Live from NASS: Best Papers from The Spine Journal

Every year at its Annual Meeting, The North American Spine Society highlights its nominations for “best papers” from its publication, The Spine Journal. Here is a sampling of a few that deal with technologies for spine care.

Spine Trauma

Paper: Comparative Study for Treatment Outcomes of Osteoporotic Compression Fractures Without Neurologic Injury Using Rigid Brace, Soft Brace and No Brace: A Prospective Randomized Controlled Non-Inferiority Trial.

Osteoporosis is a common cause of compression fractures of the spine. Braces are considered important in their treatment, but till now, no trial has provided evidence for this belief. This study examined the efficacy of rigid or soft braces compared to treatment without any brace in patients with acute osteoporotic compression fractures.

Sixty patients were randomly and equally assigned to the rigid, soft or no brace group. Progress in healing was measure with the Oswestry Disability Index (ODI) 12 weeks after the fracture occurred. The ODI scores in the no brace group were not significantly different to that in the soft or rigid brace groups, and the improvement in back pain and the progression of anterior body compression were similar across all three groups.

Imaging in Spine Care

Paper: The Prevalence of Sacroiliac Joint Degeneration in Asymptomatic Adults: A Review Of 500 CT Scans.

Degenerative changes of the sacroiliac (SI) joint have been implicated as a cause of lower back pain in adults, and there is increasing interest in invasive treatments ranging from SI joint injection to fusion.

Five hundred patients who underwent abdomen/pelvis CT (computed tomography) scans for reasons other than low back pain or pelvic girdle pain were identified. Only patients who showed no evidence of spine trauma, open physes, or implants, were included in the study (373).

Thirty-five percent of patients had degeneration in at least on SI joint, and significant change of at least one SI joint was found in 30 percent of patients.

The study concluded that CT imaging is important for developing appropriate treatment strategies for patients with both traumatic and degenerative conditions of the SI joint. This includes patients with SI joint injuries treated non-operatively or with SI screws as well as patients with low back pain and SI joint degeneration on axial imaging (CAT scans) who are being evaluated for fusion. The study authors note that the treating surgeon should be careful not to attribute low back pain to CT evidence of trauma, degeneration or penetration of the joint by screws. Diagnostic tests to distinguish SI joint pain from other sources of back pain merit additional research.

Biomechanics in Spine Care

Paper: Probing, Tapping, Toggling: Are we inserting Screws Correctly?

The clinical significance of a failed pedicle screw is often revision surgery and further prospective complications. This paper quantifies the mechanical strength of the bone/screw interface by testing under highly controlled conditions and assessing the surgical significance. Testing in this study included varying the probe/pilot hole diameter and inserting a standard size screw; using one size pilot hole and varying the tap size; and determining how toggling radically alters this interface.

The study found that the methods and instruments employed during the initial placement of a pedicle screw have a dramatic effect on the ability of the screw to resist toggling. Spinal tap sizes up to 4.5 mm show a minimum decline in pullout strength, but larger taps result in poor pullout strengths. The authors recommended that surgeons use taps two sizes smaller than indicated for the probe or pilot hole. The study also found that 84 percent of any damage to the surgical site occurs during the toggling cycle, so the authors recommended avoiding toggling at all costs. They way to do this, they wrote, is to use the correct probe/pilot hole size and under tapping by two screw sizes.