Image-Guided Intra-Articular Versus Periarticular Injection in Sacroiliac Joint Pain

Participants receive a fluoroscopy-guided intra-articular injection into the lower third of the sacroiliac joint. A 22-gauge spinal needle is advanced under C-arm fluoroscopy (15-25° ipsilateral oblique view). Needle placement is confirmed with 0.5-1 mL iohexol contrast medium demonstrating an intra-articular arthrogram. Patients receive 3 mL total injectate containing 40 mg (1 mL) methylprednisolone acetate and 2 mL bupivacaine 0.25%.

Under continuous C-arm fluoroscopic guidance (15-25° ipsilateral oblique view), a 22-gauge spinal needle is advanced into the synovial cavity of the lower third of the sacroiliac joint using a posteroanterior approach. Proper intra-articular needle position is verified by injecting 0.5-1 mL iohexol contrast medium to confirm an arthrogram pattern. A 3 mL injectate consisting of methylprednisolone acetate 40 mg (1 mL) and bupivacaine 0.25% (2 mL) is then administered.

Participants receive a fluoroscopy-guided periarticular injection targeting the posterior sacroiliac ligament complex and posterior capsular tissues overlying the middle and upper thirds of the joint. Needle position is confirmed with contrast showing spread along the posterior capsule without intra-articular filling. Patients receive up to 5 mL total injectate containing 40 mg (1 mL) methylprednisolone acetate and bupivacaine 0.25% in a fan-like distribution.

Under fluoroscopic guidance, a 22-gauge spinal needle is directed toward the posterior capsular region and posterior sacroiliac ligament complex overlying the middle and upper thirds of the joint. Correct placement is confirmed via contrast injection showing spread along the posterior capsular surface without intra-articular entry. An injectate of up to 5 mL containing methylprednisolone acetate 40 mg (1 mL) and bupivacaine 0.25% is deposited in a fan-like distribution.

Pain intensity is assessed using an 11-point Numeric Rating Scale (NRS), where scores range from 0 to 10 (0 = "no pain", 10 = "worst imaginable pain"). This measure evaluates the change in pain score from baseline to 4 weeks post-procedure. A greater reduction or lower score indicates greater pain relief.