Microfracture versus microfracture and platelet-rich plasma: arthroscopic treatment of knee chondral lesions. A two-year follow-up study.

Purpose: the aim of this study was to describe and compare the clinical results obtained in patients affected by chondral lesions of the knee submitted to an arthroscopic treatment with the microfracture technique or microfracture + intraoperative autologous platelet-rich plasma (PRP) injection. Methods: a prospective observational study was performed in patients affected by chondral lesions of the knee (classed as grade III-IV according to Outer-bridge's classification) and early osteoarthritis (classed as grade 1-2 according to the Kellgren-Lawrence classification). Their mean age was 52.4 years. Thirteen patients were treated with the microfracture technique according to Steadman (Group A), while 14 were treated with microfracture + PRP injection (Group B). Both groups were assessed using series of measures (a visual analog scale for pain, the 36-Item Short Form Health Survey and the International Knee Documentation Committee Subjective Knee Form) to compare pre-operative and postoperative values at 3, 6, 12 and 24 months. Statistical analysis was conducted using a two-factor ANOVA for repeated measures. Results: the VAS score decreased from a pre-operative value of 6.62±1.26 to 3.54 ±2.26 at 24 months in Group A (p<0.001), and from 6.43±1.91 to 3.36±2.84 in Group B (p<0.001). The IKDC subjective score increased from a pre-operative value of 37.02±12.00 to 62.13±19.00 at two years in Group A (p<0.001) and from 34.63±15.00 to 67.11±26.74 in Group B (p<0.001); the SF-36 scores showed a similar trend. Although an improvement was recorded over time in both groups, in the short term the IKDC subjective score improvement seemed to be better in Group B; a similar trend was shown by the SF-36 and VAS scores. At two years, the IKDC Subjective Scale, VAS and SF-36 scores seemed to be similar in the two groups. Over time, no significant differences were found between the two groups in any of the three outcomes. Conclusions: the use of autologous PRP in association with the microfracture technique seems to give better clinical and functional results in short-term follow-up, above all as regards pain. At two-year follow-up, however, the clinical results of the two groups were similar. Level of evidence: Level II, prospective cohort study

Platelet Concentration in Platelet-Rich Plasma Affects Tenocyte Behavior In Vitro

Since tendon injuries and tendinopathy are a growing problem, sometimes requiring surgery, new strategies that improve conservative therapies are needed. Platelet-rich plasma (PRP) seems to be a good candidate by virtue of its high content of growth factors, most of which are involved in tendon healing. This study aimed to evaluate if different concentrations of platelets in PRP have different effects on the biological features of normal human tenocytes that are usually required during tendon healing. The different platelet concentrations tested (up to 5 × 106 plt/µL) stimulated differently tenocytes behavior; intermediate concentrations (0.5 × 106, 1 × 106 plt/µL) strongly induced all tested processes (proliferation, migration, collagen, and MMPs production) if compared to untreated cells; on the contrary, the highest concentration had inhibitory effects on proliferation and strongly reduced migration abilities and overall collagen production but, at the same time, induced increasing MMP production, which could be counterproductive because excessive proteolysis could impair tendon mechanical stability. Thus, these in vitro data strongly suggest the need for a compromise between extremely high and low platelet concentrations to obtain an optimal global effect when inducing in vivo tendon healing