Objectives

We aimed to further evaluate the biomechanical characteristics of two locking screws versus three standard bicortical screws in synthetic models of normal and osteoporotic bone.

To evaluate blood transfusion practice in hip and knee arthroplasty, the development of evidence based guidelines, their implementation and prospective analysis of change. An audit was carried out in 4 stages to complete the loop. Stage 1: Retrospective analysis of blood transfusion practice in primary and revision hip and knee arthroplasty. Review of case notes, nursing record, anaesthetic sheet and pathology results from a computer database was carried out. Rates of transfusion, patients’ body weight and height, peri-and post-operative blood loss, use of anticoagulants, drains, surgical approach, type of implant and cement, grade of surgeon and anaesthetist and haemodynamic complications were recorded. Stage 2: Literature search to develop evidence based guidelines for blood transfusion.

The data in stage 1 was evaluated in the light of those guidelines to determine appropriateness of blood transfusion. Stage 3: Dissemination and implementation of guidelines. Anaesthetic, Orthopaedic and audit departments were involved. Guidelines were presented, discussed, finalised and circulated.

Stage 4: Prospective re-evaluation of blood transfusion practice was undertaken. Parameters as in stage 1 plus documentation of reason for blood transfusion by the prescriber were recorded.

For stage 1, 97 Hip arthroplasty (86 primary and 11 revisions) and 119 Total knee arthroplasty procedures (109 primary and 10 revisions) over a period of 26 weeks were studied. Blood transfusion rate was 50.5% (49/97) in hip arthroplasty and 28.5% (34/119) in knee arthroplasty. Evidence based guidelines were developed. 55% transfusions were thought to be inappropriate in the light of guidelines. Following completion of stage 2 and 3, prospective audit of blood transfusion practice was initiated. It was compulsory for the person prescribing blood to document the indication. Data was collected on a daily basis for 15 weeks. In that period 150 joint replacements were undertaken. 77 hip arthroplasty (71 primary and 6 revisions) and 73 knee arthroplasty procedures (66 primary and 7 revisions) were undertaken. Blood transfusion rates for hip arthroplasty decreased to 18% (14/77) and for knee arthroplasty to 5.4% (4/73).

Overall transfusion rates decreased from 83/216 (38.5%) to 18/150 (12%) after implementation of guidelines. This represents an overall reduction of 68%.

Conclusion: A multidisciplinary approach and putting evidence based practice in place has resulted in reduced blood transfusion rates in hip and knee arthroplasty in our institution. We feel this change is an example of implementation of evidence-based practice.

Aims: Loss of distal þxation occurs with this the blade plate, especially in the setting of a very distal femur fracture and/or in osteoporotic bone. The LISS (Less Invasive Stabilization System) provides a þxation construct for supracondylar/intracondylar distal femoral fractures, with features including submuscular þxation and percutaneous placement of self-drilling unicortical þxed angled screws. The purpose of this study was to evaluate the biomechanical characteristics of the LISS versus the angled blade plate in an osteoporotic human cadaveric femoral model. Methods: Twenty-four matched pairs of fresh frozen human femora were utilized. Three groups of eight pairs each were tested to failure in one-time axial loading, one-time torsional loading and cyclical axial loading. A fracture model was created to simulate an AO 33–A3 fracture. Results: The average axial load to failure was 34% higher for the LISS compared with the blade plate (p = 0.03). All 8 LISS constructs failed by plastic deformation of the implant only, while 3/8 blade plates failed by loss of distal þxation. The blade plate had a 47% higher torsional moment to failure (p= 0.05). Permanent deformation after cyclical axial loading was signiþcantly lower for the LISS (p = 0.01). Conclusions: Of signiþcant interest is potential loss of þxation in catastrophic loading of a supracondylar femoral fracture þxation construct. In conclusion, biomechanical testing of the LISS demonstrates in comparison to the blade plate: (1) superior þxation of the distal femoral Ç block È in axial loading, (2) lower torsional strength, and (3) less permanent deformation in cyclical axial loading. The results further indicate that one-time axial loading of the LISS þxation construct will ultimately result in þxator plastic deformation, rather than screw pullout.