Sacroiliac joint pain diagnosis
Delayed diagnosis can result in significant morbidity. The diagnosis may be missed initially if physicians do not consider the possibility of infection. The clinical index of suspicion should increase in the presence of certain historical and examination findings. These include intravenous drug use, immunosuppression, recent infection elsewhere, fever and warmth or swelling over the sacroiliac joint.
SPECT imaging helps diagnose sacroiliac joint syndrome and facet syndrome 1).
Kurosawa et al. evaluated 62 patients with SIJ pain originating from the posterior ligament and 59 patients with LDH and LSS. Pain areas, pain-increasing positions, provocation test, and tenderness points were investigated. A scoring system based on multivariate logistic regression equations using the investigated items was developed.
Two pain areas (the posterosuperior iliac spine (PSIS) detected by the one-finger test and groin), pain while sitting on a chair, provocation test, and two tenderness points (PSIS and the sacrotuberous ligament) had high odds ratios (range, 25.87–1.40) and were used as factors in the scoring system. An integer score derived from the regression coefficient and clinical experience was assigned to each identified risk factor. The sum of the risk score for each patient ranged from 0–9. This scoring system had a sensitivity of 90.3% and a specificity of 86.4% for a positivity cutoff point of 4.
The scoring system can help distinguish between patients with SIJ pain originating from the posterior ligament and those with LDH and LSS 2).
Despite the availability of safe and effective surgical treatment for chronic sacroiliac joint pain, many clinicians find the diagnosis challenging. Misdiagnosis can lead to misdirected surgery, which has important consequences. The study aimed to determine whether a combination of clinical examination, sacroiliac joint block, and selected radiographic imaging can distinguish patients with SI joint pain from those with other causes of chronic low back pain.
Prospective diagnostic accuracy study with evaluation of 364 consecutive patients seeking advice in a neurosurgical clinic for chronic low back pain. Participating patients underwent comprehensive clinical examinations (medical history items, specific physical examination maneuvers, and selected radiographic tests) followed by SI joint block. Block was used to confirm or exclude SI joint pain. Logistic regression with LASSO (least absolute shrinkage and selection operator) penalty was used to calculate the accuracy of diagnosis when looking at (1) medical history items only, (2) medical history plus radiographic testing, and (3) medical history, radiographic testing, and physical examination testing.
Results: 150 patients had a positive response (>50% acute pain relief) to SI joint block, 214 had no response to SI joint block, and 37 had minimal (<50% improvement) pain. Diagnostic accuracy for SI joint pain was lowest with medical history only (85-86%), slightly higher when radiographic testing was added (87%), and highest when physical examination testing was included (96%).
Comprehensive clinical examination (including SI joint block where relevant and selected imaging procedures) accurately distinguishes the SI joint from non-SI joint causes of chronic low back pain.
Trial registration: https://www.clinicaltrials.gov/study/NCT04381208 3).
This study provides valuable insights into the diagnostic approach for chronic low back pain caused by SI joint dysfunction, emphasizing the superiority of a comprehensive clinical examination. However, the limited contribution of radiographic testing, the reliance on SI joint block as a gold standard, and the lack of generalizability warrant cautious interpretation. Future research should aim to validate these findings across broader settings and refine diagnostic protocols to enhance clinical utility.