Clinical lmpre@oui of bleedingNanber of @eatsBleedlag presmire (cm of sailne) heavy228â€"36 A review of the world literature on cemented total hip arthroplasty reveals that there is almost a twenty-fold variation in the re-operation rate for aseptic loosening of the components at 10 years (Bosch, Kristen and Zweymüller 1980; Collis 1982; Sutherland et al. 1982; Johnstone and Crowninshield 1983; Older 1984). The lowest re-operation rates vary between 1.5% (Johnstone and Crowninshield 1983) and 7.4% (Stauffer 1982), and were achieved using very basic cementing techniques and implants that would now be considered obsolete. Indeed, advances in materials and in stem design have virtually eliminated the problem of stem fracture, which had been responsible for a significant number of the revisions due to aseptic loosening in the two series cited. If stem fractures are excluded, the revision rates for aseptic loosening only in these same two series varies between 0.88% and 5.7%, the latter being amongst the lowest published results from an institutional series as distinct from those reported by individual surgeons.Thus, by using up-to-date implants but the same cementing techniques as were used more than a decade ago, re-operation ratesof between 1%and 5% for aseptic loosening could reasonably be anticipated at 10 years.Further improvement might alsobe achieved by the more refined cementing techniques introduced in the past 10 years. Most of these, including intramedullary plugging, bone cleaning, retrograde insertion and pres surisation of cement, as well as the use of cement of Princess Elizabeth Orthopaedic Hospital, Wonford Road, Exeter, Devon, EX2 4LE, England. A. J. C. Lee, PhD, Reader in Engineering ScienceUniversity of Exeter, Northpark Road, Exeter, Devon EX4 4QF, England. Request for reprints should be sent to Mr R S M Ling.©1987BritishEditorialSocietyof Boneand Joint Surgery 030lâ€"620X/87/4l20$2.00 Table I. Saline manometry after preparation and plugging of the femoral cavity (after Heyse-Moore and Ling 1982) reduced viscosity, evolved from post-mortem studies and laboratory models Ling 1974, 1981; Markolf and Amstutz 1976;Oh et al. 1978; Miller et al. 1978a; Miller et al. l978b ; Wroblewski and van der RIjt 1984).The conclusionsfrom such studies may realistically be applied to the knee where the use of a tourniquet is common practice. The hip, however, presents a chal lenge in that cementing usually is performed in the presence of active bleeding from the bone surface. Although bleeding may be controlled by the use of hypotensive anaesthesia and by packing the acetabulum and femoral canal before cementing, there is no completely effective way of preventing it. A recent study (Heyse-Moore and Ling 1983) demonstrated significant femoral medullary bleeding pressuresduring total hip arthroplasty. In this work, the proximal end of the femur was sealed with a cement-and-rubber dam after the canal had been reamed and plugged. Attached to the rubber dam was a saline manometer that measured the intrafemoral ...