Die Technik der Mikrofrakturierung zur Behandlung von kompletten Knorpeldefekten im Kniegelenk

Abstract

Full thickness defects of the articular cartilage rarely heal spontaneously. While some patients do not develop clinically significant problems from chondral defects, most eventually develop degenerative changes associated with the cartilage damage over time. Techniques to treat chondral defects include abrasion, drilling, tissue autografts, allografts, and cell transplantation. The senior author has developed a procedure referred to as the "microfracture." This technique enhances chondral resurfacing by providing a suitable environment for tissue regeneration and by taking advantage of the body's own healing potential. This technique has now been used in more than 1400 patients. Specially designed awls are used to make multiple perforations, or "microfractures", into the subchondral bone plate. The perforations are made as close together as necessary, but not so close that one breaks into another. Consequently, the microfracture holes are approximately three to four millimeters apart (or 3 to 4 holes per square centimeter). Importantly, the integrity of the subchondral bone plate is maintained. The released marrow elements form a "super clot" which provides an enriched environment for tissue regeneration. Follow up with long term results of more than 8 years have been positive and very encouraging.

Short-Term Effects of Different Arthroscopic Techniques in the Treatment of Chondral Defects (Shaving, Coblation, and Microfacturing)

“…It is remarkable that this rate was significantly higher in group C. The same ratio was observed by Steadman et al [22]. The method of microfracturing aims at producing chondral regenerates.…”

“…Group B (n = 32) underwent electrosurgical treatment (bipolar vaporization). In the remaining patients (group C, n = 44), the chondral defect was microfractured according to Steadman et al [22], to stimulate fibrous cartilage.…”

“…Drilling according to Pridie [15], abrasion chondroplasty [4], and microfracturing according to Steadman et al [22] aim at inducing the production of fibrous chondral regenerates. Mechanical alteration of the subchondral bone stimulates the mesenchymal stem cells.…”

Mechanical confinement regulates cartilage matrix formation by chondrocytes

“…As articular cartilage is avascular and has a limited intrinsic healing capacity, even small defects of articular cartilage can deteriorate and lead to osteoarthritis 1,2 . Current clinical treatments for repairing cartilage defects include autologous chondrocyte implantation (ACI) 3 , matrix-induced autologous chondrocyte implantation (MACI) 4 , micro fracture 5 , and allografts 6 . However, each of these treatments have had limited success over the long-term.…”

Bioactive Factors in Platelet-Rich Plasma Obtained by Apheresis

“…During bone marrow stimulation, by e.g. microfracturing or drilling, the subchondral bone is perforated to induce bleeding into the defect [5]. This technique allows mesenchymal stem and progenitor cells to migrate into the scaffold which can be immersed with autologous serum [6,7] or platelet-rich plasma (PRP) [8,9] to support cell migration and chondrogenic differentiation.…”