Purpose. To evaluate the effectiveness of the perioperative erythropoietin administration, as an alternative to homologous banked blood transfusions, in total hip arthroplasty. Material and Methods. In a prospective randomized, controlled study, 101 patients who underwent unilateral total hip replacement, during the period 2004–2009, were evaluated. In all these patients, the same surgical team applied the same surgical technique (hybrid THA) and they followed the same rehabilitation program. In 50 patients (group A or study group) we administered 40,000 units of erythropoietin subcutaneously one day before the operation followed by 40,000 units (sc) every 3 days in a total scheme of 4 doses. All these patients received intraoperatively one unit of homologous blood transfusion (1 unit/patient) and additional blood transfusions postoperatively when required. A control group of 51 patients (group B) received intraoperatively one or two units of homologous blood transfusion (1.35 units/patient), according to the volume of blood collected in the suction device and to the anaesthesiologists estimation, and also additional blood transfusions postoperatively when required. The admission of banked blood transfusion was determined by the haemoglobin value (< 9mg/dl) and/or clinical signs (blood pressure, pulse etc.). The values of haemoglobin, haematocrit and platelets were recorded preoperatively and the 1st, 5th, and 15th day postoperatively. Results. 15 patients of group A required postoperatively 15 units of homologous blood (total amount for group A 65 banked blood units 1.3 units/patient). 20 patients of group B required additional 26 banked blood units postoperatively (totally 95 banked blood units, or 1.86 units/patient). In the group A (study group), the total homologous blood requirements were reduced by 30%, the postoperative blood requirements were reduced by 42% and the number of patients that required additional blood transfusion was reduced by 25%. There was no significant difference in the postoperative haematocrit and haemoglobin values between the two groups. Conclusions. The perioperative use of erythropoietin reduces effectively the total demands of homologous banked blood transfusion in total hip arthroplasty

Introduction. Femorotibial malalignment exceeding ±3° is a recognised contributor of early mechanical failure after total knee replacement (TKR). The angle between the mechanical and anatomical axes of the femur remains the best guide to restore alignment. We investigated where the femoral head lies relative to the pelvis and how its position varies with respect to recognised demographic and anatomic parameters. We have tested the hypothesis of the senior author that the position of the centre of the femoral head varies very little, and if its location can be identified, it could serve to outline the mechanical axis of the femur without the need for sophisticated imaging. Patients & Methods. The anteroposterior standing, plain pelvic radiographs of 150 patients with unilateral total hip replacements were retrospectively reviewed. All patients had Tönnis grade 0 or 1 arthritis on the non-operated hip joint. All radiographs were obtained according to a standardised protocol. Using the known diameter of the prosthetic head for calibration, the perpendicular distance from the centre of the femoral head of the non-operated hip to the centre of pubic symphysis was measured with use of TraumaCad software. Anatomic parameters, including, but not limited to, the diameter of the intact femoral head, were also measured. Demographic data (gender, age, height, weight) were retrieved from our database. Results. There were 72 men and 78 women with a mean age of 67.0 years. The mean distance of the centre of the femoral head to the pubic symphysis was 89.1 mm (standard deviation [SD], 5.8 mm). This distance was higher in men (mean, 90.5 mm; SD, 5.6 mm) than in women (mean, 87.7 mm; SD, 5.8 mm) (p=0.003). No statistically significant correlations between this distance and body-mass index or age (p=0.57 and p=0.28, respectively) were revealed. However, height was strongly correlated with this distance (r=0.52, p < 0.01), as was the diameter of the femoral head (r=0.61, p < 0.01). The latter was significantly larger in men than in women (p < 0.01). Conclusion. This is the first study to demonstrate that the position of the centre of the femoral head has very little variability, irrespective of patient age or body-mass index. As expected, it varies with patient's height and gender. Although statistically significant, the difference between genders is < 3 mm and can be explained by the smaller femoral head size of females. Our findings should prove useful during TKR surgery, as they facilitate intra-operative identification of the centre of the femoral head. Based on these results, simple trigonometry shows that if a surgeon measures 9 cm from the symphysis pubis, a line from this point to the centre of the knee will be within 2° and 2.2° of the true mechanical axis in 98% (i.e. ± 3 SD of the mean) of male and female patients, respectively