Hand Injuries Flashcards
How many bones are in the hand?
27 bones - 14 phalanges, 5 metacarpals, 8 carpal bones.
Metacarpal and phalangeal heads are __ with the bases __, midsection called the __?
Heads are distal with the bases proximal, midsection is called the shaft.
Name the 8 carpal bones?
Scaphoid-Lunate-Triquetrum-Pisiform.
Trapzium-Trapezoid-Capitate-Hamate.
Run through the palmar surface of the hand?
Refer to slide 6 of hand injuries.
What is the FDS and what does it do?
Flexor Digitorum Superficialis- superficial finger flexor.
Flexes the PIP and weakly flexes the MCP.
Where does the FDS bifurcate and insert?
Bifurcates at base of proximal phalanges and inserts at palmar aspect of the base of the middle phalanges.
How do you test the FDS or the FDP?
Place the pt’s hand dorsally on a flat surface, hold the proximal (FDS) or distal (FDP) phalanx and ask the pt to flex the finger.
What is the FDP and what does it do?
Flexor Digitorum Profundus.
Flexes the DIP and some PIP Flexion.
Where does the FDP bifurcate and insert?
Bifurcates the same as the FDS (near base of proximal phalanges) and inserts at base of the Distal Phalanges.
Why does inflammation or swelling present more on the dorsal side of the hand?
Lymphatic and venous drainage is mostly dorsal.
Extrinsic muscles of the hand…
proximal attachments in the forearm and distal attachments in the wrist or hand.
Intrinsic muscles of the hand…
proximal and distal attachments are within the hand.
Any Open, Intra-articular, Displaced or Rotational Fx requires what?
Ortho (or Plastics) consult - may be OR bound.
How much of the intra-articular surface must be involved to have an ortho consult?
1/3rd.
What is helpful when reducing a hand displacement for fracture?
Hematoma Block
- 3-5 cc of 1% Lidocaine injected into Fx sit w/a 25 needle.
- WAIT 15 mins to reduce.
Why no EPI for hand digital blocks?
EPI is a powerful vasoconstrictor; there are lots of small vessels that when vasoconstricted can cause significant necrosis.
Untreated Scaphoid fracture will lead to?
AVN -avascular necrosis.
What makes up the anatomical snuff box?
Extensor Pollicis Longus and Brevis, Abductor Pollicis Longus, Scaphoid makes up most of the floor along with the trapezium - the radial artery runs through it.
What is a Swan Neck Deformity?
Hyperextended PIP and Flexed DIP usually seen with chronic, non-traumatic arthritis.
Thumb laceration over the thenar eminence may involve what nerve? What may happen if untreated?
may involve the median nerve; untreated may lead to “Ape Hand,” which is thenar atrophy and loss of opposition.
Hypertrophic scars and contractures result from?
A perpendicular laceration of any of the major palmar creases that were not carefully realigned when suturing?
What is a paronychia? Eponychia?
A superficial infection or abscess over the lateral nail fold - Eponychia if infection over proximal nail soft tissue.
MC organism involved in a paronychia or eponychia?
Staphylococcus Aureus.
Treatment of acute and chronic paronychia/eponychia?
Acute - warm soaks, elevation, oral PCN-resistant PCS (dicloxicilin).
Chronic - I and D; usually very painful and swollen.
What is a Local block, Field Block and a Nerve Block?
Local Block - digital block into the wound edge, infiltrate on way out.
Field Block - digital block around something; ex: periauricular.
Nerve Block - complete anesthesia of an entire nerve; requires more lido - avoid injection into nerve itself, always aspirate.
What is a felon of the finger?
An infection that occurs within the closed-space compartments of the fingertip pulp - the swelling leads to intense throbbing pain.
What is Flexor Tenosynovitis?
Infection within the closed space of the synovial sheaths that surround the flexor tendons.
The synovial sheaths lubricate and decrease friction during motion.
Name the 4 Kanavel’s Signs? What does it indicate?
It indicates Flexor Tenosynovitis.
- TTP along the course of the flexor tendon and sheath.
- “Sausage Digit” - symmetric swelling of the finger.
- Pain on passive extension.
- Digit held in flexed posture.
Treatment of Flexor Tenosynovitis?
Admit for IV antibiotics; possible OR for I and D if it progresses.
What is DeQuervain’s Tenosynovitis? How do you treat?
Swelling of the thumb tendons - Abductor Pollicis Longus and Brevis, due to repetitive overuse of thumb.
Treat = rest, ice, NSAIDs, thumb spica splint.
What is the Finkelstein’s Test used for?
If positive, depicts DeQuervain’s Tenosynovitis.
-Thumb is tucked into lightly closed fist, examiner passively ulnar deviates the wrist; if pain produced, +for DeQuervain’s Tenosynovitis.
What is considered “no man’s land” when it comes to tendon lacerations of the palmar surface of the hand?
“No man’s land” = distal palmar crease to PIP crease; many important structures here - if a tendon lac, the vessels and nerves likely damaged.
Which is more easily repairable, flexor tendon or extensor tendon, and why?
Extensor tendon because there is no tendon sheath.
What are ‘notorious’ for becoming infected?
Human bites! such as Clenched fist injuries or “fight bite.”
Why is the procedure ‘Injecting A Joint’ done?
If we suspect communication b/t the outside world and a joint space; typically, involves a laceration over or near a joint space.
-Inject 1% plain lido into joint space.
Results of “Injecting A Joint?”
- When you inject the joint space, IF you see fluid pouring out of the wound during injection, then suspect the joint space is open and involved – the pt will NEED OR irrigation.
- If NO fluid is seen from the wound during injection, the the laceration can be closed after careful exploration and irrigation; will need close f/u.
What is Mallet Finger? Presentation?
Sudden forceful flexion of the DIP; sometimes associated w/an avulsion Fx by the extensor tendon.
Presentation = DIP in flexion.
(ex. when a baseball strikes the tip of the finger and forces it to bend further than it is intended to go).
Treatment of Mallet Finger? Important general rule of thumb?
Treatment = splint DIP in HYPERextension (PIP in flexion, MCP in full flexion as want extensors max stretched) for 6-8 weeks.
Rule of Thumb = if assoc. Fx is >than 1/3 the articular space, then OR.
What is Boutonniere’s Deformity?
Disruption of central extensor tendon just proximal to insertion at base of the middle phalanx.
What is the MOI and presentation of Boutonniere’s Deformity?
MOI is typically a “jersey injury,” where the finger gets caught on someones jersey and the feel a pop sensation. It can also be caused by chronic, nontraumatic arthritis due to erosion of the joint.
Presentation = flexed PIP w/Hyperextension of DIP.
Treatment of Boutenniere’s Deformity?
Splint PIP in extension and DIP and MCP free for 6-8 weeks.
Surgical repair does not shorten healing time.
What is “Trigger Finger” also known as?
Stenosing Tenosynovitis
What is Trigger finger, the cause and the typical presentation?
- Painful finger or thumb - one digit or more; can be bilateral.
- Caused by inflammation of the flexor tendon narrowing the tendon sheath; may be due to a nodule and is typically associated w/repetitive activity (gripping motion).
What is the presentation of Trigger Finger, epidemiology and treatment?
- Presentation = stiffness, catching or locking, snapping or popping sensation; may have a palpable bump.
- Age 40-60, F>M.
- Treatment = splinting, steroid injection, NSAIDs, surgery.
What happens during a High Pressure Injection injury?
The injection of toxic substances into the hand at high velocity; typically from grease guns, paint guns, etc.
The entrance of the wound may be small (appear insignificant) but the damage is far from site of entry, often w/in the fascial planes and sheaths.
Why are high pressure injection injuries worrisome?
Initially, it may not appear severe but over several days, it will worsen and symptoms may increase to include: swelling, pain, vascular compromise and paresthesias.
What is the treatment and complications of high pressure injuries?
Treatment = immediate surgical consult for exploration and irrigation, splint, elevation, tetanus prophylaxis and broad spectrum Abx.
Complications = amputation.
Pros and Cons of reimplantation?
salvaging a functionless, painful digit for cosmetic benefit, often may be the wrong decision for an otherwise healthy and active person.
What are the causes of a Degloving Injury?
Associated with machinery; jewelry may get caught on moving parts and strips bone of soft tissue.
Complication of a Degloving Injury?
Reimplantation is unlikely if proximal to FDS distal attachment, as digit would never bend at PIP.
What is the most important thing about foreign body injuries?
organic material NEEDS to be removed (fish fin, wood, spines, etc), will cause infection. Metals are typically harmless and can remain if not affecting the individual.
What is the aftercare for a F.B injury such as a fish hook?
Explore the F.B. (bait).
Irrigate, leave wound open, Abx ointment, simple dressing, tetanus consideration, F/U.
What is important about examination of the hand?
There are both SENSORY and MOTOR components.
**Always do a Sensory exam BEFORE anesthetics are given! Distal and Proximal to the injury.
What is Stereognosis?
The ability to identify familiar objects placed in the pt’s hand w/o the aid of visualization; needs to be within a reasonable time period.
It tests fine sensation and ability to discriminate (key, coin, paperclip, etc).
How far apart should one feel a two-point discrimination?
5 mm or greater; problematic if can’t distinguish.
What is the Tinel’s test and what is it used for?
Tapping/percussion over the median nerve at the wrist.
Indicates Carpal Tunnel Syndrome if the tapping produces symptoms of severe pain or paresthesia.
Tinel’s at Guyons?
The same as Tinel’s over volar wrist, but over the Guyons Tunnel, which is where the ulnar nerve runs; it is located on volar wrist/hand just radial to the pisiform bone.
Median Nerve Compression Test?
Examiner places external compression manually over the pt’s median nerve for 60 secs - if Sx reproduced, consider positive.
Moberg’s Test?
In 10 sec, 10 objects are picked-up by one hand and placed in a receptacle.
It tests dexterity and observation; may yield info about fine sensory and motor control of both median (opposition) and ulnar (intrinsics) nerves.
Fromet’s Test?
ADDuction by placing a piece of paper b/t the thumb and finger - ask the pt to hold it w/o using the thumb flexors.
It detects motor loss of ulnar nerve.
What is Ulnar Neuropathy?
The loss of finger abduction and adduction (intrinsics); specifically, the inability to form an “O” b/t thumb and index finger.
What is the physical exam presentation of ulnar neuropathy and what other injury is it associated with?
May see hollowing/atrophy of the hypothenar eminence or first dorsal interossei (webspace).
Can be associated with injuries of the ‘funny bone;’ the ulnar nerve is found b/t the medial epicondyle and olecranon and enters the hand w/the ulnar artery.
What is Median Neuropathy?
It causes an inability to flex the thumb, index and middle fingers, weakened pronation, weakened wrist flexion or ulnar-deviated flexion by overcompensation (of ulnar nerve), and loss of thumb opposition; may see thenar atrophy.
The pt will show an inability to “scratch the table top” w/index finger when the palm is palm-down on a table.
What is Radial Neuropathy?
Usually seen with Humoral Fx causing a characteristic “wrist drop,” if radial nerve innervates wrist extensors. May also see decreased extension at MCP joints, as innervates digit extensors.
