L4-L5 Facet Dislocation Treated in a Delayed Fashion with Excellent Early Clinical Results

Abstract

Introduction: Introduction: Lumbar facet fracture-dislocations are rare injuries that are generated from a significant trauma. Literature regarding these injuries is limited to case reports, and there are even more limited reports concerning whether the delay of operative intervention in neurologically intact patients can achieve good clinical results if concomitant injuries and/or medical issues preclude urgent operative intervention. There has been no consensus on which operative techniques are effective in achieving an anatomic reduction of these injuries.

Objectives: A case report of an L4-L5 facet fracture-dislocation with delayed operative intervention and previously not reported adjunctive reduction technique is presented with an excellent clinical outcome result being achieved.

Case report: A 38-year-old female who presented with an L4-L5 facet fracture-dislocation without neurological deficit after an unknown mechanism of injury. Due to concerns for elevated risk of intra and perioperative complications from general anesthesia secondary to recent drug use, the patient ultimately underwent open reduction and L4-L5 posterior instrumentation and fusion, with a resection of the superior aspect of the L5 pedicle being performed to help achieve reduction. The patient did not report any significant lower back pain and remained motor intact at 6-month post-operative, with the only neurological symptom during her post-operative course being hypesthesias in the right L5 dermatome at 6-week post-operative.

Conclusion: Excellent clinical results can be achieved with delayed open reduction and posterior stabilization in patients that sustain lumbar facet-fracture dislocations. The precise timing for operative management for patients who sustain these injuries is unknown, but medical stability should be considered before proceeding with an operative intervention in neurological intact patients. Partial resection of the pedicle is a safe and effective reduction technique in certain fracture-dislocation patterns.

Keywords: Lumbar facet; fracture-dislocation; posterior spinal fusion.

Figure 1

Preoperative initial computed tomography (CT) imaging of the patient. CT imaging demonstrates a right L4-L5 facet dislocation with a small associated right L5 superior articular process fracture [A] and a left L4-L5 perched facet without associated fracture [B]. Axial CT-imaging at the L4-L5 facet dislocation demonstrates an empty facet sign [C].

Figure 2

Preoperative magnetic resonance imaging (MRI) imaging of the patient. Sagittal (a) and coronal (b) T2-weighted MRI imaging demonstrates anterior and posterior disc protrusions and bilateral foraminal morphological changes at L4-L5.

Figure 3

Post-operative radiographs of patient. Lateral (A) and anterior-posterior radiographs (B) of the patient approximately 6 weeks post-operatively, demonstrated reduction was maintained. There was no evidence of hardware failure. The patient’s pedicle screws were appropriately positioned with no evidence of hardware failure.