Preoperative peripheral nerve blocks are not independently associated with improved functional outcome, patient satisfaction, or risk of chronic pain at one year following knee arthroplasty

Listen to Simon and Amy discuss the paper 'Preoperative peripheral nerve blocks are not independently associated with improved functional outcome, patient satisfaction, or risk of chronic pain at one year following knee arthroplasty' published in the February 2025 issue of Bone & Joint Open.

Click here to read the paper.

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Transcript

[00:00:00] Welcome back to another episode of AI Talks with Bone & Joint, presented by the publishers of Bone & Joint Open. Today we are discussing the paper, 'Preoperative peripheral nerve blocks are not independently associated with improved functional outcome, patient satisfaction, or risk of chronic pain at one year following knee arthroplasty', published in February 2025 by N D. Clement and his colleagues. I am Amy, and I'm joined by my co-host Simon. 

Hello everyone. So Amy, peripheral nerve blocks are widely discussed in orthopaedic circles. Could you start by giving us some background on why this research was undertaken? 

Certainly, Simon. The primary aim of this research was to understand if preoperative peripheral nerve blocks known as PNBs have a significant impact on functional outcomes, patient satisfaction, and chronic post-surgical knee pain one year after knee arthroplasty. [00:01:00] Essentially they were investigating whether using nerve blocks before surgery could result in better long-term outcomes for patients.

With knee replacements on the rise, it makes sense to find the most effective pain management strategies. How did the researchers carry out their study? 

The study was a retrospective cohort analysis conducted over two years involving 3,338 patients who underwent knee arthroplasty of whom 1,434 received a lower limb PNB.

They collected data using various patient-reported outcome measures, including the Oxford Knee Score, the EQ-5D, and the EQ-visual analogue scale, both preoperatively and one year postoperatively. 

That sounds quite comprehensive. What were some of the key findings from the study? 

Interestingly, the study found that PNBs were not significantly associated with improved functional outcomes or reduced chronic knee [00:02:00] pain at the one year mark.

In fact, patients who had PNBs showed a marginally worse improvement in their knee-specific outcomes. Although this was statistically significant, it was less than the minimal clinically important difference. 

That's surprising. We often hear about the benefits of nerve blocks in the acute phase after surgery, but it seems they don't provide the long-term benefits we might expect.

Exactly, during the acute phase, nerve blocks undoubtedly help control pain and reduce the need for opioids, facilitating early mobilization. However, when it comes to long-term benefits like improved knee function or reduced chronic pain, the results are not as promising. 

Did the study mention any reasons why the results turned out this way?

Yes. The authors acknowledged several limitations, including the non-randomized nature of the study and potential selection biases. They also pointed out that factors like pain catastrophizing and mental health [00:03:00] were not included in the analysis, but could significantly influence outcomes. 

That's a good point. Mental health and a patient's perspective on pain can have a significant impact on recovery. Did the researchers suggest any changes for clinical practice based on their findings?

They suggested that while PNBs are beneficial for managing acute pain, their utility for improving long-term outcomes may be limited.

They also emphasized the need for more research to assess other factors that could influence long-term recovery, post-knee arthroplasty.

Very insightful. It seems like a takeaway here is the necessity of a more holistic approach to patient care, considering both physical and mental health aspects. 

Any final thoughts, Amy?

The main insight is that while PNBs remain useful during the perioperative period, their limitations should be recognized and they should be integrated into a comprehensive care plan that includes other elements of patient health and recovery. Understanding the nuances in pain [00:04:00] management can better prepare both clinicians and patients for effective treatment strategies.

Thanks, Amy. That's a wrap for today. We hope this episode provided a clear understanding of the recent findings on peripheral nerve blocks in knee arthroplasty. Remember to follow Bone & Joint Open for more insightful discussions. Until next time, take care.