Closed-loop temporomandibular joint arthrocentesis: pilot of a technique for effective synovial fluid collection.

Temporomandibular joint (TMJ) arthrocentesis is a common minimally invasive method used for both diagnosis and treatment. However, traditional lavage techniques often cause excessive dilution of synovial fluid, reducing the accuracy of subsequent biochemical tests. This technical note introduces a closed-loop arthrocentesis technique aimed at maximizing synovial fluid recovery while maintaining protein levels and sample quality. The procedure employs a closed-loop system that prevents fluid leakage and enables controlled and efficient collection of synovial fluid. In this pilot study, synovial fluid samples obtained via this method (two joints) were compared to those collected through a single pumping approach (two joints). Protein quantification using the bicinchoninic acid (BCA) assay revealed a markedly higher mean concentration in the closed-loop group (0.438 µg/µL) versus the capsular pumping approach (0.222 µg/µL), despite standardized lavage volumes (∼1400 µL). The method also demonstrated improved total protein yield and potential for reproducibility across replicate measurements. This system is affordable, and easy to integrate into clinical practice. By enhancing the quality of synovial fluid samples, the closed-loop technique may improve biomarker analysis, including studies of proteins and cytokines. This approach offers potential for better diagnostic accuracy and advancing translational research in TMJ disorders but requires validation in further studies.