Aseptic Revision Total Knee Arthroplasty Research Articles

Prevalence of unexpected intraoperative cultures (UPIC) in revision total knee arthroplasty (TKA) and risk of periprosthetic joint infection (PJI).

Prevalence of unexpected positive intraoperative cultures (UPIC) in revision total knee arthroplasty (TKA) is reported to be 8.32% with largely varying findings in individual studies (5.92-62.07%) due to a heterogeneity in preoperative diagnostic work-up and diagnostic criteria for periprosthetic joint infection (PJI). When diagnosed as unsuspected PJI, re-revision rate is reported to be as high as 18.45% compared to 2.94% in patients with UPIC classified as contamination (p = 0.0237). We performed a monocentric retrospective analysis of revision TKA surgery to determine prevalence of UPIC, risk of developing a subsequent PJI and re-revision rate after 24 months compared to those without UPIC. All presumed aseptic total knee revision procedures from 2008 until 2017 were retrospectively reviewed. Single stage femorotibial revisions of TKA with at least 3 intraoperative cultures and a minimum follow-up of 24 months were included, whereas partial revisions or revisions from unicompartimental knee prosthesis to TKA were excluded. Demographic data were collected as well as initial reason for revision, preoperative aspiration results, micro-organism identified and postoperative antibiotics' administration. Primary outcome was survival rate after 24 months with differentiation based on UPIC interpretation: sterile, contamination, unsuspected PJI. Of 256 included cases, 75 (29.3%) were found to have at least 1 UPIC during revision surgery, 72% of whom a single UPIC was found. Thirty-four cases (13.28%) were interpreted as unsuspected PJI and therefore treated with antibiotics. In total, 13 of the 256 patients (5.08%) had to be re-revised during follow-up with 7 PJI (2.73%), none of them developing reinfection defined as PJI with the same microorganism. A statistically significant trend towards earlier failure in the unsuspected PJI group compared to the contaminant group was not observed. However, a higher incidence of re-revisions attributed to septic reasons was noted in the former group. Presence of UPIC in presumed aseptic revision TKA does not correlate with a lower survival rate, but a higher incidence of subsequent PJI was observed in cases interpreted as unsuspected PJI.

Unexpected positive cultures in aseptic revision hip and knee arthroplasty.

The outcomes of patients with unexpected positive cultures (UPCs) during revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) remain unknown. The objectives of this study were to establish the prevalence and infection-free implant survival in UPCs during presumed aseptic single-stage revision THA and TKA at mid-term follow-up. This study included 297 patients undergoing presumed aseptic single-stage revision THA or TKA at a single treatment centre. All patients with at least three UPCs obtained during revision surgery were treated with minimum three months of oral antibiotics following revision surgery. The prevalence of UPCs and causative microorganisms, the recurrence of periprosthetic joint infections (PJIs), and the infection-free implant survival were established at minimum five years' follow-up (5.1 to 12.3). Of the 297 patients undergoing aseptic revisions, 37 (12.5%) had at least three UPCs obtained during surgery. The UPC cohort included 23 males (62.2%) and 14 females (37.8%), with a mean age of 71.2 years (47 to 82). Comorbidities included smoking (56.8%), hypertension (48.6%), diabetes mellitus (27.0%), and chronic renal impairment (13.5%). The causative microorganisms included Staphylococcus epidermidis (49.6%), Bacillus species (18.9%), Micrococcus species (16.2%), and Cutibacterium acnes (16.2%). None of the study patients with UPCs developed further PJIs or required further surgical intervention during follow-up. The prevalence of UPCs during presumed aseptic revision THA and TKA was 12.5%. The most common causative microorganisms were of low virulence, and included S. epidermidis, Bacillus species, Micrococcus species, and C. acnes. Microorganism-specific antibiotic treatment for minimum three months' duration of UPCs in presumed aseptic revision arthroplasty was associated with excellent infection-free implant survival at mid-term follow-up.

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.

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.

Unsuspected Positive Intraoperative Cultures in Aseptic Revision Knee Arthroplasty: Prevalence, Management, and Infection-Free Survivorship

BackgroundThe purpose of this study was to evaluate the management and outcomes of aseptic revision total knee arthroplasty (arTKA) with unsuspected positive cultures (UPCs) compared to those with sterile cultures. MethodsThe institutional database at a single tertiary center was retrospectively reviewed for arTKA from January 2013 to October 2023. Patients who met Musculoskeletal Infection Society criteria for periprosthetic joint infection (PJI) based on available preoperative infectious workup, received antibiotic spacers, or did not have at least 1 year of follow-up were excluded. Patients were stratified based on intraoperative cultures into 4 cohorts: sterile cultures, 1 UPC, ≥ 2 UPCs with different organisms, and ≥ 2 UPCs with the same organism. Univariable analyses were used to compare these groups. Kaplan-Meier survivorship analysis assessed infection-free survival at 5 years, and Cox proportional hazards regressions were used to evaluate factors that influence infection-free survival. A total of 691 arTKAs at a mean follow-up of 4.2 years were included in the study. Of these, 49 (7.1%) had 1 UPC with a new organism, 10 (1.4%) had ≥2 UPCs of the same organism, and 2 (0.2%) had ≥2 UPCs with different organisms. ResultsPostoperative antibiotics were prescribed to 114 (16.5%) patients—13 (26.5%) with 1 UPC, 6 (60.0%) with ≥2 UPCs of the same organism, and 0 (0.0%) of patients who had ≥2 UPCs of different organisms. There were no differences in infection-free survival at 5 years between patients who had sterile cultures and 1 UPC (96 versus 89%; P = .39) nor between sterile cultures and ≥2 UPCs of different organisms (96 versus 100%; P < .72). However, patients who had ≥2 UPCs of the same organism had significantly worse infection-free survival at 5 years compared to patients who had sterile cultures (58 versus 96%; P < .001). Cox proportional hazards regression suggested that when adjusting for covariates, an American Society of Anesthesiologists classification of ≥3 (hazard ratio [HR] = 3.1; P = .007), ≥2 UPCs of the same organism (HR = 11.0; P < .001), 1 UPC (HR = 4.2; P = .018), and arTKA with hinge constructs (HR = 4.1; P = .008) were associated with increased risk of rerevision for PJI. ConclusionsPatients who had 1 UPC or ≥2 UPCs with different organisms had similar infection-free survival at 5 years as patients who had sterile cultures. However, patients who had ≥2 UPCs of the same organism had significantly worse infection-free survival at 5 years. Overall, 1 UPC or ≥2 UPCs of the same organism at the time of arTKA may suggest the patient is at higher risk of rerevision for PJI. More studies are needed to determine what interventions can be implemented to mitigate this risk.

Synovial fluid NMR-based metabolomics in septic and aseptic revision total knee arthroplasty: Implications on diagnosis and treatment.

Periprosthetic joint infection (PJI) is one of the most challenging complications following total knee arthroplasty. Despite its importance, there is a paucity of reports in the literature regarding its pathogenesis. Recently, cellular metabolic reprogramming has been shown to play an important role in the progression and outcome of infectious diseases. Therefore, the aim of this study was to evaluate the metabolites composition of the synovial fluid from patients with PJI or aseptic failure of total knee arthroplasties. The synovial fluids from 21 patients scheduled for revision total knee arthroplasty (11 with the diagnosis of PJI and 10 with aseptic failures) were analyzed using 1D 1H NMR spectroscopy. Univariate and multivariate statistical analyzes were used to identify metabolites that were differentially abundant between those groups. A total of 28 metabolites were identified and five of them found to be differentially abundant between infected and non-infected synovial fluids. Lactate, acetate and 3-hydroxybutyrate were found to be in a higher concentration, and glucose and creatine were found reduced in the synovial fluid from PJI patients. Synovial fluid from patients with PJI exhibit a distinct metabolic profile, possibly reflecting metabolic adaptation that occurs in the infected periprosthetic microenvironment. Further research and studies are warranted to gain a broader insight into the metabolic pathways engaged by both pathogen and immune cells in the context of a PJI.

Low Risk of Periprosthetic Joint Infection After Aseptic Revision Total Knee Arthroplasty With Intraosseous Vancomycin

BackgroundAseptic revisions are the most common reason for revision total knee arthroplasty (rTKA). Previous literature reports early periprosthetic joint infection (PJI) rates after aseptic rTKA to range from 3 to 9.4%. Intraosseous (IO) regional administration of vancomycin has previously been shown to produce high local tissue concentrations in primary and rTKA. However, no data exist on the effect of prophylactic IO vancomycin on early PJI rates in the setting of aseptic rTKA. The aim of this study was to determine the following: (1) what is the rate of early PJI during the first year after surgery in aseptic rTKA performed with IO vancomycin; and (2) how does this compare to previously published PJI rates after rTKA. MethodsA consecutive series of 117 cases were included in this study who underwent rTKA between January 2016 and March 2022 by 1 of 2 fellowship-trained adult reconstruction surgeons and received IO vancomycin at the time of surgery in addition to standard intravenous antibiotic prophylaxis. Rates of PJI at 3 months, 1 year, and the final follow-up were evaluated and compared to prior literature. ResultsFollow-up at 3 months was available for 116 of the 117 rTKAs, with 1 lost to follow-up. The rate of PJI was 0% at 3 months postoperatively. Follow-up at 1 year was obtained for 113 of the 117 rTKAs, and the PJI rate remained 0%. The rate of PJI at the final follow-up of ≥ 1 year was 0.88% (95% confidence interval: −0.84 to 2.61). Previous literature reports PJI rates in aseptic rTKA to range from 3 to 9.4%. ConclusionsDual prophylactic antibiotics with IO vancomycin in conjunction with intravenous cephalosporins or clindamycin were associated with a substantial reduction in early PJI compared to prior published literature. These data supplement the early evidence about the potential clinical benefits of IO vancomycin for infection prevention in high-risk cases. Level of EvidenceLevel III, therapeutic study.

Incidence of patella baja and pseudopatella baja in aseptic revision total knee arthroplasty.

There are two variants regarding the low location of the patella in relation to the tibio-femoral joint line: patella baja (PB) and pseudo-patella baja (PPB). The purpose of this study is to investigate the incidence of PB and PPB in a cohort of patients that underwent revision total knee arthroplasty (rTKA) for aseptic reasons and describe any differences in each group's ROM. This retrospective study included 114 patients that underwent aseptic revision TKA surgery between 2017 and 2022. Patients were revised either for stiffness (Group 1) or aseptic loosening/instability (Group 2). The Insall-Salvati ratio (ISR) and Blackburne-Peel ratio (BPR) were used to evaluate the patellar position. ISR < 0.8 defined PB, while cases with ISR ≥ 0.8 and BPI < 0.54 were defined as PPB. ROM was measured and a subanalysis was conducted to investigate the progression of the values of ISR and BPR. 55 patients comprised Group 1, and 59 patients comprised Group 2. Overall, 13 cases (11.4%) had PB before rTKA and 24 (21%) had PB after rTKA. Cases with PPB were 13 (11.4%) before and 34 (29.9%) after rTKA. Group 1 patients presented with more PB before and after rTKA (12.8% vs 10.2% and 27.3% vs 15.2% respectively). However, after rTKA Group 1 patients presented with less PPB (20%) compared to Group 2 (39%) (p = 0.02). In Group 1, patients with PPB after rTKA had less ROM compared to those without PPB [83.2 (± 21.9) vs 102.1 (± 19.9) (p = 0.025)]. The subanalysis (69 patients) showed a statistically significant decrease in ISR before and after rTKA (p = 0.041), and from the native knee to post-rTKA (p = 0.001). There was a statistically significant decrease in BPR before and after rTKA (p = 0.001) and from the native knee to both pre- and post-rTKA (p < 001). After undergoing rTKA, the incidences of both patella baja (PB) and pseudo-patella baja (PPB) increased. Stiffness in the knee was associated with a higher incidence of PB, while non-stiffness cases showed a significantly higher incidence of PPB. Patients with stiff knees and PPB after rTKA experienced a significant reduction in range of motion (ROM). Additionally, the study revealed a noteworthy decrease in ISR and BPR with each subsequent surgery. This information is crucial for healthcare providers, as it sheds light on potential risks and outcomes of rTKA, allowing for improved patient management and surgical decision-making. III.

Complications of periprosthetic fracture revision vs aseptic revision of total knee arthroplasty

BackgroundPeriprosthetic fractures after total knee arthroplasty (TKA) are a challenging problem due to complex fracture patterns, poor bone quality, and a high-risk patient population. Treatment of both periprosthetic fractures and aseptic complications can include revision TKA. In this study, we compared systemic and orthopaedic complications following periprosthetic fracture associated revision TKA to aseptic revision TKA. MethodsThis is a retrospective cohort study using data from the years 2010–2020 from a national administrative claims database. Billing codes were used to identify revision TKAs with a diagnosis of periprosthetic fracture or aseptic complications (loosening, dislocation, arthrofibrosis, osteolysis, or prosthetic wear) within one year prior to revision. Pertinent systemic complications and rates of repeat revision TKA, periprosthetic infection, and repeat fractures were compared between the two groups. ResultsWe identified 9891 periprosthetic fracture associated revision TKAs and 47,071 aseptic revision TKAs. Our study found higher rate of systemic complications including AKI, DVT, wound disruption, hematoma, and surgical site infections in periprosthetic fracture associated revision TKA compared to aseptic revision TKA. Furthermore, we found higher rates of repeat revision TKA, periprosthetic infections, and repeat periprosthetic fractures in fracture associated revision TKA group compared to aseptic revision group. ConclusionsOur work highlights the significant short- and long-term complications associated with periprosthetic fracture associated revision TKA. Future working comparing functional outcomes and optimal surgical techniques are needed.

Multiplex PCR test as an intra-operative diagnostic tool for periprosthetic joint infection in presumed aseptic revision hip and knee arthroplasty: a 1-year follow-up study of 200 cases.

Automated custom-made multiplex PCR techniques (mPCR) have become commercially available and are designed for intra-operative screening of concurrent periprosthetic joint infections (PJIs). The purpose of this study was to evaluate the value of a positive mPCR test in presumed aseptic revision total hip (THA) and knee (TKA) arthroplasties after a 1-year follow-up. In an earlier study, such an automated mPCR technique (Unyvero ITI G2; Curetis, Holzgerlingen, Germany) was tested on intra-operatively obtained synovial fluid in 200 patients with a presumed aseptic TKA or THA revision. At the time of revision, no therapeutic consequences were attached to a positive test result since treating personnel were blinded for the test results. We retrospectively reviewed the outcome of cases with respect to the occurrence of PJIs using the European Bone and Joint Infection Society (EBJIS) criteria during a 1-year follow-up postoperatively. A total of 10 out of 200patients had a positive mPCR test result at the time of revision. Of these 10 cases, none encountered outcome parameters fulfilling the criteria to diagnose PJIs in the first year after surgery, and one required re-revision surgery for reasons other than infection. Of the other 190 negative mPCR cases, none developed a PJI. A positive mPCR test at the time of presumed aseptic revision surgery did not correspond with intra-operatively obtained tissue cultures, and none of the encountered positive mPCR tests had developed a PJI at the 1-year follow-up. We recommend careful evaluation and monitoring of modern diagnostic tests before widespread use.

Extended Prophylactic Antibiotics for Primary and Aseptic Revision Total Joint Arthroplasty: A Meta-Analysis

BackgroundThere is growing interest in extended antibiotic prophylaxis (EAP) following total joint arthroplasty (TJA); however, the benefit of EAP remains controversial. For this investigation, both oral and intravenous antibiotic protocols were included in the EAP group. MethodsThe Cochrane Database of Systematic Reviews, Cochrane Register of Controlled Trials, PubMed, MEDLINE, Web of Science, Ovid Embase, Elton B. Stephens CO, and Cumulative Index to Nursing and Allied Health Literature were queried for literature comparing outcomes of primary and aseptic revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients who were treated with either ≤24 hours of postoperative antibiotic prophylaxis (standard of care [SoC]) or >24 hours of EAP. The primary outcome was periprosthetic joint infection (PJI). A pooled relative-risk random-effects Mantel-Haenszel model was implemented to compare cohorts. ResultsThere were 18 studies with a total of 19,153 patients included. There was considerable variation in antibiotic prophylaxis protocols with first-generation cephalosporins being the most commonly implemented antibiotic for both groups. Patients treated with EAP were 35% less likely to develop PJI relative to the SoC (P = .0004). When examining primary TJA, patients treated with EAP were 39% and 40% less likely to develop a PJI for TJA (P = .0008) and THA (P = .02), respectively. There was no significant difference for primary TKA (P = .17). When examining aseptic revision TJA, EAP led to a 36% and 47% reduction in the probability of a PJI for aseptic revision TJA (P = .007) and aseptic revision TKA (P = .008), respectively; there was no observed benefit for aseptic revision THA (P = .36). ConclusionsThis meta-analysis demonstrated that patients treated with EAP were less likely to develop a PJI relative to those treated with the SoC for all TJA, primary TJA, primary THA, aseptic revision TJA, and aseptic revision TKA. There was no significant difference observed between EAP and SoC for primary TKA or aseptic revision THA.

Re-revision Total Knee Arthroplasty: Causes, Risk Factors and Results.

The rate of re-revision total knee arthroplasty (TKA) ranges between 4% and 10%, depending on the cause of the procedure. Periprosthetic joint infection (PJI) and periprosthetic fracture are the main causes of re-revision TKA. The likelihood of implant survival of re-revision TKA diminishes with each subsequent revision, with PJI being the main cause of multiple revisions. Acute early aseptic revision TKA (within 90 days of surgery) involves a high risk of re-revision at 2 years and a high risk of subsequent PJI. The use of antibiotic-loaded cement is associated with lower risk of re-revision. Patients younger than 50 years experiencing aseptic revision TKA have a 1 in 3 risk of re-revision. Patients revised for instability or having prior TKA revisions have the highest risk of re-revision at 10 years. Patients younger than 55 years experiencing revision TKA have a 5-year revision-free survival of 80%.

Clinical Outcomes and Complications of 2-Stage Septic Versus Aseptic Revision Total Knee Arthroplasty: A Systematic Review and Meta-Analysis.

Although several studies have compared the clinical outcomes of septic and aseptic revision total knee arthroplasty (TKA), their results have been controversial. Therefore, this study aimed to compare clinical outcomes and complications of septic and aseptic revision TKA through a systematic review and meta-analysis. The PubMed (MEDLINE) and Embase databases were searched for studies evaluating the clinical outcomes and complications of 2-stage septic revision and aseptic revision TKAs. A systematic review of clinical outcomes (Knee Society Knee and Function Scores and range of motion) and complications (reoperation, infection, and failure rates) was conducted. Thirteen studies were included in the systematic review. The mean MINORS (Methodological Index for NOn-Randomized Studies) score of the included studies was 20.5 (range, 18 to 22). The meta-analysis revealed higher reoperation (risk ratio [RR], 1.98; 95% confidence interval [CI], 1.50 to 2.62; p < 0.00001), infection (RR, 4.08; 95% CI, 2.94 to 5.64; p < 0.00001), and failure rates (RR, 2.88; 95% CI, 1.38 to 6.03; p = 0.005) in septic revision TKAs than in aseptic revision TKAs. Moreover, septic revision TKAs showed lower Knee Society Knee Scores compared with aseptic TKAs (mean difference [MD], -6.86; 95% CI, -11.80 to -1.92; p = 0.006). However, the Knee Society Function Score (MD, -1.84; 95% CI, -7.84 to 3.80; p = 0.52) and range of motion (MD, -6.96°; 95% CI, -16.23° to 2.31°; p = 0.14) were not significantly different between septic and aseptic revision TKAs. Despite the heterogeneity of prosthesis designs and surgical protocols used in septic and aseptic revision TKAs, the results of this systematic review suggest that 2-stage septic revision TKAs have poorer clinical outcomes and higher complication rates than aseptic revision TKAs do. Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Maintenance of the joint line and posterior condylar offset are the most notable variables for successful outcomes of revision total knee arthroplasty.

Controversy regarding which variables should be prioritized for better outcomes in revision total knee arthroplasty (RTKA) exists. This study aimed to comprehensively analyze the variables affecting RTKA outcomes. We retrospectively identified 87 RTKAs in 82 patients who were performed between March 2014 and February 2020. Range of motion (ROM), including flexion contracture (FC) and further flexion (FF), was analyzed according to the covariates. The covariates included mode of failure, joint line position, anteroposterior (AP) position, rotational alignment of the femoral component, and patellofemoral alignment. The differences between the final follow-up values of each RTKA variable and those of the native knee were evaluated. The clinical outcomes were evaluated. No significant differences were observed between the joint line positions of the RTKA and native knees. The patellar and AP positions of the femoral component were restored to pre-TKA values. The femoral component had an external rotation of 2.78° compared with the native knee. In multivariable stepwise regression analysis, restoration of the adductor tubercle joint line and posterior condylar offset (PCO) were significant variables affecting ROM. Septic RTKA (33 knees) resulted in poor FF outcomes (p = 0.030) and Western Ontario and McMaster Universities Osteoarthritis Index stiffness (WOMAC S) scores (p < 0.001), compared with aseptic RTKA (54 knees). Restoration of the joint line position and PCO are crucial factors for improved ROM in RTKA. Joint line elevation in RTKA resulted in worse ROM than joint line lowering. In addition, RTKA due to septic failure had inferior ROM and WOMAC S scores compared with RTKA due to aseptic failure. Level III, cohort study.

Knee

The August 2023 Knee Roundup360 looks at: Curettage and cementation of giant cell tumour of bone: is arthritis a given?; Anterior knee pain following total knee arthroplasty: does the patellar cement-bone interface affect postoperative anterior knee pain?; Nickel allergy and total knee arthroplasty; The use of artificial intelligence for the prediction of periprosthetic joint infection following aseptic revision total knee arthroplasty; Ambulatory unicompartmental knee arthroplasty: development of a patient selection tool using machine learning; Femoral asymmetry: a missing piece in knee alignment; Needle arthroscopy – a benefit to patients in the outpatient setting; Can lateral unicompartmental knees be done in a day-case setting?

Age-Adjusted Modified Frailty Index Predicts 30-Day Complications and Mortality in Aseptic Revision Total Hip and Knee Arthroplasty

BackgroundThe age-adjusted modified frailty index (aamFI) has been demonstrated to effectively predict postoperative complications and healthcare resource utilization in patients undergoing primary total joint arthroplasty. The purpose of this study was to evaluate the applicability of aamFI in patients undergoing aseptic revision total hip (rTHA) and knee arthroplasty (rTKA). MethodsA national database was queried for patients undergoing aseptic rTHA and rTKA from 2015 to 2020. A total of 13,307 rTHA and 18,762 rTKA cases were identified. The aamFI was calculated by adding 1 additional point for age ≥73 years to the previously described 5-item modified frailty index (mFI-5). The area under the curve was calculated and compared to compare predictive accuracy between mFI-5 and aamFI. Logistic regression was used to investigate the relationship between aamFI and 30-day complications. ResultsThe incidence of incurring any (≥1) complication increased from 15% for aamFI 0 to 45% for aamFI ≥5 after rTHA and from 5 to 55% after rTKA. Patients who had an aamFI ≥3 (reference aamFI = 0) had increased odds (rTHA: odds ratio (OR) 3.5, 95% confidence interval (CI) 2.9 to 4.1, P < .001; rTKA: OR 4.2, 95% CI 4.4 to 5.1, P < .001) of incurring at least 1 complication. The aamFI, compared to mFI-5, was a more accurate predictor of any complication (rTHA P < .001; rTKA P < .001) and 30-day mortality (rTHA P < .001; rTKA P < .003). ConclusionThe aamFI is an excellent predictor of complications in patients undergoing rTHA and rTKA. The addition of chronological age to the previously described mFI-5 improves the predictive value of this simple metric.

Black Patients are More Likely to Undergo Early Revision Total Knee Arthroplasty in a Matched Cohort Regardless of Surgeon Experience

BackgroundBlack patients are at an increased risk of aseptic revision total knee arthroplasty (TKA) when compared to White patients. The goal of this study was to determine whether racial disparities in revision TKA risk are related to surgeon characteristics. MethodsThis was an observational cohort study. We used inpatient administrative data to identify Black patients who underwent unilateral primary TKA in New York State. There were 21,948 Black patients who were matched 1:1 to White patients on age, sex, ethnicity, and insurance type. The primary outcome was aseptic revision TKA within 2 years of primary TKA. We calculated annual surgeon TKA volume and identified surgeon characteristics such as training in North America, board certification, and years of experience. ResultsBlack patients had a higher odds of aseptic revision TKA (odds ratio (OR) 1.32, 95% CI 1.12–1.54, P < .001) and were disproportionately cared for by low volume surgeons (≤12 TKA/year). The relationship between low volume surgeons and risk of aseptic revision was not statistically significant (OR 1.24, 95% CI 0.72-2.11, P = .436). The adjusted odds ratio (aOR) for aseptic revision TKA in Black versus White patients varied across surgeon/hospital TKA volume category pairs, with the greatest aOR when TKA were performed by the highest volume surgeons at the highest volume hospitals (aOR 2.8, 95% CI 0.98– 8.09, P = .055). ConclusionBlack patients were more likely to undergo aseptic TKA revision than matched White patients. This disparity was not explained by surgeon characteristics.

Contemporary mortality rate and outcomes in nonagenarians after aseptic revision hip and knee arthroplasty.

Nonagenarians (aged 90 to 99 years) have experienced the fastest percent decile population growth in the USA recently, with a consequent increase in the prevalence of nonagenarians living with joint arthroplasties. As such, the number of revision total hip arthroplasties (THAs) and total knee arthroplasties (TKAs) in nonagenarians is expected to increase. We aimed to determine the mortality rate, implant survivorship, and complications of nonagenarians undergoing aseptic revision THAs and revision TKAs. Our institutional total joint registry was used to identify 96 nonagenarians who underwent 97 aseptic revisions (78 hips and 19 knees) between 1997 and 2018. The most common indications were aseptic loosening and periprosthetic fracture for both revision THAs and revision TKAs. Mean age at revision was 92 years (90 to 98), mean BMI was 27 kg/m2 (16 to 47), and 67% (n = 65) were female. Mean time between primary and revision was 18 years (SD 9). Kaplan-Meier survival was used for patient mortality, and compared to age- and sex-matched control populations. Reoperation risk was assessed using cumulative incidence with death as a competing risk. Mean follow-up was five years. Mortality rates were 9%, 18%, 26%, and 62% at 90 days, one year, two years, and five years, respectively, but similar to control populations. There were 43 surgical complications and five reoperations, resulting in a cumulative incidence of reoperation of 4% at five years. Medical complications were common, with a cumulative incidence of 65% at 90 days. Revisions for periprosthetic fractures were associated with higher mortality and higher 90-day risk of medical complications compared to revisions for aseptic loosening. Contemporary revision THAs and TKAs appeared to be relatively safe in selected nonagenarians managed with multidisciplinary teams. Cause of revision affected morbidity and mortality risks. While early medical and surgical complications were frequent, they seldom resulted in reoperation.

What's New in Musculoskeletal Infection.

What's New in Musculoskeletal Infection.

Time Required for Planned and Unplanned Episodes of Care in Aseptic Hip and Knee Revision Arthroplasty

BackgroundStudies indicate aseptic revision total hip arthroplasty (rTHA) and revision total knee arthroplasty (rTKA) requires much more effort but is reimbursed less than primary procedures per minute work time. This study quantified planned and unplanned work performed by the surgeon and/or their team during the entire episode of care “reimbursement window” and compared it to allowed reimbursement times by Centers for Medicare and Medicaid Services (CMS). MethodsBetween October, 2010, and December, 2020, all unilateral aseptic rTHA and rTKA procedures performed by a single surgeon at a single institution were retrospectively reviewed. Time dedicated to planned work was calculated from surgery scheduling to 90 days postoperative. Impromptu patient inquiries and treatments after discharge but within the episode of care, involving the surgeon/surgeon team constituted unplanned work. Planned and unplanned work minutes were summed and divided by the number of patients reviewed to obtain average minutes of work per patient. Work time was compared to CMS allowable times for rTHA (617 minutes) and rTKA (520 minutes). ResultsThere were 292 Aseptic rTKA and 63 aseptic rTHA procedures included. Based upon CMS allowable times per patient there were a mean of 4.4 hours (267 minutes) of uncompensated care time per rTKA patient and a mean of 2.4 hours (141 minutes) of uncompensated care time per rTHA patient. ConclusionAseptic revisions are substantially more complex than primaries, requiring work effort that is not commensurate with current reimbursements. Financially disincentivizing surgeons to care for patients requiring revision surgery could reduce patient access to care when high quality care is needed the most.