Septic complications are on the rise and aseptic loosening has decreased in total joint arthroplasty: an updated complication based analysis using worldwide arthroplasty registers.

INTRODUCTION: A decade ago, a comprehensive study was conducted to investigate the reasons for revision surgeries and their respective frequencies in cases of total hip arthroplasty (THA) and total knee arthroplasty (TKA) based on a complication-based analysis of joint replacement registries. The aim of the present study was to determine whether the causes and risks of their occurrence have changed over the last ten years and to present an updated analysis. MATERIALS AND METHODS: A systematic review of national arthroplasty registries from seven countries examined the causes and rates of revisions of THA and TKA. The study focused on a descriptive analysis that provided an updated overview without statistical significance values. RESULTS: The most common causes for revisions of THA were aseptic loosening (35.1%), deep infection (18.2%), dislocation/instability (15.9%), and periprosthetic fractures (11.4%). The most common causes for revisions of TKA were deep infection (21.6%), aseptic loosening (18.3%), instability (14.1%), and pain (10.9%). CONCLUSION: The findings of this study revealed significant shifts in the underlying causes of revision surgeries in the last decade. Notably, septic complications emerged as the predominant reason for revision of primary TKA, while they also gained prominence as a cause of failure of THA. Although aseptic loosening remains the primary cause for re-operation of THA, the relative risk has decreased for both THA and TKA.

Comparison of revision rates and epidemiological data of a single total knee arthroplasty system of different designs (cruciate retaining, posterior stabilized, mobile bearing, and fixed bearing): a meta-analysis and systematic review of clinical trials and national arthroplasty registries.

BACKGROUND: This study aimed to meta-analyze epidemiological data, revision rates, and incidences of different designs of a single Total Knee Arthroplasty System and compare these factors across different countries. METHODS: A systematic review was conducted on clinical studies and arthroplasty registries of ATTUNE TKA from 1999 to 2020. The main endpoints analyzed were revision rates and epidemiological data. RESULTS: The average age of patients was 67.8 years, with a gender distribution of 60% female and 40% male. The pooled average BMI was 29.4 kg/m2. Eight clinical studies showed a pooled revision rate per 100 observed CY of 0.5 (n = 1343 cases). Cumulative revision rates after 1, 3, and 5 years varied among registries, with the Swiss registry having the highest revision data (after 5 years: 6.3%) and the American registry having the lowest revision data (after 5 years: 1.7%). A comparison of the revision rates of mobile bearing and fixed bearing (41,200 cases) as well as cruciate retaining and posterior stabilized (n = 123,361 cases) showed no significant advantage in the first 5 years after implantation. CONCLUSION: In conclusion, pooled data from 41,200 cases of TKA with a single Total Knee Arthroplasty System in two arthroplasty registries revealed that there was no significant difference in revision rates between the mobile bearing and fixed bearing design within the first 5 years after implantation. In addition, a comparison of the revision rates in n = 123,361 cases showed no significant advantage for cruciate retaining or posterior stabilized in the first 5 years after implantation.

Soluble Urokinase Plasminogen Activator Receptor (SuPAR) Analysis for Diagnosis of Periprosthetic Joint Infection.

Soluble urokinase plasminogen activator receptors (suPARs) are a biomarker for inflammatory diseases. This study aims to investigate its diagnostic properties regarding periprosthetic joint infections (PJI). This retrospective cohort study included adult patients who underwent joint puncture for suspected PJI. The presence of PJI was determined according to the criteria of the European Bone and Joint Infection Society (EBJIS). Laboratory study analyses included the determination of white blood cells (WBC) in whole blood, C-reactive protein (CRP) in blood plasma, and suPAR in both blood plasma and synovial fluid. Appropriate diagnostic cut-off values were identified utilizing Youden's J, and their diagnostic performance was determined by calculating the positive (PPV) and negative predictive value (NPV) for each marker. Sixty-seven cases were included in the final analysis. Forty-three samples (64%) were identified as periprosthetic joint infection (PJI) and twenty-four specimen (36%) were PJI negative cases. The PPV and NPV were 0.80 and 0.70 for synovial suPAR, 0.86 and 0.55 for CRP, 0.84 and 0.31 for WBC and 1.00 and 0.31 for plasma suPAR. Synovial suPAR showed a solid diagnostic performance in this study and has the potential to be an alternative or complementary biomarker for PJI. Further investigations in larger patient collectives are indicated.

Long-term clinical and radiological outcome of a cementless titanium-coated total knee arthroplasty system.

INTRODUCTION: To ensure a high-quality standard, it is important to frequently evaluate different prostheses models to avoid prostheses with high failure rates. Thus, the aim of the study was to evaluate the long-term outcome of the uncemented titanium-coated total knee arthroplasty (TKA) system (Advanced Coated System (ACS) III, Implantcast, GERMANY). We hypothesized that the ACS III would have a similar performance as other cemented TKA systems. MATERIALS AND METHODS: A total of 540 ACS III mobile-bearing knee joint prostheses were implanted in 495 patients. The visual analogue scale (VAS) score, Tegner activity score (TAS), knee society score (KSS), Western Ontario and McMaster (WOMAC) score, and the Short Form 12 (SF-12) score for the evaluation of quality of life (QoL) were taken after at least 9 years of follow-up. In addition, we measured range of motion (ROM) and assessed potential sex differences. In addition, the survival analysis was calculated at a median follow-up of 16.7 years. RESULTS: At the final follow-up, 142 patients had died, and 38 had been lost to follow-up. The rate of revision-free implant survival at 16.7 years was 90.0% (95% CI 87.1-92.2%) and the rate of infection-free survival was 97.0% (IQR 95.2-98.2%). The reasons for revision surgery were aseptic loosening (32.9%), followed by infection (27.1%), inlay exchange (15.9%), and periprosthetic fractures (5.7%). At the clinical follow-up visit, the mean VAS score was 1.9 ± 1.9, the median TAS was 3 (IQR 2-4), and the mean KSS for pain and function were 83.5 ± 15.3 and 67.5 ± 25.2, respectively. The mean WOMAC score was 81.1 ± 14.9, and the median SF-12 scores for physical and mental health were 36.9 (IQR 29.8-45.1) and 55.8 (IQR 46.2-61.0), respectively. The mean knee flexion was 102.0° ± 15.4°. Male patients had better clinical outcome scores than female patients [SF-12 mental health score, p = 0.037; SF-12 physical health score, p = 0.032; KSS pain score (p < 0.001), and KSS functional score (p < 0.001)]. CONCLUSION: The ACS III TKA system is a suitable option for the treatment of end-stage osteoarthritis of the knee joint because of its adequate long-term survival. Our findings are in line with published data on similar TKA systems that have shown favourable clinical scores in males. LEVEL OF EVIDENCE: Level III-Retrospective cohort study.

Development of application and surgical technique of total knee arthroplasties: a systematic comparative analysis using worldwide registers.

PURPOSE: The aim was to compare total knee arthroplasty (TKA) between countries with regard to epidemiologic data and surgical technique by the use of worldwide registers and compare findings with a previous report after one decade. METHODS: A systematic search was carried out in November 2022 and compared to previous reports from 2010. We extracted data regarding implanted TKAs, patients' age distribution, procedure types, fixation and revision rates. After identification of 28 national arthroplasty registers, 8of them, namely Australia, Canada, Denmark, England and Wales, New Zealand, Norway, Scotland and Sweden, offered sufficient data and were included in final analysis. RESULTS: A large variation was found in the annual number of implantations per 100,000 inhabitants with a range from 77 to 210.2 (mean 132.8). The fixation type varied strongly as well, e.g. over 95% of totally cemented TKAs in Sweden versus 61.2% cemented fixation in Denmark. Another significant difference was the use of patellar resurfacing in TKA, ranging from 47.3% (Canada) using a patellar button in TKA to less than 5% (Sweden). Within the period of one decade, the mean overall number of annual implantations increased (10%), whilst relative number of revisions decreased, the use of cemented TKA decreased from 87 to 74%, and the use of patella button remained largely inhomogeneous. CONCLUSION: Comparison of arthroplasty registers revealed large differences regarding the annual number of primary TKAs per inhabitant as well as primary TKA procedure types with an increase of annual implantations, decrease of relative number of revisions, and a decrease of the use of cemented systems over the period of one decade.

Less Induction Time and Postoperative Pain Using Spinal Anesthesia Versus General Anesthesia With or Without the Use of Peripheral Nerve Blocks in Total Knee Arthroplasty.

BACKGROUND: Our aim was to analyze anesthetic induction time and postoperative pain using spinal anesthesia versus general anesthesia with or without the use of peripheral nerve blocks (PNBs) in total knee arthroplasty. The hypothesis was that spinal anesthesia would be beneficial with respect to induction time and postoperative pain and that PNBs would complement this effect. METHODS: Patients were stratified according to demographics, American Society of Anesthesiologists physical status classification system (ASA), and opioid intake and divided into: (A) general anesthesia without PNB; (B) general anesthesia with PNB; (C) spinal anesthesia without PNB; and (D) spinal anesthesia with PNB. Endpoints were anesthetic induction time, opioid consumption, and pain. Of 559 patients, 348 (62.3%) received general anesthesia (consisting of group A with 46 and group B with 302 patients), and 211 (37.7%) spinal anesthesia (consisting of group C with 117 and group D with 94 patients). RESULTS: We observed significantly lower total opioid intake 48 hours postoperative when applying spinal anesthesia by 2.08 mg (P < .05) of intravenous morphine-equivalent, and a reduction of 7.0 minutes (P < .05) until skin incision. The application of a PNB achieved a reduction of piritramide intake of 3.59 mg (P < .05) 48 hours postoperative and lengthened induction time by 8.5 minutes (P < .05). CONCLUSIONS: Statistically shorter anesthetic induction times without clinical relevance, but lower postoperative opioid dosages with clinical relevance were observed for patients undergoing total knee arthroplasty with spinal anesthesia. The additional application of PNBs led to a lower need for opioids and lower pain levels in the early postoperative phase.

Implant breakage after shoulder arthroplasty: a systematic review of data from worldwide arthroplasty registries and clinical trials.

BACKGROUND: Implant breakage after shoulder arthroplasty is a rare complication after aseptic loosening, infection or persistent pain, resulting in malfunction of the components requiring revision surgery. This correlates with a high burden for the patient and increasing costs. Specific data of complication rates and implant breakage are available in detailed arthroplasty registries, but due to the rare occurrence and possibly underestimated value rarely described in published studies. The aim of this systematic review was to point out the frequency of implant breakage after shoulder arthroplasty. We hypothesized that worldwide arthroplasty registry datasets record higher rates of implant breakage than clinical trials. METHODS: PubMed, MEDLINE, EMBASE, CINHAL, and the Cochrane Central Register of Controlled Trials database were utilized for this systematic review using the items "(implant fracture/complication/breakage) OR (glenoid/baseplate complication/breakage) AND (shoulder arthroplasty)" according to the PRISMA guidelines on July 3rd, 2023. Study selection, quality assessment, and data extraction were conducted according to the Cochrane standards. Case reports and experimental studies were excluded to reduce bias. The breakage rate per 100,000 observed component years was used to compare data from national arthroplasty registries and clinical trials, published in peer-reviewed journals. Relevant types of shoulder prosthetics were analyzed and differences in implant breakage were considered. RESULTS: Data of 5 registries and 15 studies were included. Rates of implant breakage after shoulder arthroplasty were reported with 0.06-0.86% in registries versus 0.01-6.65% in clinical studies. The breakage rate per 100,000 observed component years was 10 in clinical studies and 9 in registries. There was a revision rate of 0.09% for registry data and 0.1% for clinical studies within a 10-year period. The most frequently affected component in connection with implant fracture was the glenoid insert. CONCLUSION: Clinical studies revealed a similar incidence of implant failure compared to data of worldwide arthroplasty registries. These complications arise mainly due to breakage of screws and glenospheres and there seems to be a direct correlation to loosening. Periprosthetic joint infection might be associated with loosening of the prosthesis and subsequent material breakage. We believe that this analysis can help physicians to advise patients on potential risks after shoulder arthroplasty. LEVEL OF EVIDENCE: III.

Are ChatGPT's Free-Text Responses on Periprosthetic Joint Infections of the Hip and Knee Reliable and Useful?

BACKGROUND: This study aimed to evaluate ChatGPT's performance on questions about periprosthetic joint infections (PJI) of the hip and knee. METHODS: Twenty-seven questions from the 2018 International Consensus Meeting on Musculoskeletal Infection were selected for response generation. The free-text responses were evaluated by three orthopedic surgeons using a five-point Likert scale. Inter-rater reliability (IRR) was assessed via Fleiss' kappa (FK). RESULTS: Overall, near-perfect IRR was found for disagreement on the presence of factual errors (FK: 0.880, 95% CI [0.724, 1.035], p < 0.001) and agreement on information completeness (FK: 0.848, 95% CI [0.699, 0.996], p < 0.001). Substantial IRR was observed for disagreement on misleading information (FK: 0.743, 95% CI [0.601, 0.886], p < 0.001) and agreement on suitability for patients (FK: 0.627, 95% CI [0.478, 0.776], p < 0.001). Moderate IRR was observed for agreement on "up-to-dateness" (FK: 0.584, 95% CI [0.434, 0.734], p < 0.001) and suitability for orthopedic surgeons (FK: 0.505, 95% CI [0.383, 0.628], p < 0.001). Question- and subtopic-specific analysis revealed diverse IRR levels ranging from near-perfect to poor. CONCLUSIONS: ChatGPT's free-text responses to complex orthopedic questions were predominantly reliable and useful for orthopedic surgeons and patients. Given variations in performance by question and subtopic, consulting additional sources and exercising careful interpretation should be emphasized for reliable medical decision-making.

Local Periarticular Infiltration with Dexmedetomidine Results in Superior Patient Well-Being after Total Knee Arthroplasty Compared with Peripheral Nerve Blocks: A Randomized Controlled Clinical Trial with a Follow-Up of Two Years.

BACKGROUND: This study aimed to compare local periarticular infiltration (LIA) with ultra-sound guided regional anesthesia (USRA) with ropivacaine and dexmedetomidine as an additive agent in primary total knee arthroplasty (TKA). METHODS: Fifty patients were randomized into two groups in a 1:1 ratio. Patients in the LIA group received local periarticular infiltration into the knee joint. The USRA group received two single-shot USRA blocks. Functional outcomes and satisfaction (range of movement, Knee Society Knee Score, Western Ontario and McMaster Universities Osteoarthritis Index, Oxford Knee Score, and Forgotten Joint Score), including well-being, were analyzed preoperatively and at five days, six weeks, and one and two years postoperatively. RESULTS: Functional outcomes did not significantly differ between the two groups at six weeks and one and two years after the implementation of TKA. A moderate correlation was observed in the LIA group regarding well-being and pain on day five. Six weeks postoperatively, the LIA group showed significantly superior well-being but worse pain scores. No differences between the groups in well-being and functional outcomes could be observed one and two years postoperatively. CONCLUSION: Patients treated with LIA had superior postoperative well-being in the early postoperative phase of up to six weeks. Furthermore, LIA patients had similar functionality compared to patients treated with USRA but experienced significantly more pain six weeks postoperatively. LIA leads to improved short-term well-being, which is potentially beneficial for faster knee recovery. We believe that LIA benefits fast-track knee recovery with respect to improved short-term well-being, higher practicability, and faster application.

Reoperation Rate of Internal Fixation for Femoral Neck Fractures in the Elderly - A Retrospective Follow-Up Study in 116 Patients With an Exploration of Risk Factors.

Aim: Internal fixation of femoral neck fractures is a widely used procedure that is comparatively less invasive and faster than hip replacement. While head preserving internal fixation of these fractures are still preferred where feasible, a faster recovery and lower reoperation rates make arthroplasty increasingly more appealing, in spite of being a more invasive option. Our aim was to determine the reoperation rate after internal fixation at our institution and to explore relevant risk factors in a geriatric population. Methods: This monocentric follow-up study was conducted analyzing 116 patients aged 65 and older with femoral neck fractures who were surgically treated with either cancellous screws or dynamic hip screws between 2010 and 2017. We retrospectively collected longitudinal data from our patient database, supplemented by a telephone survey, with a follow-up period of at least 18 months. Results: Twenty reoperations, due to either a failure of fixation, avascular necrosis, or posttraumatic osteoarthritis, were identified in our cohort, which constituted a reoperation rate of 17.2% (20/116). Fracture displacement was significantly associated with the reoperation risk (HR 8, CI 3-20; P < .001). The reoperation rate was 52.2% in displaced fractures vs 8.9% in undisplaced fractures. No link was found between the reoperation rate and gender, age, BMI, ASA score, type of implant, quality of internal fixation, type of living accommodation, and pre-fracture mobility. Conclusion: Internal fixation has been found to be an effective option in elderly patients with undisplaced fractures regardless of their specific age, cognitive ability or physical condition. In displaced fractures the reoperation rate was found to be high, therefore a primary hip replacement should be recommended.

Smokers have increased risk of soft-tissue complications following primary elective TKA.

INTRODUCTION: Smoking has been associated with numerous adverse outcomes following surgical procedures. The purpose of this study was to investigate, whether smoking status at time of surgery influences the outcome of primary TKA. MATERIALS AND METHODS: Six hundred and eighty-one patients who underwent primary TKA between 2003 and 2006 were included in the study. Smoking status was defined as current, former, and never smoker. Complications leading to revisions were assessed until 17 years of follow-up. Functional outcome was evaluated using clinical scores: Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Visual Analogue Scale (VAS) for pain, Short Form-12 Physical and Mental Component Summaries (SF-12PCS/MCS), and Knee Society Function and Knee Score (KSFS and KSKS). RESULTS: At a mean follow-up of 95 months (± 47 months), 124 complications led to revision surgery. Soft-tissue complications (OR, 2.35 [95% CI 1.08-5.11]; p = 0.032), hematoma formation (OR, 5.37 [95% CI 1.01-28.49]; p = 0.048), and restricted movement (OR, 3.51 [95% CI 1.25-9.84]; p = 0.017) were more likely to occur in current smokers than never smokers. Current smokers were more likely to score higher at KSFS (p < 0.001) and SF-12PCS (p = 0.0197) compared to never smokers. For overall revision, differences were noted. CONCLUSION: Current smoking increases risk of soft-tissue complications and revision after primary TKA, especially due to hematoma and restricted movement. Smoking cessation programs could reduce the risk of revision surgery.

The use of an individualized intraoperative video shows no impact on the early postoperative clinical outcome after total knee arthroplasty: a prospective, randomized, controlled trial.

PURPOSE: The purpose of the study was to evaluate the potential of an intraoperatively recorded video shown to patients immediately postoperatively on early outcome after total knee arthroplasty (TKA). The hypothesis was that there is a beneficial outcome concerning range of motion (ROM) and patient-reported outcome due to enhanced trust into the artificial joint. METHODS: Seventy-three patients were randomly assigned 1:1 to two study groups in which they were either shown a video of their own postoperative range of motion or they were not. Clinically, the New Knee Society Score (nKSS) and ROM were evaluated and compared between the groups 6 weeks after surgery. Chi-square exact test, Kolmogorov-Smirnov test, Mann-Whitney U test, and the Wilcoxon signed rank test were used. Inter- and intra-class correlations were calculated for measurements of ROM. RESULTS: No clinically relevant differences were observed preoperatively and 6 weeks postoperatively between both groups in range of motion (ROM). All patients were showing a significantly improved clinical outcome 6 weeks after the procedure. Clinical scores showed statistically significant differences with respect to preoperative nKSS for satisfaction and statistically significant differences with respect to postoperative nKSS for function. CONCLUSION: Showing a video filmed immediately after implantation of primary TKA had no significant effect on ROM and clinical outcome at 6 weeks. We believe that face-to-face verbal communication in combination with video-assisted education ensures that patients understand their artificial joint in the best possible way and will continue to use intraoperatively filmed videos to enhance patient engagement during postoperative rehabilitation. LEVEL OF EVIDENCE: I.

Higher use of fixed-bearing over mobile-bearing and posterior-stabilized over medial pivot designs in total knee arthroplasty (TKA): a systematic comparative analysis using worldwide arthroplasty registers from England and Wales, Australia, Norway, New Zealand, Germany and Switzerland.

INTRODUCTION: The aim of this study was to compare the use of mobile-bearing, fixed-bearing, posterior-stabilized (PS) and medial pivot design to describe epidemiological differences and subsequent outcomes. MATERIALS AND METHODS: A systematic literature search was performed using the NORE website to identify the relevant arthroplasty registers. Inclusion criteria were the following: (1) reports had to be publicly available, (2) reports had to be written in German or English language, (3) differentiation between mobile- and fixed-bearing, posterior-stabilized, and if possible, medial pivot designs had to be possible from the present reports, and (4) data had to be reported for at least three consecutive years and the latest report had to be from the year 2020 to retrieve recent data. RESULTS: Six registries (England and Wales, Australia, Norway, New Zealand, Germany, Switzerland) offered sufficient data according to the inclusion criteria. In all countries, the dominant type of bearing used for total knee arthroplasty (TKA) was fixed-bearing, with percentages ranging from 60.8% to 84.1% in 2018, 63.6% to 85.7% in 2019 and 66.2% to 87.4% in 2020. A large variation was observed concerning mobile-bearing design, which showed a range from 2.8% to 39.2% in 2018, 2.6% to 36.4% in 2019 and 2.9% to 33.8% in 2020. Some variation was found regarding the use of PS TKA, as its percentage frequency ranged from 9.7% to 29.2% in 2018, 9.8% to 29.4% in 2019 and 10.1% to 28.5% in 2020. Medial pivot design had a share of 9.1% in 2018, 8.6% in 2019 and 8.4% in 2020 in Australia, while it only accounted for 1.4% in 2018, 2.1% in 2019 and 2.5% in 2020 in Germany. CONCLUSION: The comparison of arthroplasty registers from England and Wales, Australia, Norway, New Zealand, Germany and Switzerland revealed large differences regarding the application of posterior-stabilized designs, but also common ground considering the overwhelming use of fixed-bearing inserts, which, when inserted correctly, eradicate the potential complication of bearing dislocation. Arthroplasty registers offer a real-world clinical perspective with the aim to improve quality and patient safety.

Sexual activity after short-stem total hip arthroplasty. Does stem size matter?

BACKGROUND: Sexual activity is an important component of quality of life. To date, no studies have examined the impact of stem design on return to sexual activity (RTS) and quality of sex life after total hip arthroplasty (THA). METHODS: A questionnaire was designed to assess preoperative and postoperative sexual habits, joint awareness and physical activity in working-age patients undergoing short-stem (n = 176) or straight-stem (n = 97) THA. RESULTS: No differences were noted in time until RTS based on the stem design (short stems vs. straight stems; 6 [IQR: 4-10] vs. 6 [4-10] weeks; p = 0.996). Multivariate analysis revealed that higher patient BMI (p = 0.04), female gender (p < 0.001) and lower FJS-12 (p = 0.006) were significantly associated with delayed RTS. Improved hip mobility and reduced pain mainly contribute to improved quality of sexual activity postoperatively. CONCLUSION: This study, hence, indicates that stem design has no impact on time until resumption of sexual activity in patients < 65 years. Female obese individuals who are aware of their artificial joint in daily life are at increased risk of delayed RTS after surgery. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Patients successfully lose body weight after primary total knee arthroplasty but not more than a matched general population.

INTRODUCTION: High BMI is associated with increased risk for knee osteoarthritis, ultimately necessitating total knee arthroplasty (TKA). The aim of this retrospective study was to (1) analyse the amount of postoperative long-term weight loss as reflected by BMI change in TKA patients, (2) identify factors associated with increased change in BMI, and to (3) compare changes with BMI trends of a general population. MATERIALS AND METHODS: Overall, 298 TKA patients [198 females; mean age: 65.1 ± 7.9 years, median follow-up 8.8 (interquartile range: 5.9-10.8 years)] were included in the final evaluation and compared with an age group-matched control group from the general population regarding weight trends between 2006 and 2014. Main variable of interest in both cohorts was body mass index (BMI). Linear regression analyses were performed to assess changes in weight and BMI over time between TKA patients and the general population. Furthermore, mixed linear-effects models were constructed to analyse the potential change in BMI independent from age and gender. RESULTS: In TKA patients, a significant drop in BMI by 0.8 ± 3.2 points from postoperative to final follow-up was observed (p < 0.001), with reduction being significant independently from age (p = 0.382), gender (p = 0.310), or revision surgery (p = 0.195). In the general population, likewise a significant BMI-decrease by 0.7 ± 6.1 points was observed between 2006 and 2014, with younger people (p = 0.004) and females (p < 0.001) being more likely to reduce BMI. Yet, BMI-decrease between TKA patients and the general population over time was comparable (p = 0.734). Notably, patients with initially higher BMI were significantly more likely to lose weight postoperatively than normal-weight patients (p < 0.001). CONCLUSIONS: Our results point against the notion that TKA patients lose a considerable amount of weight in comparison to the general population as soon as improved joint function and pain relief have been achieved. Thus, individualized patient education programmes should be reinforced, promoting a healthy lifestyle.

Impact of the COVID-19 pandemic on early clinical outcome after total knee arthroplasty: a retrospective comparative analysis.

INTRODUCTION: To help combat the SARS-CoV-2 (COVID-19) pandemic, elective inpatient procedures have been reduced. The authors hypothesized that a nationwide lockdown would negatively affect the postoperative outcome after total knee arthroplasty (TKA) due to reduced physiotherapy as well as restrictions in external facilities of physiotherapy and rehabilitation. MATERIALS AND METHODS: We conducted a retrospective, comparative study including 41 patients who had undergone primary TKA during the first lockdown of the COVID-19 pandemic from March 2020 to April 2020 and a comparable control group consisting of 47 patients with a minimum follow-up of 6 months before the COVID-19 pandemic from 2019. Relevant end points were the visual analogue scale (VAS) for pain, Knee Society Function Score (KSS), Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and range of motion (ROM). RESULTS: The lockdown group had a significantly worse outcome compared to the control group 6 months after TKA regarding WOMAC (p = 0.001), KSS (p < 0.001), OKS (p < 0.001), and length of hospital stay (p < 0.001). We found no statistically significant difference between the groups in ROM (p = 0.132), KSFS (p = 0.933), VAS at rest (p = 0.9.22), and exercise (p = 0.304). CONCLUSION: The COVID-19 pandemic negatively affected early clinical outcome parameters of elective primary TKA at 6 months of follow-up due to restrictions in postoperative care. We believe that standardized protocols for physiotherapy will improve clinical outcomes for TKA in the event of future lockdowns and underline the importance of appropriate postoperative care during this pandemic.

Mobile bearing versus fixed bearing medial unicompartmental knee replacement: an independent two center matched-pairs analysis.

INTRODUCTION: The aim of the present study was to compare clinical outcome between patients following fixed-bearing (FB) or mobile-bearing (MB) unicompartmental knee replacement (UKR) for antero-medial knee osteoarthrosis (OA) at two independent orthopedic centers. MATERIALS AND METHODS: Matched-pairs were built between 35 patients receiving FB-UKR and 52 patients following MB-UKR regarding age at time of surgery, body mass index (BMI) and range of motion (ROM) preoperatively. Clinical and functional outcome was measured postoperatively by the American Knee Society Score (AKSS-O/AKSS-F), ROM, Tegner Activity Scale (TAS) as well as the Short Form 36 Health Survey (SF-36). RESULTS: The average treatment effect of the treated (ATT) after propensity score matching showed a significantly superior ROM in patients following MB-UKR (FB: 118°, MB: 124°). All remaining parameters had no statistically significant differences between both groups involving TAS, AKSS and SF-36. CONCLUSIONS: The present study suggests that MB-UKR can provide a greater ROM compared to FB-UKR on comparable patients. The authors believe that both designs are suitable for adequate improvement of clinical outcome and ROM for patients suffering from antero-medial osteoarthrosis of the knee joint. LEVEL OF EVIDENCE: Retrospective cohort study, Level IV.

No difference in clinical outcome, pain, and range of motion between fixed and mobile bearing Attune total knee arthroplasty: a prospective single-center trial.

BACKGROUND: Despite numerous scientific investigations, the tribological advantages of mobile bearing inserts have not been sustainably confirmed or refuted for modern knee prostheses in clinical studies. The purpose of this study was to compare fixed and mobile bearing inserts in order to draw conclusions regarding clinical benefits. METHODS: The present prospective single center cohort study of 2 non-randomized stratified groups consisted of 67 patients. All included patients received cemented total knee arthroplasty (Attune®) due to osteoarthritis. 34 patients were treated with a mobile and 33 patients with a fixed insert. The WOMAC score and the Visual Analogue Scale was used for the subjective assessment of success, while the Knee-Society-Score was used considering the Range of Motion for the objective assessment. The subjective and the clinical scores showed improvements for both compared groups postoperatively at 2 years of minimum follow-up. RESULTS: The overall postoperative results of the WOMAC score, the Knee-Society-Score and the Visual Analogue Scale presented no statistically difference between the compared groups (p > 0,05). The postoperative ROM showed a superior improvement of 13.2° ± 18.4° in the mobile-bearing group versus 4.9° ± 18.4° (p = 0.017) in the fixed-bearing group. The flexion of the knee joint was 114° ± 10.1° for the mobile-bearings and 109.2° ± 7.2° for fixed bearings (p = 0.012). CONCLUSION: According to the findings, both inserts showed overall promising postoperative results, in terms of objective as well as subjective parameters, without clinically relevant significant differences, except for ROM, which was superior in the mobile bearing group. The present clinical trial has been registered at the ISRCTN registry with the reverence number ISRCTN15117998 on 04/04/2022.

Revision Rates After Total Ankle Replacement: A Comparison of Clinical Studies and Arthroplasty Registers.

BACKGROUND: The aim of this study was to assess the outcome of total ankle replacement (TAR) regarding revision rates by comparing clinical studies of the last decade to data displayed in arthroplasty registers. The secondary aim was to evaluate whether dependent clinical studies show a superior outcome to independent publications. Additionally, revision rates of mobile bearing implants (MB-TARs) were compared to those of fixed bearing implants (FB-TARs). METHODS: Clinical studies on TARs between 2010 and 2020 were systematically reviewed, with the endpoint being a revision for any reason. The parameter "revision rate per 100 observed component years (CYs)" was calculated for each publication. The pooled revision rate for clinical studies was compared to the data reported in arthroplasty registers. In a second step, revision rates were subdivided and analyzed for independent and dependent publications and for FB-TARs and MB-TARs. RESULTS: A total of 43 publications met the inclusion criteria comprising 5806 TARs. A revision rate of 1.8 per 100 observed CYs was calculated, corresponding to a 7-year revision rate of 12.6%. The 3 arthroplasty registers included showed revision rates ranging from 8.2% to 12.3% after 7 years. No significant difference between dependent and independent publications nor between FB-TARs and MB-TARs was detected. CONCLUSION: Revision rates of clinical studies and arthroplasty registers are comparable. Surgeons can compare their own revision rates with those from this study. Dependent studies do not seem to be biased, and no superiority for one bearing type can be described. LEVEL OF EVIDENCE: Level III, systematic review of level III studies.

Short-stem total hip arthroplasty is not associated with an earlier return to work compared to a straight-stem design.

Return to work (RTW) has been specifically identified as a high priority in patients undergoing total hip arthroplasty (THA). This investigation sought to assess the effect of the stem design on patients' RTW. Secondly, the study aimed to identify risk factors that lead to a delayed RTW. Questionnaires inquiring about RTW, employment history, educational level, type of work, physical demands and joint awareness were administered by post. Further data were collected from patients' hospital records. 176 patients who underwent THA using a short-stem and 97 patients using a straight-stem design were compared. The median return to work time was 10 weeks [IQR 7-14 weeks], with no significant difference between the two groups (short stems vs. straight stems; 10 [IQR 7-14] vs. 11 [7.5-13.5] weeks; p = 0.693). In the multivariate linear regression analysis, self-employment vs. employee (p = 0.001), dimension of preoperative workload (p = 0.001), preoperative sick leave (p < 0.001), and hospital length of stay (LOS) (p < 0.001) independently affected the period until work was resumed. The Forgotten-Joint-Score-12 showed no significant difference between the two groups. The data show that the majority of THA patients can expect to resume work and stem design has no impact on RTW. Employees with preoperative sick leave, prolonged hospital LOS and low workload are at higher risk for a delayed RTW.