Dart thrower's motion and the injured scapholunate interosseous ligament: A scoping review of studies examining motion, orthoses, and rehabilitation

Abstract

Study design: Scoping review.

Introduction: Dart thrower's motion (DTM) of the wrist primarily arises from the midcarpal joint, and minimizes stress to the scapholunate interosseous ligament (SLIL). After SLIL injury or surgery, early controlled DTM may reduce the effects of prolonged immobilization, while protecting SLIL integrity.

Purpose of the study: To summarize the literature on the effects of DTM on the injured and surgically repaired SLIL and the extent to which various DTM orthotic designs promote SLIL recovery.

Methods: A systematic literature search was conducted within 6 databases for articles published between 2003 and March 2018. Eligible studies examined DTM in the context of SLIL injury or repair. Relevant data were extracted by 2 independent reviewers.

Results: Of 425 identified articles, 15 were eligible for inclusion. Five biomechanical studies examined the influence of DTM on the injured SLIL, whereas 5 articles described DTM orthotic designs. Also included were five articles that reported outcomes when DTM was used in the rehabilitation protocol.

Discussion: The included studies suggest limiting end ranges of DTM in the injured/repaired SLIL, while blocking orthogonal plane movements. Custom orthotic designs may accomplish this goal. DTM has been used in comprehensive therapy programs in small case studies reporting short-term and intermediate clinical outcomes.

Conclusions: Caution should be exercised with using DTM on the torn SLIL as gap increases, particularly at the end-range motion. Orthosis designs have potential to limit this motion to midrange, while allowing early movement. Further high-level research is needed to understand the influence of DTM on injured and postsurgical populations.

Keywords: Carpal kinematics; Custom orthosis; Dart thrower's motion; Ligament repair; Midcarpal joint; Scapholunate interosseous ligament; Wrist.