Questions from 1 to 20

choose the single best answer

LIBYAN ORTHOPAEDIC BOARD

APRIL 2021

01] The following are advantages of closed reduction and Intra-medullary fixation of clavicle middle third fractures except one: a) less soft-tissue disruption b) less prominent hardware c) avoids the supra-clavicular cutaneous nerves commonly injured d) bio-mechanically superior to plating

02] During lumbar decompression at L4/5, which of the following decompression techniques will destabilise the spine and require a L4/5 fusion. a) Removal of > 50% of the L4/5 nucleus pulpusus b) Removal of the L4 and L5 spinous process and interspinous ligament c) A medial facetectomy removing 20% of the right L4/5 facet joint d) Bilateral resection of the L4 inferior articular process

03] Becker Muscular Dystrophy is different from Duchenne dystrophy in one of the followings: a) It is sex-linked recessive b) CPK is elevated c) Calf pseudohypertrophy is present d) Dystrophin protein is decreased instead of absent

04] The elements chromium, molybdenum, and cobalt are basic components of which of the following implant materials? a) Tantalum b) Cobalt alloy c) Stainless steel d) Aluminum oxide

05] A 59-year-old women with known metastatic lung cancer presents with acute left hip pain with ambulation, as shown in Figure shown. She previously underwent a right lung lobectomy 2 years ago, which has been complicated by chronic chest pain. Her oncologist predicts an estimated life expectancy of 12-18 months. She currently lives independently and walks for 2 hours per day. What would be the most appropriate treatment and rehabilitation plan? a) Radiation therapy; partial weight bearing with crutch assistance b) Prophylactic intra-medullary nailing; non-weight bearing with crutch assistance c) Prophylactic intra-medullary nailing; full weight bearing with a walking aid d) Long stemmed total hip arthroplasty; full weight bearing with walker assistance

06] Which of the following factors is the best predictor of successful non-operative management of an osteochondritis dissecans lesion in the knee? a) Location in the knee b) Open femoral physis c) High signal behind the lesion on MRI d) Articular cartilage thickness

07] Which of the following answers represents the ratio of growth from the proximal and distal growth plates in a humerus, respectively? a) 80:20 b) 60:40 c) 50:50 d) 40:60

08] An orthopaedic surgeon meets with an attorney because a malpractice claim has been filed against him. Which of the following diagnoses is most likely to result in a successful malpractice claim? a) Femur fracture b) Total hip arthroplasty c) Compartment syndrome d) Herniated intervertebral disc

09] A 55-year-old patient presents with lower lumbar back pain. A lateral radiograph of the L3 vertebral bone is shown in Figure A. Figure B and C are pre-operative biopsies. From the following options, what is the most likely diagnosis? a) Osteoblastoma b) Chondrosarcoma c) Giant Cell Tumour d) Osteoblastic osteosarcoma B

CA

10] Which of the following has been shown to increase the rate of failure of cemented femoral components in total hip arthroplasty? a) Smoother implant corners b) Calcar contact of the collar c) Stems that are precoated with polymethylmethacrylate. d) Stem material with a Young's modulus higher than 115 GPa.

11] A study was designed to measure the benefit of subacromial corticosteroid injections. Participants were randomised to methyl prednisolone acetate 40 mg with lidocaine 1% or lidocaine 1% alone. The participants were not provided with information of their treatment allocation. The subacromial injection was prepared and administered by a single orthopaedic surgeon. Results were collected by the orthopaedic surgeon using clinical and patient satisfaction outcome scores at 6, 12, and 24 weeks. Which of the following would best describe this type of study? a) Double blinded randomised and controlled study b) Retrospective study c) Prospective cohort study d) Single blinded randomised study

12] A paediatric patient has just been diagnosed with osteomyelitis of the femur. All of the following are risk factors for the development of deep venous thrombosis EXCEPT? a) CRP > 6 b) Surgical treatment of osteomyelitis c) Methicillin-resistant staphylococcus aureus d) Fever of greater than 38.5 degrees Celsius

13] A 3-year-old male has a refusal to move his left elbow after his mother grabbed his arm and attempted to lead him across the street. Physical exam demonstrates guarding of the extremity with the elbow held in flexed and pronated position. A lateral radiograph is shown in Figure below. What is the most appropriate first step in management? a) Aspiration of the elbow joint with blood cultures b) Closed reduction via supination and flexion c) Closed reduction via longitudinal traction d) Placement into long arm splint with no reduction required

14] This 20 year-old male has multiple painless bony outgrowths on bilateral upper and lower limbs since childhood (radiographs and photo below). His brother and his father also suffers from the same condition.What is the diagnosis? a) Enchondromatosis b) Metachondromatosis c) Langer-Giedion syndrome d) Hereditary Multiple Osteochondromas

15] A 7-year-old boy who underwent retrograde elastic nailing of a femoral shaft fracture. What is the most common problem following this procedure? a) Rotational malalignment b) Unacceptable shortening c) Osteonecrosis of the femoral head d) Persistent pain and irritation at the nail insertion site

16] A 14-year-old boy sustains presented with Type III Ogden of tibial tubercle fracture.He subsequently develops compartment syndrome and requires fasciotomy. Injury to what artery is most likely responsible? a) Anterior tibial recurrent b) Middle geniculate c) Posterior tibial d) Peroneal

17] All of the following are true regarding osteocalcin EXCEPT: a) It is the most prevalent non-collagenous protein in bone b) It is considered a marker for osteoblast differentiation c) It is a glycoprotein that binds calcium d) Higher levels are correlated with increases in bone mineral density during osteoporosis treatment

18] The anterior Smith-Peterson approach to the hip uses a surgical plane between which of the following deep muscles following dissecting through the superficial muscles of sartorius and tensor fascia lata as illustrated below? a) Gluteus maximus Gluteus medius b) Gluteus medius and Rectus femoris c) Adductor brevis and Adductor longus d) Rectus femoris and Adductor longus

19] A 36-year-old male presents with right knee pain that is progressively worsening over the past 6 months. He is unable to perform his occupation as a construction worker. He denies constitutional symptoms. The patient had an effusion that was drained by his general practitioner 2 months ago.On examination there is an effusion in the knee and there is tenderness along the para-patellar region. He has full knee extension and flexion, but open chain knee extension exacerbates his pain. His Lachman examination demonstrates 3 mm of anterior translation with an endpoint noted. A radiograph is shown in Figure A and MRI images are shown in Figure B and C. What is the next most appropriate step in management? a) Arthroscopic or open resection of the lesion b) Arthroscopic or open plica removal and lateral retinacular release c) Neoadjuvant chemotherapy, surgical resection, adjuvant chemotherapy d) Neoadjuvant external beam radiation, wide surgical resection, and adjuvant chemotherapy

A B C

20] A 53-year-old male labourer presents to his primary care physician with complaints of acute onset of left knee pain. He has had mild episodes of knee pain in the past and is two years status post a left partial medial meniscectomy. He has had mild relief with the use of anti-inflammatories. His past medical history is significant only for hyperparathyroidism and mild hypertension. He denies any fevers or chills. His exam reveals a moderate knee effusion and diffuse pain and tenderness with palpation and range of motion. Weight-bearing radiographs are shown below. The most likely aetiology of the patient's knee pain is characterised by which finding? a) Recurrent hemarthroses b) Destructive pannus formation c) Deposits of monosodium urate crystals d) Deposits of calcium pyrophosphate-dihydrate crystals