Transforaminal Lateral Interbody Fusion Research Articles

238. Interbody spacers and instability: is there a difference in subsidence and range of motion between various cages for osteotomy techniques?

BACKGROUND CONTEXT Several types of spine osteotomy techniques have been described to maintain sagittal alignment, varying regarding degree of deformity correction and invasiveness. Intradiscal osteotomy (IDO) is an alternative osteotomy technique for correcting thoracolumbar deformity. Lordotic interbody spacers provide anterior column support and act as a fulcrum around which an osteotomy can be reduced. Partial removal of the posterior endplate during IDO may increase subsidence risk. PURPOSE The purpose of this cadaveric study was to compare the biomechanical stability of bilateral IDO with static and expandable oblique interbody spacers to that of standard Smith-Petersen osteotomy (SPO) with transforaminal lateral interbody fusion (TLIF) using a static, banana-shaped spacer, pre- and postsubsidence. STUDY DESIGN/SETTING Biomechanical cadaveric study PATIENT SAMPLE N/A OUTCOME MEASURES N/A METHODS Eighteen cadaveric functional spine units (FSU) were divided into three equal groups (n=6): SPO-TLIF, bilateral IDO and static cage (sIDO), or bilateral IDO and expandable cage (eIDO). Bilateral pedicle screws were placed proximally and distally for all specimens. Subsidence was created by cyclically loading between 400N and 1200N compression for 20000 cycles at 2Hz, and was defined as the amount of implant settling between the first 1200N cycle and last 1200N cycle. Range of motion (ROM) was captured for flexion/extension (FE), lateral bending (LB), and axial rotation (AR), pre- and postsubsidence. RESULTS ROM in FE, LB, and AR was similar for all three groups, with no significant differences in motion pre- or post-subsidence (p>.05). The eIDO group had the largest loss of stability following subsidence, with motion increasing by 111.9±50.7% in FE, 91.4±42.6% in LB, and 65.5±29.9% in AR. Motion following subsidence was significantly higher than pre-subsidence for eIDO for all three bending planes (p=.003). sIDO motion increased by 103.0±104.3% in FE, 70.3±71.4% in LB, and 73.9±72.8% in AR. SPO-TLIF motion increased by 42.0±33.9% in FE, 27.7±20.1% in LB, and 19.4±17.8% in AR. Motion following subsidence was significantly higher than pre-subsidence for SPO-TLIF for LB (p=.037). CONCLUSIONS In this cadaveric model of a single FSU, IDO with both static and expandable interbodies showed similar biomechanical stability to SPO-TLIF both pre- and postsubsidence. Motion in the eIDO group significantly increased following subsidence in all three bending modes, while sIDO did so in none, and SPO-TLIF did so in only LB. This may be due to larger amounts of subsidence in the eIDO group. Expandable spacers in the eIDO group may have been overexpanded, causing endplate damage upon reducing the osteotomy. Further studies are required to elucidate clinical significance. FDA DEVICE/DRUG STATUS RISE (Globus Medical Inc.) (Not approved for this indication), SUSTAIN (Globus Medical Inc.) (Not approved for this indication), SIGNATURE (Globus Medical Inc.) (Not approved for this indication)

Analysis of Spino-Pelvic Parameters and Segmental Lordosis with L5-S1 Oblique Lateral Interbody Fusion at the Bottom of a Long Construct in Circumferential Minimally Invasive Surgical Correction of Adult Spinal Deformity

Lateral interbody fusion (LIF) is an effective adjuvant for circumferential minimally invasive surgery (CMIS) treatment of adult spinal deformity (ASD). Accessing L5-S1 via an oblique LIF (OLIF) approach (OLIF 5-1) allows for anterior LIF (ALIF) at the lumbosacral junction without repositioning the patient. We review the early outcomes and complications of OLIF 5-1 at the bottom of a long construct for an MIS approach to treat ASD. We queried a prospectively collected registry of 111 consecutive patients with ASD (Cobb angle >20°, sagittal vertical alignment [SVA] >50, or pelvic incidence [PI]-lumbar lordosis [LL] mismatch>10) patients who underwent CMIS correction between January 2015 and January 2019. Sixty patients had ≥4 levels fused and OLIF 5-1. Multilevel pre-psoas LIF+ OLIF 5-1 were performed in the first stage. Three days later, stage 2 involved MIS installation of pedicle screws with aggressive rod contouring and derotation/translation. The mean patient age was 66.8 years (range, 48-79 years), and the mean duration of follow-up was 24 months (range, 3-60 months). A mean of 7 levels were fused (range, 4-9). Significant improvements in L5-S1 segmental lordosis (SL), LL, SVA, PI-LL mismatch, and pelvic tilt were seen following the first stage (P < 0.05). There was no intraoperative vascular, ureteral, or sympathetic chain injury, and no transient or permanent lumbar plexopathy. In 2 patients, OLIF 5-1 was abandoned due to difficult access, and transforaminal LIF was done at L5-S1 at the second stage. Five patients required intraoperative transfusion. No patient experienced postoperative ileus or L5-S1 pseudarthrosis. Significant improvements in visual analog scale pain score, Oswestry Disability Index, 36-Item Short Form Health Survey, and Scoliosis Research Society Outcomes Questionnaire were found. A single-position MIS OLIF 5-1 at the bottom of a long construct in conjunction with multilevel pre-psoas LIF seems to be a safe and effective technique for improving SL, global LL, and SVA with a low risk of perioperative and postoperative complications.

A synopsis of current practices in minimally invasive surgery for adult spinal deformity

&lt;p&gt;To provide a comprehensive summary of the status, indications and developments in the use of minimally invasive surgery in the field of adult spinal deformity. This study was performed by expert review of literature which has been published and is indexed on PubMed. The most appropriate and recent articles were selected to obtain a consolidation of information and knowledge on use and benefits of minimally invasive surgery in adult spinal deformity. Various MIS techniques have been developed to perform the complex ASD surgeries. These include the transforaminal lateral interbody fusion (TLIF), percutaneous segmental fixation as well as the lateral body interbody fusion (LLIF). It is important for a surgeon to obtain a holistic view of current literature and recommended guidelines on the procedures available for ASD surgeries. Overall, minimally invasive spine surgery has resulted in less use of pain medicine, less blood loss, lower infection rates, less requirement for intensive care, less hospitalization, reduction in physiologic stress, reduction in complication rates, reduction in muscle atrophy and preservation of normal motion with fusion rates being as high as 80-95%. More articles consolidating the vast literature on minimally invasive spine surgery need to be published to allow a surgeon to effectively weight the benefits and drawbacks of it. More research needs to be performed to compare the efficacy of sub-types of minimally invasive spine surgery.&lt;/p&gt;

Lateral Lumbar Interbody Fusion in Ambulatory Surgery Centers

Comparative analysis. To evaluate the safety and outcomes of moving lateral lumbar interbody fusion (LLIF) surgeries to an outpatient setting. 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. 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. 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. 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. 3.