Presentation of Knee Osteoarthritis in the Emergency Department: A Problem Worth Mentioning?

Osteoarthritis (OA) of the knee is a progressive debilitating disease affecting more than 27 million Americans. Treatment is often aimed at reducing pain and slowing disease progression. However, patients with significant barriers to healthcare may elect to visit the emergency department (ED) due to OA-related knee pain. The purpose of this study is to provide a detailed analysis of 1) patient demographics; 2) payor type; 3) charges; and 4) discharge status of patients presenting to the emergency department with a primary diagnosis of knee OA.

The Nationwide Emergency Department Sample from 2009 to 2013 was queried for all patients who presented to the ED with a primary diagnosis of knee OA (ICD-9 CM=715.96) and did not have a concomitant major injury. This yielded 215,253 patients. An analysis of variance (ANOVA) test with a post-hoc Turkey-Kramer test was conducted to assess mean differences of continuous data over time. All categorical data was analyzed using chi-square analysis.

The incidence of ED visits dropped significantly between the years 2009 and 2010 (68,661 to 36,846) and plateaued between the years 2010 and 2013. Patients had a mean age of 59.9 years and were primarily women (67.3%). The majority of patients were at the lowest 50% income bracket (68.8%). The Southern US census region had the highest number of ED visits (n=91,995; 42.7%), and Medicare was the primary payor in most cases (n=87,323; 40.7%). The mean charge for ED visits from 2009 to 2013 was $1,368.39, and there was a statistically significant increase in ED-related charges between 2009 and 2013 (p<0.001). The majority of discharges from the ED were routine (n=202,247; 93.8%).

While the early management of knee osteoarthritis is largely successful at delaying the need for surgery, there are still many patients who do not receive adequate care and present to the emergency room for non-emergent evaluation. This, along with rising charges for ED visits, is likely increasing resource consumption and the financial impact on the healthcare system. Future efforts should focus on improving access to care for patients with knee OA before it develops into an overwhelming burden.