Low back pain

Cauda equina syndrome is compression of the lumbosacral nerve roots below the spinal cord causing saddle anesthesia, bladder or bowel dysfunction, bilateral leg weakness with areflexia, and low tone, most often from a large central lumbar disk herniation. It is a surgical emergency diagnosed by emergent MRI of the lumbar spine and treated with urgent decompression.

A vertebral compression fracture is a collapse of the anterior or middle vertebral body, most often from osteoporotic fragility with minimal or no trauma, presenting as acute focal spinal tenderness or, in up to two-thirds of cases, as an asymptomatic finding on imaging. Diagnosis is by spine radiograph confirming the fracture, which alone establishes a clinical diagnosis of osteoporosis, and first-line management is analgesia (acetaminophen 650 mg PO every 6 hours) with antiresorptive or anabolic pharmacotherapy to prevent further fracture.

Spinal epidural abscess is a suppurative infection of the spinal epidural space, most often hematogenous Staphylococcus aureus, presenting with fever, focal spinal pain, and, if missed, progressive weakness. The diagnosis is established by emergent MRI with contrast. Treatment is empiric intravenous vancomycin plus ceftriaxone or cefepime, with emergent surgical decompression whenever a neurologic deficit is present.

Ankylosing spondylitis is the radiographic axial spondyloarthritis: a chronic, HLA-B27-associated inflammatory disease of the sacroiliac joints, spine, and entheses presenting with inflammatory back pain before age 45. Sacroiliitis on pelvic radiograph or MRI establishes the diagnosis. First-line treatment is continuous scheduled NSAIDs with active exercise, escalating to a tumor necrosis factor inhibitor, then an interleukin-17 inhibitor, when NSAIDs fail.

Spondylolisthesis is anterior displacement of a vertebral body, usually L5 on S1, through a bilateral pars interarticularis defect in children and adolescent athletes or through degenerative facet disease in older adults, graded by percentage slip on a lateral radiograph and managed with activity modification and NSAIDs for low-grade disease, escalating to fusion for a high-grade or progressive slip with neurologic compromise.

Obesity is a chronic disease of excess adiposity, defined by a body mass index of 30 or greater, that raises risk for type 2 diabetes, cardiovascular disease, sleep apnea, liver disease, and several cancers. Management is staged: lifestyle intervention for all patients, pharmacotherapy after 3 to 6 months of unmet lifestyle goals, and bariatric surgery for a body mass index of 40 or greater or 35 or greater with a comorbidity.

Osteoporosis is low bone strength that raises fragility fracture risk, diagnosed by a hip or spine T-score of -2.5 or less or by a fragility fracture itself. First-line treatment is an oral bisphosphonate, alendronate or risedronate, alongside adequate calcium and vitamin D intake.

Nephrolithiasis affects 7-11% of the US population, most often as calcium oxalate stones, and presents as colicky flank pain radiating to the groin with hematuria. Noncontrast CT confirms the diagnosis and stone size drives management: hydration, NSAID/opioid analgesia, and alpha-blocker expulsive therapy for stones under 10 mm, urologic intervention for larger, infected, or obstructing stones.

Abdominal aortic aneurysm is focal dilation of the abdominal aorta to 3 cm or more, usually degenerative and often asymptomatic until rupture. Management is risk-factor control and surveillance for small aneurysms and elective repair at 5.5 cm (men) or with rapid growth or symptoms; rupture is a catastrophic emergency.