Safety, Feasibility, Radiographic, and Clinical Outcome of Transforaminal Lumbar Interbody Fusion Using PEEK “Loop” Cage Implants

Introduction: Biomechanical properties of PEEK LOOP cages (Advanced Medical Technologies, Nonnweiler, Germany) have been shown in cadaver laboratory investigations. This study analyzes the clinical and radiological outcome of this recently developed implant in patients undergoing transforaminal lumbar interbody fusion (TLIF).

Methods: There were 41 patients who underwent fluoroscopic-guided posterior pedicle screw fixation combined with TLIF. Surgery reports were reviewed for complications and duration. Radiographic outcome measures included computed tomographic (CT) scan on first postoperative day and plain X-ray at 1, 3, and 12 months. Clinical outcome was assessed at the same time intervals using visual analog pain scale (VAS), neurological examination, and patients’ self-report at 1 year using SF-12 questionnaire.

Results: A total of 49 cages were implanted in 41 procedures with an average procedure time of 229 minutes. Of these 49, 3 patients had minor dural tear; 1 patient had postoperative new neurological motor deficit of L5; 29 patients (70%) had significantly reduced pain scores at follow-up; 36 patients (87%) had no neurological deficit at follow-up; and 1 patient had postoperative deep wound infection. Cage dislocation was observed in two patients and needed repositioning in a second procedure due to nerve root compression. Implant fracture did not occur. Fusion rate was 88% without any pedicle screw fractures.

Conclusions: TLIF procedure in addition to dorsal lumbar fusion using AMT Loop PEEK cages provides a safe and effective alternative with acceptable clinical and radiologic outcome.