Tibial component design has be been scrutinized in a number of studies in an attempt to improve tibial coverage in total knee arthroplasty. However, very few have controlled for both component rotation and resultant changes to posterolateral tibial tray overhang and posteromedial underhang. We hypothesize that asymmetrical tibial components can provide greater coverage than symmetrical trays without increasing overhang. The 6 most commonly used tibial trays on the Australian Joint Registry (2009) were superimposed on MRI slices of normal knees to assess tibial component overhang, underhang and percent coverage. Rotational alignment in this analysis was based upon the line joining the junciton of the medial and middle 1/3 of the patellar tendon and the PCL insertion.AIM
METHODS
Total knee arthroplasty is a painful operation. Peri-articular local anesthetic injections reduce post-operative pain and assist recovery. It is inconclusive whether intra-operative injections of peri-articular corticosteroids are of benefit. A prospective, randomized, double-blinded study was undertaken to assess the efficacy of adding peri-articular corticosteroids to intra-operative, peri-articular high volume local anaesthetic in post-operative pain management following TKA. 127 patients were randomised into three groups receiving local anaesthetic alone (control) or either low dose (40 mg) or high dose (80 mg) peri-articular corticosteroid plus local anaesthetic. Primary outcomes included ROM and visual analog pain scores (VAS). Pain was defined as the worst pain lasting for more than 20 minutes, measured at both rest (RVAS) and during activity (AVAS).Introduction
Methods
It is widely accepted that computer navigation more reliably restores neutral mechanical alignment than conventional instrumentation in total knee arthroplasty (TKA) surgery. Recently, magnetic resonance (MR) based instrumentation has been introduced to the market with a rapid growth in usage. However, a paucity of comparative data still exists on the precision of magnetic resonance (MR) based instruments in achieving acceptable lower limb alignment when compared to other validated techniques. In this analysis, we compare the radiographic outcomes of 3 techniques to achieve satisfactory prosthetic alignment by 2 surgeons using the same prosthesis and surgical technique. A series of 180 patients who had undergone TKA surgery were included in this study. Two fellowship-trained knee surgeons performed all surgeries using the same cemented, posterior stabilized implants (NexGen, Zimmer, Warsaw, In). Patients were stratified in to 3 groups according to the technique used to align the knee; 1. Conventional Intra-medullary Instrumentation, 2. Computer Navigation (Orthosoft), and 3. MR-based guides (Zimmer PSI). All patients underwent a post-operative CT Perth Protocol to assess coronal, sagittal and rotational alignment of the femoral and tibial implants. A radiographer who was blinded to the alignment technique used performed all radiographic measurements. Outliers were defined at a deviation of more than 3 degrees from the mechanical axis in all planes of motion.Introduction
Methods
Intravenous administration of tranexamic acid (TXA) has been shown to be effective in reducing blood loss and transfusion requirements in total knee arthroplasty (TKA). However, concern exists that I.V. TXA may heighten the risk of venous thrombo-embolism. The intra-articular administration of TXA is an attractive and simple option to deliver this agent locally with minimal systemic effects on inducing hypercoagubale states. In this study, we analysed the effect of varying dosages of intra-articular tranexamic acid on blood loss in TKA. 176 patients who underwent a unilateral TKA for osteoarthritis were retrospectively analysed. Patients were excluded if they underwent a revision knee arthroplasty, concurrent removal of hardware, extensive synovectomy, or lateral patellar retinacular release. All patients underwent a primary cemented posterior stabilised TKA by 2 surgeons using a medial parapatellar approach. Tourniquet was only inflated for initial exposure and intra-articular drains were not used. Patients were separated into three groups; a control group (n=56) who did not receive TXA, and 2 treatment groups who received intra-articular TXA with doses of 1500 mg (n=60) or 3000 mg (n=60). Once the wound was closed, tranexamic acid was injected intra-articularly via an epidural pain catheter. Haemoglobin (Hb) levels were taken pre-operatively and on post-operative days 1 and 2. The primary outcome measure was mean difference in Hb drop between the three groups.Introduction & Aims
Methods
