The Anatomic Basis for the Arthroscopic Latarjet Procedure: A Cadaveric Study

Area of Science:

• Orthopedic surgery
• Neuroanatomy
• Surgical techniques

Background:

• The Latarjet technique effectively treats recurrent anterior shoulder instability but carries a significant complication rate (up to 30%), including nerve injury (1.6%).
• The all-arthroscopic Latarjet procedure presents challenges in nerve localization and protection due to the lack of direct palpation.
• Varied instrumentation in arthroscopic Latarjet surgery can lead to distinct nerve injury mechanisms.

Purpose of the Study:

• To delineate the anatomical pathways of the musculocutaneous, axillary, and suprascapular nerves relative to the arthroscopic Latarjet approach.
• To provide actionable guidance for minimizing nerve damage during instrument use and screw fixation in this procedure.

Main Methods:

• A descriptive laboratory study involving 50 cadaveric shoulders (25 specimens) in the beach-chair position.
• Exposure of relevant structures via deltopectoral and dorsal approaches, with a subscapularis muscle split performed between the inferior and middle thirds of the tendon.
• Precise digital caliper measurements of nerve trajectories relative to anatomical landmarks and the muscle split.

Main Results:

• The musculocutaneous nerve was located within the split in 66% of specimens.
• The axillary nerve was found within or medial to the split in 50% of shoulders each.
• A 2 cm safe zone from the glenoid rim was identified for graft-fixing screw insertion to avoid suprascapular nerve injury.

Conclusions:

• Minimizing musculocutaneous and axillary nerve injury risk involves directing the switching stick towards the lateral edge of the subscapularis split.
• Preventing suprascapular nerve damage requires aiming graft-fixing screws laterally towards the glenoid rim edge.
• This anatomical data aids surgeons in reducing nerve injury risks during arthroscopic Latarjet procedures.