Lab Study Shows Processed Fat Tissue Calms Inflammation in Rotator Cuff Cells

Rotator Cuff Tears Often Fail to Heal Properly After Surgery

Rotator cuff tears are a leading cause of shoulder pain and disability. These injuries become more common as we age. While surgery can repair the torn tendon, the results are often disappointing. Studies show that tears frequently return after surgical repair. This happens because the healing process in the damaged tendon does not work well. Researchers are now exploring regenerative medicine approaches to help tendons heal better and reduce the chance of re-tearing.

Researchers Tested Fat Tissue's Healing Effects on Tendon Cells

In this laboratory study, scientists wanted to understand how micro-fragmented adipose tissue (specially processed fat from your own body) might help injured tendon cells recover. They collected both tendon tissue and fat tissue from ten patients undergoing rotator cuff surgery. The patients ranged in age from their early forties to mid-sixties. The researchers then isolated cells from the damaged supraspinatus tendon—the most commonly injured part of the rotator cuff.

Using the Lipogems® device, scientists processed the fat tissue into tiny fragments. They placed these fragments near the tendon cells in a special setup that allowed the cells to communicate through released molecules without directly touching. After 48 hours, they measured what happened to the tendon cells.

Fat Tissue Reduced Key Inflammatory Markers in Tendon Cells

The study found encouraging results. Tendon cells exposed to the processed fat tissue showed lower levels of two harmful markers:

• PTGS2 (also called COX-2): An enzyme that drives inflammation

• MMP-3: A protein that breaks down tendon tissue

Both of these markers contribute to ongoing damage in injured tendons. When their levels drop, the environment becomes more favorable for healing rather than continued breakdown.

Healing Molecules Increased in Cell Cultures

The researchers also measured helpful substances released into the cell culture fluid. They found higher levels of three important molecules:

• IL-1Ra: A natural inflammation blocker that counteracts damaging signals

• VEGF: A protein that supports blood vessel growth and tissue repair

• IL-6: A molecule that plays complex roles in healing and regeneration

These findings suggest the processed fat tissue releases signals that shift tendon cells away from inflammation and toward repair.

The Fat Tissue Works Through "Paracrine Action"

An important finding was that the fat tissue helped tendon cells without direct contact. The cells communicated through released molecules—a process scientists call "paracrine action." This means the fat tissue sends healing signals to nearby damaged cells. The processed fat contains about one million cells per milliliter. These include pericytes (helper cells that support blood vessels) and mesenchymal stem cells (regenerative cells found in fat tissue).

What This Means for Patients Considering Treatment

This laboratory study provides scientific support for why processed fat tissue might help rotator cuff injuries. By reducing inflammation and tissue breakdown at the cellular level, the treatment creates conditions that favor healing. However, patients should understand this was a lab study, not a clinical trial in people. The cells were studied in dishes, not in actual shoulders.

The research team notes these findings "potentially support the use of μFAT as adjuvant therapy in the treatment of rotator cuff disease." This means processed fat tissue could serve as an addition to surgical repair, possibly improving outcomes and reducing re-tear rates.

For patients with rotator cuff tears considering Lipogems® treatment, this study offers insight into how the therapy may work at a cellular level. The evidence suggests it helps create a healing-friendly environment by calming inflammation and protecting tendon tissue from further breakdown.

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Source: Viganò et al., International Orthopaedics, 2020.