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Biomedical subjects

G Saillant

Publications and source records attributed to G Saillant.

At least 19 recordsLinked to original sources
PubMed2006

Finite element model of the human neck during omni-directional impacts. Part II: relation between cervical curvature and risk of injury.

A detailed 3D FE model of the human neck was used to assess a possible relationship between risk of injury and cervical spine curvature for various impacts. A FE model was previously developed, representing the head and neck of a 50th percentile human with a normal lordotic curvature. The model behaviour was omni-directionally validated for various impacts using published results. For the present study, the model was deformed in order to obtain a straight and a kyphotic curvature, and for each geometry, rear-end, frontal, lateral and oblique impact were simulated. Although results showed similar kinematic patterns, significant differences were found in the distribution and peak values of ligament elongations, forces and moments along the cervical spine for the three configurations. It was concluded that the variability observed on the curvature of the human cervical spine may have a significant influence both on the behaviour and on the risk of injury of the neck during impact.

Cervical Vertebrae↗
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↗
PubMed2005

[Sequelae of intra-articular calcaneal fractures: patterns and management].

PURPOSE OF THE STUDY: We reviewed retrospectively 24 feet with sequelae of transtalar process fractures of the calcaneum in order to identify the lesion pattern and determine optimal management options, both for acute and sequelar lesions. MATERIAL AND METHODS: There were fourteen men and nine women, mean age 42 years (19-73). Twenty-three had subtalar osteoarthritis, eight had calcaneocuboid osteoarthritis, and fifteen had lateral submalleolar conflicts. There were twelve fibular tendon dislocations or fissurations, three tarsal tunnel syndromes, and two plantar splinters. Prior to treatment, all patients complained of pain. Preoperatively, walking distance was less than 500 m for thirteen patients, 2000-3000 m for four, and greater than 3000 m for five. Mean subtalar joint motion was 30% (0-100%) compared with the healthy side and mean frontal misalignment of the rear foot was 6 degrees valgus. Physical examination, podoscopy and x-rays were obtained in all patients. The Kitaoka score was noted. RESULT: Mean follow-up was 36 months (24-72). Sequelae were treated with a single procedure or with combinations: subtalar arthrodesis (n = 23) including one in association with calcaneocuboid arthrodesis, tension on fibular tendons (n = 7), neurolysis of the posterior tibial nerve (n = 3), resection of plantar splinters (n = 2), resection of the lateral shell (n = 14), and osteotomy (n = 2) to lower the greater tubercle of the calcaneum because of pain when wearing shoes. The mean Kitaoka function score was 31.7/100 (14-79) preoperatively. After treatment, the mean score was 81.7/100 (31-94), giving a 73.2% gain. The outcome was considered good in sixteen feet, fair in six, and poor in two. Mean walking distance was greater than 3000 m for 18 patients. Mean frontal misalignment of the rear foot under loading was 4.5 degrees valgus and the podoscopy demonstrated flat foot in thirteen patients. Three subtalar arthrodesis required revision for nonhealing. DISCUSSION: Initial treatment of a fracture, particularly an articular fracture, of the calcaneum must avoid disabling postoperative pain and shoe wearing problems. These sequelae basically concern: subtalar and calcaneocuboid arthritis, lateral submalleolar conflict, fibular tendon injury, plantar splinters, tarsal tunnel syndrome, loss of height, and misalignment of the rear foot. At the sequelar stage, the physical examination is primordial to confirm the lesion and search for any complication which could develop later postoperatively when walking distance becomes longer. For nine patients with residual pain, four resulted from lesions which were missed at the preoperative physical examination. Arthrodesis of the subtalar joint should be preferred over realignment of the rear foot and can be associated with the treatment of conflicts. This management scheme allows treating during a single operative time all sequelae, thus limiting recovery time. A scan of the ankle and foot with or without opacification of the fibular tendons is needed to confirm the physical examination which, for us, remains the key to successful surgery.

Adult↗
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↗
PubMed2003

Hip-spine relationship: a radio-anatomical study for optimization in acetabular cup positioning.

The criteria for acetabular cup positioning during total hip replacement are a matter of considerable discussion, particularly with regards to the optimal degree of anteversion. "Anatomical anteversion" is defined in the transverse plane, and "surgical anteversion" in the sagittal plane. Computed tomography measurements of anteversion are characteristic of a given transverse section plane and fail to take into account the position of the pelvis. We suggest a simple method for evaluating acetabular cup position in both the transverse and sagittal planes during standing and sitting. By shedding new light on the relationships between the pelvis and the spine, this method may help to understand some cases of impingement, instability or abnormal wear.

Acetabulum↗
PubMed2003

Ipsilateral fibular transposition in tibial nonunion using Huntington procedure: a 12-year follow-up study.

Eleven patients (10 men and 1 woman) with a mean age of 32 years (range: 16-61 years) and a mean follow-up of 12 years (range: 2-21 years) were studied retrospectively after ipsilateral fibular transposition. The cause of tibial nonunion was a motor vehicle collision (MVC) in eight patients, a fall from a window in one, an adamantinoma in one, and osteomyelitis in one. There was one type I and eight type IIIb open fractures according to the Gustilo classification, and the nonunion was infected in seven patients. Healing of the tibial defect was obtained in eight patients, after a mean interval of 10.5 months. In the patient with the adamantinoma, resection of the tumour left a 22 cm defect in the tibia. Two patients required amputation for acute local infection. Seven of the eight patients in whom tibial union was achieved were able to walk with no aids. The authors conclude that transposition of the ipsilateral fibula is a valuable component of the therapeutic armamentarium and a salvage procedure for patients with multi-operated, infected or uninfected, tibial nonunion.

Adolescent↗
PubMed2003

Scapulothoracic arthrodesis in facioscapulohumeral muscular dystrophy.

Forty-nine scapulothoracic arthrodeses were done in 33 patients with facioscapulohumeral muscular dystrophy to improve upper limb performance during activities of daily living. Mean followup was 102 months (range, 12-257 months). An initial average increase in shoulder abduction of 25 degrees and forward elevation of 29 degrees was seen. Complications included pleural effusion in four patients, atelectasis in one patient, stress fractures in both scapulas in one patient, asymptomatic fractures of the two lower wired ribs in one patient, and spontaneously reversible neurologic complications in two patients. No effect on respiratory function was seen.

Activities of Daily Living↗
PubMed2003

Chronic compartment syndrome of the forearm in competitive motor cyclists: a report of two cases.

Exertional compartment syndrome of the forearm is rare. However, it should be considered in cases of a painful forearm during motorcycle racing. Pressure measurements of all compartments during exercises that simulate the actions of racing confirm the diagnosis. An exertional electromyography may be useful to reveal a nerve compression associated with the compartment syndrome. Fasciotomy of the affected compartments allows relief of symptoms and return to previous activities in all cases.

Adult↗
PubMed2002

Unusual origin of the artery of Adamkiewicz from the fourth lumbar artery.

The main arterial supply of the dorso-lumbar spinal cord is usually derived from a single anterior radiculo-medullary artery called the artery of Adamkiewicz and referred to as having a middle or low location. In some cases, the artery origin is higher, and a vessel which arises in the lower part of the region supplements the supply of the anterior spinal artery. In the literature, those arteries have been described as arising from L3 upwards, and have never been previously described angiographically, to our knowledge, below this level, although Suh and Alexander and Gililan have mentioned this eventuality. Of the 4,000 spinal cord angiographies performed in our institution, we report three cases in which the fourth lumbar artery flows into the anterior spinal artery of the conus medullaris. This anatomical variant may explain the sometimes devastating post-operative neurological complications from a spinal cord infarction on surgery of the lumbar spine or the abdominal aorta below L3.

Adult↗
PubMed2002

[Medial approaches to the distal humerus for fracture fixation].

PURPOSE OF THE STUDY: We report our experience with the medial and medioposterior approaches to the humeral diaphysis for plate fixation of the proximal humerus. MATERIAL AND METHODS: Fifteen patients were treated for shaft fracture (n=13) or nonunion (n=2) of the distal third of the humerus without radial nerve involvement. The medial approach was performed in the supine position and the medioposterior approach in the prone position. Bone healing was achieved in all cases. Three patients experienced sensorial irritation in the territory of the median nerve after the medial approach; one case did not regress. There were no complications with the medioposterior approach. DISCUSSION: Dissection of the radial nerve can be avoided with these two approaches which also have a cosmetic advantage. The medioposterior approach appears to be preferable because of the comfortable operative position and the absence of risk for the median nerve. Both approaches are however contraindicated if there is preoperative involvement of the radial nerve.

Adolescent↗
PubMed2002

[Surgical decompression of cervical arthrotic myelopathies: comparison of surgical anterior and posterior approaches].

PURPOSE OF THE STUDY: Operative treatment of cervical myelopathy has focused on decompression of the spinal cord to avoid neurological deterioration. Anterior or posterior operative techniques have been used to decompress the canal with variable success. The purpose of this study was to compare surgical results after subtotal corporectomy or discectomy with an anterior approach and laminectomy or laminoplasty with a posterior approach. MATERIAL AND METHODS: We reviewed 30 patients with cervical spondylolitic myelopathy who had undergone surgery between 1989 and 1998. Mean age was 55.8 years (range 28 to 82). There were 23 men and 7 women. An anterior approach was used for 14 patients to achieve subtotal corporectomy or anterior discectomy with strut grafting. A posterior approach was used in another 14 patients to achieve laminectomy or laminoplasty. Both anterior and posterior approaches were used for two patients. The severity of the pre- and postoperative neurological deficits was assessed with the Nurick scale. RESULTS: Average follow-up was 35.7 months (range 8 to 120). Neurological status improved in 83% of the patients. Improvement was better for those operated with the anterior approach for pain or brachialgia. The duration of the posterior procedures was, however, shorter with less blood loss. There was no statistical difference between the anterior or posterior approaches for motor function, sensory function, gait anomalies, or complications. CONCLUSION: Surgical treatment is effective in cervical spondylolitic myelopathy. The anterior approach is preferred in case of pain or brachialgia; the posterior approach is indicated in case of poor health status or for bedridden patients.

Activities of Daily Living↗
PubMed2001

Delayed closed reduction of rotatory atlantoaxial dislocation in an adult.

We report a case of rotatory atlantoaxial dislocation due to a rugby injury in an adult. The patient presented with torticollis 4 weeks after the injury. The neurological evaluation was normal. Reduction proved difficult to obtain and required 10 days of skull traction followed by gentle manipulation. After reduction, dynamic cervical radiographs showed no instability and magnetic resonance imaging (MRI) confirmed that the transverse ligament was intact. After 6 weeks of immobilization in a Minerva jacket, a dynamic rotatory computed tomography (CT) scan confirmed that the atlantoaxial joint was stable. Such cases of atlantoaxial joint dislocation in adults treated by traction after a considerable delay are rare. In our patient, demonstration by MRI that the transverse ligament was intact led to the decision to use conservative therapy, which proved successful.

Adult↗
PubMed2001

Survival and therapeutic modalities in patients with bone metastases of differentiated thyroid carcinomas.

Data for patients with bone metastases (BMs) of differentiated thyroid carcinoma (DTC) were retrospectively studied to identify factors associated with survival. We especially studied the impact of therapies. Among the 1977 patients followed for DTC in our department from 1958 to 1999, 109 (77 females and 32 males; age range, 20--87 yr) presented BMS: All patients except 1 underwent total thyroidectomy, followed by radioiodine therapy (> or =3.7 gigabecquerels) in 95 cases. Survival rates at 5 and 10 yr were 41% and 15%, respectively. Univariate analyses indicated that a young age at BM discovery (P < 0.005) and the discovery of BM as a revealing symptom of DTC (P < 0.05) were features significantly associated with improved survival as well as radioiodine therapy (P < 10(-4)) and BM complete surgery (P < 0.02). Using multivariate analysis, the detection of BMs as a revealing symptom of thyroid carcinoma (P < 0.0005), the absence of metastasis appearance in other organs than bones during the follow-up (P < 0.03), the cumulative dose of radioiodine therapy (P < 0.0001), and complete BM surgery in young patients (P < 0.04) appeared as independent prognostic features associated with an improved survival.

Adult↗
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

Skeletal muscle regeneration and the mitotic clock.

Regeneration of muscle fibers following damage requires activation of quiescent satellite cells, their proliferation and finally their differentiation and fusion into multinucleated myotubes, which after maturation will replace the damaged fiber. The regenerative potential of human skeletal muscle will be determined, at least partly, by the proliferative capacity of the satellite cells. In this study, we have measured the proliferative life span of human satellite cells until they reach senescence. These analyses were performed on cell populations isolated from old and young donors as well as from one child suffering from Duchenne muscular dystrophy, where extensive regeneration had occurred. In order to see if there are any age-related changes in the myogenic program we have also compared the program of myogenic differentiation expressed by satellite cells from these subjects at different stages of their proliferative lifespan.

Age Factors↗
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↗
PubMed2000

[Comminuted fractures in multiple trauma patients: an analysis of 31 cases].

PURPOSE OF THE STUDY: We analyzed calcaneum burst fractures in multiple trauma patients and propose a management scheme. MATERIAL AND METHODS: In a retrospective study, we isolated 23 patients with 31 calcaneum burst fractures. All were stage V in the Duparc classification. We call them "pied de mine" fractures as they resembled those described in military reports. Half of them (16 cases; 54%) were open fractures. All patients suffered multiple injuries and 12 had a psychiatric history. These fractures were associated with spinal fracture in 17 cases (73%) and half had neurologic deficit, limb fracture in 16 (73%), and pelvic fracture in 12 (52%). The most frequent associated foot injuries were a talus fracture in 9 cases (29%) and Chopart displacement in 10 cases (32%). Clinical evaluation used the Maryland foot score, foot print and radiologic evaluation with lateral retrotibial view. RESULTS: Mean follow-up was 35 months. Mean Maryland foot score was 62.7 and 13 cases were pain free. Pain was due to conflict with the lateral malleolus, bony plantar thorns, medial malleolus and subtalar osteoarthritis. Orthopedic shoes were used 11 times. The other patients used sports shoes. Subtalar mobility was most frequently absent (23/29 cases, 2 amputations). Foot print showed 13/16 flat feet; 6 thorns were indirectly visible. Two patients had retraction toes and were initially treated by external fixation. Radiologic evaluation showed 23/29 complete subtalar arthrodeses, 23/29 migration of the great tuberosity, often(17/23 cases) associated with varus angulation. Eleven patients needed subsequent surgery: 5 for arthrodeses and 6 for resection of bony thorns. Rate of complication was high, especially for open fractures: 2 infections for 15 closed fractures, and 8 infections (50%) for 16 open fractures with 2 cases of chronic osteitis. Secondary amputation was required in 2/31 cases due to sepsis. TREATMENT PROPOSITIONS: For closed calcaneum burst fractures, it is better to wait one week before osteosynthesis. This delay is used to decrease edema with limb elevation and compressive bandaging. Skin tension due to trauma is increased by edema and osteosynthesis gives a high risk of wound disunion. We recommend reduction and Y-plate fixation even for burst fracture. Reduction must lower the tuberosity and correct the varus. After surgery, subtalar spontaneous arthrodesis is usually observed in a good position. Any bony plantar thorn must be resected. For open calcaneum burst fracture, the risk of sepsis is high. First treatment is debridement, stabilization and external fixation with antibiotic therapy. Stabilization should improve vascularization and facilitate internal fixation. The external fixation can be placed on the medial side to free the lateral approach to the calcaneum. Flap repair can be performed after one week when skin tension has subsided and areas of necrosis controlled.

Adult↗