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H W Neumann

Publications and source records attributed to H W Neumann.

At least 19 recordsLinked to original sources
PubMed2006

[The femoral neck prosthesis CUT. Three- to six-year results].

BACKGROUND: As the number of younger patients undergoing total hip arthroplasty is growing steadily, bone-saving implantation techniques are increasingly gaining in importance. METHODS: Fifty-six femoral neck prostheses (type CUT, ESKA Implants, Lübeck, Germany) were implanted in 50 patients between 1999 and 2002 (average age 49 years). After a mean follow-up of 4.9 years (min.: 3.2, max.: 6.5), we determined the state of all the prostheses. Forty-four patients with 50 prostheses were examined clinically with the Harris hip score and were assessed radiologically. RESULTS: The average Harris hip score improved from 48 points preoperatively to 93 points at the most recent follow-up examination. Of the 56 CUT prostheses, 6 (10.7%) had been revised. Four of these six cases (7.1%) required revision because of aseptic loosening. The radiological evaluation of these four cases revealed in three cases progressive horizontal migration with varization of the prosthesis, although the stem had been correctly positioned in primary surgery, with the femoral neck resected too widely or completely. After 4.9 years, the survival rate of the CUT prostheses is 88.4% according to Kaplan-Meier for a necessary exchange of the CUT prostheses as an endpoint. CONCLUSION: The use of the CUT prosthesis can lead to good clinical and radiological results, but shows a higher loosening rate as compared with cementless standard stems. Further studies are necessary to determine if the CUT prosthesis is a real alternative to cementless standard stems.

Adult↗
PubMed2006

Rb-loss is associated with high malignancy in chondrosarcoma.

Loss of function of the human retinoblastoma gene (Rb) is a frequent genetic abnormality in human malignancies and causes a disturbance in the cell cycle and loss of normal proliferation and differentiation. We studied the loss of heterozygosity (LOH) of the Rb gene in 31 formalin-fixed, paraffin-embedded cartilaginous tumors using polymerase chain reaction. The tumors were subdivided into 8 cases of dedifferentiated (DD) chondrosarcoma, 17 cases of conventional chondrosarcoma (nine grade 1, seven grade 2 and one grade 3), 4 enchondromas and 2 chondroblastomas. Both components of DD chondrosarcoma, the low-grade and anaplastic components, were separated by a microdissection approach. The genetic data were correlated with the expression of the Rb protein examined by Rb immunohistochemistry. We found Rb-LOH in one grade 3 chondrosarcoma, and in the anaplastic component in 7 of 8 cases of DD chondrosarcoma (89% of all high-grade chondrosarcomas). All tumors with Rb-LOH were immunohistochemically Rb-negative. The only case of DD chondrosarcoma negative for Rb-LOH in both components of the tumor also showed weak expression of the Rb protein in the anaplastic component. All benign cartilaginous tumors, low-grade chondrosarcomas and low-grade tumor components of DD chondrosarcomas were negative regarding Rb-LOH but positive in Rb immunohistostaining. We concluded that Rb-LOH predominantly occurs in high-grade chondrosarcomas. However, it is not a marker for identifying low-grade tumors with a tendency towards progression or local recurrence.

Adolescent↗
PubMed2004

Protease expression in interface tissues around loose arthroplasties.

To determine whether cathepsins and matrix metalloproteinase-1 are involved in accelerating tissue destruction, we examined, immunohistochemically, the expression of matrix metalloproteinase-1 and cathepsins B, D, L, and X in periprosthetic synovial-like interface tissues from 14 patients with failed prosthetic hips and in the synovial membranes of hips from 18 patients with rheumatoid arthritis and 25 patients with primary osteoarthritis. The expression levels of all these proteases in the interface tissue were higher than in the synovial membrane of osteoarthritis. The expression levels of cathepsins B and X in the interface tissue were higher than in the rheumatoid synovium. The results show similarities in the expression patterns of cathepsins D and L and matrix metalloproteinase-1 between aseptic prosthetic loosening and rheumatoid arthritis. In addition, these data suggest that the impact of cathepsins B and X on tissue degradation is more pronounced in aseptic prosthetic loosening than in rheumatoid arthritis.

Aged↗
PubMed2003

Relation between peri-operative antithrombin activity and deep vein thrombosis after elective hip replacement surgery.

BACKGROUND: The purpose of the study was to evaluate whether the postoperative depletion or the preoperative antithrombin (AT) activity is related to the occurrence of deep vein thrombosis (DVT) in patients receiving low-molecular-weight heparin for DVT prevention after elective hip replacement surgery. PATIENTS AND METHODS: In 93 patients AT-activity and standard laboratory parameter were determined on the preoperative day and daily for one week after operation. Furthermore, a color-coded compression sonography was performed before and 8-10 days after surgery. The amount of blood loss and blood transfusions was evaluated. Patients were divided into two groups in respect to the occurrence of a postoperative DVT. RESULTS: The overall incidence of DVT was 8.6% (n = 8). Patients with DVT had a significantly lower preoperative AT-activity (80.6 +/- 3.31%) compared to those without DVT (98.1 +/- 1.12%, p < 0.001), however, without being predictive for DVT (positive predictive value 0.71). There was no association between postoperative fall of AT, the lowest postoperative AT activity, blood loss or blood substitution and DVT. CONCLUSIONS: It has to be expected that a small fraction of patients for elective hip surgery present with AT-activity levels possibly being insufficient for a therapeutic effect of low-molecular-weight heparin even preoperatively. Those patients are subject to a significant higher risk of DVT postoperatively.

Adult↗
PubMed2003

Genetic and epigenetic alterations in tumor progression in a dedifferentiated chondrosarcoma.

In this case of a dedifferentiated chondrosarcoma, we searched for genetic or epigenetic alterations in both components of the tumor, the low grade chondroblastic component, and the high grade osteosacomatouscomponent. To date, only little is known about aberrant patterns of DNA methylation in chondrosarcomas. Microdissection was used as a valuable method for clearly separating the tissues. We examined CpG island methylation of 8 tumor suppressor genes and candidate tumor suppressor genes, which are involved in different pathways: cell cycle (p21WAF1, p16INK4, p14ARF), apoptosis (DAPK, FHIT), DNA repair (hMLH1), and cell adherence (E-Cadherin). We found p16INK4 and E-cadherin promotor methylation in the low grade chondroid compartment of the dedifferentiated chondrosarcoma. P16INK4, FHIT, and E-cadherin were methylated in the highly malignant osteosarcomatous compartment of the tumor. Earlier investigations of this chondrosarcoma showed p53 mutation and p53-LOH in the anaplastic component. As shown in this case, it was accompanied by Rb-LOH. Early methylation of p16IK4 and E-cadherin in the chondroid compartment could point to the monoclonal origin of demonstrated dedifferentiated chondrosarcoma. Further alterations, as shown in p53, Rb and FHIT, are responsible for the "switch" to a high grade anaplastic sarcoma.

Cadherins↗
PubMed2002

[Clinical and radiological results of surgical removal of periarticular ossifications after hip prosthesis implantation].

The occurrence of heterotopic ossification (HO) is a well-recognized problem after total hip replacement. In a retrospective study, we investigated 32 patients who had undergone surgical excision of symptomatic HO followed by radiation with 7 Gy and nonsteroidal anti-inflammatory drug therapy between 1994 and 1999. The mean follow-up was 20 months (range: 12-60). Clinical and radiographic follow-up examinations included Harris hip score and classification according to Brooker. The preoperative Brooker class was III in 16 cases and IV in 16 patients. Comparison of the Brooker classification at follow-up revealed a statistically significant improvement (p < 0.0001; class 0:3, class I: 14, class II: 8, class III: 7 patients). In one case with symptomatic Brooker class III ossification, surgical reexcision of HO was necessary. A statistically significant increase (p < 0.05) in mean range of motion (ROM) was observed in flexion [preoperative: 57 degrees (+/- 26), follow-up: 83 degrees (+/- 21)], in abduction [preoperative: 17 degrees (+/- 12), follow-up: 24 degrees (+/- 9)], and in rotation (preoperative: 16 degrees (+/- 17), follow-up: 31 degrees (+/- 18)]. Comparison of preoperative Harris hip score (60 +/- 11) and Harris hip score at the time of follow-up examination (73 +/- 17) revealed a statistically significant increase (p < 0.0001) after treatment. At the time of follow-up examination, 18 patients (56%) assessed their pain symptoms as low but 6 patients (19%) reported strong pain symptoms. Nevertheless, the score at the time of examination (35 +/- 10) was statistically improved (p < 0.02) when compared to the preoperative score (30 +/- 8). Surgical excision of Brooker class III or IV heterotopic ossification with limited ROM followed by irradiation and anti-inflammatory prophylaxis results in significant improvement in flexion, abduction, and rotation arc and significant reduction of HO in radiographic examination at follow-up, but pain relief was only satisfactory.

Aged↗
PubMed2001

[Comparison of 2 surgical techniques in isolated supraspinatus rupture. A matched-pair study].

The comparison of results after open surgery methods in the repair of rotator cuff ruptures needs homogen patient groups. We compared 34 patients in 2 groups who were treated with open surgery for isolated ruptures of the supraspinatus muscles (lesion type III). Patients in group I were treated with transosseous suture refixation of the supraspinatus, in group II suture anchors (type: Corkscrew) were used. Both groups were age and gender paired. Preoperatively, all patients had the same clinical status. For the evaluation of the clinical results at follow-up we used the Constant-Score. In addition, strength and pain measurement and oblique X-rays of the shoulder were performed. The follow-up time was 18 months. In all patients, the mean Constant-Score improved significantly with increase in muscle strength and marked pain reduction. Significant differences between both groups could not be observed. The mean time of surgery in group II (suture anchor) was significantly lower than in group I. In conclusion, with the anchor techniques the same good results can be achieved as with bone refixation. The shortening of the surgery time should, however, be seen in relation to the higher costs with this technique.

Adult↗
PubMed2001

[History of German orthopedics 1989-2001].

The present article describes essential aspects of the development of German orthopedics from 1989 to 2001. Special attention is given to the unification of the two German orthopedic groups after the political turnaround in the German Democratic Republic and the resultant changes in the landscape of German orthopedics. In addition, further milestones in the development of German orthopedics during the last 10 years are presented, e.g., the formation of the Alliance of German Orthopedists, the establishment of various sections of the DGOT (German Association of Orthopedics and Traumatology) as well as the main focus of scientific activity in the past few years.

Congresses as Topic↗
PubMed2001

[Results of operative therapy of periprosthetic femur shaft fractures in total hip endoprostheses].

Periprosthetic femoral shaft fracture represents an uncommon but potentially devastating complication associated with total hip arthroplasty. The treatment should result in complete union of the fracture and at the same time guarantee stability of the implant. 15 patients treated between 1992 to 1998 were analysed. Clinical and radiographic follow-up averaged 30 months (6-79 months) in 13 cases. Two patients died regardless of the fracture. The method of treatment depended on the intraoperative stability of the prosthesis and in addition on the fracture type (Bethea). In 5 cases of intraoperative stability of the prosthesis plate fixation was performed. Plate fixation was complicated by fixation failure combined with a recurrent fracture in two cases leading to shift to a long stem prosthesis. Ten cases of fractures associated with loose stems were treated with a new prosthesis using a long stem system. In these cases an uncomplicated healing of the fracture was achieved with adequate stability in radiographic examinations. The average Harris score was 70 (26-93). For fractures near the femoral stem or in case of implant loosening we recommend the shift to a long stem prosthesis. Also in fractures distally from the femoral stem tip we prefer now long stem implants rather than plate fixation to avoid large exposure of the femoral shaft and resultant complications.

Aged↗
PubMed2001

[Recurrent luxations after arthroscopic refixation of the labrum using suture anchors in traumatic ventral shoulder luxation].

OBJECTIVE: Recurrence rates after arthroscopic labral reconstruction for anterior shoulder instability are still higher than after open procedures. Therefore, proper selection of patients becomes increasingly important. The aim of this study was to investigate factors influencing recurrence rates after arthroscopic labral repair with suture anchors. PATIENTS AND METHODS: We examined 53 patients (43 male, 10 female) with traumatic anterior shoulder dislocations, who were treated with arthroscopic labral repair using Fastak-Suture anchors between 1995 and 1996. The average follow-up time was 18 (12-30) months. The mean age of the patients at the time of operation was 27 (15-44) years. RESULTS: Postoperatively, 11 patients (20.7%) reported on redislocations. Recurrence rates increased significantly in patients with more than 4 preoperative dislocations and in patients with bony Bankart lesions. In patients without redislocations, the mean Rowe score improved from 65.9 (SD +/- 12.3) preoperatively to 88.6 (SD +/- 12.5) at follow-up. Thus, there were 24 excellent, 9 good and 6 fair results, while in 3 patients with persisting signs of shoulder instability results had to be estimated as poor. Deficits in the range of motion of more than 15 degrees were seen in 7 patients with predominant affection of the external rotation. CONCLUSION: Frequent preoperative dislocations and bony Bankart lesions contribute substantially to high recurrence rates after arthroscopic labral repair. Therefore, in these cases open procedures should be preferred.

Adolescent↗
PubMed2000

Rotationplasty as a salvage procedure in revision of tumor endoprosthesis of the distal femur--a report of two cases.

We performed two rotationplasties (type A1 and A2) as salvage procedures in cases of custom-made endoprosthetic replacements of the distal femur and knee joint. The patients suffered from malignant bone and soft-tissue tumors of the knee, respectively. One of them developed chronic osteomyelitis around both stems of the prosthesis, and three local revisions turned out to be ineffective. The other patient, suffering from parossal osteosarcoma of the distal femur, developed a local recurrence following endoprosthetic reconstruction. The functional abilities following the operation of these two patients suggested that rotationplasty was a viable alternative to above-the-knee amputation in failed or severely complicated total arthroplasty of the knee with massive bone loss.

Adult↗
PubMed2000

Radiographic findings in osteoarthritis of the knee joint are not correlated with cartilage histomorphology or immunohistochemistry.

The purpose of this study was to investigate whether radiographic joint space narrowing (JSN) of the lateral knee compartment predicts the histomorphological or immunhistochemical grading in cases of osteoarthritis of the knee joint. The lateral joint space was measured on weight-bearing radiographs. Femoral osteochondral plugs of 29 patients undergoing total knee replacement were obtained from lateral condyles. All these patients had severe osteoarthritis of the medial compartment, with the lateral compartment showing different stages of osteoarthritis. The specimens were histomorphologically evaluated with the Mankin score, and the expression of the cartilage-degrading enzymes MMP1 and MMP3 was measured. There was no correlation between the joint space and histomorphological or immunohistochemical data, whereas the enzyme expression was correlated with histomorphological grading. We conclude that radiographic assessment alone is not sufficient to evaluate the cartilage damage of the lateral condyle.

Arthroplasty, Replacement, Knee↗
PubMed2000

Expression of stromelysin and urokinase type plasminogen activator protein in resection specimens and biopsies at different stages of osteoarthritis of the knee.

This study aimed at assessing the possible diagnostic value of cartilage biopsies as a convenient marker for cartilage matrix degradation. We therefore examined cartilage specimens from 56 patients with primary osteoarthritis (OA) of the knee. Resection and biopsy cartilage specimens obtained during joint replacement surgery were used for this study. In addition to histomorphology, immunohistochemistry (ICH) was performed to determine the expression levels and distribution patterns of stromelysin and u-PA protein. The latter data were compared with the degree of histomorphological changes in osteoarthritic cartilage samples, based on a modified version of Mankin's grading score. Compared to the cartilage resection specimens, the biopsies showed comparable expression patterns for both proteinases: the strongest signals were noted in the superficial zone and, as matrix destruction increased, also in the chondrocytes of the transition and deep zones. The strongest signals were ascertained in cell clusters beneath deep matrix fissures. At the immunohistochemical level, we found a direct correlation in the expression of MMP-3 and u-PA between resection specimens and biopsies. Furthermore, in both types of cartilage samples, we noticed a positive relationship between the expression of both proteins and the Mankin score. Analysis of the expression levels revealed significant differences between deep, transition and superficial zones. Histomorphological and immunohistochemical examinations of MMP-3 and u-PA in biopsies of osteoarthritic cartilage turned out to be useful for estimating the pathological changes within osteoarthritic knee joints. Therefore, in future, cartilage biopsies from osteoarthritic knee joints might serve as a diagnostic tool and thus have an influence on further therapeutic strategies.

Biopsy↗
PubMed2000

[Joint loading as a possible etiology for arthrosis development. Results of animal experiment studies of the rat model].

We review our results with an animal model for investigations on the development of osteoarthritis (OA). This model is based on running exercises of wistar rats performed in a running wheel using intracranial self-stimulation to motivate rats to excessive running. In our studies a total of 49 rats was divided into groups with running exercises of 15 km, 20 km, and 30 km respectively. In order to investigate the influence of altered sensible joint innervation on the development of OA, in addition to a total running load of 20 km in another group of 8 rats we performed Capsaicin (8 Methyl-N-vanillyl-6-noneamide) mediated partial sensible knee joint denervation. Complete knee joint sections of all rats were evaluated histologically using Mankins grading system. In addition, we performed semiquantitative assessment of the immunoreactivity of the chondrocytes to MMP-3 by immunostaining with monoclonal MMP-3 IgG antibodies. Histological assessment and immunostaining for MMP-3 of the knee joint sections revealed a significant increase in osteoarthritic changes with higher running load. Moreover, osteoarthritic changes in the knee joints of the rats with sensible joint denervation and running exercises were significantly greater as compared to those with sole running load. In conclusion, our studies revealed a significant relationship between the development of knee osteoarthritis and the extent of joint load. Hereby, an alteration of the sensible joint innervation seems to have a promoting effect on the development of osteoarthritic changes. This model offers a wide range of further approaches to studying different processes of the development of OA.

Animals↗
PubMed1999

[Medialization of the tibial tuberosity in habitual dislocation of the kneecap].

Referring to relevant literature, various concepts are discussed in the treatment of habitual dislocation of the kneecap. Between 1987 and 1997, 88 patients have been treated surgically in our clinic by uni- or bilateral medial transfer of the tibial tuberositas. In 21 of the cases lateral release was also performed. In the follow-up, after an average of 4.9 years, 79 patients were examined clinically, radiologically and isokinetically (Kintrex-Dynamometer). Isokinetic measurement of the extension showed an average deficit of 19 nm compared to the contralateral side. Using the Juliusson and Markhede scores, 51 cases had a good, 18 a fair and 10 a poor clinical outcome. In 79 % of the cases, the postoperative sports activity level was the same as preoperatively. Isokinetic measurement with the Kintrex is a useful method of evaluating the development of muscle strength.

Adolescent↗
PubMed1999

Structural bone grafting in arthroplasty for congenital hip dysplasia: 35 hips followed for 5-10 years.

We assessed 35 hip arthroplasties in 30 patients with an average follow-up of 7 years. All patients suffered from secondary osteoarthrosis due to congenital dysplasia. The mean age at the time of surgery was 54 (19-77) years. Part of the femoral head used as a graft was fixed to the superolateral region of the acetabulum. A 100% bone coverage of the acetabular component was achieved initially. The mean support by the graft was 34%. The graft size, measured in the AP view, decreased on average 29% after 7 years. The resorption caused a reduction in cup coverage to 94%. There was no correlation between the clinical outcome and the graft size. Graft resorption occurred in the horizontal and vertical axes, but hardly affected the contact region with the iliac bone. Radiolucent lines according to DeLee were found in zone I in 4, zone II in 6 and zone III in 7 cases. The Harris Hip Score improved from 37-85 points. 1 revision was necessary 7 months postoperatively after cup dislocation.

Adult↗