Comparative Study of the Difference of Perioperative Complication and Radiologic Results: MIS-DLIF (Minimally Invasive Direct Lateral Lumbar Interbody Fusion) Versus MIS-OLIF (Minimally Invasive Oblique Lateral Lumbar Interbody Fusion).

STUDY DESIGN: Retrospective observatory analysis. OBJECTIVE: The purpose of this study was to compare the incidence of perioperative complication, difference of cage location, and sagittal alignment between minimally invasive oblique lateral lumbar interbody fusion (MIS-OLIF) and MIS-direct lateral lumbar interbody fusion (DLIF) in the cases of single-level surgery at L4-L5. SUMMARY OF BACKGROUND DATA: MIS-DLIF using tubular retractor has been used for the treatment of lumbar degenerative diseases; however, blunt transpsoas dissection poses a risk of injury to the lumbar plexus. As an alternative, MIS-OLIF uses a window between the prevertebral venous structures and psoas muscle. MATERIALS AND METHODS: A total of 43 consecutive patients who underwent MIS-DLIF or MIS-OLIF for various L4/L5 level pathologies between November 2011 and April 2014 by a single surgeon were retrospectively reviewed. A complication classification based on the relation to surgical procedure and effect duration was used. Perioperative complications until 3-month postoperatively were reviewed for the patients. Radiologic results including the cage location and sagittal alignment were also assessed with plain radiography. RESULTS: There were no significant statistical differences in perioperative parameters and early clinical outcome between 2 groups. Overall, there were 13 (59.1%) approach-related complications in the DLIF group and 3 (14.3%) in the OLIF group. In the DLIF group, 3 (45.6%) were classified as persistent, however, there was no persistent complication in the OLIF group. In the OLIF group, cage is located mostly in the middle 1/3 of vertebral body, significantly increasing posterior disk space height and foraminal height compared with the DLIF group. Global and segmental lumbar lordosis was greater in the DLIF group due to anterior cage position without statistical significance. CONCLUSIONS: In our report of L4/L5 level diseases, the OLIF technique may decrease approach-related perioperative morbidities by eliminating the risk of unwanted muscle and nerve manipulations. Using orthogonal maneuver, cage could be safely placed more posteriorly, resulting in better disk and foraminal height restoration.

Safety of Lateral Interbody Fusion Surgery without Intraoperative Monitoring.

AIM: Oblique lateral interbody fusion (OLIF) is a minimally invasive surgical method that can provide an access to the lumbar spine without direct dissection of psoas muscle and the need for intraoperative neuromonitoring (IOM) is questionable. The aim of this study was to examine and document the transient and persistent perioperative complications in patients who underwent OLIF for degenerative lumbar disease without IOM. MATERIAL AND METHODS: A total of 129 consecutive patients who were diagnosed as degenerative spinal disease from L1 to S1 and underwent mini-open OLIF were identified and retrospectively reviewed. All patients were classified as two groups; non-IOM group and IOM group. According to the relation to surgical procedure, the complications were divided into two groups; "procedurerelated" and "procedure-unrelated". Based on the effect of duration, the complications were defined as "transient" where the symptom is relieved within 30 days postoperatively, and "persistent" where the symptom remains for more than 30 days postoperatively. RESULTS: The study groups comprised 57 cases in the IOM group and 72 in the non-IOM group. The complication rate was 24.6% (transient; 17.6%, persistent; 7.0%) in the IOM group and 29.2% (transient; 25.0%, persistent; 4.2%) in the non-IOM group. The incidence of postoperative leg symptoms related to lumbar plexus and/or psoas muscle injury was 6 transient and 3 persistent in the IOM group (overall 15.3%), and 12 transient and 3 persistent in the non-IOM group (overall 20.9%). CONCLUSION: Mini-open OLIF can be safely carried out without the aid of IOM.

Minimally Invasive Transforaminal Lumbar Interbody Fusion Using Banana-Shaped and Straight Cages: Radiological and Clinical Results from a Prospective Randomized Clinical Trial.

BACKGROUND: In minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), cage type and position play important roles in fusion achievement and sagittal alignment correction. However, no prospective randomized comparison of the results using different types of cage has been reported to date. OBJECTIVE: To compare the radiological and clinical outcomes of unilateral MIS-TLIF using 2 types of cage. METHODS: All candidates for single-level MIS-TLIF were randomized into banana-shaped cage and straight-cage groups. Plain radiographs and computed tomography scans were used for assessment of cage positions, fusion status, disc height, segmental lordotic angle, cage subsidence, and pelvic parameters. Clinical outcome was assessed using visual analog scale and Oswestry Disability Index scores. RESULTS: Forty-four and 40 consecutive patients were operated on using banana-shaped and straight cages, respectively. Cage position was more anterior and lateral in the straight-cage group and more medial and posterior in the banana-shaped cage group. Solid fusion was achieved in 95.2% and 96.6% of the 2 groups, respectively, at 12 mo. The change in disc height and segmental lordotic angle postoperatively was significantly greater in the banana-shaped cage group. The incidence of subsidence during follow-up was significantly higher in the banana-shaped cage group (P < .04). Clinically, the visual analog scale and Oswestry Disability Index scores decreased significantly after surgery in both groups, with no significant difference between the groups. CONCLUSION: Our preliminary outcomes suggest that the subsidence rate may be higher using banana-shaped cages in MIS-TLIF, possibly due to their more medial final position.

Endoscope-assisted oblique lumbar interbody fusion for the treatment of cauda equina syndrome: a technical note.

OBJECTIVE: The goal of this paper was to describe how endoscope-assisted oblique lumbar interbody fusion (OLIF) could remove huge lumbar disc herniation (HLDH) manifested with cauda equina syndrome (CES). METHODS: In this study, the authors made an attempt to treat CES with a direct endoscopic decompression through the OLIF corridor and performed OLIF in two patients with HLDH. RESULTS: Two patients with HLDH were successfully treated using OLIF with spinal endoscopic discectomy. We achieved direct ventral decompression by removal of herniated disc fragments located beyond the posterior longitudinal ligament (PLL). All preoperative symptoms in two patients improved postoperatively. CONCLUSIONS: Endoscope-assisted oblique lumbar interbody fusion (OLIF) could successfully achieve neural decompression without additional posterior decompression in CES and could be used as an alternative treatment in well selected cases.

Surgical Outcomes of Anterior Cervical Fusion Using Deminaralized Bone Matrix as Stand-Alone Graft Material: Single Arm, Pilot Study.

OBJECTIVE: To investigate the safety and efficacy of demineralized bone matrix (DBM) as a bone graft substitute for anterior cervical discectomy and fusion (ACDF) surgery. METHODS: Twenty consecutive patients treated with ACDF using stand-alone polyestheretherketone (PEEK) cages (Zero-P) with DBM(CGDBM100) were prospectively evaluated with a minimum of 6 months of follow-up. Radiologic efficacy was evaluated with a 6-point scoring method for osseous fusion using plain radiograph and computed tomogrpahy scans. Clinical efficacy was evaluated using the visual analogue scale (VAS), Owestry disability index (ODI), and short-form health questionnaire-36. The safety of the bone graft substitute was assessed with vital sign monitoring and a survey measuring complications at each follow-up visit. RESULTS: There were significant improvements in VAS and ODI scores at a mean 6-month follow-up. Six months after surgery, solid fusion was achieved in all patients. Mean score on the 6-point scoring system was 5.1, and bony formation was found to score at least 4 points in all patients. There was no case with implant-related complications such as cage failure or migration, and no complications associated with the use of CGDBM100. CONCLUSION: ACDF using CGDBM100 demonstrated good clinical and radiologic outcomes. The fusion rate was comparable with the published results of traditional ACDF. Therefore, the results of this study suggest that the use of a PEEK cage packed with DBM for ACDF is a safe and effective alternative to the gold standard of autologous iliac bone graft.

Minimally Invasive Transforaminal Lumbar Interbody Fusion at L5-S1 through a Unilateral Approach: Technical Feasibility and Outcomes.

Background. Minimally invasive spinal transforaminal lumbar interbody fusion (MIS-TLIF) at L5-S1 is technically more demanding than it is at other levels because of the anatomical and biomechanical traits. Objective. To determine the clinical and radiological outcomes of MIS-TLIF for treatment of single-level spinal stenosis low-grade isthmic or degenerative spondylolisthesis at L5-S1. Methods. Radiological data and electronic medical records of patients who underwent MIS-TLIF between May 2012 and December 2014 were reviewed. Fusion rate, cage position, disc height (DH), disc angle (DA), disc slope angle, segmental lordotic angle (SLA), lumbar lordotic angle (LLA), and pelvic parameters were assessed. For functional assessment, the visual analogue scale (VAS), Oswestry disability index (ODI), and patient satisfaction rate (PSR) were utilized. Results. A total of 21 levels in 21 patients were studied. DH, DA, SLA, and LLA had increased from their preoperative measures at the final follow-up. Fusion rate was 86.7% (18/21) at 12 months' follow-up. The most common cage position was anteromedial (15/21). The mean VAS scores for back and leg pain mean ODI scores improved significantly at the final follow-up. PSR was 88%. Cage subsidence was observed in 33.3% (7/21). Conclusions. The clinical and radiologic outcomes after MIS-TLIF at L5-S1 in patients with spinal stenosis or spondylolisthesis are generally favorable.

Endoscopic Radiofrequency Ablation of the Sacroiliac Joint Complex in the Treatment of Chronic Low Back Pain: A Preliminary Study of Feasibility and Efficacy of a Novel Technique.

Background. Radiofrequency ablation (RFA) is a less invasive technique for treatment of sacroiliac joint (SIJ) pain. Objective. To evaluate the feasibility and efficacy of endoscope-guided RFA for the treatment of CLBP from the SIJ complex. Methods. In this retrospective study, the medical records of 17 patients who underwent endoscope-guided RFA of the SIJ complex were reviewed. A bipolar radiofrequency probe was used to lesion the posterior capsule of the SIJ as well as the lateral branches of S1, S2, S3, and the L5 dorsal ramus in multiple locations. We visualized the ablation area using endoscope. We assessed visual analogue scale (VAS) and the Oswestry disability index (ODI) preoperatively, immediately postop, and at 1-, 3-, and 6-month postop outpatient clinic visits. Patient satisfaction of the procedure was assessed in percentages. Results. The mean duration of operation was 20 to 50 minutes. The mean VAS and the ODI scores decreased significantly immediately after the procedure and were kept significantly lower than baseline levels during the follow-up periods. No complications occurred perioperatively and during the follow-up periods. 88.6% of patients were satisfied with the procedure. Conclusions. Our preliminary results suggest that endoscope-guided RFA may be alternative option to treat CLBP secondary to SIJ complex.

Comparative Study of Posterior Lumbar Interbody Fusion via Unilateral and Bilateral Approaches in Patients with Unilateral Leg Symptoms.

OBJECTIVE: We investigated the clinical and radiological advantages of unilateral laminectomy in posterior lumbar interbody fusion (PLIF) procedure comparing with bilateral laminectomy, under the same procedural condition including bilateral instrumentation and insertion of two cages, in patients with degenerative lumbar disease with unilateral leg symptoms. METHODS: We retrospectively reviewed 124 consecutive cases of PLIF via unilateral or bilateral approach between January 2006 and April 2010. In 80 cases (bilateral group), two cages were inserted via bilateral laminectomy, and in 44 cases (unilateral group), via unilateral laminectomy. The average follow-up duration was 29.5 months. The clinical outcomes were evaluated with the Visual Analogue Scale (VAS) and the Oswestry disability index (ODI). The fusion rates and disc space heights were determined by dynamic standing radiographs and/or computed tomography. Operative times, intra-operative and post-operative blood losses and hospitalization periods were also evaluated. RESULTS: In clinical evaluation, the VAS and ODI scores showed excellent outcomes in both groups. There were no significant differences in term of fusion rate, but the perioperative blood loss and the operative time of the unilateral group were lower than that of the bilateral group. CONCLUSION: Unilateral laminectomy can minimize the operative time and perioperative blood loss in PLIF procedure. However, the different preoperative disc height between two groups is a limitation of this study. Despite this limitation, solid fusion and satisfactory symptomatic improvement could be achieved uniquely by our surgical method. This surgical method can be an alternative surgical technique in patients with unilateral leg pain.