Early retropulsion of titanium-threaded cages after posterior lumbar interbody fusion - A report of two cases

Study Design. Two patients had postoperative posterior migration of titanium fusion cages after posterior lumbar interbody fusion. They underwent a repeat posterior procedure and posterior fusion with pedicle screws. Objective. To suggest a treatment for posterior migration of titanium-threaded cages causing spinal stenosis after posterior lumbar interbody fusion. Summary of Background Data. The use of titanium fusion cages in posterior lumbar interbody fusion is gaining popularity as a technique for arthrodesis. The literature contains only a few reports concerning complications associated with their use. Methods. Two patients had retropulsion of titanium threaded cages, ten days and 2 months after posterior lumbar interbody fusion. The retropulsed cages compressing the dura, caused sudden onset of back pain and radiating pain to the lower extremities. Both patients underwent repeat posterior procedure that included repositioning of the cages and posterior fusion with pedicle screws. Results. Symptoms of back and leg pain subsided after repositioning of the cages and application of the pedicle screws. Conclusions. A repeat posterior approach and repositioning of the retropulsed titanium fusion cages in addition to posterior fusion with pedicle screws successfully managed this complication.