Understanding The PIP Joint
The PIP joint is complicated.
The PIP joint accounts for 85% of the motion for grip strength and is commonly injured in athletes.
It is basically a hinge type joint which is stable only in the sagittal plane (flexing and extending). Even though it does tolerate some ulnar/radial deviation and rotational stress, it is not very tolerant of those positions.
It has been given the analogy of a 3-sided box. On the bottom (palm side) it is supported by the volar plate and flexor tendons. On the sides it is supported by the true and accessory collateral ligaments (shown in image) as well as the central slip and lateral bands (not shown).
Of particular importance is the asymmetric nature of the joint itself. Each bone (proximal and middle phalanx of digits 2-5) has its own unique tongue-in-groove design (top right of image). This means the bony structure is inherently less stable and relies on these ligaments in a big way.
Take a closer look:
Image courtesy of Complete Anatomy
moving forward after pip injury
There are three grades of collateral ligament injuries that have been documented, each with their own specific symptoms and diagnostic findings.
The general recommendations are as follows.
Stiffness and joint contraction are common with injury.
There is no consensus on best treatment strategies!
Most injuries rarely return to full active range of motion.
Treatment within 4 weeks is key.
Immobilization beyond 3 weeks causes irreversible loss of motion!
Early diagnosis and motion are suggested (specifically extensor power).
Key takeaways:
This is not an injury you want to put aside.
You want to speak with someone who is experienced managing these injuries as quickly as possible.
There is a lot you can still do, but there’s a lot you probably shouldn’t do!