Osteoarthritis (OA) is one of the most common diseases resulting in large burdens on society.

Among the emerging treatments, Bone Marrow Concentrate (BMC) intra-articular injections are a promising regenerative approach. However, they offer only a temporary benefit since they target synovial and chondral tissues but fail to address the osteochondral interface, which plays a key role in the onset and progression of joint degeneration.

This project will investigate the efficacy of combined BMC injections, targeting both intra-articular tissues and subchondral bone, to treat OA in a Randomized Controlled Trial (RCT).

The main aim is to evaluate in a RCT the potential of a new combined BMC treatment for OA, through the use of scores for the clinical outcome, the study of imaging and biological samples for tissue regeneration and systemic effects, and the identification of BMC and patient characteristics predictive of better results.

All patients will undergo an arthroscopic procedure to debride degenerated tissues (this can offer a temporary benefit but not long lasting results) before BMC intra-articular injection. Half patients will receive also the injection of BMC at the subchondral level (bone samples obtained to allow BMC placement will be sent to the Lab).

The same minimally invasive incisions will be used for all patients, ensuring patient blinding. Evaluations, performed by medical staff not involved in the treatment to ensure double blinding, will document subjective clinical improvement, functional measurements, biomarker study, and imaging with the use of modern 3TMRI and qCT technology. BMC characterization and patient features will be analysed to identify factors predictive of a better outcome.

Inclusion Criteria:

1. Male or female patients, aged between 40 and 70;
2. Arthrosis of the medial compartment (grade 2-3 according to the Kellgren-Lawrence score> 4 months);
3. Failure after at least 6 months of conservative treatment (drug therapy with NSAIDs and painkillers, hyaluronic acid infiltration, corticosteroid infiltration, PRP);
4. Patients' ability and consent to participate in clinical and radiological follow-up;
5. Signature of informed consent.

Exclusion Criteria:

1. Patients with trauma in the 6 months prior to surgery;
2. Patients with maligncy;
3. Patients suffering from rheumatic diseases;
4. Patients suffering from non-compensated diabetes;
5. Patients suffering from uncompensated thyroid metabolic disorders;
6. Patients abusing alcoholic beverages, drugs or drugs;
7. Patients with axial deviations> 5 °;
8. Body Mass Index> 35;
9. Patients treated with joint infiltrations in the previous 6 months;
10. Patients treated with surgery at the same knee in the previous 12 months.