Arthroscopic knee surgery is a universally accepted technique, and continuing improvements in both surgical techniques and equipment mean an ever-increasing number of patients can be operated on with less insult to external and surrounding structures, decreased incidence of complications, and a more rapid recovery and rehabilitation.
As with any surgical intervention, knee arthroscopy is not completely benign, and the continual search to improve and optimise operative techniques has led to a general consideration of the infiltrates commonly utilised both during and after arthroscopy. Potentially detrimental effects on chondrosynthesis, caused by the still common practice of instilling local anaesthetic into the joint at the end of surgery have been reported. This prompted a study – published in the print edition of The Journal of Knee Surgery [J Knee Surg 2016;29(06):502-509. doi: 10.1055/s-0035-1566736] by consultant surgeon Sanjeev Anand and colleagues, that sought to determine whether restoring a more physiological environment within the joint by replacing the synovial fluid with a synthetic analogue following arthroscopy resulted in a measurably improved outcome.
VISCOSEAL® is a unique product designed to reduce pain and swelling following arthroscopic joint surgery. Developed and manufactured by TRB Chemedica, this novel, fermentative source Sodium Hyaluronate formulation is being used by an increasing number of orthopaedic surgeons instead of local anaesthetic following arthroscopic joint surgery.
Alex Flanagan (pictured), managing director of TRB Chemedica UK, spoke with Sanjeev Anand about the study he performed.
Sanjeev Anand MBBS, MS (Orth), DNB (Orth), FRCSI, FRCS (TrOrth), MFSEM, Diploma Sports/Exercise Medicine, is consultant orthopaedic surgeon, knees, sports injury and hip arthroscopy, at Nuffield Health, Leeds, and at Leeds Teaching Hospitals NHS Trust.
How did the idea for your investigation into replacing synovial fluid after knee arthroscopy come about?
We were aware that some patients seemed to do less well following fairly simple knee arthroscopy – we had examined discrepancies in surgical procedure and technique, but we were also aware of some published data that was emerging at that time regarding the deleterious effects of local anaesthetic on articular cartilage. So, when we were introduced to the concept of synovial fluid replacement following arthroscopy, we set up a study to determine if there was any measurable merit to the idea.
When was the study originally conducted and where?
The study was carried out in 2002–03 at The Royal Oldham Hospital in Lancashire, England. I designed the study, along with a number of colleagues, and we carried out the investigation over an 18-month period. The abstract and poster were presented at a number of international meetings from 2004 onwards – the full paper took a little longer to complete, it is now available in print and as an e-first publication of The Journal of Knee Surgery.
What were you particularly concerned about in terms of those patients experiencing side effects following knee arthroscopy at that point in time?
Mainly the pain and swelling – both immediately post-op and in the short to medium term. Of course, we had robust analgesic protocols in place, but we noticed that those patients with enduring pain and functional deficit did not engage as well with rehab programmes as those patients with no reported side effects.
So what did you do during the arthroscopy that was different to the standard procedure?
Well, it was a very minor change. At the end of the surgery directed to the patient’s particular pathology, we evacuated any remaining saline and instead of infiltrating Bupivacaine into the cavity, we infiltrated the synovial fluid replacement – Viscoseal® – via a syringe and needle directly into the joint.
Briefly, what were the results of such a relatively small proced difference?
The most pronounced differences, which did reach statistical significance compared with the Bupivacaine controls, were the SF-12 values, the WOMAC scores, analgesic consumption, and pain and swelling evaluations. Obviously, the full details are included in the recent journal publication, but we were very satisfied that our results supported the study intervention under investigation.
Were there any adverse events or post-operative problems that were attributed to the use of Viscoseal?
There were no adverse effects whatsoever.
A limited number of published studies on the use of viscosupplementation following arthroscopy reported no significant difference between active and control groups. Why do you think your study produced results which significantly favoured the VISCOSEAL group?
I tend to think there’s some confusion arising from the term viscosupplementation in relation to what we did in our study. Viscoseal is not a viscosupplement, it’s a synovial fluid replacement that contains fermentative source, non-modified hyaluronic acid. The volume of the majority of commercial viscosupplements is maybe 2 to 4ml, with a high concentration of hyaluronic acid and high viscosity. Viscoseal is a 10ml syringe, and relatively dilute at 0.5 per cent, allowing the fluid to easily disperse throughout the cavity and cover the intima of the synovial membrane. Further research will no doubt help to identify optimal volumes and concentration ratios in terms of therapeutic effect.