Biomedical subjects
S Rupp
Publications and source records attributed to S Rupp.
[In Process Citation]
Calcifying tendinitis of the rotator cuff is a common||| disorder of the shoulder which affects mainly individuals between 30 and 50||| years of age. The etiology is still a matter of speculation. The calcification||| is a reactive process actively mediated by cells in a viable environment. The||| deposit undergoes an evolution (precalcific stage--calcific stage with||| formative phase, resting period and resorption--postcalcific stage), which||| ultimately remodels normal tendon tissue. However, the evolutionary stages of||| the disease do not always follow the typical sequence. A symptomatic deposit||| may persist or postcalcific tendinitis develop. The treatment should be based||| on the knowledge of the natural history of the disease, which shows a strong||| tendency towards self-healing by spontaneous resorption of the deposit. The||| stage of evolution of the disease should be judged, combining pain history,||| morphology of the deposit on plain X-rays, and ultrasound findings. The||| therapeutic approach depends on the evolution of the disease. During the||| resorption phase we favor a conservative approach. For deposits which are not||| under resorption we propose a concept which consists of three steps: a||| conservative approach, extracorporal shock wave therapy (ESWT) or needling, and||| arthroscopic surgery. The efficacy of ESWT and needling has still to be proven.||| Patients with persisting pain after steps 1 and 2 are candidates for surgical||| removal of the deposit. We prefer the arthroscopic approach. In some cases an||| additional arthroscopic subacromial decompression (ASD) is||| indicated.
[Increasing interest in the shoulder].
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[Tendinosis calcarea of the rotator cuff].
Calcifying tendinitis of the rotator cuff is a common disorder of the shoulder which affects mainly individuals between 30 and 50 years of age. The etiology is still a matter of speculation. The calcification is a reactive process actively mediated by cells in a viable environment. The deposit undergoes an evolution (precalcific stage--calcific stage with formative phase, resting period and resorption--postcalcific stage), which ultimately remodels normal tendon tissue. However, the evolutionary stages of the disease do not always follow the typical sequence. A symptomatic deposit may persist or postcalcific tendinitis develop. The treatment should be based on the knowledge of the natural history of the disease, which shows a strong tendency towards self-healing by spontaneous resorption of the deposit. The stage of evolution of the disease should be judged, combining pain history, morphology of the deposit on plain X-rays, and ultrasound findings. The therapeutic approach depends on the evolution of the disease. During the resorption phase we favor a conservative approach. For deposits which are not under resorption we propose a concept which consists of three steps: a conservative approach, extracorporal shock wave therapy (ESWT) or needling, and arthroscopic surgery. The efficacy of ESWT and needling has still to be proven. Patients with persisting pain after steps 1 and 2 are candidates for surgical removal of the deposit. We prefer the arthroscopic approach. In some cases an additional arthroscopic subacromial decompression (ASD) is indicated.
MAP kinase and cAMP filamentation signaling pathways converge on the unusually large promoter of the yeast FLO11 gene.
In Saccharomyces cerevisiae, two major signal transduction pathways, the Kss1 MAPK pathway and the cAMP-regulated pathway, are critical for the differentiation of round yeast form cells to multicellular, invasive pseudohyphae. Here we report that these parallel pathways converge on the promoter of a gene, FLO11, which encodes a cell surface protein required for pseudohyphal formation. The FLO11 promoter is unusually large, containing at least four upstream activation sequences (UASs) and nine repression elements which together span at least 2.8 kb. Several lines of evidence indicate that the MAPK and cAMP signals are received by distinct transcription factors and promoter elements. First, regulation via the MAPK pathway requires the transcription factors Ste12p/Tec1p, whereas cAMP-mediated activation requires a distinct factor, Flo8p. Secondly, mutations in either pathway block FLO11 transcription. Overexpression of STE12 can suppress the loss of FLO8, and overexpression of FLO8 can suppress the loss of STE12. Finally, multiple distinct promoter regions of the FLO11 promoter are required for its activation by either Flo8p or Ste12p/ Tec1p. Thus, like the promoters of the key developmental genes, HO and IME1, the FLO11 promoter is large and complex, endowing it with the ability to integrate multiple inputs.
Ligament graft initial fixation strength using biodegradable interference screws.
The objective of this study was to evaluate the initial fixation strength of three types of biodegradable interference screws [an Endo Fix, 7 x 25 mm polyglycolic acid, non-self-tapping (Acufex); a biodegradable interference screw, 7 x 23 mm poly-L-lactic acid, self-tapping (Arthrex); a Bioscrew, 7 x 25 mm poly-L-lactic acid, self-tapping (Linvatec)] in comparison to a titanium interference screw (Linvatec, 7 x 25 mm) in anterior cruciate ligament reconstruction using a bone-patellar tendon-bone graft. Porcine lower limbs were used. To control for specimen related bias, bone mineral density of each tibia was measured. All specimens were loaded to failure. Failure mode was determined by visual analysis. The maximum load to failure [mean (SD)] was 785 (87) N (titanium screw), 555 (60) N (Acufex), 592 (211) N (Arthrex), and 844 N (Linvatec). The primary fixation strength of the titanium screw and the Linvatec screw was significantly higher (p < 0.05) than the primary fixation strength of the Arthrex screw and the Acufex screw. There was no difference in bone mineral density between the groups. With respect to primary fixation strength, all biodegradable screws were strong enough to allow accelerated rehabilitation. From this point of view the biodegradable screws may be a reasonable alternative to titanium interference screws.
Popliteal cyst accompanied by an intra-articular cartilage lesion in a child.
The case of an 11-year-old girl presenting with a symptomatic popliteal cyst is described. There was no previous knee trauma nor could any inflammation be found. On MRI a concomitant retropatellar cartilage lesion had been detected preoperatively and was confirmed and treated by arthroscopy. The prevalence and treatment of popliteal cysts in children are discussed. Whereas in adults popliteal cysts are generally accompanied by intra-articular lesions, the presence of a concomitant intraarticular lesion in children is an extremely rare finding. We conclude that intraarticular lesions in the presence of popliteal cysts might have been underestimated as most of the studies regarding popliteal cysts in children were undertaken before the advent of arthroscopy, ultrasound, or MRI.
Prevalence of popliteal cysts in children. A sonographic study and review of the literature.
Popliteal cysts in children differ from those in adults. They are considered to be less frequent and usually appear in the absence of intra-articular lesions. However, their prevalence in asymptomatic children is unknown. We present a prospective epidemiological study of 168 asymptomatic children under 15 years of age hospitalised for various pathologies. Children with knee problems and rheumatic diseases were excluded from the study. The children were examined ultrasonographically with a 7.5 MHz linear scanner. A popliteal cyst could be identified in 4 patients. The prevalence of asymptomatic popliteal cysts was thus 2.4%. For 2 of these patients, we obtained magnetic resonance image of the knee which showed no concommitant intra-articular pathology.
Resulting tensile forces in the human bone-patellar tendon-bone graft: direct force measurement in vitro.
The objective of this study was to measure the resultant force in the human bone-patellar tendon-bone graft after reconstruction of the anterior cruciate ligament under various conditions in vitro. Seven fresh-frozen cadaver lower extremities were used. Force measurement was made with a quartz force transducer mounted in a specially designed load cell. The effect of passive extension movement, quadriceps pull, varus torque, and valgus torque on the resultant force in the ligament were investigated. Passive extension of the joint generated a rapid increase of force in the graft between 30 degrees and 0 degrees of flexion, reaching its maximum (128+/-25 N) at full extension. When quadriceps pull was applied to extend the joint, resultant force increased at 50 degrees of flexion and reached its maximum (219+/-25 N) at full extension. Additional resistance applied to the level of the ankle joint generated an additional load of the graft. Increase of forces in the ligament resulted from both varus and valgus applied moments.
[Allo-arthroplasty of the knee joint].
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Gpa2p, a G-protein alpha-subunit, regulates growth and pseudohyphal development in Saccharomyces cerevisiae via a cAMP-dependent mechanism.
The small GTP-binding protein Ras and heterotrimeric G-proteins are key regulators of growth and development in eukaryotic cells. In mammalian cells, Ras functions to regulate the mitogen-activated protein kinase pathway in response to growth factors, whereas many heterotrimeric GTP-binding protein alpha-subunits modulate cAMP levels through adenylyl cyclase as a consequence of hormonal action. In contrast, in the yeast Saccharomyces cerevisiae, it is the Ras1 and Ras2 proteins that regulate adenylyl cyclase. Of the two yeast G-protein alpha-subunits (GPA1 and GPA2), only GPA1 has been well studied and shown to negatively regulate the mitogen-activated protein kinase pathway upon pheromone stimulation. In this report, we show that deletion of the GPA2 gene encoding the other yeast G-protein alpha-subunit leads to a defect in pseudohyphal development. Also, the GPA2 gene is indispensable for normal growth in the absence of Ras2p. Both of these phenotypes can be rescued by deletion of the PDE2 gene product, which inactivates cAMP by cleavage, suggesting that these phenotypes can be attributed to low levels of intracellular cAMP. In support of this notion, addition of exogenous cAMP to the growth media was also sufficient to rescue the phenotype of a GPA2 deletion strain. Taken together, our results directly demonstrate that a G-protein alpha-subunit can regulate the growth and pseudohyphal development of S. cerevisiae via a cAMP-dependent mechanism. Heterologous expression of mammalian G-protein alpha-subunits in these yeast GPA2 deletion strains could provide a valuable tool for the mutational analysis of mammalian G-protein function in an in vivo null setting.
Use of preoperative vascular embolisation in spinal metastasis resection.
Preoperative selective embolisation was carried out on 17 patients with spinal metastases from various primary tumours. There was a significant reduction in the blood loss (2088 ml) and infusion volume requirement (3500 ml) and more favourable postoperative haemoglobin (Hb) development compared with the non-embolised but otherwise identical control group. The reduced intraoperative bleeding manifested itself in the form of greater clarity and a less complicated intraoperative course. Particularly with a dorsal approach, the reduced bleeding permitted more exact preparation and more extensive tumour resection. Preoperative embolisation is thus a valuable aid in spinal metastasis resection. Given suitable indications and exact positioning of the embolising material, no significant complications should arise. The method as a whole calls for close collaboration between interventional radiologists and spinal orthopaedists.
[Shoulder arthrodesis in deltoid paralysis].
After loss of active glenohumeral motion the arm cannot be positioned in space and function is impaired. Fusion of the glenohumeral joint creates a new platform for the movement of elbow, hand and fingers and leads to an improvement of function. The use of the reconstructive plate makes the operation easier. Shoulder fusion is especially suited if the function of elbow and hand is well preserved and if the patient is physically active. But fusion is definite and the options of muscle transfer operations and above elbow amputation have to be considered.
Fixation strength of a biodegradable interference screw and a press-fit technique in anterior cruciate ligament reconstruction with a BPTB graft.
The objective of this study was to evaluate the fixation strength of a biodegradable interference screw (Arthrex, Naples, FL) compared with press fit fixation and a titanium interference screw in anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone (BPTB) graft. Porcine lower limbs were used. Ultimate failure loads of the biodegradable screw (805.2 N; range 680 to 995 N) did not differ significantly from ultimate failure loads of titanium interference screws (768.6 N; range 544 to 1094 N). Press fit fixation provided significant (P < .01) lower fixation strength (462.5 N; range 80 to 825 N). These results support the conclusion that biodegradable interference screws are a reasonable alternative in terms of primary fixation strength.
[Injuries during handball. A comparative, retrospective study between regional and upper league teams].
To evaluate the injuries in Team Handball 186 male players out of 16 teams were questioned retrospectively at the end of a season. An important difference between practice and competition injuries could be found with an injury rate of 0.8 injuries per 1000 training hours and 13.5 injuries per 1000 playing hours. Injuries were predominant at the lower extremities with ankle injuries being the most frequent injury type. 2/3 of the playing injuries occurred in offense. 1/3 of these offense injuries could be attributed to a counter-attack. These injuries were generally more severe which lead us to a proposition of changing the rules of the game in foul plays in this situation. Elbow injuries in goalkeepers and shoulder injuries in throwers were specific for these types of players. Prophylactic braces were used by nearly 2/3 of the players.
The failed back surgery syndrome: reasons, intraoperative findings, and long-term results: a report of 182 operative treatments.
STUDY DESIGN: A retrospective study was performed of 182 revisions on failed back surgery syndrome from the years 1965 to 1990. OBJECTIVE: To analyze the reasons for failure of primary discectomy, the outcome of the revisions, and factors that influenced those outcomes. SUMMARY OF BACKGROUND DATA: The reported reintervention rates after lumbar discectomy range from 5% to 33% depending on the type of surgical procedure. The authors' former investigations reported a revision rate of 10.8% in evaluating 1500 lumbar discectomies. METHODS: Because the documentation was standardized, detailed data of all patients were available. To gain further information concerning the long-term results a questionnaire was used. Computer processing and statistical tests were performed. RESULTS: One hundred eighty-two revisions were performed on 136 patients. Forty-four patients (34%) were revised multiple times. Generally, recurrent or uninfluenced sciatic pain and neurologic deficiency or lumbar instability led to reintervention. Recurrent lumbar disc herniation mainly was found at the first reintervention. In multiple revision patients the rate of epidural fibrosis and instability increased to greater than 60%. In 80% of the patients the results were satisfactory in short-term evaluation, decreasing to 22% in long-term follow up (2-27 years). CONCLUSIONS: Laminectomy performed in primary surgery could be detected as the only factor leading to a higher rate of revisions. A trend toward poor results after recurrent disc surgery seems to be fateful because of the development of epidural fibrosis and instability. In severe discotomy syndrome, a spinal fusion seems to be more successful than multiple fibrinolyses.
Does vacuum-mixing improve the fatigue properties of high-viscosity poly(methyl-methacrylate) (PMMA) bone cement? Comparison between two different evacuation methods.
The objective was to verify different reports in the literature which show an increase of stability using vacuum-mixing of bone cement, by testing the fatigue properties of bone-cement specimens (Palacos R). Evacuation of the poly(methyl-methacrylate) (PMMA) and evacuation with additional pressurization (Draenert system) were used to manufacture the specimens. Although we found improvement in the ultimate bending strength for evacuated Palacos R, an increase of fatigue stability could not be found either for vacuum-mixed cement or for vacuum-mixed and compressed cement. As fatigue failure is one of the most important factors leading to aseptic loosening of cemented alloarthroplasties, we conclude that the long-term results cannot be improved by vacuum-mixing this cement.
[Mechanical properties of new low viscosity bone cements--can be improved by vacuum mixing].
With the objective of improving mechanical properties by using a new catalyst, a new bone cement (Sulfix-60) and a new low-viscosity cement with added gentamycin (Allofix-G) were developed. Dynamic weakness was the major disadvantage of the older Sulfix-6 cement, especially in comparison with high-viscosity bone cement. Although static strength could be improved, investigations into improved fatigue strength and the effect of vacuum-mixing on the static and fatigue strength had yet to be carried out. To investigate fatigue stability specimens of the new bone cements were tested using loads under wet conditions until breakage or 20 million cycles. In a first series the cement was hand-mixed in a second series vacuum-mixed alone, and in a third series vacuum-mixed under pressure. Additionally, the ultimate static bending strength was investigated using the standard four-point bending test for the three series of bone cement. Vacuum-mixing brought about an improvement in the dynamic strength of Sulfix-60 from 6.3 MPa, to 9.1 MPa and for Allofix-G from 6.3 MPa to 8.2 MPa; additional pressure brought no further improvement. A 200% increased fatigue stability was detectable in comparison with the older cement. The ultimate bending strength was also significantly improved by vacuum-mixing for both bone cements.