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8. Foot and Ankle MCQs

Practice Set 265 of 353

This practice set contains high-yield board review questions covering key concepts in 8. Foot and Ankle. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 5281

Topic: 8. Foot and Ankle

A patient with diabetes mellitus lacks protective foot sensation as determined by monofilament testing. According to the provided text, this patient is at highest risk for developing which of the following soft tissue complications?

. Squamous cell carcinoma
. Neuropathic ulcerations
. Plantar fibromatosis
. Pyogenic granuloma
. Melanoma

Correct Answer & Explanation

. Neuropathic ulcerations

Explanation

Correct Answer: Neuropathic ulcerationsIn the absence of protective foot sensation, patients are at increased risk for the development of neuropathic ulcerations. The inability to feel pressure or pain leads to unrecognized trauma and subsequent skin breakdown, which can progress to deep ulcers and infection.

Question 5282

Topic: 8. Foot and Ankle

Loss of protective sensation in the diabetic foot is a primary risk factor for Charcot arthropathy. Which of the following best describes the underlying pathophysiology of this condition according to the neurotraumatic theory?

. Autoimmune destruction of the articular cartilage
. Crystal deposition in the joint space
. Repetitive microtrauma in an insensate foot
. Primary bacterial infection of the joint space
. Ischemic necrosis of the metatarsal heads

Correct Answer & Explanation

. Repetitive microtrauma in an insensate foot

Explanation

Correct Answer: Repetitive microtrauma in an insensate footThe neurotraumatic theory of Charcot arthropathy (neuropathic arthropathy) posits that the loss of protective sensation allows repetitive microtrauma to occur without the patient's awareness. This leads to progressive joint destruction, subluxation, and deformity. Screening with the 5.07 monofilament helps identify patients at risk.

Question 5283

Topic: 8. Foot and Ankle

In the evaluation of a diabetic foot, which of the following screening methods is considered the most reliable tool for detecting the absence of protective sensation?

. 128-Hz tuning fork
. Pinprick testing
. 5.07 Semmes-Weinstein monofilament
. Ankle-brachial index (ABI)
. Electromyography (EMG)

Correct Answer & Explanation

. 5.07 Semmes-Weinstein monofilament

Explanation

Correct Answer: 5.07 Semmes-Weinstein monofilamentThe most reliable screening tool for the presence of protective sensation is the ability to feel the 5.07 Semmes-Weinstein monofilament. While tuning forks and pinprick testing can assess other aspects of neuropathy, the 5.07 monofilament is the gold standard for protective sensation.

Question 5284

Topic: 8. Foot and Ankle

A 55-year-old female with diabetes mellitus presents with a painless, swollen, and erythematous right foot. Radiographs reveal fragmentation and subluxation of the tarsometatarsal joints. Her condition is most directly linked to a failure to perceive which of the following?

. 10 grams of linear pressure
. 128-Hz vibration
. 5 grams of linear pressure
. Deep tendon reflexes
. Two-point discrimination at 5 mm

Correct Answer & Explanation

. 10 grams of linear pressure

Explanation

Correct Answer: 10 grams of linear pressureThe patient's presentation is classic for acute Charcot arthropathy (neuropathic arthropathy). This condition is directly linked to the loss of protective sensation, which is defined clinically as the inability to perceive 10 grams of linear pressure, typically assessed using the 5.07 Semmes-Weinstein monofilament.

Question 5285

Topic: 8. Foot and Ankle

According to the study by Pinzur et al. (Foot Ankle Int 2000) referenced in the text, the absence of protective foot sensation is a critical factor in the development of which of the following conditions?

. Diabetic retinopathy
. Charcot foot
. Peripheral arterial disease
. Venous stasis ulcers
. Deep vein thrombosis

Correct Answer & Explanation

. Charcot foot

Explanation

Correct Answer: Charcot footThe reference by Pinzur et al. discusses current practice patterns in the treatment of Charcot foot. The text highlights that in the absence of protective foot sensation, patients are at increased risk for the development of neuropathic ulcerations and neuropathic arthropathy (Charcot foot).

Question 5286

Topic: 8. Foot and Ankle

A 55-year-old male with a 15-year history of poorly controlled type 2 diabetes presents for a routine foot examination. The physician uses a Semmes-Weinstein monofilament to test for loss of protective sensation. The standard 5.07 monofilament used in this screening bends when it applies what specific amount of linear pressure?

. 1 gram
. 5 grams
. 10 grams
. 25 grams
. 50 grams

Correct Answer & Explanation

. 10 grams

Explanation

Correct Answer: 10 gramsThe 5.07 Semmes-Weinstein monofilament is the gold standard screening tool for detecting loss of protective sensation (LOPS) in diabetic patients. The '5.07' refers to the logarithm of the force required to buckle the filament, which corresponds to exactly 10 grams of linear pressure. Inability to perceive this 10-gram force indicates a loss of protective sensation, placing the patient at a significantly increased risk for neuropathic ulcerations and Charcot arthropathy.

Question 5287

Topic: 8. Foot and Ankle

A 62-year-old female with diabetes mellitus is found to have an inability to perceive the 5.07 Semmes-Weinstein monofilament on her bilateral plantar feet. Due to this loss of protective sensation, she is at highest risk for developing a neuropathic ulceration at which of the following anatomic locations?

. Dorsum of the proximal interphalangeal joints
. Plantar aspect of the metatarsal heads
. Medial malleolus
. Lateral border of the fifth metatarsal base
. Posterior heel

Correct Answer & Explanation

. Plantar aspect of the metatarsal heads

Explanation

Correct Answer: Plantar aspect of the metatarsal headsNeuropathic ulcers in diabetic patients with loss of protective sensation typically occur at areas of high pressure and repetitive microtrauma during the gait cycle. The most common location for these ulcerations is the plantar aspect of the forefoot, specifically beneath the metatarsal heads. Motor neuropathy often leads to intrinsic muscle wasting, resulting in claw toe deformities and distal migration of the plantar fat pad, which further increases pressure under the metatarsal heads.

Question 5288

Topic: 8. Foot and Ankle

A 58-year-old diabetic male who fails 5.07 monofilament testing presents with a unilaterally swollen, red, and warm foot. There are no skin ulcerations. To quickly differentiate between an acute neuropathic arthropathy (Charcot foot) and cellulitis/infection in the clinic, which of the following physical examination maneuvers is most helpful?

. Assessing for a bounding dorsalis pedis pulse
. Elevating the affected extremity for 5 to 10 minutes
. Performing a sharp two-point discrimination test
. Checking for the presence of vibratory sensation
. Measuring the ankle-brachial index

Correct Answer & Explanation

. Elevating the affected extremity for 5 to 10 minutes

Explanation

Correct Answer: Elevating the affected extremity for 5 to 10 minutesDifferentiating acute Charcot arthropathy from infection can be challenging, as both present with a red, hot, swollen foot. The elevation test is a useful clinical tool: if the extremity is elevated for 5 to 10 minutes, the erythema associated with acute Charcot arthropathy (which is dependent rubor due to autonomic neuropathy and hyperemia) will typically dissipate or significantly improve. In contrast, erythema caused by an active infection (cellulitis) will persist despite elevation.

Question 5289

Topic: Midfoot & Hindfoot

A 60-year-old female with diabetes and absent protective sensation presents with a red, hot, swollen midfoot. Radiographs demonstrate periarticular debris and subluxation at the Lisfranc joint. Erythema resolves upon elevation of the limb. What is the most appropriate initial management?

. Immediate open reduction and internal fixation of the midfoot
. Intravenous antibiotics and bone biopsy
. Total contact casting and protected weight-bearing
. Custom orthotic shoe wear and unrestricted activity
. Midfoot arthrodesis with rigid plating

Correct Answer & Explanation

. Total contact casting and protected weight-bearing

Explanation

Correct Answer: Total contact casting and protected weight-bearingThe patient is presenting with acute Eichenholtz Stage I Charcot arthropathy. The mainstay of initial treatment for acute Charcot foot is strict immobilization and offloading to prevent further deformity and allow the inflammatory process to subside. This is most effectively achieved with a total contact cast (TCC) or a Charcot restraint orthotic walker (CROW), along with protected weight-bearing. Surgery is generally contraindicated in the acute, inflammatory stage due to poor bone quality and high risk of hardware failure, unless there is an impending skin breakdown or severe instability that cannot be managed conservatively.

Question 5290

Topic: Midfoot & Hindfoot
A patient with diabetic neuropathy and a history of a swollen foot presents for follow-up. Radiographs of the foot now demonstrate absorption of fine bone debris, fusion of larger fragments, and early sclerosis of the midfoot joints. According to the Eichenholtz classification of neuropathic arthropathy, which stage does this represent?
. Stage 0
. Stage I
. Stage II
. Stage III
. Stage IV

Correct Answer & Explanation

. Stage II

Explanation

The Eichenholtz classification describes the natural history of Charcot arthropathy. Stage 0 is the prodromal stage (erythema, edema, normal radiographs). Stage I is the development/fragmentation stage (joint laxity, subluxation, osteochondral fragmentation, debris). Stage II is the coalescence stage, characterized by the absorption of fine debris, fusion of larger fragments, and early sclerosis. Stage III is the reconstruction/consolidation stage, characterized by rounding and smoothing of bone fragments, decreased sclerosis, and stable joint arthrosis.

Question 5291

Topic: 8. Foot and Ankle

A diabetic patient with absent protective sensation on monofilament testing develops recurrent neuropathic ulcerations beneath the metatarsal heads despite appropriate shoe wear. Physical examination reveals a rigid equinus contracture. Which of the following surgical interventions is most commonly performed to decrease forefoot plantar pressures and aid in ulcer healing in this scenario?

. Tibialis anterior tendon transfer
. Tendo-Achilles lengthening
. First metatarsophalangeal joint arthrodesis
. Plantar fascia release
. Flexor digitorum longus tenotomy

Correct Answer & Explanation

. Tendo-Achilles lengthening

Explanation

Correct Answer: Tendo-Achilles lengtheningDiabetic motor neuropathy often leads to an imbalance between the flexors and extensors of the foot and ankle. A common manifestation is an equinus contracture due to a tight Achilles tendon. This contracture prevents normal ankle dorsiflexion during the stance phase of gait, significantly increasing peak plantar pressures under the forefoot (metatarsal heads). Tendo-Achilles lengthening (TAL) or gastrocnemius recession is frequently performed to correct the equinus, reduce forefoot pressure, and promote healing of recurrent plantar forefoot ulcers.

Question 5292

Topic: 8. Foot and Ankle

A 55-year-old male with a 15-year history of poorly controlled type 2 diabetes mellitus presents for a routine foot examination. The physician uses a Semmes-Weinstein monofilament to assess for protective sensation. Which of the following monofilament sizes is the standard threshold for determining the loss of protective sensation in the foot?

. 2.83
. 3.61
. 4.17
. 5.07
. 6.65

Correct Answer & Explanation

. 5.07

Explanation

Correct Answer: DThe 5.07 Semmes-Weinstein monofilament is the standard screening tool for protective sensation in the diabetic foot. Inability to feel this monofilament indicates a loss of protective sensation, placing the patient at risk for neuropathic ulcerations and Charcot arthropathy.

Question 5293

Topic: 8. Foot and Ankle

A 60-year-old female with diabetes mellitus is evaluated in the orthopedic clinic. She is found to have an inability to perceive the 5.07 Semmes-Weinstein monofilament on the plantar aspect of her feet. This finding indicates that she is at the greatest increased risk for developing which of the following conditions?

. Plantar fasciitis
. Neuropathic arthropathy
. Achilles tendinopathy
. Morton's neuroma
. Tarsal tunnel syndrome

Correct Answer & Explanation

. Neuropathic arthropathy

Explanation

Correct Answer: BThe inability to feel the 5.07 Semmes-Weinstein monofilament indicates a loss of protective sensation. Patients lacking protective sensation are at a significantly increased risk for developing neuropathic arthropathy (Charcot foot) and neuropathic ulcerations.

Question 5294

Topic: 8. Foot and Ankle

A 62-year-old male with long-standing diabetes mellitus presents with a painless, swollen, and erythematous right foot. Radiographs reveal fragmentation and subluxation of the tarsometatarsal joints. According to the referenced literature by Pinzur et al., which of the following screening tools would have most reliably predicted this patient's risk for developing this condition prior to its onset?

. Tuning fork for vibratory sensation
. Hot and cold sensation testing
. Sharp two-point discrimination
. 5.07 Semmes-Weinstein monofilament
. Ankle-brachial index (ABI)

Correct Answer & Explanation

. 5.07 Semmes-Weinstein monofilament

Explanation

Correct Answer: DThe patient is presenting with acute Charcot arthropathy (neuropathic arthropathy). The most reliable screening tool for the presence of protective sensation, and thus the risk of developing neuropathic arthropathy and ulcerations, is the 5.07 Semmes-Weinstein monofilament.

Question 5295

Topic: 8. Foot and Ankle

A medical student is evaluating a diabetic patient's feet in the clinic. The attending physician asks the student to perform the most reliable screening test for protective sensation to assess the risk of neuropathic ulceration. Which of the following modalities should the student select?

. Light touch sensation with a cotton wisp
. Vibratory sensation with a 128-Hz tuning fork
. Pinprick sensation with a sterile needle
. 5.07 Semmes-Weinstein monofilament testing
. Deep tendon reflex testing of the Achilles

Correct Answer & Explanation

. 5.07 Semmes-Weinstein monofilament testing

Explanation

Correct Answer: DWhile vibratory, pinprick, and light touch sensation can be altered in diabetic neuropathy, the most reliable and standardized screening tool for the loss of protective sensation is the 5.07 Semmes-Weinstein monofilament.

Question 5296

Topic: Midfoot & Hindfoot

A 58-year-old female with diabetes mellitus is found to have a loss of protective sensation on her bilateral feet. Which of the following best describes the primary clinical significance of this finding?

. It indicates the need for immediate prophylactic surgical offloading.
. It confirms the presence of severe peripheral arterial disease.
. It identifies the patient as being at high risk for neuropathic ulcerations.
. It is a contraindication to the use of custom orthotics.
. It suggests an impending need for major lower extremity amputation within 6 months.

Correct Answer & Explanation

. It identifies the patient as being at high risk for neuropathic ulcerations.

Explanation

Correct Answer: CThe primary clinical significance of losing protective sensation (as tested by the 5.07 Semmes-Weinstein monofilament) is that it identifies the patient as being at a high risk for developing neuropathic ulcerations and Charcot arthropathy. It does not confirm peripheral arterial disease, nor does it mandate immediate surgery or amputation.

Question 5297

Topic: 8. Foot and Ankle

During a routine diabetic foot screening, a physician applies a 5.07 Semmes-Weinstein monofilament to the plantar aspect of the patient's foot. To perform this test correctly, the examiner should apply the monofilament in which of the following manners?

. Stroke the monofilament across the skin until the patient reports feeling it.
. Apply the monofilament perpendicular to the skin until it buckles, holding for 1-2 seconds.
. Tap the monofilament rapidly against the skin to assess vibratory response.
. Press the monofilament into the skin until the patient reports pain.
. Drag the monofilament from the heel to the toes to assess continuous sensation.

Correct Answer & Explanation

. Apply the monofilament perpendicular to the skin until it buckles, holding for 1-2 seconds.

Explanation

Correct Answer: BThe proper technique for using a Semmes-Weinstein monofilament is to apply it perpendicular to the skin surface and apply pressure until the filament buckles or bends. It should be held in place for about 1-2 seconds. This ensures that exactly 10 grams of force is applied.

Question 5298

Topic: 8. Foot and Ankle

A 50-year-old patient with newly diagnosed type 2 diabetes mellitus asks about the purpose of the monofilament test performed during their clinic visit. The physician explains that the test assesses for the loss of protective sensation. The loss of this sensation is a primary prerequisite for the development of which of the following foot deformities?

. Hallux valgus
. Charcot arthropathy
. Hammer toe deformity
. Tailor's bunion
. Plantar fibromatosis

Correct Answer & Explanation

. Charcot arthropathy

Explanation

Correct Answer: BThe loss of protective sensation is a primary prerequisite for the development of Charcot arthropathy (neuropathic arthropathy). Without protective sensation, repetitive microtrauma goes unnoticed, leading to progressive joint destruction, fragmentation, and deformity.

Question 5299

Topic: 8. Foot and Ankle

In the evaluation of a diabetic foot, various sensory tests can be performed. According to established orthopedic guidelines, why is the 5.07 Semmes-Weinstein monofilament preferred over sharp two-point discrimination or hot and cold sensation testing for screening?

. It evaluates the function of large myelinated nerve fibers only.
. It is the most reliable and reproducible screening tool for protective sensation.
. It provides a quantitative measure of peripheral arterial perfusion.
. It is the only test that can diagnose autonomic neuropathy.
. It directly measures the velocity of nerve conduction.

Correct Answer & Explanation

. It is the most reliable and reproducible screening tool for protective sensation.

Explanation

Correct Answer: BThe 5.07 Semmes-Weinstein monofilament is preferred because it is the most reliable, reproducible, and standardized screening tool for assessing the presence or absence of protective sensation in the foot. It does not measure arterial perfusion, autonomic neuropathy, or nerve conduction velocity.

Question 5300

Topic: 8. Foot and Ankle

In the absence of protective foot sensation, patients with diabetes mellitus are at an increased risk for the development of which of the following conditions?

. Deep vein thrombosis
. Neuropathic ulcerations and neuropathic arthropathy
. Venous stasis ulcers
. Peripheral arterial disease
. Plantar fasciitis

Correct Answer & Explanation

. Neuropathic ulcerations and neuropathic arthropathy

Explanation

Correct Answer: Neuropathic ulcerations and neuropathic arthropathyIn the absence of protective foot sensation, patients are at increased risk for the development of neuropathic ulcerations and neuropathic arthropathy (Charcot foot). Screening with a 5.07 Semmes-Weinstein monofilament helps identify this risk.

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