Clinical and Radiologic Analysis of Minimally Invasive Anterior-Posterior Combined Surgery for Adult Spinal Deformity: Comparison of Oblique Lateral Interbody Fusion at L5/S1 (OLIF51) versus Transforaminal Interbody Fusion.

Background and Objectives: Although adult spinal deformity (ASD) surgery brought about improvement in the quality of life of patients, it is accompanied by high invasiveness and several complications. Specifically, mechanical complications of rod fracture, instrumentation failures, and pseudarthrosis are still unsolved issues. To better improve these problems, oblique lateral interbody fusion at L5/S1 (OLIF51) was introduced in 2015 at my institution. The objective of this study was to compare the clinical and radiologic outcomes of anterior-posterior combined surgery for ASD between the use of OLIF51 and transforaminal interbody fusion (TLIF) at L5/S1. Materials and Methods: A total of 117 ASD patients received anterior-posterior correction surgeries either with the use of OLIF51 (35 patients) or L5/S1 TLIF (82 patients). In both groups, L1-5 OLIF and minimally invasive posterior procedures of hybrid or circumferential MIS were employed. The sagittal and coronal spinal alignment and spino-pelvic parameters were recorded preoperatively and at follow-up. The quality-of-life parameters and visual analogue scale were evaluated, as well as surgical complications at follow-up. Results: The average follow-up period was thirty months (13-84). The number of average fused segments was eight (4-12). The operation time and estimated blood loss were significantly lower in OLIF51 than in TLIF. The PI-LL mismatch, LLL, L5/S1 segmental lordosis, and L5 coronal tilt were significantly better in OLIF51 than TLIF. The complication rate was statistically equivalent between the two groups. Conclusions: The introduction of OLIF51 for adult spine deformity surgery led to a decrease in operation time and estimated blood loss, as well as improvement in sagittal and coronal correction compared to TLIF. The circumferential MIS correction and fusion with OLIF51 serve as an effective surgical modality which can be applied to many cases of adult spinal deformity.

Comparative Analysis of Vascular Structures in OLIF51 and the Lateral Corridor Approach under Supine MRI and Intraoperative Enhanced CT in the Lateral Decubitus Position.

Background and Objectives: As the oblique lateral interbody fusion at L5/S1 (OLIF51) and the lateral corridor approach (LCA) have gained popularity, an understanding of the precise vascular structure at the L5/S1 level is indispensable. The objectives of this study were to investigate the vascular anatomy at the L5/S1 level, and to compare the movement of vascular tissue between the supine and lateral decubitus positions using intraoperative enhanced CT and MRI. Materials and Methods: A total of 43 patients who underwent either OLIF51 or LCA were investigated with an average age at surgery of 60.4 (37-80) years old. The preoperative MRI was taken to observe the axial and sagittal anatomy of the vascular position under the supine position. The intraoperative vein-enhanced CT was taken just before incision in the right decubitus position, and compared to supine MRI anatomy. Iliolumbar vein appearance and its types were also classified. Results: The average vascular window allowed for OLIF51 was 22.8 mm and 34.1 mm at either the L5 caudal endplate level or the S1 cephalad endplate level, respectively. The LCA was 14.2 mm and 12.6 mm at either level, respectively. The left common iliac vein moved 3.8 mm and 6.9 mm to the right direction at either level from supine to the right decubitus position, respectively. The bifurcation moved 6.3 mm to the caudal direction from supine to right decubitus. The iliolumbar vein was located at 31 mm laterally from the midline, and the MRI detection rate was 52%. Conclusions: The precise measurement of vascular anatomy indicated that the OLIF51 approach was the standard minimally invasive anterior approach for the L5/S1 disc level compared to LCA; however, there were many variations in quantitative anatomy as well as significant vascular movements between the supine and right decubitus positions. In the clinical setting of OLIF51 and LCA surgeries, careful preoperative evaluation and intraoperative 3D imaging are recommended for safe and accurate surgery.

Single-level controlled comparison of OLIF51 and percutaneous screw in lateral position versus MIS-TLIF for lumbosacral degenerative disorders: Clinical and radiologic study.

BACKGROUND: We have performed minimally invasive Oblique Lateral Interbody Fusion at L5/S1 (OLIF51) and simultaneous posterior screwing in lateral position for lumbosacral disorders. This study compared the clinical and radiologic results between OLIF51 versus Minimally Invasive Transforaminal Lumbar Interbody Fusion (MIS-TLIF) in single-level fusion for lumbosacral degenerative disorders. METHODS: A total of 71 patients underwent either OLIF51 (33 cases) or MIS-TLIF (38 cases) at L5/S1 spinal segment. The average age was 64 yrs (27-88). The disorders were L5 isthmic or degenerative spondylolisthesis, foraminal stenosis, pseudarthrosis and adjacent segment degeneration, and others. Using 35 mm oblique incision, OLIF51 was performed followed by posterior percutaneous fixation in same lateral position. MIS-TLIF was performed with midline 40 mm incision and modified cortical bone trajectory (CBT) screws. The operation time, estimated blood loss, JOABPEQ effectiveness rate (%), Visual Analogue Scale (VAS), fusion rate, radiologic alignment, and complications were evaluated. RESULTS: Average follow-up period was 25 and 31 months (12-45) in OLIF51 and MIS-TLIF, respectively. The average operation time and estimated blood loss were 165min, 62 ml and 163 min and 68 ml, respectively. The JOABPEQ effectiveness rate in OLIF51 demonstrated higher value in low back function (44% vs 17%, P < 0.02). The fusion rate was 97% and 92% in OLIF51 and MIS-TLIF, respectively. The segmental lordosis was significantly larger in OLIF51 (17 vs 11 deg, P < 0.01). There were no vascular or neural complications. CONCLUSIONS: Although two groups demonstrated the equivalent surgical invasiveness, there was the significant superiority of OLIF51 in terms of low back function over MIS-TLIF. The segmental lordosis creation was also better in OLIF51. Even in the single-level lumbosacral fusion, OLIF51 serves as the safe and viable surgical procedure with use of lateral position surgery, minimizing the residual low back dysfunction.

Clinical and radiologic comparison of anterior-posterior single-position lateral surgery versus MIS-TLIF for degenerative lumbar spondylolisthesis.

BACKGROUND: The lateral interbody fusion (LIF) has gained popularity for the surgical treatment of lumbar degenerative spondylolisthesis (DS), however, LIF often requires the position change for posterior screwing. We have performed the single-position lateral surgery of oblique lateral interbody fusion (OLIF) and posterior screwing (OLIF-LPF). The present study compared the clinical and radiologic results between OLIF-LPF and minimally invasive transforaminal interbody fusion (MIS-TLIF). METHODS: A total of 142 patients underwent either OLIF-LPF (92 cases) or MIS-TLIF (50 cases) for L3 or L4 DS. The average age was 72 and 70 years old, respectively. The OLIF-LPF was performed in right decubitus position with allograft and percutaneous modified cortical bone trajectory screws (mCBT). The MIS-TLIF utilized a single 4 cm midline incision, allograft, boomerang cage and mCBTs. The operation time, estimated blood loss, and serum CRP levels were recorded. JOABPEQ effectiveness rate (%), Visual Analogue Scale (VAS), fusion rate, segmental radiologic alignment, and complications were also evaluated. RESULTS: Average follow-up period was 31 and 57 months in OLIF-LPF and MIS-TLIF, respectively. The average operation time and estimated blood loss were 108min, 51 ml and 104 min and 69 ml, respectively. OLIF-LPF demonstrated significantly higher values of mental health domain of JOABPEQ effectiveness rate and VAS improvement of leg pain than those in MIS-TLIF. The less correction loss of posterior disc height was demonstrated in OLIF-LPF. The fusion rate and symptomatic adjacent segment degeneration (ASD) were statistically equivalent between two groups. CONCLUSIONS: The single-position surgery of OLIF combined with posterior screwing serves as a safe, minimally invasive and effective surgical modality without the need of position change. It provides comparable fusion rate, segmental radiologic alignment, and symptomatic adjacent segment degeneration to MIS-TLIF surgery.

Induction of autoimmune arthritis after direct injection of bone marrow cells from arthritis-prone SKG/Jcl mice into bone cavity of normal mice.

SKG/Jcl (SKG) mice spontaneously develop T cell-mediated autoimmune arthritis and may be an effective model for studying human rheumatoid arthritis. We sought to confirm that arthritis in SKG mice was caused by stem cell disorders. We induced systemic arthritis in normal C57/BL6 (B6) mice (H-2(b) type) by injecting lineage-negative (lin(-)) immature cells isolated from bone marrow cells (BMCs) of SKG mice (H-2(d) type) directly into bone cavities. Twenty weeks later, we analyzed arthritis scores, hematoxylin-eosin (H-E) staining and tartrate-resistant acid phosphatase (TRAP) staining in ankle joints, H-2 type of hematolymphoid and osteoblast-like cells, serum levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and percentages of CD4(+) T cells and osteoblast-like cells expressing receptor activator of nuclear factor kappa-B ligand (RANKL) in recipient mice. Donor-derived hematolymphoid cells and osteoblast-like cells had completely replaced donor-derived cells in the recipients (H-2(b) to H-2(d)). All recipients showed severe joint swelling with hyperemia and developed hypertrophic synovitis with lymphocytes accumulated around joints. All recipients also had higher TNF-α and IL-6 levels than untreated B6 controls. Furthermore, the percentages of CD4(+) T cells and osteoblast-like cells expressing RANKL and the number of TRAP(+) cells were greater in treated animals. Donor-derived hematolymphoid cells and osteoblast-like cells persisted in these recipients and promoted autoimmune arthritis and an increase in osteoclasts. Because autoimmune arthritis may be associated with abnormal lin(-) immature cells, patients with intractable autoimmune arthritis may be treated by replacing these cells with direct injection of lin(-) immature cells isolated from normal BMCs.

Comparative Clinical Analysis of Oblique Lateral Interbody Fusion at L5/S1 versus Minimally Invasive Transforaminal Interbody Fusion (MIS-TLIF) for Degenerative Lumbosacral Disorders.

Introduction: Since 2015, we have performed minimally invasive oblique lateral interbody fusion (OLIF) at L5/S1 for various lumbosacral spine disorders using percutaneous pedicle screws. This study evaluated the clinical and radiologic results between OLIF at L5/S1 and minimally invasive transforaminal interbody fusion (MIS-TLIF) for single to multilevel degenerative lumbosacral disorders. Methods: A total of 124 patients underwent either OLIF (62 cases) or MIS-TLIF (62 cases). The applied disorders were L5 isthmic spondylolisthesis, foraminal stenosis, pseudarthrosis, adjacent segment degeneration, a combination of L4/5 and L5/S1 pathology, and others. We performed OLIF with posterior percutaneous fixation in the same lateral position. MIS-TLIF was performed with modified cortical bone trajectory screws. The operation time (OT), estimated blood loss (EBL), JOABPEQ effectiveness rate (%),Visual Analog Scale (VAS), fusion rate, radiologic segmental alignment, and complications were evaluated. Results: The average follow-up periods were 51 and 69 months (24-95) in the OLIF and MIS-TLIF groups, respectively. Furthermore, the average fused segments were 1.6 and 1.5 in each group, respectively. The OT and EBL per segment were 130 min and 56 mL and 100 min and 64 mL, respectively. The JOABPEQ effectiveness rate in the OLIF group demonstrated a statistically higher value in the domains of pain, low-back function, and gait than the MIS-TLIF group (P<0.01). The follow-up VAS of low-back pain (LBP) and lower extremity numbness had lower values in the OLIF group (P<0.05). The fusion rates were 98% and 90%, respectively. Segmental lordosis at L5/S1 was significantly larger in the OLIF group (15° vs. 11°, P<0.01). Conclusions: The OLIF group demonstrated less pain as well as better low-back and gait functions at follow-up. The minimally invasive anterolateral fusion employing OLIF at L5/S1 using percutaneous screws serves as a viable and effective procedure with less residual LBP and high fusion rate.

Correlation between the Computed Tomography Values of the Screw Path and Pedicle Screw Pullout Strength: An Experimental Study in Porcine Vertebrae.

STUDY DESIGN: Biomechanical study. PURPOSE: To assess the correlation between the computed tomography (CT) values of the pedicle screw path and screw pull-out strength. OVERVIEW OF LITERATURE: The correlation between pedicle screw pull-out strength and bone mineral density has been well established. In addition, several reports have demonstrated a correlation between bone mineral density and CT values. However, no previous biomechanical studies investigated the correlation between CT values and pedicle screw pull-out strength. METHODS: Sixty fresh-frozen lumbar vertebrae from 6-month-old pigs were used. Before screw insertion, the CT values of the screw path were obtained for each sample. Specimens were then randomly divided into three equal groups. Each group had one of three pedicle screws inserted: 4.0-mm LEGACY (4.0-LEG), 4.5-mm LEGACY (4.5-LEG), or 4.5-mm SOLERA (4.5-SOL) (all from Medtronic Sofamor Danek Inc., Memphis, TN, USA). Each screw had a consistent 30-mm thread length. Axial pull-out testing was performed at a rate of 1.0 mm/min. Correlations between the CT values and pedicle screw pull-out strength were evaluated using Pearson's correlation coefficient analysis. RESULTS: The correlation coefficients between the CT values of the screw path and pedicle screw pull-out strength for the 4.0-LEG, 4.5-LEG, and 4.5-SOL groups were 0.836 (p <0.001), 0.780 (p <0.001), and 0.873 (p <0.001), respectively. Greater CT values were associated with greater screw pull-out strength. CONCLUSIONS: The CT values of the screw path were strongly positively correlated with pedicle screw pull-out strength, regardless of the screw type and diameter, suggesting that the CT values could be clinically useful for predicting pedicle screw pull-out strength.

A less-invasive cervical laminoplasty for spondylotic myelopathy that preserves the semispinalis cervicis muscles and nuchal ligament.

OBJECT: Modified cervical laminoplasty techniques have been developed to reduce postoperative axial neck pain and preserve function in patients with cervical spondylotic myelopathy (CSM). However, the previous studies demonstrating satisfactory surgical outcomes had a retrospective design. Here, the authors aimed to prospectively evaluate the 2-year outcomes of a modified cervical laminoplasty technique for CSM that preserves the paravertebral muscles. METHODS: Outcomes were analyzed for 40 patients (22 men and 18 women; mean age, 66.6 years; age range 44-92 years) with CSM who underwent C4-6 laminoplasty with C-3 and C-7 partial laminectomies or C-3 total and C-7 partial laminectomies and received hydroxyapatite spacers. Neurological, pain severity, and spinal radiographic evaluations were performed preoperatively and at 3, 6, 12, 18, and 24 months postoperatively. Plain radiography and MRI of the cervical spine were performed to evaluate the range of motion (ROM), sagittal alignment, and cross-sectional areas of the deep extensor muscles. The extent of bone-spacer bonding and bony union at the gutter was assessed by CT. RESULTS: The mean preoperative Japanese Orthopaedic Association CSM score was 10.2, but it increased to 14.4 by 24 months after surgery. Eleven patients had axial neck pain preoperatively, but only 3 reported mild pain at 24 months, and in all 3 cases the pain was mild. The mean angle of lordosis was 11.7° preoperatively and 12.0° 2 years postoperatively. Although the ROM at the C2-7 levels was significantly reduced 3 months postoperatively, an increasing trend was observed up to 12 months, and 86% of the preoperative ROM was achieved by 2 years postoperatively. The mean paravertebral muscle cross-sectional areas were 833 ± 215 mm(2) preoperatively and 763 ± 197 mm(2) 24 months postoperatively, but the difference was not statistically significant. The rates of bone-spacer bonding and bony union at the gutter were low during the early stages but increased to 90% and 93%, respectively, by 2 years after surgery. CONCLUSIONS: The modified laminoplasty technique used in this study ensured very good neurological status and ROM after 2 years and was associated with low incidences of axial neck pain and serious complications. This simple and easy operative method could benefit future laminoplasty protocols.