A biomechanical study to optimize superior capsular reconstruction operative technique.

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Shoulder Reconstruction

Background:

• Superior capsular reconstruction (SCR) aims to restore shoulder function.
• Optimizing anchor fixation and placement is crucial for successful SCR outcomes.
• Evaluating different suture anchors and glenoid locations is necessary.

Purpose of the Study:

• To compare the fixation strength of four different suture anchors for SCR.
• To assess glenoid neck locations for fixation strength and bone mineral density (BMD).
• To determine the correlation between BMD and anchor fixation strength.
• To identify optimal arthroscopic portal sites for glenoid anchor placement.

Main Methods:

• Twenty cadaveric specimens were randomized into four anchor groups: FiberTak, SutureTak, PEEK Corkscrew, and Bio-Corkscrew.
• Anchors were placed in anterosuperior, superior, and posterosuperior glenoid neck locations.
• Cyclic and load-to-failure testing were performed using a materials testing system.
• Bone mineral density (BMD) and arthroscopic portal access were evaluated using custom software.

Main Results:

• The 4.5-mm Bio-Corkscrew anchor demonstrated the highest maximum load and minimal cyclic elongation/excursion.
• No significant differences in fixation strength were found among glenoid anchor positions.
• The superior glenoid rim showed the highest BMD, but no correlation with fixation outcomes was observed.
• The posterior and anterior portals provided optimal access to the posterosuperior and anterosuperior glenoid neck, respectively.

Conclusions:

• The 4.5-mm Bio-Corkscrew anchor provides the most robust fixation for superior capsular reconstruction.
• Bone mineral density and anchor location did not correlate with biomechanical fixation outcomes.
• Specific arthroscopic portals offer optimal access for anchor placement in SCR.