Cemented Total Knee Arthroplasty Research Articles

Selective Use of Modern Cementless Total Knee Arthroplasty is Not Associated with Increased Risk of Revision in Patients Aged 65 or Greater: An Analysis from the American Joint Replacement Registry.

Introduction Modern highly porous surfaces have increased confidence and use of cementless total knee arthroplasty (TKA) in the United States. As cementless TKA use increases, there remains a paucity of literature regarding associated risk of revision in patients aged 65 or older. Methods We analyzed American Joint Replacement Registry (AJRR) data from January 2012 to March 2020 identifying patients aged 65 and older undergoing primary TKA with linked cases to supplemental Centers for Medicare and Medicaid data. Patients with hybrid fixation, reverse hybrid fixation, missing component data, highly constrained implants, and stem extension/augmentation were excluded. We identified 442,745 cemented TKAs and 19,841 modern cementless TKAs with minimum 2-year follow-up. Cumulative Incident Function (CIF) curves and cause-specific Cox models evaluated the risk of all-cause revision and revision for mechanical loosening, adjusting for BMI, sex, age, cruciate retaining (CR) vs posterior stabilized (PS) femoral design, patellar resurfacing, and Charlson Comorbidity Index (CCI). Results Patients with cementless compared to cemented TKA were younger (mean age 71.9 vs 73.2, p <0.001), more likely to be male sex (48.8% vs 39.0%, p<0.001), more likely to have a CR femoral design (81.1% vs 45.7%, p<0.001), less likely to have patellar resurfacing (92.7% vs 95.0%, P<0.001), and had a lower CCI (mean 2.9 vs 3.1, p<0.001). Adjusted Hazard Ratios (HRs) showed no difference in associated risk for all-cause revision (HR 1.07, 95% CI 0.92-1.24, p=0.382) or revision for mechanical loosening (HR 1.38, 95% CI 0.9-2.12, p=0.14) for cementless vs cemented TKA. Conclusion Our results suggest that current selective use of cementless fixation for TKA in patients aged 65 and older in the United States is not associated with an increased risk of revision. While encouraging, further study is necessary to establish indications for use in this age group prior to broader adoption in this patient population.

Antibiotic Laden Bone Cement Does Not Reduce Acute Periprosthetic Joint Infection Risk in Primary Total Knee Arthroplasty

BackgroundPeriprosthetic joint infection (PJI) can be a serious complication of total knee arthroplasty (TKA). A method believed to decrease the incidence of PJI is antibiotic-laden bone cement (ALBC). Current clinical practice guidelines do not recommend ALBC in primary TKA. The purpose of this study was to compare ALBC to plain cement (PC) in preventing PJI in primary TKA. MethodsThis retrospective analysis included 109,242 Medicare patients in the American Joint Replacement Registry who underwent a cemented primary TKA from January 2017 to March 2021, and had at least 1 year of follow-up. Patients who received ALBC were compared to patients who received PC. Demographic and case-specific variables such as age, sex, race, body mass index, Charlson Comorbidity Index, anesthesia type, and operative time were used to create propensity scores. A logistic regression was run to predict the probability of receiving ALBC. Also, a multivariate model was run on the full unstratified population, using the same covariates as were used to create the propensity model. The primary outcome was differences in PJI rates. ResultsLogistic regression analysis showed that a higher preoperative diagnosis of osteoarthritis, higher Charlson Comorbidity Index, higher body mass index, women, race, and anesthesia requirements increased a patient’s probability of receiving ALBC. In the full unstratified multivariate model, ALBC did not show a statistically significant difference in risk of revision for infection compared to PC. ConclusionsThe use of ALBC in primary TKA has not been shown to be more efficacious in preventing PJI within the population of Medicare patients in the United States. However, this study is limited given it is a retrospective database study that may inherently have biases and the large dataset has a potential for overpowering the findings.

Minimum 15-Year Survival of a Biconvex Inlay Patellar Component in Primary Total Knee Arthroplasty: An Analysis of 2,530 Total Knee Arthroplasties From a Single Institution

BackgroundRoutine patellar resurfacing during primary total knee arthroplasty (TKA) remains controversial. To our knowledge, there are no studies reporting the long-term performance of a cemented biconvex all-polyethylene inlay component implanted at the time of primary TKA. The purpose of this study was to examine the 15-year survivorship and long-term clinical outcomes of this biconvex inlay patella used at our institution. MethodsWe retrospectively reviewed our prospectively collected institutional database and identified 2,530 patients who underwent cemented TKA with a single prosthetic design (from 1996 to 2007) where the patella was resurfaced using this cemented biconvex inlay patella. The mean age at surgery was 68 years (range, 29 to 93). The mean body mass index was 33.0 (range, 16.4 to 76.3), with 61.9% women. At the time of analysis, the mean time from surgery was 20.4 years (range, 15 to 26). We used Kaplan–Meier analysis to calculate survivorship at 15 years. We analyzed clinical outcomes using 3 patient-reported outcome measures collected prospectively. ResultsThe 15-year survivorship with revision surgery for all causes as the end point was 97.1% (95% confidence interval 96.1 to 98.1%). The 15-year survivorship with revision surgery for a patella-related complication as the end point was 99.7% (95% confidence interval 99.4 to 1.0). At the final follow-up, patients showed significant improvement in scores for the Knee Society Clinical Rating System (P < .001), Western Ontario and McMaster University Osteoarthritis Index (P < .001), and Veterans Rand 12-Item Health Survey physical component (P < .001). ConclusionsRoutine patellar resurfacing using a biconvex inlay patellar component has excellent survivorship and a low rate of complications at 15 years post-TKA.

The Utilization of Press-Fit Total Knee Arthroplasty is Not Evenly Distributed: A National Registry Review.

This study evaluates trends of cemented versus press-fit total knee arthroplasty (TKA). We hypothesized that press-fit TKA is more common in younger and obese patients. There may also be racial, geographic, and institutional variation. The American Joint Replacement Registry was used to conduct a retrospective review of primary TKA procedures for osteoarthritis in the United States between January 2019 and March 2022. The objective was to identify differences in incidence, demographics, body mass index (BMI), Charlson Comorbidity Index (CCI), and institutional teaching status (teaching vs. non-teaching) between press-fit and cemented TKAs. Two hundred ninety-seven thousand four hundred two patients (61% female, average age 68 years, 88.3% White) underwent cemented TKA versus 50,880 patients (52% female, average age 65 years, 89% White) underwent press-fit TKA. Overall, 20.8% of press-fit versus 19.9% of cemented TKA had a BMI of 35 to 39.9 and 15.2% of press-fit versus 12.5% of cemented TKA had BMI >40 (P < 0.001). Patients undergoing press-fit TKA were less likely Black (OR = 0.727; P < 0.0001), Asian (OR = 0.651, P < 0.0001), and Native Hawaiian/other Pacific Islander (OR = 0.705, P < 0.02) with White as the reference group. Northeastern and Southern United States were more likely to use press-fit TKA than the Midwest (OR = 1.89 and OR = 1.87, P < 0.0001) and West (OR = 1.67; and OR = 1.65; P < 0.0001). Press-fit TKA incidence in 2019 was 9.9% versus 20.6% in 2022 (P < 0.001). Press-fit TKA is increasingly more common in Northeastern and Southern United States, and patients are older than expected. Patients with BMI >35 had a slightly higher rate of undergoing press-fit than cemented TKA. Notable racial differences also exist. Additional research addressing racial disparities and evaluating longevity of press-fit designs is needed.

Cemented is not superior to cementless total knee arthroplasty for complications: a propensity score matched analysis.

There is continued debate regarding the survivorship and revision rate of cementless versus cemented total knee arthroplasty (TKA) prostheses. This includes the assessment of early revision surgery due to aseptic loosenings and periprosthetic joint infections (PJIs). Studies have not always taken into account the impact of comorbidities, such as diabetes, obesity, and tobacco. Therefore, we compared revisions in a large population of patients undergoing cemented or cementless TKAs at 90days, 1year, and 2years. A review of an administrative claims database was used to identify patients undergoing primary TKA, either cementless (n = 8,890) or cemented (n = 215,460), from October 1, 2015 to October 31, 2020. Revision surgery for PJI and aseptic loosening were identified with diagnosis and associated procedural codes at 90days, 1year, and 2years and then compared between groups. A propensity matched-analysis was performed for age, sex, Charles Comorbidity Index (CCI) > 3, alcohol abuse, tobacco use, obesity, and diabetes. Chi square tests assessed statistical significance of differences in the matched cohorts using odds ratios (ORs) with 95% confidence intervals (CIs). A P < 0.05 was defined as statistically significant. Cementless TKA was associated with similar revisions rates due to PJIs at 90days (OR, 1.04, 95% CI 0.79-1.38, p = 0.83), 1year (OR, 0.93, 95% CI 0.75-1.14, p = 0.53, and 2years (OR, 0.87, 95% CI 0.73-1.05, p = 0.17) in comparison to the cemented TKA cohort. The odds ratio of revision due to aseptic loosening was similar as well at 90days (OR, 0.67, 95% CI 0.34-1.31, 0.31), 1year (OR, 1.09, 95% CI 0.73-1.61, p = 0.76), and 2years (OR, 1.00, 95% CI 0.73-1.61, p = 0.99). This study found a comparable risk of PJI and aseptic loosening in cementless and cemented TKA when controlling for several comorbidities, such as tobacco, diabetes, and alcohol. Therefore, with proper patient selection, cementless TKAs can be performed with expectation of low risks of infections and aseptic loosenings.

Skin Numbness after Total Knee Arthroplasty: Complication or Side-Effect?

Peri-incisional numbness occurs frequently after Total Knee Arthroplasty (TKA), yet its impact on clinical outcomes remains controversial. With some studies reporting 100% incidence and patients often perceiving it as a minor inconvenience, its categorisation as a complication is controversial. This study investigates the prevalence and temporal changes of numbness post-TKA to refine the informed consent process and improve patient satisfaction. A convenience sample of patients who underwent primary cemented TKA was studied. Demographic data, scar length, tourniquet time, and WOMAC scores were collected. Patients were grouped based on time from surgery, and areas of numbness for light touch and pinprick sensations measured. The study included 49 patients with a mean age of 68.9 years. While all patients reported numbness, the area decreased for both pinprick and light touch sensations over time. No significant correlation was found between WOMAC scores and the area of numbness. Numbness post-TKA is common, and the affected area contracts over time, implying a natural healing process. The study's findings challenge the perception of numbness as a complication and emphasise the importance of informed consent in managing patient expectations. 1. Postoperative numbness around the incision site following TKA is a common occurrence with minimal clinical impact on patients. 2. It is important to inform patients that this numbness will improve, although some residual numbness may remain.

The Alignment of the Tibial Component in Total Knee Arthroplasty: Is a Technology-Assisted System Better Than Conventional Instrumentation?

Background Technologies such as navigation and robotics are aimedat improving tibial alignment in total knee arthroplasties (TKA) and eliminating the errors resulting from the use of manual instrumentation. Methods This prospective study analyzed 130 arthroplasties in order to determine whether navigation can improve the frontal mechanical axis of the tibia and whether the postoperative angulation of this axis differs from the preoperative one. The mean patient age was 71.8 years, and the mean BMI was 31.17. Eighty-six patients were female. The same cemented TKA model and the same imageless navigation system were used in all cases. Results The mean postoperative tibial angle following implantation was 87.65°, without any statistically significant differences with respect to the previous angulation. However, navigation was seen to result in a nearly neutral tibial axis, a larger number of cases (41.5%-60.8% {p = 0.002}) aligned within the safe zone (90° ± 3°), a smaller number of outliers, and a clustering of values around the mean. Conclusions Navigation improves the frontal positioning of the tibial component in total knee arthroplasties but does not offer any advantages as compared with conventional instrumentation.

Short-Term (6 Months or Less) Pain in Cemented versus Cementless Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BackgroundCementless total knee arthroplasty (TKA) has increased in popularity to potentially improve survivorship. Radiostereometric studies demonstrate increased component migration during the first 3 to 6 months in cementless constructs, generating concern for increased postoperative pain during early osseointegration. The purpose of this study was to evaluate short-term (≤ 6 months) pain and function in cemented versus cementless TKA. We hypothesized that cementless TKA patients report increased pain during the short-term (≤ 6 months) postoperative period. MethodsThe MEDLINE, EMBASE, CINAHL, and Cochrane Libraries were searched for studies evaluating short-term (≤ 6 months) outcomes of cemented versus cementless primary TKA. Studies involving hybrid fixation were excluded. A meta-analysis was performed using standardized mean difference for primary outcomes (early postoperative pain) and weighted mean difference (WMD) for secondary outcomes (early postoperative function). ResultsThere were eleven studies included. There was no significant difference in acute postoperative pain between cemented and cementless TKA within 6 months of index TKA (standardized mean difference 0.08 in favor of cemented TKA; P = .10). Early postoperative forgotten joint scores (WMD 0.81; P = .81) and knee injury and osteoarthritis outcome scores for joint replacement (WMD 0.80 in favor of cemented TKA; P = .14) were also similar between groups. ConclusionsThere is no difference in short-term (≤ 6 months) pain or early function between patients receiving cemented and cementless TKA. This suggests that surgeons may utilize cementless TKA without fear of increased pain due to micromotion within 6 months of index arthroplasty. However, additional studies with uniform assessment methods are needed to further inform differences in short-term pain and early functional outcomes between cemented and cementless TKA.

Mode of Fixation and Survivorship in Primary Total Knee Arthroplasty in the American Joint Replacement Registry

BackgroundA recent rapid increase in cementless total knee arthroplasty (TKA) has been noted in the American Joint Replacement Registry (AJRR). The purpose of our study was to compare TKA survivorship based on the mode of fixation reported to the AJRR in the Medicare population. MethodsPrimary TKAs from Medicare patients submitted to AJRR from 2012 to 2022 were analyzed. The Medicare and AJRR databases were merged. Cox regression stratified by sex compared revision outcomes (all-cause, infection, mechanical loosening, and fracture) for cemented, cementless, and hybrid fixation, controlling for age and the Charlson comorbidity index (CCI). ResultsA total of 634,470 primary TKAs were analyzed. Cementless TKAs were younger (71.8 versus 73.1 years, P < .001) than cemented TKAs and more frequently utilized in men (8.2 versus 5.8% women, P < .001). Regional differences were noted, with cementless fixation more common in the Northeast (10.5%) and South (9.2%) compared to the West (4.4%) and Midwest (4.3%) (P < .001). No significant differences were identified in all-cause revision rates in men or women ≥ 65 for cemented, cementless, or hybrid TKA after adjusting for age and CCI. Significantly lower revision for fracture was identified for cemented compared to cementless and hybrid fixation in women ≥ 65 after adjusting for age and CCI (P = .0169). ConclusionsNo survivorship advantage for all-cause revision was noted based on the mode of fixation in men or women ≥ 65 after adjusting for age and CCI. A significantly lower revision rate for fractures was noted in women ≥ 65 utilizing cemented fixation. Cementless fixation in primary TKA should be used with caution in elderly women.

Four-Year Outcomes of Cementless Versus Cemented Fixation of a Newly Introduced Total Knee Arthroplasty Design.

Aseptic loosening continues to be a major cause of failure of total knee arthroplasty (TKA). Although cemented fixation remains the gold standard, there is renewed interest in cementless fixation as a means of decreasing this risk via biologic fixation. The purpose of this study was to evaluate the clinical outcomes of cemented and cementless versions of a newly introduced TKA design at an average of 4 years postoperatively. This was a retrospective case-control study of 100 primary TKAs comparing cementless vs cemented TKAs using the same cruciate-retaining implant design (ATTUNE Knee System; DePuy Synthes). Fifty patients undergoing cementless TKA with a mean age of 60.8 years (range, 48-71 years) and body mass index (BMI) of 31.6 kg/m2 (range, 23.7-41.9 kg/m2) were matched to 50 patients undergoing primary cemented TKA with a mean age of 62.7 years (range, 51-73 years) and BMI of 30.1 kg/m2 (range, 24.6-43.9 kg/m2). The mean follow-up was 4.2 years (range, 4.0-4.4 years) in the cementless group and 7.6 years (range, 7.5-7.7 years) in the cemented group. Complications, clinical outcomes using the Knee Society Score (KSS), and radiographic analyses were evaluated at final follow-up. Student's t tests were used for statistical analyses. There was no statistical difference in age, BMI, and preoperative KSS between the two groups (P=.12, P=.15, and P=.55, respectively). There were no complications or reoperations in either cohort. There were no statistical differences in range of motion and total KSS at final follow-up between the two groups. Final total KSS had a mean of 91.1 for the cementless group and 93.7 for the cemented group. There was no radiographic evidence of component subsidence or loosening in either cohort. When compared with its cemented counterpart, the newly introduced cementless TKA design had similar excellent clinical improvements and radiologic results at an average of 4 years of follow-up. [Orthopedics. 2024;47(3):161-166.].

Low Response Rate to Follow-Up Using Telemedicine after Total Knee Replacement during the COVID-19 Pandemic in Italy.

This study aimed to evaluate the survival rate and medium-term outcomes of patients after cemented posterior-stabilized (PS) mobile-bearing (MB) total knee arthroplasty (TKA) using a telemedicine platform during the COVID-19 pandemic in Italy. A total of 100 consecutive patients (mean age 73.5 ± 13.2 years) who received a cemented PS MB TKA were enrolled. The mean age of patients who did not complete the telemedicine follow-up (58%) was 75.8 ± 9.7 years. A dedicated software that makes it possible to perform video calls, online questionnaires, and acquire X-rays remotely was used. Subjective clinical scores and objective range-of-motion (ROM) measurements were observed at an average follow-up of 54 ± 11.3 months. A total of 42 of 100 enrolled patients (mean age 70.3 ± 8.4 years) completed the telemedicine follow-up. The mean age of patients who did not complete the telemedicine follow-up (58%) was 75.8 ± 9.7 years. Age was found to be a statistically significant difference between the group that completed the telemedicine follow-up and the one that did not (p < 0.004). KOOS scores improved from 56.1 ± 11.3 to 77.4 ± 16.2, VAS scores decreased from 7.2 ± 2.1 to 2.8 ± 1.6, KSSf scores increased from 47.2 ± 13.3 to 77.1 ± 21.1, FJS scores improved from 43.4 ± 12.3 to 76.9 ± 22.9, and OKS scores increased from 31.9 ± 8.8 to 40.4 ± 9.9. All the differences were statistically significant (p < 0.05). The mean flexion improved from 88° ± 8° to 120° ± 12°. A radiographic evaluation showed a mean pre-operative mechanical axis deviation of 5.3 ± 8.0 degrees in varus, which improved to 0.4 ± 3.4 degrees of valgus post-operation. The survivorship at 5 years was 99%. Subject to small numbers, telemedicine presented as a useful instrument for performing remote monitoring after TKA. The most important factor in telemedicine success remains the patient's skill, which is usually age-related, as older patients have much more difficulty in approaching a technological tool.

A Comparison of the Periprosthetic Fracture Rate of Cemented and Cementless Total Knee Arthroplasties: An Analysis of Data From the National Joint Registry

BackgroundPeriprosthetic fractures are serious complications of knee arthroplasty often requiring complex surgery. There is concern of increased periprosthetic fracture risk with cementless components given the reliance on interference fit for primary stability. It is unknown how the periprosthetic fracture risk compares between cemented and cementless total knee arthroplasties (TKAs). MethodsA total of 22,477 cemented and 22,477 cementless TKAs from the National Joint Registry and Hospital Episodes Statistics database were propensity score matched on patient and surgical factors. Cumulative periprosthetic fracture rates were calculated using Kaplan-Meier analyses and compared with Cox regressions. Subgroup analyses were performed in different age, body mass index, and sex groups. ResultsThe 3-month fracture rate in the cemented and cementless TKA groups were 0.02% and 0.04%, respectively. At 10 years, the cumulative fracture rate after cemented TKA was 1.2%, and after cementless was 1.4%. During the study period, there were no significant differences in fracture rates between cemented and cementless TKAs with a hazards ratio 1.14 (confidence interval 0.94 to 1.37, P = .20) at 10 years postoperatively. There were no significant differences in fracture rates between fixation types on subgroup analyses of sex, body mass index, and age groups. Female sex was a risk factor for fracture in both cemented (odds ratio 2.35, P < .001) and cementless TKAs (odds ratio 2.97, P < .001). ConclusionsThe periprosthetic fracture rates following cemented and cementless TKA surgery are low being approximately 1.2% and 1.4%, respectively at 10 years. There were no significant differences in periprosthetic fracture rates requiring readmission between cemented and cementless TKAs. Level of evidenceIII.

Postoperative Hemodynamics of Total Knee Arthroplasty Unaffected by Cementless Approach under Contemporary Patient Blood Management Protocol: A Propensity Score-Matched Study.

(1) Background: A cementless total knee arthroplasty (TKA) is a recent and an increasingly popular innovation that enhances porous fixation surfaces. However, the lack of cemented sealing of an exposed resected bone has raised concerns about the potential for greater blood loss. The goals of this study were to determine if a cementless approach impacts post-TKA hemodynamics and to identify risk factors for blood loss in instances of cementless (vs. cemented) TKAs under a contemporary patient blood management (PBM) protocol. (2) Methods: We recruited 153 consecutive patients undergoing unilateral TKAs between 2019 and 2023. All enrollees received cementless or cemented prostheses of the same design (cementless, 87; cemented, 66). After propensity score matching for demographics, there were 46 patients in each group. We then compared blood loss metrics (total [TBL] and estimated [EBL]), drainage volumes, hemoglobin (Hb) levels, and transfusion rates by group. (3) Results: Post-TKA hemodynamics (i.e., TBL, EBL, drainage, Hb level, and transfusion rate) of cementless (n = 46) and cemented (n = 46) TKA groups did not differ significantly. In addition, the proportions of patients with Hb drops > 3.0 g/dL were similar for the two groups. A logistic regression analysis revealed that only preoperative Hb and EBL during the early postoperative period were predictive of a substantial fall in Hb levels. The fixation method was not associated with Hb decline > 3.0 g/dL by postoperative Day 3. (4) Conclusion: The cementless TKA has no impact on customary post-TKA hemodynamics and is not associated with greater TKA-related blood loss when implementing a contemporary PBM protocol.

Cementless and Cemented Total Knee Arthroplasties Have Similar Outcomes but Cementless Patellar Component Migration was Observed in a Paired Randomized Control Trial

BackgroundCementless total knee arthroplasty (TKA) has become increasingly popular. Some surgeons are concerned about pain, implant stability, and metal-backed patellar component survivorship. This study investigated the outcomes of cementless compared with cemented TKA in bilateral cases. MethodsWe randomized 80 knees in 40 osteoarthritic knee patients who underwent bilateral TKA with patellar resurfacing under one anesthesia. All participants received cementless prostheses in one knee and cemented prostheses in the other. The outcomes were knee function measured by the forgotten joint scores, modified Western Ontario and McMaster Universities Osteoarthritis Index, knee ranges of motion, pain levels, operative times, radiographic outcomes, and complications. All knees were followed for a minimum of 2 years (2 to 3 years). ResultsCementless and cemented TKA had similar functional outcomes in forgotten joint score (97 ± 5 versus 98 ± 3 points, P = .52), modified Western Ontario and McMaster Universities Osteoarthritis Index score (3 ± 4 versus 3 ± 2 points, P = .96), and ranges of motion (134 ± 7° versus 134 ± 7°, P = .16). The postoperative pain was also similar (P > .05). There were 4 cementless patellar components had superior migration for an average of 3.5 mm (range, 1.77 to 4.16) without loosening. The mean time of migration was 4 (range, 2 to 6) weeks. ConclusionsCementless TKA had similar functional outcomes and recovery patterns compared with cemented TKA. However, there was concern of cementless component migration at patellae.

Fifteen-year prospective longitudinal cohort study of outcomes following single radius total knee arthroplasty.

This prospective study reports longitudinal, within-patient, patient-reported outcome measures (PROMs) over a 15-year period following cemented single radius total knee arthroplasty (TKA). Secondary aims included reporting PROMs trajectory, 15-year implant survival, and patient attrition from follow-up. From 2006 to 2007, 462 consecutive cemented cruciate-retaining Triathlon TKAs were implanted in 426 patients (mean age 69 years (21 to 89); 290 (62.7%) female). PROMs (12-item Short Form Survey (SF-12), Oxford Knee Score (OKS), and satisfaction) were assessed preoperatively and at one, five, ten, and 15 years. Kaplan-Meier survival and univariate analysis were performed. At 15 years, 28 patients were lost to follow-up (6.1%) and 221 patients (51.9%) had died, with the mean age of the remaining cohort reducing by four years. PROMs response rates among surviving patients were: one-year 63%; five-year 72%; ten-year 94%; and 15-year 59%. OKS and SF-12 scores changed significantly over 15 years (p < 0.001). The mean improvement in OKS was 18.8 (95% confidence (CI) 16.7 to 19.0) at one year. OKS peaked at five years (median 43 years) declining thereafter (p < 0.001), though at 15 years it remained 17.5 better than preoperatively. Age and sex did not alter this trajectory. A quarter of patients experienced a clinically significant decline (≥ 7) in OKS from five to ten years and from ten to 15 years. The SF-12 physical component score displayed a similar trajectory, peaking at one year (p < 0.001). Patient satisfaction was 88% at one, five, and ten years, and 94% at 15 years. In all, 15-year Kaplan-Meier survival was 97.6% (95% CI 96.0% to 99.2%) for any revision, and 98.9% (95% CI 97.9% to 99.9%) for aseptic revision. Improvements in PROMs were significant and maintained following single radius TKA, with OKS peaking at five years, and generic physical health peaking at one year. Patient satisfaction remained high at 15 years, at which point 2.4% had been revised.

A Systematic Review and Network Meta-Analysis of the Outcomes of Patients With Total Knee Arthroplasty Using Cemented, Uncemented, or Hybrid Techniques.

In this study, we aim to explore the differences among the three types of fixation methods for the components of the knee joint in patients who underwent total knee arthroplasty (TKA). These methods are cemented, uncemented, and hybrid fixation. Cemented fixation means that a special type of grout is used to attach the components to the bone.Uncemented fixation means that the components are designed to fit tightly into the bone and allow new bone growth to secure them. Hybrid fixation means that a combination of cemented and uncemented fixation is used for different components.We searched four online databases to find studies relevant to our research question. We use the R program (R Foundation for Statistical Computing, Vienna, Austria) for network meta-analysis (NMA) to analyze the data from the studies. We calculate the mean difference (MD) and the 95% confidence interval (CI) for each outcome, which are statistical measures of the difference and the uncertainty between methods. We use these measures for continuous outcomes, meaning they can have any value. For dichotomous outcomes, meaning they can only have two values, we use the risk ratio (RR) and the 95% CI, which are statistical measures of the relative risk and the uncertainty between methods. We assess the quality of randomized controlled trials, which are studies that randomly assign participants to different methods, using the Cochrane Risk of Bias Assessment Tool 1, a tool that evaluates the potential biases in the studies. We include 21 studies, and our analysis shows that cemented TKA reveals a statistically significant decrease in pain with hybrid TKA (MD = -2.82). That said, we find no significant differences between uncemented and cemented or hybrid (MD = -0.80 and -2.02, respectively). The results show that there is no significant difference between uncemented TKA and cemented TKA or hybrid technique (RR = 0.87, 95% CI 0.35-2.14; RR = 0.73, 95% CI 0.22-2.39, respectively). Also, we find no significant difference between cemented TKA and hybrid TKA (RR = 0.84, 95% CI 0.24-2.93).Cemented TKA is associated with a lower risk of deep vein thrombosis (DVT) incidence rate. Moreover, it shows a significant decrease in pain compared to hybrid TKA. Future research is needed to compare among the three interventions.

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

PurposeThe 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.MethodsA 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.ResultsA 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.ConclusionComparison 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 wear in deep-dished mobile compared to fixed bearing total knee arthroplasty of the same design at 5-year follow-up: a randomised controlled model-based Roentgen stereophotogrammetric analysis trial.

The aim of this prospective randomised controlled study was to compare wear characteristics and functional outcome between deep-dished mobile bearing (MB) and fixed bearing (FB) cemented total knee arthroplasty (TKA). We hypothesised that deep-dished MB reduces polyethylene wear and improves patient-reported outcome measures. A total of 50 patients were randomised to receive a MB or FB tibia component of the same cemented TKA design. Patients were evaluated over a 5-year follow-up period. Medial and lateral wear were assessed using model-based Roentgen Stereophotogrammetric Analysis (RSA) and compared with the direct postoperative minimal joint space measurement. Functional outcome was assessed by the clinician-derived KSS and OKS, WOMAC, LEAS, and FJS-12. All data were derived using a general linear mixed model. At 5-year follow-up, decreased wear in the MB compared to the FB group was observed on the lateral side (0.07 ± 0.17mm, p = 0.026), but not on the medial side (0.31 ± 0.055mm, p = 0.665). Functional outcomes improved with a statistical significant effect over time, with no significant differences between groups (all p > 0.17). This model-based RSA study with 5-year follow-up showed that cemented deep-dished MB reduced lateral polyethylene wear as compared to FB in a single TKA system, whilst clinical outcomes were comparable. Longer follow-up is needed to establish clinical implications of these altered wear patterns and determine type of wear. Level 1 randomised controlled trial.

Setting the distal and posterior condyle of the femoral component to restore the medial pre-arthritic femoral articular surface results in better outcomes after total knee arthroplasty

PurposeThe present study of total knee arthroplasty (TKA) describes an intra-operative method that determines the direction and quantifies the magnitude of deviation of the distal and the posterior medial and lateral (DM, PM, DL, and PL) condyle of the femoral component relative to the pre-arthritic femoral articular surface. For each femoral condyle, the deviations were categorized, and an analysis determined which had better or worse Forgotten Joint Score (FJS), Oxford Knee Score (OKS), and WOMAC scores at 1-year follow-up.MethodsFour academic arthroplasty surgeons supervised a cemented primary CR TKA (Triathlon, Stryker) on 120 consecutive patients. 103 that completed patient-reported outcome measures (PROMs) were analyzed. The surgeon determined the direction and the magnitude of deviation of the condyle of the femoral component by intraoperatively measuring the thickness of the femoral resection, adding compensations of 1 mm for the saw kerf and 2 mm for worn cartilage, and then subtracting the thickness of the femoral component’s condyle. For each femoral condyle, a Kruskal–Wallis test determined the categories of deviation with clinically important and significantly different 1-year PROMs.ResultsA 1 to 2.5 mm and 3 mm or more proximal deviation of the DM condyle of the femoral component worsened the median FJS by 35 and 40 points, OKS by 9 and 14 points, and WOMAC score by 9 and 17 points, respectively, relative to those with a –0.5 to 0.5 mm deviation (p < 0.01). A 1 to 2.5 mm and 3 mm or more anterior deviation of the PM condyle of the femoral component worsened the FJS by 34 and 48 points, OKS by 7 and 13 points, and WOMAC scores by 8 and 16 points, respectively (p < 0.01). Deviations of the DL and PL condyle of the femoral component did not affect PROMs (p ≥ 0.13).ConclusionsAlthough many factors can affect PROM, such as patient expectations, the surgeon should understand that setting the DM and the PM condyles of the femoral component within 1 mm of the patient’s pre-arthritic femoral articular surface can potentially result in better FJS, OKS, and WOMAC scores at 1 year.Level of evidenceII, Prospective cohort study

Demographics and Early Outcomes of Commercial Antibiotic Cement Usage for Infection Prophylaxis During Primary Total Knee Arthroplasty in Patients Older Than 65 Years: An American Joint Replacement Registry Study.

The use of antibiotic-laden bone cement (ALBC) for infection prophylaxis in the setting of primary total knee arthroplasty (TKA) remains controversial. Using data from the American Joint Replacement Registry (AJRR), (1) we examined the demographics of ALBC usage in the United States and (2) identified the effect of prophylactic commercially available ALBC on early revision and readmission for prosthetic joint infection (PJI) after primary TKA. This is a retrospective cohort study of the AJRR from 2017 to 2020. Patients older than 65 years undergoing primary cemented TKA with or without the use of commercially available antibiotic cement were eligible for inclusion (N = 251,506 patients). Data were linked to available Medicare claims to maximize revision outcomes. Demographics including age, sex, race/ethnicity, Charlson Comorbidity Index (CCI), preoperative inflammatory arthritis, region, and body mass index (BMI) class were recorded. Cox proportional hazards regression analysis was used to evaluate the association between the two outcome measures and ALBC usage. Patients undergoing cemented TKA with ALBC were more likely to be Non-Hispanic Black ( P < 0.001), have a CCI of 2 or 3 ( P < 0.001), reside in the South ( P < 0.001), and had a higher mean BMI ( P < 0.001). In the regression models, ALBC usage was associated with increased risk of 90-day revision for PJI (hazards ratio 2.175 [95% confidence interval] 1.698 to 2.787) ( P < 0.001) and was not associated with 90-day all-cause readmissions. Male sex, higher CCI, and BMI >35 were all independently associated with 90-day revision for PJI. The use of commercial ALBC in patients older than 65 years for primary TKA in the AJRR was not closely associated with underlying comorbidities suggesting that hospital-level and surgeon-level factors influence its use. In addition, ALBC use did not decrease the risk of 90-day revision for PJI and was not associated with 90-day readmission rates.