Fig. 22.1
Sequential tubular dilation (a), docking of expandable retractor (b), intraoperative AP fluoroscopic image with the docked retractor and Cobb elevator in the disk space (c), intraoperative view of the working zone (d), and magnified view of the working zone after diskectomy (e)
After performing the corpectomy, there are several options to reconstruct the anterior column. These options include using a structural allograft, autograft, or a static or expandable cage. The expandable cage technology facilitates the reconstruction of the corpectomy defect produced through the MISS lateral approach. After reconstructing the anterior column, supplemental fixation can be performed with anterolateral plating or posterior percutaneous transpedicular screws.
Smith et al. [2] investigated the use of MISS lateral techniques in the treatment of thoracolumbar fractures. The study included 52 patients with thoracolumbar fractures that were treated with mini-open, lateral corpectomies with anterolateral plating or percutaneous transpedicular screws to supplement fixation. The median operative time was 128 min compared to 210–617 min for open surgery [22, 43]. The lateral MISS approach had significantly lower blood loss of 300 ml compared to 2–3 l in open surgery [43, 44]. This study showed an acceptable complication rate of 15 % versus literature values that vary widely for open procedures [45]. The median length of stay in the hospital was 4 days compared to the reported 10–35 days for open surgery [5, 46]. There was no significant difference in outcome between the anterolateral plating and percutaneous posterior screw groups. Given the results of this study, lateral MISS appears to be a viable option for traumatic spine injuries, especially because these patients may be suffering from concomitant injuries that make them unfit for a larger, open procedure.
22.7 Pros of the Lateral MISS Approach
There is limited data regarding lateral MISS approaches for thoracolumbar spine trauma [5, 21, 47–49]. The lateral approach can be utilized throughout the thoracolumbar spine with the exception of L5–S1, which is obstructed by the iliac wing. The most common levels for the lateral approach are L2 to L4, which lack the anatomical difficulties of the thoracic spine and lumbosacral junction [23]. In addition to the aforementioned advantages of MISS for thoracolumbar trauma, the lateral approach also has unique benefits. Lateral MISS allows for the placement of the interbody structural support on the strongest part of the end plate, the apophyseal rim. The greatest diameter of the vertebral end plate is in the coronal plane, and a lateral approach allows for utilization of this bony morphology [23]. Additionally, the lateral approach obviates the need to mobilize the great vessels when performing the corpectomy and placing the interbody support. A lower frequency of postoperative ileus can be attributed to less manipulation of the abdominal contents [34]. The lower likelihood of injuring the superior hypogastric plexus also makes retrograde ejaculation less likely [42]. Finally, operative time and estimated blood loss are significantly lower with the lateral MISS approach [38].
Minimally invasive and open short-segment fixations demonstrate no significant differences in outcomes or loss of deformity correction. The vast majority of the patients in the Smith et al. study maintained or improved their neurologic status at 24 months of follow-up. These results are consistent with the literature regarding neurologic status following corpectomy for traumatic injuries of the spine [50, 51]. Additionally, biomechanical studies have demonstrated the superiority of direct anterior reconstruction over posterior fixation alone [26, 29, 30, 32, 52].
22.8 Cons of the Lateral MISS Approach
Despite the reported success of the lateral MISS approach, disadvantages of using this technique include a steep learning curve, reliance on imaging and nerve monitoring, increased cost, potentially difficult management of intraoperative complications, decreased visualization, and potential neurovascular injury [26, 29, 30, 32, 52]. Specifically, this approach poses a risk of injury to the sympathetic chain, genitofemoral nerve, segmental arteries, and ureter, as these structures all lie in close proximity to the dissection path [2, 42, 53]. The most common complication associated with the lateral approach, however, is transient thigh numbness, pain, or weakness, the incidence of which ranges from 1 to 60 % [54]. This could result from the dissection through the psoas major, causing trauma to the muscle and potential injury to the lumbar plexus and genitofemoral nerve [42]. There is an increased risk of damaging the intervertebral nerves when working distally, where the nerves travel anteriorly over the intervertebral disk [55]. As this approach involves the abdominal wall, it is no surprise that a case report describes an incisional hernia after undergoing a lateral MISS procedure. To avoid hernias, the authors recommended making the incision as posteriorly as possible and using blunt dissection [56]. While lateral MISS does have its drawbacks, the morbidity is generally less than a patient would experience with an open procedure.
22.9 Case Example: A 22-Year-Old Male with Thoracolumbar Injury with Incomplete Neurological Deficit
A 22-year-old male, who was involved in a high-speed motor vehicle collision, sustained multiple injuries including a subarachnoid hemorrhage, bilateral hemopneumothoraces, an open right femur fracture, and bilateral humerus fractures. He presented with incomplete neurological deficits of his lower extremities, with the right proximal muscle groups having a higher motor score. The patient was found to have a noncontiguous spine injury. Imaging revealed an L3 burst fracture (Figs. 22.2 and 22.3) with posterior ligamentous complex (PLC) disruption, as well as a T12–L1 osseoligamentous flexion-distraction injury (Fig. 22.4). Based on his physical exam findings and imaging, it was determined that his incomplete neurological deficit was due to the L3 burst fracture, with associated 90 % canal compromise. Despite this finding, both injuries required stabilization. The surgeon performed a posterior MIS T11–L4 instrumentation with facet joint fusions followed by a mini-open lateral L3 corpectomy with placement of an expandable cage and local bone graft from the corpectomy site (Figs. 22.5). Postoperatively, the patient regained normal neurological function.
Fig. 22.2
Sagittal (a) and axial (b) computed tomography scans demonstrating a comminuted L3 burst fracture with greater than 50 % loss of height, retropulsion, and severe canal stenosis
Fig. 22.3
Sagittal (a) and axial (b) T2 magnetic resonance imaging scans demonstrating a L3 burst fracture with greater than 50 % loss of height, retropulsion, severe canal stenosis, and poster ligamentous complex injury
Fig. 22.4
Sagittal magnetic resonance imaging scans showing a T12–L1 osseoligamentous flexion-distraction injury (arrows)
Fig. 22.5
Anteroposterior (a) and lateral (b) x-rays after mini-open lateral L3 corpectomy, titanium cage placement, and percutaneous transpedicular screw fixation from T11 to L4
Conclusion
Thoracolumbar trauma patients are a vulnerable subset of patients who are often under significant duress due to multiple injuries. The goals of surgical treatment of these patients include prevention of primary or secondary neurological injury, enhancement of neurological recovery, and stabilization of the spine to promote early mobilization. The challenge of minimizing the morbidity of treatment has provided an impetus for the implementation and development of MISS. The lateral MISS approach enables the surgeon to combine the benefits of an anterior approach with less morbid techniques. This is significant in light of the proven benefits of anterior decompression when compared to posterior distraction in the treatment of certain thoracolumbar injuries, including the potential for improved direct decompression to increase the likelihood of neurologic recovery and improved kyphotic correction. There is an additional advantage unique to the lateral MISS approach which includes the ability to place an interbody supportive device on the apophyseal rim. A disadvantage of MISS is the potentially steep learning curve which may initially lead to longer operative times and a higher rate of complications. As interest in the use of lateral MISS in the treatment of thoracolumbar trauma increases, novel techniques and improvements on current techniques will be developed. Further studies are needed to universally endorse this technique, but as illustrated in the case example, the lateral MISS approach may become a vital tool for spine surgeons in the treatment of thoracolumbar fractures.
References
1.
2.
Smith WD, Dakwar E, Le TV, Christian G, Serrano S, Uribe JS. Minimally invasive surgery for traumatic spinal pathologies: a mini-open, lateral approach in the thoracic and lumbar spine. Spine (Phila Pa 1976). 2010;35(26 Suppl):S338–46.CrossRef
3.
Grazier K, Holbrook T, Kelsey J. The frequency of occurrence, impact, and cost of musculoskeletal conditions in the United States (1984). An overview of the incidences and costs of low back pain. Orthop Clin N Am. 1991;22:263–71.
4.
Center NSCIS. Spinal cord injury facts and figures at a glance. Birmingham: The University of Alabama; 2011.
5.
Wood KB, Bohn D, Mehbod A. Anterior versus posterior treatment of stable thoracolumbar burst fractures without neurologic deficit: a prospective, randomized study. J Spinal Disord Tech. 2005;18(Suppl):S15–23.CrossRefPubMed
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
