High neurological complication rates for extreme lateral lumbar interbody fusion and related techniques: A review of safety concerns

A retrospective case-control study on the effectiveness of preoperative diffusion tensor imaging for mitigating nerve injury in extreme lateral interbody fusion surgery

BACKGROUND CONTEXT

Extreme Lateral Interbody Fusion (XLIF) has been established as an effective treatment for degenerative disorders of the lumbar spine. Nevertheless, there is a potential risk of lumbar plexus damage associated with XLIF, especially during surgeries at the L4-5 segment. Diffusion Tensor Imaging (DTI) evaluates the directional diffusion of water molecules in tissue, providing a more intricate depiction of internal tissue microstructure compared to conventional MRI techniques. The capability of DTI sequences to elucidate the 3-dimensional interplay between lumbar nerve pathways and adjacent musculoskeletal structures, potentially reducing the incidence of nerve injury complications related to XLIF, remains to be established.

PURPOSE

This study evaluates the effectiveness of preoperative Diffusion Tensor Imaging (DTI) in reducing neurological complications after Extreme Lateral Interbody Fusion (XLIF) surgeries at the L4-5 level, focusing on the interaction between lumbar nerves and the psoas major muscle.

STUDY DESIGN

Retrospective case-control study.

PATIENT SAMPLE

The study included 128 patients undergoing XLIF surgery for degenerative disorders at the L4-5 segment: 68 in the traditional group and 62 in the DTI group.

OUTCOME MEASURES

The study assessed Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) scores, along with complication rates. It also documented psoas major muscle morphology and its correlation with nerve pathways.

METHODS

A retrospective analysis of 128 patients undergoing XLIF surgery for degenerative disorders at the L4-5 segment between February 2020 and August 2022 was conducted. The cohort was divided into a traditional group (68 patients) receiving presurgery MRI scans to identify surgical entry points at the intervertebral space midpoint (Zones II-III junction) and a DTI group (62 patients) who additionally underwent preoperative DTI to customize entry points. The study evaluated VAS and ODI scores, complication rates, psoas major muscle morphology, and its interaction with nerve pathways.

RESULTS

The traditional group uniformly chose the Zone II-III junction for entry. In contrast, the DTI group's entry points varied. Postoperative follow-up revealed significant improvements in VAS and ODI scores in both groups. However, the DTI group experienced fewer immediate postoperative complications such as thigh pain, numbness, and motor disturbances. The study also noted a ventral shift in nerve positioning in patients with elevated psoas muscles.

CONCLUSIONS

Preoperative DTI effectively maps the relationship between the psoas major muscle and lumbar nerves. Tailoring surgical entry points based on DTI results significantly reduces the risk of nerve damage in XLIF surgeries. The study underscores the importance of recognizing variability in lumbar nerve pathways due to differing psoas muscle morphologies, highlighting a higher risk of nerve injury in patients with elevated psoas muscles during XLIF procedures.

Efficacy and Safety of the Extreme Lateral Interbody Fusion (XLIF) Technique in Spine Surgery: Meta-Analysis of 1409 Patients

(1) Objectives: The objective of this study was to quantify the exact clinical-radiological efficacy and safety of the extreme lateral interbody fusion (XLIF) technique in spinal surgery; (2) Methods: A meta-analysis was performed using PubMed, Embase, Scopus, and Cochrane Collaboration Library. Studies focusing on patients surgically treated with XLIF were included. The outcomes were as follows: visual analog scale (VAS) and Oswestry disability index (ODI), radiological outcomes, and adverse events. Cohort studies and case series were also included. Clinical outcomes were assessed at 12 months of age. Data were combined using Review Manager 5.4 and WebPlotDigitizer 13.1.4; (3) Results: Nineteen studies with a pool of 1409 patients were included in this meta-analysis. Leg pain VAS and back pain VAS significantly improved at 12 months (SMD 2.75, 95% CI 0.59-4.90; SMD 4.54, 95% CI 1.39-7.69). ODI showed significant improvement (MD 32.51, 95% CI 24.01-41.00) at 12 months. Disc height increased significantly (SMD -2.73, 95% CI -3.58 to -1.88). Lumbar lordosis and segmental lordosis were significantly corrected postoperatively (MD -2.44, 95% CI -3.45 to -1.43; MD -2.55, 95% CI -3.61 to -1.48). The fusion rates at 12 months ranged from 85.0% to 93.3%. The most frequent complications were transient neurological conditions (2.2%), hardware failure (1.9%), and transient pain (1.8%). The most frequent serious complications were nerve root injury (1.0%), gastrointestinal impairment (0.7%), and vertebral fractures (0.6%); (4) Conclusions: This is the first meta-analysis of the specific use of XLIF in spinal surgery. This study demonstrates that the XLIF technique in spine surgery is associated with good clinical and radiological results and a low complication rate.

Position of lumbar plexus nerves in the psoas major: Application to transpsoas approaches to the lumbar spine

Far lateral interbody fusion is a minimally invasive operating technique. However, the incidence of postoperative neurological complications is high, and some scholars question its safety. This study describes the neuroanatomical features and spatial orientation within the psoas major. Ten embalmed male cadavers were selected and the left psoas major was dissected. Subsequently, the area between the anterior and the posterior edges of the vertebral body was divided into three equal zones. The nerves' distribution, number, and spatial orientation of the L1/2 to L4/5 intervertebral discs were examined. A caliper was used to measure the diameter of the nerve. The safety zone of the L1/2 intervertebral disc level is located in zone I and II, the relative safe zones of the L2/3 and L4/5 intervertebral discs are located in zone II, and the safety zone of the L3/4 intervertebral disc level is located in the caudal side of zone II. The genitofemoral nerve exits the psoas major in a co-trunk or two-branch pattern, and its exit point was distributed between the L3 and L4 vertebral bodies, mainly at the L3/4 intervertebral disc level. The sympathetic ganglia in the psoas major appeared only in zone I at the L2/3 intervertebral disc level. This is a systematic anatomical study that describes the nerves of the psoas major. Spine surgeons can use this study-which consists of important clinical implications-for preoperative planning, and thus, reduce the risk of nerve injury during surgery.

Establishing a Standardized Clinical Consensus for Reporting Complications Following Lateral Lumbar Interbody Fusion

Background and Objectives: Mitigating post-operative complications is a key metric of success following interbody fusion. LLIF is associated with a unique complication profile when compared to other approaches, and while numerous studies have attempted to report the incidence of post-operative complications, there is currently no consensus regarding their definitions or reporting structure. The aim of this study was to standardize the classification of complications specific to lateral lumbar interbody fusion (LLIF). Materials and Methods: A search algorithm was employed to identify all the articles that described complications following LLIF. A modified Delphi technique was then used to perform three rounds of consensus among twenty-six anonymized experts across seven countries. Published complications were classified as major, minor, or non-complications using a 60% agreement threshold for consensus. Results: A total of 23 articles were extracted, describing 52 individual complications associated with LLIF. In Round 1, forty-one of the fifty-two events were identified as a complication, while seven were considered to be approach-related occurrences. In Round 2, 36 of the 41 events with complication consensus were classified as major or minor. In Round 3, forty-nine of the fifty-two events were ultimately classified into major or minor complications with consensus, while three events remained without agreement. Vascular injuries, long-term neurologic deficits, and return to the operating room for various etiologies were identified as important consensus complications following LLIF. Non-union did not reach significance and was not classified as a complication. Conclusions: These data provide the first, systematic classification scheme of complications following LLIF. These findings may improve the consistency in the future reporting and analysis of surgical outcomes following LLIF.

Contralateral lower limb radiculopathy by extraforaminal disc herniation following oblique lumbar interbody fusion in degenerative lumbar disorder: illustrative cases

BACKGROUND

Contralateral lower limb radiculopathy is a potential early complication of oblique lumbar interbody fusion (OLIF) in degenerative lumbar disorders. Among several pathologies related to contralateral radiculopathy following OLIF, extraforaminal disc herniation during the OLIF procedure is very rare.

OBSERVATIONS

Case 1 is a 68-year-old male underwent L4-5 and L5-6 OLIF for recurrent lumbar canal stenosis-expressed right leg pain and muscle weakness after surgery. Case 2 is a 76-year-old female on whom L4-5 OLIF was performed for L4 degenerative spondylolisthesis and who presented right leg pain and numbness postoperatively. In both patients, OLIF cages were inserted into the posterior part of the disc space or obliquely and the extraforaminal extruded disc compressed opposite exiting nerve roots (L5 root in case 1 and L4 root in case 2) as shown on magnetic resonance imaging (MRI). Surgical decompression with discectomy was required for pain relief and neurological improvement in both cases.

LESSONS

When emerging from new-onset opposite limb radiculopathy attributed to the OLIF procedure, extraforaminal disc herniation should be considered a potential pathology and MRI is useful for early diagnosis and selecting a subsequent management, including surgery.

L4/5 accessibility for extreme lateral interbody fusion (XLIF): a radiological study

Introduction

Potential advantages of the Extreme Lateral Interbody Fusion (XLIF) approach are smaller incisions, preserving anterior and posterior longitudinal ligaments, lower blood loss, shorter operative time, avoiding vascular and visceral complications, and shorter length of stay. We hypothesize that not every patient can be safely treated at the L4/5 level using the XLIF approach. The objective of this study was to radiographically (CT-scan) evaluate the accessibility of the L4/5 level using a lateral approach, considering defined safe working zones and taking into account the anatomy of the superior iliac crest.

Methods

Hundred CT examinations of 34 female and 66 male patients were retrospectively evaluated. Disc height, lower vertebral endplate (sagittal and transversal), and psoas muscle diameter were quantified. Accessibility to intervertebral space L4/5 was investigated by simulating instrumentation in the transverse and sagittal planes using defined safe zones.

Results

The endplate L5 in the frontal plane considering defined safe zones in the sagittal and transverse plane (Zone IV) could be reached in 85 patients from the right and in 83 from the left side. Through psoas split, the safe zone could be reached through psoas zone II in 82 patients from the right and 91 patients from the left side. Access through psoas zone III could be performed in 28 patients from the right and 32 patients from the left side. Safe access and sufficient instrumentation of L4/5 through an extreme lateral approach could be performed in 76 patients of patients from the right and 70 patients from the left side.

Conclusion

XLIF is not possible and safe in every patient at the L4/5 level. The angle of access for instrumentation, access of the intervertebral disc space, and accessibility of the safe zone should be taken into account. Preoperative imaging planning is important to identify patients who are not suitable for this procedure.

Comparison of Posterior Pedicle Screw Fixation and Lateral Fixation in the Extreme Lateral Interbody Fusion in Lumbar Degenerative Disease Patients with Osteopenia or Osteoporosis

OBJECTIVE

Nowadays, with the increasing proportion of osteoporosis in patients with lumbar degenerative diseases, doctors are facing the choice of intraoperative internal fixation methods. The purpose of this study was to compare and assess the clinical results of posterior bilateral pedicle screw fixation and lateral fixation in the extreme lateral interbody fusion (XLIF) in patients with osteopenia or osteoporosis.

METHODS

The retrospective review was performed on 67 degenerative lumbar diseases patients with osteopenia or osteoporosis who underwent XLIF in our hospital from January 2018 to July 2021. Patients in this study were classified into lateral screw (LS) group, lateral self-locking plate (LP) group, and bilateral pedicle screw (BPS) group. The functional evaluation factors containing Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) of leg pain, and VAS of low back pain, radiological factors such as disc height (DH), lumbar lordotic (LL) angle, segmental lordotic (SL) angle, cage subsidence degree and interbody fusion degree were compared.

RESULTS

Primary outcomes: no differences were observed with regards to the incidence of complications among LS, LP and BS group (P < 0.05). The JOA and leg pain VAS were significantly improved after operation (P < 0.05) and all groups demonstrated similar improvements in the leg pain VAS and JOA score (P > 0.05). When comparing VAS of leg pain and JOA scores, no differences were identified among LS, LP and BPS groups (P > 0.05). There are four thigh sensory complaint, one hip flexor weakness and one thigh pain occurred and no death was observed. There were significantly better DH, LL angle, SL angle, cage subsidence degree and interbody fusion degree in the BPS group than in LS and LP groups 1 year after surgery (P < 0.05). The DH loss ratio, LL angle loss ratio, SL angle loss ratio in the BPS group was significantly lower than in the LP and LS groups (P < 0.05). The 12-month SL angle improvement rate in the BPS group was significantly higher than in the LP and LS groups (20.20 ± 14.69, 0.73 ± 4.68, 6.20 ± 12.31, P < 0.05).

SECONDARY OUTCOMES

the BPS patients had significantly worse intraoperative blood loss and operation time than LS and LP patients (P < 0.05).

CONCLUSION

In lumbar diseases patients with osteopenia or osteoporosis, the bilateral pedicle screw fixation has better orthopedic effect than lateral internal fixation, and can better maintain the stability of the spine in the long-term follow-up, which is a better choice in XLIF surgery.

Efficacy and safety of a modified lateral lumbar interbody fusion in L4-5 lumbar degenerative diseases compared with traditional XLIF and OLIF: a retrospective cohort study of 156 cases

BACKGROUND

The authors designed a modified lateral lumbar interbody fusion (LLIF) procedure named as XOLIF and compared the efficacy and safety with traditional LLIF procedures.

METHODS

Patients were divided into XLIF, OLIF, and XOLIF group according to the surgical approach. Cases of psoas major and vascular space stenosis, psoas major muscle elevation, psoas major muscle hypertrophy, and high iliac crest were recorded. Basic information, composition ratio of specific cases, Visual analog scale (VAS), Oswestry Disability Index (ODI), interbody fusion rate and complications were compared between the 3 groups.

RESULTS

The study included 156 cases of L4-5 LLIF. There was no statistical difference in age, gender, BMI among the three groups. Cases with stenosis between psoas muscle and artery accounted for 11.8 and 18.4% of the XLIF and XOLIF group, respectively, while no case of this type had undergone OLIF surgery, the difference was statistically significant (P < 0.05). The proportions of high iliac crest cases in the OLIF and XOLIF group were 12.5 and 18.4%, respectively, while the XLIF group with vertical approach is not suitable for cases with high iliac crest. The postoperative VAS and ODI of the three groups were significantly improved compared with those before operation. There were 51 cases (32.7%) of complications including 21cases in XLIF group, 20 cases in OLIF Group and 10 cases in XOLIF group. XOLIF group has more advantages in reducing lumbar plexus injury and the risk of vascular injury.

CONCLUSIONS

XOLIF showed good clinical efficacy and technical advantages with a low incidence of intraoperative and postoperative complications, especially in the specific cases.

Oblique lumbar interbody fusion in management of lumbar degenerative spinal stenosis in Chinese population

Purpose:

The purpose of this study was to assess the outcomes of a cohort of local Chinese patients who underwent oblique lumbar interbody fusion (OLIF) surgery for lumbar degenerative diseases.

Methods:

We adopted a minimally invasive anterior approach to the lumbar spine through retroperitoneal access. In the first part of the surgery, a 3- to 5-cm left lateral incision over the abdomen was made guided by imaging. L2–L5 disc space was approached via the corridor between the left psoas muscle and the great vessels. A specially designed interbody cage filled with bone substitute was utilized for interbody fusion. In the second part of the surgery, posterior instrumentation with or without decompression, was performed in a prone position. Efficacy and safety of the surgery were studied.

Results:

A total of 60 patients with the mean age of 68 years underwent OLIF at 83 surgical levels. Their mean operative time was 79 min, and the average blood loss was 84 ml for the OLIF part. The mean length of hospital stay was 5.5 days. Based on plain computed tomography scan obtained at post-operative 6 months, successful fusion was achieved in 82 of the 83 surgical levels. The Oswestry Disability Index for low back pain had a mean reduction of 22.3% after 6 months. Specific complications observed include transient thigh pain or numbness, retroperitoneal hematoma, post-operative ileus and Bone Morphogenetic Protein (BMP) osteolysis. None of the patients experienced infection, symptomatic pseudo-arthrosis, hardware failure, vascular injury, nerve injury, ureteral injury, bowel injury, incisional hernia or death.

Conclusion:

OLIF is an effective procedure to treat lumbar spinal stenosis and spondylolisthesis with excellent fusion rate and good functional outcome. Complications specific to this procedure are not uncommon, but majority are minor and self-recovery. Proper training is required to minimize potential surgical risks.

Localization of the Lumbar Plexus in the Psoas Muscle: Considerations for Avoiding Lumbar Plexus Injury during the Transpsoas Approach

Introduction

Transpsoas lumbar spine surgery is minimally invasive and has very good corrective effects. However, approach-side nerve complications delay post-operative rehabilitation. We anatomically investigated the localization of the lumbar plexus running in the psoas muscle.

Methods

We examined 27 formalin-fixed cadavers. The left-sided psoas muscle was extracted and cut parallel to the intervertebral disc at the L2/3, L3/4, and L4/5 disc levels. Using digitized photographs, we calculated the ratio of the distance from the front edge of the psoas muscle to the center of the lumbar plexus in the anteroposterior diameter of the psoas muscle (%). Then, we calculated the ratio of the distance from the lateral edge of the psoas muscle to the center of the lumbar plexus in the lateral diameter of the psoas muscle (%).

Results

The anterior-posterior lumbar plexus localization was 74.5 at L2/3, 74.7 at L3/4, and 81.2 at L4/5. There was a significant difference between L2/3 and L4/5 and between L3/4 and L4/5, but not between L2/3 and L3/4 (P=0.02, 0.01, and 0.94, respectively). The lateral and medial lumbar plexus localization was 85.4 at L2/3, 83.9 at L3/4, and 77.7 at L4/5. There was a significant difference between L2/3 and L4/5 and between L3/4 and L4/5, but not between L2/3 and L3/4 (P=0.01, 0.04, and 0.41, respectively).

Conclusions

The lumbar plexus was localized in the posterior one-third and medial one-third of the psoas muscle and moved to a posterolateral location at L4/5. To avoid neuropathy, consider the psoas muscle's position relative to that of the intervertebral disc. It is essential to understand lumbar plexus localization in the psoas muscle when looking directly at this muscle to enter the pricking point or route with a lower risk of nerve damage.

Novel Implementation of Extreme Lateral Interbody Fusion to Avoid Intraoperative Lumbar Plexus Injury: Technical Note and Preliminary Results

BACKGROUND

This study modified the traditional extreme lateral lumbar interbody fusion (XLIF) surgery and was intended to reduce the approach related to lumbar plexus injury.

METHODS

The patients receiving a new modified XLIF for treatment of lumbar degenerative diseases since September 2017 in our hospital were retrospectively collected. Postoperative additional symptoms of leg numbness, pain, or weakness were recorded as lumbar plexus nerve injury. Intraoperative electromyographic monitoring was recorded during surgery to evaluate the safety of the modified entry point. The visual analog scale and Oswestry Disability Index were adopted to evaluate the postoperative clinical efficacy. Modified MacNab criteria were introduced to evaluate the patients' satisfaction 12 months after surgery. The preoperative and postoperative intervertebral height, foraminal height, and lumbar lordotic angle were measured. Repeated measurement variance analysis was used for comparison of clinical and imaging indexes in various periods. P < 0.05 indicated statistical difference.

RESULTS

Fifty-nine patients were finally included in the retrospective study. The intraoperative average blood loss and operation time were 70 mL (40-130 mL) and 77.90 ± 13.65 minutes. The average follow-up time was 18 months. Postoperative visual analog scale and Oswestry Disability Index were significantly decreased compared with those before the operation. The intervertebral height and foraminal height were dramatically higher than those before surgery. No lumbar plexus injury occurred.

CONCLUSIONS

The initial result was optimistic in reducing lumbar plexus injury and obtaining good clinical efficacy. We need to further expand the sample size and carry out a comparative study to observe the advantages and disadvantages of modified XLIF.

Review of Risks and Complications of Extreme Lateral Interbody Fusion (XLIF)

Background

Extreme lateral interbody fusions (XLIF) and Minimally Invasive (MIS) XLIF were developed to limit the vascular injuries associated with anterior lumbar interbody fusion (ALIF), and minimize the muscular/ soft tissue trauma attributed to transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF), and posterolateral lumbar fusion (PLF).

Methods

Nevertheless, XLIF/MIS XLIF pose significant additional risks and complications that include; multiple nerve injuries (e.g. lumbar plexus, ilioinguinal, iliohypogastric, genitofemoral, lateral femoral cutaneous, and subcostals (to the anterior abdominal muscles: abdominal oblique), and sympathectomy), major vascular injuries, bowel perforations/postoperative ileus, seromas, pseudarthrosis, subsidence, and reoperations.

Results

The risks of neural injury with XLIF/MIS XLIF (up to 30-40%) are substantially higher than for TLIF, PLIF, PLF, and ALIF. These neural injuries included: lumbar plexus injuries (13.28%); new sensory deficits (0-75% (21.7%-40%); permanent 62.5%); motor deficits (0.7-33.6%-40%); iliopsoas weakness (9%-31%: permanent 5%), anterior thigh/groin pain (12.5-34%), and sympathectomy (4%-12%). Additional non-neurological complications included; subsidence (10.3%-13.8%), major vascular injuries (0.4%), bowel perforations, recurrent seroma, malpositioning of the XLIF cages, a 45% risk of cage-overhang, pseudarthrosis (7.5%), and failure to adequately decompress stenosis. In one study, reviewing 20 publications and involving 1080 XLIF patients, the authors observed "Most (XLIF) studies are limited by study design, sample size, and potential conflicts of interest."

Conclusion

Many new neurological deficits and other adverse events/complications are attributed to MIS XLIF/ XLIF. Shouldn't these significant risk factors be carefully taken into consideration before choosing to perform MIS XLIF/XLIF?

Many Intraoperative Monitoring Modalities Have Been Developed To Limit Injury During Extreme Lateral Interbody Fusion (XLIF/MIS XLIF): Does That Mean XLIF/MIS XLIF Are Unsafe?

Background:

Extreme lateral interbody fusions (XLIF) and Minimally Invasive (MIS) XLIF pose significant risks of neural injury to the; lumbar plexus, ilioinguinal, iliohypogastric, genitofemoral, lateral femoral cutaneous, and subcostal nerves. To limit these injuries, many intraoperative neural monitoring (IONM) modalities have been proposed.

Methods:

Multiple studies document various frequencies of neural injuries occurring during MIS XLIF/XLIF: plexus injuries (13.28%); sensory deficits (0-75%; permanent 62.5%); motor deficits (0.7-33.6%; most typically iliopsoas weakness (14.3%-31%)), and anterior thigh/groin pain (12.5-25%.-34%). To avoid/limit these injuries, multiple IONM techniques have been proposed. These include; using finger electrodes during operative dissection, employing motor evoked potentials (MEP), eliminating (no) muscle relaxants (NMR), and using “triggered” EMGs.

Results:

In one study, finger electrodes for XLIF at L4-L5 level for degenerative spondylolisthesis reduced transient postoperative neurological symptoms from 7 [38%] of 18 cases (e.g. without IONM) to 5 [14%] of 36 cases (with IONM). Two series showed that motor evoked potential monitoring (MEP) for XLIF reduced postoperative motor deficits; they, therefore, recommended their routine use for XLIF. Another study demonstrated that eliminating muscle relaxants during XLIF markedly reduced postoperative neurological deficits/thigh pain by allowing for better continuous EMG monitoring (e.g. NMR no muscle relaxants). Finally, a “triggered” EMG study” reduced postoperative motor neuropraxia, largely by limiting retraction time.

Conclusion:

Multiple studies have offered different IONM techniques to avert neurological injuries following MIS XLIF/XLIF. Does this mean that these procedures (e.g. XLIF/MIS XLIF) are unsafe?

Short-term outcomes of lateral lumbar interbody fusion without decompression for the treatment of symptomatic degenerative spondylolisthesis at L4-5

OBJECTIVE Recently, authors have called into question the utility and complication index of the lateral lumbar interbody fusion procedure at the L4-5 level. Furthermore, the need for direct decompression has also been debated. Here, the authors report the clinical and radiographic outcomes of transpsoas lumbar interbody fusion, relying only on indirect decompression to treat patients with neurogenic claudication secondary to Grade 1 and 2 spondylolisthesis at the L4-5 level. METHODS The authors conducted a retrospective evaluation of 18 consecutive patients with Grade 1 or 2 spondylolisthesis from a prospectively maintained database. All patients underwent a transpsoas approach, followed by posterior percutaneous instrumentation without decompression. The Oswestry Disability Index (ODI) and SF-12 were administered during the clinical evaluations. Radiographic evaluation was also performed. The mean follow-up was 6.2 months. RESULTS Fifteen patients with Grade 1 and 3 patients with Grade 2 spondylolisthesis were identified and underwent fusion at a total of 20 levels. The mean operative time was 165 minutes for the combined anterior and posterior phases of the operation. The estimated blood loss was 113 ml. The most common cage width in the anteroposterior dimension was 22 mm (78%). Anterior thigh dysesthesia was identified on detailed sensory evaluation in 6 of 18 patients (33%); all patients experienced resolution within 6 months postoperatively. No patient had lasting sensory loss or motor deficit. The average ODI score improved 26 points by the 6-month follow-up. At the 6-month follow-up, the SF-12 mean Physical and Mental Component Summary scores improved by 11.9% and 9.6%, respectively. No patient required additional decompression postoperatively. CONCLUSIONS This study offers clinical results to establish lateral lumbar interbody fusion as an effective technique for the treatment of Grade 1 or 2 degenerative spondylolisthesis at L4-5. The use of this surgical approach provides a minimally invasive solution that offers excellent arthrodesis rates as well as favorable clinical and radiological outcomes, with low rates of postoperative complications. However, adhering to the techniques of transpsoas lateral surgery, such as minimal table break, an initial look-and-see approach to the psoas, clear identification of the plexus, minimal cranial caudal expansion of the retractor, mobilization of any traversing sensory nerves, and total psoas dilation times less than 20 minutes, ensures the lowest possible complication profile for both visceral and neural injuries even in the narrow safe zones when accessing the L4-5 disc space in patients with degenerative spondylolisthesis.

Lateral Lumbar Interbody Fusion Revisited: Complication Avoidance and Outcomes with the Mini-Open Approach

OBJECTIVE

To discuss lessons learned from an initial lateral lumbar interbody fusion (LLIF) experience with a focus on evolving surgical technique, complication avoidance, and new motor and sensory outcomes after implementation of a modified surgical approach.

METHODS

A retrospective analysis of a prospectively collected series of all patients undergoing LLIF by the senior author (A.D.L.) from January 2010 to January 2018 after implementation of a modified surgical mini-open technique, compared with previously reported institutional results with the originally recommended percutaneous technique. LLIF-specific complications examined included groin/thigh sensory dysfunction, flank bulge/pseudohernia, psoas-pattern weakness, and femoral nerve injury.

RESULTS

The incidence (19%, n = 98 patients) of groin/thigh sensory dysfunction in our cohort was significantly lower than that of the historical control (60%, n = 59) (P < 0.0001). The incidence of abdominal flank bulge/pseudohernia (2.0%, n = 98 patients) in our cohort was improved but not significantly lower than that of the historical control (4.2%, n = 118) (P = 0.36). The incidence of psoas-pattern weakness (3.1%, n = 98) in our cohort was significantly lower than that of the historical control (23.7%, n = 59) (P = 0.0001). The incidence of femoral nerve injury (0%, n = 98 patients) in our cohort was improved but was not significantly lower than that of the historical control (1.7%, n = 118) (P = 0.20).

CONCLUSIONS

The adoption of an exclusive mini-open muscle-splitting approach with first-look inspection of the lumbosacral plexus nerve elements may improve motor and sensory outcomes in general and the incidence of postoperative groin/thigh sensory dysfunction and psoas-pattern weakness in particular.

Extreme lateral lumbar interbody fusion: Do the cons outweigh the pros?

BACKGROUND

Major factors prompted the development of minimally invasive (MIS) extreme lateral interbody fusion (XLIF; NuVasive Inc., San Diego, CA, USE) for the thoracic/lumbar spine. These include providing interbody stabilization and indirect neural decompression while avoiding major visceral/vessel injury as seen with anterior lumbar interbody fusion (ALIF), and to avert trauma to paraspinal muscles/facet joints found with transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF), and posterior-lateral fusion techniques (PLF). Although anticipated pros of MIS XLIF included reduced blood loss, operative time, and length of stay (LOS), they also included, higher fusion, and lower infection rates. Unanticipated cons, however, included increased morbidity/mortality rates.

METHODS

We assessed the pros and cons (e.g., risks, complications, comparable value/superiority/inferiority, morbidity/mortality) of MIS XLIF vs. ALIF, TLIF, PLIF, and PLF.

RESULTS

Pros of XLIF included various biomechanical and technical surgical advantages, along with multiple cons vs. ALIF, TLIF, PLIF, and PLF. For example, XLIF correlated with a considerably higher frequency of major neurological deficits vs. other constructs; plexus injuries 13.28%, sensory deficits 0-75% (permanent in 62.5%), motor deficits 0.7-33.6%, and anterior thigh pain 12.5-25%. XLIF also disproportionately contributed to other major morbidity/mortality; sympathectomy, major vascular injuries (some life-ending others life-threatening), bowel perforations, and seromas. Furthermore, multiple studies documented no superiority, and the potential inferiority of XLIF vs. ALIF, TLIF, PLIF, and PLF.

CONCLUSION

Reviewing the pros of XLIF (e.g. radiographic, technical, biomechanical) vs. the cons (inferiority, increased morbidity/mortality) vs. ALIF, TLIF, PLIF, and PLF, we question whether XLIF should remain part of the lumbar spinal surgical armamentarium.