Interlocking Nail Screw Targeting With the Sign Interlocking System

Abstract

Long bone fracture fixation has undergone a series of developments over the years, with the use of locked intramedullary nails now being widely accepted as the treatment of choice for most long bone fractures. The challenge in the use of these locked nails has been in the accurate targeting of the screw holes to enable passage of the locked screws. The use of intraoperative imaging such as the C arm is a tool used to assist accurate screw hole targeting. Incentres that do not have such imaging assistance, the use of external jig systems are employed for screw hole targeting. The surgical implant generation network (SIGN) is one of such systems. We present the result of screw targeting with the SIGN system. Methods:This was a retrospective study carried out at the Jos University teaching hospital on patients who had fracture fixation using the SIGN interlocking nail systemfrom January 2013 to October 2014 .Results: 36 fractures were fixed using the SIGN system in patients whose ages ranged from 19 to 64 yearswith a mean age of 37years +/-13.1 years. The male female ratio was 2.3:1.A total of 94 screws were inserted.53 distal screws were inserted while 41 proximal screws were inserted. 3 screws were not within the nail. All the missed screws were distal screws. Total accurate screw hole targeting was 96.8% and total missed screw percentage 3.2% . Accurate distal screw percentage 94.3% while distal missed screw percentage was 5.7%.Conclusion:The SIGN interlocking system has a good mechanism for accurate targeting of the screw holes in interlocking nail fixation in the absence of intraoperative imaging modalities.