The document discusses the sacroiliac joint, a connection between the spine and pelvis that is often overlooked as a cause of back pain. It describes the joint's anatomy, biomechanics, common predisposing factors, symptoms, clinical exams used to diagnose it, differential diagnoses to consider, investigations that can identify sacroiliac joint pain, and potential treatments including physical therapy, injections, radiofrequency ablation, and surgical fusion.

1. Sacroiliac joint as a cause of back
pain
(underdiagnosed and
misunderstood etiology )
BY D.FAHAD AL-HASANI
ORTHOPAEDIC TRAINEE
BASRA GENERAL HOSPITAL

3. Sacroiliac joint anatomy & biomechanics
It is the joint that connect the spine with the pelvis
It is a true diarthodial joint :which is characterized by the presence of a layer of fibrocartilage or
hyaline cartilage that lines the opposing bony surfaces, as well as a lubricating synovial fluid
within the synovial cavity.
It has sacral concave surface covered by hyaline cartilage and convex Iliac surface covered by
thin fibrocartilage
It has minimal movement and it is induced by movement of other joint and it is about of less
than 4 degree of rotation and less than 1.6 mm of translation.
It has the ability to resist shear forces by strong ligaments.
while the SI Joint is vulnerable to shear during rotation or translation, compression of the joint
allows it to resist shear

4. Those structures that produce joint compression include the interosseous ligaments and the
joint capsule including strong posterior ligaments protecting the network of adjacent nerves.
The muscles that help stabilize the SI Joint include the piriformis, the psoas, the illiacus, the
glutes, and the hamstrings. The hamstring muscles do not cross the SI Joint but may be
associated with SI Joint disorder

8. Predisposing factors
Prior lumbar fusion
Trauma (RTA , FFH)
Lifting heavy objects
Twisting injury
Post partum (more than 6 months )

9. Etiology
Mechanical dysfunction
Inflammation
Infection
Trauma
Degeneration
Metabolic
Neoplastic

10. SYMPTOMS
Stabbing back pain (as a dagger )
Buttock pain or back of thigh or groin pain or even knee pain
Pain while setting and frequent change of posture
Pain going from sitting to standing and vice versa
Sleep disturbance (difficulty in turnover in bed)
Tingling and numbness in lower extremity


11. Clinical examination
Full lumbar spine examination
Hip examination to exclude hip joint pathology
 SI joint examination :
FABERS test
Gaenslen test
Distraction test
Compression test
Thigh thrust
Yoemann’s test
Gillets test (stork test )

12. PATRICK TEST
GAENSLEN TEST
DISTRACTION TEST
COMPRESSION TEST
THIGH THRUST TEST
Yoemann’s test
Gillets test

13. DIFFRENTIAL DIAGNOSIS
Trochanteric bursitis
Piriformis syndrome
Myofacial pain
Lumbosacral disc bulge and herniation
Lumbosacral facet syndrome
Lumbar radiculopathy
Sperior cluneal nerve entrampemnt

14. Investigation
BLOOD TEST : CBC , ESR. CRP , HLA B 27 , ALK
PALIN X RAY (INLET AND OUTLET VIEW )
MRI (HIPAND LUMBOSACRAL)
DIAGNOSTIC INJECTION UNDER FLUROSCOPE GUIDANCE
Local anesthetic aloneDuration of relief concordant with that of anesthetic action
Proper technique important
◦ Single vs. 2 or more injections on separate occasionsLA’s of varying duration to help
validate dx
•Local plus steroidDiagnostic and therapeutic
Longer effect duration

18. TREATMENT
Surgical fusion
PHYSICAL THERAPY
Anti-inflammatories
Intra-articular
injection
Radiofrequency
denervation

19. PHYSICAL THERAPY

20. Therapeutic SI Injection
Technique identical to diagnostic injection
Addition of steroid
Duration of effect difficult to predict

21. Radiofrequency Ablation
Recall innervation of SI joint
Predominantly dorsal innervation
From L5 dorsal ramus, S1-3 lateral

22. SURGICAL FUSION