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M Lukoschek

Publications and source records attributed to M Lukoschek.

At least 37 records · Page 2Linked to original sources
PubMed1998

Periprosthetic mineralization around cementless total hip endoprosthesis: longitudinal study and cross-sectional study on titanium threaded acetabular cup and cementless Spotorno stem with DEXA.

In a prospective longitudinal study over 2 years and a separate cross-sectional study more than 5 years after operation, we analyzed periprosthetic bone mineral density (BMD) after cementless total hip arthroplasty (THA) (press-fit cementless Spotorno stem, Mecron threaded acetabular cup) by dual-energy X-ray absorptiometry (DEXA). BMD was analyzed in a longitudinal prospective study (n = 53 patients: 29 women, 24 men) and in a separate cross-sectional study (n = 23 patients: 13 women, 10 men) with good clinical outcome (Merle d' Aubigne score > 12). Regions of interest were defined according to Gruen (ROI 1-7) and as netto average ROI (NETAVG I) for the periprosthetic femur, and according to De Lee and Charnley (ROI I-III) and as NETAVG II for the periprosthetic acetabulum. BMD during follow-up was compared with immediate postoperative values of the affected limb. Mean precision error (CV%) was 2.6 +/- 0.5% for ROI 1-7 and 1.3 +/- 0.9% for ROI I-III. BMD significantly decreased in the periprosthetic femur and acetabulum during the first 3 months after operation. At the femur, BMD (NETAVG I) for women and men, respectively, was 92.4% and 87.5% at 6 months, then 89.4% and 96.2% at 2 years. ROIs around the proximal stem showed the lowest absolute values and decreased most during follow-up (to 79.9% ROI 1 and 68.2% ROI 7, respectively). Mineralization around the cup (NETAVG II), respectively, amounted to 81.1%, 82.6% at 6 months, then 80.1% and 93.8% at 2 years. The medially placed ROI II demineralized most (respectively, 72.1% and 76.7%). More than 5 years after THA, BMD in the femur showed little change, but decreased significantly to 76.4% and 79.1%, respectively, around the cup (NETAVG II). DEXA is a useful method for analyzing changes of mineralization around cup and stem of cementless THA. The results reflect the different stress on the periprosthetic bone after implantation of THA in defined ROIs, supporting earlier reported good clinical results of the Spotorno stem and increased loosening rate of threaded acetabular cups after 5 years.

Absorptiometry, Photon↗
PubMed1998

Loss of laminin and of the laminin receptor integrin subunit alpha 6 in situ correlates with cytokine induced down regulation of alpha 6 on fibroblast-like synoviocytes from rheumatoid arthritis.

OBJECTIVE: To investigate in situ the expression of the integrin receptor subunits alpha 6 and beta 1 and the distribution of the ligand laminin in the synovia from osteoarthritis (OA) and rheumatoid arthritis (RA) patients and to study the effect of cytokines and antirheumatic drugs on the expression of the alpha 6 and beta 1 integrin subunits on long term cultures of fibroblast-like synoviocytes (FBS) derived from OA and RA. METHODS: The expression of the alpha 6 and beta 1 integrin subunits and the distribution of laminin were examined immunohistochemically in normal synovia and in synovia from patients with OA and RA. The effect of proinflammatory cytokines (IL1 beta and TNF alpha), and of antirheumatic drugs (salicylic acid, dexamethasone, and methotrexate) on the alpha 6 and beta 1 expression of cultured normal FBS and FBS from patients with OA and RA was determined by flow cytometry. RESULTS: In normal synovia and in OA synovia samples with a low grade of inflammation, synovial lining cells (SLC) showed a parallel expression and distribution of alpha 6 and laminin. In synovia samples of OA with a higher grade of inflammation and in the majority of RA synovia samples laminin was pericellularly distributed in a low number of SLC, whereas alpha 6 was expressed on the surface of a high number of SLC. In RA synovia samples with severe inflammatory changes the gradual loss of laminin generally corresponded to a decrease of the alpha 6 integrin subunit. beta 1 was always strongly expressed in all synovia samples detected. Proinflammatory cytokines up regulated the expression of alpha 6 and beta 1 on OA-FBS, whereas these effectors decreases alpha 6 and beta 1 on RA-FBS. In contrast, antirheumatic drugs, in particular methotrexate and dexamethasone, reduced the expression of alpha 6 and beta 1 on OA-FBS, whereas the same treatment on RA-FBS stimulated the expression of these integrin subunits. CONCLUSION: The gradual loss of laminin in chronic synovitis may contribute to the altered expression of alpha 6 in SLC. IL1 beta and TNF alpha down regulated the expression of the alpha 6 and beta 1 integrin subunits on long term cultures of FBS derived from RA. Therefore, these cytokines may be among the effectors regulating the expression of the alpha 6 integrin subunit in SLC in vivo. As antirheumatic drugs increase the expression of alpha 6 on RA-FBS, the presence of the laminin receptor may confer a protective effect on the synovia in vivo.

Antigens, CD↗
PubMed1997

Increased expression of integrins on fibroblast-like synoviocytes from rheumatoid arthritis in vitro correlates with enhanced binding to extracellular matrix proteins.

OBJECTIVE: To compare in vitro expression of beta 1, beta 3, and beta 4 integrins in normal fibroblast-like synoviocytes (FBS) and in FBS from rheumatoid arthritis (RA) synovium and to investigate the adhesion of normal FBS and RA-FBS to the integrin binding extracellular matrix (ECM) proteins: collagen type IV, fibronectin, laminin, and tenascin. METHODS: Expression of integrin receptors of cultured FBS was detected by flow cytometry. Attachment of FBS to ECM proteins was quantified by adhesion assays. Inhibition studies were performed using monoclonal antibodies to the integrin subunits. RESULTS: Compared with normal FBS, RA-FBS showed increased expression of alpha 1 to alpha 6, beta 1, and beta 4 integrin subunits and enhanced binding of ECM proteins. Binding to ECM proteins was partly or completely blocked by an anti-beta 1 integrin antibody and antibodies to alpha 3, alpha 5, and alpha 6 integrin subunits. The blocking efficiency was significantly (P < 0.05) higher in RA-FBS than in normal FBS. CONCLUSIONS: The enhanced expression of the beta 1 integrin receptors on cultured RA-FBS correlated with increased attachment to ECM proteins. Adhesion of normal and RA-FBS to ECM proteins is mediated through beta 1 integrin receptors. Therefore, the tight binding of rheumatoid FBS to the matrix via beta 1 integrins might play a role in ECM remodelling in the rheumatoid process in vivo.

Arthritis, Rheumatoid↗
PubMed1997

Differential expression and functional behaviour of the alpha v and beta 3 integrin subunits in cytokine stimulated fibroblast-like cells derived from synovial tissue of rheumatoid arthritis and osteoarthritis in vitro.

OBJECTIVE: The aim of this study was to investigate in situ the expression of the classic vitronectin (VN) receptor consisting of the alpha v and beta 3 subunits in synovial lining cells (SLC) of chronic synovitis occurring in osteoarthritis (OA) and in rheumatoid arthritis (RA). The expression and function of alpha v and beta 3 as VN receptor in cultured fibroblast-like synoviocytes (FBS) derived from patients with OA and RA was also compared. METHODS: Expression of alpha v and beta 3 was examined immunohistochemically in normal synovial tissue and in synovial tissue from patients with OA and RA. The effect of proinflammatory cytokines and of a synovial fluid of a patient with RA on the expression of the alpha v and beta 3 subunits of cultured FBS was determined by flow cytometry. Binding of OA and RA-FBS to VN was quantified using adhesion assays and the effect of interleukin 1 beta (IL1 beta) and tumour necrosis factor alpha (TNF alpha) on adhesion was measured. The specificity of the adhesion was tested by inhibition studies using monoclonal antibodies to integrin subunits. RESULTS: In in situ studies normal SLC showed a parallel distribution of alpha v and beta 3 subunits. OA-SLC strongly and uniformly expressed alpha v whereas RA-SLC showed heterogeneous expression of alpha v. In situ both OA-SLC and RA-SLC lacked the expression of the integrin subunit beta 3. In in vitro studies, OA-FBS and RA-FBS did not differ as regards expression of alpha v and beta 3, and VN attachment. Binding of RA-FBS to VN was partially blocked by antibodies against alpha v, beta 1, and beta 3 subunits, whereas only antibodies against alpha v and beta 3 inhibited the binding of OA-FBS to VN. The proinflammatory cytokines TNF alpha and IL1 beta increased the expression of alpha v and beta 3, and the VN binding of OA-FBS, whereas alpha v and beta 3 expression, and VN binding were downregulated in RA-FBS. Similar effects were found when the synovial fluid of an RA patient was used. CONCLUSION: The integrin subunit beta 3 seems to be one partner but not the major one with which the subunit alpha v forms functional vitronectin receptors in OA-FBS and RA-FBS. The interaction between synovial cells and inflammatory cytokines seems to be different for OA and RA; the basis for this difference, however, remains to be established.

Arthritis, Rheumatoid↗
PubMed1997

Middle-term results of threaded acetabular cups. High failure rates five years after surgery.

We report our results using three different threaded acetabular components (Mecring A, Mecring B and Weill) in 715 hips with a follow-up of between one and ten years (median: 99.1, 56.5, 38.3 months, respectively). All cups were implanted with one type of cementless stem. The clinical results were good or acceptable in about 70% of the hips, but signs of loosening with radiolucency and/or migration were found in 10.1%. Radiological evidence of loosening did not correlate significantly with the clinical outcome. Pain was not a reliable indicator of loosening and its absence sometimes allowed severe osteolysis to develop. Twenty-five hips were revised (3.5%) for aseptic loosening of the acetabular component. Kaplan-Meier estimates of the cumulative rate of failure showed a rapid increase five years after the initial operation, but no significant correlation with gender, age or weight. The high rate of failure indicates that further use of these acetabular components cannot be recommended. Annual radiographs are required to assess osteolysis even if the patients are free from pain.

Acetabulum↗
PubMed1996

Late results after subtrochanteric angulation osteotomy in young patients.

Young patients with painful congenital dislocation of the hips need surgery if conservative treatment is unsuccessful. A total of 24 patients after 28 subtrochanteric angulation osteotomies without resection of the femoral head were followed up (mean, 17 years) to evaluate long-term results. Most patients maintain improved function: 20 hips showed persistent gain of abduction, 14 patients showed improvement of gait, and 18 patients described less pain. The degree of angulation must equal the inclination of the pelvic wall to influence hip stability as well as hip range of motion. Osseous reactions of support-seen in 10 hips-are not proof of operative success. Angulation osteotomy does not exclude later surgical procedures such as total hip replacement.

Adolescent↗
PubMed1991

Morphologic and morphometric changes in synovial membrane associated with mechanically induced osteoarthrosis.

We sought to determine whether synovial leukocytic inflammation is a primary event in mechanically induced osteoarthrosis. Repetitive impulse loading (50 ms duration at 60 Hz for 40 minutes each day) was applied to the right hindlimbs of 24 New Zealand white rabbits for 3, 6, or 9 weeks. The synovial membrane from the medial suprapatellar area was examined qualitatively using transmission electron microscopy and quantitatively using light microscopic morphometry. The results indicate that synovial inflammation is not a primary event in this mechanically induced osteoarthrosis, but synovial hyperplasia occurs prior to histologically evident cartilage destruction at 6-9 weeks.

Animals↗
PubMed1991

The autologous stump plasty. Treatment for bony overgrowth in juvenile amputees.

Autologous stump capping is a procedure designed to prevent bony overgrowth in skeletally immature amputation stumps. All 19 capping procedures in the lower extremities were successful after an average follow-up of 7.3 years. All patients use their prostheses, and no secondary operations have been needed for stump problems. Of the 31 cap-plasties of the humerus, six required re-operation. The overall failure rate of 12% is low compared with the failure rate of re-amputation.

Adolescent↗
PubMed1990

[Management of unstable pertrochanteric femoral fracture by alloarthroplastic joint replacement].

The treatment of trochanteric fractures of the femur should aim at the reconstruction of the joint function and should allow early weight bearing. In the case of unstable fractures and advanced osteoarthritis of the hip joint the advantages and risks of a total hip replacement have to be compared with different methods of osteosynthesis. We report on 35 patients with trochanteric fractures primarily treated with a total hip replacement. Their perioperative mortality was 9%, the most common complication was a luxation of the replaced hip joint in 3 cases. 1 patient had to be reoperated because of a soft tissue infection. Comparing the literature the primary total hip replacement shows a lower morbidity and mortality rate than complicated methods of osteosynthesis.

Activities of Daily Living↗
PubMed1989

The effects of altered strain environments on bone tissue kinetics.

This study defines the alteration in bone tissue kinetics responsible for the "adaptive remodeling" response to altered strain environments. Adult beagle dogs were separated into three experimental groups: ulnar osteotomy, ulnar osteotomy with fracture fixation plate spanning the gap and sham surgery. Four sets of double fluorochrome labels were administered. Prior to sacrifice at 1, 3, and 6 months, strains were measured through rosette strain gages on the cranial and caudal surfaces of the intact radius. Histomorphometric analysis indicated that the increased bone mass in response to elevated strain results from increased activation frequency of modeling with more sites undergoing formation processes than resorption processes on periosteal and endocortical surfaces. Increased remodeling activation did not lead to increased bone mass. There was no evidence that elevated strain changes the individual vigor of osteoclasts or osteoblasts, or that the sigma period was altered by elevated strain.

Adaptation, Physiological↗
PubMed1989

Skeletal change in response to altered strain environments: is woven bone a response to elevated strain?

Studies demonstrate that geometric changes in bone architecture in response to altered mechanical strain occur through the formation of woven bone. The goal of this study was to test the hypothesis that these changes are partly the result of surgical manipulation rather than a true adaptive response to altered strain. Beagle dogs were subjected to either an ulnar osteotomy, an osteotomy with plate fixation, or sham operation. Strains on the radius were measured just prior to sacrifice 1, 3 or 6 months after surgery. Our results support the idea that woven bone can be a normal response to an abnormal strain environment if the mechanical challenge is intense enough; that elevated mechanical strains can cause the endocortical bone envelope to revert to a state of net formation; and that "adaptive remodeling" in adults in response to a change in mechanical strain may be a special case of modeling in which resorption is not required prior to formation at a particular skeletal site.

Adaptation, Physiological↗
PubMed1988

Synovial membrane and cartilage changes in experimental osteoarthrosis.

The Hulth instability model was performed on 25 rabbit knee joints. Electron-microscopic, light-microscopic, and histomorphometric data demonstrated consistent chondrocyte alterations and cartilage destruction. The comparison between operated, sham, and control knees shows that surgical intervention without surgically induced instability is followed by changes in the synovial membrane and cartilage. The cartilage destruction is preceded by a synovial reaction, suggesting that the inflammatory response has an important role in the onset of cartilage damage in this model. The damage was more severe in the experimental knees, suggesting that mechanical instability is also a factor in cartilage destruction.

Animals↗
PubMed1988

[Arthrotomy--a prearthrotic factor?].

UNLABELLED: Light-microscopic and electron microscopic findings of the synovial membrane and cartilage were compared, of rabbit knee joints on which arthrotomy and surgical induced instabilisation operation were performed. The joint opening was followed by an inflammation of the synovial membrane, and cartilage changes were similar in joints of arthrotomy and surgically induced instability. CLINICAL RELEVANCE: To prevent joints from further damage after arthrotomy or arthroscopy, joints should be spared from weight bearing during the time of synovial inflammation.

Animals↗
PubMed1986

Comparison of joint degeneration models. Surgical instability and repetitive impulsive loading.

We used surgical instability and repetitive impulsive loading in rabbits to initiate degenerative changes in knee joints. Synovial membrane and cartilage samples were examined by light and electron microscopy. Early synovial inflammation at three days postoperatively preceded cartilage destruction in the instability model. Synovial inflammation was only apparent after eight weeks in the loading model and increased subsequently to cartilage destruction. Cartilage breakdown was focal and limited to the weight-bearing area. Comparison of the histological data of the two arthrosis models suggests that different inductive mechanisms may be involved in cartilage degeneration, but in both models the inflammatory changes appeared to be secondary to mechanical factors.

Animals↗
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↗