During total knee arthroplasty (TKA), a tourniquet is often used intraoperatively. There are proposed benefits of tourniquet use including shorter duration of surgery, improved surgical field visualization and increased cement penetration which may improve implant longevity. However, there are also cited side effects that include increased post-operative pain, slowed recovery, skin bruising, neurovascular injury and quadriceps weakness. Randomized controlled trials have demonstrated no differences in implant longevity, however they are limited by short follow-up and small sample sizes. The objective of the current study was to evaluate the rates of revision surgery among patients undergoing cemented TKA with or without an intraoperative tourniquet and to understand the causes and risk factors for failure. A retrospective cohort study was undertaken of all patients who received a primary, cemented TKA at a high-volume arthroplasty centre from January 1999 to December 2010. Patients who underwent surgery without the use of a tourniquet and those who had a tourniquet inflated for the entirety of the case were included. The causes and timing of revision surgery were recorded and cross referenced with the Canadian Institute of Health Information Discharge Abstract Database to reduce the loss to follow-up. Survivorship analysis was performed with the use of Kaplan-Meier curves to determine overall survival rates at final follow-up. A Cox proportional hazards model was utilized to evaluate independent predictors of revision surgery. Data from 3939 cases of primary cemented TKA were available for analysis. There were 2276 (58%) cases in which a tourniquet was used for the duration of the surgery and 1663 (42%) cases in which a tourniquet was not utilized. Mean time from the primary TKA was 14.7 years (range 0 days - 22.8 years) when censored by death or revision surgery. There were 150 recorded revisions in the entire cohort, with periprosthetic joint infection (n=50) and aseptic loosening (n=41) being the most common causes for revision. The cumulative survival at final follow-up for the tourniquetless group was 93.8% at final follow-up while the cumulative survival at final follow-up for the tourniquet group was 96.9% at final follow-up. Tourniquetless surgery was an independent predictor for all-cause revision with an HR of 1.53 (95% CI 1.1, 2.1, p=0.011). Younger age and male sex were also independent factors for all cause revision. The results of the current study demonstrate higher all-cause revision rates with tourniquetless surgery in a large cohort of patients undergoing primary cemented TKA. The available literature consists of short-term trials and registry data, which have inherent limitations. Potential causes for increased revision rates in the tourniquetless group include reduced cement penetration, increased intraoperative blood loss and longer surgical. The results of the current study should be taken into consideration, alongside the known risks and benefits of tourniquet use, when considering intraoperative tourniquet use in cemented TKA

Tourniquet use in total knee arthroplasty (TKA) remains a subject of considerable debate. A recent study questioned the need for tourniquets based on associated risks. However, the study omitted analysis of crucial tourniquet-related parameters which have been demonstrated in numerous studies to be associated with safe tourniquet use and reduction of adverse events. The current utilization and preferences of tourniquet use in Canada remain unknown. Our primary aim was to determine the current practices, patterns of use, and opinions of tourniquet use in TKA among members of the Canadian Arthroplasty Society (CAS). Additionally, we sought to determine the need for updated best practice guidelines to inform optimal tourniquet use and to identify areas requiring further research. A self-administered survey was emailed to members of the CAS in October 2021(six-week period). The response rate was 57% (91/161). Skip logic branching was used to administer a maximum of 59 questions related to tourniquet use, beliefs, and practices. All respondents were staff surgeons and 88% were arthroplasty fellowship trained. Sixty-five percent have been in practice for ≥11 years and only 16% for 50 TKA/year, 59% have an academic practice, and >67% prefer cemented TKA. Sixty-six percent currently use tourniquets, 25% no longer do but previously did, and 9% never used tourniquets. For those not using tourniquets, the most common reasons are potential harm/risks and publications/conferences. Among current users, 48% use in all cases and an additional 37% use in 76-99% of cases. The top reason for use was improved visualization/bloodless field (88%), followed by performing a cemented TKA, used in training, and faster operative times. The main patient factor influencing selective tourniquet use was peripheral vascular disease and main surgical factors were operative duration and cementless TKA. The most frequent adverse events reported were bruising/pinching under the tourniquet and short-term pain, which majority believed were related to improper tourniquet use (prolonged time, high-pressures, poor cuff fit), yet only 8% use contoured tourniquets and 32% don't use limb protection. Despite substantial evidence in literature that tourniquet safety and probability of harm are affected by tourniquet time and pressure, only 83% and 72% of respondents believe reducing tourniquet time and pressure respectively reduce the probability of harm. In addition, no surgeon utilizes personalized limb occlusion pressure which has been demonstrated to substantially reduce tourniquet pressure while being safe and effective. Furthermore, 62% always use fixed pressure and 37% will modify the pressure based on patient parameters, most often systolic blood pressure and limb size. Almost all (88%) were interested in new evidence-based guidelines regarding these parameters. Tourniquet use in TKA remains prevalent among arthroplasty surgeons in the CAS; however tremendous practice variability regarding several key parameters required for optimal use exists. Current best practices of tourniquet use regarding personalized pressures, time, and type are not being utilized across Canada. There is considerable interest and need for further research and updated guidelines regarding key parameters of safe tourniquet usage to optimize tourniquet use in TKA

Aim. One of the most severe complications of primary total knee arthroplasty (TKA) is periprosthetic joint infection (PJI). Nowadays, the use of antibiotic-loaded cement for prevention of infection is still controversial. The aim of the present study is to evaluate the use of an antibiotic-loaded cement to reduce the infection rate in primary total knee arthroplasty. Method. Prospective randomized study, with 2893 cemented total knee arthroplasties performed between 2005 and 2010 in our institution. Two different groups were formed depending on which bone cement was used, without antibiotic (the control group) or loaded with erythromycin and colistin (the study group). All patients received the same systemic prophylactic antibiotics. The patients were followed for a minimum of twelve months. The rate of infection was analyzed according to the criteria of the Centers for Disease Control and Prevention (CDC). Results. In 1452 patients the prosthetic components were fixed using bone cement without antibiotic and in 1441 patients bone cement loaded with erythromycin and colistin was used. There were no differences between both groups in terms of demographic data (age, sex and BMI), either in operating time (p>0,05). The rate of infection was similar in both groups, being 2,0% (n=29) in the control group and 1,7% in the study group (p=0,58) at 8,7 years (SD 5,1) of follow up. In terms of prosthetic revision due to any cause (infected or aseptic), there wasn't differences between groups, performing a total of 61 revision arthroplasties in control group and 68 in study group (p>0,05). Moreover, we analyzed the erythromycin resistance rate, being no differences between both groups (p=0.6). Conclusions. The use of erythromycin and colistin-loaded bone cement in total knee arthroplasty did not lead to a decrease in the rate of infection when systemic prophylactic antibiotics were used, a finding that suggests that its use would not be indicated in the general population

This study aimed to analyze the effect of two different techniques of cement application: cement on bone surface (CoB) versus cement on bone surface and implant surface (CoBaI) on the short-term effect of radiolucent lines (RLL) in primary fully cemented total knee arthroplasties (TKA) with patella resurfacing. 379 fully cemented TKAs (318 patients) were included in this monocentric study. Preoperative and postoperative at week 4 and 12 month after surgery all patients had a clinical and radiological examination and were administered the Oxford Knee Score (OKS). Cement was applied in two different ways among the two study groups: cement on bone surface (CoB group) or cement on bone surface and implant surface (CoBaI group). The evaluation of the presence of RLL or osteolysis was done as previously described using the updated Knee Society Radiographic Evaluation System. The mean OKS and range of motion improved significantly in both groups at the 4-week and 12-month follow-up, with no significant difference between the groups (CoB vs. CoBaI). RLL were present in 4.7% in the whole study population and were significantly higher in the CoBaI group (10.5%) at the 4-week follow-up. At the 12-month follow-up RLL were seen in 29.8% of the TKAs in the CoBaI group, whereas the incidence was lower in the CoB group (24.0% (n.s.)). There were two revisions in each group. None of these due to aseptic loosening. Our study indicated that the application of bone cement on bone surface only might be more beneficial than onto the bone surface and onto the implant surface as well in respect to the short-term presence of RLL in fully cemented primary TKA. The long-term results will be of interest, especially in respect to aseptic loosening and might guide future directions of bone cement applications in TKA

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 TKA failure. Therefore, until there is significant data showing that cementless TKA is more durable, reliable, and reproducible compared to cemented TKA, the widespread use of these implants cannot be recommended

Introduction & Aims. In other medical fields, smart implantable devices are enabling decentralised monitoring of patients and early detection of disease. Despite research-focused smart orthopaedic implants dating back to the 1980s, such implants have not been adopted into regular clinical practice. The hardware footprint and commercial cost of components for sensing, powering, processing, and communicating are too large for mass-market use. However, a low-cost, minimal-modification solution that could detect loosening and infection would have considerable benefits for both patients and healthcare providers. This proof-of-concept study aimed to determine if loosening/infection data could be monitored with only two components inside an implant: a single-element sensor and simple communication element. Methods. The sensor and coil were embedded onto a representative cemented total knee replacement. The implant was then cemented onto synthetic bone using polymethylmethacrylate (PMMA). Wireless measurements for loosening and infection were then made across different thicknesses of porcine tissue to characterise the sensor's accuracy for a range of implantation depths. Loosening was simulated by taking measurements before and after compromising the implant-cement interface, with fluid influx simulated with phosphate-buffered saline solution. Elevated temperature was used as a proxy for infection, with the sensor calibrated wirelessly through 5 mm of porcine tissue across a temperature range of 26–40°C. Results. Measurements for loosening and infection could be acquired simultaneously with a duration of 4 s per measurement. For loosening, the debonded implant-cement interface was detectable up to 10 mm with 95% confidence. For temperature, the sensor was calibrated with a root mean square error of 0.19°C at 5 mm implantation depth and prediction intervals of ±0.38°C for new measurements with 95% confidence. Conclusions. This study has demonstrated that with only two onboard electrical components, it is possible to wirelessly measure cement debonding and elevated temperature on a smart implant. With further development, this minimal hardware/cost approach could enable mass-market smart arthroplasty implants

Lavage and preparation of the cancellous bony surface can facilitate adequate fixation of components in cemented total knee arthroplasty (TKA). Commonly used techniques for bone preparation such as pulse lavage, apart from adding to the cost, may cause local loss of loose cancellous bone and may even drive contaminants deeper into the tissue when used during TKA. We describe a simple, inexpensive and effective tool of using a sterilised toothbrush for preparing bone surface during cemented TKA. This must be followed by adequate pressurization of cement at the right time to achieve close interdigitation of cement with trabecular bone

Lavage and preparation of the cancellous bony surface can facilitate adequate fixation of components in cemented total knee arthroplasty (TKA). Commonly used techniques for bone preparation such as pulse lavage, apart from adding to the cost, may cause local loss of loose cancellous bone and may even drive contaminants deeper into the tissue when used during TKA. We describe a simple, inexpensive and effective tool of using a sterilised toothbrush for preparing bone surface during cemented TKA. This must be followed by adequate pressurization of cement at the right time to achieve close interdigitation of cement with trabecular bone

Lavage and preparation of cancellous bone surface is essential to ensure adequate fixation of components in cemented total knee arthroplasty (TKA). Commonly used techniques for bone preparation such as pulse lavage, apart from adding to the cost, may cause local loss of loose cancellous bone and may even drive contaminants deeper into the tissue when used during TKA. We describe a simple, inexpensive and effective tool of using a sterilised toothbrush for preparing bone surface during cemented TKA

Lavage and preparation of cancellous bone surface is essential to ensure adequate fixation of components in cemented total knee arthroplasty (TKA). Commonly used techniques for bone preparation such as pulse lavage, apart from adding to the cost, may cause local loss of loose cancellous bone and may even drive contaminants deeper into the tissue when used during TKA. We describe a simple, inexpensive and effective tool of using a sterilised toothbrush for preparing bone surface during cemented TKA

The initial application of bone ingrowth technology to the fixation of total knee arthroplasty (TKA) components without bone cement was based on the premise that bone cement was “not biologic”, and so over time would undergo fatigue failure with subsequent loosening. It was hoped that this problem could be obviated by cementless fixation by bone ingrowth, which would remodel over time and not fatigue. In addition, it was anticipated that the failed cementless TKA might be easier to revise and leave the surgeon with more bone to work with. Whether or not cementless fixation of TKA components was justified on any of these counts was uncertain through the first 2 decades of their use. Much of the data accumulated during that period poorly supported these contentions, while cemented TKA was increasingly reported as a reliable, consistent and less complicated form of TKA fixation. However, over the past decade, new evidence has accumulated demonstrating greater success with this technology in several well designed studies as well as from registry studies. Most of this evidence involves the use of Porous Tantalum. However, increasing evidence that loosening of well done, well designed cemented TKA is rare along with some evidence that a certain percentage of cementless TKA patients fail to achieve stability remains concerning. In addition, no studies have justified improved longevity to the extent that the increased cost of cementless devices can be justified

Introduction. Long term data on the survivorship of cemented total knee arthroplasty (TKA) has demonstrated excellent outcomes; however, with younger, more active patients, surgeons have a renewed interest in improved biologic fixation obtained from highly porous, cementless implants. Early designs of cementless total knees systems were fraught with high rates of failure for aseptic loosening, particularly on the tibial component. Prior studies have assessed the bone ingrowth extent for tibial tray designs reporting near 30% extent of bone ingrowth . (1,2). While these analyses were performed on implants that demonstrated unacceptably high rates of clinical failure, a paucity of data exists on the extent on bone ingrowth in contemporary implant designs with newer methods for manufacturing the porous surfaces. We sought to evaluate the extent of attached bone on retrieved cementless tibial trays to determine if patient demographics, device factors, or radiographic results correlate to the extent of bone ingrowth in these contemporary designs. Methods. Using our IRB approved retrieval database, 17 porous tibial trays were identified and separated into groups based on manufacturer: Zimmer Natural Knee (1), Zimmer NexGen (10), Stryker Triathlon (4) and Biomet Vanguard Regenerex (2). Differences in manufacturing methods for porous material designs were recorded. Patient demographics and reason for revision are described in Table 1. Radiographs were used to measure tibiofemoral alignment and the tibial mechanical axis alignment. Components were assessed using visual light microscopy and Photoshop to map bone ingrowth extent across the porous surface. ImageJ was used to threshold and calculate values for bone, scratched metal, and available surface for bone ingrowth (Fig. 1). Percent extent was determined as the bone ingrowth compared to the surface area excluding any scratched regions from explantation. Statistics were performed among tray designs as well as between the lateral and medial pegs, if designs had pegs available for bony ingrowth. Results. Mean bone ingrowth extent was 51.4% for the tibial tray for the entire cohort. Bone ingrowth extent was statistically greater in the Zimmer NexGen design (63.8%; p=.027) compared to the other three designs (Table 2). Four sets of pegs were excluded from analysis due to lack of porous coatings or pegs having been removed at revision surgery. Across all designs, the medial peg had 45.2% ingrowth and the lateral peg had 66.1% ingrowth. The medial peg for the NexGen design had significantly less bone ingrowth compared to the lateral peg (58.7% vs. 75.4%; p=0.044). No significant differences were found in tibiofemoral alignment or tibial mechanical axis alignment between the implant groups. No significant differences were found among implants revised for aseptic loosening versus any other reason for revision (54% vs 30%; p=.18). Discussion. Our results demonstrate high rates of bone ingrowth extent in contemporary designs, further supporting porous design rationales and a role for additive manufacturing to form enhanced porosity. We plan on exploring staining techniques to confirm our visual inspection. Contemporary designs have shown successful rates for improved longevity for cementless total knee systems. For any figures or tables, please contact the authors directly

Total knee replacements are being more commonly performed in active younger and obese patients. Fifteen-year survivorship studies demonstrate that cemented total knee replacements have excellent survivorship, with reports of 85 to 97%. Cemented knee arthroplasties are doomed to failure due to loss of cement-bone interlock over time. Inferior survivorship occurs in younger patients and obese patients who would be expected to place increased stress on the bone-cement interfaces. Roentgen stereophotogrammetric analysis (RSA) studies have indicated that cementless fixation should perform better than cemented fixation. However, cementless fixation for total knee replacement has not gained widespread utilization due to the plethora of poor results reported in early series. The poor initial results with cementless total knee replacement have occurred due to poor implant designs such as cobalt chrome porous interfaces, poor initial tibial component stability, lack of continuous porous coating, poor polyethylene, and use of metal-backed patellae. I have used cementless fixation for total knee replacements for young, active, and heavy patients since 1986 when durability over 20 years is desirable. My series of over 1,300 cementless TKAs represents about 20% of the 6,500 total knees I have performed from 1986 to 2017. I have seen initial failures in my series due to the use of metal-backed patellae with thin polyethylene, older generation polyethylene, and use of screws with the tibial components which provide access to the metaphyseal bone for polyethylene wear debris. Overall implant fixation failures were still significantly low due to the use of a highly porous titanium surface on both the tibial and femoral components. With the advent of utilizing implants with continuous porous surfaces and highly crosslinked polyethylene, and elimination of use of metal-backed patellae and tibial screws, I have only had one revision due to aseptic loosening or osteolysis in the last 1,071 cases performed since 2002. Almost 50% of total knees are now performed on patients under the age of 65. A 55-year-old patient has a 30 year life expectancy. Modern total knee replacement design has made biological fixation predictable for young and heavy patients. Because it is a biological interface, it should respond better than cement to the increased stresses that will be applied over many years by our younger, more active and heavier total knee population

INTRODUCTION. To test whether there are differences in postoperative mechanical and component alignment, and in functional results, between conventional, navigated and patient-specific total knee arthroplasties in a low-volume centre?. MATERIAL AND METHODS. Retrospective cohort study of 391 patients who received conventional, navigated or patient- specific primary cemented TKA in a low-volume hospital. RESULTS. The risk of mechanical alignment outliers was 89% lower in the navigated group compared to the conventional TKA group. There was a 63% lower risk of femoral component malalignment and a 66% lower risk of tibial component malalignment in the navigated group. No significant reduction in the risk of malalignment was seen in the patient-specific group. Total WOMAC and Oxford scores were no different between the three techniques. The patient-specific group reported better WOMAC pain scores. PSI TKA was 33% more expensive than conventional TKA and 28% more expensive than Navigated TKA. DISCUSSION. Navigated TKA improved alignment, but neither navigated nor patient-specific TKA improved functional outcomes. Patient-specific TKA was more expensive, with little additional benefit. Clinical relevance: The routine use of patient-specific instrumentation in low-volume centers is not supported by the currently available data

INTRODUCTION:. Aseptic loosening continues to be a short and long-term complication for patients with cemented knee replacements. Changes in cemented total knee replacement (TKR) fixation have been limited to assessment of radiographic changes at the implant-bone interface and quantification of component migration. The goal of this study was to determine the interlock morphology between cement and trabecular bone using en bloc postmortem retrieved TKR. Note that these retrievals were not obtained from revision surgery for a loose implant, but rather after death. Thus the implants can be considered successful for the lifetime of the patient. We hypothesized that constructs with greater time in service have less interlock between cement and bone and constructs with more estimated initial interlock sustain more interlock with in-vivo service. METHODS:. Twelve retrieved tibial components and two lab-prepared constructs with time in service from 0 to 20 years were sectioned in the transverse plane in 10 mm increments, imaged at high resolution, and the current contact fraction (curCF), estimated initial interdigation depth (inID), current interdigitation depth (curID), and loss of interdigitation depth (lossID) were quantified at the cement-bone interface. Contact fraction was determined using a stereology method using random ray projections (Figure 1A). The trabecular shape cast into the cement layer upon curing was used to document the initial penetration of bone into the cement. A line tracing algorithm was used to determine interdigiation depth (Figure 1B). RESULTS:. There was no biological resorption for the lab prepared constructs (Figure 2A-B). In contrast, a postmortem retrieval (5 years in service) illustrates trabecular resorption with some areas of bone remaining in the cement layer (Figure 2C-D). The curCF (r. 2. = 0.54, p = 0.0027) and curID (r. 2. = 0.33, p = 0.033) were lower for constructs with longer time in service (Figure 3). The lossID had a strong positive relationship with time in service (r. 2. = 0.74, p < 0.0001). Using a two-parameter regression model, constructs with more inID had higher curID (p = 0.011), but constructs with more time in service also had lower curID (p = 0.008). DISCUSSION:. The cement-trabecular bone interlock that is obtained initially appears to diminish with in-vivo service by resorption of the trabeculae within the cement interlock region. The resulting fixation for longer term constructs (>10 years) was limited, with cement-bone contact fractions of ∼7% and interdigitation depths of ∼0.4 mm. This appears to be sufficient to support load transfer between the metal tray and proximal tibia, as these retrievals were from radiographically well fixed components. The work here supports the surgical concept of obtaining sufficient initial cement interlock (∼3 mm), with the acknowledgement that there will be loss of interlock with in-vivo service. It is possible that loss of interlock contributes to the loosening process of cemented TKR. Further work is needed to understand how loss of interlock affects interface strength

Total knee arthroplasty has been demonstrated to provide durable results with excellent pain relief and improvement in function. Our institution has studied and published the longest follow-up of mobile bearing TKR, fixed bearing modular TKR, and unicompartmental replacement. Indeed these studies support the durability of the operation and the improvement in function and relief of pain. They, however, are not perfect. In tricompartmental replacement, up to 5 or 6% are revised for loosening and or wear and in unicompartmental replacement, up to 25% are revised for loosening. There are also one or two percent of cases revised for periprosthetic fracture and one or two percent for hematogenous infection. One must remember these cases were performed in patients of average age 71. When one looks at our results in more active patients with osteoarthritis who are less than 55, the results are less spectacular with 15% revised at 10 to 15 years for loosening. We all hope that better polyethylene and better tibial tray locking mechanisms (in fixed bearing modular designs) will improve these results, but to predict there will be no failures is a “leap of faith”. Long-term follow-up of cemented TKA in patients under 55 where monolithic tibial trays were utilised have demonstrated better results at 20 years (92.3%) survivorship versus those where modular tibial trays (68%) were utilised. Long-term studies of cementless total knee replacement, especially in younger patients are needed to see if this approach provides better results

Cementless fixation in TKA has been inconsistently adopted since its early use but is increasing due to a number of factors, predominantly related to a demand for improved survivorship in younger patients. Modern biomaterials have demonstrated optimal bone ingrowth and have also contributed to a renewed confidence by surgeons to utilise cementless fixation in TKA. With a modern design and appropriate surgical technique, optimal mechanical stability of new designs have been demonstrated and can build upon the excellent long-term outcomes that have rivaled traditional cemented TKA. Paramount to obtaining successful long-term osseointegration and clinical survivorship with cementless fixation is an awareness of the past failure mechanisms to improve implant modern implant design, and should also guide meticulous surgical technique. A robust implant design with optimal surgical technique is critical to success when employing cementless fixation in TKA. The tried and true principles of sufficient mechanical stability to minimise micromotion of an osteoconductive implant surface with intimate contact against viable bone are essential to allow osseointegration and long-term survivorship. The surgical techniques and tips for “getting it right” include: 1.) Meticulous planar cuts - Prevention of saw blade deviation (particularly anterior femoral cortex and sclerotic medial tibial plateau), Appropriate tolerances in cutting guides (particularly 4-in-1 femoral cutting guide), Appropriate interference fit for tibial keel/stem, patella planar cut, Perfect planar cut on tibial surface confirmed with “4-corner test”. 2.) Implantation of components to maximise mechanical stability - Intimate implant contact with bone (minimizing gaps), Consider bone slurry to minimise gaps, Prevention of femoral component flexion with impaction, Ensure parallel position of tibial baseplate with tibial cut surface during impaction, Peripheral fixation on tibial baseplate, either screws or pegs, to provide supplemental fixation and stability in titanium tray designs

Introduction & aims. Total knee Arthroplasty has revolutionized the lifestyle of patients with end stage knee arthritis. This study was conducted to describe the outcome from patient's perspective one year after TKR and patient satisfaction in terms of post operative pain and functional outcome Also, to identify preoperative characteristics predicting post operative outcome. Method. A prospective study was conducted at our institution (Dayanand Medical College and Hospital, Ludhiana) from 2010 to 2012. The study included 104 patients (74 females and 30 males) with 152 cemented TKR surgeries. The average age of the patients was 61.39 years. Out of 104 patients, 48 had bilateral TKR, 31 had left TKR and 25 had right TKR surgery. Knee injury and osteoarthritis outcome score (KOOS) and DMCH General Patient Questionnaire was used to analyse the satisfaction level, physical activity and quality of life one year after the TKR surgery. Results. There was significant improvement in all KOOS subscale scores but post operative sports and recreational scores remained at lowest level in the Likert scale. There was no significant effect of age, sex, duration of symptoms, co morbidities and BMI on post operative KOOS scores and patient satisfaction. There was no significant difference in post operative mean pain and functional scores in patients with higher and lower ranges of pre operative scores, though patients with higher pre operative scores had slightly higher post operative scores. The mean post operative KOOS scores had trend of higher scores in RA patients as compared to OA patients. However, there was no statiscally significant difference between these two groups. Post operative KOOS pain and activity daily living (ADL) scores were comparable to patient's satisfaction levels. Conclusions. TKR significantly improves patient's pain symptoms, function and activities of daily living and knee related quality of life as more than 80% patients showed excellent satisfaction one year after the surgery. Sports and recreational activities did not improve to the same extent as these activities were not applicable to more than 30% of the patients. For any figures or tables, please contact authors directly (see Info & Metrics tab above).

Introduction. The use of cementless TKA's has been gradually increasing over the past several years given the increasing life expectancy of our patient population. Cementless TKA's have not been rapidly adopted due to the challenges and uncertainty of tibial fixation especially in elderly patients. With the advent of new technologies, the results of cementless TKA's with the potential for long term biologic fixation may now be equivalent or better than cemented TKA's. A highly porous tibial baseplate was developed based on proximal tibial anatomy using CT scans using 3D printing technology with focus on length, location and design of press-fit pegs. Objectives. The purpose of this study was to review the early results with respect to fixation and complications using a new, highly porous cementless tibial baseplate designed for biologic fixation. Methods. One hundred primary cementless TKAs were retrospectively reviewed using a highly porous titanium tibial baseplate. The femoral and patella components were also press-fit using peri-apetite beaded technology. Patients were evaluated at 2 weeks, 3 months, 1 and 2 year for clinical and radiographic outcomes along with any early (within 90 day) and 2 year complications. Postoperative protocol consisted of immediate full weightbearing, as tolerated. Radiographs were evaluated for biological fixation and radiolucent lines. Results. There were 68 females and 32 males with 7 undergoing bilateral TKA. The mean age was 63.8 yrs (range 40–84). The mean BMI was 33.7. Diagnosis in all patients was osteoarthritis. The mean follow up was 24.8 months (range 15 to 33). The mean hospital length of stay was 3.2 days (range 2–7). The mean pre operative flexion was 105.8 degrees which improved to 117.9 degrees at latest follow up. KSS scores improved significantly in all patients. There were no postoperative transfusions in this group. All patients developed good radiographic fixation and stability of the tibial baseplate (Figure 1). There were no cases of loosening of the baseplate or infections in this series. Within 90 days, one patient developed a non fatal DVT and one patient was revised due to instability from a CR to a PS femur with the baseplate intact. At 8 months post-op, one patient had a liner exchange for MPFL rupture with a subluxating patella. At 18 months post-op, one patient had a liner exchange due to instability and extensor mechanism rupture. In both cases the baseplate was not revised. Conclusions. Study results indicate cementless fixation using this baseplate is a viable option with good short term clinical results and no cases of aseptic loosening at 2 years. Early stability, pain relief and good ROM were shown. Long term data will be required to determine the overall benefits of this highly porous TKA with biologic fixation versus cemented arthroplasty

Total knee replacements (TKRs) are being more commonly performed in active younger and obese patients. Fifteen year survivorship studies demonstrate that cemented total knee replacements have excellent survivorship, with reports of 85% to 97%. However, inferior survivorship occurs in younger patients and obese patients who would be expected to place increased stress on the bone cement interfaces. Cementless fixation for total knee replacement has not gained widespread utilization due to the plethora of poor results reported in early series. These poor results do not reflect that cementless fixation is not obtainable, since an almost universal acceptance of cementless fixation for total hip replacement has shown. A Cochrane database study of total knees with roentgen stereophotogrammetric analysis (RSA) demonstrated that the risk of future aseptic loosening should be 50% less with cementless fixation. The poor initial results with cementless total knee replacement have occurred due to poor implant designs such as cobalt chrome porous interfaces, poor initial tibial component fixation, lack of continuous porous coating, poor polyethylene, and use of metal-backed patellae. I have used cementless fixation for total knee replacements for young, active, and heavy patients since 1986 when durability over 20 years is desirable. My series of over 1,000 cementless TKRs represents about 20% of the total knees I have performed from 1986 to 2015. I have seen failures in my series due to the initial use of metal-backed patellae with thin polyethylene and use of screws and femoral and tibial components which provide access to the metaphyseal bone for polyethylene wear debris. Overall failures were still significantly low due to the use of highly porous titanium surfaces on the tibial and femoral components. Isolated aseptic loosening only occurred on one tibial component in my entire series. With the advent of utilizing implants with continuous porous surfaces and highly cross-linked polyethylene, and elimination of use of metal-backed patellae and tibial screws, I have only had one revision due to aseptic loosening or osteolysis in the last 760 cases performed since 2002. Almost 50% of total knees are now performed on patients under the age of 65. A 55-year-old patient has a 30-year life expectancy. Modern total knee replacement design has made biological fixation predictable for young and heavy patients. Because it is a biological interface, it should respond better than cement to the increased stresses that will be applied over many years by our younger, more active and heavier total knee population