Summary

The intra-operative injection of autologous micro-fragmented adipose tissue is safe and effective in improving short-term clinical and functional results after arthroscopic rotator cuff repair

Abstract

Background

Nonexpanded autologous micro-fragmented lipoaspirate tissue has been recently introduced in orthopaedics to support and accelerate tissue regeneration. Lipoaspirates contain human derived adipose stem cells and produce growth-factors, such as platelet derived growth-factor (PDGF), fibroblast growth-factor (FGF), transforming growth-factor beta (TGF-??), and vascular endothelial growth-factor (VEGF), which are known to play important regulatory roles in cellular functions, including adhesion, chemotaxis, proliferation, migration, matrix synthesis, differentiation, and angiogenesis. Herewith, autologous micro-fragmented lipoaspirate tissue is expected to create a suitable microenvironment for tendon repair and regeneration.
Up to date, no prospective study exist, which evaluated the use of this product in vivo on rotator cuff tendons repair. The aim of this prospective, randomized, controlled trial was to evaluate safety and efficacy of autologous lipoaspirate tissue in arthroscopic rotator cuff repair.

Methods

Patients with degenerative postero-superior rotator cuff tears were prospectively enrolled and randomized into two groups: the treatment group was treated with a single-row arthroscopic rotator cuff repair followed by intra-operative injection of autologous micro-fragmented adipose tissue processed with an enzyme-free technology (Lipogems®); the control group was treated with a single-row arthroscopic rotator cuff repair without adipose tissue injection. Post-operative protocols were identical for both groups. Pain was daily assessed using the Visual Analogue Scale (VAS) for the first four post-operative weeks. Patients’ outcomes were collected pre-operatively and at 3, 6, 12, 18 and 24 months post-operatively using the American Shoulder and Elbow Surgeons Shoulder Score (ASES), the Simple Shoulder Test (SST), and the Constant-Murley Score (CMS). Eighteen months after surgery, magnetic resonance imaging was conducted to assess tendon integrity and calculate re-rupture rate. Analysis of covariance was used to compare response means among two or more groups (Categorical variables) adjusted for a quantitative variable (Covariate), thought to influence the outcome (Dependent).

Results

One hundred and seventy-seven consecutive patients were screened for inclusion, 52 were enrolled and randomized and 44 completed the 24-months follow-up period (control group: 22; treatment group: 22). All patients showed significant clinical improvement after treatment. Statistically significant differences between the two groups of patients were found in terms of CMS, ASES, SST at 6 months (p = 0.006, p = 0.009 and p = 0.009 respectively), revealing a superiority of the treatment group. No significant differences were found at later follow-up points. No significant difference between the two groups was encountered in the complication rate and in the re-rupture rate at final follow-up. No serious adverse events were encountered.

Conclusions

This prospective, randomized, controlled trial demonstrated that the intra-operative injection of autologous micro-fragmented adipose tissue is safe and effective in improving short-term clinical and functional results after arthroscopic rotator cuff repair. Although still in the early stages of application, augmentation of surgical rotator cuff repair with autologous micro-fragmented adipose tissue appears a suitable strategy to enhance tendon repair and regeneration.