Paul Gaston

What determines patient satisfaction with surgery? A prospective cohort study of 4709 patients following total joint replacement

Objectives To investigate the factors which influence patient satisfaction with surgical services and to explore the relationship between overall satisfaction, satisfaction with specific facets of outcome and measured clinical outcomes (patient reported outcome measures (PROMs)). Design Prospective cohort study. Setting Single National Health Service (NHS) teaching hospital. Participants 4709 individuals undergoing primary lower limb joint replacement over a 4-year period (January 2006–December 2010). Main outcome measures Overall patient satisfaction, clinical outcomes as measured by PROMs (Oxford Hip or Knee Score, SF-12), satisfaction with five specific aspects of surgical outcome, attitudes towards further surgery, length of hospital stay. Results Overall patient satisfaction was predicted by: (1) meeting preoperative expectations (OR 2.62 (95% CI 2.24 to 3.07)), (2) satisfaction with pain relief (2.40 (2.00 to 2.87)), (3) satisfaction with the hospital experience (1.7 (1.45 to 1.91)), (4) 12 months (1.08 (1.05 to 1.10)) and (5) preoperative (0.95 (0.93 to 0.97)) Oxford scores. These five factors contributed to a model able to correctly predict 97% of the variation in overall patient satisfaction response. The factors having greatest effect were the degree to which patient expectations were met and satisfaction with pain relief; the Oxford scores carried little weight in the algorithm. Various factors previously reported to influence clinical outcomes such as age, gender, comorbidities and length of postoperative hospital stay did not help explain variation in overall patient satisfaction. Conclusions Three factors broadly determine the patients overall satisfaction following lower limb joint arthroplasty; meeting preoperative expectations, achieving satisfactory pain relief, and a satisfactory hospital experience. Pain relief and expectations are managed by clinical teams; however, a fractured access to surgical services impacts on the patients hospital experience which may reduce overall satisfaction. In the absence of complications, how we deliver healthcare may be of key importance along with the specifics of what we deliver, which has clear implications for units providing surgical services.

Predicting the cost-effectiveness of total hip and knee replacement: A health economic analysis

The aim of this study was to perform a cost-utility analysis of total hip (THR) and knee replacement (TKR). Arthritis is a disabling condition that leads to long-term deterioration in quality of life. Total joint replacement, despite being one of the greatest advances in medicine of the modern era, has recently come under scrutiny. The National Health Service (NHS) has competing demands, and resource allocation is challenging in times of economic restraint. Patients who underwent THR (n = 348) or TKR (n = 323) between January and July 2010 in one Scottish region were entered into a prospective arthroplasty database. A health-utility score was derived from the EuroQol (EQ-5D) score pre-operatively and at one year, and was combined with individual life expectancy to derive the quality-adjusted life years (QALYs) gained. Two-way analysis of variance was used to compare QALYs gained between procedures, while controlling for baseline differences. The number of QALYs gained was higher after THR than after TKR (6.5 vs 4.0 years, p < 0.001). The cost per QALY for THR was £1372 compared with £2101 for TKR. The predictors of an increase in QALYs gained were poorer health before surgery (p < 0.001) and younger age (p < 0.001). General health (EQ-5D VAS) showed greater improvement after THR than after TKR (p < 0.001). This study provides up-to-date cost-effectiveness data for total joint replacement. THR and TKR are extremely effective both clinically and in terms of cost effectiveness, with costs that compare favourably to those of other medical interventions.

A prospective randomised double-blind study of functional outcome and range of flexion following total knee replacement with the NexGen standard and high flexion components

Modifications in the design of knee replacements have been proposed in order to maximise flexion. We performed a prospective double-blind randomised controlled trial to compare the functional outcome, including maximum knee flexion, in patients receiving either a standard or a high flexion version of the NexGen legacy posterior stabilised total knee replacement. A total of 56 patients, half of whom received each design, were assessed pre-operatively and at one year after operation using knee scores and analysis of range of movement using electrogoniometry. For both implant designs there was a significant improvement in the function component of the knee scores (p < 0.001) and the maximum range of flexion when walking on the level, ascending and descending a slope or stairs (all p < 0.001), squatting (p = 0.020) and stepping into a bath (p = 0.024). There was no significant difference in outcome, including the maximum knee flexion, between patients receiving the standard and high flexion designs of this implant.

Comparative outcomes of total hip and knee arthroplasty: a prospective cohort study

Purpose The comparative outcome of primary hip and knee arthroplasty is not well understood. This study aimed to investigate the outcome and satisfaction of these procedures and determine predictive models for 1 year patient outcome with a view to informing surgical management and patient expectations. Study design Prospective cohort study of all primary hip and knee arthroplasty procedures performed at the Royal Infirmary of Edinburgh between January 2006 and November 2008. General health (SF-12) and joint specific function (Oxford Score) was assessed pre-operatively and at 6 and 12 months post-operatively. Patient satisfaction was assessed at 12 months. Results 1410 total hip arthroplasty (THA) and 1244 total knee arthroplasty (TKA) procedures were assessed. Oxford Score improved by 4.9 points more in THA patients than in TKA patients. SF-12 physical scores were on average 2.7 points greater in the THA patients at one year. Satisfaction was also greater (91%) following THA compared with TKA (81%). Regression modelling was not able to predict individual patient outcome; however, mean pre-operative Oxford Scores were found to be strong predictors of mean post-operative Oxford Scores for each procedure. Age, gender and pre-operative general health scores did not influence these models. Conclusions Both THA and TKA confer substantial improvement in patient outcome; however, greater joint specific, general health and satisfaction scores are reported following THA. This difference is physical in nature. Regression models are presented that can be applied to predict mean hip/knee arthroplasty outcome based on preoperative values.

Recovery of knee function following fracture of the tibial plateau

We assessed the functional outcome following fracture of the tibial plateau in 63 consecutive patients. Fifty-one patients were treated by internal fixation, five by combined internal and external fixation and seven non-operatively. Measurements of joint movement and muscle function were made using a muscle dynamometer at three, six and 12 months following injury. Thirteen patients (21%) had a residual flexion contracture at one year. Only nine (14%) patients achieved normal quadriceps muscle strength at 12 months, while 19 (30%) achieved normal hamstring muscle strength. Recovery was significantly slower in patients older than 40 years of age. We conclude that there is significant impairment of movement and muscle function after fracture of the tibial plateau and that the majority of patients have not fully recovered one year after injury.

THROMBOEMBOLIC DISEASE AFTER TOTAL KNEE REPLACEMENT: EXPERIENCE OF 5100 CASES

The aim of the study was to quantify the incidence and timing of venous thromboembolic events (VTE) after total knee replacement (TKR). Data from 5100 consecutive TKRs performed over 10 years were prospectively collected. Cases were reviewed to identify thromboprophylaxis given, the diagnosis of VTE, treatment and adverse outcomes. There were 3 deaths (0.059%) from pulmonary embolism (PE). Of 123 VTEs identified, 55 had PE, 17 had above knee deep vein thrombosis (DVT), 28 had calf DVT and 14 had been incorrectly coded as VTE. There was considerable inappropriate treatment of calf DVT with resultant morbidity. There was an increase in diagnosis of PE between days 1 and 5 post surgery in the later part of the study, corresponding with increasing use of CT Pulmonary Angiography. Increasing diagnosis of PE may be due to detection of embolic debris from surgery due to greater vigilance rather than post-operative thromboembolism. Death from PE is rare following TKR.

Adverse peri-operative outcomes following elective total hip replacement in diabetes mellitus: A systematic review and meta-analysis of cohort studies

Total hip replacement (THR) has been shown to be a cost-effective procedure. However, it is not risk-free. Certain conditions, such as diabetes mellitus, are thought to increase the risk of complications. In this study we have evaluated the prevalence of diabetes mellitus in patients undergoing THR and the associated risk of adverse operative outcomes. A meta-analysis and systematic review were conducted according to the guidelines of the meta-analysis of observational studies in epidemiology. Inclusion criteria were observational studies reporting the prevalence of diabetes in the study population, accompanied by reports of at least one of the following outcomes: venous thromboembolic events; acute coronary events; infections of the urinary tract, lower respiratory tract or surgical site; or requirement for revision arthroplasty. Altman and Blands methods were used to calculate differences in relative risks. The prevalence of diabetes mellitus was found to be 5.0% among patients undergoing THR, and was associated with an increased risk of established surgical site infection (odds ratio (OR) 2.04 (95% confidence interval (CI) 1.52 to 2.76)), urinary infection (OR 1.43 (95% CI 1.33 to 1.55)) and lower respiratory tract infections (OR 1.95 (95% CI 1.61 to 2.26)). Diabetes mellitus is a relatively common comorbidity encountered in THR. Diabetic patients have a higher rate of developing both surgical site and non-surgical site infections following THR.

Lengthening the moment arm of the patella confers enhanced extensor mechanism power following total knee arthroplasty

We investigated whether a postulated biomechanical advantage conferred to the extensor mechanism by a change in knee implant design was detectable in patients by direct physical testing. 212 TKA patients were enrolled in a double blind randomized controlled trial to receive either a traditional implant or one which incorporated new design features. Extensor mechanism power output and physical performance on a battery of timed functional activities was assessed pre‐operatively and then at 6, 26, and 52 weeks post‐operatively. Significantly enhanced power output was observed in both groups post‐arthroplasty; however, the new design implant group demonstrated a greater change in power output than the traditional implant group. Posthoc testing of between group differences highlighted greater improvement at all post‐operative assessments. At 52 weeks, patients receiving the implant with the postulated biomechanical advantage achieved 116% of the power output of their contralateral limb, whereas patients with the traditional design achieved 90%. No between group difference was detected in the patients time to complete functional tasks. Thus, patients receiving a knee implant of a modern design (theoretically able to confer a mechanical advantage to the extensor mechanism) were found to generate significantly greater extensor power than those receiving a traditional implant without the postulated mechanical advantage.

Hip arthroscopy for femoroacetabular impingement: a health economic analysis.

There has been a significant increase in use of hip arthroscopy for femoroacetabular impingement over the last 10 years. However, some care providers in the United Kingdom are not commissioning such an intervention due to cost constraints and lack of published cost effectiveness studies. A cost analysis for a prospective cohort of 58 patients undergoing hip arthroscopy for femoroacetabular impingement was performed. The short form 12 six dimension health utility score (SF12-6D) was used. This was recorded preoperatively and one year after surgery. Three time points (one, two, and 10 years) from operation were used to calculate the quality-adjusted-life-years (QALYs) gained. Predicted need for conversion to total hip replacement and diminishing gain with time (5% per year) was incorporated into the two- and 10-year models. The Scottish Tariff was used to assign the cost of surgery. The number of QALYs gained one year after surgery was 0.159, which equated to a cost per QALY of £19,335. This cost decreased to £10,118 per QALY gained at two years, and further still to £2,677 per QALY gained at 10 years. Multivariable regression analysis found that a worse preoperative SF12-6D was an independent predictor of greater QALYs gained one year after surgery (R2 = 0.51, p<0.001). At no point in time, from one year onwards, does hip arthroscopy for femoroacetabular impingement cost more than £20,000 per QALY, making it a cost-effective intervention according to the National Institute for Health and Clinical Excellence.

Predicting the cost-effectiveness of total hip and knee replacement

The aim of this study was to perform a cost-utility analysis of total hip (THR) and knee replacement (TKR). Arthritis is a disabling condition that leads to long-term deterioration in quality of life. Total joint replacement, despite being one of the greatest advances in medicine of the modern era, has recently come under scrutiny. The National Health Service (NHS) has competing demands, and resource allocation is challenging in times of economic restraint. Patients who underwent THR (n = 348) or TKR (n = 323) between January and July 2010 in one Scottish region were entered into a prospective arthroplasty database. A health-utility score was derived from the EuroQol (EQ-5D) score pre-operatively and at one year, and was combined with individual life expectancy to derive the quality-adjusted life years (QALYs) gained. Two-way analysis of variance was used to compare QALYs gained between procedures, while controlling for baseline differences. The number of QALYs gained was higher after THR than after TKR (6.5 vs 4.0 years, p < 0.001). The cost per QALY for THR was £1372 compared with £2101 for TKR. The predictors of an increase in QALYs gained were poorer health before surgery (p < 0.001) and younger age (p < 0.001). General health (EQ-5D VAS) showed greater improvement after THR than after TKR (p < 0.001). This study provides up-to-date cost-effectiveness data for total joint replacement. THR and TKR are extremely effective both clinically and in terms of cost effectiveness, with costs that compare favourably to those of other medical interventions.