Biomedical subjects

Pascal Bizot

Publications and source records attributed to Pascal Bizot.

5 recordsLinked to original sources

PubMed2005

Ceramics in total hip replacement.

Alumina-on-alumina total hip arthroplasty has been used for 32 years in Europe. The theoretical advantages of this combination are represented by its remarkable sliding characteristics, its very low wear debris generation, and its improved fracture toughness. These advantages are achieved if the material is processed properly with high density, high purity and small grains. We summarize the results obtained with the alumina-on-alumina combination concerning in vitro and in vivo wear behavior with special emphasis on wear debris characterization and quantification and histologic tissue examinations. Alumina-on-alumina seems to be one of the best choices in young and active patients provided that sound socket fixation is maintained in the long term.

Aluminum Oxide↗

PubMed2004

Use of the Cusum technique for evaluation of a CT-based navigation system for total knee replacement.

Most of the early failures of total knee replacements are related to technical flaws. Conventional ancillary devices achieve good alignment in the frontal plane in only an average of 75% of total knee replacements. Computer-assisted surgery may improve the technical quality of implantation surgery. The aim of our study was to evaluate the use of computer-assisted surgery using a quality control process. Seventy-eight total knee arthroplasties were done with a CT-based computer-assisted surgery system. The outcomes studied were alignment of the lower limb, implant positioning, and operative time. The target for alignment was 180 degrees +/- 3 degrees. Cusum analysis showed that the three outcomes were controlled during the study. The cusum test identified any existing outliers. Because few data were available at the beginning of this study regarding computer-assisted surgery for total knee replacement, a randomized study was not relevant. However, a control of the procedure was mandatory. The cusum technique allowed continuous evaluation of the performance of the new procedure, and is a useful tool in assessing new technology. The results of this study showed that it is possible to do a randomized study to determine if computer-assisted surgery can improve the technical result of total knee replacement.

Adult↗

PubMed2003

Fractures of ceramic bearings: history and present status.

During a period of 25 years (1977 to 2001), 13 fractures of an alumina component were recorded retrospectively. During the same period, approximately 5500 alumina components were implanted (3300 with all-alumina bearings and 1200 with alumina-on-polyethylene). These events occurred in seven women and six men, with a mean age of 59 years and a mean weight of 71 kg. There were eight fractures of the femoral head and five fractures of the socket component. Three fractures clearly were related to trauma (two fractures of the socket and one fracture of the head) and two were related to an abnormal design (one 22-mm head and one extra-long neck). Five fractures occurred without any rational explanation, but two fractures that occurred in the early phase could have been caused by a weaker alumina material. Finally three recent fractures of the liner were related to a change in the design of the material. This has been corrected and no additional fractures were observed. Although this dramatic event is of concern, it is infrequent and easy to solve by a limited revision procedure if done emergently. This rare complication should be balanced with the other complications of THR, including mechanical failures and osteolysis, often described with metal-on-polyethylene prostheses.

Adult↗

PubMed2003

Long-term results of alumina-on-alumina hip arthroplasty for osteonecrosis.

Alumina-on-alumina bearings in THR may, in theory, provide an effective answer to osteolysis in young patients with ON of the femoral head. The purpose of this retrospective study was to report the long-term results of a series of 52 consecutive alumina THAs (41 patients) done for ON. The mean age of the patients at surgery was 41 years (range, 22-79 years). Cemented femoral stems with a 32-mm alumina head were used. Plain alumina cups were used and were either cemented (39 hips) or press-fit (13 hips). No patients were lost to followup. Sixteen hips have been revised. Aseptic loosening of the socket was the main cause of failure. At an average 16-year followup (range, 11-23.65 years), 26 hips were rated excellent and one hip was rated good. No osteolysis was observed and wear was undetectable. If revision for aseptic loosening was the end point, the rate of survival was 88.5% at 10 years for the socket and 100% at 10 years for the stem. With the alumina-on-alumina hip replacement done for ON, absence of osteolysis can be expected for as many as 24 years after the operation. New methods of socket fixation now are being explored.

Adult↗

PubMedDate not supplied

Scapulothoracic fusion for serratus anterior paralysis.

Paralysis of the serratus anterior may lead to severe disability. Many surgical options are available, from soft-tissue procedures to scapulothoracic fusion. We report the results of 10 consecutive scapulothoracic fusions in 10 patients (7 men and 3 women) treated between 1980 and 1997. The mean age at surgery was 39 years (range, 22-57 years). Paralysis of the serratus anterior was isolated in five patients. One patient was lost to follow-up, and one patient died from an unrelated cause. Fusion was not achieved in three patients, two of whom had successful revision within 1 year postoperatively. One patient with an excellent result had a traumatic arthrodesis fracture and underwent successful revision. Results were assessed in 8 patients, including 3 who had reoperation. At a mean follow-up of 6.2 years (range, 1-15 years), 6 patients had a very good or good result and returned to manual labor. The mean active mobility was limited to 93 degrees in abduction and 101 degrees in forward elevation but was well tolerated. Two patients had a poor result because of nonunion and frozen shoulder, respectively. Scapulothoracic fusion may not be recommended as a primary procedure in the treatment of winging of the scapula due to serratus anterior paralysis. However, with the use of a careful technique, this method may be an alternative to muscle transfer, especially in patients in whom a previous soft-tissue procedure has failed or in patients with strenuous activities or combined muscular lesions.

Adult↗