Dorsal Intercarpal Ligament: Role and Management
Primary Stabilizing Function
The dorsal intercarpal ligament (DIC) is a critical dorsal stabilizer of the proximal carpal row, particularly stabilizing the scaphoid's proximal pole and the scapholunate joint. 1, 2 This ligament works in concert with the dorsal radiocarpal ligament to form what has been termed the "lateral-V construct," providing dynamic stability through its ability to modify its length up to threefold by changing angles between its V-shaped bundle morphology. 2
Anatomical Attachments and Biomechanical Role
The DIC ligament consistently originates from the dorsal tubercle of the triquetrum and spans transversely to attach to the dorsal groove of the scaphoid (97-100% of cases), lunate (75-90%), and proximal rim of the trapezium (12.5-50%). 2
It overlaps both the lunotriquetral and scapholunate interosseous ligaments, providing secondary stabilization to these critical articulations. 2
The ligament acts as a restraint to dorsal translation of the capitate in relation to the lunate, thereby limiting dorsal midcarpal instability. 2
When the DIC ligament is disrupted, particularly in combination with scapholunate ligament injury, the lunate adopts a more extended posture during wrist motion, contributing to carpal instability patterns. 3
Injury Patterns and Clinical Presentation
Classification of DIC Ligament Tears
Isolated DIC ligament injuries occur in only 25% of cases, with 75% presenting with concomitant intercarpal ligament injuries. 1
DIC ligament injuries can manifest as ligament avulsion, bony avulsion from the scaphoid insertion, or attenuation from chronic injury. 1, 4
Bony avulsion of the DIC ligament from its scaphoid insertion represents a distinct injury pattern that differs mechanically from common scapholunate complex injuries. 4
Clinical Symptoms
Patients typically present with dorsal wrist pain, decreased range of motion, reduced grip strength, and sometimes a debilitating click. 1, 5
Pain is often localized to the dorsal aspect of the wrist and may be associated with loss of power. 5
Diagnostic Approach
Imaging Evaluation
Initial evaluation should begin with conventional radiographs with careful attention to positioning to assess for carpal malalignment. 6
The accuracy of conventional MRI, MR arthrography, and CT arthrography for extrinsic ligament injuries (including the DIC ligament) remains unknown according to ACR guidelines. 7
Wrist arthroscopy remains the gold standard for diagnosing DIC ligament tears and allows for simultaneous treatment. 1, 4
High-frequency ultrasound with dynamic "clenched fist" maneuvers can visualize extrinsic carpal ligaments, though specific sensitivity data for DIC ligament tears is not established. 7
Treatment Options
Arthroscopic Repair Technique
For DIC ligament injuries, particularly bony avulsions from the scaphoid, arthroscopic repair with anchor fixation provides excellent outcomes and should be the primary surgical approach. 1, 4
Surgical Technique for Bony Avulsion
Radiocarpal arthroscopy confirms the bony avulsion of the DIC ligament from the scaphoid. 4
Under arthroscopic control, an anchor is placed into the dorsal aspect of the scaphoid and the ligament is reattached along with the dorsal capsule. 4
This technique is technically straightforward and can be performed without significant difficulty. 4
Expected Outcomes
At mean 12-month follow-up, arthroscopic repair demonstrates dramatic improvement: VAS pain scores decrease from 6.7 to 0.2, wrist flexion improves from 66° to 82°, wrist extension improves from 57° to 87°, and DASH scores improve from 68.45 to 2.23. 4
In a larger series with mean 17.8-month follow-up, statistically significant improvements were seen in wrist flexion (65.3° to 74.3°), wrist extension (77.8° to 84.5°), grip strength (46.4% to 87% compared to contralateral), VAS scores (6.3 to 0.6), and QuickDASH scores (54.8 to 4.5). 1
Viegas Capsulodesis for Combined Injuries
When DIC ligament injury occurs with irreparable scapholunate interosseous ligament lesions (Geissler stages 2-4, Garcia-Elias stages 3-4), Viegas capsulodesis provides effective stabilization. 5
This technique re-inserts the dorsal intercarpal ligament dorsally to reattach the capsule on the dorsal scapholunate interosseous ligament, respecting physiologic ligamentous isometry. 5
At mean 26-month follow-up, this approach shows improvement in radioulnar deviation (+21.1°), grip strength (+8.7 kgf), pain reduction (-3 VAS points), and PRWE scores (-59 points), with 80% good to excellent results. 5
Important Caveats
Complex regional pain syndrome (CRPS) occurred in 16% of patients in one series, requiring careful postoperative monitoring and early mobilization protocols. 5
Pin-related complications and extensor pollicis longus injuries can occur, necessitating meticulous surgical technique. 5
Isolated DIC ligament tears have better outcomes than combined injuries, emphasizing the importance of thorough arthroscopic evaluation of all carpal ligaments. 1