Electrophysiologic Changes After Extended 360° Capsular Release

Frozen shoulder (adhesive capsulitis) is a condition characterized by shoulder pain and restricted range of motion, significantly impairing daily living activities. In cases that do not respond to conservative treatment, arthroscopic capsular release is an effective surgical treatment option. The 360° capsular release technique, performed by some surgeons, involves release of the inferior capsule and therefore carries a potential risk of nerve injury due to the anatomical proximity of neurovascular structures such as the axillary nerve. In addition, surgical manipulations performed around the coracoid process may exert mechanical or compressive effects on the musculocutaneous nerve and its sensory continuation, the lateral antebrachial cutaneous nerve, due to their close relationship with the lateral cord of the brachial plexus.

The aim of this prospective, single-center observational clinical study is to objectively evaluate the morphological and functional effects of inferior capsular release and coracoid region dissection performed during arthroscopic 360° capsular release surgery on the axillary and musculocutaneous nerves, using electromyography (EMG) and nerve conduction studies (NCS) in patients with frozen shoulder.

Patients aged 21-70 years with a diagnosis of frozen shoulder who have not responded to conservative treatments and are scheduled for arthroscopic capsular release will be included in the study. EMG and NCS assessments will be performed at the preoperative baseline, and at 12 weeks postoperatively. For the axillary nerve, the deltoid and teres minor muscles will be evaluated; for the musculocutaneous nerve, the biceps brachii and brachialis muscles will be assessed. Additionally, sensory conduction of the lateral antebrachial cutaneous nerve will be examined. Along with electrophysiological findings, shoulder range of motion (ROM), pain (VAS), muscle strength (MRC), and functional scores will also be recorded.

This study is expected to provide objective evidence regarding the effects of arthroscopic capsular release surgery on peripheral nerve function, thereby contributing new data on the safety of the surgical technique and enriching the currently limited literature on electromyographic evaluation in frozen shoulder surgery.