A Randomized, Controlled Trial on the Effect of Anesthesia on Chronic Pain After Total Knee Arthroplasty

Abstract

Aim: The study sought to evaluate the influence of anesthesia on chronic pain after total knee arthroplasty (TKA). Methods: This was a single-center, randomized controlled study, with patients receiving a spinal anesthetic (SP) alone or a general anesthetic (GA) with femoral block, with follow-up at 3 and at 6 months. The primary outcome was the WOMAC^® score at 6 months. Results: 199 patients were enrolled. Group SP had better function (WOMAC: GA: 16.9 vs SP: 14.4, p = 0.015) and less pain (WOMAC pain: GA: 3.04 vs SP: 2.69, p = 0.02) at 3 months, but not at 6 months. Overall, 11% of patients had chronic postsurgical pain (CPSP), with Group GA having a higher incidence of CPSP at 6 months. Neuropathic pain increased during the follow-up and was more common in patients with CPSP. Conclusion: An SP reduces pain and incidence of CPSP after TKA.

Clinical Trial Registration: NCT04206046 (ClinicalTrials.gov)

Plain language summary

Patients who have knee replacement surgery are at risk of remaining in significant pain even up to one year after surgery. Our study aims to look into the potential of reducing this risk by comparing two common forms of anesthesia. 199 patients were randomized to either have a spinal anesthetic (SP) or a general anesthetic with a femoral nerve block. Patients were then followed-up for 6 months, and then asked to report on a validated functional and pain scoring system (WOMAC^®). Patients who had had an SP had better function and less pain at 3 months after surgery, but not at 6 months. The incidence of chronic pain at six month seems to be less with an SP

Keywords::

• analgesia
• anesthesia
• anesthesia, general
• anesthesia, spinal
• arthroplasty, replacement, knee
• chronic pain
• osteoarthritis, knee
• pain, postoperative

Supplementary data

To view the supplementary data that accompany this paper please visit the journal website at: www.tandfonline.com/doi/suppl/10.2217/pmt-2021-0081

Author contributions

SC Sciberras: principal investigator, design, data collection, methodology, statistical analysis, writeup. AP Vella: design, data collection. B Vella: data collection. J Spiteri: data collection, telephone interviews. C Mizzi: data collection. K Borg-Xuereb: data collection. G Laferla: design, supervisor, write up of article. G Grech: design, supervisor, methodology. F Sammut: statistical analysis, write up of article.

Financial & competing interests disclosure

This research is part of a doctorial program at the University of Malta, and was funded by the University of Malta. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval from the University and Research Ethics Committee, University of Malta. In addition, written informed consent has been obtained from all participants involved. Data protection policies have been observed throughout the study.

Data sharing statement

The authors certify that this manuscript reports original clinical trial data. Data reported in this manuscript are available within the article or posted publicly at www.clinicaltrials.gov, according to the required timelines. Additional data from the study (e.g., study protocol) are available upon reasonable request.

Additional information

Funding

This research is part of a doctorial program at the University of Malta, and was funded by the University of Malta. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.