Abstract
Introduction
Transpedicular fixation is associated with the risk of hardware failure, such as screw/rod breakage and/or loosening at the screw-rod interface and difficulties in the system assembly, which remains a significant clinical problem. Removal or revision of the spinal implants is often required. This is a retrospective radiological study of the single- and two-level lumbar stabilization procedures (TLIF, PLIF or PLF) performed from January 2002 to December 2012 using a non-rigid transpedicular implant system. The purpose of this study was to retrospectively analyze the radiological outcome of 1280 patients focusing on implant related complications.
Material and Methods
1280 patients were included into the study. The female/male ratio was 56%/44%, the mean age was 59 years (18–88), the mean FU time was 32 months. Indications for surgery were DDD, FBS and spondylolisthesis (DDD: 77%, FBS: 18%, spondylolisthesis: 5%). There were 727 single-level stabilizations and 553 two-level stabilizations in this cohort. The radiological status of the implants was assessed on lateral and AP X-rays and available CT scans by independent radiologists. We investigated the occurence of screw breakage, screw loosening and element rod breakage, rod slipping and movement.
Results
In the single-level group 8 screw breakage (1.1%), 27 screw loosening (3.7%), 9 element rod breakage (1.2%) and 47 element rod slippage or movement (6.5%) were detected. In the two-level group 9 screw breakage (1.6%), 30 screw loosening (5.4%), 14 element rod breakage (2.5%) and 37 element rod slippage or movement (6.7%) were present.
Conclusion
Comparing the result of this retrospective radiological study with the available literature data, we can state that the rate of implant related failures in case of the nonrigid transpedicular system is lower than in the previously published studies. Low implant complicationn rate can be associated with the effect of the non-rigid stabilization on bony remodelling at the surroundings of the transpedicular screws. The influence of non-union rate and sagittal alignment on the outcome needs further evaluations.