Tears of the Triangular Fibrocartilage Complex

Philip E. Blazar and Scott D. Mair

History and Clinical Presentation

A 19-year-old right hand dominant college student presented for evaluation of left wrist pain 5 months after closed treatment for a distal radius fracture. The pain was ulnar sided and associated with activities, particularly those involving maximal extension or pronation/supination against resistance (e.g., turning a doorknob on a heavy door). There was no clicking. The patient’s injury had been treated in a long-arm cast for 8 weeks. Office notes from the referring physician document a diagnosis of distal radius fracture and distal radioulnar joint (DRUJ) dislocation reduced and treated in a closed manner. The patient was referred for persistent ulnar sided wrist pain.

PEARLS

• Patients with injuries to the wrist, particularly displaced distal radius fractures, should be examined after reduction for instability of the DRUJ.
  
• The majority of patients presenting with ulnar-sided wrist pain can be managed non-operatively and returned to normal activities.
  
• The central component of the TPCC can be excised to a stable rim without compromising its biomechanical function.

PITFALLS

• The differential diagnosis of ulnar-sided wrist pain is lengthy. A careful examination of the ulnar side of the wrist will frequently rule in other causes of patient’s symptoms.
  
• The dorsal branch of the ulnar nerve crosses from volar to dorsal in the region of ulnar (6U) wrist arthroscopy portals. Careful dissection and protection of this nerve is mandatory to prevent complications.

Physical Examination

The hand, wrist, elbow, and shoulder were normal to inspection. There was minimal atrophy of the forearm musculature. Active range of motion of all joints was symmetric bilaterally. There was tenderness to palpation radial to the ulnar styloid with the arm in neutral rotation and mild discomfort, but no increased translation with stressing the DRUJ. TFCC grind maneuver produced no pain or clicking. The extensor carpi ulnaris (ECU) tendon did not subluxate out of its groove, and wrist instability maneuvers caused minimal discomfort and no clunking. Neurologic and vascular examinations were normal.

Diagnostic Studies

Diagnosis

Triangular Fibrocartilage Complex (TFCC) Tear

Ulnar-sided wrist pain is a common complaint. The patient’s age, hand dominance, avocations, and occupation are important historical factors, and the nature and date of injury should be sought. Patterns of injury have been associated with particular recreational activities (e.g., hook of the hamate fractures with sports involving a bat or club). Neurologic complaints are common and should be sought. The differential diagnosis above is limited to the diagnoses likely after a distal radius fracture.

Examination of the TFCC is performed in conjunction with a thorough exam of the wrist, elbow, and hand, including neurovascular structures. Direct palpation of the bony and soft tissue structures of the ulnar side to localize point tenderness is the most helpful examination maneuver. Tenderness radial or ulnar to the ECU tendon with the wrist in neutral rotation may be consistent with a TFCC lesion. The DRUJ is examined with the patient’s elbow on a table in front of the examiner. The DRUJ is stressed with one of the examiner’s hands grasping the distal ulna and the other grasping the radius. Volar and dorsal translation is assessed in neutral, pronation, and supination. A TFCC grind test is performed with the wrist in ulnar deviation and dorsiflexion with an axial load applied to the hand by the examiner as the carpus is rotated on the fixed forearm. Radiographs aid in establishing the diagnosis of a malunion of the distal radius or a nonunion of the ulnar styloid. Fractures at the base of the ulnar styloid are more likely to be associated with a TFCC injury that will produce persistent symptoms if untreated. Ulnocarpal abutment is more likely in patients with ulnar positive or ulnar neutral variance.

The term triangular fibrocartilage complex was originally used by Palmer and Werner for the group of structures that stabilize the carpus and distal radius to the fixed distal ulna. This complex includes the volar and dorsal radioulnar ligaments, the ulnar collateral and ulnocarpal ligaments, and the articular disk. The articular disk separates the carpal bones from the distal radioulnar articulation. The complex is central to three biomechanical functions of the wrist: (1) stability of the DRUJ, (2) axial load transmission from the carpus to the ulna, and (3) ulnar-sided carpal stability.