Pulleys

[Diane]

Hi Steve,
I scanned a young male with a small lump on the palmar ring finger PIPJ at the level of the middle phalanx base. It looked like a ganglion cyst but when I flexed the finger, it didn’t seem to move with the tendon. I was wondering then, do cysts that form from the pulleys stay still when the flexor is moving because the pulley is fixed?

Also, do toes have pulleys as well? I saw this recently https://link.springer.com/article/10.1007/s00256-014-2019-y/figures/1 and realise it doesn’t receive much mention as the finger pulleys nor do I remember learning about them at Uni… ?

Thanks!

[Stephen Bird]

Hi Diane,

What you saw was a ganglion arising from the A3 pulley.
The pulley is part of the tendon sheath apparatus rather than the tendons themselves,

So the ganglion will NOT move with the flexor tendons.

The sheath stays stationary during flexion and extension and the flexor tendons slide within the stationary sheath. So the ganglion will not move.

Indeed toes have a pulley system but as we don’t load our toes like we do our fingers that are rarely pathological and nobody really comes complaining of trigger toe.

It is true the pulley system is very similar to the hands, it looks like the design of the toes were cut and paste from whoever designed the hand.

I have seen a few cases of thickened toe pulleys with patients complaining of toe movement stiffness.

Nice one,

Steve

[YH LIN]

Right middle finger, palmar side, proximal phalanx

Does this look like an injured A2 pulley? or a ruptured ganglion?

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[YH LIN]

Right middle finger, palmar side, proximal phalanx

Does this look like an injured A2 pulley? or a ruptured ganglion?

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[Stephen Bird]

I guess it could be either!
Depends on the history.
If there was an overloading injury it could be a damages A2 pulley.
It is certainly at the level of the A2 pulley.
It is also quite localised so I don’t think it is a tenosynovitis event (also no vascularity)
Remember it takes a large trauma to damage an A2 pulley so the patient will report a traumatic event.

We certainly see A2 degenerative changes with associated ganglion cysts.

What I think you are seeing is a degenerative change of the A2 pulley and rather than being a nice clean ganglion cyst, it is an area of “swiss cheese” appearance small cystic spaces.

Think of what we see in the anterior labrum of the hip, sometimes it is a clean paralabral cyst, but sometimes it is a swollen labrum with small tiny cystic areas within it. Either way we call it a labral tear / degenerative changes.

So same thing here.

Yes it could be a ruptured ganglion / cyst, or it might just be a multi cystic area.

Again, the history is important. Was there an acute onset of pain?

Steve.

[YH LIN]

Thanks!

[Author]

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