Introduction. Tibial cones are often utilized in revision total knee arthroplasty (TKA) with metaphyseal defects. However, there are few studies evaluating outcomes out to five years with a sufficient cohort. The purpose of this study was to evaluate implant survivorship and complications in revision TKAs with tibial cones. Methods. A retrospective review was completed from September 2006 through March 2018 evaluating 149 revision TKAs that received a tibial cone. The mean follow-up was 5.3 years. According to the AORI classification: 8% were 1, 18% were 2A, 55% were 2B, and 19% were 3. Results. Survival analysis at 6 years showed 96% free of revision for aseptic tibial loosening, 85% free of tibial component revision for any reason, and 72% free of reoperation. Eleven knees had progressive radiolucent lines with eight having tibial construct migration on serial radiographs. Aseptic tibial loosening was associated with significant tibial bone loss, AORI 3 (p=0.0001). Tibial component revision for any reason was associated with AORI 3 (p=0.013) and a pre-revision diagnosis of reimplantation after PJI (p<0.0001). Four knees had revision for aseptic tibial loosening, 12 knees had revision of the tibial construct for reasons other than aseptic loosening (11/12 were for PJI), and 15 knees had reoperation for reasons other than tibial construct revision. Conclusions. Revision TKA with tibial cones had excellent survivorship free of revision for tibial construct aseptic loosening, 96% at 6 years. Patients receiving a tibial cone construct at the time of reimplantation for PJI were at increased risk for tibial construct revision

Cementless fixation is an alternative to cemented unicompartmental knee replacement (UKR), with several advantages over cementation. This study reports on the 15-year survival and 10-year clinical outcomes of the cementless Oxford unicompartmental knee replacement (OUKR). This prospective study describes the clinical outcomes and survival of first 693 consecutive cementless medial OUKRs implanted in New Zealand. The sixteen-year survival was 89.2%, with forty-six knees being revised. The commonest reason for revision was progression of arthritis, which occurred in twenty-three knees, followed by primary dislocation of the bearing, which occurred in nine knees. There were two bearing dislocations secondary to trauma and a ruptured ACL, and two tibial plateau fractures. There were four revisions for polyethylene wear. There were four revisions for aseptic tibial loosening, and one revision for impingement secondary to overhang of the tibial component. There was only one revision for deep infection and one revision where the indication was not stated. The mean OKS improved from 23.3 (7.4 SD) to 40.59 (SD 6.8) at a mean follow-up of sixteen years. In conclusion, the cementless OUKR is a safe and reproducible procedure with excellent sixteen-year survival and clinical outcomes

Abstract. Background. Oxidized zirconium (OxZr) has been introduced as an alternative bearing for femoral components in Total Knee Arthroplasty (TKA). It has a ceramic-like zirconium oxide outer layer with a low coefficient of friction. Early studies have found OxZr TKA to have a low incidence of early failure in young high demand patients. Currently no study has reported on the outcome of these implants beyond ten years. Objectives. The purpose of our study was to present an in-depth 15-year survival analysis of cemented Profix II OxZr TKA. Study Design & Methods. Data was collected prospectively and survival analysis undertaken with multiple strict end points. Complication rates were recorded and patient reported outcomes were measured. Results. 617 Profix II OxZr TKAs were performed over four years. Forty-nine patients underwent reoperation. Aseptic tibial loosening was the most common cause of failure (32.7%) on average occurring 2.8 years post primary procedure. There was one recorded failure due to loosening of the zirconium femoral component. Revision rate at 15-years was 6.38%. Cumulative survivorship was 91.52% with failure considered to be reoperation for any reason. WOMAC score improved in 86% of patients by year 1. The average score improved by 21.2 points and met the standard for minimum clinically important difference. Conclusions. This study presents the first 15-year survival analysis of cemented Profix II OxZr TKA. Our data supports current literature on the long-term survivorship of oxidised zirconium total knee replacements

Introduction. Recent total knee arthroplasty (TKA) designs have featured more anatomic morphologies and shorter tibial keels. However, several reports have raised concerns regarding the impact of these modifications on implant longevity. This study's purpose is to report the early performance of a modern, cemented TKA design. Methods. All patients who received a primary, cemented TKA from 2012 to 2017 with a minimum two-year follow-up were included. This implant features an asymmetric tibial baseplate and a shortened keel. Patient demographics, Knee Society Scores (KSS), and component alignment were recorded, and Kaplan-Meier survivorship analyses were performed. Results. 720 of 754 primary TKAs (95.5%) were included for analysis (mean follow-up: 3.9 ± 1.3 years; 562 cruciate-retaining, 158 posterior-stabilized). Eleven (1.5%) were revised for periprosthetic infection and seven (1.0%) for aseptic tibial loosening (5 cruciate-retaining, 2 posterior-stabilized). Aseptic loosening occurred at a mean of 3.3 ± 2.0 years. There were no cases of aseptic loosening in 33 patients who received a 14 × 30mm tibial stem extension. All-cause survivorship was 96.6% at 3 years (95% CI: 95.3%–98.0%) and 96.2% at 5 years (95% CI: 94.8%–97.7%). Survivorship for aseptic loosening was 99.6% at 3 years (95% CI: 99.1%–100.0%) and 99.1% at 5 years (CI: 98.4%–99.9%). Tibial component alignment was more varus in aseptic loosening cases (86.6° ± 3.7° vs 88.7° ± 2.0°, p=0.02). There were no other differences in demographic, radiographic, or surgical characteristics between revised and non-revised TKAs for aseptic loosening (p=0.3–1.0). KSS improved from 57.3 pre-operatively to 92.6 post-operatively (p<0.001). Conclusion. This study comprises the largest series to date of this specific implant design. At short-term follow-up, the rate of aseptic tibial loosening is not overly concerning. But, further observation is warranted to determine if there is an abnormal rate of loosening at mid- to long-term follow-up

Introduction. Tibial component loosening is a frequent cause of failure in primary total knee arthroplasty (TKA). Management options include isolated tibial component revision or full component revision. A full component revision is frequently selected by surgeons who are unfamiliar with the existing implant or have a “let's just start over attitude.” This option adds morbidity versus isolated tibial exchange. While isolated tibial exchange has lower morbidity, it is technically more challenging with regard to exposure and maintaining prosthetic stability. This study was designed to compare these two reconstructive options. Methods. Patients revised for isolated aseptic tibial loosening were identified from 2012–2017. Patients with revision implants, or those revised for infection, instability, osteolysis, or femoral component loosening were excluded. 161 patients met these criteria, 85 patients had an isolated tibial revision and 76 had revision of both components despite having only a loose tibial component. Patient demographics as well as clinical and radiographic outcomes were recorded for each cohort. Results. Patient demographical information, including age, gender, and BMI were statistically similar between the two cohorts. Median follow-up was 3.5 years. Supplemental metaphyseal fixation was used in 22 patients in the isolated tibial cohort and 19 of the full revision cohort. There was a higher incidence of radiographic loosening in the full component revision cohort (10.5% vs. 6.0%; p=0.28). There were five failures requiring revision in the isolated tibial cohort, two for sepsis, one for repeat isolated tibial loosening, one for femoral aseptic loosening, and one for an extensor mechanism disruption. There were eight failures in the full component cohort, three for patellar avascular necrosis, two for sepsis, one for repeat tibial loosening, one for arthrofibrosis, and one for a postoperative wound dehiscence. Conclusion. Isolated tibial revision for aseptic tibial loosening has similar clinical and radiographic results when compared to full component revision. Although no intraoperative complications were identified when revising the femur, there is the potential for complications unique to femoral revision. Femoral component revision for isolated tibial loosening is unnecessary and should be avoided provided adequate ligamentous stability can be obtained. Keywords: Aseptic loosening, Tibial loosening, revision total knee replacement, total knee replacement. For figures, tables, or references, please contact authors directly

Background. Secondary osteonecrosis of the knee (SOK) generally occurs in relatively young patients in their working years; at advanced stages of SOK, the only viable surgical option is total knee arthroplasty (TKA). We conducted a retrospective study to investigate implant survivorship, clinical and radiographic outcomes, and complications of cemented TKA with/without patellar resurfacing for SOK. Methods. Thirty-eight cemented TKAs in 27 patients with non-traumatic SOK with a mean age 43 years (range 17–65) were retrospectively reviewed. Twenty-one patients (78%) were female. Mean body mass index was 31 kg/m. 2. (range 20–48); 11 patients (41%) received bilateral TKAs. Twenty patients (74%) had a history of corticosteroid use and 18% had a history of alcohol abuse. Patellar osteonecrosis was coincidentally found in six knees (16%), all of which had no anterior knee pain and had no patellofemoral joint collapse. The mean follow-up was 7 years (range 2–12). Knee Society Score (KSS) and radiographic outcomes were evaluated at 6 weeks, 1 year, then every 2–3 years thereafter. Results. Ninety-two percent had implant survivorship free from revision with significant improvement in KSS. Causes of revision included aseptic tibial loosening (one), deep infection (one), and instability with patellofemoral issues (one). Four of six cases also with patellar osteonecrosis received resurfacing, including one with a periprosthetic patellar fracture after minor trauma, with satisfactory clinical results after conservative treatment. None of the unrevised knees had progressive radiolucent lines or evidence of loosening. Non-resurfacing of the patella, use of a stem extension or a varus-valgus constrained prosthesis constituted 18%, 8% and 3% of knees, respectively. Conclusion. Cemented TKAs with selective stem extension in patients with SOK had satisfactory implant survivorship and reliable outcomes at a mean of 7 years. Patellar resurfacing is unnecessary in younger patients with no symptoms of anterior knee pain and no patellar collapse radiographically. For any figures or tables, please contact the authors directly

Introduction. Metaphyseal fixation during revision total knee arthroplasties (TKAs) is important, but potentially challenging with historical cone designs. Material and manufacturing innovations have improved the size and shape of cones available, and simplified requisite bone preparation. In a very large series, we assessed implant survivorship, radiographic results, and clinical outcomes of new porous 3-D printed titanium metaphyseal cones featuring a reamer-based system. Methods. We reviewed 142 revision TKAs using 202 cones (134 tibial and 68 femoral) from 2015 to 2016. Sixty cases involved tibial and femoral cones. Most cones (149 of 202; 74%) were used for Type 2B or 3 bone loss. Mean age was 66 years, with 54 % females. Mean BMI was 34 kg/m. 2. Patients had a mean of 2.4 prior surgeries and 48% had a history of periprosthetic infection. Mean follow-up was 2 years. Results. At 2 years, survivorship free of cone revision for aseptic loosening was 100% and free of cone revision for any reason was 98%. Survivorships free of any component revision and any reoperation were 90% and 83%. Five cones had been revised at latest follow-up: 3 for infection, 1 for periprosthetic fracture, and 1 for aseptic tibial loosening. Radiographically, three unrevised femoral cones appeared loose in the presence of hinged implants, while the remainder of cones appeared stable. All cases of cone loosening occurred in Type 2B or 3 defects. Mean Knee Society scores improved from 50 preoperatively to 87 at latest follow-up (p<0.001). Three intraoperative fractures with cone impaction (two femoral, one tibial) all healed uneventfully. Conclusion. Novel 3-D printed titanium cones, with an efficient mill system, yielded excellent early survivorship and few complications in difficult revision TKAs with severe bone loss. The diversity of cone options, relative ease of preparation, and outcomes rivaling prior cone designs support the continued use of these modern cones. For figures, tables, or references, please contact authors directly

Introduction. The causes of revision total knee replacement are varied. There is a subset of these revision cases (poly wear and some cases of instability for example) where the ability to retain the metal femoral and tibial components and replacing just the polyethylene is an appealing option. We report on a series of RTKR where only the poly insert was replaced and the patients were followed for a minimum of ten years. Materials and Methods. Our study group consisted of 64 consecutive non infected RTKR patients who underwent a revision of the polyethylene alone between 1998 and 2006. All patients had been treated originally with the same cemented, CR, patella resurfaced primary TKR. Reasons for revision were 51 poly wear and/or osteolysis, 7 instability, and 6 other. The average time from the primary to the revision surgery was 9.1 years (range 2.2 to 16.1 years). All patients had an isolated poly liner change. No femurs or tibial trays were revised. Average age of the cohort at revision was 72.2 (range 48 to 88). Average BMI was 31.9 (range 23.6 to 43.9). There were 36 female patients. Of the group, 42 were ASA 1 or 2 and 22 were ASA 3. Pre-op alignment averaged 6.0 (range 2 varus to 8 valgus). Patients were followed for a minimum of 10 years (range 10 to 19 years). Results. At final follow up 13 patients had died, none were lost to follow up leaving 51 patients available for review. There were 7 reoperations in 6 patients (7 knees). Reasons for reoperation were: 4 aseptic tibial loosening at an average of 4.1 years (range 1.2 to 8.3) following first poly revision, two for polywear at an average 9 years post first poly revision, and one for deep infection (5.6 years post first poly revision). Knee society scores at 6 weeks post revision was 93.5 (range 38 to 100) and at final follow up for the non-revised knees was 91.6 (range 36 to 100). Conclusion. In appropriate settings, where the femoral and tibial components are satisfactorily aligned and well fixed and the soft tissues can be balanced, a poly change alone can provide a durable solution for the revision total knee patient. The ability to retain the metal components has advantages in terms of patient morbidity and cost

Purpose of Study. To identify the early functional outcomes, survivorship and complications associated with the Corin Uniglide Unicompartmental Knee Replacement (UKRs) from an independent centre. Methods and Results. A prospective consecutive case series of sixty Uniglide UKRs was carried out in fifty-one patients between January 2006 and March 2009. The data collected included: . Primary outcome measures:. Pre- and post-operative American Knee Society Score (AKSS), Oxford Knee Scores (OKS), WOMAC. Survivorship. Secondary outcome measures:. X-ray error scores assessing component position. Complications. No cases were lost to follow-up. Mean follow-up time was 19 months (12 to 36months) and mean age was 66 years (39 to 78 years). Kaplan-Meier Survivorship showed 95% survival at 3 years (CI:6.4). All functional outcomes showed significant improvement p <0.05. There were two revisions within the first year, which were the main complications, secondary to aseptic tibial loosening and collapse of the posteromedial tibia. The x-ray error score identified the most common error as the femoral flexion/extension angle followed by the anterior/posterior fit. Conclusion. The Uniglide UKR provides a significant improvement in early knee functional outcome and satisfactory short-term survivorship with an acceptable complication rate

Introduction. Beneath infection, instability and malalignment, aseptic tibial component loosening remains a major cause of failure in total knee arthroplasty (TKA) [1]. This emphasizes the need for stable primary and long-term secondary fixation of tibial baseplates. To evaluate the primary stability of cemented tibial baseplates, different pre-clinical test methods have been undergone: finite element analysis [2], static push-out [3,4] or dynamic compression-shear loading [5] until interface failure. However, these test conditions do not reflect the long-term endurance under in vivo loading modes, where the tibial baseplate is predominantly subjected to compression and shear forces in a cyclic profile [5,6]. To distinguish between design parameters the aim of our study was to develop suitable pre-clinical test methods to evaluate the endurance of the implant-cement-bone interface fixation for tibial baseplates under severe anterior (method I) and internal-external torsional (method II) shear test conditions. Materials & Methods. To create a clinically relevant cement penetration pattern a 4. th. generation composite bone model was customised with a cancellous core (12.5 PCF cellular rigid PU foam) to enable for high cycle endurance testing. VEGA System. ®. PS & Columbus. ®. CRA/PSA ZrN-multilayer coated tibial baseplates (2×12) were implanted in the customised bone model using Palacos. ®. R HV bone cement (Figure 1). An anterior compression-shear test (method II) was conducted at 2500 N for 10 million cycles and continued at 3000 N & 3500 N for each 1 million cycles (total: 12 million cycles) simulating post-cam engagement at 45° flexion. An internal-external torsional shear test (method II) was executed in an exaggeration of clinically relevant rotations [7,8] with ±17.2° for 1 million cycles at 3000 N tibio-femoral load in extension. After endurance testing either under anterior shear or internal-external torsion each tibial baseplate was mounted into a testing frame and maximum push-out strength was determined [3]. Results. The cement penetration depth and characteristic pattern were comparable to 3D-CT scans of 24 cemented human tibiae from a previous study [5]. From the final push-out testing, no statistical significant differences could be found for anterior compression-shear testing (method I) with VEGA System. ®. PS (2674 ± 754 N) and Columbus. ®. CRA/PSA (2177 ± 429 N) (p = 0.191), as well as internal-external torsional shear testing (method II) between VEGA System. ®. PS (2561 ± 519 N) and Columbus. ®. CRA/PSA (2825 ± 515 N) tibial baseplates (p = 0.399). Discussion. The newly developed methods allow the evaluation of the endurance behaviour of the implant-cement-bone interface fixation for tibial baseplates in comparison to clinically long-term established knee systems, based on a combination of a suitable artificial bone model and severe anterior and internal-external torsional high cycle shear test conditions

Aims

A novel enhanced cement fixation (EF) tibial implant with deeper cement pockets and a more roughened bonding surface was released to market for an existing total knee arthroplasty (TKA) system.This randomized controlled trial assessed fixation of the both the EF (ATTUNE S+) and standard (Std; ATTUNE S) using radiostereometric analysis.

Aims

The purpose of this study was to compare the clinical outcomes, mortalities, implant survival rates, and complications of total knee arthroplasty (TKA) in patients with or without hepatitis B virus (HBV) infection over at least ten years of follow-up.

Aims

Distal femoral osteotomies (DFOs) are commonly used for the correction of valgus deformities and lateral compartment osteoarthritis. However, the impact of a DFO on subsequent total knee arthroplasty (TKA) function remains a subject of debate. Therefore, the purpose of this study was to determine the effect of a unilateral DFO on subsequent TKA function in patients with bilateral TKAs, using the contralateral knee as a self-matched control group.

Aims

The primary objective of this registry-based study was to compare patient-reported outcomes of cementless and cemented medial unicompartmental knee arthroplasty (UKA) during the first postoperative year. The secondary objective was to assess one- and three-year implant survival of both fixation techniques.

Aims

Varus-valgus constrained (VVC) devices are typically used in revision settings, often with stems to mitigate the risk of aseptic loosening. However, in at least one system, the VVC insert is compatible with the primary posterior-stabilized (PS) femoral component, which may be an option in complex primary situations. We sought to determine the implant survivorship, radiological and clinical outcomes, and complications when this VVC insert was coupled with a PS femur without stems in complex primary total knee arthroplasties (TKAs).

Introduction. The precise indications for tibial component metal backing and modularity remain controversial in routine primary total knee arthroplasty. This is particularly true in elderly patients where the perceived benefits of metal backing such as load redistribution and the reduction of polyethylene strain may be clinically less relevant. The cost implications for choosing a metal-backed design over an all-polyethylene design may exceed USD500 per primary knee arthroplasty case. Methods. A prospective randomised clinical trial was carried out at the QEII Health Sciences Centre, Halifax, Nova Scotia, to compare modular metal-backed versus an all-polyethylene tibial component. Outcome measures included clinical range of motion, radiographs, survivorship, Knee Society Clinical Rating System, WOMAC and SF-12. Results. 116 patients requesting primary knee arthroplasty were recruited and randomised between the Smith & Nephew Genesis I non-modular (57) and modular (59) tibial designs between September 1995 and August 1997. At 10 years clinical follow-up, 4 implant revisions or intention-to-revise decisions were recorded in the metal-tray/modular group of which 2 were for aseptic tibial component loosening. 2 implant revisions in the all-polyethylene non-modular group were recorded, neither of which were for tibial component loosening. At 5, 7 and 10 year review; the KSCRS, WOMAC and SF12 scores were similar in both groups. As most patients randomised were over seventy years of age, this impacted significantly on the numbers available for longer term review and data was analysed by comparing pre- and post-operative scores for individual patients. Conclusion. There was no difference in performance between the all-polyethylene tibial component and the metal-backed tibial component. The case for using the all-polyethylene tibia in elderly patients is justified on both clinical efficacy and cost-containment grounds

Objectives

The Attune total knee arthroplasty (TKA) has been used in over 600 000 patients worldwide. Registry data show good clinical outcome; however, concerns over the cement-tibial interface have been reported. We used retrieval analysis to give further insight into this controversial topic.