# Preliminary Report on the Time-Related Effect of a Single Autologous Adipose-Derived Mesenchymal Stem Cells Injection in Hip Osteoarthritis: A Retrospective Observational Study

## TL;DR

This study shows that a single injection of fat-derived stem cells can improve hip pain and function in most patients with hip osteoarthritis over 12 months.

## Contribution

The study provides new evidence on the long-term effectiveness of a single autologous adipose-derived stem cell injection for hip osteoarthritis.

## Key findings

- 27 out of 30 patients showed consistent improvement in pain relief, hip function, and quality of life over 12 months.
- Two patients required total hip arthroplasty after the treatment.
- The treatment was associated with a constant amelioration of symptoms in most patients.

## Abstract

Background: Recently, intra-articular injection of mesenchymal stem cells (MSCs) had been proposed as a conservative treatment for hip osteoarthritis (HOA). Adipose tissue was demonstrated as a viable source of MSCs because of the high concentration of cells and the easy access to the donor site. The purpose of this study was to evaluate the time-related results of a single intra-articular injection of autologous adipose-derived stem cells (aASCs) in a series of patients with HOA.

Methods: A retrospective study was conducted on 30 patients with HOA, who underwent an intra-articular injection of aASCs between September 2018 and January 2021. Inclusion criteria for the procedure were as follows: onset of symptoms of the affected hip in the prior six or more months ago, failure of the conservative treatment (NSAIDs and/or physiotherapy) and age > 18 years. Exclusion criteria were trauma in the affected hip occurred in the previous 3 months, recent arthroscopic treatment, infectious joint disease, chondromatosis of the hip or any other secondary HOA, malignancy, hyaluronic acid or other injections in the previous 6 months and incomplete follow-up. Because a low BMI makes extremely difficult to harvest enough adipose tissue, patients with a BMI < 18 were also excluded. The Oxford Hip Score, the 12-item Short Form Survey and Visual Analogue Scale were used to evaluate the results of the proposed treatment at regular intervals.

Results: In 27/30 patients, a constant improvement in pain relief, hip function and quality of life was observed during the entire follow-up period of 12 months. Two patients underwent a subsequent total hip arthroplasty.

Conclusion: The single injection of aAMSCs seems to be a valuable treatment for HOA. A constant amelioration of pain and function could be observed in most patients at 12 months of follow-up.