What is the finger PIP joint and what deformities occur?
The PIP joints are the middle joints of the fingers. They are shaped as double domes side by side on the hand side of the joint and two side by side matching shallow curves on the finger side. This allows mobility in bending and straightening but stability in sideways and twisting movements. The PIP joints are therefore very stable but this makes them more prone to stiffness and other problems. Swan neck middle and ring fingers PIP joint imbalance: Two main types of deformity are described: Boutonniere deformity; and Swan-neck deformity. Boutonniere deformity: This describes a condition where the PIP joint will not straightened under its own power (actively) but can be straightened by the other hand (passively). In addition the end joint of the finger (DIP joint) over straightens and will not bend (flex) fully. Patients typically present in young adulthood following an injury or later (40yo and onwards) due to some joint arthritis. With enough MP joint (first joint of the finger) exces
