Revision Total Knee Arthroplasty Research Articles

Survivorship of Primary NexGen Knee Replacement: Comparing Cementless Trabecular Metal to Other Designs of Tibial Component.

The impact of cementless trabecular metal (TM) implants on implant survivorship are not well delineated. This study compares primary total knee arthroplasty (TKA) revision rates of cemented knee replacements with two cementless knee replacement designs-cementless TM and a non-TM cementless design. Data from a national registry queried TKA procedures performed for osteoarthritis from 1999 to 2020. The risk of revision of Zimmer NexGen TKA using cementless TM, cementless non-TM, and cemented non-TM were compared. Analyses included Kaplan-Meier estimates of survivorship and Cox hazard ratios (HR), stratified by age and gender. Cementless TM components had higher risks of revision compared with cementless non-TM implants (HR = 1.49; p ≤ 0.001). Cementless TM implants showed higher risks of revision compared with cemented non-TM prostheses for the first 2 years (HR = 1.75, p < 0.001). Non-TM prostheses posed equal risk of revision for cementless and cemented fixations (HR = 0.95, p = 0.522). Patients aged 55 to 64 years and 65 to 74 years had a higher risk of revision for cementless TM compared with cementless non-TM (HR = 1.40, p = 0.033 and HR = 1.79, p < 0.001, respectively) and cemented non-TM implants (HR = 1.51, p < 0.001 and HR = 1.54, p < 0.001, respectively). The study shows there is an increased risk of revision with TM cementless implants for patients aged 55 to 74 years. These results do not support the use of TM tibial implants for patients of this age group for primary TKA.

Conversion of Tibial Plateau Fractures to Total Knee Arthroplasty is Associated With Worse Patient-Reported Outcomes, Increased Operative Times, and Increased Complications

BackgroundPrior open reduction and internal fixation (ORIF) of tibial plateau fracture (TPF) adds complexity to subsequent total knee arthroplasty (TKA). The purpose of this study was to compare the outcomes of patients undergoing a TKA following prior ORIF of TPF to patients undergoing a primary TKA for osteoarthritis and an aseptic revision TKA. MethodsThere were 52 patients who underwent primary TKA following prior ORIF of TPF between January 2009 and June 2021, who were included and matched in a 1:4 ratio to 208 patients undergoing primary TKA. A second 1:1 matched comparison to 52 aseptic revision TKA patients was also included. The Knee injury and Osteoarthritis Outcome Score for Joint Replacement scores were obtained preoperatively and at two years postoperatively. Independent t-tests and Chi-square tests were used for statistical comparisons. ResultsThe TPF patients were significantly younger than both primary and revision cohorts (55 ± 14.0 versus 63 ± 16.3 versus 64 ± 9.5, P < 0.001). Compared to primary TKA patients, the TPF group had worse Knee injury and Osteoarthritis Outcome Score for Joint Replacement scores at two years (46.9 ± 18.5 versus 66.2 ± 17.8, P = 0.0152), higher rates of wound complications (15.4 versus 3.9%, P = 0.0020), and increased operative times (140.2 ± 45.3 versus 95.2 ± 25.7, P < 0.0001). Additionally, TPF patients were more likely to require a manipulation under anesthesia than both primary and revision patients (21.2 versus 5.8 versus 5.8%, P = 0.001). ConclusionsThe TKAs following ORIF of TPF are more like revision TKAs than primary TKAs in terms of patient-reported outcomes, operative times, and wound complications. The rate of manipulation under anesthesia was higher than in both matched groups. These findings provide valuable information that can affect preoperative patient education and postoperative management regimens. They also emphasize the need for a conversion TKA code due to increased complexity and complications seen in this more difficult subset of TKAs.

Chronic Anticoagulation in Patients Who Have Atrial Fibrillation Undergoing Outpatient Total Knee Arthroplasty: A Retrospective Matched Cohort Study

BackgroundPatients who have atrial fibrillation frequently require long-term anticoagulation with warfarin or a direct-acting oral anticoagulant (DOAC), such as apixaban or rivaroxaban, to avoid vascular complications. However, the impact of anticoagulant use on postoperative complications following total knee arthroplasty (TKA) in an outpatient setting has not been thoroughly elucidated. The purpose of this study was to examine the impact of anticoagulant use on early postoperative complications among atrial fibrillation patients undergoing outpatient TKA. MethodsAn insurance claims database was queried to identify all patients who underwent outpatient TKA between January 2010 and April 2022. There were two cohorts of patients, with associated 1:1 matched controls, who had atrial fibrillation and filled a prescription of either warfarin (N = 4,396) or DOAC (N = 5,383) for at least 30 days. The mean age was 70 years (range, 51 to 84), and 47.9% were women in the warfarin cohort, while the mean age was 70 years and 49.2% were women in the DOAC cohort. Postoperative 30-day medical and 90-day surgical complications were subsequently compared. ResultsPatients on warfarin had a higher incidence of pulmonary embolism (1.1 versus 0.2%, P < 0.001) and a lower incidence of TKA revision (0.1 versus 0.4%, P = 0.003) than matched controls. Similarly, patients on DOACs exhibited a higher incidence of pneumonia (1.4 versus 0.6%, P < 0.001) and myocardial infarction (3.2 versus 1.5%, P < 0.001) and a lower incidence of wound dehiscence (0.1 versus 0.5%, P < 0.001), joint infection (0.4 versus 0.9%, P = 0.002), and TKA revision (0.1 versus 0.4%, P = 0.002) than matched controls. ConclusionsAtrial fibrillation patients on long-term anticoagulants undergoing outpatient TKA experience higher rates of medical complications and lower rates of surgical complications than matched controls. Thus, patients on long-term anticoagulants may be considered for outpatient TKA but should be counseled appropriately on associated medical risks.

Global Trends in Patellar Resurfacing From 2004 to 2022

BackgroundInternational rates of patellar resurfacing in primary total knee arthroplasty (TKA) are highly variable. This study sought to determine how trends in patellar resurfacing rates have changed between 2004 and 2022. In addition, we investigated how modern rates of revision have varied between resurfaced and unresurfaced patellae in primary TKA among national joint registries. MethodsData between 2004 and 2022 was obtained either from the publicly available joint registry annual reports, a literature review, or via direct correspondence with registry personnel in Sweden, New Zealand, Australia, the United States, Norway, the United Kingdom, the Netherlands, Switzerland, Canada, and India. Only English language national joint registries or data via direct correspondence with registry administrators were utilized. Additionally, the 10-year cumulative risk of revision TKA with and without patellar resurfacing was pulled from those registries that had this data available. ResultsThere were persistent differences in the rates of patellar resurfacing among countries. Australia documented a 40% increase in patellar resurfacing rates, while other countries demonstrated modest or little change in resurfacing rates. This may indicate that surgeons are making the decision to resurface based on national TKA revision rates. The average rates of patellar resurfacing in primary TKA ranged from 4% in Sweden to 94% in the United States. Canada, the United States, Australia, and Switzerland documented a lower risk of revision when the patella was resurfaced, while Sweden, conversely, showed a higher risk of revision with resurfacing. ConclusionsRates of patellar resurfacing in primary TKA were highly variable among countries, as were rates of change over time. It appears that the optimal patellar resurfacing strategy may depend mostly on unique patient factors and surgeon expertise. Future studies should attempt to elucidate the individual patient characteristics that contribute to increased risks of revision or anterior knee pain to determine who will most benefit from patellar resurfacing in primary TKA.

Assessment of the Potential Role of Preoperative Dental Clearance in Total Joint Arthroplasty Optimization: A Pilot Study.

Periprosthetic joint infection (PJI) is a serious complication after total joint arthroplasty (TJA) and is associated with significant morbidity, mortality, and cost. This pilot study primarily aimed to investigate if preoperative dental screenings would impact the rate of PJI following TJA when compared to historical controls. Secondarily, this study aimed to evaluate the prevalence of dental pathology in patients undergoing TJA. Charts from 103 consecutive patients undergoing primary or revision total hip arthroplasty (THA, rTHA) or total knee arthroplasty (TKA, rTKA) by a single surgeon at a single academic institution over a two-year period were reviewed and selected for inclusion. All patients were referred to a dentist for preoperative clearance using a standardized form. The rate of dental pathology before surgery, details of the dental intervention required, and any dental work performed within six months postoperatively were evaluated. The demographic and comorbidity composition of our patient population was also collected. Finally, rates of PJI following each type of TJA were obtained for demographic- and comorbidity-matched historical controls from similar study designs to examine the potential impact of preoperative dental intervention. Of the 103 patients, 31 (30.1%) were found to have preoperative dental pathology. Twenty-eight of these 31 patients (90.3%) required dental intervention prior to surgery. Based on demographic- and comorbidity-matched historical data, we expected two (95% CI (0, 6)) PJI cases for the THA group, 0 (95% CI (0, 2)) PJI cases for the TKA group, two (95% CI (0, 5)) PJI cases for the rTHA group, and two (95% CI (0, 5)) PJI cases for the rTKA group. However, in our study, there were no PJIs after any TJA up to the latest follow-up, which was unlikely for THA, rTHA, and rTKA groups given the calculated Poisson probabilities (9.39%, 15.11%, and 11.26%, respectively). Finding 0 cases was likely for the TKA group given the calculated Poisson probability of 72.61%. This pilot study demonstrated that preoperative dental screening, which aims to decrease the chance of PJI due to bacteremia, may have an impact on the rate of PJI following THA, rTKA, and rTHA but not TKA based on Poisson probabilities calculated from demographic- and comorbidity-matched historical controls that lacked preoperative dental screening. For THA, rTKA, and rTHA, the Poisson probabilities of observing 0 cases of PJI postoperatively, as was the case in our study, were unlikely, suggesting that some variable in our cohort was decreasing the PJI rate for these groups. However, in the case of TKA, the Poisson probability of observing 0 cases was likely and matched the results of our study, suggesting that no variable in our cohort was affecting the PJI rate for this group. We cannot draw direct conclusions from this retrospective observational study, but the preliminary findings prompt further investigation through an appropriately controlled, blinded, multi-centered, and powered prospective randomized controlled trial.

The "blownknee" patient's stress fracture of distal tibial component after unilateral TKA: A case report.

Periprosthetic fractures (PPF) are rare complications of total knee arthroplasty (TKA). The most common PPF after TKA is supracondylar femoral fracture, which is a relatively rare complication that is usually associated with high-energy trauma, with a reported incidence ranging from 0.4 to 1.7% according to the AOANJRR. However, in TKA patients, it is rarer that the stress fracture around the tibial prosthesis occurs due to changes in the lower limb force line, increasing weight-bearing, and changes in walking gait. A 68-year-old woman visited our hospital with "both knees had aggravated pain and deformity for 8 years." TKA was performed first on the left knee and the patient was discharged within 1 week. Three months later, the patient complained of pain in the upper middle 1/3 part of the medial tibia for 2 weeks, which gradually worsened and affected weight-bearing. Physical examination showed that the left knee joint presented varus deformity, and the right valgus deformity, which diagnosed as osteoarthritis of both knees and was so-called "blownknee". The disease was initially diagnosed as osteoarthritis of both knees on first admission and PPF of the tibia in second. Three operations were performed on this patient. The first was TKA of the left knee, the second was open reduction and internal fixation of the PPF of the tibia 3 months after the first operation, and the third was TKA of the right knee. Until now, the patient has had no recurrent PPF, and the fracture is healing from the last X-ray. Clinicians should be aware of the possibility of PPF after TKA, especially in such patients, the most preferred surgical treatment method was open reduction and internal fixation of fractures using locking plates, and if the PPF with loosened implants, Revision TKA, or megaprosthesis was the better choice.

Outcomes of the Rotating Hinge Knee in Revision Total Knee Arthroplasty: A Short-term Report with a Median Follow-up of 2.75 Years in a Large Asian Institute

Outcomes of the Rotating Hinge Knee in Revision Total Knee Arthroplasty: A Short-term Report with a Median Follow-up of 2.75 Years in a Large Asian Institute

A comparison between 3D printed models and standard 2D planning in the use of metal block augments in revision knee arthroplasty.

The study focused on the ability to predict the need and size of femoral and tibial augmentation using standard two-dimensional (2D) templates and models created with three-dimensional (3D) printing in surgical planning. This observational cohort study included 28 consecutive patients (22 females, 6 males; mean age: 71±7.3 years; range, 54 to 82 years) with periprosthetic joint infection recruited between March 2021 and September 2023 undergoing revision total knee arthroplasty revision (TKA). Standard planning was made using calibrated X-ray images. The 3D planning started with computed tomography scans to generate a 3D template of the distal femur and proximal tibia. The model was exported to a 3D printer to produce a patient-specific phantom. The surgery was then simulated on the 3D phantom using revision knee arthroplasty instrumentation to evaluate the appropriate augmentation to use until a correct alignment was obtained. Three-dimensional planning predicted the need for femoral and tibial augments in 22 (78.6%) cases at both the tibial and femoral components, while 2D planning correctly predicted the need for augmentation in 17 (60.7%) for the tibial side and 18 (64.3%) for the femoral side. The Cohen's kappa demonstrated a significant agreement between the 3D planning for the femoral metal block and the intraoperative requirement (kappa=0.553), whereas 2D planning showed only nonsignificant poor agreement (kappa=0.083). In contrast, the agreement between 2D or 3D preoperative planning for tibial augment and the intraoperative requirement was nonsignificant (kappa=0.130 and kappa=0.158, respectively). On the femoral side, 2D planning showed only a fair nonsignificant correlation (r=0.35, p=0.069), whereas 3D planning exhibited substantial agreement with the actual thickness of the implanted augment (r=0.65, p<0.001). On the tibial side, 3D and 2D planning showed substantial agreement with the actual size of implanted augments (3D planning, r=0.73, p<0.001; 2D planning, r=0.69, p<0.001). Prediction based on 3D computed tomography segmentation showed significant agreement with the intraoperative need for augmentations in revision TKA. The results suggest that planning with 3D printed models represents a stronger aid in this kind of surgery rather than standard 2D planning, providing greater accuracy in the prediction of the required augmentation in revision TKA.

Impact of systemic lupus erythematosus (SLE) on outcomes following aseptic and septic revision total knee arthroplasty: an analysis of the 2005-2018 nationwide inpatient sample.

Systemic lupus erythematosus (SLE) can adversely affect surgical outcomes, and the impact on revision total knee arthroplasty (TKA) outcomes is unclear. This study aimed to explore the impact of SLE on in-patient outcomes of revision TKA. The Nationwide Inpatient Sample (NIS) database from 2005 to 2018 was searched for patients aged ≥ 18years old who received revision TKA. Patients with and without SLE were propensity score matched (PSM) at a 1:4 ratio. Associations between SLE and in-hospital outcomes were examined using regression analyses. The study included 133,054 patients, with 794 having SLE. After 1:4 PSM, data of 3,970 patients were analyzed (SLE, 794; non-SLE, 3,176). Multivariate-adjusted analyses revealed that SLE patients had a significantly higher risk of postoperative complications (adjusted odds ratio [aOR] = 1.23, 95% confidence interval [CI]: 1.05-1.44, p = 0.011), non-routine discharge (aOR = 1.22, 95% CI: 1.02-1.46, p = 0.028), major blood loss (aOR = 1.19), respiratory failure/mechanical ventilation (aOR = 1.79), acute kidney injury (AKI) (aOR = 1.47), and wound dehiscence (aOR = 2.09). SLE patients also had a longer length of hospital stay (aBeta = 0.31) and greater total hospital costs (aBeta = 6.35) compared to non-SLE patients. Among those with aseptic failure, SLE patients had a significantly higher risk of postoperative complications (aOR = 1.23) and non-routine discharge (aOR = 1.36). SLE is independently associated with worse in-hospital outcomes in patients undergoing revision TKA. This study highlights the importance of heightened vigilance and tailored perioperative management for patients undergoing major surgeries in the background of SLE. Key Points • SLE significantly increases the risk of non-routine discharge, major blood loss, respiratory failure, acute kidney injury, and wound dehiscence, in patients undergoing aseptic and septic revision TKA. • Patients with SLE experience longer hospital stays and higher hospital costs compared to those without SLE. • The study's findings highlight the necessity for healthcare providers to consider the presence of SLE as a critical factor in preoperative planning and postoperative care to improve outcomes in revision TKA patients.

An evaluation of the diagnostic performance of the triphasic bone scintigraphy in patients suspected of aseptic total knee arthroplasty loosening

BackgroundTotal Knee Arthroplasty (TKA) is a widely conducted and successful orthopedic procedure. However, aseptic loosening, a common cause of TKA failure, necessitates revision surgery. Diagnostic accuracy of triphasic bone scintigraphy, a common imaging modality for aseptic loosening detection, remains controversial. This study investigated the diagnostic accuracy of bone scintigraphy when separately evaluated by a nuclear physicist and an orthopedic surgeon, and the interrater reliability between the two. MethodsPatients undergoing knee revision surgery due to suspected aseptic loosening at three medical centers from 2006 to 2023 were included. Relevant demographic, clinical, and procedural data were extracted from the records. The bone scintigraphy results as noted by the nuclear physicist and orthopedic surgeon were used as index test and intraoperative findings of loosening were used as reference tests. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were calculated, and kappa's agreement was assessed. ResultsOut of 611 revision TKAs, 59 cases were analyzed. The nuclear physicist's evaluation of bone scintigraphy had a sensitivity of 73 %, specificity of 0 %, positive predictive value of 93 %, negative predictive value of 0 %, and diagnostic accuracy of 69 %. The orthopedic surgeon's evaluation showed higher sensitivity, specificity, positive and negative predictive values, and an accuracy of 84 %. Agreement levels were moderate (kappa = 0.46) between the nuclear physicist's and orthopedic surgeons evaluation. InterpretationThe diagnostic accuracy of bone scintigraphy for aseptic loosening is 84 % when evaluated by the orthopedic surgeon compared to 69 % for the nuclear physicist's evaluation. Kappa's agreement between the two was moderate.

Incidence and related risk factors for postoperative delirium following revision total knee arthroplasty: a retrospective nationwide inpatient sample database study.

Postoperative delirium (POD) is a common surgical complication. However, the incidence and risk factors associated with postoperative delirium after revision total knee arthroplasty (rTKA) have not been comprehensively explored through extensive national databases. Utilizing the National Inpatient Sample (NIS), the largest comprehensive U.S. hospital healthcare database, we undertook a retrospective investigation involving 127,400 patients who underwent rTKA between 2010 and 2019. We assessed various aspects, including patient demographics, hospital characteristics, pre-existing medical conditions, and perioperative complications. The overall incidence of postoperative delirium (POD) in patients undergoing rTKA between 2010 and 2019 was 0.97%. The highest incidence rate of 1.31% was recorded in 2013. Notably, this patient cohort demonstrated advanced age, increased burden of co-morbidities, prolonged hospital stays, increased hospitalization costs, and elevated in-hospital mortality rates (P < 0.001). Moreover, non-elective admissions, non-private insurance payments, and a preference for teaching hospitals were commonly observed among these patients. During their hospitalization, individuals who developed delirium subsequent to rTKA were more prone to experiencing certain perioperative complications. These complications encompassed medical issues like acute myocardial infarction, continuous invasive mechanical ventilation, postoperative shock, sepsis, stroke and other medical problems. Additionally, surgical complications including hemorrhage / seroma / hematoma, irrigation and debridement, prosthetic joint infection, periprosthetic fracture, and wound dehiscence / nonunion were noted. Several risk factors were found to be linked with the development of POD. These included advanced age (≥ 75years), alcohol abuse, coagulation disorders, congestive heart failure, depression, fluid and electrolyte imbalances, and more. Conversely, female sex, having private insurance, and undergoing elective hospitalization emerged as protective factors against POD. Our findings suggest that the general prevalence of POD in rTKA is relatively low according to NIS. There was a significant connection between the POD of rTKA and advanced age, prolonged length of stay (LOS), more in-patients' costs, higher in-hospital mortality rate, increased comorbidities, postoperative medical complications and postoperative surgical complications. This study helps to understand the risk factors associated with POD to improve poor outcomes.

Risk factors associated with re-revision following revision total knee arthroplasty: a systematic review.

The aim of this study was to perform a systematic review and bias evaluation of the current literature to create an overview of risk factors for re-revision following revision total knee arthroplasty (rTKA). A systematic search of MEDLINE and Embase was completed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The studies were required to include a population of index rTKAs. Primary or secondary outcomes had to be re-revision. The association between preoperative factors and the effect on the risk for re-revision was also required to be reported by the studies. The search yielded 4,847 studies, of which 15 were included. A majority of the studies were retrospective cohorts or registry studies. In total, 26 significant risk factors for re-revision were identified. Of these, the following risk factors were consistent across multiple studies: age at the time of index revision, male sex, index revision being partial revision, and index revision due to infection. Modifiable risk factors were opioid use, BMI > 40 kg/m2, and anaemia. History of one-stage revision due to infection was associated with the highest risk of re-revision. Overall, 26 risk factors have been associated with an increased risk of re-revision following rTKA. However, various levels of methodological bias were found in the studies. Future studies should ensure valid comparisons by including patients with identical indications and using clear definitions for accurate assessments.

Suction drain usage has no benefit following revision total hip and knee arthroplasty.

The use of drains after primary total joint arthroplasty (TJA) has shown little benefit. Few studies have investigated drain usage after revision TJA. The purpose of this study was to determine whether utilizing suction drains is beneficial for patients undergoing revision arthroplasty. We performed a comprehensive literature review utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines from the PubMed, Embase, Web of Science, and Cochrane Library. Inclusion criteria of this review were all original articles written in English investigating the efficacy and safety of closed suction drainage in revision TKA or THA, reporting at least one of the following outcome measures: (1) estimated blood loss (EBL), (2) perioperative hemoglobin change, (3) needs for transfusion, (4) postoperative infection, and (5) wound complications. Articles were excluded if they are not available in English or they included case reports, systematic reviews, comments, editorials, surveys, or animal studies prior to July 22, 2023. A total of six studies met inclusion criteria. In total, 655 patients had a drain while 1765 patients did not have a drain after revision total hip or knee arthroplasty. Primary outcomes included for meta-analysis included estimated blood loss (EBL), postoperative hemoglobin, need for transfusion. Other data extracted includes postoperative infections, and wound complications. Six studies met the inclusion criteria. In total, 655 patients had drains, while 1765 patients did not after revision total hip or knee arthroplasty. The average age of the patients was 66.1+/- 3.4 years, and the average BMI was 30.3 +/-0.8. There was no difference in postoperative infections (p = 0.14), wound complications (p = 0.621) or need for transfusion (p = 0.521) between the two groups. There was also no difference in EBL (Hedges' g CI[-3.52, 2.77]) or postoperative Hb (Hedges' g CI[-1.65, 2.41]) between patients with and without drains. Our results do not show any benefit from drain placement after revision total hip or knee arthroplasty. With the increased cost, time and need for drain removal, this is likely an unnecessary intervention. Level III, systematic review and meta-analysis.

Unexpected positive cultures in revision total knee arthroplasty after unicompartmental knee arthroplasty.

Unexpected positive cultures are defined as a single positive culture in intraoperative samples taken during revision surgery after prosthetic joint infection was preoperatively ruled out. This study aims to determine the prevalence of unexpected positive cultures (UPC) in revision total knee arthroplasty (TKA) after unicompartmental knee arthroplasty (UKA). As a secondary objective, this study aims to compare the re-intervention rate in this specific group, between UPC and non-UPC patients. The hypothesis is that the UPC prevalence in patients who undergo a revision TKA after UKA is not higher than in other TKA revision cases and this does not increase the risk of re-intervention. This is a retrospective study where all patients who underwent a UKA revision from January 2016 to February 2023 in a high-volume arthroplasty centre, were analyzed. Unexpected positive culture prevalence in this group of patients was obtained. During the included period, 270 UKA revision surgeries were performed. Eight cases had at least two positive cultures and were therefore excluded. The final analysis included 262 patients. Of these, 8 (3.05%) patients presented UPCs and the isolated microorganisms were low-virulence organisms. None of the UPC patients received any treatment. No statistical differences were found between UPC and non-UPC groups in the analyzed variables. The prevalence of unexpected positive cultures in patients following revision of unicompartmental knee arthroplasty is lower than in patients who undergo a revision of total knee arthroplasty. In UKA patients a UPC does not seem to increase the risk of a re-intervention, so it can be safely ignored if ICM criteria are not met.

High Rates of Early Septic Failure, but Low Rates of Aseptic Loosening After Revision Total Knee Arthroplasty With Contemporary Rotating-Hinge Prostheses

BackgroundThe purpose of this study was to determine implant survivorship and functional outcomes for revision total knee arthroplasty (rTKA) with contemporary rotating-hinge knee implants. MethodsA retrospective review identified 115 rTKAs using contemporary rotating-hinge implants from 2014 to 2018 for the treatment of instability (34, 30%), reimplantation after periprosthetic joint infection (PJI) (33, 29%), aseptic loosening (25, 22%), arthrofibrosis (14, 12%), periprosthetic fracture (4, 3%), osteolysis (4, 3%), and femoral component fracture (1, 1%). There were 70 women (61%), and the mean age was 67 years (range, 27 to 94). The mean follow-up was 3 years (range, 2 to 6). Kaplan-Meier analysis and Cox proportional hazard models estimated survivorship. ResultsThe re-revision rate was 20% (23 of 115) at an average of 18 months postoperatively. Re-revision indications included PJI (n = 14), aseptic loosening (n = 4), arthrofibrosis (n = 2), instability/malalignment (n = 1), femoral stem fracture (n = 1), and hinge mechanism disruption (n = 1). At 2 and 5 years, survivorship free from all-cause re-revision was 86 and 64%, and survivorship free from re-revision for aseptic loosening was 100 and 87%, respectively. Use of a rotating-hinge implant in reimplantation after PJI was a risk factor for subsequent re-revision (hazard ratio = 2.4, P = 0.046). On a radiographic review of unrevised rotating-hinges, there were major radiolucent lines around 2 femoral and 5 tibial components. The mean Knee Injury and Osteoarthritis Outcomes Score for Joint Replacement increased from 43 preoperatively to 60 at 1 year (P < 0.001). ConclusionsIn patients treated with a rotating-hinge implant for rTKA, there were relatively poor 2-year (86%) and 5-year (64%) survivorship free from all-cause re-revision, most commonly due to PJI. Midterm survivorship free from re-revision for aseptic loosening was modest (87%). There should be a goal to mitigate complications in complex rTKAs with rotating-hinge implants, namely PJI.

Rotating Hinge Revision Total Knee Arthroplasty Provides Greater Arc of Motion Gains for Patients Who Have Severe Arthrofibrosis

BackgroundArthrofibrosis is a common postoperative total knee arthroplasty (TKA) complication that results in limited range of motion (ROM). There is limited literature on outcomes after revision TKA (rTKA) for arthrofibrosis based on preoperative ROM restriction. The aims of this study were to: (1) examine ROM trajectory after rTKA for arthrofibrosis patients who have severe versus nonsevere limitations; (2) compare ROM gains and final arc of motion (AOM) between severe and nonsevere cohorts; (2a) compare ROM gain in a severe cohort treated with a rotating hinge (RH) versus a non-RH (NRH) construct; and (3) assess the impact of arthrofibrosis severity on patient-reported outcome measures. MethodsPatients were divided into 2 groups: group A had preoperative ROM < 70° (severe), and group B had preoperative ROM > 70° (non-severe). Patients were assessed clinically using AOM gain, absolute ROM, Knee injury and Osteoarthritis Outcomes Score for Joint Replacement, lower extremity activity scale, and pain scores. Postoperative gains in AOM were compared between both groups. ResultsA total of 56 rTKAs (group A (severe): n = 36, group B (non-severe): n = 20) were performed for patients who have postoperative fibrosis. Group B had better ROM at the 1-year time point (group B: 95.9 ± 22.5 degrees versus group A: 83.2 ± 25.7 degrees). Group A had significantly better improvement in absolute AOM than group B (31.1 ± 20.9 versus 11.4 ± 25.0 degrees, P < 0.01). The RH group demonstrated significantly better absolute AOM gain than the NRH group (41.3 ± 19.4 versus 18.3 ± 15.2 degrees, P < 0.001). However, there were no significant differences in patient-reported outcome measures between groups A and B or between RH and NRH groups at the final follow-up. ConclusionsFinal ROM achieved between severe and nonsevere arthrofibrosis groups was similar, and patients who have severe arthrofibrosis can expect greater absolute ROM gains and similar functional outcomes than nonsevere arthrofibrosis patients. The RH rTKAs provided greater AOM gains for patients who have severe arthrofibrosis, with equivalent functional outcomes to non-RH implants. For severe arthrofibrosis patients, RH designs provided twice the overall ROM gain; however, longer follow-up is necessary to determine whether RH designs have inferior overall implant survivorship.

Serum albumin-to-globulin ratio and CRP-to-albumin ratio did not outperform serum CRP in diagnosing periprosthetic joint infections.

Serum inflammatory parameters are widely used to aid in diagnosing a periprosthetic joint infection (PJI). Due to their limited performances in the literature, novel and more accurate biomarkers are needed. Serum albumin-to-globulin ratio (AGR) and serum CRP-to-albumin ratio (CAR) have previously been proposed as potential new parameters, but results were mixed. The aim of this study was to assess the diagnostic accuracy of AGR and CAR in diagnosing PJI and to compare them to the established and widely used marker CRP. From 2015 to 2022, a consecutive series of 275 cases of revision total hip (n = 129) and knee arthroplasty (n = 146) were included in this retrospective cohort study. Based on the 2021 European Bone and Joint Infection Society (EBJIS) definition, 144 arthroplasties were classified as septic. Using receiver operating characteristic curve (ROC) analysis, the ideal thresholds and diagnostic performances were calculated. The areas under the curve (AUCs) were compared using the z-test. AGR, CAR, and CRP were associated with PJI (p < 0.001). Sensitivities were 62.5% (95% CI 54.3 to 70.0), 73.6% (95% CI 65.8 to 80.1), and 71.5% (95% CI 63.6 to 78.3), respectively. Specificities were calculated with 84.7% (95% CI 77.5 to 89.9), 86.3% (95% CI 79.2 to 91.2), and 87.8% (95% CI 80.9 to 92.4), respectively. The AUC of CRP (0.797 (95% CI 0.750 to 0.843)) was significantly higher than the AUC of AGR (0.736 (95% CI 0.686 to 0.786), p < 0.001), and similar to AUC of CAR (0.799 (95% CI 0.753 to 0.846), p = 0.832). Decreased sensitivities were observed in PJIs caused by low-virulence organisms (AGR: 60%, CAR: 78%) compared to high-virulence pathogens (AGR: 80%, p = 0.042; CAR: 88%, p = 0.158). Higher sensitivities were seen in acute haematogenous (AGR: 83%, CAR: 96%) compared to chronic PJIs (AGR: 54%, p = 0.001; CAR: 65%, p < 0.001). Serum AGR and CAR showed limited diagnostic accuracy (especially in low-grade and chronic infections) and did not outperform the established marker CRP in our study. Hence, neither parameter can be recommended as an additional tool for diagnosing PJI.

Revision Total Knee Arthroplasty Achieves Minimal Clinically Important Difference Faster Than Primary Total Knee Arthroplasty

BackgroundRevision total knee arthroplasty (rTKA) remains underexplored regarding patient-reported outcome measures (PROMs), particularly in terms of time to reach minimal clinically important difference (MCID). This study addresses this gap by comparing the time to achieve MCID between primary TKA (pTKA) and rTKA patients, providing valuable insights into their recovery trajectories. MethodsA total of 8,266 TKAs (7,618 pTKA and 648 rTKA) were retrospectively studied in a multi-institutional arthroplasty registry. Patients who completed the patient-reported outcomes measurement information system (PROMIS) global physical, PROMIS physical function short form 10a (PF-10a), and knee injury and osteoarthritis outcome score physical function short form (KOOS-PS) questionnaires were identified by Current Procedural Terminology codes. Survival curves with and without interval censoring were utilized to evaluate the time to achieve MCID. ResultsComparing the time to achieve MCID, rTKAs were significantly faster than pTKA for PROMIS global physical (3.5 versus 3.7 months, P = 0.004) and KOOS-PS (3.3 versus 4.2 months, P < 0.001), but similar for PROMIS PF-10a (4.4 versus 4.8 months, P = 0.057). Interval censoring also showed similar trends with earlier times to achieve MCID for rTKAs for PROMIS global physical (0.6 to 0.61 versus 0.97 to 0.97 months, P = 0.009) and KOOS-PS (0.97 to 0.97 versus 1.47 to 1.47 months, P < 0.001), but not for PROMIS PF-10a (2.43 to 2.54 versus 1.90 to 1.91 months, P = 0.92). ConclusionsThe present study revealed that the time to achieve MCID was faster in patients undergoing rTKA compared to those undergoing pTKA. These findings allow surgeons to reassure preoperative rTKA patients that their recovery to a MCID postoperatively may be quicker than expected, especially when compared to their initial recovery after primary TKA. Level of EvidenceLevel III.

Knee fusion versus above knee amputation as two options to deal with knee periprosthetic joint infection.

Periprosthetic joint infection (PJI) poses a significant challenge in total knee arthroplasty (TKA), with recurrence rates as high as 14-28%, leading to substantial morbidity and treatment costs. When conventional treatments fail, knee fusion and above-the-knee amputation (AKA) emerge as alternative options. Existing literature offers conflicting views on the efficacy and impact of knee fusion versus AKA with varied outcomes and limitations. This retrospective national study spanning 2010-2022 investigates Knee Fusion and AKA as options for addressing Knee PJI. Utilizing PearlDiver Patient Records Database, procedural, and reimbursement data on over 100million individuals from all the US was evaluated. Readmission rates, costs, and complications of the mentioned procedures were assessed using ICD-9 and ICD-10 codes within a 90-day period and one-year post-operation. Statistical analyses, including chi-square tests and regression models, were conducted using integrated R software. The study reveals a substantial escalation (p < 0.0001) in the proportion of patients opting for AKA compared to arthrodesis. While age as a demographic factor showed no significant difference, arthrodesis patients exhibited lower comorbidity scores (3.6 ± 2.9 vs. 4.6 ± 3.4, p < 0.001). Arthrodesis correlated with higher 90-day thromboembolism rates (9.2% vs. 7.3%, p < 0.001), blood transfusion requirements (23.2% vs. 14.4%, p < 0.001), and acute renal failure incidence (p = 0.008) but demonstrated lower rates of urinary tract infections (p = 0.047) and cerebrovascular accidents (p < 0.001). At 1 year, arthrodesis was associated with higher infection rates (38.7% vs. 36.4%, p < 0.001). Arthrodesis patients had significant increased 90-day and 1-year readmission rates and hospitalization costs ($12,732 vs. $18,826, p < 0.001). We found higher rates of 1-year thromboembolism, infection, acute renal failure, and readmission in the arthrodesis group. AKA patients had more sepsis and cerebrovascular accidents. A patient-centered conversation is best for persistent infections and failed revision TKA. Considering the patient's quality of life, goals, and health status, this discussion should cover each procedure's risks and complications.

Clinical outcomes of two-stage revision arthroplasty using a spiked tibial cement spacer in infected total knee arthroplasty.

A tibial cement spacer (TCS) with spikes offers better initial stability than a conventional TCS and reduces spacer-related problems in two-stage revision total knee arthroplasty (R-TKA) for infection. We compared the clinical outcomes of two-stage revision arthroplasty for infected TKA using spiked TCS with that of conventional TCS. This retrospective cohort study included 29 patients who underwent two-stage revision arthroplasty using an articulating cement spacer and who could be followed up for at least one year. Group S comprised 14 patients using spiked TCS, whereas Group C comprised 15 patients using conventional TCS. Demographic data, the interval from first to second stage revision, motion arc, numerical rating scale (NRS), Knee Society (KS) score, serum levels of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), and frequency of repeating the first-stage and infection recurrence after R-TKA between the groups were analyzed. No significant differences were observed in the female ratio and mean age between both groups. The mean interval between the first and second stage revision was significantly shorter in Group S than in Group C. The mean motion arc was significantly larger in Group S than in Group C. The mean NRS was significantly lower in Group S than in Group C. The mean KS score in Group S was significantly higher than that in Group C. Serum ESR and CRP levels did not differ between the groups. The frequency of repeating the first stage was lower in Group S than in Group C. However, the recurrence rate after R-TKA was higher in Group S than in Group C. Compared with conventional TCS, spiked TCS shortened the period until R-TKA and improved pain and function levels. However, no significant difference existed in the rate of infection recurrence after R-TKA.