Degenerative Spine & Nerve

Epidemiology

Incidence

A very common cause of leg pain in adults; lumbar discectomy is one of the most frequently performed spinal operations.

Age peak

Young and middle-aged adults.

Location

Most often at L4–L5 and L5–S1.

Clinical Presentation

• Dermatomal leg pain that typically exceeds the back pain, often with paraesthesia and a root-specific motor, sensory, or reflex deficit; the straight-leg-raise test is frequently positive.
• Red flags demanding urgent assessment: cauda equina syndrome (saddle anaesthesia, urinary retention/incontinence, bilateral sciatica) and a significant or progressive motor deficit (e.g. foot drop).

Imaging

• MRI is the imaging modality of choice and should be correlated with the clinical findings, because asymptomatic disc herniations are common and imaging alone does not establish the pain source.
• The compressed root should match the patient's symptoms and signs before surgery is planned.

Management

Surgery. Microdiscectomy is offered for persistent radiculopathy that fails conservative care, or for a significant or progressive neurological deficit. In SPORT, both surgical and non-operative groups improved substantially over 2 years; very high crossover between groups limited the intention-to-treat conclusions, but the overall evidence supports faster relief of radicular leg pain with surgery in appropriately selected patients.

Adjuvant therapy. In the absence of red flags, initial non-operative care (analgesia, activity modification, physiotherapy, and time, usually over 6 or more weeks) is appropriate; selective nerve-root or epidural steroid injection helps some patients.

Considerations. Cauda equina syndrome and a severe or progressive motor deficit are urgent surgical indications and are not candidates for prolonged conservative treatment.

Outcomes

Most patients recover; surgery offers faster relief of leg pain in selected patients, and long-term outcomes between operative and non-operative care tend to converge.

By molecular subgroup: Predominant leg pain (radiculopathy) responds better to discectomy than predominant back pain.

Epidemiology

Incidence

A common, often disabling condition and a leading indication for spinal surgery in older adults.

Age peak

Older adults.

Location

Most often the lower lumbar levels (e.g. L4–L5).

Clinical Presentation

• Neurogenic claudication: buttock and leg pain, heaviness, or paraesthesia brought on by standing and walking and relieved by sitting or forward flexion (the 'shopping-cart sign').
• Preserved pedal pulses and relief with flexion help distinguish it from vascular claudication.

Imaging

• MRI demonstrates central canal, lateral-recess, or foraminal narrowing; findings must be correlated with the symptoms.
• Standing or flexion–extension radiographs are useful when instability or an accompanying slip is suspected.

Management

Surgery. Decompressive laminectomy is offered for symptomatic stenosis that fails conservative care. In SPORT, decompression produced significantly greater improvement than non-surgical care (as-treated analysis, sustained at 2 years). For stenosis without spondylolisthesis or instability, adding fusion is not routinely indicated; the Swedish Spinal Stenosis Study found no clinical benefit from adding fusion to decompression.

Adjuvant therapy. Non-operative care (physiotherapy, activity modification, analgesia, and epidural injections) is reasonable first-line treatment when symptoms are tolerable and there is no progressive deficit.

Considerations. The extent of decompression is chosen to relieve the neural compression adequately while preserving spinal stability.

Outcomes

Decompression reliably relieves neurogenic claudication in selected patients; symptoms can recur over years as degeneration progresses.

By molecular subgroup: Adding fusion to decompression did not improve outcomes for stenosis without instability (Försth, 2016).

Epidemiology

Incidence

A common degenerative condition, more frequent in women.

Age peak

Older adults.

Location

Most often L4–L5.

Clinical Presentation

• Neurogenic claudication and/or radiculopathy, sometimes with mechanical low-back pain that worsens with activity.
• Symptoms overlap with isolated stenosis; dynamic instability may add a mechanical component.

Imaging

• Standing and flexion–extension radiographs assess the degree of slip and any dynamic instability.
• MRI defines the neural compression and the disc/facet degeneration.

Management

Surgery. Decompression (laminectomy) with or without fusion. SPORT showed surgery superior to non-operative care over 2 years. Whether to ADD fusion is debated. In 2016 two NEJM randomized trials reached different conclusions: the SLIP trial (Ghogawala) found laminectomy plus instrumented fusion gave a small but clinically meaningful quality-of-life benefit and fewer reoperations (14% vs 34%), whereas the Swedish Spinal Stenosis Study (Försth) found decompression plus fusion no better than decompression alone at 2 and 5 years, with longer stay and higher cost.

Adjuvant therapy. Non-operative care is appropriate for tolerable symptoms without a progressive deficit.

Considerations. Demonstrable dynamic instability, deformity, or predominant mechanical back pain favour adding fusion; isolated stenosis at a stable slip can often be managed by decompression alone.

Outcomes

Surgery improves pain and function compared with non-operative care; the incremental value of fusion is patient-specific.

By molecular subgroup: The two 2016 fusion trials disagree: fusion helped modestly in SLIP but added no benefit in the Swedish study, so the decision is individualised.

Epidemiology

Incidence

A common cause of neck and arm pain in adults.

Age peak

Middle-aged adults (disc herniation) and older adults (spondylotic foraminal stenosis).

Location

The C6 and C7 roots (C5–C6 and C6–C7 levels) are most often affected.

Clinical Presentation

• Dermatomal arm pain and numbness with myotomal weakness and a depressed reflex; Spurling's manoeuvre (extension and lateral flexion towards the side of pain) may reproduce the symptoms.
• Symptoms and signs should localise to a specific root.

Imaging

• MRI demonstrates the root compression; the affected level should match the clinical root.
• CT is useful to characterise bony foraminal stenosis and osteophytes.

Management

Surgery. For persistent or disabling radiculopathy, or a significant motor deficit, that fails conservative care, surgical options include anterior cervical discectomy and fusion (ACDF), cervical disc arthroplasty, and posterior cervical foraminotomy.

Adjuvant therapy. Most cases improve with non-operative care (analgesia, physiotherapy, and time); selective nerve-root injection helps some patients.

Considerations. The choice of approach (anterior versus posterior, fusion versus arthroplasty) depends on the compressive pathology, the level, and the cervical alignment.

Outcomes

Appropriately selected surgery gives good relief of radicular symptoms; many patients recover without surgery.

By molecular subgroup: Soft-disc herniations and single-level foraminal stenosis are well suited to focused decompression.

Epidemiology

Incidence

The leading cause of acquired spinal-cord impairment worldwide.

Age peak

Older adults.

Location

The cervical spine, usually at the levels of greatest spondylosis.

Clinical Presentation

• Gait imbalance, clumsy hands with loss of fine dexterity, and numbness, with upper-motor-neuron signs (hyperreflexia, Hoffmann sign, Babinski sign, clonus).
• Severity is graded with the modified Japanese Orthopaedic Association (mJOA) score.

Imaging

• MRI shows the cord compression, sometimes with intramedullary T2 signal change.
• Dynamic radiographs and CT help assess alignment, instability, and ossification of the posterior longitudinal ligament.

Management

Surgery. Surgical decompression is the mainstay for moderate-to-severe and for progressive myelopathy. In the AOSpine North America prospective study (Fehlings, 2013), decompression improved functional (mJOA, Nurick), disability (NDI), and quality-of-life outcomes at 1 year across all severity categories, with an overall complication rate of about 19%. Approaches include anterior (ACDF or corpectomy) and posterior (laminectomy with fusion, or laminoplasty), selected by the pattern and levels of compression and by alignment.

Adjuvant therapy. Mild, non-progressive myelopathy may be monitored closely or offered surgery after shared decision-making; progressive deficits warrant surgery.

Considerations. Intervening before severe deficits develop generally yields better neurological recovery; the approach is individualised to the compressive anatomy.

Outcomes

Surgery halts progression and improves function across severity grades; baseline severity and symptom duration influence the degree of recovery.

By molecular subgroup: Functional, disability, and quality-of-life outcomes improved across mild, moderate, and severe categories after decompression (AOSpine).