Adductor Tubercle: Anatomy, Location and Imaging Features

Topic

Adductor tubercle

The adductor tubercle is a small but prominent bony projection located on the superior aspect of the medial femoral condyle. It serves as an important anatomical landmark in the distal femur and marks the insertion of the adductor magnus muscle (hamstring part). The adductor tubercle is clinically significant in orthopedic surgery, knee imaging, and anatomical localization around the medial distal femur.

It is particularly useful for identifying the level of the knee joint line and distinguishing between the medial epicondyle and condylar regions.

Synonyms

Tuberculum adductorium
Adductor tuberosity (less commonly used)

Location

Situated on the superior aspect of the medial femoral condyle
Just proximal to the medial epicondyle
Posterior to the medial supracondylar line
At the transition between the shaft and distal femur
On the medial side of the distal femur

Anatomical components

Osseous prominence of the distal femur
Attachment site of the hamstring (ischiocondylar) part of adductor magnus
Separates the medial epicondyle (ligamentous attachment) from the condylar articular region

Relations

Anteriorly:

Medial supracondylar ridge
Vastus medialis muscle

Posteriorly:

Popliteal surface of femur
Adductor hiatus (just superior and posterior)

Inferiorly:

Medial epicondyle of femur
Medial collateral ligament attachment nearby

Superiorly:

Femoral shaft (distal metaphysis)

Medially:

Adductor magnus tendon insertion

Laterally:

Medial femoral condyle articular surface

Function

Muscle attachment landmark: Serves as the insertion site for the adductor magnus (hamstring portion)
Surgical reference point: Used to identify knee joint line and medial distal femoral anatomy
Biomechanical role: Contributes to medial stabilization forces transmitted through adductor magnus

X-ray appearance

Plain radiographs (AP and lateral knee views):

Adductor tubercle: Small bony prominence on the superior-medial aspect of the distal femur
Cortical outline: Well-defined and continuous with femoral cortex
Best visualized: On oblique or lateral projections

CT appearance (pre-contrast)

Non-contrast CT:

Tubercle: Cortical bony protuberance arising from the medial femoral condyle
Margins: Smooth and sharply defined
Trabecular continuity: Continuous with medullary cavity
Useful for: Precise delineation of bony anatomy and preoperative planning

MRI appearance

T1-weighted images:

Tubercle: Low signal cortical bone with intermediate marrow signal centrally
Adductor magnus insertion: Seen as low-signal tendon attaching to the tubercle
Adjacent marrow: Normal fatty signal

T2-weighted images: