Is Direct Decompression Necessary for Lateral Lumbar Interbody Fusion (LLIF)? A Randomized Controlled Trial Comparing Direct and Indirect Decompression With LLIF in Selected Patients.

OBJECTIVE: To compare the clinical and radiographic outcomes following lateral lumbar interbody fusion (LLIF) between direct and indirect decompression in the treatment of patients with degenerative lumbar diseases. METHODS: Patients who underwent single-level LLIF were randomized into 2 groups: direct decompression (group D) and indirect decompression (group I). Clinical outcomes including the Oswestry Disability index and visual analogue scale of back and leg pain were collected. Radiographic outcomes including cross-sectional area (CSA) of thecal sac, disc height, foraminal height, foraminal area, fusion rate, segmental, and lumbar lordosis were measured. RESULTS: Twenty-eight patients who met the inclusion criteria were eligible for the analysis, with a distribution of 14 subjects in each group. The average age was 66.1 years. Postoperatively, significant improvements were observed in all clinical parameters. However, these improvements did not show significant difference between both groups at all follow-up periods. All radiographic outcomes were not different between both groups, except for the increase in CSA which was significantly greater in group D (77.73 ± 20.26 mm2 vs. 54.32 ± 35.70 mm2, p = 0.042). Group I demonstrated significantly lower blood loss (68.13 ± 32.06 mL vs. 210.00 ± 110.05 mL, p < 0.005), as well as shorter operative time (136.35 ± 28.07 minutes vs. 182.18 ± 42.67 minutes, p = 0.002). Overall complication rate was not different. CONCLUSION: Indirect decompression through LLIF results in comparable clinical improvement to LLIF with additional direct decompression over 1-year follow-up period. These findings suggest that, for an appropriate candidate, direct decompression in LLIF might not be necessary since the ligamentotaxis effect achieved through indirect decompression appears sufficient to relieve symptoms while diminishing blood loss and operative time.

Should a Narrow Corridor Be a Contraindication for Performing Oblique Lateral Interbody Fusion Procedure or Not?

STUDY DESIGN: Retrospective study. OBJECTIVES: We investigated the effect of corridor width on the postoperative outcomes of patients who underwent the OLIF procedure. METHODS: Patients who underwent OLIF surgery, which included L4-5, between 2015 and 2021 were retrospectively studied. The patients were divided into three groups by the width of the corridor: not more than 10 mm, between 10 and 20 mm, and 20 mm or more. We compared clinical and radiographic outcomes and complications between these groups. RESULTS: A total of 81 patients were included. There were no significant differences in VAS leg and back pain scores, ODI scores, or complications between each group. The radiographic findings, including cage position, anterior and posterior disc height, segmental Cobb angle, and foraminal height, also showed no significant differences between each group. The only radiographic finding that showed a significant difference between each group was the angle of the cage. We found significantly less degree of angle in the wider than 20 mm group when compared to the other two groups. (P-value = .01). There was no recorded incidence of major vascular complications. CONCLUSIONS: The width of oblique corridor does not affect clinical outcomes, complications, or radiographic findings, including position of the cage, anterior and posterior disc height, segmental angle, and foraminal height after OLIF procedure, including L4-5 level. Thus, the OLIF procedure can be performed safely even in patients with limited oblique corridors, especially at L4-5.

Perioperative Intravenous Nefopam on Pain Management and Ambulation after Open Spine Surgery: A Randomized Double-Blind Controlled Study.

STUDY DESIGN: This was a randomized double-blind controlled study. PURPOSE: This study was designed to evaluate the effects of intravenous nefopam regarding its ability to reduce morphine consumption and postoperative pain and improve recovery in patients undergoing open spine surgery. OVERVIEW OF LITERATURE: Multimodal analgesia, including nonopioid medications, is essential for pain management in spine surgery. Evidence regarding the use of intravenous nefopam in open spine surgery as part of enhanced recovery after surgery is lacking. METHODS: In this study, 100 patients undergoing lumbar decompressive laminectomy with fusion were randomized into two groups. The nefopam group received 20-mg intravenous nefopam diluted in 100-mL normal saline intraoperatively, followed by 80-mg nefopam diluted in 500-mL normal saline, administered as a continuous infusion postoperatively for 24 hours. The control group received an identical volume of normal saline. Postoperative pain was managed using intravenous morphine via patient-controlled analgesia. Morphine consumption in the first 24 hours was recorded as the primary outcome. Secondary outcomes, including postoperative pain score, postoperative function, and length of hospital stay (LOS), were assessed. RESULTS: No statistically significant differences in the total morphine consumption and postoperative pain score in the first 24 hours postoperatively between the two groups. At the post-anesthesia care unit (PACU), the nefopam group demonstrated lower pain scores while at rest (p =0.03) and upon movement (p =0.02) than the normal saline group. However, the severity of postoperative pain between the two groups was similar from postoperative day 1 to day 3. LOS was significantly shorter in the nefopam group than in the control group (p <0.01). The time to first sitting and walking and PACU discharge between the two groups were comparable. CONCLUSIONS: Perioperative intravenous nefopam demonstrated significant pain reduction during the early postoperative period and shortened LOS. Nefopam is considered safe and effective as a part of multimodal analgesia in open spine surgery.

Comparing Efficacy of Lumbar Disc Space Preparation via an Anterior-to-Psoas Approach Between Intraoperative Conventional Fluoroscopy and Computed Tomographic-Based Navigation System: A Cadaveric Study.

OBJECTIVE: To compare the efficacy of intervertebral disc space preparation via an anterior-to-psoas (ATP) approach using conventional fluoroscopy (Flu) and computer tomography (CT)-based navigation by evaluating the disc remaining area. METHODS: We equally assigned 24 lumbar disc levels from 6 cadavers into Flu and CT-based navigation (Nav) groups. Two surgeons performed disc space preparation using the ATP approach in both groups. Digital images of each vertebral endplate were obtained, and the remaining disc tissue was calculated in total and in quadrants. Operative time, number of attempts at disc removal, endplate violation area, number of endplate violation segments, and access angle were recorded. RESULTS: The overall percentage of remaining disc tissue was significantly less in the Nav group than in the Flu group (32.7% vs. 43.3% respectively, P < 0.001). A significant difference was found in the posterior-ipsilateral (4.2% vs. 7.1%, P = 0.005) and posterior-contralateral (6.1% vs. 10.9%, P = 0.002) quadrants, respectively. No significant between-group difference was found concerning operative time, number of attempts at disc removal, endplate violation area, number of endplate violation segments, or access angle. CONCLUSIONS: Intraoperative CT-based navigation may improve vertebral endplate preparation quality for an ATP approach, especially in the posterior quadrants. This technique may offer an effective alternative disc space and endplate preparation methods and may help enhance the fusion rates.

Lumbar Sympathetic Chain Tract and Mobility of Oblique Lumbar Interbody Fusion Approach: A Cadaveric Study.

OBJECTIVE: We sought to assess the lumbar sympathetic chain (LSC) relation to the surgical corridor for the oblique lumbar approach and the ability to mobilize the LSC. METHODS: Forty-three cadavers were included. A left-sided anterior retroperitoneal approach was performed in supine position. The distances between the great vessels and psoas muscle (oblique corridor) and distance between great vessels and LSC at the L2/3, L3/4, and L4/5 disk levels were measured. Mobilization of LSC at each disk level was done either close to or away from the psoas muscle, and each mobilization distance was measured. RESULTS: The presence rates of LSC in oblique corridor were 19.5%, 43%, and 75.7% at L2/3, L3/4, and L4/5 levels, respectively. At the L2/3 disk level, the mean distance between the psoas muscle and LSC and its mobility were 0.61 mm ± 1.31 mm and 2.72 mm ± 1.24 mm, respectively. At the L3/4 disk level, the mean distance between the psoas muscle and LSC and its mobility were 1.72 mm ± 2.53 mm and 3.11 mm ± 1.02 mm, respectively. At the L4/5 disk level, the mean distance between the psoas muscle and LSC and its mobility were 2.94 mm ± 3.52 mm and 2.53 mm ± 1.03 mm, respectively. The mean width of corridor of L2/3, L3/4, and L4/5 were 10.73 mm ± 5.82 mm, 12.63 mm ± 5.02 mm, and 15.43 mm ± 6.31 mm, respectively. CONCLUSIONS: The LSC tract usually lies in the oblique corridor in L4/5 but keeps decreasing in prevalence when approaching L3/4 and L2/3 levels. It can be mobilized a few millimeters close to or away from the psoas muscle. Care should be taken to prevent an LSC injury, particularly when the LSC needs to be retracted along with the psoas muscle.

Comparison of full-endoscopic and tubular-based microscopic decompression in patients with lumbar spinal stenosis: a randomized controlled trial.

PURPOSE: We aimed to demonstrate non-inferiority in terms of functional outcomes in patients with lumbar spinal stenosis who underwent full-endoscopic decompression compared with tubular-based microscopic decompression. METHODS: This prospective, randomized controlled, non-inferiority trial included 60 patients with single-level lumbar spinal stenosis who required decompression surgery. The patients were randomly assigned in a 1:1 ratio to the full-endoscopic group (FE group) or the tubular-based microscopic group (TM group). Based on intention-to-treat analysis, the primary outcome was the Oswestry Disability Index score at 24 months postoperative. The secondary outcomes included the visual analog scale (VAS) score for back and leg pain, European Quality of Life-5 Dimensions (EQ-5D) score, walking time, and patient satisfaction rate according to the modified MacNab criteria. Surgery-related outcomes were also analyzed. RESULTS: Of the total patients, 92% (n = 55) completed a 24-month follow-up. The primary outcomes were comparable between the two groups (p = 0.748). However, the FE group showed a statistically significant improvement in the mean VAS score for back pain at day 1 and at 6, 12, and 24 months after surgery (p < 0.05). No significant difference was observed in the VAS score for leg pain, EQ-5D score, or walking time (p > 0.05). Regarding the modified MacNab criteria, 86.7% of patients in the FE group and 83.3% in the TM group had excellent or good results at 24 months after surgery (p = 0.261). Despite the similar results in surgery-related outcomes, including operative time, radiation exposure, revision rate, and complication rate, between the two groups (p > 0.05), less blood loss and shorter length of hospital stay were observed in the FE group (p ≤ 0.001 and 0.011, respectively). CONCLUSION: This study suggests that full-endoscopic decompression is an alternative treatment for patients with lumbar spinal stenosis because it provides non-inferior clinical efficacy and safety compared with tubular-based microscopic surgery. In addition, it offers advantages in terms of less invasive surgery. Trial registration number (TRN): TCTR20191217001.

Comparative Outcome of Lidocaine Versus Bupivacaine for Cervical Medial Branch Block in Chronic Cervical Facet Arthropathy: A Randomized Double-Blind Study.

OBJECTIVE: This study evaluated the effect of prolonged concordant response and functional clinical improvement between lidocaine and bupivacaine for cervical medial branch block (CMBB) in chronic cervical facet syndrome. METHODS: Sixty-two patients diagnosed with chronic cervical facet syndrome were randomized into either lidocaine or bupivacaine groups. The therapeutic CMBB was performed under ultrasound guidance. Either 2% lidocaine or 0.5% bupivacaine with a volume of 0.5-1 mL per level was injected according to the patient's pain symptoms. The patients, pain assessor, and pain specialist were blinded. The primary outcome was the duration of pain reduction by at least 50%. The Numerical Rating Scale of 0-10 and the Neck Disability Index questionnaire were recorded. RESULTS: There was no significant difference in the duration of 50% and 75% pain reduction and Neck Disability Index between the lidocaine and bupivacaine groups. Lidocaine provided significant pain reduction up to 16 weeks (P < 0.05) and significant improvement in neck functional outcomes up to 8 weeks (P < 0.01) compared to the baseline. While bupivacaine yielded significant pain alleviation for up to 8 weeks for pain upon neck mobilization (P < 0.05) and demonstrated notable improvement in neck function up to 4 weeks (P < 0.01) compared to the baseline. CONCLUSION: CMBB using lidocaine or bupivacaine provided clinical benefits in prolonged analgesic effect and improving neck functions for chronic cervical facet syndrome. Lidocaine illustrated better performance and could be considered a local anesthetic of choice regarding the prolonged concordance response.

Vitamin D Inadequacy Affects Skeletal Muscle Index and Physical Performance in Lumbar Disc Degeneration.

Lumbar disc degeneration (LDD) is one of the fundamental causes of low back pain. The aims of this study were to determine serum 25-hydroxyvitamin D (25(OH)D) levels and physical performance and to investigate the relationship between serum vitamin D levels, muscle strength and physical activity in elderly patients with LDD. The participants were 200 LDD patients, including 155 females and 45 males aged 60 years and over. Data on body mass index and body composition were collected. Serum 25(OH)D and parathyroid hormone levels were measured. Serum 25(OH)D was classified into the insufficiency group: <30 ng/mL and the sufficiency group: ≥30 ng/mL. Muscle strength was assessed by grip strength, and physical performance (short physical performance battery) was evaluated by the balance test, chair stand test, gait speed, and Timed Up and Go (TUG) test. Serum 25(OH)D levels in LDD patients with vitamin D insufficiency were significantly lower than in those with vitamin D sufficiency (p < 0.0001). LDD patients with vitamin D insufficiency had a prolonged time in physical performance on gait speed (p = 0.008), chair stand test (p = 0.013), and TUG test (p = 0.014) compared to those with vitamin D sufficiency. Additionally, we found that serum 25(OH)D levels were significantly correlated with gait speed (r = -0.153, p = 0.03) and TUG test (r = -0.168, p = 0.017) in LDD patients. No significant associations with serum 25(OH)D status were observed for grip strength and balance tests among patients. These findings demonstrate that higher serum 25(OH)D levels are associated with better physical performance in LDD patients.

Biomechanical Comparison Between Posterior Long-Segment Fixation, Short-Segment Fixation, and Short-Segment Fixation With Intermediate Screws for the Treatment of Thoracolumbar Burst Fracture: A Finite Element Analysis.

BACKGROUND: Posterior long-segment (LS) fixation, short-segment (SS) fixation, and short segment fixation with intermediate screws (SI) have shown good outcomes for the treatment of thoracolumbar burst fractures. However, limited data compared the biomechanical properties between LS fixation and SI. The purpose of this study was to compare the von Mises stresses on the pedicular screw system and bone between posterior LS fixation, SS fixation, and SI for the treatment of thoracolumbar burst fracture. MATERIALS AND METHODS: The finite element model of thoracolumbar spines from T11 to L3 was created based on the computed tomography image of a patient with a burst fracture of the L1 vertebral body. The models of pedicular screws, rods, and locking nuts were constructed based on information from the manufacturer. Three models with different fixation configurations-that is, LS, SS, and SI-were established. The axial load was applied to the superior surface of the model. The inferior surface was fixed. The stress on each screw, rod, and vertebral body was analyzed. RESULTS: The motion of the spine in SS (0.5 mm) and SI (0.9 mm) was higher than in LS (0.2 mm). In all models, the lowest pedicle screws are the most stressed. The stress along the connecting rods was comparable between SI and LS (50 MPa). At the fracture level, stress was found at the pedicles and vertebral bodies in SI. There was relatively little stress around the fractured vertebral body in LS and SS. CONCLUSIONS: Posterior SI preserves more spinal motion than the LS. In addition, it provides favorable biomechanical properties than the SS. The stress that occurred around the pedicle screws in SI was the least among the 3 constructs, which might reduce complications such as implant failure. SI produces more stress in the fractured vertebral body than LS and SS, which could potentially aid in bone healing according to the Wolff law. CLINICAL RELEVANCE: SI has proved to be a biomechanically favorable construct and helps preserve the spinal motion segment. It could be an alternative surgical option for treating patients who present with thoracolumbar burst fractures.

Ultrasound-guided pulsed radiofrequency of cervical nerve root for cervical radicular pain: a prospective randomized controlled trial.

BACKGROUND CONTEXT: Pulsed radiofrequency (PRF) on cervical dorsal root ganglion (DRG) for pain management in cervical radicular pain is mainly performed via a transforaminal approach under fluoroscopic guidance. Ultrasound-guidance periradicular cervical nerve root intervention raises concern about the neuromodulatory effect. This study aims to evaluate the effectiveness and duration of pain relief between PRF treatment and steroid injection on the cervical nerve roots. PURPOSE: To evaluate the efficacy of pulsed radiofrequency for cervical radicular pain. STUDY DESIGN: A prospective, double-blinded, randomized controlled clinical trial PATIENT SAMPLE: Patients who underwent ultrasound-guided periradicular cervical nerve root PRF or steroid injection from January 2020 to May 2021 at King Chulalongkorn Memorial Hospital (KCMH), Bangkok, Thailand. OUTCOME MEASURES: The primary outcome was the pain score at 3 months postprocedure. The secondary outcomes were the duration of pain relief of at least 50%, pain scores at other time points after pain intervention, the amount of rescue pain medications, procedural time, and complications. METHOD: Forty-two patients who presented with chronic cervical radicular pain were prospectively randomized into the PRF and steroid groups. Patients in the PRF group received PRF treatment at 42°C for 4 minutes, followed by the injection of 2% lidocaine 1.5 mL and dexamethasone 10 mg to the targeted cervical nerve root. The steroid group received the same injectate. Patients and pain assessors were blinded. The numerical rating scale (NRS) and the Neck Disability Index (NDI) questionnaires were used for pain intensity and neck functional assessment before and after the procedure. Pain reduction was recorded up to a 9-month follow-up. RESULTS: Data analysis was obtained from 20 and 21 patients receiving PRF and steroid treatment, respectively. At 3-month postprocedure, there were 70% of patients in the PRF group reported 50% pain reduction compared with 23.8% of patients in the steroid group (p<.01). Moreover, patients in the PRF group had significantly less pain (NRS 2.8±2.7) compared with patients in the steroid group (NRS 5.5±2.6) (p=.01). The neck disability index demonstrated significant improvement at 3 and 6 months (p<.01) after PRF treatment compared with steroid injection alone. The duration, in which pain relief was at least 50%, was significantly longer in patients who received PRF treatment (6.0±4.1 months) compared with those in the steroid group (2.3±2.1 months) (p<.01). CONCLUSION: Ultrasound-guided periradicular cervical nerve root PRF exhibited a neuromodulatory effect and was considered effective for patients with cervical radicular pain. It provided a longer duration of pain relief and improvement of neck function for up to 6 months.

Subsidence of Interbody Cage Following Oblique Lateral Interbody Fusion: An Analysis and Potential Risk Factors.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: This study aimed to report the incidence and potential risk factors of polyetheretherketone (PEEK) cage subsidence following oblique lateral interbody fusion (OLIF) for lumbar degenerative diseases. We proposed also an algorithm to minimize subsidence following OLIF surgery. METHODS: The study included a retrospective cohort of 107 consecutive patients (48 men and 59 women; mean age, 67.4 years) who had received either single- or multi-level OLIF between 2012 and 2019. Patients were classified into subsidence and non-subsidence groups. PEEK cage subsidence was defined as any violation of either endplate from the computed tomography scan in both sagittal and coronal views. Preoperative variables such as age, sex, body mass index, bone mineral density (BMD) measured by preoperative dual-energy X-ray absorptiometry, smoking status, corticosteroid use, diagnosis, operative level, multifidus muscle cross-sectional area, and multifidus muscle fatty degeneration were collected. Age-related variables (height and length) were also documented. Univariate and multivariate logistic regression analyses were used to analyze the risk factors of subsidence. RESULTS: Of the 107 patients (137 levels), 50 (46.7%) met the subsidence criteria. Higher PEEK cage height had the strongest association with subsidence (OR = 9.59, P < .001). Other factors significantly associated with cage subsistence included age >60 years (OR = 3.15, P = .018), BMD <-2.5 (OR = 2.78, P = .006), and severe multifidus muscle fatty degeneration (OR = 1.97, P = .023). CONCLUSIONS: Risk factors for subsidence in OLIF were age >60 years, BMD < -2.5, higher cage height, and severe multifidus muscle fatty degeneration. Patients who had subsidence had worse early (3 months) postoperative back and leg pain.

An Expanded Surgical Corridor of Oblique Lateral Interbody Fusion at L4-5: A Magnetic Resonance Imaging Study.

OBJECTIVE: We introduced a new preoperative method, the "expanded surgical corridor," to evaluate the actual safety corridor, which may expand the possibility of performing oblique lateral interbody fusion (OLIF). METHODS: Axial T2-weighted magnetic resonance images at the L4-5 disc level of 511 lumbar degenerative disease patients was evaluated. The distance between the medial edge of the left-sided psoas muscle and the major artery was measured as the conventional surgical corridor (CSc). The distance between the major vein and lumbar plexus was measured as the expanded surgical corridor (ESc). RESULTS: The mean CSc and ESc were 13.9 ± 8.20 and 37.43 ± 10.1 mm, respectively. No surgical corridor was found in 7.05% of CSc and 1.76% of ESc, small corridor ( ≤ 1 cm) was found in 27.40% of CSc and 0.59% of ESc, moderate corridor (1-2 cm) was found in 42.07% of CSc and 1.96% of ESc, and large corridor ( > 2 cm) was found in 23.48% of CSc and 95.69% of ESc. A total of 33.83% (45 of 133) of whom were preoperatively categorized as having a limited surgical corridor by conventional measurement, underwent OLIF L4-5 successfully. CONCLUSION: By using the ESc, only 2.35% were categorized as having a limited surgical corridor. The other 97.65% of the patients had an approachable corridor that could be successfully operated by experienced spine surgeons who employ meticulous surgical dissection and thorough understanding of the anatomical structures. The ESc may represent true accessibility to the disc space for OLIF, particularly at the L4-5 level.

A Comparison of Polyetheretherketone and Titanium-Coated Polyetheretherketone in Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Randomized Clinical Trial.

OBJECTIVE: To compare patient-reported outcomes and radiographic outcomes between using polyetheretherketone (PEEK) and titanium-coated PEEK (TiPEEK) as an interbody cage in patients who underwent minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). METHODS: Eighty-Six patients who underwent 1-2 levels of MIS-TLIF were randomly allocated to receive a TiPEEK or PEEK cage. Patient-reported outcomes were recorded using visual analog scale, Oswestry Disability Index, and EuroQoL-5D-5L. Postoperative radiographs and computed tomography were assessed for spinal fusion and cage subsidence. RESULTS: The eligible 82 patients (41 patients, 49 operated levels in TiPEEK group and 41 patients, 50 operated levels in PEEK group) were included in the final analysis. Over total follow-up, the mean difference in visual analog scale back and leg pain scores between TiPEEK versus PEEK group was -0.04 (95% confidence interval [CI], -0.5 to 0.4; P = 0.85) and -0.12 (95% CI, -0.6 to 0.3; P = 0.62), respectively. The mean difference in Oswestry Disability Index scores was -0.71 (95% CI, -3.8 to 2.4; P = 0.65), and the mean difference in EQ-5D-5 L was 0.03 (95% CI, -0.01 to 0.06; P = 0.11) in TiPEEK group versus PEEK group as a reference. TiPEEK showed significantly higher fusion rates than PEEK at 6-month (91.8% vs. 76%; P = 0.03), but no difference at 12-month postoperation. There was no significant difference in cage subsidence rates between the 2 groups. CONCLUSIONS: The patient-reported outcomes showed significant improvements at 6- and 12-month postoperation following MIS-TLIF; the differences in those with TiPEEK versus PEEK cages were minimal with tight CIs. Fusion rates in both groups were ≥90%, with TiPEEK cages showing higher fusion rates at 6 months after the procedure.

Indirect Effects on Adjacent Segments After Minimally Invasive Transforaminal Lumbar Interbody Fusion.

OBJECTIVE: To compare radiographic parameters at adjacent segments before and after minimally invasive transforaminal lumbar interbody fusion and assess relationships of radiographic changes between adjacent segments and fused level. METHODS: Study participants included 44 patients who underwent minimally invasive transforaminal lumbar interbody fusion at L4-5 level. Radiographic parameters at adjacent segments (L3-4 and L5-S1) and clinical parameters were reviewed. RESULTS: Postoperative dural sac area significantly increased in upper (mean change 8.05 mm2, P < 0.001) and lower (14.08 mm2, P < 0.001) adjacent segments. Significant increases in SAPD were seen in upper (0.85 mm, P < 0.001) and lower (0.66 mm, P < 0.001) adjacent segments. Ligamentum flavum thickness significantly decreased in lower adjacent segments (-0.37 mm, P = 0.006). For every 1-mm increase in fused level disc height, lower SAPD increased 0.22 mm (P = 0.04), and lower segmental angle increased 0.91° (P = 0.04). For every 1° increase in fused level segmental angle, lower dural sac area increased 1.25 mm2 (P = 0.03), and lower SAPD increased 0.12 mm (P = 0.003). The 6- and 12-month postoperative visual analog scale back and leg scores significantly decreased compared with preoperatively (back: mean change -5.98 and -6.05, P < 0.001; leg: -6.86 and -6.89, P < 0.001). CONCLUSIONS: Performing minimally invasive transforaminal lumbar interbody fusion at the symptomatic index level does not worsen canal dimension of asymptomatic adjacent segments during short-term follow-up. It might be possible to improve canal dimension at adjacent segments by changing disc height or lordosis at the fused level via adjusting size and position of the interbody cage.

Successful Criteria for Indirect Decompression With Lateral Lumbar Interbody Fusion.

OBJECTIVE: No consensus criteria have been established regarding ideal candidates for indirect decompression with lateral lumbar interbody fusion (LLIF), and contributing factors of indirect decompression failure were rarely reported. We aim to investigate the success rate of indirect decompression by LLIF with proposed selection criteria and identify risk factors associated with indirect decompression failure, defined as persistent pain requiring revision with direct decompression. METHODS: Data from 191 patients undergoing LLIF were retrospectively reviewed. All the following criteria must be fulfilled: (1) dynamic clinical symptoms (pain relief in supine position), (2) presence of reducible disc height (recovered disc height in supine position), (3) no profound weakness, and (4) no static stenosis. The success rate of indirect decompression with LLIF and results after at least 1 year of follow-up were collected. Preoperative, procedure-related, and postoperative factors were assessed for their relationship with failure. RESULTS: Of 191 patients,13 patients (6.8%) required additional direct decompression due to persistent pain, giving a criteria success rate of 93.2%. Factors associated with indirect decompression failure included low bone mineral density (T-score < 2.1), low reducible disc height (<13%), low postoperative disc height (< 10 mm), high-grade cage subsidence, and use of plate fixation. CONCLUSION: We proposed patient selection criteria for indirect decompression with LLIF which had a satisfactory success rate and identified factors associated with the need for additional direct decompression. Our proposed criteria may assist selection of patients likely to achieve good results following indirect decompression with LLIF, and optimize selection based on risk factors of failure.

Surgical Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion Using Surgical Microscope vs Surgical Loupes: A Comparative Study.

BACKGROUND: Minimally invasive transforaminal interbody fusion (MIS-TLIF) is an effective procedure for lumbar spine diseases. The procedure can be done using a surgical microscope (SM) or surgical loupes (SL) magnification. However, there are no studies that compared outcomes between using these 2 magnifying devices in the MIS-TLIF procedure. The purpose of this study was to compare clinical outcomes, perioperative complications, and radiographic parameters of MIS-TLIF using SM compared with SL magnification. METHODS: We included all patients undergoing 1-level MIS-TLIF between January 2017 and December 2019. Type of magnification (SM vs SL), operative time, blood loss, perioperative complications, cross-sectional area of the spinal canal, and fusion rates were analyzed. Clinical outcomes measurement using the visual analog scale (VAS) and Oswestry Disability Index (ODI) were compared between groups. RESULTS: A total of 100 patients had underwent MIS-TLIF (SM group: 62; SL group: 38). Operative time (SM: 182.7 ± 41.5 vs SL: 165.6 ± 32.6 minutes, P = 0.043) was significantly shorter in the SL group, with a mean difference of 17.2 minutes and a 10.4% increase in operative time between SL and SM. Blood loss (SM: 187.4 ± 176.4 vs SL: 215.6 ± 99.4 mL, P = 0.36) was not different between groups, with a mean difference of 28.2 mL. Both the SM group and SL group demonstrated no significant differences in improvement from baseline in VAS back, VAS legs, ODI score, and cross-sectional area of the spinal canal. There was also no significant difference in complication rates and fusion rates between groups. CONCLUSIONS: Our study found no difference between intraoperative use of SL compared with SM in clinical outcomes through the 12-month follow-up timepoint. However, the use of SM resulted in an increased average operative time of 17 minutes compared with the SL group. CLINICAL RELEVANCE: Intraoperative use of SM and SL magnification in MIS-TLIF provides similar outcomes except prolonged operative time in the SM group.

Effects of general anesthesia with and without thoracic epidural block on length of stay after open spine surgery: a single-blinded randomized controlled trial.

BACKGROUND CONTEXT: Length of hospital stay (LOS) is an important concern in all types of surgery, and the enhanced recovery after surgery (ERAS) protocol has been developed to improve perioperative management and outcomes, which require multidisciplinary management. In terms of pain control, intraoperative regional anesthesia and postoperative opioid-sparing analgesia are recommended. For open spine surgery, we aimed to combine thoracic epidural analgesia to reduce pain and opioid-related side effects, thereby hastening recovery. PURPOSE: This study aimed to compare the length of hospital stay after open complete laminectomy with fusion between general anesthesia and combined general anesthesia involving a single thoracic epidural injection. DESIGN: A randomized single-blinded controlled study. PATIENT SAMPLE: Thirty-eight patients scheduled for elective open laminectomy with fusion between I and III levels were selected. OUTCOME MEASURES: LOS, postoperative pain, patient-controlled morphine consumption at 24 hours, patient satisfaction score, and other opioid-related side effects were recorded. METHODS: Patients were randomly selected to receive standard general anesthesia (GA) or GA combined with a single-shot thoracic epidural at T11-T12 or T12-L1, a block with 10 mL of 0.25% bupivacaine, and 4 mg of morphine. RESULTS: There were no significant differences in the demographic variables between groups. LOS was significantly lower in the combined epidural and/or GA than in the control group (3.78±0.81 [mean±standard deviation] and 4.79±1.51 days, respectively; p=.017). Numeric rating score (at rest) at the post-anesthesia care unit, 24 hours postoperative morphine consumption (mg), operating time, and blood loss were significantly lower in the epidural group. Patients who received combined epidural and/or GA were more likely to report higher patient satisfaction (p=.008). However, the incidence of intraoperative hypotension was significantly higher in the epidural group (72.2% vs. 21.1%, p=.003). The incidences of adverse events and surgical field rating scores did not differ between the 2 patient groups. CONCLUSIONS: Combined lower thoracic epidural and/or GA in patients undergoing elective lumbar spine surgery was associated with decreased LOS.

Incidence and risk factors associated with superior-segmented facet joint violation during minimal invasive lumbar interbody fusion.

BACKGROUND CONTEXT: The trend of minimally invasive lumbar interbody fusion is increasing, and adjacent segmental degeneration (ASD) is one of the complications of the procedures in which facet joint violation (FJV) is a cause. FJVs can occur during percutaneous instrumentation. This study aimed to identify the risk factors that affect FJV during minimally invasive lumbar interbody fusion. PURPOSE: To identify the risk factors for FJVs and the factors that have a strong impact on the violation. STUDY DESIGN: Retrospective study. PATIENT SAMPLE: Patients who underwent minimally invasive lumbar interbody fusion with percutaneous screw fixation between June 2018 and December 2019. OUTCOME MEASURES: Prevalence of the FJV was reviewed by CT scans which obtained within 6 months after surgery, and the axial, coronal, and sagittal cuts of the scans were evaluated. The FJV was defined as the screw being visible in the facet joint in at least one plane of the CT scan. Radiographic parameters were measured using CT scans including diameters of the facet joints in the axial, coronal, and sagittal planes defined by the facet diameter. The facet angle (FA), the pedicle angle (PA), the screw-facet angle (SFA), the screw-endplate angle (SEA), and the superior margin of the facet joint in the sagittal plane (SD) differed from the head of the screw. At Last, the depth of back muscle was measured in the axial cut of the MRI. METHODS: This study analyzed 119 patients who underwent minimally invasive lumbar interbody fusion between June 2018 and December 2019. Facet joint violation at the uppermost level was examined using CT in all dimensions. Radiographic parameters (facet diameter, facet angle, pedicle angle, screw-facet angle, screw-endplate angle, and distance between the head of the screws and the facet) were measured. BMI, age, diagnosis, and navigation assistance were included in the study. Risk factors were analyzed to determine which factors had an effect on FJV, and the cut-off was calculated for each parameter. RESULTS: This study included 119 patients, with a mean age of 63 years. FJV occurred in 13/119 (10.9%) patients and 15/238 (6.3%) joints, respectively. No FJV occurred in 120 joints operated with navigation-assistance and 15/178 (8.4%) joints operated without navigation (p=.01). We found an increasing proportion of violations at more caudal levels: no violations occurred in eight patients with lumbar at L1 or L2, and 1/40 (2.5%), 7/158 (4.4%), and 7/32 (21.9%) of violations occurred at L3, L4, and L5, respectively (p=.01). The diameter of the facet in the axial cut, facet angle, screw facet angle, and distance between the head of the screw and facet were statistically significant in determining the increasing rate of FJV after multivariate analysis was performed (AROC=0.9486, p≤.05). The cutoff point for each radiographic parameter were diameter of facet in the axial ≥17.5 mm, diameter of facet in coronal plane ≥19.5 mm, facet angle ≥41.5o, screw-facet angle ≥39o, and distance between facet and the screw ≥-2.6 mm. The estimated probability of FJV was 96.9% when every parameter was greater than the cut-off point. CONCLUSIONS: An increase in the facet diameter in the axial plane, coronal plane, facet angle, screw facet angle, and the distance between the dome of the screw and facet are risk factors for FJV. Surgeons can avoid violations when radiographic considerations are done. Careful screw placement and good entry points for instrumentation may decrease the rate of facet violation.

Full-Endoscopic Anterior Odontoid Screw Fixation: A Novel Surgical Technique.

OBJECTIVE: First, to propose a novel minimally invasive technique of full-endoscopic anterior odontoid fixation (FEAOF) that aims to reduce the risk of retropharyngeal approach (both open and percutaneous techniques) to anterior odontoid screw fixation. Second, to describe steps of the procedure and, lastly, to report the initial outcomes in patients treated with this novel technique. METHODS: Four non-consecutive patients who were diagnosed with a displaced odontoid fracture (Anderson-D'Alonzo classification type II and Grauer subclassification type A or B) from 2019 to 2020 underwent surgical fixation by our novel technique for anterior odontoid screw fixation. A detailed technical approach of FEAOF for the surgical treatment of type II odontoid fractures was described, and the patients' outcomes based on postoperative radiographic results including computed tomography (CT), clinical outcome parameters including visual analogue scale (VAS) for neck pain both preoperatively and at postoperative follow-up, and range of neck motion at the final follow-up were reported. RESULTS: The mean age was 33.5 years (24-41), three patients were male. The mean operative time was 93.75 min, and the mean blood loss was 7.5 ml. An immediate post-operative thin-sliced CT showed that all patients achieved satisfactory reduction and proper screw position. No screw malposition or penetration was found. At a 6-month follow-up, a thin-sliced CT demonstrated solid bony union in every case. The mean VAS for neck pain was reduced from 6.5 to 0.6 at the 6-months follow-up. At the final follow-up, all patients showed improvement in ranges of motion without any complications; however, one patient was lost to follow-up. CONCLUSIONS: FEAOF is a feasible and effective option for treating type II odontoid fractures. The procedure is less invasive than other techniques and provides clear direct visualization of the involved structures.