Biomedical subjects

F Dujardin

Publications and source records attributed to F Dujardin.

30 records · Page 2Linked to original sources

PubMed1996

Experimental measure of the tensile strength of biological sealant-collagen association after hepatectomy in dogs.

Fibrin sealants are commonly used in liver surgery. The aim of this study was to test the adhesive properties of a biological sealant-collagen bonding, using an experimental model. After hepatectomy in dogs, we measured the rupture stress point of a fibrin clot on the liver cross-section. The tensile strength was 0.28 N, 5 times higher than the force of arterial pressure in a 2-mm-diameter vessel. These results indicate that the adhesion of fibrin sealants is effective to prevent hemorrhage from the liver cross-section after hepatectomy.

Animals↗

PubMed1996

[Anatomical and functional results of the external fixation of upper metaphyseal tibial fractures].

PURPOSE OF THE STUDY: This study aimed to evaluate a method for the treatment of upper tibial metaphyseal fractures using an external epiphysodiaphyseal fixation with the double-frame Hoffmann device. MATERIALS AND METHODS: The study included 48 patients (37 men and 11 women) aged 16 to 82 years. The tibial fracture was simple in 15 cases, included a metaphyseal comminution, partial in 3 cases and total in 30. In 13 patients, there was also a simple articular fracture. The fracture was opened in 24 cases (type I in 10, type II in 7 and type III in 7 cases). METHODS: The gap and displacement evaluation between the fragments after reduction was made on postsurgical roentgenograms; its was considered as complete when all fragments were in contact with each other, without frontal or anteroposterior translation above 5 mm. Healing was defined as a complete bone continuity providing a painless load bearing. The patients were clinically and radiologically reexamined with a mean follow-up of 15.45 months (5 to 62 months). RESULTS: After healing, there were 2 cases of angular deformities in patients whose autonomy was otherwise already reduced. Twenty-three patients had a minor pin tract infection. There was 3 cases of secondary osteitis after a type-III open fractures and 3 other deep septic complications without functional consequences. Forty-one fractures healed without bone graft in a mean time of 18 +/- 7.6 weeks. Healing did not seem to statistically depend on the opening nor on the type of fracture, but rather on the association with a peroneal fracture and the loss of cohesion between the fragments. The duration of professional invalidity evaluated in 20 cases, varied between 4 to 21 months (means: 11.3 months), and none of the patients had to modify his activity because of the tibial fracture. At follow-up, no patient complained of invalidating pain. Thirty-two patients recovered a satisfactory knee joint mobility and among the 16 others, in only 3 no particular reason was found to explain the deficit. DISCUSSION: While good anatomic and functional results lead us to keep the principle of external fixation, it seems however necessary to modify the modalities of the treatment in order to improve healing conditions, especially by improving the cohesion of the fragments through secondary minimal internal fixation. The use of dynamic axial fixation devices could therefore bring a theoretical advantage, but it must be proven that they produce in this site a primary stabilization which is a good as that obtained with Hoffmann's device.

Adolescent↗

PubMed1996

[Experimental study of the stabilization capability of upper metaphyseal tibial fractures by different types of external fixators].

PURPOSE OF THE STUDY: The major problem in external fixation of upper metaphyseal tibial fractures with a double-frame Hoffmann device is poor healing. With a dynamic fixation, it would be possible, with no change in technique, to compress the fracture site in a second phase, and therefore to facilitate the healing process. However, a new fixation device should not compromise the primary stability of the fixation. The aim of this experimental study on cadavers was to compare, in conditions very close to a clinical situation, the initial stabilization capability of five types of external fixation. MATERIAL: Five types of external fixators were tested on cadavers specimens: 1. a standard double-frame Hoffmann device; 2. a double-frame Hoffmann's device sagittaly reinforced with two additional anterior-posterior half-pins; 3. a type-1 axial dynamic fixation device using 6-mm conical pins; 4.a type-2 dynamic axial fixation device with 5-mm cylindrical pins; and 5. a mixed device including an lizarov-type epiphyseal fixation and a monoplane diaphyseal fixation. METHODS: The metaphyseal fracture was simulated by a transversal resection of a 20-mm segment. Specimens received by increments a load of up to 310 N, with which it was possible to determine stiffness components in valgus/varus, flexion/extension, rotation around the vertical axis and axial vertical displacement. The bone mineral content of the specimens was measured by Di Energy X-ray Absorptiometry. RESULTS: The stabilization characteristics of type-1 axial dynamic fixation were identical to those of the standard Hofmann's device in flexion/extension and in rotation as well as axially, but a greater mobility in valgus/varus was observed. The sagittal reinforcement of Hoffmann's device increased its rigidity in flexion/extension. The mixed lizarov fixation was stiffer than the standard Hoffmann's device in rotation; it was equivalent in valgus/varus and flexion/extension and less stiff in axial vertical displacement. In this study it was showed that the individual variability of bone mineral content is a negligible parameter. DISCUSSION: The experimental behaviour of the mixed Ilizarov device gives to assume that it may facilitate the healing process without endangering the primary stability of the fixation. However, this theoretical advantage should be validated in a randomized prospective clinical study.

Aged↗

PubMed1996

[Acute necrotizing cutaneous streptococcal infection following bites or scratch by dog or cat].

INTRODUCTION: Domestic animal bites or scratches are quite frequent. Among banal bacteria isolated from infected bites or scratches, group A streptococcus seems to be frequently associated with severe infections. CASE REPORTS: Three cases of acute necrotizing cutaneous streptococcal infections, following cat or dog bite or scratch are reported. Twice, group A streptococcus was isolated from cutaneous swabs. In the third case, previous antibiotic therapy had sterilised bacteriological samples. Diagnosis was ascertained on the basis of clinical presentation and significant antistreptococcal antibodies elevation. Skin necrosis around the inoculation area was observed in the 3 cases. Cicatrisation required an average of two months under appropriate treatment. DISCUSSION: An evolution towards cutaneous necrosis localized to the initially injured area is common to these three cases. This peculiar evolution is worth to be known in order to choose an effective anti streptococcal antibiotherapy whenever domestic animals bites and scratches are to be treated.

Acute Disease↗

PubMed1995

Spatiotemporal gait parameters measured using the Bessou gait analyzer in 79 healthy subjects. Influence of age, stature, and gender. Study Group on Disabilities due to Musculoskeletal Disorders (Groupe de Recherche sur le Handicap de l'Appareil Locomoteur, GRHAL).

The Bessou gait analyzer provides quantitative measurements of spatiotemporal gait parameters. The purpose of this study was to determine whether and how these parameters are influenced by age, stature, and gender. Seventy-nine normal individuals (38 males aged 20 to 80 years and 41 females aged 20 to 80 years) were divided into ten-year age groups. Males and females were studied separately. In each subject, the Bessou gait analyzer was used to measure spatiotemporal gait parameters (spatial parameters: stride and step lengths; temporal parameters: cycle, stance and swing durations). Mean walking speed was calculated in each subgroup. In both males and females, all study parameter values were identical for the left and right sides. Females younger than 60 years had shorter stride and step lengths (M: 1.5 +/- 0.2 m; F: 1.3 +/- 0.1; p < 0.001) but faster pace values (M: 104.8 +/- 9.0 cycles/min; F: 115.6 +/- 7.6 cycles/min; p < 0.001) than males, and consequently mean walking speed was similar in females and males (M: 4.8 km/h +/- 0.8 km/h; F: 4.4 km/h +/- 0.6 km/h). In contrast, females older than 60 years walked at the same pace as males and consequently had slower walking speeds. Stride length was correlated with age, stature, and gender. However, age was correlated with stature, and only age and gender had independent effects on gait parameters in the multiple regression analysis. In subjects of similar age and gender, effects of stature may need to be taken into account.

Adult↗

PubMed1995

[Allergic dermatitis caused by metallic implants in orthopedic surgery].

PURPOSE OF THE STUDY: Dermatitis due to metallic implants in orthopaedic surgery are uncommon complications and are difficult to diagnose. MATERIAL AND METHODS: A literature review found descriptions of 54 cases. All types of implants, even small in size such as screws or loops, made of stainless steel or chromium-cobalt alloys have been incriminated. There was no case related to titanium alloy. RESULTS: The clinical aspects were very different; all the forms of dermatitis are possible. The most frequent were eczemas (44 per cent), bullous dermatitis (11 per cent) and inflammatory forms (13 per cent). DISCUSSION: These dermatitis result either from immuno-allergic mechanisms or from cell-toxicity. There are two main diagnostic difficulties. 1--To confirm the responsibility of the implant in the dermatitis because the cutaneous lesions appears often generalized or localized in an area distant from the implant and because their emergence may be very belated, sometime after several years. 2--To distinguish some of these dermatitis and especially inflammatory forms, from sepsis. There is no current means to state positively this diagnosis without removing the implant. The microscopic tissues analysis surrounding the implant and the cutaneous patch-tests using fillings of the implant itself are the only methods which appear able to confirm the diagnosis. There are no reliable means to detect risk subjects, the emergence of a dermatitis seems to be unpredictable. The specificity and the sensibility of the usual patch-tests are insufficient. CONCLUSION: The main means to prevent dermatitis is to reduce the production of metallic particles due to wear, fritting and corrosion. Management is based on removing of the incriminated implant. Treatment using drugs, including local applications or general dispensing of steroids, have generally a low efficiency.

Adolescent↗

PubMed1995

[Intra and interindividual variations of pelvic mobility in normal adult walk].

PURPOSE OF THE STUDY: Pelvis motion appears as a main human gait component, it is linked to the lower limb joints and to the spine. Current devices, especially the opto-electronical systems, allow quantitative and tri-dimensional gait studies. The purpose of this study was to quantify the pelvic motion individual variability in a sample of healthy subjects. MATERIALS AND METHODS: The study based on a 18 volunters sample. There were 14 men and 4 women, ranged in age from 25 to 37 years. A clinical examination and a AP radiograph of pelvis allowed to include healthy subjects. We used the three-dimensional analysis VICON system with five cameras. Nine records were performed for each subject during a free-speed walking. These nine records were distributed on three different days. RESULTS: The step length medianes varied from 1100 to 1600 mm with a significantly (p < 0.05) regression between the step length, the walking speed and the subjects height. Vertical pelvic oscillations varied in this sample from 25 to 60 mm and linked with step length and walking speed. Pelvic rotation around the vertical axis varied from 1.5 to 15 degrees. We did not found regression between this pelvic rotation and the length step. It seems there are three types of pelvic rotation around the vertical axis. At the beginning of the stance phase, in type I, the pelvis is in the transversal plane whereas in the type II, it appears with the maximal rotation. In type III, the value of pelvic rotation is very low. The successive lateral inclinations of pelvic described a complex motion which varied from 1.5 to 9 degrees. The rotation of shoulders around the vertical axis varied from 4 degrees to 13 degrees and the successive inclinations varied from 3.25 degrees to 12 degrees. We did not found any regression between the pelvic and shoulders motion values. DISCUSSION: This study showed that the pelvis motion varied considerably from one subject to another. These variations induce different ways of walking with various consequences on the hip joint and the spine. We suppose that these variations could take a part in etiology of some diseases as hip arthritis or in total hip arthroplasty failure, especially in cup wearing.

Adult↗

PubMed1994

[Femoral osteotomy for severe hip osteoarthritis: an actuarial analysis of results].

INTRODUCTION: In cases of severe hip osteoarthritis in young patients, the intertrochanteric osteotomy can delay total hip arthroplasty. The main advantage of the osteotomy is to preserve the bone stock. The main disadvantages are the lasting postoperative invalidity and the varying longterm success rate. Our aim was to quantify these disadvantages using survivorship analysis. MATERIAL AND METHODS: The study included 64 patients (65 osteotomies) ranging from 16 to 68 years. The osteotomies were performed between 1975 and 1987. The osteoarthritis was stage III or IV, with a joint space less than 50 per cent. Osteoarthritis was primitive in 25 cases and secondary in the others. The osteotomy always included a medial displacement of the shaft according to the principle of Mac Murray's procedure, but also 22 cases (33.8 per cent) had a varus angulation and 19 (29.2 per cent) a valgus angulation. The preoperative pain score according to the Merle d'Aubigné (MDA) grading was 2.6 (1 to 4) and the global functional score was 11.1 (5 to 15). The patients were reviewed in 1991 and examined clinically and radiographically. RESULTS: The results of the 65 cases were distributed into 3 groups: -29 cases having reached the follow-up without difficulty, -7 patients were lost for follow-up examination, 6 of these latter than 9 years, -29 patients taking osteotomy failure as a pain lesser than the 3 MDA score. The postoperative delay to obtain the best functional result was 6 to 24 months (mean: 13.65). This result ranged from 5 to 17 MDA score (mean: 15) with pain ranging from 2 to 6 (mean: 5). The survivorship analysis curve showed 67.5 +/- 19.5 per cent survival for all osteotomies to the interval of 9-10 years. There were 3 types of results: -3 early failures (4.6 per cent) one because of a deep infection, -in 7 cases, after a short initial functional improvement, there was a progressive degradation leading to failure in 3.7 years (2 to 6 years), -55 cases with a lasting period of functional improvement, 26 osteotomies leading to failure in 3.5 to 15 postoperative years and, 29 cases having reached the follow-up (7 to 16 years mean 10 years). There was radiographic improvement of the osteoarthritis increasing the joint space in 59 cases (90.7 per cent). There was no radiographic improvement in the 6 other cases, including the 2 functional failures. The functional degradation appeared parallel to the radiographic degradation leading to a decrease of joint space to 90 per cent. We tested differences between various groups using Log Rank test. We found no difference in survival between the 3 different types of osteotomy. DISCUSSION: The results of this study can help to choose between intertrochanteric osteotomy and THA in the case of severe osteoarthritis. The best functional result of the osteotomy is in one postoperative year, with a mean MDA score of 15 and a mean pain score of 5. It appears that we do not predict the duration of functional improvement, the patient has 2/3 chances that this improvement reaches 10 years.

Actuarial Analysis↗

PubMed1993

Measuring the rupture stress point of biological sealant-collagen bonding: validation of a technique used after hepatectomy.

The aim of this experimental study was to measure the rupture stress point of a fibrin clot situated on a liver, in realistic surgical conditions. The experimental method was carried out with a machined wooden cylinder bonded on the liver, connected with a wire to a setup and pulled at a constant speed, and a sensor was placed on the wire measuring the applied strength. This method, realized in the dog, made it possible to validate a precise and reproducible method designed for testing the adhesive characteristics of biological sealant-collagen bonding on the liver.

Adhesiveness↗

PubMed1993

[Closed locked nailing of complex femoral fractures in adults. Apropos of 68 cases].

Complex fractures of the femoral shaft rise problems due to high energy trauma with major soft-tissues injuries and bone comminution so increasing operative difficulties, risk of infection and delayed union. Our aim was to appraise the outcome of these problems when using a closed intramedullary locked nailing. There were 52 men and 16 women. Aged 16 to 83 years. 52 patients had multiple-injuries. There were 17 open fractures. The 68 cases were subdivided according to a classification in 3 types. Stable fractures type A and B1 were excluded. The shaft was divided into 5 zones. Patients were initially treated by skeletal traction closed nailing was performed 1-36 days later (average 9.5). All patients were reviewed until complete healing. Final follow-up was 6 to 35 months postoperatively (average 15). A dynamisation was performed in 19 cases at a average delay of 12 weeks. Sixty six of the 68 fractures united. Open fractures united after 26.4 weeks, in average and closed fractures after 23.25 weeks (p < .05). There was no correlation between time of surgery following the injury and the delay of healing. Shortening was noted in 4 cases. 8 patients had an angulation 5-15 degrees of in the varus or the valgus plane. 3 patients (4.4 per cent) had more than 5 degrees of angulation in the AP plane. An external rotation deformity of 10-35 degrees was noted in 4 patients. The incidence of deformities was the main problem. It could be minimize by a precise technique. Mobility of the knee was the other problem, but it appeared generally to depend much more on knee injury than on femoral fracture.

Adolescent↗

PubMed1991

[Correlation between microhardness and X-ray transparency of the proximal portion of the human femur].

In order to be able to evaluate the mechanical properties of cortical and sub-cortical bone from a radiologic acquisition, the authors have researched a link between the X-rays transparency of bone and its hardness. A device for measuring hardness has been developed which allows an almost punctual evaluation of the mechanic value of bone. This value has been compared with X-rays transparency of the studied point. The link found between these two variables on 80 measures was strong, with signification less than 0.001.

Biomechanical Phenomena↗

PubMed1990

[Use of x-ray computed tomographic data for the concept of a custom-made hip prosthesis. Exploratory approach].

A custom-made hip prosthesis has to allow to improve the arthroplasty's longevity. In a Computer Aid program Conception (CAD) of such an implant, it becomes necessary to control the accuracy of the 3-D data given by CT Scans. The method employed is based on the comparison between 3-D data given by CT Scans and by photogrammetry. The study was made with a human pelvis including femoral head, without soft tissues. The CT Scans data have been given by automatic extraction of osseous outlines on two hundreds sections (1.5 mm thickness). The photogrammetry data have required five stereocouples for the whole pelvis and four stereocouples for the hip joint (femoral head and cotyle). There nine stereocouples have provided 37,213 points of reference. The comparison between the two sorts of informations shows that the error made in CT Scans acquisition was varying between 0.65 and 1.60 mm. This error is smaller when the outlines are simple, like the femoral diaphyse. The error decreases if we reduce the field size of CT Scan acquisition. These results confirm literature data. But this study has allowed to demonstrate validity of 3-D CT reconstruction. Scanography looks like the best present way of data acquisition. The dimensional précision is sufficient to define the endo-osseous outline, but it must be preserved at the moment of the extraction of this outline. Therefore this extractive can't be manual and must be made directly with processing data given by scanography.

Hip Prosthesis↗