Recognizing detachment of the central slip
In order to recognize detachment of the central slip, ask the patient to
extend the PIP joint with the MP joint in hyperextension.
If the PIP joint can be fully extended in this position, the central slip is
still attached, and nonoperative treatment may be indicated.
Pitfall: MP joint not hyperextended
If the MP joint is not hyperextended, extension of the PIP joint may still
be possible, even with a detached central slip. In this case, the intrinsic
muscles will extend the joint.