Proximal patellar tendinopathy is much more common than distal.
In some cases there may be a rheumatological cause with insertional patellar tendinopathy especially spondyloarthropathy. In this setting there may be associated bursal changes.
No benefit for leukocyte rich or leukocyte poor PRP injections over saline. 
One of the most effective and widely used treatments Important considerations
- The exercises are painful, this is normal
- Large numbers of repetitions every day required – between 90-180
- Minimum of 3 months
Eccentric loading squats on a 25 degree decline board (3 x 15, twice daily, for 3 months) Alternatively can ddo gym based “HSR” (heavy slow resistance – eccentric-concentric isotonic)
Possibly reduces pain but original study results (n=20 study) could not be replicated = isotonic as effective (n=21 replication study) . May be useful pre-activity intervention or early on. Silbernagel et al note:
”The argument for the benefit of isometric exercise is that it causes immediate pain relief and the recommendation is that progression to other exercise should not be pursued until pain has settled and the patient is proficient at isometrics.3 This ignores previous evidence in support of using isotonic exercise as the initial stage for tendinopathy treatment. Pain during exercise has not been found detrimental for recovery and to the contrary might even be beneficial—Silbernagel et al
- Scott A, LaPrade RF, Harmon KG, et al. Platelet-rich plasma for patellar tendinopathy: a randomized controlled trial of leukocyte-rich PRP or leukocyte-poor PRP versus saline. Am J Sports Med 2019;47(7):1654-1661.
- Gravare Silbernagel, K., Vicenzino, B. T., Rathleff, M. S., & Thorborg, K. (2019). Isometric exercise for acute pain relief: is it relevant in tendinopathy management? British Journal of Sports Medicine, bjsports–2019–100591. doi:10.1136/bjsports-2019-100591
- Rudavsky & Cook. Physiotherapy management of patellar tendinopathy (jumper's knee). Journal of physiotherapy 2014. 60:122-9. PMID: 25092419. DOI.