Background: Various approaches have been proposed to treat articular cartilage lesions, which are plagued by inherent limited healing potential. Purpose: To compare the clinical outcome of patients treated with second-generation autologous chondrocyte implantation implants with those treated with the microfracture repair technique at 5-year follow-up. Study Design: Cohort study; Level of evidence, 2. Methods: Eighty active patients (mean age, 29.8 years) and grade III to IV cartilage lesions of the femoral condyles or trochlea were treated with arthroscopic second-generation autologous chondrocyte implantation Hyalograft C or microfracture (40 patients per group). Patients achieved a minimum 5-year follow-up and were prospectively evaluated. Results: Both groups showed statistically significant improvement of all clinical scores from preoperative interval to 5-year follow-up. There was a significant improvement for the International Knee Documentation Committee subjective score from preoperative to 5-year follow-up (Wilcoxon test, P < .001). In the microfracture group, the International Knee Documentation Committee objective score increased from 2.5% normal and nearly normal knees before the operation to 75% normal and nearly normal knees at 5-year follow-up, and the subjective score increased from 41.1 ± 12.3 preoperatively to 70.2 ± 14.7 at 5-year follow-up. In the group treated with Hyalograft C, the International Knee Documentation Committee objective score increased from 15% normal and nearly normal knees before the operation to 90% normal and nearly normal knees at 5-year follow-up, and its subjective score increased from 40.5 ± 15.2 preoperatively to 80.2 ± 19.1 at 5-year follow-up (Wilcoxon test, P < .001). When comparing the groups, better improvement of the International Knee Documentation Committee objective (P < .001) and subjective (P = .003) scores was observed in the Hyalograft C group at 5-year follow-up. The return to sports at 2 years was similar in both groups and remained stable after 5 years in the Hyalograft C group; it worsened in the microfracture group. Conclusion: Both methods have shown satisfactory clinical outcome at medium-term follow-up. Better clinical results and sport activity resumption were noted in the group treated with second-generation autologous chondrocyte transplantation.

Background: Platelet Rich Plasma (PRP), a blood-derived product rich in growth factors, is a promising treatment for cartilage defects but there is still a lack of clinical evidence. The aim of this study is to show, through a randomized double blind prospective trial, the efficacy of this procedure, by comparing PRP to Hyaluronic Acid (HA) injections for the treatment of knee chondropathy or osteoarthritis (OA). Methods: 109 patients (55 treated with HA and 54 with PRP) were treated and evaluated at 12 months of follow-up. The patients were enrolled according to the following inclusion criteria: age> 18 years, history of chronic (at least 4 months) pain or swelling of the knee and imaging findings of degenerative changes of the joint (Kellgren-Lawrence Score up to 3). A cycle of 3 weekly injections was administered blindly. All patients were prospectively evaluated before and at 2, 6, and 12 months after the treatment by: IKDC, EQ-VAS, TEGNER, and KOOS scores. Range of motion and knee circumference changes were measured over time. Adverse events and patient satisfaction were also recorded. Results: Only minor adverse events were detected in some patients, such as mild pain and effusion after the injections, in particular in the PRP group, where a significantly higher post-injective pain reaction was observed (p=0.039). At the follow-up evaluations, both groups presented a clinical improvement but the comparison between the two groups showed a not statistically significant difference in all scores evaluated. A trend favorable for the PRP group was only found in patients with low grade articular degeneration (Kellgren-Lawrence score up to 2). Conclusions: Results suggest that PRP injections offer a significant clinical improvement up to one year of follow-up. However, conversely to what was shown by the current literature, for middle-aged patients with moderate signs of OA, PRP results were not better than those obtained with HA injections, and thus it should not be considered as first line treatment. More promising results are shown for its use in low grade degeneration, but they still have to be confirmed.

Platelet-Rich Plasma (PRP) is a low-cost procedure to deliver high concentrations of autologous growth factors (GFs). Platelet activation is a crucial step that might influence the availability of bioactive molecules and therefore tissue healing. Activation of PRP from ten voluntary healthy males was performed by adding 10% of CaCl₂, 10% of autologous thrombin, 10% of a mixture of CaCl₂+ thrombin, and 10% of collagen type I. Blood derivatives were incubated for 15 and 30 minutes and 1, 2, and 24 hours and samples were evaluated for the release of VEGF, TGF-β1, PDGF-AB, IL-1β, and TNF-α. PRP activated with CaCl₂, thrombin, and CaCl₂/thrombin formed clots detected from the 15-minute evaluation, whereas in collagen-type-I-activated samples no clot formation was noticed. Collagen type I produced an overall lower GF release. Thrombin, CaCl₂/thrombin, and collagen type I activated PRPs showed an immediate release of PDGF and TGF-β1that remained stable over time, whereas VEGF showed an increasing trend from 15 minutes up to 24 hours. CaCl₂induced a progressive release of GFs from 15 minutes and increasing up to 24 hours. The method chosen to activate PRP influences both its physical form and the releasate in terms of GF amount and release kinetic.