Sacral Insufficiency Fracture Repair/Sacroplasty

Abstract

Sacral insufficiency fractures are a common cause of low back pain. They are often underdiagnosed as a result of low clinical suspicion. These fractures are a consequence of the imposition of physiologic stresses onto weakened bones. Spontaneous fracture of the osteoporotic sacrum was first described in 1982. It clinically manifests as back and/or buttock pain with or without lower limb pain referral.

keywords

fractures, osteoporosis, pain, sacral alae, sacral insufficiency fracture, Sacroplasty, trauma

Note: Please see pages ii , iii for a list of anatomic terms/abbreviations used throughout this book.

Sacral insufficiency fractures are a common cause of low back pain. They are often underdiagnosed as a result of low clinical suspicion. These fractures are a consequence of the imposition of physiologic stresses onto weakened bones. Spontaneous fracture of the osteoporotic sacrum was first described in 1982. It clinically manifests as back and/or buttock pain with or without lower limb pain referral.

The traditional therapeutic algorithm for sacral insufficiency fractures consists of limited bed rest, partial weight bearing, and early mobilization. The overall 1-year mortality rate associated with pelvic insufficiency fractures is 14.3%, and 50% of affected patients will not return to their prior level of functioning. Despite a favorable natural history, more aggressive treatments may benefit patients who are incapacitated by painful sacral insufficiency fractures.

The percutaneous injection of polymethylmethacrylate (PMA) into fractured vertebral bodies (i.e., vertebroplasty) has been safely performed to successfully treat painful osteoporotic compression fractures. A natural extension of the application of vertebroplasty is the percutaneous injection of synthetic bone cement into the fractured sacrum (i.e., sacroplasty) to treat persistent symptoms and disability.

Several articles have documented the efficacy of sacroplasty, including two large prospective studies. Sacroplasty appears to be a safe and effective treatment for painful sacral insufficiency fractures. The rate of improvement is rapid, with more than 50% reduction in pain achieved before the post-procedure discharge of the patient. Pain reduction primarily occurs within the first 3 months, but it is sustained through 12 months after treatment.

Complications of this procedure include (but are not limited to) bleeding, infection, bowel perforation, cement emboli, and neuritis. With the use of the technique described here, bowel perforation and neuritis can be minimized by using appropriate safety considerations and views.

Trajectory View

Confirm the level (with the anteroposterior view) before obtaining the trajectory view.

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The fluoroscope is obliqued contralaterally from the side being treated until one can superimpose the medial and lateral aspects of the sacroiliac joint. This could be approximately 5- to 25-degree contralateral oblique. If the posterior iliac crest is in the way, caudal or cephalad tilts of 0 to 25 degrees may be necessary.
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The needle tip destination is at the midpoint of the imaginary line drawn between the lateral aspect of the dorsal sacral foramina and the sacroiliac joint.
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Use an 18-gauge needle to first penetrate the skin. Use a mallet to gently tap either a 13- or 11-gauge trocar into the periosteum.
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Because this is the trajectory view, the needle entry position should be parallel to the C-arm beam ( Fig. 9.1 ).

Fig. 9.1

A, Trajectory view with S1 and S2 needle being placed. The fluoroscope is obliqued contralaterally from the side being treated until one can line up the sacroiliac joint. This could involve an approximately 5- to 25-degree oblique tilt. If the posterior iliac crest is in the way, caudal or cephalic tilts of 0 to 25 degrees may be necessary. B, Radiopaque structures, trajectory view. C, Radiolucent structures, trajectory view.