Chapter 37 Extensor Tendon Repair of the Forearm
ADVANTAGES OF WALANT VERSUS SEDATION AND TOURNIQUET IN EXTENSOR TENDON REPAIR OF THE FOREARM
You can test the strength of your forearm extensor tendon repairs by asking patients to make a fist and extend their fingers and wrist. If you see gapping, you can strengthen your repairs with more sutures to avoid rupture postoperatively.
You can allow finger movement while patients recover from the tendon repair based on what you see with active movement during the surgery. You may put them into relative motion extension splinting, which you can simulate with a tongue depressor during the surgery (see Chapters 35 and 36).
Patients can see that they can once again move their fingers without pain during the surgery. They know that they can get their movement back after they work through the pain and stiffness of the surgery.
All of the general advantages listed in Chapter 2 apply to both the surgeon and the patient.
WHERE TO INJECT THE LOCAL ANESTHETIC FOR EXTENSOR TENDON REPAIR OF THE FOREARM
See Chapter 1, Atlas, for more illustrations of the anatomy of diffusion of tumescent local anesthetic in the forearm, wrist, and hand.
SPECIFICS OF MINIMALLY PAINFUL INJECTION OF LOCAL ANESTHETIC IN EXTENSOR TENDON REPAIR OF THE FOREARM
Inject the anesthetic solution a minimum of 30 minutes before surgery to allow the epinephrine to take optimal effect and provide an adequately dry working field,1 as outlined in Chapters 4, 5, and 14.
We inject supine patients lying down on stretchers in a waiting area to decrease the risk of their fainting (see Chapter 6).
To minimize the pain of injection, use a small 27-gauge needle (not a 25-gauge).
Ask the patient to look away. Press with a fingertip just proximal to the injection site before you put in the needle to add the sensory “noise” of pressure to decrease the pain. The skin of the dorsal forearm is loose. You can therefore pinch it gently and push the skin into the needle as another technique to reduce needle insertion pain.
Insert the first needle perpendicularly into the subcutaneous fat. Stabilize the syringe with two hands and have your thumb ready on the plunger to avoid the pain of needle wobble until the skin needle site is numb. Inject the first visible 0.5 ml bleb and then pause. Wait 15 to 45 seconds until the patient tells you that all the needle pain is gone. Inject the rest of the first 10 ml slowly (over 2 to 3 minutes) without moving the needle.
Continue injecting from proximal to distal, blowing the local anesthetic slowly ahead of the needle so there is always at least 1 cm of visible or palpable local anesthetic ahead of the sharp needle tip that the patient would feel if you advanced it into “live” nerves. “Blow slow before you go.” (See Chapter 5 for further tips on how to inject the local anesthetic with minimal pain.)
Reinsert the needle within 1 cm of clearly vasoconstricted white skin that has functioning lidocaine and epinephrine so the needle reinsertion is pain free.
The goal of the injection is to bathe local anesthetic at least 2 cm outside of wherever you think you have even a small chance of dissecting in the forearm.
If you have access to blunt-tipped injection cannulas,2 you can inject the local anesthetic with minimal pain and quicker than with a sharp needle tip (see Chapter 5).