Associated factors for and progression rate of sacroiliac joint degeneration in subjects undergoing comprehensive medical checkups

Acetabular fracture pattern is altered by pre-injury sacroiliac joint autofusion

PURPOSE

Acetabular fracture shape is determined by the direction of force applied. We perceive an anecdotally observed connection between pre-existing autofused sacroiliac joints (aSIJ) and high anterior column (HAC) injuries. The purpose of this study was to compare variations in acetabular fracture patterns sustained in patients with and without pre-injury sacroiliac (SI) joint autofusion.

METHODS

All adult patients receiving unilateral acetabular fixation (level 1 academic trauma; 2008-2018) were reviewed. Injury radiographs and CT scans were reviewed for fracture patterns and pre-existing aSIJ. Fracture types were subgrouped presence of HAC injury (includes anterior column (AC), anterior column posterior hemitransverse (ACPHT), or associated both column (ABC)).

ANALYSIS

Logistic regression determined the association between aSIJ and HAC.

RESULTS

A total of 371 patients received unilateral acetabular fixation (2008-2018); 61 (16%) demonstrated CT evidence of idiopathic aSIJ. These patients were older (64.1 vs. 47.4, p < 0.01), more likely to be male (95% vs. 71%, p < 0.01), less likely to be smokers (19.0% vs. 44.8%, p < 0.01), and were injured from lower energy mechanisms (21.3% vs. 8.4%, p = 0.01). The most common patterns with autofusion were ACPHT (n = 13, 21%) and ABC (n = 25, 41%). Autofusion was associated with greater odds of patterns involving a high anterior column injury (ABC, ACPHT, or isolated anterior column; OR = 4.97, p < 0.01). After adjusting for age, mechanism, and body mass index, the connection between autofusion and high anterior column injuries remained significant (OR = 2.60, p = 0.01).

CONCLUSIONS

SI joint autofusion appears to change mode of failure in acetabular injuries; a more rigid posterior ring may precipitate a high anterior column injury.

LEVEL OF EVIDENCE

Prognostic level III.

Sacroiliac Joint Ankylosis Decreases Intervertebral Fusion Rate in L5/S1 Single Intervertebral Transforaminal Lumbar Interbody Fusion

Background Transforaminal lumbar interbody fusion (TLIF) is a common surgical procedure for lumbar spondylolisthesis and intervertebral foraminal stenosis. Sacroiliac joint ankylosis is also known to occur in patients without axial spondyloarthritis. When sacroiliac joint bony ankylosis occurs and sacroiliac joint mobility is lost, stresses from the lower extremities to the lumbar spine are no longer buffered and are expected to be concentrated between the fifth lumbar (L5) and the first sacral (S1) vertebrae. We hypothesized that sacroiliac joint bony ankylosis could adversely affect L5/S1 intervertebral fusion and investigated the postoperative intervertebral fusion rate in single intervertebral TLIF on L5/S1 among patients with bony ankylosis of the sacroiliac joint. Methods Seventy-two patients who had undergone TLIF in the L5/S1 single intervertebral segment since 2014 and had a follow-up of at least one year after surgery were included in the study. Seventy-two patients were divided into the following two groups for comparison: group A consisted of 17 patients with bony ankylosis of the sacroiliac joint on either side on preoperative CT, and group N consisted of 55 patients without ankylosis. We investigated the intervertebral segment fusion rate one year postoperatively. Fisher's exact tests were used for statistical analysis, with a significance level of P < 0.05. Results Twelve patients (71%) in group A and 50 patients (91%) in group N had a fusion of the L5/S1 intervertebral segment one year after TLIF surgery, with a significantly lower rate in group A (P = 0.049). Conclusions We conclude that the presence of preoperative sacroiliac joint bony ankylosis is a risk factor for postoperative intervertebral fusion failure after single-segment TLIF at L5/S1.

Spontaneous ankylosis of the sacroiliac joint: prevalence and risk factors

PURPOSE

Evidence on spontaneous sacroiliac joint (SIJ) ankylosis is lacking. The aim of this analysis was to assess the prevalence of spontaneous SIJ ankylosis and examined different ankylosis patterns and risk factors for spontaneous SIJ ankylosis.

METHODS

Pelvic computed tomography (CT) data of 102 consecutive patients with spinal pathologies were compared to CT of a control group consisting of 102 consecutive patients without spinal pathologies. SIJ ankylosis patterns and risk factors for SIJ ankylosis, such as age, sex, and previous spinal fusion surgery were examined.

RESULTS

Overall, 117 men and 86 women were examined between 2019 and 2020. Non-spinal patients were significantly older (mean age 70.5 years, standard deviation [SD] 11.4) than those in the spinal group (mean age 65.3 years, SD 14.3; p = 0.005). The prevalence of SIJ ankylosis was 24.5% in the non-spinal group and 23.5% in the spinal group. The anterior ankylosis type prevalence was 91.7% in the spinal group, compared to 48.0% in the non-spinal group. Factors associated with SIJ ankylosis were older age (odds ratio [OR] 1.04, 95% confidence interval [CI] 1.01-1.07, p = 0.004) and male sex (OR 5.14, 95% CI 2.29-11.55, p < 0.001).

CONCLUSION

Spontaneous ankylosis of the SIJ was a frequent phenomenon in patients with and without spinal pathologies and more likely with older age and male sex. Anterior type SIJ ankylosis was substantially more frequent in patients with spinal pathologies. This may be due to strain exerted on the anterior SIJ aspects in patients with compromised posture due to spine degeneration.

An independent inter- and intra-observer agreement assessment of the Eno classification of sacroiliac joint degeneration

BACKGROUND

Recently, a scoring system to grade sacroiliac joint (SIJ) degeneration using computed tomography (CT) scans was described. No independent evaluation has determined the inter- and intra-observer agreement using this scheme.

PURPOSE

To perform an independent inter- and intra-observer agreement assessment using the Eno classification and determining gas in the SIJ.

MATERIAL AND METHODS

We studied 64 patients aged ≥60 years who were evaluated with abdominal and pelvic computed tomography scans. Six physicians (three orthopaedic spine surgeons and three musculoskeletal radiologists) assessed axial images to grade SIJ degeneration into grade 0 (normal), grade 1 (mild degeneration), grade 2 (significant degeneration), and grade 3 (ankylosis). We also evaluated the agreement assessing the presence of gas in the SIJ. After a four-week interval, all cases were presented in a random sequence for repeat assessment. We determined the agreement using the kappa (κ) or weighted kappa coefficient (wκ).

RESULTS

The inter-observer agreement was moderate (wκ = 0.50 [0.44-0.56]), without differences among surgeons (wκ = 0.53 [0.45-0.61]) and radiologists (wκ = 0.49 [0.42-0.57]). The agreement evaluating the presence of gas was also moderate (κ = 0.45 [0.35-0.54]), but radiologists obtained better agreement (κ = 0.61 [0.48-0.72]) than surgeons (κ = 0.29 [0.18-0.39]). The intra-observer agreement using the classification was substantial (wκ = 0.79 [0.76-0.82]), without differences comparing surgeons (wκ = 0.75 [0.70-0.80]) and radiologists (wκ = 0.83 [0.79-0.87]). The intra-rater agreement evaluating gas was substantial (κ = 0.77 [0.72-0.82]), without differences between surgeons (κ = 0.71 [0.63-0.78]) and radiologists (κ = 0.84 [0.78-0.90]).

CONCLUSION

Given the only moderate agreement obtained using the Eno classification, it does not seem adequate to be used in clinical practice or in research.