Purpose

There is a postulated association between increased serum metal ions and pseudotumour formation in patients with metal-on-metal hip replacements. The primary aim of this study was to assess the prevalence of pseudotumour in 31 asymptomatic patients with a large femoral head (LFH) metal-on-metal hip implant. This was compared to the prevalence of pseudotumour in 20 matched asymptomatic patients with a hip resurfacing (HRA) and 24 matched asymptomatic patients with a standard metal-on-polyethylene (MOP) total hip. A secondary objective was to assess possible correlation between increased serum metal ions and pseudotumour formation

Introduction: The rate of homologous blood transfusion following primary total hip replacement (THR) can be as high as 30–40% and is not without risk. Postoperative blood salvage (POS) with autologous blood transfusion may minimize the necessity for HBT but the clinical, haematological and economic benefits have yet to be clearly demonstrated for primary THR.

The aim of this prospective randomized study was to determine if the use of POS affects postoperative haemoglobin and haematocrit values and reduces the rate of homologous blood transfusion. Secondary outcomes measures included length of hospital stay and patient satisfaction. A cost analysis was conducted on the basis of the results.

Methods: Calculations following a preliminary study revealed that 72 patients would be required in each group to detect a significant difference of 0.7 gdL⁻¹ in the post operative haemoglobin level (with power of 80% and an α value of 0.05). The patients were block randomized on reduction of the primary THR, prior to closure, to receive either two vacuum drains or the autologous retransfusion system.

Results: There were 82 patients in the vacuum drain group and 76 patients in the autologous retransfusion group. Haemoglobin and haematocrit values were not significantly different between the groups but significantly fewer patients with the autologous system had a postoperative haemoglobin value < 9.0 gdL⁻¹ (8% vs. 20%, p = 0.035). Significantly fewer patients with the autologous system required HBT (8% vs. 21%, p = 0.022). There was an overall cost saving in this group.

Discussion: This study confirms that POS results in significantly fewer patients with a post-operative Hb below 9.0 gdL⁻¹ and confirms that POS significantly reduces the necessity for homologous blood transfusion following primary THR. As a result, our unit uses the autologous retransfusion system for primary THR.

Homologous blood transfusion (HBT) following primary total hip replacement (THR) is not without risk. Postoperative blood salvage (POS) with autologous blood transfusion may minimize the necessity for HBT but the clinical, haematological and economic benefits have yet to be clearly demonstrated for primary THR.

The aim of this randomized prospective study was to determine if the use of POS affects postoperative haemoglobin levels, haematocrit and HBT requirement. Secondary outcomes included length of stay and patient satisfaction. A cost analysis was conducted on the basis of the results. The patients were randomized at the point of reduction of the primary THR to receive either two vacuum drains (82 patients) or an autologous retransfusion system (76 patients).

Haemoglobin and haematocrit values were not significantly different between groups but significantly fewer patients with the autologous system had a postoperative haemoglobin value < 9.0 gdL⁻¹ (8% vs. 20%, p = 0.035). Significantly fewer patients with the autologous system required HBT (8% vs. 21%, p = 0.022). There was an overall cost saving in this group.

This study has shown that use of an autologous retransfusion system for primary THR reduces the necessity for HBT and is cost effective.