Clinical trial to determine whether the timing of tranexamic acid administration influences perioperative bleeding in total knee arthroplasty

BACKGROUND AND OBJECTIVES

The ideal timing of tranexamic acid administration in total knee arthroplasty with tourniquet remains unclear. Our primary objective was to prove if administering it before surgical incision, instead of before releasing the tourniquet, reduces postoperative bleeding. A second objective was to determine whether a second dose reduces post-operative bleeding.

MATERIAL AND METHODS

A prospective, double-blind clinical trial was performed on 212 patients scheduled for total knee arthroplasty. They were randomised into 4 groups. Tranexamic acid was administered before the surgical incision in "pre-induction groups" (1 and 2), and just before the tourniquet release in "pre-release groups" (3 and 4). Groups 2 and 4 received a second dose 3h post-surgery. Main outcome was postoperative bleeding (visible blood loss and calculated total bleeding). Secondary outcomes were haemoglobin variations, complications and transfusion rate.

RESULTS

The mean calculated total bleeding was 1563ml (95%CI: 1445-1681) in preinduction groups versus 1576ml (95%CI: 1439-1713) in pre-release groups (P=0.9); 1579ml (95%CI: 1452-1706) in single-dose groups versus 1559ml (95%CI: 1431-1686) in double-dose groups (P=0.82). One patient was transfused. The mean haemoglobin at discharge was 10.4g/dl (95%CI: 10.2-10.7) in singledose groups versus 10.8 (95%CI: 10.6-11.1) in double-dose groups (P=0.06).

CONCLUSIONS

There were no differences in bleeding or transfusion regarding the time of tranexamic acid administration. The second dose had not impact on outcomes.

TRIAL REGISTRATION

EudraCT 2016-000071-24.

Validity of the KLIC and CRIME80 scores in predicting failure in late acute infection treated by debridement and implant retention

It is very important to treat prosthetic infections correctly in order to ensure a higher success rate. Debridement with implant retention (DAIR) is widely used in acute and late infections, however patients who fail after this surgery are known to have a higher risk of failure in subsequent surgeries. Therefore, it is important to find a scale that enables us to predict the risk of DAIR failure. Hence the KLIC and CRIME80 scores for acute and late acute infections, respectively. This study analysed the validity of both scores in acute late periprosthetic knee infections. We observed that the KLIC score has no predictive value for this type of infection, but the CRIME80 score does.

Arthrotomy debridement of arthrostic septic arthritis of the knee is more effective than arthroscopic debridement and delays the need for prosthesis despite progression

BACKGROUND AND OBJECTIVE

40%-50% of this septic arthritis occurs in the knee, despite rapid medical surgical treatment, 24%-50% will have a poor clinical outcome. It is not clear which debridement technique, by arthrotomy or arthroscopy, is more effective in controlling infection, or whether or not previous osteoarthritis worsens the outcome. The objective of this study on septic arthritis of the osteoarthritic knee was to analyse which surgical debridement technique, arthroscopy or arthrotomy, is more effective, the clinical and radiographic outcomes of the patients, and how many go on to require a TKR after the infection has healed.

MATERIAL AND METHODS

A retrospective study was performed in 27 patients with native septic arthritis of the knee. Eighteen were men and the mean age was 64.8 years (30-89years). Fifteen patients were debrided by arthrotomy and 12 by arthroscopy. The effectiveness of debridement in controlling infection, the radiographic progression of the osteoarthritis on the Ahlbäch scale, the need for subsequent replacement, and pain and functional status were analysed using the VAS and WOMAC scales at 52.8±11.2-month follow-up.

RESULTS

The infection was controlled in 93% and 92% of the patients, 13% and 42% required 2 or more surgeries for infection control, 18% and 44.4% showed progression of arthritis in the arthrotomy and arthroscopy groups, respectively. One patient in each group required a knee replacement. The VAS score was superior in the arthrotomy group and there were no differences in WOMAC score.

CONCLUSION

Debridement by arthrotomy in the emergency department by non-sub-specialist knee surgeons is more effective than arthroscopic debridement in controlling septic arthritis of the knee. Surgical debridement of septic arthritis in knees with previous osteoarthritis enabled control of the infection with no pain despite the progression of the osteoarthritis.

Effectiveness of a patient blood management protocol on reduction of allogeneic red blood cell transfusions in orthopedic surgery

BACKGROUND AND OBJECTIVES

Patient blood management in orthopaedic surgery reduces transfusion risk. The best protocol is unknown. The effectiveness of a protocol based on the Seville Consensus on the reduction of transfusion risk is evaluated and a predictive transfusion equation is proposed in knee surgery.

PATIENTS AND METHODS

Cohort study in patients undergoing knee and hip arthroplasty from January 2014 to December 2015 at a second level complexity hospital in Vilafranca del Penedès (Barcelona). Patients with Hb between 10 and 13g/dL were classified as anaemic with or without iron deficiency and received iron or combination of iron and erythropoietin. On the day of surgery, tranexamic acid was administered, the Hb drop was measured the next day and the requirements and the transfusion lintel were measured during the stay.

RESULTS

A total of 334 patients were included in the study. The implementation of the programme decreased the transfusion risk from 41.5% to 14.8% at the end of the study. In hip surgery, transfused patients were significantly older, sicker and with lower preoperative Hb. Tranexamic acid did not decrease bleeding. In knee surgery, the administration of tranexamic acid was the variable that most decreased the transfusion risk followed by a high preoperative Hb. The equation predicts transfusion risk with a sensitivity of 55% and specificity of 95.7%.

CONCLUSION

The implementation of the programme reduces transfusion risk. The effectiveness of tranexamic acid varies according to surgery site. The use of iron and recombinant human erythropoietin is necessary to improve Hb.

Arthroplasty knee registry of Catalonia: What scientific evidence supports the implantation of our prosthesis?

INTRODUCTION

In our environment, it is increasingly necessary to perform an activity based on scientific evidence and the field of prosthetic surgery should be governed by the same principles. The national arthroplasty registries allow us to obtain a large amount of data in order to evaluate this technique. The aim of our study is to analyse the scientific evidence that supports the primary total knee arthroplasties implanted in Catalonian public hospitals, based on the Arthoplasty Registry of Catalonia (RACat) MATERIAL AND METHODS: A review of the literature was carried out on knee prostheses (cruciate retaining, posterior stabilized, constricted and rotational) recorded in RACat between the period 2005-2013 in the following databases: Orthopedic Data Evaluation Panel, PubMed, TripDatabase and Google Scholar. The prostheses implanted in fewer than 10 units (1,358 prostheses corresponding to 62 models) were excluded.

RESULTS

41,947 prostheses (96.86%) were analysed out of 43,305 implanted, corresponding to 74 different models. In 13 models (n = 4,715) (11.24%) no clinical evidence to support their use was found. In the remaining 36 models (n = 13,609) (32.45%), level iv studies were the most predominant evidence.

CONCLUSIONS

There was a significant number of implanted prostheses (11.24%) for which no clinical evidence was found. The number of models should be noted, 36 out of 110, with fewer than 10 units implanted. The use of arthroplasty registries has proved an extremely useful tool that allows us to analyse and draw conclusions in order to improve the efficiency of this surgical technique.

Influence of the ischaemic tourniquet in antibiotic prophylaxis in total knee replacement

OBJECTIVE

There is level iv evidence that the preoperative administration of antibiotics helps in the prevention of prosthetic infection. There is controversy on whether the ischemia applied during surgery may affect the minimum inhibitory concentration of the antibiotic in the peri-prosthetic tissues. The aim of this study is to review this phenomenon through the determination of antibiotic concentration in the synovial tissue.

MATERIAL AND METHOD

A prospective observational clinical study was conducted on 32 patients undergoing total knee replacement. Cefonicid 2g was administered as prophylaxis, with a tourniquet used for all patients. The antibiotic concentration was quantified by high performance liquid chromatography in samples of synovial tissue collected at the beginning and at the end of the intervention.

RESULTS

The mean concentration of antibiotic was 23.16 μg/g (95% CI 19.19 to 27.13) in the samples at the beginning of the intervention and 15.45 μg/g (95% CI 13.20 to 17.69) in the final samples, being higher than the minimum inhibitory concentration of cefonicid, set at 8 μg/g. These results were statistically significant for both concentrations (P<.00001).

DISCUSSION

The antibiotic concentration throughout the standard total knee prosthesis surgery performed with tourniquet gradually decreases throughout the intervention. The concentration determined at the end of the intervention was higher than the minimum inhibitory concentration required for the antibiotic studied. In conclusion, the use of a tourniquet does not increase the risk of infection.

[The geometry of the keel determines the behaviour of the tibial tray against torsional forces in total knee replacement]

The keel design of the tibial tray is essential for the transmission of the majority of the forces to the peripheral bone structures, which have better mechanical proprieties, thus reducing the risk of loosening. The aim of the present study was to compare the behaviour of different tibial tray designs submitted to torsional forces. Four different tibial components were modelled. The 3-D reconstruction was made using the Mimics software. The solid elements were generated by SolidWorks. The finite elements study was done by Unigraphics. A torsional force of 6 Nm. applied to the lateral aspects of each tibial tray was simulated. The GENUTECH® tibial tray, with peripheral trabecular bone support, showed a lower displacement and less transmitted tensions under torsional forces. The results suggest that a tibial tray with more peripheral support behaves mechanically better than the other studied designs.