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Chapter Summary
• Context: Axial neck or back pain and radiating limb pain frequently originate from adjacent or distant non-spinal musculoskeletal structures rather than primary vertebral pathology. Because the vertebral column spans from the occiput to the sacrum and maintains intimate neural, mechanical, and kinetic-chain relationships with the shoulder girdle, thoracic rib cage, pelvic ring, hip joints, and peripheral nerves, non-spinal conditions frequently mimic spinal disorders. In the cervical region, rotator cuff tendinopathy, subacromial impingement, glenohumeral osteoarthritis, and thoracic outlet syndrome (TOS) can mimic cervical radiculopathy. In the thoracic region, costovertebral/costotransverse joint dysfunction, intercostal neuralgia, rib fractures, and slipping rib syndrome can mimic thoracic radiculopathy or disc disease. In the lumbosacral region, hip osteoarthritis ("hip-spine syndrome"), sacroiliac joint dysfunction, trochanteric bursitis (greater trochanteric pain syndrome [GTPS]), piriformis syndrome, plantar fasciitis, and common peroneal nerve entrapment at the fibular head can closely simulate lumbar disc herniation, radiculopathy, or spinal stenosis. Because asymptomatic degenerative disc bulges and facet arthrosis are ubiquitous on MRI, discovering a radiographic abnormality does not establish causality. A structured clinical history, regional joint physical examination, provocative maneuvers, and selective diagnostic anesthetic injections are essential for distinguishing true spinal disorders from mimicking orthopedic conditions.
• Chapter Objective: To present the primary orthopedic differential diagnoses of clinical symptoms attributed to the cervical, thoracic, and lumbar spine. The reader should be able to systematically characterize pain patterns; examine adjacent joints (shoulder, ribs, sacroiliac joint, hip); perform and interpret validated provocative orthopedic maneuvers; utilize diagnostic anesthetic blocks and electrodiagnostic testing; and distinguish primary spinal pathologies from mimicking or coexisting musculoskeletal disorders.
• Clinical Reasoning: Avoiding the MRI TrapDiagnostic reasoning begins with detailed symptom mapping using the OPQRST mnemonic: exact anatomical origin, pain radiation boundaries, aggravating motions, and relieving positions. A major pitfall in spine surgery is the "MRI trap"—attributing symptoms to asymptomatic degenerative changes (present in >40% of asymptomatic adults) without establishing clinical concordance. Clinicians must confirm that the anatomical location, dermatomal/myotomal distribution, and provocative maneuvers match the radiological abnormality before initiating invasive treatment.
• Cervical Region: Spine vs. Shoulder and Entrapment NeuropathiesCervical radiculopathy causes dermatomal pain radiating below the elbow, aggravated by neck extension/rotation (positive Spurling test) and relieved by shoulder abduction (positive Bakody sign). Shoulder pathologies (rotator cuff tear, subacromial bursitis, adhesive capsulitis) cause pain localized over the lateral deltoid that does not radiate below the elbow, aggravated by overhead arm elevation, internal rotation, and active shoulder abduction (positive Neer, Hawkins-Kennedy, and Jobe empty-can tests) with normal neurological examination. Thoracic outlet syndrome (TOS) produces diffuse arm paresthesias and vascular symptoms exacerbated by elevated arm maneuvers (Roos and Adson tests). Peripheral entrapments (carpal tunnel, cubital tunnel) feature localized focal nerve compression without neck pain.
• Thoracic Region: Spine vs. Thoracic Cage and Costovertebral JointsThoracic spine disorders (herniations, fractures, tumors) produce dermatomal band-like radiation around the chest wall, exacerbated by axial loading and coughing. Thoracic cage conditions—such as costovertebral/costotransverse joint arthrosis, costochondritis (Tietze syndrome), sternoclavicular arthritis, and slipping rib syndrome (hypermobility of the 8th–10th false ribs, positive hooking maneuver)—cause localized chest wall tenderness reproduced by direct anterior-posterior rib cage compression, trunk twisting, or deep inspiration, without true neurological deficits.
• Lumbar Region: Hip-Spine Syndrome, SI Joint, and Peripheral NervesHip osteoarthritis produces anterior groin and buttock pain that radiates along the anteromedial thigh to the knee, aggravated by weight-bearing and hip internal rotation (restricted internal rotation, positive Patrick FABER test, antalgic Trendelenburg gait). Sacroiliac (SI) joint dysfunction produces pain below the L5 level over the posterior superior iliac spine (Fortin finger test), buttock, and posterior thigh, reproduced by SI stress tests (distraction, compression, thigh thrust, FABER, Gaenslen tests; 3 or more positive tests yield >90% sensitivity). Greater trochanteric pain syndrome (GTPS) causes pinpoint tenderness over the lateral greater trochanter, aggravated by lying on the affected side. Piriformis syndrome causes sciatic notch tenderness without true spinal motor/sensory deficits. Common peroneal nerve entrapment at the fibular head causes foot drop with isolated weakness of ankle dorsiflexion and eversion (preserving ankle inversion and hip abduction) and focal Tinel sign at the fibular neck.
• Clinical Application: In clinical practice, the physical examination must systematically interrogate adjacent joints before confirming a spinal diagnosis. When a patient presents with neck and shoulder pain, examine both cervical range of motion with Spurling test and active shoulder abduction with Hawkins/Neer tests. If shoulder active and passive motion is limited and painful, administer a diagnostic subacromial local anesthetic injection: immediate pain relief confirms shoulder impingement as the primary pain driver. In a patient with buttock, thigh, and groin pain with both lumbar stenosis and severe hip osteoarthritis on radiographs (hip-spine syndrome), evaluate hip internal rotation and consider an intra-articular hip joint lidocaine injection. If hip injection resolves the predominant groin/thigh pain, total hip arthroplasty should precede lumbar decompression. In refractory buttock pain, a fluoroscopically guided sacroiliac joint injection achieving >=70–80% pain relief confirms the SI joint as the primary pain generator, avoiding unnecessary lumbar fusion.
