Scapholunate Ligament Partial Tears; Tear Localization, Extrinsic Ligament Injury Association and Conservative Treatment Responses Prior to Instability: Cross-Sectional Study.

PURPOSE OF THE STUDY Scapholunate interosseous ligament (SLIOL) tears with accompanying extrinsic ligament rupture have been associated with scapholunate (SL) instability. SLIOL partial tears were examined in terms of tear localization, grade and accompanying extrinsic ligament injury. Conservative treatment responses were scrutinized according to injury types. MATERIAL AND METHODS Patients with SLIOL tear without dissociation were evaluated retrospectively. Magnetic resonance (MR) images were reexamined in terms of tear localization (volar, dorsal or combined volar and dorsal tears), grade of injury (partial or complete) and extrinsic ligament injury accompaniment (RSC, LRL, STT, DRC, DIC). Injury associations were examined with MR imaging. All patients treated conservatively were recalled at their first year for re-evaluation. Conservative treatment responses were analyzed according to pre- and post-treatment first year visual analog scale for pain (VAS), disabilities of the arm, shoulder and hand questionnaire (DASH) and Patient-Rated Wrist Evaluation (PRWE) scores. RESULTS In our cohort, 79% (n: 82/104) of patients had SLIOL tear and 44% (n: 36) of them had accompanying extrinsic ligament injury. The majority of SLIOL tears and all extrinsic ligament injuries were partial tears. In SLIOL injuries, volar SLIOL was most commonly damaged portion (45%, n: 37). DIC (n: 17) and LRL (n: 13) were most frequently torn ligaments, radiolunotriquetral (LRL) injury generally co-existed with volar tears and dorsal intercarpal ligament (DIC) with dorsal tears regardless of injury time. Extrinsic ligament injury accompaniment was associated with higher pre-treatment VAS, DASH and PRWE scores than isolated SLIOL tears. Injury grade, location and extrinsic ligament accompaniment had no significant effect on treatment responses. Test scores reversal was better in acute injuries. CONCLUSIONS On imaging SLIOL injuries, attention should be paid to the integrity of secondary stabilizers. In partial SLIOL injuries, pain reduction and functional recovery can be achieved with conservative treatment. Conservative approach can be the initial treatment option in partial injuries especially in acute cases regardless of tear localization and injury grade if secondary stabilizers are intact. Key words: scapholunate interosseous ligament, extrinsic wrist ligaments, carpal instability, MRI of wrist, wrist ligamentous injury, volar and dorsal scapholunate interosseous ligament.