Early Clinical Outcomes of Intra-Articular Injections of Bone Marrow Aspirate Concentrate for the Treatment of Early Osteoarthritis of the Hip and Knee: A Cohort Study

Background

Bone marrow aspirate concentrate (BMC) is one of the few cell-based therapies available as a possible biological treatment for early osteoarthritis (OA). Its efficacy, safety, and benefit compared with other treatments are still to be determined.

Objective

To assess the clinical outcomes of patients undergoing intra-articular injection of BMC for the treatment of early knee and hip OA.

Design

Prospective, cohort study.

Setting

Single institution, quaternary level of care.

Patients

Nineteen patients (16 female and 3 male), totaling 25 joints (10 knees, 15 hips), treated with intra-articular BMC for early OA between 2014 and 2016. The mean age at time of the procedure was 58 ± 12.7 years (range, 30-80 years). The mean follow-up was 13.2 ± 6.3 months (range, 6-24 months). Inclusion criteria included ≥18 years; knee OA, Kellgren–Lawrence grade I-II; hip OA, Tönnis grade I-II; first-time intra-articular BMC therapy, after unsuccessful symptomatic and conservative treatments (ie, physical therapy, analgesics and anti-inflammatory drugs) for 6 months. Exclusion criteria included pregnancy; malignancy; rheumatologic diseases; infection; Kellgren–Lawrence grade III-IV; Tönnis grade III; and previous intra-articular injections or surgery.

Interventions

All patients had autologous bone marrow aspirate harvested from the iliac crest and centrifuged to achieve BMC, for intra-articular injection.

Main Outcome Measurements

The hypothesis was formulated before the study. Patient-reported outcomes measures were assessed preoperatively and at last follow-up using the Western Ontario and McMaster Universities Arthritis Index.

Results

Western Ontario and McMaster Universities Arthritis Index improved from a baseline of 40.8 ± 18.3% to 20.6 ± 17% (P < .001) at final follow-up. The satisfaction rate was 63.2%. The minimal clinically important difference threshold of 9.15 points was reached by 64% of the patients. Two patients were converted to total hip arthroplasty at 8 months after BMC injection.

Conclusions

Intra-articular injections of BMC for the treatment of early knee or hip OA were safe and demonstrated satisfactory results in 63.2% of patients. Future studies are necessary to determine the efficacy of this technique and its safety profile.

Level of Evidence

II