Conditions of the hand Flashcards
What is Dupuytren’s disease- and describe the process of the disease
a benign fibromatosis of the palmar and digital fascia of the hand which develops in the palmar ligaments
It ofen starts with palpable mass in the palm at the level of the sital palmar crease. As it enlarges it forms cords that extend distally and proximally. As they thicken and shorten they cause flexion contractures of the joint
What fingers are most commonly involved in dupuytrens
4th and 5th though all can be involved including the thumb
What conditions are more associated with dyputren’s
- diabetes
- alcoholism
- epilepsy
- smoking
- AIDs
- vascular disorders
what is a ganglion cyst
they are synovial cysts that arise from the synovial lining of either a joint or a tendon sheath.
What are main factors to look for when dianosing a ganglion
a mass that is typically non tender
cosmettically or functionally bothersom
sometimes correlated with antecedent trauma or repetitive microtrauma but often there is no clear cause
well circumscribed lesion with smooth orders and is sometimes multilobuled
if large enough transillumation is diagnostic
what is treatment for a dorsal ganglion
aspiration +- corticosteroid (60-85% cure rate)
surgical excision
What imaging do you need on the hand to assess fracture
tubular skeleton of the hand requires three radiographic views (AP, lateral, and oblique) to accurately assess the position and integrity of these small skeltal untils. Fractures involving a single digit must have at lease anteroposterior and true lateral views of the individual digit.
what other imaging should you get for fractures of the forearm and humerus
radiographs of the joints prox and distal
What is an Essex- Lopresti fracture
radial neck fracture about the elbow with distal radioulnar joint disrpution and possible interosseous membrane injury
what are diaphyseal, metaphyseal or articular fractures
diaphyseal - midportion of the bone
metaphyseal - within the area of the bony flare close to articular surface
- articular when engages with joint surface
what can increase risk of degnerative joint disease post distal radius fractures
increased step off makes it harder for bone to remodel
2mm step off or greater led to DJD in 91% of patients
Though this is not linked to decreased function
Hoe fo you assess rotational deformities
difficult to assess on plain radiogrph
metacarpal or phalangeal fractures are best assessed clinically by asking the patient to simultaneously flex all of the digits. If there is significant overlap then corrective open reduction should be considered
What is a boutoninerre’s deformity and explain why it occurs
Rupture of the central slip
Lateral bands then move volarly and thus cause hyperextension of the DIP, F at PIP and MCP E
What is a swan neck deformity and explain why it occurs
Posterior displacement of the lateral band due to triangular ligament disruption
results in F of DIP, HEP PIP, F of MCP (but this can be mostly negligible)
Explain the extensor mechanism of the hand
Google image and see
What direction do metacrapal fractures angulate and why
dorally due to the unbalanced pull of the interosseous muscles and extrinsic finger flexors on the distal fragment
happens after 30 degs of MC dorsal angulation
intrinsiv muscle shortening and altered muscle tension dynamics lad to increasing grip weakness. There may also be loss of knuckle contours, pseudoclaw and a palpable of visible MC angular deformity on the dorsum of the hand
why are the 4th and 5th MC more tolerant to dorsal angulation
due to increased carpometacarpal flexibility (satisfactory results have been reported with as much as 70 degs of subcapital MC fractures)
approx how mcuh extensor leg may develop for each 2mm of MC shortening
approx 7 degs
how much grip strength may you lose for every 2mm of MC shortening
8% grip strength. This is because the intrinsic hand muscles contribute to 40-90 % of grip strength
how much MC shortening is generally tolerable
3-4mm of shortening and occasionally more, with only minimally noticeable clinical deformity and functional loss. surgeons may choose to accept this as an alternative to the risks of scarring and stiffness from surgical intervention
how much lateral MC angulation may be tolerated
5-10 deg provided that no signficant finger impingement occurs during motion.
how do you best clinically observe MC angulation and impingement
MC angulation best with fingers straight, whereas impingement becomes more apparent as the fingers progressively flex
10 degress of MC malrotation results in how much overlap at the fingers
2cm
why does rotational deformity of the fingers become more pronounced in flexion
as a the collateral ligaments tighten
what angulation do displaced fractures of the PIP typically display and why
apex palmar angulation- the intrinsic muscles flex the proximal fragment whereas the attachment of the central slip to the dorsal proximal border of the middle phalanx extends to the distal fragment
what happens to the extensor mechanism with shortening of the PIP with displaced fracture
palmar angulation incrementally shortens the the fracture proximal phalanx, the extensor mechanism may have as much as 2 - 6mm of reserve, oweing to its viscoelastic adaptive properties, before the sagittal bands tighten to produce a progressive extensor lag at the PIP joint of an average of 12 deg for every mm of bone tendon discrepancy
what is a stable fracture
a fracture that does not displace spontaneously or with unresisted exercises. Inherently stable fractures safelty tolerate incremental tendon gliding and joint motion
why is the safe position used at fracture sights
it neutralises the effects of muscle forces and thus enhances fracture stability
discuss usual fracture pattern of MC
apex dorsal with volar angulation due to the distal portion of the bone flexing under the instrinscs
discuss usual # pattern of P1
apaex volar with dorsal angulation due to the intrinsic flexing the proximal portion and distal extending with the extensor mechanism
describe usual fracture pattern of P2 proximal 1/3 fracture
apex dorsal with volar angulation due to the central tendon the proximal extends and due to FDS the distal flexes
describe the usual fracture pattern of distal 1/3 of P2
apex volar with dorsal angulation - the proximal portion flexes due to FDS and the extensor tendon extends the distal portion
explain the normal # pattern of shaft fractures
apex dorsal with vola angulation as the FDP flexes distal portion
decribe fracture pattern for P3 tuft #
N/A due to no tendinous insertions
what are common soft tissue complications of P1 fractures
- extensor mechanism adherence to underlying callous - active PIP extensor lag/ flexion contracture and limited end range composite IP joint flexion
- FDS adherence to underlying callus = limited end-range composite finger extension and limited active isolated DIP and composite IP flexion
what are common complications of soft tissue of P2 fractures
- extensor mechanism adherence to underlying callus = active DIP extensor lag/ flexion contracture and limited end -range composite IP flexion (fist and tuck)
- FDP adherence to underlying callus = limited end range composite finger extension/ flexion contracture and limited active isolated DIP and composite IP flexion (fist and tuck)
Soft tissue complications of P3 #
wound care
neurovascular injury - pain or hypersensitivity
what is injured more - the RCL or UCL
RCL
how are grade 1 injuries to the UCL/ RCL managed
- joint stable
- less than 20 deg of passive instability
- managed non op with a brief period of positioning with an orthosis for pain
followed by AROM within a week and buddy taping
how are grade 2 injuries of UCL or RCL managed
complete rupture or treat without instability of the joint
may be associated with small avulsion fracture of the base of the middle phalanx
passive instability > 20 deg
2-4 weeks of gutter splinting however early motion can be initiated if angular stress can be avoided via buddy straps
how do you manage a grade 3 UCL or RCL injury
complete collateral ligament rupture combined with VP or dorsal capsular rupture
instability during AROM and PROM testing
operative manage or blocking orthoses
what splint is used for a volar plate dislocation/ injury
if the joint remains stable up to 25 degrees short of full extension, positioning in an extension block orthosis can be initiated - allows for active flexion of the PIP while preventing sublucation at increasing degrees of extension
what is the MOI of mallet finger. And what is mallet finger
axial load onto a flexed DIP - avulsion of the terminal extensor tendon at the dorsal lip of the distal phalanx
what are indications for surgical intervention of mallet finger
large articular fractures (>305 joint surface)
fracture displacement of >2mm
residual extensor lag 35 deg and joint subluxation
position for MCP #
instrinsic _
when would you operate on an MCP #
25% of the articular surface or those with more than a 1mm articular step off
what causes injury to UCL of thumb
combined radial deviation and hyperexnteion force applied to the thumb PCP joint often reulsts in damage to the UCL of the thumb
