INTRODUCTION

Historically, the clinical performance of novel implants was usually reported by designer surgeons who were the first to acquire clinical data. Regional and national registries now provide rapid access to survival data on new implants and drive ODEP ratings. To assess implant performance, clinical and radiological data is required in addition to implant survival. Prospective, multi-surgeon, multi-centre assessments have been advocated as the most meaningful. We report the preliminary results of such a study for the MiniHip™femoral component and Trinity™ acetabular component (Corin Ltd, UK).

Introduction

Instability accounts for one third of revision total hip arthroplasty(rTHA) performed in the United Kingdom. Removal of well-fixed femoral stems in rTHA is challenging with a risk of blood loss and iatrogenic damage to the femur. The Bioball Universal Adaptor (BUA) (Merete, Germany), a modular head neck extension adaptor, provides a mechanism for optimisation of femoral offset, leg length and femoral anteversion. This can avoid the need for femoral stem revision in selected cases. There is a relative paucity of clinical data available with the use of this device.

Objectives

This study examines variations in knee arthroplasty patient reported outcome measures according to patient age.

Using general practitioner records, hospital medical notes and through direct telephone conversation with patients, we investigated the accuracy of nine patient-reported complications after elective joint replacement surgery of the hip and knee. A total of 402 post-discharge complications were reported after 8546 elective operations that were undertaken within a three-year period. These were reported by 136 men and 240 women with an overall mean age of 71.8 years (34.3–93.2). A total of 319 (79.4%; 95% confidence interval, 75.4%–83.3%) reported complications were confirmed to be correct. Very high rates of correct reporting were demonstrated for infection (94.5%) and further surgery (100%), whereas the rates of reporting deep venous thrombosis (DVT), pulmonary embolism, myocardial infarct and stroke were lower (75%–84.2%). Dislocation, periprosthetic fractures and nerve palsy were associated with modest rates of correct reporting (36%–57.1%). More patients who had had knee surgery delivered incorrect reports of dislocation (p = 0.001) and DVT (p = 0.013). Despite these variations in accuracy, it appears that post-operative complications may form part of a larger patient-reported outcome programme for monitoring outcome after elective joint replacement surgery.

Introduction

Total hip arthroplasty (THA) is undertaken to relieve pain and to restore mobility. The orthopaedic community remains divided on the influence of surgical approach in achieving functional recovery most quickly and effectively. We report a study comparing THA performed through a posterior (Posterior) against anterior approach (Heuter).

Introduction

The outcomes programme of our institution has been developed from a system first used at Epsom and St Helier NHS Trust 15 years ago. The system was implemented at our institution when it opened in 2004, and has been used to collect data on over 17,000 joint replacement operations so far. A bespoke database is used to collect, analyse and report outcome data.

Introduction

The need for the stringent surveillance of new devices was recognised by the NICE review of hip replacement surgery in 2000 and led to the Orthopaedic Data Evaluation Panel (ODEP) developing criteria for post-marketing surveillance (PMS) studies. This requirement has been reinforced by the recent recall of ASR devices.

The Oxford Knee Score (OKS) is a valid and reliable self-administered patient questionnaire that enables assessment of the outcome following total knee replacement (TKR). There is as yet no literature on the behavioral trends of the OKS over time. Our aim is to present a retrospective audit of the OKS for patients who have undergone TKR during the past ten years.

We retrospectively analysed 3276 OKS of patients who had a primary TKR and had been registered as part of a multi-surgeon, outcome-monitoring program at St. Helier hospital. The OKS was gathered pre-operatively and post-operatively by means of postal questionnaires at annual intervals. Patients were grouped as per their age at operation into four groups: 60, 61-70, 71- 80 and >80. A cross-sectional analysis of OKS at different time points was performed.

The numbers of OKS available for analysis were 504 pre-operatively, 589 at one-year, 512 at two-year and gradually decreasing numbers with 87 knees ten-year post-operatively. There was as expected a significant decrease (improvement) of the OKS between pre-operative and one-year post-operative period and then reached a plateau. Beyond eight years, there is a gradual rise in the score (deterioration). The younger patients (60) showed a significant increase in their average OKS between one and five-years post-operatively. However beyond five years, they followed the trend of their older counterparts. When the twelve questions in the OKS were analysed, certain components revealed greater improvement (e.g. description of knee pain and limping) than others (e.g. night pain).

The OKS is seen to plateau a year after TKR. According to the OKS the outcome of the TKR is not as good in the younger age group as compared to the older age group. Further investigation is required to ascertain the cause of this observed difference.

The performance of total knee arthroplasty in deeply flexed postures is of increasing concern as the procedure is performed on younger, more physically active and more culturally diverse populations. Several implant design factors, including tibiofemoral conformity, tibial slope and posterior condylar geometry have been shown directly to affect deep flexion performance.

The goal of this study was to evaluate the performance of a fixed-bearing, asymmetric, medial rotation arthroplasty design during kneeling activities.

Thirteen study participants (15 knees) with primary total knee arthroplasty (Medial Rotation Knee, Finsbury, Surrey, UK) were observed while doing a step activity and kneeling on a padded bench from 90° to maximum comfortable flexion using lateral fluoroscopy. Subjects averaged 74 years of age and nine were female. Subjects were an average of 17 months post-operative, and scored 94 points on the International Knee Score and 99 on the Functional Score. Digitised fluoroscopic images were corrected for geometric distortion and 3D models of the implant components were registered to determine the 3D position and orientation of the implants in each image.

During the step activity, the medial and the lateral femoral contact point stayed fairly constant with no axial rotation from 0 to 100° of flexion. At maximum kneeling flexion, the knees exhibited 119° of implant flexion (101°-139°), 7° (-7° to 17°) tibial internal rotation, and the lateral condyle translated backwards by 11 mm.

Patients with medial rotation knee arthroplasty exhibited medial pivot action with no paradoxical translation. The knees exhibited excellent kneeling flexion and posterior translation of the femur with respect to the tibia. The axial rotation in MRK was within the range of normal knee kinematics from -10 to 120 (perhaps 140).

Aims

To establish the cost of primary hip (THR) and knee (TKR) arthroplasty in an elective orthopaedic centre in the UK and to compare it with current government reimbursement to NHS hospitals and the costs in North America.