The Power of Adipose Stem Cells For Knee Meniscus Tears: A Prospective Study on the Effectiveness of Microfat Injections for Knee Meniscus Tears

Abstract

Research Question: The primary question that our study aims to answer is whether adipose-derived stem cell injections improve the pain and overall functionality as determined by VAS and WOMAC survey scores for patients with image-proven meniscal tears over the course of one month, three months, six months, and 12 months after treatment.

Background and Significance: Knee meniscal injuries are a very common pathology with an increasing incidence rate throughout the United States. Symptoms include pain, limited range of motion, swelling, and sensation of knee “locking” or “popping”. Meniscal tears also increase the risk for future osteoarthritis. Current guidelines for meniscal tears focus on nonoperative management for patients who are not active or do not want surgery and meniscal repair/removal with an emphasis on maximal meniscus preservation for active patients. In fact, partial and total meniscectomies have become a controversial option with some experts arguing that they should no longer be performed. Multiple studies have also displayed that meniscal repairs in general do not have a very high success rate. In light of this, a new option of adipose-derived stem cell injection has become a possibility for meniscal injury treatment. Our study was designed as a prospective survey study to determine whether adipose-derived stem cell injection decreases VAS and WOMAC scores for patients with image-proven meniscal tears over the course of one month, three months, six months, and 12 months after treatment.

Materials and Methods: This study was designed as a prospective survey study by evaluating the patient’s knee condition at critical timepoints using VAS and WOMAC knees scores before adipose-derived stem cell treatment, one month after treatment, three months after treatment, six months after treatment, and 12 months after treatment. Patient criteria was based upon a patient presenting with a knee meniscus tear, confirmed by MRI, with minimal underlying osteoarthritis. The initial sample size was determined to be 25 but poor survey response, as well as our exclusion criteria, led to 22 total patients included in the study. The patients were asked to fill out a VAS and WOMAC prior to the treatment. Next, abdominal adipose stem cells were harvested under local anesthesia utilizing an adipose stem cell harvesting kit. After processing the tissue, the cells were then injected into the patients’ affected knee via ultrasound guidance. Patients were contacted directly at each timepoint of interest to fill out VAS and WOMAC surveys. After 12 months of data accumulation, a right tailed unpaired Welch's t-test was performed with significance as p = 0.05.

Results: Our results showed a statistically significant decrease in patients’ VAS, WOMAC-determined pain, WOMAC-determined functional impairment, WOMAC-determined stiffness, and total WOMAC survey scores at one month, three months, six months, and 12 months after adipose-derived stem cell treatment as compared to their baseline values.

Conclusion: Our data supports that adipose-derived stem cell treatment can be a viable option for knee meniscal tears. Further studies with larger sample sizes, longer follow-up, and control groups are required to establish this conclusion.