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Background: The suture bridge (SB) transosseous-equivalent rotator cuff repair reduces re-tear rates compared with single-row or other double-row constructs. However, failure rates continue to be high, especially in large and massive tears. The aim of this study was to assess the biomechanical performance of a new SB repair with use of a medial grasping suture compared with the traditional SB repair. Methods: Seven matched pairs of sheep infraspinatus tendons were randomly assigned to either SB or suture bridge with grasping suture (SBGS) repair. Each construct was subjected to cyclic loading and then loaded until failure under displacement control in a materials testing machine. Footprint displacement, ultimate load to failure, and mode of failure were assessed. Results: The rotator cuff footprint displacement was less during tensile loading with the addition of the medial grasping suture. The ultimate load to failure was significantly greater for the SBGS repair group than for the SB repair group (334.0 N vs 79.8 N). The mode of failure was the tendon pulling off the footprint in all cases (type 1 tear). There were no failures in which the tendon tore at the medial row of anchors, leaving part of the tendon still on the footprint (type 2 tear). Conclusion: The addition of a medial grasping suture significantly improved the ultimate load to failure and reduced the footprint displacement of the SB rotator cuff repair in a biomechanical model. [Copyright &y& Elsevier]

The elbow is a complex hinge joint relying on bony and soft tissue restraints for stability. The primary soft tissue stabilizers are the medial and lateral collateral ligament complexes. Injury to these structures may occur because of an elbow dislocation or due to a severe varus or valgus force. Most injuries are treated conservatively, but when associated with more severe soft tissue and bony injuries around the elbow, surgical repair or reconstruction may be required. Repair should be anatomical and should restore stability to the elbow so that early active range of motion can be initiated. Reconstruction may be required in severe cases and where primary repair is not possible. Knowledge of the normal anatomy and understanding the pathoanatomy is crucial to achieving a good result. Depending on the degree of instability, either one or both of the collateral ligament complexes may need to be repaired or reconstructed. When reconstruction is required, usually only the lateral ulnar collateral and the anterior band of the medial collateral ligament need to be reconstructed, but when severely unstable, the posterolateral capsule and the posterior band of the medial collateral ligament may also require reconstruction. This may be accomplished by 2 separate grafts or as a single circumferential graft. Arthroscopy is a valuable tool to assess the stability as well as to identify and treat associated injuries. This article describes the normal and pathoanatomy of the unstable elbow and outlines the surgical techniques for repair and reconstruction of the collateral ligaments. [Copyright &y& Elsevier]

Purpose To assess carpal kinematics in various ranges of motion in 3 dimensions with respect to lunate morphology. Methods Eight cadaveric wrists (4 type I lunates, 4 type II lunates) were mounted into a customized platform that allowed controlled motion with 6 degrees of freedom. The wrists were moved through flexion-extension (15°–15°) and radioulnar deviation (RUD; 20°–20°). The relative motion of the radius, carpus, and third metacarpal were recorded using optical motion capture methods. Results Clear patterns of carpal motion were identified. Significantly greater motion occurred at the radiocarpal joint during flexion-extension of type I wrist than a type II wrist. The relative contributions of the midcarpal and radiocarpal articulations to movement of the wrist differed between the radial, the central, and the ulnar columns. During wrist flexion and extension, these contributions were determined by the lunate morphology, whereas during RUD, they were determined by the direction of wrist motion. The midcarpal articulations were relatively restricted during flexion and extension of a type II wrist. However, during RUD, the midcarpal joint of the central column became the dominant articulation. Conclusions This study describes the effect of lunate morphology on 3-dimensional carpal kinematics during wrist flexion and extension. Despite the limited size of the motion arcs tested, the results represent an advance on the current understanding of this topic. Clinical relevance Differences in carpal kinematics may explain the effect of lunate morphology on pathological changes within the carpus. Differences in carpal kinematics due to lunate morphology may have implications for the management of certain wrist conditions. [ABSTRACT FROM AUTHOR]

Understanding the kinematics of the carpus is essential to the understanding and treatment of wrist pathologies. However, many of the previous techniques presented are limited by non-functional motion or the interpolation of points from static images at different postures. We present a method that has the capability of replicating the kinematics of the wrist during activities of daily living using a unique mechanical testing system. To quantify the kinematics of the carpal bones, we used bone pin-mounted markers and optical motion capture methods. In this paper, we present a hammering motion as an example of an activity of daily living. However, the method can be applied to a wide variety of movements. Our method showed good accuracy (1.0-2.6°) of in vivo movement reproduction in our ex vivo model. Most carpal motion during wrist flexion-extension occurs at the radiocarpal level while in ulnar deviation the motion is more equally shared between radiocarpal and midcarpal joints, and in radial deviation the motion happens mainly at the midcarpal joint. For all rotations, there was more rotation of the midcarpal row relative to the lunate than relative to the scaphoid or triquetrum. For the functional motion studied (hammering), there was more midcarpal motion in wrist extension compared to pure wrist extension while radioulnar deviation patterns were similar to those observed in pure wrist radioulnar deviation. Finally, it was found that for the amplitudes studied the amount of carpal rotations was proportional to global wrist rotations. [ABSTRACT FROM AUTHOR]