Orthopedics

CHAPTER 28
Orthopedics


Joshua Gish and Scott Sexton


Test Taking Tip


Orthopedics is not usually a high-yield topic for the ABSITE, although they will occasionally ask a question related to trauma. Look over injury patterns and know which fractures are associated with each other (eg, calcaneal fractures and spinal compression fractures).


TYPES OF FRACTURES


Which type of fracture is characterized by sharp fragments?


Acute fractures


Which type of fracture is characterized by rounded fragments with callous formation?


Chronic fractures; callous indicates an attempt at healing.


What are “greenstick” fractures?


Incomplete disruptions of all aspects of the bony cortex in children; bone can be bent but not displaced with greenstick fractures.


Which type of fracture occurs through diseased bone (eg, a tumor or osteopenic bone)?


Pathologic fractures


What are fractures called that have a communication to the skin?


Open fractures (sometimes called “compound fractures”)


What type of fracture is caused by rotational forces?


A spiral fracture


What term is given to a fracture that breaks in multiple places?


A comminuted fracture


What is a “butterfly fragment?”


A smaller portion of bone that is separated from the larger portions by comminution; implies greater force and a bending mechanism; must be at least 3 fragments


Define a Monteggia fracture:


Fracture of the proximal one-third of the ulna with associated dislocation of the radial head


Define a Galeazzi fracture:


Fracture of the mid radius with associated dislocation of the distal radial-ulnar joint


Define a Lisfranc injury:


A disruption of the Lisfranc ligament—the ligament binding the first metatarsal to the second


Scaphoid fractures most commonly occur as a result of:


Fall on an outstretched hand


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FIGURE 28-1. Scaphoid fracture: nonunion. (Reproduced from Doherty GM. Current Diagnosis and Treatment: Surgery. 13th ed. www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.)


Where does a scaphoid (navicular) fracture of the wrist classically produce tenderness?


Pain on the radial aspect of the wrist with tenderness over the anatomic snuffbox


Define a Chance fracture:


A distraction-type injury of the spine where the anterior ligament fails under tension; often caused by a seatbelt injury. There is a high likelihood of associated abdominal injury (~60%).


Define a Jefferson fracture:


Burst fracture of C1, the atlas—actually widens the spinal canal; therefore, spinal cord injury is uncommon.


Define a Hangman fracture:


Fracture of the pars interarticularis of C2, the axis, with dissociation of the C2-C3 articulation—has a high incidence of neurologic injury.


Define a clay shoveller fracture:


Avulsion of the lower cervical spinous process—no association with the spinal canal, therefore has no association with neurologic injury


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FIGURE 28-2. Salter-Harris classification of physeal injuries occurring at the zone of provisional calcification of the growth plate. (Reproduced from Doherty GM. Current Diagnosis and Treatment: Surgery. 13th ed. www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.)


What is the “Salter Harris” classification?


It is a classification of physeal fractures in children


Grade 1: Transphyseal parallel to the joint


Grade 2: Fracture extends away from the joint


Grade 3: Fracture extends toward the joint


Grade 4: Fracture crosses the physis from joint to metaphysis


Grade 5: Crush injury to the physis


What is a Holstein-Lewis fracture?


Fracture of the distal third of the humerus resulting in radial nerve entrapment


MECHANISM/TYPES OF INJURIES


What associated injury must be ruled out in posterior knee dislocations?


Popliteal artery injury


What test is indicated in posterior knee dislocations in order to rule out intimal injury?


Arteriography


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FIGURE 28-3. An anteroposterior x-ray of a spiral fracture of the distal third of the humerus. This fracture is called a Holstein-Lewis fracture. It is frequently associated with radial nerve palsy. (Reproduced from Felliciano DV, Mattox KL, Moore EE. Trauma. 6th ed. www.accesssurgery.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.)


What injuries can be associated with supracondylar humerus fractures?


Brachial artery, radial nerve, and/or median nerve (most common nerve is the anterior interosseus nerve, which is a branch of the median nerve)


What injury must you worry about with a midshaft humerus fracture?


Radial nerve injury


What injury must you worry about with an elbow dislocation?


Brachial artery injury


What injury must you worry about with a distal radius fracture?


Median nerve injury


What injury must you worry about with a anterior shoulder dislocation?


Axillary nerve injury


What injury must you worry about with a posterior shoulder dislocation?


Axillary artery injury


What injury must you worry about with a posterior hip dislocation?


Sciatic nerve injury (peroneal division)


What injury must you worry about with a fibula neck fracture?


Common peroneal nerve injury


What is the typical mechanism of action of a calcaneal fracture?


Fall from a height unto outstretched legs


What injuries are associated with calcaneal fractures?


Contralateral foot fractures, pelvic fractures (vertical shear), spinal compression fractures


Name the 3 broad types of pelvic fracture mechanisms:


Anterior-posterior compression, lateral compression, vertical shear


Which is the most common mechanism of pelvic fracture?


Lateral compression


What is the Gustilo-Anderson classification of open fractures?


Table 28-1 Classification of Open Fractures According to Gustilo and Anderson


image


What is the usual surgical treatment for type I, II, and IIIA open fractures of the tibia?


Intramedullary nailing


What is the usual surgical treatment for type IIIB and IIIC open fractures of the tibia?


Some form of external fixation with conversion to a reamed, locked nail within 2 weeks of injury


MANGLED EXTREMITY SEVERITY SCORE


What mangled extremity severity score (MESS) consistently predicts the need for amputation?


MESS >7


How many points do you get on the MESS with low-energy (stab, simple fracture, “civilian” gunshot wound) skeletal and soft tissue injury?


1


How many points do you get on the MESS with medium-energy (open or multiplex fractures, dislocation) skeletal and soft tissue injury?

Aug 13, 2019 | Posted by in ABDOMINAL MEDICINE | Comments Off on Orthopedics
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