What is the likely diagnosis and management for a 66-year-old male with a history of lower back pain, mainly on the sides of the lower back, worsening with exertion and improving with rest, radiating to the ankle, and currently managed with tramadol (tramadol hydrochloride) and paracetamol (acetaminophen)?

Likely Diagnosis: Lumbar Disc Herniation with Radiculopathy

This 66-year-old male most likely has lumbar disc herniation with radiculopathy, and you should perform a focused neurological examination now, continue his current pain regimen short-term, and arrange MRI if symptoms persist beyond 4-6 weeks or if you find significant neurological deficits. 1

Why This is Radiculopathy, Not Mechanical Back Pain

• Radiculopathy is the primary consideration when back pain radiates down the leg in a typical lumbar nerve root distribution—this patient's pain radiates all the way to his ankle, which has fairly high sensitivity for herniated disc. 1
• The lateral location of his lower back pain (rather than central/spinal) combined with leg radiation strongly suggests nerve root involvement rather than simple mechanical back pain. 1
• More than 90% of symptomatic lumbar disc herniations occur at the L4/L5 and L5/S1 levels, which would explain radiation to the ankle. 1
• The pattern of pain worsening with exertion and improving with rest is consistent with mechanical nerve root compression from disc herniation. 1
• The absence of morning stiffness argues against inflammatory spondyloarthropathy. 2

Critical Examination Steps You Must Perform Now

Perform a focused neurological examination to assess:

• Straight-leg-raise test (91% sensitivity for herniated disc) 1
• Crossed straight-leg-raise test (88% specificity) 1
• Knee strength and reflexes 1
• Great toe and foot dorsiflexion strength 1
• Foot plantarflexion and ankle reflexes 1
• Distribution of sensory symptoms 1

Red Flags to Exclude Immediately

You've already ruled out most red flags, but specifically document:

• No urinary retention, fecal incontinence, or saddle anesthesia (cauda equina syndrome requires urgent MRI and surgery) 1, 3
• No fever, IV drug use, or recent infection (excludes spinal infection) 1
• No history of cancer or unexplained weight loss (excludes malignancy) 1
• No osteoporosis history or steroid use (makes compression fracture less likely) 1

Immediate Management Plan

Continue Current Medications Short-Term

• His tramadol/paracetamol combination is appropriate and evidence-based for moderate pain from disc herniation. 4, 5
• The fixed-dose combination of tramadol 37.5mg/paracetamol 325mg has additive analgesic effects and is effective for musculoskeletal pain including acute low back pain. 5, 6
• This combination provides rapid and long-lasting analgesia with better tolerability than higher doses of single agents. 7, 5

Add NSAIDs as First-Line

• NSAIDs are the primary medication with good evidence for moderate pain relief in acute radicular pain from disc herniation and should be added if not contraindicated. 1
• Consider adding a skeletal muscle relaxant for acute low back pain, which has good evidence for short-term effectiveness. 1

Non-Pharmacologic Interventions

• Advise him to remain active—this is more effective than bed rest for acute or subacute low back pain. 8
• Superficial heat (heating pads) has good evidence for moderate benefits in acute low back pain. 1
• Spinal manipulation has fair evidence for small to moderate benefits in acute presentations. 1

Imaging Decision Algorithm

Do NOT order MRI now if:

• Symptoms have been present less than 4-6 weeks 1, 9
• No severe or progressive neurologic deficits found on examination 1, 3
• No red flags present 8, 1

Order MRI lumbar spine (without contrast) if:

• Radicular symptoms persist for at least 6 weeks despite conservative management 1
• Severe or progressive neurological deficits develop 1, 9
• Signs of nerve root irritation on examination 1
• Any red flags emerge 1

Order URGENT MRI if:

• Cauda equina syndrome symptoms develop 1, 3
• Progressive motor weakness 1
• Suspected cancer or infection 1

What to Tell the Patient

• Inform him of the generally favorable prognosis—most patients improve within the first 4 weeks with noninvasive management. 8, 1
• Explain that early routine imaging usually cannot identify a precise cause, does not improve outcomes, and incurs additional expenses. 8
• Reassure him there is a high likelihood for substantial improvement in the first month. 8
• Advise him to remain active rather than rest in bed. 8

Common Pitfalls to Avoid

• Do NOT rush to epidural steroid injections—the most recent high-quality BMJ guideline strongly recommends AGAINST epidural injection of local anesthetic, steroids, or their combination for chronic radicular spine pain. 1
• Do not order MRI prematurely (before 4-6 weeks) unless red flags or severe neurological deficits are present. 1, 9
• Do not prescribe opioids as first-line therapy beyond his current tramadol; use lowest dose for shortest time. 1
• Do not recommend bed rest—activity is superior. 8

Follow-Up Timeline

• Reassess in 2-4 weeks to evaluate response to conservative management 1
• If symptoms persist at 4-6 weeks despite conservative therapy, arrange MRI to guide further management 1, 9
• Earlier specialist referral (within 2 weeks) is appropriate only if severe radicular pain is disabling and prevents normal daily activities 1
• Routine specialist referral within 3 months for radicular pain that is not severe 1