Introduction: The aims of this study are:

To report and validate the early migration rates of the collarless polished tapered hip replacement using manual and computer measurements

To report early clinical results of the CPT hip

Patients and methods: 80 patients undergoing primary total hip replacement in a single centre were prospectively recruited into the trial. There were 59 females and 21 males: age range 31–84 years, (mean 68 years sd 9.86). Surgery was performed through an anterolateral approach in all cases. A standard cementing technique using a cement gun and cement restrictor was employed. The patients had standardised anteroposterior standing hip radiographs taken post operatively, then yearly. The migration was measured along the long axis of the femoral component In the anteroposterior plane, using the tip of the greater trochanter as a bony landmark. Measurements were made by two independent observers (specialist registrars). Plain radiographs were measured manually using a ruler and set square and digitised images using a software package designed in-house at Dundee University. Correction for magnification was incorporated. Hip assessments were performed at each review by an independent reviewer.

Results: The mean migration rates and 95% confidence intervals (Cl) and mean Harris pain and Harris hip scores and Std Deviations were:

There was no significant difference between inter or intra observer measurements for hip migration.

This is the first study to date that we are aware of that describes the subsidence rates of the CPT hip which includes validation by inter and intra observer readings.

Introduction: The aims of this paper are to compare the results of Measuring migration rates on radiographs manually and by computer assisted analysis of digitised images.

Methods: Standardised anteroposterior standing hip radiographs taken post operatively and then yearly following hip replacement were used. The radiographs were then scanned at 150 dpi (gray scale) and saved as tif files. The migration was measured manually by drawing a line along the long axis of the femoral component connecting the distal tip, to the notch, which is used to impact the stem proximally. This gives us the length of the hip replacement and an axis along which migration can be measured. The tip of the greater trochanter was selected as a bony landmark. On the plain radiographs two sets of readings were made by one observer. The digitized images were then analysed in the same way using a software package (designed in-house at the University of Dundee). Two sets of readings were performed by observer one and a second set by an independent observer. Statistics: Inter and Intra observer rates were calculated using a paired sample t test.

Results: For the manual readings intra observer mean difference was 0.53mm (Cl 0.31–0.74mm). Comparing manual vs computer readings for observer one there was a correlation of 0.89. For the computer readings intra observer mean difference was 0.36mm (CI 0.64–0.8mm) and inter observer mean difference 0.16 mm, both non-significant differences. This evidence shows that the readings made manually and by computer were not significantly different and that there was no significant inter and intra observer variation. The advantage of computer storage and reading being the faster analysis, the ability to store and access large numbers of radiographs. The disadvantages being the need to scan the radiographs to allow measurement.

Aims: To demonstrate that tranexamic acid reduces the blood loss incurred as a result of lower limb arthroplasty. Methods: We prospectively studied 30 primary hip and knee arthroplasty patients. Entry criteria were primary joint replacement, exclusion criteria were: a history of bleeding disorders, previous thromboembolic disease or renal insufþciency. The senior author (GS) performed all the operations. Surgical technique and postoperative mobilisation was standardised for both hip and knee arthroplasty cohorts. Tranexamic acid was administered at the time of surgery. The patients had haemoglobin levels assessed preoperatively and a haemoglobin level three days post operatively to allow its stabilisation following surgery. Any blood transfused was noted. Blood was transfused on a case-by-case basis the indications were a haemoglobin less than 8 g/dl or symptoms of anaemia. The results were then compared with a matched population from the bone and joint research unit database. Results: The mean fall in haemoglobin in hip arthroplasty with tranexamic acid was 2.8 ± 0.33 g/dl (95% Conþdence Interval) and 3.85 ± 0.44 g/dl (95% Conþdence Interval) without tranexamic acid this was statistically signiþcant p< 0.05. The mean fall in haemoglobin in knee arthroplasty with tranexamic acid was 1.67± 0.36 g/dl (95% Conþdence Interval) and 2.84 ± 0.35 g/dl (95% Conþdence Interval) without tranexamic acid this was statistically signiþcant p< 0.05. Transfusion requirements were reduced. Conclusions: Tranexamic acid is an inexpensive and effective way of reducing blood loss following hip and knee arthroplasty.