Carlton J. Covey, MD, FAAFP Matthew K. Hawks, MD Nellis Family Medicine Residency Program, Nellis Air Force Base, Nev (Drs. Covey and Hawks); Uniformed Services University of the Health Sciences, Bethesda, Md (Dr. Covey) carlton.covey@us.af.mil
The authors reported no potential conflict of interest relevant to this article.
The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the US Air Force Medical Department or the US Air Force at large.
Patellar tendinopathy, an overuse injury often called “jumper’s knee” because it is associated with high-intensity jumping sports like volleyball and basketball, is an insertional tendinopathy with pain most commonly at the proximal patellar tendon.10 The pathology of the injury is poorly understood, but is believed to be the result of an impaired healing response to microtears.12,14
Diagnosis. Patients with patellar tendinopathy typically present with anterior suprapatellar pain aggravated by activity. Classically, the pain can occur in any of 4 phases:12 1. pain isolated after activity; 2. pain that occurs during activity but does not impede activity; 3. pain that occurs both during and after the activity and interferes with competition ; 4. a complete tendon disruption.
Examination should include an assessment of the patellar tendon for localized thickening, nodularity, crepitus, and focal suprapatellar tenderness. The muscle-tendon function should be evaluated by assessing knee mobility and strength of the quads via straight leg raise, decline squat, or single leg squats.12 The Victorian Institute of Sport Assessment (VISA) questionnaire can be used to quantify the symptoms and to help track the patient’s progress throughout therapy.31 There are no proven special tests or radiologic studies to aid in the diagnosis of patellar tendinopathy,14 but magnetic resonance imaging (MRI) can be used for further evaluation when findings are equivocal.35
Treatment. A wide range of options, from eccentric training—eg, 3 sets of 15 repetitions performed twice a day for 12 weeks—and physical therapy to platelet-rich plasma (PRP) injections, sclerosing injections, and surgery, are available for the treatment of patellar tendinopathy.13-15 While no specific data have proven the superiority of any one therapy, expert consensus recommends eccentric exercise as initial therapy, performed for 12 weeks.14,15
Three weeks of platelet-rich plasma injections helped 75% of patients with patellar tendinopathy return to their pre-symptom activity level within 90 days. It’s also interesting to note that a recently published study showed that 3 weekly PRP injections helped 75% of patients—all of whom failed to respond to 4 months of eccentric therapy—return to their pre-symptom activity level within 90 days.16 Corticosteroid injections should not be used to treat patellar tendinopathy due to the risk of tendon rupture.15 Orthopedic referral for surgical intervention should be considered for patients who fail to respond after 3 to 6 months of conservative therapy.14
