Spine Disorders — MCQs

A 50-year-old electrician reports pain in his left upper extremity and tingling and numbness in the 4th and 5th digits of his left hand. There is mild swelling of the left hand. The patient reports most of his pain and numbness occurs when he is doing electrical work with his arms overhead. X-ray reveals the presence of a cervical rib. Which of the following structures is most likely being compressed?

Spine Disorders Indian Medical PG Practice Questions and MCQs

Question 51: A middle-aged lady presents with complaints of lower back pain. On examination, there is weakness of extension of the right great toe with no sensory impairment. An MRI of the lumbosacral spine would most probably reveal a prolapsed intervertebral disc at what level?

A. L3-L4
B. L4-L5 (Correct Answer)
C. L5-S1
D. S1-S2

Explanation: ### Explanation The clinical presentation of weakness in the **extension of the great toe** (Extensor Hallucis Longus - EHL) is a classic sign of **L5 nerve root** involvement. **1. Why L4-L5 is correct:** In the lumbar spine, a posterolateral disc prolapse (the most common type) typically compresses the **traversing nerve root** (the root exiting one level below). Therefore, a prolapse at the **L4-L5 level** compresses the **L5 nerve root**. The L5 root supplies the EHL muscle; hence, its compression leads to weakness in great toe extension. The absence of sensory impairment in this case suggests a predominantly motor fiber involvement, which is common in early or specific root compressions. **2. Why other options are incorrect:** * **L3-L4 (Option A):** This would compress the **L4 nerve root**, leading to weakness in knee extension (Quadriceps) and a diminished knee jerk reflex. * **L5-S1 (Option B):** This would compress the **S1 nerve root**, resulting in weakness of plantar flexion (Gastrocnemius/Soleus), loss of the ankle jerk reflex, and sensory loss on the lateral aspect of the foot. * **S1-S2 (Option D):** This level is rarely involved in disc prolapse and would primarily affect intrinsic foot muscles or bladder/bowel function (cauda equina). **3. High-Yield Clinical Pearls for NEET-PG:** * **L4 Root:** Weakness in Foot Inversion/Knee Extension; Reflex: Knee jerk. * **L5 Root:** Weakness in Great Toe Extension (EHL) and Foot Dorsiflexion; Reflex: None. * **S1 Root:** Weakness in Plantar Flexion/Foot Eversion; Reflex: Ankle jerk. * **Rule of Thumb:** In the lumbar spine, the nerve root involved is usually the lower one of the two vertebrae (e.g., L4-L5 affects L5). In the cervical spine, it is the upper one (e.g., C5-C6 affects C6).

Question 52: Which is the commonest level involved in lower cervical spine injury?

A. C3-C4
B. C4-C5
C. C5-C6 (Correct Answer)
D. C6-C7

Explanation: **Explanation:** The cervical spine is divided into the upper cervical (C1-C2) and lower cervical (C3-C7) segments. In the lower cervical spine, the **C5-C6 level** is the most frequently injured site. **Why C5-C6 is the Correct Answer:** The primary reason for the high incidence of injury at this level is **maximal mobility**. The C5-C6 junction represents the point of greatest flexion and extension in the cervical spine. In traumatic events like "whiplash" or high-velocity motor vehicle accidents, the mechanical stress and kinetic energy are concentrated at this fulcrum, making it highly susceptible to subluxation, dislocation, and fractures. **Analysis of Incorrect Options:** * **C3-C4 & C4-C5:** While these levels are part of the mobile subaxial spine, they are located higher up and undergo less mechanical strain compared to the C5-C6 segment. * **C6-C7:** This is the second most common site of injury. It serves as the transition zone between the mobile cervical spine and the relatively rigid thoracic spine (cervicothoracic junction), but statistically, it trails behind C5-C6 in frequency. **High-Yield Clinical Pearls for NEET-PG:** * **Most common level of Cervical Disc Herniation:** C5-C6 (affecting the C6 nerve root). * **Most common level of Spondylosis:** C5-C6, followed by C6-C7. * **Neurological Correlation:** Injury at C5-C6 often results in **C6 radiculopathy**, presenting with weakness in wrist extensors and sensory loss over the thumb and radial aspect of the forearm. * **Clay Shoveler’s Fracture:** An avulsion fracture of the spinous process, most commonly seen at **C7** (due to heavy lifting/shearing forces).

Question 53: Which of the following is a musculoskeletal abnormality associated with neurofibromatosis?

A. Hypertrophy of limb
B. Scoliosis
C. Cafe au lait spots
D. All of the above (Correct Answer)

Explanation: **Explanation:** Neurofibromatosis Type 1 (NF-1), also known as von Recklinghausen’s disease, is an autosomal dominant multisystem disorder caused by a mutation in the neurofibromin gene on chromosome 17. It has significant musculoskeletal manifestations that are frequently tested in NEET-PG. * **Scoliosis (Option B):** This is the **most common** skeletal abnormality in NF-1. It typically presents in two forms: a non-dystrophic type (similar to idiopathic scoliosis) and a **dystrophic type**, characterized by sharp, short-segment curves (usually involving 4-6 vertebrae) often associated with vertebral scalloping and rib penciling. * **Hypertrophy of limb (Option A):** This occurs due to **localized gigantism** resulting from plexiform neurofibromas and associated hemangiomatous or lymphatic overgrowth. This leads to limb length discrepancy and soft tissue hypertrophy. * **Cafe au lait spots (Option C):** While these are cutaneous markers (hyperpigmented macules), they are a cardinal diagnostic feature of NF-1. In the context of "musculoskeletal syndromes," they are often grouped with skeletal findings in clinical examinations. **Why "All of the above" is correct:** Since NF-1 is a generalized mesodermal dysplasia, it simultaneously affects the skin (Cafe au lait spots), the spine (Scoliosis), and the extremities (Limb hypertrophy/Pseudoarthrosis). **High-Yield Clinical Pearls for NEET-PG:** * **Anterolateral bowing of the tibia:** A pathognomonic skeletal finding in NF-1, often leading to **congenital pseudoarthrosis of the tibia**. * **Sphenoid wing dysplasia:** A characteristic skull deformity in NF-1. * **Diagnostic Criteria:** Remember the "Rule of 6": 6 or more Cafe au lait spots (>5mm in prepubertal, >15mm in postpubertal), 2 or more Lisch nodules (iris hamartomas), and 2 or more neurofibromas.

Question 54: In adults, cervical instability most commonly results from what?

A. A rotational injury
B. A flexion-extension injury
C. Degenerative disc disease (Correct Answer)
D. Increased ligamentous laxity

Explanation: **Explanation:** In adults, **Degenerative Disc Disease (DDD)** is the most common cause of cervical instability. As the intervertebral discs age, they lose water content and height (desiccation), leading to a loss of the disc’s structural integrity. This collapse results in **segmental hypermobility** and laxity of the surrounding ligaments (like the ligamentum flavum and posterior longitudinal ligament). Over time, this instability triggers the formation of osteophytes (spondylosis) as the body attempts to restabilize the segment, often leading to cervical spondylotic myelopathy or radiculopathy. **Analysis of Incorrect Options:** * **A & B (Rotational and Flexion-Extension Injuries):** While these are common mechanisms for *acute* traumatic instability (e.g., whiplash or fractures), they are less frequent causes of instability in the general adult population compared to the near-universal prevalence of age-related degeneration. * **D (Increased Ligamentous Laxity):** While ligamentous laxity causes instability, it is typically associated with specific systemic conditions like **Rheumatoid Arthritis** (specifically causing Atlanto-axial subluxation) or Down Syndrome, rather than being the primary cause in the general adult population. **Clinical Pearls for NEET-PG:** * **Most common level of cervical disc degeneration:** C5-C6, followed by C6-C7. * **Radiological Hallmark:** The "Vacuum Phenomenon" (gas within the disc space) is a specific sign of disc degeneration. * **Instability Definition:** On lateral flexion-extension X-rays, instability is defined as >3.5 mm translation or >11° angulation between adjacent vertebrae. * **Rheumatoid Arthritis:** Always rule out atlanto-axial instability before intubation in these patients due to transverse ligament laxity.

Question 55: What is the most common area involved in spinal tuberculosis?

A. Para-discal area (Correct Answer)
B. Central type
C. Anterior involvement
D. Appendiceal involvement

Explanation: **Explanation:** Spinal Tuberculosis (Pott’s Spine) is the most common form of skeletal tuberculosis. The infection is typically secondary to a primary focus (usually lungs) and spreads via the **Batson’s venous plexus** or arterial routes. **1. Why Para-discal is the Correct Answer:** The **Para-discal type** is the most common variety (approx. 50-80% of cases). The infection starts in the subchondral bone of the vertebral body adjacent to the intervertebral disc. Because the intraosseous arteries bifurcate and supply two adjacent vertebrae, the infection easily crosses the disc space to involve the neighboring vertebra. This leads to the characteristic destruction of the disc and narrowing of the disc space seen on X-rays. **2. Analysis of Incorrect Options:** * **Central type:** The infection starts in the center of the vertebral body. It often leads to early collapse and "vertebra plana," but it is less common than the para-discal type. * **Anterior involvement:** Also known as the "sub-periosteal" type, the infection spreads under the anterior longitudinal ligament. It is more common in children but less frequent overall. * **Appendiceal involvement:** This refers to the involvement of posterior elements (pedicle, lamina, spines). It is rare (approx. 2-5%) but clinically significant as it often leads to early neurological deficits due to spinal canal encroachment. **Clinical Pearls for NEET-PG:** * **Most common site:** Lower Thoracic and Upper Lumbar vertebrae (Thoracolumbar junction). * **Earliest sign on X-ray:** Rarefaction/blurring of the vertebral endplates and narrowing of the disc space. * **Deformity:** Destruction of the anterior part of the vertebrae leads to **Kyphosis** (Gibbus deformity). * **Cold Abscess:** A hallmark of Pott's spine; it is "cold" because it lacks the typical signs of acute inflammation (heat, redness).

Question 56: What is the most reliable diagnostic test for spinal tuberculosis?

A. Erythrocyte Sedimentation Rate (ESR)
B. Purified Protein Derivative (PPD) skin test
C. CT-guided biopsy (Correct Answer)
D. Magnetic Resonance Imaging (MRI)

Explanation: **Explanation:** Spinal tuberculosis (Pott’s disease) remains a significant cause of morbidity. The diagnosis is established through a combination of clinical, radiological, and microbiological findings. **Why CT-guided biopsy is the correct answer:** While imaging can suggest tuberculosis, the **gold standard** and most reliable diagnostic test is a **CT-guided needle biopsy**. It allows for histopathological examination (revealing caseating granulomas) and microbiological confirmation (Acid-Fast Bacilli staining or GeneXpert/CBNAAT). CT guidance ensures precision in reaching the deep-seated vertebral lesions or paravertebral abscesses while minimizing the risk of injury to the spinal cord or major vessels. **Analysis of incorrect options:** * **ESR (Option A):** This is a non-specific marker of inflammation. While it is usually elevated in Pott’s disease and useful for monitoring treatment response, it cannot confirm the diagnosis. * **PPD Skin Test (Option B):** A positive Mantoux test indicates prior exposure to *M. tuberculosis* but does not differentiate between latent infection and active spinal disease. It has low specificity in endemic regions like India. * **MRI (Option C):** MRI is the **investigation of choice (most sensitive imaging)** for early detection, assessing marrow edema, and evaluating cord compression. However, it provides radiological suspicion rather than definitive pathological proof. **NEET-PG High-Yield Pearls:** * **Most common site:** Lower thoracic and upper lumbar vertebrae. * **Earliest radiological sign:** Paradoxical expansion of the disc space (rare) or narrowing of the disc space (common). * **Cold Abscess:** Characterized by the absence of classic signs of inflammation (heat/redness). * **Gibbus Deformity:** Results from anterior wedging and collapse of the vertebral bodies.

Question 57: The CASPAR criteria is used in the diagnosis of which condition?

A. Psoriatic arthritis (Correct Answer)
B. Rheumatoid arthritis
C. Ankylosing spondylitis
D. Reactive synovitis

Explanation: **Explanation:** The **CASPAR (Clasification Criteria for Psoriatic Arthritis)** criteria were developed to provide a standardized, highly sensitive, and specific method for diagnosing Psoriatic Arthritis (PsA). Unlike other inflammatory arthritides, PsA often lacks a specific biomarker (like RF), making clinical criteria essential. To meet the CASPAR criteria, a patient must have **inflammatory arthritis** (joint, spinal, or entheseal) plus at least **3 points** from the following categories: 1. **Evidence of Psoriasis:** Current (2 pts), history of, or family history of psoriasis (1 pt). 2. **Psoriatic Nail Dystrophy:** Pitting, onycholysis, or hyperkeratosis (1 pt). 3. **Negative Rheumatoid Factor (RF):** (1 pt). 4. **Dactylitis:** Current "sausage digit" or a history of it (1 pt). 5. **Radiographic Evidence:** Juxta-articular new bone formation on X-rays of the hand or foot (1 pt). **Analysis of Incorrect Options:** * **Rheumatoid Arthritis (B):** Diagnosed using the **ACR/EULAR 2010 criteria**, which focus on joint involvement, serology (RF/Anti-CCP), and acute phase reactants. * **Ankylosing Spondylitis (C):** Diagnosed using the **Modified New York Criteria** (requiring radiographic sacroiliitis) or the **ASAS criteria** (for axial spondyloarthritis). * **Reactive Synovitis (D):** Usually diagnosed based on a clinical history of a preceding infection (GI or GU) and the presence of asymmetric oligoarthritis (part of the ESSG criteria). **High-Yield Clinical Pearls for NEET-PG:** * **Pencil-in-cup deformity:** The classic radiographic hallmark of PsA (distal phalanx base widens while the proximal phalanx head narrows). * **DIP involvement:** PsA characteristically involves the Distal Interphalangeal joints, which are typically spared in Rheumatoid Arthritis. * **HLA Association:** Strongly associated with **HLA-B27** (especially in axial/spondylitic presentations).

Question 58: Tuberculosis in Pott's disease involves which of the following joints?

A. Hip Joint
B. Knee Joint
C. Spine (Correct Answer)
D. Wrist Joint

Explanation: **Explanation:** **Pott’s Disease** is the clinical term specifically used for **Tuberculosis of the Spine**. It is the most common site of osteoarticular tuberculosis, accounting for approximately 50% of all bone and joint TB cases. The infection typically starts in the anterior part of the vertebral body (paradiscal type is most common) and spreads under the anterior longitudinal ligament, leading to bone destruction, vertebral collapse, and the characteristic **gibbus deformity** (kyphosis). **Analysis of Options:** * **Option C (Spine):** Correct. By definition, Pott’s disease refers to tuberculous spondylitis. It most frequently involves the lower thoracic and upper lumbar vertebrae. * **Option A (Hip Joint):** Incorrect. While the hip is the second most common site for osteoarticular TB, it is referred to as "Tuberculosis of the Hip," not Pott's disease. * **Option B (Knee Joint):** Incorrect. TB of the knee is common but usually presents as chronic synovitis or "triple deformity" of the knee. * **Option D (Wrist Joint):** Incorrect. TB of the wrist is relatively rare and may present as compound palmar ganglion. **Clinical Pearls for NEET-PG:** * **Most common site:** Paradiscal (involves the disc space and adjacent vertebrae). * **Cold Abscess:** A hallmark of Pott's disease; it is "cold" because it lacks the classic signs of acute inflammation (heat, redness). In the lumbar region, it may track down the psoas muscle (**Psoas Abscess**). * **Neurological Complication:** Pott’s paraplegia is the most serious complication. * **Radiology:** Earliest sign is narrowing of the disc space and blurring of the vertebral endplates.

Question 59: What are the characteristics of aspirated synovial fluid in septic arthritis?

A. Clear color
B. High viscosity
C. Markedly increased polymorphonuclear leukocytes (Correct Answer)
D. None of the above

Explanation: In septic arthritis, the synovial fluid undergoes dramatic changes due to the intense inflammatory response triggered by a bacterial infection. ### **Explanation of the Correct Answer** **Option C (Markedly increased polymorphonuclear leukocytes)** is correct because the hallmark of septic arthritis is a massive influx of neutrophils (PMNs) into the joint space. In a typical septic joint, the White Blood Cell (WBC) count is usually **>50,000 cells/mm³**, with **>75% (often >90%) being polymorphonuclear leukocytes**. This occurs as the body’s primary defense mechanism to phagocytose the invading pathogens. ### **Analysis of Incorrect Options** * **Option A (Clear color):** Incorrect. Normal synovial fluid is straw-colored and transparent. In septic arthritis, the fluid becomes **opaque, turbid, or purulent** due to the high concentration of WBCs, bacteria, and cellular debris. * **Option B (High viscosity):** Incorrect. Normal synovial fluid has high viscosity due to hyaluronan. In infection, bacterial enzymes (like hyaluronidase) and lysosomal enzymes from neutrophils break down hyaluronic acid, resulting in **low viscosity** (the fluid "watery" and does not form a long string). ### **NEET-PG High-Yield Pearls** * **Gold Standard Diagnosis:** Synovial fluid analysis (Gram stain and Culture). * **Glucose Levels:** Characteristically **low** (<60% of serum glucose) because bacteria and WBCs consume glucose. * **Lactate Levels:** Typically **elevated** in septic joints. * **Commonest Organism:** *Staphylococcus aureus* is the overall most common cause; *Neisseria gonorrhoeae* is common in sexually active young adults. * **Emergency Status:** Septic arthritis is an orthopedic emergency because proteolytic enzymes can destroy articular cartilage within 48 hours.

Question 60: A 50-year-old electrician reports pain in his left upper extremity and tingling and numbness in the 4th and 5th digits of his left hand. There is mild swelling of the left hand. The patient reports most of his pain and numbness occurs when he is doing electrical work with his arms overhead. X-ray reveals the presence of a cervical rib. Which of the following structures is most likely being compressed?

A. Axillary artery
B. Brachial artery
C. Brachiocephalic artery
D. Subclavian artery (Correct Answer)

Explanation: ### Explanation The clinical presentation describes **Thoracic Outlet Syndrome (TOS)**, specifically caused by a **cervical rib**. The thoracic outlet is an anatomical space bordered by the first rib, clavicle, and scalene muscles, through which the brachial plexus and subclavian vessels pass. **1. Why the Subclavian Artery is Correct:** A cervical rib (an accessory rib arising from the C7 vertebra) narrows the scalene triangle. When the patient performs overhead activities (abduction and external rotation), the **subclavian artery** and the **lower trunk of the brachial plexus (C8-T1)** are compressed against the cervical rib or its fibrous band. Compression of the C8-T1 nerve roots explains the numbness in the 4th and 5th digits (ulnar distribution), while vascular compression leads to hand swelling and exertional pain. **2. Why the Other Options are Incorrect:** * **Axillary Artery:** This is the continuation of the subclavian artery *after* it crosses the outer border of the first rib. Compression by a cervical rib occurs more proximally at the level of the subclavian artery. * **Brachial Artery:** This begins at the lower border of the teres major muscle in the arm, far distal to the thoracic outlet. * **Brachiocephalic Artery:** This is a large mediastinal trunk (on the right side) that bifurcates into the right common carotid and right subclavian arteries; it is not located within the narrow confines of the thoracic outlet. **3. NEET-PG High-Yield Pearls:** * **Adson’s Test:** A classic clinical test for TOS where the radial pulse disappears when the patient extends the neck and rotates the head toward the affected side during deep inspiration. * **Neurological vs. Vascular:** 95% of TOS cases are neurogenic (affecting the brachial plexus), but the presence of swelling and overhead aggravation strongly suggests a vascular component. * **Gilliatt-Sumner Hand:** Severe neurogenic TOS can lead to wasting of the thenar and hypothenar eminences. * **Treatment:** Initially conservative (physiotherapy); surgical resection of the cervical rib is indicated if symptoms persist or vascular complications arise.

Practice by Chapter

Cervical Spine Disorders

Practice Questions

Thoracic Spine Disorders

Practice Questions

Lumbar Spine Disorders

Practice Questions

Intervertebral Disc Disease

Practice Questions

Spinal Stenosis

Practice Questions

Spondylolisthesis

Practice Questions

Spinal Deformities

Practice Questions

Spinal Infections

Practice Questions

Spinal Tumors

Practice Questions

Spinal Cord Injuries

Practice Questions

Minimally Invasive Spine Surgery

Practice Questions

Rehabilitation of Spine Conditions

Practice Questions

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