Diagnostic guidelines for the histological particle algorithm in the periprosthetic neo-synovial tissue

BACKGROUND

The identification of implant wear particles and non-implant related particles and the characterization of the inflammatory responses in the periprosthetic neo-synovial membrane, bone, and the synovial-like interface membrane (SLIM) play an important role for the evaluation of clinical outcome, correlation with radiological and implant retrieval studies, and understanding of the biological pathways contributing to implant failures in joint arthroplasty. The purpose of this study is to present a comprehensive histological particle algorithm (HPA) as a practical guide to particle identification at routine light microscopy examination.

METHODS

The cases used for particle analysis were selected retrospectively from the archives of two institutions and were representative of the implant wear and non-implant related particle spectrum. All particle categories were described according to their size, shape, colour and properties observed at light microscopy, under polarized light, and after histochemical stains when necessary. A unified range of particle size, defined as a measure of length only, is proposed for the wear particles with five classes for polyethylene (PE) particles and four classes for conventional and corrosion metallic particles and ceramic particles.

RESULTS

All implant wear and non-implant related particles were described and illustrated in detail by category. A particle scoring system for the periprosthetic tissue/SLIM is proposed as follows: 1) Wear particle identification at light microscopy with a two-step analysis at low (× 25, × 40, and × 100) and high magnification (× 200 and × 400); 2) Identification of the predominant wear particle type with size determination; 3) The presence of non-implant related endogenous and/or foreign particles. A guide for a comprehensive pathology report is also provided with sections for macroscopic and microscopic description, and diagnosis.

CONCLUSIONS

The HPA should be considered a standard for the histological analysis of periprosthetic neo-synovial membrane, bone, and SLIM. It provides a basic, standardized tool for the identification of implant wear and non-implant related particles at routine light microscopy examination and aims at reducing intra-observer and inter-observer variability to provide a common platform for multicentric implant retrieval/radiological/histological studies and valuable data for the risk assessment of implant performance for regional and national implant registries and government agencies.

Histopathological Osteomyelitis Evaluation Score (HOES) - an innovative approach to histopathological diagnostics and scoring of osteomyelitis

BACKGROUND

Treatment and diagnosis of osteomyelitis are still a challenging problem for surgeons, microbiologists and histopathologists. A direct microbiological detection of bacteria in tissues is still gold standard, but it is not always successful for example in chronic osteomyelitis and/or when an antibiotic treatment has already been started or in cases of low virulent bacteria. The goal of this study was to define diagnostic criteria of osteomyelitis, the inflammatory regression of osteomyelitis ("osteomyelitis score") under specific therapy by the correlation of histopathological and microbiological and clinical standard tests.

METHODS

In this retrospective analysis patients with medical history and clinically clear signs of bacterial infection and osteomyelitis underwent surgery between 01.01.2013 and 31.12.2012. Their formal consent was given. Tissue samples were taken during surgery according to defined criteria including surgical interventions. Histopathological diagnosis was carried out by conventional techniques based on defined criteria of bacterial infection in connective tissue, peri-implant membrane and bone. These results were carried out in tables by numbers representing the histopathological criteria of acute osteomyelitis (A1 to A3) as well as the chronic criteria (C1 and C2) in a semiquantitative way (scale 0 to 3). On the other hand a notational, graduated histopathological report was performed. Preoperative clinical diagnosis, perioperative macroscopic diagnosis, histopathological and microbiological findings were correlated.

RESULTS

Histopathological samples of 52 surgical interventions based on the preoperative diagnosis "osteomyelitis" (AOM, ECOM or COM) were included. 37 times preoperatively signs of a chronic osteomyelitis (COM), 10 times preoperatively acute osteomyelitis (AOM) was diagnosed. Another 5 patients were preoperatively diagnosed as acute exacerbated osteomyelitis (ECOM). The correlation of the histopathological infection including the inflammatory activity and microbiological detection of bacteria was 57%. The correlation between preoperative diagnosis and histopathological findings was 68%.

CONCLUSION

The relatively small 68% correlation between clinical preoperative and histopathological diagnosis and 57% correlation between preoperative clinical diagnosis and microbiological findings indicates: Clinical findings are not sufficient for the diagnosis "osteomyelitis".Clinical findings are not sufficient for the differentiation between AOM, ECOM and COM.Histopathological analysis is the critical factor for the diagnosis ("osteomyelitis") and differential diagnosis (AOM vs. COM).Histopathological analysis represents the basis for further treatment.HOES facilitates the classification of the histopathological findings.HOES is a sufficient tool for the treating physician in order to define the further treatment.

[Revised consensus classification. Histopathological classification of diseases associated with joint endoprostheses]

The revised classification of the periprosthetic membrane (synovial-like interface membrane SLIM) encompasses all pathological alterations which can occur as a result of endoprosthetic replacement of major joints and lead to a reduction in durability of prostheses. This also includes the established consensus classification of SLIM by which aseptic and septic prosthetic loosening can be subdivided into four histological types and histopathological criteria for additional pathologies: endoprosthesis-associated arthrofibrosis, immunological/allergic alterations and osseous pathologies. This revision represents the foundation for the histopathological diagnostics of the total spectrum of diseases associated with joint prostheses, is a suitable basis for a standardized diagnostic procedure and etiological clarification of endoprosthesis failure and also as a data standard for endprosthesis registers, in particular for registers based on routine data (e.g. German endoprosthesis register).

[Histopathological degeneration score of fibrous cartilage. Low- and high-grade meniscal degeneration]

Although histopathology of meniscal degeneration plays an important role, no criteria to assess severity of the degeneration are available to date. Our aim was to create a histopathological scoring system for meniscal degeneration with good interobserver variability, taking matrix degradation and cellularity in meniscal tissue into consideration. Degeneration is classified as follows: grade 1 (low), grade 2 (intermediate), grade 3 (high). The pattern of NITEGE deposits (G1 fragment of aggrecan) was assessed immunohistochemically (n=38) and compared with the grades of degeneration. In 48% of the patients with grade 2 or 3 degeneration extracellular NITEGE deposits (specificity 100%) were found, whereas grade 1 patients showed no deposits. Extracellular NITEGE deposits correlated positively with the grade of degeneration. In all, 30 cases (10 per grade) were assessed by three pathologists (A, B, C). Grading conformity was 70% for grade 1, 66% for grade 2 and 100% for grade 3. Cohen's Kappa coefficient was 0.6--0.7 between pairs of observers. Combining grade 1 and 2 to low-grade degeneration, compared to a grade-3 high-grade degeneration achieved Kappa coefficients of between 0.93 and 1.0. This reproducible degeneration score for fibrous cartilage could form the basis for the standardized assessment of meniscal degeneration.

[Meniscal degeneration score and NITEGE expression : immunohistochemical detection of NITEGE in advanced meniscal degeneration]

BACKGROUND

Meniscal degeneration (MD) is a structural change of fibrous cartilage that is common in orthopaedic diagnostics and relevant for health insurance matters. So far, there has been neither a standardised scoring system nor an immunohistochemical marker for MD.

MATERIAL AND METHOD

In this retrospective trial, the meniscal tissue of 60 patients was assessed immunohistochemically for NITEGE (G1 fragment of the proteoglycan aggrecan) expression. NITEGE expression was correlated with defined grades of MD: little (grade 0/1), medium (grade 2), or severe (grade 3).

RESULTS

Detection of extracellular NITEGE deposits in grade 2 or 3 MD had a positive predictive value and specificity of 100%, whereas no deposits were found in grade 0/1 MD. Sensitivity in advanced MD was 55%. Detection of extracellular NITEGE correlated positively with the grade of degeneration, as did patient age and the grade of degeneration. The patient age of those with grade 0/1 MD was significantly lower than for grade 3 (p<0.0001).

CONCLUSION

The thoroughly defined degeneration score (grade 1 - grade 3 MD) is suitable to assess the severity of degeneration. Extracellular NITEGE deposits can be regarded as an immunohistochemical marker for advanced (grades 2 and 3) MD.

[Is bioptic assurance reasonable in patients with Sjögren's syndrome? From focus score to diagnosing vasculitides]

Sjögren's syndrome is an autoimmune disease which targets the salivary and lacrimal glands in particular, causing sicca syndrome. Extraglandular manifestations are often seen. Chronic sialadenitis of the parotid gland is the most common symptom to be assessed for differential diagnosis. Common HE and Giemsa slices are histopathologically examined and graduated for lymphocyte infiltration (focus): grade 0: absent, grade 1: slight, grade 2: moderate non-focal infiltration, grade 3: 1 focus (> or =50 lymphocytes) per 4 mm2, grade 4: >1 focus. Grade 3 infiltrates correspond to a focus score of 1, which is one of four disease-classifying criteria acknowledged for diagnosis. Bioptic examination is also performed to rule out different (non-) immunologic sialadenitises, such as the necrotizing or epithelioid-like form (in sarcoidosis), and the extranodal marginal-zone lymphoma. Extraglandular manifestations of Sjögren's syndrome can also be safely diagnosed by histopathological examination. Emphases lie on vasculitides and myositides. Bioptic work-up, therefore, is not only reasonable but also an essential tool for diagnostics in Sjögren's syndrome.

[The area of conflict between the surgeon's duty to inform about diagnosis, prognosis, operation, complications, time schedule, alternative methods and the patient's right of self-determination]

The surgeon's duty to inform patients determines the indication to a therapeutic and/ or diagnostic procedure. Despite ongoing information made available by the professional associations, the complaints against surgeons providing treatment are on the increase. Only careful health education information with records kept of the course of treatment adopted will safeguard the doctor in charge from patients' claims for damages. Case law demands that the doctor put the patient in a position to understand what is happening to him or her and for him or her to be able to make a decision freely. The patient's compliance after being provided with health education information makes the corpus delicti of bodily harm void. A special form is the matter of fact of "transfer negligence", when the doctor and/ or the hospital is aware, prior to execution of the treatment, that treatment is not possible lege artis. What continues to be applicable to health education information is that the more urgent the operation, the less information is indicated, so that in emergencies such operation can be completely done without. Apart from general risks, such as wound infection and/or the danger of thrombosis, information must also be provided about special risks and the course of any follow-up treatment. Legal practice shows that simply handing over forms is not sufficient. The patient may forgo treatment. Aborting an operation for purposes of providing health information is balancing between the patient's interests in immediate execution of the indicated measure, on the one hand, and the right of self-determination on the other. Should the operation be able to be aborted without any serious consequences for the patient, then it is to be thus done.What does principally apply in civil litigation is the rule of the burden of proof.

Tumor regression by means of magnetic drug targeting

The expression ‘magnetic drug targeting’ is understood as meaning the targeted administration of a drug, for example, a cytostatic, with the intention of optimizing the local therapeutic effect. A magnetic field strength of 0.6 T is applied externally to the body. Iron oxides are administered intravasally into a vein. Cytostatics are bonded to the iron oxides. This form of administration, also known as sluicing, is particularly suitable for cytostatics, since the intention is to achieve a high concentration of the cytostatic at the target site (site of the tumor), but to minimize the harmful effect in the rest of the tissue. A reduction in tumor volume under the magnetic field and in the liver of 45–90% has been detected by MRI.

[Synovitis score: value of histopathological diagnostics in unclear arthritis. Case reports from rheumatological pathological practice]

Histopathological assessment of synovial biopsies has an established value. The value for inflammatory joint diseases without standardized rating mechanisms was, however, unknown until recently. The exemplary use of the synovitis score in four cases all including recurrent bruises of the knee joint portrays its value for diagnosis and therapy. Usage of the score includes assessing the enlargement of the lining layer, cellular density of synovial stroma and leucocyte infiltration by giving each a score of 0-3 points and adding them. Presence of high-grade synovitis (>or=4 points) in all cases displayed the reason for the joint bruises within a primarily inflammatory, rheumatoid circle. In this report we show the broad variety of uses for the synovitis score dealing with cases of Lyme arthritis, rheumatoid arthritis, seronegative monarthritis and HLA-B27-positive peripheral arthritis.

Colocalization of C4d deposits/CD68+ macrophages in rheumatoid nodule and granuloma annulare: immunohistochemical evidence of a complement-mediated mechanism in fibrinoid necrosis

Rheumatoid nodule (RN) represents a palisading granuloma with central fibrinoid necrosis, which is not only a classical manifestation of rheumatoid arthritis (RA) and part of the American College of Rheumatology (ACR)-criteria, but also is its diagnostic hallmark. The pathogenesis of RN is still not fully understood. At present, only data on serum analyses indicating a complement-mediated pathogenesis in the development of RA are available. Equivalent examinations for RN have not yet been performed. Granuloma annulare (GA) represents another type of palisading granuloma. A special subtype of GA, subcutaneous GA (SGA), is an important differential diagnosis to RN. Therefore, our aim was to examine RN and SGA regarding the complement deposition (C4d) by immunohistochemical means. All RN and GA were stained by hematoxylin/eosin and different special stains. In addition, all specimens were stained immunohistochemically with antibodies against CD68. Five GA and five RN were analyzed immunohistochemically with antibodies against C4d and CD68, and evaluated using single- and doublestaining immunohistochemistry. All RN and GA displayed depositions of C4d within their central necroses and between the surrounding palisading macrophages. Most importantly, C4d/CD68 double staining was visible in the palisading macrophages next to the necroses, while macrophages in the periphery were negative for C4d but positive for CD68. The main difference between RN and GA was a quantitative phenomenon with less positively reacting macrophages in a more incomplete palisade in GA. The positive reactions of all central necroses to C4d and colocalization of CD68 and C4d suggest that a complement-mediated mechanism may be operative in the formation of fibrinoid necrosis. This mechanism may be involved in any form of "fibrinoid necrosis", since no different patterns of C4d/CD68 expression could be observed in GA. This may explain why RG/GA are not distinguishable morphologically.

[Necessity of increasing autopsy frequency following the introduction of DRGs]

With the introduction of DRGs (diagnosis related groups) in 2004, a new charging system was initiated in Germany. Changes primarily involve lump sum based charging of inpatient cases regardless of the duration or complexity of diagnostic procedures and therapy, and the equalization of costs for similar services. Calculation of DRGs also includes the costs of autopsy. This has three major consequences for autopsy practice: Quality assurance: continuous monitoring of professional quality under lump sum payment can only be permanently guaranteed and independently and reliably attained by autopsy. This is the only way to overcome the danger of abolishing essential diagnostic procedures because of economic pressure and thus risking incorrect diagnoses. Economy: additional diagnoses revealed by autopsy will, in many cases, raise calculated charges. This could have a significant financial impact. Legal certainty: autopsies increase the accuracy and objectivity of diagnoses. Thus, they protect the attending physician from incorrect charging which may be unintended but could be legally relevant, especially when the cause of death is unclear. For these reasons, autopsy should become more important in clinical routine.

Gene expression in endoprosthesis loosening: chitinase activity for early diagnosis?

The aim of the study was to identify markers for the early diagnosis of endoprosthesis loosening, for the differentiation between wear particle-induced and septic loosening and to gather new insights into the pathogenesis of endoprosthesis loosening. Gene expression profiles were generated from five periprosthetic membranes of wear particle-induced and five of infectious (septic) type using Affymetrix HG U133A oligonucleotide microarrays. The results of selected differentially expressed genes were validated by RT-PCR (n = 30). The enzyme activity and the genotype of chitinase-1 were assessed in serum samples from 313 consecutive patients hospitalized for endoprosthesis loosening (n = 54) or for other reasons, serving as control subjects (n = 259). Eight hundred twenty-four genes were differentially expressed with a fold change greater than 2 (data sets on http://www.ncbi.nlm.nih.gov/geo/ GSE 7103). Among these were chitinase 1, CD52, calpain 3, apolipoprotein, CD18, lysyl oxidase, cathepsin D, E-cadherin, VE-cadherin, nidogen, angiopoietin 1, and thrombospondin 2. Their differential expression levels were validated by RT-PCR. The chitinase activity was significantly higher in the blood from patients with wear particle-induced prosthesis loosening (p = 0.001). However, chitinase activity as a marker for early diagnosis has a specificity of 83% and a sensitivity of 52%, due to a high variability both in the disease and in the control group.

[Legally effective consent with minors and incompetent patients]

Legal consent to medical treatment requires comprehensive clarification and the patient's capability to consent. Minors under 14 years are usually not capable of consent -- the right to decide rests with the parents. With persons over 14 years the doctor must test for capability to consent. With adults incapable of consent the court-appointed guardian decides. In acute cases the doctor may act first and obtain permission afterwards. Contractual capability is decisive for a treatment contract to be effective and the doctor's claim for remuneration. Minors up to 7 years are absolutely contractually incapable. Since minors under 18 years are only limitedly contractually capable, the approval of the statutory guardian suffices. With contractually incapable adults the court-appointed guardian or in serious cases the Guardianship Court decides. The legal position is explained, using three sample cases.

[Indications for surgery from the viewpoints of surgeon and juror]

Whether an operation is indicated or not is a question that is a frequent subject of discussion between physicians and the legal front. As the state has the duty to protect its citizens, any physical surgical operation is legally seen as a personal injury. Only if the patient completely agrees to the surgery after being carefully informed about it is the element of criminal offense (personal injury) revoked. The obligation to disclose medical information on the surgery applies to information on the operation itself and on the possible consequences to the patient in his/her physical and mental social environment. In particular, the patient must be given all information about the risks that could arise during and after the surgery. The legislative aim of this is not to treat a list of questions and to mention all possible risks, but the legislator wants to oblige physicians to give patients who have reached the age of majority full information on diagnosis and therapy and to enable them to consider the pros and cons of the surgery carefully and then to agree to the operation or to refuse it. Besides the obligation to disclose medical information in emergency cases, the obligation to disclose medical information to minors also makes heavy demands on the physician. Examples of contraindications are given.

[Differential diagnosis of rheumatoid granuloma]

Rheumatoid granuloma (RG) is histomorphologically defined as a subcutaneous palisading granuloma with central fibrinoid necrosis. Clinically, it presents as a nodule typically localized at pressure points near the joints. From the rheumatic pathological point of view, the main diagnostic challenge is the differentiation of RG from granuloma anulare, especially if clinical information on the site of removal, known diseases, duration of illness, medication and existing American College of Rheumatology (ACR) criteria are missing. Other granulomatous lesions, such as mycobacterial infections, foreign body granulomas, necrobiosis lipoidica or sarcoidosis, can be differentiated from RG by histopathological criteria or by additional examinations such as pathogen specification or PCR. An immunohistochemical marker for the differential diagnosis of granulomas is not yet available. Diagnosis is based on conventional H-E staining, alcian blue-PAS staining, polarizing analysis or PCR. In the following article, the most important granulomatous entities in the differential diagnosis of RG are introduced and the main diagnostic characteristics are discussed.

Procollagen-I-propeptide and β-crosslaps are prognostic markers for pretherapeutic estimation of treatment success of combined radio- and bisphosphonate therapy in patients with bone metastases—A phase-II study

9096

Background: Multiple painful bone metastases are a common problem in patients suffering from breast and prostate cancer. Side effects of morphines can impair quality of life. Pain reduction can also be achieved by radiotherapy combined with bisphosphonates; however, this treatment is not successful in all patients. Methods: 35 patients with breast and prostate cancer suffering from painful bone metastases (multiple metastases in 29 cases, solitary metastasis in 6 cases: were locally irradiated (30 - 40 Gy over 3 - 4 weeks, conventional dose fractionation). In addition they received a bisphosphonate therapy (zoledronate). Before and after radiotherapy procollagen-I- propeptide and β-crosslaps were measured as parameters for the intensity of bone metabolism. Results: 24 patients experienced complete pain relief, 10 patients partial pain relief and one patient noticed no effect of treatment. The values of procollagen-I-propeptide (normal range 19–102 μg/l) and β-crosslaps (normal range <= 1,0 μg/l) were correlated with treatment success. At pretherapeutical procollagen-I- propeptide levels above 190 μg/l, all patients became entirely free of pain. All patients with β-crosslaps values above 0.5 μg/l became equally free of pain, irrespective of the number of metastases and tumour entity. The mean levels of procollagen-I-propeptide as well as β-crosslaps correlate directly and without exception with analgesia, reduction of pain or persistency of pain as final results. No correlation concerning the values was found before and after therapy. Conclusion: Procollagen-I-propeptide as well as β-crosslaps measurements before the beginning of a radio- and bisphosphonate therapy due to painful bone metastases are an excellent prognostic parameter to predict the success of therapy. Where high initial values (procollagen-I-propeptide > 190 μg/l or β-crosslaps > 0.5 μg/l) were measured, complete analgesia was achieved through therapy. Despite this clinically clear statement, a statistical significance with a t-Test was not evaluable at the current collection of patient data. Therefore, 20 more patients were examined; the results are yet to come.

No significant financial relationships to disclose.

Hb-level stabilisation with epoetin alfa in patients with advanced NSCLC undergoing concurrent neoadjuvant chemo-radiation therapy (phase III study)

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Background: Patients suffering from advanced stage IIIA/B NSCLC still have a bad prognosis despite the development of new and more effective treatment methods. Improved therapy options include multi-modal treatment approaches with sequential and/or concurrent chemo-radiation therapy and, alternatively, subsequent surgery. The patients have to accept a higher incidence of side effects and longer therapy cycles, which can last up to six months. This means that most patients spend a considerable part of their survival time undergoing therapy, where, in the short or medium term, they are likely to die of a relapse or haematogenous metastatic spread. Therefore we have decided to offer patients with unfavourable prognostic factors (poor general health, high age, comorbidity) a shortened, three-week neoadjuvant and concomitant chemo-radiation therapy plus possible surgery. This form of treatment is expected to produce more positive outcomes than the purely palliative radiation therapy at 40–50 Gy. Preventive dosing with Epoetin alfa as part of an intensive therapy regimen might lead to higher compliance, increased quality of life and possibly even to a better prognosis as a result of stabilising patients’ Hb levels. Methods: 51 stage IIIA/B NSCLC patients received neoadjuvant concurrent chemo-radiation therapy (daily cisplatin (6 mg/m2), 45 Gy hyperfractionated accelerated radiotherapy). 25 patients received additional treatment with Epoetin alfa 3 times a week (10,000 IU sc). Results: While Hb levels dropped significantly (−0.54 g/dL) during therapy in the control group, the Epoetin-alfa group showed a significant rise after only three weeks (+1,35 g/dL). There were no significant differences in remission rates between the goups. Conclusions: In this patient group, preventive treatment with Epoetin alfa stabilises Hb levels at a target level of around 12 g/dL even under intensive therapy. To what extent treatment with erythropoietin affects prognosis should be examined in further studies.

No significant financial relationships to disclose.

[Legal aspects of deadly acute appendicitis]

Appendicitis is diagnosed by synoptic evaluation of typical symptoms, laboratory tests and sonography. The only therapy is a prompt operation. The main reason for appendicitis mortality is the condition not detected or not detected in time. The case of a 50 year old male who died from a non-detected perityphlitic appendicitis with abscesses in the liver is presented. Only if appendicitis can be reliably ruled out an operation is not indicated. The not performed surgical intervention is often interpreted as a treatment error by the courts. In doubt, an operation should therefore be performed.

C4d in acute rejection after liver transplantation--a valuable tool in differential diagnosis to hepatitis C recurrence

Hepatitis C is the most common indication for liver transplantation. Recurrence of HCV is universal leading to graft failure in up to 40% of all patients. The differentiation between acute rejection and recurrent hepatitis C is crucial as rejection treatments are likely to aggravate HCV recurrence. Histological examination of liver biopsy remains the gold standard for diagnosis of acute rejection but has failed in the past to distinguish between acute rejection and recurrent hepatitis C. We have recently reported that C4d as a marker of the activated complement cascade is detectable in hepatic specimen in acute rejection after liver transplantation. In this study, we investigate whether C4d may serve as a specific marker for differential diagnosis in hepatitis C reinfection cases. Immunohistochemical analysis of 97 patients was performed. A total of 67.7% of patients with acute cellular rejection displayed C4d-positive staining in liver biopsy whereas 11.8% of patients with hepatitis C reinfection tested positive for C4d. In the control group, 6.9% showed C4d positivity. For the first time we were able to clearly demonstrate that humoral components, represented by C4d deposition, play a role in acute cellular rejection after LTX. Consequently C4d may be helpful to distinguish between acute rejection and reinfection after LTX for HCV.

Structural problems in the German hospital system

The German health care system has been based on the Hospital Financing Act, which the German government introduced in 1972. According to that, the federal states plan hospitals and make investments. The health insurance funds finance the operating costs. But now the Hospital Financing Act is obsolete, because both the health insurance funds and the federal states are in financial trouble and try to avoid the costs, which are nevertheless rising. In order to freeze costs, the legislators have introduced a new remuneration system, called DRGs (Diagnosis Related Groups), which will be mandatory from 2007 onwards. In this system, the treatment provided will be coded and remunerated on the basis of the primary diagnosis. Periods of hospitalisation and different remuneration systems will no longer be relevant. Transparency and quality will thus be promoted, and the upshot will be more competition among the hospitals. Hospitals that cannot meet quality standards will lose patients and will ultimately have to close. Other participants in the health care system, such as, for example, nursing staff, physicians, pharmacies, rehabilitaion centres and patients, will also be concerned in many ways. The consequences of the DRGs for the health care system, its future development and possible alternatives are discussed in this article.