Greater than 5-year follow-up of outpatient L4-L5 lumbar interspinous fixation for degenerative spinal stenosis using the INSPAN device.

BACKGROUND: Lumbar spinal stenosis is treated with decompression directly such as laminectomies and indirectly with an interspinous device through distraction and extension block. Interspinous devices (IPD) have also been used as an adjunct to spinal fusion. However, the design for IPD to treat spinal stenosis does not fixate the spine while the design for spinal fusion is designed to fixate the spine. There is a paucity of data on a single device that has been used for both fusion and stenosis. Authors aim to demonstrate the long-term outcomes of interspinous fixation at L4-5 for degenerative spinal stenosis. METHODS: We evaluated patients with spinal stenosis and degenerative disc disease who were treated with open decompression and distraction of the spinous processes at L4-L5 using an interspinous device. All patients complained of lower back pain and neurogenic claudication. This is a retrospective review of prospectively collected data (level 3) under an IRB approved study cohort. The charts of patient undergoing lumbar decompression with Interspinous Distraction, Fixation using InSpan device (INSPAN LLC) in an outpatient setting were reviewed with over a 5-year follow-up period. RESULTS: 122 surgical cases of lumbar decompression with interspinous fixation, spanning between the timeframe of September 2011 to October 2016. A total of 56 patients had instrumentation at L4-L5. Total female population was 46%. The median age of the patients included in the population was 50.9±10.7 years with a median BMI of 24.8±11.4 kg/m2. Two-year VAS and ODI showed significant improvement from 8.1±1.2 to 1.5±1.1 and 42.9±14.3 to 14.8±5.1. All surgeries were completed in less than one hour. There was a total of 1 revision case with removal of INSPAN and open hemilaminectomy decompression. CONCLUSIONS: Long term results demonstrated improved outcomes in patients who underwent Interspinous distraction decompression in an ambulatory surgery center using the INSPAN IPD at L4-L5 for Degenerative Spinal Stenosis. There was one revision converted to hemilaminectomy. There were no complications or blood transfusions.

Experience of using a 3-blade LES-Tri retractor over 5 years for lumbar decompression microdiscectomy.

BACKGROUND: Lower back pain is the fifth most common reason for visiting a physician in the United States. Degenerative disc disease, degenerative spondylolisthesis, arthritis, and facet arthrosis are leading causes for lumbar spinal stenosis. The previous gold standard involved open laminectomy combined with medial facetectomy and foraminotomy. The advent of minimally invasive surgery (MIS) and endoscopic technologies has led to less invasive and targeted interventions. In this study, the authors aim to show a five-year experience using a three-blade retractor for lumbar decompression and microdiscectomy. METHODS: A database review of a single spine surgeon over the last 5 years with a total of 306 patients undergoing single-level lumbar decompression with and without microdiscectomy. RESULTS: The average age was 47 ± 12 years and the average BMI was 29.7 ± 5.7 kg/m2 with a total of 52% male patients. Operative levels included L3-4, L4-L5, and L5-S1, with 65% of procedures at the L5-S1 level and follow-up was for two years. Overall mean VAS back scores decreased from 7.9 ± 1.6 to 2.5 ± 1.1 at two-year follow-up, p = 0.001. Preoperative ODI scores improved from 32.1 ± 5.1 to 17.9 ± 4.3 at two-year follow-up, p = 0.002. The mean EBL and surgeon time was 21 ± 15 ml and 35 ± 17 min, respectively. CONCLUSION: This less exposure surgery technique can be performed to allow lumbar decompression, with or without microdiscectomy. This is an anatomy preserving technique with improved outcomes.

Platysma sparing approach to anterior cervical spine surgery: A less exposure surgery technique.

INTRODUCTION: Authors aim to demonstrate the surgical technique and outcomes of using a platysma sparing approach to anterior cervical spine surgery. METHODS: Medical records of 496 prospective patients, group 1 (259 patients) with an outpatient platysma muscle-sparing approach. Group 2 (237 patients) with inpatient standard muscle-splitting approach. RESULTS: Intergroup comparison showed statistical significant improvement in VAS neck and NDI scores p = 0.009 and p = 0.012 and surgical operative time and estimated blood loss, p = 0.003 and p = 0.006 respectively. CONCLUSION: This anatomy sparing technique demonstrates a safe, effective and reproducible approach to cervical spine surgery which is a goal of less exposure surgery philosophy.

Incidence of Fusion Across Total Disc Replacement With Heterotopic Ossification: Are Ball and Socket Disk Replacements Fusing With and Without Radiographic Evidence.

STUDY DESIGN: This is a level III retrospective study. OBJECTIVE: The authors aim to review the outcomes and complications of ball and socket total disk replacements (TDRs). SUMMARY OF BACKGROUND DATA: TDR is a motion-preserving technique that closely reproduces physiologic kinematics of the cervical spine. However, heterotopic ossification and spontaneous fusion after implantation of the total cervical disk have been reported in several studies to decrease the range of motion postulated by in vitro and in vivo biomechanical studies. METHODS: The medical records of 117 consecutive patients undergoing cervical TDR over a 5-year period with Mobi-C, Prodisc-C, Prestige LP, and Secure-C implants were followed. Outcomes assessed included Visual Analogue Scale neck and arm and Neck Disability Index scores. The radiographic assessment looked at heterotopic ossification leading to fusion and complication rates. RESULTS: Of the 117 patients that underwent TDR, 56% were male with the group's mean age being 46.2±10.3 years and body mass index of 18.9±13.6 kg/m. The longest follow-up was 5 years with Prodisc-C group, with overall fusion noted in 16% of patients. One patient was also noted to have fusion which was not seen radiographically but noted intraoperatively for adjacent segment disease. There has been no demonstrable radiographic fusion seen in the Prestige LP group, however, the follow-up has only been 12-24 months for this group. CONCLUSION: In this study, we have demonstrated radiographic fusion anterior to the ball and socket TDR as well as the uncovertebral joint. We postulate that with the use of a mobile core disk there is an increased potential for fusion leading to a nonfunctional disk replacement.

Placing ball and socket cervical total disc replacement using instant center of rotation.

BACKGROUND: Authors aim to evaluate the correct placement of TDR using the instant center of rotation (ICR) as a guide. METHODS: Placement of disc would be divided into three groups using a standard of 1 mm from the ICR: Posterior to ICR, In line with ICR and Anterior to ICR. RESULTS: 49 patients, mean age was 39.96 ±â€¯1.45 years. 42 intraop fluoroscopy images compared to 41 post op radiographic images demonstrated TDR in line with ICR. CONCLUSION: Total discs replacements can be placed intraoperatively using proper technique with verification confirmed using the ICR postoperatively. KEYWORDS: Total disc replacement; instant center of rotation; ideal placement; fluoroscopy; adjacent segment disease; less exposure surgery.

A Prospective Analysis of the Supine and Sitting Straight-Leg Raise Test and Its Performance in Litigation Patients.

BACKGROUND: The supine straight-leg raise (SLR) test has the potential to be exploited by malingering patients. The sitting SLR is believed to be less recognizable, therefore decreasing the chance of fabrication. The authors aim to compare the supine and sitting SLR test in patients with radiculopathy. METHODS: A total of 107 patients with radiculopathy were included in this study. Two groups were created: patients with workman's compensation (Group 1) and a control group of patients without litigation claims (Group 2). RESULTS: Mean age was 47.3 ± 1.3 years with a 51% female population. Correlation analysis demonstrated association between mean angles in both positions, r = 0.248 with significance P = .01. There was equivalence in the mean angles in sitting position of 37 ± 3° compared to 35 ± 2° in supine position (P = .549). There was no significant difference in the mean angle at which the test became positive in the litigation group in the sitting or supine position compared to the nonlitigation group, P = .616 and P = .49 respectively. CONCLUSION: This study demonstrated that the SLR test is equivalent in the sitting and supine position. Therefore, patients with a positive test should have similar angles in both positions, decreasing the chance of falsifying the examination. LEVEL OF EVIDENCE: Prospective analysis. CLINICAL RELEVANCE: Clinical practice.

Sentinel sign in standalone anterior cervical fusion: Outcomes and fusion rate.

BACKGROUND: The authors aim to demonstrate the feasibility, outcomes and fusion rate of a standalone PEEK cage in the outpatient setting. METHODS: 48 consecutive patients undergoing standalone ACDF (S-ACDF) (Group 1) were compared to control group of 49 patients who had ACDF with ACP (Group 2). RESULTS: Analysis of follow-up at the one year period postoperative outcomes between groups 1 and 2 demonstrated no intergroup statistical significant difference in VAS neck, arm and NDI scores p = 0.414, 0.06 and p = 0.328 respectively. CONCLUSION: We conclude that S-ACDF can be safely done in an ambulatory surgery center with satisfactory clinical and patient-reported outcomes.

A psoas splitting approach developed for outpatient lateral interbody fusion versus a standard transpsoas approach.

BACKGROUND: The technique of transpsoas lateral interbody fusion has been adopted to avoid direct anterior interbody fusion, but lateral fusions have been limited to disc spaces above L5 and are associated with neurologic injuries especially to the lumbar plexus when approaching L4-5. The authors aim to demonstrate a psoas splitting technique to decrease risk of complications associated with the standard transpsoas technique. METHODS: Medical records of 84 patients with prospectively collected data reviewed. Two groups created 44 patients with standard lateral transpsoas approach (group 1) and 40 patients with psoas splitting approach (group 2). The psoas splitting approach utilizes two blades placed anteriorly and posteriorly to split the psoas fibers anteriorly while keeping the posterior blade docked in place where it enters the psoas muscle. The cephalocaudal blades sit above the psoas muscle measuring 30-40 mm shorter than the posterior docking blade. RESULTS: Thirty-nine males and 45 females, age range 31-71 years, average 58±2 years. Average body mass index (BMI) was 28.4±1.1 kg/m2. Mean preoperative standard approach Oswestry disability index (ODI) increased from 48.4±3.0 to 55.2±4.0 compared to psoas splitting approach preoperative ODI means reduced from 45.1±5.0 to 34.9±6.0 (P=0.010). Group 1 mean preoperative visual analogue scale (VAS) score improved from 7.8±0.3 to 3.8±0.6 compared to group 2 mean preoperative VAS score which improved from 7.2±0.4 to 2.7±0.5 (P=0.048). Major complication rate of 20.5% was noted in standard transpsoas approach patients, including inability to walk and dermatome numbness. CONCLUSIONS: The outcomes of this study have shown that patients who had lateral lumbar interbody fusion (LLIF) with the psoas splitting approach had statistically significant improvement in ODI scores compared to the standard approach. Fusion was achieved in all patients and there was no evidence of implant failure or subsidence. In the psoas splitting group the major complication rate was only 5%.

Limiting fusion levels by combining anterior cervical decompression and fusion with posterior laminectomy: Technical note.

BACKGROUND: Authors aim to report on the outcomes of combining selective anterior cervical decompression and fusion (ACDF) with laminectomy in patients with cervical spondylotic radiculomyelopathy (CSR). METHODS: 10 patients with ACDF and posterior laminectomy reviewed. RESULTS: 60% female population, mean age 61 ±â€¯3 years, mean BMI 24.7 ±â€¯3.4 kg/m2. VAS and NDI showed significant improvement, p < 0.001, p = 0.02 respectively. Mean PCS 31.9 ±â€¯2.7, MCS 38.9 ±â€¯3.4 improved to mean PCS 42.2 ±â€¯5.1, MCS 51.0 ±â€¯4.7, p = 0.09 and 0.06 respectively. At final follow up fusion rate was 90% and all patients had Nurick Grade 0. CONCLUSION: In this pilot study, procedure shown to be safe with improved symptoms.

Option for transverse midline incision and other factors that determine patient's decision to have cervical spine surgery.

BACKGROUND: Authors aim to determine patients' preference for surgical incision and factors affecting the decision for surgery to the anterior neck. METHODS: A questionnaire was presented prior to evaluation and if preceded to surgery followup given. RESULTS: 243 patients completed questionnaire, with 60% female population and younger than 50 years. 151 patients preferred a transverse midline incision with a statistically significant increase in outcomes and cosmesis importance and a decrease in the importance of board certification. CONCLUSION: Findings of questionnaire demonstrate that patients' prefer a transverse midline anterior neck incision, with surgical outcomes being the overall factor affecting decision making.

Decreasing radiation dose with FluoroLESS Standalone Anterior Cervical Fusion.

BACKGROUND: Radiation dose continues to be a concern especially in the field of spine surgery, where anterior and posterior instrumentation is frequently utilized to treat multiple pathologies. The authors aim to demonstrate the feasibility of decreasing the radiation dose in standalone anterior cervical discectomy and fusion (ACDF). METHODS: Standalone ACDF (S-ACDF) with 48 consecutive patients (Group 1) with a comparison control group with ACDF with an anterior cervical plate (ACP) of 49 patients (Group 2). Fluoroscopy was performed for positioning, identification of level, placement of the implant, each screw, final AP and lateral images for the first 20 patients in Group 1. Screw placement could then be performed confidently based on cosine rule of cosine (Ѳ) = adj/hyp. RESULTS: Forty-eight patients in Group 1 (S-ACDF) and 49 patients in Group 2 (ACDF-ACP). Statistical significance not demonstrated for age, BMI or gender, P=0.691, 0.947 and 0.286 respectively. Mean radiation dose in group 1 of 17.9±6.6 mAs and 0.8±0.3 mSv was significantly less compared to group 2 which was 29.8±5.4 and 1.3±0.2 mSv, P<0.001. The average radiation dose for single-level fusion in Group 1 was 12.5±3.5 mAs and 0.5±0.1 mSv this is compared to Group 2 of 27.8±3.9 mAs and 1.2±0.2 mSv, P=0.001. The average radiation dose for two level fusion in Group 1 was 22.2±5.1 mAs and 0.9±0.2 mSv this is compared to Group 2 of 33.9±6.0 and 1.4±0.3 mSv, P=0.001. CONCLUSIONS: In the outpatient setting, S-ACDF has shown a statistically significant intergroup difference in overall radiation dose, as well as single and two-level fusions, (P<0.001). We conclude that S-ACDF can decrease overall radiation exposure to patients.

Utility of Mobile Apps for Video Conferencing to Follow Patients at Home After Outpatient Surgery.

INTRODUCTION: Outpatient surgery has a great opportunity to demonstrate the role of using mobile video conference (VC) postoperatively. Our patients use technology to help decision making in finding physicians. The authors aim to assess patient's perception on the use of mobile apps for VC with the surgeon and/or staff. METHODS: Consenting patients completed a questionnaire of 10 questions preoperatively and postoperatively to assess the difference in opinion. RESULTS: Overall, 120 patients completed the questionnaire preoperatively with 58% female population, 71% younger than 65 years, and 67% having a GED/higher education. Fifty-two patients had surgery with 54% female population, and 60% were younger than 65 years. All patients had mobile apps for VC with 55% using WhatsApp, 40% using Facetime, and 5% other. In person, being with a trained educator at the office was the preferred method for learning about surgical procedures. Overall, four patients contacted the surgeon directly preoperatively. After surgery, 8 of 52 patients (15%) used VC to the surgeon directly, and 37 patients used the VC with the team. CONCLUSION: With advances in new technology, the use of mobile video conferencing adds a new forum for communication with patients. In the outpatient surgical setting, this forum would improve patient-physician relations.

Soft tissue swelling incidence using demineralized bone matrix in the outpatient setting.

AIM: To assess use of demineralized bone matrix (DBM) use in anterior cervical discectomy and fusion (ACDF) in outpatient setting. METHODS: One hundred and forty-five patients with prospectively collected data undergoing single and two level ACDF with DBM packed within and anterior to polyetheretherketone (PEEK) cages. Two groups created, Group 1 (75) outpatients and control Group 2 (70) hospital patients. Prevertebral soft tissue swelling (PVSTS) was measured anterior to C2 and C6 on plain lateral cervical radiographs preoperatively and one week postoperatively and fusion assessed at two years. RESULTS: There was no intergroup significance between preoperative and postoperative visual analogue scales (VAS) and neck disability index (NDI) scores between Group 1 and 2. Mean preoperative PVSTS in Group 1 was 4.7 ± 0.2 mm at C2 level and 11.1 ± 0.5 at C6 level compared to Group 2 mean PVSTS of 4.5 ± 0.5 mm and 12.8 ± 0.5, P = 0.172 and 0.127 respectively. There was no radiographic or clinical evidence of adverse reaction noted. In Group 1 mean postoperative PVSTS was 5.5 ± 0.4 mm at C2 and 14.9 ± 0.6 mm at C6 compared Group 2 mean PVSTS was 4.9 ± 0.3 mm at C2 and 14.8 ± 0.5 mm at C6, P = 0.212 and 0.946 respectively. No significant increase in prevertebral soft tissue space at C2 and C6 level demonstrated. CONCLUSION: ACDF with adjunct DBM packed PEEK cages showed a statistical significant intragroup improvement in VAS neck pain scores and NDI scores (P = 0.001). There were no reported serious patient complications; post-operative radiographs demonstrated no significant difference in prevertebral space. We conclude that ACDF with DBM-packed PEEK cages can be safely done in an ASC with satisfactory outcomes.

Misaligned Versus Straight Placement of Anterior Cervical Plates: A Clinical and Radiologic Outcomes Study.

BACKGROUND: In anterior cervical diskectomy and fusion (ACDF), misaligned plates are concerning because of the risk of screw-and-plate failure; however, these plates also hypothetically have the potential for asymmetric micromotion on the facet and uncovertebral joint. The aim of this study was to determine whether misaligned plate placement during ACDF had clinical benefits compared with straight plate placement. METHODS: Postoperative AP radiographs of 128 consecutive patients who underwent ACDF with anterior cervical plate (ACP) fixation were reviewed, and plate alignment was assessed. Patients were separated into control group 1 (straight plates) or group 2 (misaligned plates). RESULTS: The mean age of patients was 51.5 ± 0.9 years, and women represented 51% of the total population. There was no significant difference between groups with regard to the preoperative visual analog scale (VAS) and Neck Disability Index (NDI) scores (P = 0.744 and P = 0.943, respectively). At 6 weeks postoperatively, the VAS scores for group 1 decreased from 7.6 ± 0.2 to 4.0 ± 0.2 compared with the scores in group 2, which decreased from 7.7 ± 0.2 to 2.1 ± 0.1, which demonstrated statistical significance (P = 0.019). At 2-year follow-up, no significant difference was demonstrated between the groups' VAS and NDI scores (P = 0.670 and P = 0.266). CONCLUSION: Misaligned plates have increased torsional strength and are associated with better clinical outcomes compared with those of straight plates in the early postoperative period. After fusion, no significant difference in clinical outcomes between the groups was noted, which may reduce the concerns regarding misaligned plates. LEVEL OF EVIDENCE: Retrospective comparative study.

Eligibility of Outpatient Spine Surgery Candidates in a Single Private Practice.

STUDY DESIGN: Level III. PURPOSE: To retrospectively review the eligibility of surgical patients meeting predetermined outpatient surgery criteria in a single-surgeon private practice. SUMMARY OF BACKGROUND DATA: There is a burgeoning awareness among patients, surgeons, and insurers of the cost benefits and safety of outpatient spine surgeries. At the end of 2014, Centers for Medicare & Medicaid Services have released its final 2015 payment rules and codes for spinal decompression and fusion. This move confirms the safety of procedures being performed in the ambulatory surgery centers (ASCs). METHODS: We conducted a database review between 2008 and 2014 and identified 1625 orthopedic procedures. All nonsurgical spine procedures were excluded from the study. Eligibility for outpatient spine surgery was based on criteria generated from a combination of published standard of care for major operations and the chief surgeon's experience. A matched cohort based on type of surgery in each facility of all spine surgery patients was created, group 1 (hospital patients) and group 2 (ASC patients). RESULTS: A total of 708 patients underwent spinal surgery during this time period with a 53% female population. A total of 557 of 708 (79%) patients were eligible for outpatient spine surgery. There were 210 surgical procedures in group 1 (inpatient) comprised of 72 decompression and 138 fusion procedures. In group 2 (outpatient), there were 347 procedures made up of 150 patients undergoing decompression and 197 undergoing fusion or disc replacement. To confirm that hospital procedures are eligible to be performed in the ASC, the χ test was performed. We found that ASC-eligible hospital patients can indeed be done in an ASC (P=0.037). CONCLUSIONS: Outpatient spine surgery is feasible in 79% of patients in this single-surgeon private practice. On the basis of these results, a majority of spine procedures can be performed in an outpatient setting following our eligibility criteria.

Clinical Outcomes With Midline Cortical Bone Trajectory Pedicle Screws Versus Traditional Pedicle Screws in Moving Lumbar Fusions From Hospitals to Outpatient Surgery Centers.

STUDY DESIGN: Level III. OBJECTIVE: To report on the outcomes of midline cortical bone trajectory (CBT) pedicle screw surgical technique for posterior lumbar fixation in the outpatient surgery center (OSC) compared with traditional pedicle screws in the hospital. SUMMARY OF BACKGROUND DATA: Traditional pedicle screws have been the gold standard for posterior lumbar fusion. Advances in spine surgery, including less invasive procedures have propelled the design of instruments and implants to achieve greater posterior spinal fixation, with decreased tissue destruction and higher safety margins. Biomechanical studies have validated the superior pullout strength of cortical screws versus the traditional pedicle screws and represent an opportunity to perform safe lumbar fusions in OSCs with same day discharge. MATERIALS AND METHODS: The medical records of 60 patients with prospectively collected data were reviewed. Two matched cohort groups consisting of 30 patients each, CBT pedicle screws performed in OSC patients (group 1) was compared with traditional pedicle screws performed in hospital patients (group 2). Outcomes were assessed with self-reported Visual Analog Scale (VAS) scores, Oswestry Disability Index scores, and radiologic fusion rate. RESULTS: Totally, 33 males and 27 females, age range (28-75), average 58±3 years. Average body mass index was 29±1.15 kg/m. A total of 65% of surgeries were at L5-S1 level. Significant improvement noted in VAS back pain scores in the OSC group from 7.8±0.5 to 2.5±0.7, P=0.001. Comparing intergroup VAS back pain scores and Oswestry Disability Index scores, OSC group demonstrated significant improvement, P=0.004 and 0.027, respectively. Fusion rate at 2 years was similar, P=0.855 between groups. CONCLUSIONS: We successfully transitioned our lumbar fusions from hospitals to OSCs using a midline CBT pedicle screw technique. Although traditional pedicle screw placement is effective and may be viable in an OSC, we see more advantages to use midline cortical screws over traditional pedicle screws.

Clinical Outcomes of Outpatient Cervical Total Disc Replacement Compared With Outpatient Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: A single-center, retrospective study. OBJECTIVE: The aim of this study was to determine the safety and outcomes of total disc replacement (TDR) as an outpatient procedure in the ambulatory surgery center (ASC). SUMMARY OF BACKGROUND DATA: Anterior cervical discectomy and fusion (ACDF) has been demonstrated to be safe in the outpatient setting, as the awareness of same-day surgery procedures is on the rise due to better outcome and shorter recovery time. There is a need for motion preservation in a subset of patients TDR provides a solution. Transitioning spine surgery to the outpatient setting including cervical TDR is the next logical step. METHODS: The medical records of 55 consecutive patients undergoing single level TDR (Group 1) were compared with our control group of 55 patients who had single-level ACDF (Group 2). Outcomes assessed included Visual Analogue Scale (VAS) neck, arm, neck disability index (NDI) scores, and complication rate. RESULTS: Fifty-five patients in Group 1 (TDR, 60%) were male with the group's mean age being 42.6 ±â€Š1.4 years and body mass index (BMI) 24.8 ±â€Š1.2 kg/m. Fifty-five patients in Group 2 (ACDF), 57%, were male with the group's mean age being 53 ±â€Š1.0 years and mean BMI 27.9 ±â€Š0.8 kg/m. There was no statistically significant intergroup difference in 2-year VAS neck, arm and NDI scores. Dysphagia was the most common postoperative compliant in both groups (six patients), with no intergroup significance, P = 0.4. CONCLUSION: In the ambulatory setting, TDR has shown statistical significant intragroup improvement in VAS neck, arm pain scores, and NDI scores (P < 0.001). In this study, no patients reported serious complications, no incidence of hematoma formation, or worsening postop pain. We conclude that single-level TDR can be safely done in an ASC with satisfactory clinical and patient-reported outcomes. This is comparable to single-level ACDF in the outpatient setting and previous 2-year TDR studies. LEVEL OF EVIDENCE: 3.

Lateral Lumbar Interbody Fusion in Ambulatory Surgery Centers: Patient Selection and Outcome Measures Compared With an Inhospital Cohort.

STUDY DESIGN: Comparative analysis. OBJECTIVE: To evaluate the safety and outcomes of moving lateral lumbar interbody fusion (LLIF) surgeries to an outpatient setting. SUMMARY OF BACKGROUND DATA: 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. METHODS: 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. RESULT: A total of 34 males and 36 females, age range (31-71) average 59.3 ±â€Š2.3 years. Average BMI was 29.6 ±â€Š1.1 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 ±â€Š3.0 to 55.5 ±â€Š3.2 compared with outpatient preoperative ODI means reduced from 45.2 ±â€Š5.1 to 39.1 ±â€Š4.6. There was no statistically significant change in VAS scores between groups. There was however significant improvement in outpatient preoperative VAS scores from 7.3 ±â€Š0.5 to 4.1 ±â€Š0.5, P = 0.045. CONCLUSION: 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. LEVEL OF EVIDENCE: 3.

Biomechanics of posterior instrumentation in L1-L3 lateral interbody fusion: Pedicle screw rod construct vs. transfacet pedicle screws.

BACKGROUND: The use of pedicle screws is the gold standard for supplemental posterior fixation in lateral interbody fusion. Information about the performance of transfacet pedicle screws compared to standard pedicle screws and rods in the upper lumbar spine with or without a lateral interbody fusion device in place is limited. METHODS: Fifteen fresh frozen human cadaveric lumbar spine segments (T12-L4) were studied using standard pure moment flexibility tests. Specimens were divided into two groups to receive either bilateral transfacet pedicle screws (n=8) or bilateral pedicle screws (n=14). Stability of each motion segment (L1-L2 and L2-L3) was evaluated intact, with posterior instrumentation with an intact disc, with posterior instrumentation and a lateral interbody fusion device in place, and following cyclic loading with the interbody device and posterior instrumentation still in place. Both raw values of motion (range of motion, lax zone and stiff zone) and normalized mobility (ratios to intact) were analyzed for each case. FINDINGS: In terms of immediate stability, transfacet pedicle screws performed equivalent to similarly sized pedicle screws, both with intact disc and with lateral interbody fusion device in all directions of loading. Stability following cyclic loading decreased significantly during lateral bending and axial rotation. INTERPRETATION: Posterior fixation with transfacet pedicle screws provides equivalent immediate stability to similarly sized pedicle screws. However, in the presence of a lateral interbody fusion device, pedicle screws seem to resist loosening more and may be a better option for fusion in the upper lumbar spine.