Statement of purpose:

A randomised clinical trial was undertaken to find out if treatment time and failure rate in children treated by the Ponseti method differed between below-knee vs above-knee cast groups.

Introduction: Blood conservation is important in surgery for adolescent idiopathic scoliosis due to the potential for significant blood loss and need to avoid allogeneic transfusion in young, commonly female, patients. Previous studies have shown that a combination of blood conservation methods may be effective in reducing the need for allogeneic blood transfusion. We have carried out a study to investigate if the sole use of intraoperative red cell salvage in surgery for adolescent idiopathic scoliosis is effective and can lead to a reduced rate of allogeneic transfusion.

Patients and Methods: 56 patients aged between 10 and 17 underwent posterior spinal surgery for correction of idiopathic scoliosis. In 34 patients intraoperative cell salvage was used and salvaged blood re-infused perioperatively. This group was compared with a control group of 22 patients in whom only allogeneic blood transfusion was used. All patients underwent hypotensive anaesthesia. Other forms of blood conservation, such as predonation, were not used. Data was gathered on patient demographics, operative details, quantity of blood reinfused, pre and post operative haemoglobin levels and total allogeneic transfusion requirement. Operative data was gathered prospectively and blood transfusion data provided by the transfusion centre.

Results: In the cell salvage group an average of 309mls of blood was reinfused and these patients were transfused an average of 1.8 units less allogeneic blood in the peri-and post-operative period (p< 0.001). 74% of these patients required no allogeneic blood compared with 27% in the control group. There were no complications related to the use of intraoperative red cell salvage.

Conclusion: Intraoperative red cell salvage is effective in reducing the need for allogeneic transfusion in children undergoing posterior surgery for scoliosis correction.

Introduction: Bone cements produced by different manufacturers vary in their mechanical properties and antibiotic elution characteristics. Small changes in the formulation of a bone cement, which may not be apparent to surgeons, may also affect these properties. The manufacturing method of Palacos bone cement with added gentamicin has recently changed. We have carried out a study to examine the mechanical characteristics and antibiotic elution of Schering-Plough Palacos (‘old’ version), Heraeus Palacos (‘new’ version) and Depuy CMW Smartset bone cements.

Methods: Schering-Plough Palacos R40G (contains 0.5g gentamicin per 40g mix), Heraeus Palacos R+G (contains 0.5g gentamicin per 40g mix) and Depuy-CMW Smartset GHV (contains 1g gentamicin per 40g mix) were used. 40g samples of the three cements with no additional vancomycin, 1g and 2g vancomycin were prepared by a standard method using vacuum mixing in a syringe. Antibiotic elution over a five week period was measured using an immunoassay method. Standard mechanical testing was carried out according to methods defined in ISO 5833.

Results: Both Heraeus Palacos and Smartset bone cements performed significantly better than Schering-Plough Palacos in terms of mechanical characteristics both with and without additional antibiotics. All cements show a deterioration in flexural strength with increasing addition of vancomycin although staying above ISO minimum levels. Both Heraeus Palacos and Smartset elute significantly more gentamicin cumulatively than Schering-Plough Palacos. Smartset elutes significantly more vancomycin cumulatively compared with Heraeus Palacos.

Discussion: Both Heraeus Palacos and Smartset Bone cements elute significantly more gentamicin than Schering-Plough Palacos with no deterioration in mechanical characteristics. Smartset also elutes significantly more vancomycin than Heraeus Palacos without adverse affect on mechanical characteristics. Although marketed as the ‘original’ Palacos, Heraeus Palacos has significantly altered mechanical and antibiotic elution characteristics compared with previous versions.

Introduction: It is common practice to use additional antibiotics in bone cement for revision hip surgery. Ideally antibiotic elution would initially be rapid and then reduce to zero in order to reduce the risk of antibiotic resistance developing. There is evidence that the addition of antibiotics to bone cement leads to deterioration in mechanical properties. We have carried out a study to see if the addition of vancomycin to Palacos R40G and Smartset GHV affects their in-vitro antibiotic elution and mechanical properties.

Methods: Palacos R40G (contains 0.5g gentamycin per 40g mix) and Smartset GHV (contains 1g gentamycin per 40g mix) were used. 40g samples of the two cements with no additional vancomycin, 1g and 2g vancomycin were prepared by a standard method using vacuum mixing in a syringe. Antibiotic elution over a five week period was measured using an immunoassay method. Standard mechanical testing was carried out according to methods defined in ISO 5833.

Results: Smartset GHV eluted double the quantity of gentamycin as Palacos R40G, as would be expected. Both cements eluted more gentamycin when vancomycin was added. Smartset appears to elute more vancomycin than Palacos initially and then shows a more rapid tailing off. The mechanical properties of the two cements were the same with no statistical differences found between them. Both showed deterioration in flexural strength with addition of increasing vancomycin.

Discussion: Smartset may have improved qualities of antibiotic elution as compared with Palacos with similar mechanical properties. The presence of higher initial quantities of gentamycin does not lead to reduced mechanical properties.

Background: Perioperative red cell salvage may be of use in cases where significant blood loss is likely. The purpose of this investigation was to see if its use in revision hip surgery led to a reduction in homologous blood transfusion requirement.

Methods: 48 patients were identified who had undergone revision hip surgery with the use of a Cell Saver device for perioperative autologous transfusion. Patients were individually matched to control patients who had undergone revision hip surgery without the Cell Saver. Patients were matched for age, sex and eight operative variables, which were chosen to indicate the type of revision surgery and possible level of blood loss, to ensure that the groups were comparable. Total homologous transfusion requirement in both groups was recorded as well as pre and post-operative haemoglobin levels.

Results: The groups were well matched for age, sex and operative variables. The total homologous transfusion requirement was significantly lower in the Cell Saver group than the control group (mean 2.6 v 6.4 units of packed cells respectively, p 0.0006). There was no difference in pre-operative haemoglobin between the groups but it was lower in the Cell Saver group post-operatively (Cell Saver 10.1g/dl v Control 10.6g/dl, p 0.06). There was no difference in length of operation.

Conclusions: Use of perioperative red cell salvage was associated with significantly lower homologous transfusion requirement. This is the first study looking at the use of perioperative red cell salvage in revision hip surgery with matching of patients on the basis of operative variables. A cost analysis shows that use of the Cell Saver has significant financial advantage in these patients.

Background: Perioperative red cell salvage may be of use in cases where significant blood loss is likely. The purpose of this investigation was to see if its use in revision hip surgery led to a reduction in homologous blood transfusion requirement.

Methods: 48 patients were identified who had undergone revision hip surgery with the use of a Cell Saver device for perioperative autologous transfusion. Patients were individually matched to control patients who had undergone revision hip surgery without the Cell Saver. Patients were matched for age, sex and eight operative variables ,which were chosen to indicate the type of revision surgery and possible level of blood loss, to ensure that the groups were comparable. Total homologous transfusion requirement in both groups was recorded as well as pre and post-operative haemoglobin levels.

Results: The groups were well matched for age, sex and operative variables. The total homologous transfusion requirement was significantly lower in the Cell Saver group than the control group (mean 2.6 v 6.4 units of packed cells respectively, p 0.0006). There was no difference in pre-operative haemoglobin between the groups but it was lower in the Cell Saver group post-operatively (Cell Saver 10.1g/dl v Control 10.6g/dl, p 0.06). There was no difference in length of operation.

Conclusions: Use of perioperative red cell salvage was associated with significantly lower homologous transfusion requirement. This is the first study looking at the use of perioperative red cell salvage in revision hip surgery with matching of patients on the basis of operative variables. A cost analysis shows that use of the Cell Saver has significant financial advantage in these patients.

A high incidence of complications with wound healing in calcaneum fractures treated with open reduction and internal fixation (25 – 33% of cases) has been reported. In one study 80% of those who had wound complications required surgical treatment of these. Two recent studies have shown that the risk factors for wound complications in this injury are single layered closure, high BMI, extended time between injury and surgery, diabetes, open fractures and smoking. In our unit, out of a small sample of 56 patients undergoing calcaneal fracture fixation, all those who developed wound complications were smokers.

Transcutaneous oximetry is a technique that has been used routinely to assess oxygen perfusion in neonates and also sometimes in peripheral vascular disease (PVD). It has seen greater use as a research tool in PVD and orthopaedic surgery, being used to look at oxygenation around wounds to assess different surgical approaches. This study was performed to assess whether a difference in the oxygen perfusion around the ankle joint could be measured in smokers and non-smokers. A transcutaneous oximetry probe was used to assess the tissue oxygen perfusion at the ankle (posterior to lateral malleolus where the incision line would be) and on the chest (just to the side of the sternum). A standardised technique was used for each patient.

Patients were chosen who had no lower limb orthopaedic problem or known PVD. The groups were matched in terms of sex and average age. The data was analysed after logarithmic transformation using a two-tailed Students t-test. The average pO2 chest/foot ratio was higher in the non-smokers than smokers but this was not significant (p=0.704). The average ankle pO2 was higher in the non-smokers and this was shown to be significant (p=0.026).

Although a small sample, these data suggest that tissue oxygenation around the ankle may be significantly lower in smokers. This would help to explain why they are at increased risk of wound healing complications. This work also demonstrates that transcutaneous oximetry can be a useful tool in orthopaedic research. Tissue oxygenation around other joints could also be assessed in relation to position to discover the optimum position for wound healing.