Biomechanics of the VC

Question 1

When the density of the cancellous bone of the VBs is decreased, as in osteoporosis, the load through the anterior lumbar spine is decreased meaning more is taken by the posterior column

Answer 1

Pitzen et al., (2001)

Question 2

Loads applied to the spine are shared among spinal components, in the lumbar spine load sharing passes 80-96% of the load through the VBs and discs and rest to posterior

Answer 2

Pitzen et al., (2001)

Question 3

Surgical disc implants should aim to mimic the physiological pattern of load sharing as in failure of the disc the facets will take the force, if the posterior column is not reconstructed will not be able to function adequately and may fail early

Answer 3

Pitzen et al., (2001)

Question 4

Weight bearing function of the VB and how structure and internal architecture reflect the loads they can stably sustain

Answer 4

Bogduk, (2005)

Question 5

Trabeculae are formed along lines of principle stress
Within the VC the vertebrae are subjected to various load yet each has a typical trabecular pattern suggesting each carries a typical load

Answer 5

Smit et al., (1976)

Question 6

Trabeculae mostly concentrated through S1 and 2 in the sacrum so does bear load/ weight

Answer 6

Ebraheim et al., (2000)

Question 7

Vertical trabecular system sustains body weight/ axial compression
Secondary oblique tracts resist torsion
Vertical + oblique resist bending and shear
Secondary horizontal tracts resist tension

Answer 7

Palastanga and Soames, (2012)

Question 8

Table of cortical vs trabecular bone

Answer 8

Ross and Pawlina, (2010)

Standring et al., (2008)

Question 9

Higher cortical thickness in cervical and lumbar regions potentially due to biphasic curve or S shape of spine

Answer 9

Ritzel et al., (1997)

Question 10

Walking may be the main activity that determines vertebral architecture (trabecular structure and vertical orientation of facets) but is not enough itself to prevent resorption
Dynamic loading > static loading

Answer 10

Smit et al., (1976)

Question 11

Vertebral endplate formed of an osseous and hyaline cartilage component, separates bone from disc itself and prevent herniation of NP

Answer 11

Moore, (2006)

Question 12

During degeneration of the endplate proteoglycan molecules which are critical for solute transport control are lost and the endplate may also ossify, all of which can contribute to disc degeneration

Answer 12

Moore, (2006)