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P Chiron

Publications and source records attributed to P Chiron.

17 recordsLinked to original sources
PubMed2006

Prospective and comparative study of the anterolateral mini-invasive approach versus minimally invasive posterior approach for primary total hip replacement. Early results.

The interest in minimally invasive approaches for total hip replacement (THR) has not waned in any way. We carried out a prospective and comparative study in order to analyse the interest of the anterolateral minimal invasive (ALMI) approach in comparison with a minimally invasive posterior (MIP) approach. A group of 35 primary THRs with a large head using the ALMI approach was compared with a group of 43 THR performed through a MIP approach. The groups were not significantly different with respect to age, sex, bony mass index, ASA score, Charnley class, diagnoses and preoperative Womac index and PMA score. The preoperative Harris Hip Score was significantly lower in the ALMI group. The duration of surgical procedure was longer and the calculated blood loss more substantial in the ALMI group. The perioperative complications were significantly more frequent in this group, with four greater trochanter fractures, three false routes, one calcar fracture, and two metal back bascules versus one femoral fracture in MIP group. Other postoperative data (implant positioning, morphine consumption, length of hospital stay, type of discharge) are comparable, such as the early functional results. No other complication has been noted during the first 6 months. The ALMI approach uses the intermuscular interval between the tensor fascia lata and the gluteus medius. It leaves intact the abductor muscles, the posterior capsule and the short external rotators. The early clinical results are excellent, despite the initial complications related to the initial learning curve for this approach and the use of a large head. The stability and the absence of muscular damage should permit acceleration of the postoperative rehabilitation in parallel with less perioperative complications after the initial learning curve.

Adult↗
PubMed2005

[Not Available].

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Journal Article↗
PubMed2004

[Percutaneous fluoroscopic and arthroscopic controlled screw fixation of posterior facet fractures of the calcaneus].

We describe a new technique for reduction and percutaneous osteosynthesis of displaced posterior facet fractures of the calcaneus which appears to overcome the problems encountered with other percutaneous methods described for this type of surgery. The method relies on the use of traction which allows automatic reduction of the greater tubersosity. The patient is installed on an orthopedic traction table. Pin traction provides anatomic reduction of the posterior articular surface and restitution of Böhler's angle under fluoroscopic and arthroscopic control. We used this technique in thirteen patients with fifteen displaced posterior facet fractures of the calcaneum. Mean patient age was 50.4 Years. Mean follow-up was twenty Months. We did not have any cutaneous or infectious complications in this short series. In the majority of the cases, the overall functional and physical results were excellent or good. The mean Böhler's angle was 27 degrees, corresponding to 83% correction compared with the healthy side. These preliminary results are encouraging. We were able to restitute calcaneum anatomy, shorten hospital stay, and avoid all skin complications. Indications for this percutaneous technique could be widened. It is a valid alternative to open treatment of posterior facet fractures of the calcaneum.

Adult↗
PubMed2003

Coracoclavicular joints. Reflections upon incidence, pathophysiology and etiology of the different forms.

Since the first description of the coracoclavicular joint in 1861, many papers have been published reporting its occurrence, anatomical description, and geographical distribution. However, there are as yet no published articles with a convincing explanation for the rather variable forms of this variant. In this study, we investigated the occurrence of the coracoclavicular joint in the current and medieval population of Toulouse city and propose, through biometric measures, an explanation for the different forms of this anatomical variant. A total of 2192 chest X-rays taken for various conditions at a receiving hospital and 392 specimens (784 scapulae and an equal number of clavicles) of the L'Isle-Jourdain Series were examined with this aim. When present in the osteologic collection, the sizes of the articular conoid process as well as the height of the corresponding coracoid and acromial processes were noted. A coracoclavicular joint was noted in 0.82% and in 1.78% of the individuals examined in the radiological and osteologic series, respectively. The conoid process varied in size and correlated with the disposition of each correspondent coracoacromial arch. Osteoarthritis was noted in some of these joints when there was discordance between the conoid process size and the architecture of the correspondent coracoacromial arch, suggesting impingement. Our findings support a genetic origin for this variant, and suggest that its occurrence is also probably influenced by environmental factors. Osteoarthritis of this joint may be responsible for shoulder pain.

Acromioclavicular Joint↗
PubMed2003

[Effect of alendronate on periprosthetic bone loss after cemented primary total hip arthroplasty: a prospective randomized study].

PURPOSE OF THE STUDY: Bone remodeling and osteolysis around total hip prostheses, with its inevitable corollary, prosthesis loosening, remains a difficult problem in orthopedic surgery. Alendronate (bisphosphonate) has proven its efficacy for the treatment of osteoporosis of the lumbar spine and femoral neck. A few in vitro studies have pointed out its inhibiting effect on particle-induced osteolysis. In vivo, one study has demonstrated its usefulness in preventing osteolysis around non-cemented total hip arthroplasties (THA). The purpose of this work was to study the efficacy of this agent for the prevention of changes in peri-prosthetic bone mineral density (BMD) after primary THA. MATERIAL AND METHODS: The study series included 38 patients with degenerative hip disease who underwent THA. The patients were randomized in double-blind fashion to two treatment arms: 10 alendronate and 600 mg calcium per day for 2 years (20 patients) or placebo and 600 mg calcium per day for 2 years (18 patients). Conventional x-rays and x-ray biphotonic absorptiometry (DPX) was performed on day four postop and at 3, 6, 12, and 24 months postop. The periprosthetic zones described by Grüen were used for analysis. RESULTS: DPX demonstrated a significant reduction in BMD in all patients included in the study. The bone loss was the same in both groups during the early postoperative period reaching maximum loss at 3 months. Differences were observed after this time. In the placebo group, bone loss reached a plateau at 6 months then BMD started to increase progressively, reaching 12.7% bone loss at 2 years follow-up (p<0.002). In the alendronate group, there was no plateau, BMD increased continuously starting from three months and reached 6.857% bone loss at 2 years (p<0.003). DISCUSSION: Administration of alendronate led to a significant reduction in peri-prosthetic bone loss at 2 years follow-up. These results are the first to our knowledge demonstrating the beneficial effect in vivo of alendronate on bone behavior around cemented THAs. CONCLUSION: This beneficial effect observed in vivo should be confirmed in further studies including a larger number of patients and longer follow-up. The action of alendronate could facilitate and even retard revision surgery by preserving bone stock.

Alendronate↗
PubMed1998

[3-dimensional imaging of thalamic fractures of the calcaneum. Validation of classifying fractures into 3 forms].

UNLABELLED: Three dimensional CT scans enables to visualize the calcaneum and to follow the fracture pattern without any risk of errors. PURPOSE OF THE STUDY: This technique has been used to validate our previous classification (using three forms: vertical, horizontal, and mixed) which resulted from a two dimensional tomodensitometric study. MATERIAL: The study was based on a series of 74 fractures, all of them studied with 3D CT and 71 of which were operated. METHOD: The previous classification relied on correlation between lateral radiographs and position on coronal CT plane of the Palmer's fracture line. This we called the Fundamental Line (FL); so the vertical form had medial fundamental line, with thalamic verticalization; and so that the horizontal form with thalamic horizontalization had a lateral FL; the mixed form had a medio thalamic FL with double contoured image. RESULTS: In vertical fractures (16 cases, i.e. 20 per cent), the FL was seen denting the thalamus inwards, continuing forward and damaging the forward facet in about two thirds of cases. The thalamic fragment tilted on its axes frequently, with a great rotation movement; in about half cases, it extended backwards (propagated variation). This lateral fragment, called "cortico thalamic" (CT) explained the vertical thalamic x-ray image. In the horizontal fractures (15 cases, i.e. 20 per cent), the FL dents the thalamus outwards, the medial fragment, pushed downwards, explaining the horizontal image. In the mixed cases (40 cases i.e. 55 per cent) the FL was medio thalamic; the two fragments, downed medially and tilted laterally, are of equivalent importance, hence the double contoured image. In half cases, an accessory line separates the sustentaculum tali, creating the two lined mixed form (14 cases i.e. 35 per cent of the mixed). In those cases, the medial thalamic fragment is unsoldered, when in 50 per cent of cases (i.e. 7 out of 14), the pre-thalamic line, following the sinus tarsi, separates it from the forward part and completely isolates it. Therefore, the initial classification in three forms was in fact confirmed. Moreover, the fundamental line appears in all three forms, being the boundary between the lateral thalamic fragment (always tilted) and the medial fragment (always pushed downside). The anterior of cuboidian joint facets are frequently damaged by the forward prolongation of the Fundamental Line according to studied cases. DISCUSSION: This three form classification emphasizes the role of the Fundamental Line, which in effect acts as a boundary between the two typical displacements of this fracture: downward or rotation movement of the thalamic fragments (since it is there that the main displacements occur). A comparison with the Eastwood and Sanders classifications has been carried out. CONCLUSION: This three dimensional CT approach validates, visualizes and completes the three form classification. This will help us to understand fracture displacements in different forms, and therefore, the particular fracture reduction and osteosynthesis best suited for each case.

Calcaneus↗
PubMed1997

Influence of the volume of osteonecrosis on the outcome of core decompression of the femoral head.

OBJECTIVES: To assess the outcome of core decompression in the treatment of osteonecrosis of the femoral head related to the volume of necrotic bone measured according to a previously reported method. METHODS: Twenty hips corresponding to strictly Ficat stage II underwent magnetic resonance imaging and the volume of necrotic bone was expressed as a percentage of the volume of the entire head measured on each slice. All hips underwent core decompression and the outcome was evaluated at 24 months. The primary evaluation criterion was radiological appearance: the outcome was considered as good if the hip remained stage II and poor if the disease progressed. RESULTS: Twenty four months after core decompression, half the cases remained stable and in half the disease had progressed. Outcome seemed to be related to the volume of necrotic bone (average 22% in the good outcome group versus 45% in the poor outcome group (p = 0.0051)) and was independent of risk factors, age, and histological type. CONCLUSIONS: The volume of necrotic bone should be taken into account in the evaluation of any treatment, bearing in mind that in more than one third of cases this volume will probably decrease, especially at the beginning of the disease process.

Adult↗
PubMed1996

[Fibrous dysplasia associated with intramuscular myxoma].

PURPOSE OF THE STUDY: The association of fibrous dysplasia and of soft tissue myxoma is rare. The authors report a new case and discuss the underlying mechanism. CASE REPORT: A 45 years male consulted for a large painful swelling of the right gluteal muscle. The CT scan revealed the soft tissue tumor associated with a bone cyst of the right pelvic bone. The mass was removed at operation and tumoral bone tissue was curetted, there were no evidence of tissue continuity between the two lesions. The histological diagnosis was intra muscular myxoma and fibrous dysplasia. DISCUSSION: Intra muscular myxoma associated to fibrous dysplasia of bone is a rare syndrome described by Mazabraud in 1957. A review of the literature until 1995 reveals that only 17 cases of this syndrome have been reported. Intra muscular myxoma is a rare benign soft tissue tumour arising from fibroblast. Fibrous dysplasia is a hamartomatous bony disorder, which appears in mono or polyostotic forms, with or without extraskeletal manifestation. CONCLUSION: It was not possible to demonstrate a clear correlation between the two lesions. The authors suggest that myxoma result from bone mechanical disorders.

Fibrous Dysplasia of Bone↗
PubMed1995

Study of the intraosseous vessels of the femoral head in patients with fractures of the femoral neck or osteoarthritis of the hip.

Bearing in mind earlier studies which established a link between arteriosclerosis and mineral loss, or fragility of the bones, and also our recent study showing that patients with arterial disorders of the lower limbs also suffered from osteoporosis, we carried out a histological study of the number and appearance of the intraosseous vessels and trabecular bone volume in the femoral heads of patients undergoing surgery for either fracture of the femoral neck or osteoarthritis of the hip. The number of thick-walled vessels, arterioles or arterial capillaries was significantly diminished in the femoral heads of patients with fractures of the femoral neck (p = 0.007). In addition, in the latter patients, arteriosclerotic vascular lesions (rupture of the internal elastic lamina, medial thickening and fibrosis) were more frequent than in patients with osteoarthritis of hip. The possibility that, through chronic ischemia, arteriosclerosis may lead to disturbance of bone remodelling and loss of the mechanical properties of bone has not been contradicted by these findings.

Aged↗
PubMed1993

[Proximal fibulo-tibial dislocation and ischemia associated with a leg fracture. Apropos of 2 cases].

Proximal fibulotibial dislocation may remain escape detection in leg injuries. Posterior dislocations are unusual and are associated with shortening of the limb due to the tibial fracture. Two cases of such dislocation are reported, associated with lower limb ischemia due to an injury of the arterial popliteal trifurcation. An anatomical model indicates the mechanism of this lesion. Such an unusual association has not be found elsewhere in literature.

Adolescent↗
PubMed1993

[Intraarticular fractures of the calcaneus: pathological description. Contribution of x-ray computed tomography].

Computed tomography (CT) is of cardinal importance in the study of displaced intra-articular fractures of the calcaneus, as with this imaging technique the primary fracture line of Palmer can be followed and its various locations visualised. If the three-stage classification system of these fractures as vertical, horizontal or mixed fractures, based on their radiological appearance, is adopted, a correlation can be established between the location of Palmer's line and these three anatomical types. The fundamental fracture line is medial in the vertical types, lateral in the horizontal types and is located in the centre of the posterior facet in the mixed types. It can be seen that the fundamental fracture line separates a laterally detached fragment which is always tilted, giving a vertical slope to the surface of the posterior facet which it supports and thus giving a vertical image. This fragment is itself separated from a medially detached fragment which is tilted horizontally and produces a horizontal image on the lateral view. The CT sections must be examined for the presence of a secondary sagittal line completely isolating the horizontally tilted fragment. The importance of the location of the fundamental fracture line, which is on the borderline between tilting and horizontalisation, suggests that pronation-supination of the foot is a factor in the causal mechanism of these fractures. A clear understanding of the three-dimensional position of the fragments and of their displacement, essentially defined by the location of the fracture line, is a prequisite before attempting surgical reduction of calcaneal fractures.

Calcaneus↗
PubMed1991

[Osteoid osteoma of the trapezoid bone].

The present report describes a case of osteoid osteoma of the trapezoid. It'is an unusual localisation. Synovitis was the first clinical symptom. Tomograms allowed diagnosis and guided the treatment. Radical excision prevented recurrence.

Adult↗
PubMed1990

[A large vascularized allograft of the femoral diaphysis in man].

A fresh vascularised femoral allograft was used to replace a 27 centimetre section of the diaphysis of the femur following a crush injury in a 35 year old man. The technique of operation and details of management are described. After nine months the graft junctions were incorporated, and vascular perfusion was satisfactory.

Adult↗
PubMed1990

[Posterior sternoclavicular luxation. Apropos of 6 cases].

The authors have reviewed six retro-sternal dislocations of the clavicle. The indirect mechanism of this dislocation was in 3 cases, due to sport accidents (rugby). The radiological incidence of Heining allowed the diagnosis and the CT examination carried out the checkup of the associated lesions. The surgical reduction revealed lesions of the meniscus which were found in 3 cases out of 6 and allowed one to realize a plastic operation using the tendon of the subclavian muscle (4 times out of 6) in order to stabilize by sternoclavicular joint, as well in recent injuries as in old ones. The results were satisfactory.

Adolescent↗