The Angular Relationships Between the Coracohumeral Ligament and Adjacent Shoulder Structures Are Variable.

Area of Science:

• Orthopedic Surgery
• Anatomy
• Shoulder Biomechanics

Background:

• The coracohumeral ligament (CHL) is a key static stabilizer of the shoulder joint.
• Accurate identification of the CHL during arthroscopy is crucial for effective rotator interval closure.
• Existing literature offers limited detailed arthroscopic anatomical descriptions of the CHL relative to common surgical landmarks.

Purpose of the Study:

• To arthroscopically describe the anatomy of the coracohumeral ligament (CHL).
• To establish angular relationships between the CHL and specific anatomical reference points.
• To provide guidance for improved arthroscopic rotator interval closure techniques.

Main Methods:

• Gross dissection of 4 fresh-frozen cadaveric shoulders using a deltopectoral approach to identify the CHL.
• Determination of the angular relationship between the CHL and the superior subscapularis tendon border via dissection.
• Arthroscopic imaging to ascertain the CHL's angular position relative to the glenoid articular surface and the long head of the biceps brachii (LHB) tendon.

Main Results:

• Gross dissection revealed the CHL subtends a mean angle of 29° (range 16°-39°) to the superior subscapularis tendon border.
• Arthroscopic analysis showed the CHL forms a mean angle of 59° (range 38°-77°) with the glenoid articular surface.
• Arthroscopic analysis indicated a mean angle of 29° (range 11°-47°) between the CHL and the intra-articular LHB tendon.

Conclusions:

• The CHL exhibits moderate anatomical variability in its position relative to the subscapularis tendon, glenoid, and LHB tendon.
• These adjacent structures serve as valuable anatomical reference points for identifying the CHL during arthroscopy.
• A thorough understanding of these angular relationships can enhance the precision of arthroscopic rotator interval closure.