low back pain

epidemiology

· life-time incidence

· 60-80%

· severe in 15-20%

· annual incidence

· 5-20%

· point prevalence of 7%

· 90% resolve within 2 mths

· 5% develop chronic LBP

· prognosis poor if pain persists > 6 mths

· account for 85% of total cost of LBP

cause

Aetiology

· not identified in 90%

Precipitants

· some evidence that pain increased with

· heavy manual work

· driving

· vibration

· cigarette smoking

Pathogenesis

· initiation

· mechanical and/or chemical irritation of primary sensory neurones

· site of activation

1. peripheral terminal endings of

· muscles

· joints

· skin

· periosteum

· meninges

2. dorsal root ganglion

pathology

FACETS	STAGE	DISC
synovitis	DYSFUNCTION	circular tears
articular degeneration	herniation	radial tears
capsular laxity	INSTABILITY	internal disruption
subluxation	nerve entrapment	disc resorption
facet enlargement	STABILITY	osteophyte formation
	stenosis

clinical features

History

Pain

· most common complaint

· may be precipitated by minor incident

· usually in mid low back

· can be referred to leg

· buttocks

· posterior thigh

· groin

· usually worse with activity

· esp. bending and lifting

Psychosocial factors

· depression

· lack of energy

· inability to enjoy oneself

· sleep disturbance

· spontaneous weeping

· feeling of depression

· drug addiction

· litigation

· worker’s compensation

Examination

General

· loss of lordosis

· paravertebral spasm

· decreased ROM, esp. flexion

Waddell’s nonorganic signs

· superficial tenderness

· skin pinch test

· axial compression

· pain on axial loading of skull

· inconsistent neurological signs

· cog-wheel weakness

· distraction

· flip test (sit up with legs extended)

· overreaction

· tremor, collapse and groaning

investigations

Of spine

Plain x-rays

· plain x-rays yield unexpected finding in 1 in 2500

· no correlation between LBP and

· disc space narrowing

· transitional vertebrae

· Schmorl’s nodes

· lumbar lordosis

· vacuum sign

· traction osteophytes

· spina bifida occulta

CT scan

· of asymptomatic subjects

· 35% had abnormality

· age < 40 - 20%

· age > 40 - 50%

MRI

· disc pathology reflected by decreased signal intensity on T2-weighted image

· of asymptomatic subjects

· age < 60 - 30% had abnormality and 20% had disc herniation

· age > 60 - 60% had abnormality, 35% had disc hernation and 20% had spinal stenosis

Discography

· of asymptomatic subjects

· 35% had abnormal discogram

· none had reproduction of pain

· of symptomatic subjects

· 65% had abnormal discogram

· all had reproduction of pain

Screening

· full blood count

· ESR

· LFT's

· protein electrophoresis

· prostatic markers

· chest x-ray

· bone scan

differential diagnosis

Viscerogenic

· may be due to disorders of

· kidneys

· pelvic viscera

· retroperitoneal tumours

· backache is rarely the sole symptom

· other symptoms usually present

· differentiating feature is that pain

· not aggravated by movement

· not relieved by rest

Vascular

· abdominal aortic aneurysm

· may give deep-seated lumbar pain unrelated to activity

· insufficiency of superior gluteal artery

· may cause buttock pain of claudicant character

· ischaemic claudication of peripheral vascular disease

· may mimic sciatic pain from nerve root irritation

· may mimic spinal stenosis

· both give pain and weakness of legs initiated by walking a short distance

· settles with rest

· in spinal stenosis, pain radiates from buttocks (not limited to calves) and pain is not releived by standing still (only sitting)

Neurogenic

· primary pathology of the nerve roots of the lumbar spine

· eg. neurilemmoma, neurofibromata, ependymoma, other cysts and tumours

· may be indistinguishable from nerve root pressure due to disc herniation

Psychogenic

· pure psychogenically induced pain uncommon

· confusion of the clinical picture by emotional overlay is common

Spondylogenic

· pain derived from the spinal column and its associated structures

· from bone or soft tissue

· aggravated by activity

· relieved somewhat by rest

· most common source of low back pain

Traumatic

· crush (wedge) fractures

· soft tissue injury

· stress fracture (isthmic spondylolisthesis)

Infective

· vertebral osteomyelitis

· discitis

Neoplastic

· benign

· haemangioma, osteoid osteoma, osteoblastoma, eosinophilic granuloma, aneurysmal bone cyst

· malignant

· primary (chordoma, myeloma)

· metastatic

Metabolic

· osteoporosis

· Paget's disease

Rheumatological

· spondyloarthropathies

· ankylosing spondylitis

· Reiter's syndrome

· psoriatic arthritis

· enteropathic disease

Degenerative

· disc degeneration

· spinal stenosis

·

treatment

Nonoperative

Acute LBP

Patient

· rest

· 2 days RIB as good as 7 days

Physical

· local measures

· symptomatic relief with manipulation and massage

· no long-term effect

· exercise

· once acute pain settles

· no particular exercise superior

· general fitness important

· brace

· no benefit

Pharmacological

· analgesics

· regular simple analgesia

· NSAIDs

· inappropriate

Chronic LBP

· best co-ordinated in structured rehabilitation programme

Patient

· lifestyle modification

· relaxation

Physical

· exercise programme

· back education programme

Pharmacological

· detoxification from narcotic analgesics

· antidepressants

Operative

· controversial

· no definite role for spinal fusion