When you sustain a PIP joint dislocation, the volar rim of the middle phalanx--P-2--may fracture. If it is a small percentage of the bone, on the lateral xray, early range of motion with the use of a splint to limit extension, may be an option----since the collateral ligaments are still attached to the base of P-2. However, if the joint is unstable because of the size of the bone piece, and if the piece is more than 50% of the joint surface, few options exist for reconstruction.
Hemi-hamate arthroplasty was introduced in the 1990's to solve this complex problem--and the literature, as well as my own experience with the procedure, have shown how valuable it is. A small piece of hamate bone is used to restore the volar lip of P-2, effectively restoring PIP joint stability and enabling range of motion. Though full range is unlikely, functional flexion to 75-80 degrees is expected.
