Current Concepts in Scapholunate Instability Without Arthritic Changes

Abstract

Scapholunate instability (SLI) is the most common carpal instability described. SLI leads to a degenerative arthritic pattern known as scapholunate advanced collapse (SLAC). Diagnosis of SLI can be challenging in pre-dynamic and dynamic stages. CT arthrogram, MR arthrogram and dynamic fluoroscopy are helpful in diagnosis while arthroscopy remains the gold standard. SLI is a multi-ligament injury, which involves not only the scapholunate interosseous ligament (SLIL) but also the extrinsic carpal ligaments. Hence, it is better described as an injury compromising the ‘dorsal scapholunate(dSLL) complex’. A repair can be attempted for acute SLI presenting within 6 weeks of injury. Reconstruction is the mainstay of treatment for chronic SLI without degenerative changes. Multiple repair techniques have been described which include capsulodesis and tenodesis procedures. The clinical outcomes of the techniques have improved over the years. However, a common problem of all these techniques is the lack of long-term data on the outcomes and deteriorating radiological parameters over time. SLI staging is an important factor to be considered in choosing the reconstruction techniques for a better outcome. Currently, there is a trend towards more biological and less invasive techniques. Regardless of the technique, it is important to preserve the nerve supply of the dorsal capsuloligamentous structures of the wrist. Arthroscopic techniques being minimally invasive have the advantage of less collateral damage to the capsuloligamentous structures. Rehabilitation involves a team approach where a protected dart thrower’s motion is allowed after a period of immobilization. Strengthening SL-friendly muscles and inhibiting SL-unfriendly muscles is a key principle in rehabilitation.

Therapie der SL-Bandruptur, SLAC-Wrist und Folgeoperationen

“…Die operative SL-Bandrekonstruktion kann durch Fixation der vorhandenen Bandstümpfe kombiniert mit einer Umlagerung eines karpalen Bandes (Ligamentum intercarpale dorsale), sogenannte dorsale Kapsulodese oder Bandersatzplastiken mit autologen Sehnenstreifen, die durch Bohrlöcher durch die Karpale hindurchgefädelt werden, erfolgen. Dabei ist die Rekonstruktion bei einer älteren statischen DISI-Formation (DISI = Dorsal Intercalated Segment Instability) zunehmend in Frage gestellt worden, da die postoperativen Ergebnisse sich nicht immer als befriedigend erweisen [1,4].…”