Shoulder Synovial Fluid Lipoprotein Levels and Their Relationship to the Rotator Cuff

Rotator cuff pathology has been proposed to occur through intrinsic and extrinsic mechanisms. Hyperlipidemia has been proposed as a mechanism of intrinsic rotator cuff pathology. This prospective observational study evaluates serum and synovial lipid profiles in patients with and without rotator cuff tears to further define the relationship of cholesterol and rotator cuff pathology.

Patients were prospectively enrolled with intact rotator cuff (37 patients) and rotator cuff tear requiring a repair (40 patients) groups. Exclusion criteria were medication for hypercholesterolemia, smoking, previous ipsilateral shoulder surgery, inflammatory arthritis, or history of shoulder infection. Serum and synovial fluid samples were collected at the time of surgery and analyzed for total cholesterol, HDL, non-HDL, and triglycerides.

There were no significant differences seen in any lipid values between patients with rotator cuff and those without a tear. The calculated ratio of synovial lipids to serum lipids was also not significantly different between the patient groups with and without cuff tears.

This study successfully evaluates the correlation between serum and synovial lipid levels in the glenohumeral joint. The ratio of lipid values between the serum and the synovial fluid was similar, thus defining a ratio of lipid levels between the blood and the shoulder joint regardless of the presence of a rotator cuff tear. All lipid values measured were similar in both the serum and synovial fluid between patients with and without cuff tears.