Postoperative Adjacent Segment Disease in Minimally Invasive Transforaminal Lumbar Interbody Fusion with Adjacent Laminectomy for Grade I-II Spondylolisthesis and Adjacent Spinal Stenosis.

BACKGROUND AND OBJECTIVES: Studies have demonstrated increased risk of adjacent segment disease (ASD) after open fusion with adjacent-level laminectomy, with rates ranging from 16%-47%, potentially related to disruption of the posterior ligamentous complex. Minimally invasive surgical (MIS) approaches may offer a more durable result. We report institutional outcomes of simultaneous MIS transforaminal lumbar interbody fusion (MISTLIF) and adjacent-level laminectomy for patients with low grade spondylolisthesis and ASD. METHODS: Retrospective analysis was performed on patients who underwent MISTLIF with adjacent level laminectomy to treat grade I-II spondylolisthesis with adjacent stenosis at a single institution from 2007-2022. RESULTS: A total of 34 patients met criteria, with mean follow-up of 23.1 months. In total, 37 levels were fused and 45 laminectomies performed. In this group, 21 patients received a single level laminectomy and single-level MISTLIF, 10 patients received a 2-level laminectomy and single-level MISTLIF, 2 patients received a single-level laminectomy and 2-level MISTLIF, and 1 patient received a 2-level laminectomy and 2-level MISTLIF. Three (8.8%) patients experienced clinically significant postoperative ASD requiring reoperation. Three other patients required reoperation for other reasons. Multiple logistic regression did not reveal any association between development of ASD and surgical covariates. CONCLUSION: MISTLIF with adjacent-level laminectomy demonstrated a favorable safety profile with rates of postoperative ASD lower than published rates after open fusion and on par with the published rates of ASD from MISTLIF alone. Future prospective studies may better elucidate the durability of adjacent-level laminectomies when performed alongside MISTLIF, but retrospective data suggests it is safe and durable.

Mycobacterium xenopi vertebral osteomyelitis in a patient with systemic lupus erythematosus: illustrative case.

BACKGROUND: Mycobacterium xenopi is a common nontuberculous Mycobacterium (NTM) that is slow growing and an infrequent cause of infection. When infections do occur, it is by exposure to contaminated soil or water or to infectious aerosols. Nontuberculous mycobacterial infections in the spine are exceedingly rare. Risk factors can include immunosuppression, particularly human immunodeficiency virus; however, other systemic diseases such as systemic lupus erythematosus (SLE) have been reported. OBSERVATIONS: The authors report a case of cord compression due to M. xenopi vertebral osteomyelitis with an epidural abscess in a patient with SLE on hydroxychloroquine and recent steroid use. The authors explore the presentation of a patient who developed acute neurological deficits concerning for spinal pathology secondary to NTM. Although considered a rare occurrence, patients with autoimmune pathologies are susceptible to infection by unusual organisms. Standard treatment of autoimmune diseases can predispose patients to infection and warrant surgical correction to prevent long-term neurological deficits. LESSONS: There is still much work and research to be done in the exploration and understanding of nontuberculous mycobacterial infection, pathophysiology, and treatment in the immunocompetent population and in patients with autoimmune disorders.

Upstream Effects: Intraoperative Migration of Intradural Extramedullary Tumor After Non-Adjacent Level Stenosis Decompression.

A 74-year-old man with back pain, foot numbness, and hip/thigh radiculopathy was found to have an L1-L2 intradural extramedullary neoplasm and severe L4-L5 stenosis. L4-L5 minimally invasive laminectomy for decompression and concomitant L1-L2 minimally invasive laminectomy for tumor resection were planned. L4-L5 laminectomy was completed first followed by the L1-L2 laminectomy. On extensive intradural exploration at L1-L2, no neoplasm was found. Immediate postoperative imaging showed that the intradural extramedullary tumor had migrated caudally by nearly a complete spinal level, presumably due to changes in cerebrospinal fluid pressure and resultant shift in intradural contents after the L4-L5 laminectomy. Successful resection of the intradural extramedullary tumor was performed, with improvement in the patient's symptoms.

Perception of frailty in spinal metastatic disease: international survey of the AO Spine community.

OBJECTIVE: Frailty has not been clearly defined in the context of spinal metastatic disease (SMD). Given this, the objective of this study was to better understand how members of the international AO Spine community conceptualize, define, and assess frailty in SMD. METHODS: The AO Spine Knowledge Forum Tumor conducted an international cross-sectional survey of the AO Spine community. The survey was developed using a modified Delphi technique and was designed to capture preoperative surrogate markers of frailty and relevant postoperative clinical outcomes in the context of SMD. Responses were ranked using weighted averages. Consensus was defined as ≥ 70% agreement among respondents. RESULTS: Results were analyzed for 359 respondents, with an 87% completion rate. Study participants represented 71 countries. In the clinical setting, most respondents informally assess frailty and cognition in patients with SMD by forming a general perception based on clinical condition and patient history. Consensus was attained among respondents regarding the association between 14 preoperative clinical variables and frailty. Severe comorbidities, extensive systemic disease burden, and poor performance status were most associated with frailty. Severe comorbidities associated with frailty included high-risk cardiopulmonary disease, renal failure, liver failure, and malnutrition. The most clinically relevant outcomes were major complications, neurological recovery, and change in performance status. CONCLUSIONS: The respondents recognized that frailty is important, but they most commonly evaluate it based on general clinical impressions rather than using existing frailty tools. The authors identified numerous preoperative surrogate markers of frailty and postoperative clinical outcomes that spine surgeons perceived as most relevant in this population.

Comparison of Perioperative Complications After Anterior-Posterior Versus Posterior-Anterior-Posterior Cervical Fusion: A Retrospective Review of 153 Consecutive Cases.

BACKGROUND: Although published data support the utilization of circumferential fusion to treat select cervical spine pathologies, it is unclear whether the posterior-anterior-posterior (PAP) fusion has increased risks compared with the anterior-posterior fusion. OBJECTIVE: To evaluate the differences in perioperative complications between the 2 circumferential cervical fusion approaches. METHODS: One hundred fifty-three consecutive adult patients who underwent single-staged circumferential cervical fusion for degenerative pathologies from 2010 to 2021 were retrospectively reviewed. Patients were stratified into the anterior-posterior ( n = 116) and PAP ( n = 37) groups. The primary outcomes assessed were major complications, reoperation, and readmission. RESULTS: Although the PAP group was older ( P = .024), predominantly female ( P = .024), with higher baseline neck disability index ( P = .026), cervical sagittal vertical axis ( P = .001), and previous cervical operation rate ( P < .00001), the major complication, reoperation, and readmission rates were not significantly different from the 360° group. Although the PAP group had higher urinary tract infection ( P = .043) and transfusion ( P = .007) rates, higher estimated blood loss ( P = .034), and longer operative times ( P < .00001), these differences were insignificant after the multivariable analysis. Overall, operative time was associated with older age (odds ratio [OR] 17.72, P = .042), atrial fibrillation (OR 158.30, P = .045), previous cervical operation (OR 5.05, P = .051), and lower baseline C1 - 7 lordosis (OR 0.93, P = .007). Higher estimated blood loss was associated with older age (OR 1.13, P = .005), male gender (OR 323.31, P = .047), and higher baseline cervical sagittal vertical axis (OR 9.65, P = .022). CONCLUSION: Despite some differences in preoperative and intraoperative variables, this study suggests both circumferential approaches have comparable reoperation, readmission, and complication profiles, all of which are high.

Comparison of Fusion versus Nonunion After 4-Level and 5-Level Anterior Cervical Diskectomy and Fusion With Anterior Plate Fixation.

BACKGROUND: Nonunion remains a concern in multilevel anterior cervical discectomy and fusion (ACDF), yet there are limited data on nonunion after 4 to 5-level ACDF. In fact, the largest series on 4-level or 5-level ACDF focused specifically on the swallowing outcomes. OBJECTIVE: To assess nonunion after 4 to 5-level ACDF. METHODS: Forty-one patients treated with 4 to 5-level ACDF with minimum of 12-month radiographic follow-up were retrospectively reviewed. Nonunion was found in 25 patients (61%) and 42 levels (25%) and complete fusion in 16 (39%) patients and 126 levels (75%). The 2 groups were further compared. RESULTS: One-level nonunion was by far the most common pattern compared with multilevel nonunion. Nonunion occurred more frequently at the caudal than the cranial or middle segments ( P < .0001). There were significantly more subsidence ( P < .0001) and screw fractures/pullouts ( P < .0001) in the nonunion compared with the fusion group. The symptomatic patients were significantly younger than the asymptomatic patients ( P = .044). The symptomatic levels were significantly more than asymptomatic levels ( P = .048). Equal proportion of patients implanted with allograft and polyetheretherketone had nonunion. However, there were markedly more nonunion than fused levels with allograft and more fused than nonunion levels with polyetheretherketone ( P = .023). The reoperation rate was 24.4% and mostly due to nonunion. There were no reoperations within 90 days of the primary surgery. CONCLUSION: The nonunion rate for 4-level and 5-level ACDF may be higher than previously reported. Symptomatic nonunion remains a major reason for reoperation after multilevel ACDF. Baseline characteristics that negatively affect fusion may be obviated by careful patient selection.

Recurrent IgG4-Related Meningeal Disease of the Cervicothoracic Spine: A Case Report and Review of the Literature.

Background: IgG4-related disease is a rare, recently recognized chronic inflammatory disease. IgG4-related hypertrophic pachymeningitis (IgG4-RHP) of the central nervous system predominantly involves the cranial meninges. Spinal involvement remains rare. Objective: We report a case of recurrent cervicothoracic IgG4-RHP and review the surgical literature. Methods and Materials: A 35-year-old woman presented with a 6-month history of neck and right shoulder pain, progressive right triceps weakness and paresthesias in the right C8 and T1 dermatomes. MRI demonstrated a T2 hypointense epidural soft tissue mass extending from C6-T1. The patient underwent C6-T1 laminoforaminotomy and partial resection with near complete symptom resolution. Histopathology was consistent with diagnosis of IgG4-RHP. Eighteen months postoperatively, she experienced symptom recurrence necessitating re-operation and adjuvant postoperative prednisone with complete resolution at 40-months' follow-up. Results and Conclusions: Of the now nineteen confirmed cases of IgG4-RHP, fifteen underwent surgery. A majority achieved partial resection. Three surgical patients did not receive adjuvant therapy with symptomatic recurrence between 2 and 18 months.

Cervical Alignment Analysis Comparing Two-Level Cervical Disc Arthroplasty with Anterior Cervical Discectomy and Fusion with Anterior Plate Fixation.

OBJECTIVE: This study assesses cervical alignments after 2-level cervical disc arthroplasty (CDA) versus anterior cervical discectomy and fusion (ACDF) with anterior plate fixation. METHODS: Eighty-two patients who underwent 2-level CDA or ACDF in 2014-2019 were identified. Cervical alignment parameters were compared between the 2 cohorts. Subgroup analyses were performed to determine factors that differentiate alignment outcomes between the 2 procedures. RESULTS: Although both cohorts achieved significant focal lordosis (FL) and overall cervical lordotic (CL) gains, CDA cohorts achieved significantly greater 12-month FL gain (P = 0.022). However, in a multivariate analysis controlling for preoperative variables, FL gain was no longer significant. Although the CDA cervical sagittal vertical axis (cSVA) significantly improved at 3 (P = 0.030) and 12 (P = 0.007) months, these improvements were not superior to the ACDF cSVA. Male patients undergoing CDA achieved greater 12-month CL gain. Patients undergoing CDA with body mass index >25 kg/m2 achieved greater 12-month FL gain. Patients undergoing CDA with symptom duration >12 months achieved greater FL gain at 3 and 12 months. Patients undergoing CDA with high baseline T1 slope or cSVA achieved greater 12-month cSVA reduction. Clinical outcomes were comparable between the 2 cohorts. Unlike the ACDF group, CL gain in the CDA group was significantly correlated with the cSVA reduction, which was associated with significant improvement in the Neck Disability Index, arm pain, and 12-Item Short-Form Mental Component Scores. Heterotopic ossification was not found to significantly affect patient outcome and cervical alignment in both cohorts. CONCLUSIONS: ACDF and CDA are viable options for 2-level degenerative disc disease in carefully selected patients. Both approaches produced equivalent postoperative alignment changes in a 2-level operation.

Clinical Outcomes After 4- and 5-Level Anterior Cervical Discectomy and Fusion for Treatment of Symptomatic Multilevel Cervical Spondylosis.

OBJECTIVE: There are limited patient-reported outcome measure (PROM) data on 4-level and 5-level anterior cervical discectomy and fusion (ACDF). The largest series to date solely focused on complications. This retrospective series evaluates PROMs after 4-level and 5-level ACDF. METHODS: Pertinent data from adult patients treated with a 4-level or 5-level ACDF in 2011-2019 were analyzed. PROMs and minimal clinically important differences (MCIDs) were assessed. Factors associated with favorable and unfavorable outcomes were identified. RESULTS: There were 34 patients (30 underwent 4-level and 4 underwent 5-level ACDFs) with a mean age of 59.6 years; 55.9% were women. At 3 months, there were significant improvements in PROMs except Short-Form 12-Item Survey (SF-12) mental component subscale, which showed modest improvement. At 12 months, there were significant improvements in PROMs except SF-12 physical component subscale (PCS), which showed moderate improvement. The proportions of patients who met the MCID cutoffs ranged from 35.3% (numeric rating scale [NRS]-neck) to 75% (Veteran RAND 12-Item Survey [VR-12] PCS) at 3 months and 38.2% (NRS-arm) to 65.5% (VR-12 mental component subscale) at 12 months. Shorter symptom duration was associated with significantly reduced postoperative pain and Neck Disability Index scores. Shorter length of stay was associated with significantly improved postoperative functional outcomes. patients undergoing 4-level compared with 5-level ACDF achieved better postoperative PROMs. Shorter procedure duration was associated with improved PROMs at 3 months. No patient returned to the operating room within 30 days. Patients who required reoperation achieved significantly inferior Neck Disability Index, NRS-neck, and SF-12 PCS scores at 3 months. CONCLUSIONS: This study showed satisfactory PROMs up to 12 months after 4-level and 5-level ACDF despite the complication rate. With thorough preoperative planning and meticulous technique, performing this procedure in carefully selected patients may be associated with acceptable PROMs.

Minimally Invasive Posterior Cervical Foraminotomy Versus Anterior Cervical Fusion and Arthroplasty: Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVES: Patients with lateral cervical disc and foraminal pathology can be treated with anterior and posterior approaches including anterior cervical discectomy and fusion(ACDF), cervical total disc arthroplasty(TDA), and minimally invasive posterior cervical foraminotomy(MIS-PCF). Although MIS-PCF may have some advantages over the anterior approaches, few comparative studies and meta-analyses have been done to assess superiority. METHODS: This study includes a systematic review of the literature and meta-analysis of studies directly comparing minimally invasive posterior cervical foraminotomy to either anterior cervical discectomy and fusion or cervical total disc arthroplasty. RESULTS: In comparing patients undergoing ACDF and MIS-PCF, operative time ranged from 68 to 97.8 minutes in the ACDF group compared to 28 to 93.9 minutes in the MIS-PCF group. Mean postoperative length of stay ranged from 33.84 to 112.8 hours in the ACDF group compared to 13.68 to 83.6 hours in the MIS-PCF group. The total complication rates were 3.72% in the ACDF group and 3.73% in the MIS-PCF group. A random-effects model meta-analysis was carried out which failed to show a statistically significant difference in the complication rate between the two procedures(OR .91; 95% CI 0.13, 6.43; P = .92, I2 = 59%). The total reoperation rate was 3.5% in the ACDF group and 5.4% in the MIS-PCF group. A random-effects model meta-analysis was carried out which failed to show a statistically significant difference in the reoperation rate between the two procedures(OR .66; 95% CI 0.33, 1.33; P = .25, I2 = 0). In comparing patients undergoing TDA and MIS-PCF, operative time ranged from 90.3 to 106.7 minutes in the TDA group compared to 77.4 to 93.9 minutes in the MIS-PCF group. Mean postoperative length of stay ranged from 103.2 to 165.6 hours in the TDA group and 93.6 to 98.4 hours in the MIS-PCF group. The complication rate ranged from 23.5 to 28.6% in the TDA group and 0 to 14.3% in the MIS-PCF group. The overall reoperation rates were 2.6% in the TDA group and 10.2% in the MIS-PCF group. CONCLUSIONS: There is no clear superiority between MIS-PCF and ACDF/TDA in terms of operative time, postoperative length of stay, or rate of complications/reoperations. Further studies with increased follow-up intervals >48 months, and higher sample sizes are necessary to determine the true superiority of MIS-PCF and anterior neck approaches in treatment of lateral disc and foraminal pathology.

ACR Appropriateness Criteria® Low Back Pain: 2021 Update.

In the United States, acute low back pain, with or without radiculopathy, is the leading cause of years lived with disability and the third ranking cause of disability-adjusted life-years. Uncomplicated acute low back pain and/or radiculopathy is a benign, self-limited condition that does not warrant any imaging studies. Imaging is considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain. It is also considered for those patients presenting with red flags, raising suspicion for a serious underlying condition, such as cauda equina syndrome, malignancy, fracture, or infection. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Patient Satisfaction Following Minimally Invasive and Open Surgeries for Adult Spinal Deformity.

BACKGROUND: Patient satisfaction has become an important variable in assessing outcomes after spine surgery. Although minimally invasive surgery (MIS) techniques have become popular owing to reduced perioperative complications compared with open deformity surgery, whether patient-reported postoperative satisfaction differ between the 2 surgical approaches is unclear. The aim of this study was to characterize postoperative patient-reported outcomes (PRO) in patients who underwent open surgery or MIS for adult spinal deformity (ASD). METHODS: PRO scores were prospectively collected for patients undergoing deformity correction surgery between 2016 and 2018. Inclusion criteria were age >18 years, ASD, and completed PRO surveys. Patient demographic, clinical, and radiographic data and PRO survey responses were analyzed. A post hoc analysis comparing patients who were satisfied with their outcome and those who were unsatisfied was performed. RESULTS: Forty patients who underwent operative management of ASD (19 in the open surgery group and 21 in the MIS group) met the criteria for inclusion in this study. Patients in the MIS group reported higher mental health and self-image scores at 6 months; however, at the 12-month follow-up, both the open surgery and MIS groups reported minimal clinically important differences in back pain, leg pain, and functional status. Patient satisfaction scores did not differ based on surgical approach or intraoperative complications. CONCLUSIONS: PRO after open surgery and after MIS for ASD reflected successful outcomes with significant improvements in PRO survey scores but with subtle differences in the postoperative recovery process. The MIS group reported faster recovery with earlier improvement in self-image and mental health scores, which may stem from correction of smaller deformities. At the 12-month follow-up, postoperative satisfaction was high for the majority of patients in both groups.

A retrospective comparison of radiographic and clinical outcomes in single-level degenerative lumbar disease undergoing anterior versus transforaminal lumbar interbody fusion.

BACKGROUND: Single-level lumbar degenerative disc disease (DDD) remains a significant cause of morbidity in adulthood. Anterior lumbar interbody fusion (ALIF) and Transforaminal lumbar interbody fusion (TLIF) are surgical techniques developed to treat this condition. With limited studies on intermediate term outcomes in a single cohort, we compare radiographic and clinical outcomes in patients undergoing ALIF and TLIF. METHODS: A retrospective chart review was performed on 164 patients (111 TLIF; 53 ALIF) over a 60-month period. X-ray radiographs obtained pre-operatively, prior to discharge, and at one year were utilized for radiographic assessment. Segmental lordosis, lumbar lordosis and HRQOL scores were measured preoperatively and at one-year timepoints. RESULTS: Changes in lumbar lordosis and segmental lordosis were significantly greater after ALIF (4.6° vs. -0.6°, P=0.05; 4.7° vs. -0.7°, P<0.05) at one year (mean time, 366±20 days). At one year or greater, there was a greater reduction in mean VAS-leg score in TLIF patients (3.4 vs. 0.6, P<0.05) and ODI score (16.2 vs. 5.4, P<0.05). Similar outcomes were seen for VAS-back, SF-12 Physical Health, and SRS-30 Function/Activity. SF-12 Mental Health scores were found to be lower in patients undergoing TLIF (-3.5 vs. 2.7, P<0.05). CONCLUSIONS: ALIF demonstrated a superior method of increasing lumbar and segmental lordosis. TLIF was utilized more in patients with higher pre-operative VAS-leg pain scores and therefore, showed a greater magnitude of VAS-leg pain improvement. TLIF also demonstrated a greater improvement in ODI scores despite similar baseline scores, suggesting a possible enhanced functional outcome.

Multilevel Minimally Invasive Lumbar Decompression: Clinical Efficacy and Durability to 2 Years.

BACKGROUND: The clinical efficacy of single-level minimally invasive lumbar decompression and/or microdiscectomy is well established, with improved postoperative functional outcome and pain scores. However, there is a paucity of clinical data supporting the use of minimally invasive (MIS) techniques in a single operation to address pathology at multiple lumbar levels, and this study attempts to address this issue. METHODS: A retrospective review of prospectively collected data from patients with symptomatic lumbar stenosis and/or disc herniations who underwent multilevel minimally invasive decompression or microdiscectomy from November 2014 to February 2018 was conducted at a single academic medical center. Patient-reported outcome measures (PROMs), including the Oswestry Disability Index (ODI), visual analog scale (VAS) for back and leg pain, 12-Item Short Form Health Survey (SF-12) Physical Component Summary Score (PCS) and Mental Component Summary Score (MCS), and Scoliosis Research Society survey (SRS-30), were prospectively collected before surgery and at 3 months, 6 months, 1 year, and 2 years postoperatively. RESULTS: During the study period, 92 patients received multilevel (≥2 level) MIS lumbar decompression and/or discectomy (69 two level, 21 three level, 2 four level). The mean age at surgery was 69.7 years, and 23 (25%) patients were women. Patient-reported outcomes were significantly improved both in the short and long term except for the SF-12 MCS. Average improvement from baseline was (at 3 months and 2 years, respectively): VAS back, -3.9 and -2.8; VAS leg, -3.6 and -2.6; ODI, -13 and -14.6; SF-12 MCS, 2.8 and -0.3; SF-12 PCS, 6.9 and 10.1; and SRS-30, 0.57 and 0.55. Minimal clinically important difference for the study population was reached for every PROM except SF-12 MCS. Surgical complications occurred in 16 patients (17.4%), and 8 patients (8.6%) required postoperative fusions within 2 years. CONCLUSION: The use of MIS techniques to perform lumbar decompression and/or discectomy at multiple levels was found to be both clinically effective and durable. Fusion rates remained low 2 years after the index surgery and were consistent with literature data for open procedures. LEVEL OF EVIDENCE: 2.

The modified frailty index and patient outcomes following transforaminal lumbar interbody fusion surgery for single-level degenerative spine disease.

OBJECTIVE: The modified frailty index (mFI) is a simple tool that measures physiological reserve based on a thorough history and physical examination. Its use has been validated in several surgical specialties, including spinal deformity surgery. Prior research has suggested no significant differences in clinical outcomes between elderly and nonelderly patients undergoing posterior lumbar interbody fusion. The authors sought to investigate the use of the mFI in patients undergoing transforaminal lumbar interbody fusion (TLIF) and the relationship between frailty scores and clinical outcomes. METHODS: A retrospective chart review was conducted on 198 patients who underwent a single-level TLIF over a 60-month period at a single institution. For all patients, an mFI score was computed incorporating a set of 11 clinical factors to assess preexisting comorbidities and functional status. Clinical follow-up and health-related quality-of-life (HRQOL) scores were obtained at baseline and regular intervals of 6 weeks, 6 months, and 1 year following surgery. RESULTS: Patients were grouped according to their level of frailty: no frailty (mFI = 0), mild frailty (mFI = 0.09), moderate frailty (mFI = 0.18), and severe frailty (mFI ≥ 0.27). One-way ANOVA revealed increasing levels of frailty to be associated with an increased rate of complications, from 10.3% to 63.6%. In addition, increasing levels of frailty were associated with longer hospital length of stay (LOS), from 3.1 days to 6.5 days, and lower rates of disposition to home. At the 1-year follow-up, increased levels of frailty were associated with worse HRQOL measures. CONCLUSIONS: Increasing mFI score was associated with higher morbidity, longer inpatient LOS, and a lower probability of discharge to home in patients undergoing single-level TLIF. Consideration of the mFI may help surgeons improve decision-making across the spectrum of patients who are at risk from frailty.

Changes in Segmental and Lumbar Lordosis After Lateral Lumbar Interbody Fusion With Different Lordotic Cage Angulations.

BACKGROUND: Lateral lumbar interbody fusion (LLIF) affords a wide operative corridor to allow for a large interbody cage implantation for segmental reconstruction. There is a paucity of data describing segmental lordosis (SL) achieved with lordotic implants of varying angles. Here we compare changes in SL and lumbar lordosis (LL) after implantation of 6°, 10°, and 12° cages. METHODS: We retrospectively reviewed LLIF cases over a 5.5-year period. We derived SL and LL using the standard cobb angle measurement from a standing lateral radiograph. We analyzed mean changes in SL and LL over time using the linear mixed effect model to estimate these longitudinal changes. RESULTS: The most frequently treated level was L3-4, followed by L4-5. Significant increases in mean SL were found at each follow-up time point for all the cohorts. In an intercohort comparison, the mean changes in SL at immediate postoperative and last follow-up were significantly greater in the 10° cohort than 6° ([7.4° versus 3.1°, P = .004], [6.1° versus 2.3°, P = .025] respectively). The 12° cohort had higher mean change in SL at last follow-up than the 6° cohort (5.9° versus 2.3°, P = .022). There was no difference in mean change in SL between the 10° and 12° cohorts. No difference in overall mean LL over time was found. In terms of mean change in LL, no difference was observed except at immediate and 6-month postoperative in the 10° cohort ([9.6°, P = .001], [8.5, P = .003] respectively). By comparing mean change in LL, no difference existed except between the 10° and 6° immediately after surgery (9.6° versus 0.2°, P = .006). CONCLUSIONS: LLIF cages significantly improve SL at the index level. However, this increase in SL is greater for 10° and 12° cages than the standard 6° cage. Use of 10° cages also resulted in overall improved LL than 6° cages. LEVEL OF EVIDENCE: 3. CLINICAL RELEVANCE: Lateral lumbar interbody fusion.

Nonunion Rates After Anterior Cervical Discectomy and Fusion: Comparison of Polyetheretherketone vs Structural Allograft Implants.

BACKGROUND: Although advances in implant materials, such as polyetheretherketone (PEEK), have been developed aimed to improve outcome after anterior cervical discectomy and fusion (ACDF), it is essential to confirm whether these changes translate into clinically important sustained benefits. OBJECTIVE: To compare the radiographic and clinical outcomes of patients undergoing up to 3-level ACDF with PEEK vs structural allograft implants. METHODS: In this cohort study, radiographic and symptomatic nonunion rates were compared in consecutive patients who underwent 1 to 3 level ACDF with allograft or PEEK implant. Prospectively collected clinical data and patient-reported outcome (PRO) scores were compared between the allograft and PEEK groups. Regression analysis was performed to determine the predictors of nonunion. RESULTS: In total, 194 of 404 patients met the inclusion criteria (79% allograft vs 21% PEEK). Preoperative demographic variables were comparable between the 2 groups except for age. The rate of radiographic nonunion was higher with PEEK implants (39% vs 27%, P = .0035). However, a higher proportion of nonunion in the allograft cohort required posterior instrumentation (14% vs 3%, P = .039). Patients with multilevel procedures and PEEK implants had up to 5.8 times the risk of radiographic nonunion, whereas younger patients, active smokers, and multilevel procedures were at higher risk of symptomatic nonunion. CONCLUSION: Along with implant material, factors such as younger age, active smoking status, and the number of operated levels were independent predictors of fusion failure. Given the impact of nonunion on PRO, perioperative optimization of modifiable factors and surgical planning are essential to ensure a successful outcome.