Mark Loeffler

Return to theatre for elective hip and knee replacements: what is the relative importance of patient factors, surgeon and hospital?

The aim of this study was to define return to theatre (RTT) rates for elective hip and knee replacement (HR and KR), to describe the predictors and to show the variations in risk-adjusted rates by surgical team and hospital using national English hospital administrative data. We examined information on 260 206 HRs and 315 249 KRs undertaken between April 2007 and March 2012. The 90-day RTT rates were 2.1% for HR and 1.8% for KR. Male gender, obesity, diabetes and several other comorbidities were associated with higher odds for both index procedures. For HR, hip resurfacing had half the odds of cement fixation (OR = 0.58, 95% confidence intervals (CI) 0.47 to 0.71). For KR, unicondylar KR had half the odds of total replacement (OR = 0.49, 95% CI 0.42 to 0.56), and younger ages had higher odds (OR = 2.23, 95% CI 1.65 to 3.01) for ages < 40 years compared with ages 60 to 69 years). There were more funnel plot outliers at three standard deviations than would be expected if variation occurred on a random basis. Hierarchical modelling showed that three-quarters of the variation between surgeons for HR and over half the variation between surgeons for KR are not explained by the hospital they operated at or by available patient factors. We conclude that 90-day RTT rate may be a useful quality indicator for orthopaedics.

Mortality and morbidity following hip fractures related to hospital thromboprophylaxis policy.

Chemical thromboprophylaxis has been shown to reduce the incidence of venous thromboembolism (VTE) for patients with fractures of the hip, but it is not known with certainty whether it use also reduces mortality. Using postal and telephone questionnaires we collected data from English National Health Service (NHS) hospitals about their thromboprophylaxis policy for hip fractures patients from April 2003 to April 2007. Using Hospital Episode Statistics (HES) we ascertained in-hospital mortality rates at 30 days and at one year following admission to hospital. Unplanned hospital readmission rates for all causes (including episodes of thromboembolism and bleeding) within 30 days (all years) and one year (2003 to 2005) were also established. A total of 150 hospitals were contacted and data gathered from 62 hospitals (response rate 41.3%) There were 255841 patients with neck of femur fractures during this five year period who were assessed for morbidity and mortality, and we correlat these with thromboprophylaxis policy. There was no significant difference in hospital readmission within 30 days, or diagnosis of thromboembolism or haemorrhage among hospitals with different thromboprophylaxis policies. The hospitals using low molecular weight heparin (LMWH) in half the dose recommended by the British National Formulary had significantly reduced mortality in-hospital (odds ratio (OR) 0.79, 95% CI 0.69–0.90, P=0.0006), at 30 days (OR 0.8 (0.70 – 0.92), P=0.001) and at one year (OR 0.89 (0.80 – 1.00), P=0.050), compared with those with no such policy. Our data suggest that the thromboprophylaxis regimen for patients with fracture neck of femur should be half dose LMWH for the duration of the hospital stay.

Does laminar flow ventilation reduce the rate of infection?: an observational study of trauma in England

AIMS To determine whether there is any difference in infection rate at 90 days between trauma operations performed in laminar flow and plenum ventilation, and whether infection risk is altered following the installation of laminar flow (LF). PATIENTS AND METHODS We assessed the impact of plenum ventilation (PV) and LF on the rate of infection for patients undergoing orthopaedic trauma operations. All NHS hospitals in England with a trauma theatre(s) were contacted to identify the ventilation system which was used between April 2008 and March 2013 in the following categories: always LF, never LF, installed LF during study period (subdivided: before, during and after installation) and unknown. For each operation, age, gender, comorbidity, socio-economic deprivation, number of previous trauma operations and surgical site infection within 90 days (SSI90) were extracted from Englands national hospital administrative Hospital Episode Statistics database. Crude and adjusted odds ratios (OR) were used to compare ventilation groups using hierarchical logistic regression. Subanalysis was performed for hip hemiarthroplasties. RESULTS A total of 803 065 trauma operations were performed during this time; 19 hospitals installed LF, 124 already had LF, 13 had PV and the type of ventilation was unknown in 28. Patient characteristics were similar between the groups. The rate of SSI90 was similar for always LF and PV (2.7% and 2.4%). For hemiarthroplasties of the hip, the rates of SSI90 were significantly higher for LF compared with PV (3.8% and 2.6%, OR 1.45, p = 0·001). Hospitals installing LF did not see any statistically significant change in the rate of SSI90. CONCLUSION The results of this observational study imply that infection rate is similar when orthopaedic trauma surgery is performed in LF and PV, and is unchanged by installing LF in a previously PV theatre. Cite this article: Bone Joint J 2016;98-B:1262-9.

Patient-specific instrumentation versus conventional instrumentation in total knee arthroplasty

Purpose To compare patient-specific instrumentation (PSI) with conventional instrumentation in total knee arthroplasty (TKA) in terms of component alignment, operating time, and the learning curve required in a non-teaching hospital. Methods Records of 33 men and 29 women aged 50 to 88 (mean, 71) years who underwent TKA for osteoarthritis using PSI (n=31) or conventional instrumentation (n=31) by a single surgeon were reviewed. The choice of instrumentation was made by the patient; the surgeon did not express any preference and had not used PSI before. All patients used the same cemented, cruciate-retaining system. Results The PSI and conventional instrumentation groups were comparable in terms of age, body mass index (BMI), American Society of Anesthesiologists grade, pre- and post-operative haemoglobin level, and the need for blood transfusion. Compared with conventional instrumentation, PSI resulted in a smaller coronal femoral component angle (7.7° vs. 6.4°, p=0.003) and posterior tibial slope angle (6.4° vs. 3.2°, p=0.0001), and smaller variance of the respective angles (p=0.006 and p=0.003). In patients with a BMI ≥30, PSI still resulted in a smaller posterior tibial slope angle (5.8° vs. 3.1°, p=0.015) and variance of the angle (p=0.02). The mean tourniquet time was shorter in the PSI group in all patients (p=0.013) and in patients with BMI ≥30 kg/m2 (p=0.0008), and its variance was also smaller in the PSI group (p=0.0004). There was no learning curve required. Conclusion PSI was simple to use, with no learning curve required. It can be used in non-teaching hospitals and in patients with a high BMI and in cases where the use of an intramedullary alignment guide would be problematic due to previous femoral trauma.

Factors Associated With 30-Day Readmission After Primary Total Hip Arthroplasty: Analysis of 514 455 Procedures in the UK National Health Service

Importance Thirty-day readmission to hospital after total hip arthroplasty (THA) has significant direct costs and is used as a marker of hospital performance. All-cause readmission is the only metric in current use, and risk factors for surgical readmission and those resulting in return to theater (RTT) are poorly understood. Objective To determine whether patient-related predictors of all-cause, surgical, and RTT readmission after THA differ and which predictors are most significant. Design, Setting, and Participants Analysis of all primary THAs recorded in the National Health Service (NHS) Hospital Episode Statistics database from 2006 to 2015. The effect of patient-related factors on 30-day readmission risk was evaluated by multilevel logistic regression analysis. The analysis comprised all acute NHS hospitals in England and all patients receiving primary THA. Main Outcomes and Measures Thirty-day readmission rate for all-cause, surgical (defined using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision primary admission diagnoses), and readmissions resulting in RTT. Results Across all hospitals, 514 455 procedures were recorded. Seventy-nine percent of patients were older than 60 years, 40.3% were men, and 59.7% were women. There were 30 489 all-cause readmissions (5.9%), 16 499 surgical readmissions (3.2%), and 4286 RTT readmissions (0.8%); 54.1% of readmissions were for surgical causes. Comorbidities with the highest odds ratios (ORs) of RTT included those likely to affect patient behavior: drug abuse (OR, 2.22; 95% CI, 1.34-3.67; P = .002), psychoses (OR, 1.83; 95% CI, 1.16-2.87; P = .009), dementia (OR, 1.57; 95% CI, 1.11-2.22; P = .01), and depression (OR, 1.52; 95% CI, 1.31-1.76; P < .001). Obesity had a strong independent association with RTT (OR, 1.46; 95% CI, 4.45-6.43; P < .001), with one of the highest population attributable fractions of the comorbidities (3.4%). Return to theater in the index episode was associated with a significantly increased risk of RTT readmission (OR, 5.35; 95% CI, 4.45-6.43; P < .001). Emergency readmission to the hospital in the preceding 12 months increased the risk of readmission significantly, with the association being most pronounced for all-cause readmission (for >2 emergency readmissions, OR, 2.33; 95% CI, 2.11-2.57; P < .001). Hip resurfacing was associated with a lower risk of RTT when compared with cemented implants (OR, 0.69; 95% CI, 0.54-0.88; P = .002) but for other types of readmission, implant type had no significant association with readmission risk. Increasing age and length of stay were strongly associated with all-cause readmission. Conclusions and Relevance Many patient-related risk factors for surgical and RTT readmission differ from those for all-cause readmission despite the latter being the only measure in widespread use. Clinicians and policy makers should consider these alternative readmission metrics in strategies for risk reduction and cost savings.

Comparison of 3 Types of Readmission Rates for Measuring Hospital and Surgeon Performance After Primary Total Hip and Knee Arthroplasty

BACKGROUND All-cause 30-day hospital readmission is in widespread use for monitoring and incentivizing hospital performance for patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA). However, little is known on the extent to which all-cause readmission is influenced by hospital or surgeon performance and whether alternative measures may be more valid. METHODS This is an observational study using multilevel modeling on English administrative data to determine the interhospital and intersurgeon variation for 3 readmission metrics: all-cause, surgical, and return-to-theater. Power calculations estimated the likelihood of identifying whether the readmission rate for a surgeon or hospital differed from the national average by a factor of 1.25, 1.5, 2, or 3 times, for both average and high-volume providers. RESULTS 259,980 THAs and 311,033 TKAs were analyzed. Variations by both surgeons and hospitals were smaller for the all-cause measure than for the surgical or return-to-theater metrics, although statistical power to detect differences was higher. Statistical power to detect surgeon-level rates of 1.25 or 1.5 times the average was consistently low. However, at the hospital level, the surgical readmission measure showed more variation by hospital while maintaining excellent power to detect differences in rates between hospitals performing the average number of THA or TKA cases per year in England. In practice, more outliers than expected from purely random variation were found for all-cause and surgical readmissions, especially at hospital level. CONCLUSION The 30-day surgical readmission rate should be considered as an adjunctive measure to 30-day all-cause readmission rate when assessing hospital performance.

Patient Satisfaction: Receiving a copy of the GP letter following fracture or elective orthopaedic clinic

Abstract Following orthopaedic/fracture clinics at our hospital, patients now receive a copy of the letter summarizing an outpatient consultation that is sent to their General Practitioner. We undertook a patient satisfaction questionnaire to determine if patients found this change in practice beneficial. Of the 83 patients who had received this letter, most patients had read the letter (96%) and understood the content (90%). 13% were worried after having read the content and 86% found it helpful. Of the 40 patients who did not receive a copy, 32 (80%) specified that they would wish to in the future. The results support the new practice although it could be improved by identifying those who do not wish to be included thereby reducing costs.

Does early return to theatre add value to rates of revision at 3 years in assessing surgeon performance for elective hip and knee arthroplasty? National observational study

Background Joint replacement revision is the most widely used long-term outcome measure in elective hip and knee surgery. Return to theatre (RTT) has been proposed as an additional outcome measure, but how it compares with revision in its statistical performance is unknown. Methods National hospital administrative data for England were used to compare RTT at 90 days (RTT90) with revision rates within 3 years by surgeon. Standard power calculations were run for different scenarios. Funnel plots were used to count the number of surgeons with unusually high or low rates. Results From 2006 to 2011, there were 297 650 hip replacements (HRs) among 2952 surgeons and 341 226 knee replacements (KRs) among 2343 surgeons. RTT90 rates were 2.1% for HR and 1.5% for KR; 3-year revision rates were 2.1% for HR and 2.2% for KR. Statistical power to detect surgeons with poor performance on either metric was particularly low for surgeons performing 50 cases per year for the 5 years. The correlation between the risk-adjusted surgeon-level rates for the two outcomes was +0.51 for HR and +0.20 for KR, both p<0.001. There was little agreement between the measures regarding which surgeons had significantly high or low rates. Conclusion RTT90 appears to provide useful and complementary information on surgeon performance and should be considered alongside revision rates, but low case loads considerably reduce the power to detect unusual performance on either metric.