Tranexamic Acid (TA) has been shown to decrease peri-operative bleeding in primary Total Knee Replacement (TKR) surgery. There are still concerns with regards to the increased risk of thromboembolic events with the use of TA. The aim of this study was to assess whether the use of pre-operative TA increased the incidence of Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE) in TKR. Patients who underwent primary TKR between August 2007 and August 2009 were identified from the databases of three surgeons within the lower limb arthroplasty unit. A retrospective case notes analysis was performed. DVT was diagnosed on Duplex Ultrasound Scan and PE on CT Pulmonary Angiogram. A positive result was a diagnosis of DVT or PE within 3 months of surgery.INTRODUCTION
METHODS
To determine the effectiveness, complications and side effects of Rivaroxaban when used for extended thromboprophylaxis in patients undergoing primary and revision knee arthroplasty. Venous Thromboembolism (VTE) prophylaxis following knee arthroplasty remains controversial. As an Orthopaedic Unit, in July 2009 we developed guidelines to help ensure that our patient management was fully compliant with National Institute for Health and Clinical Excellence (NICE) guidelines regarding risk assessment and extended oral prophylaxis following primary and revision knee arthroplasty. We opted to trial the oral anticoagulant drug Rivaroxaban for an initial period of 12 months. All patients undergoing primary or revision knee arthroplasty between 1st July 2009 and 30th June 2010 and who had no contraindications to the prescription of Rivaroxaban were included in a prospective audit aimed at determining compliance with the newly developed unit guidelines as well as the effectiveness and possible side effects/complications associated with the drug therapy. All patients were monitored for a period of 90 days post operatively.Purpose of the study
Methods
A consecutive group of 150 patients undergoing primary TKA performed by a single surgeon using single prosthesis were studied prospectively. The purpose of this study was to compare the clinical and radiographic results of TKA in obese and non-obese patients. The patients were categorized into two groups: non-obese (body mass index (BMI <
30 kg/m2) and obese (BMI >
30 to 40 kg/m2). The Primary outcome measures: SF-12 and WOMAC scores were used as generic outcome measures, and the Knee Society scores were used to assess clinical outcome of TKA. The scores were done pre-operatively and at 1, 3 and 5 years post-operatively. Secondary outcome measures included patellar position, anterior knee pain, infections, revision rates, deep-vein thrombosis and pulmonary embolism, length of hospital stay and mortality. Seventeen patients have died since and none were lost to follow-up. Obese patients had less benefit and overall KSS outcome scores at one year (p-value 0.05) but had similar scores at 3 and 5 years (p-values 0.3 and 0.5). Pre-operative WOMAC and SF-12 scores were significantly worst in obese patients (p-value 0.009 and 0.005) but had the similar outcome at 1, 3 and 5 years. Three patients in the series required revision surgery for infection. One patient had DVT and another had PE post-operatively. Overall obese patients although had lower KSS scores at one year but had better outcome in SF-12 and WOMAC scores at one year. There was no difference at 3 and 5 years. We found that body weight did not influence adversely the outcome of TKA at medium term.
The emergence of minimally-invasive total knee replacement (TKR) has led to the refinement of several surgical approaches, including the quadriceps-sparing and sub-vastus. There is some disagreement as to the precise definition of the term ‘minimally-invasive’, especially in regard to the preservation of vastus medialis obliquus (VMO). It is known that the termination of VMO is variable and may make these approaches difficult. We have attempted to assess the factors influencing the insertion of VMO and the impact which they have on the approach for TKR. The MR scans of 198 knees were examined to assess the variation in the insertion of VMO in relation to the patella and the effect of variables such as age, gender and the presence of concurrent osteoarthritis of the knee on the insertion. Our findings showed that both age and the presence of osteoarthritis were contributing factors to changes in the level of insertion of VMO. Therefore, not all capsular incisions which extend proximal to the midpole of the patella will violate the quadriceps tendon.
Hips and knees are commonly replaced joints for which several types of prostheses are available. As newer versions of the prostheses are brought in, older versions are phased out. When revision is for an isolated component failure as in, wear of acetabular cup, isolated revision of the acetabular cup is an accepted procedure. If the plan is to revise just the isolated component then that particular model of prosthesis should still be available. In an attempt to check the availability of revision components for joint replacements we wrote to ten prostheses manufacturers enquiring the availability of prosthetic components. To have a comparison, we also wrote to eighteen leading car manufacturers enquiring about the duration and any guarantees on the availability of car spare parts. From our survey we found that the availability of the revision implants was satisfactory in that all the prostheses manufacturers were eager to provide as much assistance as possible. The draw back is that there are no regulations to ensure the availability of these prosthetic components for any length of time after discontinuation of a particular model. The car manufacturers are not under any obligation to provide spare parts for discontinued models. The argument put forward by some manufacturers for providing spare parts up to ten years from discontinuing the model was that “it would not reflect well on the company” if it were for any lesser length of time.
