Mid-term results of cemented hip arthroplasties through the direct anterior approach in the lateral decubitus position: a retrospective cohort study.

BACKGROUND: Reports show a high complication rate when starting with the Direct Anterior Approach (DAA) in a supine position for hip arthroplasty. The DAA with the patient in lateral decubitus position may avoid this problem because it supposedly provides better visibility, especially on the femoral side. However, this approach did show a rather high complication rate during the adoption of the approach at 1 year follow up in our previous report. We were interested what the overall 7 year survival estimate would be and whether improvement could be seen with growing experience. METHODS: A cohort of patients undergoing total hip arthroplasty right from the start of applying the DAA in lateral decubitus position was analysed. RESULTS: In total 175 hip prostheses (162 patients) were evaluated. The 7-year survival estimate was 95.1%, 95 CI: 91.8-98.4%. In 6 of 8 revisions there was aseptic loosening of the stem. By dividing the cohort into 3 consecutive groups in time we did not see a significantly improving revision rate. CONCLUSIONS: In our experience, the adoption of the direct anterior approach in lateral decubitus position caused a relatively low 7-year survival estimate without an apparent decrease with growing experience, however given the low number of cases further research is needed to investigate the long-term risk of adopting a new approach.

Comparison of osteolysis around 3 different cement restrictors in total hip arthroplasty.

BACKGROUND AND AIM: Several studies reported osteolysis around polyethylene glycol/polybutylene terephthalate (PEG/PBT) based femoral cement restrictors. Our goal was to evaluate and compare osteolysis around 3 different plug designs: the slow biodegradable PEG/PBT cement restrictor; the fast biodegradable gelatin cement restrictor; and the non-biodegradable polyethylene plug. PATIENTS AND METHODS: In a retrospective multicentre cohort study chart data were extracted of patients who received a total hip arthroplasty between 2008 and 2012. A total of 961 hips were included. Cortical ratio between inner and outer cortices at the centre of the plug was measured on routine postoperative follow-up moments. Median follow up of all 3 hospitals was 3.5 years (1.4-7.3). The primary outcome was evidence of osteolysis (i.e. the difference in cortical ratio [CR]) on anteroposterior (AP) radiographs at final follow-up. RESULTS: Progressive osteolysis was found around the PEG/PBT cement restrictor represented by a significantly increasing cortical ratio (ΔCR 0.067 (95% CI, 0.063-0.071). Distance from tip prosthesis to plug and size of the plug were found to be independent factors in predicting increased cortical ratio. CONCLUSIONS: Our multicentre cohort shows increase of cortical ratio around the PEG/PBT cement restrictor which progresses over time. Physicians should be aware of this fact and are advised to intensify follow-up of patients who received this cement restrictor.

Foot orthoses for flexible flatfeet in children and adults: a systematic review and meta-analysis of patient-reported outcomes.

BACKGROUND: This systematic review and meta-analysis examined the effectiveness of orthoses for flexible flatfeet in terms of patient-reported outcomes in children and adults. METHODS: EMBASE, Medline (OvidSP), Web-of-Science, Scopus, CINAHL, Cochrane Central Register of Controlled Clinical Trials, i.e., Cochrane Central and Pubmed were searched to identify relevant studies since their inception up to February 2021. We included randomized controlled trials (RCT) and prospective studies in which patient reported outcomes at baseline and follow-up in an orthoses group were compared with a no orthoses or sham sole group. Methodological quality of the studies was assessed using the Revised Cochrane risk-of-bias tool for randomized trials (RoB 2) and the Risk Of Bias In Non-Randomized Studies of Interventions (ROBINS-I). A meta-analysis was performed where there were multiple studies with the same outcome measures, which was the case for the Visual Analogue Scale (VAS) for pain in adults. RESULTS: In total nine studies were included: four RCT in children (N = 353) and four RCT and one prospective study in adults (N = 268) were included. There was considerable heterogeneity between studies. A meta-analysis demonstrated that pain reduction between baseline and follow-up was significantly larger in the orthoses (N = 167) than in the control groups in adults (N = 157; - 4.76, 95% CI [- 9.46, - 0.06], p0.05). CONCLUSION: Due to heterogeneity in study designs, we cannot conclude that foot orthoses are useful for flexible flatfoot in children and adults. However, based on the meta-analysis orthoses might be useful in decreasing pain in adults. The authors did not receive support from any organization for the submitted work.

Ten-year results of a prospective cohort of large-head metal-on-metal total hip arthroplasty : a concise follow-up of a previous report.

AIMS: Large-diameter metal-on-metal (MoM) total hip arthroplasty (THA) has demonstrated unexpected high failure rates and pseudotumour formation. The purpose of this prospective cohort study is to report ten-year results in order to establish revision rate, prevalence of pseudotumour formation, and relation with whole blood cobalt levels. METHODS: All patients were recalled according to the guidelines of the Dutch Orthopaedic Association. They underwent clinical and radiographical assessments (x-ray and CT scan) of the hip prosthesis and whole blood cobalt ion measurements. Overall, 94 patients (95 hips) fulfilled our requirements for a minimum ten-year follow-up. RESULTS: Mean follow-up was 10.9 years (10 to 12), with a cumulative survival rate of 82.4%. Reason for revision was predominantly pseudotumour formation (68%), apart from loosening, pain, infection, and osteolysis. The prevalence of pseudotumour formation around the prostheses was 41%, while our previous report of this cohort (with a mean follow-up of 3.6 years) revealed a 39% prevalence. The ten-year revision-free survival with pseudotumour was 66.7% and without pseudotumour 92.4% (p < 0.05). There was poor discriminatory ability for cobalt for pseudotumour formation. CONCLUSION: This prospective study reports a minimum ten-year follow-up of large-head MoM THA. Revision rates are high, with the main reason being the sequelae of pseudotumour formation, which were rarely observed after five years of implantation. Blood ion measurements show limited discriminatory capacity in diagnosing pseudotumour formation. Our results evidence that an early comprehensive follow-up strategy is essential for MoM THA to promptly identify and manage early complications and revise on time. After ten years follow-up, we do not recommend continuing routine CT scanning or whole cobalt blood measurements, but instead enrolling these patients in routine follow-up protocols for THA. Cite this article: Bone Jt Open 2022;3(1):61-67.

Resection or preservation of the metatarsal heads in rheumatoid forefoot surgery? A randomised clinical trial.

BACKGROUND: Despite impressive results of the pharmacological management of rheumatoid arthritis, still certain patients suffer from rheumatoid forefoot problems. Surgical treatment of these forefoot deformities can be an option. In literature no high-quality studies on this topic can be found. The goal of present study is to compare the results of a metatarsal head (MTH) resecting technique with a MTH preserving technique in the operative treatment of severe rheumatoid forefoot deformity. METHODS: Patients suffering from well-defined rheumatoid forefoot deformity were prospectively enrolled in three institutions. This non-blinded study had a randomised clinical design and eligible patients were randomly assigned to undergo either resection of preservation of the MTH. The primary outcome measure consisted of the AOFAS score. Secondary outcome measures were: the FFI, the VAS for pain and the SF-36. RESULTS: Twenty-three patients (10 in MTH preservation group) were included and analysed. After one year follow-up no significant differences in AOFAS score and additional outcome factors were found. A total of 10 complications in 23 patients were reported. CONCLUSIONS: This randomised clinical study did not show significant clinical difference between a MTH resecting and a preserving procedure in patients suffering from rheumatoid forefoot deformity. Both procedures resulted in considerable improvement of pain and activity scores.

Changes in Perceived Supervision Quality After Introduction of Competency-Based Orthopedic Residency Training: A National 6-Year Follow-Up Study.

OBJECTIVE: To evaluate the perceived quality of the learning environment, before and after introduction of competency-based postgraduate orthopedic education. DESIGN: From 2009 to 2014, we conducted annual surveys among Dutch orthopedic residents. The validated Dutch Residency Educational Climate Test (D-RECT, 50 items on 11 subscales) was used to assess the quality of the learning environment. Scores range from 1 (poor) to 5 (excellent). SETTING: Dynamic cohort follow-up study. PARTICIPANTS: All Dutch orthopedic residents were surveyed during annual compulsory courses. RESULTS: Over the 6-year period, 641 responses were obtained (response rate 92%). Scores for "supervision" (95% CI for difference 0.06-0.28, p = 0.002) and "coaching and assessment" (95% CI 0.11-0.35, p < 0.001) improved significantly after introduction of competency-based training. There was no significant change in score on the other subscales of the D-RECT. CONCLUSIONS: After the introduction of some of the core components of competency-based postgraduate orthopedic education the perceived quality of "supervision" and "coaching and assessment" improved significantly.

The learning environment and resident burnout: a national study.

INTRODUCTION: Concerns exist about the negative impact of burnout on the professional and personal lives of residents. It is suggested that the origins of burnout among residents are rooted in the learning environment. We aimed to evaluate the association between the learning environment and burnout in a national sample of Dutch residents. METHODS: We conducted a cross-sectional online survey among all Dutch residents in September 2015. We measured the learning environment using the three domain scores on content, organization, and atmosphere from the Scan of Postgraduate Educational Environment Domains (SPEED) and burnout using the Dutch version of the Maslach Burnout Inventory (UBOS-C). RESULTS: Of 1,231 responding residents (33 specialties), 185 (15.0%) met criteria for burnout. After adjusting for demographic (age, gender and marital status) and work-related factors (year of training, type of teaching hospital and type of specialty), we found a consistent inverse association between SPEED scores and the risk of burnout (aOR 0.54, 95% CI 0.46 to 0.62, p < 0.001). DISCUSSION: We found a strong and consistent inverse association between the perceived quality of the learning environment and burnout among residents. This suggests that the learning environment is of key importance in preventing resident burnout.

Quantitative analysis of orthopedic metal artefact reduction in 64-slice computed tomography scans in large head metal-on-metal total hip replacement, a phantom study.

PURPOSE: Quantification of the effect of O-MAR on decreasing metal artefacts caused by large head metal on metal total hip arthroplasty (MoM THA) in a dedicated phantom setup of the hip. BACKGROUND: Pathological reactions of the hip capsule on Computed tomography (CT) can be difficult to diagnose due to different metal artefacts. The O-MAR algorithm deploys an iterative loop where the metal sinogram is identified, extracted, and subsequently serves as a mask to correct the measured sinogram. Main goal of this study is to quantify the ability of the O-MAR technique to correct deviation in medullary bone attenuation caused by streak artefacts from the large-head MoM THA embedded in a phantom. Secondary goal is to evaluate the influence of O-MAR on CNR. METHODS: The phantom was designed as a Perspex box (PMMA) containing water and a supplementary MOM THA surrounded by Perspex columns comprising calibrated calcium pellets. Each column contains 200 mg of hydroxyapatite/calcium carbonate to simulate healthy bone tissue. Scans were obtained with and without a MoM THA at different dose levels. Different reconstructions were made with filter A, iDose(4) level 5 and with and without O-MAR. The scans without the prosthesis were used as the baseline. Information about the attenuation in Hounsfield units, image noise in standard deviation within the ROI's were extracted and the CNR was calculated. RESULTS: Pellet L0 and R0 (proximal of the MoM THA) were defined as reference, lacking any disturbance by metal artefacts; L5, L6 and L8 were respectively visually categorized as 'light' 'medium' and 'heavy disturbance'. Significant improvements in attenuation deviation caused by metal artefact were 43, 68 and 32 %, for respectively pellet L5, L6 and L8 (p < 0.001). Significant CNR improvements were present for L5 and L6 and were respectively 72 and 52 % (p < 0.001). O-MAR showed no improvement on CNR for L8. CONCLUSION: This phantom study significantly increases image quality by the use of O-MAR in the presence of metal artefacts by significantly reducing metal artefacts subsequently and increasing CNR on a 64 slice CT system in light and medium disturbance of the image.

Long-term outcomes of the Bi-Metric proximally hydroxyapatite-coated femoral stem.

PURPOSE: Promising clinical results and survival rates have been reported for the Bi-Metric proximally hydroxyapatite (HA)-coated femoral stem in short- and mid-term studies. In this study we evaluated the long-term survival as well as clinical and radiological results of this stem. METHODS: From 1992 to 1998 we prospectively included 112 consecutive patients who received a total hip arthroplasty (THA) with an uncemented proximally HA-coated Bi-Metric femoral component (Biomet).At 3 months, 1 year and thereafter every 2 to 3 years, patients were clinically and radiologically monitored. Primary endpoint was revision of the stem for any reason. Secondary endpoints were survival of the cup and THA, radiological characteristics and clinical scores (HHS, HOOS, SF-36 and VAS). RESULTS: Median follow-up was 20 (16-22.25) years. Median age at surgery was 52 (22-63) years. At final follow-up, survival analysis showed an all-cause stem survival of 96.8% (95% CI, 93.3-100). Median HHS scores improved from 57 preoperatively to 94 at final follow-up (p<0.001). At final follow-up the median HOOS score was 80 (9-100); median SF-36 score 71 (18-100); median VAS pain score at rest 0 (0-6) and during activity 0 (0-10). CONCLUSIONS: In this prospective cohort study the 20-year survival rate of the Bi-Metric proximally HA-coated femoral stem was excellent.

CT-based quantification of bone stock in large head metal-on-metal unilateral total hip replacements.

PURPOSE: To explore ipsilateral and contralateral acetabular roof bone stock density in unilateral large head MoM THA whether there is a significant lower acetabular bone stock in the hip with a metal-on-metal (MoM) total hip replacement compared to the contralateral side. Second part of this study is to examine if there are any associates with regard to potential bone stock density difference. MATERIALS & METHODS: A database of 317 patients with unilateral metal-on-metal (MoM) total hip replacements was set up retrospectively for this study. On computed tomography scans, conducted after a relative short in situ time period averaging 2.8 years, regions-of-interests were drawn in the trabecular bone of the acetabulum to measure average Hounsfield Units (HU). HU differences were calculated and tested by Wilcoxon signed-rank test. Univariate analysis was conducted to examine associates of potential bone loss. RESULTS: In a population of 317 patients (156 male, 161 female) with an average age of 61.9 ± 7.8, the median HU on the side of the MoM replacement was 123.3 (7.6-375.4). On the contralateral side, median HU was 144.7 (-0.4 to 332.8). The median HU difference was 21.4 after a mean post-operative in situ time of 2.8 years. The Wilcoxon signed-rank test proved a significant difference (p<0.001). Univariate analyses show that the in situ time of the MoM THA has a significant correlation with the bone density difference. CONCLUSION: Results show a significant lower bone density at the acetabular roof at the side of the prosthesis compared with the contralateral side after short in situ time of the MoM THA in patients with unilateral MoM total hip replacements. In our patient population, the in situ time showed a significant association with the acetabular bone density difference. As acetabular roof bone stock measurements are feasible and show temporal decline this could become an important parameter to be used in orthopedic decision making for revision surgery.

Lesser Toe PIP Joint Resection Versus PIP Joint Fusion: A Randomized Clinical Trial.

BACKGROUND: It is unclear whether proximal interphalangeal joint (PIPJ) resection or fusion leads to superior clinical outcome in patients undergoing hammertoe surgery. The purpose of this study was to prospectively evaluate a series of patients undergoing this surgery. METHODS: Patients with one or more toes with rigid PIP flexion deformity were prospectively enrolled. These patients were randomly assigned to undergo either PIPJ resection or PIPJ fusion. In addition to the PIPJ procedure, a metatarsophalangeal joint (MTPJ) release was performed if deemed necessary. Follow-up was up to 1 year postoperatively. Twenty-six patients (39 toes) were included in the PIPJ resection group and 29 (50 toes) in the PIPJ fusion group. RESULTS: Thirty-four underwent an MTPJ release. No significant difference in foot outcome scores (American Orthopaedic Foot & Ankle Society scale, the Foot Function Index, and visual analog scale pain) could be detected after 1-year follow-up. A statistically significant difference was found regarding the toe alignment in the sagittal plane in favor of PIPJ fusion. CONCLUSIONS: Our randomized controlled study did not show any clinical outcome difference between PIPJ fusion and PIPJ resection. Both procedures resulted in good to excellent outcome in pain and activity scores. LEVEL OF EVIDENCE: Level II, lesser quality RCT or prospective comparative study.

Does Insert Type Affect Clinical and Functional Outcome in Total Knee Arthroplasty? A Randomised Controlled Clinical Trial With 5-Year Follow-Up.

New insert types have been developed to improve clinical and functional outcome in mobile bearing (MB-TKA) and fixed bearing total knee arthroplasty (FB-TKA). A prospective single blinded randomised controlled clinical trial was performed to evaluate 2 types of MB-TKA inserts and 2 types of FB-TKA inserts of the Genesis II prosthesis (Smith & Nephew) in 146 patients with 5-years follow-up. A significant difference (P=.042) between the MB-TKA inserts was found in KSS function scores, but clinical significance is expected to be limited. Goniometry, temporal gait parameters and QoL were similar in all groups. Survival was significantly better (P=.047) for FB-TKA. The comparable outcome and higher revision rate in MB-TKA indicate that FB-TKA may be preferential for the Genesis II implant system.

Development and first validation of a simplified CT-based classification system of soft tissue changes in large-head metal-on-metal total hip replacement: intra- and interrater reliability and association with revision rates in a uniform cohort of 664 arthroplasties.

OBJECTIVE: After implantation of a metal-on-metal total hip arthroplasty (MoM THA), a large incidence of pseudotumor formation has been described recently. Several centers have invited patients for follow-up in order to screen for pseudotumor formation. The spectrum of abnormalities found by CT in MoM THA patients can be unfamiliar to radiologists and orthopedic surgeons. Previously, a CT five-point grading scale has been published. In this paper, a simplification into a three-point classification system gives insight in the morphological distinction of abnormalities of the postoperative hip capsule in MoM implants in relation to the decision for revision. The reliability of this simplified classification regarding intra- and interrater reliability and its association with revision rate is investigated and discussed. MATERIALS AND METHODS: All patients who underwent MoM THA in our hospital were invited for screening. Various clinical measures and CT scan were obtained in a cross-sectional fashion. A decision on revision surgery was made shortly after screening. CT scans were read in 582 patients, of which 82 patients were treated bilaterally. CT scans were independently single read by two board-certified radiologists and classified into categories I-V. In a second meeting, consensus was obtained. Categories were subsequently rubricated in class A (categories I and II), B (category III), and C (categories IV and V). Intra- and inter-radiologist agreement on MoM pathology was assessed by means of the weighted Cohen's kappa. Categorical data were presented as n (%), and tested by means of Fisher's exact test. Continuous data were presented as median (min-max) and tested by means of Mann-Whitney U test (two group comparison) or Kruskal-Wallis test (three group comparison). Logistic regression analysis was performed in order to study independence of CT class for association with revision surgery. Univariate statistically significant variables were entered in a multiple model. All statistical analysis was performed two-tailed using alpha 5% as the significance level. RESULTS: In total, 664 scores from 664 MoM hips obtained by two observers were available for analyses. Interobserver reliability for the non-simplified version (I-V) was κw = 0.71 (95% CI: 0.62-0.79), which indicates good agreement between the two musculoskeletal radiologists. Intra- and interobserver reliability for the simplified version (A-C) were respectively κw 0.78 (95% CI: 0.68-0.87), and κw = 0.71 (95% CI: 0.65-0.76). This indicates good agreement within and between the two observers. The simplified A-C version is significantly associated with revision exclusively due to MoM pathology, in both patients with unilateral MoM THA (p < 0.001) and patients with bilateral MoM THA (p < 0.044). The simplified A-C version is associated with several clinical measures. In patients with unilateral MoM THA, with or without contralateral THA, in situ time (p < 0.008), cobalt and chromium (p < 0.001) were statistically significant. In patients with bilateral MoM, cobalt (p < 0.001) and chromium (p < 0.027) were statistically significant. Revision is significantly associated with cup size (p < 0.001), anteversion of the cup (p < 0.004), serum ion levels of cobalt and chromium (p < 0.001) and the adapted classification system (p < 0.001). In univariate logistic regression analysis on revision, cup, anteversion of the cup, cobalt-chromium ion serum levels, and the simplified (A-C) CT category system were statistically significant. The simplified (A-C) CT category system was an independent associate of revision, in several multiple logistic regression models. CONCLUSIONS: The presented simplified CT grading system (A-C) in its first clinical validation on 48- and 64-multislice systems is reliable, showing good intra- and interrater reliability and is independently associated with revision surgery.

Revision of a single type of large metal head metal-on-metal hip prosthesis.

Large-head metal-on-metal (MoM) total hip arthroplasties were introduced because of their purported advantages. Inflammatory pseudotumours occasionally occur after MoM hip arthroplasty and often lead to revision. The purpose of this study was to assess the outcome of revision of large-head MoM total hip arthroplasties after an extensive screening protocol for all MoM articulations with a minimum 2 year follow-up. We identified 50 hips that had undergone large-head MoM total hip arthoplasty and required revision at a mean of 44 months after index operation. Of these, 38 were revised for pseudotumours, 7 for loosening, 2 for infection and 3 for instability. There was bone loss in 44 hips. The majority were revised to a 28 mm metal or ceramic head on a polyethylene-cemented cup. In 12 patients there was a complication. There was a decrease of whole blood cobalt from 20.8 µg/L preoperatively to 1.8 µg/L 1 year after revision. We found 6 residual masses on routine postoperative CT scans. The indication for revision of this cohort is inevitable but the clinical outcome 2 years after revision for pseudotumour is disappointing. Revising a MoM hip arthroplasty to a conventional cemented polyethylene or dual-mobility cup with bone impaction grafting and a 28 mm head can adequately treat the high ion levels and probably the disease of ARMD.

Patient-reported outcome measures in hallux valgus surgery. A review of literature.

BACKGROUND: Up to a third of patients may be dissatisfied with the outcome of hallux valgus surgery. This stresses the importance of uniform and relevant outcome measures. The purpose of the current systematic review is to identify and rate available patient-reported outcome measures (PROMs) in hallux valgus surgery. METHODS: We performed a systematic literature search for outcome measures directed at hallux valgus. We searched electronic databases for relevant content according to the PRISMA standard. Eligible articles were used to give an overview of available PROMs, with qualitative evaluation of their properties. RESULTS: Twenty-eight eligible studies were included. Most adapted general health assessment tools, in studies on hallux valgus surgery, were the EQ5D and the SF-36 score. The visual analogue scale (VAS) was most cited as pain score. Three disease-specific outcome scores were identified: the Manchester-Oxford foot questionnaire (MOXFQ), the foot and ankle outcome score (FAOS) and the self-reported foot and ankle score (SEFAS). The MOXFQ showed the best psychometric properties. CONCLUSIONS: The MOXFQ scores best on positively rated qualities based on our criteria. The SEFAS may be a good alternative, however it contains less items which are regarded as important by patients with foot/ankle complaints. A relative drawback of the MOXFQ consists of the copyright licence. The VAS is the best pain score and the SF36 the best general health assessment tool. Availability in native languages and future research should lead to uniformity in application of these tools.

First experiences with the direct anterior approach in lateral decubitus position: learning curve and 1 year complication rate.

The direct anterior approach (DAA) in supine position for hip arthroplasty has been reported to suffer from high complication rates initially. The DAA with the patient in lateral decubitus position is believed to provide better visibility and especially femoral accessibility with potential fewer complications.The first cohort of total hip prostheses, which were implanted by a single surgeon using DAA in lateral decubitus position more than 1 year ago, was analysed retrospectively.In total 182 hip prostheses (172 patients) were analysed. Three consecutive time periods based on equal number of surgical procedures were compared. The technical complication rate and operating time improved significantly between the 3 consecutive groups. The 1 year infection rate was 0.5% and survival rate of 98.9%.This is the first series of patients that were subjected to a hip replacement based on the direct anterior approach in a lateral decubitus position in which decreasing complication rates suggest the presence of a learning curve in surgeons conducting this type of surgery. Initial complication rate was high but decreased significantly in time and was acceptable certainly in the third group of our cohort. An unacceptable complication rate with the straight uncemented stem forced us to discontinue this configuration after only 7 surgical procedures. Complication, infection and revision rates were acceptable for the all cemented hip replacements using a curved anatomical stem.

Finding the right hip implant for patient and surgeon: the Dutch strategy--empowering patients.

We describe the implementation process of hip prostheses selection in the Netherlands. The recent problems with large head metal-on-metal hip prostheses resulted in substantial damage to the surgeons' credibility and reputation in the media. This led to a true sense of urgency among orthopaedic surgeons to increase their activities to secure patient safety. The board of the Dutch Orthopaedic Association (NOV) in the Netherlands established a Dutch Hip Task Force (DHTF) with the explicit assignment of formulating criteria to classify the quality of total hip implants on the Dutch market based on survivorship. The aim was to offer unequivocal information enabling a balanced choice of total hip prosthesis. The ultimate goal of the NOV is that all implanted total hip prostheses implanted in the Netherlands are based on reliable clinical evidence. The DHTF decided to adapt the principles of the National Institute for Health and Care Excellence (NICE, UK) (www.nice.org.uk). The taskforce uses data from the registries as well as the Orthopaedic Data Evaluation Panel (ODEP). If the ODEP guidelines had been chosen as standard alone, one quarter of our listed hip components would not have been included. In our view this underlines the strength in the Dutch approach where high quality registry data and ODEP ratings are complementary and result in a list of reliable hip prostheses. Most importantly we offer patients insights into the known quality of the implants by sharing the results of our implant review. This will facilitate shared decision making by empowering patients in their knowledge on available hip arthroplasties.

Basic principles and uniform terminology for the head-neck junction in hip replacement.

Recent problems with large head metal on metal hip replacements have spiked renewed interest in the head-neck junction. A thorough knowledge of the principles of the locking mechanism, the assembly technique and affecting factors on the strength of this junction is needed. Currently a confusing variability in terms is used to describe this junction. This overcomplicates an already complex issue. The purpose of this literature review is to collect and list the different terms used and to propose a uniform terminology. Two authors independently searched the electronic databases of PubMed, CINAHL and MEDLINE with specific key words and combinations according to the PRISMA guidelines. The initial search yielded a total of 518 articles with ultimately 53 articles included in the present analysis. No consensus for a uniform term for the 2 sides of the head-stem junction was found. Since there is already pronounced variability in taper designs between different manufacturers (even so similarly named, e.g. "12/14"), a uniform terminology could be the first step to simplify the situation. "Male" and "female taper" is proposed as the appropriate terminology for the stem and head junction in hip replacement, respectively. The importance of the assembly technique understanding the principles of the locking mechanism is emphasised.