Introduction: There is a general conception in the orthopaedic community that blood loss/transfusion rate in hip resurfacing procedures is greater than that conventional Total Hip Arthroplasty (THA). The theoretical basis is that uncemented procedures leave large bleeding bone surfaces and that resurfacing arthroplasty needs larger incisions, greater exposure and more extensive soft tissue releases. Although this theory has gained informal
Acceptance in orthopaedic practice, there is little evidence in the literature to support this.
Background The purpose of this study was to determine the actual blood loss and transfusion rate (including hidden blood loss) in a consecutive cohort of patients undergoing hip re-surfacing by a single surgeon using the Articular Surface Replacement (ASR – DePuy).
Materials and Methods: The cohort consisted of 58 patients who were followed prospectively. All patients underwent a standardized surgical procedure performed by one senior surgeon. Hypotensive anaesthesia was used in all cases and surgery was via a standard posterior approach. Drains were not routinely placed, but if used, were removed within 24 hours. Low Molecular Weight Heparin was given 24 hours post procedure until discharge. Surgical blood loss was calculated in a standard fashion (suction volume plus swab weight). Drain volume (if used) was added after removal at 24 hours. Unseen loss of blood in soft tissues, joint space, as well as loss due to haemolysis, is calculated by the modified formula of Kallos1:
\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \[MABL=\ EBV\ x\ (\underline{Hct\ pt\ -\ Hct\ min})\] \end{document}
Hct pt, Where is
MABL = Maximum allowable blood loss
EBV =Estimated blood volume, 70 ml/kg
Hct pt= Pre operative haematocrit of patient
Hct min=Minimum allowable haematocrit
This was modified to
\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(ABL=\ EBV\ {\times}\ \frac{(Hct\ pre\ op\ {-}\ Hct\ post\ opD2)}{Hct\ pre\ op}\) \end{document}
where is
ABL= Actual blood loss, Unseen loss = ABL – Visible loss (Loss in OT + Drain)
Results: 58 Patients undergoing ASR, the aeitology was Osteoarthritis in 50 Patients, Dysplasia in 3, Inflammatory Arthritis in 1 and in 1 patient the aetiology was arthrosis secondary to trauma. The average blood loss during the procedure was 221 mls. After 24 hours this had risen to 377 ml, Mean Unseen blood loss was 787.6 ml, Mean Total actual blood loss was 1385.6 ml. There was a mean drop in haemoglobin of 3.6 g/dl and mean drop of Hematocrit was 10.33%. Only 3 patients required blood transfusion.
Conclusion: The mean blood loss in this study was 598 ml and actual blood loss was 1385.60. This is considerably lower than expected for resurfacing arthroplasty and results in a low transfusion rate of only 5% patients undergoing the procedure. Meticulous haemostasis combined with hypotensive anaesthesia reduced the perioperative blood loss and transfusion rate
