Scapholunate Interosseous Ligament Injury: A Review of the Diagnosis, Treatment, and Outcomes

Background/Objectives: The scapholunate interosseous ligament (SLIL) is a C-shaped structure composed of dorsal, proximal, and volar segments and is the primary stabilizer of the scapholunate joint. Injury leads to loss of wrist motion and altered carpal mechanics, and chronic laxity may produce radiocarpal and midcarpal degenerative change. Because isolated SLIL injuries frequently lack overt radiographic findings, delayed diagnosis allows progression to fixed carpal malalignment and arthritis, substantially narrowing later treatment options. Methods: A narrative review was conducted. PubMed, Embase, and Google Scholar were searched for English-language articles published between January 1974 and 2025 using combinations of the terms “scapholunate interosseous ligament,” “scapholunate instability,” “scapholunate dissociation,” “carpal instability,” “wrist arthroscopy,” and “scapholunate reconstruction.” Articles were selected for relevance to SLIL anatomy, biomechanics, injury, and treatment, and were appraised with attention to level of evidence. Results: The SLIL is compositionally heterogeneous, ranging from cartilage-like proximally to ligamentous dorsally, and is supported by dorsal and volar secondary stabilizers. Radiographs are frequently normal in partial and predynamic tears; MRI has limited sensitivity for partial tears, arthrography improves accuracy, and arthroscopy remains the diagnostic gold standard. Management is stage-dependent: non-operative care for occult and predynamic instability, direct repair with dorsal capsulodesis for acute reducible injuries, ligament reconstruction such as three-ligament tenodesis for chronic reducible injuries, and salvage procedures for scapholunate advanced collapse. Reported outcomes are favorable but variable, and no reconstructive technique demonstrates consistent superiority. Nearly all outcome data derive from retrospective series with heterogeneous outcome measures. Conclusions: Early recognition and stage-appropriate treatment selection are central to optimizing outcomes in SLIL injury. Current recommendations rest largely on low-level, heterogeneous evidence, and prospective multicenter comparative studies using validated patient-reported and radiographic outcomes represent the field’s most important unmet need.