Stable Regional and Global Alignment in Patients Treated With Minimally Invasive Lateral Retropleural Thoracic Diskectomy Without Fixation

Operative Neurosurgery 26:511–518, 2024

Thoracic disk herniations are challenging to treat, and open transthoracic or minimally invasive thoracoscopic approaches are associated with significant morbidity, substantial costs, and steep learning curves. The minimally invasive lateral retropleural thoracic diskectomy (MIS-LRP-TD) approach is straightforward and is associated with lower perioperative morbidity. With MIS-LRP-TD, the overlying rib, ipsilateral pedicle, ligamentum flavum, posterior longitudinal ligament, and posterior third of the adjacent vertebral bodies are resected. Adjunct fixation is typically not performed, eliminating hardware-related complications and costs. This radiographic study investigates long-term global and thoracic spine alignment after MIS-LRP-TD without fixation.

METHODS: This study was a single-institution, retrospective evaluation of all patients who underwent MIS-LRP-TD without fixation between November 7, 2017 and July 19, 2022. Preoperative and the most recent postoperative radiographs were used to determine the C7 plumb line to central sacral vertical line, thoracic Cobb angle (TCA), segmental Cobb angle, C7 to sagittal vertical axis, thoracic kyphosis, and segmental kyphosis.

RESULTS: In total, 22 patients with 24 disk herniations underwent MIS-LRP-TD without fixation. The mean (SD) radiographic follow-up was 12.9 (11.2) months. Overall, no significant differences were seen in C7 plumb line to central sacral vertical line (P = .65), C7 to sagittal vertical axis (P = .99), thoracic kyphosis (P = .30), TCA (P = .28), segmental kyphosis (P = .27), or segmental Cobb angle (P = .56) at follow-up. One patient demonstrated a >5°change in TCA but remained asymptomatic.

CONCLUSION: Despite requiring extensive resection of the middle column and ipsilateral costovertebral joint at the index level, MIS-LRP-TD without adjunct fixation does not lead to significant global, regional, or segmental deformity. Thus, MIS-LRP-TD appears to be a safe, effective treatment approach for challenging thoracic disk herniations.

Radiological and clinical outcomes following extreme lateral interbody fusion

Radiological and clinical outcomes following extreme lateral interbody fusion

 J Neurosurg Spine 20:623–635, 2014

Extreme lateral interbody fusion (ELIF) is a popular technique for anterior fixation of the thoracolumbar spine. Clinical and radiological outcome studies are required to assess safety and efficacy. The aim of this study was to describe the functional and radiological impact of ELIF in a degenerative disc disease population with a longer follow-up and to assess the durability of this procedure.

Methods. Demographic and perioperative data for all patients who had undergone ELIF for degenerative lumbar disorders between 2007 and 2011 were collected. Trauma and tumor cases were excluded. For radiological outcome, the preoperative, immediate postoperative, and latest follow-up coronal Cobb angle, lumbar sagittal lordosis, bilateral foraminal heights, and disc heights were measured. Pelvic incidence (PI) and PI–lumbar lordosis (PI-LL) mismatch were assessed in scoliotic patients. Clinical outcome was evaluated using the Oswestry Disability Index (ODI) and visual analog scale (VAS), as well as the Macnab criteria.

Results. One hundred forty-five vertebral levels were surgically treated in 90 patients. Pedicle screw and rod constructs and lateral plates were used to stabilize fixation in 77% and 13% of cases, respectively. Ten percent of cases involved stand-alone cages. At an average radiological follow-up of 12.6 months, the coronal Cobb angle was 10.6° compared with 23.8° preoperatively (p < 0.0001). Lumbar sagittal lordosis increased by 5.3° postoperatively (p < 0.0001) and by 2.9° at the latest follow-up (p = 0.014). Foraminal height and disc height increased by 4 mm (p < 0.0001) and 3.3 mm (p < 0.0001), respectively, immediately after surgery and remained significantly improved at the last follow-up. Separate evaluation of scoliotic patients showed no statistically significant improvement in PI and PI-LL mismatch either immediately postoperatively or at the latest follow-up. Clinical evaluation at an average follow-up of 17.6 months revealed an improvement in the ODI and the VAS scores for back, buttock, and leg pain by 21.1% and 3.7, 3.6, and 3.7 points, respectively (p < 0.0001). According to the Macnab criteria, 84.8% of patients had an excellent, good, or fair functional outcome. New postoperative thigh numbness and weakness was detected in 4.4% and 2.2% of the patients, respectively, which resolved within the first 3 months after surgery in all but 1 case.

Conclusions. This study provides what is to the authors’ knowledge the most comprehensive set of radiological and clinical outcomes of ELIF in a fairly large population at a midterm follow-up. Extreme lateral interbody fusion showed good clinical outcomes with a low complication rate. The procedure allows for at least midterm clinically effective restoration of disc and foraminal heights. Improvement in coronal deformity and a small but significant increase in sagittal lordosis were observed. Nonetheless, no significant improvement in the PI-LL mismatch was achieved in scoliotic patients.