Transforaminal lumbar interbody fusion versus posterolateral fusion for the treatment of low-grade isthmic spondylolisthesis in adults

Background
Isthmic spondylolisthesis means slippage of one vertebra relative to the next caudal vertebra as a result of an abnormality in the pars interarticularis. Isthmic spondylolisthesis has three subtypes: subtype A in which there is stress fracture of the pars (spondylolysis), subtype B in which the pars is elongated, and subtype C in which there is acute fracture of the pars. Isthmic spondylolisthesis is the most common cause of low back pain in adolescents. Spinal fusion is the mainstay of the surgical treatment of low-grade isthmic spondylolisthesis. Spinal fusion can be achieved by posterolateral fusion (PLF) or circumferential fusion. The three basic techniques for circumferential fusion include anterior lumbar interbody fusion, posterior lumbar interbody fusion, and transforaminal lumbar interbody fusion (TLIF).
Patients and methods
Fifty patients with low-grade isthmic spondylolisthesis managed with spinal fusion at the Zagazig University Hospital. Patients were divided into two groups: group I included patients managed by TLIF and group II included patients managed by PLF. The mean age of patients was 34.6 years (range: 26–43 years) in group I and 36.8 years (range: 28–46) in group II. Sex distribution was nine males and 16 females in group I and seven males and 18 females in group II. Exclusion criteria included patients with high-grade spondylolisthesis, traumatic spondylolisthesis, degenerative spondylolisthesis, neoplastic spondylolisthesis, patients with acute or chronic infection, and congenital malformation.
Results
No patients were dropped in the follow-up. In both groups, the mean visual analog scale (VAS) for back pain and leg pain and the Oswestry disability index (ODI) showed statistically significant difference between the values obtained preoperatively and the values obtained at the 1-year follow-up visit. In comparison between both groups for the change in the VAS for back and leg pain and ODI score, group I gave a significant difference regarding the change in the VAS for back pain compared to group II. However, the change in the VAS for leg pain and ODI was not statistically significant.
Conclusion
Both TLIF and PLF are effective options for the treatment of low-grade isthmic spondylolisthesis in adults. However, TLIF gives better clinical outcome, so it is considered a better option.