An 85-year-old woman with advanced dementia sustains an undisplaced intracapsular neck of femur fracture following a fall in her care home. She was independently mobile with a frame prior to the fall. Her past medical history includes atrial fibrillation, hypertension, and osteoporosis. What is the most appropriate definitive management?
Q222
A 38-year-old woman presents to her GP with a 3-week history of lower back pain that is worse at night and in the morning, with significant stiffness lasting over an hour. She reports improvement with exercise. She has no history of trauma. Her inflammatory markers are elevated (CRP 45 mg/L, ESR 38 mm/hr). Which investigation would be most appropriate to confirm the underlying diagnosis?
Q223
A 70-year-old woman presents to the Emergency Department after slipping on ice. She complains of right hip pain and is unable to weight-bear. On examination, her right leg is shortened and externally rotated. Radiographs confirm a subcapital neck of femur fracture. Which anatomical structure is most at risk of damage in this type of fracture, potentially leading to avascular necrosis?
Q224
A 50-year-old man presents with a 2-week history of acute severe lower back pain following heavy lifting. The pain radiates down both legs and he reports difficulty passing urine with reduced sensation around his perineum. On examination, he has bilateral leg weakness, reduced anal tone, and absent bulbocavernosus reflex. What is the timeframe within which surgical decompression should ideally be performed to optimize neurological recovery?
Q225
A 69-year-old woman with multiple comorbidities including chronic kidney disease stage 4 sustains a displaced intracapsular neck of femur fracture. Pre-injury, she was mobile with a walking frame indoors only and had moderate dementia. Her abbreviated mental test score is 5/10. Regarding her surgical management, which procedure is most appropriate?
Q226
A 42-year-old office worker presents with chronic lower back pain and left leg pain for 8 months. He has tried physiotherapy and analgesia with limited benefit. MRI shows a large L4/L5 disc prolapse with nerve root compression. He has no red flag symptoms and neurological examination reveals mild L5 weakness (4/5 ankle dorsiflexion) but no cauda equina features. What is the most appropriate next step in management?
Q227
A 72-year-old man presents following a mechanical fall. Radiographs show an undisplaced intracapsular neck of femur fracture (Garden II). He is medically fit with no significant comorbidities and was independently mobile. He undergoes internal fixation with three cannulated screws. Six months post-operatively, he develops progressive groin pain and difficulty weight-bearing. Repeat radiographs show collapse of the femoral head with a crescent sign on the AP view. What is the most likely complication?
Q228
A 35-year-old man with known intravenous drug use presents with severe lower back pain, fever of 39.2°C, and difficulty mobilizing. He has been unwell for 5 days with rigors. On examination, he has marked tenderness over the L3-L4 region. Neurological examination reveals normal power, sensation, and reflexes in both lower limbs. His blood tests show WCC 18 × 10⁹/L and CRP 285 mg/L. What is the most appropriate immediate investigation?
Q229
Which of the following blood vessels provides the primary blood supply to the femoral head that is most at risk in intracapsular neck of femur fractures?
Q230
A 28-year-old woman presents to her GP with a 4-month history of lower back pain. She describes early morning stiffness lasting more than an hour that improves with exercise. She has occasional bilateral buttock pain. Blood tests reveal raised ESR and CRP. HLA-B27 is positive. Which feature would constitute a red flag requiring urgent investigation rather than being consistent with her likely inflammatory condition?
Orthopaedics & MSK UK Medical PG Practice Questions and MCQs
Question 221: An 85-year-old woman with advanced dementia sustains an undisplaced intracapsular neck of femur fracture following a fall in her care home. She was independently mobile with a frame prior to the fall. Her past medical history includes atrial fibrillation, hypertension, and osteoporosis. What is the most appropriate definitive management?
A. Dynamic hip screw fixation
B. Total hip replacement
C. Hemiarthroplasty
D. Cannulated hip screw fixation (Correct Answer)
E. Conservative management with analgesia and early mobilisation
Explanation: ***Cannulated hip screw fixation***
- For **undisplaced intracapsular** hip fractures, internal fixation with **cannulated screws** is the standard treatment to preserve the femoral head and minimize surgical morbidity.
- Despite the patient's advanced dementia, her **pre-morbid mobility** (walking with a frame) warrants surgical fixation to facilitate early mobilization and prevent complications of bed rest.
*Dynamic hip screw fixation*
- This approach is the gold standard for **extracapsular** (intertrochanteric) fractures, rather than intracapsular fractures.
- Using it for an undisplaced intracapsular fracture would involve unnecessary extensive surgical exposure and bone removal compared to **cannulated screws**.
*Total hip replacement*
- Typically reserved for fit, active patients with **displaced intracapsular** fractures who meet specific criteria like walking independently out-of-doors.
- Is contraindicated here due to the patient's **advanced dementia**, which significantly increases the risk of post-operative **dislocation** and necessitates a simpler procedure.
*Hemiarthroplasty*
- This is the preferred treatment for **displaced intracapsular** fractures in patients with limited functional demands or cognitive impairment.
- Since the fracture is **undisplaced**, internal fixation is preferred as it is less invasive and carries a lower risk of infection than joint replacement.
*Conservative management with analgesia and early mobilisation*
- This is usually reserved only for patients who are **medically unfit** for any anesthesia or are in the very final stages of terminal illness.
- It is associated with high rates of **non-union**, chronic pain, and fatal complications like **pressure sores** and pulmonary embolism due to prolonged immobility.
Question 222: A 38-year-old woman presents to her GP with a 3-week history of lower back pain that is worse at night and in the morning, with significant stiffness lasting over an hour. She reports improvement with exercise. She has no history of trauma. Her inflammatory markers are elevated (CRP 45 mg/L, ESR 38 mm/hr). Which investigation would be most appropriate to confirm the underlying diagnosis?
A. MRI lumbar spine (Correct Answer)
B. Plain radiographs of sacroiliac joints
C. HLA-B27 typing
D. Bone density scan (DEXA)
E. CT lumbar spine
Explanation: ***MRI lumbar spine***- In patients with suspected **axial spondyloarthropathy**, MRI is the most sensitive imaging modality as it can detect **bone marrow oedema** and early **sacroiliitis** before structural changes occur.- The clinical presentation of **inflammatory back pain** (night pain, prolonged morning stiffness, and improvement with exercise) warrants MRI when plain films are normal or to confirm early-stage disease.*Plain radiographs of sacroiliac joints*- While often used as a first-line test, radiographs can be normal in early disease as **structural changes** like erosions and fusion take years to develop.- A normal X-ray does not rule out **non-radiographic axial spondyloarthropathy**, making it less sensitive for early diagnosis compared to MRI.*HLA-B27 typing*- The **HLA-B27** allele is highly associated with ankylosing spondylitis but is not diagnostic because it is present in approximately 8% of the healthy population.- It acts as a supportive marker rather than a confirmatory investigation to objectively identify the **inflammatory changes** in the spine.*Bone density scan (DEXA)*- A **DEXA scan** is used to evaluate bone mineral density for conditions like **osteoporosis**, which presents differently than inflammatory arthropathy.- While patients with chronic axial spondyloarthropathy are at increased risk of spinal **osteoporosis**, this test cannot confirm the primary diagnosis of the inflammatory condition.*CT lumbar spine*- CT provides excellent detail of **bony anatomy** and chronic erosions but is inferior to MRI for visualizing **active inflammation**.- It involves significant **radiation exposure** and lacks the soft-tissue contrast required to detect marrow oedema associated with early-stage disease.
Question 223: A 70-year-old woman presents to the Emergency Department after slipping on ice. She complains of right hip pain and is unable to weight-bear. On examination, her right leg is shortened and externally rotated. Radiographs confirm a subcapital neck of femur fracture. Which anatomical structure is most at risk of damage in this type of fracture, potentially leading to avascular necrosis?
A. Obturator artery
B. Medial circumflex femoral artery (Correct Answer)
C. Lateral circumflex femoral artery
D. Profunda femoris artery
E. Inferior gluteal artery
Explanation: ***Medial circumflex femoral artery***- This artery is the **primary blood supply** to the femoral head in adults, providing 60-80% of its vasculature via the **retinacular vessels** along the femoral neck.- In **intracapsular fractures** like a subcapital fracture, these delicate vessels are frequently disrupted, leading to a high risk of **avascular necrosis (AVN)** of the femoral head.*Obturator artery*- The obturator artery provides blood to the femoral head via the **artery of the ligamentum teres**, which is a minor contributor in adults.- This vessel is usually insufficient to maintain **viability of the femoral head** if the primary circumflex arteries are damaged.*Lateral circumflex femoral artery*- This artery primarily supplies the **greater trochanter** and the anterior/lateral thigh muscles, not the femoral head itself.- It contributes significantly less to the **proximal femoral epiphysis** compared to its medial counterpart.*Profunda femoris artery*- This is the large **deep artery of the thigh** that serves as the parent vessel for both the medial and lateral circumflex femoral arteries.- While it is the source, it is not the specific anatomical structure directly ruptured at the level of the **subcapital femoral neck** leading to AVN.*Inferior gluteal artery*- This artery primarily supplies the **gluteus maximus muscle** and contributes to the **cruciate anastomosis** of the hip.- It does not provide significant direct perfusion to the **femoral head**, making it irrelevant to the development of AVN in neck fractures.
Question 224: A 50-year-old man presents with a 2-week history of acute severe lower back pain following heavy lifting. The pain radiates down both legs and he reports difficulty passing urine with reduced sensation around his perineum. On examination, he has bilateral leg weakness, reduced anal tone, and absent bulbocavernosus reflex. What is the timeframe within which surgical decompression should ideally be performed to optimize neurological recovery?
A. Within 6 hours of symptom onset
B. Within 24 hours of symptom onset
C. Within 48 hours of symptom onset (Correct Answer)
D. Within 72 hours of symptom onset
E. Within 1 week of symptom onset
Explanation: ***Within 48 hours of symptom onset***- For patients with **Cauda Equina Syndrome (CES)**, performing surgical decompression within **48 hours** is the generally accepted clinical threshold for optimizing bladder, bowel, and sexual function recovery.- While the patient has already been symptomatic for 2 weeks, the standard academic teaching identifies the **48-hour window** as the critical timeframe for emergency intervention to prevent permanent neurological deficits.*Within 6 hours of symptom onset*- Although faster intervention is always preferred in surgical emergencies, a **6-hour target** is not the standard benchmark used in clinical literature or guidelines for CES recovery.- Attempting to meet a 6-hour window is often logistically impossible due to the time required for **urgent MRI confirmation** and surgical preparation.*Within 24 hours of symptom onset*- Some studies suggest that surgery within **24 hours** (CES-incomplete) may offer superior outcomes compared to later surgery, but it is not the widely established "ideal threshold" for general exam purposes.- The **48-hour mark** remains the most significant prognostic divider cited in major meta-analyses regarding **neurological recovery**.*Within 72 hours of symptom onset*- Performing surgery at **72 hours** is associated with a significantly higher risk of **permanent saddle anesthesia** and chronic urinary incontinence.- This timeframe is considered a **delay in treatment** and is often linked to poor medical-legal outcomes and irreversible nerve root damage.*Within 1 week of symptom onset*- Waiting **one week** is clinically inappropriate for an acute presentation, as the risk of **permanent motor paralysis** and autonomic dysfunction becomes extremely high.- Even if a patient presents late (as in this case), surgery is still performed urgently to salvage remaining function, but it is far beyond the **ideal recovery window**.
Question 225: A 69-year-old woman with multiple comorbidities including chronic kidney disease stage 4 sustains a displaced intracapsular neck of femur fracture. Pre-injury, she was mobile with a walking frame indoors only and had moderate dementia. Her abbreviated mental test score is 5/10. Regarding her surgical management, which procedure is most appropriate?
A. Total hip replacement using an uncemented prosthesis
B. Cemented hemiarthroplasty (Correct Answer)
C. Uncemented hemiarthroplasty
D. Total hip replacement using a cemented prosthesis
E. Dynamic hip screw fixation
Explanation: ***Cemented hemiarthroplasty***
- **Cemented hemiarthroplasty** is the treatment of choice for patients with **displaced intracapsular** hip fractures who have low mobility needs, cognitive impairment (**AMTS < 8/10**), or significant comorbidities.
- Using **bone cement** provides immediate stable fixation, leads to better post-operative pain relief, and is associated with lower rates of **periprosthetic fracture** compared to uncemented options.
*Total hip replacement using an uncemented prosthesis*
- **Total hip replacement (THR)** is reserved for patients who were pre-operatively mobile with no more than one stick, have no **cognitive impairment**, and are medically fit for a longer procedure.
- Uncemented prostheses are generally avoided in the elderly as they carry a higher risk of **intra-operative fracture** and poor biological integration due to osteoporotic bone.
*Uncemented hemiarthroplasty*
- **NICE guidelines** recommend against using uncemented implants in hip fracture surgery because they are associated with increased long-term **thigh pain** and failure rates.
- While it avoids the risk of **Bone Cement Implantation Syndrome (BCIS)**, the mechanical stability in osteoporotic bone is significantly inferior to **cemented fixation**.
*Total hip replacement using a cemented prosthesis*
- Although cemented fixation is preferred, a **Total Hip Replacement** is not indicated here because the patient is not a "high-demand" walker and has **dementia**, which increases the risk of post-operative **dislocation**.
- THR is more appropriate for patients who are fully independent, expected to live more than 5 years, and lack significant **cognitive impairment**.
*Dynamic hip screw fixation*
- A **Dynamic Hip Screw (DHS)** is typically the standard treatment for **extracapsular** (intertrochanteric) fractures, not displaced intracapsular fractures.
- In **displaced intracapsular fractures**, internal fixation has an unacceptably high risk of failure due to **avascular necrosis** and non-union of the femoral head.
Question 226: A 42-year-old office worker presents with chronic lower back pain and left leg pain for 8 months. He has tried physiotherapy and analgesia with limited benefit. MRI shows a large L4/L5 disc prolapse with nerve root compression. He has no red flag symptoms and neurological examination reveals mild L5 weakness (4/5 ankle dorsiflexion) but no cauda equina features. What is the most appropriate next step in management?
A. Urgent surgical decompression within 48 hours
B. Epidural steroid injection
C. Continue conservative management for another 6 months
D. Referral to spinal surgery for consideration of microdiscectomy (Correct Answer)
E. Commence oral corticosteroids
Explanation: ***Referral to spinal surgery for consideration of microdiscectomy***- In a patient with **chronic radiculopathy** (8 months) who has failed **conservative management** (physiotherapy, analgesia) and has an **MRI-confirmed large disc prolapse** with **nerve root compression**, surgical referral is indicated.- The presence of **objective neurological deficit** (mild L5 weakness, 4/5 ankle dorsiflexion) further supports the need for surgical assessment to prevent permanent nerve root damage and improve long-term outcomes.*Urgent surgical decompression within 48 hours*- This is typically reserved for **Cauda Equina Syndrome** or rapidly **progressive severe neurological deficits**, which are absent in this case.- The patient specifically has **no red flag symptoms** and no features of cauda equina syndrome, negating the need for emergency surgery.*Epidural steroid injection*- While epidural steroid injections can offer **temporary pain relief** for radiculopathy, they do not address the underlying mechanical compression.- Given the **chronicity of symptoms** (8 months), failure of conservative measures, and **objective motor weakness**, an injection is unlikely to be a definitive solution and may only delay more effective treatment.*Continue conservative management for another 6 months*- The patient has already undergone 8 months of **conservative management** with limited benefit, indicating its ineffectiveness for this chronic condition.- Further delaying definitive treatment increases the risk of **chronic pain syndromes** and potentially irreversible neurological deficits due to prolonged nerve compression.*Commence oral corticosteroids*- **Oral corticosteroids** have limited evidence for significant long-term benefit in treating **chronic radiculopathy** caused by mechanical disc prolapse.- They do not resolve the **mechanical compression** on the nerve root and are not considered a primary or definitive treatment for persistent symptoms with objective weakness after extensive failed conservative care.
Question 227: A 72-year-old man presents following a mechanical fall. Radiographs show an undisplaced intracapsular neck of femur fracture (Garden II). He is medically fit with no significant comorbidities and was independently mobile. He undergoes internal fixation with three cannulated screws. Six months post-operatively, he develops progressive groin pain and difficulty weight-bearing. Repeat radiographs show collapse of the femoral head with a crescent sign on the AP view. What is the most likely complication?
A. Non-union of the fracture
B. Surgical site infection
C. Avascular necrosis of the femoral head (Correct Answer)
D. Implant failure with screw loosening
E. Osteoarthritis of the hip joint
Explanation: ***Avascular necrosis of the femoral head***
- The development of progressive groin pain, difficulty weight-bearing, **collapse of the femoral head**, and a **crescent sign** on radiographs six months post-op are pathognomonic for **avascular necrosis (AVN)**. The crescent sign indicates a subchondral fracture due to necrotic bone.
- **Intracapsular neck of femur fractures**, even when undisplaced (Garden II), are highly susceptible to AVN due to the compromise of the **medial circumflex femoral artery**, which is the primary blood supply to the femoral head.
*Non-union of the fracture*
- **Non-union** would typically present with persistent pain and instability, but radiographs would show a persistent **fracture line** with absent callus formation, not the specific **femoral head collapse** or **crescent sign** seen here.
- While it causes ongoing pain and difficulty weight-bearing, its radiographic appearance is distinct from that of AVN.
*Surgical site infection*
- A **surgical site infection** would usually manifest earlier with signs such as **fever**, local **erythema**, **swelling**, and possibly purulent drainage, which are not described in this case.
- Radiographic features of infection are typically **periosteal reaction** or osteomyelitis-related changes, not **femoral head collapse** with a **crescent sign**.
*Implant failure with screw loosening*
- **Implant failure** or **screw loosening** would be characterized by specific radiographic findings like **radiolucencies around the screws**, screw migration, or breakage of the hardware components.
- While these can cause pain and mechanical issues, they do not directly account for the **collapse of the femoral head** and the **crescent sign**, which point to a primary bone pathology.
*Osteoarthritis of the hip joint*
- **Post-traumatic osteoarthritis** is a chronic condition that typically develops over a longer period, characterized by **joint space narrowing**, **osteophytes**, and **subchondral sclerosis**.
- At six months, the specific signs of **femoral head collapse** and a **crescent sign** are indicative of AVN, which is a precursor or an acute event distinct from chronic degenerative changes of osteoarthritis.
Question 228: A 35-year-old man with known intravenous drug use presents with severe lower back pain, fever of 39.2°C, and difficulty mobilizing. He has been unwell for 5 days with rigors. On examination, he has marked tenderness over the L3-L4 region. Neurological examination reveals normal power, sensation, and reflexes in both lower limbs. His blood tests show WCC 18 × 10⁹/L and CRP 285 mg/L. What is the most appropriate immediate investigation?
A. Plain radiographs of lumbar spine
B. CT lumbar spine with contrast
C. MRI whole spine with gadolinium contrast (Correct Answer)
D. Bone scintigraphy
E. Lumbar spine ultrasound
Explanation: ***MRI whole spine with gadolinium contrast***- **MRI with gadolinium** is the gold-standard investigation for suspected **spinal infection** (discitis/osteomyelitis), offering 96% sensitivity for early detections within days.- **Whole spine** imaging is essential as infection can be **multifocal**, and it effectively evaluates for complications like **epidural abscess** or spinal cord compression.*Plain radiographs of lumbar spine*- X-rays have very low sensitivity in the early stages of infection, as **bony destruction** is often not visible until 2–4 weeks after the onset of symptoms.- They cannot reliably identify **soft tissue collections** or clarify the involvement of the intervertebral discs.*CT lumbar spine with contrast*- CT is less sensitive than MRI for detecting early **bone marrow edema** and inflammatory changes in the **epidural space**.- While useful for guiding **biopsies**, it provides inferior visualization of the neural structures compared to MRI.*Bone scintigraphy*- **Technetium-99m bone scans** lack the anatomical detail required to distinguish between different types of inflammatory or degenerative spinal processes.- It has a high rate of **false positives** and cannot adequately assess for the presence of an **epidural abscess**.*Lumbar spine ultrasound*- Ultrasound cannot penetrate **bony structures** and is therefore ineffective for evaluating intra-spinal or vertebral body pathology.- It has no clinical role in the diagnostic workup for **vertebral osteomyelitis** or discitis.
Question 229: Which of the following blood vessels provides the primary blood supply to the femoral head that is most at risk in intracapsular neck of femur fractures?
A. Obturator artery
B. Profunda femoris artery
C. Medial circumflex femoral artery (Correct Answer)
D. Lateral circumflex femoral artery
E. Inferior gluteal artery
Explanation: ***Medial circumflex femoral artery***- The **medial circumflex femoral artery** is the primary source of blood supply to the **femoral head** in adults. Its **retinacular branches** ascend along the femoral neck, penetrating the joint capsule.- **Intracapsular neck of femur fractures** often disrupt these delicate retinacular vessels, particularly the posterior superior and inferior retinacular arteries, leading to a high risk of **avascular necrosis (AVN)** of the femoral head.*Obturator artery*- The **obturator artery** gives rise to the artery of the **ligamentum teres**, which supplies a small area of the femoral head, primarily in children.- In adults, this supply is typically **insufficient** to maintain the viability of the femoral head if the main circumflex vessels are compromised.*Profunda femoris artery*- The **profunda femoris artery** (deep femoral artery) is a major branch of the femoral artery, and it typically gives rise to the medial and lateral circumflex femoral arteries.- However, the profunda femoris itself does not directly supply the **femoral head**; its main role is to supply the adductor and hamstring muscles of the thigh.*Lateral circumflex femoral artery*- The **lateral circumflex femoral artery** contributes to the blood supply around the hip but primarily supplies the **greater trochanter** and the muscles of the lateral thigh.- While it forms part of the **extracapsular arterial ring**, its contribution to the direct arterial supply of the femoral head itself is significantly less than that of the medial circumflex femoral artery.*Inferior gluteal artery*- The **inferior gluteal artery** primarily supplies the **gluteus maximus muscle** and the posterior aspect of the hip joint.- It contributes to the **cruciate anastomosis** around the hip but is not a direct or primary blood supply to the **femoral head**.
Question 230: A 28-year-old woman presents to her GP with a 4-month history of lower back pain. She describes early morning stiffness lasting more than an hour that improves with exercise. She has occasional bilateral buttock pain. Blood tests reveal raised ESR and CRP. HLA-B27 is positive. Which feature would constitute a red flag requiring urgent investigation rather than being consistent with her likely inflammatory condition?
A. Morning stiffness lasting 90 minutes
B. Improvement with exercise
C. Bilateral buttock pain alternating sides
D. Progressive thoracic kyphosis with fever (Correct Answer)
E. Age under 45 years at symptom onset
Explanation: ***Progressive thoracic kyphosis with fever***
- While spinal deformity (like **kyphosis**) can develop in long-standing **Ankylosing Spondylitis**, the acute presence of **fever** is a significant **red flag**, suggesting a serious underlying issue such as **infection** (e.g., osteomyelitis, discitis, spinal tuberculosis) or **malignancy**.
- **Fever** in the context of back pain, especially with progressive deformity, necessitates urgent investigation (e.g., MRI, blood cultures) to rule out conditions requiring immediate intervention and prevent potential **neurological compromise**.
*Morning stiffness lasting 90 minutes*
- Prolonged **morning stiffness** (typically >30 minutes, here 90 minutes) that improves with activity is a cardinal feature of **inflammatory back pain**, strongly suggestive of spondyloarthropathy.
- This is a diagnostic criterion for inflammatory back pain and does not warrant urgent "red flag" protocols, but rather confirms the likely inflammatory condition.
*Improvement with exercise*
- A key characteristic differentiating **inflammatory back pain** from mechanical back pain is that symptoms **improve with exercise** and worsen with rest.
- This finding supports a diagnosis of **spondyloarthropathy** and is a classic clinical indicator rather than an urgent warning sign.
*Bilateral buttock pain alternating sides*
- **Alternating buttock pain** is highly suggestive of **sacroiliitis**, reflecting inflammation within the sacroiliac joints common in **HLA-B27** positive patients.
- This symptom is included in the **ASAS criteria** for inflammatory back pain and is considered a typical disease manifestation.
*Age under 45 years at symptom onset*
- Inflammatory spinal conditions typically present in **younger adults** (under the age of 45), which helps differentiate it from degenerative disc disease.
- Onset at a younger age is a distinguishing feature consistent with inflammatory back pain, rather than a red flag for an alternative, urgent pathology.
