The knee joint has two types of cartilage – shiny hyaline cartilage firmly adheres at the end of the bones that allows smooth translation of the hard bone surface on each other. The second type of cartilage is placed firmly in the inner and outer joint space known as the meniscus fibrocartilage.
The meniscus is like a bumper that allows shock absorption during loading/pivot stress and offers stability to the joint. The meniscus in the inner (medial) aspect is attached to the joint ligament and more prone to injury- commonly resulting in a medial meniscal tear. The outer (lateral) meniscus is less prone to injury and is the lateral meniscus.
The fact is that, once a portion of a meniscus is removed, there is a loss of cushioning of the joint from external forces. There is a high chance of post meniscectomy arthritis and eventually joint replacement surgery. The rationale for ‘keeping your meniscus’ stems from the obvious need to avoid this sequelae. Whilst this may not be always possible due to certain clear surgical reasons eg: a large displaced unstable fragment etc, every attempt should be made to keep ones meniscus where reasonably possible. When surgery is contemplated, one should seek a meniscal preserving option where possible.
In those patients who have had meniscectomy, consideration should be given to PRP due to the possibility of a favourable effect. In those patients who are at high risk of arthritis post meniscectomy, cadaver meniscal allograft is now increasingly used.
Treatment in an individual would depend on the extent of injury, degeneration already present in the meniscus and the joint, levels of activity required, other comorbid conditions and available local expertise.
Image Guided PRP in meniscal tears:
The rationale for PRP is for the purposes of not only symptom control but also on the basis of tissue regeneration and augmentation. I use autologous Platelet Rich Plasma for degenerative and non degenerative meniscal tears and have obtained good clinical outcome in patients with age range of 23 years to the 70 year old. These patients have avoided meniscectomy and have preserved joint function. Horizontal degenerative tears, flap tears, are some of the meniscal lesions that I have treated. Peripheral meniscal tears with marked pain may also be considered although these tears are in the ‘red zone’ (the zone of good blood supply) and are prone to good healing. However I have found that patients with posteromedial corner peripheral tears also tend to require PRP due to persisting pain. All injections are performed under high resolution ultrasound control that can localize the painful lesion. This also ensures real time visualization of PRP during the procedure.
Typically patients need at least two procedures of PRP spaced about 2 to 4 weeks apart.
Post procedure rehabilitation is crucial. Depending on the extent of the procedure ie: simple injection versus percutaneous tenotomy etc, I prescribe a post care exercise program, knee brace with no or partial weight bearing for a few days and gradual resumption of activities. Typically this is not more than 10 days therefore much shorter than post meniscal repair rehabilitation. Exercises are continued for a few months at least
and follow up is arranged at 3 months.
Future: Image Guided
Delivery of PRP and autologous stem cells into torn menisci will change the way we treat meniscal tears in the near future.
Key Points:
- Keep your meniscus and avoid arthritis.
- 2. Image Guided Injection of PRP is helpful in the short and long term with meniscal tears.
- If surgery is contemplated, seek a meniscal preserving option where possible. PRP can still be used to augment healing and also in those patients who have had a meniscectomy.
- Rehabilitation is crucial in Post meniscal PRP.
Disclaimer: This article is not a medical opinion. Patients should seek an opinion from their medical practitioner.
Dr Arockia Doss MBBS MRCP(UK) FRCR FRANZCR
Radiologist
Image Guided Therapy Clinic
Suite 3, 55 Hampden Road
Nedlands WESTERN AUSTRALIA 6009
