It just so happens that the first ever study comparing the results of these two treatments (and specifically for athletes with “Jumper’s Knee”) was recently published. We can share the results with you and that may help you formulate your own opinions and direct your path.
Running and jumping over and over often leads to this condition in athletes known as patellar tendinosis or jumper’s knee. Pain along the front of the knee during the activity that goes away with rest is a cardinal symptom of this condition. Dancers, gymnasts, and basketball, soccer, and volleyball players like yourself are affected most often.
As you have been told, jumper’s knee goes away when the muscles along the front of the knee (extensor mechanism) that pull across the patella (kneecap) stop pulling. It is a self-limiting, self-resolving condition. Therefore, the first recommended treatment is always to stop overloading the extensor mechanism. Rest, anti-inflammatory medications, and specific exercises under the supervision of a physical therapist are advised.
But many athletes (for various reasons including scholarship pressures) work through the pain until conservative (nonoperative care as described above) is no longer successful in reducing pain. At that point other treatment options are considered. In the study we mentioned, sports medicine experts compared two treatment approaches for chronic tendinopathy of the extensor mechanism: 1) platelet-rich plasma (blood injection therapy) and 2) extracorporeal shock wave therapy (ESWT).
Platelet-rich plasma (PRP) refers to a sample of serum (blood) plasma that has four (up to 10) times more than the normal amount of platelets and growth factors. This treatment enhances the body’s natural ability to heal itself and is used to improve healing and shorten recovery time from acute and chronic soft tissue injuries. The group of athletes in this study who received PRP were given two injections over a two week period.
Extracorporeal shock wave therapy (ESWT) is a way to generate sound waves outside the body that can be focused at a specific site within the body (in this case, the knee). This treatment technique is also referred to as pressure or sound wave therapy. It is a noninvasive, outpatient procedure.
Pressure waves travel through fluid and soft tissue to sites where there is a change in tissue density. A common interface is where the soft tissues meet bone. A special device delivers shockwaves to the target point where treatment is needed. The shockwaves break down scar tissue that has built up. The body’s repair mechanisms are stimulated to promote healing. New blood vessels develop in the injured area to help jump start the healing process. Three sessions of ESWT were delivered to the second group in this study in 48- to 72-hour intervals.
Both treatments focus on the failed healing of the overused tendon by promoting cell growth, release of growth factors, and improving tissue remodeling. In comparing the two groups responses to treatment, they found everyone in both groups had significant improvements throughout the follow-up time period.
At the end of two months, there was no real difference between the two groups. But later (at the six-month and one-year recheck), the platelet-rich plasma (PRP) injection group pulled ahead with significantly better improvement. Significantly more athletes in the PRP group (compared with the shock therapy group) were also able to return to full sports participation (at a level equal to before their injury).
As this study showed, both are effective in the short term but platelet-rich plasma may have better mid-term results. Further study is needed to asses long-term results. But something you should know is that these athletes were NOT allowed to continue participating in their chosen sports activities. During the treatment, they were given a stretching and strengthening program and then started on water activities if and when they had only mild (or no) discomfort.
Only after four weeks were they allowed to GRADUALLY return to their previous level of training. And only if there was no (or only mild) pain. Full activity was resumed when they could do so pain free. Athletes in other studies who had shock wave therapy and who did not improve were the ones who continued training/playing at their usual and customary level. Healing cannot occur when there is continued, unrestricted load on the healing tendon. Whatever treatment decision you make, keep in mind that soft tissues must be given enough time to recover!