Revision knee arthroplasty is a complex procedure with the number and cost of knee revision procedures performed per year expected to rise. Few studies have examined adverse events following revision arthroplasty. The objective of this study was to determine rates of serious adverse events in patients undergoing revision knee arthroplasty with consideration of the indication for revision (urgent versus elective indications) and to compare these with primary arthroplasty and re-revision arthroplasty. Patients undergoing primary knee arthroplasty were identified in the UK Hospital Episode Statistics. Subsequent revision and re-revision arthroplasty procedures in the same patients and same knee were identified. The primary outcome was 90-day mortality and a logistic regression model was used to investigate factors associated with 90-day mortality and secondary adverse outcomes including infection (undergoing surgery), pulmonary embolism, myocardial infarction, stroke. Urgent indications for revision arthroplasty were defined as infection or fracture, and all other indications were included in the elective indications cohort. 939,021 primary knee arthroplasty cases were included of which 40,854 underwent subsequent revision arthroplasty, and 9,100 underwent re-revision arthroplasty. Revision surgery for elective indications was associated with a 90-day rate of mortality of 0.44% (135/30,826; 95% CI 0.37-0.52) which was comparable to primary knee arthroplasty (0.46%; 4,292/939,021; 95% CI 0.44-0.47). Revision arthroplasty for infection, however, was associated with a much higher mortality of 2.04% (184/9037; 95% CI 1.75-2.35; odds ratio [OR] 3.54; 95% CI 2.81-4.46), as was revision for periprosthetic fracture at 5.25% (52/991; 95% CI 3.94-6.82; OR 6.23; 95% CI 4.39-8.85). Higher rates of pulmonary embolism, myocardial infarction, and stroke were also observed in the infection and fracture cohort. These findings highlight the burden of complications associated with revision knee arthroplasty. They will inform shared decision-making for patients considering revision knee arthroplasty for elective indications. Patients presenting with infection of a knee arthroplasty or a periprosthetic fracture are at very high risk of adverse events. It is important that acute hospital services and tertiary referral centres caring for these patients are appropriately supported to ensure appropriate urgency and an anticipation for increased care requirements

Background. Frequency of primary total hip (THA) and total knee (TKA) arthroplasty procedures is increasing, with a subsequent rise in revision procedures. This study aims to describe timing and excess surgical mortality associated with revision THA and TKA compared to those on the waiting list. Methods. All patients from 2003–2013 in a single institution who underwent revision THA and TKA, or added to the waiting list for the same procedure were recorded. Mortality rates were calculated at cutoffs of 30- and 90-days post-operation or addition to the waiting list. Results. 561 and 547 patients were available for the survivorship analysis in the revision THA and TKA groups respectively. Following exclusion, 901 and 832 patients were available for the 30-day analysis and 484 and 568 patients for the 90-day analysis in the revision THA and revision TKA waiting list groups respectively. The 30- and 90-day mortality rate was significantly greater for the revision THA group compared to the waiting list group (excess surgical mortality of 0.357%, 95% confidence interval 0.098% to 0.866%; p=0.037) (odds ratio of 5.22, 95% confidence interval 0.626 to 43.524; excess surgical mortality of 0.863%, 95% confidence interval 0.455% to 1.153%; p=0.045). The 30- and 90-day mortality rate was not significantly greater for the revision TKA group compared to the waiting list group (excess surgical mortality of zero) (excess surgical mortality of 0.366%, 95% confidence interval 0.100% to 0.651%; p=0.075). Conclusions. Revision THA is associated with a significant excess surgical mortality rate at 30- and 90-days post operation when compared to the waiting list for the same procedure. However, we have been unable to quantify any increased risk after revision TKA. We would encourage other authors with access to larger samples to use our method to quantify excess mortality after revision TKA. Level of Evidence. III-Retrospective Cohort Study

Objectives. This study reports on a secondary exploratory analysis of the early clinical outcomes of a randomised clinical trial comparing robotic arm-assisted unicompartmental knee arthroplasty (UKA) for medial compartment osteoarthritis of the knee with manual UKA performed using traditional surgical jigs. This follows reporting of the primary outcomes of implant accuracy and gait analysis that showed significant advantages in the robotic arm-assisted group. Methods. A total of 139 patients were recruited from a single centre. Patients were randomised to receive either a manual UKA implanted with the aid of traditional surgical jigs, or a UKA implanted with the aid of a tactile guided robotic arm-assisted system. Outcome measures included the American Knee Society Score (AKSS), Oxford Knee Score (OKS), Forgotten Joint Score, Hospital Anxiety Depression Scale, University of California at Los Angeles (UCLA) activity scale, Short Form-12, Pain Catastrophising Scale, somatic disease (Primary Care Evaluation of Mental Disorders Score), Pain visual analogue scale, analgesic use, patient satisfaction, complications relating to surgery, 90-day pain diaries and the requirement for revision surgery. Results. From the first post-operative day through to week 8 post-operatively, the median pain scores for the robotic arm-assisted group were 55.4% lower than those observed in the manual surgery group (p = 0.040). At three months post-operatively, the robotic arm-assisted group had better AKSS (robotic median 164, interquartile range (IQR) 131 to 178, manual median 143, IQR 132 to 166), although no difference was noted with the OKS. At one year post-operatively, the observed differences with the AKSS had narrowed from a median of 21 points to a median of seven points (p = 0.106) (robotic median 171, IQR 153 to 179; manual median 164, IQR 144 to 182). No difference was observed with the OKS, and almost half of each group reached the ceiling limit of the score (OKS > 43). A greater proportion of patients receiving robotic arm-assisted surgery improved their UCLA activity score. Binary logistic regression modelling for dichotomised outcome scores predicted the key factors associated with achieving excellent outcome on the AKSS: a pre-operative activity level > 5 on the UCLA activity score and use of robotic-arm surgery. For the same regression modelling, factors associated with a poor outcome were manual surgery and pre-operative depression. Conclusion. Robotic arm-assisted surgery results in improved early pain scores and early function scores in some patient-reported outcomes measures, but no difference was observed at one year post-operatively. Although improved results favoured the robotic arm-assisted group in active patients (i.e. UCLA ⩾ 5), these do not withstand adjustment for multiple comparisons. Cite this article: M. J. G. Blyth, I. Anthony, P. Rowe, M. S. Banger, A. MacLean, B. Jones. Robotic arm-assisted versus conventional unicompartmental knee arthroplasty: Exploratory secondary analysis of a randomised controlled trial. Bone Joint Res 2017;6:631–639. DOI: 10.1302/2046-3758.611.BJR-2017-0060.R1

Introduction. Infections in total joint arthroplasty (TJA) are a burden to the healthcare system. An infection in total joint arthroplasty costs nearly $60,000–80,000 to the system. 3 major tenets to decrease surgical site infections, focus on patient preoperative optimization, intraoperative techniques, and postoperative care. Intraoperative vancomycin powder been successful in lowering infection rates in other areas of orthopaedics. The purpose of our study was to investigate whether topical intraoperative vancomycin powder had any effect on surgical site infection, complication rate, or reoperation rate. Our hypothesis was vancomycin powder may decrease the rate of surgical site infections without any effect on wound complications. Materials & Methods. 208 consecutive patients undergoing either total hip or total knee arthroplasty (THA or TKA) were given intraoperative vancomycin powder or none. 64 patients received vancomycin poweder compared to 164 patients who did not. All preoperative, intraoperative and postoperative management was similar. Preoperative data including age, sex, BMI, diabetes status and comorbidities were recorded. Surgical techniques included medial parapatellar or subvastus for TKA, posterolateral for THA. 90-day culture positive infection and reoperation rates were recorded. Results. Preoperative variables between the two groups were similar. Average age, ASA, BMI, diabetes status and other preoperative patient variables were not significantly different (p=0.31, 0.19, 0.65, 0.31). 5/64 patients (7.8%) in the vancomycin group underwent reoperation, compared with 13/164 (9.0%) in the no vancomycin group. There was no difference in the rate of reoperations (p=0.777). Of these patients, 3/64 (4.69%) patients in the vancomycin group had a positive infection compared with 8/164 (5.55%) in the no vancomycin group. There was no significant differences between the two infection rates (p=0.807). Discussion. Surprisingly, vancomycin powder did not have any effect on reoperation nor infection rates in our study group. Although other studies may have shown a decrease in infection, ours failed to do so. Due to low study numbers, we could not differentiate deep versus superficial surgical site infections. Based on our study, we are unable to recommend the use of intraoperative vancomycin powder for total joint arthroplasty

Objectives

We have increased the dose of tranexamic acid (TXA) in our enhanced total joint recovery protocol at our institution from 15 mg/kg to 30 mg/kg (maximum 2.5 g) as a single, intravenous (IV) dose. We report the clinical effect of this dosage change.