Jaewoo Pak, Jung Hun Lee, and Sang Hee Lee
Regenerative Repair of Damaged Meniscus with Autologous Adipose Tissue-Derived Stem Cells
The menisci are two semilunar, fibrocartilaginous disks located between the medial and lateral articular surfaces of the femur and tibia in each knee. Their key functions are (i) the transfer of weight, (ii) absorption of shock during dynamic movements of the knee, and (iii) protecting the cartilage in the joint . Therefore, damage in the meniscus can cause continuous knee pain. The meniscal damage can be diagnosed usually by physical exam and confirmed by magnetic resonance imaging (MRI) scans . With diagnosis, the knee pain due to meniscus tear is initially treated conservatively [3, 4]. If the initial conservative treatment fails, a meniscectomy is normally performed. However, the current treatment with meniscectomy, even with partial one, is associated with early onset of osteoarthritis of the knees [5–8].Thus, the lack of noninvasive cure for themenisci damage presents amajor therapeutic challenge.However, recent studies have shown possible articular cartilage regeneration using mesenchymal stem cells (MSCs) in human patients with osteoarthritis and chondromalacia patellae [9–11]. The same MSCs have also been shown to regenerate bone-like tissue in osteonecrosis patients .However, there has been no report of fibrous cartilage restoration in a patient with meniscus tear. Further, from June 2009, the Korean Food and Drug Administration has allowed medical uses of nonexpanded stem cells processed in a medical facility . Here, we describe the possible regenerative mechanisms of damaged meniscus with MSCs (especially adipose tissue-derived stem cells (ASCs: one kind of MSCs)) and the first successful approach to reduce the knee pain by percutaneously injected autologous ASCs along with platelet-rich plasma (PRP), hyaluronic acid and CaCl2, an ASCmixture.