| 摘要 |
A improved distraction bone screw (10) and a method for its use are described. The distraction screw (10) is comprised of an implantable distal segment (120) and a detachably secured proximal segment (130). The distal segment (20) includes a head portion (122) and a threaded shank portion (124). The proximal segment (130) is represented as an elongated body (132) having an internal bore that estends through its lrngth. A deployable member is disposed within the bore (134), which is extendible outside the internal bore to securely couple to the distal segment (120). As an assembly, the distraction screw (10) is used to affix and realign bone during surgical reconstruction. Upon completion of the surgical work, the proximal segment (130) is removed and the distal segment (120) is left attached to the reconstruction bone. Securely affixed, the distal segment (120) provides an additional point of fixation for the skeletal plates that are used to preserve the bony alignment while bone healing occurs. The affixed distal segment (120) will also provide a ready mechanism for distraction screw replacement at the time of surgical revision without obligatory plate removal. Different embodiments of the proximal segment, distal segment and the rotational locking mechanisms which inhibit the rotation of one segment relative to the other during deployment were also described. In addition, in cases where the distraction screw (10) must be placed into the bone at an inclined angle, poly-axial heads were provided so that proper skeletal plate placement can still be accomplished. |
