Disability of a finger with chronic boutonnière deformity is caused primarily by the extended posture of the distal interphalangeal joint and the failure of this joint to flex adequately.
Extensor tenotomy to correct a boutonnière deformity of long standing is described. The tenotomy is complete and is performed just distal to the triangular ligament near the middle of the middle phalanx.
Two cases are presented. In one patient, the proximal interphalangeal joint was mobile; in the other, it was ankylosed. In both, disability was markedly lessened by extensor tenotomy with restoration of flexion of the distal joint. In neither case did a mallet finger develop.