# Intra‐articular and intra‐osseous expanded adipose‐derived stromal cell injections for knee osteoarthritis‐related bone marrow lesions yield promising outcomes: Preliminary results in 16 athletes

## TL;DR

Injecting fat-derived stem cells into the knee joint and bone marrow of athletes with osteoarthritis and bone marrow lesions led to significant pain reduction and improved function over 12 months.

## Contribution

This study demonstrates the safety and effectiveness of combined intra-articular and intra-osseous stem cell injections for knee osteoarthritis in athletes.

## Key findings

- Significant improvements in pain, activity levels, and quality of life were observed at 6 and 12 months.
- MRI scores showed improvement in 12 out of 27 evaluated regions after 12 months.
- No major complications were reported during the study period.

## Abstract

To explore the results of a fluoroscopic‐guided intra‐osseous (IO) and intra‐articular (IA) injection of expanded adipose‐derived stromal cells (ASCs) in athletes with bone marrow lesions (BML) associated with knee osteoarthritis (OA).

A prospective study was conducted on 16 athletes (9 males, 7 females; mean age 30.5 ± 2.8 years), including two with bilateral knee involvement. All had Kellgren‐Lawrence grades 2–4 and received IA and IO injections of 24.3 ± 2.1 million and 23.4 ± 1.9 million ASCs, respectively. Clinical outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS), Numeric Pain Rating Scale (NPRS), and Tegner activity scale at baseline, 6 months, and 12 months. Radiological changes were evaluated using Magnetic Resonance Imaging Osteoarthritis Knee Scores (MOAKS) at baseline and 12 months.

Significant improvements were observed in NPRS, Tegner, and all KOOS subscales at 6 months and 12 months with respect to baseline (p < 0.05). At 12 months, NPRS decreased from 6.6 ± 0.9 to 2.4 ± 0.5, and Tegner increased from 4.4 ± 1.8 to 7.8 ± 1.1. All KOOS subscale scores improved at 12 months. Symptoms: 49.3 ± 6.4 to 74.1 ± 4.9; pain: 49.4 ± 4.3 to 75.8 ± 3.2; sport and recreation: 30.6 ± 6.2 to 67.8 ± 4.3; activities of daily living: 57.6 ± 3.6 to 79.9 ± 4.8; and quality of life: 35.4 ± 10.3 to 66.3 ± 5.3. A mild decline yet significant in the KOOS sport and recreation subscale was noted between 6 and 12 months (p = 0.02), but remained significantly improved from baseline. MOAKS analysis showed improvement in 12 of 27 evaluated regions. No major complications occurred.

Combined IA and IO ASC injections are a safe and effective treatment for OA‐BMLs in athletes, offering sustained clinical and radiological benefits over 12 months.

Level III.