Tendon Injuries and Finger Deformities Flashcards
Apply the concave-convex rule to the MCP/PIP/DIP
Concave distal portion on convex proximal portion = joint surface and bone shaft moving in the same direction.
What type of joint is the DIP?
Hinge type, does flexion and extension
What structures at the digits connect to the Distal Phalanx?
Flexor Digitorum Profundus & Terminal Tendon of the Dorsal Apparatus
What happens anatomically to cause a mallet finger deformity?
Avulsion or laceration of the terminal tendon insertion of the dorsal apparatus.
What would you notice clinically? with Mallet finger
A droop of the distal phalanx of the finger and an inability to extend it.
What is the conservative treatment option? for Mallet finger
Splinting with the DIP in full extension or slight hyperextension x 6 weeks.
What is the non-conservative treatment option? for Mallet finger
Surgical reattachment of the terminal tendon or bony avulsion.
What is the difference between a tendon avulsion and a bony avulsion?
Tendon avulsion involves only the tendon pulley away from or detaching from the bone, versus a bony avulsion when the tendon pulls a chunk of bone away with it. A bony avulsion increases the likelihood that surgery will be needed.
What is something that should be checked at the distal digit with splinting so that further injury is prevented?
Tissue perfusion at the distal digit - make sure blood supply is not being cut off.
Where anatomically does a Boutonniere Deformity occur and what structures are damaged to cause this?
At the DIP joint, causing it to go into hyperextension. This is caused by avulsion or laceration of the central slip of the dorsal apparatus, which in turn causes the lateral bands to slip in a volar direction, eventually pulling the PIP into flexion. A closed avulsion can sometimes take 2-3 weeks to present with the deformity.
What would you notice clinically with Boutonniere Deformity?
Flexion of the PIP with an inability to actively extend it, and hyperextension at the DIP.
What is the Specialty Test for this called
Elson’s Test - Hang fingers off the table and ask the client to extend them at the PIP joint. An inability to do so is a positive test indicating a Boutonniere Injury.
What are the three pathways that a Swan Neck Deformity can occur?
(describe anatomical progression of each)
Untreated or poorly treated Mallet Finger Deformity - laceration or lengthened/lag of terminal tendon causes a laxity of the lateral bands so that they slip dorsally and pull the PIP into hyperextension while the DIP droops into flexion.
Traumatic rupture of the volar plate at the PIP allows the joint to hyperextend and the lateral bands become lax so that the DIP droops into flexion.
Rheumatoid Arthritis erodes the joints in the fingers, enlarging them until the volar plate ruptures causing hyperextension of the PIP and beginning the process listed above.
What would Swan Neck Deformity look like?
DIP flexion and PIP hyperextension.
What is one of the primary treatment concerns after a flexor tendon laceration in the hand?
Adhesions within the flexor sheath is the primary concern.
Anatomically, how do the flexor tendons travel from the forearm to their insertion sites?
Through the carpal tunnel and under the palmar fascia within a synovial sheath, and then into each digit through the flexor tendon sheath within a series of pulleys.
What is bowstringing and what would cause this?
Bowstringing is a pulling away of the flexor tendons from the bones and this is caused by damage to or laceration of the A2 and/or A4 pulleys primarily.
How could an open laceration occur?
Cutting an avocado and trying to take the pit out, the knife could slip and cut the palmar side of the fingers and into the sheath and tendons.
How could a closed tendon injury occur?
On the dorsal side, jamming a finger playing basketball can cause a Mallet Finger. On the flexor/volar side, rock climbing or grabbing the jersey of another football player while they try to run from you can cause Jersey Finger.
What would additional concerns be for a client who sustained an open tendon laceration?
Infection, laceration of nerves and blood vessels
What happens anatomically to cause a Jersey Finger?
An avulsion of the FDP from the distal insertion so that the client can no longer flex the finger at the DIP.
Does Jersey finger Can this be splinted for healing similar to the way a Mallet Finger can be?
No, this requires surgery to fix. The FDP is contractile tissue and will pull away from the insertion site toward Camper’s Chiasm when it detaches from the distal phalanx.
Why is the balance of the number of strands in a flexor tendon suture important?
More strands increase the strength of the repair and decrease the risk for rerupture as well as gapping, but also increase the bulk of the scar so that it may not be able to fit through the flexor sheath and pulleys for needed glide of the flexor tendons. Fewer sutures decrease the bulk of the scar, but also make the risk for rerupture higher.
What is a Dorsal Blocking Splint?
A splint that is placed with the splinting material on the dorsal side of the hand to block digit extension and wrist extension.
Why is the position of the wrist important here?
All of the long finger flexor and extensor tendons cross the wrist, and so motion of the wrist will put tension on those tendons.
What is the benefit to early active motion after a flexor tendon repair and what could potentially be the downsides (2)?
Early active motion decreases the risk for adhesions during healing but increases the risk for rerupture and overlengthening/gapping/lag.
If the rehab after a zone one extensor injury is progressed too quickly, what could happen to the structures that are in the process of repair?
Some additional tension can cause overlengthening which will then cause a lag in the tendon, and too much tension can cause a rerupture of the tendon.
Zone one extensor injury iif progressed too quckly. What would be the long term consequence of this?
A lag in the tendon will cause a loss of active range of motion and potentially deformity. A rerupture will require additional surgery to repair it or will have a permanent loss of function. Additional surgery increases scar tissue and adhesion risk. Untreated or poorly treated mallet finger deformity will progress to swan neck deformity over time.
Why are mallet finger splints often fabricated with the DIP in slight extension?
To decrease the risk for a lag which would lead to Swan Neck Deformity over time.
What is the benefit to immobilization after a tendon repair surgery?
Protection of the healing tissue to decrease the risk for rerupture or overlengthening/gap/lag.
immobilization after a tendon repair surgery? What is the downside?
Adhesions and contracture of tissues
What is the benefit to immediate passive motion in the direction of the repair?
This allows gliding of the tendon to decrease the risk for adhesions, decreases the risk of joint contracture, and does so without putting tension through the tendon.
immediate passive motion in the direction of the repair?
What does it avoid?
Rerupture and overlengthening as well as adhesions and joint contracture.
What is the benefit to early active motion?
The above but also prevents atrophy of the muscles and maintains some functional use.
to early active motion? What is the downside?
Increased tension that could increase the risk of rerupture and overlengthening/lag.
Where is “no man’s land” in the hand?
Zone 2 on the Flexor Side
Which Extensor Zone(s) are located over the joints?
The odd numbered zones
What is the Bunnell-Littler Test for?
To differentiate between DIP/PIP joint contracture and lumbrical contracture
What is the benefit of additional sutures in a tendon versus the potential complication created?
he benefit is added strength to the repair and the potential complication is the added bulk to the scar formation
Which of the following would put the least amount of strain via the flexor tendons after a surgical repair but promote some gliding of the tendons to prevent adhesions from forming?
Passive flexion with unlimited passive extension at the wrist and fingers
Which of the following would put the least amount of strain via the extensor tendons after a surgical repair but promote some gliding of the tendons to prevent adhesions from forming?
Passive extension motion and active flexion within a limited range of motion
Which of the following is an accurate description of how a closed Boutonniere deformity occurs.
Rupture of the central slip insertion allows the dorsal portion of the dorsal apparatus to stretch out so that the lateral bands slip volarly and pull the PIP into flexion rather than extension
What is the concern regarding a Boutonniere deformity that is discovered late, for example 2-3 weeks after the initial injury?
Adhesions and joint contracture may have already begun to form
How does a mallet finger become a swan neck deformity?
When the terminal tendon is ruptured it allows the lateral bands to become slack and slip dorsally, pulling the PIP into hyperextension and eventually rupturing the volar plate
How does RA cause a swan neck deformity?
RA causes the PIP to swell and put pressure on the checkrein ligaments around the volar plate, eventually causing it to become ruptured or loose and allowing PIP hyperextension and resulting DIP flexion with slack lateral bands
Which annular pulley is released surgically to resolve a Trigger Finger?
A1
