Lunate-triquetral and midcarpal joint instability

Area of Science:

• Orthopedics
• Hand Surgery
• Sports Medicine

Background:

• Ulnar carpal instability involves the triquetrum, supported by ligaments and the triangular fibrocartilage complex (TFCC).
• Disruption of the lunotriquetral (LT) ligament can cause triquetral instability, VISI (volar-intercalated segment instability), and degenerative changes.
• Midcarpal instability at the triquetral-hamate joint presents as dynamic subluxation during ulnar deviation.

Purpose of the Study:

• To review the pathophysiology, diagnosis, and treatment of ulnar carpal instability, focusing on LT and midcarpal joints.
• To highlight the progression from ligamentous injury to degenerative arthritis.
• To discuss surgical options for chronic and complex cases.

Main Methods:

• Review of diagnostic modalities including stress radiographs, arthrography, video-fluoroscopy, and arthroscopy.
• Discussion of nonoperative and operative treatment strategies.
• Analysis of outcomes for various surgical procedures like debridement, ligament repair/reconstruction, and intercarpal arthrodesis.

Main Results:

• Diagnosis of LT injuries relies on imaging and arthroscopic evaluation.
• Nonoperative treatment is the initial approach, with surgery indicated for persistent symptoms.
• Intercarpal arthrodesis, particularly limited for isolated LT joint issues, provides predictable pain relief and preserves motion.

Conclusions:

• Chronic LT joint instability, especially without dissociation, is best managed with limited intercarpal arthrodesis.
• Extensive intercarpal arthrodesis is necessary for dissociation patterns.
• Midcarpal instability often requires arthrodesis in chronic, symptomatic cases unresponsive to conservative care.