The ulnar interosseous tuberosity exists: a radiological and descriptive cadaveric study.

Area of Science:

• Anatomy
• Radiology
• Orthopedics

Background:

• The middle third of the ulna's anatomy is less understood compared to its extremities.
• Previous descriptions of ulnar anatomy have not detailed a specific tuberosity on the interosseous border.

Purpose of the Study:

• To report the existence of a previously undescribed bony prominence on the ulnar shaft's interosseous border.
• To name and characterize this feature as the "tuberositas interossea ulnarii" (TIU).

Main Methods:

• Radiographic analysis (X-rays and CT scans) of 91 forearms to identify and measure the TIU.
• Cadaveric dissection of 10 forearms to determine the soft tissue attachments of the TIU.

Main Results:

• The TIU was present in all analyzed radiographs and CT scans.
• Mean TIU length was 107.5 mm, representing a significant thickening of the ulnar interosseous cortex.
• Dissections revealed TIU attachment sites for the interosseous membrane and specific forearm muscles.

Conclusions:

• The tuberositas interossea ulnarii is a distinct anatomical feature of the ulna.
• The TIU's cortical thickening suggests a role in forearm stability.
• This structure may be important for the function of muscles controlling the long fingers.