Background Data: The management of high grade spondylolisthesis remains controversial; with advocates for in-situ fusion and others for reduction. Purpose: To report the clinical and radiological results and the operative technique
of a personal case series of adult Grade 4 isthmic spondylolisthesis that underwent instrumented reduction and TLIF.
Study Design: Retrospective clinical and radiological evaluation of a case series. Patients and Methods: Twelve patients with grade 4 isthmic spondylolisthesis were retrospectively reviewed. All patients presented with disabling back pain, 83% with leg pain, 66% crouched while walking and 16.5% presented with caudae quina syndrome. They all underwent posterior decompression, instrumented reduction and TLIF at the slipped level. Results: The mean preoperative VAS for back pain of 7.3 dropped to 2.2 and of 8 to  1.9 for leg pain. The mean preoperative ODI of 41 dropped to 12 at the latest follow up. Solid fusion was obtained in 75% with another 16.7% stable constructs without bridging bony fusion.
Conclusion: Instrumented surgical reduction and TLIF provides a safe and effective way of treating adult high grade spondylolisthesis. (2012ESJ023)