# Intra-articular administration of extra-virgin olive oil in degenerative osteoarthritis

## TL;DR

Injecting extra virgin olive oil into rabbit knees showed potential in treating osteoarthritis by improving cartilage health and reducing degeneration.

## Contribution

This study is the first to investigate the intra-articular use of extra virgin olive oil for osteoarthritis in a rabbit model.

## Key findings

- EVOO-treated rabbits showed significantly better morphological and histological outcomes compared to controls.
- MRI and Mankin scoring confirmed EVOO's positive effects on cartilage restoration in both short- and long-term assessments.
- EVOO demonstrated potential as a cartilage regenerative agent for osteoarthritis treatment.

## Abstract

We aimed to analyze the outcomes of intraarticular extra virgin olive oil (EVOO) injection on mechanically induced rabbit knee osteoarthritis (OA) by studying the morphological, histological, and radiological findings.

The study was conducted on 32 New Zealand White rabbits. The randomly numbered subjects were divided into two main groups. The rabbits numbered 1 to 16 were selected to be the group to receive EVOO, and the remaining were selected into a control group. Both groups were separated into two subgroups for short-term (five weeks) and long-term (10 weeks) follow-up. Anterior cruciate ligament transection was applied on the left knees of all the rabbits via medial parapatellar arthrotomy to simulate knee instability. Immediately after the surgical procedure, 0.2 cc of EVOO was injected into the knee joint of rabbits numbered 1–16, and the control group received 0.2 cc of sterile saline. On the 14th day, long-term group subjects were administered another dose of 0.2 cc EVOO intraarticularly.

The gross morphological scores of the control group subjects were significantly different from the EVOO group for both short-term (p = 0,055) and long-term (p = 0,041) scores. In parallel, the MRI results of the EVOO subjects were significantly different from the control group for both short-term and long-term follow-up assessment scores (p = 0.017, p = 0.014, respectively). The Mankin scoring results showed that there were statistically significant differences between the EVOO and control group in the comparison of both total scores (p = 0.001 for short-term and p = 0.004 for long-term) and subgroup scoring, including macroscopic appearance, chondrocyte cell number, staining, and Tidemark integrity in both short-term (p = 0.005, p = 0.028, p = 0.001, p = 0.005, respectively) and long-term assessments (p = 0.002, p = 0.014, p < 0.001, p = 0. 200, respectively).

We have observed promising outcomes of intra-articular application of extra virgin olive oil in the treatment of acute degenerative osteoarthritis in rabbit knees. Due to its potential cartilage restorative and regenerative effects, EVOO, when administered intra-articularly, may be a promising agent to consider for further research in the treatment of OA.