The Effect of Nonspecific Knee Injury on Radiographic OA
The Effect of Nonspecific Knee Injury on Radiographic OA
Among US adults, nearly 27 million had clinical osteoarthritis in 2008 (up from 21 million in 1995). Being strongly related to age and body mass index (BMI), with the increasing average age and adiposity of populations, osteoarthritis (OA) presents an increasing burden. Kellgren Lawrence (KL) grade, an integer index ranging from 0 to 4, is a standard radiographic measurement of joint deterioration used in diagnosing OA. Radiographic OA (ROA) is simply defined as a KL grade of 2 or higher. In this paper we study incidence and progression of ROA, defined as any increase in KL grade (with grades 0/1 collapsed).
There is a large body of literature suggesting that knee injury leads to an increased risk of OA (mostly incident or prevalent OA). However, while the general topic of knee injury affecting OA has been studied fairly extensively, it has either been limited to the study of certain specific injuries (SIs) that have been widely identified as posing elevated risks for OA (torn ligament, torn meniscus, injured/dislocated patella), or used a definition that included these injuries. The present study seeks to elucidate the effects (if any) of injuries that do not fall within those specific categories. We term this "nonspecific injury" (NSI). Similar to the specific injuries listed above, NSI can arise during physical exercise, or activities of daily living, and may be mild or severe. We define both SI and NSI as either "severe" (requiring a walking aid for at least one week), or else "moderate". In comparison to the topic of SI versus OA, there is a dearth of literature on the area of NSI (as we have defined it) and OA, yet the long-term effect of non-specific knee injuries is important to understand, as many knee injuries are nonspecific. The purpose of this study is to better understand the effect of moderate and severe knee NSI, defined as a knee injury other than torn ligament, torn meniscus, or injured/dislocated patella, on the long term rate of ROA incidence/progression.
Background
Among US adults, nearly 27 million had clinical osteoarthritis in 2008 (up from 21 million in 1995). Being strongly related to age and body mass index (BMI), with the increasing average age and adiposity of populations, osteoarthritis (OA) presents an increasing burden. Kellgren Lawrence (KL) grade, an integer index ranging from 0 to 4, is a standard radiographic measurement of joint deterioration used in diagnosing OA. Radiographic OA (ROA) is simply defined as a KL grade of 2 or higher. In this paper we study incidence and progression of ROA, defined as any increase in KL grade (with grades 0/1 collapsed).
There is a large body of literature suggesting that knee injury leads to an increased risk of OA (mostly incident or prevalent OA). However, while the general topic of knee injury affecting OA has been studied fairly extensively, it has either been limited to the study of certain specific injuries (SIs) that have been widely identified as posing elevated risks for OA (torn ligament, torn meniscus, injured/dislocated patella), or used a definition that included these injuries. The present study seeks to elucidate the effects (if any) of injuries that do not fall within those specific categories. We term this "nonspecific injury" (NSI). Similar to the specific injuries listed above, NSI can arise during physical exercise, or activities of daily living, and may be mild or severe. We define both SI and NSI as either "severe" (requiring a walking aid for at least one week), or else "moderate". In comparison to the topic of SI versus OA, there is a dearth of literature on the area of NSI (as we have defined it) and OA, yet the long-term effect of non-specific knee injuries is important to understand, as many knee injuries are nonspecific. The purpose of this study is to better understand the effect of moderate and severe knee NSI, defined as a knee injury other than torn ligament, torn meniscus, or injured/dislocated patella, on the long term rate of ROA incidence/progression.
