Rivaroxiban is a factor Xa inhibitor and is a newer oral alternative for thromboprophylaxis after joint replacements. Its major advantage is its oral administration and hence better patient compliance. However there are some doubts about its efficacy compared to dalteparin/heparin. We have recently changed over from using dalteparin injections to rivaroxiban tablets for thromboprophylaxis after hip replacements. We assessed our results to find efficacy and specificity of its action in patients undergoing THR.

504 patients underwent hip replacement in last 2 years. 316 were treated with dalteparin injections (fragmin) for thromboprophylaxis while 189 patients were treated with oral rivaroxiban for 35 days after their hip replacement.

Average haemoglobin drop at 24 hours postop was 2.79 in Rivaroxiban group compared to 3. 10 in dalteparin group. 19 patients (of 189 i.e. 10.05%) required postop blood transfusion in rivaroxiban group as against 60 (of 315 i.e. 19.04%) in Dalteparin group. This difference was statistically significant. Incidence of DVT was no different in either groups, but the number of patients was too small to compare this.

Rivaroxiban appears to be more specific in its action and our results suggest a significant reduction in postop blood transfusion following hip replacements without any increase in rate of Deep Vein Thrombosis. We would like to present our findings and discuss role of oral thromboprophylaxis after joint replacements.

Background: Patients undergoing elective Lower limb arthroplasty are at increased risk of deep vein thrombosis (DVT). On reviewing the literature, there is a lack of evidence about the best time to administer anticoagulants post-operatively - recommended between 6 and 12 hours. In addition the recent American College of Chest Physicians guidelines recommends that postoperative DVT prophylaxis is given for a minimum of 10 days.

The principal aim of this audit was to assess the timing and duration of thromboprophylaxis post-arthroplasty in our unit.

Methods: Data was collected prospectively. We recorded the timing of the first post operative dose of Fragmin following closure of the wound along with duration of treatment. 5 months of data were analysed; changes were suggested and implemented. This included 2 post operative Fragmin ward rounds. The first at 6pm for patients undergoing surgery in morning and a second at 10pm for those in the afternoon. All patients now receive prophylaxis for 10 days. If they were discharged before 10 days they were sent home on Fragmin. A further analysis was carried out six months later for a further five months.

Results: Initial Audit – 330 patients – primary hip or knee replacement

The timing from finishing surgery to receiving Fragmin ranged from 0:31 to 8:37. 11% received Fragmin less than 2 hours post operatively, 12% 2–4 hours post operatively, 27% 4–6 hours and 49% 6–8 hours

The Duration of prophylaxis ranged from 3 to 32 days. 54% received prophylaxis for less than 7 days.

Second Audit – 337 patients – primary hip or knee replacements

The delay from completing surgery to receiving Fragmin ranged from 2:05 to 9:38. Now only 2% received Fragmin less than 4 hours post operatively. Only 51%, however received Fragmin 6–10 hours post op.

All patients received Fragmin for a minimum of 10 days in the second audit

Discussion: The initial audit highlighted potentially dangerous practice in our venous throboprophylaxis regime. Changes were instituted.

The new protocol for post-operative Fragmin administration had little impact on the percentage of patients receiving Fragmin within 6 hours of surgery. The results, however, show that only 8 of these patients received anti-coagulation within 4 hours, a definite improvement on the initial audit.

Following the changes to Fragmin continuation at discharge, inpatient stay is now not an indicator of duration of Fragmin therapy. All patients now receive 10 days of Fragmin, either as inpatients or in the community.

Conclusion: The change in protocol has reduced the number of patients receiving anti-coagulation less than 4 hours after surgery. However there are still a significant number of patients who receive Fragmin under the recommended 6 hours post-operative.

Whilst clinical pathways have reduced the length of inpatient stay (LOS) and costs associated with total hip replacement (THR), it would be useful to be able to predict which factors affect the LOS following THR. In this way units could improve patient flow, and thus increase efficiency, by optimising case loads and staffing levels in all related departments. We hypothesised that there were pre-operative factors that will predict the length of inpatient stay following a unilateral primary THR.

Prospective data from 2302 patients who underwent primary unilateral THR for osteoarthritis during a nine-year period from January 01 1998 were included. The relationship between each prospectively recorded factor and LOS was analyzed separately using t-tests or Pearson correlation. Multiple linear regression was used to analyze the effect of each significant factor adjusted for others.

Length of stay varied from 3 to 58 days, with a mean of 8.1 and a median of 7.0. The pre-operative factors that were not significantly associated with the LOS were BMI, Scottish Index of Multiple Deprivation, disabling knee, back or contra-lateral hip pain. A number of pre-operative factors were found to be highly significant predictors of LOS when subjected to univariate analysis, but not significant after multivariate analysis. These were smoking, heart disease, diabetes, pre-operative aspirin, pre-operative haemoglobin and overall Short Form (SF-36) score. Pre-operative factors that were significantly associated with LOS after adjusting for the effect of others were age, sex, pre-operative NSAIDs, consultant surgeon, combined function/activity dimension to Harris hip score, general health perception (GHP) dimension of SF-36, the day of the week and the year of surgery.

Younger age, male sex, higher combined Harris hip function and activity score, higher GHP dimension of SF-36 score and NSAID use are all significantly associated with reduced length of inpatient stay following primary THR for osteoarthritis.

Hip and knee arthroplasty account for over 95 000 hospital days annually in Scotland. The gross cost of over £81 million can be reduced by £10 million by decreasing length of stay by just one day per patient.

We performed a retrospective analysis of the data from the Scottish Arthroplasty Project (SAP). We specifically looked at length of stay in patients undergoing total hip and knee replacements between 1996 and 2007. We analysed the data on over

91000 total hip and knee replacements. In addition we looked at the influence of age, volume and day of admission on the 2007 data

Over the 11 year period there were significant variations in improved length of stay across the health boards. For the 2007 data, we found that patients treated in boards with high patient volume had shorter hospital stays. Admission policy and age of the patients affected the length of stay it did not account for the large differences between health boards.

The data from the Scottish Arthroplasty Project shows that higher surgical volume correlates with reduced length of stay in arthroplasty patients. The reasons for this are likely to be multifactorial but generalisable and need to be examined more closely with another study.

Our aim was to identify intra-operative and post-operative factors that predict those patients most at risk of dislocation.

Data was prospectively collected on a consecutive series of 2899 total hip replacements undertaken between July 1997 and December 2007. All operations were undertaken in one institution by fourteen orthopaedic consultants. In order to ensure accuracy, our regional database was cross-referenced with the Scottish Arthroplasty Project. Age; sex; BMI; surgeon; surgical approach; monthly caseload per surgeon; and the head size of the implanted prosthesis were analyzed using chi-squared tests for categorised factors and t-tests for quantitative factors.

Of the 2899 patients, 78 (2.7%) were found to have had one or more dislocation. BMI > 35kg/m2 was a significant pre-operative predictor of dislocation (P< 0.001). BMI < 35kg/m2 had a dislocation rate of 2.3% compared with a rate of 6.7% in those > 35kg/m2. Operating surgeon was the only intra-operative factor predictive of dislocation (P< 0.001). Head size was found to be insignificant.

Three surgeons with an overall dislocation rate of < 1% had a dislocation rate of 0.8% for patients with a BMI < 35kg/m2 and 2.0% for BMI > 35kg/m2. In comparison, the remainder of the surgeons had rates of 3.3% for BMI < 35kg/m2 and 9.6% for BMI > 35kg/m2.

Analysis of this consecutive series has shown that a BMI > 35kg/m2 is associated with a significant increase in rates of dislocation. The operating surgeon is also a significant factor and the highest risk is seen in surgeons with a > 1% overall dislocation rate operating on obese patients.

In Scotland, the number of primary total knee replacements (TKRs) performed annually has been steadily increasing. Data from the Scottish Arthroplasty Project has recently demonstrated that the number of knee replacements performed annually has now outstripped the number of hip replacements. The price of the implant is fixed but the length of hospital stay (LOHS) is variable. An understanding of what currently influences LOHS may therefore be of paramount importance in order that we can influence some of these parameters, with resulting benefit to our patients as well as contributing significantly and favourably towards the health economics of this procedure. This study investigates the influence of intra- and post-operative variables on LOHS.

All patients who underwent primary unilateral TKR in the region of Fife, Scotland, United Kingdom, during the period December 1994 to February 2007 were prospectively investigated. The following intra and postoperative details were recorded: length of operation, need for urinary catheterisation, patella resurfacing, lateral release, blood transfusion, the presence of superficial or deep infection, day 1 post-operative haemoglobin and haemoglobin drop (haemoglobin drop between admission haemoglobin and day 1 post-operative haemoglobin). The data was analysed using univariate and multiple linear regression statistical analysis.

Data on LOHS was available from a total of 2105 primary unilateral TKRs. The median LOHS was 8.0 days. The highly significant intra and post-operative factors associated with an increased LOHS were lateral release, post-operative haemoglobin, blood transfusion, urinary catheterisation, deep and superficial infection. An awareness and understanding of these factors may enable us to influence them favourably with resulting reduction in the LOHS and, therefore, the associated costs.

Introduction: Total Hip Replacement (THR) is an effective procedure that improves Quality of Life (QoL) in patients with hip arthritis. Co-existing back pain is common in these patients. We assessed the impact of back pain on the medium term outcomes of patients undergoing unilateral THR using a disease specific measure, Harris Hip Score (HHS) and a general health questionnaire, Short Form-36 Health Evaluation (SF-36). The SF-36 generates scores on 8 dimensions of QoL; physical functioning (PF), role limitation due to physical problems (RP), role limitation due to emotional problems (RE), social functioning (SF), mental health (MH), energy/vitality (EV), bodily pain (Pain) and general health perception (GHP). It also contains an item requesting information on perceived health change over the past year (CH).

Methods: Between 4th January 1998 and 22nd July 2001, 909 consecutive patients undergoing unilateral THR were entered into a regional arthroplasty database. An audit nurse collected data prospectively. Patients were assessed pre-operatively and demographic details recorded. Patients were asked specifically about the presence or not of back pain. Post-operative follow up was at 6 mnths, 18 mnths, 3 yrs and 5 yrs. At each point the HHS and SF-36 were measured.

There were more females in our study population (61.2% v 38.8%). Statistical analysis was performed for males and females after adjusting for age, body mass index and pre -op scores.

Results: Pre-op, mean HHS and SF-36 score were lower for patients with back pain. Post-THR, patients had overall better outcome scores. Male patients with back pain had significantly lower (P< 0.01) post-THR outcome scores at all time points for HHS, PF, SF and Pain compared to their male peers without back pain. These changes persisted to 5 yrs. This effect was not demonstrated in female patients. The only exception was in the Pain domain of SF-36 where female patients with back pain had lower scores (P< 0.01) than those without back pain.

Conclusion: Patients with back pain obtain significant benefit from unilateral THR in the medium term and this is maintained at 5 yrs. Despite the clinical benefit to the group as a whole, the absolute scores for males with pre-op back pain remain significantly lower than their peers without back pain. Pre-op back pain did not significantly affect outcome in females.

Introduction: The aim of this study was to determine the impact of deprivation on access to and outcome from total hip replacement in a district general setting.

Methods: A prospective audit was undertaken in an elective orthopaedic centre serving an entire health region. Hip function was collected using the Harris Hip Score (HHS) Patients were followed up for a mean 71 months and the presence of complications noted.

Patients were allocated a deprivation category by retrospective application of the Scottish Index of Multiple Deprivation (SIMD) quintiles.

Results: A total of 2270 hip replacements were carried out in 2177 patients. There were 93 bilateral simultaneous procedures. The overall incidence of THR was 79.5/100,000 per year. This rate was significantly higher in more deprived areas. 37.4% of THRs occurred in males but there was no significant change with deprivation. Deprivation was not linked with age, length of stay or BMI. There was no association with the prevalence of diabetes, cancer, ischaemic heart disease or hypertension in this group. The incidence of smoking increased with deprivation, with a prevalence of 21.5% in the most deprived group compared to 7.7% in the least (p=0.0001). There was no observed difference in mortality, infection, dislocation, thrombosis or transfusion requirement. Preoperative and postoperative function was significantly different between groups with HHS being lower in the most deprived group compared to the least (p=0.01, p=0.005). There were ‘pockets’ of low and high incidence of THR. These correlate with the age of the population (r=0.69, p< 0.001).

Conclusion: We could identify no inequality in access to total hip replacement in our centre and health board region. The incidence of smoking increased with increasing deprivation. Areas with a greater proportion of the population over 60 had an increased incidence of THR. Pre-operative function and outcomes were found to be lower in more deprived groups.

Introduction: Increasingly, clinical pathways and fast-track protocols are reducing hospital in-patient stay following elective joint replacement surgery. In order to improve efficiency in our unit, we undertook a prospective observational study to identify pre–and peri-operative factors associated with increased length of stay.

Methods: From our prospective primary hip arthroplasty database we analysed data from 2678 consecutive patients over a 9-year period from 1998–2007. Patients were excluded who had bilateral hip replacement, died within 30 post-operative days, or had surgery for a diagnosis other than primary osteoarthritis. This left 2302 patients who were analysed using multiple logistic regression analysis

Results: Length of stay varied from 3 to 58 days, with a mean of 8.1 days, and median 7 days. After multivariate analysis, factors that were found to be significantly associated with shorter length of stay were younger age (p< 0.001), male sex (p< 0.001), more recent year of admission (p=0.008), regular non-steroidal anti-inflammatory medication (p< 0.001), lower Harris Hip Score (p< 0.001), and higher General Health Perception dimension score on SF-36 questionnaire (p< 0.001). In addition, the absence of blood transfusion during admission (p< 0.001) and absence of post-operative urinary catheter (p< 0.001) were also associated with shorter length of stay. The following factors, in particular, were not found to be significantly associated with increased length of stay: obesity, diabetes, smoking, medical comorbidity, other disabling joint condition, use of wound drain post-operatively.

Conclusions: We have identified a number of pre-operative factors that predict likely length of stay in a large cohort of patients undergoing primary hip replacement. This data could be used in the future for resource allocation and to improve efficiency in this significant area of healthcare.

Background: Back pain is a common presenting feature in patients with hip arthritis. Hip replacement surgery is performed primarily to relieve hip pain but is known to improve global function. The aim of this study was to quantify the effects of total hip arthroplasty on back pain.

Patients and Methods: A prospective study was conducted from 2001 to 2005 at the Victoria Hospital, Kirkcaldy, Fife. A novel body diagram was devised to collect and quantify back pain. Patients were asked to localize their pain on this diagram prior to their surgery and six months later. The patients were also asked to record their level of satisfaction on a visual analogue scale (VAS) and to complete validated functional and psychological assessments (SF-36; Harris Hip Score).

Results: Preoperative and postoperative data were complete for 872 patients. Preoperatively, 234 (27%) patients complained of pain in the lumbar region. A low score in the baseline SF-36 correlated with low back pain. At six-month post total hip arthroplasty, the low back pain had resolved in 50% (n=116) of these patients, and resolution of this pain correlated with improved post-operative SF-36 score. The mean postoperative satisfaction score was 8.8 out of a maximum 10 (VAS). Satisfaction correlated with reduced back pain.

Conclusion: We describe a novel method of pain assessment in total hip arthroplasty. These data from a large prospective cohort indicate that many patients may expect an improvement in their back pain following hip replacement. This data will be useful in the preoperative counselling of patients considering arthroplasty.

Aim: To study the effect of smoking on the rate of complications and functional outcome after Total Hip Replacement (THR).

Methods: Data was prospectively collected for all patients undergoing a unilateral, primary THR in one hospital during the period 1998 to 2006 Data was collected at pre-operative assessment, in the peri-operative period and at 6 months, 18 months, 3 years and 5 years. Patients were placed in one of three groups; smokers, ex-smokers and those who had never smoked.

Outcome measures included rate of complications: infection, DVT, PE, length of hospital stay and Harris Hip Score (HHS).

Statistical analysis was undertaken to determine any correlation between smoking and these outcome measures using chi-squared tests, t-tests and multiple regression adjusting for confounding factors.

Results: 1765 patients underwent THR during the study period, of whom 635 were males and 1130 females, with a mean age at operation of 69.

268 patients (15%) were smokers, 582 patients (33%) were ex-smokers and 917 patients (52%) had never smoked. As there was little data available on when the ex-smokers had stopped smoking we studied current smokers compared to patients that had never smoked

There were no significant differences in complications such as DVT, PE, Deep infection and Superficial infection, these were all rare events. Neither was there any significant difference in hospital stay times. After adjusting for pre-operative HHS, age, sex and ASA status current smokers had significantly lower HHS at 6 months (p< 0.001, 95% confidence interval for effect size 1.6 to 5.3), and also showed a lower HHS at 18 months, 3 years and 5 years although not significantly so.

Conclusion: Current smokers have a significantly lower HHS post-operatively in comparison to non-smokers. In a health system where more and more patients wish to know the risk associated with potential operative interventions, we can now say that patients who smoke will have a poorer outcome post Total Hip Replacement. This may also allow us to discourage some patients wishing to have THR whom are poor operative candidates.

We plan to further analysis the data to try and ascertain why this is the case.

Introduction: SF-36 is a validated 36-item questionnaire that measures eight dimensions of quality of life(QoL): physical functioning(PF), role physical(RP), role emotional(RE), social functioning(SF), mental health(MH), energy/vitality(EV), bodily pain(Pain) and general health perception(GHP). The primary aim of the study was to evaluate QoL outcomes after total hip replacement(THR) using SF-36.

Methods: From 5/1/1998 until 16/8/2005, we prospectively collected data on 569 patients who had THR in Fife. 30 of them had bilateral THR. Each patient was assessed pre-operatively and was reviewed at 6 months, 18 months, 3 years and 5 years post-operatively. A SF-36 was filled in at each appointment.

Results: During the period, 6 patients died, 4 had revision, 19 were lost to follow-up and 46 did not attend their 5-year review. Subsequently, 494 patients had a 5-year review but 46 of them did not fill in the questionnaire. Analysis was performed on the remaining 448 patients (male=179, female=269).

Mean scores of PF, RP, RE, SF, EV and Pain improved significantly following THR. The improvement remained significant throughout the follow-up (p< 0.0005). MH was the only dimension which did not change significantly after THR. There was a significant decline in GHP (p< 0.0005).

Females reported lower scores in all dimensions apart from GHP. They were also significantly older than the males (66.66±9.41 vs. 64.69±10.27 years; p< 0.037).

Patients who had unilateral or bilateral THR reported similar scores preoperatively and in the initial follow-up. Significant differences were only noted at 3 and 5 years with the bilateral group reported a higher score.

Discussion: THR improved QoL and the benefit was still evident at 5 years post-operatively. However the perception of general health continued to deteriorate, probably due to the effects of aging. More advanced age of females might partly contribute to their lower scores.