Tendons Flashcards
(100 cards)
How many annular and cruciform pulleys does the finger flexor pulley system contain?
There are 5 annular pulleys and 3 cruciform pulleys. The annular pulleys (A1–A5) guide tendons closely, while cruciform pulleys (C1–C3) provide flexible spacing.
What is the significance of dividing A1 and A2 pulleys regarding finger movement range?
Dividing A1 and A2 reduces total finger range of movement by approximately 5.7%, indicating their crucial role in effective tendon excursion.
Which annular pulleys of the flexor tendon pulley system are considered the largest, thickest, and most consistent?
The second (A2) and fourth (A4) annular pulleys are the largest, thickest, and most consistent, playing key roles in tendon excursion efficiency.
What is the initial imaging modality to confirm a suspected Zone 1 FDP avulsion (‘Jersey finger’) injury?
X-ray of the finger is necessary initially to identify any avulsed bone fragments or fractures at the distal phalanx, assisting in surgical planning.
Why is a mallet splint not suitable for Zone 1 FDP avulsion injuries?
A mallet splint addresses extensor injuries at the DIP joint; Zone 1 FDP avulsion is a flexor injury requiring surgical repair to restore flexion.
What is the classification system typically used for describing Zone 1 FDP avulsion injuries?
Zone 1 FDP avulsion injuries (‘Jersey finger’) are classified according to the Leddy and Packer system, modified into five types based on tendon retraction and bony fragment presence.
What is the appropriate management step for persistent finger stiffness 6 months after flexor tendon repair, confirmed as intact by ultrasound?
Exploration and flexor tenolysis are indicated, as passive movement is present, indicating adhesions rather than tendon rupture or injury.
Why is steroid injection into the A1 pulley ineffective in established tendon adhesions post-flexor tendon repair?
Steroid injections target inflammatory conditions like trigger finger; established adhesions require surgical intervention (tenolysis) for functional recovery.
In cases of persistent stiffness post-flexor tendon repair, why is arthrodesis of the DIP and PIP joints generally not the first-line treatment?
Arthrodesis significantly reduces function; adhesions can be addressed by tenolysis, preserving joint movement and functional tendon glide.
Which tendon core suture repair technique involves a 4-strand cruciate configuration described by McLarney?
The Cruciate (McLarney) suture technique is a 4-strand cruciate pattern designed for balance between strength, bulkiness, and ease of performance.
Compared to the Cruciate (McLarney) suture, how many strands does the Savage technique typically utilize?
The Savage technique employs a 6-strand repair, providing greater strength but increased bulk compared to McLarney’s 4-strand cruciate technique.
Why might excessive bulk from tendon suture techniques like the Savage method lead to increased complications post-repair?
Increased bulk raises friction and gliding resistance, potentially impairing tendon excursion and increasing the risk of adhesion formation and rupture.
Anatomically, where is the plantaris tendon located relative to the tendoachilles for graft harvesting?
The plantaris tendon is located medial and anterior to the tendoachilles at the ankle, facilitating easy identification and harvest.
What percentage of patients typically have a plantaris tendon suitable for harvesting?
Approximately 80% of individuals possess a plantaris tendon, making it commonly available as a graft source for flexor tendon reconstruction.
Describe the recommended incision site for harvesting a plantaris tendon graft.
A vertical incision approximately 5 cm in length just anterior to the medial aspect of the Achilles tendon insertion is recommended, progressing proximally.
What clinical term describes paradoxical extension at the IP joints upon attempting flexion, commonly seen with un-repaired FDP injuries?
Lumbrical plus finger, where attempted FDP flexion paradoxically extends IP joints due to proximal lumbrical origin pull.
Why does the lumbrical plus finger phenomenon occur after an FDP injury?
It occurs because the FDP tendon retraction proximally drags lumbrical origins proximally, paradoxically extending the IP joints upon attempted flexion.
What tendon graft-related complication can lead to lumbrical plus finger after staged FDP reconstruction?
Excessive graft length or inadequate graft tensioning during staged reconstruction places abnormal proximal pull on lumbricals, causing paradoxical IP joint extension.
What anatomical feature helps identify the FPL tendon during exploration at the wrist level after proximal retraction?
Unipennate tendon with muscle fibers extending until the wrist helps differentiate the FPL tendon from other flexor tendons at this level.
Why does the FPL tendon typically retract proximally after transection?
Due to significant resting muscle tension and its unique anatomical path, the FPL tendon commonly retracts proximally into the forearm post-injury.
At wrist level exploration, why would a lack of muscle fibers not be indicative of the FPL tendon?
Lack of muscle fibers at wrist level usually characterizes the other digital flexors (FDS, FDP), whereas FPL typically has muscle fibers present at this level.
After delayed presentation (>3 weeks) of FDP injury with a 2 cm tendon gap, what is the preferred initial management?
Insert a silicone rod as preparation for a two-stage tendon reconstruction due to inadequate tendon approximation and gap tension.
Why is primary grafting with the FDS tendon contraindicated in delayed FDP repairs with considerable gap and tension?
Using FDS for grafting leads to significant scarring, adhesion formation, and potentially quadriga effect, compromising finger function.
Why is leaving a gap in the FDP tendon repair without further intervention likely detrimental to hand function?
Untreated gaps predispose to lumbrical plus deformities and poor flexion, making later two-stage reconstructions complicated and functionally suboptimal.
