CHAPTER 43: Arm, Forearm, and Hand Lacerations Flashcards
TRUE or FALSE?
No distinct threshold for infection from time of injury to closure
TRUE
There is no distinct threshold for infection from time of injury to closure, but wounds sutured >12 hours after injury
TRUE or FALSE?
Agents containing epinephrine cannot be used in digital nerve blocks
FALSE
The belief that a local anesthetic with epinephrine should not be used for digital nerve blocks is without evidence, and clinical observation studies have found agents containing epinephrine safe for digital nerve blocks.
Motor Testing of the Peripheral Nerves of the Upper Extremity (Table 43-1 page 292)
Dorsiflexion of wrist
Radial nerve
Motor Testing of the Peripheral Nerves of the Upper Extremity (Table 43-1 page 292)
Thumb abduction away from the palm
Thumb interphalangeal joint flexion
Median nerve
Motor Testing of the Peripheral Nerves of the Upper Extremity (Table 43-1 page 292)
Adduction/abduction of digits
Ulnar nerve
Tendon which splits and inserts at the PIP joint
Examined by holding all other digits in extension and flexing the PIP joint against resistance
Flexor Digitorum Superficialis
Tendon runs below the FDS past the split to attach at the DIP joint
Examined by holding PIP joint in extension and flexing the DIP joint against resistance
Flexor Digitorum Profundus
Tendon that can be assessed by sequentially flexing the digit at the MCP, PIP, and DIP joints and having the patient extend the digit
Extensor Digitorum
Sensory Testing of Peripheral Nerves in the Upper Extremity (Table 43-2 page 292)
First dorsal web space
Radial nerve
Sensory Testing of Peripheral Nerves in the Upper Extremity (Table 43-2 page 292)
Volar tip of index finger
Median nerve
Sensory Testing of Peripheral Nerves in the Upper Extremity (Table 43-2 page 292)
Volar tip of little finger
Ulnar nerve
Normal two-point discrimination is defined as —?—mm
<6 mm
Good: 6 to 10 mm
Fair: 11 to 15 mm
Poor: >15 mm
The two most important areas to maintain sensation to preserve pinch sensation
Ulnar side of the distal thumb & the radial side of the index volar pad
Test performed to better assess the integrity of the radial and ulnar arteries
Allen test
The test is performed by first instructing the patient to make a fist as tightly as possible. Then, apply digital pressure to both the radial and ulnar artery at the volar aspect of the wrist. Next, while maintaining compression of the radial and ulnar artery, have the patient open the hand—a blanched palm indicates that arterial inflow is occluded. Now release the radial artery and note the time for the hand to return to normal color.
In Allen test, refill times of —?— seconds raise suspicion for a significant vascular injury
> 3 seconds
Use to assess the vascular integrity of an injured arm or leg by the ratio of the systolic blood pressure between the injured and the uninjured side
Arterial pressure index
Is used to exsanguinate the limb and prevent backflow bleeding
Esmarch’s technique
Elevate the injured extremity and apply an elastic bandage starting distally and wrapping proximally to the area where the cuff will be applied. The cuff is applied around the upper arm and inflated to pressures above the systolic blood pressure of the patient, but not to exceed 250 mm Hg (33 kPa). The cuff tubing is clamped with a hemostat instead of closing the air release valve to prevent slow air leakage. The maximum cuff inflation time is limited to 30 minutes to avoid ischemic damage to the distal muscles and nerves.
Can be done to determine extension of injury into the joint capsule
Saline Load Test
TRUE or FALSE?
No advantage of adding methylene blue to the injected saline in saline load test
TRUE
There is no advantage of adding methylene blue to the injected saline in saline load test, and it may affect operative management by staining the intra-articular surfaces.
Uncomplicated hand lacerations are those that —?—
(1) Not caused by a human or animal bite
(2) Not complicated by a fracture through bone or a joint
(3) Not involve tendons, bones, large vessels, or nerves
(4) No severe soft tissue damage or maceration
Major issues in upper arm & elbow lacerations
(1) Arterial laceration
(2) Nerve laceration
(3) Elbow joint penetration
Most common bacterial species isolated from human bite wounds
Staphylococcus aureus
Inability to extend the DIP joint, resulting in the joint being held in flexion
Mallet finger deformity
Hyperextension of the proximal interphalangeal joint resulting from unrepaired mallet finger deformity, caused by the complete disruption of the terminal extensor mechanism and subsequent proximal and dorsal displacement of the lateral bands
Swan neck deformity
Hyperflexion of the PIP joint with hyperextension of the DIP joint
Boutonniere deformity
The strongest contraindications to replantation of amputated digit
Crush & avulsion injuries
Suspected when static two-point discrimination is distinctly greater on one side of the volar pad than the other, or when it is >10 mm
Digital nerve injuries
TRUE or FALSE?
Skin grafting is successful in digital tip injury with even with a significant loss of tissue at the fingertip exposes the distal phalanx tuft
FALSE
Skin grafting will be unsuccessful if a significant loss of tissue at the fingertip exposes the distal phalanx tuft, as bone does not provide adequate vascularity to support donor tissue
Digital tip amputations defined by the retention of the neurovascular bundle as well as portions of the underlying bone
Incomplete digital tip amputations
TRUE or FALSE?
Replantation of a complete amputation distal to the lunula is not usually advocated for adults
TRUE
Replantation of a complete amputation distal to the lunula is not usually advocated for adults because the procedure is technically demanding and has a generally poor prognosis
Structure made by the nail, nail bed, and surrounding soft tissue
Perionychium
Nail structure made up of the germinal and sterile matrices
Nail bed
Begins at the proximal base of the nail (typically 3 to 5 mm proximal to the eponychium) and extends to the lunula
Germinal matrix
Most common nail injury due to closure of the fingertip in a door and is usually located at the distal portion of the nail bed
Injury to the perionychium
TRUE or FALSE?
Simple trephination produces a good to excellent outcome depending on the subungual hematoma size, injury mechanism, or the presence of fracture
FALSE
Simple trephination produces a good to excellent outcome in most patients regardless of subungual hematoma size, injury mechanism, or the presence of fracture.
Nail removal in nail bed injuries is recommended only if with —?—
Partial nail avulsion OR surrounding nail fold disruption
