• When introducing an implant, surgeons are subjected to steep learning curves, which may lead to a heightened revision rate. Stepwise introduction revolutionized implant introduction but lacks a last step.

• No guidelines exist for the introduction of a well-documented implant not previously used in a department. This is problematic according to the European Union’s legislated tendering process, potentially leading to increased revisions. In this systematic review, the introduction of a well-documented total hip arthroplasty implant to experienced surgeons is explored amid concerns of higher revision rate.

• Literature search strategies were deployed in the Embase and Medline databases, revealing a total of 14,612 articles. Using the Covidence software (Cochrane, London), two reviewers screened articles for inclusion.

• No articles were found that fulfilled our eligibility criteria. A post hoc analysis retrieved two national register-based studies only missing information about the surgeon’s knowledge of the introduced implant. None of the introduced implants decreased the revision rate and around 30% of the introduced implants were associated with a higher revision rate.

• The review showed that no data exist about revision rates when introducing well-documented implants. In continuation thereof, the introduction of well-documented implants might also be associated with increased revision rates, as has been shown for total knee arthroplasty. We therefore suggest that special attention should be focused on changes of implants in departments, which can be achieved by way of specific registration in national registers.

Cite this article: EFORT Open Rev 2021;6:3-8. DOI: 10.1302/2058-5241.6.200047

• Choice of articulating materials, head size and the design of the articulation will become decisive for the long-term performance of a total hip arthroplasty (THA) and especially in terms of risk for dislocation and wear-related problems. Here we account for common alternatives based on available studies and the evidence that can be derived from them.

• Metal or ceramic femoral heads articulating against a liner or cup made of highly cross-linked polyethylene and ceramic-on-ceramic articulations have about similar risk for complications leading to revision, whereas the performance of metal-on-metal articulations, especially with use of big heads, is inferior. The clinical significance of problems related to ceramic-on-ceramic articulations such as squeaking remains unclear. With use of current technology ceramic fractures are rare.

• Large femoral heads have the potential to increase the range of hip movement before impingement occurs and are therefore expected to reduce dislocation rates. On the other hand, issues related to bearing wear, corrosion at the taper-trunnion junction and groin pain may arise with larger heads and jeopardize the longevity of THA. Based on current knowledge, 32-mm heads seem to be optimal for metal-on-polyethylene bearings. Patients with ceramic-on-ceramic bearings may benefit from even larger heads such as 36 or 40 mm, but so far there are no long-term reports that confirm the safety of bearings larger than 36 mm.

• Assessment of lipped liners is difficult because randomized studies are lacking, but retrospective clinical studies and registry data seem to indicate that this liner modification will reduce the rate of dislocation or revision due to dislocation without clear evidence of clinically obvious problems due to neck-liner impingement.

• The majority of studies support the view that constrained liners and dual mobility cups (DMC) will reduce the risk of revision due to dislocation both in primary and revision THA, the latter gaining increasing popularity in some countries. Both these devices suffer from implant-specific problems, which seem to be more common for the constrained liner designs. The majority of studies of these implants suffer from various methodological problems, not least selection bias, which calls for randomized studies preferably in a multi-centre setting to obtain sufficient power. In the 2020s, the orthopaedic profession should place more effort on such studies, as has already been achieved within other medical specialties, to improve the level of evidence in the choice of articulation when performing one of the most common in-hospital surgical procedures in Europe.

Cite this article: EFORT Open Rev 2020;5:763-775. DOI: 10.1302/2058-5241.5.200002

Cite this article: EFORT Open Rev 2020;5:519-521. DOI: 10.1302/2058-5241.5.200300

• Establishment of orthopaedic registers started in 1975 and many registers have been initiated since. The main purpose of registers is to collect information on patients, implants and procedures in order to monitor and improve the outcome of the specific procedure.

• Data validity reflects the quality of the registered data and consists of four major aspects: coverage of the register, registration completeness of procedures/patients, registration completeness of variables included in the register and accuracy of registered variables.

• Survival analysis is often used in register studies to estimate the incidence of an outcome. The most commonly used survival analysis is the Kaplan–Meier survival curves, which present the proportion of patients who have not experienced the defined event (e.g. death or revision of a prosthesis) in relation to the time. Depending on the research question, competing events can be taken into account by using the cumulative incidence function. Cox regression analysis is used to compare survival data for different groups taking differences between groups into account.

• When interpreting the results from observational register-based studies a number of factors including selection bias, information bias, chance and confounding have to be taken into account. In observational register-based studies selection bias is related to, for example, absence of complete follow-up of the patients, whereas information bias is related to, for example, misclassification of exposure (e.g. risk factor of interest) or/and outcome.

• The REporting of studies Conducted using Observational Routinely-collected Data guidelines should be used for studies based on routinely-collected health data including orthopaedic registers.

• Linkage between orthopaedic registers, other clinical quality databases and administrative health registers may be of value when performing orthopaedic register-based research.

Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180097

• Excessive anterior pelvic tilt is suspected of causing femoroacetabular impingement, low back pain, and sacroiliac joint pain. Non-surgical treatment may decrease symptoms and is seen as an alternative to invasive and complicated surgery. However, the effect of non-surgical modalities in adults is unclear. The aim of this review was to investigate patient- and observer-reported outcomes of non-surgical intervention in reducing clinical symptoms and/or potential anterior pelvic tilt in symptomatic and non-symptomatic adults with excessive anterior pelvic tilt, and to evaluate the certainty of evidence.

• MEDLINE, EMBASE, Web of Science and Cochrane (CENTRAL) databases were searched up to March 2019 for eligible studies. Two reviewers assessed risk of bias independently, using the Cochrane Risk of Bias tool for randomized trials and the ROBINS-I tool for non-randomized studies. Data were synthesized qualitatively. The GRADE approach was used to assess the overall certainty of evidence.

• Of 2013 citations, two randomized controlled trials (RCTs) (n = 72) and two non-RCTs (n = 23) were included. One RCT reported a small reduction (< 2°) in anterior pelvic tilt in non-symptomatic men. The two non-RCTs reported a statistically significant reduction in anterior pelvic tilt, pain, and disability in symptomatic populations. The present review was based on heterogeneous study populations, interventions, and very low quality of evidence.

• No overall evidence for the effect of non-surgical treatment in reducing excessive anterior pelvic tilt and potentially related symptoms was found. High-quality studies targeting non-surgical treatment as an evidence-based alternative to surgical interventions for conditions related to excessive anterior pelvic tilt are warranted.

Cite this article: EFORT Open Rev 2020;5:37-45. DOI: 10.1302/2058-5241.5.190017

• Hip pain is highly prevalent in both the younger and the elderly population. In older patients, pain arising from osteoarthritis (OA) is most frequent, whereas in younger patients, non-degenerative diseases are more often the cause of pain. The pain may be caused by hip dysplasia and femoroacetabular impingement (FAI).

• Abnormal mechanics of the hip are hypothesized by some authors to cause up to 80% of OA in the hip. Therefore, correction of these abnormalities is of obvious importance when treating young patients with hip pain.

• Hip dysplasia can be diagnosed by measuring a CE angle < 25° on a plain standing radiograph of the pelvis.

• Dysplastic or retroverted acetabulum with significant symptoms should receive a periacetabular osteotomy (PAO).

• FAI with significant symptoms should be treated by adequate resection and, if necessary, labrum surgery.

• If risk factors for poor outcome of joint-preserving surgery are present (age > 45 to 50 years, presence of OA, joint space < 3 mm or reduced range of motion), the patient should be offered a total hip arthroplasty (THA) instead of PAO.

• THA can be performed following PAO with outcomes similar to a primary THA.

• Hip arthroscopy is indicated in FAI (cam and pincer) and/or for labral tears.

Cite this article: EFORT Open Rev 2018;3:408-417. DOI: 10.1302/2058-5241.3.170042

• Total joint arthroplasty is performed to decreased pain, restore function and productivity and improve quality of life.

• One-year implant survivorship following surgery is nearly 100%; however, self-reported satisfaction is 80% after total knee arthroplasty and 90% after total hip arthroplasty.

• Patient-reported outcomes (PROs) are produced by patients reporting on their own health status directly without interpretation from a surgeon or other medical professional; a PRO measure (PROM) is a tool, often a questionnaire, that measures different aspects of patient-related outcomes.

• Generic PROs are related to a patient’s general health and quality of life, whereas a specific PRO is focused on a particular disease, symptom or anatomical region.

• While revision surgery is the traditional endpoint of registries, it is blunt and likely insufficient as a measure of success; PROMs address this shortcoming by expanding beyond survival and measuring outcomes that are relevant to patients – relief of pain, restoration of function and improvement in quality of life.

• PROMs are increasing in use in many national and regional orthopaedic arthroplasty registries.

• PROMs data can provide important information on value-based care, support quality assurance and improvement initiatives, help refine surgical indications and may improve shared decision-making and surgical timing.

• There are several practical considerations that need to be considered when implementing PROMs collection, as the undertaking itself may be expensive, a burden to the patient, as well as being time and labour intensive.

Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180080

• Total hip arthroplasty (THA) registers are established in several countries to collect data aiming to improve the results after THA. Monitoring of adverse outcomes after THA has focused mainly on revision surgery, but patient-reported outcomes have also been investigated.

• Several surgery-related factors influencing the survival of the THA have been thoroughly investigated and have changed clinical practice. These factors include surgical approach, specific implants, the size of the components, type of fixation and different bone cements.

• Register data have been used to examine the risk of venous thromboembolism and bleeding after THA. These investigations have resulted in shorter duration of thromboprophylaxis and a reduced frequency of blood transfusion.

• Registers may provide specific information to surgeons on the outcome of all THAs that they have performed with a detailed analysis of revisions rates and reasons for the revisions.

• A number of other stakeholders can use register data to provide benchmarks. The National Joint Registry for England, Wales, Northern Ireland and the Isle of Man supplies data to the Orthopaedic Device Evaluation Panel (ODEP), which provides benchmarks at 3, 5, 7, 10, and 13 years graded from A*, A, B and C.

• Future perspectives: National registers have to play a major role in documenting the quality of THA in order to describe best practice and report implant outliers. The registers have to be used for research and post-market surveillance and register data may be a source for intelligent decision tools.

Cite this article: EFORT Open Rev 2019;4 DOI: 10.1302/2058-5241.4.180091

• The objectives of the 1st EFORT European Consensus on ‘Medical and Scientific Research Requirements for the Clinical Introduction of Artificial Joint Arthroplasty Devices’ were foremost to focus on patient safety by establishing performance requirements for medical devices.

• The 1st EFORT European Consensus applied an a priori-defined, modified Delphi methodology to produce unbiased, high-quality recommendation statements, confirmed by consensus voting of a European expert panel.

• Intended key outcomes are practical guidelines justified by the current stage of knowledge and based on a broad European Expert Consensus, to maintain innovation and optimisation of orthopaedic devices within the boundaries of MDR 2017/745.

• Twenty-one main research areas of relevance were defined relying on input from the EFORT IPSI WG1 ‘Introduction of Innovation’ recommendations and a related survey.

• A modified Delphi approach with a preparatory literature review and work in small groups were used to prepare answers to the research questions in the form of 32 draft Consensus statements.

• A Consensus Conference in a hybrid format, on-site in the Carl Gustav Carus University of Dresden was organised to further refine the draft statements and define consensus within the complete group of participants by final voting, intended to further quantify expert opinion knowledge.

• The modified Delphi approach provides practical guidelines for hands-on orientation for orthopaedic surgeons, research institutes and laboratories, orthopaedic device manufacturers, patient representatives, Notified Bodies, National Institutes and authorities.

• For the first time, initiated by the EFORT IPSI (WG1 ‘Introduction of Innovation’), knowledge of all related stakeholders was combined in the 1st EFORT European Consensus to develop guidelines and result in a comprehensive set of recommendations.

• With the implementation of the new MDR 2017/745 by the European Parliament, more robust clinical and pre-clinical data will be required due to a more stringent approval process.

• The EFORT Implant and Patient Safety Initiative WG1 ‘Introduction of Innovation’, combined knowledge of orthopaedic surgeons, research institutes, orthopaedic device manufacturers, patient representatives and regulatory authorities to develop a comprehensive set of recommendations for the introduction of innovations in joint arthroplasty within the boundaries of MDR 2017/745.

• Recommendations have been developed to address key questions about pre-clinical and clinical requirements for the introduction of new implants and implant-related instrumentation with the participation of a steering group, invited by the EFORT Board in dialogue with representatives from European National Societies and Speciality Societies.

• Different degrees of novelty and innovation were described and agreed on in relation to when surgeons can start, using implants and implant-related instrumentation routinely.

• Before any clinical phase of a new implant, following the pre-market clinical investigation or the equivalent device PMCF pathway, it is a common understanding that all appropriate pre-clinical testing (regulatory mandatory and evident state of the art) – which has to be considered for a specific device – has been successfully completed.

• Once manufacturers receive the CE mark for a medical device, it can be used in patients routinely when a clinical investigation has been conducted to demonstrate the conformity of devices according to MDR Article 62 or full equivalence for the technical, biological and clinical characteristics has been demonstrated (MDR, Annex XIV, Part A, 3.) and a PMCF study has been initiated.