did not affect the outcomes of treatment and should not therefore influence decisions in treatment. The criteria of Roy-Camille seem to be reliable and useful. We prefer the posterior approach to the cervical spine, which allows both stabilisation of the fracture and correction of a local kyphosis.

Adolescent↗

PubMed1999

Anatomic basis of minimal anterior extraperitoneal approach to the lumbar spine.

Anterior lumbar spine approaches may be indicated for fusion in degenerative lumbar spine disorders or to fill discal and bone gaps after fracture reduction. We present an anterior extraperitoneal approach applicable to any discal and vertebral levels from T12 to S1. The anatomic study, based on 25 cadavers, highlights retroperitoneal dissection principles for easy kidney and duodenopancreatic mobilisation and direct left anterior access to the entire lumbar spine. We established a precise description of the lumbar veins and the anastomoses between the left renal vein and hemiazygos system, in order to define different topographic and anatomic factors related to safe and easily reproducible approaches for cage or graft implementation. Independent of the level and previous intraperitoneal surgery, lumbar spine access with this approach safeguards the kidney, ureter, spleen, hypogastric plexus and duodenopancreatic system. Regarding operating time, blood-loss and possibilities for freshening and grafting, this technique seems an effective counterbalance to the difficulties and complex technology of endoscopic approaches. The clinical study includes our first 42 cases in traumatic and degenerative lesions. Avoiding the neurologic or hemorrhagic risk inherent in classical posterior lumbar interbody fusion (PLIF) techniques, it can be considered as a reasonable and valid alternative. This technique could be used in the near future for mini invasive discal prosthesis insertion.

Cadaver↗

PubMed1999

Vertical atlantoaxial dislocation.

An unusual case of vertical atlantoaxial dislocation without medulla oblongata or spinal cord injury is reported. The pathogenic process suggested occipito-axial dislocation. The case was treated surgically with excellent results on mobility and pain.

Arthrodesis↗

PubMed1999

Acute spinal cord compression due to intraspinal bleeding from a vertebral hemangioma: two case-reports.

Vertebral hemangiomas can cause acute spinal cord compression either after a minor trauma or during the last 3 months of pregnancy. Failure to recognize the lesion can lead to potentially serious treatment delays. An emergency MRI scan usually establishes the diagnosis of vertebral hemangioma responsible for spinal cord compression requiring laminectomy. We report two cases showing that posterior fixation should be considered: in our experience it prevents vertebral collapse during the interval preceding secondary vertebroplasty, which, if performed, provides highly significant pain relief.

Acute Disease↗

PubMed1999

Intraoperative ultrasonography evaluation of posterior vertebral wall displacement in thoracolumbar fractures.

Intraoperative ultrasonography (IOUS) was used to evaluate the location and compressive effects of intraspinal fragments in thoracolumbar fractures and the efficacy of reduction maneuvers in patients operated on for isolated or attached intraspinal fragments or for global posterior wall disruption. Dynamic IOUS was used to evaluate the effects of traction and lordosis. Fifty-eight patients were evaluated using a 7.5 MHz ultrasound probe, including 27 treated by impaction, 19 by removal of apparently isolated fragments, and 12 by traction followed by lordosis for global posterior wall disruption. IOUS had limitations and problems caused by split fragments and residual pedicular attachments that can compromise intraoperative maneuvers. The risk of secondary displacement of isolated fragments treated by impaction was very high. In particular, the pinching effect produced by T-shaped fractures was commonly responsible for secondary displacement. IOUS evaluation of canal clearance after fragment removal was satisfactory, but did not provide quantitative data. IOUS was easier to perform and apparently more reliable than intraoperative myelography. The dynamic IOUS data suggest that, except for severely tilted fragments that are completely free or remain attached to a pedicle, residual discal attachments significantly influence the likelihood of successful reduction.

Adult↗

PubMed1999

Severe hyperflexion sprains of the lower cervical spine in adults.

Severe sprains of the cervical spine result from a traumatic rupture of the intervertebral disc and ligaments. Although rare, these lesions may lead to a significant kyphotic deformity if they are not surgically treated. The treatment of such a kyphotic deformity may consist of surgical fixation of the lesion through either an anterior or posterior approach. A retrospective study has been done examining 44 severe cervical sprains in 41 patients surgically treated through a posterior approach, using Roy-Camille plates. With an average followup of 29 months (range, 6-60 months), 73% of the patients recovered a normal range of spinal motion, with either moderate or no pain. No neurologic or vascular complications directly attributable to posterior plating and no secondary kyphosis were observed. A moderate sagittal displacement with kyphotic angulation occurred above the fusion in five patients. Posterior screw plate fixation appears to be a safe and effective treatment for severe hyperflexion sprain of the lower cervical spine in the adult.

Adolescent↗

PubMed1999

[Value and limits of determining serum cobalt levels in patients with metal on metal articulating prostheses].

PURPOSE OF THE STUDY: The purpose of this study was to measure the serum cobalt levels and their correlation with clinical and radiological findings in patients with metal on metal hip articulating surfaces. METHOD: Forty-one patients with metal on metal hip arthroplasty were reviewed retrospectively at mean follow-up of 12.9 months. Serum cobalt levels were determined for each patient by atomic absorption spectrometry at the maximal follow-up and were compared to a control group (19 patients). Two patients and one control subjects also performed exercise on a treadmill in order to appreciate the influence of physical activity on serum cobalt levels. RESULTS: The metal on metal group presented higher serum cobalt levels than those of the control group (p < 0.0001). There was no correlation between serum cobalt and clinical and radiological findings at the exception of patient age (n = 40, r = 0.37). However, when the follow-up was greater than 18 months, mean serum cobalt was significantly higher compared to a follow-up less than 18 months. The physical exercise test led to a moderate elevation (around 10 p. 100) of cobalt in the two patients but not in the control subject. DISCUSSION AND CONCLUSION: The interpretation of an elevated cobalt serum level is difficult. Cobalt-containing drugs, other implants, excess of activity and diseases (renal failure) may influence serum cobalt level. In this study, the high serum cobalt levels seem not linked to a failure of the implant, mainly because of the short follow-up. They could rather be attributed to an increase of the patient activity beginning 18 months after the surgery. Because potential long-term cobalt toxicity and carcinogenicity is not well known, careful medical follow-up should be emphasized specially in young patients.

Adult↗

PubMed1998

[Practical aspects of knee anatomy].

The anatomy of the knee provides a standardised description of articular surfaces, ligament and tendinous insertions in order to understand the combined action of the femoro-tibial and femoro-patellar compartments, as well as their stabilisation mechanisms. Nevertheless, the isolated vision of the articulation is insufficient; one also needs to study the global action of the limb by integrating the rotation of the whole skeletal body and its positions in the sagittal and frontal plans.

Biomechanical Phenomena↗

PubMed1998

[Intraoperative ultrasound study of thoracolumbar spinal fractures with spinal canal fragments. Determining canal width and anatomic control of decompression: comparative analysis with CT].

Intraoperative ultrasonography is recommended for operations on the thoracolumbar spine to complement the information provided by standard X-ray, intensifier screen or myelography. There are no unanimates opinions concerning the impaction or exeresis of these fragments. The aim of this study was to show the advantages of intraoperative ultrasonography for anatomic determination and control of the maneuvers used. This study included 46 cases with fractures from T11 to L2. Ultrasonography was performed during the intraoperative reduction provided by the installation and the pedicular instruments. The authors stress the limits of the anatomic and geographic determination, as well as tilting of the fragments because of the size of the ultrasonographic head. The quality of the exeresis may be falsely interpreted in the presence of fragments with a section of less than 4 mm, lateralized, double fragments or in the presence of massive intraoperative haemorrhage. Analysis of the impaction results is more complicated because all of these fragments displaced themselves secondarily. The ligamentum communis vertebralis posterior has no anatomical containing role. The tilting before the impaction and the state of the overlying intervertebral disk represent essential factors for failures. Ultrasonography is better than intraoperative myelography. Nevertheless, it still needs to be complemented by intraoperative profile X-rays and a very precise preoperative CT scan of the intervertebral disk lesions analysis of complicated cases (fragments with residual pedicular attachments--type A 3.1.2.; T-like fractures--type A 3.2.1.).

Adult↗

PubMed1998

Anatomic bases of a new technique of juxta-acetabular osteotomy. Technical principles and performance.

Pelvic osteotomies were developed to increase or restructure the acetabular surface. Periacetabular osteotomies are considered the most difficult from the technical point of view and necessitate sufficient residual cartilaginous surface. Juxta-acetabular osteotomies avoid major disorganization of the pelvic framework and allow easier reorientation of the acetabulum. The authors present a technical variant that preserves the entire posterior column, as in the Ganz osteotomy. The effects on the vascularisation of the periacetabular region are strictly the same and there is no necrosis of the subchondral bone. This osteotomy is easier to perform, because of a single positioning associating two simultaneous approaches. The osteotomies are rectilinear and easy to check peroperatively by fluoroscopy thanks to this positioning. Another valuable aspect of this double approach consists of very easy correction of "automatic" unwanted retroversion due to the lowering of the acetabular roof. This unintended displacement is rarely reported in the literature, despite its anatomic evidence in 3-dimensional CT-scan reconstructions for pre- and peroperative evaluation.

Acetabulum↗

PubMed1997

Surgery of the deformities in ankylosing spondylitis: our experience of lumbar osteotomies in 31 patients.

Corrective surgery for kyphotic deformities of the spine in ankylosing spondylitis is a major surgery for rare indications. The authors report 31 lumbar osteotomies. The goal is to correct the deformity through a posterior limited approach and to minimise the neurological risks. The modifications developed by the authors for monosegmental closing wedge osteotomies are explained. The posterior resection is rhomboid shaped with a bilateral lamina removal. An osteotomy is performed in a forwards direction on the lateral aspects of the vertebral body without bone resection. This osteoclasty allows progressive vertebral body compression. Pediclectomy is associated if the corresponding foramen at the osteotomy level becomes too narrow in the process of redressing the spine. The resection level is adjusted so that superior and inferior posterior arches come into contact with a good compression. The authors point out the risk of lateral translation. Before the osteotomy, the two adjacent vertebrae are implanted with 5-mm cylindrical pedicular screws, so that posterior fixation can be carried out at any time. Posterior monobloc fixation allows for very great compression of the osteoclasty. The authors compare the results of their experiences in opening and closing osteotomy. They progressively changed their technique for closing osteotomies, because of published vascular complications and mechanical risks (instability and pseudarthrosis in opening osteotomies). Closing osteotomy also minimises the risk of stenosis with radicular compression or traction if an important correction is performed. The level of the osteotomy varied in this series, which had a correction rate of up to 75 degrees. The choice of level depends on secondary effects on pelvic position and projection of the centre of gravity. The preferred procedure remains a monosegmental correction because it is faster and easier, with minimum bleeding. Short monobloc posterior fixation is sufficient to maintain reduction and to obtain stability from posterior compression.

Adult↗

PubMed1997

Dynamic anatomy of the acetabulum: an experimental approach and surgical implications.

The deformations and stresses acting on the acetabular rim have not been very precisely documented. The authors present a study based on an experimental simulation of hip loading with anatomic correlations. 122 dissections were performed in order to define the anatomic aspect of the roof (and especially of Byers's "area 17") and the intermediate area between the anterior and posterior acetabular cornua. Ten fresh cadavers were tested on the lines of previous studies on monopodal or bipodal loading. An extensometric study was performed with special attention to the transverse acetabular ligament, supra-acetabular area and obturator foramen. The area 17 of Byers is a transitional zone and the mobility of the posterior cornu is 3 times that of the anterior cornu. Resection of the acetabular ligament modifies the displacement of the posterior cornu under loading but has no influence on deformation of the oburator foramen. The biomechanical behavior of the acetabular roof in the standing position is influenced by the conditions of monopodal or bipodal loading and by femoral rotation, but a tendency to extrusion was constantly noted.

Acetabulum↗

PubMed1997

[Possibilities of anterior approach to the lumbar spine by minimal retroperitoneal access. Anatomical bases. Technical principles and initial results].

Anterolateral approach to the lumbar spine using a retroperitoneal approach is a common technique. But conventional approaches are performed laterally, resulting in parietal muscular damage, which may alter functional results. The authors present their experience about a minimized pararectal retroperitoneal approach from T12 to S1. Some anatomical aspects are important for a safe and reproductive procedure. The authors used mainly this technique in association with posterior correction and fixation in traumatic and degenerative pathologies. They point out the simplicity of this technique which is performed without special equipment. It seems a real alternative to laparoscopic techniques and micro-surgical antero-lateral interbody fusion, especially because of minimal potential complications and low post operative morbidity.

Humans↗

PubMed1996

[Surgical treatment of deformities of the thoracic and lumbar spine by posterior spinal osteotomy].

From 1987 to 1993, we performed spinal osteotomy with posterior closing-wedge using a single-operation technique in 20 patients with kyphosis. Spinal deformity resulted from mal union after spinal injury in 13 patients and from ankylosing spondylarthritis in 7. Mean duration of the procedure was 4 h 15 min (range 2 h 30 min to 7 h) for mal union and 3 hours (2 h 30 to 4 h) for ankylosing spondylarthritis. Intraoperative blood loss was estimated at 1.8 liters (0.5-4) and 1 liter (0.5-1.5) respectively. Osteotomy was performed at L3 in all cases of spondylarthritis with a mean 30 degrees correction (24-37 degrees) which was maintained after 5 to 18 months follow-up (mean 10 months). For mal union, the mean angular correction was better and more stable after 3 to 84 months (mean 23 months) for the thoracic or thoraco-lumbar segments than for the lumbar spine. Functional results were excellent or good for 11 patients, acceptable for 1 and poor for 1. Three patients with recurrent radiculalgia with mal union were cured after the operation while the neurological status of the paraplegic patients remained unchanged. There were no fatal complications nor neurological or vascular complications among the 20 patients. There were 4 complications in patients with an abnormal callus including 3 mechanical complications and one deep infection. For spondylarthritis, there were no complications at maximum follow-up.

Adult↗