Instrument-Related Complications Following Lumbar Transpedicular Screw Fixation

Kim, Chang Hee; Kim, Choong Hyun; Cheong, Jin Hwan; Bak, Koang Hum; Kim, Jae Min; Oh, Suck Jun

Abstract

OBJECTIVE
Transpedicular screw fixation systems are coming into wide use as an effective adjunct to lumbar spinal fusion procedures. However, there are some problems concerning hardware failure. In this report, we present an analysis of instrument-related complications following lumbar transpedicular screw fixation.
METHODS
Lumbar spinal fusion using a transpedicular screw has been performed between 1995 and 2000 in 298 patients. We retrospectively investigated the complications related to screws and/or rods, which have been used in lumbar spinal fusions.
RESULTS
The 262 patients(87.9%) who had undergone the surgery were satisfied with the results of their operations. The wound infection rate was 4.0%(n=12). Neural injuries occurred in 4 patients(1.3%); one patient was related to decompressive procedure and the others were related to instrumentation. The unsatisfactory screw placement occurred in 3.8%(60 of 1,582 screws placed). Forty-nine screws(81.7%) were misplaced in lateral direction in a total of 60 unsatisfactorily placed screws. Screw fractures occurred in 5(1.7%) patients, and the overall fracture rate was 0.3%(5 of 1,582 screws placed). Rod fractures occurred in 3(1.0%) patients and the overall fracture rate was 0.5%(3 of 596 rods placed). The breakage was usually apparent in the late stage of the clinical course, as seen on follow-up radiographs.
CONCLUSION
We believe that failure of arthrodesis and multilevel fusion are the predisposing factors of instrument failure. The authors conclude that to minimize the complications following transpedicular screw fixation, it would be necessary to make a precise insertion of the transpedicular screw with adequate bone fusion.