The August 2024 Knee Roundup. 360. looks at: Calcification’s role in knee osteoarthritis: implications for surgical decision-making; Lower complication rates and shorter lengths of hospital stay with technology-assisted total knee arthroplasty; Revision surgery: the hidden burden on surgeons; Are preoperative weight loss interventions worthwhile?; Total knee arthroplasty with or without prior bariatric surgery: a systematic review and meta-analysis; Aspirin triumphs in knee arthroplasty: a decade of evidence; Efficacy of DAIR in unicompartmental knee arthroplasty: a glimpse from Oxford

Aims. The aims of this study were to compare the efficacy of two agents, aspirin and warfarin, for the prevention of venous thromboembolism (VTE) after simultaneous bilateral total knee arthroplasty (SBTKA), and to elucidate the risk of VTE conferred by this procedure compared with unilateral TKA (UTKA). Patients and Methods. A retrospective, multi-institutional study was conducted on 18 951 patients, 3685 who underwent SBTKA and 15 266 who underwent UTKA, using aspirin or warfarin as VTE prophylaxis. Each patient was assigned an individualised baseline VTE risk score based on a system using the Nationwide Inpatient Sample. Symptomatic VTE, including pulmonary embolism (PE) and deep vein thrombosis (DVT), were identified in the first 90 days post-operatively. Statistical analyses were performed with logistic regression accounting for baseline VTE risk. Results. The adjusted incidence of PE following SBTKA was 1.0% (95% confidence interval (CI) 0.86 to 1.2) with aspirin and 2.2% (95% CI 2.0 to 2.4) with warfarin. Similarly, the adjusted incidence of VTE following SBTKA was 1.6% (95% CI 1.1 to 2.3) with aspirin and 2.5% (95% CI 1.9 to 3.3) with warfarin. The risk of PE and VTE were reduced by 66% (odds ratio (OR) 0.44, 95% CI 0.25 to 0.78) and 38% (OR 0.62, 95% CI 0.38 to 1.0), respectively, using aspirin. In addition, the risk of PE was 204% higher for patients undergoing SBTKA relative to those undergoing UTKA. For each ten-point increase in baseline VTE risk, the risk of PE increased by 25.5% for patients undergoing SBTKA compared with 10.5% for those undergoing UTKA. Patients with a history of myocardial infarction or peripheral vascular disease had the greatest increase in risk from undergoing SBTKA instead of UTKA. Conclusion. Aspirin is more effective than warfarin for the prevention of VTE following SBTKA, and serves as the more appropriate agent for VTE prophylaxis for patients in all risk categories. Furthermore, patients undergoing SBTKA are at a substantially increased risk of VTE, even more so for those with significant underlying risk factors. Patients should be informed about the risks associated with undergoing SBTKA. Cite this article: Bone Joint J 2018;100-B(1 Supple A):68–75

Aims. We studied the safety and efficacy of multimodal thromboprophylaxis in patients with a history of venous thromboembolism (VTE) who undergo total hip arthroplasty (THA) within the first 120 postoperative days, and the mortality during the first year. Multimodal prophylaxis includes discontinuation of procoagulant medications, VTE risk stratification, regional anaesthesia, an intravenous bolus of unfractionated heparin prior to femoral preparation, rapid mobilization, the use of pneumatic compression devices, and chemoprophylaxis tailored to the patient’s risk of VTE. Methods. Between 2004 to 2018, 257 patients with a proven history of VTE underwent 277 primary elective THA procedures by two surgeons at a single institution. The patients had a history of deep vein thrombosis (DVT) (186, 67%), pulmonary embolism (PE) (43, 15.5%), or both (48, 17.5%). Chemoprophylaxis included aspirin (38 patients), anticoagulation (215 patients), or a combination of aspirin and anticoagulation (24 patients). A total of 50 patients (18%) had a vena cava filter in situ at the time of surgery. Patients were followed for 120 days to record complications, and for one year to record mortality. Results. Postoperative VTE was diagnosed in seven patients (2.5%): DVT in five, and PE with and without DVT in one patient each. After hospitalization, three patients required readmiss-ion for evacuation of a haematoma, one for wound drainage, and one for monitoring of an elevated international normalized ratio (INR). Seven patients died (2.5%). One patient died five months postoperatively of a PE during open thrombectomy. She had discontinued anticoagulation. One patient died of a haemorrhagic stroke while receiving Coumadin. PE or bleeding was not suspected in the remaining five fatalities. Conclusion. Multimodal prophylaxis is safe and effective in patients with a history of VTE. Postoperative anticoagulation should be prudent as very few patients developed VTE (2.5%) or died of suspected or confirmed PE. Mortality during the first year was mostly unrelated to either VTE or bleeding. Cite this article: Bone Joint J 2020;102-B(7 Supple B):71–77

Aims. The place of thromboprophylaxis in arthroplasty surgery remains controversial, with a challenging requirement to balance prevention of potentially fatal venous thrombo-embolism with minimising wound-related complications leading to deep infection. We compared the incidence of fatal pulmonary embolism in patients undergoing elective primary total hip arthroplasty (THA) between those receiving aspirin, warfarin and low molecular weight heparin (LMWH) for the chemical component of a multi-modal thromboprophylaxis regime. Patients and Methods. A prospective audit database was used to identify patients who had died within 42 and 90 days of surgery respectively between April 2000 and December 2012. A case note review was performed to ascertain the causes of death. Results. During this period 7983 THAs were performed. The rate of mortality was 0.43% and 0.58% at 42 and 90 days respectively. The groups comprised 1571 patients (19.7%) on warfarin, 1838 (23.0%) on LMWH and 4574 (57.3%) on aspirin. The 90-day mortality for these three groups was 0.38%, 1.09% and 0.43% respectively. The higher mortality rate for LMWH was significant (p < 0.05). There were six fatal pulmonary emboli (PEs) (0.08%). A total of three occurred within 42 days, all in the LMWH group. A total of three occurred between 42 and 90 days; one on warfarin, two on LMWH. The leading causes of death in all three groups were lower respiratory tract infections and myocardial infarction. Conclusion. We confirmed that fatal PE following elective THA with a multi-modal prophylaxis regime is rare. We further found that LMWH conferred no benefit over aspirin in this context, and is associated with a higher all-cause rate of mortality. Take home message: This study proposes that aspirin may be an appropriate thromboprophylaxis agent when used as part of a multi-modal regimen, suggesting current guidelines should be reviewed. Cite this article: Bone Joint J 2016;98-B:585–8

Thromboprophylaxis after elective orthopaedic surgery remains controversial. Recent guidelines from the National Institute for Clinical Excellence (NICE) have suggested that low molecular weight heparin should be given to all patients undergoing total hip replacement. The British Orthopaedic Association is currently debating this guideline with NICE, as it is not clear whether published evidence supports this view. We present the early mortality in our unit after total hip replacement using aspirin as chemical thromboprophylaxis. The 30-day and 90-day mortality after primary total hip arthroplasty was zero. We compare this with that reported previously from our unit without using chemical thromboprophylaxis. With the introduction of routine aspirin thromboprophylaxis, deaths from cardiovascular causes have dropped from 0.75% to zero. These results demonstrate that there is a strong argument for the routine administration of aspirin after elective total hip replacement

We studied 4253 patients undergoing primary joint replacement between November 2002 and November 2007, of whom 4060 received aspirin only as chemical prophylaxis; 46 were mistakenly given low molecular weight heparin initially, which was stopped and changed to aspirin; 136 received no chemoprophylaxis and 11 patients received warfarin because of a previous history of pulmonary embolism. We identified the rate of clinical thromboembolism before and after discharge, and the mortality from pulmonary embolism at 90 days. The overall death rate was 0.31% (13 of 4253) and the rate of fatal pulmonary embolism was 0.07% (3 of 4253). Our data suggest that fatal pulmonary embolism is not common following elective primary joint replacement, and with modern surgical practice elective hip and knee replacement should no longer be considered high-risk procedures

We performed a meta-analysis of the English literature to assess the efficacy of four common regimes for thromboembolic prophylaxis after total knee arthroplasty: aspirin, warfarin, low-molecular-weight heparin (LMWH) and pneumatic compression. We reviewed 136 articles and abstracts published between January 1980 and December 1997. Papers not using routine venography and a lung scan or angiography to detect deep-venous thrombosis (DVT) and pulmonary emboli (PE) respectively, were excluded. Of the 136 studies, 23 with 6001 patients were selected. The incidence of DVT was 53% (1701/3214) in the aspirin group, 45% (541/1203) in the warfarin group, 29% (311/1075) in the LMWH group, and 17% (86/509) in the pneumatic compression device group. Intermittent pneumatic compression devices and LMWH were significantly better than warfarin (p < 0.0001) or aspirin (p < 0.0001) in preventing DVT. The incidence of asymptomatic PE was 11.7% in the aspirin group (222/1901), 8.2% (101/1229) in the warfarin group and 6.3% (24/378) in the pneumatic compression group. No studies with LMWH used routine lung scans. Warfarin and pneumatic compression were significantly better than aspirin in preventing asymptomatic PE (p < 0.05). The incidence of symptomatic PE was 1.3% (23/1800) in the aspirin group, 0.4% (2/559) in the warfarin group, 0.5% (2/416) in the LMWH group and 0% (0/177) in the pneumatic compression group. No statistically significant difference was noted between the above prophylatic regimes due to the very small incidence of symptomatic PE. Prophylaxis for thromboembolic disease in TKA may have to include a combination of some of the above regimes to incorporate their advantages

Aims. We studied the impact of direct anterior (DA) versus non-anterior (NA) surgical approaches on prosthetic joint infection (PJI), and examined the impact of new perioperative protocols on PJI rates following all surgical approaches at a single institution. Patients and Methods. A total of 6086 consecutive patients undergoing primary total hip arthroplasty (THA) at a single institution between 2013 and 2016 were retrospectively evaluated. Data obtained from electronic patient medical records included age, sex, body mass index (BMI), medical comorbidities, surgical approach, and presence of deep PJI. There were 3053 male patients (50.1%) and 3033 female patients (49.9%). The mean age and BMI of the entire cohort was 62.7 years (18 to 102, . sd. 12.3) and 28.8 kg/m. 2. (13.3 to 57.6, . sd. 6.1), respectively. Infection rates were calculated yearly for the DA and NA approach groups. Covariates were assessed and used in multivariate analysis to calculate adjusted odds ratios (ORs) for risk of development of PJI with DA compared with NA approaches. In order to determine the effect of adopting a set of infection prevention protocols on PJI, we calculated ORs for PJI comparing patients undergoing THA for two distinct time periods: 2013 to 2014 and 2015 to 2016. These periods corresponded to before and after we implemented a set of perioperative infection protocols. Results. There were 1985 patients in the DA group and 4101 patients in the NA group. The overall rate of PJI at our institution during the study period was 0.82% (50/6086) and decreased from 0.96% (12/1245) in 2013 to 0.53% (10/1870) in 2016. There were 24 deep PJIs in the DA group (1.22%) and 26 deep PJIs in the NA group (0.63%; p = 0.023). After multivariate analysis, the DA approach was 2.2 times more likely to result in PJI than the NA approach (OR 2.2 (95% confidence interval 1.1 to 3.9); p = 0.006) for the overall study period. Conclusion. We found a higher rate of PJI in DA versus NA approaches. Infection prevention protocols such as use of aspirin, dilute povidone-iodine lavage, vancomycin powder, and Gram-negative coverage may have been positively associated with diminished PJI rates observed for all approaches over time. Cite this article: Bone Joint J 2019;101-B(6 Supple B):2–8

Aims. The purpose of this article was to review the current literature pertaining to the use of mobile compression devices (MCDs) for venous thromboembolism (VTE) following total joint arthroplasty (TJA), and to discuss the results of data from our institution. Patients and Methods. Previous studies have illustrated higher rates of post-operative wound complications, re-operation and re-admission with the use of more aggressive anticoagulation regimens, such as warfarin and factor Xa inhibitors. This highlights the importance of the safety, as well as efficacy, of the chemoprophylactic regimen. Results. Studies have shown a symptomatic VTE rate of 0.92% with use of MCDs for prophylaxis, which is comparable with rates seen with more aggressive anticoagulation protocols. A prior prospective study found that use of a pre-operative risk stratification protocol based on personal history of deep vein thrombosis, family history of VTE, active cancer, or a hypercoaguable state allowed for the avoidance of aggressive prophylactic anticoagulation in over 70% of patients while maintaining a low incidence of symptomatic VTE. Conclusion. Further investigation is needed into the role of aspirin in VTE prophylaxis as well as the efficacy of MCDs as stand-alone prophylactic treatment. Cite this article: Bone Joint J 2017;99-B(1 Supple A):8–13

The August 2014 Research Roundup. 360 . looks at: Antibiotic loaded ceramic of use in osteomyelitis; fibronectin implicated in cartilage degeneration; Zinc Chloride accelerates fracture healing in rats; advertisements and false claims; Net Promoter Score: substance or rhetoric?; aspirin for venous thromboembolism prophylaxis and dissection, stress and the soul

Since the introduction of the National Institute for Health and Care Excellence (NICE) guidelines on thromboprophylaxis and the use of extended thromboprophylaxis with new oral agents, there have been reports of complications arising as a result of their use. We have looked at the incidence of wound complications after the introduction of dabigatran for thromboprophylaxis in our unit. We investigated the rate of venous thromboembolism and wound leakage in 1728 patients undergoing primary joint replacement, both before and after the introduction of dabigatran, and following its subsequent withdrawal from our unit. We found that the use of dabigatran led to a significant increase in post-operative wound leakage (20% with dabigatran, 5% with a multimodal regimen; p < 0.001), which also resulted in an increased duration of hospital stay. The rate of thromboembolism in patients receiving dabigatran was higher (1.3%) than in those receiving the multimodal thromboprophylaxis regimen, including low molecular weight heparin as an inpatient and the extended use of aspirin (0.3%, p = 0.047). We have ceased the use of dabigatran for thromboprophylaxis in these patients. Cite this article: Bone Joint J 2014;96-B:122–6

The October 2013 Hip & Pelvis Roundup. 360 . looks at: Young and impinging; Clothes, weather and femoral heads?; Go long, go cemented; Surgical repair of the abductors?; Aspirin for DVT prophylaxis?; Ceramic-on-polyethylene: a low-wear solution?; ALVAL and ASR™: the story continues….; Salvaging Legg-Calve-Perthes’ disease

Antiplatelet agents are widely prescribed for the primary and secondary prevention of cardiovascular events. A common clinical problem facing orthopaedic and trauma surgeons is how to manage patients receiving these agents who require surgery, either electively or following trauma. The dilemma is to balance the risk of increased blood loss if the antiplatelet agents are continued peri-operatively against the risk of coronary artery/stent thrombosis and/or other vascular event if the drugs are stopped. The traditional approach of stopping these medications up to two weeks before surgery appears to pose significant danger to patients and may require review. This paper covers the important aspects regarding the two most commonly prescribed antiplatelet agents, aspirin and clopidogrel

We report an audit of 208 patients with a mean age of 39 years (16 to 65) attending the Orthopaedic Assessment Unit at the Wellington Hospital between January 2006 and December 2007 with an injury of the tendo Achillis requiring immobilisation in a cast. Information on assessment of venous thromboembolism (VTE) risk, prophylactic measures and VTE events for all patients was obtained from the medical records. A VTE risk factor was documented in the records of three (1%) patients. One of the 208 patients received aspirin prophylaxis; none received low molecular weight heparin. In all, 13 patients (6.3%, 95% confidence interval 3.4 to 10.5) developed symptomatic VTE during immobilisation in a cast, including six with a distal deep-vein thrombosis (DVT), four with a proximal DVT, and three with a confirmed pulmonary embolus. This incidence of symptomatic VTE is similar to that reported following elective hip replacement. We propose that consideration is given to VTE prophylaxis during prolonged immobilisation of the lower limbs in a cast, to ensure that the same level of protection is provided as for patients undergoing elective hip replacement

We performed a meta-analysis of modern total joint replacement (TJR) to determine the post-operative mortality and the cause of death using different thromboprophylactic regimens as follows: 1) no routine chemothromboprophylaxis (NRC); 2) Potent anticoagulation (PA) (unfractionated or low-molecular-weight heparin, ximelagatran, fondaparinux or rivaroxaban); 3) Potent anticoagulation combined (PAC) with regional anaesthesia and/or pneumatic compression devices (PCDs); 4) Warfarin (W); 5) Warfarin combined (WAC) with regional anaesthesia and/or PCD; and 6) Multimodal (MM) prophylaxis, including regional anaesthesia, PCDs and aspirin in low-risk patients. Cause of death was classified as autopsy proven, clinically certain or unknown. Deaths were grouped into cardiopulmonary excluding pulmonary embolism (PE), PE, bleeding-related, gastrointestinal, central nervous system, and others (miscellaneous). Meta-analysis based on fixed effects or random effects models was used for pooling incidence data. In all, 70 studies were included (99 441 patients; 373 deaths). The mortality was lowest in the MM (0.2%) and WC (0.2%) groups. The most frequent cause of death was cardiopulmonary (47.9%), followed by PE (25.4%) and bleeding (8.9%). The proportion of deaths due to PE was not significantly affected by the thromboprophylaxis regimen (PA, 35.5%; PAC, 28%; MM, 23.2%; and NRC, 16.3%). Fatal bleeding was higher in groups relying on the use of anticoagulation (W, 33.8%; PA, 9.4%; PAC, 10.8%) but the differences were not statistically significant. Our study demonstrated that the routine use of PA does not reduce the overall mortality or the proportion of deaths due to PE

Our aim was to determine the total blood loss associated with surgery for fracture of the hip and to identify risk factors for increased blood loss. We prospectively studied 546 patients with hip fracture. The total blood loss was calculated on the basis of the haemoglobin difference, the number of transfusions and the estimated blood volume. The hidden blood loss, in excess of that observed during surgery, varied from 547 ml (screws/ pins) to 1473 ml (intramedullary hip nail and screw) and was significantly associated with medical complications and increased hospital stay. The type of surgery, treatment with aspirin, intra-operative hypotension and gastro-intestinal bleeding or ulceration were all independent predictors of blood loss. We conclude that total blood loss after surgery for hip fracture is much greater than that observed intra-operatively. Frequent post-operative measurements of haemoglobin are necessary to avoid anaemia

We report a retrospective review of the incidence of venous thromboembolism in 463 consecutive patients who underwent primary total hip arthroplasty (487 procedures). Treatment included both total hip replacement and hip resurfacing, and the patients were managed without anticoagulants. The thromboprophylaxis regimen included an antiplatelet agent, generally aspirin, hypotensive epidural anaesthesia, elastic compression stockings and early mobilisation. In 258 of these procedures (244 patients) performed in 2005 (cohort A) mechanical compression devices were not used, whereas in 229 (219 patients) performed during 2006 (cohort B) bilateral intermittent pneumatic calf compression was used. All operations were performed through a posterior mini-incision approach. Patients who required anticoagulation for pre-existing medical problems and those undergoing revision arthroplasty were excluded. Doppler ultrasonographic screening for deep-vein thrombosis was performed in all patients between the fourth and sixth post-operative days. All patients were reviewed at a follow-up clinic six to ten weeks after the operation. In addition, reponse to a questionnaire was obtained at the end of 12 weeks post-operatively. No symptomatic calf or above-knee deep-vein thrombosis or pulmonary embolism occurred. In 25 patients in cohort A (10.2%) and in ten patients in cohort B (4.6%) asymptomatic calf deep-vein thromboses were detected ultrasonographically. This difference was statistically significant (p = 0.03). The regimen followed by cohort B offers the prospect of a low incidence of venous thromboembolism without subjecting patients to the higher risk of bleeding associated with anticoagulant use

The August 2024 Research Roundup³⁶⁰ looks at: Effect of vitamin D deficiency on periprosthetic joint infection and complications after primary total joint replacement; Postoperative angiotensin receptor blocker use associated with decreased rates of manipulation under anaesthesia in patients undergoing total knee arthroplasty; Central sensitization: the missing link between psychological distress and poor outcome following primary total knee arthroplasty; Thromboprophylaxis for the trauma and orthopaedic surgeon; Life expectancy after treatment of metastatic bone disease: an international trend analysis.