[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.

Functional interest of an articulating spacer in two-stage infected total knee arthroplasty revision.

INTRODUCTION: Deep periprosthetic infection is one of the most serious complications after total knee replacement. The two-stage procedure with implantation of a temporary cement spacer and later re-implantation of a revision total knee prosthesis is an accepted procedural standard. The use of articulating spacers has been proposed to enhance ease of revision and functional results. PATIENTS AND METHODS: Twenty-three patients treated with an articulating spacer were retrospectively studied. All patients had undergone a two-stage surgery. The infected prosthesis was explanted and the femoral component was sterilized and re-implanted. On the tibial side a block of gentamicin-loaded bone cement was produced intraoperatively using specially manufactured templates. Eighteen total knee arthroplasty revisions and 5 arthrodesis were finally performed. RESULTS: A total of three (13%) re-infections occurred 5-20 months after revision total knee arthroplasty in a mean follow-up period of 47 months. Prior to re-implantation, flexion with the articulating spacer ranged between 15 and 100° (mean 68±28°). The average postoperative flexion after re-implantation of total knee replacement was 105±11°. CONCLUSION: The articulating spacer used in this study appears to be as effective as the standard procedures in terms of re-infection risk rate and postoperative range of motion recovery. LEVEL OF EVIDENCE: Level IV.

[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.

[Accuracy of rotational positioning of the femoral component using the tibial-cut-first technique]. / Bestimmung der Rotationsgenauigkeit der Femurkomponente bei Tibial-Cut-First-Technik.

AIM: Problems with the patellofemoral joint are still one of the most common difficulties after total knee arthroplasty. One of the main reasons for these problems seems to be the rotatory malposition of the femoral component. We examined the rotation of the femoral component and the symmetry of the flexion gap of knee prostheses implanted using the tibial-cut-first technique. METHOD: The radiographs of 58 consecutive patients who underwent primary LCS total knee arthroplasty in 2008 were examined retrospectively. The rotation of the femoral component was determined intraoperatively using the femoral positioner and depended on the amount of tibial resection and the tension of the collateral ligaments. The position was then checked by means of three anatomic landmarks: the epicondylar axis, the posterior condyles and the Whiteside line. We used Kanekasu's technique for the radiographs. With this technique it was possible to ascertain the rotation of the femoral component after total knee arthroplasty easily and with a low level of radiation. It was also possible to determine the opening of the flexion gap. RESULTS: The radiographs showed a slight external rotation of the femoral component of 1.31°. The opening of the flexion gap was increased laterally, but only by 1.5°. CONCLUSION: In this study, determination of femoral rotation using the tibial-cut-first technique resulted in a slight external rotation of the femoral component. Furthermore, it is possible to create an almost symmetrical flexion gap with this method.

[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.

[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.

[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 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.

[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.

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.

[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.

[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.

Polyethylene particle-induced bone resorption in substance P-deficient mice.

Aseptic loosening is the major cause of total joint replacement failure. Substance P (SP) is a neurotransmitter richly distributed in sensory nerve fibers, bone, and bone-related tissue. The purpose of this study was to investigate the potential impact of SP on bone metabolism in polyethylene particle-induced osteolysis. We utilized the murine calvarial osteolysis model based on ultrahigh molecular weight polyethylene (UHMWPE) particles in 14 wild-type mice (C57BL/J6) and 14 SP-deficient mice. Group 1 (C57BL/J 6) and group 3 (SP-knockout) received sham surgery, and group 2 (C57BL/J6) and group 4 (SP-knockout) were treated with polyethylene particles. Analytical methods included three-dimensional micro-computed tomographic (micro-CT) analysis and histomorphometry. Bone resorption was measured within the midline suture. The number of osteoclasts was determined by counting the tartrate-resistant acid phosphatase-positive cells. UHMWPE-particle treated SP-deficient mice showed significantly reduced osteolysis compared to wild-type mice, as confirmed by histomorphometry (P < 0.001) and micro-CT (P = 0.035). Osteoclast numbers were significantly reduced in groups 3 and 4 compared to groups 1 and 2 (P < 0.001). Unexpectedly, SP-deficient mice (group 3) showed a significantly increased absolute bone mass compared to wild-type mice (group 1) (P = 0.02). The findings of our murine calvaria model lead to the assumption that SP is a promoter in particle-induced osteolysis. The pathophysiology of aseptic loosening is complex, and neuropeptides are not solely responsible for the progress of implant loosening; however, we conclude that there could be coherence between neurotransmitters and particle-induced osteolysis in patients with aseptic loosening.

[Endosteal reaction in the region surrounding the stem of a cement-free prosthesis. An early radiological sign of imminent fracture of the femoral shaft?]. / Endostale Reaktion im Schaftbereich einer zementfreien Prothese. Ein radiologisches Frühzeichen einer drohenden Femurschaftfraktur?

Periprosthetic fractures are familiar complications after total hip arthroplasty and have often been reported in the literature. The most frequent localization of such fractures is the middle third of the shaft. In the case described here a minor trauma resulted in a periprosthetic fracture with fracture of the femur and of the femoral component of a Lord prosthesis. A radiograph taken prior to trauma showed an endosteal reaction at the level at which the fracture later occurred. This might have been an indication that the stem of the prosthesis was already broken; had this radiological sign been correctly interpreted, it is possible that the fracture could have been avoided.

[Structural femoral head allografts in revision surgery of loosened acetabular cups]. / Strukturelle Femurkopfallografts in der Revisionschirugie von gelockerten Hüftendoprothesenpfannen.

BACKGROUND: Treatment of acetabular bone defects presents a great challenge in revision total hip arthroplasty (THA). Many methods of acetabular reconstruction have been described. The purpose of this study was to evaluate the midterm results of structural femoral head allografts for acetabular reconstruction. METHODS: Thirty-six patients (33 females and 3 males) with acetabular defects ranging from type 2C to type 3B according to Paprosky's classification were included in the study. In all cases acetabular defects were closed using allografts from femoral heads. In 13 cases an uncemented press-fit cup, in 17 cases a cemented polyethylene socket, and in 6 cases a Burch-Schneider antiprotrusion cage was implanted. The mean follow-up period was 84.2 months (range: 5-147). RESULTS: Four acetabular components failed. All 36 grafts were osseointegrated radiographically and formed a mechanically stable construction. The mean Harris Hip Score at the most recent follow-up was 79.8 points. The distance from the obturator line to the prosthesis head center was 3.73 cm (1.17-5.80 cm) preoperatively and 2.79 cm (0.85-4.8 cm) postoperatively (p<0.05). The distance from the teardrop figure to the prosthesis head center was 3.02 cm (1.0-5.8 cm) preoperatively and 3.25 cm (1.6-4.8 cm) postoperatively (p<0.001). CONCLUSIONS: Closure of acetabular defects of types 2C to 3B according to Paprosky's classification can be satisfactorily accomplished using femoral head allografts. These allografts may facilitate future revision surgery. Femoral heads are readily available due to widespread primary total hip replacement surgery. However, the use of structural femoral head allografts for acetabular reconstruction is cost intensive. Individual patient-related aspects, such as the function of revision arthroplasty, have to be considered when planning revision arthroplasty using femoral head allografts.