Orthopedic Trauma MCQs & Clinical Insights: Advanced Exam Preparation

Place blocking screws medial and posterior to the nail. Use a nail with a Herzog curve proximal to the fracture site.

Place blocking screws medial and posterior to the nail. Use a nail with a Herzog curve distal to the fracture site.

Place blocking screws lateral and posterior to the nail. Use a nail with a Herzog curve proximal to the fracture site.

Place blocking screws lateral and posterior to the nail. Use a nail with a Herzog curve distal to the fracture site.

Place blocking screws lateral and anterior to the nail. Use a nail with a Herzog curve proximal to the fracture site. Proximal tibial fractures develop an apex anterior (procurvatum) and valgus malalignment. Blocking (poller) screws should be placed in the concavity of the deformity, thus posterior and lateral to the nail. The Herzog curve should be proximal to the fracture site. Up to 58% of proximal tibial fractures are malaligned. Malalignment arises because the nail fits loosely in the wide metaphyses and cannot control alignment. Without close fit of the nail at the fracture site, the nail will not align the fracture independent of a stable reduction and careful nail path. Blocking screws serve to reduce the size of the proximal metaphyseal canal and guide final nail passage. Stinner et al. discuss strategies in proximal tibial fracture nailing. They describe an accurate starting point (using the twin peaks AP view or fibular bisector AP view, and flat plateau lateral view). They emphasize fracture reduction prior to reaming and implant placement. Hiesterman reviewed nailing of extra-articular proximal tibial fractures. Techniques described include blocking screws, unicortical plating, using a universal distractor, nailing in flexion/locking in extension, semiextended nailing (including percutaneous suprapatellar quads-splitting approaches), multiple proximal interlocking screws (>=3). Illustration A shows placement of a coronal blocking screw. Illustration B shows placement of a sagittal blocking screw. Illustration C shows the effect of the Herzog curve. A more distal Herzog curve leads to a "wedge" effect and fracture displacement whereas a proximal Herzog curve contains the fracture. The "wedge" effect occurs as the nail is seated and impinges on the posterior cortex of the distal segment accentuating an apex anterior deformity because of the effective widening of the nail above the bend and posterior force on the distal segment to match the nail shape. Incorrect Answers: Answers 1, 2, 4, 5: Blocking screws in the proximal fragment should be lateral and posterior to the nail. The Herzog curve should be proximal to the fracture site. What would be the most appropriate surgical indication for transferring fascicles of the ulnar nerve to the motor nerve of the biceps and fascicles of the median nerve to the motor nerve of the brachialis? ](http://www.orthobullets.com/trauma/1008/brachial-plexus-injuries)