[Return to Work After Shoulder Arthroscopy as an Index of Cost Effectiveness]. / Nutzenbewertung der minimal-invasiven Schulterchirurgie aus Sicht der Kostenträger.

Cost-effectiveness of shoulder arthroscopy was analyzed and assessed by the days off work as part of the indirect costs. We retrospectively evaluated a group of 266 inpatients on sick leave after arthroscopic shoulder surgery. Mean duration till return to full duty was 9.5 days, the mean sick leave benefit was € 485. There was a statistically significant difference in the mean time to return to work between the older (age >50) and the younger group (age under 50). Secondary data analysis of sick leave and sickness benefits as indirect costs of medical treatment seems to be well suited to provide essentiell information to health care policy makers and those charged with distributing disability funds.

The natural course of shoulder instability and treatment trends: a systematic review.

BACKGROUND: The natural course of shoulder instability is still not entirely clear. We aimed in this review to analyse the current scientific evidence of the natural history of shoulder instability. MATERIALS AND METHODS: A systematic review of the English literature was performed using the PubMED database throughout January 2014. This review was guided, conducted and reported according to PRISMA criteria. The criteria for inclusion in the study were (1) the article was written in English, (2) the level of evidence was 1-4, (3) the article was available in full text, (4) the article investigated the natural history or course of shoulder instability, the outcome of non-operative management, or the regression of the shoulder symptoms to the mean. The methodological quality of each included study was individually assessed using a newly developed general assessment tool-Assessing the Methodological Quality of Published Papers (AMQPP). RESULTS: Eight articles related to shoulder instability met the inclusion criteria. Four papers were considered high-quality studies (evidence level 1 and 2). One paper assessed the natural history and the natural course of shoulder instability directly. The other studies indirectly assessed the natural history by studying non-operative and operative therapy trends. We found no articles which clearly referred to the role of 'regression to the mean'. CONCLUSION: Following the natural history and the implementation of standardised non-operative treatment programmes are an effective therapy and superior to surgery in many cases. However, primary acute shoulder dislocation in young active individuals partaking in demanding physical activities could benefit from early surgical intervention. The AMQPP score works as a quick quality-checking tool which helps researchers to identify the key points in each paper and reach a decision regarding the eligibility of the paper more easily. The AMQPP scoring system is still open for further development and expansion. Level of evidence Level IV.

[Do Learning Effects Lead to Path Dependencies in Hospitals? Study of the Effects on Reorganisation Processes]. / Führen Lerneffekte zu Pfadabhängigkeiten in Krankenhäusern? Untersuchung zu Auswirkungen auf Reorganisationsprozesse.

Based on the observations concerning the economic situation, a fundamental restructuring of hospital organisations is repeatedly called for in the literature. Strengthening the process orientation by "raising" the grade of efficiency is frequently argued as an organisational measure. This work theoretically investigates where the obstacles to organisational change in hospitals can lie using the path dependency theory. Specifically, socio-professional influences on the learning behaviour of hospital staff will be discussed. Influences that affect inter-professional cooperation in hospitals are identified.

[Path dependencies as constraints on reorganisational processes in hospitals: using the example of coordination effects]. / Pfadabhängigkeiten als Hemmnisse von Reorganisationsprozessen in Krankenhäusern: Am Beispiel von Koordinationseffekten.

It is the objective of this theoretical study to examine whether archetypical hospital structures promote the creation of path dependencies. In the outcome, coordination effects lead potentially to the development of decentralised informal rules in hospital departments. The successful implementation of organisational target conditions, which are focused on increased work cooperation between individual hospital departments, is hereby called into question.

Survivorship of second-generation metal-on-metal primary total hip replacement.

BACKGROUND: Second generation metal-on-metal total hip replacements (THR) were introduced in the late 1980s and various studies reported conflicting data on their outcome. METHODS: Implant survival of 1,270 second-generation 28 mm metal-on-metal primary THR in 1,121 patients followed prospectively at a mean of 6.8 years postoperatively was evaluated retrospectively. The probability of survival at 10 years was estimated using the method of Kaplan and Meier, and relative risk factors including age, gender, BMI, type of implant fixation and component size were calculated using the Cox proportional-hazards model. RESULTS: Sixty-three (5%) THRs were revised, these being 28 hips for aseptic loosening and 35 for reasons other than aseptic loosening. The probability of survival at 10 years, with revision for any reason as the endpoint, was 0.90 (95% confidence interval (CI) 0.86-0.94) for the THR as a whole, 0.91 (95% CI 0.87-0.95) for the cup, and 0.96 (95% CI 0.94-0.98) for the stem. No demographic factors or covariates were found to significantly affect the implant survivorship. DISCUSSION: As there was no superior probability of survival, and there have been concerns on putative local and systemic toxicity of metal debris, the use of second-generation metal-on-metal articulations for primary THR remains moot.

[Modification of the method of Figgie for determination of joint line shifting in total knee arthroplasty]. / Modifizierung der Messmethode nach Figgie zur Bestimmung der Gelenklinienverschiebung in der Knieendoprothetik.

An important factor for a good result after total knee arthroplasty is the position of the patella in relation to the tibiofemoral joint line. The position of the patella itself is not influenced by arthroplasty, therefore any changes in the position of the tibiofemoral joint line are of special interest. The Figgie method to describe patella height delivers only absolute measurements, which makes it difficult to compare different radiographs. For this reason we developed a new JL/P quotient (JL: distance from the tibial plateau to the tibial tubercle, P: distance from the inferior pole of the patella to the tibial plateau) to enable better comparison. Furthermore, we modified the JL/P quotient and instead of taking the tibial plateau as the reference line, we constructed a tangent on the femoral condyle. With this modification, problems such as tibial inlays of different heights which have to be taken into account in the measurements, the slope of the tibial component or difficult assessment of the tibial joint surface in osteoarthritic knees do not arise. The JL/P quotient shows massive shift to cranialisation of the tibiofemoral joint line which does not correspond to reality. The modified method also shows cranialisation of the tibiofemoral joint line, but in a realistic way. Both methods show a minimal interobserver variability. The modified JL/P quotient seems to be a good method for determining the shift in the tibiofemoral joint line after total knee arthroplasty.

[Modification of the Blackburne-Peel ratio for improved application in total knee arthroplasty]. / Modifizierung des Blackburne-Peel-Index zur besseren Anwendung in der Knieendoprothetik.

BACKGROUND: The methods currently used to measure patella height in relation to the tibiofemoral joint line after total knee arthroplasty are not easily reproducible. For this reason we modified the Blackburne-Peel ratio. MATERIALS AND METHODS: Instead of taking the tibial joint line as the reference line, we constructed a tangent on the femoral condyle. In addition, we took the greatest diameter of the patella from the tip of the patella as a measuring line. RESULTS: Compared with the classic Blackburne-Peel and Caton-Deschamps ratios, it was much easier to determine the patella height in osteoarthritic knees and after total knee replacement using this modified Blackburne-Peel ratio. Factors such as the height of the polyethylene inlay, the slope of the tibial component, and superimposition of the patellar joint line can be disregarded. Preoperative and postoperative reference lines can be compared readily. Furthermore, the classic Blackburne-Peel ratio shows a greater tendency to interpret the measurements after total knee arthroplasty as pseudo-patella baja. The interobserver variability was good for all ratios. CONCLUSION: We can therefore recommend the modified Blackburne-Peel ratio for measuring patella height in relation to the tibiofemoral joint line after total knee arthroplasty.

[Breakdancer's "Headspin Hole" - first description of a common overuse syndrome]. / Das "Headspin Hole" bei Breakdancern - medizinische Erstbeschreibung eines häufigen Uberlastungsschadens.

INTRODUCTION: Several typical injuries due to breakdancing have been described in medical literature, but until now the "headspin hole" has not been mentioned. METHODS: We conducted internet research and interviewed 106 breakdancers. RESULTS: 60.4 % of the breakdancers suffered from overuse of the scalp due to the headspin. Loss of hair was found in 31.1 % and painless lumps on the head in 23.6 %. Inflammation of the scalp was reported in 36.8 %. DISCUSSION: The "Headspin Hole" is a common overuse syndrome of the scalp specific to headspins causing hair loss, inflammation and lumps on the skull.

[Amendment to the law governing the professional activities of physicians in "Medizinische Versorgungszentren"]. / Neuerungen für Medizinische Versorgungszentren nach dem Vertragsarztrechtsänderungsgesetz.

The amendment to the law governing the professional activities of physicians in general, free practice came into force on 1st January 2007 bringing important changes relevant to medical centres, which were first permitted by the government three years ago. Under the new regulations, for example, medical centres with the status of a private limited company now must provide a guarantee as a condition for the licence to operate. Some of the other most important new regulations include the abolishment of the restriction to practice in one place only and permission for physicians to hold positions in a hospital and a medical centre at the same time.

[Amendment to the law governing the professional activities of physicians in general practice]. / Neue Möglichkeiten für niedergelassene Arzte durch das Vertragsarztrechtsänderungsgesetz.

The amendment to the law governing the activities of physicians in general free practice, which came into force on 1st January 2007, has brought a large number of changes. The age limit has been abolished, partial licences to practice and the formation of professional communities covering more than one district are permitted and new employment possibilities for physicians have been created. With these new regulations, many traditional principles of this law have been fundamentally changed. The purpose of the amendment is to make the health service more flexible and increase competition among providers of medical services.

Fracture of the lateral process of the talus in snowboarders.

We investigated the clinical and radiological outcome after unilateral fracture of the lateral process of the talus in 23 snowboarders with a mean follow-up of 3.5 years (12 to 76 months). In this consecutive cohort study both operative and non-operative cases were considered. The mean American Orthopaedic Foot and Ankle Society hindfoot score was 94 (82 to 100). The non-operative group of seven with a minimally-displaced fracture scored higher (98 points) than the operative group of 16 with displaced or unstable fractures (93 points). In 88% of operative cases, significant concomitant hindfoot injuries were found at operation. All but eight (35%) patients (six operative and two non-operative) regained their pre-injury level of sporting activity. Subtalar osteoarthritis was present in nine (45%) of the 20 patients available for radiological review, including one late-diagnosed non-operative case and eight operative cases with associated injuries or fracture comminution. The outcome after fracture of the lateral process of the talus in snowboarders is favourable provided an early diagnosis is made and adequate treatment, which is related to the degree of displacement and associated injuries, is undertaken.

[The legal form of "medizinische versorgungszentren"]. / Rechtsformen für Medizinische Versorgungszentren.

The "Medizinische Versorgungszentrum", established on January 1, 2004, is a new service provider within the German health system. With regard to the potential legal forms a number of questions remain unanswered. The choice of the legal form interacts with the professional code of conduct of the national medical association.

[Differences in taxation between medical care centers and conventional medical practices]. / Unterschiede in der Besteuerung von Medizinischen Versorgungszentren und Arztpraxen.

With the introduction of "Medizinisches Versorgungszentrum", a new medical provider was established in the German health sector as a competitor to conventional medical practices. With regard to the various legal forms, there are differences concerning taxation. This article examines these differences for the limited company and the civil law association.

Trochleaplasty for recurrent patellar dislocation in association with trochlear dysplasia. A 4- to 14-year follow-up study.

We investigated the clinical and radiological outcome of trochleaplasty for recurrent patellar dislocation in association with trochlear dysplasia in 38 consecutive patients (45 knees) with a mean follow-up of 8.3 years (4 to 14). None had recurrence of dislocation after trochleaplasty. Post-operatively, patellofemoral pain, present pre-operatively in only 35 knees, became worse in 15 (33.4%), remained unchanged in four (8.8%) and improved in 22 (49%). Four knees which had no pain pre-operatively (8.8%) continued to have no pain. A total of 33 knees were available for radiological assessment. Post-operatively, all but two knees (93.9%) had correction of trochlear dysplasia radiologically but degenerative changes of the patellofemoral joint developed in 30% (10) of the knees. We conclude that recurrent patellar dislocation associated with trochlear dysplasia can be treated successfully by trochleaplasty, but the impact on patellofemoral pain and the development of patellofemoral osteoarthritis is less predictable. Overall, subjective patient satisfaction with restored patellofemoral stability after trochleaplasty appeared to outweigh its possible sequelae.

[A comparison of the antiresorptive effects of bisphosphonates and statins on polyethylene particle-induced osteolysis]. / Ein Vergleich der antiresorptiven Effekte von Bisphosphonaten und Statinen auf Polyethylenpartikel-induzierte Osteolysen.

An ongoing unraveling of the molecular mechanisms in aseptic loosening of hip arthroplasty has opened up novel potential pharmacological interventions. In this study the antiresorptive effects of the bisphosphonate zoledronate and the statin simvastatin on ultra high molecular weighted polyethylene (UHMWPE) particle-induced osteolysis were compared. Two previous studies of our group based on the murine calvarial model of UHWMPE particle-induced osteolysis were pooled to form four study groups. Animals in group I (n=14) underwent sham surgery only. In groups II (n=14), III (n=7) and IV (n=7) UHMWPE particles were implanted on the calvariae. Animals in groups III and IV were additionally treated with zoledronate (single 25 microg/kg s.c. injection) and simvastatin (120 mg/day p.o. for 14 days), respectively. After two weeks, calvaria were processed for undecalcified histomorphometry. Bone resorption was measured using Giemsa staining. Osteoclast numbers were determined using TRAP-staining. UHMWPE particle implantation resulted in a grossly pronounced osteolytic activity with significantly increased values of bone resorption (p < 0.001) and osteoclast numbers (p < 0.001). Additional treatment with zoledronate or simvastatin counteracted the particle-induced effects. A comparison of the two medical treatments revealed no statistically significant differences in bone resorption (p = 0.63) and osteoclast numbers (p = 0.41). A single dose of the bisphosphonate zoledronate decreased UHMWPE particle-induced osteolysis in a murine calvarial model as effectively as a daily treatment with simvastin. Both drug groups may have a preventive and therapeutic role as antiresorptive agents in wear particle-induced bone resorption following total joint replacement.

A new oxygen applicator for simultaneous mouth and nose breathing.

We have developed a new O2 applicator to try to overcome the problems of long-term oxygen therapy that ensures a sufficient oxygen supply for both nasal and oral breathing and prevents mucosal irritation. Placed on the upper lip, it is unobtrusive. The principle is as follows: due to an enlarged outlet area, turbulence occurs and the oxygen is reduced. Thus, an oxygen cloud is formed that can be inhaled by both mouth or nose. The efficiency of our O2 applicator was compared with a face mask in six healthy subjects and patients with COPD. A similar increase in PO2 was found up to an oxygen flow of 2 L/min for nasal and oral breathing. Mild hypercapnia resulted in three patients with COPD only when a face mask was used and only when patients breathed through the nose. All patients preferred the new applicator.

In vitro comparison of aortic heart valve prostheses. Part 1: Mechanical valves.

The hydrodynamic performance of a series of mechanical heart valve prostheses is measured in the aortic position. All experiments are performed in an electrohydraulic, computer-controlled pulse duplicator simulating the left side of the human circulatory system. Testing conditions are set according to a Food and Drug Administration interlaboratory comparison protocol with cardiac outputs of 3.0, 4.5, 6.5, and 8.0 L/min at a constant heart rate of 70 beats/min. Mean systolic pressure differences, volume losses, and energy losses, as well as dimensionless pressure losses and energy loss coefficients, are calculated from the recorded pressure, volume, and flow tracings. The results of 10 mechanical heart valve prostheses (eight tilting disc valves and two bileaflet valves) are presented and their clinical relevance is discussed.

Decrease in particle-induced osteolysis in obese (ob/ob) mice.

There may be variability in the susceptibility of different individuals to osteolysis from wear debris, and it is not clear whether some individuals may have a genetic predisposition for a more marked osteolytic response. The purpose of this study in mice was to determine whether genetically determined obesity can alter the response to particulate debris. Polyethylene particles were implanted onto the calvaria of seven wild-type mice and seven obese mice (ob/ob). Calvaria from unimplanted wild-type and obese mice served as controls. Calvaria were harvested after 7 days, stained with toluidine blue and for tartrate-specific alkaline phosphatase, and analyzed by histomorphometry. The osteoclast number per mm total bone perimeter was 8.000+/-3.464 in wild-type animals with particles and 2.857+/-1.676 in ob/ob animals with particles (p=0.002; Fisher's PLSD). Bone resorption was 1.895+/-0.713 mm/mm(2) in wild-type animals with particles and 1.265+/-0.494 mm/mm(2) in ob/ob animals with particles (p=0.0438; Fisher's PLSD). Particles induced a diminished osteolytic response in genetically determined obese mice, suggesting that obesity may have a protective role against particle-induced bone resorption-similar to obesity and osteoporosis. These important new findings may help to stimulate clinical studies which may define criteria to better identify patients at risk to develop particle-induced osteolysis.

Lung deposition from four nebulizers.

The total and regional deposition of aerosol has been compared using four nebulizers; the Pari Boy 37.80, Pari IS-2, RespirGard II and Penta-Sonic. The aerosol was radiolabelled with [99Tcm]DTPA, administered to ten healthy subjects and the distributions monitored by gamma scintigraphy. Median lung aerosol depositions expressed as percentages of the doses initially loaded into the nebulizers were: Pari IS-2 19%, Pari Boy 37.80 13%, RespirGard II 9% and Penta-Sonic 2%. The ratios of the peripheral to central lung deposition, however, were greater with the RespirGard II and Penta-Sonic nebulizers. The choice of the most appropriate nebulizer depends on the pharmaceutical being administered, since aerosol must be delivered to the required site in sufficient quantity, whilst minimizing the incidence of local or systemic side-effects.