Management and outcomes of cerebrovascular injuries after gunshot wounds to the cervical spine.

STUDY DESIGN: This study was a multicenter retrospective analysis of cervical spine gunshot wound (GSW) patients. OBJECTIVE: The present study was conducted to evaluate the management and outcomes of vascular injuries following GSW involving the cervical spine. SUMMARY OF BACKGROUND DATA: Gunshot wounds (GSW) injuring the cervical spine are associated with high rates of vascular injury. METHODS: Charts of patients with GSW involving the cervical spine at two Level 1 trauma centers were reviewed from 2010 to 2021 for demographics, injury characteristics, management and follow-up. Statistical analysis included T tests and ANOVA for comparisons of continuous variables and chi-square testing for categorical variables, non-parametric tests were used when indicated. Beta-binomial models were used to estimate the probabilities outcomes. Bayesian regression models were utilized to compute risk ratios (RR) and their 95 % confidence intervals (CI) to enhance the inferential robustness. RESULTS: 40 patients with cervical spine GSW and associated cerebrovascular injury were included in our analysis. 15 % of patients had Biffl grade (BG) V injuries, 50 % grade IV, and 35 % grade III-I. Angiography was performed in 35 % of patients. 5 of these patients (BG V-III) required endovascular treatment for pseudoaneurysm obliteration or parent vessel sacrifice. 7 patients (22 %) showed evidence of progression. 70 % of patients were placed on antiplatelet therapy for stroke prevention. Bayesian regression models with a skeptical prior for cerebral ischemia revealed a mean RR of 4.82 (95 % CI 1.02-14.48) in the BG V group, 0.75 (95 % CI 0.13-2.26) in the BG IV group, and 0.61 (95 % CI 0.06-2.01) in the combined BG III-I group. For demise the mean RR was 3.41 (95 % CI 0.58-10.65) in the BG V group and 1.69 (95 % CI 0.29-5.97) in the BG IV group. In the high BG (V, IV) group, 54.55 % of patients treated with antiplatelet therapy had complications. None of the patients that were treated with antiplatelet therapy in the low BG (III-I) group had complications. CONCLUSIONS: Cervical spine GSWs are associated with high-grade vascular injuries and may require early endovascular intervention. Additionally, a high rate of injury progression was seen on follow up imaging, requiring subsequent intervention. Reintervention and demise were common and observed in high BG (V, IV) groups. The incidence of stroke was low, especially in low BG (I-III) groups, suggesting that daily aspirin prophylaxis is adequate for long-term stroke prevention.

Multi-institutional review of characteristics and management of gunshot wounds to the spine.

BACKGROUND CONTEXT: Gunshot wounds (GSWs) to the vertebral column represent an important cause of morbidity and mortality in the United States, constituting approximately 20% of all spinal injuries. The management of these injuries is an understudied and controversial topic, given its heterogeneity and lack of follow-up data. PURPOSE: To characterize the management and follow-up of GSWs to the spine. STUDY DESIGN/SETTING: A multi-institutional retrospective review of the experience of two urban Level 1 trauma centers. PATIENT SAMPLE: Patients with GSWs to the spine between 2010-2021. OUTCOME MEASURES: Measures included work status, follow-up healthcare utilization, and pain management were collected. METHODS: Charts were reviewed for demographics, injury characteristics, surgery and medical management, and follow-up. Statistical analysis included T-tests and ANOVA for comparisons of continuous variables and chi-square testing for categorical variables. All statistics were performed on SPSS v24 (IBM, Armonk, NY). RESULTS: A total of 271 patients were included for analysis. The average age was 28 years old, 82.7% of patients were black, 90% were male, and 76.4% had Medicare/Medicaid. The thoracic spine (35%) was most commonly injured followed by lumbar (33.9%) and cervical (25.6%). Cervical GSW was associated with higher mortality (p<.001); 8.7% of patients developed subsequent osteomyelitis/discitis, 71.3% received prophylactic antibiotics, and 56.1% of cervical GSW had a confirmed vertebral or carotid artery injury. ASIA scores at presentation were most commonly A (26.9%), D (20.7%), or E (19.6%), followed by C (7.4%) and B (6.6%). 18.8% of patients were unable to be assessed at presentation. ASIA score declined in only 2 patients, while 15.5% improved over their hospital stay. Those who improved were more likely to have ASIA B injury (p<.001). Overall, 9.2% of patients underwent spinal surgery. Of these, 33% presented as ASIA A, 21% as ASIA B, 29% as ASIA C, and 13% as ASIA D. Surgery was not associated with an improvement in ASIA score. CONCLUSIONS: Given the ubiquitous and heterogeneous experience with GSWs to the spine, rigorous attempts should be made to define this population and its clinical and surgical outcomes. Here, we present an analysis of 11 years of patients presenting to two large trauma centers to elucidate patterns in presentation, management, and follow-up. We highlight that GSWs to the cervical spine are most often seen in young black male patients. They were associated with high mortality and high rates of injury to vertebral arteries and that surgical intervention did not alter rates of discitis/osteomyelitis or propensity for neurologic recovery; moreover, there was no incidence of delayed spinal instability in the study population.

Depression State Correlates with Functional Recovery Following Elective Lumbar Spine Fusion.

OBJECTIVE: To determine how depression state impacts postoperative Patient-Reported Outcomes Measurement Information System (PROMIS) scores and achievement of minimum clinically important difference (MCID) following lumbar fusion. Depression has been shown to negatively impact outcomes following numerous orthopedic surgeries. Situational and major clinical depression can differentially affect postoperative outcomes. METHODS: Adult patients undergoing elective 1-3 level lumbar fusion were reviewed. Patients with a formal diagnosis of major depression were classified as "clinically depressed" whereas patients with at least "mild" PROMIS Depression scores in the absence of formal depression diagnosis were deemed "situationally depressed." analysis of variance testing was used to assess differences within and between groups. Multivariate regression was used to identify features associated with the achievement of MCID. RESULTS: Two hundred patients were included. The average age was 65.9 ± 12.2 years. 75 patients (37.5%) were nondepressed, 66 patients (33.0%) were clinically depressed, and 59 patients (29.5%) were situationally depressed. Situationally depressed patients had worse preoperative physical function (PF) and pain interference (PI) scores and were more likely to have severe symptoms (P = 0.001, P = 0.001). All groups improved significantly from preoperative baseline scores. All groups met MCID PF at different rates, with highest proportion of situationally depressed reaching this metric (P = 0.03). Rates of achieving MCID PI were not significantly different between groups (P = 0.47). Situational depression was predictive of achieving MCID PF (P = 0.002) but not MCID PI. CONCLUSIONS: Our study investigated the relationship between depression and postoperative PROMIS scores and identified situationally depressed patients as having the worst preoperative impairment. Despite this, the situationally depressed cohort had the highest likelihood of achieving MCID PF, suggestive of a bidirectional relationship between lumbar degenerative disease and subclinical, situational depression. These findings may help guide preoperative counseling on expectations, and patient selection.

The Catastrophe of Intracerebral Hemorrhage Drives the Capillary-Hemorrhage Dementias, Including Alzheimer's Disease.

This review advances an understanding of several dementias, based on four premises. One is that capillary hemorrhage is prominent in the pathogenesis of the dementias considered (dementia pugilistica, chronic traumatic encephalopathy, traumatic brain damage, Alzheimer's disease). The second premise is that hemorrhage introduces four neurotoxic factors into brain tissue: hypoxia of the tissue that has lost its blood supply, hemoglobin and its breakdown products, excitotoxic levels of glutamate, and opportunistic pathogens that can infect brain cells and induce a cytotoxic immune response. The third premise is that where organisms evolve molecules that are toxic to itself, like the neurotoxicity ascribed to hemoglobin, amyloid- (A), and glutamate, there must be some role for the molecule that gives the organism a selection advantage. The fourth is the known survival-advantage roles of hemoglobin (oxygen transport), of A (neurotrophic, synaptotrophic, detoxification of heme, protective against pathogens) and of glutamate (a major neurotransmitter). From these premises, we propose 1) that the brain has evolved a multi-factor response to intracerebral hemorrhage, which includes the expression of several protective molecules, including haptoglobin, hemopexin and A; and 2) that it is logical, given these premises, to posit that the four neurotoxic factors set out above, which are introduced into the brain by hemorrhage, drive the progression of the capillary-hemorrhage dementias. In this view, A expressed at the loci of neuronal death in these dementias functions not as a toxin but as a first responder, mitigating the toxicity of hemoglobin and the infection of the brain by opportunistic pathogens.

A Simple 3D Printed Model for Intracranial Vascular Anastomosis Practice and the Rochester Bypass Training Score.

BACKGROUND AND OBJECTIVES: Surgical simulation models in cranial neurosurgery are needed to allow affordable, accessible, and validated practice in resident education. Current bypass anastomosis practice models revolve around basic tube tying or complex animal and 3-dimensional models. This study sought to design and validate a 3-dimensional printed model for intracranial anastomosis training. METHODS: A computer-aided design (CAD) generic skull was uploaded into Meshmixer (v.3.5), and a 55-mm opening was created on the right side, mimicking a standard orbitozygomatic craniotomy. The model was rotated 15° upward and 35° left, before a 10-mm square frame was added 80-mm deep to the right orbit. The CAD model was uploaded to GrabCAD and printed using a J750 PolyJet 3D printer before being paired with a vascular anastomosis kit. The model was validated with standardized assessments of residents and attendings by simulating an "M2 to P2" bypass. The Rochester Bypass Training Score (RBTS) was created to assess bypass patency, back wall suturing, and suture quality. Postsimulation survey data regarding the realism and usefulness of the simulation were collected. RESULTS: Five junior residents (Postgraduate Year 1-4), 3 senior residents (Postgraduate Year 5-7), and 2 attendings were participated. The mean operative time in minutes was as follows: junior residents 78, senior residents 33, and attendings 50. The RBTS means were as follows: junior residents 2.4, senior residents 4.0, and attendings 5.0. Participants agreed that the model was realistic, useful for improving operative technique, and would increase comfort in bypass procedures. There are a few different printing options, varying in model infill and printing material used. For this experiment, a mix of Vero plastics were used totaling $309.09 per model; however, using the more common printing material polylactic acid brings the cost to $17.27 for a comparable model. CONCLUSION: This study presents an affordable, realistic, and educational intracranial vascular anastomosis simulator and introduces the RBTS for assessment.

Twelve protections evolved for the brain, and their roles in extending its functional life.

As human longevity has increased, we have come to understand the ability of the brain to function into advanced age, but also its vulnerability with age, apparent in the age-related dementias. Against that background of success and vulnerability, this essay reviews how the brain is protected by (by our count) 12 mechanisms, including: the cranium, a bony helmet; the hydraulic support given by the cerebrospinal fluid; the strategically located carotid body and sinus, which provide input to reflexes that protect the brain from blood-gas imbalance and extremes of blood pressure; the blood brain barrier, an essential sealing of cerebral vessels; the secretion of molecules such as haemopexin and (we argue) the peptide Aß to detoxify haemoglobin, at sites of a bleed; autoregulation of the capillary bed, which stabilises metabolites in extracellular fluid; fuel storage in the brain, as glycogen; oxygen storage, in the haemoprotein neuroglobin; the generation of new neurones, in the adult, to replace cells lost; acquired resilience, the stress-induced strengthening of cell membranes and energy production found in all body tissues; and cognitive reserve, the ability of the brain to maintain function despite damage. Of these 12 protections, we identify 5 as unique to the brain, 3 as protections shared with all body tissues, and another 4 as protections shared with other tissues but specialised for the brain. These protections are a measure of the brain's vulnerability, of its need for protection. They have evolved, we argue, to maintain cognitive function, the ability of the brain to function despite damage that accumulates during life. Several can be tools in the hands of the individual, and of the medical health professional, for the lifelong care of our brains.

Delayed myelopathy after remote C1-2 sublaminar wire fixation: illustrative case.

BACKGROUND: Atlantoaxial sublaminar wiring complications, both early and delayed, have been documented. However, delayed neurological compromise 27 years after successful fusion is a rare but possible occurrence. OBSERVATIONS: A 76-year-old male, who had undergone C1-2 sublaminar wire fusion for atlantoaxial instability in 1995, presented with symptoms of progressive right arm weakness, falls, and incontinence of bowel and bladder over a 1-week period. Initial imaging workup revealed bowing of the C1-2 sublaminar wires resulting in cervical spinal cord compression and T2-weighted signal changes. A C1-2 laminectomy was performed to remove the wires and decompress the spinal cord with improvement in the patient's neurological status. LESSONS: This rare case highlights the potential for delayed cervical myelopathy and cord compression from sublaminar wires, even after a successful fusion. In patients with a history of sublaminar wiring who experience new neurological deficits, it is essential to evaluate the hardware for migration.

Treatment of hydrocephalus in an ovine model with an intraparenchymal stent.

OBJECTIVE: While CSF diversion is highly effective at treating hydrocephalus, shunting is unfortunately associated with a very high revision rate. Studies have demonstrated that proximal catheter obstruction is a major cause of failure. A novel proximal access device was developed, and pilot testing was performed in a sheep model of hydrocephalus. METHODS: Hydrocephalus was induced in 8 sheep using a cisternal injection of 4 ml of 25% kaolin, and the sheep were randomized to either a standard ventricular catheter or a novel intraparenchymal stent (IPS). Both groups received identical valves and distal catheters. The novel device included a 3D-printed stainless steel port and a 6 × 40-mm covered peripheral vascular stent. Animals were euthanized for signs of hydrocephalus or at a time point of 2 months. MRI was performed to determine ventricular size. Time to failure and Evans indices were compared using the Wilcoxon rank-sum test. RESULTS: All 4 experimental devices were placed without difficulty into the right lateral ventricle. There was a trend toward longer survival in the experimental group (40 vs 26 days, p = 0.24). Within the IPS group, 3 of the 4 sheep did not experience clinical symptoms of shunt failure and had an average of 37% decrease in Evans index. While 3 of 4 traditional proximal catheters demonstrated debris within the inlet holes, there was no obstructive material found in the IPSs. CONCLUSIONS: An IPS was successfully used to treat hydrocephalus in a sheep model. While statistical significance was not achieved, there were clear benefits to using a stent, including a decreased clog rate and the ability to perform a percutaneous revision. Further testing is needed to ensure efficacy and safety prior to human application.

Best Medicine for Dementia: The Life-Long Defense of the Brain.

This review deals with an unwelcome reality about several forms of dementia, including Alzheimer's disease- that these dementias are caused, in part or whole, by the aging of the vasculature. Since the vasculature ages in us all, dementia is our fate, sealed by the realit!ies of the circulation; it is not a disease with a cure pending. Empirically, cognitive impairment before our 7th decade is uncommon and considered early, while a diagnosis in our 11th decade is late but common in that cohort (>40%). Projections from earlier ages suggest that the prevalence of dementia in people surviving into their 12th decade exceeds 80%. We address the question why so few of many interventions known to delay dementia are recognized as therapy; and we try to resolve this few-and-many paradox, identifying opportunities for better treatment, especially pre-diagnosis. The idea of dementia as a fate is resisted, we argue, because it negates the hope of a cure. But the price of that hope is lost opportunity. An approach more in line with the evidence, and more likely to limit suffering, is to understand the damage that accumulates with age in the cerebral vasculature and therefore in the brain, and which eventually gives rise to cognitive symptoms in late life, too often leading to dementia. We argue that hope should be redirected to delaying that damage and with it the onset of cognitive loss; and, for each individual, it should be redirected to a life-long defense of their brain.

Remote photobiomodulation targeted at the abdomen or legs provides effective neuroprotection against parkinsonian MPTP insult.

Photobiomodulation (PBM)-the irradiation of tissue with low-intensity light-mitigates neuropathology in rodent models of Parkinson's disease (PD) when targeted at the head ('transcranial PBM'). In humans, however, attenuation of light energy by the scalp and skull necessitates a different approach. We have reported that targeting PBM at the body also protects the brain by a mechanism that spreads from the irradiated tissue ('remote PBM'), although the optimal peripheral tissue target for remote PBM is currently unclear. This study compared the neuroprotective efficacy of remote PBM targeting the abdomen or leg with transcranial PBM, in mouse and non-human primate models of PD. In a pilot study, the neurotoxin MPTP was used to induce PD in non-human primates; PBM (670 nm, 50 mW/cm2 , 6 min/day) of the abdomen (n = 1) was associated with fewer clinical signs and more surviving midbrain dopaminergic cells relative to MPTP-injected non-human primates not treated with PBM. Validation studies in MPTP-injected mice (n = 10 per group) revealed a significant rescue of midbrain dopaminergic cells in mice receiving PBM to the abdomen (~80%, p < .0001) or legs (~80%, p < .0001), with comparable rescue of axonal terminals in the striatum. Strikingly, this degree of neuroprotection was at least as, if not more, pronounced than that achieved with transcranial PBM. These findings confirm that remote PBM provides neuroprotection against MPTP-induced destruction of the key circuitry underlying PD, with both the abdomen and legs serving as viable remote targets. This should provide the impetus for a comprehensive investigation of remote PBM-induced neuroprotection in other models of PD and, ultimately, human patients.

The brain's weakness in the face of trauma: How head trauma causes the destruction of the brain.

Of all our organs, the brain is perhaps the best protected from trauma. The skull has evolved to enclose it and, within the skull, the brain floats in a protective bath of cerebrospinal fluid. It is becoming evident, however, that head trauma experienced in young adult life can cause a dementia that appears decades later. The level of trauma that induces such destruction is still being assessed but includes levels well below that which cracks the skull or causes unconsciousness or concussion. Clinically this damage appears as dementia, in people who played body-contact sports in their youth or have survived accidents or the blasts of combat; and appears also, we argue, in old age, without a history of head trauma. The dementias have been given different names, including dementia pugilistica (affecting boxers), chronic traumatic encephalopathy (following certain sports, particularly football), traumatic brain injury (following accidents, combat) and Alzheimer's (following decades of life). They share common features of clinical presentation and neuropathology, and this conceptual analysis seeks to identify features common to these forms of brain injury and to identify where in the brain the damage common to them occurs; and how it occurs, despite the protection provided by the skull and cerebrospinal fluid. The analysis suggests that the brain's weak point in the face of trauma is its capillary bed, which is torn by the shock of trauma. This identification in turn allows discussion of ways of delaying, avoiding and even treating these trauma-induced degenerations.

Lumbar cistern Candida intradural abscess following epidural anesthesia.

Background: This report describes a case of an immunocompetent patient with an intradural abscess from Candida dubliniensis. The majority of fungal spine infections, although rare in general, are due to Aspergillus or C. albicans through systemic fungemia. To date, there have only been two reports of spondylodiscitis from C. dubliniensis. Case Description: A 37-year-old immunocompetent female patient presented to the neurosurgical service for worsening headaches with nausea, vomiting, vision changes, and weight loss. MRI studies showed diffuse leptomeningeal enhancement of the distal spinal cord, conus medullaris, and nerve roots of the cauda equina extending beyond the neural foramina bilaterally. She had persistent symptoms and no clear diagnosis on lumbar puncture or systemic testing therefore L5-S1 laminectomy for an intradural tissue biopsy was performed. During surgery, cultures were taken and grew colonies of C. dubliniensis. Conclusion: This organism has been reported rarely in the literature as being an infectious agent, thus diagnosing remains a challenge but should be considered in patients with a suggestive history.

Meningitis due to intra-abdominal cerebrospinal fluid fistula following gunshot wound successfully treated with antibiotics and blood patch: A case report and literature review.

Background: Penetrating spinal cord injury (PSCI) represents an average of 5.5% of all SCIs among civilians in the United States. The formation of a cerebrospinal fluid (CSF) fistula following PSCI occurs in approximately 9% of cases. Intra-abdominal CSF fistulae are rarely reported. Case Description: We present the case of a 28-year-old Caucasian female who suffered a single gunshot wound to the abdomen with a missile fragment lodged within the left L2 pedicle and transverse process without obvious canal compromise. The patient developed bacterial meningitis 13 days after the initial injury, treated with IV antibiotics. CT myelogram demonstrated intra-abdominal ventral CSF fistula from the left L2-L3 neuroforamen. The patient was successfully treated with fluoroscopy-guided dorsal autologous blood patch graft. Conclusion: This case highlights a rare complication of PSCI successfully managed with the use of a blood patch graft.

Remote surgical education using synthetic models combined with an augmented reality headset.

Objective: The objective was to investigate the use of an augmented reality headset to remotely train clinicians on medical devices using anatomic models. Design: Disease-specific phantoms were developed to train physicians in mpMRI-guided fusion prostate biopsy, brachytherapy, and rectal spacer insertion. Training was remotely demonstrated using 1-way virtual video conferencing format. Participants responded to an educational content survey. A heads-up display with software and augmented reality was used for remote 2-way training with the proctor and student using on their own phantoms. Setting: The virtual video meeting took place during a prostate cancer conference in 2020, while the augmented reality training occurred in 2021. The proctor and student wore a heads-up display containing a projector and webcam where the ultrasound image was displayed onto a see-through optic along with the physician's hands. The heads-up display allowed the proctor to teach by line-of-sight while the student watched and repeated the steps. Participants: Faculty with expertise with the medical devices used in these procedures provided training to urologists unfamiliar with these techniques. Results: Participants responded that the 1-way training on the phantoms was realistic and mimicked human tissue. A total of 70.9% requested more training or training on the phantoms. The remote training platform was successfully beta tested at the 2 locations in transperineal prostate biopsy and rectal spacer insertion. Conclusion: Remote training using augmented reality eliminates the need for travel. For training programs and workshops, this technology may mitigate the risk of infectious exposures, reduce training cost, and increase proctor availability, allowing training from their own institution or clinic.This investigation qualifies for the Accreditation Council for Graduate Medical Education competency in medical knowledge.

Editorial Commentary: For Single-Bundle Anterior Cruciate Ligament Reconstruction, Graft Fixation Should Be Performed at a Medium Tension in Full Extension: Multiple Bundle Reconstruction May Require a Different Strategy.

Successful anterior cruciate ligament reconstruction requires a multifaceted approach to replicate normal knee anatomy and biomechanics. Graft tensioning force and the angle at which this tension is applied intraoperatively are factors under the surgeon's control. The literature suggests the best tensioning strategy for single bundle reconstructions is at medium tension in full extension, while tensioning multiple bundles is best done at 20° at lower overall tension. Graft tensioning should be individualized with attention paid to graft choice and fixation. Generally, stiffer grafts are thought to require additional force to create the same amount of lengthening. For example, bone-patellar tendon-bone grafts tend to be stiffer than quadrupled hamstring grafts and the native anterior cruciate ligament. Hamstring grafts also are thought to exhibit greater stress relaxation over time, thus elongating and potentially causing increased laxity over time. Pretensioning may eliminate some postoperative graft creep, typically more of an issue with hamstring grafts.

Unusual case of spinal subdural empyema with ventriculitis managed conservatively with lumbar drain.

It has long been believed that spinal subdural empyemas (SDEs) with neurological symptoms result in death if operative intervention is not performed. We present a case of addressing an extensive spinal SDE with a minimally invasive procedure: a bedside lumbar drain. Our patient is a 67-year-old man with medical history significant for type I diabetes who presented 2 weeks after a right shoulder steroid injection with septic arthritis. An MRI was obtained for back pain which revealed spinal SDE from the cervical to lumbosacral spine. Given patient's acute sepsis, haemodynamic instability, and extent of empyema, we placed a lumbar drain for decompression. The patient had a prolonged complicated hospital course. Imaging 2 months later revealed interval decrease in the spinal SDE. Although this severe septic event left the patient with significant deficits, he was able to return to ambulation without surgical intervention.

The Majority of Patients Aged 40 and Older Having Allograft Anterior Cruciate Ligament Reconstruction Achieve a Patient Acceptable Symptomatic State.

PURPOSE: To evaluate patient satisfaction, retear rates, and patient-reported outcomes (PROs) in patients aged 40 and older undergoing allograft anterior cruciate ligament reconstruction (ACLR). The secondary goal was to compare these parameters between groups of patients with intact versus failed grafts, and to evaluate these in relation to a historically reported International Knee Documentation Committee (IKDC) patient-acceptable symptoms state (PASS) score. METHODS: Records of patients aged 40 and older who underwent ACLR between 2005 and 2016 at a single institution with a minimum 2-year follow-up were retrospectively reviewed. Patient-reported satisfaction, outcome scores, and failure rates were analyzed. The rate of achieving a previously defined IKDC PASS score based on younger cohorts was reported, and an updated PASS threshold for older patients was calculated. RESULTS: 201 patients were included with a mean age of 48.6 years (range: 40-68) and mean follow-up of 6.2 years (range: 2.8-11.2). 182 (90.5%) patients reported satisfaction following surgery. 16 (8.0%) patients experienced failure of their ACLR, 10 of which underwent revision ACLR. The median IKDC score in the intact ACLR group was 86.2, compared to 66.7 in the failure group (P < .001). In total, 134 (72.4%) patients in the intact group achieved the historical PASS score of 75.9 on IKDC compared to only 4 (25%) in the failure group (χ2 = 15.396, P < .001). An updated IKDC PASS threshold for older cohorts was calculated to be 66.7. CONCLUSION: Patients aged 40 and older who underwent allograft ACLR had an 8.0% failure rate at a mean follow-up of 6 years. Graft failure in patients aged 40 and older was associated with worse PROs. The majority of patients achieved the historically reported IKDC PASS threshold. Additionally, an updated age-appropriate IKDC PASS score of 66.7 was calculated to aid in future ACLR studies assessing older patients. STUDY DESIGN: Level IV.

Acute Response and Neuroprotective Role of Myo/Nog Cells Assessed in a Rat Model of Focal Brain Injury.

Focal brain injury in the form of a needlestick (NS) results in cell death and induces a self-protective response flanking the lesion. Myo/Nog cells are identified by their expression of bone morphogenetic protein inhibitor Noggin, brain-specific angiogenesis inhibitor 1 (BAI1) and the skeletal muscle specific transcription factor MyoD. Myo/Nog cells limit cell death in two forms of retinopathy. In this study, we examined the acute response of Myo/Nog cells to a NS lesion that extended from the rat posterior parietal cortex to the hippocampus. Myo/Nog cells were identified with antibodies to Noggin and BAI1. These cells were the primary source of both molecules in the uninjured and injured brain. One day after the NS, the normally small population of Myo/Nog cells expanded approximately eightfold within a 1 mm area surrounding the lesion. Myo/Nog cells were reduced by approximately 50% along the lesion with an injection of the BAI1 monoclonal antibody and complement. The number of dying cells, identified by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), was unchanged at this early time point in response to the decrease in Myo/Nog cells. However, increasing the number of Myo/Nog cells within the lesion by injecting BAI1-positive (+) cells isolated from the brains of other animals, significantly reduced cell death and increased the number of NeuN+ neurons compared to brains injected with phosphate buffered saline or exogenous BAI1-negative cells. These findings demonstrate that Myo/Nog cells rapidly react to injury within the brain and increasing their number within the lesion is neuroprotective.