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Biomedical subjects

G Zeiler

Publications and source records attributed to G Zeiler.

33 records · Page 2Linked to original sources
PubMed2003

[Impingement of the iliopsoas muscle after revision of a loosened acetabular cup with an acetabular reinforcement ring].

Impingement of the iliopsoas muscle due to a protruding acetabular component is an uncommon cause of pain after total hip arthroplasty. We report the case of a 59 year old female patient who developed groin pain one year after revision arthroplasty and reconstruction of the acteabular defect with an acetabular reinforcement ring due to a loosened cup. THERAPY AND FOLLOW UP: After revision of the right hip via an anterior approach we used bone cement to smooth the anterior edge of the acetabular reconstruction ring and created a smooth rim for the iliopsoas tendon. At follow up 2 years later the patient was satisfied with the result, she complained about very rare recurrent groin pain, without any need for further treatment.

Acetabulum↗
PubMed2003

[Delayed neuropathy of the sciatic nerve after total hip replacement with an acetabular reinforcement ring].

AIM: Lesions of the sciatic or femoral nerve after THR are typical complications. Delayed neuropathies of the sciatic or femoral nerve are rare conditions. CASE REPORT: We report the case of a delayed neuropathy of the sciatic nerve after THR with reconstruction of the acetabulum with an acetabular reinforcement ring. After electrophysiologic evaluation we performed a revision of the sciatic nerve. Intraoperatively we found an impingement of the sciatic nerve between the dorsal aspect of the acetabular reinforcement ring and scar tissue. After revision of the nerve, resection of the scar tissue and interposition of a fat pad the patient was out of any complaints but reported some sensory deficits of the first toe. CONCLUSION: Using acetabular reinforcement rings for reconstruction of acetabular defects care has to be taken of the correct position. In anatomically cramped positions a protruding of the dorsal edge of the ring may cause a lesion of the sciatic nerve.

Acetabulum↗
PubMed2001

Apoptotic cell death is not a widespread phenomenon in normal aging and osteoarthritis human articular knee cartilage: a study of proliferation, programmed cell death (apoptosis), and viability of chondrocytes in normal and osteoarthritic human knee cartilage.

OBJECTIVE: Chondrocytes are crucial for adequate matrix balance and function. Cell proliferation and, recently, extensive apoptotic cell death have been reported in osteoarthritic (OA) cartilage. Apoptotic cell death would be an obvious central factor in the initiation and progression of OA, since there is no potential for replacing articular chondrocytes in the adult. Therefore, we studied the occurrence of apoptotic cell disintegration and cell proliferation in OA and normal articular cartilage obtained from the knees of adult donors of all ages. METHODS: Following immunostaining for cellular proteins as well as staining for nuclear DNA, we performed triple-channel confocal laser scanning microscopy on thick cartilage slices to evaluate lacunar emptying and cell viability. Cell proliferation and apoptotic cell death were evaluated morphologically, by immunodetection of the proliferation-associated Ki-67 antigen, and by the TUNEL reaction. RESULTS: With the exception of the calcified layer, we were not able to detect any major (apoptotic or nonapoptotic) cell disintegration in normal young or aged articular knee cartilage. Single apoptotic cells were detected in OA articular knee cartilage. A significant increase in lacunar emptying was observed in late-stage specimens with higher Mankin scores compared with age-matched normal control cartilage specimens, but not in low-grade lesions. A significant (but lesser) increase in empty lacunae was also observed with age in normal cartilage. Cell proliferation was rarely detected in OA cartilage samples and was not detected at all in normal cartilage samples. CONCLUSION: Our results confirm the findings of previous studies showing that cell proliferation occurs in OA cartilage. They also show that, contrary to previous suggestions, apoptotic cell death is not a widespread phenomenon in aging or OA cartilage.

Adult↗
PubMed2000

A modular femoral implant for uncemented stem revision in THR.

We present the early results of 142 uncemented femoral stem revisions using the modular MRP-Titan system. There were 70 cases with marked preoperative femoral bone defects (Paprosky type 2C and type 3); and bone grafts were used in 31 cases. At a mean follow-up of 2.3 years five cases were re-revised due to dislocation and two due to aseptic loosening. The mean Harris hip score improved from 37.4 preoperatively to 92.4. In 122 cases progressive bone regeneration on X-ray was seen; and no further osteolysis was observed.

Adult↗
PubMed1998

Severe disturbance of the distribution and expression of type VI collagen chains in osteoarthritic articular cartilage.

OBJECTIVE: The aim of this study was to evaluate the messenger RNA (mRNA) expression and distribution of the major pericellular type VI collagen in normal and osteoarthritic (OA) cartilage. METHODS: Conventional and confocal laser scanning immunohistochemistry, as well as in situ hybridization experiments, were performed for all 3 collagen type VI chains in sections of normal and OA articular cartilage. RESULTS: Normal adult articular chondrocytes were surrounded by a type VI collagen-positive pericellular matrix and showed significant levels of mRNA expression for all 3 type VI collagen chains. In OA cartilage, the expression and overall distribution of type VI collagen was largely increased in the lower middle and upper deep zones. In contrast, the upper zones showed a significant loss of pericellular type VI collagen staining. CONCLUSION: Our results suggest that there is a significant basic turnover of type VI collagen in normal articular cartilage. In OA cartilage, the chondrocytes of the lower middle and upper deep zones account for a net increase in type VI collagen synthesis. The loss of type VI collagen staining in the upper zones is most likely the result of increased protein degradation rather than reduced synthetic activity.

Aged↗
PubMed1997

Suppression of cartilage matrix gene expression in upper zone chondrocytes of osteoarthritic cartilage.

OBJECTIVE: To evaluate the anabolic activity of osteoarthritic chondrocytes in situ by investigating the messenger RNA (mRNA) expression of 3 major cartilage components, type II collagen, aggrecan, and link protein: METHODS: In situ hybridization experiments and histochemical analysis for proteoglycan content were performed on parallel sections of normal and osteoarthritic (OA) cartilage specimens. RESULTS: Most chondrocytes in the deeper.zones of OA cartilage showed an increase in mRNA expression, in particular, of type II collagen and to a lesser extent, aggrecan, compared with normal specimens. However, chondrocytes of the upper zone were largely negative for aggrecan or type II collagen mRNA. The expression of link protein mRNA was low in normal and OA specimens. CONCLUSION: These observations suggest that suppression of the anabolic activity of chondrocytes in the upper zones contributes to the metabolic imbalance observed in OA cartilage. Stimulation of matrix anabolism in superficial chondrocytes might be a suitable target for therapeutic intervention.

Aged↗
PubMed1992

Activation of collagen type II expression in osteoarthritic and rheumatoid cartilage.

In situ hybridization and immunohistochemical techniques were applied to investigate gene expression and extracellular deposition of collagen type II in normal, osteoarthritic and rheumatoid human articular cartilage. Normal cartilage showed an essentially even extracellular distribution of type II collagen with poly- and monoclonal antibodies, while only a few cells were positive for alpha 1(II) collagen mRNA. In situ hybridization of osteoarthritic and rheumatoid cartilage, however, showed strong enhancement of type II collagen gene expression; transcripts were observed predominantly in the upper middle zone of the articular cartilage while the upper layer was mostly negative and correlated with a zone of reduced proteoglycan staining. The elevated mRNA levels frequently coincided with pericellular immunostaining for type II collagen, indicative for enhanced synthesis of the protein. In two samples, however, pericellular loss of collagen type II staining was found despite positive cytoplasmic signals with the alpha 1(II) RNA probe, suggesting enhanced collagen destruction. Control hybridization with a probe for 18S rRNA revealed very few negative cells throughout both normal and arthritic cartilage samples, ruling out major cell necrosis in the specimens investigated. Thus, our observations identify sites of activated type II collagen synthesis in osteoarthritic cartilage that were predicted by previous biochemical studies and support the notion that damaged cartilage attempts to restore matrix by enhanced synthesis of its components.

Adolescent↗
PubMedDate not supplied

[Results of uncemented revision arthroplasty of the hip with the MRP-stem using an intrafemoral approach with vascularized distal fenestration].

AIM: THR is one of the most successful principles in orthopaedics. With the increasing number of primary THR more and more revision arthroplasties of the hip are necessary. Many factors including loss of bone stock, instability of the joint, infection, fractures, removal of the implant or cement mantles are a challenging condition for the surgeon. Many approaches and techniques for the removal of cement mantles are published. We prefer the intrafemoral approach with an distal vascularized femoral window. METHOD: We want to describe our surgical technique and report the short term results of 45 revision arthroplasties of the hip using the uncemented modular titanium MRP stem. Mean follow-up was 2.6 years (min:1 year, max: 7 years). RESULTS: Mean Harris hip score increased from preoperative 53,2 (16 - 89) to postoperative 90.4 (35 - 100) points. We could find remodelling of the bone and spontaneous refill of bony defects in all cases. After 14 weeks we could find bony consolidation of the femoral window. The Trendelenburg sign was positive preoperatively in 26 cases, postoperatively in 11 cases. Just one single dislocation of the revised hip occurred postoperatively. CONCLUSION: The intrafemoral approach with distal vascularized femoral fenestration is a mild approach without further weakening of the pelvitrochanteric muscles. Removal of cement mantles is possible without any problems. Using the vascularized technique of the femoral fenestration prompt bony consolidation can be achieved.

Arthroplasty, Replacement, Hip↗