Surgeons want to counsel their patients accurately about the risks of rare complications. This is difficult for venous thromboembolism (VTE), as most studies report rates of asymptomatic disease. We calculated the rate of confirmed, symptomatic deep vein thrombosis (DVT) and pulmonary embolism (PE) after elective lower limb surgery in our hospital.

We scrutinised referrals for venous Doppler ultrasound and computed tomography pulmonary angiography, identifying all cases of DVT or PE over an 18 month period. These patients were cross-referenced with our elective orthopaedic database and Healthcare Resource Group coding data.

Out of 1071 total hip replacements, there were three DVTs and two PEs, giving an incidence of 0.28% for DVT and 0.19% for PE. Out of 1351 total knee replacements, there were four DVTs and three PEs (incidence 0.29% and 0.22% respectively). Out of 1988 non-arthroplasty hip and knee procedures, there were no DVTs and two PEs (incidence 0.1%). For 1763 elective surgical foot procedures, there were five DVTs (incidence 0.28%), and no PEs.

Currently, Rivaroxaban is offered to patients undergoing hip and knee replacement surgery, but other patients do not receive anticoagulants routinely. Our low incidence of VTE supports this policy and is reassuring for surgeons.

Since NICE issued guidance on preventing venous thromboembolism (VTE), the use of chemoprophylaxis has increased dramatically in trauma and orthopaedics. However, enthusiasm is tempered by a lack of data regarding the true incidence of VTE in everyday practice. We investigated the epidemiology of VTE among ambulatory patients with lower limb injuries within our Trust.

We identified all patients who suffered pulmonary embolism (PE) or deep vein thrombosis (DVT) over an 18 month period, and cross-referenced them with our trauma database. All lower limb injuries were included, whether operated or not. Hip fractures routinely receive dalteparin and were excluded.

There were 11,594 new attendances or post-operative attendances in all fracture clinics over 18 months. Of these, 4530 had lower limb injuries and were immobilised. There were 21 DVTs and 7 PEs in these patients, an incidence of 0.43% and 0.14% respectively. Of note, three DVTs were in patients with Achilles tendon rupture.

The incidence of symptomatic VTE is low in a population of ambulant patients with lower limb injuries in casts, without chemical thromboprophylaxis. Prophylaxis for VTE would thus have a large number needed to treat. The costs and complications of chemoprophylaxis should also be considered before it is introduced universally.

Rivaroxaban was introduced for thromboprophylaxis at the Royal Cornwall Hospital for hip and knee arthroplasty surgery in October 2009. We identified 140 patients from theatre logbooks who underwent elective joint replacement between October 2009 and March 2010. Patient notes, computer and DVT clinic records and WebPacs data were collected to determine the uptake of the new drug and the incidence of wound problems, DVTs and any other post-operative complications. In our sample 55.7% [78/140] patients received rivaroxaban. 10.3% [8/78] of patients on rivaroxaban suffered wound complications compared with 6.6% [4/62] of patients on alternative anticoagulation. Three patients suffered DVT's, 1 of whom was taking rivaroxaban. There were a further 6 patients, 4 on rivaroxaban, with leg swelling severe enough to merit investigation, all of whom had negative doppler scans. Bleeding events included 4 patients with postoperative haematemesis of which 2 were taking rivaroxaban. Five patients, all under different surgical operators of which 3 had taken rivaroxaban, developed stiff total knee replacements and were offered MUA or physiotherapy.

We carried out a comparison of the analgesic requirements, length of stay in hospital, complications and cost effectiveness of patients who had either a continuous disposable infusion pump or standard treatment for unicompartmental knee replacement.

This study began as an audit. We completed the audit loop with a prospective study after implementing our recommendations. The device is a single use disposable elastometric pump, set immediately after surgery to deliver a continuous flow of 0.5% bupivacaine at a rate of 2mls per hour for 48 hrs into the knee joint via a fine catheter with a fenestrated tip.

The case notes of all patients in the study were analysed to establish their total analgesic requirements for 48hrs following surgery. Complications and length of stay in hospital were recorded This has changed our clinical practice. Results of our study of 50 patients, 25 in each group (age and sex matched) confirmed that there was a significant reduction in opiate requirements after introduction of the pain pump. Length of stay in hospital was reduced from 5.7 to 3.9 days. Patients' requirements for NSAIDs were reduced. There were no significant complications in the pain pump group. The costs of the pump (£40) were offset by the reduction in analgesic requirements and shortened length of stay in hospital.

We conclude this form of analgesia is safe, effective and cost effective. Our department has now changed to using the pump for all unicompartmental knee replacements.