Broadly taken, there are five major types of articular cartilage repair:[citation needed] Arthroscopic lavage is a "cleaning up" procedure of the knee joint.
This short-term solution is not considered as an articular cartilage repair procedure but rather a palliative treatment to reduce pain, mechanical restriction and inflammation.
Studies, however, have shown that marrow stimulation techniques often have insufficiently filled the chondral defect and the repair material is often fibrocartilage (which is not as good mechanically as hyaline cartilage).
[citation needed] Further on, chances are high that after only 1 or 2 years of the surgery symptoms start to return as the fibrocartilage wears away, forcing the patient to reengage in articular cartilage repair.
[1] Microfracture techniques show new potential, as animal studies indicate that microfracture-activated skeletal stem-cells form articular cartilage, instead of fibrous tissue, when co-delivered with a combination of BMP2 and VEGF receptor antagonist.
It is then exposed to UVA light for 90 seconds, turning it into a solid, soft implant that completely occupies the space of the cartilage defect.
It protects the repair site from infiltration of undesired fibrous tissue while providing the appropriate environment for hyaline cartilage matrix formation.
}}[7] A 2011 study reports histologically confirmed hyaline cartilage regrowth in a 5 patient case-series, 2 with grade IV bipolar or kissing lesions in the knee.
The successful protocol involves arthroscopic microdrilling/ microfracture surgery followed by postoperative injections of autologous peripheral blood progenitor cells (PBPC's) and hyaluronic acid (HA).
Khay Yong Saw and his team propose that the microdrilling surgery creates a blood clot scaffold on which injected PBPC's can be recruited and enhance chondrogenesis at the site of the contained lesion.
They explain that the significance of this cartilage regeneration protocol is that it is successful in patients with historically difficult-to-treat grade IV bipolar or bone-on-bone osteochondral lesions.
[11] Depending on the severity and overall size of the damage multiple plugs or dowels may be required to adequately repair the joint, which becomes difficult for osteochondral autografts.
Then these extracted cells are transferred to an in vitro environment in specialised laboratories where they grow and replicate, for approximately four to six weeks, until their population has increased to a sufficient amount.
For years, the concept of harvesting stem cells and re-implanting them into one's own body to regenerate organs and tissues has been embraced and researched in animal models.
The researchers did however find that arthroscopic surgery did help a minority of patients with milder symptoms, large tears or other damage to the meniscus — cartilage pads that improve the congruence between femur and tibia bones.