PATHOLOGY

Degenerative changes in the lumbar spine

disc degenerationvertebral compression deformitiesligamentous laxitydeterioration of facet joint cartilage

May cause instability and subluxation of one vertebra on another (degenerative spondylolisthesis)

Anterolisthesis at L4-L5

PATHOLOGY

Backward slippage (retrolisthesis) is generally believed to be asymptomatic and of little clinical significance.

Forward slippage (anterolisthesis) may result in narrowing of vertebral canal and neural foramina (spinal stenosis) leading to development of chronic back pain (with or without leg pain). Compression of L5 spinal nerve may be involved.

PATHOLOGY

When LS joint is particularly stable, L4 and L5 are more vulnerable to stress forces. If degenerative changes have occurred, anterolisthesis at L4 is more likely.

Clinical symptoms associated with anterior subluxation

at L4-L5 80% at L3-L4 10-20%

PATHOLOGY

Spinal stenosis symptoms:

back pain progressing to leg painfunctional independence deterioratesreduced ability to walkreduced ability to carry out ADLs

Symptoms often episodic, no natural resolution over time

EPIDEMIOLOGY

Several clinical and cadaveric studies suggest that anterolisthesis is 5 times more common in women vs men

2-4 times more common in blacks than whites

4 times more prevalent in diabetics

3 times more common in oophorectomized women compared to controls

Prevalence of lumbar listhesis (L3-S1) in elderly white women (SOF)

05

1015202530354045

65-69 70-74 75-79 80+

Age in years

% p

reva

len

ce

anterolisthesis

retrolisthesisp for trend = 0.027

p for trend = 0.75

listhesis defined as subluxation > 3mm

CLINICAL RELATIONSHIPS

Relationship between radiographic abnormalities and spinal symptoms is unclear.

People with no back pain show disc abnormalities (64%), stenosis (7%) andanterolisthesis (7%) (Boden, JBJS 1990, Jensen NEJM 1994 ).

Not known whether people with sub-clinical disease later develop symptoms.

Veteran’s Health Study

0

5

10

15

20

25

30

35

40

45

LBP only LBP+LP to thigh LBP+LP below knee

% o

f co

ho

rt

n= 428 men

Selim, et al. Spine 1998

Veteran’s Health Study

Medic use

MRI

Surgery LBP alone

1.0

1.0

1.0

LP to thigh

1.5

(0.7,3.1)

3.2

(1.5,6.7)

0.9

(0.3,3.0)

LP below knee (-ve SLR)

1.8

(1.0,3.4)

3.5

(1.9,6.5)

3.7

(1.7,8.1)

LP below knee (+ve SLR)

5.1

(1.2,22.9)

6.8

(2.7,17.2)

3.9

(1.3,11.4)

Selim, et al. Spine 1998

0

10

20

30

40

50

60

70

PF RP BP GH VT MH SF RE

LBP onlyLBP/LP to thigh

LBP/LP below knee (-ve SLR)LBP/LP below knee (+ve SLR)

SF-36 scores for men with LBP enrolled in the Veteran’s Health Study

Sco

re

p for trend <0.05 for all domains

Selim, et al. Spine 1998

Distribution of lower back and leg pain symptoms w/in last month among white WHI women aged 50 years and older

0

10

20

30

40

50

60

No LBP LBP only LBP+LP LBP+LP imprby sitting

% o

f c

oh

ort

n=295 n=182n=47 n=49

Vogt et al. J Gerontol 2002

30

40

50

60

70

80

90

100

PF RP BP GH VT MH SF RE

no LBPLBP

LBP/LPLBP/LP improved by sitting

SF-36 scores for white women enrolled in WHI (adjusted for age and BMI)

Sco

re

Vogt et al. J Gerontol 2002

Relationship of race to prevalence and use of health care resources for LBP

Whites (%) AAmer (%)

Prev acute LBP last yr 8.3 (7.3, 9.3) 5.2 (3.8, 6.6)

Prev chronic LBP last yr 4.1 (3.4, 4.7) 3.0 (2.0, 4.0)

Prev seeking care 36 59

Random digit dialing + structured interview4,437 households in NC 8067 individuals

Carey, et al, Spine 1996

Relationship of race to prevalence and use of health care resources for LBP

Whites AAmer p

Pain score 5.25 5.92 <0.01

Disability score 11 12.1 0.01

X-rays (%) 49 40 0.05

Other imaging 10 6 0.05

Cohort study, random group of health care providers

Carey, et al, 2000

Elderly African American women (SOF) reporting back pain during previous four

weeks

50%

23%

20%

7%

no LBP

mild LBP

moderate LBP

severe LBPN=470

Back/leg symptoms in women aged 65 years and older during month prior to clinic visit (white women enrolled in

WHISTEN, black women enrolled in SLIP)

54.1 49.7

21.6

36.1 28.7

9.8

0102030405060708090

100

White women N=399

Black women N=470

% f

req

uen

cy Back pain, with legsymptomsBack pain, no leg symptomsNo back pain

Prevalence of lumbar listhesis (L3-S1) in black elderly women by age

0

10

20

30

40

50

60

70

80

65-69 70-74 75-79 80+

Age in years

% p

reva

len

ce

Anterolisthesis

Retrolisthesis

p for trend = 0.095

p for trend = 0.207

listhesis defined as subluxation > 3mm

% prevalence of listhesis among women 65 years and older

Antero Retro

White Black White Black

L3-L4 4 13 6 1

L4-L5 20 36 4 2

L5-S1

9 30 7 3

L3-S1 29 58 14 4

Vogt, et al, The Spine J 2002

Effect of back pain & leg pain on daily life of black women during previous month

0

1

2

3

4

5

6

mood walk/move sleep work recreation enjoy

Od

ds

rat i

o

expressed as age-adj odds ratio using back pain only as the reference - all p<0.001

Vogt, et al, The Spine J 2002

PREVENTION

Because most people experience LBPduring their lifetime, the distinction between primary and secondary prevention is blurred.

• which interventions can prevent occurrence of LBP?

• which interventions can prevent development of chronic LBP?

PREVENTION

Evidence-based medicine categories

Level A - strong consistent - multiple RCTs

Level B - moderate - one RCT + multiple CCTs

Level C - limited - one CCT

Level D - no evidence

PREVENTION

Lumbar supports

•provide support• remind to lift properly intra-abdom pressure and intradiscal pressure

RCTs negativeCCTs positive – reduce incidence of LBP and back injury

Level A - ve

PREVENTION

Back Schools and Education

• provide knowledge about body mechanics, stress, exercise• aim to influence behavior

9 RCTs - most are negative5 CCTs - positive

Level A -ve

PREVENTION

Exercises

• strengthen back muscles• increase blood supply • improve mood and alter perception of pain

6 RCTs – reduced pain and sick leave

Level A + ve

PREVENTION

Ergonomics

• job related interventions

No RCTs or CCTs

Level D - ve

PREVENTION

Risk Factor Modification

• individual (weight, strength, smoking)

• biomechanical (lifting, posture)

• psychosocial (job control, job dissatisfaction, depression)

No RCTs or CCTs

Level D - ve

Review of 47 epidemiologic studies concluded that smoking may be a ‘weak risk indicator and not a cause of low back pain’ Le-Bouef-Yde Spine 1999

Smoking may have a systemic effect on the musculoskeletal system - associated with generalized pain.

Biological basis unknown - neuroendocrine effect?

Decrement in SF-36 scores (compared to age-sex specific norms) for patients with

spinal problems by smoking status

-80

-70

-60

-50

-40

-30

-20

-10

0

PF RP BP HP MH EF SF RE

Smokers (n = 4249)

Non-smokers (n = 21206)

General population in US

SF

-36

sco

re

Vogt, et al, Spine 2002

PREVENTION

Currently only exercise seems to be helpful in prevention of LBP.

Consistent evidence – Level A.

Linton, van Tulder, Spine 2001

PREVENTION

Why the disappointing results?

• small studies, low power, short follow-up, variation in intervention, varying outcome

• natural course of back pain, hard to define and categorize, multi-factorial causation

• single modal programs studied mostly, maybe multi-dimensional approach needed

• timing, compliance