Acute scapholunate dissociation diagnosis and treatment

Scapholunate interosseous ligament (SLIL) is the most frequent injured carpal ligament among all the intrinsic wrist ones. The scapholunate (SL) joint kinetics appear to be handled by a more sophisticated complex of intrinsic and extrinsic ligaments: cadaveric studies investigated the role of the long radiolunate (LRL), short radiolunate (SRL), radioscaphoid (RS), and dorsal intercarpal ligament (DIC) in SL joint stability. The most common traumatic mechanism leading to SL lesions is the FOOSH (fall on outstretched hand), with the wrist in extension, ulnar deviation and carpal supination. Defining the clinical stage and the time elapsed since the injury is of utmost importance in planning an effective treatment: an injury is considered as “acute” when time lapse from the trauma to the presentation lies within 6 weeks. This paper will focus on the acute/subacute setting. Acute SL lesions can frequently be misdiagnosed as minor wrist sprains; since early recognition and prompt treatment can lead to better outcomes, a delay in the correct diagnosis is detrimental for clinical results. Furthermore, interrupting the natural progression from SLIL injury to SLAC is of utmost importance. Partial lesions can be treated conservatively with immobilization and proprioceptive reeducation, percutaneous K-wires pinning of SL and SC joints and thermal shrinkage. Complete lesions should be treated operatively; open repair with suture anchors and capsulodesis show good results, even if arthroscopic techniques are now gaining popularity, although further studies with long-term follow-up are needed to evaluate the durability of those procedures.