Biomedical subjects

J P Carret

Publications and source records attributed to J P Carret.

At least 19 recordsLinked to original sources

PubMed2005

[Desmoplastic fibroma or bone desmoid tumor: two cases].

Desmoplastic fibroma or desmoid bone tumor is a rare tumor described for the first time by Jaffe in 1958. It accounts for 0.1 to 0.3% of all benign bone tumors. To date, about 150 cases involving the locomotor system have been reported. Histology is required for certain diagnosis of desmoplastic fibroma. The tumor is composed of sparse fibroblasts in a rich background of collagen fibers, a histological presentation exactly the same as soft tissue desmoid fibroma. We report two new cases of desmoplastic fibroma of the locomotor system. The observations illustrate the radiological diagnosis. MRI was used to search for local extension in bone or soft tissues. Biopsy is necessary to confirm the diagnosis. The histological presentation may be difficult to recognized and distinguish from low grade fibrosarcoma. After treatment, the rate of local recurrence is high in the event of partial resection. Surgery is the optimal treatment, with tumor resection as wide as possible depending on the localization.

Adult↗

PubMed2001

[Unstable pelvic ring fracture: osteosynthesis of the posterior lesion by percutaneous sacroiliac fixation].

PURPOSE OF THE STUDY: We report our experience with percutaneous sacroiliac screwing for unstable pelvic ring fracture. MATERIAL AND METHODS: Twenty unstable pelvic ring fractures with sacroiliac disjunction (9 cases), trans-sacral fracture (9 cases), or bilateral posterior fractures (5 cases) were managed with percutaneous sacroiliac fixation using 1 or 2 screws. There was also pubic disjunction in 7 cases, managed by osteosynthesis in 5 cases. No fixation of fractures of one or both of the obturator rings, present in 13 cases, was attempted. The posterior screwing was performed under fluoroscopic guidance in 15 cases and computed tomographic guidance in 5. RESULTS: There were no infectious or neurological complications. Radiographically, anatomic reduction of the posterior fracture was achieved in 10 cases. A vertical ascension persisted in 4 patients and a rotation in 6. Radiographic results were correlated with delay to surgery: correction of the vertical displacement was achieved in 80% of the patients operated before five days and in 55% of the others. Two patients experienced a secondary displacement. There was no cases of nonunion of either the anterior or posterior fracture. Follow-up was available for 14 patients (2 patients died and follow-up was too short for 4). The mean Majeed score was 92/100 and none of the patients experienced anterior pain. Three patients had moderate pain in the sacroiliac area. DISCUSSION: The ventral position appears to be best adapted for percutaneous sacroiliac screwing but can be contraindicated by concomitant lesions. We prefer fluoroscopic guidance for these emergency procedures. Two views, ascending and descending, appear sufficient. The better stability provided by two screws can be achieved under computed tomographic guidance without risk of neurovascular damage. CONCLUSION: Percutaneous sacroiliac screwing is a good management strategy for unstable pelvic ring fractures with little risk of morbidity.

Activities of Daily Living↗

PubMed2001

[Surgical treatment of acetabular fractures: outcome in a series of 60 consecutive cases].

PURPOSE OF THE STUDY: The aim of this study was to analyze clinical and radiographic results after surgical treatment of acetabular fractures. MATERIAL AND METHODS: We reviewed 60 consecutive fractures of the acetabulum with loss of joint congruency at mean 5-years follow-up after treatment. There were 49 men and 11 women, mean age 41 years. According to the R.O. grading, the fractures were: 22 class A (33.3%) including 17 type A1, 23 class B (38%) including 10 type B1a2, 14 class C (23.3%) and 1 unclassifiable. Eight of the patients had associated pelvic injury, 40 had hip dislocations and 9 had sciatic nerve injury. Ten femoral head fractures were discovered during the surgical procedure. Three surgical approaches were used: 1) Kocher Langenbeck approach (28 cases), 2) Mears and Rubash triradiate approach (8 cases), 3) extended iliofemoral approach (22 cases), 4) other approaches (2 cases). Anteroposterior and 45 degrees oblique view of the pelvis were obtained for all patients following admission. Computerized tomography scans were performed in all cases. Fracture displacement and congruency of the femoral head with the roof were documented according to the SOFCOT radiographic criteria. The quality of reduction was assessed using the Matta criteria and the Duquennoy and Senegas criteria. Clinical outcome was assessed at follow-up using the Postel-Merle-d'Aubigné score. RESULTS: Anatomic reduction was achieved in 62% of the cases (1 mm or less displacement on all views) and congruency of the femoral head with the roof was excellent in 73% of the cases. Clinical outcome was satisfactory in 80% (excellent or good). Operative complications included significant ectopic bone in 21, and in 2 others sciatic nerve palsy that had resolved at 1 year follow-up. Three patients developed avascular necrosis of the femoral head. DISCUSSION: Clinical outcome depends on the quality of the reduction. Class C and class B fractures with roof injury should thus be treated by large surgical exposure. The triradiate approach increases the incidence of ectopic bone. The higher incidence of ectopic bone in patients treated by osteotomy of the trochanter compared with patients without osteotomy of the trochanter was significant (p<0.05). Avascular necrosis of the femoral head was associated with delayed reduction (66% of the cases). CONCLUSION: Our good clinical results are encouraging; we are pursuing the use of surgical treatment for displaced acetabular fractures. Clinical outcome depends on the use of the appropriate surgical approach.

Acetabulum↗

PubMed2000

Radiologic anatomy of the spinal dorsal horn at the cervical level (anatomic-MRI correlations).

The spinal dorsal horn is known for its important functional role in the field of transmission and modulation of sensory afferents. Because of this, the dorsal horn represents a target for numerous analgesic and antispastic procedures. Thus, it would be interesting to develop imaging dedicated to this spinal structure. The purpose of this study was to investigate the radiologic anatomy of the cervical dorsal horn by magnetic resonance imaging (MRI) (1.5T). The first step consisted in the validation of the anatomic information provided by MRI on 5 human cadavers. A spin-echo sequence (T2, 2000/45) enabled the demonstration of good correlations between histologic sections and axial MRI slices performed at the corresponding cervical levels. The second step was the < > exploration of 20 subjects, aiming at the development of a gradient echo sequence (T2*) with a conventional MRI unit, compatible with a routine clinical examination. The dorsal horn was clearly identified in 77% of the axial slices performed (n = 300). The angle between the dorsal horn axis and the sagittal plane was measured as from 25.5 degrees at C2 to 40 degrees at C8 segments. The results of this anatomico-radiologic study of the cervical dorsal horn suggest that preoperative MRI could be useful to design the surgical approach to this structure, as performed during cervical microsurgical drezotomy (DREZ = dorsal root entry zone) for the treatment of selected cases of chronic pain or disabling spasticity in the upper limbs.

Aged↗

PubMed1999

Locating the center of rotation of the hip.

In prosthetic surgery of the hip joint it is essential to recenter the hip to recreate the leverage of the gluteus medius muscle. Determination of the center of rotation of the hip is difficult if both hip joints have been destroyed. On the basis of 70 frontal radiographs of the hip in the standing position, the authors measured the position of the center of the femoral head in relation to Köhler's line and the TD line joining the two radiological Us ("tear-drops"). On the same radiograph they defined the horizontal and vertical indices. The descriptive analysis of these parameters stresses the influence of sex on the coordinates of the center of rotation of the hip. The authors demonstrated the statistical correlations between the coordinates of this center of rotation of the joint and certain horizontal and vertical indices. It emerged that knowledge of these indices suffices to define the theoretic position of the center of rotation. The method is compared with other principles set out in the literature. The procedure has a clinical application in the context of preoperative planning of prosthetic reconstruction of the acetabulum, whenever it is destroyed bilaterally (after trauma, in congenital dislocation or acetabular loosening, etc).

Adult↗

PubMed1999

The left retro-aortic brachiocephalic vein: morphologic data and diagnostic ultrasound in 27 cases.

A left retro-aortic brachiocephalic vein is a rare anatomic entity. A retrospective study was made of 5218 congenital cardiopathies treated between 1982 and 1998 in a medico-surgical department of paediatric cardiology. A left retro-aortic brachiocephalic vein was demonstrated in 27 patients, i.e. an incidence of 0.5%. The chief cardiopathy in these patients was a tetralogy of Fallot in 25 cases (93%). Among these 25 cases of Fallot's tetralogy the aortic arch was rightsided in 19 cases (70%). The paraclinical diagnosis of this anomaly was facilitated by ultrasonography, provided it was sought for. In this series 6 cases (22%) were discovered during surgery without previous ultrasound diagnosis. The embryological origin of the left retro-aortic brachiocephalic v. differs from that of the venous trunk in its classical anatomic form. It derives from the inferior (but not superior) transverse plexuses, connecting the two anterior cardinal veins. One of the main consequences of this anomaly is its possible confusion with other vascular structures, particularly the right pulmonary artery. Such confusion may give rise to inappropriate surgical procedures. The differential diagnosis is facilitated by the use of the Doppler: the venous flow is biphasic and regulated by respiration, whereas the Doppler recording from a pulmonary artery is that of a characteristic systolic arterial flow.

Adolescent↗

PubMed1999

[Total hip arthroplasty. Risk factors and prevention of iatrogenic vascular complications].

Vascular injuries during orthopaedic hip surgery are rare. However, they must always be feared because they threaten life and limb. We present 11 vascular injuries observed over a 12-year period. Seven women and 4 men, treated by elective surgery, presented 14 vascular injuries (6 arterial, 5 venous and 3 prosthetic vascular graft). Four injuries occurred during revision procedures. They were all operated as an emergency for ischaemic syndrome (6 cases) and/or haemorrhage (7 cases). Four patients (37%) died and 4 developed sequelae, various directly attributable to the vascular injury. In the light of these cases, we tried to determine the various mechanisms of the injury and the orthopedic and vascular risk factors. Preoperative detection and well defined therapeutic rules are very important for the prevention of these severe vascular accidents.

Adult↗

PubMed1997

Morphometry of the talocrural joint.

Based on two orthogonal radiologic views, the authors present a morphometric study of the talocrural joint. In 50 normal subjects, 10 parameters were measured and divided into 3 groups: the distal tibial joint surface parameters, the malleolar parameters and the talar parameters. These parameters were treated in both a descriptive and a correlative analysis. If the talocrural joint is a hinge joint whose talar articular surface can be simplified and classed as a cylinder segment, it is possible to calculate its curve radius. Then the correlative analysis allows to define the talar parameters and the corresponding parameters of the distal tibial joint surface. The malleolar parameters are independent factors. This study is the first morphologic analysis to serve as a basis for an ankle arthroplasty.

Adult↗

PubMed1996

The weight-bearing knee after anterior cruciate ligament rupture. An in vitro biomechanical study.

Unilateral weight bearing was simulated on 12 cadaver knees to quantitate anterior tibial translation (ATT) after anterior cruciate ligament (ACL) transection and to asses the role of the posteromedial structure and the hamstrings in controlling laxity. With the ACL intact, ATT was 3.5 +/- 2.8 mm in extension and 4.3 +/- 3.6 mm at 60 degrees flexion. After sectioning the ACL, ATT was 6.5 +/- 4.7 mm in extension and 17.5 +/- 10 mm at 60 degrees flexion (P = 0.001). Applying a force in the hamstrings was unable to correct the pathological ATT observed after ACL section. Partial medial meniscectomy did not increase ATT after the ACL section. Disinsertion of the posterior horn of the medial meniscus and total medial meniscectomy increased ATT significantly compared to isolated ACL section. After ACL transection, sectioning the meniscotibial fibers or posteromedial capsule significantly increased ATT (6.5 +/- 0.5 mm in extension). Section of the postero-oblique ligament or popliteus tendon had no effect on ATT.

Aged↗

PubMed1996

Relationship between rearfoot and forefoot orientation and ground reaction forces during running.

In this study, footprint and ground reaction forces (GRF) were simultaneously recorded from 32 male subjects running barefoot. Angle between the rearfoot and the forefoot in static (alpha S) and in running (alpha R) conditions, and orientation of both, rearfoot (alpha rf) and forefoot (alpha ff) with the direction of running (DOR), were measured and correlated to selected GRF parameters. The dynamic rearfoot/forefoot angle (alpha R) was correlated, positively with arch deformation (r = 0.58, P < 0.001), vertical Fz loading peak (r = 0.60, P < 0.001), mediolateral, and anteroposterior force rates (r = 0.47 and 0.48, P < 0.01), and negatively with stance time (r = -0.41, P < 0.05) and total course of the force application point path (r = -0.71, P < 0.001). Both a medial and a lateral rotation were observed on footprint between the rearfoot and the forefoot in the horizontal plane. A medially rotated forefoot ("closed foot") was associated to a rigid and inverted foot, whereas a laterally rotated forefoot ("open foot") was associated to a flexible and everted foot.

Adult↗

PubMed1995

[Arthrodesis of the ankle under arthroscopy. Apropos of 10 cases reviewed after a year].

PURPOSE OF THE STUDY: The technique, results and indications for arthroscopic ankle fusion are detailed and compared with open technics. MATERIAL AND METHODS: 10 arthroscopic ankle fusions were performed between 1991 and 1993. This procedure was used in 4 cases of rheumatoid arthritis, 5 cases of osteoarthritis and 1 case of joint destruction consecutive to hemophilia. All patients were followed until fusion with an average follow-up of 12 months. The quality and position of the fusion were analyzed clinically and on radiograms. RESULTS: 9 patients obtained fusion in a neutral position and were able to walk with normal shoes. The average time to fusion was 14.5 weeks (8 to 40). 1 case failed and required reoperation after 15 months. No local complications were observed. DISCUSSION: Arthroscopic ankle fusion is a safe procedure with good results in cases with relatively little deformities. Its main interest lies in the low rate of complications. The technique does not increase the rate of fusion when compared to open technics. CONCLUSION: Arthroscopic fusion is recommended in cases with little to moderate deformities in the presence of poor wound healing factors.

Adult↗

PubMed1993

Characterization of gangliosides from normal and osteoarthritic human articular cartilage.

OBJECTIVE: Glycosphingolipids (GSLs) are biologically active molecules in the physiology and pathology of cells. Since changes in GSLs might be associated with the impaired metabolism of articular cartilage in osteoarthritis (OA), we investigated gangliosides from normal and OA human cartilage. METHODS: OA and control cartilage was obtained from patients with hip OA and femoral neck fracture, respectively. Gangliosides were extracted and quantified by determining their lipid-bound sialic acid concentration. Major gangliosides were identified by immuno-detection on thin-layer plates, purified by high performance liquid chromatography, and analyzed for their carbohydrate, fatty acid, and long-chain base composition. RESULTS: The total ganglioside content of OA cartilage was decreased by 40% (per mg of DNA). Major gangliosides, GM3 and GD3, separated into 3 on thin-layer chromatography bands. All were decreased except for the lowest migrating band of GM3, which was increased 5-fold. This ganglioside had the same carbohydrate moiety and fatty acids as the other two, but differed by a long-chain base composed mainly of C20-sphingosine. CONCLUSION: OA cartilage is characterized by a decrease in all gangliosides except GM3, which demonstrates a large increase in the lowest band. These results indicate that there are changes in the biochemical composition of chondrocyte membranes in OA. The causes and roles of these changes remain to be determined.

Aged↗

PubMed1991

Calmodulin-dependent collagenase and proteoglycanase activities in chondrocytes from human osteoarthritic cartilage.

Chondrocyte metalloproteinases appear to play a major role in the development of osteoarthritis. The intracellular post-traductional mechanisms regulating collagenase and proteoglycanase are not known. Calmodulin antagonists including phenothiazine and sulfonamide derivatives significantly increased proteoglycanase activity and decreased collagenase activity. H-7, a specific inhibitor of protein kinase C, had no effect on the two metalloproteinase activities, and calmodulin was ineffective in in vitro assays upon metalloproteinase activities. We postulate that collagenase and proteoglycanase activities are controlled by calmodulin-dependent regulation.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed1991

Serotonin-stimulated phospholipase A2 and collagenase activation in chondrocytes from human osteoarthritic articular cartilage.

We have previously described several receptors on the chondrocyte membrane. In an attempt to further characterize the coupling mechanisms of serotoninergic receptors, here we examined the involvement of serotonin in the phospholipase A2 activity. Serotonin dose-dependently stimulated phospholipase A2. This activation enhanced collagenase type II activity and had no effect on proteoglycanase activity.

Aged↗

PubMed1991

[Total hip prosthesis after high femoral osteotomy].

This study reviews a series of 75 total hip prosthesis (THP) after high femoral osteotomy operated on between 1968 and 1986. The mean delay between osteotomy and THP was 14 years. 53 prosthesis were available for long term follow-up with a mean follow up of 7 years. It was included in the category of total hip prosthesis operations considered as difficult. The lateral view is indispensable to plan the operation. Valgus intertrochanteric osteotomies and moderate internal translations posed no problems. Trochanteric osteotomy did not have to be systematic; it's inconveniences were not neglectible. It was reserved for isolated varizations for it modifies the axis of entry of the stem. The reamer was used in cases of narrowing of the femoral canal; notably after significant medializations. Derotation osteotomy was the last resort when it was impossible to position the stem secondary to a subtrochanteric osteotomy or significant angulation in the sagittal plane. An intertrochanteric osteotomy, when correctly realised, posed few problems during placement of a total hip prosthesis and licits a continued use in young subjects. Results of THP after intertrochanteric osteotomy compared well with primary THP, with 77.5 per cent good results and 15 per cent loosening. In addition to problems posed by etiologies (congenital dislocations), subtrochanteric osteotomies rendered cementing extremely difficult, even impossible. At long term, only 14.5 per cent of the results were good and the loosening rate was 45 per cent. Fortunately subtrochanteric osteotomies are practically abandoned.

Adolescent↗

PubMed1991

[Extra-abdominal desmoid tumors. Therapeutic indications. Apropos of 28 cases].

Between 1965 and 1989, 46 desmoid tumors were observed in the hospitals of Lyon. Twenty-eight patients with an extra-abdominal tumor, with a follow-up of at least 6 months were observed. In this group, there were 12 males and 16 females with an average of 26.7 years. Surgical treatment was performed in 26 cases (in one case no treatment was given and in another case isolated chemotherapy was given). In 21 cases (80%) a recurrence of the tumor was seen after the first excision, incomplete in 6 cases. The highest rate of recurrence was seen in the neck, the girdles and the lower limbs; at the end of our review, 9 patients still had a tumor. No primary amputation were performed but two late amputations, one of which was major, were necessary. One tumor evolved into a sarcoma and in another case, lung metastases were seen. Associated radiotherapy was given in 9 cases with resolution in 55%. Tamoxifen was used in 5 cases with stabilization of the tumor. The risk of recurrence was higher in males (p = 0.0147). Age less than 30 years, and incomplete removal of the tumor were the other predictive factors for recurrence (the difference was not significant).

Adolescent↗

PubMed1990

An anatomical and radiological study of the femoropatellar articulation.

An analytical study was made of 30 knees by dissection, 200 by conventional radiology, 120 by CT scans, and of 2,400 pathological knees by conventional radiology, and 900 by CT. The radiological and scanning methods most used for a study of the femoropatellar articulation are described and the normal values of each feature determined by a computer study. The femoral trochlea and its shape are very important for the stability of the patella. The normal and pathological types of trochlea are described. This study established a number of anatomical factors which influence patellar stability, and form a basis for proposing the correction of anatomical anomalies in the treatment of instability of the joint.

Fascia↗

PubMed1990

Glycosyltransferase activities in chondrocytes from osteoarthritic and normal human articular cartilage.

Six glycosyltransferases (mannosyl-, glucosyl-, N-acetyl-glucosaminyl-, galactosyl-, sialyl- and fucosyltransferases) are studied and characterized for their optimal conditions and their relations with interfering reactions (glycosyl-nucleotide pyrophosphatases, glycosidases and proteinases) in chondrocytes from osteoarthritic and normal human articular cartilage. Osteoarthritis induces increased activities for five glycosyl-transferases. The observed modifications are not explained by alterations in physico-chemical parameters of the enzymes or by intervention of glycosyl-nucleotide pyrophosphatases, glycosidases or proteolytic enzymes.

Cartilage, Articular↗