FP-00004

Section 1 - Basic information about you and your application:

Title of research project
Analgesic effects of using local anaesthetic to insufflate the elbow for arthroscopy: a randomized control trial.

Grant Type
The ORUK Inspiration Fund

Research area
Treatment

Duration
18

Start date
January 15, 2024

Have you previously received funding from ORUK?
No.

Profession
Orthopaedic surgeon

Your current job title/position
Upper Limb Fellow

Are you an early-career researcher (ECR)? (definition of ECR)
yes

Section 2 - Lay summary

Lay summary:

We would like to assess the effect of inflating the elbow joint with local anaesthetic instead of saline solution for elbow arthroscopy. We seek to investigate whether local anaesthetic administered this way provides pain relief, or has an impact on analgesic requirements around the time of surgery.

When local anaesthetic is used this way in wrist and knee arthroscopy, the analgesia is so good, that the surgery can be performed under local anaesthetic alone. However, this analgesic effect is not so great when this technique is used in shoulder and hip arthroscopy. The effect of using local anaesthetic to inflate the elbow joint prior to arthroscopy has never been studied in the literature.

If using local anaesthetic in this way for elbow arthroscopy is effective, then it can improve patient comfort post-operatively, and potentially decrease opiate use perioperatively.

The exact number of elbow arthroscopies performed across the UK is difficult to estimate. Our service has performed over 400 elbow arthroscopies over the past 10 years alone. What is known, is that there is a growing crisis of opiate abuse worldwide, and it is now known that perioperative administration of opiates can contribute to addiction and misuse. Therefore any measures that can be taken to decrease the need for opiates perioperatively, whilst still ensuring comfort of the patient, is worth investigating.

Traditionally, surgeons have been apprehensive to use local anaesthetic in elbow surgery. This is because there are many nerves which run millimeters from the elbow joint, and are therefore vulnerable to injury during surgery. The effect of local anaesthetic (numbness, diminished sensation, muscle weakness or paralysis) can mask a inadvertent nerve injury caused by surgery. However, we have reviewed the 400+ elbow arthroscopies performed in our institution, and there were no nerve injuries seen in our series, thus suggesting the concern for nerve injury is overstated in the literature.

We would like to see if we can improve the comfort and pain relief of our patients by performing a prospective, randomised, blinded, placebo controlled trial – either inflating the elbow joint with local anaesthetic or saline – prior to elbow arthroscopy, in our hospital. This research question has never before been investigated in the literature, and we wish to address this deficit in knowledge.

 

Section 3 - Purpose of research

Purpose of research:

The aim of this project is to investigate whether inflating the elbow joint with local anaesthetic prior to performing an elbow arthroscopy has an effect on analgesia requirements and pain, both during and after the procedure, when compared to using normal saline solution.

We will perform a prospective, blinded, placebo controlled trial, using normal saline solution as the placebo arm. Perioperative analgesia will be assessed by converting administered opiates to morphine milligram equivalents. This is calculation which is performed to standardise the amount of opiate administered to a patient as an equivalent of oral morphine, as different opioid analgesic agents have differing amounts, strengths or active metabolites of opiate. As a secondary objective, we will assess any difference in post-operative pain scores between the two groups. Postoperative complications, such as the requirement for a “rescue block” (whereby a patient’s pain is so severe post-operatively that they require local anaesthetic to be injected directly around the nerves supplying the operative site).

 

 

Section 4 - Background to investigation

Background to investigation:

It is common practice to inflate the elbow joint with fluid prior to arthroscopy, in order to expand the space available in the joint, which in turn facilitates the ability to view structures adequately through the arthroscope (1).

In other joints around the body, for instance, the knee or the wrist joint, it has become increasingly common to use local anaesthetic to insufflate the joint, instead of normal saline, as it provides excellent analgesic effects, to the extent that often no additional general anaesthesia is required (2, 3).

Traditionally, there has been hesitancy regarding the use of local anaesthetic with elbow arthroscopy – either for a regional nerve block, or for local tissue infiltration – as it may confuse a post-operative examination of nerve function (4-6). This is of particular importance with elbow arthroscopy, as there are many nerves that run within millimeters of the elbow joint and can theoretically be injured during elbow arthroscopy (4, 5). However there is increasing evidence that the benefits of the additional analgesia provided by local anaesthetic infiltration are outweighed by the potential risk of nerve damage, as the technique of elbow arthroscopy is improving over time (6). Wada et al have shown in their RCT that simple local anaesthetic infiltrate to the portal sites provides equivalent pain relief in elbow arthroscopy when compared to an axillary block (7). An audit of over 400 elbow arthroscopies performed in our institution found no permanent nerve injuries post-operatively, and one case of temporary altered sensation in the median nerve distribution, which self-resolved.

There have been reports of chondrotoxicity with intra-articular administration of local anaesthetic agents, however this is largely due to continuous infusions of local anaesthetic over 24-48 hours (8, 9). The effect of a single injection of local anaesthetic on cartilage cells has been found to be negligible (9-11), and therefore safe for us to consider using for our study.

Ropivacaine 0.75% is a local anaesthetic agent routinely used for intra-articular local anaesthetic injections (12, 13). Ropivacaine has a moderate onset of action with a longer duration of anaesthesia than lignocaine with adrenaline (14, 15), therefore is preferred for longer surgeries, such as elbow arthroscopy. Most of the literature regarding intra-articular absorption use bupivacaine as their testing agent, and have repeatedly been shown to have low serum absorption levels after intra-articular injection (16). One study comparing intra-articular injection of bupivacaine compared to ropivacaine showed that serum levels of the local anaesthetic measured for up to 3 hours after injection were well below the threshold for systemic toxicity(13). Comparing ropivacaine to bupicacaine, it has a safer risk profile for cardiac toxicity, and lower chondrotoxicity risk (16).

We aim to determine whether there is a difference in pain relief when using local anaesthetic to insufflate the elbow joint prior to commencing arthroscopy when compared to normal saline solution, in terms of morphine milligram equivalents given perioperatively and post-operative pain scores. To our knowledge, this has never been examined in the literature for elbow arthroscopy.

 

1. Pederzini LA, Di Palma F, Safran MR, Bain GI. Elbow arthroscopy: state of the art. Journal of ISAKOS. 2017;2(5):279-94.
2. Liu B, Ng CY, Arshad MS, Edwards DS, Hayton MJ. Wide-awake wrist and small joints arthroscopy of the hand. Hand clinics. 2019;35(1):85-92.
3. Iossifidis A. Knee arthroscopy under local anaesthesia: results and evaluation of patients’ satisfaction. Injury. 1996;27(1):43-4.
4. Freehill MT, Poehling GG, Bain G. Portals and diagnostic elbow arthroscopy. Surgical techniques for trauma and sports related injuries of the elbow. 2020:107-17.
5. Harrison WD, Tonge X, Bhalaik V. Avoiding complications in elbow arthroscopy. Journal of arthroscopy and joint surgery. 2019;6(1):42-7.
6. Marco SM, Lafuente JÁ, Edo ÓJ, Pequerul JG. Perioperative pain management in arthroscopy of the elbow. Rev Esp Artrosc Cir Articul En. 2022;29(2):98-107.
7. Wada T, Yamauchi M, Oki G, Sonoda T, Yamakage M, Yamashita T. Efficacy of axillary nerve block in elbow arthroscopic surgery: a randomized trial. Journal of Shoulder and Elbow Surgery. 2014;23(3):291-6.
8. Kinkartz JD, Mansour AA, Noonan TJ. Post-arthroscopic elbow chondrolysis after continuous intra-articular ropivacaine infusion. Journal of Shoulder and Elbow Surgery. 2012;21(11):e1-e5.
9. Gulihar A, Robati S, Twaij H, Salih A, Taylor GJ. Articular cartilage and local anaesthetic: a systematic review of the current literature. Journal of orthopaedics. 2015;12:S200-S10.
10. Ravnihar K, Barlič A, Drobnič M. Effect of intra-articular local anesthesia on articular cartilage in the knee. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2014;30(5):607-12.
11. Ravnihar K, Marš T, Pirkmajer S, Alibegović A, Koželj G, Stožer A, et al. The influence of a single intra-articular lidocaine injection on the viability of articular cartilage in the knee. Cartilage. 2021;13(1_suppl):456S-63S.
12. Marret E, Gentili M, Bonnet MP, Bonnet F. Intra-articular ropivacaine 0.75% and bupivacaine 0.50% for analgesia after arthroscopic knee surgery: a randomized prospective study. Arthroscopy: The Journal of Arthroscopic & Related Surgery. 2005;21(3):313-6.
13. Convery P, Milligan K, Quinn P, Sjövall J, Gustafsson U. Efficacy and uptake of ropivacaine and bupivacaine after single intra‐articular injection in the knee joint. British Journal of Anaesthesia. 2001;87(4):570-6.
14. Kalath RN, Kulal R, Gopinath S. Comparison of clinical efficacy of ropivacaine and lignocaine with adrenaline for implant surgery anesthesia: a split-mouth randomized controlled clinical trial. Journal of Dental Anesthesia and Pain Medicine. 2021;21(4):337.
15. Caballero M, Kobayashi Y, Gottschalk AW. Local Anesthetic Use in Musculoskeletal Injections. The Ochsner Journal. 2022;22(3):200.
16. Vereecke H, ALMọvsT F, Herre Goos L. The peri-operative use of intra-articular local anesthetics: a review. Acta Anaerh Belg. 2009;60:J01-108.

Section 5 - Plan of investigation

Plan of investigation:

Potential participants will be identified from the public waiting list and prospective bookings at our institution. Patients meeting the selection criteria will be invited to participate in the study:

Inclusion:

• Patients who require an elbow arthroscopy; with or without a mini-open procedure (e.g., for removing large loose bodies)
• Male and Female patients
• Age >18 years and <90 years at the time of operation
• Patients able to consent to participate in this placebo double blinded randomized controlled trial

Exclusion:

• Patients unable to comply with assessment requirements
• Patients unable to provide informed consent
• Patients who decline to participate
• Patients with the following conditions: patients who require concurrent open procedures (e.g., ulna nerve decompression), patients who have allergies to any of the drugs used in the study protocol, patients who routinely use opioid analgesia pre-operatively

Once the eligible patients are identified, they will be contacted via telephone to explain the project and offer to invite the patients to participate prior to surgery. A follow up confirmation and written consent form will be then posted to the patients with a paid, self-addressed envelope to return the written consent to the research co-ordinator.

Patients will then be randomized to either the local anaesthetic group (LA group) or the saline group (NA group). The LA group will receive 10mL of 0.75% ropivacaine to insufflate the elbow joint prior to arthroscopy, whereas the NA group will receive 10mL of normal saline solution to insufflate the elbow joint prior to arthroscopy. Both groups will receive 20mL of 0.75% ropivacaine at the end of the case, divided between the portal sites and the articular space. Please note that these doses are for adult patients who weigh ≥70kg. For those who weigh ≤69kg, a weight dependent dosage will be calculated as 3mg/kg, not to exceed 225mg per dose.

Intraoperative anaesthesia and analgesia will be standardized to induction with 1.5-3mg/kg IV propofol and 50-100mcg IV fentanyl, spontaneous or assisted ventilation with sevoflurane and oxygen-air mixture, and administration of 1g (500mg if patient’s weight is under 50kg) IV paracetamol and 5mg (0.1mg/kg if patient’s weight is under 50kg) IV morphine from the start of the procedure. All patients received 6.6mg IV dexamethasone and 4mg IV ondansetron for prevention of postoperative nausea and vomiting.

Random permuted block sizes of 4 will be used to achieve balanced group sizes whilst minimising excessive runs of single group allocations. A web-based randomization program (Sealed Envelope Ltd, London, UK) will be used by a team member not involved with assessment of any patient outcome measures to allocate each patient’s treatment group.

The allocation will be present in a sealed envelope and will be revealed to a specifically appointed study nurse. This study nurse will then draw up the assigned fluid for insufflation, out of sight of the operative team. This study nurse will then hand this syringe to the surgical staff for use, without disclosing the contents to the rest of the team.

The following data regarding patient demographics, condition specific information and operation details and analgesia requirements will be reviewed. Only the patient, patient’s surgeon, and the research co-ordinator have access to the patient’s identified data.

The following demographic data will be collected: age, gender, ASA, weight (as the local anaesthetic dosage is weight based), past medical history (including regular opiate analgesia usage, and allergies to any study medications).

The following condition specific information will be collected: side affected, diagnosis.

The following operative data will be collected: operation date, operation description, intra-operative complications (type, management, expected to affect outcome yes/no). Intra-operative analgesia administration will be collected (with specific notation of opiate analgesia use).

In order to standardize the dosage of opiates prescribed, these medications will be converted to morphine milligram equivalent doses. These will be calculated using the Australian and New Zealand College of Anaesthetists Online Calculator (http://www.opioidcalculator.com.au/opioidsource.html).

Post-operative pain assessment in the recovery room will consist of the Numerical Rating Scale – 11 (Appendix 1). The morphine milligram equivalent doses of analgesia received in the recovery room will also be collected.

Once the patient is transferred to the post-recovery room ward, a Visual Analogue Scale (VAS) will be used for the patient rate their pain scores at 2, 4, 6 and 24 hours post-operatively (Appendix 2). Morphine milligram equivalent doses of analgesia will also be recorded during this time. Patients will be sent home with a pamphlet (Appendix 3) for documenting VAS as well as analgesia requirements after discharge, which can be emailed, posted or returned to the care team at their post-operative outpatient review.

Postoperative complications will also be investigated and reported, such as local anaesthetic toxicity, nerve injury, whether a “rescue block” was required in recovery or any other complications.

Every effort will be made to ensure complete data sets; should missing data not be available, this will be reported on and statistical analysis will be adjusted – the intention to treat analysis will be used; assuming the “worst case scenario” by using the worst pain scales and highest morphine milligram equivalent doses present in the data series.

This study does not involve any commercial entities – the local anaesthetic used is what is standard in our hospital. No investigators have a financial conflict of interest with any element in this study. Therefore we believe that the opportunity for commercial exploitation is negligible.

Should this study show that the use of local anaesthetic to insufflate the elbow joint is beneficial, then this can decrease the requirement for opiate analgesia and improve patient comfort. Should it not be effective, then this can provide guidance to avoid this method, thus provide a saving to the healthcare system, and avoiding the potential side effects associated with local anaesthetic usage.

Section 6 - Research environment and resources

Research environment and resources:

This project will take part in our hospital’s operating theatre, as part of our normal daily activities.

We will have support from additional research staff, who work in the research department at our institution. We will require funding for these support personnel.

Grant amount requested: ₤5000

Total budget estimate for project: ₤13,000.

Research nurse – The UK requires any personnel who are directly involved in research have certification of Good Clinical Practice in research. They require the circulating nurse who will be drawing up the solution for injection (local anaesthetic or saline) to have a GCP certificate. Therefore, in order to gain sponsorship and ethics approval, we require a research nurse for this purpose. This is a “Band 6” position for 0.5 days per week for the 18 months we estimate will take to execute the trial, which costs ₤6651.

Research coordinator – non-clinical personnel are essential for running a RCT. They will be vital in collating data, and also as being a central contact point for patients for returning questionnaires, or for patient questions to be sent onto the investigators to answer. They will also assist in data entry. This is a “Band 4″position for 0.5 days per week for the 18 months we estimate will take to execute the trial, which costs ₤4864.80.

Conference and publication costs – It is the culture in the UK that researchers receive funding to attend conferences to present, and to receive funding to publish in an open access journal. Registration to present at the British Shoulder and Elbow Society meeting is ₤450. Publishing in the Journal of Shoulder and Elbow Surgery International is $1250USD = ₤1000.

We have also sought additional funding from the following institutions:

• Australian Orthopaedic Association Research Foundation
  • Requested $10,000 AUD (approximately ₤5000)
  • Grant application results will be announced mid-August 2023
• European Society for Surgery of the Shoulder and Elbow
  • Requested ₤4000
  • Grant application results will be announced mid-September 2023

As these other grant applications have not been judged yet, I have completed Section 9 with the full costings of the project.

Section 7: Research impact

Who will benefit from this research?

We believe that patients and surgeons can benefit from this research – whether the results show a difference between the two intervention arms or not.

In the event that our results show that using local anaesthetic to inflate the elbow prior to arthroscopy provides superior pain relief, the benefits will be as follows:

• Benefit to patients
  • Improved pain relief and comfort
  • Decreased need for opiate analgesia (and their associated adverse effects)
•  Benefits to surgeons and the healthcare system
  • Reassurance that it is safe and efficacious to use local anaesthetic in elbow arthroscopy

In the event should our project show no superiority between the two intervention arms, then the benefits will be as follows:

•  Benefit to the patients
  • No need to use local anaesthetic and risk the potential side effects
• Benefits to surgeons and the healthcare system
  • Decreased cost of surgery by using saline instead of the more expensive local anaesthetic

How can your research be translated in real-life?

Our project is imminently translatable to real life, as it is a clinically based project.

There is great apprehension amongst the orthopaedic community for using local anaesthetic during elbow arthroscopy, for fear of masking an iatrogenic nerve injury.

From our case series of over 400 arthroscopies, this fear is unfounded, as we only had 1 temporary sensory neuropraxia, and local anaesthetic was used routinely in the majority of these cases.

By performing our RCT and reporting on the complications, we can infer the safety of the technique.

As stated in the previous section, we can potentially improve the pain relief and comfort for our patients, minimise their exposure to opiate analgesic agents and their associated adverse effects. Or if the technique is shown to be no better than placebo (saline), then we can cease our use of local anaesthetic in elbow arthroscopy, inducing a modest saving for the healthcare system.

How will your research be beneficial for ORUK and its purpose?

This is a British study involving visiting surgeons from Australia. This project has never been studied before. By performing this research project and disseminating the results, it once again shows that British Orthopaedic Surgeons are world leaders, and “pioneer[s] of new forms of treatment”.

This is clinically based research, and therefore the findings are easily translatable into real benefits for our society.

Furthermore, we are quite literally investigating pain relief for joint surgery, thus aligning with the ORUK ethos of “pain-free movement for all”.

If our hypothesis is rejected or not, this still provides benefits to the health service, thus “easing the burden on the NHS”, as stated earlier in Section 7.

 

Section 8: Outreach and engagement

Participants in the study will be provided with a plain English summary and infographic pamphlet of the results, upon request.

This study will also be published on the Trust’s research website.

Furthermore, the clinical fellows at our service have an active and engaged Twitter account, where the infographic pamphlet will be posted to this account when available.

Section 9: Research budget

Requested funding from ORUK

University fees (if any)
£0

Salary
£11515.8

Consumables
£0

Publications
£1000

Conference attendance
£450

Other items
£

Total 'requested fund'
£12965.8



Other items




Other secured funds

Internal funding
£0

Partner (University)
£0

Partner (Commercial)
£0

Partner (Charity)
£0

Other sources
£0

Total 'other funds)
£0

Section 10: Intellectual property and testing on animal

Is there an IP linked to this research?
No

Who owns and maintains this patent?


Does your research include procedures to be carried out on animals in the UK under the Animals (Scientific Procedures) Act?
No

If yes, have the following necessary approvals been given by:

The Home office(in relation to personal, project and establishment licences)?


Animal Welfare and Ethical Review Body?


Does your research involve the use of animals or animal tissue outside the UK?
No

Does the proposed research involve a protected species? (If yes, state which)



Does the proposed research involve genetically modified animals?


Include details of sample size calculations and statistical advice sought. Please use the ARRIVE guidelines when designing and describing your experiments.


There should be sufficient information to allow for a robust review of any applications involving animals. Further guidance is available from the National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), including an online experimental design assistant to guide researchers through the design of animal experiments.

Please provide details of any moderate or severe procedures


Why is animal use necessary, are there any other possible approaches?


Why is the species/model to be used the most appropriate?