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Biomedical subjects

F Duparc

Publications and source records attributed to F Duparc.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Experimental study of the primary stability of locked centro-medullary nailing of the humeral diaphysis].

PURPOSE OF THE STUDY: A clinical trial on the treatment of humeral shaft nonunions with locked nailing evidenced 5 failures among 13 cases. The circumstances leading to the nonunion, the patient's condition, and the nailing method were not found to have a predominant effect explaining this outcome. Inversely, clinical data suggested that abnormal mobility of the nonunion appeared to result from play in the assembly. To check this hypothesis, we measured primary stability in three nailing models using cadaver bones. MATERIALS AND METHODS: Three nailing models, Seidel (S), Russel-Taylor (RT) and ACE were tested, each on 5 cadaver specimens. A 1 cm segmental resection was made in the mid third of the humerus to simulate an unstable nonunion. The nailing was performed in accordance with the instructions furnished by the manufacturers. The nailed specimens were placed in a testing device which alternatively applied a rotation force around the longitudinal axis (+/- 0.5 Nm), an axial compression-traction force (+/- 20 N) and a transverse shear force applied at the level of the osteotomy (+/- 20 N). RESULTS: This study demonstrated an instability of the three nails when submitted to a rotation force or a shear force: 14 to 28 degrees and 1.6 to 3.4 mm respectively for the RT nail; 8 to 20 degrees and 1 to 3 mm for the S nail; 5 to 15 degrees and 1.7 to 3.2 mm for the ACE nail. The ACE nail appeared to be more stable when submitted to compression-traction force; the S nail accepted a 0.05 to 0.65 mm play which reached 9.7 mm for the RT nail. This instability appeared to result from play in the locking systems. DISCUSSION: These findings would demonstrate that these nailing systems cannot, in themselves, provide satisfactory primary stability. The experimentally evidenced instability would contribute, probably in association with locally unfavorable physiological or biological conditions, to the failure rate observed when nailing is used alone. CONCLUSION: The locking system for tested nails would have to be modified to eliminate play in the assembly before continuing their use for the treatment nonunion of the humeral shaft.

Aged↗
PubMed1999

[Transgluteal approach to the hip by anterior hemimyotomy of the gluteus medius].

Authors describe a transgluteal approach of the hip which is not based on the somewhat unsure common insertion of gluteus medius and vastus lateralis. Anatomical basis and technical particularities of division of anterior part of gluteus medius, of gluteus minimus and capsule are given which allow preservation of gluteal nerve, stability of the joint, and solid reparation of abductor muscles.

Buttocks↗
PubMed1998

[Kinematics of the healthy and arthritic hip joint during walking. A study of 136 subjects].

PURPOSE OF THE STUDY: The study aimed to analyze the spatiotemporal parameters and 3-dimensional pelvic and hip kinematic components during gait in two groups: patients with a primitive osteoarthritis of the hip and control normal subjects. MATERIAL: The study included 51 patients, ranged from 42 to 81 years, and 86 normal subjects. METHOD: Gait analysis was performed using the optoelectronic system VICON with 5 cameras in free-speed conditions. Functional grading of the patients was assessed by Lequesne's score. Thickness of the hip cartilage was measured on pelvis AP radiograph. A preliminary study was performed to measure reliability of the data on 11 patients. RESULTS: At the initial stage of osteoarthritis, speed, cadence, stride length and hip flexion-extension motion appeared as very close to normal data. After this initial stage, there was a statistical relationship between these parameters and arthritis functional grading. Pelvis rotation around the vertical axis did not change according to severity of functional grading. The mean value of this component of pelvis motion was 10 degrees in the pathological group, whereas it was 8 degrees in the female normal group, and 7 degrees in the male group. There were no significant relationship between radiographical thickness of hip cartilage and functional grading of patients or gait parameters. DISCUSSION: This study demonstrates that spatiotemporal gait parameters and kinematic data appear as quantitative index which could be used in future studies. It also shows that pelvic rotation is greater in pathological group than in normal subjects, even in the extreme beginning of the hip osteoarthritis. This particularity can be explained as a very early consequence of the arthritis or, in the opposite, as risk factor.

Adult↗
PubMed1998

[Embryology of the human carpal bones (triangular cartilage, central carpal bone, morphogenesis of the scaphoid)].

Wax reconstructions according to Born's methods were performed from serial 10-micron sections of the wrists of human embryos (B. Tardif) to study the triangular cartilage and central bone of the carpus. A subsequent morphological study of the adult scaphoid bone was conducted in the light of embryological data. The triangular cartilage was observed in 4 of 38 carpi of embryos with a craniocaudal length of 40 to 69 mm, flatten between the ulna and triquetrum, on the inferior surface of the mesenchymal bud of the triangular ligament. The central bone of the carpus is constant in the embryo, between the inferior surface of the radial chondrification centre, capitatum, trapezium and trapezoid. In one case, the two wrists of the same embryo presented two central nuclei, leading to the distinction of two different formations:--the constant C2 embryonic central bone, trapped between capitatum, trapezoid and trapezium, which participates in the constitution of the scaphoid by fusion with the radial chondrification centre;--the C1 central bone, a rare supernumerary bone in adults, close to the inferolateral angle of the lunatum, on the dorsal surface of the carpus. These embryological data support. Westoll's theory concerning the filiation of the thoracic limb since the fin of crossopterygians, with deviation of the mechanical axis related to the development of weightbearing on the ground. The scaphoid bone must to be assimilated to a cube, but to an irregular tetrahedron, composed of two inverted pyramids joined by their bases. The inferior pyramid, articulating with he trapezium, trapezoid and capitatum, is concerned by morphological variations of the bone, which can present variable configurations between the two extreme morphotypes: the massive type and the strangulated type. The inferior pyramid, constituting the scaphoid, is derived from the central cartilage and presents the same relations. Variations of the volume of this inferior part of the bone are related to the more or less marked regression of this chondrification centre of the embryonic carpus. These variations of the bone can be expressed in terms of a scaphoid index, by calculating the relationship between the greatest dimension and the width of the narrowed portion.

Adult↗
PubMed1997

Anatomical basis of the variable aspects of injuries of the axillary nerve (excluding the terminal branches in the deltoid muscle).

The course of the axillary n. is complex with three points of angulation that may be used to delineate four segments and a fifth segment that corresponds to the intramuscular ending of the nerve in the deltoid m. The purpose of this study was to determine the precise anatomy of the nerve and of its branches, and some morphologic features for each segment. Thirty-two shoulders from embalmed adult cadavers have been studied. The axillary n. was divided in five segments: 1) from its origin to the inferior border of the subscapularis m., 2) from the subscapularis m. to the anterolateral border of the tendon of the long head of the triceps brachii m., 3) from the triceps to the posteromedial part of the surgical neck of the humerus, 4) from the humerus to the entry into the deltoid m., 5) the intramuscular distribution of the nerve in the deltoid m. In each segment from 1 to 4 were noted the origins of the branches to the subscapularis and teres minor mm. and to the scapulohumeral joint, and the origins of the lateral cutaneous branchial n. and of the terminal motor branches to the deltoid m. The length and the diameter of the nerve in the segments and the distance from the segment S1 to the musculotendinous junction of the subscapularis m. were measured. The results showed that the mean diameters were about 4.1 mm in segment 1, 4.1 mm in segment 2 and 3.4 mm in segment 3. The mean distance to the musculotendinous junction was 7.7 mm. Many variations in the levels of origin of the different muscular, articular or cutaneous branches were found without symmetry between the right and left sides. The lateral cutaneous brachial n. was absent in four cases. The results are compared with those in the literature. The division into five segments is proposed to radiologists and surgeons for evaluation or operative procedures on the axillary n., and to provide a hypothesis about the variable aspects of injuries of the nerve.

Adult↗
PubMed1997

Anatomic basis of the transgluteal approach to the hip-joint by anterior hemimyotomy of the gluteus medius.

The authors present a study of the intrinsic anatomy of the gluteus medius m, and of its innervation through the caudal branch of the superior gluteal n. The existence of an intramuscular tendon in the thickness of the gluteus medius was constantly prooved in 40 muscles. The relations of the intrinsic fibrous structure of the muscle and its innervation were studied. The authors deduce from that the topography of a gluteus medius incision, with respect to a safety area towards its innervation, which leads to an exposure of the acetabulum that is satisfying and gives opportunities of a sound repair after the surgery of the hip joint through the transgluteal approach. They propose the "anterior hemimyotomy of the gluteus medius m" designation.

Buttocks↗
PubMed1997

[Recent palmar dislocations of the proximal interphalangeal joint].

PURPOSE OF THE STUDY: Recent anterior dislocations of the proximal interphalangeal (PIP) joint are uncommon injuries. Chronic and irreducible dislocations have been most often reported. This study aims to precise the anatomic and radiologic aspects of these lesions about three cases, and to compare these cases and their treatment with thirteen cases published in the literature between 1966 and 1994. MATERIAL AND METHODS: Three patients presented an anterior dislocation of the PIP joint after direct or twisting traumatism. One had an avulsion of the central slip of the extensor tendon and remained unstable after closed reduction needing pin fixation. Two had a longitudinal tear between central and lateral bands of the tendon with an entrapment of the condyle of the proximal phalanx, and the dislocations were irreducible. After open reduction, the joint was stable. RESULTS: The first case showed a limited flexion after three months. In the two other cases without rupture, full range of motion was recovered after two months. DISCUSSION: These cases have been compared with thirteen cases of recent papers from nine authors. Two types of anterior dislocations of the PIP joint may be described. TYPE I: Without rupture of the central slip fo the extensor tendon. One distal condyle of the proximal phalanx is entrapped between the central slip and a lateral band of the extensor tendon, that are separated by a longitudinal partial tear. The deformity is made by flexion, axial rotation and lateral displacement of the middle phalanx. Open reduction is required and may carry out good functional result. TYPE II: With rupture of the central slip of the extensor tendon. These very unstable lesions need a fixation after closed or open procedure. The treatment is often lately carried out, and the results not so good as in type I. CONCLUSION: Two different types of PIP joint anterior dislocations are described. Earlier diagnosis and surgical treatment can allow early rehabilitation and better final functional results.

Adult↗
PubMed1996

Isolated subacromial decompression for the treatment of chronic shoulder pain with rotator cuff calcification. A review of twenty-seven shoulders, including eighteen evaluated by magnetic resonance imaging after surgery.

We conducted a retrospective study of functional results and imaging study changes after isolated anterosuperior decompression of 27 chronically painful shoulders with calcification of the supraspinatus tendon at the time of surgery (n = 22) or at an earlier date (n = 5). Mean duration of pain at surgery was 4.5 years. Mean time between surgery and evaluation of results was three years. Absence of pain and full range of motion were noted in most cases (70%), usually after four to six months. There were no postoperative exacerbations of pain. The best results were obtained in those patients with a heterogeneous supraspinatus calcification. Most calcifications (18/22) disappeared within one year of surgery. Magnetic resonance imaging findings at last follow-up are reported for 18 shoulders. Functional results were nearly as good as those reported after calcification removal. In patients with shoulder pain and rotator cuff tendon calcifications who fail to respond to conservative therapy and aspiration with lavage, anterosuperior decompression may be the treatment of choice when the calcification is either heterogeneous and located within the tendon or no longer visible. In contrast, curettage may be the best treatment for superficial homogeneous calcifications that can be removed without damaging the rotator cuff.

Adult↗
PubMed1996

Rib graft or cement to enhance screw fixation in anterior vertebral bodies.

This study analyzed the use of a rib graft or cement to enhance the holding power of a screw in a vertebral body. The results were correlated to provide a rationale for surgically enhancing the holding power of a screw when stripping of the bone thread has occurred. Human lumbar vertebral bodies obtained at autopsy were used in this study. The screws were inserted at three different sites of each vertebra and a load necessary to strip the thread was applied. Then costal fixation and cement fixation were tested to determine whether it was possible to restore the ability of the screw to withstand pullout load in the same hole. The main finding was that methacrylate placement or costal fixation restored the ability of the screw to withstand pullout load to within 5% (cement) or 15% (rib graft) of the original value. These results validate the possibility of using a rib graft or cement to enhance screw fixation.

Bone Cements↗
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↗
PubMed1995

[Humeral retroversion and shoulder prosthesis].

PURPOSE OF THE STUDY: From a theoretical point of view, humeral torsion is described as the angle between the transcondylar plane and the posteromedially facing joint surface of the humeral head. In this study, humeral torsion was also identified as the angle between the anatomical neck of the humerus and at the inferior part the axis of rotation of the elbow and the axis of the forearm. MATERIALS: 60 cadaveric humeral shafts were obtained. The axis were defined and measured by CT Scans. METHODS: The orientation of the cartilage of the humeral head was determined as a line perpendicular to the limits of the joint area of the humeral head. The axis of the humeral anatomical neck was defined as the plane that contains both the long axis of the humerus and the center of the humeral head. The rotation axis of the elbow was defined as the line passing through the centers of the capitellum and the trochlear sulcus. RESULTS: The angle between the orientation of the humeral head and the orientation of the transcondylar line averaged 23 degrees. The angle between the humeral neck and the orientation of the transcondylar line averaged 38 degrees. The angle between the humeral neck and a line perpendicular to the axis of the forearm averaged 41 degrees. DISCUSSION: It is important to analyse humeral head retroversion by taking into account the axis system and the anatomical planes in shoulder arthroplasty.

Humans↗
PubMed1994

Lateral exposure of the cervicothoracic spine for anterior decompression and osteosynthesis.

A lateral exposure of the cervicothoracic spine by an approach giving access to the anterolateral aspect of the vertebral bodies between C3-T10 is described. The approach of that region is obtained by the association of a cervicotomy and a standard thoracotomy with a costal flap situated at the place of the scapula. This approach was used for one patient with tumor invasion in the anterior part of the spinal canal on T1-T3; it allowed extensive resection of the three successive metastatic vertebral bodies and permitted stabilization of the spine.

Aged↗
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↗
PubMed1994

[Anorectal manometry and ileo-anal anastomosis: pre- and postoperative manometric comparison].

The aim of this study was to evaluate the physiological and manometric changes of anorectal function after proctocolectomy and ileal J pouch anastomosis performed in 13 patients. A short muscular rectal cuff was conserved in the first 5 patients, mucosectomy was performed in the next patients (Group M), and the entire rectum and proximal portion of the anal canal (1 mm above the dentate line) were resected without mucosectomy (Group WM) in the most recent patients. With a median postoperative follow-up of 18 months, anorectal continence was perfect in 9 patients, and minimal incontinence were observed in 4 patients (2 patients in Group M, and 2 patients in Group SM). In Group M, the resting lower anal canal pressure was significantly decreased after the operation and was less than the postoperative resting lower anal canal pressure observed in Group SM. The resting upper anal canal pressure in continent patients was inferior to the postoperative values measured in patients with minimal incontinence. In all the groups, no change in squeeze pressure was observed after the operation. During the postoperative period, the rectoanal inhibitory reflex was absence in all patients. The volume necessary for sensation threshold was increased after the operation, in the same number of patients in Group M and SM, and more frequently in continent patients compared with patients with soiling. The absence of muscular rectal cuff and mucosectomy seems to provide best results than rectal cuff preservation. After the operation, a marked decrease in the resting pressure and an increase in the volume necessary to onset of threshold sensation, were associated with the presence of minimal incontinence.

Adult↗
PubMed1992

[Femoral and tibial bone torsions associated with internal femoro-tibial osteoarthritis. Index of cumulative torsions].

Among the hypothesis about pathogenesis of medial knee osteoarthritis, the participation of modifications of the alignment of the limb in the frontal plane is known. The participation of the femoral and tibial torsions had been assessed by a few authors. In this study, the torsions have been measured by computerized tomodensitometry. The global torsional morphology of the limb has been defined by the measure of the Index of Cumulated Torsions. The values of torsions have been compared with the angle deformities measured in the frontal plane. The effects of the bone torsions on the position of the lower limb during the weight-bearing phase of the gait and the consequences about the knee have been studied.

Aged↗