Soft Tissue, Back Pain & Fibromyalgia

Approach to low back pain

Mechanical versus inflammatory. Most back pain is mechanical (muscle strain, disc degeneration): worse with activity, better with rest, without systemic features, and self-limited. Inflammatory back pain from a spondyloarthropathy behaves in the opposite way.

No red flags, no imaging. For acute nonspecific low back pain without red flags, do NOT image in the first 6 weeks. Advise staying active, with NSAIDs or acetaminophen, superficial heat or a short course of a muscle relaxant; bed rest is discouraged. Most cases resolve within 4–6 weeks.

Red flags. These override the no-imaging rule and call for prompt MRI, with ESR and CRP when infection or cancer is possible:

• Malignancy: age over 50, unexplained weight loss, night pain, history of cancer.
• Infection: fever, IV drug use, immunosuppression (vertebral osteomyelitis, epidural abscess).
• Fracture: major trauma, osteoporosis, chronic steroid use.
• Cauda equina: saddle anesthesia, urinary retention, bilateral leg weakness.

New back pain in a patient with cancer is spinal metastasis until proven otherwise; with any neurologic deficit, give IV dexamethasone and obtain an emergent MRI of the spine.

Cauda equina, radiculopathy and stenosis

Cauda equina syndrome. Compression of the lumbosacral roots by a large central disc, tumor, abscess or hematoma causes saddle anesthesia, urinary retention then overflow incontinence, bilateral leg weakness and decreased rectal tone. Obtain EMERGENT MRI and surgical decompression to prevent permanent deficits.

Urinary retention is the most consistent early sign; a post-void residual helps screen.

Sciatica. A herniated disc at L4–L5 or L5–S1 compresses a nerve root, radiating pain below the knee with a positive straight-leg raise; a crossed straight-leg raise is more specific. Most cases resolve conservatively within weeks; MRI and surgical referral are for progressive deficits or persistent disabling pain.

Lumbar spinal stenosis. Degenerative narrowing in older adults causes neurogenic claudication: leg pain with standing and walking, because lumbar extension narrows the canal, RELIEVED by sitting or leaning forward (the shopping-cart sign). MRI confirms the diagnosis; physical therapy and NSAIDs come first, with epidural steroid injection or decompressive surgery for refractory symptoms.

Polymyalgia rheumatica and giant cell arteritis

Polymyalgia rheumatica. A patient over 50 has bilateral shoulder and hip girdle pain and morning stiffness lasting over 45 minutes, with a high ESR (often over 50), a NORMAL CK and NO true weakness. A dramatic response within days to low-dose prednisone (12.5 to 25 mg/day) supports the diagnosis, after which the dose is tapered slowly over a year or more. Protect bone during long-term glucocorticoids: calcium and vitamin D for all, a fracture risk assessment, and an oral bisphosphonate for moderate or high fracture risk (ACR 2022).

PMR is pain, not weakness: strength is preserved once pain is controlled, and the CK is normal, unlike an inflammatory myopathy.

The GCA link. Up to 15–20% of PMR patients develop giant cell arteritis. New headache, scalp tenderness, jaw claudication or visual loss demands HIGH-dose steroids urgently to prevent blindness, not the low dose used for PMR alone, and before the biopsy.

Fibromyalgia

Diagnosis. Fibromyalgia is chronic widespread pain for over 3 months with fatigue, unrefreshing sleep and cognitive fog, reflecting central sensitization (pain amplification). It predominates in women and often coexists with depression, anxiety, irritable bowel syndrome and headache. Labs and inflammatory markers are NORMAL; a limited panel (CBC, ESR or CRP, TSH) excludes mimics such as hypothyroidism and PMR. The diagnosis is clinical, based on the widespread pain index and symptom severity, not on tender-point counting alone.

Treatment. First-line management is nonpharmacologic: graded aerobic exercise, cognitive behavioral therapy and sleep hygiene. Medications include duloxetine or milnacipran (SNRIs), pregabalin or gabapentin, and low-dose amitriptyline at bedtime.

AVOID opioids and glucocorticoids in fibromyalgia: they do not help and add harm.

Bursitis and tendinopathy

Bursitis. Overuse or pressure inflames a bursa: olecranon, prepatellar (housemaid's knee), trochanteric and subacromial. It causes focal swelling and tenderness with preserved joint motion. Treat with rest and NSAIDs; aspirate for cell count, Gram stain, culture and crystals if septic bursitis is suspected (warmth, erythema, fever), which is usually S. aureus in the superficial olecranon and prepatellar bursae.

• Rotator cuff (supraspinatus) tendinopathy: painful arc of abduction and pain with overhead activity.
• Lateral epicondylitis (tennis elbow): pain with resisted wrist extension.
• Medial epicondylitis (golfer's elbow): pain with resisted wrist flexion.
• De Quervain tenosynovitis: first dorsal compartment (abductor pollicis longus, extensor pollicis brevis), positive Finkelstein test, common in new mothers.

Tendinopathy care. Rest, activity modification, physical therapy and NSAIDs, with a corticosteroid injection or splint for persistent cases.