Background: Platelet-rich plasma (PRP) injections have been proposed as a new conservative option for knee degeneration to provide symptomatic relief and delay surgical intervention. Although the current literature provides some evidence on the benefits of this technique compared with viscosupplementation, no studies have been performed to compare their long-term effects. Purpose: To compare the long-term clinical outcomes provided by intra-articular injections of either PRP or hyaluronic acid (HA) to treat knee degenerative disease. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: Patients with a history of chronic symptomatic knee degenerative changes and osteoarthritis (Kellgren-Lawrence grade 0-3) were enrolled: 192 patients were randomized to undergo 3 blinded weekly intra-articular injections of either PRP or HA. Patients were prospectively evaluated before the injection and then at 2, 6, 12, and 24 months and a mean of 64.3 months (SD, 7.8 months) of follow-up. Evaluation was based on International Knee Documentation Committee (IKDC) subjective (main outcome), EuroQol visual analog scale, and Tegner scores; 167 patients reached the final evaluation. Results: Both treatments were effective in improving knee functional status and symptoms over time: Mean ± SD IKDC subjective score improved significantly for both PRP and HA groups ( P < .0005) and remained stable over time up to 24 months (from 53.3 ± 14.3 to 67.3 ± 18.1 and from 50.3 ± 13.2 to 62.1 ± 20.8 for PRP and HA groups, respectively). At final evaluation, a significant IKDC reduction was observed in both treatment groups, with the PRP group still presenting significantly higher values compared with baseline: PRP 60.5 ± 19.0 ( P < .001 vs baseline), HA 55.7 ± 18.8 (not significant vs baseline). A comparative analysis showed no significant intergroup difference in any of the clinical scores at any follow-up point. The median duration of patient subjective perception of symptomatic relief was 9 months for HA and 12 months for PRP (not significant). The only significant difference was observed in the rate of reintervention at 24 months, which was significantly lower in the PRP group (22.6% vs 37.1%, P = .036). Conclusion: Both treatments were effective in improving knee functional status and symptoms over time. PRP did not provide an overall superior clinical improvement compared with HA in terms of either symptomatic-functional improvement at different follow-up points or effect duration. Registration: NCT01670578 (ClinicalTrials.gov identifier).

Objective Osteochondritis dissecans (OCD) lesions are a relevant problem that affects the long-term prognosis of young patients. The purpose of this study was to analyze the evidence on potential and indications of nonsurgical treatment strategies for knee OCD. Design The search was conducted on 3 medical electronic databases according to PRISMA guidelines, including reports of any level of evidence dealing with the conservative management of knee OCD. Of 1688 identified records, 55 full-text articles were screened: 27 studies met the inclusion criteria, for a total of 908 knees, and were used for the analysis. Results No high-level studies were found: 24 articles were case series and 3 case reports, reporting on different treatments summarized in (1) restriction of physical activity, (2) physiokinesitherapy and muscle-strengthening exercises, (3) physical instrumental therapies, (4) limitation of weightbearing, and (5) immobilization. The analysis showed an overall healing rate of 61.4%, with large variability (10.4%-95.8%). A conservative treatment based on restriction of sport and strenuous activities seems a favorable approach, possibly combined with physiokinesitherapy. Negative prognostic factors were also identified: larger lesion size, more severe lesion stages, older age and skeletal maturity, discoid meniscus, and clinical presentation with swelling or locking. Conclusions The literature on conservative treatments for knee OCD is scarce. Among different non-surgical treatment options, strenuous activity restriction seems a favorable approach, whereas there is no evidence that physical instrumental therapy, immobilization, or weightbearing limitation could be beneficial. However, further studies are needed to improve treatment potential and indications for the conservative management of knee OCD.

Background: Osteochondritis dissecans is a pathology affecting young patients that involves the entire osteochondral unit. In the case of unfixable fragments, regenerative cartilage treatments are a viable solution, but little is known about the use of these procedures for the treatment of juvenile osteochondritis dissecans (JOCD). The aim of this study was to evaluate the long-term results offered by matrix-assisted autologous chondrocyte transplantation combined with autologous bone grafting for the treatment of JOCD. Methods: Nineteen patients have been enrolled. The mean age at the time of treatment was 16.8±1.5 years, with a mean body mass index of 22.9±2.7. The average size of the defects was 2.8±1.2 cm2. All patients were evaluated prospectively before surgery and at 12, 24, 60, and at a final follow-up of 120 months with International Knee Documentation Committee scores, EuroQol-Visual Analogue Scale, and the Tegner Score. Results: A statistically significant improvement in all clinical scores was observed from baseline evaluation to 120 months of final follow-up. In particular, the International Knee Documentation Committee subjective score improved from the preoperative evaluation of 38.7±17.3 to 74.0±21.8 at 12 months (P<0.0005), with scores remaining stable for up to 120 months (83.8±20.7), with all follow-ups showing a statistically significant improvement compared with the basal value (P<0.0005). Three patients failed at 12 months, for a failure rate of 16% at 10 years of follow-up. Lesions >3.5 cm2 obtained worse subjective results. In addition, lesion size and female sex were significantly associated with failures. Conclusions: The matrix-assisted autologous chondrocyte transplantation technique with autologous bone grafting is a valid treatment option for JOCD in case of unfixable fragments. The clinical improvement obtained is significant and stable, with good results maintained for up to 10 years of follow-up and an overall low failure rate. Lesion size and sex could influence the clinical outcome and should be considered in the treatment choice. Level of Evidence: Level IV—case series.

Objective Osteoarthritis (OA) is an inflammatory and degenerative disease, and the numerous treatments currently used are not fully effective. Mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) are proposed for OA treatment as biologic therapies. The aim of the study was to observe the role of autologous protein solution (APS), a type of PRP, on chondrogenic differentiation of 2 types of MSCs, from bone marrow (BMSCs) and adipose tissue (ADSCs), in an in vitro osteoarthritic microenvironment. Design Inflammatory culture conditions, mimicking OA, were obtained by adding interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα), or synovial fluid from patient osteoarthritic knees (OSF), to the culture medium. MSCs were then treated with APS. Results After 1 month of culture, both cell types formed mature micromasses, partially altered in the presence of IL-1β and TNFα but quite preserved with OSF. Inflammatory conditions hindered differentiation in terms of gene expression, not counterbalanced by APS. APS triggered type I collagen deposition and above all contributed to decrease the expression of metalloproteinases in the most aggressive conditions (IL-1β and TNFα in the culture medium). ADSCs originated micromasses more mature and less prone toward osteogenic lineage than BMSCs, thus showing to better adapt in an aggressive environment than BMSC. Conclusions APS seems to act better on inflammation front and, between cell types, ADSCs respond better to the inflammatory microenvironment of OA and to the treatment with APS than BMSCs.