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At least 109 records · Page 6Linked to original sources
PubMed2006

[Analysis of short-term results of post total knee arthroplasty using TC-Dynamic posterior stabilized prostheses].

OBJECTIVE: To assess the feasibility, safety, and validity of the TC-Dynamic posterior stabilized prostheses implanted in the total knee arthroplasty (TKA). METHODS: Twelve knees of 10 patients (the TC-Dynamic group) were followed up, who had been implanted with the TC-Dynamic posterior stabilized prostheses from September 2003 to March 2004. Preoperative KSS knee scores were 16.08 +/- 11.58, function scores 13.75 +/- 19.79, and the range of motion (ROM) of the knee 75.00 +/- 26.46 degrees. Meanwhile, 50 knees of 30 patients (the Scorpio group) were followed up, who had undergone TKA with the Scorpio posterior stabilized prostheses. Preoperative KSS knee scores were 19.48 +/- 9.67, function scores 3.16 +/- 19.82, and the ROM of the knee 80.80 +/- 22.82 degrees. The anteroposterior and lateral X-ray films of each knee were examined before and after operation. The statistical Z-test was used to analyze the differences between the 2 groups in the improvement of the KSS knee scores, function scores, and ROM after operation. RESULTS: The average of the 130 days' follow-up revealed that the patients implanted with the TC-Dynamic prostheses had an excellent result. In the TC-Dynamic group, the KSS knee scores were 88.83 +/- 4.04 with improved scores of 72.75 +/- 14.47 compared with those before operation; function scores were 79.17 +/- 5.15 with improved scores of 65.42 +/- 19.47; the ROM of the knee was 107.92 +/- 11.57 degrees with increased degrees of 32.92 +/- 32.22 degrees. Meanwhile, in the Scorpio group, the KSS knee scores were 85.68 +/- 7.36 with improved scores of 66.20 +/- 10.44 compared with those before operation; function scores were 71.40 +/- 12.70 with improved scores of 68.24 +/- 25.35; the ROM of the knee was 109.20 +/- 11.13 degrees with increased degrees of 28.40 +/- 26.41 degrees. There was no significant difference in the improvement of the KSS knee scores, function scores, and ROM after operation between the 2 groups (P > 0.01). All the X-ray films of the knees implanted with both the Scorpio prostheses and the TC-Dynamic prostheses were analyzed. No mal-alignment or lucent line with the prostheses was seen in all these X-ray films. CONCLUSION: The short-term follow-up indicates that the patients implanted with the TC-Dynamic prostheses have an excellent result. The TC-Dynamic prostheses with a scientific and proper design is more suitable for the Chinese. However, the long-term outcome of the patients implanted with the TC-Dynamic prostheses should be observed in a larger number of TKA operations. The basic surgical principles, including excision of both the cruciate ligaments and correction of the bone deformity with the proper balancing of the soft tissues in flexion and extension, are still crucial to successful TKA and to the long-term high survival rate of the knee prostheses.

Adult↗
PubMed1994

Intraosseous incorporation of composite collagen prostheses designed for ligament reconstruction.

Composite collagen prostheses are potentially useful for reconstruction of the anterior cruciate ligament (ACL). We evaluated the intraosseous response to composite collagen prostheses to determine if "biological fixation" could be used to secure the prostheses within surgical bone tunnels. The rate of degradation of the prosthesis and the response of the tissue were evaluated, as a function of collagen crosslinking agent and time, in nonloaded bone tunnels in rabbits. Prostheses were fabricated by the alignment of 200 reconstituted type-I collagen fibers (60 microns in diameter) and the embedding of the fibers within a collagen matrix. The prostheses degraded rapidly within the bone tunnels in comparison with soft-tissue implantation sites. Dehydrothermal-cyanamide crosslinked collagen fibers were completely degraded by 8 weeks. Only 10% of glutaraldehyde cross-linked collagen fibers remained intact at 12 weeks. Fibrous tissue and inflammatory cells rapidly infiltrated the prostheses, and new bone surrounded the circumference of the prostheses, advancing toward the center at longer times. At the lateral cortex, where fibrous tissue emerged, the bone/soft-tissue interface was delineated by a tidemark, similar to that observed in a normal ligament insertion site. Preliminary pull-out testing of the soft tissue from the bone was discontinued because failure consistently occurred in the soft tissue; this suggests rapid incorporation of the prostheses within the bone tunnels. Composite collagen prostheses designed for ACL reconstruction degrade rapidly in bone and induce rapid ingrowth of fibrous tissue and bone. These results suggest that tissue ingrowth in the bone tunnels might provide biological fixation for collagen prostheses used for ACL reconstruction.

Animals↗
PubMed1999

Immunohistochemical analysis of vascular prostheses implanted with the left ventricular assist system.

BACKGROUND: Dacron vascular prostheses are associated with thromboembolic complications and inflammatory responses; impregnation with bovine collagen reportedly stimulates additional inflammatory/immunologic complications. The Novacor (Baxter Healthcare Corp., Oakland, CA, USA) left ventricular assist system uses Dacron inflow and collagen-impregnated Dacron outflow prostheses. METHODS: Explanted inflow and outflow prostheses were evaluated for inflammatory/immunologic, hemostatic, anticoagulant, and fibrinolytic pathways. Non-implanted prostheses immersed in whole blood or plasma were used as controls. RESULTS: Immunoglobulins and complement components were observed in all prostheses with activated macrophages being present only in implanted prostheses. Antithrombin III was observed in all prostheses whereas fibrin, tissue plasminogen activator, and alpha-2 plasmin inhibitor were present only in implanted prostheses. Endothelial and smooth muscle cells associated with vascular structures containing collagen type IV and laminin were observed solely in implanted prostheses. CONCLUSION: An inflammatory response occurs and key components of hemostatic, anticoagulant, and fibrinolytic pathways are present within implanted prostheses. These processes are accompanied by endothelial and smooth muscle cell infiltration which appear to lay the foundation for neovessel development.

Antithrombin III↗
PubMed1989

Patency and healing of 10-cm long microarterial polytetrafluoroethylene prostheses in the rat abdominal aorta.

Many studies have been undertaken on the experimental evaluation of microarterial polytetrafluoroethylene (PTFE) prostheses of short length. This study was undertaken to obtain insight into the performance of longer microvascular PTFE prostheses, which would be of more clinical utility. Microvascular PTFE prostheses of 10 cm in length (n = 8) were implanted into the rat abdominal aorta, fixed in a loop, and were compared regarding patency and healing with microvascular PTFE prostheses of 1 cm in length (n = 8) at three months after implantation (all prostheses: I.D.--1.5 mm, fibril length--30 microns). At three months, all prostheses, except one 10-cm prosthesis, were patent. In all PTFE microarterial prostheses, healing was observed only at the anastomotic sites with ingrowth of endothelial cells for a few millimeters into the lumen. There was no evidence of healing in the central areas of the prostheses. It was concluded that microvascular PTFE prostheses of useful clinical length show encouraging patency rates in the rat, despite poor endothelial cover. For possible clinical application of microvascular PTFE prostheses, further experimental studies should be undertaken to improve their healing capabilities.

Anastomosis, Surgical↗
PubMed1984

Patency and neo-intima development in 10 cm-long microvascular polyurethane prostheses implanted into the rat aorta.

Microvascular fibrous polyurethane prostheses (inner diameter 1.5 mm, length 10 cm) were implanted in the abdominal aorta of rats. The prostheses were fixed in a loop. All rats (n = 37) were reoperated 6 weeks after implantation to verify the patency of the prostheses. Eight prostheses were obliterated from various causes. The remaining 29 prostheses were found to be patent 3 months after implantation, which gives a patency rate of 79%. Six weeks and 3 months after implantation 7 and 4 rats, respectively, with patent prostheses were sacrificed. The remaining 18 rats of this study are still alive, more than 4 months after implantation, and will be included in long-term observation studies. The prostheses were examined using both light and scanning electron microscopy. The patent prostheses exhibited macroscopically a clear and transparent inner surface. No obliterative processes could be found either macroscopically or microscopically. Neo-intima ingrowth had advanced +/- 10 mm into the prostheses over the anastomotic line from both ends 3 months after implantation, and was continued by a single endothelium layer for several centimeters. An acellular, stable fibrin film was found inbetween the cellular lining. The neo-intima was anchored at the prosthesis by cellular protrusions extending between the polyurethane fibers. Though 10 cm long prostheses were implanted under unfavorable hemodynamic conditions, a patency rate of 79% was achieved, both 6 weeks and 3 months after implantation. This patency rate could have been higher if evident technical failures had been avoided.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2004

In vivo kinematics for fixed and mobile-bearing posterior stabilized knee prostheses.

This is the first in vivo kinematic study to compare mobile-bearing with fixed-bearing prostheses in patients who had total knee arthroplasties. Femorotibial contact positions for 40 patients implanted with either a fixed-bearing or mobile-bearing prosthesis were analyzed using videofluoroscopy. Femorotibial contact paths were determined using a computer automated model-fitting technique. Nineteen of 20 patients in each group experienced posterior femoral rollback of their lateral condyles, with a mean of 3.6 and 3.7 mm for fixed-bearing and mobile-bearing prostheses respectively. Eighteen patients who had mobile-bearing prostheses and 17 patients with fixed-bearing knee prostheses experienced a normal pattern of axial rotation of 7.3 degrees and 4.1 degrees respectively. Eleven of 20 (55%) patients who had mobile-bearing prostheses implanted and eight of 20 (40%) patients who had fixed-bearing prostheses implanted did not experience femoral condylar lift-off. The remaining knees had condylar lift-off less than 2.4 mm for fixed-bearing prostheses and 1.7 mm for mobile-bearing prostheses, respectively. Patients who had mobile-bearing prostheses implanted experienced greater axial rotation and less condylar lift-off than patients who had fixed-bearing prostheses implanted. Both cruciate ligaments are sacrificed for the mobile and fixed-bearing total knee replacements. The results from the current study showed that, in both groups, the majority of patients experienced kinematics similar to those of a normal knee. However, the extent of lateral femoral condyle posterior rollback and the extent of axial rotation were less.

Humans↗
PubMed1998

Loads in hip disarticulation prostheses during normal daily use.

As a result of deficiency at birth, disease or trauma, there are people who have no limbs from the hip joint downwards. These people have no possibility of locomotion without the use of other devices such as wheelchairs or hip disarticulation prostheses. As these prostheses are used by people of all ages, people who are different in their grade of physical activities and their weights, the prostheses are subject to different stresses related to these different circumstances. The European Level 2 Draft Standard prEN 12523: 1966 "External limb prostheses and external orthoses - requirements and test methods" contains strength requirements for lower limb prostheses. These requirements shall be verified, where appropriate, by the application of the International Standard ISO 10328 "Prosthetics - Structural testing of lower limb prostheses" and ISO/FDIS 15032 "Prosthetics: Structural testing of hip prostheses". In order to allow the prostheses to be tested to the stresses that are experienced in real life, it is necessary to measure the stress that is induced in the prostheses while the patient is in an everyday situation, such as walking on level floor, walking on grass and/or walking on an uneven surface. This work is concerned with the acquisition of loads generated in hip units of hip disarticulation prostheses by amputees during various activities. More than 30 patients were tested in Germany, France, and Belgium. The measurements were carried out with financial support from the European Commission and coordinated by the secretariat of CEN TC 293.

Amputees↗
PubMed2000

Magnetic resonance imaging of stapes prostheses.

OBJECTIVE: To assess the magnetic resonance imaging (MRI) compatibility of stapes prostheses. DATA SOURCES: A comprehensive review of the English literature evaluating MRI compatibility of stapes prostheses. Multiple series of stapes prostheses from different manufactures placed in a 1.5-tesla MRI field to determine ferromagnetic properties. RESULTS: When MRI was first introduced, reports demonstrated the MRI compatibility of stapes prostheses. The testing was performed on single copies of various prostheses from several manufacturers. Although implant manufacturers have indicated MRI compatibility, several reports of variable ferromagnetic properties of aneurysm clips have been reported. This variability has led to rotation of the clips and hemorrhage in patients with supposed MRI-compatible clips. These findings suggest that testing single stapes prostheses from a manufacturer might not completely assess the safety of MRI on patients with stapes prostheses. We performed MRI compatibility testing on several series of stapes prostheses from Xomed Surgical Products and Smith & Nephew Richards. Two series of Xomed stapes prostheses were found to have ferromagnetic properties. CONCLUSION: Manufacturing variability could lead to stapes prostheses being MRI incompatible. Each prosthesis should be tested before implantation for ferromagnetic properties.

Consumer Product Safety↗
PubMed2002

Risk of connective-tissue disease in men with testicular or penile prostheses: a preliminary study.

AIM: To help clarifying the possibility of connective-tissue diseases in men with penile or testicular prostheses. METHODS: Eight patients underwent inflatable penile prostheses and 15, testicular prostheses consented to the study. Their medical records were reviewed and a follow-up interview and physical and serological examinations were performed. RESULTS: In patients with penile prostheses, there was no abnormal antinuclear antibody (ANA) or IgM elevation. The serum levels of the rheumatoid factor (RF), C4, IgA and IgG were abnormal in one patient, and the levels of erythrocyte sedimentation rate (ESR) and C3, abnormal in two. Four had elevated IgE. In patients with testicular prostheses, there was no abnormal RF, ANA or IgM. The serum levels of ESR and IgA were abnormal in two, and three had abnormal C4, ten abnormal C3, and eleven decreased IgG. All had increased IgE. Men with penile prostheses had higher serum levels of IgG and IgM than those with testicular prostheses (P=0.001, P=0.016, respectively). The rates of abnormal values of IgE and IgG were higher in men with testicular prostheses than in men with penile prostheses (P=0.008, P=0.009, respectively). Physical examination was normal in all patients and nobody had documented symptoms pertinent to connective-tissue diseases. CONCLUSION: Our findings suggest that the risk of connective-tissue diseases is not higher in patients wearing prostheses as the ANA is negative and there is no apparent manifestation suggestive of connective-tissue diseases.

Adolescent↗
PubMedDate not supplied

Implant-supported fixed partial prostheses: a retrospective study.

PURPOSE: The purpose of this retrospective study was to present treatment outcome and patient reactions to rehabilitation with implant-supported fixed partial prostheses. MATERIALS AND METHODS: Eighty-three patients were consecutively treated with implant-supported fixed partial prostheses (Brånemark system) from 1986 to 1995. Seventy-six of these 83 patients were examined (66 maxillary and 31 mandibular prostheses). The mean observation time was 53.9 months. In total, 285 implants were placed. Eleven implants were lost before loading. The first 41 prostheses were removed and the implants examined regarding the criteria for "success" and tightness of the screw joints. Only one implant had lost integration. RESULTS: The survival rate before and after loading was 96%, which included implants placed in augmented bone. All prostheses were stable at the time of examination. In prostheses with cantilevers (98 implants), 12% of the gold screws and 17% of the abutment screws showed a "not acceptable" loosening, compared to none in the prostheses without cantilevers (17 implants). The difference was not statistically significant. The mean marginal bone loss was 0.4 mm for the first year after prosthesis insertion and less than 0.1 mm per year in the following years. The most frequent prosthesis design was one pontic supported by two implants. Prostheses made in gold acrylic and titanium acrylic had more complications and showed a higher need for repair than metal-ceramic restorations. Patients reacted very positively to the esthetic results and comfort with eating, and were overall satisfied with their prostheses. CONCLUSION: Implant-supported fixed partial prostheses seem to have a very good prognosis and are well-accepted by patients.

Acrylic Resins↗
PubMedDate not supplied

Reduced thrombogenicity of vascular prostheses by coating with ADP-ase.

In this pilot study ADP-ase coated polyurethane (PU) vascular prostheses and noncoated (control) PU vascular prostheses (all vascular prostheses: ID 1.5 mm, length 1.5 cm) were implanted into the carotid artery of the rabbit to test whether ADP-ase might function as an adequate anti-thrombogenic coating. The prostheses were evaluated after 1 hour (n = 4) and 3 weeks (n = 8). After 1 hour, there was extensive accumulation of thrombus on the inner surface of the control PU vascular prostheses, in contrast to the ADP-ase coated prostheses. At 3 weeks, all control PU vascular prostheses (n = 8) were occluded, whereas only 1 of the 8 ADP-ase coated PU vascular prostheses. The patient ADP-ase coated PU prostheses showed already extensive endothelial healing. These results indicate the potential of ADP-ase to function as an effective antithrombogenic coating of small-caliber and microvascular PU prostheses.

Animals↗
PubMedDate not supplied

A retrospective study on the maintenance and repair of implant-supported prostheses.

This study reviewed the prosthodontic treatment and aftercare required by 29 patients with 32 implant-supported prostheses (12 fixed and 20 removable) placed on 107 implants. Patients were followed for 4 to 39 months. The majority of implant-supported prostheses (53%) were placed in the mandible. Visual analogue scales were used by the patients to rate their satisfaction with their prostheses and their chewing ability. Approximately one third of the patients studied required three or more relines of their existing dentures between first- and second-stage surgeries, while over half of the definitive implant-supported prostheses required a major adjustment or repair. Removable prostheses required 78% of the total repairs and accounted for 80% of those prostheses that needed repeated repairs. In general, patients were very satisfied with their implant-supported prostheses, but 17% complained of mild speech difficulties and 7% noted slight difficulty in cleaning their fixed prostheses. Overall, the short-term prosthetic management required for the implant-supported prostheses in this study was substantial, particularly with the removable prostheses, and this should be taken into account when evaluating prosthetic options.

Dental Clasps↗
PubMed1990

Hydroxylapatite ossicular replacement prostheses: preliminary results.

Hearing results and extrusion rate for 89 consecutive patients receiving hydroxylapatite prostheses for hearing reconstruction were evaluated and compared to a control group of 75 patients who had received homograft bone or Plasti-Pore prostheses. At the 3-month follow-up, there were no cases of extrusion of the hydroxylapatite prostheses. Hearing success was defined as a postoperative air-bone gap of less than or equal to 15 dB for incus prostheses and partial ossicular replacement prostheses or less than or equal to 25 dB for incus-stapes prostheses and total ossicular replacement prostheses. There was a statistically significant difference in the distribution-of-success rate by prosthesis type for the hydroxylapatite. Incus, incus-stapes, and total ossicular replacement prosthesis results were similar, but partial ossicular replacement prosthesis results were poorer. The overall success rate in the hydroxylapatite group was 51.2%; in the control group, it was 60%. Hearing results tended to be better with the hydroxylapatite incus prosthesis than with the homograft bone incus, but poorer with the hydroxylapatite partial ossicular replacement prosthesis than with the Plasti-Pore. Several technical modifications of the prosthesis that may improve results with the hydroxylapatite partial ossicular replacement prosthesis are suggested. Hydroxylapatite middle ear prostheses appear to be a reasonable alternative to other more commonly used prostheses, which carry disadvantages related to the use of human tissue.

Adolescent↗
PubMed1999

Biofilm formation in vivo on perfluoro-alkylsiloxane-modified voice prostheses.

OBJECTIVE: To study the influence of perfluoroalkylsiloxane (PA) surface modification of silicone rubber voice prostheses on biofouling. DESIGN: Placebo-controlled clinical trial. SETTING: Tertiary referral center, with specialization in head and neck cancer treatment. PATIENTS: Eighteen consecutive patients with laryngectomies and experienced in the use of a voice prosthesis who visited the outpatient clinic for prosthesis replacement. MATERIAL: Eighteen partially surface-modified voice prostheses (3 with short-chain PAs [1 fluorocarbon unit] and 15 with long-chain PAs [8 fluorocarbon units]) were inserted via the patients' tracheoesophageal shunts and remained in place for 2 to 8 weeks. INTERVENTION: Replacement of the prostheses. MAIN OUTCOME MEASURES: Evaluation of biofilm formation on short- and long-chain PA-modified and original silicone rubber surfaces on the esophageal side of the voice prosthesis. RESULTS: The planimetrical biofilm scores of the surfaces of all 3 short-chain PA-treated voice prostheses indicated more biofouling on the treated surfaces than on the untreated surfaces of the same prostheses. For the long-chain PA-treated prostheses, the planimetrical biofilm scores, as well as the numbers of colony-forming units per cm(-2) for bacteria and yeasts, indicated less biofouling on the treated side than on the control side for 9 of the 13 prostheses that could be analyzed (2 were lost to analysis). Identical fungal strains, mainly Candida sp, were isolated from biofilms on each side of the esophageal flange. CONCLUSIONS: Chemisorption of long-chain PAs by the silicone rubber used for voice prostheses reduces biofilm formation in vivo and therefore can be expected to prolong the life of these prostheses. Chemisorption of short-chain PAs by silicone rubber seems to have an adverse effect.

Biofilms↗
PubMed1998

The effect of buttermilk consumption on biofilm formation on silicone rubber voice prostheses in an artificial throat.

Biofilm formation on indwelling silicone rubber voice prostheses in laryngectomized patients is still the main reason for dysfunction of the valve, leading to frequent replacements. Within patient support groups in The Netherlands, laryngectomees have suggested that the consumption of buttermilk prolongs the life-time of indwelling silicone rubber voice prostheses. The aim of the present study was to compare biofilm formation on Groningen button voice prostheses in a so-called artificial throat. Ten prostheses were placed in a simulated control group and ten other prostheses in a group with a simulated consumption of 700 ml buttermilk three times a day. Biofilms were allowed to grow on the prostheses by inoculating two artificial throats with the total cultivable microflora (bacteria and yeasts) isolated from an explanted Groningen button voice prosthesis. After 3 days, one artificial throat was perfused three times daily with phosphate buffer (control group) for 8 days, while the other artificial throat was perfused with buttermilk. Prostheses removed from the artificial throat in the control group were covered with a thick biofilm. Scanning electron microscopy showed microcolonies growing into the silicone rubber, similar to the ingrowth observed on explanted Groningen buttons. The simulated consumption of buttermilk in the other artificial throat almost fully prevented the formation of a biofilm on the prostheses during the experimental period. These in vitro experiments in the artificial throat demonstrate that the deterioration of voice prostheses can be lessened by the daily intake of buttermilk through its inhibitory effects on biofilm formation.

Animals↗
PubMed2005

Safety evaluation of titanium middle ear prostheses at 3.0 tesla.

OBJECTIVE: To assess the magnetic resonance imaging (MRI) safety of titanium middle ear prostheses at 3.0 tesla (T). STUDY DESIGN AND SETTING: Titanium middle ear prostheses from 3 commercial vendors were examined for magnetic field interactions at 3 T. Initially, ex vivo studies were performed to test for rotational motion and forward displacement (translational motion) of the prostheses in a static magnetic field. If movement was observed during this screening study, then the prosthesis was tested to determine the translational or rotational force acting upon the prosthesis. In addition to testing for prosthesis displacement, temperature changes of the prostheses were measured to assess for radiofrequency heating during imaging. RESULTS: Twenty-one of the 24 titanium prostheses tested revealed no movement when tested in the 3 T static magnetic field. Three prostheses revealed minimal movement during the screening study. A translational force test (string test) was performed upon these 3 prostheses, and the measured angle of displacement was used to determine the force. This calculated force acting upon each prosthesis was essentially zero. Therefore, we conclude that the magnetic field interaction is negligible. A positive control with a ferromagnetic stainless steel prosthesis demonstrated obvious displacement during the screening study, as well as deflection of the prosthesis by 90 degrees in the translational force test. Last, heating of the titanium prostheses did not occur in the 7 models tested. CONCLUSIONS: Middle ear prostheses made from titanium are safe, neither deflecting nor heating during magnetic resonance examinations conducted at 3 T. EBM RATING: C-1.

Equipment Failure Analysis↗
PubMed1998

Endothelialization of biosynthetic vascular prostheses after laser perforation.

OBJECTIVE: This study was undertaken to investigate the feasibility of transmural capillary ingrowth into the inner surface of biosynthetic vascular prostheses (Omniflow, BioNova, Melbourne, Australia) through perforations created by an excimer laser, thus inducing an endothelial cell coverage. METHOD: Biosynthetic vascular prostheses (Omniflow, 10 cm length, 6 mm diameter) were perforated with an excimer laser (diameter of the holes 50 to 100 microm, distance 4 mm) and implanted into the carotid arteries of eight sheep. They were compared to untreated Omniflow prostheses implanted at the contralateral side. Three months after implantation the prostheses were explanted and evaluated by gross morphology, histologic examination, scanning electron microscopy, and immunohistochemical staining for factor VIII to identify endothelial cells. RESULTS: All grafts remained patent. Gross morphologic examination revealed no significant difference in the thrombus-free surface between perforated and untreated prostheses. However, scanning electron microscopy showed endothelial cells in the midgraft portion of all perforated prostheses, whereas collagen fibers, fibrin meshwork, and activated platelets formed the inner layer in six of eight untreated Omniflow prostheses. Transmural capillary ingrowth in the laser group was verified by positive factor VIII staining for endothelial cells in the laser channels. CONCLUSION: Spontaneous endothelialization of biosynthetic vascular prostheses can be achieved by transmural capillary ingrowth through perforations in the wall of the prostheses in an experimental sheep model.

Anastomosis, Surgical↗
PubMed2002

Discriminating the loosening behaviour of cemented hip prostheses using measurements of migration and inducible displacement.

In vitro pre-clinical tests of hip prostheses have not yet been developed to the extent that inferior prostheses can be 'screened-out' prior to animal or clinical trials. This paper reports the experimental part of a project to develop a pre-clinical testing platform for cemented femoral hip implants. It is based on the clinical observation (Kärrholm et al. JBJS, 76B (1994) 912-916) that higher subsidence (distal migration) correlates with early revision of hip prostheses. A protocol to measure the relative movement between implant and bone was designed to test whether or not such a measurement, if made in a laboratory, could discriminate between hip prostheses. The protocol was applied to the Lubinus SPII prosthesis (W. Link, Germany) and a Müller Curved Stem (JRI Ltd., UK)-these prostheses were chosen because they are known to have different loosening rates in vivo. Five prostheses of each design were tested. The migration, the rate-of-migration, and the inducible displacement of each prosthesis was recorded over two million cycles of loading. For each implant, rapid initial migration was found, followed by a period of steady-state migration. In the majority of cases, the prostheses migrated medially, distally and posteriorly. On average, the Lubinus migrated less than the Müller in all directions. The average Lubinus migration was less than half that of the Müller, and this difference was significant at a level of p=0.05. Inducible displacement was greater for the Müller compared to the Lubinus. Furthermore, the inducible displacement decreased over time for the majority of Lubinus prostheses whereas it increased over time for the majority of the Müller prostheses leading to the conclusion that a rapid pre-clinical test based on measurement of inducible displacement may be possible.

Bone Cements↗