6. Spine MCQs

A 25-year-old male presents with chronic pain and stiffness in his right lower extremity. Radiographs show linear, dense cortical thickening along the medial aspect of the femur and tibia, resembling 'dripping candle wax.' This condition typically follows which distribution pattern?

A 5-year-old boy presents with left shoulder asymmetry. Physical examination reveals an elevated and hypoplastic left scapula with restricted shoulder abduction. If an omovertebral bone is identified on radiographs, which of the following associated regional anomalies must be most carefully evaluated?

A 6-year-old girl is brought in because her left shoulder sits higher than her right, with limited glenohumeral abduction. A palpable bony bridge connects the cervical spine to the scapula. This deformity results from a failure of which developmental process?

Which of the following classical "determinants of gait" primarily functions to limit the maximal upward vertical excursion (peak) of the body's center of mass during the mid-stance phase?

A 6-year-old child with spastic diplegic cerebral palsy presents with a severe crouch gait pattern. This pattern is primarily characterized by excessive knee flexion during stance. Which of the following secondary pelvic deviations is most typically associated with crouch gait due to hamstring tightness?

In a standing long-leg anteroposterior radiograph of a normally aligned adult lower extremity, where does the mechanical axis line (drawn from the center of the femoral head to the center of the ankle plafond) pass in relation to the knee joint center?

A patient with symptomatic cerebral palsy exhibits a 'crouch gait'. Surgical correction often targets hamstring tightness. If isolated hamstring lengthening is performed without addressing other concurrent deformities, which of the following is a common postoperative complication?

A 9-year-old boy with normal intelligence presents with short stature, severe genu valgum, and a barrel chest.

He reports recent clumsy gait and tingling in his hands. What is the most critical radiographic evaluation required immediately?

A 3-year-old child presents with coarse facial features, severe corneal clouding, hepatosplenomegaly, and a prominent thoracolumbar kyphosis (gibbus deformity). Which accumulated glycosaminoglycans are most likely to be found in the urine?

In a patient with Progressive Diaphyseal Dysplasia (Camurati-Engelmann disease), which of the following extra-appendicular manifestations is most commonly responsible for significant morbidity?

A 6-year-old child with normal intelligence presents with short stature, severe knock-knees, and a waddling gait. Radiographs reveal platyspondyly and a hypoplastic odontoid.

Which of the following enzyme deficiencies is the primary cause of this condition?

A 6-year-old boy with normal intelligence presents with severe genu valgum, short trunk dwarfism, and a waddling gait. Radiographs reveal platyspondyly with central anterior beaking of the vertebrae and severe odontoid hypoplasia. Urine spot testing is positive for keratan sulfate. Which enzyme is most likely deficient in this patient?

A 6-year-old boy with short trunk dwarfism and normal intelligence presents for evaluation. Radiographs demonstrate severe platyspondyly, anterior central vertebral beaking, and odontoid hypoplasia. What is the underlying enzyme deficiency?

A 6-year-old boy with a known diagnosis of Morquio syndrome (MPS IV) presents for orthopedic evaluation. Which of the following screening examinations is most critical to prevent a catastrophic complication in this patient?

What is the characteristic spinal deformity finding associated with Hurler syndrome (MPS I)?

A 6-year-old boy with a known diagnosis of Morquio syndrome (MPS IV) presents for an orthopedic evaluation. He has pronounced genu valgum and a short trunk.

Which of the following is the most critical screening evaluation required before he undergoes any elective surgical procedure?

A 6-year-old child presents with short-trunk dwarfism, knock knees, and a barrel chest, but possesses normal intelligence. Cervical spine radiographs reveal atlantoaxial instability. A diagnosis of Morquio syndrome (MPS IV Type A) is suspected. Which specific lysosomal enzyme is deficient in this patient?

A 2-year-old boy presents with corneal clouding, coarse facial features, severe kyphosis, and progressive intellectual disability. Urinary tests reveal high levels of dermatan sulfate and heparan sulfate. What is the inheritance pattern and deficient enzyme for this condition?

A 7-year-old child with Morquio syndrome presents to the orthopedic clinic with increasing clumsiness, hyperreflexia, and a positive Babinski sign.

What is the primary etiology of the neurologic deterioration in this patient?

A 6-year-old boy presents with short-trunk dwarfism, knock knees, and normal intelligence. Radiographs demonstrate platyspondyly with central anterior beaking.

What is the most life-threatening orthopedic complication associated with this specific metabolic disorder?