In the Unites States, approximately 24% of people undergoing primary total knee or total hip arthroplasty (TKA, THA) are chronic opioid users pre-operatively. Few studies have examined the incidence of opioid use prior to TKA/THA and whether it predicts outcomes post-surgery in the Australian context. The aim was to determine: (i) the proportion of TKA and THA patients who use opioids regularly (daily) pre-surgery; (ii) if opioid use pre-surgery predicts (a) complication and readmission rates to 6-months post-surgery, (b) patient-reported outcomes to 6-months post-surgery. A retrospective cohort study was undertaken utilising linked individual patient-level data from two independent databases comprising approximately 3500 people. Patients had surgery between January 2013 and June 2018, inclusive at Fairfield and Bowral Hospitals. Following data linkage, analysis was completed on 1185 study participants (64% female, 69% TKA, mean age 67 (9.9)). 30% were using regular opioids pre-operatively. Unadjusted analyses resulted in the following rates in those who Adjusted regression analyses controlling for multiple co-variates indicated no significant association between pre-op opioid use and adverse events/patient-reported outcomes. Pre-operative opioid use was high amongst this Australian arthroplasty cohort and was not associated with increased risk of adverse events post-operatively. Further research is needed in assessing the relationship between the amount of pre-op opioid use and the risk of post-operative adverse events.
Total Knee Arthroplasty (TKA) is a successful treatment for end stage osteoarthritis of the knee joint. However, post-operative pain can lead to patient dissatisfaction and poorer outcomes. Cooled radiofrequency nerve ablation (CRNA) has reportedly been effective at treating pain osteoarthritic knee pain by targeting the periarticular nerves of the knee. We undertook a prospective, controlled pilot study to determine if CRNA provides effective post-operative analgesia when utilised intra-operatively during total knee arthroplasty. Participants were recruited from January 2019 to February 2020. Those meeting inclusion criteria underwent TKA with intraoperative CRNA to 6 target sites prior to the cementing of implants. The primary outcomes were pain scores and opiate usage in the first 4 days post-operatively, then weekly up to 6 weeks. A total of 62 patients were screened and allocated sequentially; 18 were recruited to the control group and 12 recruited to the study group. The two groups did not have any significant difference in demographics. There were no clinically significant differences between the two groups in terms of pain scores nor opiate usage. There were complications as a result of the intervention. This study demonstrated no benefit of using intraoperative CRNA for improving post-operative pain scores or reducing opiate use after TKA.
Tourniquet use in TKA is common practice. A recent meta-analysis concluded that whilst early release (prior to closure of the quadriceps mechanism) increases blood loss, it protects patients from complications. However, there has been no research evaluating tourniquet use during cement fixation only. This study proposed to establish whether tourniquet application during cement fixation only (Short Duration) was associated with better functional recovery compared to standard tourniquet (Long Duration) application during TKA. We planned to randomise 230 patients to receive Short or Long Duration tourniquet application. The primary outcomes were in-hospital donor transfusion rate and the Oxford Knee Score at 10 weeks post-surgery. Serial measures (pre-operative, day 4 then 2, 10, 26 and 52 weeks post-operation) of knee range and function were undertaken. Pre- and post-operative Doppler ultrasounds were obtained. The trial was discontinued after randomisation of 65 patients. Interim analysis indicated the risk of transfusion (odds ratio 7.38, P = 0.015) was higher in the Short Duration group. At 10 weeks post-surgery, no significant difference was observed in Oxford Knee Score. There were no between-group differences in rate of recovery up to 26 weeks for any outcome. We conclude that restricting tourniquet application to the period of cementing is associated with a significantly higher risk of transfusion. This approach is impractical if it is not offset by very impressive gains in functional recovery.
S epidermidis and P aeruginosa are recognised major biofilm pathogens in medical device contamination and chronic wounds. Within biofilms, bacteria are enclosed in a polymeric matrix that cements them to each other and to the surface and protects them by increasing resistance to host immunity, antibiotics and biocides. Staph and pseudomonas spp biofilm were grown on glass coupons for 48 hours and the coupons randomly inserted into the wound model for 24 hours and subjected to TNP and the following: No instillation 0.1% w/v formulated hypocholorous acid (FHA) instillation Saline instillation Betadine instillation Betadine and saline instillations were for 30 minutes, while FHA was for three minutes, every eight, four and two hours per day. The biocides were at sub-lethal concentrations. The coupons were then extracted to avoid damaging the biofilms and effect of TNP was assessed by colony forming units and electron microscopy. The results show that lower frequency of instillation did not have significant effect on bacterial load for both types of bacteria. Increase in frequency of instillations resulted in no growth of pseudomonas while increase in frequency of instillations resulted in a significant decrease in growth of staph spp. Frequent flushing of the wound model resulted in a loss of biofilm bacteria for both Pseudomonas and Staph epi. The biocides combined with TNP were more effective in killing Pseudomonas compared with Staph epi.
