Repair of complete median nerve transection from shoulder arthroscopy following rotator cuff injury

•Nerve injury following arthroscopic shoulder procedures is a rare complication.•Most patients, including both those with nerve injuries preoperatively and those with surgical complications, will have gradual resolution of symptoms.•New onset nerve injuries as a complication from surgical repair should not be overlooked.•If neurologic function is not improved by 6 weeks, a more in-depth workup should be performed.•Special attention should be paid to patients whose symptoms persist despite an adequate physical therapy regiment. Nerve injury following arthroscopic shoulder procedures is a rare complication. Most patients will have gradual resolution of symptoms. Operative management may be required in the setting of complete nerve injury. We present a case detailing our experience managing a patient with a complete median nerve transection following shoulder arthroscopy for a rotator cuff injury. A thirty-nine-year-old female was referred to our office five months after undergoing a shoulder arthroscopy for a rotator cuff repair. Upon waking up from her initial surgery, she reported pain, numbness, and weakness in her right arm and hand, including the inability to make a fist or fully flex her first or second fingers. She was found to have right thenar eminence atrophy. Motor exam revealed profound weakness in flexors of the thumb and index finger. Because of the high likelihood of median nerve injury given the patient’s clinical presentation and surgical history along with an unremarkable brachial plexus MRI, surgery was recommended. Upon surgical exposure, the median nerve was found to be completely transected with a large neuroma. The neuroma was removed, and the nerve ends were trimmed with a sural nerve graft used to complete the repair. At her one and a half year follow up, she continued to demonstrate improvement although still complained of numbness in her first three fingers and weakness in her right hand. However, unlike preoperatively, her pain was well-controlled. Although distal neuropathies are a common preoperative complaint of patients with rotator cuff injuries, new onset nerve injuries as a complication from surgical repair should not be overlooked. Prevention of nerve injury is critical through adequate exposure and positioning during surgery. If a nerve injury does occur, examination during follow up visits are critical for monitoring the progression of symptoms and need for additional interventions

Influence of instrumentation type on outcomes after surgical management of spondylodiscitis: a systematic review and meta-analysis

Spondylodiscitis refers to infection of the intervertebral disk and neighboring structures. Outcomes based on instrumentation type are not well reported in the literature, but are important in establishing guidelines for surgical management of spondylodiscitis. This study aims to clarify the effect of instrumentation material selection on clinical and radiographic outcomes in patients with spondylodiscitis. Studies that evaluated the use of polyetheretherketone (PEEK), titanium, allograft, and/or autologous bone grafts for spondylodiscitis were identified in the literature. Radiographic and clinical data were analyzed using a meta-analysis of proportions, with estimated risk and confidence intervals reported for our primary study outcomes. Thirty-two retrospective studies totaling 1088 patients undergoing surgical management of spondylodiscitis with PEEK, TTN, allograft, and autologous bone graft instrumentation were included. There were no differences in fusion rates (p-interaction = 0.55) with rates of fusion of 93.4% with TTN, 98.6% with allograft, 84.2% with autologous bone graft, and 93.9% with PEEK. There were no differences in screw loosening (p-interaction = 0.52) with rates of 0.33% with TTN, 0% with allograft, 1.3% with autologous bone graft, and 8.2% with PEEK. There were no differences in reoperation (p-interaction = 0.59) with rates of 2.64% with TTN, 0% with allograft, 1.69% with autologous bone graft, and 3.3% with PEEK. This meta-analysis demonstrates that the choice of instrumentation type in the surgical management of spondylodiscitis resulted in no significant differences in rate of radiographic fusion, screw loosening, or reoperation. Future comparative studies to optimize guidelines for the management of spondylodiscitis are needed

Risk factors for vascular injuries in anterior lumbar interbody fusion: a single-institution retrospective study

Vascular injuries in anterior lumbar interbody fusion (ALIF) occur due to the vascular manipulation needed to achieve optimal disc space exposure. In this study, the authors aimed to evaluate intraoperative vascular injuries in patients undergoing single- and multilevel ALIF at a large tertiary academic center. Prospectively collected data specifically addressing postoperative complications in patients who underwent ALIF by neurosurgery spine faculty working with a specialized vascular surgeon were retrospectively reviewed. Demographic characteristics and intraoperative data were collected. Patients were split into vascular injury and non-vascular injury groups. Outcome comparisons were conducted using the chi-square exact and Wilcoxon rank-sum tests for categorical and continuous data, respectively. Logistic regression was used to investigate associations with vascular injury, with univariate analysis first conducted to identify candidate associations. Based on these results, variables demonstrating a between-groups test statistic of p < 0.10 were included in the multivariate analysis to determine the independent predictors of vascular injuries. In total, 323 patients who underwent ALIF procedures were identified: 51% were male (n = 166) and 49% were female (n = 157). The mean age was 57.1 years, with 56% (n = 182) having undergone prior lumbar surgery. Vascular injuries were encountered intraoperatively in 7.1% (n = 23) of patients, and the majority (91% [n = 21]) involved the left common iliac vein. Patients with vascular injuries were statistically older (mean 63.6 vs 56.6 years), had greater incidence rates of coronary artery disease, opioid use, multilevel ALIF surgery involving the L2-3 level, and surgery involving multiple disc spaces, had more multilevel anterior instrumentation, and experienced greater blood loss during surgery and longer length of stay (all p < 0.05). Overall, there was 1 death (0.3%) secondary to aortic artery injury. Multivariate analysis identified opioid use, multilevel ALIF involving L2-3, and multiple interbodies as statistically independent predictors of vascular injury (all p < 0.05). Identifying patient risk factors can reduce the risk of vascular injuries in ALIF. Opioid use, multilevel ALIF involving L2-3, and multiple interbodies were independent predictors of vascular injuries in ALIF

Infrasellar nasopharyngeal craniopharyngiomas: an individual participant data meta-analysis and review of the literature

Craniopharyngiomas are benign tumors of the anterior skull base arising from epithelial remnants of Rathke's pouch. They mainly occur in the suprasellar space, can be incredibly debilitating, and remain difficult to resect as they frequently involve critical neurovascular structures. Although it is embryologically possible for craniopharyngiomas to arise extracranially along the entire migrational path of Rathke's pouch, these remain exceedingly rare, especially among adults, and can be mistaken for nasopharyngeal cancer. As such, minimal data exists evaluating the management and outcomes of such lesions. We evaluated our institutional experience with purely infrasellar nasopharyngeal craniopharyngiomas and obtained individual patient data reported in the contemporary literature to better characterize the demographics, presentation, surgical management, and long-term outcomes of these lesions. A systematic review of the literature was performed to identify previously published cases of purely infrasellar nasopharyngeal craniopharyngioma in three electronic databases: MEDLINE (PubMed), Embase, Scopus. Search terminology included "infrasellar craniopharyngioma", "nasopharyngeal craniopharyngioma". Twenty-five total cases were identified and 72% presented with symptoms of nasal obstruction, epistaxis, or headache. 40% were resected via an endoscopic approach and 83.3% of all patients had a gross total resection with 60% having no recurrence at a median follow-up of 13 months. No patients had post-operative complications. Tumor location involving the cavernous sinus was associated with incomplete resection (100%) compared to those tumors not involving the cavernous sinus (87%), p = 0.033. While uncommon, infrasellar nasopharyngeal craniopharyngiomas appear to have better perioperative and long-term surgical outcomes than their suprasellar counterparts

African and European local ancestry surrounding Apolipoprotein E has a differential biological effect upon acute amyloid beta exposure in iPSC‐differentiated astrocytes

Background Studies have shown that the lower risk associated with the ε4 allele for African ancestry is associated with the local ancestry (LA) surrounding the ApoE gene. Previous studies have shown differences between ApoE3 and ApoE4 alleles in isogenic induced pluripotent stem cell (iPSC) models when exposed to Aβ. We hypothesized that ApoE4 individuals with African LA would respond differently to Aβ compared to European ApoE3 and European ApoE4 LA lines. However, as we cannot produce isogenic lines to test LA, we used RNA expression changes to Aβ exposure to increase our sensitivity to potential differences. Method We differentiated European LA ε4/ε4 and African LA ε4/ε4 allele astrocytes from iPSC lines. Astrocytes were exposed to exogenous Aβ and RNA was obtained at 0 and 24 hours. We performed bioinformatic analyses with the STAR algorithm and differential expression calculation using linear models implemented in edgeR. Pathway enrichment analysis for Gene Ontology Biological Processes, KEGG and Reactome pathways was performed using Metascape. Result Twenty‐four hours following Aβ exposure, 524 and 671 genes were deferentially expressed from baseline in African and European LA lines respectively. Analysis of the unregulated genes in the two different ancestries revealed markedly different pathways. The unregulated genes in African LA astrocytes were enriched for Ribosome Biogenesis and RNA modification processes while the upregulated genes in the European LA astrocytes were enriched for Cell Cycle and DNA modification processes. In the European LA astrocytes, downregulated genes were enriched for Synaptic Assembly and Kainate Receptor Activity while in the African LA astrocytes downregulated genes enriched for Extracellular Matrix‐related processes. Conclusion Our initial results suggest that the two ancestries respond differently to Aβ exposure. Whether this is due to global or local ancestry differences is unclear. Further studies including astrocytes bearing African LA ε3/ε3 are needed to clarify that question. Both ribosomal dysfunction and astrocyte‐neuronal and astrocyte‐microglia synaptic assembly have been implicated in Aβ clearance and/or AD. A potential link between LA and the regulation of these processes due to Aβ exposure could pave the path to a better understanding of LOAD pathology

Transgenic APOEε4/4 overexpression induces reactivity in astrocytes with a European APOEε4/4 local ancestry, but not in astrocytes with an African APOEε4/4 local ancestry

Recently we demonstrated that local genomic ancestry (LA) drives the difference in AD risk between European (EU) and African (AF) carriers of APOEε4/4. As a follow-up study using single-nuclei RNAseq, we found that AD APOEε4 homozygotes with EU Local Ancestry (LA) had a significantly increased APOEε4 expression compared to AD APOEε4/4 homozygotes with AF LA. In two of the EU LA patients, an astrocyte cluster with the highest APOEε4 expression was observed and expressed a panel of genes consistent with A1 reactive astrocytes (A1RA). No such cluster was seen in the AF LA. As a previous study in mice suggested that APOEε4 expression was a contributor to the development of A1RA, we sought to explore the relationship of increased APOEε4 expression and A1RA using inducible pluripotent stem cells (iPSC)-derived astrocytes. APOEε4/4 astrocytes from one European and one African LA were derived from iPSC lines. The astrocytes were brought to maturity (Day 54 in-vitro), and then each group was treated with either a cytokine cocktail (IL-1a, hTNFa, C1q) or overexpressed with APOEε4 by lentiviral transduction for 14-days (two replicates per line). mRNA was extracted and qPCR was performed to measure changes in APOEε4 and markers of A1RA (C3, GBP2, IFITM3). iPSCs were validated by immunocytochemistry (ICC) and qPCR for Nanog, SOX2 and OCT4 and subsequently differentiated into astrocytes. Astrocyte validation was performed by GFAP and βS100 ICC. Astrocytes treated with the cytokine cocktail had a 100- and 600-fold increase in C3 in EU and AF LA astrocytes respectively, as well as significant increase in GBP2 and IFITM3 compatible with A1RA. When overexpressing APOEε4, a significant increase in C3 was observed in the EU LA astrocytes, while no increase was observed in the AF LA astrocytes. Our preliminary results support the hypothesis that APOEe4 overexpression can increase the conversion of astrocytes to the toxic A1RA state in EU LA astrocytes. It is intriguing that this effect was not seen in the African LA astrocytes. By increasing the sample size, we will increase the significance of the association between APOEe4 overexpression and A1RA induction in EU LA astrocytes compared to their AF counterparts