Objectives. Venous thromboembolism (VTE) is a major potential complication following orthopaedic surgery. Subcutaneously administered enoxaparin has been used as the benchmark to reduce the incidence of VTE. However, concerns have been raised regarding the long-term administration of enoxaparin and its possible negative effects on bone healing and bone density with an increase of the risk of osteoporotic fractures. New oral anticoagulants such as rivaroxaban have recently been introduced, however, there is a lack of information regarding how these drugs affect bone metabolism and post-operative bone healing. Methods. We measured the migration and proliferation capacity of mesenchymal stem cells (MSCs) under enoxaparin or rivaroxaban treatment for three consecutive weeks, and evaluated effects on MSC mRNA expression of markers for stress and osteogenic differentiation. Results. We demonstrate that enoxaparin, but not rivaroxaban, increases the migration potential of MSCs and increases their cell count in line with elevated mRNA expression of C-X-C chemokine receptor type 4 (CXCR4), tumor necrosis factor alpha (TNFα), and alpha-B-crystallin (CryaB). However, a decrease in early osteogenic markers (insulin-like growth factors 1 and 2 (IGF1, IGF2), bone morphogenetic protein2 (BMP2)) indicated inhibitory effects on MSC differentiation into osteoblasts caused by enoxaparin, but not by rivaroxaban. Conclusions. Our findings may explain the adverse effects of enoxaparin treatment on bone healing. Rivaroxaban has no significant impact on MSC metabolism or capacity for osteogenic differentiation in vitro. Cite this article: Dr H. Pilge. Enoxaparin and rivaroxaban have different effects on human mesenchymal stromal cells in the early stages of bone healing. Bone Joint Res 2016;5:95–100. DOI: 10.1302/2046-3758.53.2000595

Since the establishment of our department a multi-modal approach to thromboprophylaxis that uses aspirin for chemical prophylaxis was adopted. In accordance with the latest national recommendations, our routine chemical prophylaxis following arthroplasty was changed to rivaroxaban in 2012 and then dalteparin in 2013. This study aimed to compare venous thromboembolism (VTE) rates during the use of the aspirin-based protocol used from 2004 to 2011 with recent, rivaroxaban and dalteparin-based guidelines. Outcome data from ISD Scotland was retrieved and radiology reports performed for CT pulmonary angiograms and lower limb doppler ultrasound scans in our institution were assessed to identify cases of VTE following primary hip or knee arthroplasty. The incidence of pulmonary embolism (PE) and proximal deep venous thrombosis (DVT) was calculated for each year and compared using a Chi-squared test. Additionally, the change in extended thromboprophylaxis regimen was surveyed by recording the discharge prescriptions for consecutive arthroplasty patients for March every year. There were 90 radiologically confirmed cases of DVT or PE between 2004 and 2011 (incidence of 0.71%). The DVT/PE rate was subsequently 0.67% in 2012 and 0.69% in 2013, with a further 29 cases identified. This does not represent a significant change in the venous thromboembolism rates and remains below the national incidence of VTE (1.06%). Aspirin alone was used as chemical thromboprophylaxis in 80.8% of patients from 2004 to 2011, 50.9% in 2012, and 12.1% in 2013. The incidence of VTE at our centre remains favourable to national figures, but the modification of thromboprophylaxis guidelines will incur additional financial costs and has not had a significant reduction on the rate of VTE

Introduction. Guidelines from the North American Spine Society (2009 and 2013) are the best evidence-based instructions on venous thromboembolism (VTE) and antibiotic prophylaxis in spinal surgery. NICE guidelines exist for VTE prophylaxis but do not specifically address spinal surgery. In addition, the ruling of the UK Supreme Court in 2015 resulted in new guidance on consent being published by the Royal College of Surgeons of England (RCSEng). This study assesses our compliance in antibiotic, VTE prophylaxis and consent in spinal surgery against both US and UK standards. Methods. Retrospective review of spinal operations performed between August and December 2016. Case notes, consent forms and operation notes were analysed for consent, peri-operative antibiotic prescribing and post-operative VTE instructions. Results. Four Spinal surgeons performed 45 operations during this period. 31 patients (69%) received a copy of the signed consent with this process being formally documented in 22 (71%) of those cases. All patients were consented by a competent surgeon. 82% of cases consented prior to the date of procedure were countersigned on the day of operation. There was a mean time of 25.3 days between initial consent and operation (Range: 0–170). 37 (82%) cases had clear instructions for VTE and antibiotic prophylaxis. All prescribed post-operative antibiotics were administered. Discussion. The North American Guidelines state that prophylactic antibiotic is appropriate in all spinal surgery with prolonged cases requiring intraoperative re-dosing and only complex cases needing a postoperative regimen. Eight patients underwent a complex procedure and 7 appropriately received postoperative antibiotics. Of the 29 patients that underwent a simple procedure, 12 did not receive post-operative regimen, in line with the guidelines. However, the remainder 17 were over treated. The US Guidelines recommend mechanical VTE prophylaxis only in elective spinal surgery except in high risk patients. All our patients received VTE mechanical prophylaxis. RCSEng guidelines require consent being taken prior to procedure by a competent surgeon and confirmed on day of procedure. All patients in our cohort were consented prior to the date of operation allowing time for considering options and independent research. 82% of patients had consent confirmed on day of operation. Conclusion. This study demonstrates that we met guideline advice for all patients with regards VTE prophylaxis. We have a tendency to over treat with post-operative antibiotics and not all patients had their consent confirmed on day of procedure but was consented well before day of operation. North America still lead the way with guidelines on spinal surgery to which we should adhere, with NICE guidelines providing limited instructions. New consenting guidelines from RCSEng may not be currently widely known and thus should be a source of education for all surgeons

Newer irreversible oral anticoagulants such as rivaroxaban, a direct factor 10a inhibitor, are increasingly employed to prevent thromboembolic events in atrial fibrillation (AF) patients, and to manage venous thromboembolism (VTE). Unlike warfarin, these agents require no monitoring and involve infrequent dose adjustment. We report the case of a patient treated with rivaroxaban for AF. Patient presented with unprovoked sudden onset right shoulder pain which clinically resembled shoulder haemarthrosis. A single case was anonymised and retrospectively reviewed through examination of clinical and radiographic data. A 70 year old female with known AF presented to Accident and Emergency with sudden onset of right shoulder pain and limited movement, which developed over one hour. The pain was constant, localised to the shoulder and without trauma. Past medical history included severe aortic regurgitation and associated thoracic aortic aneurysm, heart failure, atrial fibrillation and hypertension. Observations were normal upon admission with no haemodynamic compromise or pyrexia. Examining the right shoulder demonstrated distension of shoulder joint capsule, tenderness and a reduced range of movement. Temperature and neurovascular status in the right arm were normal. Investigations upon admission included an INR of 1.2. An anteroposterior right shoulder radiograph showed no evidence of fracture. Patient was managed conservatively with simple oral analgesia. Importantly, rivaroxaban was withheld for 5 days and symptoms resolved. Warfarin therapy was subsequently commenced instead as treatment for AF. Patient was discharged one week later and seen in clinic two weeks post-discharge. A full recovery occurred and with a full range of movement in the right shoulder. In the UK, current National Institute for Health and Care Excellence (NICE) guidelines recommend the use of factor 10a inhibitors, for prevention of stroke in AF patients, and following elective total hip and knee replacement operations to prevent VTE. In turn, rivaroxaban is increasingly prescribed as first line therapy. Whereas warfarin has a documented association with haemarthrosis, there is no primary literature evaluating the incidence of factor 10a therapy associated haemarthrosis. In our case, the unprovoked shoulder haemarthrosis resolved following rivaroxaban cessation. In comparison with warfarin, rivaroxaban is irreversible. With warfarin and a high INR, vitamin K can be used to reverse the anticoagulation. There is no equivalent for rivaroxaban. We suggest further studies into incidence of haemarthrosis associated with oral anticoagulant therapy be undertaken, and treating physicians be aware of such complication

Due to working time restrictions a full-shift cross-covering system is commonplace. As more than one surgeon is responsible for trauma admissions in a 24-hour period a complete handover is paramount to ensure continuity of care. The purpose of this audit was to determine whether the introduction of a formal handover/admission form would improve this continuity with regards to prescription of venous thromboembolism (VTE) prophylaxis in hip fracture patients. In Stirling Royal Infirmary chemical VTE prophylaxis for hip fracture patients is 40mg enoxaparin at 6pm unless there is a contraindication. Over a 14-day period we prospectively documented the prescription of VTE prophylaxis and doses missed under the current admissions system. Following this a proforma was introduced that was to be exchanged at handover meetings. The proforma included patients' name/details, admission ward, and tasks to be completed during clerk-in, including VTE prophylaxis prescription. Tasks outstanding at handover had to be documented and completed by the subsequent doctor. Each form was signed and dated by the receiving doctor. We subsequently re-evaluated the prescription of VTE prophylaxis in hip fracture patients. Between 1/12/10-15/12/10, 23 patients were admitted with hip fracture. 12 had appropriate VTE prophylaxis, 6 missed one dose, 4 missed two, and 1 missed three all due to failure of prescription. Following the introduction of the proforma, 12 patients were admitted with hip fractures between 31/12/10-14/1/11. All were prescribed appropriate VTE prophylaxis and missed no doses. 1 patient was on warfarin and had enoxaparin prescribed but withheld until INR< 2.0. After the introduction of a handover form VTE prophylaxis prescription vastly improved. This proforma ensured that all elements of initial management were completed allowing for physician accountability, greater efficacy of handover and continuity of care

Rivaroxaban has been recommended for routine use as a thromboprophylactic agent in patients undergoing lower-limb arthroplasty. Starting January 2011, our unit has converted from aspirin to Rivaroxaban use routinely following lower-limb arthroplasty for venous thromboembolism (VTE) prophylaxis. The aim of this audit was to retrospectively review its efficacy and the morbidity associated with its use. All patients undergoing primary and revision lower-limb arthroplasty between February 2011 and July 2011 were reviewed. All patients undergoing total knee replacement surgery and total hip replacement surgery received oral rivaroxaban 10 mg daily post-operatively for 14 days and 35 days respectively. Outcome measures recorded were; investigation for DVT/PE, rate of DVT/PE, wound complications (infection, dehiscence, leaking, bleeding), blood transfusion rate and readmission rate within 6 weeks of surgery. Of the 162 patients identified, 19 were excluded due to insufficient information or because they did not receive rivaroxaban as VTE prophylaxis. 141 patients (mean age 71.7 years) were included. 69 primary and 5 revision total knee replacements were performed. 60 primary and 7 revision total hip replacements were performed. 9 patients (6.4%) underwent Doppler USS for a painful swollen leg with 1 (0.7%) DVT diagnosed. None were investigated for a pulmonary embolus. 25 (17.7%) patients developed wound complications: 10 superficial infections requiring oral antibiotics, 2 deep infections requiring theatre washout, 1 wound dehiscence, 5 continuously leaking wounds, 5 bleeding wounds/haematomas. 26 (18.4%) patients required post-operative blood transfusion (average 2.2 units). 12 (8.5%) patients were re-admitted within 6 weeks with post-op complications (6 wound complications, 5 painful/swollen limbs, 1 large per-vaginal bleed). In keeping with previous literature, the rate of VTE following lower-limb arthroplasty using rivaroxaban as prophylaxis is low. However, the rate of morbidity was higher when compared with the use of aspirin in our centre between April and September 2010