Arthroscopic Treatment of Patellar Tendinopathy (Jumper’s Knee)
Jason L. Koh, MD and Neil C. Dunleavy MD
Patellar tendinopathy is widely recognized as a degenerative process of the patellar tendon, occurring with increased frequency in jumping athletes. In 1973, Blazina et al coined the term jumper’s knee to describe the condition, which has a strong predilection for affecting athletes involved in intense repetitive jumping activity, such as basketball and volleyball. Lian et al showed an overall prevalence of jumper’s knee in 613 elite athletes of 14.2%, with the highest prevalence in volleyball (44.6%) and basketball (31.9%) players.
Although first viewed as an inflammatory condition and often referred to as patellar tendinitis, it is now understood from histopathological study that the condition is mostly degenerative and multifactorial, likely involving a complex cascade of events resulting in damaged, painful tissue. Excessive or repetitive loading during jumping has been implicated as a cause. Some evidence has found a longer distal nonarticular facet in patients with patellar tendiopathy, but others have not identified significant differences that could contribute to impingement as a cause of patellar tendinopathy. The proximal posterior degenerated tendon tissue has shown evidence of neoinnervation and neovascularity in addition to collagenous disorganization. In addition, Hoffa’s fat pad bas been implicated for impinging on a protruded inferior pole of the patella and developing sensitive pain receptors as part of the disease process.