Efficacy and safety of single-dose local infiltration of analgesia in total knee arthroplasty: a meta-analysis of randomized controlled trials

PURPOSE

To examine the efficacy and safety of single-dose local infiltration of analgesia (LIA) for post-operative pain relief in total knee arthroplasty (TKA) patients.

METHODS

A systematic electronic literature search (up to Aug 2013) was conducted to identify the RCTs that address the efficacy and safety of single-dose LIA in the pain management after TKA. Subgroup analysis was conducted to determine changes of visual analog score (VAS) values at six different postoperative time points. Weighted mean differences or relative risks with accompanying 95% confidence intervals were calculated and pooled using a random effect model.

RESULTS

Eighteen trials involving 1858 TKA patients met the inclusion criteria. The trials were liable to medium risk of bias. The VAS values at postoperative 2h, 4h, 6h, 12h, 24h, and 48h per patient were significantly lower in the LIA group than in the placebo group, and the former group also had less morphine consumption and better early functional recovery including range of motion, time to straight leg raise and 90° knee flexion than the latter group. No significant difference in length of hospital stay or side effects was detected between the two groups.

CONCLUSIONS

The current evidence shows that the use of single-dose LIA is effective for postoperative pain management in TKA patients, with satisfactory short-term safety. More high-quality RCTs with long-term follow-ups are required for examining the long-term safety of single-dose LIA.

LEVEL OF EVIDENCE

I, II.

Factors influencing length of stay following primary total knee replacement in a UK specialist orthopaedic centre

AIM

To identify factors significant in influencing LOS following primary TKA in a UK specialist arthroplasty centre.

METHOD

We retrospectively reviewed factors affecting LOS of 514 patients who underwent primary TKA in a single specialist arthroplasty centre in the UK over a one-year period. Surgical and patient factors that may influence LOS were recorded.

RESULTS

The median LOS was 5days. 85% were discharged within 10days. Those staying longer were classified as long stay (up to 3months). The only surgical factor that influenced length of stay was postoperative blood transfusion (p<0.0001). Females stayed longer as did those who lived in more deprived areas. These factors did not remain significant in multivariate analysis. The other most significant predictors at multivariate analysis were pre-operative patient factors such as poor anaesthetic fitness (ASA3 and ASA4) (p=0.001), BMI=30-35 (p=0.04), BMI>35 (p=0.009) and age>80 (p=0.01).

CONCLUSION

Length of stay is largely due to case mix and this should be considered when planning a local arthroplasty service.

LEVEL OF EVIDENCE

2-II.

The local infiltration of analgesia following total knee replacement

Controversy remains regarding the optimal post-operative analgesic regimen following total knee replacement. A delicate balance is required between the provision of adequate pain relief and early mobilisation. By reviewing 29 randomised trials we sought to establish whether local infiltration of analgesia directly into the knee during surgery provides better pain relief and a more rapid rehabilitation. Although we were able to conclude that local infiltration can provide improved post-operative pain relief, and to suggest the most promising technique of administration, there is no evidence that it reduces hospital stay.