[The modular endoprosthetic system Munich-Luebeck (MML): potential applications and results in the lower extremities]. / Modulares Endoprothesensystem München-Lübeck (MML) : Anwendungsmöglichkeiten und Ergebnisse an den unteren Extremitäten.

The modular endoprosthetic system Munich-Luebeck (MML) has been in clinical use since 1994. A total of 2.118 pelvic and lower extremity surgeries using the MML system were carried out up until 2010. The modular construction allows substituting or bridging any kind of bone defect. We analyzed 572 operative interventions, which were performed in 5 centers. The most frequent indications were tumors (50.3%) followed by revision arthroplasty due to loosening, periprosthetic fractures, and joint resection surgery due to infection (43.3%). Proximal and distal femoral replacement amounted to 78% of cases, whereas partial pelvic replacement accounted for 10.4% of the cases. Complications were reported in 27.27% of the cases, where dislocations (14.9% of the cases with simultaneous hip replacement) and infections (10.48%) were the most common, as expected. Revision surgery was necessary in 140 (24.8%) of the 572 patients, of which 68 were partial or total replacement of the implants, 16 removal of the implants and 10 above-knee amputations or rather exarticulations of the hip.

[Intracellular signaling pathways of synovial fibroblasts in rheumatoid arthritis]. / Intrazelluläre Signalwege synovialer Fibroblasten bei rheumatoider Arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune disease of still unknown etiology that results in characteristic destructive changes of the joints. Research of the past years has demonstrated that synovial fibroblasts play a central role in the initiation and perpetuation of these destructive changes. Stimulation of the synovial fibroblasts through complex and interacting intracellular signaling pathways results in a stable activation that is maintain even without continuous stimulation by inflammatory cells and their mediators. The pathological attachment to articular cartilage, increased secretion of matrix degrading enzymes and alterations in programmed cell death are main characteristics of synovial fibroblasts from patients with RA and result in the progressive destruction of articular structures. The permanent activation of a number of intracellular signaling pathways constitutes the underlying responsible mechanism for the activation of synovial fibroblasts in RA. These signaling pathways do not only show a high degree of complexity, but are also interconnected in multiple ways. This article summarizes recent findings on the activation of intracellular signaling pathways in fibroblasts and points to potential targets for novel therapeutic strategies.

[Clinical and radiological results of surgical removal of periarticular ossifications after hip prosthesis implantation]. / Klinische und radiologische Ergebnisse der operativen Entfernung von periartikulären Ossifikationen nach Hüftendoprothese.

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.

Telemedicine and clinical genetics: establishing a successful service.

There is a surprising lack of published experience on the use of videoconferencing in clinical genetics. Patients were randomly allocated to either a telegenetic (cases) or face-to-face (control) conventional clinic. The telegenetic consultation was done by videoconferencing, using ISDN lines at 384 kbit/s. Evaluation by the doctor and counsellor took place immediately after each appointment. The patient was asked to evaluate the appointment by telephone questionnaire about four weeks after the event. Forty-two patients were invited to participate and 33 (79%) returned their consent forms. Four patients declined to participate and were seen in ordinary face-to-face clinics. Preliminary results showed that the assessment of the telegenetics consultations by doctors, counsellors and patients was very favourable, and they responded positively when asked if they would be happy to use telemedicine in the future. For use in selected consultations, videoconferencing does appear to fulfil a useful role in clinical genetics.

[Significance and incidence of type II heparin-induced thrombocytopenia. A prospective study]. / Beitrag zur Bedeutung und Inzidenz der Heparininduzierten Thrombozytopenie (HIT) Typ II. Eine prospektive Studie.

AIM: The incidence of heparin-induced thrombocytopenia (HIT type II) as a consequence of postoperative thrombosis prophylaxis after hip or knee prosthesis was investigated in this study. Furthermore the platelets count was postoperatively analysed in patients without HIT II. PATIENTS AND METHODS: Patients with knee and hip prosthesis were included in a prospective study during an 8 months period. All patients received 3 x 5,000 Liquemin (Hoffmann-LaRoche) from the day of the operation until discharge. In cases with a platelet count drop of more than 40% and in patients with clinically manifest thrombosis or embolism a HIT type II test was initiated. RESULTS: 5 of 252 patients included in this study developed a HIT type II. The platelet count drop was on average 65.7% (40.9-81.6). One patient died of a lung embolism (lethality 20%). Four patients were treated with Hirudin and 1 patient with Danaproid-Natrium. There was no drop of the platelet count between the 5th and 7th postoperative day of more than 15% in the other patients without HIT type II. CONCLUSION: In operative departments not enough attention is paid to HIT type II. Knowing the risks with an appropriate monitoring HIT type II can be early detected. Under these conditions the advantages of a heparin prophylaxis outweigh the risk of developing a HIT type II with it's life threatening sequelae.

[Results of operative therapy of periprosthetic femur shaft fractures in total hip endoprostheses]. / Ergebnisse der operativen Therapie periprothetischer Femurschaftfrakturen bei Hüfttotalendoprothesen.

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.

Influence of stimulus cross talk on results of the twitch-interpolation technique at the biceps brachii muscle.

Biceps brachii muscles of five healthy volunteers were tested with a high-resolution twitch-interpolation technique. Parameters of the electrical surface stimulation were varied. It was found that a supramaximal stimulus strength activates both biceps and triceps brachii motor units simultaneously severely affecting twitch-interpolation results. Crosstalk contamination of twitches, however, can be avoided, if submaximal stimuli are used yielding twitch-interpolation results for the biceps-brachii that are similar to those of the quadriceps muscle.