Multiple Choice Questions

Lower Limb Pathology

Please use the comments section at the bottom of the page if you have any query or feedback about any of the questions.

30. All of the disorders listed below are examples of osteochondrosis except:

A) Legg-Calvé-Perthes disease
B) Scheuermann’s disease 
C) Osgood Schlatter disorder 
D) Gorham’s disease
E) Blount disease

Correct Answer: D

The term osteochondrosis refers to symptomatic disorders involving cartilage growth. Cartilage affected by osteochondrosis may be epiphyseal, physeal, or apophyseal. Gorham’s disease is not an example of osteochondrosis. Gorham’s disease is a lymphatic disorder known as disappearing bone disease.

Author: Fouad Chaudery

 

29. What is the histological difference between avascular necrosis of the femoral head in children versus adults ?

A) Children have less creeping substitution than adults
B) Children do not demonstrate osseous collapse. 
C) Large areas of fibrovascular tissue do not form in children. 
D) There is no osteoclastic resorption in children. 
E) Children do not have any residual changes after 2 years. 

Correct Answer: A

Avascular necrosis models of the femoral head in immature animals show more osteoclastic resorption, fibroblastic response, and little creeping substitution when compared to models of mature animals. Osseous collapse is common, and there are often long-term residual changes in the shape of the femoral head.

Author: Fouad Chaudery

 

28. The result of treatment of developmental dysplasia of the hip with Salter osteotomy is is worse with which of the following:

A) A higher degree of the dislocation before treatment (Tonnis grade)
B) Bilaterality 
C) Higher preoperative acetabular index
D) Increased age at surgery 
E) Performing open reduction at a separate surgery than the osteotomy

Correct Answer: A

Salter osteotomy is effective in treating developmental dysplasia of the hip in young children. The result is worse with higher degrees of dislocation as assessed by the Tonnis system. It is better if the open reduction (if needed) is performed as a separate step than the osteotomy. The other factors have not been shown to be predictive.

Author: Fouad Chaudery

 

27. Which of the following is an appropriate position for arthrodesis of the hip in a young person:

A) Flexion of 45°
B) Abduction of 15° if there is shortening
C) Adduction of 0°
D) External rotation of 25° 
E) Shortening of at least 3 cm

Correct Answer: C

Neutral abduction is important in preventing back pain.

• The flexion should be between 25° and 35°.
• Any abduction beyond neutral poses increased risk of back pain.
• External rotation beyond approximately 5° is not needed.
• Arthrodesis often produces some mandatory shortening; therefore, intentional shortening is not needed.

Author: Fouad Chaudhry

 

26. Osteochondral defects occur bilaterally in the distal femur in approximately:

A) 10% to 20% of patients. 
B) 20% to 30% of patients. 
C) 30% to 40% of patients.
D) 60% to 70% of patients. 

Correct Answer: B

Osteochondral defects occur bilaterally in the distal femur for approximately 20% to 30% of patients. The fact that 20% to 30% of patients with an osteochondral lesion in the distal femur have bilateral involvement suggests that there is a predisposition to the development of a lesion at this location, either genetic or secondary to repetitive microtrauma.

Author: Fouad Chaudhry


25. A patient underwent bone-patellar-bone anterior cruciate ligament reconstruction. Postoperative radiographs show the femoral tunnel has been placed too far anteriorly. 

What is the most likely clinical result of anterior placement of the femoral tunnel?

A) Limited extension
B) Anterior instability
C) Anterior knee pain
D) Limited flexion
E) Posterior instability

Correct Answer: A

A femoral tunnel that has been placed too anterior will limit extension. Numerous studies have shown the most common technical mistake intraoperatively is placement of either the tibial or the femoral tunnel, or both, too far anteriorly. Either of these aberrant placements may cause impingement of the graft and thus promote formation of a large lump of fibrous tissue, known as a Cyclops lesion. This lesion forms anterior to the graft, potentially blocking extension of the knee.

Author: Fouad Chaudhry

 

24. In the setting of chronic anterior cruciate ligament (ACL) deficiency .

which of the following meniscal tear patterns is most common:

A) Peripheral posterior horn tears of the medial meniscus
B) Peripheral posterior horn tears of the lateral meniscus
C) Peripheral anterior horn tears of the medial meniscus
D) Peripheral anterior horn tears of the lateral meniscus
E) Central posterior horn tears of the medial meniscus

Correct Answer: A

Explanation: Medial meniscal tears account for approximately 45% of acute tears and 70% of chronic tears in patients with ACL insufficiency. Peripheral posterior horn tears of the medial meniscus are the most common type of tear associated with chronic ACL deficiency.

Author: Fouad Chaudhry

 

23. After landing awkwardly on his flexed knee, a 22-year-old basketball player has immediate onset of pain and difficulty bearing weight. With the knee flexed 30°, examination reveals increased varus, external rotation, and posterior translation which decreases when the knee is flexed to 90°. 

The patient most likely has injured what structures:

A) Posterolateral complex
B) Posterolateral complex and posterior cruciate ligament
C) Posterior cruciate ligament
D) Lateral collateral ligament
E) Posterior cruciate ligament and medial collateral ligament

Correct Answer: A

With an isolated injury to the posterior cruciate ligament (PCL), posterior translation increases at greater degrees of flexion demonstrating the greatest posterior translation at 90°. Injury to the lateral collateral ligament leads to varus laxity in 30° flexion without posterior translation. With an injury to the PCL and posterolateral complex, varus, external rotation, and posterior translation are detectable at 30° and increase as the knee is flexed to 90°. Isolated tears of the posterolateral complex lead to increased varus, external rotation, and posterior translation at 30° that decreases as the knee is flexed to 90° and the PCL tightens.

Author: Fouad Chaudhry

 

22. Which tear pattern is most responsive to meniscus repair:

A) Radial
B) Complex
C) Parrot beak
D) Longitudinal
E) Horizontal Cleavage

Correct Answer: D

Longitudinal tears are the most responsive tear pattern to successful repairs. Longitudinal tears occur in the plane of the radial orientation of the meniscal infrastructure. Other patterns of tears disrupt this radial orientation, resulting in high stress across the repair site and difficulty in reconstituting lost meniscal function

Author: Fouad Chaudhry

 

21. Which of the following most accurately describes the location of the tibial attachment of the posterior cruciate ligament:

A) At the level of the tibial plateau
B) 0 mm to 5 mm inferior to the level of the tibial plateau
C) 5 mm to 10 mm inferior to the level of the tibial plateau
D) 10 mm to 15 mm inferior to the level of the tibial plateau
E) 15 mm to 20 mm inferior to the level of the tibial plateau

Correct Answer: D

The tibial attachment of the posterior cruciate ligament is usually 10 mm to 15 mm inferior to the joint line. Reconstructions of the posterior cruciate ligament should attempt to replicate this tibial attachment site.

Author: Fouad Chaudhry

 

20. All of the following are either primary or secondary stabilizers of the knee to posterior translation except:

A) Posterior cruciate ligament 
B) Anterior cruciate ligament 
C) Medial collateral ligament 
D) Lateral collateral ligament 
E) Posterolateral corner 

Correct Answer: B

The posterior cruciate ligament is the primary stabilizer to posterior translation of the knee. 

Secondary stabilizers include the medial and lateral collateral ligaments and the posterolateral corner.

Author: Fouad Chaudhry

 

19. Placing a highly tensioned soft tissue graft across the open femoral physis during anterior cruciate ligament reconstruction results in which of the following outcomes

A) Premature closure of the physis 
B) No growth disturbance 
C) Development of femoral varus 
D) Development of femoral valgus 
E) Femoral overgrowth 

Correct Answer: D

An excessively tensioned soft tissue graft placed across the  femoral physis causes inhibition of growth of the lateral aspect of the distal femur resulting in the development of femoral valgus. The physis remains open during this process. Although this canine model illustrates potential harm that may result in a similar situation the human, the precise clinical implications of this canine model are unclear at this time. 

Author: Fouad Chaudhry

 

18. All of the following are either primary or secondary stabilizers of the knee to posterior translation except:

A) Posterior cruciate ligament 
B) Anterior cruciate ligament 
C) Medial collateral ligament 
D) Lateral collateral ligament 
E) Posterolateral corner 

Correct Answer: B

The posterior cruciate ligament is the primary stabilizer to posterior translation of the knee. 

Secondary stabilizers include the medial and lateral collateral ligaments and the posterolateral corner.

Author: Fouad Chaudhry

 

15. Which of the following findings has not been reported following abrasion arthroplasty as treatment for the painful, arthritic knee:

A) An increase of the medial joint space on radiograph 
B) Intermediate or long-term symptomatic improvement in the majority of patients 
C) Formation of a fibrocartilage articular surface 
D) Formation of primarily type I collagen 
E) Worsening of symptoms in 10% to 20% of patients 

Correct Answer: B

Although popular in the 1980s, abrasion arthroplasty for the treatment of osteoarthritis of the knee has not been shown to reliably improve patients’ symptoms. Although some authors have found radiographic evidence of an increased joint space in approximately 50% of patients, these findings have not corresponded to an improvement in symptomatology. Abrasion arthroplasty results in the formation of a fibrocartilaginous articular surface that varies in composition with immature type I collagen predominant.

Author: Fouad Chaudhry

 

14. In which of the following anatomic locations have authors described a characteristic osteochondral lesion that occurs with an acute anterior cruciate ligament (ACL) injury:

A) Posterolateral aspect of the tibia and the anterolateral aspect of the lateral femoral condyle 
B) Posterolateral aspect of the tibia and the posterolateral aspect of the lateral femoral condyle 
C) Lateral patellar facet and lateral trochlear groove 
D) Anterolateral aspect of the tibia and the posterolateral aspect of the lateral femoral condyle 
E) Posteromedial aspect of the tibia and the anteromedial aspect of the lateral femoral condyle 

Correct Answer: A

During anterior cruciate ligament (ACL) injury, anterior translation of the tibia and the associated valgus force create a compressive load on the articular cartilage in the posterolateral aspect of the tibia and the anterolateral aspect of the lateral femoral condyle. 

It has been estimated that approximately 80% of acute ACL injuries demonstrate this pattern on magnetic resonance imaging.

Author: Fouad Chaudhry

 

13. Which of the following processes may produce cystic bone erosions in the cortex on both sides of a joint:

A) Septic Arthritis
B) Synovial chondormatosis
C) Pigmented villonodular synovitis 
D) Ochronosis
E) Hemochromatosis

Correct Answer: C

Pigmented villonodular synovitis is a synovial proliferative disorder characterized by atraumatic recurrent effusions and cystic erosions of the periarticular bone surfaces. The synovial tissue becomes hypertrophic and can cause large erosions on both sides of the joint. These erosions most commonly occur in the hip joint because of the tight capsule and the limited amount of space for extension of the disease. Conversely, in the knee, there is room for expansion and these erosions occur late in the disease.

Author: Fouad Chaudhry

 

12. A 40y old man has had hip pain with increased activity over the past year. Examination reveals restriction of motion and tenderness with combined hip fl exion, adduction, and internal rotation. An AP radiograph is shown in the figure attached. 

What is the most likely diagnosis?

A) Developmental dysplasia of the hip
B) Osteonecrosis
C) Pseudogout
D) Femoral acetabular impingement                                                                                                                                                                                              E) Perthes disease                                                

The correct answer is : D

Femoral acetabular impingement (FAI) is a pathologic entity leading to pain, reduced range of motion in fl exion and internal rotation, and development of sec-ondary arthritis of the hip. There are two types of FAI: cam impingement and pincer impingement. 

Cam impingement is seen when a nonspherical femoral head pro-duces a cam effect when the prominent portion to the femoral head rotates into the joint. This mechanism produces shear forces that damage articular cartilage. Radiographs reveal early joint degeneration and fl attening of the head neck junction (pistol grip deformity) as seen in this image. 

The pincer type of impingement involves abnormal contact between the femoral head neck junction and the acetabulum, in the presence of a spherical femoral head.

Author : Salam Al-Abayachi

 

11. Bleeding is encountered while developing the internervous plane between the tensor fascia lata and the sartorius during the anterior approach to the hip. 

The most likely cause is injury to what artery?

A) Ascending branch of the lateral femoral circumf ex
B) Superior gluteal
C) Femoral
D) Profunda femoris
E) Medial femoral circumfl ex

The correct answer is : A

The ascending branch of the lateral femoral circumfl ex artery crosses the gap between the tensor fascia lata and the sartorious and must be identifi ed and ligated or coagulated. The other ves-sels are out of the f eld of dissection.

Author : Salam Al-Abayachi

 

10. Which of the following images is best for detecting anterior acetabular deficiency in the dysplastic hip?

A) Pelvic inlet
B) Judet
C) AP pelvis
D) False profile
E) Frog lateral

The correct answer is : D

The false profi le view of Lequesne and de Seze is obtained with the patient standing with the affected hip on the cassette, the ipsilateral foot parallel to the cassette, and the pelvis rotated 65° from the plane of the cassette. This view best assesses anterior coverage of the femoral head.

Author : Salam Al-Abayachi

 

9. At the level of tibial bone resection in TKA, where does the common peroneal nerve lie?

A) Deep to the arcuate ligament
B) Closer to bone in larger legs
C) On the muscle belly of the popliteus
D) On the bony posterolateral corner of the tibia
E) Superficial to the lateral head of the gastrocnemius

The correct answer is : E

At the level of tibial bone resection in total knee arthroplasty, the common peroneal nerve lies superfi cial to the lateral head of the gastrocnemius and is therefore protected by this structure. In an MRI study of 60 knees, the mean distance from the bony posterolateral corner of the tibia to the nerve was 1.49 cm, with no distance less than 0.9 cm. The distance from the bone to nerve was greater in larger legs.

Author : Salam Al-Abayachi

 

8. What complication is more likely following excessive medial retraction of the anterior  structures during the anterolateral (Watson-Jones) approach to the hip?

A) Numbness over the anterolateral thigh
B) Ischemia to the leg
C) Quadriceps weakness
D) Abductor insufficiency
E) Foot drop

The correct answer is : C

The femoral nerve is the most lateral structure in the anterior neurovascular bundle. The femoral artery and vein lie medial to the nerve. Retractors placed in the anterior acetabular lip should be safe, although neurapraxia of the femoral nerve may occur if retraction is prolonged or forceful lead-ing to quadriceps weakness. The femoral artery and nerve are well protected by the interposed psoas muscle. Damage to the lateral femoral cutaneous nerve, causing numbness over the anterolateral thigh, can occur while developing the interval between the tensor fascia latae and sartorious in the anterior (Smith-Petersen) approach but less likely in the Watson-Jones approach. Superior gluteal injury and accompanying abductor insuffi ciency may occur during excessive splitting of the glutei during the direct lateral (Hardinge) approach. Foot drop secondary to sciatic injury is more common with a posterior exposure or posterior retractor placement.

Author : Salam Al-Abayachi

 

7. Trenderburg’ s sign can be elicited in all of the following except :

Trendelenburg test or sign | Epomedicine
A) Congenital dislocation of the hip.
B) Infantile paralysis of the gluteal muscles.
C) Coxa vara.
D) Tuberculous arthritis of the hip joint.
E) Non-united fracture of the femoral neck.

The correct answer is : D

Several dysfunctions can produce a positive Trendelenburg Test:
1-Weakness of gluteus medius.
2-Hip instability and subluxation.
3-Hip osteoarthritis.
4-Initially, post Total Hip Replacement.
5-Superior Gluteal Nerve Palsy.
6-Lower back pain.
7-Legg-Calvé-Perthes Disease.
8-Congenital hip dislocation.

Author : Firas Arnaout

 

6.  A football player fell on his flexed knee with the foot in plantar flexion. On examination, he has a positive quadriceps active test, Which knee ligament in most likely injured in this patient?

Quadriceps Active Test

 A) Anterior cruciate ligament (ACL)
B) Posterior cruciate ligament (PCL)
C) Lateral collateral ligament (LCL)
D) Medial collateral ligament (MCL)
E) Posterolateral corner complex (PLC)

Best answer: B

The PCL extends from the medial femoral condyle to the tibial sulcus Overall the most common mechanism of PCL injury is a direct blow to the proximal aspect of the tibia such as dash board injury. The most common mechanism of PCL injury in athletes is a fall onto the flexed knee with the foot in plantar flexion, which places posterior forces on the tibia and leads to rupture of the PCL.Treatment of isolated PCL injury is mainly focused on protected weight bearing, followed with quadriceps rehabilitation

Janousek AT, Jones DG, Clatworthy M, Higgins LD, Fu FH. Posterior cruciate ligament injuries of the knee joint. Sports Med 1999; 28:429-441

Author : Firas Arnaout

 

5.  The posterior approach to the acetabulum and hip provides good exposure for fixing for hip fractures and hip arthroplasty. 

Where is the sciatic nerve likely to be found?

A) Under the piriformis muscle
B) Above the piriformis muscle
C) Under the quadratus femoris
D) Underneath the gluteus minimus
E) Exits through the obturator foramen

Best answer:  A

The sciatic nerve supplies the muscles at the back of the thigh to extend the hip and flex the knee. It exits through the greater sciatic notch and appears in the gluteal region below the lower border of the piriformis muscle in the vast majority of cases. In the surface anatomy, it is located in the lower medial quadrant of gluteal region; it is accompanied by the inferior gluteal artery.

The superior gluteal nerve and artery leave the pelvic above the piriformis and underneath the gluteus minimus. The medial circumflex femoral artery passes underneath the quadratus femoris.

Netter FH: Atlas of Human Anatomy. West Caldwell, NJ,
CIBA-Geigy, 1989

Author :Firas Arnaout

 

4.  A  69 years old man presented with ipsilateral hip and knee pain. On examination, he has painful and restricted movement of the hip, but knee movements were complete and painless.Radiographes of the hip and knee show severe degenerative arthritis of the hip and mild arthritis of the knee. 

Which nerve is responsible for this patient’s referred pain from hip to knee?

 A) The femoral nerve
B) The sciatic nerve
C) The lateral femoral cutaneous nerve
D) The saphenous nerve
E) The obturator nerve 

Best answer:  E

The obturator nerve come from L2, L3 and L4 nerve roots and enters the thigh through the obturator canal before dividing into anterior and posterior branches.it is at risk during anteromedial (Ludloff) approach to the hip.
It provides sensation to medial aspect of thigh and to both hip and knee joints, therefore some of hip pain could radiate to the knee.

Author :Firas Arnaout

 

3.  A 28 years old man was involved in a motorbike road traffic accident sustaining head injury resulting in a coma and hip fracture. 

Indomethacin is indicated here to prevent which complication?

A) Non union
B) Infection
C) Vascular compromise
D) Pressure ulcers
E) Heterotopic ossification 

Best answer:  E

Heterotopic ossification is formation of bone in the soft tissues, may occur spontaneously or following trauma .It is usually not painful, but presents with loss of movements. Prolonged ventilation time, brain injury, spinal cord injury, burns, and amputation thru the zone of injury in a patient injured in a blast are all literature proven risk factors for development of heterotopic ossification. Prophylaxis is with the use of Bisphosphonates and Indomethacin and raditherpay.Surgical excision could be performed if there is sever loss of movements.

 Pape HC, Lehmann U, van Griensven M, Gänsslen A, von Glinski S, Krettek C. Heterotopic ossifications in patients after severe blunt trauma with and without head trauma: incidence and patterns of distribution. J Orthop Trauma. 2001 May; 15(4):229-37

Author :Firas Arnaout

 

2.  25 years old rugby player sustained posterior hip dislocation when several players landed on his back with the hip flexed to 90 degrees, resulting in posterior hip dislocation. 

Hip Dislocation – Core EM

What is the most common complication of hip dislocation?

A) Posttraumatic arthritis
B) Avascular necrosis
C) Sciatic nerve injury
D) Recurrent dislocation
E) Femoral artery occlusion

Best answer: B

 

All the above are recognised complication of hip dislocation. Arthritis incidence is up to 20% and is dependent on the severity of dislocation and associated fractures.

Sciatic nerve injury is up to 20% and increases with longer time to reduction.

AVN incidence is up to 40% and recurrent dislocation is 2%

 Author :Firas Arnaout


1.  A 14 years old boy attended the orthopaedic clinic with a swollen painful knee and inability to weight bear. 

What is the most common cause of recurrent haemoarthrosis ?

A) Minor trauma
B) Septic Arthritis
C) Haemophilic arthropathy
D) Osteoarthritis
E) Inflammatory arthritis

Best answer: C

Minor trauma should not cause recurrent haemoarthropathety unless it is associated with a bleeding disorder. Septic and inflammatory arthritis very rarely cause haemoarthrosis.Osteoarthritis is rare in the young patient.

Causes Haemophilic arthropathy include: haemophilia and Von Willebrand disease. They are X linked affecting boys only. Sever cases could require factor VIII transfusion 

 http://www.orthobullets.com/basic-science/9051/hemophilic-arthropathy

 Author :Firas Arnaout

1 thought on “Lower Limb Pathology”

Leave a Reply

Your email address will not be published. Required fields are marked *