Endoscopic lateral transpsoas approach to the lumbar spine

Postoperative Radiculitis After L5-S1 Anterior Lumbar Interbody Fusion

STUDY DESIGN

Retrospective chart review.

OBJECTIVE

This study aimed to examine postoperative radiculitis after isolated L5-S1 anterior lumbar interbody fusion (ALIF), determine which factors contribute to its development, and investigate the comparative outcomes of patients with versus without postoperative radiculitis.

SUMMARY OF BACKGROUND DATA

Both standalone and traditionalALIF are common and safe lumbar spine fusion techniques. Although optimal safety and effectiveness are achieved through appropriate patient selection, postoperative radiculitis after L5-S1 ALIF is a potential complication that seems to be the least predictable in the absence of iatrogenic injury.

PATIENTS AND METHODS

All adult patients (18-80 yr) with preoperative radiculopathies who underwent L5-S1 ALIF by 9 board-certified spine surgeons at a single academic institution from January 2016 to December 2021 with a minimum of 3 months follow-up were included. Patient records were assessed for data on clinical characteristics and patient-reported outcome scores (patient-reported outcome measures). All patient records were evaluated to determine whether postoperative radiculitis developed. Radiographic measurements using x-rays were completed using all available pre and postoperative imaging. Multivariable logistic regressions were performed utilizing radiculitis as the dependent variable and various independent predictor variables.

RESULTS

One hundred forty patients were included, 48 (34%) patients developed postoperative radiculitis, with symptom onset and resolution occurring at 14.5 and 83 days, respectively. The two groups had no differences in preoperative or postoperative radiographic parameters. Multivariable regression showed 3 independent predictors of postoperative radiculitis: methylprednisolone use [OR: 6.032; (95% CI: 1.670-25.568)], increased implant height [OR: 1.509; (95% CI: 1.189-1.960)], and no posterior fixation [OR: 2.973; (95% CI: 1.353-0.806)].

CONCLUSIONS

Of the 34% of patients who developed postoperative radiculitis after L5-S1 ALIF, it resolved on average within 3 months of surgery. These findings may help reduce the risk of undue short-term morbidity after isolated L5-S1 ALIF by informing preoperative counseling and intraoperative decision-making.

The Feasibility of 3D Intraoperative Navigation in Lateral Lumbar Interbody Fusion: Perioperative Outcomes, Accuracy of Cage Placement and Radiation Exposure

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To evaluate perioperative outcomes, accuracy of cage placement and radiation exposure in lateral lumbar interbody fusion (LLIF) using 3D intraoperative navigation (ION), compared to conventional 2D fluoroscopy only.

METHODS

The perioperative outcomes and accuracy of cage placement were examined in all patients who underwent LLIF using ION (ION group) or fluoroscopy only (non-ION group) by a single surgeon. The radiation exposure was examined in patients who underwent stand-alone LLIF.

RESULTS

A total of 87 patients with 154 levels (ION 49 patients with 79 levels/ non-ION 38 patients with 75 levels) were included. There were no significant differences in operative time (ION 143.5 min vs. non-ION 126.0 min, P = .406), time from induction end to surgery start (ION 31.0 min vs. non-ION 31.0 min, P = .761), estimated blood loss (ION 37.5 ml vs. non-ION 50.0 ml, P = .351), perioperative complications (ION 16.3% vs. non-ION 7.9%, P = .335) and length of stay (ION 50.6 hours vs. non-ION 41.7 hours, P = .841). No significant difference was found in the accuracy of cage placement (P = .279). ION did not significantly increase total radiation dose (ION 51.0 mGy vs. non-ION 47.4 mGy, P = .237) and tended to reduce radiation dose during the procedure (ION 32.2 mGy vs. non-ION 47.4 mGy, P = .932).

CONCLUSIONS

The perioperative outcomes, accuracy of cage placement and radiation exposure in LLIF using ION were comparable to those using fluoroscopy only. The use of ION in LLIF was feasible, safe and accurate and may reduce radiation dose to the surgeon and surgical team.

Early effect of standalone oblique lateral interbody fusion vs. combined with lateral screw fixation of the vertebral body on single-level lumbar degenerative disc disease: A pilot study

BACKGROUND

For the treatment of single-level lumbar degenerative disc disease (DDD), oblique lateral interbody fusion (OLIF) has clinical advantages. Whether internal fixation needs to be combined for treatment has been the subject of debate.

OBJECTIVE

To compare the early clinical effects of standalone oblique lateral interbody fusion (S-OLIF) versus OLIF combined with lateral screw fixation of the vertebral body (F-OLIF) on single-level lumbar DDD.

METHODS

A retrospective analysis was performed on the data of 34 patients for whom the OLIF technique was applied to treat single-level lumbar DDD from August 2018 to May 2021. Patients were divided into the S-OLIF (n= 18) and F-OLIF groups (n= 16). Intraoperative blood loss, operative time, and length of hospital stay were recorded. The pain visual analogue scale (VAS) and Oswestry disability index (ODI) before and after the operation were evaluated. The disc height (DH), foraminal height (FH), fused segment lordosis (FSL), lumbar lordosis (LL), cage subsidence, and fusion by CT examination were measured before and after the operation.

RESULTS

The S-OLIF group experienced a shorter operative time and less intraoperative blood loss than the F-OLIF group, and the differences were statistically significant (p< 0.05), but the difference in the length of hospital stay was not statistically significant. The postoperative VAS score and ODI of the two groups were significantly lower than those before the operation, but the postoperative differences between the two groups were not statistically significant. Differences were not statistically significant in postoperative FH, DH, FSL and LL of the two groups. Both groups were followed up for no less than 12 months. In the two groups, fusion was achieved at the last follow-up visit.

CONCLUSION

According to short-term follow-up results, both S-OLIF and F-OLIF can achieve reliable and stable fusion and good clinical effect in the treatment of single-level lumbar DDD.

L4 Corpectomy: Surgical Approaches and Mitigating the Risk of Femoral Nerve Injuries

OBJECTIVE

Because of the challenging anatomic location, corpectomies are performed less often at the fourth lumbar vertebral body than at other levels. Our objective was to review the literature of L4 corpectomy and anterior column reconstruction.

METHODS

A literature search in the Medline/PubMed database was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify all relevant cases and cases series describing corpectomies of the L4 vertebral body using "lumbar" AND "corpectomy" as search terms. We present an illustrative case to describe the technique.

RESULTS

We identified 18 articles with 30 patients who met the search criteria. Including our case illustration, the most common approach used was the lateral retroperitoneal approach (n = 17, 54.8%), of which 8 (26.7%) were performed via a transpsoas approach. Seven (23%) patients underwent corpectomy through a posterior approach, 4 (12.9%) through an anterior retroperitoneal approach, and 3 (10%) through combined anterior and lateral retroperitoneal. The overall complications rate was 19.3% including 1 case each of femoral nerve injury and iatrogenic lumbar nerve root injury.

CONCLUSIONS

Corpectomies of the L4 vertebral body are challenging. None of the various approaches described clearly demonstrates any superiority in mitigating the risk of neural complications. Decision making about which surgical approach to use should be based on patient-specific characteristics.

Challenges Hindering Widespread Adoption of Minimally Invasive Spinal Surgery

Minimally invasive spinal surgery (MISS) techniques offer several beneficial prospects and are being increasingly requested by patients. However, these techniques have not been uniformly adopted by spinal surgeons, and they remain controversial among some. Several barriers have prevented widespread adoption of MISS. These include concerns regarding high start-up costs, limited evidence base, and lack of surgeon training. In addition, the unique approaches involved in MISS expose spinal surgeons to unfamiliar anatomy. Further, while MISS can address a growing spectrum of spinal pathology, some conditions, as well as complications encountered during MISS procedures, require open surgery. This requires surgeons to not only acquire the new and specialized MISS skillset but also maintain their ability to perform open surgery. These factors present challenges common to developing and innovative surgical techniques. Here, we review the barriers preventing wider adoption of MISS and present a framework to promote the safe and effective growth of MISS.

A New Treatment Algorithm That Incorporates Minimally Invasive Surgery for Pyogenic Spondylodiscitis in the Thoracic and Lumbar Spines: The Results of Its Clinical Application to a Series of 34 Patients

Background and Objectives: Spinal minimally invasive surgery (MIS) experts at the university hospital worked as a team to develop a new treatment algorithm for pyogenic spondylodiscitis in lumbar and thoracic spines. They modified a flow chart introduced for this condition in a pre-MIS era to incorporate MIS techniques based on their extensive experiences accumulated over the years, both in MIS for degenerative lumbar diseases and in the treatment of spine infections. The MIS procedures incorporated in this algorithm consisted of percutaneous pedicle screw (PPS)–rod fixation and transpsoas lateral lumbar interbody fusion (LLIF). The current study analyzed a series of 34 patients treated with prospective selection of the methods according to this new algorithm. Materials and Methods: The algorithm first divided the patients into those who had escaped complicated disease conditions, such as neurologic impairment, extensive bone destruction, and the need to be mobilized without delay (Group 1) (19), and those with complicated pyogenic spondylodiscitis (Group 2) (15). Group 1 had image-guided needle biopsy followed by conservative treatment alone with antibiotics and a spinal brace (12) (Group 1-A) or a subsequent addition of non-fused PPS–rod fixation (7) (Group 1-B). Group 2 underwent an immediate single-stage MIS with non-fused PPS–rod fixation followed by posterior exposure for decompression and debridement through a small midline incision (12) (Group 2-A) or an additional LLIF procedure after an interval of 3 weeks (3) (Group 2-B). Results: All patients, except four, who either died from causes unrelated to the spondylodiscitis (2) or became lost to follow up (2), were cured of infection with normalized CRP at an average follow up of 606 days (105–1522 days). A solid interbody fusion occurred at the affected vertebrae in 15 patients (50%). Of the patients in Group 2, all but two regained a nearly normal function. Despite concerns about non-fused PPS–rod instrumentation, only seven patients (21%) required implant removal or replacement. Conclusions: Non-fused PPS–rod placements into infection-free vertebrae alone or in combination with posterior debridement through a small incision worked effectively in providing local stabilization without contamination of the metal implant from the infected tissue. MIS LLIF allowed for direct access to the infected focus for bone grafting in cases of extensive vertebral body destruction.

Intraoperative neuromonitoring during surgery for lumbar stenosis

The indications for neuromonitoring during lumbar stenosis surgery are defined by the risks associated with patient positioning, the approach, decompression of neural elements, deformity correction, and instrument implantation. The routine use of EMG and SEP alone during lumbar stenosis surgery is no longer supported by the literature. Lateral approach neuromonitoring with EMG only is also suspect. Lumbar stenosis patients often present with multiple co-morbidities which put them at risk during routine pre-surgical positioning. Frequently encountered morbid obesity and/or diabetes mellitus may play a role in monitorable and preventable brachial plexopathy after "superman" positioning or femoral neuropathy from groin pressure after prone positioning, for example. Deformity correction in lumbar stenosis surgery often demands advanced implementation of multiple neuromonitoring modalities: EMG, SEP, and MEP. Because the bulbocavernosus reflex detects the function of the conus medullaris and sacral somato afferent/efferent fibers of the cauda equina, it may also be recorded. The recommendation to record pedicle screw thresholds has become more nuanced as surgeon dependence on 3D imaging, navigation, and robotics has increased. Neuromonitoring in lumbar stenosis surgery has been subject mainly to uncontrolled case series; prospective cohort trials are also needed.

Incidence of major and minor vascular injuries during lateral access lumbar interbody fusion procedures: a retrospective comparative study and systematic literature review

During lateral lumbar fusion, the trajectory of implant insertion approaches the great vessels anteriorly and the segmental arteries posteriorly, which carries the risk of vascular complications. We aimed to analyze vascular injuries for potential differences between oblique lateral interbody fusion (OLIF) and lateral lumbar interbody fusion (LLIF) procedures at our institution. This was coupled with a systematic literature review of vascular complications associated with lateral lumbar fusions. A retrospective chart review was completed to identify consecutive patients who underwent lateral access fusions. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were used for the systematic review with the search terms "vascular injury" and "lateral lumbar surgery." Of 260 procedures performed at our institution, 211 (81.2%) patients underwent an LLIF and 49 (18.8%) underwent an OLIF. There were no major vascular complications in either group in this comparative study, but there were four (1.5%) minor vascular injuries (2 LLIF, 0.95%; 2 OLIF, 4.1%). Patients who experienced vascular injury experienced a greater amount of blood loss than those who did not (227.5 ± 147.28 vs. 59.32 ± 68.30 ml) (p = 0.11). In our systematic review of 63 articles, major vascular injury occurred in 0-15.4% and minor vascular injury occurred in 0-6% of lateral lumbar fusions. The systematic review and comparative study demonstrate an increased rate of vascular injury in OLIF when compared to LLIF. However, vascular injuries in either procedure are rare, and this study aids previous literature to support the safety of both approaches.

Efficacy and radiographic analysis of oblique lumbar interbody fusion in treating adult spinal deformity

Adult spinal deformity (ASD) is usually rigid and requires a combined anterior–posterior approach for deformity correction. Anterior lumbar interbody fusion (ALIF) allows direct access to the disc space and placement of a large interbody graft. A larger interbody graft facilitates correction of ASD. However, an anterior approach carries significant risks. Lateral lumbar interbody fusion (LLIF) through a minimally invasive approach has recently been used for ASD. The present study was performed to evaluate the effectiveness of oblique lumbar interbody fusion (OLIF) in the treatment of ASD. We performed a retrospective study utilizing the data of 74 patients with ASD. The inclusion criteria were lumbar coronal Cobb angle > 20°, pelvic incidence (PI)–lumbar lordosis (LL) mismatch > 10°, and minimum follow–up of 2 years. Patients were divided into two groups: ALIF combined with posterior spinal fixation (ALIF+PSF) (n = 38) and OLIF combined with posterior spinal fixation (OLIF+PSF) (n = 36). The perioperative spinal deformity radiographic parameters, complications, and health-related quality of life (HRQoL) outcomes were assessed and compared between the two groups. The preoperative sagittal vertical axis (SVA), LL, PI–LL mismatch, and lumbar Cobb angles were similar between the two groups. Patients in the OLIF+PSF group had a slightly higher mean number of interbody fusion levels than those in the ALIF+PSF group. At the final follow–up, all radiographic parameters and HRQoL scores were similar between the two groups. However, the rates of perioperative complications were higher in the ALIF+PSF than OLIF+PSF group. The ALIF+PSF and OLIF+PSF groups showed similar radiographic and HRQoL outcomes. These observations suggest that OLIF is a safe and reliable surgical treatment option for ASD.

Treatment of Degenerative Lumbar Scoliosis with Oblique Lumbar Interbody Fusion in Conjunction with Unilateral Pedicle Screw Fixation via the Wiltse Approach

Objective

To evaluate the clinical outcomes of oblique lumbar interbody fusion (OLIF) in conjunction with unilateral pedicle screw fixation (UPSF) via the Wiltse approach in treating degenerative lumbar scoliosis (DLS).

Methods

The article is a retrospective analysis. Twelve patients with DLS who underwent combined OLIF and UPSF between July 2017 and December 2018 were included. The study included 2 male and 10 female patients, with a mean age at the time of the operation of 67.2 ± 9.1 years. The surgical characteristics and complications were evaluated. The clinical and radiological data such as the correction of deformity, coronal and sagittal profile were analyzed.

Results

The mean follow‐up time of the study was 26.8 ± 1.8 months. At the final follow‐up, all patients who underwent combined OLIF and UPSF achieved statistically significant improvements in coronal Cobb angle (from 19.6° ± 4.8° to 6.9° ± 3.8°, P < 0.01), distance between the C7 plumb line and central sacral vertebral line (from 2.5 ± 1.7 cm to 0.9 ± 0.6 cm, P < 0.01), sagittal vertebral axis (from 4.3 ± 4.3 cm to 1.5 ± 1.0 cm, P = 0.03), lumbar lordosis (from 29.4° ± 8.6° to 40.8° ± 5.8°, P < 0.01), pelvic tilt (from 27.6° ± 10.8° to 18.3° ± 7.0°, P < 0.01), pelvic incidence‐lumbar lordosis mismatch (from 23.3° ± 10.5° to 11.9° ± 8.4°, P < 0.01), and cross‐sectional area of the dural sac (from 87.33 ± 39.41 mm² to 124.70 ± 39.26 mm², P < 0.01). The visual analogue score for back and leg pain and Oswestry Disability Index of all patients significantly improved postoperatively (P < 0.01). One case of lumbar plexus injury was found after surgery. During the follow‐up period, one patient had cage subsidence. A fusion rate of 100% and good positioning of the pedicle screws were achieved in all patients at the final follow‐up.

Conclusion

OLIF in conjunction with UPSF is a safe and effective minimally invasive procedure for correcting both coronal and sagittal deformities, as it results in an improved quality of life in patients with DLS.

Extreme Lateral Interbody Fusion for Thoracic and Thoracolumbar Disease: The Diaphragm Dilemma

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Complication profiles for lateral approaches to the spine are well established. However, the influence of level of surgery on complication rates and subtypes are less well established. To determine risk factors for complications as determined by level and surgery type in patients undergoing a lateral (retroperitoneal or retropleural approach) to the thoracolumbar spine.

METHODS

All adult patients undergoing a lateral thoracolumbar fusion with or without posterior instrumentation performed at a single institution were identified. Primary outcomes assessed were presence of complication, complication subtype, and need for reoperation. The primary independent variables were spinal level (thoracic, thoracolumbar, or lumbar) and type of surgery (discectomy or corpectomy). Categorical outcomes were compared using chi-square test. Unadjusted and adjusted odds ratios for corpectomy status were calculated to determine risk of complication by level. P < .05 was considered statistically significant.

RESULTS

A total of 165 patients aged 18 to 75 years were identified as having undergone a lateral fusion. Complication rates were 28.6%, 36.4%, and 11% for thoracic, thoracolumbar, and lumbar lateral approach fusions, respectively. Under univariate analysis, patients undergoing lateral approach in the thoracic spine group had significantly higher rates of postoperative complications than those in the lumbar group (P = .005). After adjusting for corpectomy status, there was no difference in complication rates.

CONCLUSIONS

Lateral (retroperitoneal or retropleural) approaches to the thoracic and thoracolumbar spine may be used with complication rates comparable to well-established lumbar approaches. Extent of surgery (corpectomy vs discectomy) rather than level of surgery may represent the primary driver of complications.

Managing Incomplete and Complete Thoracolumbar Burst Fractures (AO Spine A3 and A4). Results from a Prospective Single-Center Study Comparing Posterior Percutaneous Instrumentation plus Mini-Open Anterolateral Fusion versus Single-Stage Posterior Instrumented Fusion

OBJECTIVE

The treatment strategy for thoracolumbar burst fractures is still debated. The aim of this study is to evaluate clinical and radiologic outcomes of a 2-stage strategy with immediate posterior percutaneous instrumentation and delayed anterolateral fusion (group A) versus a single-stage open posterior instrumented fusion (group B).

METHODS

Demographics and clinical and surgical data of patients operated for AO Spine A3 and A4 fractures were prospectively collected. Vertebral height and deformity were evaluated before and after surgery. Visual analog scale score for back pain, Oswestry Disability Index, and 12-Item Short Form Health Survey results for quality-of-life assessment were collected during follow-up.

RESULTS

Among the 110 patients enrolled, 66 were allocated to group A and 44 to group B; the most common fractured level was T12 (34%). Postoperative complications were higher in group B, especially the wound infection rate (18% vs. 3%), and pseudomeningocele (14% vs. 0%). The 2-stage approach allowed an average long-term gain of 15.8° at the local kyphosis of fractured vertebra and 5.8° at the regional level (Cobb angle), versus 15.4° and 5.5° in group B. At 2 years follow-up, both groups showed significant functional improvements; however, the visual analog scale and Oswestry Disability Index metrics seemed more favorable for group A patients (P < 0.0001 vs. P < 0.003). A complete fusion rate was obtained in 100% of group A vs. 65% of group B.

CONCLUSIONS

Our study indicates that percutaneous instrumentation and anterior fusion or an expandable cage lead to excellent long-term clinical and radiologic outcomes with a lower complication rate and higher fusion rate than those of open posterior approaches.

Intraoperative image guidance for lateral position surgery

Recent advances in minimally invasive spine surgery techniques have precipitated the popularity of lateral position spine surgery, such as lateral lumbar interbody fusion (LLIF) and oblique lumbar interbody fusion (OLIF). Lateral position surgery offers a unique, minimally invasive approach to the lumbar spine that allows for preservation of anterior and posterior spinal elements. Traditionally, surgeons have relied upon fluoroscopy for triangulation and implant placement. Over the last decade, intraoperative 3-dimensional navigation (ION) has risen to the forefront of innovation in LLIF and OLIF. This technology utilizes intra-operative advanced imaging, such as comminuted tomography (CT), to map the patient’s 3D anatomy and allows the surgeon to accurately visualize instruments and implants in spatial relationship to the patient’s anatomy in real time. ION has the potential to improve accuracy during instrumentation, decrease operating room times, lower radiation exposure to the surgeon and staff, and increase feasibility of single-position surgery during which the spine is instrumented both laterally and posteriorly while the patient remains in the lateral decubitus position. Despite the advantages of ION, the intra-operative radiation exposure risk to patients is controversial. Future directions include continued innovation in ultra low radiation imaging (ULRI) techniques and image enhancement technology and in uses of robot-assisted navigation in single-position spine surgery.

Lateral Lumbar Interbody Fusion: Review of Surgical Technique and Postoperative Multimodality Imaging Findings

The lateral lumbar interbody fusion (LLIF) approach is a minimally invasive surgery that can be used as an alternative to traditional lumbar interbody fusion techniques. LLIF accesses the intervertebral disk through the retroperitoneum and psoas muscle to avoid major vessels and visceral organs. The exposure of retroperitoneal structures during LLIF leads to unique complications compared with other surgical approaches. An understanding of the surgical technique and its associated potential complications is necessary for radiologists who interpret imaging before and after LLIF. Preoperative imaging must carefully assess the location of anatomic structures, including major retroperitoneal vasculature, lumbar nerve roots, lumbosacral plexus, and the genitofemoral nerve, relative to the psoas muscle. Multiple imaging modalities can be used in postoperative assessment including radiographs, CT, CT myelography, and MRI. Of these, CT is the preferred modality, because it can assess a range of complications relating to both the retroperitoneal exposure and the spinal instrumentation, as well as bone integrity and fusion status. This article describes surgical approaches for lumbar interbody fusion, comparing the approaches' indications, contraindications, advantages, and disadvantages; reviews the surgical technique of LLIF and relevant anatomic considerations; and illustrates for interpreting radiologists the normal postoperative findings and potential postsurgical complications of LLIF.

Minimally Invasive Lateral Retroperitoneal Approach for Resection of Extraforaminal Lumbar Plexus Schwannomas: Operative Techniques and Literature Review

BACKGROUND

Traditional approaches for retroperitoneal lumbar plexus schwannomas involve anterior open or laparoscopic resection. For select tumors, the lateral retroperitoneal approach provides a minimally invasive alternative.

OBJECTIVE

To describe a minimally invasive lateral transpsoas approach for the resection of retroperitoneal schwannomas.

METHODS

A lateral retroperitoneal transpsoas approach was used to resect a 3.1 × 2.7 × 4.1 cm schwannoma embedded within the psoas muscle. A minimally invasive retractor system allows for appropriate visualization and complete resection with the aid of the microscope. The patient tolerated the procedure without complication and was discharged on postoperative day 2 in good condition at her neurological baseline.

RESULTS

The lateral retroperitoneal approach provides a minimally invasive alternative for select retroperitoneal schwannomas. In theory, this procedure allows for faster recovery and less blood loss compared to traditional open anterior approaches. For a subset of tumors, anterior laparoscopy may provide better access, but the lateral approach is well known to most neurosurgeons who perform lateral interbody fusions and can be easily tailored to extraforaminal tumor resection.

CONCLUSION

Retroperitoneal schwannomas pose a challenge due to their deep location. The lateral retroperitoneal approach provides a useful alternative for resection of a subset of retroperitoneal schwannomas.

Minimally invasive anterior and lateral transpsoas approaches for closed reduction of grade II spondylolisthesis: initial clinical and radiographic experience

OBJECTIVE Minimally invasive anterior and lateral approaches to the lumbar spine are increasingly used to treat and reduce grade I spondylolisthesis, but concerns still exist for their usage in the management of higher-grade lesions. The authors report their experience with this strategy for grade II spondylolisthesis in a single-surgeon case series and provide early clinical and radiographic outcomes. METHODS A retrospective review of a single surgeon's cases between 2012 and 2016 identified all patients with a Meyerding grade II lumbar spondylolisthesis who underwent minimally invasive lateral lumbar interbody fusion (LLIF) or anterior lumbar interbody fusion (ALIF) targeting the slipped level. Demographic, clinical, and radiographic data were collected and analyzed. Changes in radiographic measurements, Oswestry Disability Index (ODI), and visual analog scale (VAS) scores were compared using the paired t-test and Wilcoxon signed rank test for continuous and ordinal variables, respectively. RESULTS The average operative time was 199.1 minutes (with 60.6 ml of estimated blood loss) for LLIFs and 282.1 minutes (with 106.3 ml of estimated blood loss), for ALIFs. Three LLIF patients had transient unilateral anterior thigh numbness during the 1st week after surgery, and 1 ALIF patient had transient dorsiflexion weakness, which was resolved at postoperative week 1. The mean follow-up time was 17.6 months (SD 12.5 months) for LLIF patients and 10 months (SD 3.1 months) for ALIF patients. Complete reduction of the spondylolisthesis was achieved in 12 LLIF patients (75.0%) and 7 ALIF patients (87.5%). Across both procedures, there was an increase in both the segmental lordosis (LLIF 5.6°, p = 0.002; ALIF 15.0°, p = 0.002) and overall lumbar lordosis (LLIF 2.9°, p = 0.151; ALIF 5.1°, p = 0.006) after surgery. Statistically significant decreases in the mean VAS and the mean ODI measurements were seen in both treatment groups. The VAS and ODI scores fell by a mean value of 3.9 (p = 0.002) and 19.8 (p = 0.001), respectively, for LLIF patients and 3.8 (p = 0.02) and 21.0 (p = 0.03), respectively, for ALIF patients at last follow-up. CONCLUSIONS Early clinical and radiographic results from using minimally invasive LLIF and ALIF approaches to treat grade II spondylolisthesis appear to be good, with low operative blood loss and no neurological deficits. Complete reduction of the spondylolisthesis is frequently possible with a statistically significant reduction in pain scores.

Perioperative Factors Influencing Postoperative Satisfaction After Lateral Access Surgery for Degenerative Lumbar Spondylolisthesis

BACKGROUND

Lateral access surgery (LAS) for lumbar degenerative spondylolisthesis is a minimally invasive lumbar fusion technique which has been gaining increasing popularity in the recent years. This study aims to identify perioperative factors that influence postoperative satisfaction after LAS for lumbar degenerative spondylolisthesis.

METHODS

From August 2010 to November 2014, 52 patients with lumbar degenerative conditions (16 male: 36 female, mean age 64.0 ± 8.7 years) were prospectively recruited and underwent LAS by a single surgeon. All patients were assessed preoperatively and 2 years postoperatively with Numerical Pain Rating Scale (NPRS), Oswestry Disability Index, Short-Form 36 (SF-36) scores, North American Spine Society score for neurogenic symptoms, patient satisfaction, and expectation fulfillment. Cobb angles, global lumbar lordosis, disc heights, adjacent disc heights, fusion, and subsidence were rates assessed. Multiple linear regression performed with satisfaction as dependent variable to identify predictive independent variables.

RESULTS

Lower preoperative SF-36 general health scores (P = .03), higher NPRS leg pain scores (P = .04), and longer surgical duration (P = .02) were significant predictors of lower satisfaction (P < .05). NPRS back and leg pain decreased by 80.3 and 83.0%, respectively. Oswestry Disability Index and North American Spine Society score for neurogenic symptoms improved by 76.2 and 75.9%, respectively. Ninety percent of patients reported excellent/good satisfaction. Significant correction and maintenance of Cobb and global lumbar lordosis angles were achieved. There was significant increase in disc heights postoperatively (P = .05) and no significant difference in adjacent disc heights at 2 years (P > .05). Ninety-eight percent of patients achieved Bridwell Fusion Grade 1, and 5.8% had Marchi Grade 3 subsidence.

CONCLUSIONS

Lower preoperative SF-36 general health, higher NPRS leg pain, and longer surgical duration are predictors of lower satisfaction in patients undergoing LAS for lumbar degenerative spondylolisthesis.

LEVEL OF EVIDENCE

III.

CLINICAL RELEVANCE

Identifying preoperative predictors for postoperative clinical outcome can assist clinicians in patient education prior to operation.

Treatment of Adult Spinal Deformity with Sagittal Imbalance Using Oblique Lumbar Interbody Fusion: Can We Predict How Much Lordosis Correction Is Possible?

Study Design

Prospective, single-center study.

Purpose

The current trend of operative treatment for adult spinal deformity (ASD) is combined anterior-posterior staged surgery. When anterior surgery was first performed, oblique lumbar interbody fusion (OLIF) was employed; this method became increasing popular. This study aimed to determine the lordosis correction that can be achieved using OLIF and assess whether we can preoperatively predict the lordosis correction angle achieved using OLIF.

Overview of Literature

Many previous studies on OLIF have shown improved clinical and radiologic outcomes. With the increase in the popularity of OLIF, several surgeons have started using larger cages to attain greater lordosis correction. Moreover, some studies have reported complications of OLIF because of immoderate cage insertion. To our knowledge, this is the first prospective study that attempted to determine whether it is possible to predict the lordosis correction angle achieved with OLIF preoperatively, using fullextension lateral view (FELV).

Methods

Forty-six patients with ASD were enrolled. All the operations were performed by a single surgeon in two stages (first, anterior and second, posterior) with a 1-week interval. Radiological evaluation was performed by comparing the Cobb’s angle of the segmental and regional lordosis obtained using preoperative and postoperative simple radiography (including the FELV) and magnetic resonance imaging (MRI).

Results

Regional lordosis (L1–S1) in the whole-spine standing lateral radiograph was −3.03°; however, in the supine lateral MRI, it was 20.92°. The regional lordosis of whole-spine standing lateral and supine lateral (MRI) was significantly different. In the FELV, regional lordosis was 25.72° and that in the postoperative supine lateral (MRI) was 25.02°; these values were not significantly different.

Conclusions

Although OLIF offers many advantages, it alone plays a limited role in ASD treatment. Lordosis correction using OLIF as well as lordosis determined in the FELV was possible. Hence, our results suggest that FELV can help predict the lordosis correction angle preoperatively and thus aid the selection of the appropriate technique in the second staged operation.

Outcome After Extreme Lateral Transpsoas Approach: Corpectomies Versus Interbody Fusion

INTRODUCTION

The lateral transpsoas approach (LTPA) has gained popularity in thoracolumbar spine surgery procedures; however, there is an insufficient amount of data pertaining to motor and sensory complications that arise when a corpectomy is performed through the LTPA approach.

METHODS

Patients who underwent a corpectomy through a LTPA at a single institution between 2006 and 2016 were analyzed. Demographics, neurological outcomes, and complications were recorded. The minimum follow-up was 6 months. Univariate analysis was performed to compare demographics, surgical characteristics, complications, and outcome scores. To compare categorical variables, the χ² test was used. For continuous outcomes, simple linear regression was used. Statistical significance was set at P < 0.05.

RESULTS

A total of 166 patients were included. The patients were divided into 2 groups; LTPA without corpectomy (n = 112) versus LTPA with corpectomy (n = 54). Patients without corpectomy showed a significantly lower rate of postoperative infections compared with patients with corpectomy (3.6% vs. 22.2%; P < 0.000). A higher percentage of postoperative complications was found in patients with corpectomy (31.5% vs. 13.4%; P = 0.006). The rate of neurologic complications at the 6-month follow-up and the reoperation rate (22.7% vs. 32.4%; P = 0.256) were higher in the corpectomy group (8.9% vs. 7.4%; P = 0.741), no significant difference was found between the groups.

CONCLUSION

Patients who underwent an LTPA corpectomy have a higher risk to suffer from postoperative complications. The results at the 6-month follow-up did not significantly differ between the groups.

Perioperative complications associated with minimally invasive surgery of oblique lumbar interbody fusions for degenerative lumbar diseases in 113 patients

OBJECTIVES

To describe perioperative complications occurring during oblique lumbar interbody fusion (OLIF) assisted by a retractor system for degenerative lumbar diseases.

PATIENTS AND METHODS

The perioperative complications in 113 cases series utilizing a minimally invasive approach were recorded and analyzed. One hundred thirteen patients who received OLIF for degenerative lumbar diseases between November 2014 and February 2017 at a single center were evaluated. The most frequent diagnosis was spondylolisthesis (59 cases, 52.2%), followed by lumbar instability (24 cases, 21.2%), adjacent segmental disease (12 cases, 10.6%), adult degenerative scoliosis (11 cases, 9.8%) and discogenic low back pain (7 cases, 6.2%). One hundred thirty-four levels were treated, 88.5% one-level, 4.4% two-level, and 7.1% three-level surgeries. The most fused level was L4-5 (94 levels, 70.2%), followed by L3-4 (31 levels, 23.1%), and L2-3 (9 levels, 6.7%).

RESULTS

All perioperative complications only included adverse events related to the OLIF procedure. The most observed complications were donor-site pain (24 cases, 21.2%), followed by vertebral endplate fracture (15 cases, 13.3%), thigh numbness/pain (12 cases, 10.6%), psoas/quadriceps weakness (5 cases, 4.4%), sympathetic nerve injury (2 case, 1.8%), paralytic ileus (one case, 0.9%), segmental artery injury (one case, 0.9%), intervertebral infection (one, 0.9%), and contralateral femoral nerve palsy (one, 0.9%). All complications, including postoperative ipsilateral or contralateral thigh paresthesia, pain, and psoas/quadriceps weakness, were observed when operating at L4-L5. The incidence of complications excluding donor-site pain was 24.8% (28/113 cases). The patients with donor-site pain, thigh numbness/pain, psoas/quadriceps weakness, sympathetic nerve injury and paralytic ileus recovered within two months following surgery. The patient with intervertebral infection recovered at 3 months after surgery. One case of contralateral femoral nerve palsy recovered completely with no residual sensory or motor deficit at 6 months.

CONCLUSIONS

OLIF performed using a retractor system is a validated option to treat a wide spectrum of degenerative lumbar diseases with few perioperative complications and a quick recovery. Judicious use of this technique at the L4/5 level is recommended. Close attention to detail during the procedure can minimize complications that may be associated with the learning curve.

Lateral lumbar interbody fusion without intraoperative neuromonitoring: a single-center consecutive series of 157 surgeries

OBJECTIVE

Lateral lumbar interbody fusion (LLIF) is frequently used for anterior column stabilization. Many authors have reported that intraoperative neuromonitoring (IONM) of the lumbar plexus nerves is mandatory for this approach. However, even with IONM, the reported motor and sensory deficits are still considerably high. Thus, the authors' approach was to focus on the indication, trajectory, and technique instead of relying on IONM findings per se. The objective of this study therefore was to analyze the outcome of our large cohort of patients who underwent LLIF without IONM.

METHODS

The authors report on 157 patients included from 2010 to 2016 who underwent LLIF as an additional stabilizing procedure following dorsal instrumentation. LLIF-related complications as well as clinical outcomes were evaluated.

RESULTS

The mean follow-up was 15.9 ± 12.0 months. For 90.0% of patients, cage implantation by LLIF was the first retroperitoneal surgery. There were no cases of surgery-related hematoma, vascular injury, CSF leak, or any other visceral injury. Between 1 and 4 cages were implanted per surgery, most commonly at L2-3 and L3-4. The mean length of surgery was 92.7 ± 35 minutes, and blood loss was 63.8 ± 57 ml. At discharge, 3.8% of patients presented with a new onset of motor weakness, a new sensory deficit, or the deterioration of leg pain due to LLIF surgery. Three months after surgery, 3.5% of the followed patients still reported surgery-related motor weakness, 3.6% leg pain, and 9.6% a persistent sensory deficit due to LLIF surgery.

CONCLUSIONS

The results of this series demonstrate that the complication rates for LLIF without IONM are comparable, if not superior, to those in previously reported series using IONM. Hence, the authors conclude that IONM is not mandatory for LLIF procedures if the surgical approach is tailored to the respective level and if the visualization of nerves is performed.

Efficacy of Oblique Lateral Interbody Fusion in Treatment of Degenerative Lumbar Disease

OBJECTIVE

This study aimed to analyze the efficacy of oblique lumbar interbody fusion (OLIF) in the treatment of degenerative lumbar disease.

METHODS

Twenty-two patients with degenerative lumbar disease who underwent OLIF between October 2016 and January 2017 were included. Radiography, computed tomography, and magnetic resonance imaging were performed preoperatively and postoperatively. The cross-sectional area (CSA) of the dural sac, disk height, cross-sectional height of the intervertebral foramina, and intervertebral foramina CSA were measured. Scores from the visual analog scale, Oswestry Disability Index, and Medical Outcome Study 36-Item Short-Form Health Survey, obtained preoperatively, 1 week and 3 months postoperatively, and at the final follow-up, were compared.

RESULTS

Forty-five segments were fused in 22 patients using OLIF. Postoperatively, CSA increased from 0.79 ± 0.32 cm2 to 1.40 ± 0.37 cm2, disk height increased from 0.67 ± 0.24 cm to 1.15 ± 0.31 cm, cross-sectional height increased from 1.51 ± 0.25 cm to 2.01 ± 0.31 cm, and intervertebral foramina increased from 1.11 ± 0.28 cm2 to 1.86 ± 0.38 cm2 (P <0.01). The visual analog scale, Oswestry Disability Index, and 36-Item Short-Form Health Survey scores of all patients significantly improved postoperatively (P < 0.05). There were no complications involving injuries to spinal nerves, great vessels, abdominal viscera, or ureters. Only 1 patient experienced injury to the psoas major.

CONCLUSIONS

OLIF is a safe and effective minimally invasive procedure for the treatment of degenerative lumbar disease.

Limitations and complications of minimally invasive spinal surgery in adult deformity

Minimally invasive spine (MIS) surgery has rapidly progressed from simple short segment fusions to large adult deformity corrections, with radiographic and clinical outcomes as good as those of open surgery. Anterior longitudinal ligament release (ALLR) and anterior column realignment (ACR) have been key advancements in the ability to correct deformity using MIS techniques. However, patient selection and appropriate preoperative workup is critical to obtain good outcomes and for complication avoidance. Despite favorable outcomes in spinal deformity surgery, MIS techniques are limited in (I) pronounced cervical or thoracic deformity; (II) patients with prior fusion mass; and (III) severe sagittal imbalance necessitating Schwab 5 osteotomy or higher. Guidelines for proper patient selection are needed to guide MIS spine surgeons in choosing the right candidate.

Outcomes of oblique lateral interbody fusion for degenerative lumbar disease in patients under or over 65 years of age

Background

Oblique lateral interbody fusion (OLIF) offers the solution to problems of anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF). However, OLIF technique for degenerative spinal diseases of elderly patients has been rarely reported. The objective of this study was to determine the clinical and radiological results of OLIF technique for degenerative spinal diseases in patients under or over 65 years of age.

Methods

Sixty-three patients who underwent OLIF procedure were enrolled, including 29 patients who were less than 65 years of age and 34 patients who were over 65 years of age. Fusion rate, change of disc height and lumbar lordotic angle, Numeric Rating Scale (NRS), return to daily activity, patient’s satisfaction rate (PSR), and Oswestry disability index (ODI) were used to assess clinical and functional outcomes.

Results

The mean NRS scores for back and leg pain decreased, respectively, from 4.6 and 5.9 to 2.3 and 1.8 in the group A (less than 65 years) and from 4.5 and 6.8 to 2.6 and 2.2 in the group B (over 65 years) at the final follow-up period. The mean ODI scores improved from 48.4 to 24.0% in the group A and from 46.5 to 25.2% in the group B at the final follow-up period. In both groups, the NRS and ODI scores significantly changed preoperatively to postoperatively (p <  0.001). However, statistical analysis yielded no significant difference in postoperative NRS/ODI scores between two groups. In both groups, the changes in the disc height, segmental lordosis, and fusion rate between the preoperative and postoperative periods were significant. The amount of change between preoperative and postoperative disc height, segmental lordosis, and whole lumbar lordosis demonstrated significant intergroup differences (p <  0.05). Overall perioperative complications occurred in 8 of 29 (27.6%) patients in the group A and in 10 of 34 (29.4%) patients in the group B. In both groups, the major complication incidence was 0 and 3%, respectively.

Conclusion

Although there was the slightly high incidence of complication associated with high rate of co-morbidities in elderly patients, OLIF for degenerative lumbar diseases in elderly patients showed favorable clinical and radiological outcomes.

Transcranial Motor Evoked Potential Alarm Criteria to Predict Foot Drop Injury During Lumbosacral Surgery

STUDY DESIGN

A retrospective cohort analysis.

OBJECTIVE

This study aims to investigate whether waveform alterations in transcranial motor evoked potentials (TCMEPs) can reliably predict postoperative foot drop.

SUMMARY OF BACKGROUND DATA

Nerve injury leading to foot drop is a potential complication of lumbosacral surgery. Very limited data exist on the use of intraoperative TCMEPs to identify iatrogenic foot drop.

METHODS

We retrospectively reviewed neuromonitoring data from 130 consecutive spine surgeries with instrumentation involving L4-S1. TCMEP waveform analysis included amplitude (A), area under the curve (AUC), latency (L), and duration (D). Patient outcomes were correlated with neuromonitoring results. Intraoperative alert criteria were established on the basis of observed intraoperative changes.

RESULTS

Three patients developed severe foot drop with a muscle weakness functional grade ranging from 0/5 to 3/5. Two patients developed a mild foot drop with functional grade 4/5. Twenty-three patients had preoperative weakness in an L5 distribution. One-hundred two patients who had neither preoperative nor postoperative neurological complications served as a control group. Amplitude significantly decreased in patients with a severe postoperative deficit (P = 0.005) as did AUC and duration (P < 0.05). Intraoperative alert criteria defined as a >65% decrease in AUC resulted in a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 100%, 91.4%, 12%, and 100%, respectively. When defining an alert criteria as a >50% decrease in amplitude, sensitivity, specificity, PPV, and NPV were 100%, 87.9%, 8.8%, and 100%, respectively.

CONCLUSION

Reduction of TCMEP waveform associated with postoperative severe foot drop can be detected during lumbar surgery. Other waveform parameters such as AUC may predict foot drop better than the amplitude. Additional examinations in larger samples of foot drops are needed to validate these alert threshold findings.

LEVEL OF EVIDENCE

4.

Utility of Intraoperative Neuromonitoring for Lumbar Pedicle Screw Placement Is Questionable: A Review of 9957 Cases

STUDY DESIGN

A retrospective database study.

OBJECTIVE

The goal of this study was to (1) evaluate the trends in the use of electromyography (EMG) for instrumented posterolateral lumbar fusions (PLFs) in the United States and (2) assess the risk of neurological injury following PLFs with and without EMG.

SUMMARY OF BACKGROUND DATA

Neurologic injuries from iatrogenic pedicle wall breaches during screw placement are known complications of PLFs. The routine use of intraoperative neuromonitoring (ION) such as EMG during PLF to improve the accuracy and safety of pedicle screw implantation remains controversial.

METHODS

A retrospective review was performed using the PearlDiver Database to identify patients who had PLF surgery with and without EMG for lumbar disorders from years 2007 to 2015. Patients undergoing concomitant interbody fusions or spinal deformity surgery were excluded. Demographic trends and risk of neurological injuries were assessed.

RESULTS

During the study period, 2007 to 2015, 9957 patients underwent PLFs. Overall, EMG was used in 2495 (25.1%) of these patients. There was a steady increase in the use of EMG from 14.9% in 2007 to 28.7% in 2009, followed by a steady decrease to 21.9% in 2015 (P < 0.0001). The risk of postoperative neurological injuries following PLFs was 1.35% (134/9957) with a risk of 1.36% (34/2495) with EMG and 1.34% (100/7462) without EMG (P = 0.932). EMG is used most commonly for PLFs in the Southern part of the United States.

CONCLUSION

In this retrospective national database review, we found that there was a steady increase in the routine use of EMG for PLFs followed by a steady decline. Regional differences were observed in the utility of EMG for PLFs. The risk of neurological complications following PLF in the absence of spinal deformity is low and the routine use of EMG for PLF may not decrease the risk.

LEVEL OF EVIDENCE

4.

Minimally Invasive Direct Lateral Transpsoas Approach for the Resection of a Lumbar Plexus Schwannoma: Technique Report

Objective  Traditional techniques for resection of lumbar plexus tumors have been associated with approach-related morbidity. We describe a case utilizing a minimally invasive transpsoas lateral access approach to resect a retroperitoneal tumor of the lumbar plexus.

Methods  We report a case with an extradural retroperitoneal schwannoma of the L4 nerve root that was treated with a minimally invasive direct lateral transpsoas approach using atraumatic tissue dilators and an expandable tubular retractor. The use of directional and continuous electromyographic monitoring was critical in locating the plexus and positioning the retractor immediately anterior to the tumor.

Results  The patient tolerated the procedure well without postoperative complications. The operative approach was direct and intraoperative blood loss was negligible. The patient demonstrated improved left leg strength and ambulation and resolution of paresthesias.

Conclusions  A minimally invasive direct lateral transpsoas access approach is an effective technique to safely and adequately resect extradural retroperitoneal lumbar plexus tumors.

Novel Transabdominal Motor Action Potential (TaMAP) Neuromonitoring System for Spinal Surgery

INTRODUCTION

Minimally invasive lateral lumbar interbody fusion (LLIF) approaches to the lumbar spine reduce patient morbidity compared to anterior or posterior alternatives. This approach, however, decreases direct anatomical visualization, creating the need for highly sensitive and specific neurophysiological monitoring. We seek to determine feasibility in 'transabdominal motor action potential (TaMAP)' monitoring as an assessment for the integrity of the neural elements during lateral-approach surgeries to the lumbar spine.

METHODS

Cathode and anode leads were placed on the posterior and anterior surfaces of two porcine subjects. Currents of varying degrees were transmitted across, from front to back. Motor responses were monitored and recorded by needle electrodes in specific distal muscle groups of the lower extremity. Lastly, the cathode and anode were placed anterior and posterior to the chest wall and stimulated to the maximum of 1500 mA to determine any effect on cardiac rhythm.

RESULTS

Responses were seen by measuring vertical height differences between peaks of corresponding evoked potentials. Recruitment began at 200 mA in the lower extremities. Stimulation at 450 mA recruited a reliable and distinguishable electrographic response from most muscle groups. Responses were recorded and reliably measured and increased in proportion to the graduation of transabdominal stimulation current; no responses were seen in the arms or face. 1500 mA across the chest wall failed to stimulate or induce cardiac arrhythmia on repeated stimulation, indicating safety of stimulation.

CONCLUSION

TaMAPs seen in the animal model provide a potential alternative to standard transcranial motor evoked potentials done in the lateral approach of LLIFs. TaMAP recordings in most muscle groups were recordable and reliable, though some muscle groups failed to stimulate. Safety of transabdominal motor evoked potentials was confirmed in this porcine study. Future studies should examine TaMAPs reliability in detecting compressive lesions of nerve roots and peripheral nerves.

Lateral Lumbar Interbody Fusion in Ambulatory Surgery Centers: Patient Selection and Outcome Measures Compared With an Inhospital Cohort

STUDY DESIGN

Comparative analysis.

OBJECTIVE

To evaluate the safety and outcomes of moving lateral lumbar interbody fusion (LLIF) surgeries to an outpatient setting.

SUMMARY OF BACKGROUND DATA

LLIF has been popularized as a less invasive lumbar fusion surgery as an alternative approach to anterior lumbar interbody fusions, posterior lateral interbody fusion, and transforaminal lateral interbody fusion (TLIF). Lumbar fusions have been traditionally performed in a hospital setting because of the potential blood loss, length of surgery, and need for longer recovery. There is a movement to transition spine surgeries to outpatient settings with many benefits afforded by less invasive techniques and technologies.

METHODS

The medical records of 70 consecutive patients with prospectively collected data were retrospectively reviewed. Two cohort groups, inpatients (40 patients) and outpatients (30 patients), were created. Patient demographics, risk factors, and body mass index (BMI) were evaluated to determine inclusion criteria for study.

RESULT

A total of 34 males and 36 females, age range (31-71) average 59.3 ± 2.3 years. Average BMI was 29.6 ± 1.1 kg/m. The most common level operated on being L3-L4 in both groups (63%). Mean preoperative inpatient Oswestry Disability Index (ODI) increased from 48.5 ± 3.0 to 55.5 ± 3.2 compared with outpatient preoperative ODI means reduced from 45.2 ± 5.1 to 39.1 ± 4.6. There was no statistically significant change in VAS scores between groups. There was however significant improvement in outpatient preoperative VAS scores from 7.3 ± 0.5 to 4.1 ± 0.5, P = 0.045.

CONCLUSION

The outcomes of the present study have shown that patients who had LLIF performed in the outpatient setting had statistically significant improvement in ODI scores compared with the inpatient setting (P = 0.013). Fusion was achieved in all patients and there was no evidence of implant failure or subsidence. Complications were transient in both settings. We conclude that outpatient LLIF improves patients' outcomes with similar safety profile as the hospital setting.

LEVEL OF EVIDENCE

3.

Systematic Review of Thigh Symptoms after Lateral Transpsoas Interbody Fusion for Adult Patients with Degenerative Lumbar Spine Disease

BACKGROUND

Lateral transpsoas interbody fusion (LTIF) is a minimally invasive technique for achieving lumbar spinal fusion. While it has many advantages over open techniques it carries with it a distinct set of risks, most commonly post-operative ipsilateral thigh pain, weakness and sensory disturbances. It is vital for both the surgeon and patient to understand the risks for and outcomes of injury associated with this procedure. We conducted a systematic review of the literature to evaluate the incidence, risks, and long-term clinical outcomes of post-operative thigh symptoms in patients treated with LTIF.

METHODS

We conducted a search of MEDLINE, EMBASE, CINAHL, Scopus, Web of Science and the Cochrane Collaboration Library, using keywords and MeSH terms, for English-language literature published through September 2014, as well as reference lists from key articles. Studies were then manually filtered to retrieve articles that met inclusion criteria. We were interested in studies that reported postoperative lower extremity symptoms after LTIF, such as pain, weakness and changes in sensation. The strength of evidence was determined based on precepts outlined by the Grades of Recommendation Assessment, Development and Evaluation Working Group (GRADE).

RESULTS

A total of 392 articles were initially retrieved, with 24 ultimately meeting criteria for inclusion. The incidence of any post-operative thigh symptom varied, ranging as high as 60.7%, with 9.3% of patients experiencing a motor deficit related to direct nerve injury. Several studies reported cases of persistent symptoms at 6 months follow up. Additionally, inclusion of the L4-5 disc space and a longer duration of surgery were both identified as risks for developing postoperative thigh symptoms.

CONCLUSION

The risk of postoperative thigh symptoms after LTIF is high. Thigh pain, paresthesias and weakness were the most commonly reported symptoms. While most patients' symptoms resolved by 6 months follow up, several studies reported patients with symptoms persistent as far as 12 months removed from surgery. Surgery at the L4-5 disc space and longer surgical duration place the patient at greater risk for developing postoperative and long-term thigh symptoms.

Outcomes of Two Different Techniques Using the Lateral Approach for Lumbar Interbody Arthrodesis

Study Design Retrospective cohort study. Objective To determine the short-term outcomes of two different lateral approaches to the lumbar spine. Methods This was a retrospective review performed with four fellowship-trained spine surgeons from a single institution. Two different approach techniques were identified. (1) Traditional transpsoas (TP) approach: dissection was performed through the psoas performed using neuromonitored sequential dilation. (2) Direct visualization (DV) approach: retractors are placed superficial to the psoas followed by directly visualized dissection through psoas. Outcome measures included radiographic fusion and adverse event (AE) rate. Results In all, 120 patients were identified, 79 women and 41 men. Average age was 64.2 years (22 to 86). When looking at all medical and surgical AEs, 31 patients (25.8%) had one or more AEs; 22 patients (18.3%) had a total of 24 neurologically related AEs; 15 patients (12.5%) had anterior/lateral thigh dysesthesias; 6 patients (5.0%) had radiculopathic pain; and 3 patients (2.5%) had postoperative weakness. Specifically, for neurologic AEs, the DV group had a rate of 28.0% and the TP group had a rate of 14.2% (p < 0.18). When looking at the rate of neurologic AEs in patients undergoing single-level fusions only, the DV group rate was 28.6% versus 10.2% for the TP group (p < 0.03). Conclusion Overall, 18.3% of patients sustained a postoperative neurologic AE following lateral interbody fusions. The TP approach had a statistically lower rate of neurologic-specific AE for single-level fusions.

Mini-Open Anterior Retroperitoneal Lumbar Interbody Fusion: Oblique Lateral Interbody Fusion for Degenerated Lumbar Spinal Kyphoscoliosis

Study Design

Prospective case series.

Purpose

To examine the clinical efficacy of mini-open anterior retroperitoneal lumbar interbody fusion: oblique lateral interbody fusion (OLIF) for degenerated lumbar spinal kyphoscoliosis.

Overview of Literature

The existing surgical procedures for the treatment of spinal kyphotic deformity, including Smith-Petersen osteotomy, pedicle subtraction osteotomy, and vertebral column resection procedures, are invasive in nature. Extreme lateral interbody fusion to provide less invasive treatment of the deformity has been reported, but complications including spinal nerve and psoas muscle injury have been noted. In the current study, we examined the clinical efficacy and complications of OLIF for degenerated lumbar spinal kyphoscoliosis.

Methods

Twelve patients with degenerated lumbar spinal kyphoscoliosis were examined. All patients underwent OLIF surgery (using a cage and bone graft from the iliac crest) with open pedicle screws or percutaneous pedicle screws, without real-time monitoring by electromyography. Visual analog scale score and Oswestry disability index were evaluated before and 12 months after surgery, and fusion rate at OLIF cage, correction of the deformity, total blood loss, and surgical complications were also evaluated.

Results

Pain scores significantly improved after surgery (p<0.05). Fusion rate was found to be 90%, balance parameters also improved after surgery (p<0.05), and average total blood loss was less than 350 mL. There was no spinal nerve, major vessel, peritoneal, or urinary injury, or breakage of instrumentation.

Conclusions

OLIF surgery for degenerated lumbar spinal kyphoscoliosis is less invasive than other procedures and good surgical results were produced without major complications.

Relationship between psoas muscle dimensions and post operative thigh pain. A possible preoperative evaluation factor

INTRODUCTION

Advanced intraoperative neuromonitoring (IONM) is used to attenuate postoperative complications and side effects of extreme lateral interbody fusion (XLIF). Specific factors relate to the presence of postoperative injury are not well understood. This study aims to identify intraoperative variables with correlations to new postoperative anterior thigh/groin sensory changes.

METHODS

Twenty-nine patients with various degenerative lumbar conditions were treated with XLIF at a single institution. Mean age was 59 years, 69% were female, and 21% had undergone previous lumbar surgery. A total of 47 levels (mean 1.6, range 1-3) were treated with XLIF. Supplemental pedicle screw and rod fixation was used in 24 patients (83%). Dynamically-evoked electromyography was used in all cases. Analysis of baseline demographic and treatment variables were performed at a per patient basis (n = 29), whereas analysis of intraoperative variables were performed at a per levels treated basis (n = 47).

RESULTS

Within 24 hours postoperative, 10 (34%) patients experienced anterior thigh/groin sensory changes (4 reported pain only, 5 reported pain plus other sensory changes, and 1 paresthesia without pain). Symptom resolution occurred at 1 month postoperative for 4 patients, at 3 months postoperative for 2 patients. At 3 months postoperative, 6 patients had complete symptom resolution, 3 patients had symptom improvements, and 1 patient had no change in perioperative symptoms. Psoas dimension in the lateral-latero direction were significantly smaller for patients with postoperative sensory changes (p = 0.025), and similarly, patients with postoperative sensory changes had a significantly higher ratio of psoas muscle in the anterior-posterior to lateral-latero directions (p = 0.026).

CONCLUSIONS

In addition to IONM, MRI evaluation of psoas shape, position, and dimension may be of help in preoperative planning of a safe XLIF access and eventually, predict those cases with higher risk of approach-related post-operative events.

Mini-Open Anterior Retroperitoneal Lumbar Interbody Fusion: Oblique Lateral Interbody Fusion for Lumbar Spinal Degeneration Disease

PURPOSE

Surgery for lumbar spinal degeneration disease is widely performed. While posterior decompression and fusion are popular, anterior lumbar interbody fusion (ALIF) is also used for treatment. Extreme lateral interbody fusion (XLIF) is commonly used for noninvasive ALIF; however, several complications, such as spinal nerve and psoas muscle injury, have been reported. In the current study, we examined the clinical efficacy and complications of oblique lateral interbody fusion (OLIF) for lumbar spinal degeneration disease.

MATERIALS AND METHODS

Thirty-five patients with degenerated spondylolisthesis, discogenic pain, and kyphoscoliosis were examined. All patients underwent OLIF surgery (using a cage and bone graft from the iliac crest) with or without posterior decompression, without real-time electromyography monitoring. Posterior screws were used in all patients. Visual analog scale (VAS) score and Oswestry Disability Index (ODI) were evaluated before and 6 months after surgery. Surgical complications were also evaluated.

RESULTS

Pain scores significantly improved after surgery, compared to those before surgery (p<0.05). There was no patient who underwent revision surgery. There was no spinal nerve, major vessel, peritoneal, or urinary injury. Few patients showed symptoms from psoas invasion.

CONCLUSION

OLIF surgery produced good surgical results without any major complication.

Combined anterior lumbar interbody fusion and instrumented posterolateral fusion for degenerative lumbar scoliosis: indication and surgical outcomes

Background

Traditional approaches to deformity correction of degenerative lumbar scoliosis include anterior-posterior approaches and posterior-only approaches. Most patients are treated with posterior-only approaches because the high complication rate of anterior approach. Our purpose is to compare and assess outcomes of combined anterior lumbar interbody fusion and instrumented posterolateral fusion with posterior alone approach for degenerative lumbar scoliosis with spinal stenosis.

Methods

Between November 2002 and November 2011, a total of 110 patients with degenerative spinal deformity and curves measuring over 30°were included. Of the 110 patients who underwent surgery, 56 underwent the combined anterior and posterior approach and 54 underwent posterior surgery at our institution. The following were the indications of anterior lumbar interbody fusion: (1) rigid or frank lumbar kyphosis, (2) anterior or lateral bridged traction osteophytes, (3) gross coronal and sagittal deformity or imbalance, and (4) severe disc space narrowing that is not identifiable when performing posterior or transforaminal lumbar interbody fusion. The clinical outcomes were evaluated using the Oswestry disability index and the visual analog scale. The status of fusion were assessed according to the radiographic findings.

Results

All patients received clinical and radiographic follow-up for a minimum of 24 months, with an average follow-up of 53 months (range, 26–96 months). At the final follow-up, the mean ODI score improved from 28.8 to 6.4, and the mean back/leg VAS, from 8.2/5.5 to 2.1/0.9 in AP group and the mean ODI score improved from 29.1 to 6.2, and the mean back/leg VAS, from 9.0/6.5 to 2.3/0.5 in P group. The mean scoliotic angle changed from 41.3° preoperatively to 9.3°, and the lumbar lordotic angle, from 3.1° preoperatively to 35.7°in AP group and the mean scoliotic angle from 38.5 to 21.4 and the lumbar lordotic angle from 6 to 15.8 in P group. There were significant differences in sagittal (P = 0.009) and coronal (P = 0.02) plane correction between the two groups.

Conclusions

Our results demonstrate that combined anterior lumbar interbody fusion and instrumented posterolateral fusion for adult degenerative lumbar scoliosis effectively improves sagittal and coronal plane alignment than posterior group and both group were effectively improves clinical scores.

Minimally invasive procedures on the lumbar spine

Degenerative disease of the lumbar spine is a common and increasingly prevalent condition that is often implicated as the primary reason for chronic low back pain and the leading cause of disability in the western world. Surgical management of lumbar degenerative disease has historically been approached by way of open surgical procedures aimed at decompressing and/or stabilizing the lumbar spine. Advances in technology and surgical instrumentation have led to minimally invasive surgical techniques being developed and increasingly used in the treatment of lumbar degenerative disease. Compared to the traditional open spine surgery, minimally invasive techniques require smaller incisions and decrease approach-related morbidity by avoiding muscle crush injury by self-retaining retractors, preventing the disruption of tendon attachment sites of important muscles at the spinous processes, using known anatomic neurovascular and muscle planes, and minimizing collateral soft-tissue injury by limiting the width of the surgical corridor. The theoretical benefits of minimally invasive surgery over traditional open surgery include reduced blood loss, decreased postoperative pain and narcotics use, shorter hospital length of stay, faster recover and quicker return to work and normal activity. This paper describes the different minimally invasive techniques that are currently available for the treatment of degenerative disease of the lumbar spine.

Mini posterior lumbar interbody fusion with presacral screw stabilization in early lumbosacral instability

BACKGROUND

Surgical options for the management of early lumbosacral spondylolisthesis and degenerative disc disease with instability vary from open lumbar interbody fusion with transpedicular fixation to a variety of minimal access fusion and fixation procedures. We have used a combination of micro discectomy and axial lumbosacral interbody fusion with presacral screw fixation to treat symptomatic patients with lumbosacral spondylolisthesis or lumbosacral degenerative disc disease, which needed surgical stabilization. This study describes the above technique along with analysis of results.

MATERIALS AND METHODS

Twelve patients with symptomatic lumbosacral (L5-S1) instability and degenerative lumbosacral disc disease were treated by micro discectomy and interbody fusion using presacral screw stabilization. Patients with history of bowel, bladder dysfunction and local anorectal diseases were excluded from this study. Postoperatively all patients were evaluated neurologically and radiologically for screw position, fusion and stability. Oswestry disability index was used to evaluate results.

RESULTS

We had nine females and three males with a mean age of 47.33 years (range 26-68 years). Postoperative assessment revealed three patients to have screw placed in anterior 1/4(th) of the 1(st) sacral body, in rest nine the screws were placed in the posterior 3/4(th) of sacral body. At 2 years followup, eight patients (67%) showed evidence of bridging trabeculae at bone graft site and none of the patients showed evidence of instability or implant failure.

CONCLUSION

Presacral screw fixation along with micro discectomy is an effective procedure to manage early symptomatic lumbosacral spondylolisthesis and degenerative disc disease with instability.

Fusion via transpsoas lateral approach: considerations and initial results

OBJECTIVE: To present some technical considerations about interbody fusion by direct lateral retroperitoneal transpsoas approach and its initial results. METHODS: Non-randomized prospective study of 14 patients undergoing interbody fusion via lateral approach, with evaluation of initial results and complications. RESULTS: We collected and analyzed data from 14 patients with a total of 27 levels operated. The average operative time was 146 minutes and blood loss was on average less than 50 ml. Ten patients required supplemental percutaneous fixation with pedicle screws. VAS scores for the lumbar region and lower limbs and ODI had significant improvement in the postoperative period. There was an associated case of postoperative infection and thromboembolism that required reoperations. CONCLUSION: This technique has revolutionized the care of patients requiring fusion of T6-7 to L4-5. Following the five basic steps and using intraoperative monitoring, this technique is safe and reproducible with encouraging clinical results and low rate of serious complications.

Mini-open approach for direct lateral lumbar interbody fusion

Study Design

Retrospective analysis.

Purposes

To introduce the mini-open lateral approach for the anterior lumbar interbody fusion (ALIF), and to investigate the advantages, technical pitfalls and complications by providing basic knowledge on extreme lateral interbody fusion (XLIF) or direct lumbar interbody fusion (DLIF).

Overview of Literature

Recently, minimally invasive lateral approach for the lumbar spine is revived and receiving popularity under the name of XLIF or DLIF by modification of mini-open method when using the sequential tubular dilator and special expandable retractor system.

Methods

Seventy-four patients who underwent surgery by the mini-open lateral approach from September 2000 to April 2008 with various disease entities were included. Blood losses, operation times, incision sizes, postoperative time to mobilization, length of hospital stays, technical problems and complications were all analyzed.

Results

The blood losses and operation times of patients who underwent simple ALIF were 61.2 mL and 86 minutes for one level, 107 mL and 106 minutes for two levels, 250 mL and 142.8 minutes for three levels, and 400 mL and 190 minutes for four levels of fusion. The incision sizes were on average 4.5 cm for one level, 6.3 cm for two levels, 8.5 cm for three levels and 10.0 cm for four levels of fusion. The complications were retroperitoneal hematoma (2 cases), pneumonia (1 case) and transient lumbosacral plexus palsy (3 cases).

Conclusions

Trials of mini-open lateral approach would be helpful before the trial of XLIF or DLIF. However, special attention is required for complications such as transient lumbosacral plexus palsy.