Minimally invasive anterior lumbar interbody fusion followed by percutaneous pedicle screw fixation for isthmic spondylolisthesis: minimum 5-year follow-up

Background context: We previously reported the preliminary results of minimally invasive anterior lumbar interbody fusion (mini-ALIF) with percutaneous pedicle screw fixation (PPF) in 2004. Purpose: To investigate the long-term results of mini-ALIF followed by PPF for the treatment of back and leg pain in adult isthmic spondylolisthesis. Study design: Retrospective study with a minimum 5-year follow-up. Sixty-three patients with a mean age of 49 years were included in this study. Each patient had mini-ALIF followed by PPF. Visual analog scale pain and intensity (back and leg), Oswestry Disability Index scores, and the patient's return-to-work status. Methods: Of the initial 73 patients who underwent mini-ALIF with PPF between October 2000 and February 2002, 63 patients could be contacted after 5 to 7 years. Clinical follow-up and radiological follow-up with dynamic lumbar X-ray, three-dimensional computed tomography scans, and lumbar magnetic resonance imaging for checking the adjacent segmental disease (ASD) were completed in patients. Radiological results including the intervertebral disc height, the degree of listhesis, segmental lumbar lordosis, and whole lumbar lordosis were analyzed by statistical analysis. Results: The mean follow-up period was 72 months. Among the 63 patients, 56 (88.9%) had an excellent or good clinical result and five (7.9%) had a fair result based on the Macnab criteria. Two (3.2%) patients had a poor result. The last scores of visual analog scale and Oswestry Disability Index were significantly decreased compared with the preoperative baseline. Radiographs of all patients at the last follow-up showed solid fusion. There was one case of screw fracture. However, last follow-up study showed solid fusion state. ASD was proven to be progressing in 6 out of 63 (9.5%) patients, but only two patients (3.2%) had symptoms associated with ASD. Conclusions: The long-term outcome after mini-ALIF with PPF in patients with low-grade isthmic spondylolisthesis was successful. Furthermore, in terms of ASD, there is low incidence of ASD after the procedure.