Open reduction and internal fixation with plate of the fibula is the standard method of fixation in surgically treated ankle fractures. During fixation, stripping of the distal screws is common.
The study -which is the first clinical according to the literature- included 136 patients with surgical fractures of the ankle. Patients presenting any evident factors influencing porosis as well as open fractures were excluded. Fibula reduced anatomically and fixed by a 1/3 tubular plate placed laterally. Proximal screws had bicortical fixation grip strength while distal screws had only unicortical. Screws with a reduced fixation grip strength during insertion were left in place. Numbers were assigned for the plate screws, placed in sequential manner from one to ten, from distal to proximal and we recorded which of them had reduced fixation grip strength during their placement. Postoperatively, patients were immobilized in a below knee plaster for 6 weeks and bone healing evaluated with X-ray. Further evaluation was performed after 3 and 6 months postoperative.
Proximal bicortical screws had satisfactory fixation grip strength. Distal unicortical screws, Nr1, Nr2 and Nr3 presented reduced fixation grip strength in 36%, 63% and 21%, respectively. Postoperative there were no serious complications and all fractures healed uneventfully. Delayed union occurred in 4 cases and treated by prolonged immobilization.
Screws with reduced fixation grip strength in the distal holes of the fibula plate do not compromise the success of the osteosynthesis. The outcome of surgery was not affected whether or not the screws have grip or not. We recommend that screws irrespective their grip should be left in place, as they don't influence the final outcome.