When are patients with osteoarthritis referred for surgery?

Current treatment strategies in hip and knee osteoarthritis (OA) involve a combined approach that includes not only modification of risk factors and conservative treatment but also joint-preserving surgical therapy in the early stages, or joint replacement in late OA. With the recent development of new etiological concepts (i.e. hip dysplasia and femoroacetabular impingement as major risk factors for hip OA), treatment alternatives for joint preservation could be extended significantly. Satisfactory results of osteotomies and other reconstructive procedures around hip and knee joints can only be expected in early OA (Kellgren/Lawrence grade 0-II). If patients with advanced radiographic OA grades III-IV do not respond to conservative treatment over at least 3 months and express a relevant burden of disease, joint replacement might be considered. Prior to surgery, potential contraindications must be excluded, patient expectations need to be discussed, and modifiable risk factors, which may negatively influence the outcome, should be optimized.

[Partial or full component exchange in hip revision? : The relevance of off-label use and mix & match]. / Partieller oder vollständiger Wechsel in der Hüftrevisionsendoprothetik? : Bedeutung von Off-Label-Anwendung und Mix & Match.

Off-label use is frequently practiced in hip revision arthroplasty, as there may be indications for the application of implants for purposes outside the one the manufacturers intended (i.e. large bone and soft tissue defects, obesity). Patients may also benefit from selective application of mix & match in hip revision, when the exchange of one component only is necessary and the invasiveness of surgery can be reduced. Currently, there are no formal guidelines for these situations. Therefore, within a recent EFORT initiative, evidence- and consensus-based recommendations have been developed for the safe application of off-label use and mix & match in revision hip and knee arthroplasty.

[Complication profile and revision concepts for megaprosthetic reconstruction following tumour resection at the hip]. / Komplikationsprofil und Revisionsstrategien nach Tumorspezialendoprothetik am Hüftgelenk.

BACKGROUND: Tumourous destruction of the periacetabular region and the proximal femur is a typical consequence of either primary malignant bone tumour manifestation or skeletal metastatic diseases. Pathological fractures of the proximal femur and periacetabular regions due to primary manifestation or metastatic disorders are frequent. OBJECTIVES: Presentation of the most common complications of tumour endoprostheses at the hip and a description of management strategies, including therapeutic recommendations and concepts for complication avoidance. MATERIALS AND METHODS: The current knowledge and our own experience of complication management with the use of megaprostheses around the hip are presented. RESULTS: Compared to elective/primary total hip arthroplasty, megaprosthetic reconstructions following tumour resections have an increased rate of postoperative deep infections, dislocations, incidence of pathological and periprosthetic fractures and of deep vein thrombosis. The postoperative mortality and local tumour recurrence along with deep infections represent the most serious complications. CONCLUSIONS: In comparison to primary arthroplasty, the risk of failure and complications following tumour-endoprosthetic replacement is increased. Precise surgical planning and careful selection and preoperative preparation of suitable patients should be performed in close interdisciplinary cooperation with final decision-making on an interdisciplinary tumour board. Wide resection and advanced reconstruction, as well as complicated palliative stabilization due to malignant bone tumour growth around the hip joint should be performed in musculoskeletal tumour centres with profound expertise in osteosynthetic and endoprosthetic reconstruction and consecutive complication management of the pelvis and the proximal femur.

Reality of care for musculoskeletal diseases at the population level : Results of the PROCLAIR collaborative project.

BACKGROUND: The objective of the research consortium PROCLAIR was to gain population level knowledge on the treatment of patients with rheumatoid arthritis (RA), axial spondylarthritis (axSpA) and osteoarthritis (OA) in Germany. AIMS: A main question of the consortium was whether it is possible to identify groups of people who were exposed to a particular risk of undersupply or oversupply of treatment. In addition, the study investigated the validity of claims data for these diseases as a basis for further studies. PATIENTS AND METHODS: Cross-sectional surveys were carried out among insurees of the BARMER statutory health insurance fund whose claims data included RA, axSpA and OA diagnoses. The questionnaire data were linked with the claims data of the insured persons if they agreed. RESULTS: In all three diseases risk groups for care deficits could be identified. Persons with RA who are not treated by a specialist have less access to drug treatment. Physical therapy is prescribed for all three diagnoses at a low level, even for people undergoing joint replacement surgery. A connection between depressive symptoms and disease activity or function in axSpA was shown. In addition to the results relevant to care, the PROCLAIR network has also made contributions to critically assess the quality of health insurance data. DISCUSSION: The combination of billing data with survey data enables a comprehensive description of the treatment of musculoskeletal diseases. Particularly relevant factors are the specialization of the physician, sociodemographic parameters of the patients and the region of residence. In particular, access to treatment cannot be investigated in randomized clinical trials.

[Reality of care for musculoskeletal diseases at the population level : Results of the PROCLAIR collaborative project. German version]. / Versorgungswirklichkeit muskuloskeletaler Erkrankungen auf Bevölkerungsebene : Erkenntnisse aus dem Verbundprojekt PROCLAIR.

BACKGROUND: The objective of the research consortium PROCLAIR was to gain population level knowledge on the treatment of patients with rheumatoid arthritis (RA), axial spondylarthritis (axSpA) and osteoarthritis (OA) in Germany. AIMS: A main question of the consortium was whether it is possible to identify groups of people who were exposed to a particular risk of undersupply or oversupply of treatment. In addition, the study investigated the validity of claims data for these diseases as a basis for further studies. PATIENTS AND METHODS: Cross-sectional surveys were carried out among insurees of the BARMER statutory health insurance fund whose claims data included RA, axSpA and OA diagnoses. The questionnaire data were linked with the claims data of the insured persons if they agreed. RESULTS: In all three diseases risk groups for care deficits could be identified. Persons with RA who are not treated by a specialist have less access to drug treatment. Physical therapy is prescribed for all three diagnoses at a low level, even for people undergoing joint replacement surgery. A connection between depressive symptoms and disease activity or function in axSpA was shown. In addition to the results relevant to care, the PROCLAIR network has also made contributions to critically assess the quality of health insurance data. DISCUSSION: The combination of billing data with survey data enables a comprehensive description of the treatment of musculoskeletal diseases. Particularly relevant factors are the specialization of the physician, sociodemographic parameters of the patients and the region of residence. In particular, access to treatment cannot be investigated in randomized clinical trials.

[Management of complications following tumor endoprosthetic replacement]. / Komplikationsmanagement nach Tumorendoprothesen.

BACKGROUND: Tumor endoprostheses are available as modular systems with which bone defects can be partially reconstructed, usually close to the joints, or as a total replacement of long tubular bones. As a result of continuously improved survival times, they are used with bone tumors, skeletal metastases and, increasingly, in revision arthroplasty. OBJECTIVES: Presentation of the most common complications of tumor endoprostheses and a description of their management, including treatment recommendations. MATERIALS AND METHODS: The current knowledge and our own experience of complication management with the use of megaprostheses are presented. RESULTS: The number of tumor endoprostheses procedures is limited, so that a limited number of studies and classifications are available. Periprosthetic infections involving the soft tissues represent the most serious failure after perioperative dying and local recurrence of the tumor. Two-stage revision remains the gold standard in periprosthetic infection, even if one-stage revision is justifiable in selective indications. Periprosthetic infection and local recurrence is associated with the risk of secondary amputations. Mechanical failure can be treated more easily. Specific socket systems for proximal femoral replacement and attachment tubing allow for adequate soft tissue reconstruction, restoration of joint function, and minimize the risk of dislocation. CONCLUSIONS: In comparison to primary arthroplasty, the risk of failure following tumor endoprosthetic replacement is increased but is basically controllable by revision surgery.

[The S2k guideline: Indications for knee endoprosthesis : Evidence and consent-based indications for total knee arthroplasty]. / S2k-Leitlinie: Indikation Knieendoprothese : Evidenz- und konsensbasierte Indikationsstellung in der Knie-Endoprothetik (EKIT-Knie).

Total knee arthroplasty (TKA) is one of the most frequent surgical procedures in orthopaedic surgery. Until now there have not been any standardized indication criteria, which might contribute to the large geographical differences in the frequency of TKA. This guideline aims to consent minimal requirements (main criteria), additional important aspects (minor criteria), as well as relative and absolute contraindications for TKA. The following main criteria have been consented: knee pain, radiological confirmation of osteoarthritis or osteonecrosis, inadequate response to conservative treatment, adverse impact of knee disease on the patient's quality of life and the burden of suffering due to the knee disease. Relative contraindications have been consented as severe general disease with reduced life expectancy and a BMI ≥40; absolute contraindications are an active infection and if the patient is not able to undergo major surgery.

Factors associated with the orthopaedic surgeon's decision to recommend total joint replacement in hip and knee osteoarthritis: an international cross-sectional study of 1905 patients.

OBJECTIVE: To determine factors associated with orthopaedic surgeons' decision to recommend total joint replacement (TJR) in people with knee and hip osteoarthritis (OA). DESIGN: Cross-sectional study in eleven countries. For consecutive outpatients with definite hip or knee OA consulting an orthopaedic surgeon, the surgeon's indication of TJR was collected, as well as patients' characteristics including comorbidities and social situation, OA symptom duration, pain, stiffness and function (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), joint-specific quality of life, Osteoarthritis Research Society International (OARSI) joint space narrowing (JSN) radiographic grade (0-4), and surgeons' characteristics. Univariable and multivariable logistic regressions were performed to identify factors associated with the indication of TJR, adjusted by country. RESULTS: In total, 1905 patients were included: mean age was 66.5 (standard deviation [SD], 10.8) years, 1082 (58.0%) were women, mean OA symptom duration was 5.0 (SD 7.0) years. TJR was recommended in 561/1127 (49.8%) knee OA and 542/778 (69.7%) hip OA patients. In multivariable analysis on 516 patients with complete data, the variables associated with TJR indication were radiographic grade (Odds Ratio, OR for one grade increase, for knee and hip OA, respectively: 2.90, 95% confidence interval [1.69-4.97] and 3.30 [2.17-5.03]) and WOMAC total score (OR for 10 points increase: 1.65 [1.32-2.06] and 1.38 [1.15-1.66], respectively). After excluding radiographic grade from the analyses, on 1265 patients, greater WOMAC total score was the main predictor for knee and hip OA; older age was also significant for knee OA. CONCLUSION: Radiographic severity and patient-reported pain and function play a major role in surgeons' recommendation for TJR.

Osteoarthritis-patterns, cardio-metabolic risk factors and risk of all-cause mortality: 20 years follow-up in patients after hip or knee replacement.

Osteoarthritis (OA) is a common musculoskeletal disorder and occur in different patterns. However, its impact on long-term all-cause-mortality is inconclusive. STUDY AIMS: Investigate 20-year all-cause-mortality in patients with hip/knee arthroplasty (recruited 1995/1996, N = 809) from the Ulm Osteoarthritis Study-cohort, in comparison to general population. Furthermore, to enlighten the triangle between baseline life-style and cardio-metabolic risk factors, phenotypic OA-patterns (laterality, generalization, cause) and all-cause-mortality. Mortality was assessed during 20 years follow-up. Standardized mortality ratios (SMR), adjusted odds ratios and hazard ratios (aHR) were calculated. After five years cohort-mortality was reduced compared to the general population, however 20 years later assimilated (SMR = 1.11; 95%-CI 0.73-1.49). OA-patterns were associated with age, cholesterol, and overweight/obesity. In comparison to primary OA decreased mortality was observed for patients with secondary OA (aHR = 0.76; 95%-CI 0.61-0.95) adjusted for age, smoking, overweight/obesity, diabetes, hypertension, cardiac insufficiency, uric acid, and lower cholesterol. There was no increased mortality in patients after 20 years follow-up compared to general population. Significantly decreased mortality in secondary compared to primary OA suggests a subtype-specific involvement of systemic co-factors in determination of all-cause-mortality. Because cardio-metabolic risk factors were associated with increased risk of bilateral OA and lower long-term survival, those risk factors should be consequently targeted in OA-patients.

[Periacetabular osteotomy-what influence does age have on patient-relevant results? : A prospective 5­year investigation]. / Periazetabuläre Osteotomie ­ Welchen Einfluss hat das Alter auf patientenrelevante Ergebnisse? : Eine prospektive 5­Jahres-Untersuchung.

INTRODUCTION: Periacetabular osteotomy (PAO) is an effective procedure in treatment of symptomatic hip dysplasia. To achieve a good outcome a strict patient selection has to be applied. The aim of this study was to evaluate the influence of patient age at surgery on clinical outcome. METHODS: In a prospective study 86 patients (106 hips) underwent clinical and radiographic follow-up at a mean time of 5 years (2.5-8.5 years) after PAO. Patient-related outcome measurements (PROMs: EQ-5D, WOMAC, OHS, GTO) were applied preoperatively as well as postoperatively and the deformity correction as well as development of osteoarthritis were evaluated. In order to analyze the influence of patient age at surgery on clinical outcome, we subdivided the patient cohort into four different age groups (<20 years, 20-29 years, 30-39 years, >40 years). RESULTS: Of the patients 90% were very satisfied or satisfied with the results 5 years after surgery, and in all age groups PROMs significantly increased. Even though preoperative as well as postoperative algofunction declined in cohorts with increasing age, the overall benefit as measured in WOMAC and EQ-5D scores was equal in all age groups. Increasing age is associated with a progression in osteoarthritis as well as a higher conversion rate to total arthroplasty. DISCUSSION: Age is an important influencing factor on the long-term outcome after PAO. A certain age as cut off for indications could not be identified in this study. Even patients in the age groups 30-39 years and > 40 years showed PROM improvement and satisfaction with outcome at medium-term follow-up. The expected success rate has to be discussed preoperatively with the patient; however, as a higher conversion rate to hip arthroplasty as well as progressive osteoarthritis is associated with higher age, not only patient age alone but also morphological characteristics of the hip joint have to be taken into consideration.

[Validity and Reliability of the German Version of the HSS Expectation Questionnaire on Hip Joint Replacement]. / Validität und Reliabilität der deutschen Version des HSS-Erwartungsfragebogens zum Hüftgelenkersatz.

Background: Total hip arthroplasty is one of the most successful operations in medicine. The clinical result after surgery and compliance during rehabilitation are influenced by the patient's expectations. There is a lack of a validated German instrument to record these expectations in a standardised manner. Patients: 193 patients from the Dresden Hip Register with osteoarthritis of the hip were surveyed with respect to their expectations before the operation. The study sample consists of 108 women and 85 men. The average age of the patients was 59.7 years, with a standard deviation of 12.2 years. Methods: The Hospital for Special Patient Expectations Survey was translated into German and culturally adapted. In addition, the RKI demographic core data set, the HADS-D, LOT-R and the SCL-(K-)9 were collected to validate the instrument. In the statistical analysis, four main factors could be distinguished. These were "everyday activities", "pain relief and improvement in function", "medication and social participation" and "gait improvement". Results: Patients were predominantly married. 20 % of the women were widowed. 20 % had received higher education. Almost half of the patients were retired, 30 % were employed, 15.1 % self-employed and 7.3 % were unemployed. For most of the items, patients expected major improvements up to normalisation of their health. There were many different answers to several items, such as the question on occupation. For sporting and sexual activities no high expectations were given. The average expectation of the whole sample shows major differences to individual expectations. Men showed higher expectations for medication, social participation and gait improvement than did women. There were lower expectations for everyday activities, medication and social participation and gait improvement for older patients. Summary: The German version of the HSS patients expectation survey was validated. The instrument is useful in the preoperative setting to give the surgeon a first impression on the patient's expectations.

[Consequences of the Foundation of a University Centre for Orthopaedics and Accident Surgery]. / Effekte der Gründung eines UniversitätsCentrums für Orthopädie und Unfallchirurgie.

Background: Since the combination of orthopaedic and traumatology surgery as a single speciality, an extremely wide variety of orthopaedic and trauma surgery centres have been founded in Germany. The present investigation analysed the degree to which additional value has been generated by merging two previously independent university departments - one for orthopaedics, the other for trauma surgery - into a single orthopaedics and trauma surgery centre. Material and Methods: The centre, merged in 1 June 2013, is led by two equal co-chairs (a full professor for orthopaedics and a full professor for trauma surgery). It consists of an acute division and five other divisions for specific parts of the body. The pre-existing certifications (level 1 trauma- and joint arthroplasty centre) were maintained in the new merged entity. Data from patient and employee questionnaires, as well as key economic indicators, were compared before and after the merger. Results: 11 % of the patients rated the medical treatment as mediocre or bad before the merger. After the merger, 5.7 % of the patients were moderately satisfied or unsatisfied; 92 % would recommend the merged centre to others and would return for further treatment. The evaluation of patient complaints before and after the merger showed no change. The evaluation of the employee questionnaires showed heterogeneous results. Overall, positive evaluations predominated, but in areas where there had been major changes, negative aspects were occasionally reported. The merger did not bring about any essential change in the number of in-patients (2012: 6693; 2014: 6649) or in the severity of the medical cases (CMI in 2012: 1.41; in 2014: 1.45). But in 2015, there was an increase in the number of in-patients (6837) and in the CMI (1.54). In the out-patient clinic, the merger led to a reduction in the material costs per patient (2012: 3.53 €/patient; 2014: 3.07 €/patient) and in the staff costs. The material costs for the entire centre were also reduced by 14 %. Conclusion: By merging the university orthopaedic and trauma surgery centres, transdisciplinary and transdepartmental improvements in patient care were achieved for musculoskeletal illnesses and injuries, and a sustainable structure was established for the advanced training for the joint specialist title of orthopaedics and trauma surgery. The merger also led to additional economic synergies, with a mid-term potential for increases in the number of patients and in CMI. To improve or at least maintain the level of employee satisfaction, staff must be actively included in the process.

[Personality and comorbidity: are there "difficult patients" in hip arthroplasty?]. / Persönlichkeitsprofil und Komorbidität: Gibt es den "schwierigen Patienten" in der primären Hüftendoprothetik?

BACKGROUND: Concomitant disorders at the time of surgery in addition to psychological and socioeconomic patient characteristics may influence treatment outcomes in hip arthroplasty. OBJECTIVES: To describe the impact of these factors on perioperative complications and postoperative results in terms of function, quality of life, and patient satisfaction. MATERIALS AND METHODS: Review of relevant clinical studies, meta-analyses, and presentation of our own results. RESULTS: Comorbidities in general, especially in combination, increase the perioperative risk profile. Socioeconomic factors (education, professional qualifications, social deprivation) in addition to psychological variables (depression, distressed personality) can have a major impact on postoperative functional outcomes and patient satisfaction. CONCLUSIONS: It is of crucial importance to avoid inequalities in the provision of joint replacement for patients with hip osteoarthritis and co-existing risk factors. Preventive strategies should be implemented to reduce the negative impact of comorbidities on treatment outcome. Personalized communication and education may be helpful in avoiding unrealistic patient expectations before hip replacement.

[Arthroplasty for osteoarthritis secondary to hip dysplasia: Problem-oriented treatment strategies]. / Endoprothese bei Dysplasiecoxarthrose: Problemorientierte Versorgungsstrategien.

BACKGROUND: Because of anatomical variations total hip arthroplasty (THA) can be demanding in patients with osteoarthritis secondary to hip dysplasia. OBJECTIVES: Depending on the degree of bony deformation, hip dislocation and soft tissue alteration numerous treatment strategies are available. This review describes current approaches that address frequent deformities. MATERIALS AND METHODS: Review of relevant clinical studies, meta-analyses, and presentation of our own approach. RESULTS: Pre-operative planning (based on a thorough clinical and radiographic examination) is essential. Acetabular reconstruction close to the primary acetabulum should always be intended. Roof augmentation and/or cup medialization can support stable bony implant fixation. Subtrochanteric shortening osteotomy of the femur is a demanding but reliable technique that avoids nerve damage in cases where inappropriate lengthening would be necessary (i.e., high riding dislocation). CONCLUSIONS: Although the post-operative complication rate is elevated after THA for dysplastic hips compared with primary osteoarthritis, the overall functional results and implant survival are comparable.

[Objectifying results in total knee arthroplasty: Is "patient satisfaction" adequate]. / Ergebnisobjektivierung bei Knietotalendoprothesen : Reicht die "Patientenzufriedenheit"?

BACKGROUND: Arthroplasty is an effective treatment for end-stage osteoarthritis of the knee and is one of Germany's most frequently performed orthopedic procedures. DISCUSSION: However, a considerable number of patient are not satisfied with the results after knee arthroplasty. The patient's perspective is particularly important for shared decision making. "Patient satisfaction" with the surgery is an expression of the patient's perspective, but might not be sufficient as the only outcome measure. There is no international consensus which outcome measures should be used after knee arthroplasty. CONCLUSION: Therefore, different measurement tools are used for the acquisition of a variety of outcome measures in order to quantify the results of knee arthroplasty. These tools should be used according to their reliability, validity, and responsiveness. This article provides an overview about available measurement tools.

[Modular reconstruction in acetabular revision with antiprotrusio cages and metal augments : the cage-and-augment system]. / Modulare Defektrekonstruktion beim Pfannenwechsel mit Abstützschale und metallischen Augmenten : "Cage-and-Augment"-System.

OBJECTIVE: Restore primary center of rotation and reconstruct extensive bone defects in hip revision surgery with a modular off-label implant combined with antiprotrusion cage and metal augment, thus, achieving improved hip function. INDICATIONS: Large segmental acetabular defects with nonsupportive columns (Paprosky type 3a and 3b) in cup loosening or Girdlestone situation. In case of pelvic discontinuity posterior column-plating is possible. CONTRAINDICATIONS: Persisting hip infection and severe systemic disorders impairing achievement of secondary stability through bony integration of metal augment. SURGICAL TECHNIQUE: Posterolateral (if dorsal column plating) or other approach. Remove loose implant and granulation tissue with sufficient exposure of bleeding bone. Size acetabular defect with trial components of augment and appropriate antiprotrusio cage. Fixation of selected metal augment with screws. Fill additional acetabular defects with morsellized bone graft. Open a slot into the ischium to fix the distal flange of the cage. If necessary, bend both flanges according to patient's anatomy. Enter the ischium with distal flange and gradual impaction of the antiprotrusio ring. Final stabilization of the ring with several screws aiming at the posterior column or the acetabular dome. Inject cement between ring and augment to stabilize the construction and avoid metal wear. Final cement fixation of a polyethylene liner or a dual-mobility cup into the antiprotrusio ring. In pelvic discontinuity with major instability osteosynthesis of the dorsal column can be performed prior to cementation. POSTOPERATIVE MANAGEMENT: Prophylaxis of periprosthetic infection, DVT and heterotopic ossification. Physical therapy with partial weight bearing (20 kp) for 6 weeks; in discontinuity initial wheel chair mobilization. RESULTS: Since 2008, 72 off-label implantations of a combined antiprotrusio cage and a Trabecular Metal™ Augment were performed. A total of 44 patients (46 operations) were investigated at 38.8 (36-51) months postoperatively. In all, 36 patients had a bone defect according to Paprosky type 3a/b and in 3/4 patients with pelvic discontinuity additional osteosynthesis was performed. The WOMAC score increased from 39.8 (8.7-75) points preoperatively to 57.9 (16.7-97.9) points at follow-up. Migration or failure of implant components was not observed. In 11 % of dislocations and 11 % periprosthetic infections surgical revision was necessary.

Periacetabular bone metabolism following hip revision surgery. PET-based evaluation of allograft osteointegration.

UNLABELLED: The treatment of loosened total hip replacement (THR) acetabular components may require the management of severe bone defects. Although being applied for decades, there is only limited scientific data about the osteointegration of cancellous bone allografts (CBA) and other void fillers. Monitoring of periprosthetic bone regeneration could possibly help to optimize this process thereby reducing late failure rates. The aim of this study was to show osteometabolic changes in periprosthetic CBA after THR revision with the use of sodium-[18F]-fluoride (NaF) and positron emission tomography (PET). PATIENTS, METHODS: Twelve patients undergoing THR revision with the use of CBA were prospectively enrolled in the study. Nine patients completed all necessary examinations and were included in the evaluation. The temporal pattern of osteointegration was assessed via NaF-PET at one (PET1) and six weeks (PET2) after surgery. CBA, tantalum implants, supraacetabular regions ipsilateral and contralateral, and parasymphyseal pubic bones were delineated as volumes of interest (VOI) in postop CT scans, which were then merged with the PET data. RESULTS: In comparison to the contralateral supraacetabular reference bone, a significant 1.5-fold increase of osteometabolic activity from PET1 to PET2 was seen in the CBA region. Also, the ipsilateral supraacetabular host bone showed a higher NaF-influx in week 6, compared to the first postoperative week. The supraacetabular site exhibited a significantly 1.8- to 2-fold higher influx and uptake than bone regions in non-operated sites. Tantalum implants had a low NaF influx at both time points investigated. CONCLUSION: Using NaF-PET osteometabolic changes of CBA and implant-bone-interfaces can be monitored. Applying this method we demonstrated early periprosthetic temporal bone regeneration patterns in THR cup revision patients.

[Re-evaluation of the AOK hospital navigator with a focus on total knee replacement]. / Re-Evaluation des Krankenhausnavigators der AOK für das "QSR-Verfahren" unter besonderer Berücksichtigung des Themenschwerpunkts Knieendoprothetik.

BACKGROUND: One of the biggest health insurance companies in Germany (AOK, Allgemeine Ortskrankenkasse) has published new results focussing on process quality of total knee replacement in 2010. These results were published in the online portal "Weiße Liste", which is based on health insurance routine data. The German Association of Orthopeadic Surgery questions the credibility of the rating system of the "Weiße Liste". To prove the system an interdisciplinary task force was created. MATERIAL AND METHODS: The task force identified patient-specific parameters, which influence the outcome of total knee replacement based on the literature and expert opinions. Out of 907 orthopaedic departments, 4 above average and four below average were identified. The AOK was asked to provide 80 data sets for each department. These anonymised data sets could be converted into patient-specific data sets in the identified departments. Statistical analysis was performed to answer the question of whether there are differences between the below and the above average groups. RESULTS: 625 cases could be investigated. We found an increased rate of postoperative complications in the below average group. There are differences between both groups in terms of factors influencing the procedure. In the below average group an increased rate of patients with one or more comorbidities and a preoperative extension lag of over 10° was found. The above average group has a higher rate of operations before the knee replacement. CONCLUSION: The results need to be proven on a larger scale. Further, prospective investigations are planned.

European multidisciplinary consensus statement on the use and monitoring of metal-on-metal bearings for total hip replacement and hip resurfacing.

INTRODUCTION: There is an ongoing debate about the optimal use of metal-on-metal (MoM) bearings in total hip replacement, since there are uncertainties about local and systemic adverse effects due to wear and corrosion of these bearings. Despite various national recommendations, efforts to achieve international harmonization of specific evidence-based recommendations for best practice are still lacking. HYPOTHESIS: An international consensus study group should be able to develop recommendations on the use and monitoring of MoM bearings, preferably at the European level, through a multidisciplinary approach, by integrating the perspectives of various stakeholders. MATERIALS AND METHODS: Twenty-one experts representing three stakeholder groups and eight countries participated in this European consensus study, which consisted of a consensus meeting, subsequent structured discussion, and consensus voting. RESULTS: The current statement defines first of all benefits, local and systemic risks, as well as uncertain issues related to MoM bearings. Safety assessment after implantation of MoM comprises all patients. A closer follow-up is recommended for large head MoM (≥36mm) and resurfacing. In these implants basic follow-up should consist of x-rays and metal ion measurement of cobalt in whole blood, performed with GF-AAS or ICP-MS. Clinical and/or radiographic abnormality as well as elevated ion levels needs additional imaging (ultrasound, CT-scan and/or MARS-MRI). Cobalt values less than 2 µg/L are probably devoid of clinical concern, the threshold value for clinical concern is expected to be within the range of 2-7 µg/L. DISCUSSION: This is the first multinational, interdisciplinary, and multiprofessional approach for developing a recommendation for the use and monitoring of MoM bearings in total hip replacement. The current recommendations are in partial agreement with previous statements regarding the extent of follow-up and imaging techniques. They however differ from previous communications regarding measurement of metal ions and especially the investigated medium, technique, and eventual threshold levels. LEVEL OF EVIDENCE: Level V, expert opinion/agreement conference.