Folau C, Maugle T, Parekh S, Yevtukh A
UPMC Pinnacle, Harrisburg, PA, United States
Interbody fusion of the degenerative lumbar spine can stabilize painful motion segments, indirectly decompress neural elements, restore lordosis, and correct deformities. Lateral lumbar interbody fusion (LLIF), also referred to as eXtreme Lateral Interbody Fusion (XLIF) or Direct Lateral Interbody Fusion Interbody Fusion (DLIF) is the focus of this report. Indications for XLIF include spondylolisthesis, adult de novo lumbar scoliosis, central and foraminal stenosis, degenerative disc disease, pseudoarthrosis, total disc arthroplasty conversion, among others.
An important advantage is a reduced risk of injury to major vascular or visceral structures when compared to other approaches. Additional benefits include increased disc space height, less blood loss, shorter operative time, and reduced length of stay. According to Sembrano et all, notable advantages that are particularly relevant in our case is the ability to improve lordosis, without resecting the ALL as performed during anterior lumbar interbody fusion (ALIF), and the ability to place interbody cages with a larger footprint than other approaches.
In this case, we present an unusual complication that occurred during a multilevel XLIF. We identified asymptomatic avulsion fractures of the anterior vertebral bodies of L2 and L3 after routine postoperative radiographs were obtained. This has not been well described in the literature. In fact, to our knowledge it has not been described at all. We aim to present the case details, background on the surgical indications, techniques, advantages/disadvantages to XLIF (DLIF/LLIF), and offer a possible mechanism explaining these fractures.
In conclusion, we report a case of intraoperative anterior vertebral body avulsion fractures at L2 and L3 during XLIF at L2-L3, L3-L4, and L4-L5. We propose the mechanism of intraoperative anterior vertebral body avulsion fractures during XLIF to have occurred due to the bone failing under shear forces between the anterior longitudinal ligament and vertebral body interface as implants were impacted, increasing disc height and lumbar lordosis. These fractures did not appear to be clinically important or result in adverse effects for our patient, but to our knowledge no descriptions of this phenomena are found in the literature, so the incidence and clinical relevance is unknown. We encourage surgeons to be cognizant of this iatrogenic injury and to carefully evaluate intra-op and postop images for this subtle fracture pattern. Improved diagnosis and documentation could help with better understanding the incidence, clinical significance, and mechanism of this phenomena.
