The chimera of reaching a universal consensus on platelet-rich plasma treatment for knee osteoarthritis: a review of recent consensus statements and expert opinion.

INTRODUCTION: Osteoarthritis (OA) is a prevalent cause of disability worldwide, affecting millions and posing significant socioeconomic burdens. Various conservative measures like hyaluronic acid (HA) and platelet-rich plasma (PRP) injections aim to manage OA symptoms and delay surgical interventions. Despite the increasing utilization of PRP, consensus on its efficacy remains elusive, reflecting the evolving landscape of OA management. AREAS COVERED: This study reviews guidelines and recommendations on intra-articular PRP injections for OA globally, highlighting divergent perspectives among different medical societies. A comprehensive literature search identified 19 relevant guidelines, indicating a temporal and geographic evolution in attitudes toward PRP use. While some guidelines endorse PRP for mild-to-moderate OA, others express caution due to concerns about product standardization and clinical evidence heterogeneity. EXPERT OPINION: The lack of universal consensus on PRP for OA underscores the complex interplay between clinical evidence, practice patterns, and evolving perspectives. Recent shifts toward endorsing PRP may reflect advancements in preparation techniques and personalized medicine approaches. However, challenges persist, including patient selection and product standardization. Efforts to develop consensus and refine PRP classification systems are essential for guiding clinical practice and advancing OA management.

Regulatory and Ethical Aspects of Orthobiologic Therapies.

Orthobiologic therapies show significant promise to improve outcomes for patients with musculoskeletal pathology. There are considerable research efforts to develop strategies that seek to modulate the biological environment to promote tissue regeneration and healing and/or provide symptomatic relief. However, the regulatory pathways overseeing the clinical translation of these therapies are complex, with considerable worldwide variation. The introduction of novel biologic treatments into clinical practice raises several ethical dilemmas. In this review, we describe the process for seeking approval for biologic therapies in the United States, Europe, and Japan. We highlight a number of ethical issues raised by the clinical translation of these treatments, including the design of clinical trials, monitoring outcomes, biobanking, "off-label" use, engagement with the public, marketing of unproven therapies, and scientific integrity.

Aragonite-Based Scaffold for the Treatment of Joint Surface Lesions in Mild to Moderate Osteoarthritic Knees: Results of a 2-Year Multicenter Prospective Study.

BACKGROUND: Osteoarthritis (OA) is considered a contraindication to most cartilage repair techniques. Several regenerative approaches have been attempted with the aim of delaying or preventing joint replacement, with controversial results. Currently, there is a paucity of data on the use of single-step techniques, such as cell-free biomimetic scaffolds, for the treatment of joint surface lesions (JSLs) in OA knees. PURPOSE: To present the 2-year follow-up clinical and radiological outcomes after implantation of a novel, cell-free aragonite-based scaffold for the treatment of JSLs in patients with mild to moderate knee OA in a multicenter prospective study. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 86 patients, 60 male and 26 female, with a mean age of 37.4 ± 10.0 years, mild to moderate knee OA, and a mean defect size of 3.0 ± 1.7 cm2, were recruited at 8 medical centers according to the following criteria: radiographic mild to moderate knee OA (Kellgren-Lawrence grade 2 or 3); up to 3 treatable chondral/osteochondral defects (International Cartilage Repair Society grades 3 and 4) on the femoral condyles or trochlea; a total defect size ≤7 cm2; and no concurrent knee instability, severe axial malalignment, or systemic arthropathy. All patients were evaluated at baseline and at 6, 12, 18, and 24 months after implantation using the Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) subjective score. Additionally, magnetic resonance imaging (MRI) was performed to assess the amount of cartilage defect filling at the repaired site. RESULTS: Significant improvement on all KOOS subscales was recorded from baseline (Pain: 49.6 ± 13.1; Activities of Daily Living [ADL]: 56.1 ± 18.4; Sport: 22.8 ± 18.8; Quality of Life [QoL]: 23.5 ± 16.5; Symptoms: 55.4 ± 19.9) to the 24 months' follow-up (Pain: 79.5 ± 21.1 [P < .001]; ADL: 84.1 ± 21.4 [P < .001]; Sport: 60.8 ± 31.9 [P < .001]; QoL: 54.9 ± 30.4 [P < .001]; Symptoms: 77.7 ± 21.2 [P < .001]). The IKDC subjective score showed a similar trend and improved from 37.8 ± 14.7 at baseline to 65.8 ± 23.5 at 24 months (P < .001). MRI showed a significant increase in defect filling over time: up to 78.7% ± 25.3% of surface coverage after 24 months. Treatment failure requiring revision surgery occurred in 8 patients (9.3%). CONCLUSION: The use of an aragonite-based osteochondral scaffold in patients with JSLs and mild to moderate knee OA provided significant clinical improvement at the 24-month follow-up, as reported by the patients. These findings were associated with good cartilage defect filling, as observed on MRI.

Osteochondral regeneration with a novel aragonite-hyaluronate biphasic scaffold: up to 12-month follow-up study in a goat model.

BACKGROUND: The regeneration of articular hyaline cartilage remains an elusive goal despite years of research. Recently, an aragonite-hyaluronate (Ar-HA) biphasic scaffold has been described capable of cartilage regeneration over a 6-month follow-up period. This study was conducted in order to assess the fate of the regenerated osteochondral tissue in a 12-month-long validated caprine model. HYPOTHESIS/PURPOSE: The hypothesis was that the implantation of the Ar-HA implant leads to tissue regeneration and maturation. STUDY DESIGN: A two-arm caprine model of a critical osteochondral defect compares the fate of acute osteochondral defects (group A) to Ar-HA implanted defects (group B). METHODS: Critical 6 mm in diameter and 10-mm in depth osteochondral defects were created in the load-bearing medial femoral condyle of 20 mature goats and randomized into two groups. In group A (n = 6), a blood clot spontaneously filled the defect; in group B (n = 14), a single Ar-HA implant reconstructed the defect. The animals were sacrificed after either 6 or 12 months. Parameters assessed included clinical evaluation, x-rays, micro-CT, ultrasound and histology at both time points, and specimen high-field magnetic resonance imaging with T2 mapping at the 12-month time point. RESULTS: In most group A animals, the defects were not reconstructed (1/3 at 6 months, and 0/3 at 12 months). Defects in group B were mostly reconstructed (5/7 at 6 months and 6/7 at 12 months). Group A defects were either empty or contained fibrous repair tissue; while group B filling was compatible with hyaline cartilage and normal bone. CONCLUSION: Ar-HA scaffolds implanted in critical osteochondral defects result in hyaline cartilage formation and subchondral bone regeneration. The results improved at the 12-month time point compared to the 6-month time point, indicating a continuous maturation process without deterioration of the repair tissue. CLINICAL RELEVANCE: Osteochondral defects are common in humans; the results of the current study suggest that an acellular Ar-HA scaffold might induce cartilage and subchondral bone regeneration.

Chronic posttraumatic cartilage lesion of the knee treated with an acellular osteochondral-regenerating implant: case history with rehabilitation guidelines.

Osteochondral defects are often symptomatic and lead to deranged joint function. The spontaneous healing capacity of osteochondral defects is limited. In this case study, use of an acellular scaffold capable of induction of mesenchymal stem-cell migration is described. This scaffold was used on an Outerbridge grade IV medical condylar defect measuring ~2 cm2. At 24 mo follow-up, the articular surface appeared restored by MRI, and the patient returned to sports.