Q-141. A 15-year-old boy presented with painful swelling over the left shoulder. Radiograph of the shoulder showed an osteolytic area with stippled calcification over the proximal humeral epiphysis. Biopsy of the lesion revealed an immature fibrous matrix with scattered giant cells. Which of the following is the most likely diagnosis?
a) Giant cell tumor
b) Chondro-blastoma
c) Osteosarcoma
d) Chondro-myxoid Fibroma
Answer: Chondro-blastoma
Explanation:
Chondro-blastomas are rare benign cartilaginous neoplasms that characteristically arise in the epiphysis or apophysis of a long bone in young patients (< 20 years of age). Despite being rare, they are one of the most frequently encountered benign epiphyseal neoplasms in skeletally immature patients. Clinical presentation is non-specific and may include joint pain, muscle wasting, tenderness, and swelling or local mass. Microscopically they are composed of chondroblasts, chondroid matrix, and cartilage with occasional giant multi-nucleated cells. Surrounding the chondroblasts, which are typically polyhedral cells, is thin calcification which resembles chicken-wire. Chondro-blastomas are seen as well defined lytic lesions, with either smooth or lobulated margins with a thin sclerotic rim, arising in the epiphysis or apophysis of long tubular bone such as the femur, humerus, or tibia. Internal calcifications can be seen in up to 40-60% of cases. A joint effusion may be seen in some patients. Treatment typically consists of curettage and packing of the resulting cavity with either bone or bone cement (poly-methyl-methacrylate). Radiofrequency ablation has also been used. Unfortunately due to their proximity to the articular surface and growth plate complete eradication is difficult. As a result recurrence rates are relatively high (8-20%) and injury to the growth plate may result in growth arrest and limb-length discrepancy. Q-142. De Quervain’s disease classically affects the: a) Flexor pollicis longus and brevis b) Extensor carpi radialis and extensor pollicis longus c) Abductor pollicis longus and brevis d) Extensor pollicis brevis and abductor pollicis longus Answer: Extensor pollicis brevis and abductor pollicis longus Explanation: De Quervain’s disease is a painful inflammation of the common sheath of extensor pollicis brevis and abductor pollicis longus tendons in the thumb that extend to the wrist (tenosynovitis). The swollen tendons and their coverings rub against the narrow tunnel through which they pass. The result is pain at the base of the thumb and extending into the lower arm. Finkelstein’s test is used to diagnose De Quervain’s syndrome in people who have wrist pain. Q-143. The pain around the hip with flexion, adduction & internal rotation of lower limb in a young adult after a road traffic accident is suggestive of: a) Intra-capsular fracture of the femoral neck b) Extra-capsular fracture of the femoral neck c) Posterior dislocation of hip d) Anterior dislocation of hip Answer: Posterior dislocation of hip Explanation: Posterior dislocation of the hip- Adduction, Internal rotation and flexion Anterior dislocation of the hip- Abduction, External rotation and flexion Fracture neck of femur- Adduction, External rotation and flexion Q-144. All of the following are complications of supra-condylar fracture of humerus in children, except; a) Compartment syndrome b) Myositis ossificans c) Mal-union d) Non-union Answer: Non-union Explanation: Simple supra-condylar fractures are typically seen in younger children, and are uncommon in adults; 90% are seen in children younger than 10 years of age, with a peak age of 5-7 years Typically supra-condylar fractures occur as a result of a fall on a hyper-extended elbow. Complications: Mal-union (Commonest complication)- resulting in cubitus varus (varus deformity of the elbow, also known as gunstock deformity) Ischemic contracture (Volkmann contracture) due to damage / occlusion to the brachial artery and resulting in volar compartment syndrome Damage to the ulnar nerve, median nerve (Most common injured nerve) or radial nerve Myositis ossificans Q-145. In Bankart’s lesion involves which of the following part of glenoid labrum? a) Anterior part b) Posterior part c) Antero-superior part d) Antero-inferior part Answer: Antero-inferior part Explanation: A Bankart’s lesion results from detachment of the anterior inferior labrum from the underlying glenoid. A Bankart’s lesion is usually as a result of previous anterior shoulder dislocation, and is associated with matching humeral lesion: the Hill-Sachs defect. Q-146. Osgood Schlatters disease involves a) Tibial tuberosity b) Femoral condyle c) Lateral malleolus d) Medial malleolus Answer: Tibial tuberosity Explanation: Osgood Schlatters disease is a traction phenomenon resulting from repetitive quadriceps contraction through the patellar tendon at its insertion upon the skeletally immature tibial tubercle. This occurs in preadolescence during a time when the tibial tubercle is susceptible to strain. OSD is a very common cause of knee pain in children aged 10-15 years. Q-147. Charlie Chaplin gait is seen in a) Congenital coxa vara b) Tibial torsion c) Genu valgus d) CDH Answer: Tibial torsion Explanation: Charlie - Chaplin gait: Occurs in tibial torsion. Circumduction gait: Occurs in hemiplegia High stepping gait: Occurs in foot drop Q-148. Keller’s operation done for a) Hallux valgus b) Hallux varus c) Genu varus d) CTEV Answer: Hallux valgus Explanation: The Keller procedure is an excision arthroplasty of the 1st MTP joint, which can be used for both Hallux rigidus and valgus. Hallux valgus is considered to be a medial deviation of the first metatarsal and lateral deviation and/or rotation of the hallux, with or without medial soft-tissue enlargement of the first metatarsal head. Q-149. Hawkins sign denotes a) Retained vascularity b) Decreased vascularity c) Non union d) Avascular necrosis Answer: Retained vascularity Explanation: The Hawkins sign is a subchondral radiolucent band in the talar dome that is indicative of viability at 6 to 8 weeks after a talus fracture. It is visible in the anterior-posterior view. The Hawkins sign is a good indicator of talus vascularity following fracture. Q-150. Tumor sensitive to NSAID is a) Osteosarcoma b) Osteoclastoma c) Osteoid osteoma d) Bone cyst Answer: Osteoid osteoma Explanation: Osteoid osteoma is a benign osteoblastic tumor. Osteoid osteoma can occur anywhere. Osteoid osteoma is reported to occur in the cortex of the shafts of long bones. The lower extremities are the most common sites of osteoid osteomas. It can cause pain (usually worse at night, reflecting increased nocturnal prostaglandin-mediated inflammation). Pain is typically relieved by mild NSAIDs that target prostaglandins. Characteristic appearance on imaging studies is a small radiolucent zone surrounded by a larger sclerotic zone.