Reconstruction of the proximal interphalangeal joint collateral ligaments using the Mitek Micro Arc Anchor: an in vitro biomechanical assessment.

Proximal interphalangeal joint (PIP) collateral ligament injuries are common and sometimes result in painful, stiff fingers. A number of techniques have been utilized in the past to reconstruct complete collateral ligament injuries. Recently, bone anchor systems have been described that allow collateral ligament reconstruction without the necessity of pull-out wires and other more cumbersome methods to reconstruct these ligaments. The Mitek bone anchor system has been used successfully in a variety of anatomic locations throughout the body to reattach soft tissues to bone. The current study was conducted to evaluate the biomechanical effects of the use of the Mitek Micro Arc Anchor in collateral ligament injuries of the PIP joint. In cadaveric PIP joints, the collateral ligament was isolated and then transsected in its mid substance. The authors compared suturing the ligament alone in standard fashion to repair of the ligament using a bone anchor inserted in the base of the middle phalanx. The joints were stressed to failure, with a lateral load applied at the distal end of the middle phalanx on a materials testing machine. The mean tensile failure loads of the two groups were the following: Mitek anchor, 16.4 +/- 3.7 N; suture repair, 19.3 +/- 7.6 N. The authors found no significant difference in the force required for failure of the repair or in the pattern of failure in the two groups. The Mitek Micro Arc Anchor appears to be adequate biomechanically to reconstruct the collateral ligaments of the finger PIP joint.