The head to foot screw fixation. A new technique of percutaneous screw fixation of the scaphoid bone.

OBJECTIVES

Many techniques have been described for screw fixation of the scaphoid bone. The approach is either proximal or dorsal. A new percutaneous technique is presented by the authors called the head to foot screw fixation. Indications and results are evaluated.

METHODS

It is a percutaneous technique with fixation of the scaphoid bone by two screws introduced in an opposite direction: a proximal screw and a distal screw. No postoperative immobilization was necessary. A prospective study was conducted in 40 patients over a period of three years. The average age was 25 years with extremes of 14 and 44 years. This technique was practiced in fractures (30 cases) and nonunion (10 cases) in which the localization was proximal, corresponding to Schernberg types I, II and III. Forms associated with perilunate dislocation of the carpus were excluded from the study.

RESULTS

The results were analysed with a mean of 8 months (6-30). Union was obtained in all the cases. No tendon injury related to percutaneous approach was noted. The technique required a learning curve with progressive decrease in operative time from 45 to 15 minutes. It was necessary in two cases to change protruding screws which were not diagnosed during the first intervention. Percutaneous screw fixation was achieved again in both cases.

Conclusions

The combination in our experience of two screws allowed us to prevent rotation around the unthreated area of a single screw. Our technique, bringing together the head to the foot of the screw, reduces the crowding at the proximal part of the scaphoid bone. This non-invasive method permitted early mobilization with no pain until biological union.