The relationship between pain catastrophising and emotional disorders including anxiety and depression in patients with osteoarthritis (OA) undergoing total joint replacement (TJR) is an emerging area of study. The purpose of this study was to examine the association between pain catastrophising, anxiety, depression and preoperative patient characteristics.

A prospective cohort study of preoperative TJR patients at one centre over 12-months was conducted. We examined association between catastrophising, anxiety, depression and preoperative patient characteristics including demographics, pain and function. Pain catastrophising was assessed using the Pain Catastrophising Scale (PCS), and anxiety/depression using the Hospital Anxiety and Depression Scale (HADS-A, HADS-D). Patient perceived level of hip/knee pain was measured using a visual analogue (VAS) pain scale. Patient perception of function was measured using the Oxford Score. Preoperative radiographic grading of OA was determined using the Kellgren and Lawrence (K-L) scale. Logistic regression was used to assess pattern of relationship between preoperative characteristics and PCS or HADS. Adjusted odds ratio (OR) and 95% confidence interval (CI) were reported. A secondary quantile regression analysis examined whether a model not restricted to pre-defined PCS and HADS categories would yield comparable results to the logistic regression model described in the primary analysis. P-values less than 0.05 were considered statistically significant.

The sample included 463 TJR patients (178 hips, 285 knees). VAS pain (OR 1.23,95%CI 1.04–1.45) and Oxford score (OR 1.13,95%CI 1.07–1.20) were identified as significant predictors for PCS. The same two variables were the strong predictors for all sub-domains of PCS excluding rumination. Oxford Score was the only significant predictor for abnormal HADS-A (OR 1.10,95%CI 1.04–1.17) while VAS pain (OR 1.27,95%CI 1.02–1.52) and Oxford (OR 1.09,95%CI 1.01–1.17) were significant predictors for abnormal HADS-D. Similar pattern of association for PCS and HADS was observed in the quantile regression model, where larger VAS pain and Oxford scores significantly increased median PCS across all domains. Female gender, younger age or having a higher ASA grade were associated with higher median HADS-A, but unlike in the logistic regression, this association was statistically significant.

Pain catastrophising and emotional disorders generally result in poor functional outcomes in TJR patients. The most important predictor of catastrophising, anxiety/depression is pain and subjective function. At risk patients include those with high preoperative pain with generally good preoperative function, as well as younger females with significant comorbidities. Such patients should be identified, and targeted psychological therapy implemented preoperatively to optimise coping strategies and adaptive behaviour to mitigate inferior TJR outcomes including pain and patient dissatisfaction.

Purpose: Medical research has classically been based on the male model, this is no different in the design of arthroplasty implants. Focus has recently shifted to gender-specific implant design but evidence is just developing in the literature as to gender specific outcomes. We hypothesised that outcomes in arthroplasty patients are affected by gender.

Methods: Patients were retrospectively identified from a prospectively collected database of total joint arthroplasties performed at one center. Six surgeons performed 1123 primary unilateral cemented TKA’s, and 989 primary unilateral cementless THA’s over a period of seven years. General demographic data was collected along with preoperative and 1-year clinical outcomes including the Harris Hip/Knee Society Score and Oxford Hip/Knee scores. These were compared to determine differences, if any, between males and females using independent samples t-test.

Results: The TKA sample was comprised of 540 (55%) females and 449 (45%) males. The THA sample included 744 (66%) females and 379 (34%) males.

In the TKA group, females were significantly younger, had higher BMI and had differing rates of comorbidities and complications. Female KSS, Oxford and ROM outcomes were significantly inferior to male scores preoperatively and at 1 year follow up. Significantly more females reported higher pain scores than males from pre-op to 1 year. Interestingly, females showed significantly more improvement from pre-op to 1 year in both scores.

In the THR group there were varying rates of complications and comorbidities by gender. Females did significantly worse in the HHS and Oxford hip score from pre-op until one year when results equalized. Similarly pain scores were higher for females preop and at 6 weeks but became equivalent thereafter. Females showed significantly greater improvements from pre-op to 1 year in both outcome scores.

Conclusion: As reported in the literature, results of this study indicate that women choose TJR at a later stage of disease than men do, presenting with inferior functional status. The effect of waiting seems most marked in the knee arthroplasty population with inferior outcomes and pain relief persisting out to 1 year. Surgeons must counsel females differently about expectations and recovery in joint arthroplasty.

The association between obesity and sleep apnea syndrome (SAS) is well known, as is the fact that TJR patients are often obese. Based on review of 5819 primary TJR patients at our institution, 53% of patients presenting for TJR were obese (mean BMI 31), and of those obese patients 61.3% were female. The potential impact of SAS, diagnosed and undiagnosed, on TJR outcomes has not been well described. In the literature it has been suggested that such patients may be at increased risk of prolonged hospital length of stay (LOS), increased risk of postoperative MI, and risk of postoperative respiratory compromise requiring unplanned transfer to a special care unit (SCU). At our institution, unless deemed required for preoperatively identified co-morbidities, all TJR patients are managed acutely on an orthopaedic ward with no formal step down unit available for enhanced monitoring, even when receiving PCA or epidural for postoperative pain control.

We undertook a prospective non-randomised survey of 1927 primary TJR patients over a fifteen-month period to screen for a preoperative diagnosis of SAS, or symptoms suggestive of SAS using the self-report Epworth Sleep Apnea Questionnaire. In addition, we evaluated impact of SAS on LOS, risk of postoperative MI, risk of postoperative respiratory compromise and unplanned transfer to SCU.

Of our sample, 88/1927 patients (4.6%) had a confirmed preoperative diagnosis of SAS. An additional 74/1927 patients (3.8%) had 3/3 symptoms suggestive of undiagnosed SAS. SAS patients were younger; mean sixty-six years, p=0.005, and predominantly male; 58%, p< 0.0001, as compared to non-SAS patients comprised of 60% females and mean age sixty-nine years. Mean BMI was higher in the SAS group; 32.3 versus 30, p< 0.0001. There was no correlation between SAS and risk of postoperative MI, LOS (mean 5.2 days, both groups), nor unplanned SCU admission.

Despite concerns expressed in the literature, we found that SAS, both diagnosed and suspected, was not associated with prolonged LOS, increased risk of postoperative MI, postoperative respiratory compromise, or unplanned postoperative transfer to a SCU.

Digital radiography has replaced traditional radiography in many hospitals yet little is known regarding the accuracy of this new technology in THA templating. Our study analyzed the reproducibility and reliability of computer templating in primary uncemented THA as compared to standard on-lay templating techniques with hardcopy radiographs from a digital source.

In December 2004 our hospital converted from standard hardcopy radiography to digital radiography. Patients undergoing THA had preoperative digital radiographs taken which included an AP pelvis with a 50mm magnification marker place in the groin, AP hip, and a cross-table lateral. Forty patients were selected that met our inclusion criteria to begin the templating process, including adequate placement of the magnification marker and optimal hip implant positioning on the postoperative films. Cases that did not have a marker, had significant deformity or mal-positioned implants were excluded. Hardcopies of digitised radiographs were printed and a traditional templating technique using 120% magnified on-lay transparent templates was performed (Capello, 1984). Digital templating was performed using OrthoView Software (Bono, 2004). Templating was conducted by two staff surgeons and one resident. Intra-observer and inter-observer effects were calculated using an Intraclass Correlation Coefficient (ICC).

Digital templating showed good inter-observer and intra-oberserver reliability with ICC values > 0.7. Using computer templating, the femoral stem was accurately predicted to within one size in 85% of the cases, and the acetabular cup was accurately predicted to within one size in 80% of the cases.Using on-lay templating, the femoral stem was accurately predicted to within one size in 85% of the cases, and the acetabular cup was accurately predicted to within one size in 60% of the cases.

There was a significant difference between the accuracy of acetabular cup templating between techniques, likely as a result of the ability of computer templating to adjust for magnification error. Computer templating was able to accurately predict postoperative leg-length discrepancy, abduction angle and horizontal offset. Overall, computer templating was found to be a reproducible and reliable technique for uncemented THA. Problems and lessons learned in the implementation of a digital templating system will be discussed.

Controversy exists surrounding best practice for antibiotic prophylaxis in TJR. Practicing orthopedic surgeons performing TJR in Canada were surveyed to inform regarding the most common antibiotic prophylaxis practice.

Cross-sectional survey of five hundred and ninety practicing Canadian orthopaedic surgeons was conducted. Three orthopaedic surgeons, and one infectious disease specialist established face and content validity of the survey. The survey was mailed to surgeons, and re-mailed to non-responders at twelve-weeks. Survey included questions pertaining to prophylaxis indications, antibiotic choice, dosing, route and timing of administration in the primary and revision setting, as well as postoperative wound drainage investigation and management.

Response rate after two mail-outs was 410/590 (69.5%). 96.6% indicated routine use of systemic prophylactic antibiotics for uncomplicated primary TJR. Cefazolin was most commonly prescribed (97.3 %), with 1gm Cefazolin the most common dosage (70.2%). Vancomycin was prescribed 26% of the time as first line. 48.5% administer the antibiotic in the operating suite, and 90% administer within < sixty minutes prior to skin incision. 47.8% routinely use antibiotics in acrylic cement, and 50% use it in a commercially prepared form. Postoperative prophylaxis duration varied widely with 42% preferring twenty-four hours. 33% routinely culture serous wound drainage within one-week postoperative in the absence of redness or fever. 19.8% prescribe antibiotics if wound drainage persists beyond hospital stay. 15.6% would conduct intraoperative wound exploration if drainage persists beyond postoperative day four. 63.9% stated they routinely withhold antibiotics until they have obtained a deep tissue culture specimen in revision TJR. 74% use the same antibiotic prophylaxis regimen for both primary and revision procedures. Of responding surgeons, 47/410 (11.8%) were categorised as high volume performing > two hundred TJR’s per year, and 40/410 (9.8%) were categorised as low volume performing < twenty-five per year. Comparative results to be discussed.

Opinions vary widely amongst surgeons in Canada, illustrating the controversy in what constitutes ‘best practice’. Despite available published data, a large proportion of Canadian surgeons may fall short in meeting optimal standards of care in some domains such as the dose prescribed and timing of administration. This survey also illustrates the lack of available information to guide current management of postoperative wound drainage in the face of shorter patient hospital stays. Much work is needed in this area to determine risks and benefits of these costly tests and interventions in treating arthroplasty patients.

To evaluate the mechanism by which orthopedic implant wear particles induce apoptosis in immature osteoblasts in an in-vitro setting.

Stromal cells from femurs of thirty day-old Swiss Webster Mice were isolated, cultured in-vitro, and incubated with orthopedic wear particles in the micrometer size range. After incubation with wear-particles, the cells were assessed for Caspase three expression and activity in the presence or absence of specific inhibitor(s) in order to delineate potential mechanism for cellular changes previously reported.

Here we report the induction of caspase three protein expression and activity with incubation of stromal cells with titanium wear particles. Caspase three activity however was not demonstrated to be up regulated in a time dependent manner or at lower concentration of particles (2 x 107 particles/ml). However, there was a significant (P< 0.05) increase in caspase three activity with titanium particle at higher concentration (4 x 107 particles/ml) that was not reversible when the extrinsic arm of the apoptotic pathway was blocked with anti-TNFƒa antibodies.

Our previous studies have suggested that aseptic loosening of orthopedic implants may be independent of inflammatory processes, and may be associated with induction of programmed cell death. Our current results would strengthen this idea by demonstrating induction of expression and activity of caspase three involved in apoptosis in cells incubated with wear particles. In addition, titanium wear particles may induce apoptosis through direct cellular effects rather than through the extrinsic TNFƒa pathway. Delineating the mechanism by which wear particles induce apoptosis in immature osteoblasts will allow for the selection and/or development of inhibitors to the process of asceptic loosening by targeting a specific pathway.

A ligament tensioning device was used during total knee arthroplasty procedures to determine the effective stiffness of the soft tissue envelope around osteoarthritic knees. This information was used to calculate the resting forces on polyethylene components in well balanced knees. Various patient and implant factors were investigated to see if they correlated with the stiffness of the soft tissues around arthritic knees. The effective stiffness of the soft tissues was found to be higher when the posterior cruciate ligament was preserved compared to when it was sacrificed.

The purpose of this study was to determine, in vivo, the effective stiffness of the soft tissue envelope around the knee and to estimate the resting force on the implanted polyethylene component during total knee arthroplasty (TKA). A ligament tensioning device was used to measure displacement between the tibia and the femur versus load during eighty-six consecutive TKA procedures. A maximum of five measurements were made in both flexion and extension. The measurements were taken after bone cuts were made and soft tissue balancing was performed. The effective stiffness of the knee soft tissue envelope was determined in flexion and extension. Post- operative range of motion was measured while the patient was still under anesthetic. There was no significant difference in the average effective stiffness between men and women or between flex-ion and extension. Age did not appear to correlate with effective stiffness. The average effective stiffness was significantly higher in posterior cruciate retaining knees compared to those in which the posterior cruciate was sacrificed. There was no statistical significance between the average resting force on the polyethylene in men versus women, in flexion versus extension, or in posterior cruciate retaining knees versus posterior cruciate sacrificing knees. The immediate post-operative range of motion did not correlate with the resting force on the implanted polyethylene

Retrospective analysis of three hundred and seventy-one obese (BMI _ 30) and two hundred and forty-nine non-obese (BMI < 30) primary unilateral TKA patients with minimum one-year follow-up to determine influence of obesity versus non-obesity on clinical outcomes following primary unilateral total knee arthroplasty (TKA) for osteoarthritis. Obese patients fare just as well as non-obese patients, experiencing a greater degree of improvement in observed and self-reported outcome measures.

Multiple factors determine outcome of TKA. This study aimed to determine influence of obesity versus non-obesity, as measured by body mass index (BMI), on clinical outcomes following primary unilateral total knee arthroplasty (TKA) for osteoarthritis. Compared to non-obese patients, obese patients had inferior preoperative clinical scores, but achieved comparable ultimate clinical outcomes.

Despite inferior preoperative clinical scores, obese patients undergoing primary TKA for osteoarthritis can expect the same ultimate clinical outcome as non-obese patients.

Statistically significant differences for; mean age of obese 69.2 ±9 and non-obese 73±8 (p< 0.0001), with a higher preponderance of obese females, 70.2% vs. 30% male (p=0.033).

Despite statistically significant differences among all preoperative clinical outcomes including; KSS clinical (p=0.019), KSS function (p=0.02), Oxford (p=0.02), and flexion (p=0.001), there were no statistically significant differences among these outcomes at one-year postoperative. No statistical difference among surgical outcomes, hospital length of stay, pain scores or stair climbing ability at any interval.

Retrospective analysis of three hundred and seventy-one obese (BMI _ 30) and two hundred and forty-nine non-obese (BMI < 30) primary unilateral TKA patients with minimum one-year follow-up. Statistical analysis to determine differences in demographics, surgical time, intraoperative complications, hospital length of stay, and clinical outcomes including; flexion, KSS and Oxford score, pain-level and stair climbing ability at six-week, six-month, and one-year postoperative. Patients with previous high tibial osteotomy, ORIF, or receiving associated WSIB benefits were excluded.

Obese patients fare just as well as non-obese patients, experiencing a greater degree of improvement in observed and self-reported outcome measures.

To evaluate the effect of implant articular geometry on postoperative range of motion (ROM) after primary total knee arthroplasty for osteoarthritis, we conducted a retrospective case-control study of one hundred and twenty patients (sixty in each group) comparing Scorpio® Posterior Cruciate Substituting implant using Superflex® versus traditional tibial insert. Cases and controls were matched 1:1 for surgeon and gender. Both groups had similar baseline characteristics. Except for KSS Clinical Score at six months (mean: 92.8 for Superflex® versus 87.6 for traditional insert; p=0.029), there was no statistically significant difference between the two groups in knee scores or ROM up to one-year postoperatively.

To evaluate the effect of implant articular geometry on postoperative range of motion (ROM) after primary TKA.

Despite the advent of high flexion knee designs, surgical technique and patient driven factors remain the overriding determining factors for ultimate flexion range achieved following TKA.

One hundred and twenty patients (sixty in each group) were included. Both groups had similar baseline characteristics. Except for KSS Clinical Score at 6 month (mean ± SD: 92.8 ± 5.8 for Superflex® versus 87.6 ± 14.6 for traditional insert; p=0.029), there was no statistically significant difference between the two groups in knee scores or ROM. Flexion at one year for Superflex® was 113.5° ± 10.5 compared with 113.2° ± 11.9 for traditional tibial insert (p=0.869).

Retrospective cohort study of a prospectively gathered database of TKA’s performed at a high-volume arthroplasty center from 1998 to 2003. Inclusion Criteria: primary TKA for osteoarthritis using Scorpio® Posterior Cruciate Substituting implant with Superflex® tibial insert versus traditional insert. Exclusion Criteria: WSIB, prior history of septic arthritis, and previous knee surgery. Cases and controls were matched 1:1 for surgeon and gender. Postoperative care was standardized. Data points included demographics, operative details, pre- and post-operative Knee Society Score (KSS), Oxford Knee Score and range of motion at six weeks, six months and one year postoperatively. P< 0.05 was considered statistically significant.

Despite improvements in knee prostheses design, patient factors and surgical technique remain the most important determinants of outcome in primary TKA, particularly ROM.

A prospective evaluation was undertaken utilizing the SF12 score, Oxford Knee score, Knee Society Score (KSS), visual analog pain score, and a non-validated questionnaire to determine patient self-perception of leg alignment after knee arthroplasty, and impact of satisfaction with alignment on clinical outcomes. 21/84 (25%) patients were dissatisfied with their new leg alignment and this group subsequently reported greater pain scores (p< 0.001) and lower SF12 scores (p< 0.002). Oxford Scores and KSS showed no difference between groups. We suggest that patient satisfaction with postoperative lower extremity alignment is an important issue affecting subjective outcomes in total knee arthroplasty (TKA).

This study was undertaken to determine how patients perceive their leg alignment after knee arthroplasty and whether their level of satisfaction with alignment affects clinical outcomes.

The results of this study suggest that there may be some benefit to preoperative counselling on what to expect in regard to leg alignment following surgery. Additionally, given the adverse impact of dissatisfaction with limb alignment on subjective outcomes, we suggest that patient satisfaction regarding leg alignment should be considered for inclusion in the design of subjective outcomes measures for total knee arthroplasty.

21/84(25%) patients were dissatisfied with their new leg alignment while all but one had an anatomic axis between 4–100 valgus radiographically. This group subsequently reported greater pain scores (p< 0.001) and lower SF12 scores (p< 0.002). At six months follow-up, there was no difference between groups on the Oxford Knee or KSS (p> 0.05).

A non-validated questionnaire was utilized to prospectively ask patients to self-rate their alignment, their satisfaction with their alignment, and their pain scores on a visual analog scale (VAS). Additional outcome measures included pre and postoperative SF-12, Oxford Knee and KSS.

There is still no consensus regarding any one single scoring system with regard to clinical outcomes of primary TKA. Also, it has been widely reported that surgeons often perceive outcomes of TKA with more success than patients. 21/84 of our patients were dis-satisfied with their alignment while all but one had an anatomic axis between 4–100 valgus radiographically.

Purpose: Peri-implant osteolysis after total joint arhtro-plasty (TJA) is a major cause of implant loosening. Cellular responses to wear particles have been reported to play a role in asceptic loosening due to their cytotoxic nature to cellular components. Purpose of this study is to evaluate the effect of orthopedic implant wear particles on immature osteoblasts in an in-vitro setting in order to further understand the mechanisms involved in asceptic loosening of implants.

Methods: Stromal cells from femurs of 30 day-old Swiss Webster Mice were isolated, cultured in-vitro, and incubated with Titanium and Ceramic (smooth and angular) particles in the micrometer size range. After 9 days of incubation the cells were assessed for Alkaline phosphatase (ALP) activity or stained for cellular changes consistent with apoptosis.

Results: Here we report both a dose-dependent decrease (P< 0.05) in ALP activity and a significant increase in programmed cell death when murine stromal cells were cultured with orthopedic implant wear particles of differing compositions. Ceramic wear particles were consistently less toxic at lower concentrations (1 x 107 to 2 x 107 particles/ml) than were wear particles composed of titanium. However, at high concentrations (4 x 107 particles/ml) all particles regardless of composition were equally toxic. These findings suggest that ceramic particles may be less cytotoxic to bone marrow stromal cells/osteoblasts than are titanium particles.

Conclusions: Previous studies have suggested that inflammatory responses to orthopedic wear particles are responsible for the asceptic loosening of orthopedic implants. In the current study however, we found that wear particles may also induce cellular apoptosis of primary bone forming cells. This suggests that the asceptic loosening of orthopedic implants may be independent of inflammatory processes, and that implant material selection should be directed, in part, by its inability to cause programmed cell death.

Historically, cemented THA femoral stems inserted in varus have yielded poor clinical results. Very few studies to date have addressed the question of the effects of varus alignment on uncemented stems. We have conducted a retrospective review of one hundred and twenty-five uncemented THA femoral stems implanted by a single surgeon from 1994 to 1999. Within this single surgeon group we were able to identify sixteen stems implanted in varus and thus proceeded to analyze the effect of varus alignment on functional outcome.

To assess functional and radiographic outcome of uncemented primary THA femoral stems implanted in varus.

After four-years of follow-up, there have been no radiographic or clinical problems associated with implanting uncemented femoral stems in varus.

Although it is not recommended to implant stems in varus, radiographic and clinical problems associated with implanting uncemented femoral stems in varus appear to be non-consequential.

Of the study sample, one hundred and sixteen hips were in neutral alignment as compared to sixteen varus hips. We could not show any significant difference in Harris Hip scores between the varus and non-varus hips (p> 0.5). No cases showed evidence of radiographic loosening, or subsidence (p=0.3) at four-year follow-up.

Retrospective radiographic review of one hundred and twenty-five uncemented primary THA femoral stems implanted by a single surgeon (now retired) from 1994 to 1999, using the Watson-Jones approach, identified sixteen femoral stems implanted in varus. These sixteen stems were matched 1:1 for demographics and preoperative diagnosis to a cohort of sixteen non-varus uncemented stems implanted by the same surgeon over the same study period. Functional outcome included Harris Hip score and range of motion at four-years postoperative. Radiographic signs of loosening and subsidence, defined as > 2mm, were measured. Varus alignment was defined as ≥ 5°. Paired t-tests were conducted on all outcome variables, p< 0.05 was considered statistically significant.

Study results suggest there to be no consequence of varus femoral alignment in uncemented stems. Patients will need to be followed for a longer duration to further examine the effects of varus implantation of unce-mented femoral stems.

Purpose: Our purpose was to evaluate why some patients achieve excellent range of motion (ROM) following total knee arthroplasty (TKA) and to determine its relation to outcome.

Methods: We evaluated 618 primary unilateral TKA’s for osteoarthritis from a prospective arthroplasty database using a single implant design. 209 TKA’s with ROM greater than 120 degrees at one year follow-up were compared to 409 TKA’s with ROM less than 120 degrees to determine if age, BMI, gender, ASA class, and preop ROM differed between the two groups. Knee society and oxford knee scores were also compared both preoperatively and at one year follow-up using independent samples t-test. A multiple logistical regression analysis was performed to determine predictors of ROM.

Results: Preoperative ROM was higher (115 vs 106, p< 0.0001), BMI was lower (30.7 vs 32.9. p< 0.0001), and there was a higher proportion of males (p< 0.0001) in those patients with exceptional ROM at one year (> 120 degrees). Knee Society Score (93.7 vs 87.8, p< 0.0001) and Oxford Knee Score (20.4 vs 24.4, p< 0.0001) were superior in the exceptional ROM group at one year follow-up. In multiple logistic regression, only preoperative ROM (p< 0.0001) was a significant predictor of postoperative flexion range.

Conclusions: Body habitus may play a role in our ability to achieve exceptional flexion following TKA. Implant design has historically favoured male anatomy which may influence exceptional flexion range. Preoperative ROM still seems to be the biggest predictor of postoperative ROM. Perhaps timely surgical intervention, pre-habilitation and implant design choice can influence our ability to achieve exceptional ROM following TKA.

Failed open reduction internal fixation (ORIF) of the proximal femur can render patients severely disabled. This study analyzed the short-term functional results and complications of total hip arthroplasty (THA) for complications of ORIF of the proximal femur. Using the Hamilton Arthroplasty Database, thirty-six patients treated with a THA for complications of ORIF of the proximal femur were compared to a matched cohort. Analysis showed that THA for complications of ORIF of the proximal femur is a successful procedure despite increased intraoperative difficulty that results in comparatively lower short-term Harris Hip Scores. No statistically significant differences in intraoperative or postoperative complications were noted.

Open reduction internal fixation (ORIF) of the proximal femur is a common, successful orthopedic procedure. However, failed ORIF of the proximal femur can render patients severely disabled. The purpose of this study is to analyze and compare the short-term functional results and complications of total hip arthroplasty (THA) for complications of ORIF of the proximal femur.

After ethics approval, the Hamilton Arthroplasty Registry, a prospective database, was used to identify thirty-seven patients treated with THA for complications of ORIF of the proximal femur. From September 1998 to the present a group consisting of sixteen males and twenty females, with a mean age of sixty-seven, were matched to a cohort of patients treated with a primary THA. Using Wilcoxon Test and Chi-Square Tests, the two groups were compared (p< 0.05).

Initially, ORIF was used to treat thirty-six patients for proximal femur fracture. The mean follow-up was 13.5 months. The experimental group had a significantly lower (p=0.035) Harris Hip Score at the one year follow-up, however both groups showed a significant improvement from preoperative scores (p=0.0001). A significant difference was noted between the two groups in estimated blood loss (p=0.01) and operative time (p=0.01). There was no significant difference in complication rate.

THA for complications of ORIF of the proximal femur is a successful procedure improving patient’s pain and functional status. This is a more complicated procedure than primary THA, at times requiring the use of a revision stem, which results in significantly lower Harris Hip Scores. Nonetheless, there appears to be no comparative increase in short-term complications.

A retrospective review was conducted to evaluate short-term (one year) outcomes of primary total knee arthroplasty (TKA) patients receiving Ontario Worker’s Safety and Insurance Board Benefits (WSIB) compared to a matched cohort of non-WSIB patients. Postoperatively, WSIB patients had higher pain scores, poorer self-perceived functional outcomes and lower flexion range. WSIB patients required more postoperative clinic visits and were more reluctant to answer questions regarding functional outcome. All differences were statistically significant. The short-term outcomes of primary TKA in patients receiving WSIB benefits are inferior to those obtained by non-WSIB patients.

Retrospective review to evaluate short-term outcomes of primary TKA patients receiving WSIB as compared to non-WSIB patients.

Short-term outcomes of primary TKA in WSIB patients are inferior both subjectively and objectively to non-WSIB patients. WSIB patients are seen more frequently for postoperative follow-up which we would attribute to the persistence of subjective complaints following primary TKA.

Short-term outcomes of primary TKA in WSIB patients are inferior to those obtained by non-WSIB patients. WSIB patients undergoing primary TKA require more postoperative visits with a greater prevalence of subjective postoperative complaints.

Thirty-eight WSIB patients who underwent primary TKA were matched to thirty-eight non-WSIB patients. There were no statistical differences in preoperative Knee Society (KSS) and Oxford Score. Six-week total KSS (p=0.011), pain as measured by KSS (p=0.015), and flexion (p=0.012) were significantly different between the groups. At six-months similar results were noted among KSS function (p=0.027) and pain (p=0.024), Oxford Score (p=0.027), and flexion (p=0.035). One-year Oxford Score (p=.011) and flexion (p=0.013) were statistically significant, as were the McGrory Modified Knee Score (p=0.001), patient expectations (p=0.030), perceived quality of life (p=0.009), and number of postoperative clinic visits (p=0.024).

Retrospective review on successive WSIB patients undergoing primary TKA, at a single arthroplasty centre, matched to a cohort of non-WSIB patients for demographics and preoperative diagnosis. Outcomes included Knee Society, Oxford Knee, and McGrory et al Modified Knee scores, patient satisfaction, and number of postoperative clinic visits. Unpaired t-tests were used to determine differences in outcomes.

There are few reports but many allusions regarding inferior outcomes of TKA in WSIB patients. Our study provides further evidence to support this view. Multiple factors may account for this variance, including psychosocial factors. Further prospective studies are needed to address this burgeoning issue.

Introduction and Aims: Computer-assisted bone and soft tissue balancing in total knee arthroplasty (TKA) may aid in achieving perfect knee alignment leading to better function and prosthesis survival. The ‘Measured Resection’ technique was compared to a ‘Computer Assisted Gap Equalisation’ (CAGE) technique of knee balancing in TKA.

Method: TKAs were performed on eight pairs of cadaver knees. One side of each pair was randomly selected to the control group in which measured resection was used for balancing. The experimental technique (CAGE) using a computer-assisted ligament-tensioning device to equalise gap symmetry and load was used on the contralateral side. Post-operatively, a simulator applied forces to the quadriceps and hamstring tendons and a tibial load transducer measured compartmental force at five flexion angles (0, 30, 45, 60, 90 degrees). Outcome assessment consisted of measuring gap loads and symmetry under ligament tension pre-component insertion and compartmental force post-component insertion.

Results: Although there was no significant difference between the two groups in the symmetry of the extension (p = 0.27) and flexion (p=0.07) gaps pre-component insertion, there was a trend towards improved gap symmetry in the CAGE group. As well, pre-component insertion there was a significant (p< 0.05) equalisation of flexion and extension gap loads in the CAGE group. However, post-component insertion there was no significant difference (p> 0.05 using 2-way repeated measures ANOVA) in medial to lateral compartment load balance between the two groups. As well, the measured loads with the knee in full extension (zero degrees of flexion) were significantly higher (p< 0.001) in both groups compared to other flexion angles.

Conclusion: CAGE improves knee balance pre-component insertion by improving surgical accuracy with computer-assistance. However, component design, posterior capsular tension and tibial rotation preclude sustaining the improved balance post-component insertion leaving final knee balance unchanged. Further work is needed to translate the improved surgical accuracy into improved balance following component insertion.

Introduction and Aims: Although cortical hypertrophy (CH) in total hip arthroplasty (THA) has been associated with thigh pain and loose femoral stems, its presence has been variable in the literature, and it is an implant-specific phenomenon. The relationship of bony change to clinical outcome has not previously been examined in ceramic THA.

Method: Hardened-bearing surfaces such as ceramics have the potential for altered patterns of force transmission into the femoral stem-bone interface, and as such could lead to altered bone remodelling. We investigate here the incidence and magnitude of CH at the Gruen zones, about the femoral stem of THA utilising ceramic-on-ceramic bearing surfaces without (n=36) or with (n=4) cement, and metal-polyethylene bearing surfaces without (n=40) or with (n=40) cement. Using multifactorial analysis, we examined the relationship of implant alignment, Harris and Oxford hip scores, and bone remodelling parameters.

Results: In this study of 120 patients, the hip scores and x-rays are examined in the first year after total hip arthroplasty (THA), in order to evaluate bone remodelling in relation to clinical outcomes. Ceramics had the highest incidence (25%) and mean size (1.5 mm) of CH, followed by metal-polyethylene (17%, < 1 mm). No cemented implants exhibited CH. There was no significant relationship of bone remodelling to one-year hip scores, although there were significantly reduced pain scores in cases that exhibited endosteal remodelling at one year. CH in ceramic hips appears to be a mechanical phenomenon that is not associated with pain, varus drift, subsidence, or altered clinical outcome. Cement may buffer the stresses seen by the femur, and hence the stimulus for CH appears to be simply mechanical, and is increased with hardened-bearing surfaces.

Conclusion: CH was more common in ceramic THA than metal-polyethylene, but was not associated with increased thigh pain or altered function. CH did not occur when cement was used, and as such we argue for a mechanical origin of the phenomenon, via altered load transmission into the femur through hardened-bearing surfaces.