Internal fixation methods US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Internal fixation methods. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Internal fixation methods US Medical PG Question 1: A 6-week-old boy is brought for routine examination at his pediatrician’s office. The patient was born at 39 weeks to a 26-year-old G1P1 mother by normal vaginal delivery. External cephalic version was performed successfully at 37 weeks for breech presentation. Pregnancy was complicated by gestational diabetes that was well-controlled with insulin. The patient’s maternal grandmother has early onset osteoporosis. On physical examination, the left hip dislocates posteriorly with adduction and depression of a flexed femur. An ultrasound is obtained that reveals left acetabular dysplasia and a dislocated left femur. Which of the following is the next best step in management?
- A. Pavlik harness (Correct Answer)
- B. Closed reduction and spica casting
- C. Observation
- D. Physiotherapy
- E. Open reduction and femoral osteotomy
Internal fixation methods Explanation: ***Pavlik harness***
- A Pavlik harness is the **gold standard treatment** for **developmental dysplasia of the hip (DDH)** in infants younger than 6 months. It maintains the hips in a **flexed and abducted position**, promoting proper acetabular development and hip reduction.
- The patient's age (6 weeks), clear diagnosis of **acetabular dysplasia**, and a dislocated hip on ultrasound make the Pavlik harness the **most appropriate and least invasive initial treatment**.
*Closed reduction and spica casting*
- This treatment is typically reserved for children older than 6 months or those who **fail Pavlik harness treatment**.
- It involves a more aggressive reduction technique, often requiring **anesthesia**, and is followed by prolonged immobilization in a **spica cast**.
*Observation*
- **Observation is not appropriate** for a 6-week-old infant with a **diagnosed dislocated hip** and **acetabular dysplasia**.
- Untreated DDH can lead to **permanent hip instability**, pain, and early arthritis.
*Physiotherapy*
- While physiotherapy may play a role in rehabilitation after other interventions, it is **not sufficient as a primary treatment** for a dislocated hip in an infant.
- It cannot achieve or maintain the necessary **reduction and stabilization** required for proper hip development.
*Open reduction and femoral osteotomy*
- This is an **invasive surgical procedure** typically reserved for older children (older than 18-24 months) or in cases of **failed non-operative management** and closed reduction, especially in irreducible or severely dysplastic hips.
- It involves directly opening the joint to reduce the hip and may include reshaping bone (osteotomy) to improve hip stability. This is **premature** for a 6-week-old.
Internal fixation methods US Medical PG Question 2: A 65-year-old man presents to the emergency department with a complaint of intense pain in his right foot for the past month, along with fever and chills. He denies any traumatic injury to his foot in recent memory. He has a medical history of poorly-controlled type II diabetes and is a former smoker with extensive peripheral vascular disease. On physical exam, the area of his right foot around the hallux is swollen, erythematous, tender to light palpation, and reveals exposed bone. Labs are notable for elevated C-reactive protein and erythrocyte sedimentation rate. The physician obtains a biopsy for culture. What is the most likely causative organism for this patient’s condition?
- A. Pasteurella multocida
- B. Mycobacterium tuberculosis
- C. Staphylococcus aureus (Correct Answer)
- D. Pseudomonas aeruginosa
- E. Neisseria gonorrhoeae
Internal fixation methods Explanation: ***Staphylococcus aureus***
- This patient presents with signs of **osteomyelitis** (foot pain, fever, chills, exposed bone, elevated inflammatory markers) in the setting of **diabetes** and **peripheral vascular disease (PVD)**.
- **_S. aureus_** is the most common cause of osteomyelitis, especially in patients with diabetes and PVD where skin integrity is compromised or there's hematogenous spread.
*Pasteurella multocida*
- **_Pasteurella multocida_** is typically associated with infections following **animal bites**, specifically cat or dog bites.
- There is no history of animal bite in this patient, making this organism less likely.
*Mycobacterium tuberculosis*
- **_Mycobacterium tuberculosis_** can cause osteomyelitis, known as **Pott's disease** when affecting the spine, but it's typically a **chronic, granulomatous infection** often without acute purulence or the rapid progression seen here.
- It usually occurs in patients with active tuberculosis elsewhere or those from endemic regions, and the clinical presentation is not as acute as described.
*Pseudomonas aeruginosa*
- **_Pseudomonas aeruginosa_** is a common cause of osteomyelitis in specific contexts, such as **puncture wounds** through footwear (especially in diabetic patients) or in **IV drug users**.
- While possible in diabetic foot infections, **_S. aureus_** remains overwhelmingly more common given the general presentation of osteomyelitis without a specific puncture wound history.
*Neisseria gonorrhoeae*
- **_Neisseria gonorrhoeae_** causes **gonococcal arthritis** or disseminated gonococcal infection, which can affect joints.
- However, it typically presents with migratory polyarthralgia, tenosynovitis, or dermatitis, rather than localized acute osteomyelitis with exposed bone in the foot as described.
Internal fixation methods US Medical PG Question 3: A 69-year-old woman presents with pain in her hip and groin. She states that the pain is present in the morning, and by the end of the day it is nearly unbearable. Her past medical history is notable for a treated episode of acute renal failure, diabetes mellitus, obesity, and hypertension. Her current medications include losartan, metformin, insulin, and ibuprofen. The patient recently started taking high doses of vitamin D as she believes that it could help her symptoms. She also states that she recently fell off the treadmill while exercising at the gym. On physical exam you note an obese woman. There is pain, decreased range of motion, and crepitus on physical exam of her right hip. The patient points to the areas that cause her pain stating that it is mostly over the groin. The patient's skin turgor reveals tenting. Radiography is ordered.
Which of the following is most likely to be found on radiography?
- A. Loss of joint space and osteophytes (Correct Answer)
- B. Posterior displacement of the femoral head
- C. Hyperdense foci in the ureters
- D. Femoral neck fracture
- E. Normal radiography
Internal fixation methods Explanation: ***Loss of joint space and osteophytes***
- The patient's presentation with **hip and groin pain worsened by activity**, improved with rest, and associated with **crepitus** and **decreased range of motion**, is highly suggestive of **osteoarthritis**.
- **Osteoarthritis** is characterized radiographically by **loss of joint space**, **osteophytes** (bone spurs), subchondral sclerosis, and subchondral cysts.
*Posterior displacement of the femoral head*
- This finding is characteristic of a **posterior hip dislocation**, which usually presents with severe pain and an inability to bear weight after a significant traumatic event.
- While the patient fell, her symptoms are chronic and progressive, and she has signs of arthritis rather than acute dislocation.
*Hyperdense foci in the ureters*
- These would indicate **kidney stones**, which typically present with acute, severe flank pain radiating to the groin, and hematuria.
- The patient's symptoms are chronic and localized to the hip joint, making kidney stones an unlikely cause of her primary complaint.
*Femoral neck fracture*
- A **femoral neck fracture** would cause acute, severe hip pain, inability to bear weight, and often external rotation and shortening of the leg, usually following a fall.
- Although she fell, her chronic, activity-related pain and crepitus are more indicative of a degenerative process.
*Normal radiography*
- Given the patient's age, chronic and worsening hip pain, physical exam findings of crepitus and decreased range of motion, and risk factors like obesity, it is highly improbable that her hip X-rays would be normal.
- These symptoms are classic for **osteoarthritis**, which shows distinct radiographic changes.
Internal fixation methods US Medical PG Question 4: A 63-year-old female recovering from a total shoulder arthroplasty completed 6 days ago presents complaining of joint pain in her repaired shoulder. Temperature is 39 degrees Celsius. Physical examination demonstrates erythema and significant tenderness around the incision site. Wound cultures reveal Gram-positive cocci that are resistant to nafcillin. Which of the following organisms is the most likely cause of this patient's condition?
- A. Streptococcus pyogenes
- B. Escherichia coli
- C. Streptococcus viridans
- D. Staphylococcus epidermidis
- E. Staphylococcus aureus (Correct Answer)
Internal fixation methods Explanation: ***Staphylococcus aureus***
- The combination of **post-surgical infection**, **erythema**, and fever with **Gram-positive cocci** that are **nafcillin-resistant** is highly indicative of **Methicillin-Resistant Staphylococcus aureus (MRSA)**.
- *S. aureus* is a common cause of **surgical site infections**, and its resistance to nafcillin implies it is MRSA, a significant clinical concern for its difficulty in treatment.
*Streptococcus pyogenes*
- While *S. pyogenes* is a Gram-positive coccus that can cause skin and soft tissue infections, it is typically **susceptible to penicillin** and related antibiotics like nafcillin, unlike the organism described.
- It is more commonly associated with **streptococcal pharyngitis** or **cellulitis**, and while it can cause severe disease, its resistance profile doesn't match the clinical picture.
*Escherichia coli*
- *E. coli* is a **Gram-negative rod**, not a Gram-positive coccus.
- It is a common cause of **urinary tract infections** and **gastrointestinal infections**, making it an unlikely pathogen for a post-surgical joint infection unless contaminated from a visceral source.
*Streptococcus viridans*
- **Viridans streptococci** are Gram-positive cocci but are typically associated with **endocarditis** or dental infections, especially after poor dental hygiene or procedures.
- They are usually **susceptible to penicillin** and do not typically exhibit nafcillin resistance as the primary feature in a post-arthroplasty infection.
*Staphylococcus epidermidis*
- *S. epidermidis* is a **coagulase-negative Staphylococcus** known for forming **biofilms on prosthetic devices**, leading to chronic, low-grade infections.
- While it can be nafcillin-resistant, the **acute presentation** with fever and significant inflammation suggests a more virulent pathogen like *S. aureus*, as *S. epidermidis* infections are typically indolent.
Internal fixation methods US Medical PG Question 5: A 35-year-old man is referred to a physical therapist due to limitation of movement in the wrist and fingers of his left hand. He cannot hold objects or perform daily activities with his left hand. He broke his left arm at the humerus one month ago. The break was simple and treatment involved a cast for one month. Then he lost his health insurance and could not return for follow up. Only after removing the cast did he notice the movement issues in his left hand and wrist. His past medical history is otherwise insignificant, and vital signs are within normal limits. On examination, the patient’s left hand is pale and flexed in a claw-like position. It is firm and tender to palpation. Right radial pulse is 2+ and left radial pulse is 1+. The patient is unable to actively extend his fingers and wrist, and passive extension is difficult and painful. Which of the following is a proper treatment for the presented patient?
- A. Surgical release (Correct Answer)
- B. Botulinum toxin injections
- C. Collagenase injections
- D. Needle fasciotomy
- E. Corticosteroid injections
Internal fixation methods Explanation: ***Surgical release***
- The patient presents with classic signs of **established Volkmann's ischemic contracture** (claw-like hand, firm fibrotic tissue, limited movement, decreased radial pulse), which is the end-stage result of untreated compartment syndrome that occurred during fracture healing.
- Since this is **chronic contracture (one month post-injury)**, the appropriate surgical treatment involves **reconstructive procedures** such as muscle slide operations, tendon lengthening, tendon transfers, neurolysis, or in severe cases, free functional muscle transfer to restore hand function.
- Emergency fasciotomy would have been appropriate for **acute compartment syndrome** (within 6-8 hours of onset), but at this stage, the treatment focuses on releasing fibrotic tissue and restoring function through reconstructive surgery.
*Botulinum toxin injections*
- **Botulinum toxin** is used to relax spastic muscles in neurological conditions (e.g., cerebral palsy, stroke), but it does not address the underlying **ischemic fibrosis and muscle necrosis** of Volkmann's contracture.
- It would not improve the structural contracture or restore blood flow in this patient.
*Collagenase injections*
- **Collagenase injections** are used for localized fascial contractures like Dupuytren's contracture, where enzymatic breakdown of collagen cords can restore finger extension.
- They are ineffective for **Volkmann's contracture**, which involves widespread ischemic muscle necrosis, fibrosis, and nerve damage requiring surgical reconstruction.
*Needle fasciotomy*
- **Needle fasciotomy** is a minimally invasive technique for Dupuytren's contracture, involving percutaneous disruption of fascial cords.
- It is not suitable for **Volkmann's contracture**, which requires extensive surgical release of fibrotic muscle compartments, possible tendon transfers, and neurolysis—procedures that cannot be accomplished with needle techniques.
*Corticosteroid injections*
- **Corticosteroids** reduce inflammation in conditions like tenosynovitis or trigger finger.
- They would not address the **ischemic muscle necrosis and fibrotic contracture** in Volkmann's contracture and could potentially delay appropriate surgical treatment.
Internal fixation methods US Medical PG Question 6: A 56-year-old woman comes to the emergency department because of worsening pain and swelling in her right knee for 3 days. She underwent a total knee arthroplasty of her right knee joint 5 months ago. The procedure and immediate aftermath were uneventful. She has hypertension and osteoarthritis. Current medications include glucosamine, amlodipine, and meloxicam. Her temperature is 37.9°C (100.2°F), pulse is 95/min, and blood pressure is 115/70 mm Hg. Examination shows a tender, swollen right knee joint; range of motion is limited by pain. The remainder of the examination shows no abnormalities. Arthrocentesis of the right knee is performed. Analysis of the synovial fluid shows:
Appearance Cloudy
Viscosity Absent
WBC count 78,000/mm3
Segmented neutrophils 94%
Lymphocytes 6%
Synovial fluid is sent for culture and antibiotic sensitivity. Which of the following is the most likely causal pathogen?
- A. Staphylococcus aureus
- B. Escherichia coli
- C. Pseudomonas aeruginosa
- D. Staphylococcus epidermidis (Correct Answer)
- E. Streptococcus agalactiae
Internal fixation methods Explanation: ***Staphylococcus epidermidis***
- This patient's symptoms (worsening pain and swelling in a knee with a history of **total knee arthroplasty 5 months ago**, increased WBC count and neutrophil predominance in synovial fluid), point towards a **prosthetic joint infection**.
- **Coagulase-negative Staphylococci**, particularly *S. epidermidis*, are the most common cause of **late prosthetic joint infections**, typically occurring months to years after surgery.
*Staphylococcus aureus*
- *Staphylococcus aureus* is a common cause of **acute prosthetic joint infections**, which usually manifest within the **first 3 months post-surgery**. This patient's symptoms began 5 months after surgery.
- While it can cause late infections, *S. epidermidis* is more characteristic for this timeline in prosthetic joint infections.
*Escherichia coli*
- *Escherichia coli* is typically associated with **urinary tract infections** or **gastrointestinal infections**.
- It is an uncommon cause of prosthetic joint infections unless there's a direct spread from a local infection or systemic sepsis, which is not suggested here.
*Pseudomonas aeruginosa*
- *Pseudomonas aeruginosa* is often associated with **healthcare-associated infections**, particularly in immunocompromised patients or those with indwelling catheters or extensive burns.
- While it can cause prosthetic joint infections, it's less common than Staphylococci and usually linked to specific clinical settings or water contamination.
*Streptococcus agalactiae*
- *Streptococcus agalactiae* (Group B Strep) is primarily known to cause serious infections in **neonates** and **pregnant women**, and in adults with underlying conditions like **diabetes** or **immunocompromise**.
- It is an infrequent cause of prosthetic joint infections in otherwise healthy adults without specific risk factors for GBS infection.
Internal fixation methods US Medical PG Question 7: An MRI of a patient with low back pain reveals compression of the L5 nerve root. Which of the following muscles would most likely show weakness during physical examination?
- A. Tibialis posterior
- B. Tibialis anterior (Correct Answer)
- C. Gastrocnemius
- D. Quadriceps femoris
Internal fixation methods Explanation: ***Tibialis anterior***
- The **L5 nerve root** primarily innervates muscles responsible for **dorsiflexion** of the foot, with the **tibialis anterior** being the primary dorsiflexor.
- Weakness of the tibialis anterior would manifest as difficulty lifting the front of the foot, potentially leading to a **foot drop** gait.
*Tibialis posterior*
- The **tibialis posterior** is primarily innervated by the **tibial nerve** (S1-S2) and is responsible for **plantarflexion** and **inversion** of the foot.
- Weakness in this muscle would not be the most likely presentation of L5 nerve root compression.
*Gastrocnemius*
- The **gastrocnemius** muscle is primarily innervated by the **tibial nerve** (S1-S2) and is a powerful **plantarflexor** of the foot.
- Weakness in this muscle would indicate an S1 or S2 nerve root issue, not typically L5.
*Quadriceps femoris*
- The **quadriceps femoris** is innervated by the **femoral nerve**, predominantly originating from the **L2, L3, and L4 nerve roots**.
- Weakness would manifest as difficulty extending the knee, which is not characteristic of L5 compression.
Internal fixation methods US Medical PG Question 8: A 17-year-old boy comes to the emergency department following an injury during football practice. He fell and landed on the lateral aspect of his right shoulder. He is holding his right arm supported by his left arm, with his right arm adducted against his side. He is tender to palpation directly over the middle third of his clavicle. Radiographs reveal a non-displaced fracture of the middle third of the clavicle. Which of the following is the most appropriate treatment at this time?
- A. Open reduction and internal fixation with a compression plate
- B. Open reduction and internal fixation with an intramedullary nail
- C. Figure-of-eight splinting (Correct Answer)
- D. Mobilization
- E. Open reduction and internal fixation with lag screws
Internal fixation methods Explanation: ***Figure-of-eight splinting***
- For **undisplaced or minimally displaced midshaft clavicle fractures**, conservative management with a **simple arm sling or figure-of-eight splint** is the preferred initial treatment.
- Both methods provide **adequate immobilization** and support for healing, especially in pediatric and adolescent patients, with excellent functional outcomes.
- Current evidence suggests **simple sling support** is equally effective and often better tolerated than figure-of-eight splinting.
*Open reduction and internal fixation with a compression plate*
- **ORIF with a compression plate** is typically reserved for **displaced or comminuted clavicle fractures** (displacement >2cm, shortening >2cm, or open fractures), or those with associated neurovascular compromise, which are not present in this non-displaced fracture.
- Surgical intervention for non-displaced fractures carries **risks of infection, hardware irritation**, and non-union that often outweigh the benefits when conservative options are effective.
*Open reduction and internal fixation with an intramedullary nail*
- **Intramedullary nailing** is an alternative surgical option for some clavicle fractures but is generally considered for **displaced or comminuted fracture patterns**, and is not indicated for a non-displaced fracture.
- It involves specific technical challenges and is **less commonly used** for routine, non-displaced mid-shaft clavicle fractures, especially when simpler conservative measures suffice.
*Mobilization*
- **Immediate mobilization** without any form of immobilization would **risk further displacement** of the non-displaced fracture and hinder proper bone healing in the acute phase.
- Although early motion is introduced during the healing process, **initial support and immobilization** is crucial for stability and pain control.
*Open reduction and internal fixation with lag screws*
- **Lag screws** are primarily used for **interfragmentary compression** in specific oblique or spiral fracture patterns, which is not the typical mechanism for midshaft clavicle fractures.
- This method is a form of surgical fixation, which is **not indicated for a non-displaced clavicle fracture** given the excellent outcomes (>95% union rate) with conservative care.
Internal fixation methods US Medical PG Question 9: A 50-year-old manual laborer sustained a comminuted distal radius fracture treated with ORIF 3 months ago. Despite supervised hand therapy, he has persistent stiffness with 30-degree wrist extension (normal 70), weak grip strength at 40% of contralateral side, and visible muscle atrophy. He reports burning pain with light touch and keeps his hand wrapped in a sock. Skin appears mottled with decreased hair growth. He is applying for disability and has a pending lawsuit. Evaluate the clinical picture and appropriate next step.
- A. EMG/NCS to evaluate for nerve injury
- B. Psychiatric evaluation for malingering assessment
- C. Repeat surgery for hardware removal and capsular release
- D. Independent functional capacity evaluation
- E. Triple-phase bone scan and referral to pain management (Correct Answer)
Internal fixation methods Explanation: ***Triple-phase bone scan and referral to pain management***
- The presence of **allodynia** (pain with light touch), **autonomic dysfunction** (mottled skin, hair changes), and **atrophy** following trauma is classic for **Complex Regional Pain Syndrome (CRPS)**.
- A **triple-phase bone scan** typically shows increased periarticular uptake in the delayed phase, and multidisciplinary **pain management** is the gold standard for treatment.
*EMG/NCS to evaluate for nerve injury*
- While nerve injury can cause pain, it does not explain the **vasomotor changes** and skin/hair trophic changes seen in this patient.
- This patient likely has **CRPS Type I** (reflex sympathetic dystrophy), which occurs in the absence of a defined nerve injury.
*Psychiatric evaluation for malingering assessment*
- Despite the **secondary gain** considerations (lawsuit/disability), the physical findings of **mottled skin** and decreased hair growth are objective clinical signs that cannot be faked.
- Labeling the patient as malingering before ruling out organic conditions like **CRPS** is inappropriate and delays necessary care.
*Repeat surgery for hardware removal and capsular release*
- Additional surgery is often **contraindicated** in the acute/active phase of CRPS as it can significantly worsen the pain and inflammatory response.
- Stiffness in CRPS is due to **neurogenic inflammation** and sympathetic overactivity rather than simple mechanical obstruction by hardware.
*Independent functional capacity evaluation*
- While useful for measuring work readiness, this is a **diagnostic tool** for disability status rather than a clinical management step for an active pathology.
- The priority is to confirm the diagnosis of **CRPS** and initiate treatment to prevent permanent **joint contracture** and functional loss.
Internal fixation methods US Medical PG Question 10: A 16-year-old basketball player presents with chronic anterior knee pain worse with jumping and kneeling. Examination shows tenderness at the inferior pole of the patella and pain with resisted knee extension. X-ray shows elongation and fragmentation of the inferior patellar pole. He has failed 6 months of physical therapy, activity modification, and NSAIDs. His AAU season starts in 6 weeks and a college scout will be attending. His parents want definitive treatment. Evaluate the management approach balancing medical and contextual factors.
- A. Recommend season withdrawal, continued conservative management for 6 more months (Correct Answer)
- B. Corticosteroid injection to allow play through season with surgery after
- C. Arthroscopic excision of inferior pole fragments allowing return to play in 4 weeks
- D. Open excision of ossicle with patellar tendon repair, 4-6 month recovery
- E. PRP injection series with continued play and close monitoring
Internal fixation methods Explanation: ***Recommend season withdrawal, continued conservative management for 6 more months***
- This patient presents with **Sinding-Larsen-Johansson syndrome**, a traction **apophysitis** of the inferior patellar pole that typically resolves with skeletal maturity and conservative care.
- Despite external pressures like college scouting, standard medical management mandates at least **12 months of conservative treatment** before considering surgery, as outcomes for surgical intervention in adolescents are often poor.
*Corticosteroid injection to allow play through season with surgery after*
- **Intratendinous corticosteroid injections** are strictly contraindicated as they significantly increase the risk of **patellar tendon rupture**.
- While they may provide short-term pain relief, they do not address the underlying **apophysitis** and compromise the structural integrity of the extensor mechanism.
*Arthroscopic excision of inferior pole fragments allowing return to play in 4 weeks*
- Surgical excision is rarely indicated in **skeletally immature** patients and is never the first-line treatment even after 6 months of failed therapy.
- A 4-week return-to-play timeline is clinically unrealistic following any surgical intervention on the **patellar tendon** or bone interface.
*Open excision of ossicle with patellar tendon repair, 4-6 month recovery*
- **Open excision** is considered only in refractory cases after the growth plates have closed and at least one year of non-operative management has failed.
- Performing an invasive repair in a 16-year-old unnecessarily risks damaging the **physes** and may lead to long-term functional deficits.
*PRP injection series with continued play and close monitoring*
- There is currently **insufficient evidence** to support the use of Platelet-Rich Plasma (PRP) as a definitive treatment for pediatric traction apophysitis.
- Continuing high-impact jumping and kneeling while relying on injections does not allow the **traction-induced inflammation** and fragmentation to heal.
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