Novel Biomarkers of Health and Degeneration in Human Intervertebral Discs: In-depth Proteomic Analysis of Collagen Framework of Fetal, Healthy, Scoliotic, Degenerate, and Herniated Discs

Methods@#Forty NP tissues were snap-frozen in liquid nitrogen (–196°C) immediately before being subjected to proteomic and bioinformatic analyses from five different disk phenotypes (eight each). @*Results@#Tandem mass spectrometric analysis revealed a total of 1,050 proteins in FDs, 1,809 in ND, 1,487 in SD, 1,859 in DH, and 1,538 in the DD group. Of 28 major collagens reported in the human body, this study identified 24 different collagens with 34 subtypes in NP. Fibril-forming collagens (COL-1, 2, and 11A1) and fibril-associated collagens with interrupted triple helices (COL-9A1, 12A1, and 14A1) were abundantly expressed in FDs, representing their role in the development of NP. Multiplexin (COL-15), a hybrid proteoglycan–collagen molecule, was discovered only in FDs. Degeneration was associated with COL2A1 downregulation and COL-10A1 upregulation. @*Conclusions@#COL10 was discovered to be a new biomarker for disk degeneration. Besides COL-1 and 2, other important COLs (6, 9, 11, 12, 14, 15) with anabolic potential and abundant expression in the fetal phenotype could be investigated for tissue engineering and novel DDD therapy.

Presence of preoperative Modic changes and severity of endplate damage score are independent risk factors for developing postoperative surgical site infection: a retrospective case-control study of 1124 patients.

PURPOSE: There is increasing evidence of an association between Modic changes (MC) and subclinical infection. However, the association of MC with postoperative surgical site infection (SSI) has not been adequately probed. This study primarily aimed to investigate a probable association between preoperative MC, total endplate damage score (TEPS), and SSI. METHODS: A retrospective analysis of 1124 patients who underwent surgery in a single institution (2016-2018) was performed, using both univariate and multiple logistic regression analyses to identify independent risk factors for SSI. RESULTS: The prevalence of SSI was 4% (44/1124 patients), with no association with age or sex. The prevalence of MC in the SSI group was significantly higher-79.54% (35/44) compared to 58.79% (635/1080) (p value = 0.006) in the control group with no specific relation to type or location of MC. A higher TEPS was associated with SSI (p value = 0.009). A receiver operating characteristic (ROC) curve for TEPS values to assess predictiveness of SSI showed TEPS ≥ 5.5 to have a better sensitivity of 84% than 72% for a TEPS ≥ 6.5. Univariate analysis showed TEPS > 6 (odds ratio 3.887) to have a stronger association with SSI than the presence of MC (odds ratio 2.725). Among various types of surgeries, discectomy had a higher association with SSI (p value = 0.03) when compared to fusion (p value = 0.071). However, multiple logistic regression analysis revealed only TEPS > 6, presence of MC and hypothyroidism as independent risk factors for SSI. CONCLUSION: Our data suggest that preoperative MC and TEPS > 6 are independent risk factors for developing surgical site infections. MC could be foci of chronic subclinical infection and not mere markers of degeneration, as initially described.

Bezold-Jarisch reflex causing bradycardia and hypotension in a case of severe dystrophic cervical kyphotic deformity: a case report and review of literature.

PURPOSE: A 17-year-old adolescent with neurofibromatosis and severe cervicothoracic deformity was identified to have thoracic inlet compression leading to bradycardia and hypotension, only during prone positioning, and we discuss its successful management. METHODS: Preoperative halo-gravity traction reduced the deformity from 126° to 91°. During prone positioning, sudden onset bradycardia was followed by asystole, which disappeared immediately on turning over to supine position. Surgery was called off after two additional failed attempts of prone positioning. RESULTS: A retrospective analysis of CT and MRI showed severe narrowing of the thoracic inlet. In this patient, the right thoracic inlet was severely narrow, and prone positioning caused a further dynamic compromise stimulating right vagal nerve. The right vagus supplies the sinoatrial node, which is the natural pacemaker of the heart, and its stimulation causes sympathetic inhibition. Bezold-Jarisch reflex is a cardio-inhibitory reflex occurring due to vagal stimulation resulting in sudden bradycardia, asystole, and hypotension. To facilitate prone positioning, the medial end of the clavicles, along with limited manubrium excision, was performed relieving the vagal compression. C2-T4 instrumented decompression followed by anterior reconstruction and cervical plating was performed. The postoperative period was uneventful, and the final deformity was 45°. CONCLUSION: Bezold-Jarisch Reflex as a result of narrow thoracic inlet caused by cervical kyphosis and compensatory hyperlordosis of the upper thoracic spine has never been reported. This case highlights the need to introspect into thoracic inlet morphology in severe cervicothoracic deformities. Thoracic inlet decompression is an efficient way of addressing this unique complication.