Unloading knee brace is a cost-effective method to bridge and delay surgery in unicompartmental knee arthritis.

Lee PY, Winfield TG, Harris SR, et al. BMJ Open Sport & Exercise Medicine 2017;2:e000195. doi: 10.1136/bmjsem-2016-000195 [online link to full paper]

This is the editor's interpretation of a paper published in the orthopaedic literature in 2017 - our attempt to make relevant medical articles accessible to lay readers. If you wish to read the original it is easy to ask your librarian to obtain a reprint for you from any medical library.

This paper takes an unusual viewpoint with regard to the use of unloading braces for the conservative management of unicompartmental osteoarthritis inasmuch as the authors followed a prospective cohort of such patients for up to 8 years, and attempted to calculate the health economics of such brace use within the United Kingdom (UK) medical system. By 'prospective' I mean that the patients were followed up as they progressed through the study, rather than the research analysis being done at the end of the period.

The important issues of cost and effectiveness - the study

Unicompartmental osteoarthritis means that the joint damage was confined to the one half of the knee. With 18% of the UK population over the age of 45 years seeking intervention for unicompartmental osteoarthritis of the knee, the authors were interested to see how the use of an unloader brace over an extended time compared from a cost perspective with similar patients on the waiting list for a total knee replacement. The patients had already had a period of non-surgical ('conservative') management with painkillers and physiotherapy, then they were put into an unloader brace as they entered the study.

[Ed: Patients are quite often given such braces while they wait for their surgery, and the sort of surgery appropriate to arthritis confined to the one side like this is increasingly a partial (unicompartmental or 'uni') knee replacement or an osteotomy (a procedure that realigns the bones to take the pressure off the damaged side. Some are unfortunately asked to bide their time until the arthritis is severe enough to warrant a total knee replacement.]

In this study, the authors tried to do something quite challenging. They took published cost analysis figures for total knee replacement, for which procedure the waiting lists in their region was 8 months (and 18 months in their hospital) and which patients had not worn an unloader brace, extrapolated the figures back to the 8 year mark, and then they compared the overall costs with their group who were given unloader braces to wear during the waiting period. They followed up their 63 patients whether or not they continued in the braces or went on to surgery.

They tried to take into account the costs of the brace or knee replacement implant, the staff costs, the investigations and any surgery, and then compared the overall figures.


Their findings

The age groups were different in the two populations that were compared, with their group averaging 59 years while the other study's patients averaged 71 years. In their paper they remark that it would have been good to have the two groups more clearly comparable, with the patients waiting for unicompartmental knee replacement or osteotomy rather than total knee replacement, but they did not have such a group to compare with in terms of published figures for cost analysis.

Overall the braces were found to provide good short-term pain relief. The average unloader knee brace duration of wear was longer than the current 8 months waiting list as some patients opted out of surgery. In fact, twenty-five of their patients continued with the brace and did not proceed to surgery at all. Of the 38 who did proceed to surgery 50% had a total knee replacement, 37% had a unicompartmental knee replacement and 13% had high tibial osteotomy.

Their conclusions -

  • Six months of brace use halved the chance for surgery compared with 3 months or less use.
  • Patients who wore the brace for 2 years or more did not require surgery at 8 years follow-up.
  • Unloader knee brace has a similar QALY gain compared with TKR at 8 years follow-up (0.435).
  • Short-term use of unloader knee brace can improve quality of life.
  • It is cost-effective to use the unloader knee brace while patients are waiting for surgery.