Avulsion fractures are the result of side-to-side (coronal) forces acting on the finger, putting the collateral ligament under sudden tension. The ligament is usually stronger than the bone, causing the ligament to avulse a fragment of bone at its insertion. Avulsion fractures result in marked joint instability. If the fracture is not displaced, nonoperative treatment is usually indicated (buddy taping to the adjacent finger). Displaced fractures, however, must be internally fixed. In some circumstances, the fracture is severely comminuted with multiple tiny fragments. It may be preferable to excise the fragments and reattach the collateral ligaments directly to the bone.
Suture anchors or tunneling
Two alternative techniques are available for collateral ligament reattachment: suture anchors, or tunneling. The advantage of suture anchors is the relative ease of the procedure. It is also a time-saving technique. Tunneling is the more demanding procedure, but it is significantly less expensive.