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Bicipital groove

The bicipital groove, also known as the intertubercular sulcus of the humerus, is a deep vertical groove on the anterior aspect of the proximal humerus. It lies between the greater and lesser tubercles and serves as the passage for the tendon of the long head of the biceps brachii muscle, which runs within it enveloped by a synovial sheath.

The groove acts as an important anatomical channel for the biceps tendon, stabilizing it during shoulder and elbow movements. It also provides attachment for key muscles forming the anterior shoulder wall, including pectoralis major, teres major, and latissimus dorsi, which insert along its lips and floor.

Synonyms

  • Intertubercular sulcus

  • Bicipital sulcus

  • Groove for the long head of the biceps tendon

Location and Structure

  • Position: On the anterior surface of the proximal humerus, extending downward from between the greater and lesser tubercles.

  • Shape: Deep and narrow superiorly, becoming shallower distally.

  • Boundaries:

    • Lateral lip: Formed by the greater tubercle, providing insertion for the pectoralis major.

    • Medial lip: Formed by the lesser tubercle, providing insertion for the teres major.

    • Floor: Formed by the humeral shaft, providing insertion for the latissimus dorsi.

  • Roof: Bridged by the transverse humeral ligament, converting the groove into a canal that holds the long head of biceps tendon in place.

Relations

  • Contents: Tendon of the long head of biceps brachii enclosed in a synovial sheath.

  • Anteriorly: Deltoid and pectoralis major muscles.

  • Posteriorly: Humeral shaft and attachments of teres major and latissimus dorsi.

  • Medially: Lesser tubercle and subscapularis tendon.

  • Laterally: Greater tubercle and supraspinatus/infraspinatus tendons.

  • Superiorly: Continuous with the supraglenoid tubercle (origin of the long head of biceps).

Attachments

  • Lateral lip: Pectoralis major

  • Medial lip: Teres major

  • Floor: Latissimus dorsi

  • Roof (transverse humeral ligament): Extends between tubercles, retaining the biceps tendon in the groove

Nerve Supply

  • Periosteal innervation from axillary and musculocutaneous nerves.

  • The biceps tendon receives sensory fibers via the musculocutaneous nerve.

Function

  • Tendon housing: Provides a bony channel for the long head of the biceps brachii tendon.

  • Stabilization: Prevents biceps tendon displacement during shoulder motion.

  • Muscle attachment site: For latissimus dorsi, pectoralis major, and teres major.

  • Force transmission: Facilitates the coordinated movement of the humerus and forearm during flexion and supination.

  • Clinical landmark: Important in diagnosing bicipital tendinitis and groove morphology variants on imaging.

Clinical Significance

  • Bicipital tendinitis: Inflammation of the biceps tendon within the groove causing anterior shoulder pain.

  • Tenosynovitis: Fluid accumulation in the sheath seen on MRI or ultrasound.

  • Tendon dislocation or subluxation: Due to rupture of the transverse humeral ligament or subscapularis tear.

  • Groove dysplasia: Shallow groove predisposes to tendon instability.

  • Fracture involvement: Groove fractures may disrupt biceps anchorage.

  • Imaging importance: MRI and CT evaluate groove morphology, tendon integrity, and synovial inflammation.

MRI Appearance

  • T1-weighted images:

    • Cortex: Low signal (dark).

    • Bone marrow: Bright, due to fatty content in normal humerus.

    • Biceps tendon: Low-signal cord-like structure within the groove.

    • Synovial sheath: Thin, low-signal rim outlining the tendon.

    • Pathology: Tendon thickening or fluid collection appears as intermediate-to-bright signal surrounding the tendon.

  • T2-weighted images:

    • Cortex: Low signal.

    • Marrow: Bright (slightly less than on T1).

    • Tendon: Low-signal linear structure.

    • Fluid or inflammation: Bright hyperintense signal outlining the tendon (indicative of tendinitis or tenosynovitis).

    • Dislocation: Tendon visualized medially, lying anterior to subscapularis tendon.

  • STIR:

    • Normal marrow: Intermediate-to-dark signal.

    • Inflammation or edema: Bright hyperintensity around the tendon sheath or within surrounding soft tissue.

    • Useful for detecting early tendon inflammation or occult bony edema.

  • Proton Density Fat-Saturated (PD FS):

    • Normal tendon: Uniformly dark with smooth margins.

    • Pathology: Bright hyperintense rim from peritendinous fluid or synovial thickening.

    • Ideal for evaluating bicipital tendinitis, partial tendon tears, and sheath distention.

  • T1 Fat-Sat Post-Contrast:

    • Normal groove and tendon: Minimal enhancement.

    • Inflamed sheath or synovium: Shows avid contrast enhancement.

    • Chronic tendinopathy: Patchy or peripheral enhancement with low-signal fibrosis.

CT Appearance

Non-Contrast CT:

  • Cortex: High attenuation defining groove contours.

  • Marrow: Fat density within humeral shaft.

  • Groove margins: Clearly delineated; shape and depth easily measured.

  • Pathology: Identifies fractures, groove shallowness, or bony ridging associated with chronic tendinitis.

  • Calcifications: May be seen along tendon sheath or at tendon insertion.

Post-Contrast CT (standard):

  • Bone: Minimal enhancement.

  • Soft-tissue enhancement: Seen in bicipital tenosynovitis or peri-groove inflammation.

  • Useful for: Evaluating tendon displacement, osseous remodeling, and periarticular pathology when MRI is unavailable.

CT VRT 3D image

Bicipital groove ct 3d image

MRI image

Bicipital groove axial cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

CT image

Bicipital groove CT AXIAL image