ABOS Part I Comprehensive Review - Batch 3

Question 1

A 38-year-old male sustains a highly comminuted, segmental femoral shaft fracture after a high-energy motor vehicle collision. He is otherwise healthy. The orthopedic surgeon opts for intramedullary nailing. Biomechanically, what is the primary advan

Accepted Answer

It acts as a load-sharing device, converting bending moments into axial compression, which is advantageous for comminuted fractures.

Question 2

A 55-year-old male presents with a spiral mid-shaft tibial fracture, classified as an AO/OTA 42-A2. The surgeon plans for intramedullary nailing. Given the fracture pattern, what biomechanical strategy is most crucial to prevent post-operative malrot

Accepted Answer

Employing multiple interlocking screws in different planes at both the proximal and distal fragments.

Question 3

A 72-year-old female with severe osteoporosis sustains a comminuted subtrochanteric femoral fracture. She is treated with an intramedullary nail. During the procedure, the surgeon considers the optimal nail diameter. Biomechanically, what is the most

Accepted Answer

To maximize the area moment of inertia, thereby increasing the bending and torsional stiffness of the construct.

Question 4

A 45-year-old male sustains a transverse mid-shaft tibial fracture (AO/OTA 42-A1). He is treated with an intramedullary nail with static interlocking screws proximally and distally. Six weeks post-operatively, radiographs show minimal callus formatio

Accepted Answer

To allow for controlled axial micromotion at the fracture site, stimulating callus formation.

Question 5

A 28-year-old male presents with a comminuted distal tibia fracture extending into the metaphysis. The soft tissue envelope is compromised due to the open nature of the injury. The surgeon is considering an intramedullary nail. Biomechanically, what

Accepted Answer

IM nails allow for less soft tissue stripping and better preservation of periosteal blood supply, promoting biological healing.

Question 6

A 60-year-old male undergoes antegrade intramedullary nailing for a mid-shaft femoral fracture. Post-operatively, he complains of persistent pain over the greater trochanter. Radiographs confirm that the proximal end of the nail protrudes approximate

Accepted Answer

Impacting the greater trochanteric bursa and surrounding soft tissues, causing irritation.

Question 7

A 40-year-old male sustains a comminuted subtrochanteric femoral fracture. The surgeon chooses a reconstruction (recon) intramedullary nail. What is the primary biomechanical rationale for using a recon nail design in this specific fracture pattern c

Accepted Answer

Recon nails provide multi-planar locking in the femoral head/neck, offering superior stability to the proximal fragment.

Question 8

A 50-year-old male with a history of chronic alcoholism and poor nutrition presents with a nonunion of a mid-shaft femoral fracture treated with an intramedullary nail. Radiographs show a persistent fracture gap and sclerotic bone ends. The nail itse

Accepted Answer

The prolonged, cyclical loading of the implant due to the absence of bone healing.

Question 9

A 32-year-old male sustains a distal tibia fracture with significant metaphyseal comminution and a wide medullary canal proximally. The surgeon plans for antegrade intramedullary nailing. To improve nail centralization and stability in the wide metap

Accepted Answer

To guide the nail into a desired position within a wide canal, improving fit and stability.

Question 10

A 25-year-old male undergoes intramedullary nailing for a mid-shaft femoral fracture. Post-operatively, a lateral radiograph reveals that the nail has a sagittal curvature that does not perfectly match the natural anterior bow of the femur, leading t

Accepted Answer

The 'windshield wiper effect' and potential for malunion.

Intramedullary Nails and External Fixators: Advanced Biomechanics, Design Principles, and Clinical Performance

Orthopedic Fracture Fixation Biomechanics Review: IM Nailing & Plating for ABOS Part I Exam | Part 22142

Key Takeaway