A biomechanical investigation of the sacroiliac joint in the setting of lumbosacral fusion: impact of pelvic fixation versus sacroiliac joint fixation

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>The sacroiliac joint (SIJ) is a known source of low-back pain. Randomized clinical trials support sacroiliac fusion over conservative management for SIJ dysfunction. Clinical studies suggest that SIJ degeneration occurs in the setting of lumbosacral fusions. However, there are few biomechanical studies to provide a good understanding of the effect of lumbosacral fusion on the SIJ. In the present study, researchers performed a biomechanical investigation to discern the effect of pelvic versus SIJ fixation on the SIJ in lumbosacral fusion.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>Seven fresh-frozen human cadaveric specimens were used. There was one intact specimen and six operative constructs: 1) posterior pedicle screws and rods from T10 to S1 (PS); 2) PS + bilateral iliac screw fixation (BIS); 3) PS + unilateral iliac screw fixation (UIS); 4) PS + UIS + 3 contralateral unilateral SIJ screws (UIS + 3SIJ); 5) PS + 3 unilateral SIJ screws (3SIJ); and 6) PS + 6 bilateral SIJ screws (6SIJ). A custom-built 6 degrees-of-freedom apparatus was used to simulate three bending modes: flexion-extension (FE), lateral bending (LB), and axial rotation (AR). Range of motion (ROM) was recorded at L5–S1 and the SIJ.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>All six operative constructs had significantly reduced ROM at L5–S1 in all three bending modes compared to that of the intact specimen (p &lt; 0.05). In the FE mode, the BIS construct had a significant reduction in L5–S1 ROM as compared to the other five constructs (p &lt; 0.05). SIJ ROM was greatest in the FE mode compared to LB and AR. Although the FE mode did not show any statistically significant differences in SIJ ROM across the constructs, there were appreciable differences. The PS construct had the highest SIJ ROM. The BIS construct reduced bilateral SIJ ROM by 44% in comparison to the PS construct. The BIS and 6SIJ constructs showed reductions in SIJ ROM nearly equal to those of the PS construct. UIS and 3SIJ showed an appreciable reduction in unfused SIJ ROM compared to PS.</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>This investigation demonstrated the effects of various fusion constructs using pelvic and sacroiliac fixation in lumbosacral fusion. This study adds biomechanical evidence of adjacent segment stress in the SIJ in fusion constructs extending to S1. Unilateral pelvic fixation, or SIJ fusion, led to an appreciable but nonsignificant reduction in the ROM of the unfused contralateral SIJ. Bilateral pelvic fixation showed the greatest significant reduction of movement at L5–S1 and was equivalent to bilateral sacroiliac fusion in reducing SIJ motion.</jats:p></jats:sec>

Radiculopathy with concomitant sacroiliac dysfunction and lumbosacral degenerative disease: illustrative case

“…21,22 Finally, biomechanical data indicate that long-segment fusion to S1 may predispose to adjacent segment changes in the SIJ. 23 Outcomes After SIJ Fusion Improvement of lower extremity complaints related to SIJ dysfunction has been reported in previous clinical series for both medical and surgical cohorts. 4,15 Nonsurgical therapy for SIJ-related leg pain has also been shown to be successful in an RCT.…”

Comparative Analysis of Optoelectronic Accuracy in the Laboratory Setting Versus Clinical Operative Environment: A Systematic Review

“…Additional studies on intact SIJ kinematics reported translations along the 3-dimensional coordinate axes on the order of 0.1 mm to 1.04 mm with corresponding rotations of 0.11 to 1.14 degrees. 16 , 91 , 92 …”

“…Multidirectional flexibility testing is typically performed along 3 predominant loading axes-flexionextension, lateral bending, and axial rotation under controlled displacement rates of 1 to 3 degrees per second for multiple cycles. To this end, a series of laboratory investigations using the NDI Certus and Vicon MX13 camera systems (Vicon Motion Systems Ltd., Oxford, UK) reported the peak limits of optoelectronic accuracy when evaluating kinematics of the osteoligamentous spine [13][14][15][16][17][18][19][86][87][88][89][90][91][92] (Figure 5A and B).…”

“…Additional studies on intact SIJ kinematics reported translations along the 3-dimensional coordinate axes on the order of 0.1 mm to 1.04 mm with corresponding rotations of 0.11 to 1.14 degrees. 16,91,92 Laboratory workflow methods and conditions for experimental musculoskeletal kinematic studies are streamlined and optimized for maximizing optoelectronic accuracy. Factors of specimen stabilization, alignment, camera resolution, proximity to fiducials, planar visualization of the active arrays, and controlled motion application account for the high degree of accuracy reported in these studies.…”

“…The principles of optoelectronic measurement systems are founded on the basis of devices which have the capability to source, detect and control light and are typically considered a subdivision of photonics. The spectrum of optoelectronic technology platforms are quite diverse, with utilization in sports performance activities such as speed skating and soccer, 1 - 4 human ergonomics, 5 , 6 clinical gait and motion analysis, 7 - 12 musculoskeletal kinematics, 13 - 20 and clinical operative procedures. 21 - 33 To this end, the degree of accuracy and errors acceptable across optoelectronic motion measurement platforms differ considerably based on application.…”