Recently, in tissue engineering several methods using stem cells have been developed to repair chondral and osteochondral defects. Most of these methods rely on the use of scaffolds. Studies in the literature have demonstrated, first in animals and then in humans, that the use of mesenchymal stem cells withdrawn by several methods from adipose tissue allows to regenerate hyaline articular cartilage. In fact, it has been cleared that adipose-derived cells have multipotentiality equivalent to bone marrow-derived stem cells and that they can very easily and very quickly be isolated in large amounts enabling their immediate use in operating room for one-step cartilage repair techniques. The purpose of this study is to evaluate the therapeutic effect of adipose-derived stem cells on cartilage repair and present our experience in the treatment of knee cartilage defects by the novel AMIC REPAIR TECHNIQUE AUGMENTED by immersing the collagen scaffold with mesenchymal stem cells withdrawn from adipose tissue of the abdomen. Fat tissue processing involves mechanical forces and does not mandatorily require any enzymatic or chemical treatment in order to obtain the regenerative cells from the lipoaspirate. In our study, mesenchymal adipose stem cells were obtained by non-enzymatic filtration or microfragmentation of lipoaspirates of the abdomen adipose tissue that enabled the separation of the stromal vascular fraction and were used in one-step reconstruction of knee cartilage defects by means of this new AUGMENTED AMIC TECHNIQUE. The focal defects underwent bone marrow stimulation microfractures, followed by coverage with collagen double layer resorbable membrane (Chondro-gideTM-Geistlich Pharma AG, Wolhusen, Switzerland) soaked in the cells obtained from fat in 18 patients, aged between 31 and 58 years, at the level of the left knee in 10 cases and in the right in eight, with follow-up ranging between 12 and 36 months. RESULTS: Surgical procedures have been completed without technical problems neither intraoperative or early postoperative complications. The evaluation scores (IKDC, KOOS and VAS) showed a significant improvement, more than 30%, at the initial 6 months follow-up and furtherly improved in the subsequent follow-ups. Also the control MRIs showed a progressive filling and maturation of the repair tissue of the defects.PURPOSE
MATERIALS AND METHODS
Follow-up MRI images revealed normal healing process, without signs of osteolysis or wear. No synovial joint reaction has been observed, but one case of implant’s dislocation occurred.
Although various treatment options are available, which include shaving, microfractures, abrasion arthroplasty osteochondral allografts and autografts, chondrocyte grafts and unicondylar prostheses, symptomatic articular cartilage defects represent a therapeutic challenge. Since November 2002, as a non-biological answer to the problem, we started using synthetic cartilage implants made of polyvinyl alcohol- hydrogel (PVA – H) (SaluCartilage). This is a transparent synthetic polymer with a molecular weight of 308,000 daltons and 20% of water content, available in cylindrical shape of various diameters. Following the second part of the OATS technique, under arthroscopic control and by mini-arthrotomy, or completely arthroscopically assisted, the cylindrical implant is inserted, using press-fit technique, into previously punched out and dilatated osteochondral defects. Our patients, whose mean age was 56 years (range 48–68 years) have been post-operatively reviewed clinically and by serial MRI exams. Patients showed significant improvement over pre-operative values in the IKDC score, with an average increase of 20 points. Follow-up MRI images revealed a normal healing process, without signs of osteolysis or wear. As complications we had one case of implant dislocation 1 year after surgery and one case of progressive loosening due to osteoarthritic disease, both of which have required a knee prosthesis. Our experience has led us to emphasise the use of this type of treatment only in cases that fullfil precise indications: (a) Third and fourth degree chondral or osteochondral symptomatic defects; (b) focal unicompartmental defects with 15 mm maximum extent; (c) patient’s age limited from fourth to seventh decade of life; and (d) absence of angular deformities or articular instabilities. The synthetic cartilage resurfacing technique has the advantages of no donor defect, one short-step surgical procedure, immediate weight-bearing and no extensive rehabilitation programme. Early results of first 15 patients are being presented, expecting a longer observation follow-up study.