Outcomes in arthroplasty have 3 general sources of variability: the patient, the prosthesis, and the medical-surgical-rehab. services. There are numerous factors that can contribute to earlier-than-usual clinical failure of a TKA (failure = need for revision). There are intense debates regarding design and material factors. There are technical factors such as misalignment, soft tissue imbalance, and inadequate fixation. The greatest source of variability in the outcome equation is, however, the patient. In cohort studies, the amount and type of patient activity influences the longevity of TKA. Quantitative studies have demonstrated >45-fold variation in the number of steps per day. Semi-quantitative data and survey studies show variability in the types of recreational activities and in the intensity. Age is often used as a surrogate, but BMI has a better correlation with activity than age. There is no formula, however, that can predict the longevity of an arthroplasty in a specific patient. For this reason, activity recommendations following arthroplasty continue to be debated. Which do you prioritise; lifestyle or longevity? More importantly, which does the patient prioritise?

Total hip arthroplasty (THA) is effective, reproducible, and durable in the treatment of hip joint arthritis. While improvements in polyethylene materials have significantly reduced wear rates and osteolysis, aseptic loosening of implants remains one of the leading causes of revision THA. Additionally, fears of dislocation and instability have driven the increase in the utilization of larger diameter femoral heads in primary THA which can lead to increased wear when coupled with a polyethylene articulation. Finally, the increasing number of younger and active patients undergoing THA raises questions with regards to the ability of modern conventional bearings to provide durability and longevity beyond second and third decades following joint implantation. Ceramic-on-ceramic articulations are ideally suited for today's young and high demand patients undergoing primary THA. It has the lowest in-vitro wear properties of any bearing couple and the wear characteristics are further improved by its wettability and lubrication particularly when larger heads are utilised. Additionally, improvements in material properties and prosthesis design have significantly decreased fracture rates and increased the reliability of these implants. Furthermore, reported outcomes and longevity of modern ceramic-on-ceramic THAs in younger patients have all shown excellent survivorship despite patients achieving and maintaining a very high level of activity and function. In short, it is the bearing couple most in tune with current market demands and utilization trends. While registry data and meta-analyses of published literature have failed to show the superiority of ceramic-on-ceramic articulations compared to conventional bearings at 10 years, there is evidence that even highly crosslinked polyethylene (HXPE) is not immune to wear. Selvarajah et al. reported steady, in-vivo wear rates of HXPE exceeding 0.1mm/year threshold in young THA patients with 36mm ceramic ball heads. Additionally, small osteolytic lesions have been observed in hips with HXPE bearings at 12–14 years follow up. Finally, analysis of all controlled randomised studies have shown less osteolysis of ceramic-on-ceramic hips compared to polyethylene articulations. The significance of these lesions are unclear but the question remains: Can HXPE as a bearing be able to provide over 30 years of service needed to outlast patients younger than 60 years?. Concerns with cost, squeaking, and fractures do not make ceramic-on-ceramic bearings suitable for all patients undergoing primary THA. However, in young, healthy and active patients, a modern ceramic- on-ceramic articulation is most likely to provide the lowest wear rates, lowest risk of osteolysis, and greatest chance for life-long durability

Both the patient and the surgeon want hip and knee arthroplasties to last a lifetime. As a result, many patients have been told to defer arthroplasty as long as possible. After arthroplasty, many patients have been advised to limit physical activity. Such management strategies prioritise longevity but compromise lifestyle. Given that the technical aspects of the arthroplasty are satisfactory, modern total hip and knee prostheses have demonstrated remarkable durability. Quantitative studies of patient activity have measured up to 48 million cycles in vivo, with impact, without evidence of loosening, osteolysis, or other impending failure. These data suggest that with current technology, an active lifestyle is compatible with implant longevity

Total hip arthroplasty (THA) is effective, reproducible, and durable in the treatment of hip joint arthritis. While improvements in polyethylene materials have significantly reduced wear rates and osteolysis, aseptic loosening of implants remains one of the leading causes of revision THA. Additionally, fears of dislocation and instability have driven the increase in the utilization of larger diameter femoral heads in primary THA which can lead to increased wear when coupled with a polyethylene articulation. Finally, the increasing number of younger and active patients undergoing THA raises questions with regards to the ability of modern conventional bearings to provide durability and longevity beyond second and third decades following joint implantation. Ceramic-on-ceramic articulations are ideally suited for today's young and high demand patients undergoing primary THA. It has the lowest in-vitro wear properties of any bearing couple and the wear characteristics further improved by its wettability and lubrication particularly when larger heads are utilised. Additionally, improvements in material properties and prosthesis design have significantly decreased fracture rates and increased the reliability of these implants. Furthermore, reported outcomes and longevity of modern ceramic-on-ceramic THAs in younger patients have all shown excellent survivorship despite patients achieving and maintaining a very high level of activity and function. In short, it is the bearing couple most in tune with current market demands and utilization trends. While registry data and meta-analyses of published literature have failed to show the superiority of ceramic-on-ceramic articulations compared to conventional bearings at 10 years, there is evidence that even highly crosslinked polyethylene (HXPE) is not immune to wear. Selvarajah et al. reported steady, in-vivo wear rates of HXPE exceeding 0.1 mm/year threshold in young THA patients with 36 mm ceramic ball heads. Additionally, small osteolytic lesions have been observed in hips with HXPE bearings at 12–14 years follow up. Finally, analysis of all controlled randomised studies have shown less osteolysis of ceramic-on-ceramic hips compared to polyethylene articulations. The significance of these lesions are unclear but the question remains: Can HXPE as a bearing be able to provide over 30 years of service needed to outlast patients younger than 60 years?. Concerns with cost, squeaking, and fractures do not make ceramic-on-ceramic bearings suitable for all patients undergoing primary THA. However, in young, healthy and active patients, a modern ceramic-on-ceramic articulation is most likely to provide the lowest wear rates, lowest risk of osteolysis, and greatest chance for life-long durability

At the present time, there is no bearing in total hip arthroplasty that a surgeon can present to a younger and/or more active patient as being the bearing that will necessarily last them a lifetime. This is the driver to offering alternative bearings (crosslinked polyethylene with either a CoCr or ceramic head, resurfacings, and ceramic-on-ceramic) to patients. Each of these bearings has pros and cons, and none has emerged as the clear victor in the ongoing debate. Ceramic-on-ceramic (CoC) bearings have been available for decades. Earlier generation CoC bearings did encounter problems with rare fractures, however, with a greater understanding and improvement in the material, the fracture incidence has been significantly reduced. However, what has emerged in the past few years is an increasing reporting of significant squeaking. The incidence of squeaking, reported in the literature in various series, has varied from less than 1% to over 20%, depending on the definition used. The primary reasons that ceramic-on-ceramic is not truly the articulation of choice for younger patients are: 1) There is absolutely no evidence that this bearing has a lower revision rate. Data from the Australian joint registry actually shows that at 15 years it has a significantly increased rate of revision (7.2%) compared with using a highly crosslinked liner with either a ceramic (5.1%) or a CoCr (6.3%) head; 2) This bearing is by far the most costly bearing on the market. In 2017 with significant constraints on health care systems across the globe, this is a significant concern; 3) This bearing has unique complications including squeaking and both liner and head fracturing. While ceramic-on-ceramic can be considered a viable alternative bearing in total hip arthroplasty, it can be in no way considered the articulation of longevity for the younger patient

At the present time, there is no bearing in total hip arthroplasty that a surgeon can present to a younger and/or more active patient as being the bearing that will necessarily last them a lifetime. This is the driver to offering alternative bearings (crosslinked polyethylene with either a CoCr or ceramic head, resurfacings, and ceramic-on-ceramic) to patients. Each of these bearings has pros and cons, and none has emerged as the clear victor in the ongoing debate. Ceramic-on-Ceramic (CoC) bearings have been available for decades. Earlier generation CoC bearings did encounter problems with rare fractures, however, with a greater understanding and improvement in the material, the fracture incidence has been significantly reduced. However, what has emerged in the past few years is an increasing reporting of significant squeaking. The incidence of squeaking, reported in the literature in various series, has varied from less than 1% to over 20%, depending on the definition used. The primary reasons that Ceramic-on-Ceramic is not truly the articulation of choice for younger patients are:. 1). There is absolutely no evidence that this bearing has a lower revision rate. Data from the Australian joint registry actually shows that at 15 years it has a significantly increased rate of revision (7.2%) compared with using a highly crosslinked liner with either a ceramic (5.1%) or a CoCr (6.3%) head. 2). This bearing is by far the most costly bearing on the market. In 2017 with significant constraints on health care systems across the globe, this is a significant concern. 3). This bearing has unique complications including squeaking and both liner and head fracturing. While Ceramic-on-Ceramic can be considered a viable alternative bearing in total hip arthroplasty, it can be in no way considered the articulation of longevity for the younger patient

Total Knee Arthroplasty has proven to be a successful procedure for improving pain and function. Long-term studies have shown survivorship to be 90% or greater at 20 years. Most patients in those studies were over 60 years old. There has been a large increase in patients under 60 years old who are undergoing knee arthroplasty. Younger patients have much greater demands on the artificial articular surfaces. The average 55 year old is likely to perform two to three time as many gait cycles as the average 65 or 70 year old. Long-term studies demonstrate that polyethylene wear is a major cause of long-term failure. Newer bearing materials such as cross-linked polyethylenes show promise in reducing wear in THA and more recently in TKA. Femoral component material can significantly influence wear. Studies reveal that in vivo femoral component scratching significantly increases polyethylene wear. Oxidised Zirconium (OxZr) has been shown to significantly reduce polyethylene wear in knee simulators. The ceramic surface has greater lubricity and is harder. We have examined the in vivo performance on Oxidised Zirconium in several studies. These studies reveal that the harder Oxidised Zirconium femoral surface is much more resistant to scratching than CrCo femurs. Retrieval analysis revealed a 12 fold increase in scratching of CrCo femoral components compared to OxZr. Profilometry analysis of matched pairs of femoral components demonstrates that the surfaces of the CrCo implants significantly roughen over time while the OxZr do not significantly change in vivo. These comparative studies also showed less damage to the tibial polyethylene bearings with the OxZr femoral components compared to CrCo. Extending longevity of TKA requires improved materials to reduced wear. To optimise this, bearing surfaces must be coupled with improvements in both tibial polyethylene and femoral component materials

Cemented total hip arthroplasty has become an extremely successful operation with excellent long term results. Although showing decreasing popularity in North America, it always remained a popular choice for the elderly patients in Europe and other parts of the world. Besides optimal component orientation, a proper cementing technique is of major importance to assure longevity of implant fixation. Consequently a meticulous bone bed preparation assures the mechanical interlock between the implant component, cement and the final bone bed. Cementing the acetabular side should include preservation of the transverse acetabular ligament and clear identification of the medial wall. Medialisation and deepening of the socket are important at reaming, to ensure a containment of the cup. The contact of the cup to cancellous bone should be maximised. Either smaller reamers or 4–6mm anchoring holes can be drilled to the superior sclerosis. Smaller defects can be curettage, while larger ones might require cancellous bone grafting. Of major importance is the thoroughly pulsatile jet lavage with saline to irrigate the cancellous bone bed, to reduce fat and blood lamination. After final irrigation, before cementation, dry sponges are slightly impacted into the cavity, to dry it out. Cementation usually requires 40g of high viscosity bone cement. Immediate pressurisation of the cement into the bone bed should start after a general application time in our institution between 2.5 to 3 minutes after mixing; with either a sterile glove filled with a sponge or designated company specific pressuriser. Sustained pressurisation should be done for 1 minute. The original cup should be 3–4mm smaller than the last reamer, to ensure circumferential cement mantle. Insertion principle includes medialisation first, followed by gradual angulation of the cup. In appropriate position, a balled pressuriser maintains pressure without further moving of the implant, until cement hardening. Remnant cement can be removed with osteotomes, while remaining osteophytes should be flush with implant. Femoral Side: First the fossa pyriformis should be clearly identified, including the posterolateral entry point of the prosthesis. The femoral neck cut is usually 1.5–2cm above the minor trochanter, based on the preoperative planning and implant type. Opening of the canal is done with an awl or osteotome, followed by any blunt tipped instrument, to follow the intramedullary direction. A box osteotome opens the lateral portion of the femoral neck, gently to preserve as much cancellous bone as possible. Sequential broaching follows carefully and according to the planning, to ensure preservation of 2–3mm cancellous bone for interdigitation. Some systems might require over-broaching by one size. Trialing is done with the broach. Following, irrigation using a long nozzle pulsatile lavage, reduces the chance for fat embolism. A cement restrictor is then placed 1.5–2cm distal to the tip of the stem, to ensure an adequate cement mantle distally. A second complete pulsatile irrigation of the canal follows, to minimise bleeding, followed by a dry sponge. Cement mixing is vacuum based in the meantime, usually 60–80g. We prefer the use of low dose antibiotic laden cement in our set up. Two to three minutes after mixing, the cement is applied rapidly in a retrograde technique with a cement gun, placing the nozzle tip against the cement restrictor. The gun is “pushed” out during the application, rather than being withdrawn from the canal. Proximal pressurisation is first done by thumb, then with a proximal seal for 1 minute. The stem is inserted slowly using steady manual pressure, in the center of the cement mantle, however, should never be impacted. The stem is aligned with the previously defined lateral entry point and is held in position until the cement hardens. The desired outcome is a cement interdigitation into cancellous bone for 2–3mm and an additional mantle of 2mm pure cement

Background. Loss of muscle mass (sarcopenia) and function in ageing are associated with reduced functional ability, quality of life and reduced life expectancy. In cancer patients, age related muscle loss may be exacerbated by cachexia and poor nutritional intake. Individuals with widespread disseminated disease are most prone to increasing functional decline, increased morbidity and accelerated death. However subjective assessments of physical performance have been shown to be poor indicators of life expectancy in these patients. Aims. To develop an objective measure to aid calculation of life expectancy in cancer by investigating the association between objectively measured lean muscle mass and longevity, in 41 patients with known spinal metastases from all cause primaries. Methods. Lean muscle mass was calculated as total psoas area (TPA)/height (m)2. Two blinded doctors independently calculated TPA from CT images at the L3 level, performed routinely within 7 days of diagnosis of spinal metastases. Time to death was recorded from retrospective analysis of hospital notes. Results. Of patients within the highest tertile for muscle mass 85% were alive at one year, compared with 50% in the lowest tertile. Conclusion. Death within one year in individuals with spinal metastases is significantly higher in patients with low lean muscle mass at presentation

Introduction. A thorough understanding of wear patterns and failure mechanisms of TKA components in the context of pre-revision knee kinematics is advantageous for component designers, manufacturers and surgeons alike. Traditional gait analysis provides an experimental technique to determine in vivo kinematics but is often limited by its cumbersome nature, infrastructure intensiveness and time. The recent introduction of the KneeKG (Emovi Inc, Canada) as a stand-alone knee motion tracking system which uses infrared technology provides a great opportunity to quickly, easily and routinely monitor patients at the clinical level, especially those being revised for component failure. This pilot study was conducted to examine pre-revision knee kinematics and subsequent wear patterns and failure mechanisms observed on the UHMWPE inserts upon retrieval in a cohort of TKA revision patients. We hypothesize that motion patterns can provide surgeons a unique insight into the status of the UHMWPE insert and implant longevity. Methods. Patients requiring revision due to failure of the UHMWPE insert were recruited in this study after institutional ethical approval and written informed consent of the patients was obtained. Motion of the affected knee was quantified using a stand-alone infrared tracking system (KneeKG, Emovi Inc, Canada) whilst the patient was walking on a treadmill. All analyses were conducted within our institutional Physiotherapy Department. The KneeKG system is composed of passive motion sensors fixed on a validated knee harness, an infrared motion capture system (Polaris Spectra, Northern Digital Inc, USA) and a computer equipped with the Knee3D software suite (Emovi). Following application of the KneeKG trackers a calibration procedure was performed to identify joint centres and define a coordinate system on each body segment. After a treadmill habituation period of between 6 and 10 min, a trial was then conducted at the patient's comfortable treadmill gait speed over 45 sec. Averaged clinical rotations and translations of the tibia as a function of gait cycle were output by the system, and a report highlighting and detailing biomechanical deficiencies as compared to a database of normal controls automatically generated. Following the scheduled revision surgery the retrieved components were formalin-fixed and brought to our laboratory for a routine retrieval workup. All revisions were performed by a single surgeon. Components were analysed using optical and scanning electron microscopy techniques for regions of polishing, burnishing, pitting, delamination, deformation, scratching and embedded debris. Wear maps and scores were generated and correlated with pre-revision kinematics for each patient. Results. The KneeKG was successfully applied to patients in this pre-revision scenario, requiring less than 30 minutes to complete per case. Variations in knee kinematics have been observed, and the analysis of retrieved components is ongoing. Discussion. This study has demonstrated that knowledge of pre-revision knee kinematic patterns can provide a unique insight into wear and failure mechanisms of the UHMWPE liner. Whilst this study is currently limited by a relatively small sample size, recruitment is continuing with a view to the possible generation of odds ratios for UHMWPE insert failure mechanisms based on kinematic signatures

Ceramic-on-ceramic bearings provide a solution to the osteolysis seen with traditional metal-on-polyethylene bearings. Sporadic reports of ceramic breakage and squeaking concern some surgeons and this bearing combination can show in vivo signs of edge loading wear which was not predicted from in vitro studies. Taper damage or debris in the taper between the ceramic and metal may lead to breakage of either a ceramic head or insert. Fastidious surgical technique may help to minimise the risk of ceramic breakage. Squeaking is usually a benign complication, most frequently occurring when the hip is fully flexed. Rarely, it can occur with each step of walking when it can be sufficiently troublesome to require revision surgery. The etiology of squeaking is multifactorial origin. Taller, heavier and younger patients with higher activity levels are more prone to hips that squeak. Cup version and inclination are also relevant factors.

Fifty-five ceramic bearings revised at our center were collected over 12 years. Median time to revision was 2.7 years. Forty-six (84%) cases had edge loading wear. The median femoral head wear volume overall was 0.2mm³/yr, for anterosuperior edge loading was 2.0mm³/yr, and the median volumetric wear rate for posterior edge loading was 0.15mm³/yr (p=0.005).

Osteolysis following metal-on-polyethylene total hip arthroplasty (THA) is well reported. Earlier generation ceramic-on-ceramic bearings did produce some osteolysis, but in flawed implants. As 3rd and now 4th generation ceramic THAs come into mid- and long-term service, the orthopaedic community has begun to see reports of high survival rates and very low incidence of osteolysis in these bearings. The technique used by radiologists for identifying the nature of lesions on Computed Tomography (CT) scan is the Hounsfield score which will identify the density of the tissue within the lucent area. Commonly the radiologist will have no access to previous imaging, especially pre-operative imaging if a long time has elapsed. With such a low incidence of osteolysis in this patient group, what, then, should a surgeon do on receiving a CT report on a ceramic-on-ceramic THA, which states there is osteolysis? This retrospective review aims to determine the accuracy of CT in identifying true osteolysis in a cohort of long-term 3rd generation ceramic-on-ceramic uncemented hip arthroplasties in our department.

Ceramic-on-ceramic bearings provide a solution to the osteolysis seen with traditional metal-on-polyethylene bearings. Sporadic reports of ceramic breakage and squeaking concern some surgeons and this bearing combination can show in vivo signs of edge loading wear which was not predicted from in vitro studies. Taper damage or debris in the taper between the ceramic and metal may lead to breakage of either a ceramic head or insert. Fastidious surgical technique may help to minimise the risk of ceramic breakage. Squeaking is usually a benign complication, most frequently occurring when the hip is fully flexed. Rarely, it can occur with each step of walking when it can be sufficiently troublesome to require revision surgery. The etiology of squeaking is multifactorial in origin. Taller, heavier and younger patients with higher activity levels are more prone to hips that squeak. Cup version and inclination are also relevant factors.

Osteolysis following metal-on-UHMW polyethylene Total Hip Arthroplasty (THA) is well reported. Earlier generation ceramic-on-ceramic bearings did produce some osteolysis, but in flawed implants. As third and now fourth generation ceramic THAs come into mid- and long-term service, the orthopaedic community has begun to see reports of high survival rates and very low incidence of osteolysis in these bearings. The technique used by radiologists for identifying the nature of lesions on Computed Tomography (CT) scan is the Hounsfield score which will identify the density of the tissue within the lucent area. Commonly the radiologist will have no access to previous imaging, especially pre-operative imaging if a long time has elapsed. With such a low incidence of osteolysis in this patient group, what, then, should a surgeon do on receiving a CT report on a ceramic-on-ceramic THA, which states there is osteolysis? This retrospective review aims to determine the accuracy of CT in identifying true osteolysis in a cohort of long-term third generation ceramic-on-ceramic uncemented hip arthroplasties in our department.

Pelvic CT scans were performed on the first 27 patients from a cohort of 301 patients undergoing 15-year review with third generation alumina-alumina cementless THAs. The average follow-up was 15 years (15–17). The CT scans were reviewed against pre-operative and post-operative radiographs and reviewed by a second musculoskeletal specialist radiologist.

Eleven of the CT scans were reported to show acetabular osteolysis, two reported osteolysis or a possible pre-existing cyst and one reported a definitive pre-existing cyst. After review of previous imaging including pre-operative radiographs, eleven of the thirteen patients initially reported to have osteolysis were found to have pre-existing cysts or geodes in the same size and position as the reported osteolysis, and a further patient had spot-welds with stress-shielding. One patient with evidence of true osteolysis awaits aspiration or biopsy to determine if he has evidence of ceramic wear or metallosis.

Reports of osteolysis on CT should be interpreted with care in modern ceramic-on-ceramic THA to prevent unnecessary revision. Further imaging and investigations may be necessary to exclude other conditions such as geodes, or stress shielding which are frequently confused with osteolysis on CT scans.

Introduction

The common causes of failure leading to revision Total Knee Replacement (TKR) include instability, infection, improper alignment, implant wear and osteolysis and improper cementation. This presentation outlines the details of the art of cementation.

In 1998, lysis / wear were the biggest concerns in THR. 3 distinct tacks emerged: Alternatives to polyethylene: Ceramic / Ceramic; Metal / Metal; Make a better polyethylene

MOM story is well known: bad ending!!

Large adoption of Ceramic / Ceramic: positives: low wear, benign MR findings, even low dislocation rates !! negatives: fractures still occurred, noise generation, liner malseating, metal transfer (edge effects)

Crosslinked Polyethylene: Update: 13–15 year follow-up of 1st generation XLPE with remelted product: Annual wear rates of 0.004 (metal heads) 0.002 (ceramic heads)!

No lysis!! Wear rates for “standard” heads and large heads both low approaching the lower limits of detection!!

CONCLUSION: Crosslinked Polyethylene with Ceramic Heads: The Winner and Still Champion!

Implant selection in TKA remains highly variable. Surgeons consider preoperative deformity, surgical experience, retention or substitution for the PCL, type of articulation and polyethylene, and fixation with or without cement. We have most frequently implanted the same implant for the majority of patients. This is based on the fact that multiple large series of TKA's have demonstrated that the most durable TKA's have been non-modular metal backed tibial components, retention of the PCL, with a cemented all poly patellar component.

The debate of how to handle the PCL continues. In most studies at 10 years there is little reported difference. Second decade concerns usually result from polyethylene issues related to polymer wear. Sagittal “dishing” or ultracongruent implants may be a middle road that allow PCL release or resection and controlled kinematics offering improved short term results. Long term function remains the goal and it appears a CR knee offers that capacity.

Newer implants such as “high flex” and “gender” specific designs have not demonstrated significant functional improvements in controlled series. Uncemented knees in many series have performed well for many surgeons from a fixation standpoint. Polymer wear must be addressed for long term durability.

Introduction

Cup positioning in total hip arthroplasty (THA) is an important variable for short and long term durability of any hip implant. This novel method utilises internal and external bony landmarks, and the transverse acetabular ligament for positioning the acetabular component.

Introduction

Currently, knee and hip implants are evaluated experimentally using mechanical simulators or clinically using long-term follow-up. Unfortunately, it is not practical to mechanically evaluate all patient and surgical variables and predict the viability of implant success and/or performance. More recently, a validated mathematical model has been developed that can theoretically simulate new implant designs under in vivo conditions to predict joint forces kinematics and performance. Therefore, the objective of this study was to use a validated forward solution model (FSM) to evaluate new and existing implant designs, predicting mechanics of the hip and knee joints.

Introduction

Total hip replacement is an established surgical procedure done to alleviate hip pain due to joint diseases. However, this procedure is avoided in yonger patients with higher functional demands due to the potential for early failure. An ideal prosthesis will have have a high endurance against impact loading, with minimal micromotion at the bone cement interface, and a reduced risk of fatigue failure, with a favourable stress distribution pattern in the femur. We study the effect of varying the material properties and design element in a standard cemented total hip using Finite Element Analysis.

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

The reverse total shoulder replacement (rTSR) has excellent clinical outcomes and prosthesis longevity, and thus, the indications have expanded to a younger age group. The use of a stemless humeral implant has been established in the anatomic TSR; and it is postulated to be safe to use in rTSR, whilst saving humeral bone stock for younger patients. The Lima stemless rTSR is a relatively new implant, with only one paper published on its outcomes. This is a single-surgeon retrospective matched case control study to assess short term outcomes of primary stemless Lima SMR rTSR with 3D planning and Image Derived Instrumentation (IDI), in comparison to a matched case group with a primary stemmed Lima SMR rTSR with 3D planning and IDI. Outcomes assessed: ROM, satisfaction score, PROMs, pain scores; and plain radiographs for loosening, loss of position, notching. Complications will be collated. Patients with at least 1 year of follow-up will be assessed. With comparing the early radiographic and clinical outcomes of the stemless rTSR to a similar patient the standard rTSR, we can assess emerging trends or complications of this new device. 41 pairs of stemless and standard rTSRs have been matched, with 1- and 2-year follow up data. Data is currently being collated. Our hypothesis is that there is no clinical or radiographical difference between the Lima stemless rTSR and the traditional Lima stemmed rTSR