Subscapularis structural integrity and function after arthroscopic Latarjet procedure at a minimum 2-year follow-up

Area of Science:

• Orthopedic Surgery
• Sports Medicine
• Shoulder Arthroscopy

Background:

• Subscapularis function is crucial for shoulder stability and motion.
• While extensively studied after Bankart repair, its performance post-arthroscopic Latarjet remains less understood.
• This research addresses the gap in knowledge regarding subscapularis outcomes following arthroscopic Latarjet procedures.

Purpose of the Study:

• To assess the clinical and radiological outcomes of the subscapularis muscle after arthroscopic Latarjet surgery.
• To compare the functional and structural integrity of the subscapularis in the operated arm versus the contralateral side.
• To identify factors influencing subscapularis muscle quality post-procedure.

Main Methods:

• A cohort of 40 patients with a minimum 2-year follow-up after arthroscopic Latarjet procedure was analyzed.
• Clinical assessments included the Western Ontario Shoulder Instability Index, Rowe scores, isokinetic testing, and lift-off tests.
• Radiological evaluation utilized CT scans to measure graft consolidation, muscle dimensions, and fatty atrophy via mean muscle attenuation (MMA).

Main Results:

• A statistically significant decrease of 8.3% in maximum internal rotation peak torque was observed in the operated arm (P = .02).
• No significant difference was found in the agonist-antagonist ratio (76.9% vs. 76%, P = .82) or final lift-off strength (P = .38).
• A 23% decrease in lift-off distance (P < .001) and diminished subscapularis MMA, particularly in the superior part, were noted, correlating with hyperlaxity and dislocation history.

Conclusions:

• Arthroscopic Latarjet procedures yield satisfactory clinical results for shoulder instability.
• Subscapularis muscle quality, assessed by MMA, may be diminished, especially in the superior portion, influenced by patient hyperlaxity and prior dislocations.
• Despite a reduction in peak torque, functional outcomes like the agonist-antagonist ratio and final lift-off strength remain comparable between operated and contralateral sides.