Obstruction on the Tefillin Straps

I need to undergo ear surgery, which requires a bandage on the head where the tefillin straps are placed, but not where the box is. Can I put on tefillin with a blessing?

When there is a wound on the head, it is permissible to be lenient if there is an obstruction at the place of the straps. And to put on tefillin with a blessing. However, when there is no wound on the head, one should be stringent to remove the obstruction even from the straps.

Mishna Berura, Siman 27, S"K 16: "The later authorities wrote that one should not be lenient except in the place of the wrappings, but regarding the tying, one should be stringent even with the straps, both on the hand and on the head. They wrote an open rebuke to those who place tefillin on a wig called a paruka, even if only the strap is placed on the wig. However, it is implied from the words of the MA and HA that if he has a wound on his head, and only in the place where the straps are placed, and not in the place of the box, he is permitted to place the straps on the cloths covering the wound or on a thin hat and bless, even though there is an obstruction between the straps, since in the place of the box there is no obstruction. And also on the hand, if he has a wound even in the place of the wrapping of the knot around his hand, he is permitted to place the wrapping of the knot on cloths and bless, but in this case, he should be careful to cover it from above, so that it is a sign for you and not for others.