Short-segment percutaneous osteosynthesis with long pedicle screw fixation of the injured vertebra for thoracolumbar and lumbar non neurological fractures: The Trident Fixation.

STUDY

DESIGN

Prospective cohort study

OBJECTIVE

This study aimed to assess the interest of a short percutaneous monaxial pedicle screw (PS) osteosynthesis, named the Trident Fixation (TF): fixation of one vertebra above and below the vertebral fracture and including two long monoaxial PS into the injured vertebra to treat thoracolumbar (TL) and lumbar (L) fractures.

METHODS

Patients operated by this surgical method were prospectively included. Preoperative data and immediate, one-year follow-up, and two-year follow-up postoperative data were collected. The surgical correction was studied, evaluating the radiologic parameters as follows: vertebral body angle, regional traumatic kyphosis, regional traumatic angulation, Anterior/Middle Column Vertebral Body Compression Ratio (VBCR) and Anterior Vertebral Body Compression Percentage and the mid sagittal diameter of the spinal canal. PS placement, bone fusion and the occurrence of instrumentation failure were sought.

RESULTS

Sixty-six patients were included (mean follow-up of 1.9 years (95% CI [1.9-2.6]). Regarding the accurate position of the PS, 11 of them (16.7%) presented a cortical bone violation. At the last follow-up, 3 patients (4.5%) presented a screw loosening, but no one progressed to a screw pull-out. One patient (1.5%) suffered from a rod breakage. All the radiologic parameters improved postoperatively, except the VBCR, which remained unchanged, despite the surgery. Vertebral fracture was healed for 54 patients (82%). Twenty (30.3%) patients presented an intervertebral fusion, either posterior facet fusion (12 patients [18.2%]) or interbody fusion (11 patients [16.6%]).

CONCLUSION

TF gives relevant postoperative radiological outcomes and is an alternative to the kyphoplasty, which remains an expensive method.