Research

Trials in Canterbury

As there are considerable uncertainties about the effectiveness of several forms of therapy for carpal tunnel syndrome we are planning a small selection of treatment trials in Canterbury. These trials are in various states of preparation as noted below. If you wish to participate in any of these please discuss it with us when you attend for testing.

2007 cohort study

We have recently attempted to follow up all of the patients who were first seen by us for carpal tunnel syndrome in 2007 and began treatment with local steroid injection. Some of you we have seen recently and we already know how your symptoms have responded to treatment but there are 235 patients with whom we have had no contact for more than a year. We wrote to these 235 patients during the week beginning 13th April 2015 with an invitation to participate in this small study. The only action required of patients who received one of these letters was to reply to us with some further information about the current state of their CTS symptoms and any further treatment they have had. Patients are however welcome to contact us through the website forums or by other means to ask further questions. We obtained full follow-up data from 157 patients, 22 were deceased and 75 either could not be contacted or declined to provide full information on their current symptoms and treatment. This paper has now been published in the Journal of Hand Surgery (European Volume). The bottom line conlcusion is that, 8 years after beginning treatment with steroids, only 41% of patients have had surgery.

INDICATE-P

This was a pilot study funded by the British Society for Surgery of the Hand which took patients with moderately severe CTS and randomly allocated them to either local steroid injection or surgery as first line treatment. 40 patients were recruited across 4 different UK hospitals and followed up for 1 year to assess the outcomes. 18 patients were recruited in Canterbury. The results have been presented at the British Society for Surgery of the Hand and published as a short paper in the Journal of Hand Surgery (European Volume)

Therapeutic ultrasound for CTS

The three existing methodologically reasonable trials of ultrasound treatment have conflicting results. We are therefore carrying out a further randomised, double blind trial of this treatment to try and resolve the issue once and for all, replicating the methodology of the one existing trial which reported a positive effect of ultrasound. Ultrasound treatment is very safe and painless but is quite time consuming - five visits per week for two weeks followed by two visits per week for 5 weeks - each taking about 20 minutes or so. It therefore requires a good deal of time and commitment from the patient. We carry out these treatments in the early evening so that hopefully they can be after work for most people. This trial is now complete and has been published in Muscle and Nerve.

'C-trac' splinting for CTS

The C-trac splint is a US patented device which attempts to stretch the transverse carpal ligament using externally applied pressure. We have no business connection with the manufacturer/vendor and we are planning to complete a trial which has been performed partially in Canada. This is awaiting ethical committee approval here in the UK at present.

Single or double local steroid injections for CTS

One previous study comparing surgery with steroid injection for CTS used an unusual injection protocol in which one injection was given initially. The patients were then reviewed two weeks later and, if there were still ANY residual symptoms, given a second injection. Thus only patients who were totally asymptomatic after one injection received a single dose. All other patients (the majority) had two consecutive injections two weeks apart. The study is interesting because the clinical outcomes in the injection group were unusually good for a steroid injection study. We would like to compare this 'conditional second injection' approach with our current policy of using a single injection only as initial treatment to see if it really is more effective. This idea has not yet been submitted for research governance/ethics approval however and is unlikely to start for some time.

Choice of steroid and dose for CTS injection

There are only two previous studies comparing different steroids/doses in the treatment of CTS, one small and methodologically poor one (O'gradaigh 2000) and one very good one (Atroshi 2013 - see the trial evidence page). At present most trials which have reported good results from steroid injection have used 40mg methyprednisolone or equivalent. Dr Atroshi's study suggests that those given 80mg had a lower rate of surgery at one year, whereas Dr O'Gradaigh's paper suggested that dose and steroid choice made little difference. More work is clearly needed and we may consider a study in Canterbury comparing doses and steroids.

Amyloidosis as a cause of CTS

In older patients a proportion of CTS is thought to be a result of deposition of a protein known as amyloid in the tissues of the carpal tunnel. Amyloid can also be depositied in other tissues and in particular can affect the heart. It has been noted that many patients who present with heart failure due to amyloidosis have a prior history of carpal tunnel syndrome some years beforehand and it is possible that checking for this disorder when operating on the carpal tunnel might give early warning of later, more serious problems. This is becoming more important as possible treatments for this type of amyloidosis are on the horizon. We will therefore be collaborating with the National amyloidosis unity at the Royal Free Hospital to study how many of our patients having surgery have evidence of amyloidosis. This requires only taking a small sample of tissue at the time of surgery and sending it to the Royal Free laboratory for analysis. This study is recruiting now (OCtober 2021)

Trials Elsewhere

There is a fair amount of research interest in carpal tunnel syndrome at present and the following are links to significant trials in progress now:

INSTINCTS - Coordinated by the University of Keele, this prospective, randomised study compares a single injection of 20mg depo-medrone with 6 weeks of splinting in patients diagnosed as having CTS by their general practitioner or a hospital clinic on clinical grounds (ie without confirmation by nerve conduction studies). The intention is to follow up patients for 2 years. This has now completed and been published in the Lancet. It found a single steroid injection to be more effective than splinting, despite using quite a small steroid dose.

CAPS - Imperial College is conductiing a study of pain in CTS, attemting to elucidate the impact of neuropathic pain and somatosensory phenotype on post-operative outcome. Results are awaited.

PALMS - a prospective, observational study of prognostic factors in the treatment of CTS is coordinated form the University of East Anglia in Norwich. It has finished recruiting and is following up a cohort of patients for 2 years without interfering in their treatment to try and identify prognostic factors. This too has now been published.

Revision date - 12th October 2021