Revision Total Knee Arthroplasty Research Articles

Utilization of Rehabilitation Services and Rehabilitation-Related Patient Satisfaction Following Total Knee Arthroplasty—Results of the Prospective FInGK Study

(1) Background: This study aims to examine rehabilitation service utilization among total knee arthroplasty (TKA) subjects and the influencing factors associated with rehabilitation-related satisfaction. (2) Methods: The FInGK study was a single-center prospective cohort study. Patients (≥18 years) undergoing primary or revision TKA in a German university hospital were consecutively recruited between December 2019–May 2021. The subjects filled in a questionnaire one day before surgery (t0) and at two (t1) and 12 (t2) months postoperatively. Multivariable logistic regression was conducted to determine the variables associated with the subjects’ rehabilitation-related satisfaction. (3) Results: A total of 236 out of 241 (97.9%) subjects participated in t1 (59.3% female; mean age: 68.2 years). Overall, 94.7% underwent post-TKA rehabilitation measures, with inpatient rehabilitation being the predominant choice (85.4%). In total, 77.6% of those with rehabilitation were satisfied or very satisfied with their rehabilitation in general. Multivariable logistic regression showed that female sex (OR 3.42; CI 1.73–6.75) and satisfaction with the surgery in general after two months (OR 4.50; CI 1.96–10.33) were associated with the subjects’ rehabilitation-related satisfaction. (4) Conclusions: We found a high utilization of rehabilitation services following TKA and a high rehabilitation-related satisfaction. In international comparison, the utilization of inpatient rehabilitation services was very high. Future research should investigate the effective components for rehabilitation-related satisfaction in both in- and outpatient TKA rehabilitation.

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.

Isolated aseptic loosening in total knee arthroplasty: a comprehensive 10-year review of partial vs. total component revisions

BackgroundIn total knee arthroplasty (TKA), isolated aseptic loosening (IAL) requires the replacement of prosthetic components, with ongoing debate regarding the effectiveness of partial component revision (PCR) compared to total component revision (TCR). This study aims to compare implant survival and surgical outcomes between PCR and TCR in the context of IAL.MethodsThis retrospective study analyzed data from 285 patients who underwent revision TKA for IAL between January 2000 and December 2013. After applying exclusion criteria, 112 patients were included in the analysis—60 undergoing TCR and 52 undergoing PCR.ResultsPCR was associated with shorter operative times and hospital stays compared to TCR, alongside significant differences in the choice of revision prostheses. Although the prosthesis failure rates were comparable between the groups (13.6% for TCR and 18.33% for PCR), significant risk factors for failure were identified, including a canal filling ratio (CFR) below 0.8 and a discrepancy over 0.2 between CFR views. However, no significant differences in overall survivorship were observed between the groups.ConclusionsBoth PCR and TCR provide similar survival rates and clinical outcomes for managing IAL in TKA. PCR provides advantages in terms of surgical efficiency and patient recovery, while reducing the need for more constrained prosthetic solutions. The study identifies CFR as a critical predictor of prosthesis failure, highlighting the importance of detailed preoperative planning and implant selection. These findings contribute valuable insights for improving revision strategies in IAL, enhancing surgical outcomes in TKA.Level of evidenceIII.

Examining Disparities in Regional Anesthesia Utilization, Opioid Prescriptions, and Pain Scores Among Patients Who Received Primary or Revision Total Knee Arthroplasty at a Veterans Affairs Medical Center: A Retrospective Cohort Study.

Total knee arthroplasty (TKA) is one of the most performed surgical operations in the United States. Managing postoperative pain after TKA is of vital importance, as it is positively associated with outcome measures related to recovery of function and quality of life. Two commonly used methods to control postoperative pain are regional anesthesia (RA), consisting of a single or a combination of peripheral nerve and epidural blocks, and pain medication, such as opioids. Our retrospective analysis sought to better understand whether revision versus primary TKA impacted previously discovered disparities in perioperative pain management and use of RA at the Atlanta Veterans Affairs Health Care System (AVAHCS). Before data collection, we hypothesized that revision TKA would have a higher proportion of Black and older patients and that revision TKA patients would have lower postoperative pain scores. This was a retrospective analysis of AVAHCS patients who underwent elective unilateral primary or revision TKA surgery between 2014 and 2020. After application of our exclusion criteria, data from 562 patients were analyzed. Data collected included demographics information, type of RA used, and pain scores. Statistical analyses included chi-square test, t-tests, multiple logistic regression, and multiple linear regression, as appropriate to the outcomes of interest. Revision TKA patients were more likely to be Black (P = .018) and younger (P = .023 for <50 years of age group, P = .006 for 50 to 64 years of age compared to the >65 years group). Black patients, compared to White patients, had significantly higher pain scores at baseline (P = .0086) and at 24 hours postsurgery (P = .0037). Older patients (≥50 years old) had significantly higher baseline pain scores (P = .021 for the 50 to 64 years group, P < .01 for the >65 years group) and significantly lower first postanesthesia care unit pain scores (P < .05). Black race (P < .01) and age > 65 years (P < .01) were associated with a significant decrease in total oral morphine equivalents (OME) prescribed at discharge. None of the predictor variables-race, age, type of surgery (primary versus revision), baseline, and first postanesthesia care unit pain scores-were significantly associated with the use of RA in our cohort. Sociodemographic disparities in pain management have been reported in all healthcare systems, including the VAHCS. This moderately sized retrospective study, conducted at a single veterans affairs site, yielded several noteworthy findings. One finding of particular interest was that, despite Black patients reporting higher baseline and 24-hour postoperative pain scores, they were prescribed fewer opioids at discharge. Our results highlight the presence of clinically significant disparities in perioperative TKA pain management, emphasizing the need for continuous investigation and focused mitigation efforts among Veterans.

Big data analysis reveals significant increases in complications, costs, and hospital stay in revision total knee arthroplasty compared to primary TKA.

Despite significant advancements in total knee arthroplasty (TKA), some patients require revision surgery (R-TKA) due to complications such as infection, mechanical loosening, instability, periprosthetic fractures, and persistent pain. This study aimed to explore the specific causes leading to R-TKA, associated complications, including infection, mechanical failure, and wound issues, as well as costs, mortality rates, and hospital length of stay (LOS) using data from a large national database. Data from the nationwide inpatient sample (NIS), the largest publicly available all-payer inpatient care database in the United States were analysed from 1 January 2016 to 31 December 2019. The study included 44,649 R-TKA cases, corresponding to 223,240 patients, with exclusions for nonelective admissions. Various statistical analyses were used to assess clinical outcomes, including in-hospital mortality, postoperative complications, LOS, and hospitalization costs. Among 2,636,880 TKA patients, 8.4% underwent R-TKA. R-TKA patients had higher rates of chronic conditions, including mental disorders (36.4%) and renal disease (9.9%). Additionally, these patients often experienced instability, necessitating revision surgery. Infection (22.3%) was the primary reason for R-TKA, followed by mechanical loosening (22.9%) and instability. Compared to primary TKA patients, R-TKA patients exhibited higher in-hospital mortality (0.085% vs. 0.025%), longer LOS (3.1 vs. 2.28 days), and higher total charges ($97,815 vs. $62,188). Postoperative complications, including blood transfusion (4.6% vs. 1.3%), acute kidney injury (4.4% vs. 1.8%), venous thromboembolism (0.55% vs. 0.29%), infection, and wound problems, were significantly higher in R-TKA patients. This study provides detailed insights into t LOS, costs, and complications associated with specific etiologies of revision TKA. Our findings emphasize the need for targeted preoperative optimization and patient education. This approach can help reduce the incidence and burden of R-TKA, improve patient care, optimize resource allocation, and potentially decrease the overall rates of complications in revision surgeries. Level III.

Epidemiology, Classification and Treatment of Femur and Tibia Fractures around Total Knee Arthroplasty (Literature Review)

Summary. Periprosthetic fractures around total knee arthroplasty (TKA) are difficult to treat due to complex fracture morphology, high proportions of injuries associated with osteopenia, and the variability of injury patterns. Periprosthetic fractures associated with TKA are defined as fractures around the knee joint (femur, tibia, or patella) occurring within 5 cm of the intramedullary stem of the prosthesis or 15 cm of the joint. The incidence is estimated to be between 0.3% and 2.5% after primary TKA and up to 28% after revision TKA. There are several surgical and nonsurgical risk factors associated with postoperative periprosthetic fractures. Distal femoral periprosthetic fractures following TKA are the most common and reported to occur in 0.2–1.8% of patients after primary TKA. Tibial periprosthetic fractures have a reported prevalence of 0.07–0.1% in primary and 0.36% in revision knee arthroplasties. Patella fractures are the second most common periprosthetic fractures following TKA, with prevalence ranging from 0.68% to 1.19%, and are usually associated with a resurfaced patella. Several classification systems of periprosthetic fractures around TKA have been published and some treatment recommendations have been provided. However, most systems are subject to criticism and use different classification systems for the tibia, patella, and the femur.A variety of treatment methods are available for periprosthetic fractures. Conservative treatment can include protected weight bearing, splinting, or traction. Surgical treatment commonly involves closed intramedullary nailing or open reduction and internal fixation by plates. In cases of significant bone loss, a revision TKA may be indicated. In general, treatment must be guided based on the stability of the implant and the remaining bone quality, as determined by the presence of osteolysis and the location of the fracture.

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.

Unbalanced metaphyseal fixation is associated with an increased aseptic loosening of revision total knee arthroplasty at mean 4-year follow-up.

The total number of total knee arthroplasty performed is rising, and the number of revisions is rising accordingly. Periprosthetic joint infection emerged in recent years as a leading cause of total knee revisions. Bone loss is a real challenge when facing septic knee revisions since radical debridement is crucial to overcome infection. Many devices have already demonstrated to reliably address bone loss and guarantee enhanced fixation. However, the role of balancing metaphyseal fixation and its interplay with the level of constraint has not been elucidated yet. An institutional arthroplasty registry was retrospectively reviewed looking for patients who underwent two-stage revision of the knee and metaphyseal cones implantation. Patients were divided into two groups based on the presence of cones only on one side (femoral or tibial, Group U) or both femoral and tibial side (Group B). Failure, aseptic loosening, and revision rates were compared between groups, as were values of patient-reported outcome measure. Kaplan-Meier analysis was used to assess survival of implants. A total of 65 patients were included in the analysis and were evaluated at a mean final follow-up of 4years (range, 2-7). Mean age was 67 (range, 43-81) years. Mean BMI was 27.4 (range, 20-37) kg/m2. The overall mean KSS, OKS, ROM significantly increased from baseline values to last follow-up (p < 0.001). Kaplan-Meier analysis demonstrated that patients included in Group U had a significantly lower rate of implant survival compared to those included in Group B. Patients undergoing revision total knee arthroplasty for periprosthetic infection present considerable rates of complication and failure. Management of bone loss represents a concern for the surgeon, who must achieve a stable fixation. Our study demonstrated that implants characterized by an unbalanced metaphyseal fixation are at higher risk of aseptic loosening and consequent revision, especially when coupled with hinged inserts.

Very High Early Failure Rate Following Primary Repair of Acute Extensor Mechanism Disruption After Total Knee Arthroplasty

IntroductionExtensor mechanism disruption is a devastating complication following total knee arthroplasty (TKA). Despite its morbidity, there is no consensus regarding the optimal treatment strategy. We aimed to determine the survivorship, clinical outcomes, and improvement in patient-reported outcome measures (PROMs) after primary repair of acute extensor mechanism disruptions following primary or revision TKA. MethodsA retrospective review identified 41 acute extensor mechanism disruptions (33 primary TKAs and eight revision TKAs) from 2015 to 2021. The study group was 56% women, the mean BMI was 33, the mean age was 66 years, and the mean follow-up was three years. Extensor mechanism disruption occurred at the patellar tendon (n = 17), quadriceps tendon (n = 15), and patella (n = 9) at a mean of 10 months following TKA. Surgical management was primary repair (n = 30) or primary repair with augmentation (allograft or autograft) (n = 11). Kaplan-Meier analysis estimated survivorship. ResultsThe two-year survivorship free from all-cause reoperation was 72 and 23% following primary and revision TKA, respectively (P = 0.013). The two-year survivorship free from all-cause reoperation was 66% for primary repair versus 61% for primary repair with augmentation (P = 0.95). There were 17 (41%) patients who underwent reoperation, most commonly for re-rupture (n = 4) in two primary repairs and two primary repairs with augmentation (P = 0.288). Revision TKA (P = 0.049) and increased time from disruption to repair (P = 0.039) were risk factors for reoperation. The mean extensor lag did not significantly improve, nor did patients see improvement in their PROMs. ConclusionAfter primary and revision TKA, acute extensor mechanism disruption treated with primary repair with or without augmentation had very poor early survivorship free from all-cause reoperation. Patients should be counseled appropriately, and alternative surgical techniques should be considered.

What is the preferred fixation method for stems used in revision total knee arthroplasty?

What is the preferred fixation method for stems used in revision total knee arthroplasty?

Undergoing Meniscectomy Within One Year Before Primary Total Knee Arthroplasty Is Associated With Worse Postoperative Outcomes

BackgroundPatients undergoing primary total knee arthroplasty (TKA) who have a history of meniscectomy have worse postoperative functional outcomes, increased rates of early postoperative complications, and higher revision rates. Despite knowing this, to the best of our knowledge, it has not been previously studied whether the timing of meniscectomy before TKA impacts functional outcomes after undergoing TKA. Compared to patients who underwent meniscectomy more than one year before TKA, do patients who have meniscectomy less than one year before TKA have significantly different postoperative outcomes? MethodsA retrospective cohort study was conducted at an academic medical center. Patients who did not have a history of meniscectomy (controls) were matched in a 1:3 ratio with patients who underwent meniscectomy before primary TKA (cases) based on age, sex, race, body mass index, and non-age-adjusted Charlson Comorbidity Index. Inclusion criteria consisted of patients undergoing TKA from 2013 to 2020, with a minimum of one-year follow-up for Knee Injury and Osteoarthritis Outcome Score Joint Replacement (KOOS-JR). Exclusion criteria comprised patients undergoing revision or conversion TKA. There were 1,767 patients in the control cohort and 589 patients in the cases cohort who were included. ResultsPreoperative KOOS-JR scores did not significantly differ between the five cohorts, while postoperative KOOS-JR scores were significantly lower for patients who underwent meniscectomy less than six months before TKA, and between six months and one year before TKA. Patients undergoing meniscectomy within six months of TKA had a significantly higher rate of aseptic revision, while patients who had a history of meniscectomy at other timeframes did not have a significantly increased rate of aseptic revision. ConclusionsPatients undergoing TKA who had a history of meniscectomy within one year of the TKA may experience worse postoperative functional outcomes, and patients undergoing meniscectomy within six months of TKA may have an increased risk of revision TKA.

Asymptomatic Elevated Inflammatory Markers: Is There a Risk for Infection or Revision in Primary Total Knee Arthroplasty?

BackgroundTotal knee arthroplasty (TKA) is the treatment of choice for advanced knee osteoarthritis. Long-term studies report high patient satisfaction, while complications such as periprosthetic joint infection (PJI) can be devastating. Knowledge regarding risk factors for PJI is critical to minimize and ideally avoid complications. The purpose of this study was to investigate the risk of PJI and revision in patients who had preoperative asymptomatic high C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels in primary TKAs. MethodsPatients undergoing primary TKA between 2010 and 2022 were eligible. Inclusion criteria were patients who had preoperative complete biochemical parameters and a minimum follow-up of 12 months. Patients who died during the first year, and those who had a history of inflammatory arthritis, autoimmune disease, renal pathologies or septic arthritis, were excluded. Patients who had elevated blood CRP and ESR levels taken within 48 hours before surgery underwent a thorough medical examination with a focus on infection symptoms. After screening and consultation, residual elevated CRP and ESR levels were classified as asymptomatic. After exclusions, 1,528 patients were included. The mean age was 66 years (range, 35 to 92) and the mean follow-up time was 6.4 years (range, 1.6 to 12.3). ResultsThe rate of revision within one year after surgery was 1.6%, whereas the rate of revision in the first five years was 3.8%. The PJI rates for the 1st and 5th postoperative years were 1.7 and 2.9% respectively. Regression analysis did not show any of the potential variables to be a risk factor for revision or PJI. ConclusionAsymptomatic elevated acute-phase reactants are not a risk factor for periprosthetic joint infection or aseptic revision. At a mean follow-up of 6.4 years, overall survival was 96.7%, with only 2.2% of patients revised due to a PJI.

Outcomes of Liner Exchange Versus Component Revision for the Treatment of Stiffness Following Primary Total Knee Arthroplasty

BackgroundThis study aimed to compare outcomes of revision total knee arthroplasty (rTKA) with liner exchange (LE) versus component revision (CRev) for stiffness post-TKA. MethodsWe retrospectively identified all rTKA performed for stiffness after primary TKA using our institutional database (2003 to 2021). Cases with infection, loosening, or < two years follow-up were excluded. There were 129 rTKA included, 91 in the LE, and 38 in the CRev cohorts. The mean follow-up was 8.5 years (range, two to 21). The LE and CRev cohorts had similar baseline demographics (P > 0.05), previous manipulation (P = 0.45), time from primary TKA (P = 0.14), and pre-rTKA arc of motion (AOM) (P = 0.08). The primary outcomes were the achievement of a successful range of movement (ROM), defined as flexion ≥ 90⁰ with an extension deficit of ≤ 10⁰, and AOM improvement. Kaplan-Meier analysis was used to compare survival free from re-revision between cohorts. ResultsFor the entire cohort, 69% achieved a successful ROM, and the mean AOM improved (P < 0.001). Achievement of successful ROM was comparable between LE (72%) and CRev (62%) cohorts (P = 0.29). The mean gain in AOM was similar between LE (24.9⁰) and CRev (25.4⁰) cohorts (P = 0.45). Preoperative extension deficit was associated with poorer outcomes (P = 0.006). The 10-year re-revision-free survival was similar between the LE (86.2%) and CRev (81.1%) cohorts (P = 0.55). Survival from re-revision for stiffness at 10-years was also similar (P = 0.6). The CRev group had increased surgical times (P < 0.0001), blood loss (P < 0.0001), and length of stay (P = 0.01). ConclusionsLE resulted in similar achievement of a successful ROM and re-revision-free survival compared with CRev. In properly selected patients, LE is a reasonable option for the treatment of stiffness after TKA.

Staged revision of the infected knee arthroplasty and endoprosthesis.

Periprosthetic joint infection (PJI) is a challenging complication of any arthroplasty procedure. We reviewed our use of static antibiotic-loaded cement spacers (ABLCSs) for staged management of PJI where segmental bone loss, ligamentous instability, or soft-tissue defects necessitate a static construct. We reviewed factors contributing to their failure and techniques to avoid these complications when using ABLCSs in this context. A retrospective analysis was conducted of 94 patients undergoing first-stage revision of an infected knee prosthesis between September 2007 and January 2020 at a single institution. Radiographs and clinical records were used to assess and classify the incidence and causes of static spacer failure. Of the 94 cases, there were 19 primary total knee arthroplasties (TKAs), ten revision TKAs (varus-valgus constraint), 20 hinged TKAs, one arthrodesis (nail), one failed spacer (performed elsewhere), 21 distal femoral endoprosthetic arthroplasties, and 22 proximal tibial arthroplasties. A total of 35/94 patients (37.2%) had spacer-related complications, of which 26/35 complications (74.3%) were because of mechanical failure of the spacer construct, while 9/35 (25.7%) were due to recurrence of infection. Risk factors for internal failure were a construct where the total intramedullary spacer length was less than twice the length of the central osseous defect (p = 0.009), where proximal or distal intraosseous spacer contact was < 10%, and after tibial tubercle osteotomy (p = 0.005). The incidence of spacer complications significantly increased the time to second stage: mean 157 days (42 to 458) in those without complications versus 227 days (11 to 528) with complications (p = 0.014). The failure rate of static antibiotic-loaded cement spacers is much higher than anticipated. Complications of the spacer significantly increased the time to second-stage revision. The risk of mechanical failure is significantly increased if the spacer is less than double the size of the segmental defect, or if inadequate reinforcement is inserted into the residual bone. These findings serve as a guide for surgeons to avoid mechanical complications with static spacers.

Predictors of outcome following two-stage revision total knee arthroplasty.

Two stage revision arthroplasty remains the gold standard for peri-prosthetic joint infections of the knee. However, the functional outcomes of revision surgeries and the factors governing them require further investigation. The purpose of this study was to (a) evaluate impact of early and late stage I surgery and interval between stage I and stage II; (b) understand the impact of infecting organism and resistance; (c) to estimate long term survivorship and causes of failure. A retrospective review of 86 patients, who underwent two stage revision for prosthetic joint infections of the knee, was performed. Time between onset of symptoms to stage I (T1), and T1 to re-implantation (T2), along with microbiological studies, were analysed for their impact on functional outcomes, failure modalities and survivorship. In this study, the mean KSS-Knee improved from 64.0 ± 10.0 pre-operatively to 76.9 ± 10.4, and 77.2 ± 10.1 at the 5 and 10 year follow up respectively. The KSS-Function improved from 44.4 ± 8.8 pre-operatively to 72.2 ± 9.5 and 79.8 ± 8.1 at 5 and 10 year follow-up respectively. This study also found that T1 and T2 remained critical factors in determining functional outcome and longevity of the implant and a delay in these intervals was a significant predictor of failure. Gram negative, poly-microbial infections and organisms with methicillin and vancomycin resistance demonstrated lower survivorship (p-value, 0.001 at 5, 10 and 12 years). Re-infections occurred in 4 cases while 9 cases failed due to aseptic causes. Two-stage revision arthroplasty produced good functional outcomes when the infection was caused by single sensitive organism that did not exhibit high resistance to antibiotics. Stage I performed within 4 weeks and the subsequent re-implantation procedure undertaken within 6 weeks demonstrated better outcomes.

Association of Technology Usage and Decreased Revision TKA Rates for Low-Volume Surgeons Using an Optimal Prosthesis Combination: An Analysis of 53,264 Primary TKAs.

Technology (navigation and robotics) usage during total knee arthroplasty (TKA) is often supported by literature involving high-volume surgeons and hospitals, but the value of technology for lower-volume surgeons is uncertain. This study aimed to determine if there was a relationship among surgeon volume, technology usage, and revision rate when using an optimal prosthesis combination (OPC). Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) data were obtained from January 1, 2008, to December 31, 2022, for all primary TKA procedures performed for osteoarthritis using an OPC by a known surgeon ≥5 years after their first recorded procedure. The interaction between surgeon volume and conventional-instrumentation (CV) versus technology-assisted (TA) TKA was assessed. The cumulative percent revision (CPR) was determined by Kaplan-Meier estimates. Cox proportional-hazards methods were used to compare rates of revision by surgeon volume and by the interaction of volume and technology. Subanalyses were undertaken to examine major and minor revisions separately, and to assess the influence of technology on revision rates relative to those of a surgeon undertaking 100 TKA/year. Of the 53,264 procedures that met the inclusion criteria, 31,536 were TA-TKA and 21,728 were CV-TKA. Use of technology reduced the all-cause revision rate for surgeons with a volume of <50 TKA/year and the rate of minor revisions for surgeons with a volume of <40 TKA/year. No interaction between surgeon volume and the rate of major revision surgery was found. With CV-TKA by a surgeon with a 100-TKA/year volume as the comparator, all-cause and major revision rates were significantly elevated for surgeons undertaking <50 and <100 TKA/year, respectively. In contrast, analysis of TA-TKA showed no difference in rates of all-cause or major revisions for surgeons undertaking <100 TKA/year compared with 100 TKA/year. TA-TKA was associated with a decrease in the revision rate for lower-volume surgeons but no significant alterations in revision rate for higher-volume surgeons. Preferential use of TA-TKA by lower-volume surgeons should be considered. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

No shortening of the patellar tendon during two-stage total knee arthroplasty revision using articulating spacers.

Surgical techniques in two-stage revision total knee arthroplasty(rTKA) include the use of articulating spacers and static spacers. Shortening of the patellar tendon could be a reason for inferior functional outcomes in two-stage septic rTKA. The aim of this study was to determine if articulating spacers also have negative effects on the extensor mechanism in rTKA. This retrospective study includes 65 consecutive patients (23 women, 42 men, age 71.3 ± 1.2; range, 51.2-88.6 years) undergoing septic two-stage rTKA using an articulating spacer between 2014 and 2021 in a single orthopedic center. For all patients, calibrated true lateral radiographs before total knee arthroplasty (TKA) explantation (T0), directly after TKA explantation (T1), shortly before TKA reimplantation (T2) and 6-8 days after TKA reimplantation (T3) were used to calculate the modified Insall Salvati ratio (mISR). Overall, the mISR decreased significantly immediately after explantation (T0 vs. T1, p = 0.002) from 1.43 ± 0.03 to 1.36 ± 0.03 and remained stable until T2 (1.37 ± 0.02, p = 0.74). Following TKA reimplantation, the mISR increased again to 1.43 ± 0.03 (T3). There were no significant differences between T0 and T3 (p = 0.88). Six out of 65 patients (9%) experienced patellar tendon shortening > 10% at T3. Septic two-stage revision TKA using an articulating spacer does not lead to patellar tendon shortening in the majority of cases. This study suggests that one reason for the improved range of motion after reimplantation may be the use of articulating spacers compared to static spacers.

Predicting prolonged length of stay following revision total knee arthroplasty: A national database analysis using machine learning models

BackgroundAs the number of revision total knee arthroplasty (TKA) continues to rise, close attention has been paid to factors influencing postoperative length of stay (LOS). The aim of this study is to develop generalizable machine learning (ML) algorithms to predict extended LOS following revision TKA using data from a national database. Methods23,656 patients undergoing revision TKA between 2013 and 2020 were identified using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Patients with missing data and those undergoing re-revision or conversion from unicompartmental knee arthroplasty were excluded. Four ML algorithms were applied and evaluated based on their (1) ability to distinguish between at-risk and not-at-risk patients, (2) accuracy, (3) calibration, and (4) clinical utility. ResultsAll four ML predictive algorithms demonstrated good accuracy, calibration, clinical utility, and discrimination, with all models achieving a similar area under the curve (AUC) (AUCLR=AUCRF=AUCHGB=0.75, AUCANN=0.74). The most important predictors of prolonged LOS were found to be operative time, preoperative diagnosis of sepsis, and body mass index (BMI). ConclusionsML models developed in this study demonstrated good performance in predicting extended LOS in patients undergoing revision TKA. Our findings highlight the importance of utilizing nationally representative patient data for model development. Prolonged operative time, preoperative sepsis, BMI, and elevated preoperative serum creatinine and BUN were noted to be significant predictors of prolonged LOS. Knowledge of these associations may aid with patient-specific preoperative planning, discharge planning, patient counseling, and cost containment with revision TKA.

Mid-term Survivorship and Functional Outcomes of Metaphyseal Sleeves for Addressing Anderson Orthopaedic Research Institute (AORI) Type 2 and 3 Bone Defects in Revision Total Knee Arthroplasty.

Introduction Revision Total Knee Arthroplasty (RTKA) is a complex procedure challenged by significant bone loss, necessitating effective restoration techniques. This study investigates the clinical outcomes and complications of metaphyseal sleeves in RTKA with severe metaphyseal bone loss, aiming to evaluate their efficacy over a minimum four-year follow-up. Methods This was a retrospective observational study on 29 patients who underwent RTKA with Anderson Orthopaedic Research Institute (AORI) type II or III bone defects using porous coated tibial and/or femoral metaphyseal sleeves from December 2016 and January 2019. Data collection included demographic information, etiology for revision, and functional outcomes assessed by the Knee Society Score (KSS) and Oxford Knee Score (OKS). Statistical analysis and Kaplan-Meier survival analysis were performed. Results The cohort comprised patients with a mean age of 62.6 years (SD=7.8), predominantly female (N=21, 71.4%). The primary indication for RTKA was aseptic loosening (N=18, 62.1%) followed by Prosthetic Joint Infection (PJI). Significant improvements were noted in the range of motion. Both KSS (Pre-op:57.97 vs. Post-op:73.59) and OKS (Pre-op:15.86 vs. Post-op:30.66) showed highly significant improvement (p<0.0001). Radiographic assessments indicated stable component position and signs of osseous integration without any osteolysis. No sleeve-related complications were observed. Survival analysis demonstrated a high cumulative survival probability over the study period. Conclusion Metaphyseal sleeves offer a viable solution for managing severe bone loss in RTKA, providing stable fixation, restoring joint line kinematics, and facilitating stress distribution to the metaphyseal region. This study corroborates the effectiveness of metaphyseal sleeves in challenging revision scenarios, aligning with previous research.

Conversion of UKA to TKA using identical standard implants—How does it compare to primary UKA, primary TKA and revision TKA?

BackgroundUKA is a well-established treatment option for anteromedial osteoarthritis of the knee, resulting in superior functional outcomes but also higher revision rates than TKA. This study aimed to compare the outcomes of UKA, TKA, UKA converted to TKA using identical standard implants and revised TKA to support clinical decision-making.MethodsIn this study, we retrospectively examined 116 patients who underwent UKA, 77 patients who received TKA, 28 patients whose UKA was converted to TKA using identical standard implants, and 21 patients who had a one-stage revision of TKA. The mean age at operation was 66.5 years (39–90 years), with a mean BMI of 28.8 kg/m2 (17.4–58.8) and a mean follow-up period of four years (0.9–9.9 years). We assessed various PROMs, including Oxford Knee Score, UCLA score, KSS score, and a modified WOMAC-Score as well as patient satisfaction and ability to resume daily activities, work, and sports.ResultsThe highest patient satisfaction was seen in the UKA. All scores were significantly higher for UKA than for TKA, converted UKA, and revised TKA. None of the scores showed a significant inferiority of converted UKA to TKA. In the case of revision, two scores showed significantly better results for converted UKA than for revised TKA.ConclusionsOur results indicated that patients initially treated with UKA did not have significantly worse functional outcomes after conversion to TKA, given the use of identical standard implants. This highlights the effectiveness of UKA as a therapeutic option with outcomes superior to those of primary TKA and the importance of a bone-sparing procedure. Conversely, revision TKA is linked to poorer functional outcomes compared to both primary arthroplasties.