The most commonly involved nerve in lunate dislocation is -
In hand injury, the first structure to be repaired should be?
Dequervain's tenosynovitis is a stenosing tenosynovitis of the
Cubital tunnel syndrome involves compression of which nerve?
Kienböck's disease is due to avascular necrosis of-
What causes mallet finger?
De-Quervain's disease classically affects the -
Carpal tunnel syndrome is due to compression of -
True about carpal tunnel syndrome - a) Occurs in pregnancy b) Affects medial 3½ fingers c) Associated with hypothyroidism d) Froment sign is positive e) Median nerve involvement is present
Tinel's sign that is positive and non-progressive is seen in:
Explanation: ***Median nerve*** - In a **lunate dislocation**, the lunate bone dislocates anteriorly and rotates. This displaced lunate can directly compress the **median nerve** within the carpal tunnel, which lies just anterior to it. - Compression of the median nerve leads to symptoms of **carpal tunnel syndrome**, including numbness and tingling in the thumb, index, middle, and radial half of the ring finger. *Ulnar nerve* - The **ulnar nerve** passes through Guyon's canal, which is located more medially and is generally not directly compressed by an isolated lunate dislocation. - While other wrist injuries can affect the ulnar nerve, it is not the most common nerve involved in lunate dislocation. *Posterior interosseous* - The **posterior interosseous nerve** is a branch of the radial nerve and supplies muscles in the posterior compartment of the forearm; it is located away from the carpal bones and is very rarely affected by lunate dislocation. - Injury to this nerve typically results in wrist drop or issues with finger extension. *Anterior interosseous* - The **anterior interosseous nerve** is a branch of the median nerve that supplies deep flexor muscles in the forearm; it also lies away from the direct path of a dislocated lunate. - Injury to this nerve leads to an inability to make the "ok" sign due to paralysis of the flexor pollicis longus and flexor digitorum profundus to the index finger.
Explanation: ***Bone*** - In hand injury, **skeletal stability** is paramount and is typically the first structure to be addressed to provide a stable foundation. - Repairing bone first allows for proper alignment and length restoration, which is crucial for the subsequent repair of soft tissues like tendons, nerves, and vessels. *Skin* - While skin closure is the final step in wound management, it should only be performed after deeper structures like bone, tendons, and nerves have been repaired. - Repairing the skin first would prevent access to underlying damaged structures and could lead to functional impairment. *Muscle* - Muscle repair is important for restoring function but should follow bone stabilization to ensure proper length and tension. - Unstable bone fragments can impede effective muscle repair and healing. *Nerve* - Nerve repair is critical for restoring sensation and motor function and should be done with meticulous attention to detail. - However, nerve repair typically follows bone stabilization and sometimes tendon repair, as a stable environment is necessary for successful nerve coaptation and healing.
Explanation: ***First extensor compartment of the wrist*** - **De Quervain's tenosynovitis** specifically involves the tendons of the **abductor pollicis longus (APL)** and **extensor pollicis brevis (EPB)** as they pass through the first dorsal extensor compartment of the wrist. - Inflammation and thickening of the tendon sheaths within this compartment lead to **pain and tenderness** on the radial side of the wrist, aggravated by movements of the thumb and wrist. *Median nerve* - The **median nerve** is associated with **carpal tunnel syndrome**, which presents with numbness, tingling, and weakness in the thumb, index, middle, and radial half of the ring fingers. - This condition involves compression of the median nerve as it passes through the carpal tunnel, not tenosynovitis of a specific tendon compartment. *Tendo Achilles* - The **Achilles tendon** is located at the back of the ankle and connects the calf muscles to the heel bone. - Conditions affecting the Achilles tendon include **Achilles tendinopathy** or rupture, causing pain and stiffness in the heel, which is distinct from wrist pain. *Iliolumbar ligament* - The **iliolumbar ligament** connects the transverse process of the fifth lumbar vertebra to the iliac crest. - Pain in this area is typically associated with **low back pain** or iliolumbar ligament sprain, not tenosynovitis in the wrist.
Explanation: ***Ulnar nerve*** - **Cubital tunnel syndrome** specifically refers to the compression of the **ulnar nerve** as it passes through the cubital tunnel at the elbow. - Symptoms include **numbness** and **tingling** in the little finger and half of the ring finger, and sometimes weakness of intrinsic hand muscles. *Radial nerve* - The **radial nerve** is compressed in conditions like **radial tunnel syndrome** or **wrist drop**, but not cubital tunnel syndrome. - It supplies sensation to the **dorsum of the hand** and motor function to the **extensor muscles** of the forearm and hand. *Popliteal nerve* - The **popliteal nerve** is located in the **lower limb**, specifically in the posterior knee region. - Compression of this nerve is typically associated with conditions like **peroneal nerve palsy**, affecting foot and ankle function, and is unrelated to the elbow. *Brachial nerve* - The term "brachial nerve" is generally not used in clinical anatomy; rather, it refers to the nerves originating from the **brachial plexus**. - The **brachial plexus** gives rise to several major nerves of the upper limb, including the ulnar, radial, and median nerves, but itself is not a specific site of compression in cubital tunnel syndrome.
Explanation: ***Lunate bone*** - **Kienböck's disease** is specifically defined as **avascular necrosis** of the **lunate bone** in the wrist. - This condition leads to the collapse and fragmentation of the lunate, causing wrist pain, stiffness, and weakness. *Medial cuneiform bone* - Avascular necrosis of the medial cuneiform is rare and not associated with Kienböck's disease. - This bone is located in the midfoot and is primarily involved in supporting the arch of the foot. *Femoral neck* - Avascular necrosis of the femoral neck is known as **avascular necrosis of the hip** or **osteonecrosis of the femoral head**, not Kienböck's disease. - It most commonly affects individuals with risk factors like steroid use, alcohol abuse, or trauma, and presents with groin pain. *Scaphoid bone* - Avascular necrosis of the scaphoid bone is known as **Preiser's disease**, which is distinct from Kienböck's disease. - The scaphoid is another carpal bone, and its avascular necrosis is often associated with trauma and presents with radial wrist pain.
Explanation: ***Bony avulsion of distal phalanx at the extensor tendon*** - Mallet finger commonly results from a **sudden forceful flexion** of an extended finger, leading to avulsion of the **extensor tendon's insertion** from the distal phalanx. - This specific injury, where a piece of bone is pulled away, results in the inability to **actively extend the distal interphalangeal (DIP) joint**. *Strain and subsequent stretching of the extensor tendon* - While stretching of the extensor tendon can occur, it is a less severe injury and typically does not result in the distinct **drooping deformity** characteristic of mallet finger. - This would manifest as weakness rather than a complete loss of **active extension** of the DIP joint. *Extensor tendon rupture* - A simple extensor tendon rupture means the tendon itself is torn, but it does not specify if a piece of bone has been avulsed. - While a rupture causes the inability to extend the DIP joint, the **bony avulsion** is a more precise and common mechanism for mallet finger, especially when due to trauma. *Extensor tendon rupture and bony avulsion of distal phalanx* - This option is partially correct but less precise than the most accurate answer. Mallet finger is specifically defined by the disruption of the **extensor mechanism at the DIP joint**. - Whether it's a pure tendon rupture or an avulsion fracture, the critical aspect is the loss of the tendon's attachment, with **bony avulsion** being a very common and specific cause.
Explanation: ***Extensor pollicis brevis and abductor pollicis longus*** - **De Quervain's tenosynovitis** is an inflammation of the tendons of the **extensor pollicis brevis** and **abductor pollicis longus** within the first dorsal compartment of the wrist. - This condition is characterized by pain and tenderness at the **radial styloid process**, often exacerbated by movements of the thumb or wrist. *Extensor carpi radialis and extensor pollicis longus* - The **extensor carpi radialis** muscles (longus and brevis) primarily extend and abduct the wrist, while the **extensor pollicis longus** extends the distal phalanx of the thumb. - While these muscles are in the forearm and wrist, they are not directly involved in De Quervain's tenosynovitis, which specifically affects the tendons of the first dorsal compartment. *Flexor pollicis longus and brevis* - The **flexor pollicis longus** flexes the interphalangeal joint of the thumb, and the **flexor pollicis brevis** flexes and opposes the thumb at the metacarpophalangeal joint. - These are **flexor muscles** located on the palmar side of the forearm and hand, and their tendons are not affected in De Quervain's disease. *Abductor pollicis longus and brevis* - While the **abductor pollicis longus** is one of the affected tendons in De Quervain's tenosynovitis, the **abductor pollicis brevis** is not. - The abductor pollicis brevis is a thenar muscle that abducts the thumb at the carpometacarpal joint and is typically not involved in the pathogenesis of De Quervain's.
Explanation: ***Median nerve*** - **Carpal tunnel syndrome** is a condition caused by the compression of the **median nerve** as it passes through the confined space of the carpal tunnel in the wrist. - Symptoms include numbness, tingling, and weakness in the thumb, index finger, middle finger, and the radial half of the ring finger, correlating with the median nerve's sensory and motor innervation. *Radial nerve* - The **radial nerve** is primarily responsible for innervation of the extensor muscles of the forearm and hand, and sensation over the back of the hand. - Compression of the radial nerve typically causes symptoms like **wrist drop** or sensory deficits on the dorsal aspect of the hand, which are not characteristic of carpal tunnel syndrome. *Ulnar nerve* - The **ulnar nerve** provides innervation to the little finger and the ulnar half of the ring finger, as well as some intrinsic hand muscles. - Compression of the ulnar nerve (e.g., in **Guyon's canal** or at the elbow in **cubital tunnel syndrome**) results in sensory or motor deficits in its distribution, distinctly different from carpal tunnel syndrome. *Palmar branch of the Ulnar nerve* - The **palmar branch of the ulnar nerve** is a superficial sensory branch of the ulnar nerve that innervates the skin over the hypothenar eminence. - Compression of this specific branch would cause isolated sensory changes in the hypothenar region, not the characteristic distribution seen in carpal tunnel syndrome.
Explanation: ***Median nerve involvement is present*** - Carpal tunnel syndrome is characterized by **compression of the median nerve** as it passes through the carpal tunnel in the wrist. - This compression leads to the classic symptoms of **numbness, tingling, and pain** in the median nerve distribution. *Associated with Hypothyroidism* - While **hypothyroidism** can *contribute* to carpal tunnel syndrome, it is not always present, nor is it a defining characteristic of the syndrome itself. - Hypothyroidism can cause **fluid retention** and deposition of mucopolysaccharides, which can increase pressure within the carpal tunnel. *Affects medial 3 1/2 finger* - The median nerve supplies sensation to the **thumb, index finger, middle finger, and the radial half of the ring finger** (which totals 3½ digits), not the medial 3½ fingers. - **Medial fingers** would refer to the ulnar digits, which are supplied by the ulnar nerve. *Occur in pregnancy* - **Pregnancy** is a known risk factor for developing carpal tunnel syndrome due to **hormonal changes and fluid retention**, but it is not a universally present feature in all cases. - Many individuals develop carpal tunnel syndrome without being pregnant. *Froment sign positive* - **Froment's sign** is a clinical test for **ulnar nerve palsy**, specifically weakness of the adductor pollicis muscle. - It is **not associated with carpal tunnel syndrome**, which primarily involves the median nerve.
Explanation: ***Neurotmesis*** - A positive and non-progressive **Tinel's sign** indicates that regenerating nerve fibers are unable to cross an existing **neuroma** or scar tissue, which is characteristic of **neurotmesis**. - In **neurotmesis**, there is a complete disruption of the axon, myelin, and surrounding connective tissue, making regeneration across the gap highly improbable without surgical intervention. *Neuropraxia* - In **neuropraxia**, there is a **concussion** of the nerve without disruption of the axon; nerve conduction is temporarily blocked. - A **Tinel's sign** is typically **negative** in neuropraxia because there is no axonal regeneration occurring and the nerve is fundamentally intact. *Axonotmesis* - **Axonotmesis** involves axonal disruption, but the **endoneurium** and other connective tissue layers remain intact. - While regeneration occurs in axonotmesis, a **Tinel's sign** would typically be **progressive**, indicating the advancement of regenerating axons, rather than non-progressive. *All of the options* - This option is incorrect because **neuropraxia** generally does not present with a positive Tinel's sign, and in **axonotmesis**, the sign should be progressive, not non-progressive.
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