Objective: The aim of this study is to investigate, through the analysis of a case report and the literature review, indications and contraindications of Interspinous Process Device (IPD) in the surgical treatment of Lumbar Isthmic Spondylolisthesis (LIS).
Patients and methods: A 37-years-old male with L5-S1 grade 2 LIS, treated with IPD at another center, referred to us eight months later with a worsening of back and leg pain. A revision surgery was performed with IPD removal and a L5-S1 TLIF.
Results: Clinical evaluation highlighted an improvement of pain, functionality, and quality of life scores at six months (VAS 4; ODI 30; EQ-5D 70) and twelve months follow-up (VAS 1; ODI 20; EQ-5D 90). CT scan was performed at six months and one-year follow-up to evaluate the fusion rate and stability of the implant.
Conclusions: Given the pathologic anatomy and the biomechanics of LIS, IPD is ineffective in preventing further vertebral body slippage resulting in segmental kyphosis, because of the lack of connection between the posterior arch and the vertebral body due to the isthmic lesion.