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Biomedical subjects

J J Comtet

Publications and source records attributed to J J Comtet.

At least 37 records · Page 2Linked to original sources
PubMed1989

Biomechanical basis of transfers for shoulder paralysis.

Elevation of the scapulohumeral joint can be executed by two different and distinct systems, both capable of separately performing this movement. The deltoid muscle is composed of several parts contracting independently, sometimes antagonistically between them and providing elevation in different directions. Parts two and three (Fick) of the deltoid are essential because they are lateral to the centers of rotation and work in the plane of the scapula. The supraspinatus and adjacent muscle system can produce compensatory movements with full elevation in the plane of the scapula. Lateral rotation is absolutely necessary for abduction in the coronal plane. Rotatory muscles inserted on the tuberosities of the proximal part of the humerus are more efficient than those inserted on the humeral diaphysis. Vertical and horizontal stabilization of the humeral head in the glenoid fossa is the result of a complex balance between several muscles and passive factors. Trapezius and serratus anterior are essential for the rotation of the scapula around its centers of rotation.

Biomechanical Phenomena↗
PubMed1988

Proposed digital arthroplasty critical study of the preliminary results.

In view of the results of Swanson implants, particularly the long-term course of silicone implants, the authors studied and developed semi-constrained sliding arthroplasty designed for metacarpo-phalangeal and proximal interphalangeal joints. The preliminary study on bones and then on cadaver hands and finally on the knee of the rabbit allowed the design and experimentation of a prototype which led to the creation of a semi-constrained arthroplasty for which the elastic diaphyseal anchoring is ensured without cement and which possesses sliding surfaces composed of a metallic (proximal piece)--polyethylene (distal piece) interface. We therefore describe the principles of functioning of this arthroplasty, its technique of insertion, dorsal trans-tendon incision, its accessory (drill for diaphyseal preparations), its anatomical requirements (preservation of the palmar plate and lateral ligaments, bone section) and the postoperative course. To date, 52 arthroplasties have been inserted and we present the results of the first 36 cases for which the follow-up is equal to or a greater than one year (20 MP-16 PIP), indicating the technical modalities according to the various aetiologies (21 cases of rheumatoid arthritis--15 post-traumatic cases) and the complications. The average gain in mobility is 40 degrees with a mean range of movement of 64 degrees. In terms of pain, none of the arthroplasties were associated with pain apart from pain on cold in certain post-traumatic cases. The global and thumb-finger prehensile forces were evaluated to be an average of 90% in relation to the healthy side. Radiological assessment demonstrated fixation of the pieces in every case. Lastly, we discuss the outcome of this arthroplasty and its current indications in relation to the problems of instability essentially occurring in dislocated MP joints of rheumatoid arthritis.

Arthritis, Rheumatoid↗
PubMed1988

Duchenne-Erb palsy. Experience with direct surgery.

Between 1973 and 1984, 31 direct explorations of traumatic Duchenne-Erb palsy (C5 and C6) were performed in two hospitals. Simple neurolysis was performed in 12 cases, in which C5 and C6 were found to be in continuity; the operation resulted in useful motor function in nine of the 12 cases. A cause-and-effect relationship of neurolysis to the recovery of function was difficult to prove. In five cases where only one root was completely damaged, four nerve graftings produced useful motor results but the function of one graft was not demonstrable when the other root was in continuity. In 14 cases of complete lesions of both C5 and C6 treated by nerve grafting, there were seven functional motor results that were attributable to the grafts. Both the overall results and the result of elbow flexion were statistically correlated with the number of grafts used to repair the corresponding nerve structure (p less than 0.01). Favorable results were not obtained when the graft had been delayed for more than nine months. All of the patients who had nerve grafts within five months had favorable results.

Adolescent↗
PubMed1987

[Sensitivity: physiology, examination, principles of rehabilitation of sensation].

This is the text of a lecture devoted to the physiology of sensibility studied in the recent publications. The author describes successively the role of the peripheral receptors, clinical and electrophysiological assessment of sensibility, central mechanism of sensation, sequential recovery or sensibility after peripheral nerve lesion, rational basis for reeducation of sensation.

Humans↗
PubMed1985

Biodynamics of the wrist: radiologic approach to scapholunate instability.

A study of 126 normal wrists has allowed us to determine the normal laxity of the scapholunate complex (36 degrees) by measuring and comparing the range of movement of each of these two bones on sagittal views on x-ray films. There was no difference between dominant and nondominant hands. A study of eight cadaver wrists and 13 pathologic wrists has shown greater SL in the presence of scapholunate ligament lesions. The measurement of SL on dynamic sagittal views on x-ray films can detect a pathologic laxity between these two bones. A minimal 15 degrees difference between a normal and a pathologic wrist is reliable.

Biomechanical Phenomena↗
PubMed1985

Lesions of digital arteries in Dupuytren's disease. A study of twelve cases.

Twelve cases of histologically examined digital collateral arteries severed accidentally during surgery for Dupuytren's disease are presented. All arteries were repaired immediately after specimen retrieval for histological examination. Only one artery had a normal structure; 11 cases showed subendothelial fibrosis while two arteries thrombosed. These changes might account for the confusion of these arteries with adhesions and might explain their severance. Typically the zone involved was the distal part of the palm, in which the neurovascular bundle twists around the spiral cord. We believe that the lesions are a consequence rather than a cause of Dupuytren's disease.

Aged↗
PubMed1985

Microsurgical relations of the roots of the brachial plexus. Practical applications.

The brachial plexus roots were studied in 20 cadavers under magnification from their origin (division of the corresponding cervical spinal nerves) until their ending (origin of the corresponding trunks). Regional vascular injections were performed in 10 cases using colored latex. The means of fixation of each plexus root to the spine, as well as the collateral branches, the anastomoses and the vascular connections are described. The authors conclude by the description of a microsurgical posterior approach of C5-C6 and C7 up to their origin, with clinical applications.

Aged↗
PubMed1985

Radiological study of the mobility of the scapho-lunate joint.

Based on the study of 126 wrists, it was possible to determine that 36 degrees of normal laxity exists in the scapholunate complex. This was documented by the comparative measurements of the total range of movement of these two bones on sagittal plane X-rays. No difference between the dominant and non dominant hands was observed. Cadaveric experimental studies as well as the records of 13 pathological wrists showed that scapholunate laxity was greater when the scapholunate ligament was involved. Measuring scapholunate movements on sagittal motion roentgenographic views can detect pathological laxity between these two bones, considering that 15 degrees is the minimal difference permitted.

Female↗
PubMed1982

[Hemi-epiphyseal lengthening of the ulna in Kienboeck's disease].

The authors report the first results of a hemiepiphyseal lengthening of the ulna in a case of Kienböck's disease. Only the articular portion of the inferior epiphysis of the ulna is lengthened, the position of the styloid ulna being left untouched. The results of 17 cases are analysed. There were no cases of pseudarthrosis. The risk of conflict between the styloid ulna and the triquetrum is avoided.

Adolescent↗