An evidence-based review of enhanced recovery after surgery in total knee replacement surgery

Rationale: Enhanced recovery after surgery is gaining popularity among orthopaedic surgeons across the globe and hence a strong evidence base had to be reviewed to make an evidence-based sustainable protocol.

Methods

The following databases, PubMed, OVID, Cochrane database and EMBASE were searched. The search was limited to 15 components of enhanced recovery after surgery programme which is divided into preoperative, intraoperative and postoperative phases. Inclusion criteria were restricted to articles published in English within the last 15 years and articles comprising of unicompartmental arthroplasty, revision knee arthroplasty, bilateral simultaneous knee arthroplasty and only hip arthroplasty excluded. The full texts were analysed and controversies and limitations of various studies were summarised.

Discussion

Each component of the programme was thoroughly reviewed and strength and weaknesses of the evidence base summarised. The strength of the evidence was assessed by critically appraising the study methodology and justifying the appropriateness of the inclusion in enhanced recovery after surgery protocol.

Conclusion

Enhanced recovery after surgery has already been used successfully in various surgical specialities. Enhanced recovery after surgery programmes in knee arthroplasty are yet to be established as a universal practice to be adopted globally. This evidence-based review provides an insight into the best evidence linked to each component and their rationale for inclusion in the proposed enhanced recovery after surgery protocol.

Downregulation of ABCB1 gene in patients with total hip or knee arthroplasty influences pharmacokinetics of rivaroxaban: a population pharmacokinetic-pharmacodynamic study

PURPOSE

Rivaroxaban is a substrate for ABCB1 transporter and is commonly used in patients undergoing hip or knee replacement surgery for thromboprophylaxis. The objective of this study was to develop a population pharmacokinetic-pharmacodynamic (PK-PD) model to investigate the influence of ABCB1 gene expression and polymorphism on rivaroxaban exposure and anticoagulation effects.

METHODS

Five blood samples per patient were collected during 5 days after the surgery for the determination of rivaroxaban concentration in plasma and for determination of prothrombin time and partial thromboplastin time. Non-linear mixed effects model was used for a population PK-PD analysis and for testing covariate effects.

RESULTS

A one-compartment PK model with first-order absorption adequately described the pharmacokinetic data. The typical oral clearance (CL/F) was 6.12 L/h (relative standard error, 15.8%) and was associated with ABCB1 expression. Compared to base line before the surgery, a significant ABCB1 downregulation was observed 5 days after the surgery (p < 0.001). Prothrombin time and partial thromboplastin time were both linearly associated to the logarithm of the rivaroxaban plasma concentration.

CONCLUSIONS

We confirmed that variable rivaroxaban CL/F is associated with ABCB1 expression, which is in accordance with previous studies on P-glycoprotein involvement in rivaroxaban PK. Furthermore, we observed the downregulation of ABCB1 expression after the surgery. The cause remains unclear and further research is needed to explain the underlying mechanisms.