EFFECT OF AGING ON SPINE
BY SWETA BHATIA

CONTENTS
• Introduction
• Adult spine
• Aging effect on spine
• Common spinal conditions
• Changes in diagnostic imaging
• Risk factors
• Physiotherapy effect on Aging
• Prevention
• Precautions

SPINE

Aging effect on:
1. Vertebral body
2. IVD
3. Endplate
4. Facet joints
5. Muscle and ligament
6. Biomechanical changes

VERTEBRAL BODY
Trabeculae Cortical

CORTICAL BONE
• Decreased Cortical Thickness

TRABECULAR BONE
Increase risk of fracture due to off axis impact
Increase axial load
Increase anisotropy
Loss of connectivity between trabecula
Increase intratrabecular spacing
Thinning of Trabeculae
Loss of Bone Mineral Density

Normal (top) and osteoporotic (bottom) vertebral bodies.
Decreased structural strength is not only the result of reduced apparentbone density but also
changes in the architecture of the trabecularbone. The increase in bone fragility is due to
replacementof platelike close trabecular structures with more open, rodlike structures. The
more porous cancellous bone appearance is the result of reduced horizontal cross-linking struts

Intervertebral disc
Dehydration and stiffening
of annulus
Replace by collagen
Loss of water
Decrease Proteoglycan

Disc collapses and height decreases
Decrease in intradiscal pressure and
altered load transmission
Disc disloged gradually from
vertebral rim
Cracks in annulus

ENDPLATE
FUNCTION
Increase risk of endplate fracture
due to nutrition and hydration of
IVD.
Ossification of endplate
Thinning of endplate
Loss of bone mineral density

FACET JOINT
Functions:
Denudation and ulcerative lesions of
articular cartilage, inflammatory
hypertrophy of synovial membrane
Arthritis
Multiplies load on facet
Disk degeneration

FACET JOINT
Stabilize joint but loss of mobility
Degeneration activate remodeling
process
Sclerosis of subchondral bone
Osteophyte formation

MUSCLE AND LIGAMENT
FUNCTION
PROPERTIES

LIGAMENTS
Decrease IV height
Decrease strength and elasticity of ligament.
Increase crosslinks of collagen
Increase Elastin: collagen

Spinal stenosis
Folding of ligamentum flavum
Increase in thickness due to remodeling
Decrease tension of ligamentum flavum

MUSCLES
Degeneration of sensory end organs
Decrease force generation
Tendon degenerate as ligament
Fatty degeneration in muscle

BIOMECHANICAL CHANGES
1. Creep characteristics of IVD
2. Kinematics of FSU
3. Compressive strength of vertebral
body
4. Stress and intradiscal pressure across
IVD
5. Load sharing

CREEP CHARACTERISTICS OF IVD
Non Degenerative Degenerative
Uneven stress
distribution
Attenuates decrease
shock absorption
Deforms fast
Load
Viscoelastic property and
regain back normal space
Creep slowly
Load

Temporal change in the displacement of an intervertebral
disc under a constant load (i.e., creep) with different
stages of degeneration. As degeneration worsens, two effects are
observed: a) the final displacement increases and b) the rate of
deformation increases significantly, in particular, immediately after
the load is applied

KINEMATICS OF FSU
Non Degenerative Degenerative
IAR and ROM due to ligament, facet, IVD changes
lead to hypomobility, hypermobility, immobility or
paradoxical motion
Spontaneous fusion
Decrease in advance IDD
ROM increase in initial IDD
Spread out even out side FSU
Small area in posterior
aspect of FSU
Axis of rotation

In a normal FSU, the
instantaneous center of rotation
(COR) stays within a narrow region
in the posterior aspect of the FSU
(shown in the yellow circle; F:
Flexion; E: Extension). In the case
of a degenerated disc, the COR
may vary over a wide area, even
outside the FSU

COMPRESSIVE STRENGTH OF
VERTEBRAL BODY
Increase risk of vertebral fracture
Thinning of cortical bone.
Decrease maximal compressive
strength at central region.
Decrease bone mineral density

COMPRESSIVE STRENGTH OF
VERTEBRAL BODY
Hard to compensate by muscle and
ligament alone.
Flexion posture
COG forward
Anterior wedging

STRESS AND INTRADISCAL
PRESSURE ACROSS IVD
Decrease tension in annulus, load transfer
and compression throughout annulus
Decrease intradiscal pressure
Increase pressure on annulus and loss of
height
Nucleus dehydration

Comparison of the stress profiles between a normal and
a degenerated disc. In a normal disc, a plateau in the stress profile
is observed whereas, in the degenerated disc, spikes are seen in
the annular regions and diminished stress profile is observed in the
nucleus pulposus.43 Modified and adapted from McMillan, D.W.,
McNally, D.S., Garbutt, G. & Adams, M.A. Stress distributions inside
intervertebral discs: the validity of experimental “stress profilometry’.
Proc Inst Mech Eng H 210, 81-87 (1996).

Decrease of intradiscal pressure with increasing grade
of disc degeneration. The pressure measurements were taken in
the prone body position. Horizontal and vertical refers to the alignment
of the pressure-sensitive membrane of the pressure sensor.45
Modified and adapted from Sato, K., Kikuchi, S. & Yonezawa, T. In
vivo intradiscal pressure measurement in healthy individuals and
in patients with ongoing back problems. Spine (Phila Pa 1976) 24,
2468-2474 (1999).

LOAD SHARING
Increase loading of annulus and
facet joint
Load distribution alter
Bone loss and hypertrophy in
facet and pars interartcularis
Increase compressive load on
neural arch

Effects of lumbar disc degeneration on compressive
load sharing. In a normal disc, the neural arch resists only 8% of
the applied compressive force, and the remainder is distributed
between the anterior and posterior aspects of the vertebral body.
Disc degeneration forces the neural arch to resist 40% of the
applied compressive force, whereas the anterior vertebral body
resists only 19%

DIAGNOSTIC IMAGING

HOW CAN PHYSIOTHERAPY HELP?
• Cannot Treat Condition But We Can Treat
Symptoms And Avoid Complication
• Maintenance Phase And Prevent From
Worsening
• After Surgery
• Preventive Physiotherapy

REFERENCES
1. THE AGING SPINE : NEW TECHNOLOGIES AND
THERAPEUTICS FOR OSTEOPOROTIC SPINE (
JOSEPH M. LANE , MICHAEL J. GARDNER, JULIE T.
LIN, ELIZABETH MYERS)
2. BIOMECHANICS OF AGING SPINE: ( STEPHEN J.
FERGUSON, THOMAS STEFFEN)
3. SPINE BIOMECHANICS AND AGE (AKASH
AGARWAL, VIKAS KAUL, VIJAY K GOEL)

REFERENCES
4. PATHOPHYSIOLOGY AND BIOMECHANICS OF
THE AGING SPINE (MICHAEL PAPADAKIS,
GEORGIOS SAPKAS, ELIAS C. PAPADOPOULOS,
PAVLOS KATONIS)
5. THE AGING SPINE (NDRNNIGEL KELLOW)
6. AGE ASSOCIATED CHANGES IN INNERVATION OF
MUSCLE FIBERS AND CHANGES IN MECHANICAL
PROPERTIES OF MOTOR UNITS (LUFF AR)
7. EXERCISE AND PHYSICAL ACTIVITY FOR OLDER
ADULTS ( WOITEK J. CHODZKO – ZAIKO , DAVID N
PROCTOR)
8. WEB ( PHYSIOPEDIA)

THANK YOU!