BISS: concept and biomechanical investigations of a new screw system for electromagnetically induced internal osteostimulation.

INTRODUCTION: The aim of an intraosseous application of electromagnetic alternating fields is to speed up both the regeneration of osteonecroses and bone regeneration. In clinical studies, the efficiency of the technique could be successfully proven by using a transducer coil. The advantage of the traditional technique was the variety of its applications in connection with various osteosynthesis systems; the disadvantage was a possible failure of the contacting leads and the resulting functional breakdown. MATERIALS AND METHODS: A newly developed BISS screw (bipolar induction screw system) with integrated coil and electrodes was compared to a standard cannulated screw used in the traditional technique. The strength of BISS screws ( n=6) and of cannulated screws ( n=6) was evaluated in comparative biomechanical tests. Examinations consisted of torsional and static and dynamic cantilever tests. All screws were made of the same material (TiAl(6)V(4)) and had identical outer dimensions. RESULTS: No significantly lower strengths could be observed when we compared BISS screws with cannulated screws. The BISS screws even showed significantly higher mechanical values due to a reinforcing effect by the attached electrode. CONCLUSION: In the modified concept of the new BISS screw, both coil and electrodes are housed in only one cannulated screw. No negative effects concerning mechanical strength and durability were associated with the new screw concept. This provides for a simpler implantation and makes removal easier, while the risk of a cable tear is avoided.

[Antigranulocyte scintigraphy of septic loosening of hip endoprosthesis: effect of different methods of analysis]. / Antigranulozytenszintigraphie bei septischer Hüft-Endoprothesen-Lockerung: Einfluss unterschiedlicher Auswertemethoden.

AIM: Diagnosis of infection with help of antigranulocyte scintigraphy near body stem is difficult because of contemporary visualisation of bone marrow. Therefore, we investigated, whether it is possible to improve the accuracy in diagnosing septic loosening of hip endoprosthesis by changing the analyzing methods. METHODS: In 28 patients, the results of a visual interpretation of late scan, a visual interpretation and a quantitative interpretation of time-activity-course were compared. These results were verified by histology respectively microbiology. RESULTS: Histological and microbiological verification found 14 septic loosening and 14 aseptic loosening of the hip prothesis. Therefore, sensitivity, specificity, negative and positive predictive value for the visual interpretation of late scan were 0.86, 0.57, 0.80 and 0.67. For visual and quantitative interpretation of time-activity-course we found 0.86, 0.79, 0.85 and 0.80 respectively 1, 0.93, 1, 0.93. For interobserver agreement we found kappa coefficients of 0.28 +/- 0.2 for visual interpretation of late scan, 0.48 +/- 0.17 for visual interpretation and 1.0 +/- 0 for quantitative interpretation of time-activity-course. CONCLUSION: In all investigated values quantitative interpretation of time-activity-course was superior to the other analyzing methods. Therefore, antigranulocyte scintigraphy for septic loosening of hip endoprosthesis should be interpreted quantitatively.

Biomechanical examinations of cancellous bone concerning the influence of duration and temperature of cryopreservation.

The influence of cryopreservation of cancellous bone at different temperatures and different storage periods was investigated for mechanical changes. Standardized cancellous cylinders (50 x 25 mm) were stored at -20 degrees C or -80 degrees C for 6 or 12 months, respectively, or for 2 years and then subjected to a screw pull-out test. No significant differences were found among the various storage temperatures and periods investigated. We conclude that different cryopreservation temperatures do not have any influence on the mechanical properties of cancellous bone. Also, storage duration up to 2 years has no effects on the mechanical strength of the bone.

Comparison of HIG scintigraphy and bloodpool scintigraphy using HDP in arthritic joint disease.

AIM: Because of a similar tracer accumulation, we assumed to get the same information about synovitis in arthritic joint disease with HIG scintigraphy and bloodpool scintigraphy using HDP. Therefore, we compared retrospectively 23 patients. METHODS: In HIG scintigraphy, synovitis was diagnosed according to increasing activity from early to late image. In bloodpool scintigraphy according to an increased activity in comparison to the surrounding tissues. RESULTS: In 694 joints comparison of both scintigraphic modalities was possible, resulting in a 2 x 2 kappa coefficient of 0.93 or 0.97 by using late-phase bone scintigraphy as an anatomical marker. For intra- and interobserver agreement, 2 x 2 kappa coefficients of 0.93 and 0.88 in HIG scintigraphy, respectively 0.96 and 0.90 in blood-pool scintigraphy were calculated. CONCLUSION: This study shows an excellent agreement in the visualization of synovitis by HIG and bloodpool scintigraphy. Because of its higher objectivity and lower cost, investigation of synovitis should be performed by bloodpool scintigraphy.

[Activity leakage and radiation exposure in radiation synovectomy of the knee: influence of different therapeutic modalities]. / Aktivitätsabtransport und Strahlenexposition durch die Radiosynoviorthese des Kniegelenkes: Einfluss unterschiedlicher Therapiemodalitäten.

In rheumatic diseases, radiation synovectomy is a reliable method. Meanwhile, radiation synovectomy is an outpatient therapy. In addition, combination with arthroscopic synovectomy is an increasing therapeutic modality. In comparison to the hitherto inpatient modality, a greater lymphatic emigration of the radionuclide and, therefore, a higher radiation exposure is possible. In 35 patients we found radionuclide emigration in 17 cases by whole body scintigraphy, resulting in a 50%-percentile with 68.27%-confidence interval of 1.8 (0.45-4.78)% of the injected yttrium-90-activity. Comparison of 3 groups with the above mentioned therapy modalities resulted in no statistical difference (p>0.05). Because of the found radionuclide emigration, a radiation dose of 0. 1 (0.05-0,18) mSv in women and 0.2 (0.1-0.38) mSv in men was calculated. For lymph nodes, liver, spleen and whole body radiation doses of 619 (154-1644) mSv, 62 (15-165) mSv, 62 (15-165) mSv and 37 (9-99) mSv were calculated. Gonadal radiation dose can be neglected and the morbidity rate for tumors because of the whole body radiation dose is low with a value of 0.4 per thousand. Therefore, radiation synovectomy can be used unlimited by patients age and independent of the therapeutic modality.

[Standardized ultrasound examination of the ankle joint. Clarification of ultrasound standard image sections by corresponding MRI sections]. / Standardisierte sonographische Untersuchung des Sprunggelenkes. Erläuterungen der sonographischen Standard-Schnittebenen durch korrespondierende MRT-Schnitte.

AIM: The sonographical examination of the ankle was demonstrated in five standard cross-sections presented by the DEGUM (German Society for the Development of Ultrasonography in the Locomotor Apparatus) and compared with corresponding MRI cross-sections. METHOD: The sonographical examination was done in a real-time method with an ultrasound unit Type Versa (Siemens, Erlangen, Germany) and with a linear transducer (frequency 7.5 Mhz). The MRI tomographies were taken in two planes with the unit Type Magnetom (Siemens, Erlangen, Germany) with a 1.5 Tesla head-coil in T1- and T2-weighted spin echo sequences. RESULTS: Focus on the ventral, lateral and dorsal region provided a good overview of the superior ankle joint and the periarticular soft tissues. CONCLUSION: Being a cross-sectional method, the sonographical examination of the ankle joint offers additional information with regard to pathological changes of the joint and the periarticular soft-tissues.

[Possibilities of ultrasound diagnosis in Tossy type III acromioclavicular joint injuries in comparison with loaded roentgen images]. / Möglichkeiten der sonographischen Diagnostik bei Akromioklavikulargelenk-Verletzungen Typ Tossy III im Vergleich mit gehaltenen Röntgenaufnahmen.

We inform about 20 patients (19 men, 1 woman) with acute acromioclavicular striking, type Tossy III, which were operated. By usual preoperative diagnostic and physical examination, x-ray standard pictures of the shoulder in two planes and x-ray panoramic picture (loaded with 10 kp and unloaded) in ap-axis we made an additional sonographic examination of the hurt shoulder. This is practiced in the commendable standardised pattern of DEGUM (German Society of Ultrasound in Medicine). After the standardised sonographic examination we focussed the acromioclavicular joint sonographically in a modified lateral vertical axis. All of the 20 examined shoulder joints belong to the stage Tossy III. In the preoperative diagnosis the difference in elevation between the lateral portion of the clavicula and the medial portion of the acromion amounts in comparison to the two shoulders (loaded versus unloaded shoulder joints) sonographically 6.2 +/- 2.6 mm (max. difference of the sides 10 mm), by the radiological examination 6.5 +/- 3.7 mm (max. difference of the sides 14 mm). The sonographical examination of the shoulder joint makes it possible to get more information about the acromioclavicular lesion, especially by an AC examination according to Tossy degree III. At present there is no possibility of substituting the standardised x-ray pictures in two axes to diagnose or exclude fractures.

[Hygienic and economic significance of sewer drainage in hospitals. Architectural changes in the guidelines of the Federal Health Office]. / Hygienische und ökonomische Bedeutung von Schleusen im Krankenhaus. Die bauliche Umsetzung der Richtlinie des Bundesgesundheitsamtes.

The hygienic importance of barrier zoning in hospitals has been evaluated on the basis of the relevant international literature between 1970 and 1989. There have been only a very few pertinent publications and in none has there been any pointer which would support the hypothesis of barriers having an infection-preventing effect. Using four University Hospitals in Baden-Würtemberg as paradigms, a model was prepared for calculating what space and cost savings were possible, if a simpler system could be installed, instead of the one demanded under federal regulations and already planned for the four hospitals. It was found that it would save a realizable area of 319,5 m2 at a potential cost saving of DM 1,138,335. By dispensing with hygienically not justifiable building work at the planning stage of new hospitals considerable greater costs could be avoided.

A sensitive method for immunophenotyping stored leukemia and lymphoma cells with preservation of morphological detail.

We describe a method by which density-separated mononuclear preparations of blood and bone marrow may be stored and batch-processed for immunophenotyping by the indirect immunoperoxidase (IP) technique. The method gives excellent preservation of cellular detail thus permitting clear morphological categorization of IP-positive and IP-negative cells. We compared the immunofluorescence (IF) and IP techniques for estimation of the proportions of cells displaying a variety of antigens; with normal blood cells the results were closely similar but with chronic lymphocytic leukemia (CLL) cells, IP was superior to conventional IF. Using 910 D7, a new anti-la antibody, we were able to observe directly the presence of la-positive lymphocytes and monocytes in normal peripheral blood and la-positive granulocyte precursor cells from 2 cases of chronic granulocytic leukemia (CGL) in transformation. The method is useful for immunophenotyping of cases of lymphoproliferative disorder (LPD) and for morphological identification of specific antigen-positive cells.