Anatomy Function allows spinal motion and provides stability links adjacent vertebral bodies together responsible for 25% of spinal column height Composition annulus fibrosus outer structure that encases the nucleus pulposus composed of type I collagen that is obliquely oriented, water, and proteoglycans characterized by high tensile strength and its ability to prevent intervertebral distraction remains flexible enough to allow for motion high collagen / low proteoglycan ratio (low % dry weight of proteoglycans) fibroblast-like cells responsible for producing type I collagen and proteoglycans nucleus pulposus central portion of the intervertebral disc that is surrounded by the annulus fibrosis composed of type II collagen, water, and proteoglycans approximately 88% water hydrophilic matrix is responsible for height of the intervertebral disc characterized by compressibility a hydrated gel due to high polysaccharide content and high water content (88%) proteoglycans interact with water and resist compression Aggrecan is a proteoglycan primarily responsible for maintaining water content of the disc viscoelastic matrix distributes the forces smoothly to the annulus and the end plates low collagen / high proteoglycan ratio (high % dry weight of proteoglycans) chondrocyte-like cells responsible for producing type II collagen and proteoglycans survive in hypoxic conditions Blood Supply the disk is avascular with capillaries terminating at the end plates nutrition reaches nucleus pulposus through diffusion through pores in the endplates annulus is not porous enough to allow diffusion Innervation the dorsal root ganglion gives rise to the sinuvertebral nerve which innervates the superficial fibers of annulus no nerve fibers extend beyond the superficial fibers neuropeptides thought to participate in sensory transmission include substance P calcitonin VIP CPON Fixation attached to vertebral bodies by hyaline cartilage Disc Biomechanics Disc viscoelastic characteristics demonstrates creep which allows for deformity over time demonstrates hysteresis which allows for energy absorption with repetitive axial compression this property decreases with time Stresses annulus fibrosus highest tensile stresses nucleus pulposus highest compressive stress intradiscal pressure is position dependent pressure is lowest when lying supine pressure is intermediate when standing pressure is highest when sitting and flexed forward with weights in the hands when carrying weight, the closer the object is to the body the lower the pressure Stability following subtotal discectomy, extension is most stable loading mode Pathoanatomy Disc Herniation herniated disks are associated with a spontaneous increase in the production of osteoprotegrin (OPG) interleukin-1 beta receptor activator of nuclear factor-kB ligand (RANKL) parathyroid hormone (PTH) Disc aging leads to an overall loss of water content and conversion to fibrocartilage. Specifically there is a decrease in nutritional transport water content absolute number of viable cells proteoglycans pH increase in an increase keratin sulfate to chondroitin sulfate ratio lactate degradative enzyme activity density of fibroblast-like cells fibroblast-like cells reside in the annulus fibrosus only no change in absolute quantity of collagen
QUESTIONS 1 of 16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ13.192) Which of following is pathognomonic of intervertebral disk degeneration? QID: 4827 Type & Select Correct Answer 1 Increased water content in the nucleus pulposus 7% (485/7087) 2 Loss of Type X collagen in the nucleus pulposus 5% (331/7087) 3 Decreased thickness of the inner annulus fibers 5% (350/7087) 4 Degradation of large proteoglycans molecules in the nucleus pulposus 71% (5059/7087) 5 Annular tears and fissuring occurring most frequently in the central disc 12% (830/7087) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (SBQ12SP.13) A 37-year-old male feels a "pop" in his low back while lifting a heavy object. Four weeks later he continues to have significant low back pain, with no complaints of symptoms in his leg. A T2-weighted MRI is shown in Figure A with a red arrow identifying abnormal signal intensity in an anatomic structure. What type of collagen is primarily responsible for the biological properties of this anatomic structure? QID: 3711 FIGURES: A Type & Select Correct Answer 1 Type I 69% (3846/5571) 2 Type II 27% (1481/5571) 3 Type V 1% (79/5571) 4 Type IX 2% (118/5571) 5 Type XI 0% (17/5571) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic (OBQ12.87) Which of the following are progressive changes seen with aging of the intervertebral disc? QID: 4447 Type & Select Correct Answer 1 Increase in water content 8% (374/4878) 2 Increase in large aggregated proteoglycans 12% (561/4878) 3 An increased keratan sulfate to chondroitin sulfate ratio 77% (3753/4878) 4 A decrease in degradative enzyme activity 3% (136/4878) 5 An increase in nutritional transport 1% (29/4878) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic (OBQ12.45) Which of the following statements is true with regard to the aging process of the intervertebral disc along the endplate? QID: 4405 Type & Select Correct Answer 1 Water content increases with age 10% (489/4701) 2 Proteoglycans increase with age 16% (746/4701) 3 Degradative enzyme activity decreases with age 10% (461/4701) 4 pH increase with age 16% (770/4701) 5 There is a conversion to fibrocartilage 47% (2210/4701) L 4 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ06.268) Recent studies have shown that cells of the intervertebral discs are biologically responsive and increase their production of matrix metalloproteinases, nitric oxide, interleukin-6, and prostaglandin E2 when stimulated by what molecule QID: 279 Type & Select Correct Answer 1 osteoprotegerin (OPG) 6% (193/3081) 2 interleukin-1 beta 47% (1457/3081) 3 transforming growth factor-beta 32% (994/3081) 4 receptor activator of nuclear factor-kB ligand (RANKL) 10% (323/3081) 5 parathyroid hormone (PTH) 3% (91/3081) L 3 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic (OBQ06.271) Which of the following processes is involved in age-related intervertebral disc degeneration? QID: 282 Type & Select Correct Answer 1 increased cell number in the nucleus pulposus 4% (77/2185) 2 increased matrix synthesis 2% (36/2185) 3 increased disc height 1% (17/2185) 4 increased degradative enzyme activity 86% (1879/2185) 5 increased chondrotin sulfate 8% (166/2185) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK
All Videos (0) Podcasts (2) Intervertebral Disc Derek W. Moore Spine - Intervertebral Disc Listen Now 6:35 min 10/16/2019 595 plays 4.6 (8) Question Session⎪Intervertebral Disc Orthobullets Team Spine - Intervertebral Disc Listen Now 20:2 min 11/6/2019 156 plays 0.0 (0)