STUDY DESIGN.Retrospective cohort study.
OBJECTIVE.The aim of this study was to determine the differences in 30-day readmission, reoperation, and morbidity for patients undergoing multilevel anterior ...cervical discectomy and fusion (ACDF) or single and multilevel anterior cervical corpectomy and fusion (ACCF).
SUMMARY OF BACKGROUND DATA.Despite increasing rates of surgical treatment of cervical spine disease, few studies have compared outcomes by surgical technique. To the best of our knowledge, this is the only large-scale administrative database study that directly evaluates early outcomes between multilevel ACDF and single and multilevel ACCF.
METHODS.Patients who underwent ACDF and ACCF were identified using the NSQIP database. Multivariate regression was utilized to compare rates of readmission, reoperation, morbidity, and specific complications between surgical techniques, and to evaluate for predictors of primary outcomes.
RESULTS.We identified 15,600 patients. ACCF independently predicted (P < 0.001) greater reoperation (odds ratio OR = 1.876) and morbidity (OR = 1.700), but not readmission, on multivariate analysis. ACCF was also associated with greater rates of transfusion (OR = 3.273, P < 0.001) and DVT/thrombophlebitis (OR = 2.852, P = 0.001). ACCF had significantly (P < 0.001) greater operative time and length of stay. In the cohort, increasing age (P < 0.001), diabetes (P = 0.025), chronic obstructive pulmonary disease (P = 0.027), disseminated cancer (P = 0.009), and American Society of Anesthesiologists (ASA) class ≥3 (P < 0.001) predicted readmission. Age (P = 0.011), female sex (P = 0.001), heart failure (P = 0.002), ASA class ≥3 (P < 0.001), and increased creatinine (P = 0.044), white cell count (P = 0.033), and length of stay (P < 0.001) predicted reoperation. Age (P < 0.001), female sex (P = 0.002), disseminated cancer (P = 0.010), ASA class ≥3 (P < 0.001), increased white cell count (P = 0.036) and length of stay (P < 0.001), and decreased hematocrit (P < 0.001) predicted morbidity. Within ACDF, three or more levels treated compared to two levels did not predict poorer 30-day outcomes.
CONCLUSION.Compared to multilevel ACDF, ACCF was associated with an 88% increased odds of reoperation and 70% increased odds of morbidity; readmission was similar between techniques. Older age, higher ASA class, and specific comorbidities predicted poorer 30-day outcomes. These findings can guide surgical solution given specific factors.Level of Evidence3
STUDY DESIGN.A retrospective cohort study.
OBJECTIVE.The aim of this study was to determine the difference in 30-day readmission, reoperation, and morbidity for patients undergoing either posterior ...or anterior lumbar interbody fusion.
SUMMARY OF BACKGROUND DATA.Despite increasing utilization of lumbar interbody fusion to treat spinal pathology, few studies compare outcomes by surgical approach, particularly using large nationally represented cohorts.
METHODS.Patients who underwent lumbar interbody fusion were identified using the NSQIP database. Rates of readmission, reoperation, morbidity, and associated predictors were compared between posterior/transforaminal (PLIF/TLIF) and anterior/lateral (ALIF/LLIF) lumbar interbody fusion using multivariate regression. Bonferroni-adjusted alpha-levels were utilized whereby variables were significant if their P values were less than the alpha-level or trending if their P values were between 0.05 and the alpha-level.
RESULTS.We identified 26,336 patients. PLIF/TLIF had greater operative time (P = 0.015), transfusion (P < 0.001), UTI (P = 0.008), and stroke/CVA (P = 0.026), but lower prolonged ventilation (P < 0.001) and DVT (P = 0.002) rates than ALIF/LLIF. PLIF/TLIF independently predicted greater morbidity on multivariate analysis (odds ratio1.155, P = 0.0019).In both groups, experiencing a complication and, in PLIF/TLIF, ASA-class ≥3 predicted readmission (P < 0.001). Increased age trended toward readmission in ALIF/LLIF (P = 0.003); increased white cell count (P = 0.003), dyspnea (P = 0.030), and COPD (P = 0.005) trended in PLIF/TLIF. In both groups, increased hospital stay and wound/site-related complication predicted reoperation (P < 0.001). Adjunctive posterolateral fusion predicted reduced reoperation in ALIF/LLIF (P = 0.0018). ASA-class ≥3 (P = 0.016) and age (P = 0.021) trended toward reoperation in PLIF/TLIF and ALIF/LLIF, respectively. In both groups, age, hospital stay, reduced hematocrit, dyspnea, ASA-class ≥3, posterolateral fusion, and revision surgery and, in PLIF/TLIF, bleeding disorder predicted morbidity (P < 0.001). Female sex (P = 0.010), diabetes (P = 0.042), COPD (P = 0.011), and disseminated cancer (P = 0.032) trended toward morbidity in PLIF/TLIF; obesity trended in PLIF/TLIF (P = 0.0022) and ALIF/LLIF (P = 0.020).
CONCLUSION.PLIF/TLIF was associated with a 15.5% increased odds of morbidity; readmission and reoperation were similar between approaches. Older age, higher ASA-class, and specific comorbidities predicted poorer 30-day outcomes, while procedural-related factors predicted only morbidity. These findings can guide surgical approach given specific factors.Level of Evidence3
STUDY DESIGN.Preclinical animal study.
OBJECTIVE.Determine the in vivo effects of platelet-derived growth factor BB (PDGF-BB) delivered in a thiol-modified hyaluronic acid (TMHA) hydrogel on ...intervertebral disk (IVD) degeneration.
SUMMARY OF BACKGROUND DATA.IVD degeneration is a worldwide health concern and remains without an effective treatment. Several in vitro studies have demonstrated the potential of PDGF-BB, a primary component of platelet-rich plasma, as a therapy for IVD degeneration. Our hypotheses were that treatment of injured IVDs with PDGF would inhibit degeneration and that administration of PDGF in a TMHA hydrogel would improve its efficacy.
METHODS.IVD degeneration was induced using the rabbit annular puncture model. Four weeks after injury, IVDs were treated with either PDGF-BB or PDGF-BB delivered within a TMHA hydrogel. The efficacy of treatment was determined using x-ray, MRI, histology, and biomechanical testing.
RESULTS.At 4 weeks after treatment, cell apoptosis and deposition of matrix containing type III collagen a1 (Col3a1) was demonstrated in both the nucleus pulposus and annulus fibrosus, while this was inhibited by PDGF. At 8 weeks after treatment, disc area and MRI indices of injured IVDs treated with PDGF were significantly higher (P < 0.05) than those treated with the TMHA alone. Similarly, degenerative scores for saline- and TMHA-treated IVDs demonstrated significantly more degeneration (P < 0.05) than PDGF-treated IVDs at 8 weeks. Biomechanical assessments found fewer indicators of degeneration in PDGF-TMHA-treated IVDs at both 4 and 8 weeks post-treatment, compared to saline-, TMHA-, and PDGF-only-treated IVDs. Both PDGF- and PDGF-TMHA-treated IVDs also demonstrated a significant increase (P < 0.05) in compressive strength to failure, compared with controls at 8 weeks post-treatment.
CONCLUSION.The results of this study suggest that PDGF-BB significantly decreases disc degeneration and when delivered in a TMHA gel scaffold, helps prevent both apoptosis and Col3 matrix production, while maintaining disc structure and biomechanical function.Level of EvidenceNA
Lateral lumbar interbody fusion is an evolving procedure in spine surgery allowing for the placement of large interbody devices to achieve indirect decompression of segmental stenosis, deformity ...correction and high fusion rates through a minimally invasive approach. Traditionally, this technique has been performed in the lateral decubitus position. Many surgeons have adopted simultaneous posterior instrumentation in the lateral position to avoid patient repositioning; however, this technique presents several challenges and limitations. Recently, lateral interbody fusion in the prone position has been gaining in popularity due to the surgeon's ability to perform simultaneous posterior instrumentation as well as decompression procedures and corrective osteotomies. Furthermore, the prone position allows improved correction of sagittal plane imbalance due to increased lumbar lordosis when prone on most operative tables used for spinal surgery. In this paper, we describe the evolution of the prone lateral approach for interbody fusion and present our experience with this technique. Case examples are included for illustration.
Loss or damage to the mandible caused by trauma, treatment of oral malignancies, and other diseases is treated using bone-grafting techniques that suffer from numerous shortcomings and ...contraindications. Zebrafish naturally heal large injuries to mandibular bone, offering an opportunity to understand how to boost intrinsic healing potential. Using a novel her6:mCherry Notch reporter, we show that canonical Notch signaling is induced during the initial stages of cartilage callus formation in both mesenchymal cells and chondrocytes following surgical mandibulectomy. We also show that modulation of Notch signaling during the initial post-operative period results in lasting changes to regenerate bone quantity one month later. Pharmacological inhibition of Notch signaling reduces the size of the cartilage callus and delays its conversion into bone, resulting in non-union. Conversely, conditional transgenic activation of Notch signaling accelerates conversion of the cartilage callus into bone, improving bone healing. Given the conserved functions of this pathway in bone repair across vertebrates, we propose that targeted activation of Notch signaling during the early phases of bone healing in mammals may both augment the size of the initial callus and boost its ossification into reparative bone.
Traumatic spinal cord injury (SCI) has devastating implications for patients, including a high predisposition for developing chronic pain distal to the site of injury. Chronic pain develops weeks to ...months after injury, consequently, patients are treated after irreparable changes have occurred. Nociceptors are central to chronic pain; however, the diversity of this cellular population presents challenges to understanding mechanisms and attributing pain modalities to specific cell types. To begin to address how peripheral sensory neurons below the injury level may contribute to the below-level pain reported by SCI patients, we examined SCI-induced changes in gene expression in lumbar dorsal root ganglia (DRG) below the site of injury. SCI was performed at the T10 vertebral level, with injury produced by a vessel clip with a closing pressure of 15
for 1 min. Alterations in gene expression produce long-term sensory changes, therefore, we were interested in studying SCI-induced transcripts before the onset of chronic pain, which may trigger changes in downstream signaling pathways and ultimately facilitate the transmission of pain. To examine changes in the nociceptor subpopulation in DRG distal to the site of injury, we retrograde labeled sensory neurons projecting to the hairy hindpaw skin with fluorescent dye and collected the corresponding lumbar (L2-L6) DRG 4 days post-injury. Following dissociation, labeled neurons were purified by fluorescence-activated cell sorting (FACS). RNA was extracted from sorted sensory neurons of naïve, sham, or SCI mice and sequenced. Transcript abundances validated that the desired population of nociceptors were isolated. Cross-comparisons to data sets from similar studies confirmed, we were able to isolate our cells of interest and identify a unique pattern of gene expression within a subpopulation of neurons projecting to the hairy hindpaw skin. Differential gene expression analysis showed high expression levels and significant transcript changes 4 days post-injury in SCI cell populations relevant to the onset of chronic pain. Regulatory interrelationships predicted by pathway analysis implicated changes within the synaptogenesis signaling pathway as well as networks related to inflammatory signaling mechanisms, suggesting a role for synaptic plasticity and a correlation with pro-inflammatory signaling in the transition from acute to chronic pain.
There are a wide variety of interbody devices available for use in transforaminal lumbar interbody fusion (TLIF). While traditionally these interbodies are bullet-shaped, crescent-shaped cages have ...become increasingly common. There is a paucity of literature comparing the effect of cage geometry with substratification for surgical approach (minimally invasive (MIS) vs. open). The aim of this study was to determine the effect of implant geometry, positioning, and surgical approach on the correction of different spinal alignment parameters in patients undergoing TLIF. A retrospective chart and imaging review was performed on 103 patients with a total of 131 instrumented segments performed by a single surgeon. Preoperative, initial postoperative, and final postoperative standing lateral lumbar radiographs were evaluated for lumbar lordosis (LL), segmental lordosis (SL), anterior disc height (ADH), and posterior disc height (PDH). Anterior-posterior implant positioning was recorded for initial and final postoperative radiographs. These measurements were compared among four groups: open bullet (OB), MIS bullet (MB), open crescent (OC), and MIS crescent (MC). SL increased in all groups by a mean of 2.9° at initial imaging and 2.2° at final imaging. The OC group had greater initial improvement in SL compared to the MB group (p = 0.02), though this effect was lost at final follow-up (p = 0.11). The OB and OC groups conferred greater initial improvement in ADH (p = 0.02; p = 0.04), while the OC group had greater final improvement in ADH compared to the MB and MC groups (p = 0.01; p = 0.01). The OC group had less initial improvement in PDH compared with the other groups (p = 0.03, p = 0.02, p < 0.01). The MB group provided greater final improvement in PDH compared with the MC and OC groups (p = 0.04, p = 0.01). Cage geometry, surgical approach, and implant position all demonstrated a statistically significant but clinically minor impact on segmental alignment for TLIF procedures.
Millions of people worldwide suffer from low back pain and disability associated with intervertebral disc (IVD) degeneration. IVD degeneration is highly correlated with aging, as the nucleus pulposus ...(NP) dehydrates and the annulus fibrosus (AF) fissures form, which often results in intervertebral disc herniation or disc space collapse and related clinical symptoms. Currently available options for treating intervertebral disc degeneration are symptoms control with therapy modalities, and/or medication, and/or surgical resection of the IVD with or without spinal fusion. As such, there is an urgent clinical demand for more effective disease-modifying treatments for this ubiquitous disorder, rather than the current paradigms focused only on symptom control. Hydrogels are unique biomaterials that have a variety of distinctive qualities, including (but not limited to) biocompatibility, highly adjustable mechanical characteristics, and most importantly, the capacity to absorb and retain water in a manner like that of native human nucleus pulposus tissue. In recent years, various hydrogels have been investigated in vitro and in vivo for the repair of intervertebral discs, some of which are ready for clinical testing. In this review, we summarize the latest findings and developments in the application of hydrogel technology for the repair and regeneration of intervertebral discs.
Lumbosacral fixation is commonly used for the management of lumbosacral instability. As the sacrum mainly consists of cancellous bone, bicortical fixation, in which the pedicle screw penetrates the ...anterior sacral cortex, can help increase the strength of fixation. However, this method carries a risk to the L5 nerves which lie anterior to the sacrum at this level.
The goal of this study is to determine a safe zone for the placement of S1 pedicle screws to decrease the likelihood of L5 nerve injury.
Retrospective imaging review.
This study evaluated imaging data of patients who underwent lumbar spine magnetic resonance imaging (MRI) at our institute between September 1, 2020 and September 1, 2021.
T1-weighted axial MRIs were measured at the level of S1 pedicle screw placement. The space medial and lateral to the L5 nerve root on the anterior sacrum were measured and defined as safe zones. Additionally, the nerve width and sacral lengths were measured at this level.
The distribution of the measurements were evaluated to determine a medial and lateral safe zone, as well as the average nerve width at the level of S1 pedicle screw placement. Correlation analysis was performed to determine a relationship between safe zone sizes and sacral size.
A total of 400 MRIs were analyzed. The average medial safe zone measured was 32.8 mm (95% CI: 32.2–33.4) with no nerves lying within 22.3 mm of the midline sacrum. The average lateral safe zone measured was 17.7 mm (95% CI: 17.1–18.2), with no nerves within 5.3 mm of the lateral border of the sacrum. The average nerve root width was 6.2 mm (95% CI: 6.13–6.34). An increased sacral length was associated with a larger medial (p<.001) and lateral (p<.001) safe zone.
Our study revealed lateral and medial safe zones for the placement of S1 pedicle screws to avoid iatrogenic nerve injury in a retrospective cohort of 400 patients. There were no L5 nerve roots found within 22.3 mm of the sacrum's mid-axis or within 5.3 mm of the sacrum's anterolateral border. These defined safe zones can be used during pedicle screw planning and placement to decrease the risk of injury to the L5 nerve root.
(1)
: Since first approved by the FDA, on-label and off-label usage of recombinant human bone morphogenetic protein 2 (rhBMP2) for spinal fusion surgeries has become widespread. While many studies ...have investigated the safety and efficacy of its use, as well as its economic impact, few have looked at the current trends in its on- and off-label use. The goal of this study is to evaluate the current trends of on- and off-label rhBMP2 use for spinal fusion surgery. (2)
: A deidentified survey was created and electronically distributed to members of two international spine societies. Surgeons were asked to report their demographic information, surgical experience, and current usage of rhBMP2. They were then presented with five spinal fusion procedures and asked to report if they use rhBMP2 for these indications in their current practice. Responses were stratified between rhBMP2 users vs. non-users and on-label vs. off-label use. Data were analyzed using chi-square with Fisher's exact test for categorical data. (3)
: A total of 146 respondents completed the survey with a response rate of 20.5%. There was no difference in overall rhBMP2 usage based on specialty, experience, or number of cases per year. Fellowship-trained surgeons and those who practice in the United States were more likely to use rhBMP2. Surgeons who were trained in the Southeast and Midwest regions reported the highest usage rates. rhBMP2 use was more common among fellowship-trained and US surgeons for ALIFs; non-US surgeons for multilevel anterior cervical discectomy and fusions; and fellowship-trained and orthopedic spine surgeons for lateral lumbar interbody fusions. Non-US surgeons were more likely to use rhBMP2 for off-label indications compared to surgeons from the US. (4)
: While various demographics of surgeons report different rates of rhBMP2 use, off-label use remains relatively commonplace amongst practicing spine surgeons.
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