Total hip arthroplasty (THA) has high rates of patient satisfaction; however patient expectations for recreational and sporting activities are not always met. Our study aimed to identify preoperative factors that predict whether patient expectations for sporting or recreational activity are met 12 months following THA. Patient reported outcome measures (PROMs) were collected prospectively from 2015-2018 at one private hospital in Sydney. Age, gender, postcode, weight, and height were recorded preoperatively. Included participants underwent primary THA by one of the investigating surgeons. Univariable and multivariable analyses were performed with an expectation fulfilment score used as the primary outcome variable. Preoperative predictor variables included: age, gender, BMI, Socio-economic Indexes for Areas (SEIFA), Oxford Hip Score, Hip Osteoarthritis Outcome Score, EQ-5D-5L and EQ Visual Analogue Scale (EQ VAS). 1019 participants were eligible and included. 13% reported that preoperative expectations of sport or recreation were not met at 12 months. Younger age, lower preoperative EQ VAS, and
Background. Obesity has been linked with increased rates of knee osteoarthritis. Limited information is available on the survival and functional outcome results of rTKR in the obese patients. This registry-based study aimed to identify whether BMI is an independent risk factor for poorer functional outcomes and /or implant survival in rTKA. Methods. New Zealand Joint Registry (NZJR) data of patients who underwent rTKA from 1st January 2010 to January 2023 was performed. Demographics, American Society of Anesthesiologists (ASA), BMI, Operative time, indications for revision and components revised of the patients undergoing rTKA was collected. Oxford knee score (OKS) at 6 months and rates of second revision (re- revision) were stratified based on standardised BMI categories. Results. Of the 2687 revisions, functional outcome scores were available for 1261 patients. Oxford knee scores following rTKA are significantly inferior in
Aims. Bone and joint infections cause significant morbidity, often requiring combination medical and surgical treatment. The presence of foreign material reduces the number of organisms required to cause an infection. The aim of this study was to assess whether there was a difference in the species of organism identified on culture in osteomyelitis compared to prosthetic joint infection. Method. This was a retrospective observational cohort study of patients that had surgical intervention for prosthetic joint infection or osteomyelitis with positive microbial culture between 2019 and 2022. Data including patient demographics, site of injury, BACH score for osteomyelitis and JS-BACH score for prosthetic joint infection, organism classification and antibiotic resistance to vancomycin and gentamicin were extracted from the medical record. Logistic and multiple regressions were used to adjust for potential confounding variables. Results. A total of 445 patients were included in the study; 267 patients with osteomyelitis or fracture-related infection and 177 patients with prosthetic joint infection. The patients with prosthetic joint infection were older (Mean age 70 for PJI; IQR 60-77 vs 56 for OM/FRI; IQR 39-64), more likely to be female (55.6% vs 26.2%) and had a
Background. In recent years, ‘Get It Right First Time (GIRFT)’ have advocated cemented replacements in femoral part of Total hip arthroplasty (THA) especially in older patients. However, many studies were unable to show any difference in outcomes and although cemented prostheses may be associated with better short-term pain outcomes there is no clear advantage in the longer term. It is not clear when and why to do cemented instead of cementless. Aim. To assess differences in patient reported outcomes in uncemented THAs based on patient demographics in order to decide when cementless THA can be done safely. Method. Prospective data collection of consecutive 1079 uncemented THAs performed for 954 patients in single trust between 2010 and 2020. Oxford Hip Score (OHS) and complications were analysed against demographic variables (age, sex, BMI, ASA) and prosthesis features (femoral and acetabular size, offset and acetabular screws). Results. The mean pre-operative OHS was 14.6 which improved to 39.0 at 1 year follow up (P Value=0.000). There was no statistically significant difference between OHS outcome in patients aged over 70 versus younger groups. With a small number of revisable complications increase with age from 50s upwards. Male patients’ OHS score was on average 2.4 points higher than women. Men, however were 2.9 times more likely to experience fractures and high offset hips were 2.5 times more likely to experience dislocations. DAIR, intraoperative calcar fractures, post-operative fractures and dislocations were not associated with worse OHS. Patients with increased BMI had worse pre and post-operative hip functions yet, there was a significant multivariate association between increased BMI and increased improvement in OHS from pre-op to 1 year in women aged 55–80 and men under the age of 60. Femoral stem size increases with age but decreases in male patients over 80. There was no difference found in OHS between bilateral hip replacements and unilateral, nor was there any change found with laterality side of the replacement. Conclusions. This study suggests that ageing >70 is not associated with poorer outcomes despite small number of revisable complication rates that increase with age from 50 upwards. Men had marginally higher average OHS than women At 1 year.
Aim. Prosthetic joint infection (PJI) is a devastating and costly complication of total joint arthroplasty (TJA). Use of extended oral antibiotic prophylaxis (EOAP) has become increasingly popular in the United States following a highly publicized study (Inabathula et al) from a single center demonstrating a significant protective effect (81% reduction) against PJI in ‘high-risk’ patients. However, these results have not been reproduced elsewhere and EOAP use directly conflicts with current antibiotic stewardship efforts. In order to study the role of EOAP in PJI prevention, consensus is needed for what defines ‘high-risk’ patients. The revision TJA (rTJA) population is an appropriate group to study due to having a higher incidence of PJI. The purpose of the current study was to rigorously determine which preoperative conditions described by Inabathula et al. (referred to as Inabathula criteria (IBC)) confer a higher rate of PJI in patients undergoing aseptic rTJA. Method. 2,256 patients that underwent aseptic rTJA at a single high-volume institution between 2016–2022 were retrospectively reviewed. Patient demographics and comorbidities were recorded to determine if they had 1 or more ‘IBC’, a long list of preoperative conditions including autoimmune diseases, active smoking, body mass index (BMI)>35, diabetes mellitus, and chronic kidney disease (CKD). Reoperation for PJI at 90-days and 1-year was recorded. Chi-squared or Fischer's exact tests were calculated to determine the association between preoperative presence/absence of IBC and PJI. Multivariable logistic regressions were conducted to determine if specific comorbidities within the IBC individually conferred an increased PJI risk. Results. 1223 patients (54.2%) had at least one IBC condition. IBC-positive patients were more likely to be female, have an increased ASA score, and
Aims. Periprosthetic fungal infections are rare and account for 1–2% of all periprosthetic joint infections (PJI). This study aims at presenting treatment details, clinical and microbiological results in a large single centre cohort. Methods. We retrospectively identified 29 patients (9 total knee replacements (TKA) and 20 total hip replacements (THA) treated for a fungal infection between 2007 and 2019. Microbiological findings, patient demographics and complications were analysed. Statistical analysis was performed using descriptive statistics; non-parametric analysis were performed using the Mann-Whitney U-Test. Infection-free survival was determined using Kaplan-Meier analysis and differences in survival were analysed using the log-rank test. The p value was set at p<0.05 with 95% confidence intervals (95% CI) provided. Results. 28% (8/29) suffered from reinfection. The reinfection-free survival probability was 65% (95% CI 45–85) after a median follow- up period of 28 months (IQR 6 – 39). With the numbers we had, we were not able to detect a difference between THA and TKA re-infections (p=0.517). Four patients underwent amputation, 3 patients had a definitive girdlestone hip and eight patients died after a median of 5 months after first-stage surgery (IQR 1–7). All patients treated had positive synovial fluid or tissue cultures for Candida species. In 22 /29 patients C. albicans, in 3 patients C. parapsilosis, in 2 patients C. glabrata and in 1 patient each C. famata, C. dubliniensis and C. gulliermondii. Polymicrobial bacterial infection was found in 86% of patients with staphylococci in 20 patients, E. coli in 2 patients, vancomycin-resistant enterococci, pseudomonas, acinetobacter and achromobacter species in 1 patient each. When investigating risk factors for reinfection, with the numbers we had we were not able to find a significant difference for patients with polymicrobial infection (p=0.974), azole-resistant Candida (p=0.491), tobacco users (p=0.175), or diabetics (p=0.54). Furthermore, median age (73 vs. 72, p=0.756) and Charlson comorbidity score (6 (interquartile range (IQR) 4–8) vs. 8 (IQR 5–10), p=0.184) were not different between the groups while on the other hand there was a trend for a higher body mass index in patients with reinfection (34 (IQR 31–38) vs. 28 (IQR 25–33), p=0.075). Conclusions. Fungal PJI is associated with poor reinfection free survival, frequent revisions, and high mortality. All infections were caused by Candida spp. in which azole-resistance most be considered when planning treatment. While polymicrobial infection complicated treatment there was no difference in survival. A
The prevalence of gluteal tendinopathy (GT) associated with osteoarthritis of the hip is difficult to determine as it is frequently undiagnosed or misdiagnosed as trochanteric bursitis. Its relationship to total hip arthroplasty (THA) outcomes is currently unknown. The aim of this study was to determine the incidence of GT at the time of hip arthroplasty and examine the relationship between GT and patient reported outcomes (PROMS) before and after THA. Patients undergoing THA for primary osteoarthritis between August 2017 and August 2020 were recruited. Tendinopathy was assessed and graded at time of surgery. PROMS included the Oxford Hip Score (OHS), HOOS JR, EQ-5D, and were collected preoperatively and at one year after THA. Satisfaction with surgery was also assessed at 1 year. 797 patients met eligibility criteria and were graded as Grade 1: normal tendons (n =496, 62%), Grade 2: gluteal tendinopathy but no tear (n=222, 28%), Grade 3: partial/full thickness tears or bare trochanter (n=79, 10%). Patients with abnormal gluteal tendons were older (p=0.001), had a
Introduction. A common goal of total knee arthroplasty (TKA) is to restore normal knee kinematics. While substantial data is available on TKA kinematics, information regarding non-implanted knee kinematics is less well studied especially in larger patient populations. The objectives of this study were to determine normal femorotibial kinematics in a large number of non-implanted knees and to investigate parameters that yield higher knee flexion with weight-bearing activities. Methods. Femorotibial kinematics of 104 non-implanted healthy subjects performing a deep knee bend (DKB) activity were analyzed using 3D to 2D fluoroscopy. The average age and BMI were 38.1±18.2 years and 25.2±4.6, respectively. Pearson correlation analysis was used to determine statistical correlations. Results. On average, subjects experienced 21.5±7.2 mm, 13.8±8.9 mm, and 27.1°±12.1° of lateral rollback, medial rollback, and external femorotibial axial rotation, respectively (Figure 1). Most rollback occurred in early flexion, with 10.2±6.4 mm and 5.3±6.3 mm of rollback for the lateral and medial condyles, respectively. While the lateral condyle consistently moved posteriorly, the medial condyle experienced 1.8±4.8 mm of anterior sliding between 90° to 120° of flexion. There was a positive correlation between higher weight-bearing flexion and lateral condylar rollback (r=0.5480, p<.0001) (Figure 2), medial condylar rollback (r=0.3188, p=0.001) (Figure 3), and external axial rotation (r=0.5505, p<.0001) (Figure 4). There was an inverse correlation between advancing age and knee flexion (r=-0.7358, p<.0001) as well as
Up to one-third of patients experience limited benefit following surgical intervention for LS-OA. Thus, identifying contributing factors to this is important. People with OA often have multijoint involvement, yet this has received limited attention in this population. We documented the occurrence and evaluated the influence of multijoint symptoms on outcome following surgery for LS-OA. 141 patients undergoing decompression surgery+/−fusion for LS-OA completed the Oswestry Disability Index (ODI) pre- and 12-months post-surgery. Also captured pre-surgery: age, sex, education, BMI, smoking, depressive symptoms and comorbidities. Any joints with “pain/stiffness/swelling most days of the month” were indicated on a homunculus. A symptomatic joint site count (e.g. one/both knees= one site), excluding the back, was derived (range zero to nine) and considered as a predictor of magnitude of ODI change, and likelihood of achieving minimally clinically important improvement in ODI (MCID=12.8) using multivariable adjusted linear and log-Poisson regression analyses. Mean age: 66 years (range:42–90), 46% female. 76% reported one+ joint site other than the back, 43% reported three+, and nearly 10% reported six+. (< MCID) for those with three sites, and four units for those with six+ sites. Associated with a greater likelihood of not achieving MCID were increasing joint count (11% increase per site (p=0.012)),
Introduction. Body Mass Index (BMI) is an essential tool for orthopaedic surgeons in regards to preoperative risk stratification as well as assessment of overall health and nutritional status. Patient's self-awareness of their height, weight and BMI is crucial in maintaining a healthy lifestyle. The purpose of our study was to determine the accuracy of orthopaedic patient's reported height and weight. We hypothesized that a patient's age, sex and/or BMI may affect the accuracy of these reported values. Methods. After IRB approval, we performed a prospective, observational study in the setting of our orthopaedic clinic. Patients were asked to report their predicted height and weight and then were weighed and measured using a single standardized scale. All values, including age and sex, were recorded. Differences were then calculated. Patients were categorized based on their age (younger than 65 vs older than 65), sex, and actual BMI (less than 30 vs greater than 30). Student t-test was used to calculate significance (p <0.05 conferred significance). Results. A total of 211 patients participated in our study (127 females, 84 males). Females had an average height discrepancy of 2.21cm, whereas males had an average height discrepancy of 1.56 cm (p=0.22). Females had an average weight discrepancy of 2.46 kg compared to 2.13 kg in males (p=0.58). The average height discrepancy in patients less than 65 years old was 2.09 cm compared to 1.76 cm in patients older than 65 (p=0.81). The average weight discrepancy in patients less than 65 years old was 2.50 kg compared to 2.12 kg in patients older than 65 (p=0.54). The average height discrepancy in the high BMI group was 2.29 cm compared to 1.42 in the low BMI group (p=0.11). The average weight discrepancy in the high BMI group was 2.71 kg compared to 1.72 kg in the low BMI group. This difference approached statistical significance (p=0.094). In regards to BMI changes based on values reported, 64 patients had a lower actual BMI than reported (range −0.015 to −5.29 kg/cm. 2. ), 6 patients had no change in BMI, and 141 had an increase in BMI (range 0.0006 to 16.6 kg/cm. 2. ). Average BMI of those patients with less than 1 kg/cm. 2. change in BMI was 30.9 kg/cm. 2. , whereas those with greater than 1 kg/cm. 2. change in BMI had an average of 35.18 kg/cm. 2. (p=2.27×10. −5. ). There were 9 patients' whose reported weights gave them a BMI of less than 40 kg/cm. 2. , whereas their actual weight put their BMI over 40 kg/cm. 2. Conclusion. There was a trend towards
BACKGROUND. Some papers recently reported conflicting results on implant survivorship in all-poly tibial UKRs. Furthermore, the influence of BMI on this specific implant survivorship remains unclear, since existing reports are often based on small series of non-consecutive patients with different follow up durations, enabling to generate meaningful conclusions. PURPOSE. To determine the 10-years survival rate of an all-poly tibial UKR in a large series of consecutive patients and to investigate whether a correlation exists between a
Introduction. Revision Total Knee Arthroplasty (TKA) is becoming increasingly prevalent as the number of TKA procedures grow in a younger, higher-demand population. Factors associated with patients requiring multiple revision TKAs are not yet well understood. The purpose of this study is to investigate the epidemiology of re-revision TKA, and identify risk factors that are associated with failure of re-revision TKA. Methods. A retrospective analysis was performed on 358 patients who underwent revision TKA at a single institution between 1/2012 and 12/2013. Patients who underwent revision knee arthroplasty two or more times were included. Patients were excluded if their indication for the first revision was periprosthetic joint infection (PJI). Patient demographics, surgical indications, revision details, and available follow-up information were collected. Re-revision failure was defined as the need for any additional operative intervention. A logistic regression analysis was performed to assess for significant predictors of re-revision failure. Results. A total of 66 re-revision TKA patients were included in this study. Mean age at re-revision was 60 (±11 years). There were 48 (73%) females. Mean BMI was 31.8 (±6.9). Median ASA level was 2 (40/59; 68%). Average follow up was 2.1 (±1.0) years, with 68% (45/66) of patients having greater than 2 year follow up (Table 1). The median number of revisions was 2 (range 2–11). The most common indication for re-revision was arthrofibrosis (15; 23%), followed by PJI (14; 21%) and aseptic component loosening (13; 20%). Among re-revision patients, the most common indication of the first revision was aseptic component loosening (17; 30%), followed by arthrofibrosis (16; 28%) and instability (9; 16%) (Table 2). Among the top four indications for re-revision, both the re-revision and initial revision indication were the same. Additionally, 42% of patients possessed the same indication for re-revision as the initial revision. The proportion of patients that had a lateral release performed in either the index procedure or initial revision was higher in re-revisions performed for patellar maltracking (p=0.013). There was a significantly increased risk of re-revision failure if the patient had a
Total knee replacement (TKA) is one of the most successful procedures in orthopaedic surgery. Although originally limited to more elderly and less active individuals, the inclusion criteria for TKA have changed, with ever younger, more active and heavier patients receiving TKA. This broadening of indications coincided with the widespread adoption of modular cemented and cementless TKA systems in the 1980's, and soon thereafter wear debris related osteolysis and associated prosthetic loosening became major modes of failure for TKA implants of all designs. Initially, tibial components were cemented all polyethylene monoblock constructs. Subsequent long-term follow-up studies of some of these implant designs have demonstrated excellent durability in survivorship studies out to twenty years. While aseptic loosening of these all polyethylene tibial components was a leading cause of failure in these implants, major polyethylene wear-related osteolysis around well-fixed implants was rarely (if ever) observed. Cemented metal-backed nonmodular tibial components were first introduced to allow for improved tibial load distribution and protection of the underlying (often osteoporotic) bone. Eventually, modularity between the polyethylene tibial component and the metal-backed tray was introduced in the mid-80s mainly to facilitate screw fixation for cementless implants. These designs also provided intraoperative versatility by allowing interchange of various polyethylene thicknesses, and also aided the addition of stems and wedges. Modular vs. All Polyethylene Tibial Components in Primary TKA: Kremers et al. reviewed 10,601 adult (>18 years) patients with 14,524 condylar type primary TKA procedures performed at our institution between 1/1/1988 and 12/31/2005 and examined factors effecting outcome. The mean age was 68.7 years and 55% were female. Over an average 9 years follow-up, a total of 865 revisions, including 252 tibia revisions were performed, corresponding to overall survival of 89% (Confidence intervals (CI): 88%, 90%) at 15 years. In comparison to metal modular designs, risk of tibial revision was significantly lower with all polyethylene tibias (HR 0.3, 95% CI: 0.2, 0.5). With any revision as the endpoint, there were no significant differences across the 18 designs examined. Similarly, there were no significant differences across the 18 designs when we considered revisions for aseptic loosening, wear, osteolysis. Among patient characteristics, male gender, younger age,
The use of fluoroscopy in orthopaedic surgery creates risk of radiation exposure to surgeons. Appropriate personal protective equipment (PPE) can help mitigate this. The primary aim of this study was to assess if current radiation protection in orthopaedic trauma is safe. The secondary aims were to describe normative data of radiation exposure during common orthopaedic procedures, evaluate ways to improve any deficits in protection, and validate the use of electronic personal dosimeters (EPDs) in assessing radiation dose in orthopaedic surgery. Radiation exposure to surgeons during common orthopaedic trauma operations was prospectively assessed using EPDs and thermoluminescent dosimeters (TLDs). Normative data for each operation type were calculated and compared to recommended guidelines.Aims
Methods
Limited literature exists providing comprehensive assessment of complications following opening wedge high tibial osteotomy (OWHTO). We performed a retrospective study of local patients who underwent OWHTO for isolated medial compartment knee osteoarthritis from 1997–2013. One hundred and fifteen patients met inclusion criteria. Mean follow-up = 8.4years. Mean age = 47 (range 32–62). Mean BMI = 29.1 (range 20.3–40.2). Implants used included Tomofix (72%), Puddu plate (21%) and Orthofix (7%) (no significant differences in age/ sex/ BMI). Wedge defects were filled with autologous graft (30%), Chronos (35%) or left empty (35%). Five year survival rate (conversion to arthroplasty) = 80%. Overall complication rate = 31%. 25% of patients suffered 36 complications including minor wound infections (9.6%), major wound infections (3.5%), metalwork irritation necessitating plate removal (7%), non-union requiring revision (4.3%), vascular injury (1.7%), compartment syndrome (0.9%), and other minor complications (4%). No thromboembolic complications were observed. A
There is nothing going to ruin your day like a complication after shoulder arthroplasty, either hemiarthroplasty (HA) anatomical (TSA) or reverse arthroplasty (RTSA). While complications are fortunately uncommon with anatomical shoulder arthroplasty (approximately 8% but as high as 40%), the complication rate for RTSA has been reported as high as 70%. Most complications are multifactorial and cannot all be blamed on the patient. Basically you do not want to operate upon a young patient who is an insulin dependent diabetic, has an ASA of 3 or 4, who smokes, has HIV disease and has a BMI over 40. The most common predictors of failure are determined by the indication for surgery, the type of implant used and the skill of the surgeon. The major risk factors for HA are eccentric glenoids, young age and rotator cuff failure. The biggest risk factors for TSA are metal backed glenoid components, younger age of the patient, rotator cuff pathology and insufficient glenoid bone. The major risk factors for RTSA are the type of component used (Grammont type versus lateral center of rotation designs) and the indication for surgery. Infection risks include previous infected arthroplasty, previous joint infection, immunosuppression (e.g. steroid use, insulin dependent diabetes, HIV disease), ASA 3 or 4 and
Total knee replacement (TKR) is one of the most successful procedures in orthopaedic surgery. Although originally limited to more elderly and less active individuals, the inclusion criteria for TKR have changed, with ever younger, more active and heavier patients receiving TKR. Currently, wear debris related osteolysis and associated prosthetic loosening are major modes of failure for TKR implants of all designs. Initially, tibial components were cemented all polyethylene monoblock constructs. Subsequent long-term follow-up studies of these implants have demonstrated excellent durability in survivorship studies out to twenty years. Aseptic loosening of the tibial component was one of the main causes of failure in these implants. Cemented metal-backed nonmodular tibial components were subsequently introduced to allow for improved tibial load distribution and to protect osteoporotic bone. Long-term studies have established that many one-piece nonmodular tibial components have maintained excellent durability. Eventually, modularity between the polyethylene tibial component and the metal-backed tray was introduced in the mid-80s mainly to facilitate screw fixation for cementless implants. These designs also provided intraoperative versatility by allowing interchange of various polyethylene thicknesses, and to also aid the addition of stems and wedges. Other advantages included the reduction of inventory, and the potential for isolated tibial polyethylene exchanges as a simpler revision procedure. However, several studies have documented the high failure rate of isolated polyethylene exchange procedures, probably because technical problems related to the original components are left uncorrected. Since the late 1980s, the phenomena of polyethylene wear and osteolysis have been observed much more frequently when compared with earlier eras. The reasons for this increased prevalence of synovitis, progressive osteolysis, and severe polyethylene wear remain unclear, but there is no question that it was associated with the widespread use of both cementless and cemented modular tibial designs. Mayo Data. The study population included 10,601 adult patients with 14,524 primary TKA procedures performed at our institution between 1/1/1988 and 12/31/2005. Mean age was 68.7 years and 55% were female. Overall revision rates and revisions for loosening, wear/osteolysis were compared across different designs. Over an average 9 year follow-up, a total of 865 revisions, including 252 tibia revisions were performed, corresponding to overall survival of 89% (Confidence intervals (CI): 88%, 90%) at 15 years. In comparison to metal modular designs, risk of tibial revision was significantly lower with all-poly tibias (HR 0.3, 95% CI: 0.2, 0.5). Overall, posterior cruciate-retaining designs performed better than the posterior-stabilised designs (p=0.002). With any revision as the endpoint, there were no significant differences across the 18 designs examined. Similarly, there were no significant differences across the 18 designs when we considered revisions for aseptic loosening, wear, and osteolysis. Among patient characteristics, male gender, younger age, and
What are the data on obesity and THA risk? Which complications are elevated? If you decide on surgery, how can you minimise complications? These are timely questions because the rates of obesity are rising in the US and in many other parts of the world. Does obesity increase risk of THA complications? Answer: yes: at least for some complications. Complications which are increased: infection, wound healing, nerve injury; possibly: dislocation, periprosthetic fractures. The data are mixed on whether aseptic loosening and/or bearing surface wear problems are increased in the obese.
Purpose. To determine how patient characteristics; health status and pre-operative knee function effect patient reported satisfaction and operative success following total knee replacement (TKR). We hypothesised that a number of patient factors would influence the reported levels of symptomatic improvement (success) and satisfaction and that these two outcomes would represent different aspects of the patient's perception of outcome. Design. Retrospective cohort analysis of patient reported outcome measures (PROMs) and National Joint Registry (NJR) data. Complete patient data was available for 9,874 TKRs performed for osteoarthritis between 1/8/08 and 31/12/10. The relationship of the background factors to patient perceived satisfaction and success was investigated using ordinal logistic regression and structural equation modelling (SEM). Results. Gender, pre-operative general health, depression, ASA grade and Euroqol index scores individually influenced satisfaction and/or success. When the interactions between variables were considered the size of the improvement in the Euroqol score and female gender were the most important predictors of lower levels of satisfaction/success. The effects of female gender were largely through its association with
Total knee replacement (TKR) is one of the most successful procedures in orthopaedic surgery. Although originally limited to more elderly and less active individuals, the inclusion criteria for TKR have changed, with ever younger, more active and heavier patients receiving TKR. Initially, tibial components were cemented all-polyethylene monoblock constructs. Subsequent long-term follow-up studies of these implants have demonstrated excellent durability in survivorship studies out to 20 years. Aseptic loosening of the tibial component was one of the main causes of failure in these implants. Polyethylene wear with osteolysis around well-fixed implants was rarely (if ever) observed. Cemented metal-backed nonmodular tibial components were subsequently introduced to allow for improved tibial load distribution and to protect osteoporotic bone. Long-term studies have established that many one-piece nonmodular tibial components have maintained excellent durability. Eventually, modularity between the polyethylene tibial component and the metal-backed tray was introduced in the mid-80s mainly to facilitate screw fixation for cementless implants. These designs also provided intra-operative versatility by allowing interchange of various polyethylene thicknesses, and also aided the addition of stems and wedges. Other advantages included the reduction of inventory, and the potential for isolated tibial polyethylene exchanges. Since the late 1980's, the phenomena of polyethylene wear and osteolysis have been observed much more frequently when compared with earlier eras. The reasons for this increased prevalence of synovitis, progressive osteolysis, and severe polyethylene wear remain unclear, but there is no question that it was associated with the widespread use of both cementless and cemented modular tibial designs. Mayo Data: Modular versus All Polyethylene Tibial Components in Primary TKA: The study population included 10,601 adult (>18 years) patients with 14,524 primary TKR procedures performed at our institution between 1/1/1988 and 12/31/2005. Mean age was 68.7 years and 55% were female. Overall revision rates and revisions for loosening, wear/osteolysis were compared across different designs using Cox proportional hazards regression models adjusting for age, sex, calendar year and body mass index (BMI). Over an average 9 years follow-up, a total of 865 revisions, including 252 tibia revisions were performed, corresponding to overall survival of 89% (Confidence intervals (CI): 88%, 90%) at 15 years. In comparison to metal modular designs, risk of tibial revision was significantly lower with all-poly tibias (HR 0.3, 95% CI: 0.2, 0.5). Overall, posterior cruciate-retaining (CR) designs performed better than the posterior-stabilised (PS) designs (p=0.002). With any revision as the endpoint, there were no significant differences across the 18 designs examined. Similarly, there were no significant differences across the 18 designs when we considered revisions for aseptic loosening, wear, and osteolysis. Among patient characteristics, male gender, younger age,
