Sacroiliac Joint Degeneration After Lumbopelvic Fixation

Intraoperative fat embolism syndrome associated with implantation of titanium sacroiliac joint fusion implants: a report of two cases

Background

For patients undergoing long-construct fusion surgeries, simultaneous sacroiliac joint (SIJ) fusion is a growing trend in spine surgery. Some options for posterior SIJ fusion include 3D-printed triangular titanium implants or self-harvesting SIJ screws. Both implants require fixation within the sacrum and ileum. Fat embolism syndrome is a rare but known complication of lumbar pedicle instrumentation but has never been reported in association with SIJ fusion, regardless of implant type. We report the first two known cases of fat embolism associated with placement of SIJ fusion devices during long construct posterior spine fusion.

Case Description

Case 1-a 50-year-old female with multiple previous spine surgeries complicated by osteomyelitis/diskitis that was successfully eradicated, underwent T10-pelvis posterior spinal fusion (PSF), L4 pedicle-subtracting-osteotomy, and bilateral SIJ fusion. During implantation of each SIJ fusion device, the patient's hemodynamic status deteriorated necessitating vasopressor support, intravenous fluid bolus, and hyperventilation, but quickly resolved. The case was completed without further issue, and she had an uneventful post-operative course. Case 2-a 71-year-old female with a past medical history of ankylosing spondylitis, previous L2-L5 PSF, rheumatoid arthritis on chronic steroids, underwent a T9-pelvis PSF, bilateral SIJ fusion, L4 pedicle subtraction osteotomy, T10-L1 Smith Peterson osteotomies. After implantation of the second SIJ fusion device, she became hypotensive and tachycardic, pulses were absent, and cardiopulmonary resuscitation was initiated. Pulses returned quickly, the index surgery was terminated, and she was transferred to the intensive care unit (ICU). In the ICU she was quickly weaned off the ventilator on post-operative day 1. On post-operative day 4, the patient returned to the operating room for completion of the surgery and had an extended, but uneventful, recovery afterwards.

Conclusions

We report on the first two known cases of fat embolism syndrome occurring immediately after implantation of SIJ fusion devices. Spine surgeons should be aware of this rare, but potentially fatal, complication. Collaboration with the anesthesia team and optimization of the patient's hemodynamic status prior to implantation may help prevent catastrophic complications.

The effects of topping-off instrumentation on biomechanics of sacroiliac joint after lumbosacral fusion

BACKGROUND

Lumbar/lumbosacral fusion supplemented with topping-off devices has been proposed with the aim of avoiding adjacent segment degeneration proximal to the fusion construct. However, it remains unclear how the biomechanics of the sacroiliac joint (SIJ) are altered after topping-off surgery. The objective of this study was to investigate the biomechanical effects of topping-off instrumentation on SIJ after lumbosacral fusion.

METHODS

The validated finite element model of an intact lumbar spine-pelvis segment was modified to simulate L5-S1 interbody fusion fixed with a pedicle screw system. An interspinous spacer, Device for Intervertebral Assisted Motion (DIAM), was used as a topping-off device and placed between interspinous processes of the L4 and L5 segments. Range of motion (ROM), von-Mises stress distribution, and ligament strain at SIJ were compared between fusion (without DIAM) and topping-off (fusion with DIAM) models under moments of four physiological motions.

RESULTS

ROM at the left and right SIJs in the topping-off model was higher by 26.9% and 27.5% in flexion, 16.8% and 16.1% in extension, 18.8% and 15.8% in lateral bending, and 3.7% and 7.4% in axial rotation, respectively, compared to those in the fusion model. The predicted stress and strain data showed that under all physiological loads, the topping-off model exhibited higher stress and ligament strain at the SIJs than the fusion model.

CONCLUSIONS

Motion, stress, and ligament strain at SIJ increase when supplementing lumbosacral fusion with topping-off devices, suggesting that topping-off surgery may be associated with higher risks of SIJ degeneration and pain than fusion alone.

Sacroiliac Joint Degeneration and Pain After Spinal Arthrodesis: A Systematic Review

STUDY DESIGN

This was a systematic review.

OBJECTIVE

The present study aims to review the available literature concerning sacroiliac joint (SIJ) pain and degeneration after lumbosacral fixation to identify the prevalence and potential risk factors.

SUMMARY OF BACKGROUND DATA

Although numerous factors can predispose patients to SIJ degeneration and pain various clinical studies indicate lumbosacral arthrodesis as a major cause.

MATERIALS AND METHODS

The PubMed-MEDLINE, Cochrane Central Registry of Controlled Trials, and Embase Biomedical database were searched. Peer-reviewed comparative studies, cohort studies, case series studies and case control studies, conducted either in a retrospective or prospective design, that registered data about SIJ pain and degeneration after lumbosacral fixation were included.

RESULTS

Twenty-one studies including 2678 patients met the inclusion criteria. The percentage of SIJ pain after lumbosacral fixation diagnosed with injections and physical examination varied widely, from 3% to 90%. Among patients who underwent spinal fusion, SIJ pain prevalence was higher when arthrodesis was fixed compared with floating fusions (59% vs. 10%, P -value >0.05). The prevalence of SIJ degenerative changes at computed tomography scan was more frequent in patients who underwent spinal arthrodesis than in those who did not (75% vs. 38.2%, P -value ≤0.05).

CONCLUSION

According to current evidence, patients who received lumbosacral fixation are at risk of SIJ pain. Number of fused levels, involvement of pelvis or sacrum in the arthrodesis area, inadequate lumbosacral sagittal alignment, and site of bone graft harvesting could be possible risk factor leading to sacroiliac degeneration and pain after lumbar spine fixation that should be investigated by physicians. However, there is a lack of homogeneity of the studies that address the problem, therefore, further prospective comparative studies, with a homogeneous architecture and cohorts are needed.

LEVEL OF EVIDENCE

Level III.

Sacroiliac joint degeneration in degenerative lumbar spondylolisthesis and related risk factors: a retrospective study

OBJECTIVE

This study was performed to evaluate the degree of radiological sacroiliac joint (SIJ) degeneration in patients with degenerative lumbar spondylolisthesis (DLS). The related risk factors for SIJ degeneration were also investigated.

METHODS

We retrospectively analyzed the lumbar and pelvic computed tomography (CT) scans of 303 patients with DLS admitted from January 2018 to December 2021. One hundred and fifty-six age-, gender-, and body mass index-matched patients without lumbar anomality who underwent lower abdominal or pelvic computed tomography scans were included in the control group. Sagittal parameters were measured on full-length lateral radiographs. Two protocols (Backlund's grade and Eno's classification) were used to assess SIJ degeneration. Univariate analysis and bivariate and multivariate regression analysis were performed to identify the factors affecting SIJ degeneration in patients with DLS.

RESULTS

According to Backlund's grade and Eno's classification, SIJ degeneration was more severe in the DLS group than in the control group (P < 0.001). Multi-segment degenerative changes (P = 0.032), two-level DLS (P = 0.033), a history of hysterectomy (P < 0.001), lower extremity pain (P = 0.016), and pelvic pain (P = 0.013) were associated with more significant SIJ degeneration as assessed by Backlund's grade. The results of Pearson's correlation analysis showed positive correlation between the sagittal vertical axis and SIJ degeneration (r = 0.232, P = 0.009). The multivariate linear regression analysis showed that a history of hysterectomy was significantly correlated with SIJ degeneration in patients with DLS (r = 1.951, P = 0.008).

CONCLUSIONS

SIJ degeneration was more severe in patients with than without DLS. We should take SIJ degeneration into consideration when diagnosing and treating DLS especially those who had undergone previous hysterectomy or showed sagittal malalignment.