FRCS Mock Exam 4: High Yield Trauma & Elective

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.

Decreased shoulder muscle strength and endurance. McKee found that patients who had non-operative treatment of displaced (> 2 cm) midshaft clavicle fractures had significant decrease in both strength and endurance of about 80% compared to the contralateral side. Range of motion (ROM) of the affected shoulder was unaffected.

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

A posteromedial approach between medial gastrocnemius and semimembranosus. The tibial insertion of the posterior cruciate ligament is best exposed through a posteromedial approach between medial gastrocnemius and semimembranosus. The former is retracted laterally and inferiorly, pulling the nerves and vessels out of the way to reach the posteromedial corner of the joint. The posterolateral corner of the joint is exposed between the lateral head of the gastrocnemius and biceps femoris muscle. Muscle-splitting approaches are generally not used at the back of the knee.

Ca10 (PO4)6 (OH)2. Calcium hydroxyapatite (Ca10 (PO4)6 (OH)2) forms part of the inorganic component of the bone matrix and gives it compressive strength.

Complete spinal cord injury. An intact bulbocavernous reflex indicates that the patient is not in a state of spinal shock and therefore the cord injury can be classified as a complete injury pattern in this scenario.

Budd–Chiari syndrome. Neural tube defects (NTDs) are a spectrum of disorders caused by failure of the posterior neural elements to fuse at around 3–4 weeks’ gestation. The causes are multifactorial although a raised level of homocysteine, a consequence of folate deficiency, is strongly implicated. NTDs are either open or closed. Open lesions usually involve the entire central nervous system (CNS) with leakage of cerebrospinal fluid (CSF) and result from failure of primary neurulation. Closed lesions are usually localized to the spine and result from failure of secondary neurulation. Closed types are covered by an epithelial layer and neural elements are therefore not exposed. However, any overlying skin may be dysplastic and cutaneous stigamata such as a pit or a hairy patch may be noticeable. The effects of NTDs depend on their location and severity although paralysis (flaccid and/or spastic) and bowel and bladder incontinence are characteristic. A type II Arnold–Chiari malformation is the commonest associated condition: downwards displacement of the cerebellar tonsils through the foramen magnum which can lead to hydrocephalus and mental retardation. Budd–Chiari syndrome is occlusion of the hepatic veins and is unrelated to NTDs.

Homeobox genes. Limb buds are formed from mesoderm covered with surface ectoderm. The upper limb bud appears at 4 weeks post-fertilization and the lower limb bud appears two days later. Two areas form within the mesoderm – the lateral mesoderm which forms bone, cartilage and connective tissues and the somite which forms the muscular elements. Homeobox (Hox) genes via fibroblast growth factors (FGFs) influence development of the apical ectodermal ridge (AER), which is responsible for proximal to distal growth. Hox gene abnormalities therefore lead to proximal/distal losses. The AER is a transient region of activity from which the digits develop. Separation of the digits occurs at around 50 days. Apoptosis under the influence of BMPs allows digits to separate and prevents webbing whereas noggins block apoptosis thereby preserving the webbing of the digits. The Sonic hedgehog genes control the zone of proliferating activity (ZPA) in the mesoderm that is responsible for radial to ulnar growth and differentiation, i.e. the little (fifth) finger from the thumb.

Elmslie–Trillat procedure. Surgical procedures for chronic patellofemoral instability are often used in combination and include soft tissue or bony procedures performed proximally, at the level of the joint or distal to it. A TT-TG distance of greater than 15 mm on CT suggests an increased Q-angle necessitating medial tibial tubercle transfer (Elmslie–Trillat). Unlike the Hauser technique, the Elmslie–Trillat does not involve posterior displacement which increases patellofemoral contact pressures contributing to pain and degeneration. Patellar alta is an indication for distal TT transfer. Trochlear dyplasia is recognized on lateral radiographs by the presence of the ‘crossing sign’ and may require a trochleoplasty to deepen and lateralize the trochlear groove. Lateral release is only indicated for isolated lateral patellar tilt and should be combined with another procedure if other factors are present. In the presence of a normal Q-angle, proximal soft tissue realignment procedures should be considered such as MPFL reconstruction and vastus medialis oblique (VMO) advancement. 189

Nerve stimulation therapy. If symptoms are not severe and there is not significant and progressive neuropathy then non-operative management must be considered. This includes splintage, hand therapy, steroid injection and even yoga has been proven to be beneficial. Alternatively a patient could be referred for either open or endoscopic release.

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.

Diabetic cheirarthropathy. This is a poorly understood condition. It is thought to be as a result of a muscular or tendon imbalance with soft tissue disruption. There is a microangiopathy of the dermal and subcutaneous blood vessels. It is more common in Type 1 diabetics and can affect 8–50% of the population. Loss of function is painless, and progresses from distal to proximal. The prayer sign is an inability to oppose palmar surfaces.

Painful nodules are an indication for surgery. The disease is usually in its early phases. The stages, according to Luck’s classification, are proliferative, involutional and finally residual. Early surgery will certainly lead to recurrence and can stimulate the disease process. Carpal tunnel surgery must be performed at a separate occasion for a similar reason. Unfortunately in the long term recurrence rates are high (50%).

Gram-positive coccus Gram-negative coccus Gram-positive bacillus Gram-negative bacillus Steptococcus Actinomyces Escherichia coli Coryneform Salmonella typhi Diphtheroids Klebsiella pneumoniae Helicobacter pylori

Radiolucent lines in Gruen zones 1, 2, 6 and 7. Gruen described seven zones around a cemented femoral stem starting with zone 1 at the greater trochanter round to zone 7 at the calcar, zone 4 being at the tip of the prosthesis. He described different modes of failure of cemented stems: 238 Mode Mechanism Cause Findings 1A Pistoning Stem subsiding within cement Radiolucent lines in zones 1 and 2 1B Pistoning Stem and cement subsiding within bone Radiolucent lines in all 7 zones Medial stem pivot Lack of supermedial and inferolateral support Medial migration proximally and lateral migration distally Calcar pivot Medial-lateral toggling of distal stem Radiolucent lines in zones 4 and 5 Cantilever bending Loss of proximal support with a well-fixed distal stem Stem fracture, radiolucent lines on zones 1, 2, 6 and 7

Closed or open reduction and combined screw and K-wire stabilization. The tarsometatarsal joint is best thought of in three columns: a medial column (first tarsometatarsal joint), a middle column (second and third tarsometatarsal joints) and a lateral column (fourth and fifth tarsometatarsal joints). Any dislocation or subluxation needs reduction. A cast or external fixator does not hold the reduction adequately. Although there are many ways to stabilize the fracture-dislocation after reduction, it is generally accepted that the medial and middle columns should be treated with permanent fixation (for example screws) and the lateral column should have temporary fixation (for example K-wires removed after 6–12 weeks). This is due to the relatively greater mobility of the lateral column.

Decompression of the syrinx in patients above the age of 10 years will improve or stabilize the scoliotic curve. Syringomyelia usually results from lesions that partially obstruct cerebrospinal fluid (CSF) flow including craniocervical junction abnormalities (Chiari malformations), spinal cord trauma and tumours. It often presents with central cord syndrome. Light touch, proprioception and vibration sensation are usually preserved. In most patients over the age of ten, surgical treatment of scoliosis is most likely necessary due to a large initial scoliosis curve or curve progression even after syrinx drainage.

Total elbow replacement. The Larsen classification of the rheumatoid elbow is based on plain radiographs and is graded I–V: Grade I – soft tissue swelling and osteoporosis. Grade II – mild narrowing of the joint space and some marginal erosion. Grade III – significant joint space narrowing. Grade IV – integrity of subchondral plates is breached by deep erosions. Grade V – total joint destruction

Physiotherapy and passive range of motion, 10 days following the injury. Immediate physiotherapy and prolonged immobilization are not appropriate in this situation. Although surgical management is an option, a good result can be achieved with non-operative treatment, if the physiotherapy is started within 2 weeks. 212

The posterior, transverse portion of medial collateral ligament is the primary stabilizer of the elbow to valgus stress. Coronoid fractures are classified as follows: Type I – tip/shear/avulsion; Type II – less than 50% height; Type III – more than 50% height. Based on cadaveric studies, the anterior portion of the medial collateral ligament is the primary stabilizer of the elbow to valgus stress with minimal contribution from the posterior ligament.

Vertebral fractures may give rise to false low density values. DEXA scanning is used to assess bone mineral density, in particular to diagnose osteoporosis. Vertebral fractures may give rise to falsely elevated bone density values.

Less in ceramic than polyethylene cups. The Swedish Hip Registry reports that deep infections are slightly lower with ceramic components. The exact mechanism is unclear, but may be due to bacterial adhesion being poorer on the smoother surface of ceramic components.

Scapholunate angle <60º. This question is a test of the indications for fixation of a scaphoid fracture. The unstable fracture generally needs fixation. Other signs of instability include radiolunate angle >15
, scapholunate angle >60
, intrascaphoid angles >35
and a proximal pole fracture.

She has a claw hand. She has tight intrinsic muscles and her Bunnell test is positive as the intrinsic muscles are more powerful than her extrinsic extensors and flexors. The tight intrinsic muscles are treated with distal releases when fibrotic and a proximal slide when spastic. An intrinsic minus hand is one where there is a loss of function in the ulna and sometimes the median nerve (claw). The patient presents with a monkey grip.

The middle genicular artery. The middle genicular artery supplies the anterior and posterior cruciate ligaments and the synovial membrane. The medial superior genicular supplies the vastus medialis, lower femur and the knee joint. The lateral superior genicular supplies the vastus lateralis, lower femur and the knee joint. The medial inferior genicular supplies the upper end of the tibia and the articulation of the knee.

None of the above. The talus is made up of a head, neck, body and posterior process. It articulates with the tibia and fibula in the ankle, and the navicular and calcaneum in the foot. It has many ligamentous attachments but no muscle attachments. There is a groove posteriorly in which the flexor hallucis longus tendon runs. It is important to be aware of the blood supply of the talus; the primary source is the artery of the tarsal canal (derived from the posterior tibial artery); additional supply is from the superior neck vessels (derived from the anterior tibial artery) and the artery of the sinus tarsi (derived form the dorsalis pedis).

Risk of dislocation. As part of a deltopectoral approach, the subscapularis is taken down off the humerus. This may be done trans-tendon, directly off bone, or with a lesser tuberosity osteotomy. In the initial post-operative period passive external rotation is limited to a maximum 30
to allow healing and protect the repair.

Patella baja. Patellofemoral disorders are extremely common and tend to have a mutlifactorial aetiology. Predisposing factors include the condition femoral anteversion, lateral patella tilt, patella alta (not baja), a reduced trochlea sulcus and a lateral tibial tuberosity. Others include gluteal dysfunction, vastus medialis oblique dysfunction, tight iliotibial band, tight rectus femoris, tight calves/hamstrings, lateral tibial torsion and increased foot pronation.

Risser 3. Risser staging 1–5 depends on the amount of ossification of the iliac apophysis visible on the anteroposterior (AP) radiograph. Ossification begins anterolaterally and proceeds posteromedially. The first 25% equates to Risser 1 and grade 4 equates to 100% ossification. Grade 5 is signified by fusion of the apophysis. The relevance of Risser staging is in predicting the progression of scoliotic curves. Small curves and greater skeletal maturity according to the Risser stage predicts a smaller likelihood of curve progression compared to larger curves and skeletal immaturity.

A ligamentous chance fracture should be treated using a compression construct with one level above and one level below the fracture. A chance fracture is the result of a flexion-distraction injury (seatbelt injury). It can be bony, ligamentous or mixed. Gastrointestinal injuries occur in 50% of cases. The bony lesions unite non–operatively with a brace in extension. The ligamentous type may remain unstable and therefore should be treated operatively using a compression construct (restore the tension band) with one level above and one level below the fracture. A chance fracture is seldom associated with a neurological deficit unless translation occurs.

A V-Y advancement of the gastrocnemius would be required if the gap is 6 cm. Repair of an Achilles tendon is usually undertaken with the patient prone, and an incision just medial to midline to avoid sural nerve injury. Immobilizing the foot in 20
plantarflexion allows maximum skin perfusion over the tendon, by decreasing skin tension, and protects the tendon repair. A direct repair is usually possible if the gap is less than 3 cm. A V-Y advancement of the gastrocnemius can be considered if the gap is between 3 and 5 cm, and if greater than 5 cm, a flexor hallucis longus transfer must be considered.

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.

Bilateral fractures occur in 5–10% of cases. Calcaneal fractures occur after an axial load and are bilateral in 5–10% of cases. They are associated with a spinal injury in about 10%. The majority (75%) are intra-articular, and result in a decreased Bohler’s angle (line drawn by connecting the anterior process, highest point on posterior articular surface and superior tuberosity on the lateral radiograph). The Sanders classification is based upon the number and location of articular fragments on the coronal CT scan, with four types, based on the number of fragments of the posterior facet, with displacement of 2 mm considered significant. The wound complication rate is reported to be up to 30%.

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.

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.

Superior placement of the glenoid component. Superior positioning of the glenoid component as well as superior tilt of the component with respect to the scapula can lead to scapular notching, with a resultant poorer outcome. Inferior tilt and proper placement of the glenoid component protects against notching.

Intermediate dorsal cutaneous branch of the superficial peroneal nerve. The two most common portals used in ankle arthroscopy are the anterolateral and anteromedial. The anterolateral portal is established medial to the lateral malleolus and lateral to the peroneus tertius, and risks injury to the intermediate dorsal cutaneous branch of the superficial peroneal nerve. The anteromedial portal is made lateral to the medial malleolus and medial to tibialis anterior, and risks injury to the saphenous nerve and vein. The anterocentral portal, medial to extensor digitorum longus and lateral to extensor hallucis longus, risks damaging the deep peroneal nerve and anterior tibial artery.

Tunnel placement is less important when using synthetic grafts. A femoral tunnel in the roof of the notch (12 o’clock position) would result in a vertical graft. This would restore anteroposterior stability, but would not impact on the rotational stability. Several reference points are described for the tibial tunnel. These include the anterior border of the posterior cruciate ligament (10–11 mm anterior to) and the posterior border of the anterior horn of the lateral meniscus (along a line from this point to the tibial spine). Mal-positioning of the femoral tunnel can limit post-operative range of motion; an anterior tunnel could limit flexion and a posterior tunnel could limit extension. Tunnel placement is probably even more important when using synthetic grafts as these are less forgiving of mal-positioning.

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.

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.

Revision to a constrained knee prosthesis. Medial collateral ligament deficiency in a total knee replacement may present with pain, instability or both. A knee brace may provide a temporary solution. Repair or reconstruction of the ligament is unlikely to provide the necessary valgus resistance, and the only sensible option is to revise to a constrained prosthesis. There is some debate as to whether this can be a high posted design (non-linked) or whether it has to be hinged. 112 a. Sural. b. Saphenous. c. Tibial. d. Deep peroneal. e. Superficial peroneal. the most important factor in predicting a satisfactory outcome? a. Severity of initial injury. b. The state of the articular cartilage. c. The age of the patient. d. The smoking status of the patient. e. Whether or not a compensation claim is involved. a. Absent fibula. b. Deficient knee ligaments. c. An equinovarus deformity. d. Talocalcaneal coalition. e. Proximal femoral focal deficiency. a. Oligohydramnios. b. Arthrogryposis. c. Congenital talipes equinovarus. d. Tarsal coalition. e. Developmental dysplasia of the hip. performing. The likely diagnosis is? a. Hallux valgus. b. Hallux rigidus. 119

Deficient anterior cruciate ligament. A high tibial, valgus-producing osteotomy, either lateral closing or medial opening, is an effective surgical option for medial compartment osteoarthritis. It suits younger patients with varus alignment, fixed flexion less than 15º and flexion greater than 90º. Contraindications include lateral compartment degeneration, loss of a significant portion of the lateral meniscus, lateral tibial subluxation of greater than 1 cm, medial compartment bone loss, symptomatic patellofemoral degeneration, inflammatory arthritis and poor patient compliance. Anterior cruciate ligament deficiency alone is not a contraindication.

Nail patella syndrome. This syndrome is a result of an abnormality on chromosome 9. Patients may have subluxed or dislocated radial heads and never realize they have a problem until they have an X-ray. The syndrome can include abnormalities of the patella and nail growth, generalized ligamentous laxity and bony exostoses.

Changing to a finer pitch. The relationship of the inner to the outer diameter affects pull-out strength – a relatively smaller inner (or larger outer) diameter increases pull-out strength. A finer pitch allows for more threads to grip each cortex increasing pull-out strength. A locking screw/plate combination may increase the pull-out strength of the construct as a whole but the addition of the locking thread has no effect on the screw in isolation. 240

In the prediction of malunion, the presence or absence of comminution is not an important factor. Important factors in predicting early and late instability and radiographic outcome after distal radial fractures include patient age, metaphyseal comminution of the fracture and ulnar variance. Dorsal angulation has not been shown to be significant in the prediction of radiographic outcome for displaced fractures.

Ischial tuberosity. The pelvic apophyses appear in early adolescence and fuse around age 14–16. Avulsions therefore occur most commonly in teenagers during sporting activities. Football and gymnastics are commonly associated with these injuries. Avulsion of the ischial tuberosity is the commonest type caused by sudden hip flexion with knee extension such as striking a football. The diagnosis is usually apparent on plain radiographs. Avulsion injuries are best treated conservatively with a gradual return to sporting activity after 3 months. Unrecognized avulsions may heal with abundant callus and can be misdiagnosed as bone tumours. The situation can be clarified with CT or MR imaging.

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.

C-reactive protein (CRP) >20. Due to the rapid chondrolytic effect of pus within the joint, pyogenic septic arthritis of the hip in children represents a surgical emergency. It can be difficult to distinguish a septic hip from other causes of hip pain in children. In such cases, whilst clinical suspicion remains of paramount importance, Kocher’s diagnostic algorithm is a useful tool. The four diagnostic criteria are non-weight-bearing, ESR >40, WBC >12 and fever. The predicted risk of a septic arthritis varies with the number of positive criteria. The algorithm has been tested retrospectively and prospectively. In the prospective validation study the probabilities were lower: Number of criteria met Chance of septic arthritis (original study) Chance of septic arthritis (validation study) 3% 40% 35% 93% 73% 93%

Patella baja. Total knee replacement after a proximal tibial osteotomy presents a number of technical difficulties. Studies have shown that these knee replacements are more prone to complications such as persisting pain, malalignment and infections. Any number of problems can be encountered during surgery, but the most common is patella baja, seen with both opening and closing wedge osteotomies, although more commonly in the latter. Another important consideration is the change in tibial slope as closing wedge tends to decrease the posterior tibial slope and opening wedge increases it.

Quadrigia effect. Though this was a bony avulsion it must be thought of like any other FDP tendon injury. In this case because of the proximal migration of the tendon it was probably repaired tightly with an adhesed improperly tensioned FDP. Because the adjacent remaining fingers share a common muscle belly, they cannot flex entirely (quadrigia effect).