Biomedical subjects

S J Breusch

Publications and source records attributed to S J Breusch.

47 records · Page 3Linked to original sources

PubMedDate not supplied

[Effect of a rasp surface on cement penetration in paired cadaver femurs].

AIM: The purpose of this investigation was to study two different broach surface designs with regard to cement penetration into human cancellous bone. METHODS: In a cadaver study 15 paired human cadaver femora were prepared using broaches of identical geometry but different surface characteristics. All left femora were prepared using chipped toothed broaches, all right femora using diamond shaped broaches. Cancellous bone was irrigated with 1 liter pulsed lavage. The specimens were imbedded in specially designed pots. Bone cement was applied in a retrograde manner and subjected to a standard pressure protocol with a constant force of 3000 N. Radiographs were taken and horizontal sections were obtained at predefined levels using a diamond saw. Microradiographs were taken and analyzed using image analysis to assess cement penetration into cancellous bone. RESULTS: Pressure curves recorded during cement pressurisation were comparable. The microradiographic evaluation revealed no significant morphometric differences in the different groups with regard to cement penetration into cancellous bone. These findings were similar in all sections obtained. CONCLUSIONS: A standardized model was developed allowing comparison of cement penetration into cancellous bone depending on bone preparation. In the presence of pulsed lavage there is no significant influence of broach surface characteristics on cement penetration into cancellous bone of the upper end of the femur.

Bone Cements↗

PubMedDate not supplied

[Significance of jet lavage for in vitro and in vivo cement penetration].

AIM: The purpose of this study was to determine the efficacy of pulsatile jet lavage and manual syringe lavage with regard to their cleansing capabilities as measured by cement penetration into cancellous bone both in vivo and in vitro. METHODS: Three separate experiments were performed. Study A: In a cadaver study 36 left human cadaver femora were used for implantation of cemented femoral components. Conventional broaches were used for femoral preparation. Bone lavage was carried out either using jet lavage or manual syringe lavage of equal volume. The allocation to two different lavage groups was randomised. In both groups high-pressurising cementing techniques were implemented with the use of a proximal seal and additional finger packing. Study B: To guarantee standardised cement pressurisation and equal bone quality, the influence of jet lavage (1000 ml) versus syringe lavage (1000 ml) was studied in 11 paired human cadaver femora in an additional study without prosthesis implantation. The specimens were imbedded in specially designed pots. Bone cement was applied in a retrograde manner and subjected to a standard pressure protocol with a constant force of 3000 N. Study C: To directly compare the effectiveness of both pulsatile jet and syringe lavage with regard to cement penetration in vivo, a new sheep model allowing for standardised bilateral, simultaneous cement pressurisation was used. After femoral neck osteotomies both femoral cavities of 10 sheep were prepared for retrograde cement application. After randomisation one side was lavaged with 250 ml irrigation using a bladder syringe, the contralateral femur with the identical volume but using a pulsatile lavage. A specially designed apparatus was used to allow for bilateral simultaneous cement pressurisation. ANALYSIS: In all studies horizontal sections were obtained from the femoral specimens at predefined levels using a diamond saw. Microradiographs were taken and analysed using image analysis to assess cement penetration into cancellous bone. RESULTS: Study A: Compared with syringe lavage the use of jet lavage significantly improved the penetration of cement into cancellous bone (p = 0.027). In the presence of strong, dense cancellous bone the findings were more pronounced. Study B: Our results show that in equal quality bone, the use of jet lavage yields significantly (p < 0.001) improved cement penetration compared to syringe lavage specimens. Study C: The results of the in vivo study confirmed the superiority of jet lavage bone surface preparation (p = 0.002). CONCLUSIONS: The use of jet lavage yields significantly improved interdigitation between cancellous bone and cement both in vitro and in vivo and should be regarded as mandatory in cemented total hip arthroplasty. High pressurising techniques are effective means to improve cement penetration, but should only be administered with jet lavage to reduce the risk of fat embolism.

Animals↗

PubMedDate not supplied

[Thromboembolic complications related to the use of bone cement in hip arthroplasty--pathogenesis and prophylaxis].

INTRODUCTION: Cemented total hip arthroplasty (THA) has to be considered a high-risk procedure with respect to cardiovascular complications. The insertion of cement and prosthesis may lead to intravasation of fat and bone marrow into the circulation. METHODS: This article represents a review on the relevant literature about thromboembolic complications associated with the use of bone cement in THA. RESULTS/DISCUSSION: The method of canal preparation and lavage is of paramount importance to reduce the potential embolic load. Additionally, thorough cleaning of the intramedullary cavity (using jet lavage) improves the cement penetration into the bone and increases the shear strength of the bone-cement interface. Modern cementing techniques include the use of high pulsatile lavage, a cement restrictor and cement pressurization. With the application of these techniques a sufficient drainage of the medullary canal should be guaranteed to minimise the risk for thromboembolic complications. During the insertion of cementless implants the intravasation of embolic material seems to be less, but it is likewise possible to have a thromboembolic complication during cementless THA. However, it is not justified as a consequence to use the thromboembolic risk as the main indication for implant choice, in particular as the overall risk of a serious fatal complication is low.

Arthroplasty, Replacement, Hip↗

PubMedDate not supplied

[Cement delivery depends on cement gun performance and cement viscosity].

AIM: Retrograde cement application is considered an integral part of the modern femoral cementing technique. Both pressurisation and rapid cement application reduce the risk of interface bleeding and blood laminations. In this context cement gun performance has received little attention. METHOD: In our study we examined the handling characteristics of four different cement delivery systems (Syringe, Vaku-Mix, Optivac and MixOR-System). To allow for cement viscosity as another variable, six different bone cements (Palacos R, Palamed G, CMW 1 Radiopak, CMW 2000, Simplex P, VersaBond) were used with each system. We recorded cement gun performance and measured extrusion times and maximum cement delivery speeds of all possible combinations (gun/mixing system plus cement type). RESULTS: The fastest cement application could be achieved with the Vaku-Mix cement delivery system and the corresponding cement gun (Mark III). With regard to cement type, VersaBond and prechilled Palacos yielded significantly shorter extrusion times than most of the other cements due to their lower viscosities. CONCLUSION: Our results have shown significantly different efficacies of commonly used cement delivery systems/guns in clinical routine. Improved systems should be provided by the suppliers.

Arthroplasty, Replacement, Hip↗

PubMedDate not supplied

[Femoral fissure after cement restrictor implantation].

Cement restrictors are accepted parts of modern cementing technique and reduce the risk of revision. The restrictor should seal the intramedullary cavity to ensure sustained pressurization and optimal cement penetration into cancellous bone. Significant complications after use of a cement restrictor are rarely described. Dislocation and cement leakage are well known problems. We describe the occurrence of a femoral fissure after insertion of a resorbable Gelatine cement restrictor.

Aged↗

PubMedDate not supplied

[Cemented total hip arthroplasty in Germany--an update].

AIM: The results of a national survey from 1998 had shown at the time that only around 10 % of orthopaedic surgeons in Germany had strictly implemented modern cementing techniques in total hip arthroplasty (THA). The same study was repeated 5 years later to evaluate the current situation and to determine whether modern cementing techniques have become more popular. METHODS: A detailed, slightly modified questionnaire regarding cement and bone preparation, cementing techniques on acetabulum and femur, and implant types was sent to 572 German orthopaedic and trauma hospitals, as well as to visiting surgeons with an interest in THA. In total, 293 questionnaires were available for evaluation and statistical analysis. RESULTS: Palacos bone cement remained the most widely used cement (> 90 %). The mixing times given varied significantly. Vacuum mixing systems had become more popular (67.9 %). In the femur 81.8 % of the surgeons attempted to preserve cancellous bone and 57.2 % used pulsatile lavage (jet-lavage). Retrograde cement application via a cement gun was done in 71.1 %. Cement restrictors were used in more than 95 %. Only two-thirds of the surgeons implemented sustained cement pressurisation and preferred a cement mantle thickness > 2mm (64 %). Only 16.9 % made multiple small acetabular keyholes and 48.6 % used jet-lavage. In 73.1 % no cement gun was used and in 68.3 % the cement was applied at high viscosity. Manual cement pressurisation was done in 58.1 %. The Muller straight stem device remained the most popular implant. For only 5 of the over 50 stem designs implanted have long-term results been published as yet. Only 10.6 % of surgeons/centres performed > 20 and almost 50 % implanted > 100 cemented THAs/year. CONCLUSION: The results of this survey demonstrated that, in comparison to 1998, the current state of cemented THA, in particular cementing technique has significantly improved. Future emphasis should be on continued surgeon education and training, as the operative, i. e., cementing techniques are of utmost importance for long-term success.

Arthroplasty, Replacement, Hip↗

PubMedDate not supplied

[Current status of autologous chondrocyte transplantation].

PURPOSE: Autogenous chondrocyte transplantation (ACT) is a promising but disputable new method for the treatment of full thickness hyaline cartilage defects. Neither long-term follow-up studies nor prospective randomised comparative clinical trials exist to measure the outcome. METHODS: Several bioengeneering companies have emerged (Genzyme, Verigen, Co.don, etc.) and commercialised this new method of ACT which has generated enormous interest. Each company uses its own (secret) protocol for culturing human cartilage cells. These protocols vary considerably from each other with regard to culture media, enzymes and other additives (e.g. antibiotics) used. However, no quality control requirements for the culturing process of cartilage cells have been proposed which the companies have to fulfill. At the time of surgery the treating surgeon has to assume (and hope) that the cultured cells are viable, sterile, active and potent but a control mechanism does not exist. RESULTS: Considering the enormous price for ACT which the patients and the insurance companies are asked to pay quality control standards should be developed with the following informations given: cell viability, grade of differentiation, cell morphology, secretion levels of essential matrix components (collagen type II, IX, X and XI, Aggrecan) and the total cell number. None of the above information is currently provided by any of the companies involved. CONCLUSION: The widespread clinical use of this technique cannot be recommended at this stage as the scientific proof for reproducibility of ACT has not been given so far. The operative technique of ACT is demanding and should only be used by surgeons having attended special practical training courses and workshops to minimise technical failure rates. Clinical results should be documented in a uniform standardised way using established outcome scores and modern diagnostic measures (e.g. intraoperative biomechanical testing of repair tissue). Further controlled clinical trials, experimental research and the establishment of quality control standards are required.

Aggrecans↗

PubMedDate not supplied

[Status of cementation technique in total hip endoprostheses in Germany].

AIM: The correlation between improved cementing techniques and improved long-term results after total hip arthroplasty (THA) is well documented. The purpose of this study was to assess the use of modern cementing techniques in Germany. METHODS: A detailed questionaire regarding cement and bone preparation, cementing techniques on actabulum and femur, and implants used was sent to 584 German orthopaedic and trauma hospitals, as well as to visiting surgeons with an interest in THA. In total, 333 questionaires were available for evaluation and statistical analysis. RESULTS: In this survey, Palacos bone cement is used in 84%, low viscosity cement in 9%. Cement chilling is performed in 58%. Mixing is done by hand without vacuum mixing systems in 53%, the mixing time is standardised in 66%. For the femur 83% and for the acetabulum 74% preserve cancellous bone, 13% use pulsed lavage. Cement application is done via cement gun in 97%, in 41% in a retrograde manner and in 18% without drainage of the intramedullary canal. A cement pressurising technique is used in 63% for the femur and in 57% for the acetabulum. A cement mantle of less than 2 mm is attempted in 41%. More than 50 different stem design are implanted with the Müller straight stem being used most often, followed by anatomic designs. Almost 50% of hips are used with a 28 mm head, and almost 50% are implanted with a 32 mm head. Half the heads are ceramic, half are metal. CONCLUSIONS: The results from this survey document, that overall only slightly more than 10% of hips are implanted using second/third generation (modern) cementing techniques with application of pulsed lavage. This has implications on the number of arthroplasties that may require revision. From the data available the current status of cementing technique in Germany cannot be judged satisfactory.

Arthroplasty, Replacement, Hip↗

PubMedDate not supplied

[Anatomic basis of the cemented femur shaft. A comparative study of straight and anatomic design].

AIM: The purpose of this study was to compare cemented anatomic stems with cemented straight stems regarding cement mantle and stem orientation in the medullary canal. METHODS: In a cadaver study, 10 anatomic SP II stems and 10 MEM straight stems were implanted in paired human femora using a standardised modern cementing technique. In one group the femoral canal was prepared using conventional broaches, in the other group diamond hollow-cutters were used. Standardised horizontal cuts were made and evaluated regarding stem orientation and cement mantle using digitised image analysis. RESULTS: All SP II stems in the "diamond group" showed good stem centralisation without cement mantle defects. In the "broach group" all diaphyseal cancellous bone had been removed and only 3/5 stems were well orientated. No reproducible stem centralisation was achieved with the straight stems. All stems showed an oblique orientation from antero-proximally to postero-distally with direct stem to bone contact. The variation from the optimal stem alignment along the canal axis showed a mean deviation of 3.1 mm in the anatomic stem group and 10 mm in the straight stem group. The canal preparation using broaches showed frequent fractures of the cancellous bone and debris interposition despite the use of jet-lavage. Most of the cancellous bone in the diaphysis had been destroyed. CONCLUSIONS: Anatomic stems show a better stem centralisation and a more even cement mantle than straight MEM stems. The use of high volume straight stems carries a significant risk of producing cement mantle defects. Diamond instruments are less traumatic than broaches for femoral canal preservation and help to preserve diaphyseal cancellous bone, which improves stem self-centralisation.

Biomechanical Phenomena↗

PubMedDate not supplied

[Effectiveness of intra-articular application of hyaluronic acid on early forms of femoropatellar arthrosis--an experimental study in dogs].

PURPOSE: We investigated the effects of intraarticularly applied hyaluronic acid on the cartilage-integrity with early-forms of retropatellar cartilage degeneration (chondromalacia patellae) in dogs. METHODS: We used the Pond-Nuki model (tenotomy and resection of the anterior cruciate ligament = ACL) in 27 dogs (foxhounds) (3 groups of 9 animals) PILOT STUDY: ACL-tenotomy and resection, no therapy, specimens retrieval after 3, 6, 12 weeks (3 animals each period). VERUM: ACL-tenotomy and resection, hyaluronic acid (start after 3, 6, 12 weeks), 5 injections in 4 weeks, specimens retrieval after 5 weeks following final injection (12, 15, 21 weeks postoperatively, 3 dogs each period). PLACEBO: same procedure as verum, but saline-injections. Specimens were taken from the medial/lateral patellar pole from both, the operated and the normal knee and examined histologically using various staining methods (HE, Azan, Toluidin, Masson-Goldner, Safranin-O). A modified Mankin score was used to grade cartilage degeneration. RESULTS: Our results demonstrate that the Pond-Nuki model is suitable to experimentally induce chondromalacia patellae. There were significantly less degenerative cartilage changes in the knees treated with hyaluronic acid compared to the placebo-group. CONCLUSION: Our results let assume that hyaluronic acid could be indicated i.e. after arthroscopically diagnosed early cartilage-degeneration, the final conclusions concerning the actual mechanisms and therapeutical effectiveness need however further prospective clinical and experimental investigations.

Animals↗

PubMedDate not supplied

Acute pseudo-obstruction of the colon following left-sided total hip replacement: an analysis of five patients.

We report five cases of acute large bowel pseudo-obstruction following left-sided total hip replacement. All five cases presented with a similar sequence of clinical symptoms and physical signs. Acetabular trauma and heat generation from bone cement may lead to an imbalance of the autonomic nervous supply of the colon. We discuss a possible explanation for this phenomenon. We conclude that this condition is probably more common after total hip replacement than is currently diagnosed.

Aged↗