Knee instability likely to cause recurrent falls

By Jane Lewis
People who fall when a knee gives way (knee buckling) have a high risk of recurrent falls and fear of falling, reports a study published online in Arthritis Care and Research. 

The prospective study is the first to investigate symptoms of knee instability as a risk factor for falls, fall injuries and psychological consequences of falls in people with, or at risk for, knee osteoarthritis (OA), the study authors claim. 

‘This study looks at a common problem – OA of the knee – and has identified an issue that is potentially amenable to intervention in order to reduce falls and prevent functional decline,’ Professor Jacqueline Close, President of the Australian and New Zealand Society of Geria­tric Medicine, and Director of the Falls and Injury Prevention Group at Neuroscience Research Australia, in Sydney, told Medicine Today. 

To investigate the link between knee instability and falls, the study looked at 1842 participants (59% women; mean age 66.9 years) in the US Multicenter Osteoarthritis Study, a longitudinal study of people with, or at high risk of, knee OA. At their five­ year clinic visit (baseline), 16.8% of participants reported knee buckling, and at seven years, 14.1% had experienced recur­ rent falls (two or more falls). 

Participants who reported buckling knees at five years were found to have up to 2.5-fold greater odds of recurrent falls, fear of falling and poor balance confidence at seven years. Participants who fell as a result of knee buckling at baseline were at an even greater risk of adverse outcomes, with a 4.5­-fold increased odds of recurrent falls, twofold increased odds of significant fall injuries, and threefold increased odds of activity ­limiting fall injuries. They were also four times more likely to have poor balance confidence. 

‘These results suggest that knee buckling is an independent risk factor for falls that is unique to persons with knee pain or knee OA,’ the authors concluded. ‘Finding effective treatments for knee instability should be a priority and may help prevent knee buckling and falls and their adverse consequences in older persons with knee pain.’ 

According to Professor Close, the study ‘highlights a potential risk factor for falls in a particular population,’ and ‘the next step is to show that an intervention can alter this level of risk.’ 

‘An exercise intervention is likely to improve knee function and will have benefits beyond falls,’ she noted. ‘Maintaining function and improving pain and quality of life are all important in this population.

A number of people with OA of the knee will go on to have surgery, and exercise to improve function before surgery is likely to have a positive impact on the recovery phase.’
Arthritis Care Res 2016; doi: 10.1002/acr.22812.