Knee buckling associated with increased risk for recurrent falls in older adults
The researchers noted that determining effective treatments for knee instability should be an important priority as clinicians care for aging patients.
Knee buckling in people with knee osteoarthritis (OA), particularly when a fall results, is associated with an increased risk of recurrent falls and adverse consequences from them 2 years later, a study found.
Researchers prospectively studied participants in the Multicenter Osteoarthritis Study (MOST), a longitudinal study of people with knee OA or at high risk of it based on the presence of risk factors. At the 60-month visit of the Multicenter Osteoarthritis Study, men and women ages 55 to 84 (mean age, 67) were asked about knee buckling in the past 3 months and whether they fell when a knee buckled. Knee buckling was defined as “the sudden loss of postural support across the knee during weight bearing, often described as a knee ‘giving way.’” Falls and fall-related injuries in the past 12 months and balance confidence were assessed at 60 and 84 months.
Results were published online Feb. 8 by Arthritis Care & Research.
For the 3 months prior to baseline, 16.8% of participants reported knee buckling, 29.6% reported sensations of knee shifting/slipping without the knee giving way, and 8.8% reported both. Of those who reported buckling at baseline, 92% had either knee pain on most days of the past month or radiographic OA of the knee (grade ≥2 on the Kellgren and Lawrence 5-grade scale, with 0 indicating best and 4 indicating worst), and 44% also reported buckling at 84 months.
At 60 and 84 months, respectively, 13.9% and 13.2% of subjects had 1 fall and 16.1% and 14.1% had 2 or more falls during the preceding 12 months. Among those who had fallen at either timepoint, 1 in 4 had a significant injury and a similar proportion limited their activity due to a fall injury.
Those who had knee buckling once or more in the past 3 months at baseline were more likely to have had recurrent falls in the 12 months before baseline (29.1%) and 2 years later (25.2%) compared with those who hadn't (13.5% and 12.0%, respectively). People who reported knee buckling had twice the odds of recurrent falls both at baseline and 2 years later. Shifting/slipping at baseline was associated with multiple falls at baseline but not with falls 2 years later. Instability symptoms were not associated with having 1 fall.
Those reporting both buckling and shifting/slipping had an increased risk of falls at both 60 months and 2 years later, compared with those with neither symptom. Those who experienced buckling but not shifting/slipping were more likely to have multiple falls 2 years later but not at 60 months, while those reporting only shifting/slipping but not buckling did not have an increased risk of falls. Those who reported buckling were more likely to have had significant and activity-limiting fall-related injuries in the 12 months prior to baseline.
Those who reported buckling did not have an increased risk of fall-related injuries at 84 months. Their confidence was assessed using the Activities-specific Balance Confidence (ABC) Scale, which assesses self-reported confidence in performing 16 activities without becoming unsteady or falling. The summary ABC score ranges from 0 to 100 (higher scores indicate more confidence), with poor confidence defined as a score <67. Despite not having more injuries, those who reported knee buckling were more likely to have poor balance confidence (adjusted OR, 2.47; 95% CI, 1.58, 3.85) and fear of falling (adjusted OR, 1.62; 95% CI, 1.16, 2.26) 2 years later.
The researchers noted that determining effective treatments for knee instability should be an important priority as clinicians care for aging patients and that interventions that reduce knee buckling may help prevent falls, fall-related injuries, and adverse psychological consequences of falls.
“Although individuals with a history of having fallen when a knee gave way represent 1 in 5 of those who reported buckling and only 3% of the overall cohort, targeting this readily identifiable subgroup at especially high risk of falls and injuries may be an efficient approach to preventing serious adverse consequences of knee instability,” the researchers wrote.