Sacroiliac Intraarticular Joint Injection—Posterior Approach, Inferior Entry: Fluoroscopic Guidance

Abstract

Unlike other procedures with orthogonal imaging (i.e., anteroposterior and lateral), the typical views used here are anteroposterior and oblique views that optimize the visualization of the sacroiliac joint (SIJ). The only safety view for consideration is a lateral fluoroscopic view. The clinical response to SIJ injection is dependent on the intraarticular delivery of medication; therefore, the use of radio-opaque contrast medium is considered essential to confirm intraarticular versus suboptimal flow.

Keywords

fluoroscopy, injection, sacroiliac joint

Trajectory View

The Trajectory View Is Also a Multiplanar View

Tilt the fluoroscope cephalad approximately 10 to 15 degrees to elongate the posterior plane of the joint and improve the target lucency.

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Oblique the fluoroscope, starting with 5 to 10 degrees of ipsilateral oblique.
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Under live fluoroscopy, move the C-arm to 10- to 20-degree contralateral oblique. Live fluoroscopy confirms that the more superficial aspect of the joint is visualized as described in Chapter 3, Fig. 3.29 .
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Watch for the optimal “hyperlucent” region at the inferior portion of the SIJ. C-arm rotation is stopped when the “hyperlucent” region appears.
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  The target needle destination is the inferior aspect of the medial joint space; this corresponds to the posterior aspect of the SIJ. Confirm that the medial joint space is most posterior and superficial under live fluoroscopy
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  Because this is the trajectory view, the needle entry and trajectory should be parallel to the C-arm beam ( Fig. 10A.1 ).
  
  Fig. 10A.1
  
  A, Fluoroscopic image of the trajectory view with the needle in position at the medial aspect of the inferior sacroiliac joint. B, Radiopaque structures, trajectory view.

Notes on Positioning in the Trajectory View

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The needle is introduced into the medial aspect of the sacroiliac joint 1 to 2 cm superior to the inferior aspect of the joint.
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The needle is advanced in this position until it is felt to be firmly placed within the joint. If the periosteum is encountered, the needle should be rotated while gentle pressure is used to facilitate further advancement into the joint.

We recommend observing the safety considerations described in other views. There are no consistent safety considerations in this view.

Optimal Needle Position in Multiplanar Imaging ( Figs. 10A.2 and 10A.3 )

The Trajectory View Is Also a Multiplanar View

Notes on Multiplanar Imaging

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Multiplanar imaging in the case of sacroiliac intraarticular joint injections is helpful while driving the needle into the joint to assess proper depth. The C-arm is positioned approximately 15-degree ipsilateral oblique to visualize the needle’s approach to the joint line.
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In the ipsilateral oblique view, the needle enters the joint when it is advanced to the space between the medial and lateral joint margins.
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Further confirmation of intraarticular needle placement includes the movement of the C-arm ipsilaterally and contralaterally to ensure that needle placement within the joint space can be seen with different views.