Tendon Injuries and Conditions Flashcards
(38 cards)
what is minimal active muscle-tendon tension (MAMTT)?
MAMTT is defined as the minal tension required to overcome the viscoelastic resistance of the antagonistic muscle-tendon unit. Tendon forces are the sum of the muscle contraction and the resistance of viscoelastic drag imposed on the repair site by the swollen tendon, periarticular soft tissues, edema, tension in the antragonistic muscle-tendon unit, and bandaging.
how are the tendons managed in an MAMTT program?
digit flexors are worked with wrist in slight extension and digit extensors are worked with wrist in slight flexion
what are juncturae tendinum (JT)?
interconnections of the EDC in zone 6. Thicker on the ulnar side of the hand.Assist with transmission of force during digital extension. ALso function to stabilize MCPJs. Limit independent function of EDC tendons, but preserve extension in the absence of EDC fucntion proximal to the JT
how many pulleys are in the thumB?
3 – one oblique pulley at the proximal phalanx and 2 annular pulleys: A1 just proximal to MCP and A2 at the volar plate of the IP
The surgeon has orders for you to follow Silfverskiold & May’s Early Active Mobilization protocol for flexor tendon lacerations. The correct splint for this protocol is:
Wrist at neutral, MPs flexed 50 to 70 degrees, dynamic flexion to all four digits, use a palmar pulley, fingers held in IP extension at night only
what is Vaughan-Jackson syndrome
disruption of the digital extensor tendons, beginning on the ulnar side with the extensor digiti minimi and extensor digitorum communis tendon of the small finger. It is most commonly associated with rheumatoid arthritis.
what is Mannerfelt syndrome?
Mannerfelt syndrome refers to rupture of the flexor pollicis longus (FPL) tendon from attrition caused by a bony spur in the carpal tunnel.
how do the extensor tendons get nutrition under the extensor retinaculum?
vascular perfusion through the mesotendons provides 30% of the nutrition, and synovial diffusion provides 70%
what pharmacological agent has been shown to reduce tendon adhesion?
ibuprofen
through inhibition of COX-1 and COX-2, which can also increase tendon excursion
what are vincula?
folds of the mesotendon that provide blood supply to flexor tendons. supplied by transverse communicating branches of the common digital artery
what is mesotendon?
connecive tissue sheath attaching the tendon to its fibrous sheath
what is a late deformity of an unrepaired FDS?
a swan neck from an unbalanced pull of FDP
median or ulnar nerve injuries are most commonly found in which flexor tendon zones?
IV and V
what must be true in order to perform a primary flexor tendon graft after a delayed injury?
the fibre-osseous tunnel must be in adequate position
how to chose between flexor tendon graft or a primary repair?
if appropriate muscle length-tension can be achieved or if the gap distance between the tendon ends is small, a primary repair should be performed?
when does a tendon have the least amount of tensile strength?
3-5 days after surgical repair, secondary to softening of the tendon ends
from days 5-21, strength slowly increases as collagen matures and cross-linking continues
studies indicate that this decrease in strength may not occur with an early motion program
small finger FDS is absent in what % of the population?
21%
after EPL rupture, which tendon can still allow for some IP joint extension?
Abductor pollicis brevis (APB)
originates on scaphoid tubercle and flexor retinaculum and inserts on lateral side of P1 and the dorsal apparatus, which is also part of EPL
what are the anatomical differences of FPL, compared to the other flexor tendons?
travels alone in its flexor sheath
has only on vincula
no associated lumbricals originate on it
spans onto two digital joints
inserts at base of distal phalanx
in the Evan’s active short arc motion (SAM) protocol, what position should the wrist be in and why?
30 degress of wrist flexion, which reduces flexor tendon resistance, facilitates interossei function to extend the PIP, and thus reduces the force required of the EDC to extend the PIPJ
when should you NOT perform DIP flexion exercises after central slip repair?
DIP flexion exercises can be performed with the PIPJ held in absolute 0, UNLESS the lateral bands were involved.
DIP flexion transmits force through the lateral bands, which is contraindicated if they were repaired
If lateral bands involved, DIP flexion is delayed until week 4-5 post-op and start from 30deg and progress slowly to avoid overstretching repair
What is the Evans recommended “place and hold” fist position using the MAMTTor SAM?
wrist in 20deg extension
MCPs in 83deg flexion
PIPs in 75deg flexion
DIPs in 40deg flexion
how many muscle bellies does EDC have?
usually only ONE; hoever, in some cases, EDC has 4 distinct muscle bellies with separate and distinct innervation from the PIN
with isolated loss of EDM, how can small finger extension still be retained?
EDC anatomy is variable, and in some cases, juncturae tendinum from the RF can exclusively extend the SF in the absence of EDM