Biomedical subjects

P Liverneaux

Publications and source records attributed to P Liverneaux.

12 recordsLinked to original sources

PubMed2006

[Dynamic mesh of carpal scaphoid].

Despite the use of cannulated compression screws, it is still difficult to screw non-displaced fractures of the scaphoid percutaneously. That is due in particular to the difficulty in assessing the correct position for the guide pin from the 2D fluoroscopic images. This work is designed to enable 3D visualisation of the scaphoid during surgical operations by using the technique of dynamic meshing and having the image appearing on a computer screen rather than as a mental image. In this context, the MEFP3C software includes applications for converting a generic scaphoid into a virtual scaphoid, based on the fluoroscopic 2D images of a given scaphoid. These applications include a module for acquiring a cloud of points, a modeller, a dynamic meshing system, an animation module, a texture module and a multi-resolution meshing system. The result of this process, the virtual scaphoid, in spite of the imperfections, enables images to be obtained comparable with those from tomodensitometric reconstruction of the same scaphoid specimen. The virtual scaphoid can be moved over the computer screen in the three spatial planes in translation, rotation and scaling. In conclusion, we think that dynamic meshing is a powerful, simple and ergonomic method of viewing a scaphoid in 3D, which could, in future, be routinely integrated into the fluroroscopic monitor.

Computer Simulation↗

PubMed2006

[Hand involvement in Thevenard's disease: a new "phlegmonous" form. An exceptional case report].

Thévenard's disease is a rare familial ulcero-mutilating acropathology involving the peripheral nervous system. It typically begins on the feet and only rarely spreads to the hands late in the course of the disease. It first causes cutaneous ulcerations and then secondary osseous deformations and osteoarticular destruction, due to a distal loss of temperature sensation. We report the case of an 87 year old patient who suffered from a particular clinical form, undescribed as yet in the literature and characterized by local and general superinfections predominately on the hands. We term this the "cellulitic" presentation or form of Thévenard's disease.

Aged↗

PubMed2005

[Long-term follow-up after leg replantation].

Leg replantation is generally considered to yield good results, particularly since the widespread use of progressive lengthening procedures. This optimism must be weighted against the very long and difficult operative program, the social and occupational implications, and the functional outcome of the replanted limb. We report a case of below knee leg replantation in a young patient whose operative program lasted 29 months. Occupational activities were interrupted for three years. The clinical result was satisfactory but with 14 degrees residual valgus suggesting a potential risk of osteoarthritis and difficult therapeutic decisions. The alternatives to replantation are controversial. Leg transplantation is not a valid option in our opinion. Amputation with orthesis should be considered more often because complications are rare and recovery much shorter. Indications for leg replantation should be considered with prudence.

Adult↗

PubMed2004

[Experimental increase in resistance of the osteoporotic distal radius with a calcium phosphate cement].

Diagnosis and treatment of osteoporosis are focused on demineralisation but bone mineral density is not directly correlated with bone strength. As with every material, the mechanical strength of bone depends upon its Young's modulus and its cross-sectional moment of inertia. In the clinical situation, bone strength can be quantified using peripheral quantitative computed tomography imaging (pQCT), a non-invasive imaging method, which allows calculation of a strength index. In this study, we tried to increase the fracture threshold of the distal radius by directly increasing bone strength rather than density. Twenty wrists in 10 cadavers were filled percutaneously with a calcium phosphate cement. Fluoroscopy and pQCT were performed twice, once before cementing and again 24 h after cement crystallisation to hydroxyapatite. We obtained measurements of trabecular and total bone density, and also stress strain index (SSI). Our results showed that trabecular bone density increased by a factor of 2.85, whereas total bone density increased by 1.61 and SSI by 1.99. Fluoroscopy showed two small leaks of cement at the point of injection. This study demonstrated that percutaneous injection of calcium phosphate cement increased distal radius strength, and consequently its fracture threshold. This technique could be employed in the future to prevent the occurrence of fractures in osteoporotic patients.

Aged↗

PubMed2004

[Jaccoud's arthropathy. Surgical results of 41 hands].

Jaccoud's arthropathy, which was first described in 1869, is a rare syndrome that is characterized by a painless or relatively painless deformity of the digits II, II, IV and V with a dislocation of the extensor tendons into the metacarpal valley. When the thumb is affected, a Z deformity is observed. The present analysis was based on 40 patients (56 hands, 41 of which were operated on over the period 1989 to 2001). A distinction should be made between Jaccoud's disease following a known inflammatory arthropathy (23 hands; average patient age 55 years) and the idiopathic form of the disease (18 hands, average patient age 70 years). From a clinical point of view, a classification of the deformities is needed so that appropriate surgical treatment can be determined. In the present study, four groups were therefore proposed, in groups I and III the realignment to centre of the extensor tendons of the metacarpophalangeal joint and joint stabilization yielded 83% positive results. In groups II and IV the results were only 66% good after Swanson implant. The pathogenesis of Jaccoud's disease has not yet been determined, but now that more information has become available and a better analysis can be made of its various clinical and anatomopathological charasteristics, these should assist in defining precise surgical indications.

Aged↗

PubMed2004

[What wrist fracture did Pouteau actually describe?].

The so-called " Pouteau-Colles" fracture was never specifically described by Pouteau. This surgeon from Lyons wrote a paper published in his posthumous works in 1783. The author was allowed access to an original edition of the paper at the "Ancienne Ecole de Médecine Navale de Rochefort". When reading this paper, it seems that Pouteau described a great variety of different kinds of forearm fractures. His original contribution was to define the mechanism of injury as occurring during a fall on the outstretched hand as opposed to direct injury. Pouteau presents a hypothetical muscular theory of fracture pattern etiology, but one that is useful in the understanding of the displacemnt of the bone fragments. He questions the principal role attributed to sprains and luxations at this time in the differential diagnosis of forearm injury. He described four clinical signs to diagnose, at a glance, which bone was injured, the site of the fracture, its displacements and mechanism of inury. Pouteau also presented a precise method of reduction and an original system of immobilisation, able to accomodate secondary displacements and avoid complications that were not fully recognised at that time, namely compartment syndrome and nosocomial infection. Pouteau simply concludes with a question concerning the future methods needed to reduce bony collapse and to fill the bone defects. In order to render special homage to this visionary surgeon, the author propose to attribute to the nosologic entity "fore-arm bone fractures" the qualificative of "Pouteau's fractures", or to associate to every fracture of the fore-arm described by any other author the name of the Lyons surgeon!

Colles' Fracture↗

PubMed2003

[Treatment of bony fibrous dysplasia with calcium-phosphate cement: a case report].

We report successful use of calcium-phosphate cement for the treatment of benign polyostotic fibrous dysplasia in a patient who had undergone several unsuccessful surgical procedures. As no autologous bone was available for further grafting, we used a bone substitute to fill two defects, one in the upper part of the humerus and the other in the radial shaft. The curettage cavity was filled with calcium-phosphate hydroxyapatite cement. The type of bone substitute was chosen for its specific properties: mineral structure similar to bone, microporosity, resistance to compression between cancellous and cortical bone, composition favorable to exchange between the crystals and the interstitial medium. Outcome was favorable early for the shoulder and later for the forearm after surgery for recurrence. Due to progress in the development of diphosphonates, indications for surgery for fibrous dysplasia have been reduced. There remains a risk of recurrence and incomplete results but bone substitute filling can be a useful alternative to autografts and complementary fixation. Calcium-phosphate cement is an easy-to-use paste-like product with interesting physicochemical and biological properties making it a leading choice for bone substitution.

Bone Cements↗

PubMed2002

[Hand replantation in an 88-year-old man: replanted senior?].

Indications of hand replantation need to take into account the patient overall condition and assess the magnitude of the injury. Although elderly people are usually considered as a limiting factor for microsurgery, indications of replantation may sometimes be extended. The author reports the case of a complete right hand amputation by a circular saw in an active right-handed 88 year man. The trans-carpal section was clean and general condition of the patient was satisfying. It was decided with the patient consent and the anaesthetist and the surgeon to perform the replantation. The procedure was carried on during 6 hours and revascularization took place 5 h 1/2 after injury. Post-operative period has been easy, but superficial nosocomial wound infection appeared which recovered with antibiotic therapy. It was not necessary to reoperate and the patient did not stay in intensive care department. After almost a 2 years follow-up, peripheral pulses were present, and the hand was warm and well coloured. Poor sensibility was found in median nerve area. Intrinsic motion was missing and extrinsic range of motion was weak. From a functional point of view, the patient was able to write, to dig his garden, and to drive his car. Analysis of this supposed hand replanted senior case report demonstrates that, when general and local conditions are safe, a hand replantation, even with a poor result, may be better than a prosthesis or an allograft, whatever the age of the patient.

Age Factors↗

PubMed2000

[Jaccoud's arthropathy].

Jaccoud's arthropathy, which was first described in 1869, is a rare syndrome that is characterized by a painless or relatively painless deformity of the digits II, II, IV and V with a dislocation of the extensor tendons in the metacarpal fossae. When the thumb is affected, a Z-deformity is observed. The present analysis was based on 21 patients (30 hands, 24 of which were operated on over the period 1989 to 1996). A distinction should be made between Jaccoud's disease following a known inflammatory arthropathy (15 hands; average patient age 55 years) and the idiopathic form of the disease (9 hands; average patient age 70 years). From a clinical point of view, a classification of the deformities is needed so that appropriate surgical treatment can be determined. In the present study, four groups were therefore proposed: in groups I and II, the realignment to centre of the extensor tendons over the metacarpophalangeal joint and joint stabilization yielded 87% positive results. In groups III and IV, the results were not as satisfactory either for the Swanson implant or for metacarpal shortening osteotomy. The pathogenesis of Jaccoud's disease has not yet been determined, but now that more information has become available and a better analysis can be made of its various clinical and anatomopathological characteristics, these should assist in defining precise surgical indications.

Aged↗

PubMed1996

[Lesions to the axillary nerve].

PURPOSE OF THE STUDY: The authors have reviewed 67 axillary nerve lesions from 1987 to 1993. 35 times the lesion was isolated; 20 times it was associated to other nerve lesions (9 times supra scapular nerve, 3 times musculocutaneous nerve, 8 times posterior cord) and 12 times lesions were associated to rotator cuff injury. MATERIAL AND METHODS RESULTS DISCUSSION: Injury corresponded 9 times to stretching mechanism in upper limb traction and came 58 times with osteoarticular lesions (30 anterior dislocations and 28 shoulder fractures). In 11 cases, shoulder active abduction was normal, inspite of deltoïd's complete palsy and this accounted for diagnosis delay. Concerning axillary nerve isolated lesions (35 cases), 7 recovered spontaneously and 28 have been operated. Surgical operation was undertaken 9 months after injury using a combined anterior and posterior approach. Rupture was located in the quadrilateral space and 23 nerve grafts, 4 neurolysis and 1 direct suture were performed. Results were good (muscle measured to M4) and excellent (muscle measured to M5) in 57 per cent of cases. Concerning axillary nerve lesions associated to suprascapular nerve lesions (9 cases) and musculocutaneous nerve (3 cases), all axillary nerve lesions were grafted with 50 per cent of good and very good results. The scapular nerve was neurolysed 6 times with 4 good and excellent results and evaluated irreparable in 3 cases. Musculocutaneous nerve was grafted in all cases with 2 good results out of 3. Posterior cord lesions (8 cases) required an osteotomy of the clavicle. Five grafts and 3 neurolysis were performed with aleatory results. At last, when associated lesions of the rotator cuff muscle were found (12 cases), 6 cases recovered spontaneously and 3 times cuff rupture was small enough to be reinserted with 2 good results. The 6 other cases corresponded to an axillary nerve rupture which were all grafted with 2 good results. On the cuff, result was in relation with lesion's type. Twice a supraspinatus tendon rupture was reinserted with 1 good result and 1 fair result. In 3 older patients, there was a small size rupture which has been reinserted with 1 good result, 1 fair result and 1 failure. At last, one surgical repair of a large rupture couldn't be justified. CONCLUSION: These encouraging results suggest to propose repair of axillary nerve when deltoid muscle palsy does not recover until 3 to 6 months. Rupture diagnosis is then suspected and the best surgical technique is a nerve graft.

Accidents, Traffic↗

PubMed1994

[Recent injuries of the nerves of the wrist and hand].

The advent of microsurgery has in the last few decades considerably improved the results of treatment of lesions of nerves in the wrist and the hand, both with regard to functional restoration of sensation and movement and to reduction of local irritant factors or those linked to cold injury. Peripheral nerves are frequently injured at the wrist and the hand by contusion, compression, straining or total or partial section. In the case of wrist, hand or finger wound, only well-directed, precise and systematic clinical examination can determine the neurological deficit. Surgery is always indicated. There are often associated complex lesions, and all injured elements must be completely repaired. The order of this repair is always the same: tendons, nerves, then vessels. Concerning nerves, therapy depends on the severity of the contusion and (or) the loss of substance. If the section is distinct, direct suture with physiological tension can be made. On the other hand, if there is contusion or loss of substance, direct suture cannot be performed since nonphysiological tension leads to endoneural ischaemia and fibrosis. Rather, the extremities should be brought closer together in order to avoid retraction and subsequent secondary sutures or short grafts should be made.

Hand↗

PubMedDate not supplied

[Scaphoid percutaneous osteosynthesis by screw using computer assisted surgery: an experimental study].

Scaphoid fractures are sometimes difficult to diagnose and even more difficult to fix. Recent progress such as miniaturization of osteosynthesis material, adoption of the percutaneous route, and widening of the indications to include undisplaced fractures has still not abolished complications. In this context, computer assisted surgery (CAS) may be useful and deserves further study. To apply it to the scaphoid, it is initially necessary to immobilize the "wrist hand fingers" unit in a device adapted to make it a rigid unit. It is then necessary to choose the correct configuration of CAS system. The pedicular fluoroscopic navigation system, which is apparently similar to scaphoid screw insertion, was chosen for this study. The goal of this study is to define the osteosynthesis bases of the scaphoid with CAS. A fresh anatomical subject divided at the elbow joint was prepared at the DETERCA laboratory of the university Bordeaux 2. The solid "wrist hand fingers" unit was immobilized in extension and ulnar deviation of the wrist by a malleable, stable and radio transparent device. The first stage consisted of a calibration of the surgical instruments and the "wrist hand fingers" unit, with a three-dimensional optical localization system. The guide wire was simulated by a gauged stylet. When the axis and the length of the screw had been determined virtually, insertion of the guide wire was carried out under guidance of the virtual images of the computer's screen, without the assistance of the fluoroscopy. Finally the canulated screw was inserted over the guide wire. Insertion was stopped when the screw reached the intra osseous virtually predetermined length. A check using conventional fluoroscopy made it possible to ensure the correct positioning of the screw. Our results show that it is possible to insert a screw into a scaphoid without conventional fluoroscopy, by using the fluoroscopic navigation system. The procedure was performed without difficulty, apart from the need for calibration of the navigation tools one by one. The solid immobilization device, although having the potential for micromovement, did not lead to any misdirection of the guide wire or screw. Our technique cannot be employed at the moment in live human surgery. Its limits are of a geometrical nature "two images available in two planes", data processing "non-specific software dedicated", instrumental "instrument calibration, micromobility of the immobilisation device" and live surgery "no current validation on a fractured scaphoid". Meantime, the development of a percutaneous scaphoid osteosynthesis procedure by CAS can only bring advantages: reduction in the learning curve, widening of the indications, comfort in the technique, reduction in the errors of ostesynthesis and, reduction in the exposure to x-rays. In the current state of knowledge, the method would only be applicable to undisplaced fractures.

Bone Screws↗