Clinical Data
Comparing lateral and posterolateral SI joint fixation (Payne - J Orthop Surg Res 2020)
Comparative Analysis of the Lateral and Posterolateral Trajectories for Fixation of the Sacroiliac Joint: A Cadaveric Study.
Payne C, Jaffee S, Swink I, Cook D, Yeager M, Oh M, Schmidt G, Lindsey DP, Yerby SA, Cheng B.
J Orthop Surg Res. 2020 Oct 22;15(1):489.
doi: 10.1186/s13018-020-02013-w. PMID: 33092604; PMCID: PMC7579994.
ABSTRACT
Background: A number of minimally invasive sacroiliac (SI) joint fusion solutions for placing implants exist, with reduced post-operative pain and improved outcomes compared to open procedures. The objective of this study was to compare two MIS SI joint fusion approaches that place implants directly across the joint by comparing the ilium and sacrum bone characteristics and SI joint separation along the implant trajectories.
Methods: Nine cadaveric specimens (n = 9) were CT scanned and the left and right ilium and sacrum were segmented. The bone density, bone volume fraction, and SI joint gap distance were calculated along lateral and posterolateral trajectories and compared using analysis of variance between the two orientations.
Results: Iliac bone density, indicated by the mean Hounsfield Unit, was significantly greater for each lateral trajectory compared to posterolateral. The volume of cortical bone in the ilium was greater for the middle lateral trajectory compared to all others and for the top and bottom lateral trajectories compared to both posterolateral trajectories. Cortical density was greater in the ilium for all lateral trajectories compared to posterolateral. The bone fraction was significantly greater in all lateral trajectories compared to posterolateral in the ilium. No differences in cortical volume, cortical density, or cancellous density were found between trajectories in the sacrum. The ilium was significantly greater in density compared with the sacrum when compared irrespective of trajectory (p < 0.001). The posterolateral trajectories had a significantly larger SI joint gap than the lateral trajectories (p < 0.001).
Conclusion: Use of the lateral approach for minimally invasive SI fusion allows the implant to interact with bone across a significantly smaller joint space. This interaction with increased cortical bone volume and density may afford better fixation with a lower risk of pull-out or implant loosening when compared to the posterolateral approach.
Keywords: Bone mineral density; Lateral approach; Posterolateral approach; Sacroiliac fusion; Sacroiliac joint; Virtual trajectory.
Author Information
- Payne C, Jaffee S, Swink I, Cook D, Yeager M, Cheng B - Neuroscience Institute, Allegheny General Hospital, Pittsburgh, PA, USA.
- Oh M - Department of Neurosurgery, University of California Irvine, Irvine, CA, USA.
- Schmidt G - Orthopaedic Institute, Allegheny General Hospital, Pittsburgh, PA, USA.
- Lindsey DP, Yerby SA - SI-BONE, Inc., 471 El Camino Real, Suite 101, Santa Clara, CA, 95051, USA.