Sodium Hyaluronate for Myofascial Thoracic Pain

The myofascial complex is increasingly recognized as a potential source of thoracic backpain. Sodium hyaluronate is a key component of synovial fluid and has more recently beenrecognized as an important element of interfascial spaces. The hypothesized mechanism ofaction of sodium hyaluronate differs from that of local anesthetic agents and is expectedto influence outcome timing. Sodium hyaluronate is a key determinant of interfasciallubrication and viscoelastic behavior, facilitating low‐friction gliding between adjacentfascial layers. Experimental and biomechanical studies suggest that alterations in sodiumhyaluronate concentration or molecular organization may increase interfascial shearresistance, potentially contributing to nociceptive input through abnormal tissue strainand impaired movement patterns. Restoration of sodium hyaluronate is therefore postulatedto improve fascial sliding and mechanical load distribution rather than producingimmediate analgesia. Although corticosteroids are used by some clinicians as part ofinjection‐based management of spinal and myofascial pain, they were intentionally notincluded in the present study. The primary objective of this trial was to evaluate theincremental effect of interfascial sodium hyaluronate on pain and function whileminimizing pharmacological confounding and potential long‐term tissue effects. This trialis designed as a superiority study evaluating the incremental benefit of sodiumhyaluronate compared to normal saline added to standard lidocaine injection, whichreflects current clinical practice. For this purpose, a clear, colorless, viscoelastic 1%sodium hyaluronate saline solution (10 mg/ml) in a sterile package for single use, wasused. Participants will be randomized in a 1:1 ratio by computer‐generated randomsequence into two groups. Group 1. Interventional ‐ (4 mL of 1% lidocaine followed by 12mL of sodium hyaluronate) or Group 2. ‐ control group receiving standard lidocaineinjection with saline (4 mL of 1% lidocaine followed by 12 ml of normal saline). Group 2.is a control group with no sodium hyaluronate administration; however, the administrationof lidocaine represents a standard procedure, so patients will not be left withouttreatment even in this study arm. All procedures will be performed by two experiencedphysicians using a standardized technique. Patients will be positioned prone in theprocedure room. The transverse processes at the level corresponding to maximal tendernesswill be identified using ultrasound guidance.