Aims. Current guidelines consider analyses of joint aspirates, including leucocyte cell count (LC) and polymorphonuclear percentage (PMN%) as a diagnostic mainstay of periprosthetic joint infection (PJI). It is unclear if these parameters are subject to a certain degree of variability over time. Therefore, the aim of this study was to evaluate the variation of LC and PMN% in patients with aseptic revision total knee arthroplasty (TKA). Methods. We conducted a prospective, double-centre study of 40 patients with 40 knee joints. Patients underwent joint aspiration at two different time points with a maximum period of 120 days in between these interventions and without any events such as other joint aspirations or surgeries. The main indications for TKA revision surgery were aseptic implant loosening (n = 24) and joint instability (n = 11). Results. Overall, 80 synovial fluid samples of 40 patients were analyzed. The average time period between the joint aspirations was 50 days (SD 32). There was a significantly higher percentage change in LC when compared to PMN% (44.1% (SD 28.6%) vs 27.3% (SD 23.7%); p = 0.003). When applying standard definition criteria, LC counts were found to skip back and forth between the two time points with exceeding the thresholds in up to 20% of cases, which was significantly more compared to PMN% for the European Bone and Joint Infection Society (EBJIS) criteria (p = 0.001), as well as for Musculoskeletal Infection Society (MSIS) (p = 0.029). Conclusion. LC and PMN% are subject to considerable variation. According to its higher interindividual variance, LC evaluation might contribute to false-positive or false-negative results in PJI assessment. Single LC testing prior to TKA revision surgery seems to be insufficient to exclude PJI. On the basis of the obtained results, PMN% analyses overrule LC measurements with regard to a conclusive diagnostic algorithm. Cite this article: Bone Jt Open 2021;2(8):566–572

Patient function is poorly characterised following revision TKA. Modern semi-constrained implants are suggested to offer high levels of function, however, data is lacking to justify this claim. 52 consecutive aseptic revision TKA procedures performed at a single centre were prospectively evaluated; all were revision of a primary implant to a Triathlon total stabiliser prosthesis. Patients were assessed pre-operatively and at 6, 26, 52 and 104 weeks post-op. Outcome assessments were the Oxford Knee Score (OKS), range of motion, pain rating scale and timed functional assessment battery. Analysis was by repeated measures ANOVA with post-hoc Tukey HSD 95% simultaneous confidence intervals as pairwise comparison. Secondary analysis compared the results of this revision cohort to previously reported primary TKA data, performed by the same surgeons, with identical outcome assessments at equivalent time points. Mean age was 73.23 (SD 10.41) years, 57% were male. Mean time since index surgery was 9.03 (SD 5.6) years. 3 patients were lost to follow-up. All outcome parameters improved significantly over time (p <0.001). Post-hoc analysis demonstrated that all outcomes changed between pre-op, 6 week and 26 weeks post-op assessments. No difference was seen between primary and revision cohorts in OKS (p = 0.2) or pain scores (p=0.19). Range of motion and functional performance was different between groups over the 2 year period (p=0.03), however this was due to differing pre-operative scores, post-hoc analysis showed no difference between groups at any post-operative time point. Patients undergoing aseptic revision TKA with semi-constrained implants made substantial improvements in OKS, pain scores, knee flexion, and timed functional performance, with the outcomes achieved comparable to those of primary TKA. High levels of function can be achieved following revision knee arthroplasty, which may be important considering the changing need for, and demographics of, revision surgery

Aim

Evaluate the metabolites composition of the synovial fluid from patients with PJI or aseptic failure of total knee arthroplasties.

Aims

Enhanced perioperative protocols have significantly improved patient recovery following primary total knee arthroplasty (TKA). Little has been investigated the effectiveness of these protocols for revision TKA (RTKA). We report on a matched group of aseptic revision and primary TKA patients treated with an identical pain and rehabilitation programmes.

The August 2023 Knee Roundup. 360. 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?

Introduction. Tranexamic acid (TXA) is proven to reduce blood loss following total knee arthroplasty (TKA), but there are limited data on the impact of similar dosing regimens in revision TKA that is associated with greater blood loss. The purpose of this multi-center randomized trial was to determine the optimal regimen to maximize the blood-sparing properties of TXA in revision TKA. Methods. 233 Septic and aseptic revision TKA from six-centers were randomized to either receive 1g pre-incision intravenous (IV) TXA, 1g pre- and post-incision IV TXA, 1g pre-incision IV and 1g intra-operative topical TXA, or three doses of 1950mg oral TXA given 2 hours pre-operatively, 6 hours post-operatively, and the morning of postoperative day 1. Randomization was performed based on type of revision to ensure equivalent distribution among groups. The primary outcome was reduction in hemoglobin. Power analysis determined 40 patients per group were necessary to identify a 1g/dL difference with an alpha of 0.05 and beta of 0.80. Per-protocol analysis involved regression analysis and two one-sided t-tests for equivalence. Results. One patient withdrew, 3 didn't undergo surgery, 16 were screen failures, and 17 did not receive the assigned treatment, leaving 196 patients for the analysis. There was no significant difference in reduction in hemoglobin amongst treatment groups (2.88g/dL for oral TXA, 2.79g/dL for single-dose IV TXA, 2.59g/dL for combined IV/topical TXA, and 2.58g/dL for double-dose IV TXA; p=0.48). Similarly, calculated blood loss (p=0.63) and transfusions (p=0.78) were not significantly different between groups. Finally, equivalence testing assuming a 1g/dL difference in hemoglobin change as clinically relevant showed all possible pairings were statistically equivalent. Conclusions. Despite the higher risk of blood loss in revision TKA, all TXA regimens tested had equivalent blood-sparing properties. Surgeons should consider using the lowest effective dose and the least costly regimen for TXA use in revision TKA

Converting UKA to TKA can be difficult, and specialised techniques are needed. Issues include bone loss, joint line approximation, sizing, and rotation. Determining the complexity of conversion preoperatively helps predict the need for augmentation, grafting, stems, or constraint. In a 2009 study from our center, 50 UKA revised to TKA (1997–2007) were reviewed: 9 modular fixed-bearing, 4 metal-backed nonmodular fixed-bearing, 8 resurfacing onlay, 10 all-polyethylene step-cut, and 19 mobile bearing designs; 5 knees failed due to infection, 5 due to wear and/or instability, 10 for pain or progression of arthritis, 8 for tibial fracture or severe subsidence, and 22 due to loosening of either one or both components. Insert thickness was no different between implants or failure modes. Stemmed component use was most frequent with nonmodular components (50%), all-polyethylene step-cut implants (44%), and modular fixed-bearing implants (33%; P=0.40). Stem use was highest in tibial fracture (86%; P=0.002). Augment use was highest among all-polyethylene step-cut implants (all-polyethylene, 56%; metal-backed, 50%; modular fixed-bearing, 33%; P=0.01). Augmentation use was highest in fracture (86%) and infection (67%), with a significant difference noted between failure modes (P=0.003). Failure of nonmodular all-polyethylene step-cut devices was more complex than resurfacing or mobile bearing. Reestablishing the joint line, ligamentous balance, and durable fixation are critical to assuring a primary outcome. In a 2013 multicenter study of 3 institutions including ours, a total of 175 revisions of medial UKA in 168 patients (average age: 66 years) performed from 1995 to 2009 with a minimum 2-year clinical follow-up were reviewed. The average time from UKA to revision TKA was 71.5 months (2–262). The four most common reasons for failure were femoral or tibial loosening (55%), progressive arthritis of the lateral or patellofemoral joints (34%), polyethylene failure (4%) and infection (3%). Mean follow-up after revision was 75 months. Nine of 175 knees (4.5%) were subsequently revised at an average of 48 months (6–123). The average Knee Society pain and function score increased to 75 and 66, respectively. In the present series, the re-revision rate after revision TKA from UKA was 4.5% at an average of 75 months. In a current study from our center, 184 patients (193 UKA) underwent revision procedures (1996–2015) with minimum 2-year follow-up. Mean age was 63.5 (37–84) years, body mass index was 32.3 (19–57) kg/m. 2. , and interval after UKA was 4.8 (0–35) years. Most prevalent indications for revision were aseptic loosening (42%), arthritic progression (20%) and tibial collapse (14%). At 6.1 years mean follow-up (2–20), 8 knees (4.1%) have required re-revision involving any part, which is similar to what we recently reported at 5.5 years in a group of patients who underwent primary TKA (6 of 189; 3.2%), and much lower than what we observed at 6.0 years in a recent report of patients who underwent aseptic revision TKA (35 of 278; 12.6%). In the study group, Knee Society clinical and function scores improved from 50.8 and 52.1 preoperatively to 83.4 and 67.6 at most recent evaluation, respectively. Re-revisions were for aseptic loosening (3), instability (2), arthrofibrosis (2), and infection (1). Compared to published individual institution and national registry data, re-revision rates of failed UKA are equivalent to revision rates of primary TKA and substantially better than re-revision rates of revision TKA. These data should be used to counsel patients undergoing revision UKA to TKA

Aim. Dissolvable antibiotic-loaded calcium sulphate beads have been utilized for management of periprosthetic joint infection (PJI) and for aseptic revision arthroplasty. However, wound drainage and toxic reactive synovitis have been substantial problems in prior studies. Currently a commercially pure, physiologic product has been introduced that may reduce complications associated with this treatment modality. We aim to answer the question: does a commercially pure, physiologic version of antibiotic-loaded calcium sulfate beads reduce wound drainage and provide efficacious treatment for PJI and aseptic revision arthroplasty?. Method. Starting January 2010, 756 consecutive procedures were performed utilizing a set protocol of Vancomycin and Tobramycin antibiotics in commercially pure dissolvable antibiotic beads. There were 8 designated study groups:. Aseptic Revision TKA. N = 216. Aseptic Revision THA. N = 185. DECRA. *. TKA. N = 44. DECRA. *. THA. N = 16. 1. st. Stage Resection TKA. N = 103. 1. st. Stage Resection THA. N = 62. Reimplant TKA. N = 81. Reimplant THA. N = 49. *. DECRA = Debridement, modular Exchange, Component Retention, iv Antibiotics for acute PJI. Results. Wound drainage in the entire series was 4.2%. Wound drainage was generally seen in cases using higher bead volumes (≥30cc). The rate of heterotopic ossification was 1.6%. With bead volumes of ≥30cc, we did notice transient hypercalcemia in 12% of the study group (14% hips, 10% knees). The overall rate of infection failure was 2.5%. In the DECRA groups, reinfection failure rate was encouraging, measuring 9.1% in knees and 6.3% in hips. The non-DECRA group with the highest infection rate was Reimplant TKA (6.2%). Conclusions. We utilized a large series of commercially pure dissolvable antibiotic-loaded beads in a wide variety of clinical scenarios in patients with substantial comorbidities. Our rate of wound drainage, compared to prior studies utilizing gypsum products, was reasonably good. Additionally, our infection failure rates were encouraging. Over-stuffing knee joints with too many beads, in our clinical review, does affect wound drainage rates. By removing impurities from calcium sulfate, we do not see the substantial toxic synovial reaction compared to the traditional gypsum-washed products. We feel that commercially pure, physiologic antibiotic-loaded dissolvable beads are an acceptable delivery tool for local antibiotic delivery in aseptic and septic revision joint arthroplasty of the hip and knee. In our opinion, further study is warranted. We advocate future randomized studies to examine the potential of improving outcomes of PJI and aseptic revision arthroplasty

Early and/or prolonged wound discharge after total knee arthroplasty often raises the question whether this is a sign of an early infection or if the prolonged discharge leads to a secondary deep wound infection from migrating skin bacteria. Confronted with the dilemma of what to do with early PWC our department implemented a new treatment protocol in 2002 to deal with early PWC after TKA in order to standardize decision-making. The aim of this study was to report our long-term results using this protocol on a prospective cohort primary TKA and revision TKA performed for other reasons than infection. This report focuses on the results of DAIR (debridement, antibiotics and implant retention) performed for early PPJI and/or early wound complications without clinical signs of infection. After implementing our treatment algorithm regarding postoperative wound complications in early 2002, we initiated a quality registration including every primary and non infected revision TKA performed. Between January 2002 and August 2012 1439 consecutive primary knee arthroplasties were performed at our institution. During the same period a total of 120 knee revisions for reasons not related to infection were performed. All patients undergoing DAIR within three months of the index procedure where divided into two groups: successful and unsuccessful. Successful DAIR didn't require any more surgery and the implant could be retained with a minimum follow up time of two years. Unsuccessful DAIR required at least one more surgical intervention. Treatment with DAIR was successful in 47 of 62 patients operated with primary and revision TKA as index operation. Those patients had no signs of infection and no antimicrobial therapy after a minimum of one year follow up time. The remaining 15 patients were in need of further surgery. Positive cultures could be obtained in 41 of 62 patients including those operated for aseptic revision arthroplasty. Staphylococcus aureus was by far the most common isolated organism with 24 isolations and the sole causative pathogen in 15 cases. When looking at all patients even including those with aseptic revision TKA we could see that the algorithm resulted in 57 of 62 patients (91,9%) ending up with a working knee prosthesis at the final follow up. In 47 (75,8%) cases prosthesis retention could be achieved with only a single DAIR procedure. We therefore conclude that the algorithm applied at our centre leads to satisfactory results

Converting UKA to TKA can be difficult, and specialised techniques are needed. Issues include bone loss, joint line approximation, sizing, and rotation. Determining the complexity of conversion pre-operatively helps predict the need for augmentation, grafting, stems, or constraint. In a 2009 study from our center, 50 UKA revised to TKA (1997–2007) were reviewed: 9 implants (18%) were modular fixed-bearing, 4 (8%) were metal-backed nonmodular fixed-bearing, 8 (16%) were resurfacing onlay, 10 (20%) were all-polyethylene step-cut, and 19 (38%) were mobile bearing designs; 5 knees (10%) failed due to infection, 5 (10%) due to wear and/or instability, 10 (20%) for pain or progression of arthritis, 8 (16%) for tibial fracture or severe subsidence, and 22 (44%) due to loosening of either one or both components. Insert thickness was no different between implants (P=0.23) or failure modes (P=0.27). Stemmed component use was most frequent with nonmodular components (50%), all-polyethylene step-cut implants (44%), and modular fixed-bearing implants (33%; P=0.40). Stem use was highest in tibial fracture (86%; P=0.002). Augment use was highest among all-polyethylene step-cut implants (all-polyethylene, 56%; metal-backed, 50%; modular fixed-bearing, 33%; P=0.01). Augmentation use was highest in fracture (86%) and infection (67%), with a significant difference noted between failure modes (P=0.003). Failure of nonmodular all-polyethylene step-cut devices was more complex than resurfacing or mobile bearing. Failure mode was predictive of complexity. Reestablishing the joint line, ligamentous balance, and durable fixation are critical to assuring a primary outcome. In a 2013 multicenter study of 3 institutions including ours, a total of 175 revisions of medial UKA in 168 patients (81 males, 87 females; average age of 66 years) performed from 1995 to 2009 with a minimum of 2-year clinical follow-up were reviewed. The average time from UKA to revision TKA was 71.5 months (range: 2 months to 262 months). The four most common reasons for failure of the UKA were femoral or tibial loosening (55%), progressive arthritis of the lateral or patellofemoral joints (34%), polyethylene failure (4%) and infection (3%). Mean follow-up after revision was 75 months. Nine of 175 knees (4.5%) were subsequently revised at an average of 48 months (range 6 months to 123 months.) The rate of revision was 1.23 revisions per 100 observed component years. The average Knee Society pain and function score increased to 75 and 66, respectively. In the present series, the re-revision rate after revision TKA from UKA was 4.5 % at an average of 75 months or 1.2 revisions per 100 observed component years. In a current study from our center, 174 patients (180 UKA) underwent revision procedures (1996–2017). Most prevalent indications for revision were aseptic loosening (45%) arthritic progression (17%) and tibial collapse (13%). At 4 years mean follow-up, 5 knees (2.8%) have required re-revision involving any part, which is similar to what we recently reported at 5.5 years in a group of patients who underwent primary TKA (6 of 189; 3.2%), and much lower than what we observed at 6.0 years in a recent report of patients who underwent aseptic revision TKA (35 of 278; 12.6%). Compared to published individual institution and national registry data, re-revision of a failed UKA is equivalent to revision rates of primary TKA and substantially better than re-revision rates of revision TKA. These data should be used to counsel patients undergoing revision UKA to TKA

Aims

In the last decade, perioperative advancements have expanded the use of outpatient primary total knee arthroplasty (TKA). Despite this, there remains limited data on expedited discharge after revision TKA. This study compared 30-day readmissions and reoperations in patients undergoing revision TKA with a hospital stay greater or less than 24 hours. The authors hypothesized that expedited discharge in select patients would not be associated with increased 30-day readmissions and reoperations.

Aims

To compare rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications), and compare these with primary arthroplasty and re-revision arthroplasty.

Aims

Infection complicating primary total knee arthroplasty (TKA) is a common reason for revision surgery, hospital readmission, patient morbidity, and mortality. Increasing incidence of methicillin-resistant Staphylococcus aureus (MRSA) is a particular concern. The use of vancomycin as prophylactic agent alone or in combination with cephalosporin has not demonstrated lower periprosthetic joint infection (PJI) rates, partly due to timing and dosing of intravenous (IV) vancomycin administration, which have proven important factors in effectiveness. This is a retrospective review of a consecutive series of primary TKAs examining incidence of PJI, adverse reactions, and complications using IV versus intraosseous (IO) vancomycin at 30-day, 90-day, and one-year follow-up.

Aims

Surgeons commonly resect additional distal femur during primary total knee arthroplasty (TKA) to correct a flexion contracture, which leads to femoral joint line elevation. There is a paucity of data describing the effect of joint line elevation on mid-flexion stability and knee kinematics. Thus, the goal of this study was to quantify the effect of joint line elevation on mid-flexion laxity.

Aims

This study aimed to determine outcomes of isolated tibial insert exchange (ITIE) during revision total knee arthroplasty (TKA).

Aims

The aim of this study was to investigate the differences in 30-day outcomes between patients undergoing revision for an infected total hip arthroplasty (THA) compared with an aseptic revision THA.

Aims

The aim of this study was to give estimates of the incidence of component incompatibility in hip and knee arthroplasty and to test the effect of an online, real-time compatibility check.

Objectives

Preservation of posterior condylar offset (PCO) has been shown to correlate with improved functional results after primary total knee arthroplasty (TKA). Whether this is also the case for revision TKA, remains unknown. The aim of this study was to assess the independent effect of PCO on early functional outcome after revision TKA.