Originally Posted by Chas Tennis
I'm trying to understanding this injury and so far have the following picture: The tendon that goes to the end of the finger on the top attaches at more than one location on the bones of the finger (I have to check this). ?. The last attachment on a finger is small and if an impact or other stress occurs in an unfortunate way the tendon rips off at the last attachment. There is difficulty in healing if the tendon is completely off the bone and somehow must find & reattach to the bone. If some of the tendon is still attached I guess healing is much more likely. ?
There's often a lot of uncertainty with injuries even after MRI's and other imaging. Since you had this injury, do you know the nature of your tendon damage, complete or partial detachment? If you don't know, can you speculate on what might have happened especially since you healed so well?
Most with this injury have a complete tear of the tendon from a very sudden force applied to the finger tip:
Besides the more common complete tear of the tendon, if the force is applied more slowly, it is more likely that the tendon pulls off a piece of the bone it is attatched to, as in the second pic below (fracture of distal phalanx):
Both types of injuries usually respond to a splint.
Occasionally, a more complex injury occurs where the bone and tendon retract. My understanding is that complex injuries are more likely with unusually high forces like in an auto accident, or a crush injury involving machinery.
The examining hand surgeon would then more likely find on physical exam a larger bony fragment palpable under the skin, or the bump of a retracted bone and tendon further down the finger.
These unusual circumstances might prompt an MRI to further investigate what is going on, but I don't think an MRI is obtained with mallet fingers that occur with a common ball injury, and that don't have a larger fragment of bone or curled up tendon under the skin.
More complex injuries may have to be surgically repaired, to pull the retracted tendon/bone into alignment and fix it there with sutures or a pin.
["Mechanism of injury
" is a term taught to all who are involved in trauma care.
The greater the force involved, the greater the resultant injury.
Also understanding the way the injury incurred often allows one to predict the type of injury, or at least be more alert to order further imaging to better delineate the extent of the injury.]