This study aimed to examine surgical trends in knee arthroplasty over past 18 years and identify the factors associated with risk of revision surgeries following total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) in South Korea.

This study was conducted using National Health Insurance Service - National Sample Cohort database, approximately 1 million individuals from 2002 to 2019. We analyzed general trends and procedural rates of knee arthroplasty, stratified by age, location of residence, and hospital size. Additionally, we investigated the risk factors of knee arthroplasty failure in UKA and TKA.

The average age of the 15,395 individuals who underwent UKA (n = 664) or TKA (n = 14,731) was 69.8 years (standard deviation 7.2), and 77.3% were women. In TKA, occurrence increased by approximately 4.9 times from 2002 to 2010 and by 1.5 times 2010 onward. In contrast, the number of UKA procedures did not increase until 2008, after which it increased 6.1-fold by 2019. An increasing trend in TKA procedures was observed among individuals aged 70-79 and >80 years, whereas the UKA procedural rates increased across all age groups. The revision rate was higher in UKA than that in TKA (13.7% vs. 2.8%). The risk factors were younger age, diabetes mellitus for TKA, and osteoporosis for UKA.

Unlike that of TKA, procedural rate increment of UKA occurred in younger people recently and featured a considerably higher revision rate. Given that UKA has a higher revision rate and different risk factors than TKA, monitoring should be tailored specifically for each procedure.

The aim of this study was to determine the lifetime risk of revision surgery after primary knee arthroplasty (KA) according to implant choice and patient age.

The risk of revision according to the implant type (unicondylar, unconstrained, semiconstrained, and fully constrained) was obtained from the National Joint Registry of England and Wales. Mortality risk according to age was estimated from the Scottish Arthroplasty Project (1998 to 2019). The cumulative incidence of revision and death was calculated up to 20 years. The lifetime risk was calculated as a percentage using a multiple decrement life-table methodology.

The lifetime risk of revision varied according to the implant, with unconstrained having the lowest risk and fully constrained and unicondylar having the highest risks, which increased with younger age. For an "average" patient aged between 65 and 69 years, the revision risks for an unconstrained (3.6%, 95% confidence interval [CI] 3.4 to 3.9), semiconstrained (7.2%, 95% CI 3.9 to 13.6), unicondylar (13.7%, 95% CI 12.4 to 15.2), and fully constrained (15.4%, 95% CI 9.2 to 25.7) total KA gradually increased. Relative to an unconstrained KA, the risk of revision for a semiconstrained implant was similar in patients aged < 65 years (relative risk < 2), whereas when this was employed in those ≥ 65 years, the relative risk was more than double (relative risk ≥ 2). Relative to an unconstrained KA, the risk of revision for a fully constrained or a unicondylar KA was more than double in patients aged < 55 years (relative risk > 2) and more than triple (relative risk ≥ 3) in patients ≥ 55 years CONCLUSION: The estimated lifetime risk of revision following KA was dependent on patient age and implant type, with fully constrained and unicondylar KA being associated with a higher lifetime revision risk. There are limitations in the data, and the indication for surgery and the reasons for revision were not assessed.

III.

The surgical options for patients with osteoarthritis (OA) of the patellofemoral joint (PFJ) involve a patellofemoral joint arthroplasty (PFA) or a total knee arthroplasy (TKA). The aim of this study was to describe and compare the safety profile and risk of revision of these two procedures.

The records of patients from the UK National Joint Registry who underwent PFA or TKA between April 2003 and December 2021 were linked to the Hospital Episode Statistics database. Using Poisson regression, a 30-day safety profile was created by plotting risk ratios, absolute risk, and the differences in risk of myocardial infarction, respiratory tract infection, urinary tract infection (UTI), stroke, delirium, deep vein thrombosis/pulmonary embolism (DVT/PE), wound infection, and death. A parametric survival model was used to model the survival of a PFA compared with a TKA over the course of the postoperative time period. Differences in hazard ratios were plotted by sex for PFA. Confounding was handled by inverse proportional treatment weighting. The indications for revision and the length of stay in hospital were compared between the procedures.

A total of 7,819 PFAs and 662,141 TKAs were analyzed. Patients who underwnt PFA were significantly less likely to have complications than those who underwent TKA: respiratory tract infection (risk ratio (RR) 0.65 (95% CI 0.47 to 0.90); p = 0.011), DVT/PE (RR 0.35 (95% CI 0.24 to 0.52); p < 0.001), UTI (RR 0.59 (95% CI 0.40 to 0.88); p = 0.001), wound infection (RR 0.73 (95% CI 0.57 to 0.91); p = 0.006), and death within 30 days postoperatively (RR 0.36 (95% CI 0.14 to 0.98); p = 0.045). Over ten years, PFAs had an 85% survival (95% CI 0.84 to 0.86) and TKAs had a 95% survival (95% CI 0.95 to 0.96). Within two years, the indication for revision of a PFA was most likely to be pain, while infection was the most common indication for revision of a TKA at this time.

PFA may be a safer procedure than TKA, being less likely to have complications, with a reduced length of stay. Despite an increased risk of revision, patients should still be counselled about the advantages of undergoing a PFA.

 Pooling data on the performance of total knee (TK) implants across registries is only possible if the same TK implant is used across multiple registries and if used in patients with similar characteristics. We assessed to what extent specific TK implants: (i) are used across multiple registries or only in a single registry; and (ii) differ in patient characteristics between registries.

 All primary TK implants implanted between January 2020 and December 2021 in the Danish, Dutch, German, and Italian registries were included. We determined the number of registries using a specific TK implant (based on combined femoral-tibial component brand name and fixation/congruency/mobile bearing insert/patella usage). Patient characteristics (age/body mass index [BMI]/sex/diagnosis osteoarthritis) were compared across registries for TK implants used in ≥ 2 registries ≥ 100 times.

 813 different TK implants (577,351 procedures) were used across the 4 registries, of which 53 TK implants (7%) were used in 1 registry (8,000 procedures). 760 different TK implants (569,351 procedures; 99%) were used in ≥ 2 registries of which 47 different TK implants (393,954 procedures; 68%) were used in ≥ 2 registries and ≥ 100 times. Statistically and clinically significant differences in age for the same TK implant across registries were observed for 29 TK implants (62%) and 3 TK implants (6%), respectively; for other characteristics these were for BMI 30 (64%) and 0 (0%) TK implants; for male proportion 23 (49%) and 17 (36%) TK implants; and for diagnosis of osteoarthritis 42 (89%) and 34 (72%) TK implants, respectively.

 Most specific TK implants and TK procedures were used across multiple registries, but they were often used in patients with different characteristics. This has an impact on comparing implant performances between registries.

Conversion of arthrodesis to total knee arthroplasty (TKA) is technically demanding surgical procedure. In the literature, most cases are treated with stemmed semi-constrained or hinged prostheses. We present a case of a robotic-assisted conversion of arthrodesis to primary TKA (rTKA) in a 35-year-old patient using a non-constrained posterior stabilized implant. At follow-up, the patient reported outcomes improved remarkably with the highest increase for function and activities of daily living and a substantial improvement of health-related quality of life. This article is the first report of robotic-assisted conversion of arthrodesis to TKA using a non-constrained implant, thus it may serve as a proof of concept for the use of robotics for desarthrodesis. Future studies are warranted to investigate the long-term outcomes in a larger patient cohort.

Anterior cruciate ligament (ACL) ruptures are a potent risk factor for post-traumatic knee osteoarthritis (PTOA). Annually, in Aotearoa New Zealand, approximately 2,500 people under the age of 30 undergo ACL reconstruction surgery. Due to the young age of injury and surgery, many develop osteoarthritis before age 50 and have a higher likelihood of requiring total knee replacement compared to the general population. This study aimed to gain insight into the medium- to long-term impacts of ACL rupture on people's well-being in Aotearoa New Zealand, by exploring their lived experiences five or more years post-injury.

In this Interpretive Description observational study, we conducted semi-structured interviews with people who had ruptured their ACL and had or were at risk of developing PTOA. Analysis was conducted guided by Braun and Clarke's Reflexive Thematic Analysis.

Twelve people (7 women, median age 49.5 [25-62] years) were interviewed. Three themes were generated from the data: 1) Nobody Ever Told Me…, 2) The Post-Rehabilitation Void, and 3) The Elephant in the Room: The Psychosocial Impact. Participants commonly described fear, grief and long-term psychological impacts, and most reported wanting to know more about the long-term management of their knees.

The study highlights opportunities to provide better long-term support and management, improve outcomes, and reduce the burden on these individuals. ACL injury can profoundly impact people's lives in the long term. Better education, support services, and consideration of psychosocial factors are needed. Addressing identified barriers could reduce the individual and socioeconomic burden of PTOA for New Zealanders. Future research involving stakeholders must establish acceptable long-term management programmes tailored to ensure they meet the population's needs and address the unique socioeconomic context and ethnic disparities in Aotearoa New Zealand.

Cementless total knee arthroplasty (TKA) is rising in popularity. The literature supporting its use over cemented TKA remains sparse. Using the Canadian Joint Replacement Registry (CJRR), we sought to investigate cementless versus cemented fixation in modern primary TKA and (1) determine whether there is an overall difference in revision by fixation, (2) perform a subanalysis of the most-commonly used cementless TKA brand in Canada, and (3) identify the reasons for revision.

The CJRR data was used to analyze TKA designs with cemented and cementless versions. Revision risk is reported as all-cause cumulative percent revision (CPR). Reasons for revision were analyzed. Cox proportional hazards models were used to report adjusted hazard ratios (HR) controlling for age, sex, patella resurfacing, and bearing constraints. We included 202,880 primary TKAs performed between 2012 and 2021. Of those, 9,163 (4.5%) were cementless.

The CPR at 8 years was 4.49% for cementless and 3.14% for cemented implants. After adjusting for confounders, we did not detect a difference in revision risk overall (HR 0.87 [95% CI (confidence interval) 0.73 to 1.04], P = 0.128). However, the most commonly used cementless TKA brand demonstrated a CPR of 1.95% compared to 2.19% for its cemented version at 4 years. Furthermore, we detected a significantly lower revision risk compared to its cemented version after adjusting for confounders (HR 0.66 [95% CI 0.51 to 0.85], P = 0.001). The 4 most common reasons for revision in both groups were the following: (1) infection, (2) instability, (3) aseptic loosening, and (4) pain of unknown origin.

Using CJRR data adjusted for confounding factors, no difference in revision risk was detected between cemented and cementless implants overall. However, for the most common brand of cementless TKA used in Canada, there was a lower risk of revision than its corresponding cemented version. The reasons for revision were similar.

This multicentre retrospective observational study's aims were to investigate whether there are differences in the occurrence of radiolucent lines (RLLs) following total knee arthroplasty (TKA) between the conventional Attune baseplate and its successor, the novel Attune S+, independent from other potentially influencing factors; and whether tibial baseplate design and presence of RLLs are associated with differing risk of revision.

A total of 780 patients (39% male; median age 70.7 years (IQR 62.0 to 77.2)) underwent cemented TKA using the Attune Knee System) at five centres, and with the latest radiograph available for the evaluation of RLL at between six and 36 months from surgery. Univariate and multivariate logistic regression models were performed to assess associations between patient and implant-associated factors on the presence of tibial and femoral RLLs. Differences in revision risk depending on RLLs and tibial baseplate design were investigated with the log-rank test.

The conventional and novel Attune baseplates were used in 349 (45%) and 431 (55%) patients, respectively. At a median follow-up of 14 months (IQR 11 to 25), RLLs were present in 29% (n = 228/777) and 15% (n = 116/776) of the tibial and femoral components, respectively, and were more common in the conventional compared to the novel baseplate. The novel baseplate was independently associated with a lower incidence of tibial and femoral RLLs (both regardless of age, sex, BMI, and time to radiograph). One- and three-year revision risk was 1% (95% CI 0.4% to 1.9%)and 6% (95% CI 2.6% to 13.2%), respectively. There was no difference between baseplate design and the presence of RLLs on the the risk of revision at short-term follow-up.

The overall incidence of RLLs, as well as the incidence of tibial and femoral RLLs, was lower with the novel compared to the conventional tibial Attune baseplate design, but higher than in the predecessor design and other commonly used TKA systems.

Optimal timing of knee arthroplasty (KA) is complex: operating at a younger age increases life time risk of revision, while delay results in an increased risk of job loss. This study evaluates whether disability benefits recipients due to knee osteoarthritis have an increased odds of returning to work (RTW) following KA.

A retrospective cohort study was performed among long-term disability benefits recipients due to knee osteoarthritis using data of the Dutch Employee Insurance Agency. Logistic regression assessed whether recipients with KA had a higher odds of RTW in 10 years following start of disability benefits, compared to those without KA.

A total of 159 participants were included. During 10-year follow up, 42% had received KA and 37% had returned to work. No association was observed between KA and RTW (OR 1.39, 95% CI 0.62-3.12). Prognostic factors for RTW were being the main breadwinner (OR 7.93, 95% CI 2.95-21.32) and classification as 100% work disability (OR 0.20, 95% CI 0.09-0.45).

KA has no beneficial effect on RTW among patients with knee osteoarthritis granted long-term disability in the Netherlands. For RTW, KA is probably best performed within the two years of paid sick leave before long-term disability is assessed in the Netherlands.

The implantation rate of total knee arthroplasties (TKA) is continuously growing. Aseptic problems are a major cause of revision. The aim of the following study was to determinate the incidence of aseptic revisions in primary knee arthroplasty as well as aseptic revision rates and influencing factors according to the patients' age and type of procedure.

Data collection was performed using the German Arthroplasty Registry. Influencing factors were analyzed according to the patients' age and type of procedure. Risk factors were calculated using multiple Log-rank test with the Holm's method. Incidence and comparison of aseptic revisions according to the patients' age and type of procedure were analyzed using Kaplan-Meier-estimates. Cox regression was applied to calculate the hazard ratio.

Overall, 300,998 knee arthroplasties with 254,144 (84.4%) unconstrained TKA, 9,993 (3.3%) constrained TKA and 36,861 (12.3%) unicondylar knee arthroplasties (UKA) were analyzed. Patients younger than 65 years suffered a significantly higher aseptic revision rate than older patients (p < 0.0001). After one year, a revision rate of 1.1% was recorded for patients 65-74 years, 1.6% for patients under 65 years, and 1.3% for patients beyond 74 years. After seven years, patients younger than 65 years sustained in 5.0%, patients 65-74 years in 2.9% and patients beyond 74 years in 2.4% revision. In unconstrained TKA, an increased Elixhauser-score (HR = 1,75; HR = 1,54; HR = 1,7; p < 0,001) was a risk factor regardless the age. A TKA volume of 101-250 regardless the age (HR = 0,66; HR = 0,69; HR = 0,79) and > 250 under 75 years (< 65: HR = 0,72; 65-74: HR = 0,78; p = 0,001) were protective for aseptic revision. In UKA, male gender (HR = 0,81; HR = 0,72; HR = 0,57; p < 0,001), a UKA volume ≥ 51 for patients under 75 years (< 65: HR = 0,62; 65-74: HR = 0,59; p = 0,003) as well as cemented UKA for patients younger than 75 years (< 65: HR = 0,37; 65-74: HR = 0,37; p < 0,001) were detected as preventive factors.

A significant increased rate of aseptic revisions was reported for patients younger than 65 years compared to older patients. An increased Elixhauser score was a risk factor, whereas male and a high volume of performed UKA or TKA could be identified as preventive factors.

III, cohort study.

Growing numbers of younger patients are electing to undergo total knee arthroplasty (TKA) for end-stage osteoarthritis. The purpose of this study was to compare established literature regarding TKA outcomes in patients under age 55, to data from an ongoing longitudinal young patient cohort curated by our study group. Further, we aimed to provide a novel update on survivorship at 40 years post-TKA from our longitudinal cohort.

A literature search was conducted using the electronic databases PubMed, Embase, and Cochrane Library, using terms related to TKA, patients under age 55, and osteoarthritis. Demographic and outcome data were extracted from all studies that met the inclusion criteria. Data were divided into the "longitudinal study (LS) group," and the "literature review (LR) group" based on the patient population of the study from which it came.

After screening, 10 studies met the inclusion criteria; 6 studies comprised the LR group, and 4 studies comprised the LS group. 2613 TKAs were performed among the LR group, and 114 TKAs were longitudinally followed in the LS group. The mean patient ages of the LR and LS groups were 46.1 and 51, respectively. Mean follow-up was 10.1 years for the LR group. Mean postoperative range of motion was 113.6° and 114.5° for the LR and LS groups, respectively. All-cause survivorship reported at 10 years or less ranged from 90.6% to 99.0%. The LS cohort studies reported survivorship ranges of 70.1-70.6% and 52.1-65.3% at 30 and 40 years, respectively.

Young TKA patients demonstrated improved functionality at each follow-up time point assessed. Survivorship decreased with increasing lengths of follow-up, ultimately ranging from 52.1-65.3% at 40 years post-TKA. The paucity of literature on long-term TKA outcomes in this patient population reinforces the necessity of further research on this topic.

Age and sex are known demographic risk factors for requiring revision surgery following primary total knee arthroplasty (TKA). Military service members are a unique population with barriers to long-term follow up after surgery. This study aims to compare demographic data between active duty military personnel and a nationwide sample to identify differences that may impact clinical and economic outcomes.

A retrospective observational analysis was performed using the Military Health System Data Repository (MDR) and the National Surgical Quality Improvement Program (NSQIP). Databases were queried for patients undergoing primary TKA between January 1, 2015 and December 31, 2020. The MDR was queried for demographic data including age, sex, duty status, facility type, geographic region, history of prior military deployment, history of deployment-related health condition, branch of military service, and military rank. National Surgical Quality Improvement Program was queried for age and sex. Median age between populations was compared with the Mann-Whitney U test, and gender was compared with a chi-squared test.

During the study period, 2,094 primary TKA patients were identified from the MDR, and 357,865 TKA patients were identified from the NSQIP database. Military TKA patients were 79.4% male with a median age of 49.0, and NSQIP TKA patients were 38.9% were male, with a median age of 67. Military TKA patients were significantly more likely to be male (P < .001) and younger (P < .001).

Patients undergoing TKA in the military are younger and more likely to be male compared to national trends. Current evidence suggests these factors may place them at a significant revision risk in the future. The application of quality metrics based on nationwide demographics may not be applicable to military members within the Military Health System.

As a solution to restore knee function and reduce pain, the demand for Total Knee Arthroplasty (TKA) has dramatically increased in recent decades. The high rates of dissatisfaction and revision makes it crucially important to understand the relationships between surgical factors and post-surgery knee performance. Tibial implant alignment in the sagittal plane (i.e., posterior tibia slope, PTS) is thought to play a key role in quadriceps muscle forces and contact conditions of the joint, but the underlying mechanisms and potential consequences are poorly understood. To address this biomechanical challenge, we developed a subject-specific musculoskeletal model based on the bone anatomy and precise implantation data provided within the CAMS-Knee datasets. Using the novel COMAK algorithm that concurrently optimizes joint kinematics, together with contact mechanics, and muscle and ligament forces, enabled highly accurate estimations of the knee joint biomechanics (RMSE <0.16 BW of joint contact force) throughout level walking and squatting. Once confirmed for accuracy, this baseline modelling framework was then used to systematically explore the influence of PTS on knee joint biomechanics. Our results indicate that PTS can greatly influence tibio-femoral translations (mainly in the anterior-posterior direction), while also suggesting an elevated risk of patellar mal-tracking and instability. Importantly, however, an increased PTS was found to reduce the maximum tibio-femoral contact force and improve efficiency of the quadriceps muscles, while also reducing the patellofemoral contact force (by approximately 1.5% for each additional degree of PTS during walking). This study presents valuable findings regarding the impact of PTS variations on the biomechanics of the TKA joint and thereby provides potential guidance for surgically optimizing implant alignment in the sagittal plane, tailored to the implant design and the individual deficits of each patient.

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.

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.

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.

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.

A successful outcome after total knee arthroplasty (TKA) includes the restoration of patellofemoral function. Modern patella component designs in TKA include a medialized dome and more recently, an anatomic design. There is a paucity of literature comparing these 2 implants.

This prospective nonrandomized study examined 544 consecutive TKAs with patella resurfacing using a posterior-stabilized, rotating platform knee prothesis performed by a single surgeon. A medialized dome patella design was used in the first 323 cases and an anatomic design in the subsequent 221 cases. Patients were assessed preoperatively, at 4 weeks and 1-year post-TKA for Oxford Knee Score (OKS) (total, pain, and kneeling components) and range of movement (ROM). Radiolucent lines (RLLs), patellar tilts and displacements, as well as reoperations were assessed at 1-year post-TKA.

At 1-year post-TKA, both groups demonstrated similar improvements in ROM, OKS, pain, and kneeling scores, and had a similar incidence of fixed-flexion deformity (all P > .05). Radiographically, there was no clinically significant difference in the incidence of RLLs, patellar tilts, and displacements. The prevalence of reoperations (1.8 versus 3.2%, P = .526) was similar between the designs with no patella-related complications.

Both medialized dome and anatomic patella designs result in improved ROM and OKS with no patella-related complications. However, our study showed no differences between the designs at 1 year.

In patients with monocompartmental knee osteoarthritis, unicompartmental knee arthroplasty (UKA) can be performed. This study compared the medial versus lateral UKA in patients with monocompartimental knee arthroplasty. It was hypothesised that both implants achieve a similar outcome in OKS.

The UKAs were fixed-bearing medial PPK (Zimmer-Biomet, Warsaw, Indiana, USA) and fixed-bearing lateral Zuk (Lima Corporate, Udine, Italy). An intraarticular drain was placed and removed on the first postoperative day. Enoxaparin sodium 4000 units subcutaneously daily for 45 days was used as thromboembolic prophylaxis. The Italian version of the OKS was used for the clinical assessment. The following complications were also recorded: anterior knee pain, infection and revision surgeries.

Data from 203 patients were collected. The mean age of the patients was 68.9 ± 6.7 years and the mean BMI was 28.1 ± 4.1 kg/m2. The mean OKS on admission was 22.1 ± 4.5 points. On admission, women, patients older than 70 years, and those with a BMI lower than 28 kg/m2 who underwent lateral UKA evidenced lower OKS. At the last follow-up, 26.7 and 26.9 months for the lateral and medial UKA, respectively, no between groups difference in OKS was evidenced. No patients experienced complications.

Medial and lateral UKA achieve similar outcomes in OKS at a minimum of two years of follow-up.

Implant survival in total shoulder arthroplasty (TSA) is currently defined with reference to a set time period (eg, 5-year implant survival). This is a difficult concept for patients to understand, especially for younger patients who have more years of life remaining. Our study aims to calculate a patient's lifetime revision risk after primary anatomic (aTSA) and reverse (rTSA) total shoulder arthroplasty-a more meaningful projection of revision risk over a patient's remaining lifetime.

The New Zealand Joint Registry (NZJR) and national death data was used to calculate the incidence of revision and mortality in all patients who underwent primary aTSA and rTSA in New Zealand between 1999 and 2021. Lifetime revision risk was calculated using previously described methods, and this risk was stratified by age (46-90 years, 5-year bins), sex, and procedure type (aTSA and rTSA).

In total, there were 4346 patients in the aTSA cohort and 7384 patients in the rTSA cohort. Lifetime revision risk was highest in the youngest age group (46-50 years) at 35.8% (95% CI 34.5%-37.0%) for aTSA and 30.9% (95% CI 29.9%-32.0%) for rTSA, with risk decreasing with increasing age. Across all age groups, the lifetime revision risk was higher for aTSA compared to rTSA. By sex, females reported higher lifetime revision risk for each age group in the aTSA cohort whereas males reported higher lifetime revision risk for each group in the rTSA cohort.

Our study demonstrates that younger patients have higher lifetime revision risk after total shoulder arthroplasty. Our results highlight the long-term revision risks associated with the trend of offering shoulder arthroplasty to younger patients. The data may be used among various health care stakeholders to inform the surgical decision-making process and plan for future health care resource use.

Aseptic loosening is the most common cause of failure following cemented total knee arthroplasty (TKA), and has been linked to poor cementation technique. We aimed to develop a consensus on the optimal technique for component cementation in TKA.

A UK-based, three-round, online modified Delphi Expert Consensus Study was completed focusing on cementation technique in TKA. Experts were identified as having a minimum of five years' consultant experience in the NHS and fulfilling any one of the following criteria: a 'high volume' knee arthroplasty practice (> 150 TKAs per annum) as identified from the National joint Registry of England, Wales, Northern Ireland and the Isle of Man; a senior author of at least five peer reviewed articles related to TKA in the previous five years; a surgeon who is named trainer for a post-certificate of comletion of training fellowship in TKA.

In total, 81 experts (round 1) and 80 experts (round 2 and 3) completed the Delphi Study. Four domains with a total of 24 statements were identified. 100% consensus was reached within the cement preparation, pressurization, and cement curing domains. 90% consensus was reached within the cement application domain. Consensus was not reached with only one statement regarding the handling of cement during initial application to the tibial and/or femoral bone surfaces.

The Cementing Techniques In Knee Surgery (CeTIKS) Delphi consensus study presents comprehensive recommendations on the optimal technique for component cementing in TKA. Expert opinion has a place in the hierarchy of evidence and, until better evidence is available these recommendations should be considered when cementing a TKA.

National projections of future joint arthroplasties are useful in understanding the changing burden of surgery and related outcomes on the health system. The aim of this study is to update the literature by producing Medicare projections for revision total joint arthroplasty procedures from 2040 through 2060.

The study uses 2000-2019 data from the CMS Medicare Part-B National Summary and combines procedure counts using CPT codes for revision total joint arthroplasty procedures. In 2019, revision total knee arthroplasty (rTKA) and revision total hip arthroplasty (rTHA) procedures totaled 53,217 and 30,541, respectively, forming a baseline from which we generated point forecasts between 2020 and 2060 and 95% forecast intervals (FI).

On average, the model projects an annual growth rate of 1.77% for rTHAs and 4.67% for rTKAs. By 2040, rTHAs were projected to be 43,514 (95% FI = 37,429-50,589) and rTKAs were projected to be 115,147 (95% FI = 105,640-125,510). By 2060, rTHAs was projected to be 61,764 (95% FI = 49,927-76,408) and rTKAs were projected to be 286,740 (95% FI = 253,882-323,852).

Based on 2019 total volume counts, the log-linear exponential model forecasts an increase in rTHA procedures of 42% by 2040 and 101% by 2060. Similarly, the estimated increase for rTKA is projected to be 149% by 2040 and 520% by 2060. An accurate projection of future revision procedure demands is important to understand future healthcare utilization and surgeon demand. This finding is only applicable to the Medicare population and demands further analysis for other population groups.

Knee arthrodesis is predominantly a salvage procedure. In present time, knee arthrodesis is mostly considered for cases of unreconstructable failed total knee arthroplasty after prosthetic joint infection or trauma. Knee arthrodesis has shown better functional outcomes than amputation for these patients but has a high complication rate. The purpose of this study was to characterize the acute surgical risk profile of patients undergoing a knee arthrodesis for any indication.

The American College of Surgeons National Surgical Quality Improvement Program database was queried to determine 30-day outcomes after knee arthrodesis between 2005 and 2020. Demographics, clinical risk factors, and postoperative events were analyzed, along with reoperation and readmission rates.

A total of 203 patients that underwent a knee arthrodesis were identified. Forty-eight percent of patients had at least 1 complication. The most common complication was acute surgical blood loss anemia requiring a blood transfusion (38.4%), followed by organ space surgical site infection (4.9%), superficial surgical site infection (2.5%), and deep vein thrombosis (2.5%). Smoking was associated with higher rates of reoperation and readmission (odds ratio 9, P < .01, and odds ratio 6, P < .05).

Overall, knee arthrodesis is a salvage procedure that has a high rate of early postoperative complications and is most often performed in patients at higher risk. Early reoperation is strongly associated with a poor preoperative functional status. Smoking places patients at higher risk of early complications.

Recent publications have drawn attention to the fact that some brands of joint replacement may contain variants which perform significantly worse (or better) than their 'siblings'. As a result, the National Joint Registry has performed much more detailed analysis on the larger families of knee arthroplasties in order to identify exactly where these differences may be present and may hitherto have remained hidden. The analysis of the Nexgen knee arthroplasty brand identified that some posterior-stabilized combinations have particularly high revision rates for aseptic loosening of the tibia, and consequently a medical device recall has been issued for the Nexgen 'option' tibial component which was implicated. More elaborate signal detection is required in order to identify such variation in results in a routine fashion if patients are to be protected from such variation in outcomes between closely related implant types.

Ceramic coatings in total knee arthroplasty have been introduced with the aim of reducing wear and consequently improving implant survivorship. We studied both cobalt-chrome-molybdenum (CoCrMo) and ceramic-coated components of the same implant design from a single center to identify if the ceramic coating conferred any benefit.

We identified 1641 Columbus total knee arthroplasties (Aesculap AG, Tüttlingen, Germany) from a prospectively collected arthroplasty database. Of the 1641, 983 were traditional CoCrMo, and 659 had the Columbus AS ceramic coating. Patients were followed up until death or revision of any component of the implant.

There was no significant difference in implant survivorship using any component revision as the endpoint between the CoCrMo femur and the ceramic-coated femur at a mean of 9.2 years in follow-up for the CoCrMo group and 5 years for the ceramic-coated group (37 vs 14; P = .76). There was no reduction in the proportion of components revised for aseptic loosening or infection in the ceramic-coated cohort.

At midterm follow-up, there was no benefit in terms of implant survivorship in using a ceramic coating.

Unicompartmental knee arthroplasty (UKA) has a higher risk of revision than total knee arthroplasty (TKA), particularly for younger patients. The outcome of knee arthroplasty is typically defined as implant survival or revision incidence after a defined number of years. This can be difficult for patients to conceptualize. We aimed to calculate the 'lifetime risk' of revision for UKA as a more meaningful estimate of risk projection over a patient's remaining lifetime, and to compare this to TKA.

Incidence of revision and mortality for all primary UKAs performed from 1999 to 2019 (n = 13,481) was obtained from the New Zealand Joint Registry (NZJR). Lifetime risk of revision was calculated for patients and stratified by age, sex, and American Society of Anesthesiologists (ASA) grade.

The lifetime risk of revision was highest in the youngest age group (46 to 50 years; 40.4%) and decreased sequentially to the oldest (86 to 90 years; 3.7%). Across all age groups, lifetime risk of revision was higher for females (ranging from 4.3% to 43.4% vs males 2.9% to 37.4%) and patients with a higher ASA grade (ASA 3 to 4, ranging from 8.8% to 41.2% vs ASA 1 1.8% to 29.8%). The lifetime risk of revision for UKA was double that of TKA across all age groups (ranging from 3.7% to 40.4% for UKA, and 1.6% to 22.4% for TKA). The higher risk of revision in younger patients was associated with aseptic loosening in both sexes and pain in females. Periprosthetic joint infection (PJI) accounted for 4% of all UKA revisions, in contrast with 27% for TKA; the risk of PJI was higher for males than females for both procedures.

Lifetime risk of revision may be a more meaningful measure of arthroplasty outcomes than implant survival at defined time periods. This study highlights the higher lifetime risk of UKA revision for younger patients, females, and those with a higher ASA grade, which can aid with patient counselling prior to UKA. Cite this article: Bone Joint J 2022;104-B(6):672-679.