Abstract
Four-corner fusion (4CF) is an accepted and regularly performed procedure when managing
posttraumatic degenerative disorders in the wrist. This procedure consists of excision
of the entire scaphoid in association with midcarpal fusion of the remaining four
ulnar carpal bones (hamate, capitate, lunate, and triquetrum). In the majority of
cases, the long-term outcome is a functional painless wrist. However, the exact procedure
to best achieve a rapid solid bone union of the fusion mass without hardware complications
remains controversial. The authors have developed a precise system to ensure precise
positioning, firm fixation, and fusion at the midcarpal joint together with an early
postoperative recovery, avoiding some of the issues reported with other implants used
for 4CF. The described implant is a circular plate accommodating variable angle locking
screws as well as compression screws that can firmly fix the plate to the carpal bones.
The locking technology produces a very solid construct. A special reaming-distraction-compression
guide has also been developed to both countersink the plate on the underlying carpal
bone mass and allow distraction of the midcarpal joint for debridement and cancellous
bone graft interposition. The features of the implant, its surgical technique, and
a relevant case are described.
Keywords
four-corner fusion - SLAC wrist - SNAC wrist - wrist
