FRCS Mock Exam 3: Board Simulation

patients following correction of scoliosis by a cast or instrumentation. As a result of the curve correction, the angle between the SMA and the aorta is narrowed resulting in the compression of the third part of the duodenum. Initial treatment includes oral intake restriction, nasogastric suction and intravenous fluid administration. The majority of cases settle with conservative measures. In rare cases of failed non-operative treatment, surgical intervention is indicated.

Complete C5. Spinal cord injury levels are defined by the ASIA classification. Complete injuries are defined as: No voluntary anal contraction with a distal power MRC 0 and 0/2 distal sensory score (absent perianal sensation) with an intact bulbocavernous reflex (patient not in spinal shock). This patient is functional at C5 (deltoid and biceps) and not functional at C6 (wrist extensors) and C7 (wrist flexion and triceps). His last functional level is C5 indicating a C5 neurological level. It is complete as his distal motor and sensory function is absent.

Previous formation of heterotopic ossification. Although the exact aetiology is poorly understood, if there is a history of heterotopic ossification, then it is very likely to recur at a new site of surgery. Other factors include: ankylosing spondylitis, hypertrophic osteoarthritis, and diffuse idiopathic skeletal hyperostosis, with weaker evidence for extensive soft tissue handling/stripping, or bone debris from reamings. Although patients with head injuries are found to produce extensive calcific deposits a patient would not have elective total hip replacement so soon after significant head injury. Over-expression of bone morphogenetic protein-4 BMP-4) may be implicated in the pathogenesis of heterotopic ossification.

Flexion/extension of the C-spine is often reduced. Contrary to the common belief, the classic triad of low posterior hairline, short neck and reduced range of movement is seen in fewer than 50% of patients with Klippel–Feil syndrome. A Sprengel deformity is seen in 33% of cases, congenital scoliosis occurs in 60% and renal abnormalities is encountered in 33% of cases. Lateral side bending is usually limited whilst flexion/extension is often preserved.

Pain avoidance. Yellow flags are psychological factors shown to be indicative of long-term chronicity and disability which include a negative attitude that back pain is harmful or severely disabling resulting in fear avoidance behaviour and reduced activity levels. There is a tendency to depression, low morale and social withdrawal.

Homogentisic acid oxidase. This patient has degenerative arthritis resulting from alkaptonuria. This condition is also known as ochronosis. The deficient enzyme is homogentisic acid oxidase. Homogentisic acid is deposited in joints and turns black. It is also responsible for the black urine.

Tendon pull must be synergistic. These rules must be appreciated and short cuts will only lead to disaster. Donor muscles must be expendable and have adequate power, ideally MRC grade 5. Joints must be mobile with no contracture.

The tumour should be approached through normal tissue before entering the reactive zone. When performing a biopsy of a suspected bone tumour the following principles must be followed (in addition to A, B, C, E): avoid contamination of normal compartments enter the tumour through the reactive zone place the biopsy tract in line with incision to allow excision when performing a longitudinal extensile incision avoid contamination of intermuscular planes avoid contamination of neurovascular bundles

Compression of the lateral cutaneous nerve of thigh. The lateral cutaneous nerve of thigh may typically be compressed at several locations, such as the inguinal ligament, by tight belts (e.g. weightlifter’s belt), resulting in pain in the anterolateral part of the thigh.

The zone of proliferating activity controls limb growth in a proximal to distal direction. The zone of proliferating activity influences limb growth in an anteroposterior direction which, as the limb has not yet rotated, equates to a radial-ulnar direction in the case of the upper limb.

Decreased chondroitin 4-sulphate concentration. Chondroitin sulphate concentration increases in osteoarthritis and this includes both chondroitin 4- and 6-sulphate. Keratin sulphate concentration decreases and hence the ratio of keratin to chondroitin sulphate decreases as well.

A space available for the cord (SAC) of less than 14 mm or an ADI of more than 9–10 mm is an indication for spinal stabilization. An atlantoaxial subluxation occurs in 60–80% of cases of rheumatoid arthritis (RA) as the result of pannus formation at the synovial joints between the dens and the ring of C1. An ADI of >3.5 mm on flexion extension is a common finding in RA and indicates instability; however, it is not necessarily an indication for surgery. A SAC <14 mm or an ADI >9–10 mm is associated with an increased risk of neurological injury and usually requires surgical intervention. A Ranawat C1–C2 index is the distance from the centre of the C2 pedicle to a line connecting the anterior and posterior arches of C1. It is the most reproducible measurement of invagination. A C1–C2 index <13 mm indicates basilar invagination. Subaxial subluxation occurs in 20% of cases of RA, a subluxation >4 mm or more than 20% of the body is indicative of cord compression.

Vascularized fibular graft. As long as there is no collapse of the femoral head, vascularized fibular graft has been shown to be superior to non-vascularized by reducing progression to collapse, as well as having better Harris Hip Scores.

Ewing’s sarcoma. Chondrosarcomas typically occur in middle age and have a predominance for the pelvis and shoulder. Osteosarcomas have a bimodal age distribution with a peak in childhood and the elderly. They most commonly occur in the distal femur and proximal tibia. Giant cell tumours generally occur after skeletal maturity. It usually appears as an eccentric, lytic, expanding lesion in the distal metaphysic/epiphysis. It is locally aggressive but rarely malignant.

Gestational diabetes. The two most important risk factors for developmental dysplasia of the hip are a positive family history and breech position. The other important risk factors are first 187 born children and female sex. Gestational diabetes is not particularly associated with developmental dysplasia of the hip.

Anterior band of the medial ulnar collateral ligament. The anterior band provides the major contribution to valgus stability. The olecranon is an important stabilizer of the elbow in extension; at 25
flexion the olecranon is unlocked from its fossa and the ulnar collateral ligament becomes the most important stabilizer. The radial head is an important secondary stabilizer in flexion and extension. The posterior band of the medial ulnar collateral ligament is a secondary stabilizer at 30
of flexion. The transverse band plays no role in joint stability because it originates and inserts on the same bone.

According to Waddell et al, non-organic signs should be equated with malingering or the presence of a psychological problem. Waddell’s inappropriate/non-organic signs include: pain on axial compression and pelvic rotation, resisted hip flexion, non-dermatomal sensory loss, non-anatomical tenderness to light touch, cogwheel ‘give way’ weakness, straight leg rise (SLR) discrepancy and overreaction. The presence of more than three signs indicates non-organic features; however, the presence of the non-organic signs should not be equated with malingering but should alert the clinician to the need for more comprehensive testing.

Synovial cell sarcoma. Although primary cutaneous melanoma is the most common malignant tumour of any type in the foot (acral lentiginous melanoma), the most common primary soft tissue malignant tumour in the foot is synovial sarcoma. They make up approximately 8–10% of all sarcomas and most commonly affect adults in the third to fifth decades of life. They are often seen as soft tissue swelling with calcification on plain radiographs. The characteristic histological feature is a biphasic pattern with an epithelial component and a spindle cell component. Other common tumours or tumour-like conditions in the foot include enchondroma, osteoid osteoma, fibrous dysplasia, adamantinoma, osteochondroma, ganglion, clear cell sarcoma and fibromatosis.

Clinical governance. Appraisal for consultants is designed to be a professional process of constructive dialogue in which the doctor being appraised has a formal structured meeting to reflect on their work and to consider how their clinical effectiveness might be improved. Revalidation is the process whereby the General Medical Council establishes a doctor’s fitness to practise and with it, the right to remain on the medical register. Licensing is the first step towards the introduction of revalidation. To practise medicine in the UK all doctors are required by law to be both registered and hold a license to practice. Clinical effectiveness is defined as the extent to which specific clinical interventions do what they are intended to do. It is described as the right person doing the right thing in the right way at the right time in the right place with the right result. Clinical governance is how health services are held accountable for the safety, quality and effectiveness of clinical care delivered to patients.

Cuboid. The calcaneum (anterior), talus and cuboid ossification centres are usually present at birth. The lateral cuneiform appears during the first year, the medial cuneiform appears during the second year, the intermediate cuneiform and navicular appear during the third year and the posterior calcaneal centre appears during the eighth year.

Anteroinferior labral tear. It has been shown in one study that 87% have an anterior glenoid labral tear (Bankart lesion), 79% had anterior capsular insufficiency, 68% had a Hill–Sachs lesion, 55% had glenohumeral ligament insufficiency, 14% had complete rotator cuff tears, 12% had posterior glenoid labral tears and 7% had SLAP tears.

Femoral head/neck junction prominence. The patient is likely to be suffering from cam-type femoro-acetabular impingement, often presenting secondary to DDH, Perthes, or slipped upper femoral epiphysis, with a head/ neck junction prominence that may also lead to labral degeneration, cysts and tear. Degenerate changes at the articular surface in mild DDH is rare in a patient of this age, although cysts may be seen at the head/neck junction if there is impingement.

A type II rotator subluxation indicates an insufficiency of the transverse and alar ligaments. Atlantoaxial rotatory instability can occur after trauma or spontaneously. It is associated with Morquio syndrome, spondyloepiphyseal dysplasia, Larsen’s syndrome, achondroplasia and Grisel’s syndrome. It is present in 25% of children with Down syndrome. In type I, the odontoid acts as a pivot point and there is no anterior subluxation. In type II, one facet acts as a pivot with an ADI 3–5 mm. The transverse ligament is insufficient. In type III, the alar and transverse ligaments are incompetent resulting in bilateral facet subluxation with an ADI >5 mm.

Proliferative. Fibroblast growth factors (FGFs) affect the growth of long bones through stimulation of the proliferative zone. In achondroplasia, a defective FGF receptor gene (FGFR3) is responsible for the characteristic limb shortening.

It is the 10 cm perforator from the posterior tibial artery, medially which is usually the largest and most reliable for distally based fascio-cutaneous flaps. Current management of open fractures has evolved and the involvement of specialist centres is recommended. All wounds do not require immediate exploration. Indications for urgent surgery include gross contamination of the wound, compartment syndrome, a devascularized limb and a multiply injured patient. Otherwise initial surgery (bony and soft tissue) should be performed by senior plastic and orthopaedic surgeons working together on scheduled trauma operating lists within normal working hours and within 24 hours of the injury (unless there is marine, agricultural or sewage contamination).

Coxa vara. Achondroplasia is a type of rhizomelic dwarfism caused by an autosomal dominant genetic defect in the FGFR3 gene that is responsible for long bone growth. Therefore, individuals may have a normal sitting height with a reduced standing height. Progressively short pedicles in the distal spine predispose the child to problems with spinal stenosis. There is often an excessive lumbar lordosis and a junctional kyphosis in the non-ambulant child. 188 Achondroplasia is associated with coxa valga and genu varum with a disproportionately long fibula whereas spondyloepiphyseal dysplasia congenita is associated with the opposite deformities of coxa vara and genu valgum. Other features of achondroplasia comprise frontal bossing, trident hands, radial bowing, radial head subluxation, a champagne glass pelvis, inverted V-shaped distal femoral physes and tibial bowing.

External rotation deficit. Healing of the tuberosities and their attached rotator cuff tendons is crucial in functional outcome after arthroplasty. Failure to properly position tuberosity fragments in the horizontal plane may result in insurmountable post-operative motion restriction.

Presentation at 12–16 years. Tarsal coalition is due to failure of segmentation of the tarsal bones of the hind- and midfoot and can be partial or complete, fibrous, cartilaginous or bony. It is an autosomal dominant condition with a 20% incidence of multiple coalitions. Although congenital, symptoms occur when the coalition ossifies explaining why each type of coalition presents during a particular age range. Calcaneonavicular coalitions tend to present earlier between 8 and 12 years whereas talocalcaneal coalitions present later, at 12–16 years. Ossification causes loss of subtalar motion, adaptive shortening of the peronei and flatfeet; hence the term ‘spastic peroneal flatfoot’. The typical presentation comprises recurrent ankle sprains, calf pain and flatfeet. The radiographic ‘anteater sign’ represents the elongated anterior process of the calcaneum in calcaneonavicular coalition whereas talar beaking can be seen whenever there is stiffness of the subtalar joint complex. Middle facet talocalcaneal coalition 190 produces the greatest subtalar stiffness, with a valgus hindfoot. Over time, the adaptive shortening of the peroneal tendons contributes to posterior facet arthrosis in the subtalar joint regardless of the type of coalition.

Enlarged intervertebral foramina. Diastematomyelia is a congenital anomaly caused by a bony, cartilaginous or fibrous bar that results in the ‘splitting’ of the spinal cord in a sagittal direction. When the split does not reunite distally, the condition is referred to as diplomyelia. Diastematomyelia can lead to tethering of the cord and may be associated with neurological deficit. An intrapedicular widening is suggestive. An enlarged intervertebral foramina is seen in patients with neurofibroma.

Varus – Extension – Supination. All supracondylar fractures should be reduced by correcting the coronal plane deformity first, followed by the sagittal plane and lastly the axial plane. The exact manoeuvres are determined by the direction of displacement and the location of the periosteal hinge. The more common posteromedial fractures have an intact medial periosteal hinge which aids fracture reduction when the forearm is pronated. The same manoeuvre performed for the less common posterolateral fracture will displace the distal fragment further owing to the lateral periosteal hinge and supination is therefore required to aid fracture reduction.

Young woman, injured hill-running. In general, outcome following operative management of calcaneal fractures relies on the number of intra-articular fragments and the quality of articular reduction. A number of factors have been shown to be associated with a poor outcome and they include age >50, obesity, manual labourers, work insurance cases, smokers, bilateral fractures and vascular disease. In addition, men appear to do worse with surgery than women.

An injury with external tibial rotation with the knee at 90
of flexion is likely to injure the posterior cruciate and lateral collateral ligaments. Neuromuscular training indeed explains the gender difference in the incidence of anterior cruciate ligament in similar sports, but it is higher in women. Furthermore, women have a greater total valgus knee loading when landing from a jump. A grade 3 posterior cruciate ligament injury does not necessarily need reconstruction. The majority of grade 1 and 2 injuries can be treated with protected weight bearing and quadriceps rehabilitation. Grade 3 injuries require immobilization in full extension for 2 to 4 weeks to protect the posterior cruciate ligament and the other posterolateral structures presumed to be damaged. Prophylactic knee bracing has not been shown to reduce anterior cruciate ligament injuries in contact sports, but has been shown to reduce medial collateral ligament injuries. 111

Anterior cervical decompression and fusion. This patient has myelopathic changes within the cord probably as a result of an anterior degenerative disc. The presence of a fixed kyphosis of >10
is a contraindication to a 64 posterior decompression þ/ fusion. In addition, posterior procedures are ineffective in this case as the anterior compression on the cord will remain. The anterior approach provides direct access to the disc herniation and provides immediate and long-term stability to the motion segment.

Fibrocartilage. Microfracture involves making multiple holes through the subchondral plate at the base of the articular cartilage defect. This allows undifferentiated mesenchymal stem cells to proliferate in the defect, and they subsequently differentiate into fibrocartilage. There is initially a high proportion of type II collagen but this reverts to predominantly type I collagen. The resulting ‘cartilage’ fill is not as hard wearing as true hyaline cartilage, but the procedure has been shown to produce long-lasting symptomatic relief.

Radial head arthroplasty, coronoid open reduction internal fixation, and lateral collateral ligament repair. A terrible triad of the elbow includes dislocation of the elbow with associated fractures of the radial head and the coronoid process. Ring et al. stressed that these injuries are prone to complications and advised against resection of the radial head due to instability, 41 and instead recommended a radial head replacement if too comminuted for open reduction and internal rotation (ORIF). Coronoid fractures compromise elbow stability as well and require open reduction and internal fixation as with the lateral collateral ligament.

Internal rotation (IR) 30º, Flexion 30º, Abduction 30º. Shoulder arthrodesis should be performed so that the arm rests comfortably at the side without scapular winging and so that the hand can be brought easily to the mouth and perineum. 42 a. Instability of a vertebral fracture can be determined by loss of vertebral height >50%. b. There is no direct relationship between canal compromise and neurological deficit. c. Instability of injuries can be determined by further neurological deterioration under normal physiological load. d. Widening of the interpedicular distance on plain radiograph can indicate a burst fracture. e. In a thoracic burst fracture, a thoracolumbar orthosis is indicated if there is <50% loss of vertebral body height and >30% kyphosis. scoliosis are true except? a. With curves of 20–29
, 40% of patients who are Risser 0–1 are at risk of curve progression. b. With curves of 20–29
, 22% of patients who are Risser 2–4 progress. c. After skeletal maturity, a lumbar curve >35
can progress by 1–2
/year. d. A late curve progression in males is more common than in females. e. A rapid curve progression in females occurs before menarche and before Risser 1. retroperitoneal approach, all of the following statements are correct except? a. The ureter is adherent to the posterior peritoneum and falls away from the psoas through the dissection. b. The sympathetic trunk, lying longitudinally along the lateral border of the psoas, is at risk during this procedure. c. The ilioinguinal nerve emerges from the lateral border of the psoas and travels to the quadratus lumborium. d. A cold and pale right foot is a recognized post-operative examination finding. e. The genitofemoral nerve lies on the anteromedial surface of the psoas. except? a. Non-dystrophic deformities are indistinguishable from idiopathic scoliosis. 47

Young age (<25 years old) at time of dislocation. The only consistent predictor of recurrence has been the age of the patient. In young patients (<25 years old), recurrence rates have ranged from 60% to 94%. Family history confers a 34% risk of recurrence, while dislocation in the contralateral shoulder is seen in 25% of recurrently unstable patients according to Hovelius et al. No difference in dominant and non-dominant extremities was noted.

Enchondral ossification. Primary healing (also known as Haversian remodelling) is a direct healing process at the cortex requiring anatomical reduction and rigid stability. Secondary bone healing involves responses in the periosteum and external soft tissues. There are two types; enchondral healing which occurs with non-rigid fixation (such as fracture braces, external fixation, bridge plating, intramedullary nailing); and intramembranous healing which occurs with semi-rigid fixation (such as locked plating in a non-absolute stability construct).

Internal fixation of the symphysis pubis and internal fixation of the sacrum. Pelvic ring injuries must be assessed for stability, according to the pattern of injury. Classification is either by Tile: A – stable B – partially stable (rotationally unstable, vertically stable) C – unstable (rotationally unstable, vertically unstable) or by Young–Burgess: Anteroposterior (AP) compression Lateral compression Vertical shear Combined This injury described is unstable and requires both anterior and posterior fixation.

Gluteus maximus and adductor magnus. The sciatic nerve passes through the interval between piriformis and superior gemellus to lie under gluteus maximus, and passes over the gemelli, obturator internus, and quadratus femoris, before passing over the posterior surface of adductor magnus until it divides into its terminal branches. Cross-sectional anatomy of the limbs at different levels is a popular exam question, and it is worth memorizing the major structures in relation to each other.

50%. Because of the morbidity and prolonged rehabilitation associated with tendon repair it is advisable to repair lacerations over 50% of the tendon width. The exception to this rule is if there is visible triggering under a local anaesthetic block it may be necessary to address this.

No sensation from tip of acromion to tip of fingers. The prognosis for avulsion of the roots is far worse than just rupture or traction. All of these markers suggest severe trauma and may point to root avulsion. Numbness on its own is not as worrying as the other signs.

Third and fourth pharyngeal pouches. This child has DiGeorge syndrome. The third pharyngeal pouch gives rise to the thymus and inferior parathyroid glands. The fourth pharyngeal pouch gives rise to the superior parathyroid glands. These patients therefore develop symptoms and signs of hypocalcaemia due to hypoparathyroidism and recurrent infections due to a T-cell deficiency which arises from inadequate development of the thymus. Other associations include tetralogy of Fallot, abnormal facies and cleft palate.

Chondrocyte number increases in ageing. Chondrocyte numbers decrease in ageing cartilage. The others are all true: Osteoarthritis Ageing Water content Increases Decreases Proteoglycan degradation Increases Decreases Chondrocyte number Decreases Decreases Young’s modulus of elasticity Decreases Increases

Ligament avulsion off the humeral origin. The LUCL is most commonly injured at the proximal origin. McKee et al. noted that in 62 consecutive operative elbow dislocations and fracture/dislocations, the LUCL was ruptured in all of the patients, proximally in 32, bony avulsion proximally in 5, midsubstance rupture in 18, ulnar detachment in 3, ulnar bony avulsion in 1 and combined patterns in 3.

The ligament of Struthers. The leash of Henry refers to the recurrent branches of the radial artery in the forearm. The arcade of Frohse is the tendinous proximal border of supinator. The tendinous origin of ECRB is a potential site of compression. The ligament of Struthers is a fibrous band extending from a large bony projection of the humerus, known as the supracondylar process, to the medial epicondyle. It is probably present in less than 1% of humans, and may cause median nerve compression.

With age, the proteoglycan (PG) synthesis decreases; however, the PG concentration increases due to the drop in the water content. The intervertebral disc is made up of the annulus fibrosis and nucleus pulposus. The annulus is rich in collage type I and resists tensile forces; the nucleus is rich in type II collagen and resists compressive forces. Age-related changes include: A decrease in proteoglycan synthesis resulting in an overall decrease in the proteoglycan concentration despite a drop in the water content. Chondroitin sulphate concentration decreases. The absolute quantity of collagen remains constant (there is a decrease in type I and increase in type III collagen).

The disease should be one in which late treatment is as effective as early treatment. The following criteria are accepted by the WHO (as described by Wilson and Jungner in 1968): The condition sought should be an important health problem for the individual and community. There should be an accepted treatment or useful intervention for patients with the disease. The natural history of the disease should be adequately understood. There should be a latent or early symptomatic stage. There should be a suitable and acceptable screening test or examination. Facilities for diagnosis and treatment should be available. There should be an agreed policy on whom to treat as patients. Treatment started at an early stage should be of more benefit than treatment started later. The cost should be economically balanced in relation to possible expenditure on medical care as a whole. Case-finding should be a continuing process and not a ‘once and for all’ project.

Lesser trochanter group. There are four main trabecular patterns in the proximal femur. There are two compressive, one tensile, and one greater trochanteric group but none relating specifically to the lesser trochanter.

Infantile scoliosis commonly affects girls and is usually left-sided. Infantile scoliosis occurs between the ages of 2 months and 3 years. It commonly affects boys and is usually left-sided. An MRI scan should be performed in infantile scoliosis to 62 exclude a Chiari, syrinx or cord tethering. The term early onset scoliosis is now widely used and includes infantile, juvenile and any scoliosis that occurs before the age of 10 years.