The purpose of this study was to assess mid-term survivorship following primary total knee arthroplasty (TKA) with Optetrak Logic components and identify the most common revision indications at a single institution. We identified a retrospective cohort of 7,941 Optetrak primary TKAs performed from January 2010 to December 2018. We reviewed the intraoperative findings of 369 TKAs that required revision TKA from January 2010 to December 2021 and the details of the revision implants used. Kaplan-Meier analysis was used to determine survivorship. Cox regression analysis was used to examine the impact of patient variables and year of implantation on survival time.Aims
Methods
Purpose: Most series on revision total knee arthroplasty (TKA) have cited femorotibial instability as a frequent cause of failure, after loosening and patellar complications. The purpose of this study was to analyse
In 1983 we underscored the importance of understanding the cause or mechanism of
Most presentations about total knee arthroplasty begin with a statement that the procedure has been one of the great successes of modern surgery. However, not all patients consider their total knee a success. Success requires that patients experience relief of arthritic pain, return of function, and express satisfaction with the result. Patients need to be aware of the limitations of implants and accept reasonable expectations for the arthroplasty. If they don't, your next revision will likely be on a unsatisfied patient who had unrealistic expectations. The surgeon who operated on the patient for the primary intervention may feel obliged to try to make it better. Don't make that mistake. In a recent patient survey, 15–20% of patients (and maybe more) were not completely satisfied with their arthroplasty in spite of having recent implant designs. It is a fact that some patients will not be satisfied with any intervention. Fibromyalgia, depression, high narcotic use for arthritic pain, secondary gain (e.g., Worker's Compensation claims pending) are some of the conditions that predict a difficult post-operative course and an unsatisfied patient who will push for revision. T Design surgeons and engineers have developed techniques for a specific implant system to minimise the problems of malrotation, malalignment, instability, anterior knee pain, stiffness, loosening and polyethylene wear. Surgeons should be careful to use the recommended implantation philosophy and technique to avoid these problems. Choose implant systems with a proven track record. Learn how and why to use the instruments correctly. Study a system well and know the nuances. If you don't know the system well enough, take a course from the designers and ask questions. Prosthetic joint infection remains a major reason for revision. Some patients have a greater chance of developing infection. Attention to detail from pre-operative preparation to rehabilitation will minimise, but cannot eliminate, the occurrence of infection. The recently published International Consensus on Prosthetic Joint Infection contains recommendations that should be followed to minimise the chance of infection. The indication for revision is diagnosis of a problem that can be corrected with surgery. If a patient is satisfied with a result, revision surgery would only rarely be indicated regardless of the radiographic result. (Severe wear would be an exception to this.)
Most presentations about total knee arthroplasty begin with a statement that the procedure has been one of the great successes of modern surgery. However, not all patients consider their total knee a success. Success requires that patients experience relief of arthritic pain, return of function, and satisfaction with the result. Patients need to be aware of the limitations of implants and accept reasonable expectations for the arthroplasty. If they don't, your next revision will likely be on a dissatisfied patient who had unrealistic expectations. The surgeon who operated on the patient for the primary intervention may feel obliged to try to make it better. Avoid your next revision by only intervening when there is a clear indication. In a recent patient survey, 15–20% of patients were not completely satisfied with their arthroplasty in spite of having recent implant designs. It is a fact that some patients will not be satisfied with any intervention. Fibromyalgia, depression, high narcotic use for arthritic pain, secondary gain (e.g., Worker's Compensation claims pending) are some of the conditions that predict a difficult post-operative course and an unsatisfied patient who will push for revision. To avoid your next revision, choose patients wisely and make sure they understand that the total joint is a poor substitute for the normal knee. Design surgeons and engineers have developed techniques for a specific implant system to minimise the problems of malrotation, malalignment, instability, anterior knee pain, stiffness, loosening and polyethylene wear. Surgeons should be careful to use the recommended implantation philosophy and technique to avoid these problems. Choose implant systems with a proven track record. Learn how and why to use the instruments correctly. Study a system well and know the nuances. If you don't know the system well enough, take a course from the designers and ask questions. Using a system as it was intended will help avoid your next revision. Prosthetic joint infection remains a major reason for revision. Some patients have a greater chance of developing infection. Attention to detail from pre-operative preparation to rehabilitation will minimise, but cannot eliminate, the occurrence of infection. The recently published International Consensus on Prosthetic Joint Infection contains recommendations that should be followed to minimise the chance of infection and thus help avoid your next revision for infection. The indication for revision is presentation of a problem that can be corrected with surgery. If a patient is satisfied with a result, revision surgery would only rarely be indicated regardless of the radiographic result. (Severe wear would be an exception to this.) Recognising that “the enemy of good is better” will help you avoid your next revision.
Knee arthrodesis (KA) and above knee amputation (AKA) have been used for salvage of failed total knee arthroplasty (TKA) in the setting of periprosthetic joint infection (PJI). The factors that lead to a failed fusion and progression to AKA are not well understood. The purpose of our study was to determine factors associated with failure of a staged fusion for PJI and predictive of progression to AKA. We retrospectively reviewed a single-surgeon series of failed TKA for PJI treated with two-stage KA between 2000 and 2016 with minimum 2-year follow-up. Patient demographics, comorbidities, surgical history, tissue compromise, and radiographic data were recorded. Outcomes were additional surgery, delayed union, Visual Analog Pain scale (VAS) and Western Ontario and McMaster Activity score (WOMAC). No power analysis was performed for this retrospective study. Medians are reported as data were not normally distributed.Aim
Method
Due to the success, quantified by both clinical improvement and durability, the number of TKA procedures performed annually has steadily increased since its introduction and it is predicted that approximately 3 million knee arthroplasties will be performed in 2030. Part of this exponential growth is due to indication expansion and TKA is now often performed for younger, more active and heavier patients that historically would have been denied the procedure. Combined with an aging population, often afflicted with comorbidities, it is not surprising that the number of TKA revisions performed annually is also increasing.
Introduction. The utilization of lymphocyte transformation testing (LTT) has increased for diagnosing metal sensitivity associated with TKA, but its validity for the diagnosis of
Introduction. Mechanical or corrosive
Purpose. To identify the modes of
Aseptic loosening is the most common cause of failure following cemented total knee arthroplasty (TKA), and has been linked to poor cementation technique. We aimed to develop a consensus on the optimal technique for component cementation in TKA. A UK-based, three-round, online modified Delphi Expert Consensus Study was completed focusing on cementation technique in TKA. Experts were identified as having a minimum of five years’ consultant experience in the NHS and fulfilling any one of the following criteria: a ‘high volume’ knee arthroplasty practice (> 150 TKAs per annum) as identified from the National joint Registry of England, Wales, Northern Ireland and the Isle of Man; a senior author of at least five peer reviewed articles related to TKA in the previous five years; a surgeon who is named trainer for a post-certificate of comletion of training fellowship in TKA.Aims
Methods
The goal was to evaluate tibiofemoral knee joint kinematics during stair descent, by simulating the full stair descent motion in vitro. The knee joint kinematics were evaluated for two types of knee implants: bi-cruciate retaining and bi-cruciate stabilized. It was hypothesized that the bi-cruciate retaining implant better approximates native kinematics. The in vitro study included 20 specimens which were tested during a full stair descent with physiological muscle forces in a dynamic knee rig. Laxity envelopes were measured by applying external loading conditions in varus/valgus and internal/external direction.Aims
Methods
Introduction. The Rotational alignment is an important factor for survival total knee Arthroplasty. Rotational malalignment causes knee pain, global instability, and wear of the polyethylene inlay. Also, the anterior cortex line was reported that more reliable and more easily identifiable landmark for correct tibial component alignment. The aims of the current study is to identify effect of inserting the tibial baseplate of using anterior cortex line landmark of TKA on stress/strain distributions within cortical bone and bone cement. Through the current study, final aim is to suggest an alternative position of tibia baseplate for reduction of
Unicompartmental knee arthroplasty (UKA) is the preferred treatment for anterior medial knee osteoarthritis (OA) owing to the rapid postoperative recovery. However, the risk factors for UKA failure remain controversial. The clinical data of Oxford mobile-bearing UKAs performed between 2011 and 2017 with a minimum follow-up of five years were retrospectively analyzed. Demographic, surgical, and follow-up data were collected. The Cox proportional hazards model was used to identify the risk factors that contribute to UKA failure. Kaplan-Meier survival was used to compare the effect of the prosthesis position on UKA survival.Aims
Methods
Introduction. Polyetheretherketone (PEEK) has been proposed as an implant material for femoral total knee arthroplasty (TKA) components. Potential clinical advantages of PEEK over standard cobalt chrome alloys include modulus of elasticity and subsequently reduced stress shielding potentially eliminating osteolysis, thermal conduction properties allowing for a more natural soft tissue environment, and reduced weight enabling quicker quadriceps recovery. Manufacturing advantages include reduced manufacturing and sterilization time, lower cost, and improved quality control. Currently, no PEEK TKA implants exist on the market. Therefore, evaluation of mechanical properties in a pre-clinical phase is required to minimize patient risk. The objectives of this study include evaluation of implant fixation and determination of the potential for reduced stress shielding using the PEEK femoral TKA component. Methods and Materials. Experimental and computational analysis was performed to evaluate the biomechanical response of the femoral component (Freedom Knee, Maxx Orthopedics Inc., Plymouth Meeting, PA; Figure 1). Fixation strength of CoCr and PEEK components was evaluated in pull-off tests of cemented femoral components on cellular polyurethane foam blocks (Sawbones, Vashon Island, WA). Subsequent testing investigated the cemented fixation using cadaveric distal femurs. The reconstructions were subjected to 500,000 cycles of the peak load occurring during a standardized gait cycle (ISO 14243-1). The change from CoCr to PEEK on implant fixation was studied through computational analysis of stress distributions in the cement, implant, and the cement-implant interface. Reconstructions were analyzed when subjected to standardized gait and demanding squat loads. To investigate potentially reduced stress shielding when using a PEEK component, paired cadaveric femurs were used to measure local bone strains using digital image correlation (DIC). First, standardized gait load was applied, then the left and right femurs were implanted with CoCr and PEEK components, respectively, and subjected to the same load. To verify the validity of the computational methodology, the intact and reconstructed femurs were replicated in FEA models, based on CT scans. Results. The cyclic load phase of the pull-off experiments revealed minimal migration for both CoCr and PEEK components, although after construct sectioning, debonding at the implant-cement interface was observed for the PEEK implants. During pull-off from Sawbones the ultimate failure load of the PEEK and CoCr components averaged 2552N and 3814N respectively. FEA simulations indicated that under more physiological loading, such as walking or squatting, the PEEK component had no increased risk of loss of fixation when compared to the CoCr component. Finally, the DIC experiments and FEA simulations confirmed closer resemblance of pre-operative strain distribution using the PEEK component. Discussion. The biomechanical consequences of changing implant material from CoCr to PEEK on implant fixation was studied using experimental and computational testing of cemented reconstructions. The results indicate that, although changes occur in implant fixation, the PEEK component had a fixation strength comparable to CoCr. The advantage of long term bone preservation, as the more compliant PEEK implant is able to better replicate the physiological loads occurring in the intact femur, may reduce stress shielding around the distal femur, a common clinical cause of
Micromotion of the polyethylene (PE) inlay may contribute to backside PE wear in addition to articulate wear of total knee arthroplasty (TKA). Using radiostereometric analysis (RSA) with tantalum beads in the PE inlay, we evaluated PE micromotion and its relationship to PE wear. A total of 23 patients with a mean age of 83 years (77 to 91), were available from a RSA study on cemented TKA with Maxim tibial components (Zimmer Biomet). PE inlay migration, PE wear, tibial component migration, and the anatomical knee axis were evaluated on weightbearing stereoradiographs. PE inlay wear was measured as the deepest penetration of the femoral component into the PE inlay.Aims
Methods
Bone loss creates a challenge to achieving fixation in revision
Total knee arthroplasty (TKA) is reliable, durable, and reproducible in relieving pain and improving function in patients with arthritis of the knee joint. Cemented fixation is the gold standard with low rates of loosening and excellent survivorship in several large clinical series and joint registries. While cementless knee designs have been available for the past 3 decades, changing patient demographics (i.e. younger patients), improved implant designs and materials, and a shift towards TKA procedures being performed in ambulatory surgery centers has rekindled the debate of the role of cementless knee implants in TKA. The drive towards achieving biologic implant fixation in TKA is also driven by the successful transition from cemented hip implants to uncemented THA. However, new technologies and new techniques must be adopted as a result of an unmet need, significant improvement, and/or clinical advantage. Thus, the questions remain: 1) Why switch; and 2) Is cementless TKA more reliable, durable, or reproducible compared to cemented TKA?. There are several advantages to using cement during TKA. First, the technique can be universally applied to all cases without exception and without concerns for bone health or structure. Second, cement can mask imprecisions in bone cuts and is a remarkably durable grout. Third, cement allows for antibiotic delivery at the time surrounding surgery which has been shown in some instances to reduce the risk of subsequent infection. Finally, cement fixation has provided successful and durable fixation across various types knee designs, surface finishes, and articulations. On the other hand, cementless knee implants have had an inconsistent track record throughout history. While some have fared very well, others have exhibited early failures and high revision rates. Behery et al. reported on a series of 70 consecutive cases of cementless TKA matched with 70 cemented TKA cases based on implant design and demographics and found that cementless TKA was associated with a greater risk of aseptic loosening and revision surgery at 5 years follow up. Finally, to date, there has not been a randomised controlled clinical trial demonstrating superiority of cementless fixation compared to cemented fixation in TKA. Improvements in materials and designs have definitely made cementless TKA designs viable. However, concerns with added cost, reproducibility, and durability remain. Cement fixation has withstood the test of time and is not the main cause of
The goal of the current systematic review was to assess the impact of implant placement accuracy on outcomes following total knee arthroplasty (TKA). A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using the Ovid Medline, Embase, Cochrane Central, and Web of Science databases in order to assess the impact of the patient-reported outcomes measures (PROMs) and implant placement accuracy on outcomes following TKA. Studies assessing the impact of implant alignment, rotation, size, overhang, or condylar offset were included. Study quality was assessed, evidence was graded (one-star: no evidence, two-star: limited evidence, three-star: moderate evidence, four-star: strong evidence), and recommendations were made based on the available evidence.Aims
Methods