Problem: Osteoarthritis (OA) is a debilitating, degenerative disease characterized by progressive erosion of articular cartilage and is a major cause of disability and chronic pain. Articular cartilage, due to its structural characteristics, has demonstrated poor regenerative capacity after injury.
Background evidence: Autologous mesenchymal stem cells have been used to treat degenerative orthopedic conditions for over two decades. Intra-articular injection of bone marrow mononuclear cells (BMMNCS) appears to be a safe manipulation for the treatment of knee osteoarthritis (knee OA). In addition, bone marrow aspirate concentrate (BMAC) is one of the best options in the US. Bone marrow-derived growth factors (BMPC) appear to be potential treatments for damaged cartilage. Hypothesis: Intra-articular application of BMMNCS and BMCPC in a single dose is a safe and effective option for the treatment of knee osteoarthritis.
Research: This is a prospective, level I descriptive study, conducted between January 2018 and December 2019. 69 patients, aged 45-89 years, with Kellgren Lawrence (KL) grade III and IV knee osteoarthritis received an intra-articular injection of BMMNCs and BMPCs in a single syringe (3 ml) at a mean dose of 1.26 x 10⁹ mononuclear cells/ml and 655,000 platelets/ml. (Table 1) The main symptoms of knee osteoarthritis and changes in tissue structure were assessed after 12 months by comparing the visual analogue score (VAS) and the knee injury and orthopedic outcome (KOOS) score at different time points.
Observations and results: The KOOS score was obtained at different time points after the first visit: up to 3 months later for 25 patients, 3 to 6 months later for 12 patients, and 12 months later for 7 patients. The categories “6 to 9 months” and “more than 9 months” were considered separately, but the small number of observations in each (3 and 4, respectively) led to combining them into the “12 months” category. Table 2 and Figure 1 present the median scores for each of the aforementioned time points. The mean KOOS score at the “0 to 3 months” time point showed a statistically significant increase compared to the baseline (p < 0.001) and a reduction at the “3 to 6 months” time point compared to the previous time point, which was not statistically significant (p = 0.313). Finally, the median KOOS score again showed a reduction at the last time point, “12 months,” compared to “3 to 6 months,” of a magnitude similar to the previous reduction. The small number of patients at this time point precluded a formal comparison using statistical testing. The initial VAS score ranged from 4 to 10, with a median of 8.5. The overall KOOS score was calculated from subscales for symptoms, stiffness, pain, functioning in daily activities, participation in sports and recreational activities, and quality of life. Table 3 and Figure 2 present the average score for each combination of subscales and measurement points.
In each subscale, medians were compared between baseline and the “0 to 3 months” time point, and between the “0 to 3 months” and “3 to 6 months” time points. In all cases, the increase in score from baseline to the “0 to 3 months” time point was significant (p < 0.001 for all subscales). No significant differences were found between the median scores at the “0 to 3 months” and “3 to 6 months” time points (symptoms: p = 1.000; stiffness: p = 0.423; pain: p = 0.313; functioning in daily activities: p = 0.313; functioning in sports and recreational activities: p = 0.125; quality of life: p = 1.000). A formal comparison between the medians at the “3 to 6 months” and “12 months” time points could not be made due to the small number of observations collected at the latter time point.
Conclusion: Intra-articular injection of a single dose of BMMNC and BMPC for the treatment of knee OA is a safe protocol and could improve the patient’s quality of life.
