Damage of articular cartilage in the knee: surgical approach

Abstract

Articular cartilage is able to repair but cannot regenerate itself. Hyaline cartilage is avascular, aneural and alymphatic with very limited healing response when damaged. Chondrocytes are disrupted by genetic, vascular, metabolic, mechanical, traumatic injury, prolonged inactivity, chemical issues and changes in pH. Currently, no gold standard seems to exist as to surgical cartilage repair and different surgical treatment options are available for chondral defects of the knee. After direct arthroscopic examination, the surgeon characterizes the lesion in terms of its location, size, shape, depth, and Outerbridge Classification. In this article, we selectively review the pertinent literature, focusing on the recent studies and older standard texts. This review updates current evidence concerning the surgical approach to knee cartilage damage, describing microfracture (MF), arthroscopic debridement (AD) and chondroplasty, osteochondral autologous transplantation (OATs), osteochondral allograft transplantation (OCAs), autologous chondrocyte implantation (ACI), tissue engineering techniques, mesenchymal stem cells (MSCs) therapy, fixation of unstable osteochondral fragment. MF is considered as the first-line option for smaller articular cartilage injuries, with good short-term clinical results. AD is traditionally considered the gold standard for assessment of chondral injuries direct arthroscopic examination and also for partial thickness articular cartilage lesions. OATis indicated typically in active younger patients with smaller (<2-4 cm2) chondral and osteochondral defects. OCAis normally undertaken in young active patients with focal cartilage defects >2 cm2. ACIand Matrix autologous chondrocyte implantation (MACI) are indicated in high-grade femoral condylar cartilage lesions with subchondral bone involvement, failure of other palliative and reparative cartilage treatments and failure after nonoperative treatment. MSCs therapy is recommended for patients with chondral lesions and degenerative changes, but there are no real guidelines and indications regarding the use of this technique at present.