Ulnar impaction syndrome
I share with you a case of chronic ulnar side pain. He is 50 years old.
X rays of ulnar impaction syndrome :
The bony protuberance of the ulnar styloid process is prominent. Dense calcific opacities are noted at the anatomical site of the Triangular fibrocartilage complex. That reflects the underlying pathological changes.Further investigation of ulnar impaction syndrome :
MRI
It may show
- high signal intensity of the TFC suggesting chronic degenerative tear.
- erosions or bone marrow edema at the articulating surfaces
* ulnar aspect of lunate.
* proximal pole of the triquetral.
* ulnar styloid.
Pathology of ulnar impaction syndrome
Excessive loads through the ulnocarpal joint for a long time, causes degenerative TFCC tears.
Anatomy of Triangular fibrocartilage disc
The Triangular fibrocartilage (TFC) is an articular disc that lies on the distal ulna. It is triangular in shape and has a biconcave body. The peripheral part (well vascularised) is more thick than the central part ( poorly vascularised).
Function of the TFC
The primary functions of the TFCC:
- It supports the ulnar portion of the carpus and covers the ulna head.
- It has an important role in Load transmission and absorption across the ulnocarpal joint.
- Allows supination and pronation by giving a connection between the distal radius and ulna.