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Dorsal lunotriquetral ligament

The dorsal lunotriquetral ligament (LTL) is one of the key intrinsic carpal ligaments of the wrist, connecting the dorsal aspects of the lunate and triquetrum bones. It provides dorsal stability to the lunotriquetral joint, which is part of the proximal carpal row, and works in coordination with the volar component to maintain carpal alignment and interosseous spacing during wrist motion.

This ligament is thinner but stronger than its volar counterpart and is crucial in preventing dorsal subluxation of the triquetrum and lunate during flexion-extension and ulnar deviation. Disruption of the ligament can result in lunotriquetral instability, a form of carpal instability dissociative pattern.

Synonyms

  • Dorsal LT ligament

  • Dorsal lunate-triquetral interosseous ligament

  • Dorsal component of the lunotriquetral interosseous ligament

Origin, Course, and Insertion

  • Origin: Dorsal ridge of the lunate bone

  • Course: Short, obliquely oriented fibers pass dorsoulnarly across the dorsal aspect of the lunotriquetral joint

  • Insertion: Dorsal surface of the triquetrum at its proximal and medial portion near the articular margin

Relations

  • Dorsally: Extensor carpi ulnaris tendon sheath and dorsal wrist capsule

  • Ventrally: Lunotriquetral joint space and articular cartilage

  • Laterally: Dorsal lunocapitate ligament and dorsal radiocarpal fibers

  • Medially: Triquetrohamate ligament and ulnocarpal joint capsule

Attachments

  • Firmly attaches to the fibrocartilaginous margins of the lunate and triquetrum

  • Continuous with the dorsal intercarpal ligament complex

  • Reinforced by fibers merging with the dorsal capsule of the wrist

Function

  • Stabilization: Maintains dorsal stability between the lunate and triquetrum

  • Force transmission: Helps distribute forces across the proximal carpal row during wrist motion

  • Kinematic control: Coordinates lunate and triquetrum movement during flexion, extension, and ulnar deviation

  • Joint congruity: Prevents abnormal translation or gapping of the lunotriquetral articulation

Clinical Significance

  • Ligament tear: Partial or complete tear can lead to lunotriquetral instability and chronic wrist pain

  • Lunotriquetral dissociation: Characterized by increased motion between lunate and triquetrum, often post-traumatic

  • Carpal instability: May coexist with scapholunate ligament injury or perilunate dislocation

  • Chronic strain or degeneration: Seen in repetitive wrist loading or degenerative arthritis

  • Surgical relevance: Evaluated during wrist arthroscopy or ligament reconstruction procedures

MRI Appearance

  • T1-weighted images:

    • Ligament: low signal (dark linear band) between lunate and triquetrum

    • Adjacent bone marrow: bright fatty signal in normal state

    • Partial tear: focal discontinuity or irregular low-signal fibers with small intermediate-signal gaps

  • T2-weighted images:

    • Normal ligament: dark (low signal) band

    • Partial tear: focal hyperintense (bright) signal within ligament substance

    • Complete tear: discontinuity or absence of normal low-signal band with joint fluid interposed

    • Reactive bone edema: bright subchondral signal in adjacent carpal bones

  • STIR:

    • Normal ligament: intermediate-to-dark signal

    • Pathology: bright hyperintense signal in torn or inflamed regions

    • Detects associated soft-tissue edema and small joint effusions

  • Proton Density Fat-Saturated (PD FS):

    • Ligament: intermediate-to-dark continuous band

    • Tear: bright intraligamentous signal or focal discontinuity

    • Excellent for detecting partial tears, degeneration, or capsular inflammation

  • T1 Fat-Sat Post-Contrast:

    • Normal ligament: minimal enhancement

    • Inflamed or scarred ligament: linear or nodular enhancement

    • Periligamentous enhancement may indicate synovitis or post-traumatic change

MRI Arthrography Appearance

  • Contrast injected into the radiocarpal or midcarpal joint outlines the ligament margins

  • Partial tear: small contrast seepage or irregular outline at dorsal aspect of LT joint

  • Complete tear: contrast freely passes between the lunate and triquetrum, indicating communication between joint compartments

  • Degenerative change: irregular thickened ligament with contrast pooling in adjacent recess

CT Appearance

Non-Contrast CT:

  • Ligament itself: not directly visible due to low soft-tissue contrast

  • Joint space: preserved smooth articular margins in normal cases

  • Pathology: may show sclerosis, small avulsion fragments, or subchondral cysts at ligament attachments

  • Used primarily for evaluating osseous changes secondary to ligament injury

Post-Contrast CT (standard):

  • Mild enhancement of pericapsular tissues in inflammatory conditions

  • Useful to assess associated synovial thickening or post-traumatic changes

CT Arthrography Appearance

  • Contrast fills the lunotriquetral joint space, sharply outlining ligament margins

  • Partial tear: focal irregular contrast tracking around dorsal ligament fibers

  • Complete tear: direct contrast communication between midcarpal and radiocarpal joints

  • Chronic injury: widened LT joint space with irregular cartilage surfaces or subchondral cysts

  • Provides excellent spatial resolution for small dorsal ligament defects or perforations

MRI images

Dorsal lunotriquetral ligament axial cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

MRI images

Dorsal lunotriquetral ligament coronal mri image

MRI images

Dorsal lunotriquetral ligament mri sag image