PRP is an Evidence-Based Treatment for Degenerative Meniscus Tears
What is the Meniscus?
The meniscus is a structure in the knee located between the tibia (shin bone) and femur (thigh bone) which functions to absorb shock, distribute load, and stabilize the joint. It is composed of fibrocartilage, which is a thick rubbery substance in a “C-shape.” Each knee has two menisci – one on the outside part of the knee joint (lateral meniscus) and one on the inside part of the knee joint (medial meniscus).
Figure 1 - Meniscus (Photo courtesy of OrthoInfo)
What is a Meniscus Tear?
The meniscus can be injured by two methods:
Acute meniscus tear: Tears which occur due to a specific mechanism of injury at a specific point in time are called acute tears. Such tears may occur when someone suddenly twists their knee and feels a pop. Symptoms may include swelling of the knee. The patient may also notice “mechanical symptoms” in which the knee locks (cannot fully bend or straighten) or catches (there is an interruption in the otherwise smooth motion of the knee).
Degenerative meniscus tear: Tears which occur gradually over time without a specific mechanism of injury are called degenerative tears. Such tears may cause pain at the inside or outside part of the knee joint with activities such as bending or twisting, but usually do not cause locking or catching of the knee. There may or may not be associated swelling.
Figure 2 - Degenerative Meniscus Tear (Photo courtesy of OrthoInfo)
How Are Meniscus Tears Diagnosed?
A careful history and physical examination is first conducted. X-rays may be obtained to assess the amount of osteoarthritis (joint degeneration) present in the knee as this may influence treatment options. If indicated, an MRI may be ordered to further evaluate the meniscus to see the extent and type of tearing that is present.
How are Degenerative Meniscus Tears Typically Treated?
Typical first-line treatments for degenerative meniscus tears may include physical therapy to strengthen the muscles supporting the knee to help improve function and decrease pain. Braces may also be used to help support the knee. Other treatments may include injections such as cortisone, but caution should be taken given studies show cortisone may actually harm the cartilage (cushioning) in the knee (Wernecke et al., Orthop J Sports Med 2015).
What if Physical Therapy and Bracing Do Not Work? Should Surgery be Considered?
There may be instances in which physical therapy and bracing do not provide the desired improvement in pain and function. In such instances a surgery such as an arthroscopic partial meniscectomy (removal of the damaged portion of the meniscus) may be a consideration.
However, a landmark multi-center, randomized, double-blind, sham-controlled study compared arthroscopic partial meniscectomy to sham (fake) surgery in 146 patients ages 35-65 years old with a degenerative medial meniscus tear and no knee osteoarthritis. The study results found there were no significant differences in pain, function, or health-related quality of life (HRQoL) at 1 year after intervention (Sihvonen et al., N Engl J Med, 2013).
Furthermore, there is evidence that arthroscopic partial meniscectomy may lead to earlier knee osteoarthritis. A study of 2487 patients aged 16-45 evaluated the rate of seeking medical care for knee osteoarthritis after meniscus repair, arthroscopic partial meniscectomy, and the general population. The study results showed the risk of seeking medical care for knee osteoarthritis was 17% after arthroscopic partial meniscectomy, 10% after meniscus repair, and 2.3% in the general population. This study suggests there is a higher risk of developing osteoarthritis after arthroscopic partial meniscectomy than in the general population (Persson et al., Osteoarthritis Cartilage, 2018).
Platelet-Rich Plasma (PRP) May Be an Effective Alternative to Surgery
We have learned that surgery may not be an effective long-term treatment for degenerative meniscus tears. Therefore patients who have not responded to physical therapy and bracing may fall into a treatment gap in which seemingly no evidence-based options exist.
Platelet-rich plasma (PRP) is a treatment which is gaining evidence and may fill the aforementioned gap for the treatment of degenerative meniscus tears.
A prospective, randomized, double-blind, placebo-controlled study of 72 patients with a degenerative meniscus tear evaluated pain, function, and meniscus healing (via MRI) for 1 year after procedure (Kaminski et al., Int J Mol Sci. 2019). 30 patients received meniscal trephination, in which a small needle is used to gently poke the meniscus to stimulate a healing response, while 42 patients received meniscal trephination plus PRP.
Figure 3 - PRP + Meniscal Trephination (Kaminski et al., Int J Mol Sci. 2019).
The study results found the following:
The PRP group had a significantly lower failure rate of meniscus healing on MRI (48% vs 70%, p = 0.04).
The PRP group had decreased necessity for knee arthroscopy (surgery) in the future, measured out to 150 weeks (8% vs 28%, p = 0.032).
There was a statistically significant greater number of patients in the PRP group who had improvement in their pain and function.
No complications were reported in either group.
A separate study of 392 patients with degenerative meniscus tears who underwent PRP injection evaluated pain and function for 18 months after procedure and also evaluated the need to undergo arthroscopic meniscus surgery (Sánchez et al., Knee Surg Sports Traumatol Arthrosc. 2023).
The study results found the following:
90.3% of patients did not require surgery after PRP injection (measured to 54.4 months)
All pain and function scores showed statistically significant improvement from baseline at 6 months and 18 months.
The number of patients with minimal clinically important improvement was 69.9% at 6 months and 65.2% at 18 months.
Key Take-Home Points
Degenerative meniscus tears are a common cause of knee pain.
First-line treatment of degenerative meniscus tears typically consists of physical therapy with consideration for bracing
While cortisone injections may be used, there is a risk of damage to the cartilage of the knee
Surgery for degenerative meniscus tears has been shown to be no better than sham (fake) surgery and may also result in earlier-onset osteoarthritis
PRP injection is an evidence-based treatment which may provide meaningful durable improvements in pain and function for the treatment of symptomatic degenerative meniscus tears
Appointment
Dr. Verma provides treatment for numerous orthopaedic and sports medicine conditions, including ultrasound-guided procedures such as PRP for conditions like degenerative meniscus tears. If you are a patient interested in exploring treatment for your condition, please schedule a consultation with Dr. Verma to discuss the available options.
References
American Academy of Orthopaedic Surgeons. Meniscus Tears - OrthoInfo - AAOS. Aaos.org. Published 2014. https://orthoinfo.aaos.org/en/diseases--conditions/meniscus-tears/
Wernecke C, Braun HJ, Dragoo JL. The Effect of Intra-articular Corticosteroids on Articular Cartilage: A Systematic Review. Orthop J Sports Med. 2015;3(5):2325967115581163.
Sihvonen R, Paavola M, Malmivaara A, et al. Arthroscopic partial meniscectomy versus sham surgery for a degenerative meniscal tear. N Engl J Med. 2013;369(26):2515-2524.
Persson F, Turkiewicz A, Bergkvist D, Neuman P, Englund M. The risk of symptomatic knee osteoarthritis after arthroscopic meniscus repair vs partial meniscectomy vs the general population. Osteoarthritis Cartilage. 2018;26(2):195-201.
Kaminski R, Maksymowicz-Wleklik M, Kulinski K, Kozar-Kaminska K, Dabrowska-Thing A, Pomianowski S. Short-Term Outcomes of Percutaneous Trephination with a Platelet Rich Plasma Intrameniscal Injection for the Repair of Degenerative Meniscal Lesions. A Prospective, Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Study. Int J Mol Sci. 2019;20(4):856.
Sánchez M, Jorquera C, Bilbao AM, et al. High survival rate after the combination of intrameniscal and intraarticular infiltrations of platelet-rich plasma as conservative treatment for meniscal lesions. Knee Surg Sports Traumatol Arthrosc. 2023;31(10):4246-4256.