eCerto-versatile software for interlaboratory data evaluation and documentation during reference material production.

The statistical tool eCerto was developed for the evaluation of measurement data to assign property values and associated uncertainties of reference materials. The analysis is based on collaborative studies of expert laboratories and was implemented using the R software environment. Emphasis was put on comparability of eCerto with SoftCRM, a statistical tool based on the certification strategy of the former Community Bureau of Reference. Additionally, special attention was directed towards easy usability from data collection through processing, archiving, and reporting. While the effects of outlier removal can be flexibly explored, eCerto always retains the original data set and any manipulation such as outlier removal is (graphically and tabularly) documented adequately in the report. As a major reference materials producer, the Bundesanstalt für Materialforschung und -prüfung (BAM) developed and will maintain a tool to meet the needs of modern data processing, documentation requirements, and emerging fields of RM activity. The main features of eCerto are discussed using previously certified reference materials.

Adaptive Force of hamstring muscles is reduced in patients with knee osteoarthritis compared to asymptomatic controls.

BACKGROUND: Quadriceps strength deficits are known for patients with knee osteoarthritis (OA), whereas findings on hamstrings are less clear. The Adaptive Force (AF) as a special neuromuscular function has never been investigated in OA before. The maximal adaptive holding capacity (max. isometric AF; AFisomax) has been considered to be especially vulnerable to disruptive stimuli (e.g., nociception). It was hypothesized that affected limbs of OA patients would show clear deficits in AFisomax. METHODS: AF parameters and the maximal voluntary isometric contraction (MVIC) of hamstrings were assessed bilaterally comparing 20 patients with knee OA (ART) vs. controls (CON). AF was measured by a pneumatically driven device. Participants were instructed to maintain a static position despite an increasing load of the device. After reaching AFisomax, the hamstrings merged into eccentric action whereby the force increased further to the maximum (AFmax). MVIC was recorded before and after AF trials. Mixed ANOVA was used to identify differences between and within ART and CON (comparing 1st and 2nd measured sides). RESULTS: AFisomax and the torque development per degree of yielding were significantly lower only for the more affected side of ART vs. CON (p ≤ 0.001). The percentage difference of AFisomax amounted to - 40%. For the less affected side it was - 24% (p = 0.219). MVIC and AFmax were significantly lower for ART vs. CON for both sides (p ≤ 0.001). Differences of MVIC between ART vs. CON amounted to - 27% for the more, and - 30% for the less affected side; for AFmax it was - 34% and - 32%, respectively. CONCLUSION: The results suggest that strength deficits of hamstrings are present in patients with knee OA possibly attributable to nociception, generally lower physical activity/relief of lower extremities or fear-avoidance. However, the more affected side of OA patients seems to show further specific impairments regarding neuromuscular control reflected by the significantly reduced adaptive holding capacity and torque development during adaptive eccentric action. It is assumed that those parameters could reflect possible inhibitory nociceptive effects more sensitive than maximal strengths as MVIC and AFmax. Their role should be further investigated to get more specific insights into these aspects of neuromuscular control in OA patients. The approach is relevant for diagnostics also in terms of severity and prevention.

Inferior patellar mobility before and after knee arthroplasty: A comparison with healthy knees.

PURPOSE: The aim of this study was to evaluate patellar mobility in patients before and after knee arthroplasty (KA) and compare it with that of healthy subjects. It was hypothesised that patellar mobility is diminished in patients with osteoarthritis (OA) and remains unchanged after KA. METHODS: A total of 101 patients (59 females and 42 males) with a mean age of 70.9 ± 9.9 years underwent KA and were compared with 25 healthy individuals (seven females and 18 males) with a mean age of 32.3 ± 9.3 years. Mediolateral patellar displacement was measured by applying a force of 10 N, and the medial and lateral patellar shifts were recorded separately using a validated novel patellostabilometer. Patients were examined preoperatively and at 3 months postoperatively, assessing the range of knee motion and the clinical and functional status based on the Oxford Knee Score (OKS), Kujala Score, subjective Knee Society Score (sKSS), Forgotten Joint Score (FJS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC). RESULTS: Total patellar displacement was 42.1 ± 6 mm for healthy subjects, 31 ± 6 mm before surgery and 32.8 ± 7.8 mm after surgery in osteoarthritic patients (p < 0.01). The mean lateral patellar shift differed significantly between healthy individuals (17.9 ± 4 mm) and osteoarthritic patients (15.1 ± 6 mm) (p < 0.01). The mean medial patellar mobility of healthy individuals (24.2 ± 7 mm) was significantly greater than that of osteoarthritic patients (15.8 ± 4.8 mm) (p < 0.01). All scores improved significantly postoperatively. No correlation was found between patellar mobility and OKS, Kujala Score, sKSS, FJS and WOMAC (r = -0.11). Improvement in patellar mobility also showed no correlation with clinical outcomes according to OKS, Kujala Score, sKSS, FJS and WOMAC (r = 0.08). CONCLUSION: This study has demonstrated reduced patellar mobility in patients with OA. While patellar mobility significantly improved after KA, it may not hold clinical significance (p = 0.04). No impact on clinical outcome can be expected when the presurgical patella mobility is preserved in KA. LEVEL OF EVIDENCE: Level IV.

Robotic-assisted total knee arthroplasty reduces postoperative complications and length of stay without increased cost compared to navigation-guided techniques: A national analysis.

INTRODUCTION: This study compares postoperative outcomes of robotic-assisted total knee arthroplasty (RA-TKA) versus navigation-guided total knee arthroplasty (NG-TKA). Using Nationwide Inpatient Sample (NIS) data, it provides an analysis of postoperative complications, mortality, hospital costs and duration of stay. METHODS: The study analysed 217,715 patients (81,830 RA-TKA; 135,885 NG-TKA) using NIS data from 2016 to 2019. Elective TKA patients were identified through the International Classification of Diseases, 10th Revision codes. Statistical analyses, including logistic regression modelling, were performed using Statistical Package for the Social Sciences and MATLAB. RESULTS: RA-TKA patients were younger (66.1 vs. 67.1 years, p < 0.0001) and had similar mortality rates (0.024% vs. 0.018%, p = 0.342) but shorter length of stay (LOS) (1.89 vs. 2.1 days, p < 0.0001). Mean total charges were comparable between RA-TKA ($66,180) and NG-TKA ($66,251, p = 0.669). RA-TKA demonstrated lower incidences of blood-related complications (11.67% vs. 14.19%, p < 0.0001), pulmonary oedema (0.0306% vs. 0.066%, p < 0.0001), deep vein thrombosis (0.196% vs. 0.254%, p = 0.006) and acute kidney injury (AKI) (1.356% vs. 1.483%, p = 0.016). CONCLUSION: RA-TKA reduces postoperative complications and LOS without increasing costs, highlighting the relevance of this technology in patient care. LEVEL OF EVIDENCE: Level III.

High three-dimensional accuracy of component placement and lower limb alignment using a robotic arm-assisted system and gap-balancing instrument in total knee arthroplasty.

PURPOSE: It was hypothesized that robotic arm-assisted total knee arthroplasty (RA-TKA) using additionally a gap-balancing instrumentation will show high accuracy in executing the planning in femoral and tibial component placement throughout the range of knee motion (ROM) during TKA surgery. METHODS: Prospectively collected data were analysed for patients undergoing RA-TKA. A cruciate retaining cemented design was implanted using the MAKO® robotic system. Lower limb alignment at 0°, 30°, 45°, 60° and 90° of flexion was recorded at the beginning of surgery and finally after implantation of the components. A ligament tensioner was inserted after tibial precut to measure the extension and flexion gap, and final component placement was planned based on 3D CT images. Femoral and tibial component placement was measured in all three planes. RESULTS: A total of 104 patients were included (mean age 69.4 ± 9 years; 44 male, 60 female). The difference in component placement after planning and final implantation showed less valgus of 0.7° ± 1.4° (p < 0.001), less external rotation of 0.6° ± 1.9° (p = 0.001) and less flexion of 0.9° ± 1.8° (p < 0.001) for the femoral component. The tibial component was placed in more varus of 0.2° ± 0.9° (p = 0.056) and more posterior slope of 0.5° ± 0.9° (p < 0.001). The lower limb alignment in extension was 4.4° ± 5.2° of varus of the native knee and changed to 1.2° ± 1.9° of varus after TKA (p < 0.01). CONCLUSION: Robotic-assisted TKA helps to achieve the target of alignment and component placement very close to the planning. It allows optimal component placement of off-the-shelf implants respecting patient's specific anatomy. LEVEL OF EVIDENCE: Level II.

Evaluating the Reliability of MyotonPro in Assessing Muscle Properties: A Systematic Review of Diagnostic Test Accuracy.

Background and Objectives: Muscle properties are critical for performance and injury risk, with changes occurring due to physical exertion, aging, and neurological conditions. The MyotonPro device offers a non-invasive method to comprehensively assess muscle biomechanical properties. This systematic review evaluates the reliability of MyotonPro across various muscles for diagnostic purposes. Materials and Methods: Following PRISMA guidelines, a comprehensive literature search was conducted in Medline (PubMed), Ovid (Med), Epistemonikos, Embase, Cochrane Library, Clinical trials.gov, and the WHO International Clinical Trials platform. Studies assessing the reliability of MyotonPro across different muscles were included. A methodological quality assessment was performed using established tools, and reviewers independently conducted data extraction. Statistical analysis involved summarizing intra-rater and inter-rater reliability measures across muscles. Results: A total of 48 studies assessing 31 muscles were included in the systematic review. The intra-rater and inter-rater reliability were consistently high for parameters such as frequency and stiffness in muscles of the lower and upper extremities, as well as other muscle groups. Despite methodological heterogeneity and limited data on specific parameters, MyotonPro demonstrated promising reliability for diagnostic purposes across diverse patient populations. Conclusions: The findings suggest the potential of MyotonPro in clinical assessments for accurate diagnosis, treatment planning, and monitoring of muscle properties. Further research is needed to address limitations and enhance the applicability of MyotonPro in clinical practice. Reliable muscle assessments are crucial for optimizing treatment outcomes and improving patient care in various healthcare settings.

High variation among clinical studies in the assessment of physical function after knee replacement: a systematic review.

PURPOSE: The purpose of this study was to summarise the current use of outcome measures for the assessment of physical function after knee joint replacement. METHODS: A systematic approach following the PRISMA guidelines was used. Literature search was performed on MEDLINE database via PubMed and on Epistemonikos. Clinical trials (level of evidence I-II) on knee joint replacement reporting data on the 'physical function' domain published between January 2017 and June 2022 were included. Descriptive statistics were used to summarise the evidence. RESULTS: In the 181 articles that met the inclusion criteria, 49 different outcome measurements were used to evaluate clinical outcomes after knee joint replacement. The most frequently adopted patient-reported outcome measures (PROMs) were the Knee Society Score (KSS) (78 studies; 43.1%), the Western Ontario and McMaster Universities (WOMAC) Arthritis Index (62 studies; 34.3%), the Oxford Knee Score (OKS) (51 studies; 28.2%) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) (36 studies; 20%). The most frequently used performance-based outcome measures (PBOMs) were the Timed-Up-and-Go (TUG) test (30 studies; 16.6%) and the 6-min-walk test (6MWT) (21 studies; 11.6%). Among impairment-based outcome measures (IBOMs), range of motion (ROM) was the most used (74 studies; 40.9%). CONCLUSION: There is considerable variation among clinical studies regarding the assessment of the physical function of patients after knee joint replacement. PROMs were found to be the most commonly adopted outcome measures; however, no single PROM was used in more than half of the papers analysed. LEVEL OF EVIDENCE: Level II, systematic review of level I-II studies.

The number of arthroscopies performed by trainees does not deduce the level of their arthroscopic proficiency.

PURPOSE: It is reasonable to question whether the case volume is a suitable proxy for the manual competence of an arthroscopic surgeon. The aim of this study was to evaluate the correlation between the number of arthroscopies previously performed and the arthroscopic skills acquired using a standardized simulator test. METHODS: A total of 97 resident and early orthopaedic surgeons who participated in arthroscopic simulator training courses were divided into five groups based on their self-reported number of arthroscopic surgeries: (1) none, (2) < 10, (3) 10 to 19, (4) 20 to 39 and (5) 40 to 100. Arthroscopic manual skills were evaluated with a simulator by means of the diagnostic arthroscopy skill score (DASS) before and after training. Seventy-five points out of 100 must be achieved to pass the test. RESULTS: In the pretest, only three trainees in group 5 passed the arthroscopic skill test, and all other participants failed. Group 5 (57 ± 17 points; n = 17) scored significantly higher than the other groups (group 1: 30 ± 14, n = 20; group 2: 35 ± 14, n = 24; group 3: 35 ± 18, n = 23; and group 4: 33 ± 17, n = 13). After a two-day simulator training, trainees showed a significant increase in performance. In group 5, participants scored 81 ± 17 points, which was significantly higher than the other groups (group 1: 75 ± 16; group 2: 75 ± 14; group 3: 69 ± 15; and group 4: 73 ± 13). While self-reported arthroscopic procedures were n.s. associated with higher log odds of passing the test (p = 0.423), the points scored in the pretest were found to be a good predictor of whether a trainee would pass the test (p < 0.05). A positive correlation was observed between the points scored in the pretest and the posttest (p < 0.05, r = 0.59, r2 = 0.34). CONCLUSIONS: The number of previously performed arthroscopies is not a reliable indicator of the skills level of orthopaedic residents. A reasonable alternative in the future would be to verify arthroscopic proficiency on the simulator by means of a score as a pass-fail examination. LEVEL OF EVIDENCE: III.

Improving the reliability of measurements in orthopaedics and sports medicine.

A large space still exists for improving the measurements used in orthopaedics and sports medicine, especially as we face rapid technological progress in devices used for diagnostic or patient monitoring purposes. For a specific measure to be valuable and applicable in clinical practice, its reliability must be established. Reliability refers to the extent to which measurements can be replicated, and three types of reliability can be distinguished: inter-rater, intra-rater, and test-retest. The present article aims to provide insights into reliability as one of the most important and relevant properties of measurement tools. It covers essential knowledge about the methods used in orthopaedics and sports medicine for reliability studies. From design to interpretation, this article guides readers through the reliability study process. It addresses crucial issues such as the number of raters needed, sample size calculation, and breaks between particular trials. Different statistical methods and tests are presented for determining reliability depending on the type of gathered data, with particular attention to the commonly used intraclass correlation coefficient.

Metaphyseal cones and sleeves are similar in improving short- and mid-term outcomes in Total Knee Arthroplasty revisions.

PURPOSE: The purpose of this systematic review and metanalysis was to assess clinical and radiological outcomes of metaphyseal sleeves and cones and to identify their possible advantages and disadvantages. METHODS: A comprehensive search from the inception of the databases to March 2021 was performed on Medline, Scopus, CINAHL, Cochrane, Embase, Ovid, and Google scholar databases. Coleman Methodology Score was used for quality assessment. Author, year of publication, type of study, level of evidence, sample size, number of patients, number of knees treated, mean age, gender, mean follow-up, clinical outcomes, complications, the reason for revision and, type of prosthesis were extracted for analysis. Clinical studies providing data about patient's outcomes after the primary and Total Knee Arthroplasty revision with the usage of sleeves or cones and a minimum of 2 years of follow-up were included. RESULTS: The literature search and cross-referencing resulted in a total of 93 articles, but only 30 articles were appropriate for the systematic review. Comparable clinical results were reported between cones and sleeves. The meta-analysis showed a greater incidence of intraoperative fractures in patients treated with sleeves (1.6%, [95% CI 0.7; 3.4] in cones and 4.6%, [95% CI 3.3; 6.4] in sleeves, p = 0.01), while the risk of postoperative fractures (4.3%, [95% CI 2.7; 7] in cones and 2.1%, [95% CI 1.2; 3.5] in sleeves, p = 0.04) and infections (8.5%, [95% CI 6; 12] in cones and 3.7%, [95% CI 2.1; 7.3] in sleeves, p = 0.03) was higher with cones. CONCLUSION: A higher incidence of intraoperative fracture was reported in patients treated with sleeves, while a higher rate of postoperative fractures and infections was described in patients treated with cones. Nonetheless, complications were reported in both groups. LEVEL OF EVIDENCE: III.

ESSKA and EBJIS recommendations for the management of infections after anterior cruciate ligament reconstruction (ACL-R): prevention, surgical treatment and rehabilitation.

PURPOSE: Infection after anterior cruciate ligament reconstruction (ACL-R) is a rare but severe complication. Despite an increase in articles published on this topic over the last decade, solid data to optimized diagnostic and therapeutic measures are scarce. For this reason, the European Bone and Joint Infection Society (EBJIS) and the European Society for Sports Traumatology, Knee Surgery and Arthroscopy (ESSKA) collaborated in order to develop recommendations for the diagnosis and management of infections after ACL-R. The aim of the workgroup was to perform a review of the literature and provide practical guidance to healthcare professionals involved in the management of infections after ACL-R. METHODS: An international workgroup was recruited to provide recommendations for predefined clinical dilemmas regarding the management of infections after ACL-R. MEDLINE, EMBASE, Cochrane Library and Scopus databases were searched for evidence to support the recommended answers to each dilemma. RESULTS: The recommendations were divided into two articles. The first covers etiology, prevention, diagnosis and antimicrobial treatment of septic arthritis following ACL-R and is primarily aimed at infectious disease specialists. This article includes the second part of the recommendations and covers prevention of infections after ACL-R, surgical treatment of septic arthritis following ACL-R and subsequent postoperative rehabilitation. It is aimed not only at orthopedic surgeons, but at all healthcare professionals dealing with patients suffering from infections after ACL-R. CONCLUSION: These recommendations guide clinicians in achieving timely and accurate diagnosis as well as providing optimal management, both of which are paramount to prevent loss of function and other devastating sequelae of infection in the knee joint. LEVEL OF EVIDENCE: V.

Assessment of learning in simulator-based arthroscopy training with the diagnostic arthroscopy skill score (DASS) and neurophysiological measures.

PURPOSE: Virtual arthroscopic training has become increasingly popular. However, there is a lack of efficiency-based tracking of the trainee, which may be critical for determining the specifics of training programs and adapting them for the needs of each trainee. This study aims to evaluate and compare the measures obtained with a non-invasive neurophysiological method with The Diagnostic Arthroscopy Skill Score (DASS), a commonly used assessment tool for evaluating arthroscopic skills. METHODS: The study collected simulator performance scores, consisting of "Triangulation Right Hand", "Triangulation Left Hand", "Catch the Stars" and "Three Rings" and DASS scores from 22 participants (11 novices, 11 experts). These scores were obtained while participants underwent a structured program of exercises for the fundamentals of arthroscopic surgery training (FAST) and knee module using a simulator-based arthroscopy device. During the evaluation, data on oxy-hemoglobin and deoxy-hemoglobin levels in the prefrontal cortex were collected using the Functional Near-Infrared Spectroscopy (fNIRS) imaging system. Performance scores, DASS scores, and fNIRS data were subsequently analyzed to determine any correlation between performance and cortex activity. RESULTS: The simulator performance scores and the DASSPart2 scores were significantly higher in the expert group compared to the novice group (200.1 ± 28.5 vs 172.5 ± 48.9, p = 0.04 and 9.4 ± 5.6 vs. 5.4 ± 5.6 p = 0.02). In the expert group, fNIRS data showed a significantly lower prefrontal cortex activation during fundamental tasks in the FAST module, indicating significantly more efficient mental resource use. CONCLUSION: The analysis of cognitive workload changes during simulation-based arthroscopy training revealed a significant correlation between the trainees' DASS scores and fNIRS data. This correlation suggests the potential use of fNIRS data and DASS scores as additional metrics to create adaptive training protocols for each participant. By incorporating these metrics, the training process can be optimized, leading to more efficient arthroscopic training and better preparedness for clinical operations. LEVEL OF EVIDENCE: III.

Management of anterior cruciate ligament revision in adults: the 2022 ESSKA consensus part I-diagnostics and preoperative planning.

PURPOSE: The aim of this ESSKA consensus is to give recommendations based on evidence and expert opinion to improve diagnosis, preoperative planning, indication and surgical strategy in ACL revision. METHODS: The European expert surgeons and scientists were divided into four groups to participate in this consensus. A "literature group" (four surgeons); "steering group" (14 surgeons and scientists); "rating group" (19 surgeons) and finally "peer review group" (51 representatives of the ESSKA-affiliated national societies from 27 countries). The steering group prepared eighteen question-answer sets. The quality of the answers received grades of recommendation ranging from A (high-level scientific support), to B (scientific presumption), C (low level scientific support) or D (expert opinion). These question-answer sets were then evaluated by the rating group. All answers were scored from 1 to 9. The comments of the rating group were incorporated by the steering group and the consensus was submitted to the rating group a second time. Once a general consensus was reached between the steering and rating groups, the question-answer sets were submitted to the peer review group. A final combined meeting of all the members of the consensus was held to ratify the document. RESULTS: The literature review for the diagnosis and preoperative planning of ACL revision revealed a rather low scientific quality. None of the 18 questions was graded A and six received a grade B. The mean rating of all the questions by the rating group was 8.4 ± 0.3. The questions and recommendations are listed below. CONCLUSION: ACL revision surgery is a widely debated subject with many different opinions and techniques. The literature reveals a poor level of standardisation. Therefore, this international consensus project is of great importance. LEVEL OF EVIDENCE: II.

Management of anterior cruciate ligament revision in adults: the 2022 ESSKA consensus: part II-surgical strategy.

PURPOSE: The aim of this ESSKA consensus is to give recommendations based on scientific evidence and expert opinion to improve the diagnosis, preoperative planning, indication and surgical strategy in Anterior Cruciate Ligament revision. METHODS: Part 2, presented herein, followed exactly the same methodology as Part 1: the so-called ESSKA formal consensus derived from the Delphi method. Eighteen questions were ultimately asked. The quality of the answers received the following grades of recommendation: Grade A (high level scientific support), Grade B (scientific presumption), Grade C (low level scientific support) or Grade D (expert opinion). All answers were scored from 1 to 9 by the raters. Once a general consensus had been reached between the steering and rating groups, the question-answer sets were submitted to the peer-review group. A final combined meeting of all the members of the consensus was then held to ratify the document. RESULTS: The review of the literature revealed a rather low scientific quality of studies examining the surgical strategy in cases of ACL reconstruction failure. Of the 18 questions, only 1 received a Grade A rating; 5, a Grade B rating; and 9, grades of C or D. The three remaining complex questions received further evaluations for each portion of the question and were looked at in more detail for the following grades: B and D; A, C and D; or A, B, C and D. The mean rating of all questions by the rating group was 8.0 + - 1.1. The questions and recommendations are listed in the article. CONCLUSION: ACL revision surgery, especially the surgical strategy, is a widely debated subject with many different opinions and techniques. The literature reveals a poor level of standardization. Therefore, this international European consensus project is of great importance and clinical relevance for guiding the management of ACL revision in adults. LEVEL OF EVIDENCE: Level II.

The Patellostabilometer: A New Device for Quantification of Mediolateral Patella Displacement.

Mediolateral patella displacement is of interest for diagnostics and clinically relevant research questions. Apart from manual testing, no standardized method is currently available. Proper quantification of patella mobility is necessary to better understand pathologies at the patellofemoral joint. Patella mobility was assessed in 25 healthy individuals using a Patellostabilometer, a new prototype instrument for quantification of the mediolateral patella displacement. The participants underwent measurements of the mediolateral displacement three times using the Patellostabilometer. A maximal force of 10 N was applied for patella movement. Additionally, leg length and circumference of the knee, upper- and lower-leg were measured. Lateral patella displacement of 18.27 ± 3.76 mm (range 15.85-20.64 mm, interquartile range (IQR) of 4.79) was measured. The medial patella displacement showed 24.47 ± 6.59 mm (range 19.29-29.76 mm, IQR of 10.47). The test-retest measurement error was 2.32 ± 1.76 mm (IQR of 2.38 mm), with five outliers. There was greater test-retest variability between the measurements of the medial displacement compared to the lateral one. The test-retest variability reached 7% of the patella displacement. Other parameters provided no significant correlations. Based on the natural patellofemoral mobility, a precise and clinically relevant quantification of patella mobility is allowed.

Acetabular cup placement and offset control in robotic total hip arthroplasty performed through the modified anterolateral approach.

PURPOSE: The modified anterolateral approach (Röttinger) for total hip arthroplasty (THA) offers great advantages over conventional approaches, especially concerning early postoperative symptoms, which are mild and well tolerated by patients. Robotic-assisted implantation might facilitate rapid adoption of the modified anterolateral approach without exposing surgeons to risks encountered during the learning curve. This study posits that the use of robotic assistance in conjunction with the modified anterolateral approach for total hip arthroplasty (THA) can provide a substantial enhancement in the accuracy of cup placement in comparison to manual surgery. METHODS: Thirty-two robotic-assisted THAs met the inclusion criteria and were matched to 32 conventional cases. Acetabular cup inclination, anteversion, limb-length discrepancy, and acetabular offset were assessed using certified planning software by two independent observers using pre- and postoperative anterior-posterior radiographs. Data was analyzed for normal distribution. Chi2 test was used to determine whether implanted acetabular cups that were within Lewinnek's safe zones were influenced by type of implantation. Effect size estimates and statistical power analysis were also performed to appreciate the appropriateness of the chosen sample size. RESULTS: Robotic-assisted implantation was found to significantly improve acetabular cup placement in terms of inclination (p < 0.001) but not anteversion (p = 0.783). Although mean postoperative limb-length discrepancy and mean acetabular offset did not differ between groups, a significantly smaller variance was found in the robotic-assisted group (p < 0.001) and (p = 0.04), respectively. There were no significant differences between the two groups in terms of consistently implanting the acetabular cup within the Lewinnek safe zones p = 0.641 for anteversion and p = 0.230 for inclination, respectively. CONCLUSIONS: Our results show that although robotic-assisted acetabular cup implantation performed through the modified anterolateral approach did not significantly differ from conventional implantation, it did offer increased accuracy in cup positioning, acetabular bone preservation, and limb-length restoration.

No correlation between symmetry-based performance measures and patient-related outcome prior to and after total knee arthroplasty.

PURPOSE: Standardized outcome measures are crucial for the evaluation of different treatment and rehabilitation regimes in patients after total knee arthroplasty (TKA). Performance-based measures are necessary to capture different aspects of physical function. High reliability and agreement of five performance-based measures were hypothesized to differentiate between measurement error and change in test performance. Secondary outcomes are the correlation of performance-based measurements to KSS and WOMAC prior to surgery (baseline) and 10 weeks thereafter (t3). METHODS: The test-retest reliabilities and agreements of the 1-m walk test, the stair-climbing test, the timed-up-and-go test, the weight-balanced-chair-rising test and the isometric maximum knee extension force in patients undergoing total knee replacements were studied. The intraclass correlation coefficient was calculated and a Bland-Altman analysis performed. RESULTS: The weight-balanced-chair-rising test showed a symmetry at baseline = 0.77, 5 ± 1 days after surgery (t1) = 0.50, 9 ± 1 days (t2) = 0.59 and (t3) = 0.80. All performance tests showed high intraclass correlation coefficients (ICC = 0.81-0.99). The 10-m walk test, stair climbing test, and the timed-up-and-go test showed high agreement in the Bland-Altman analysis. The Bland-Altman analysis for the weight-balanced-chair-rising test and isometric knee extension force indicated high agreement at 5 and 9 days postoperatively, but the relative measurement error increased pre- and 10 weeks postoperatively. CONCLUSION: In conclusion, symmetry, as an important outcome after TKA, is a reliable and rather unique item that should unquestionably be added to established measurements like walking tests or survey-based function assessment. The implementation of standardized performance-based measures to assess physical function in rehabilitation procedures will help to improve the more objectively based assessment of different rehabilitation protocols. LEVEL OF EVIDENCE: II.

The Diagnostic Arthroscopy Skill Score (DASS): a reliable and suitable assessment tool for arthroscopic skill training.

PURPOSE: To develop and validate a novel score to more objectively assess the performance of diagnostic knee arthroscopy using a simulator. METHODS: A Diagnostic Arthroscopy Skill Score (DASS) was developed by ten AGA (AGA-Society for Arthroscopy and Joint-Surgery) instructors for the assessment of arthroscopic skills. DASS consists of two parts: the evaluation of standardized diagnostic knee arthroscopy (DASSpart1) and the evaluation of manual dexterity, including ambidexterity and triangulation, using objective measurement parameters (DASSpart2). Content validity was determined by the Delphi method. One hundred and eleven videos of diagnostic knee arthroscopies were recorded during simulator training courses and evaluated by six specially trained instructors using DASS. Construct validity, measurement error calculated by the minimum detectable change (MDC), internal consistency using Cronbach's alpha and interrater and intrarater reliability were assessed. The Bland-Altman method was used to calculate the intrarater agreement. RESULTS: Six skill domains were identified and evaluated for each knee compartment. DASS, DASSpart1, and DASSpart2 showed construct validity, with experts achieving significantly higher scores than competents and novices. MDC was 4.5 ± 1.7 points for DASSpart1. There was high internal consistency for all domains in each compartment from 0.78 to 0.86. The interrater reliability showed high agreement between the six raters (ICC = 0.94). The evaluation of intrarater reliability demonstrated good and excellent agreement for five raters (ICC > 0.80) and moderate agreement for one rater (ICC = 0.68). The Bland-Altman comparison showed no difference between the first and second evaluations in five out of six raters. Precision, estimated by the regression analysis and comparison with the method of Bland and Altman, was excellent for four raters and moderate for two raters. CONCLUSIONS: The results of this study indicate good validity and reliability of DASS for the assessment of the surgical performance of diagnostic knee arthroscopy during simulator training. Standardized training is recommended before arthroscopy surgery is considered in patients. LEVEL OF EVIDENCE: II.

Ten hours of simulator training in arthroscopy are insufficient to reach the target level based on the Diagnostic Arthroscopic Skill Score.

PURPOSE: Simulator arthroscopy training has gained popularity in recent years. However, it remains unclear what level of competency surgeons may achieve in what time frame using virtual training. It was hypothesized that 10 h of training would be sufficient to reach the target level defined by experts based on the Diagnostic Arthroscopic Skill Score (DASS). METHODS: The training concept was developed by ten instructors affiliated with the German-speaking Society of Arthroscopy and Joint Surgery (AGA). The programme teaches the basics of performing arthroscopy; the main focus is on learning and practicing manual skills using a simulator. The training was based on a structured programme of exercises designed to help users reach defined learning goals. Initially, camera posture, horizon adjustment and control of the direction of view were taught in a virtual room. Based on these skills, further training was performed with a knee model. The learning progress was assessed by quantifying the exercise time, camera path length and instrument path length for selected tasks. At the end of the course, the learners' performance in diagnostic arthroscopy was evaluated using DASS. Participants were classified as novice or competent based on the number of arthroscopies performed prior to the assessment. RESULTS: Except for one surgeon, 131 orthopaedic residents and surgeons (29 women, 102 men) who participated in the seven courses agreed to anonymous data analysis. Fifty-eight of them were competents with more than ten independently performed arthroscopies, and 73 were novices, with fewer than ten independently performed arthroscopies. There were significant reductions in exercise time, camera path length and instrument path length for all participants after the training, indicating a rapid increase in performance. No difference in camera handling between the dominant and non-dominant sides was found in either group. The competents performed better than the novices in various tasks and achieved significantly better DASS values on the final performance test. CONCLUSIONS: Our data have demonstrated that arthroscopic skills can be taught effectively on a simulator, but a 10-h course is not sufficient to reach the target level set by experienced arthroscopists. However, learning progress can be monitored more objectively during simulator training than in the operating room, and simulation may partially replace the current practice of arthroscopic training. LEVEL OF EVIDENCE: III.

Computer-assisted surgery and patient-specific instrumentation improve the accuracy of tibial baseplate rotation in total knee arthroplasty compared to conventional instrumentation: a systematic review and meta-analysis.

PURPOSE: To determine whether patient-specific instrumentation (PSI), computer-assisted surgery (CAS) or robot-assisted surgery (RAS) enable more accurate rotational alignment of the tibial baseplate in primary total knee arthroplasty (TKA) compared to conventional instrumentation, in terms of deviation from the planned target and the proportion of outliers from the target zone. METHODS: The authors independently conducted three structured electronic literature searches using the PubMed, Embase®, and Cochrane Central Register of Controlled Trials databases from 2007 to 2020. Studies were included if they compared rotational alignment of the tibial baseplate during TKA using conventional instrumentation versus PSI, CAS, and/or RAS, and reported deviation from preoperatively planned rotational alignment of the tibial baseplate in terms of absolute angles and/or number of outliers. Methodological quality of eligible studies was assessed by two researchers according to the Downs and Black Quality Checklist for Health Care Intervention Studies. RESULTS: Fifteen studies, that reported on 2925 knees, were eligible for this systematic review, of which 6 studies used PSI, and 9 used CAS. No studies were found for RAS. Of the studies that reported on angular deviation from preoperatively planned rotational alignment, most found smaller deviations using PSI (0.5° to 1.4°) compared to conventional instrumentation (1.0° to 1.6°). All studies that reported on proportions of outliers from a target zone (± 3°), found lower rates of outliers using PSI (0 to 22%) compared to conventional instrumentation (5 to 96%). Most studies reported smaller angular deviation from preoperatively planned rotational alignment using CAS (0.1° to 6.9°) compared to conventional instrumentation (1.1° to 7.8°). Of the studies that reported on proportions of outliers from a target zone (± 3°), most found fewer outliers using CAS (10 to 61%) compared to conventional instrumentation (17 to 78%). CONCLUSION: This systematic review and meta-analysis revealed that both CAS and PSI can improve the accuracy of rotational alignment of the tibial baseplate by decreasing angular deviation from the preoperatively planned target and reducing the proportion of outliers from the target zone. The clinical relevance is that PSI and CAS can improve alignment, though the thresholds necessary to grant better outcomes and survival remain unclear. LEVEL OF EVIDENCE: IV.