What is a tendon?
A tendon is made of collagen and is like a rope that attaches muscles to bones. Contraction of the muscles pulls on the tendons, which then cause movement of the bones such as flexion and extension of the fingers.
How do tendon lacerations occur?
Tendon lacerations most commonly occur as a result of a cut to the hand or wrist from a sharp object such as a knife or glass. Tendons of the hand and wrist are fairly superficial (i.e. close to the skin), so a knife or other sharp object does not have to cut very deep in order to damage a tendon. We see tendon lacerations commonly from accidents in the kitchen such as cutting bagels, separating frozen meats with a knife, glasses breaking while washing dishes, and especially pitting an avocado with a knife. In general we recommend that a knife never be pointed back towards your hand.
Tendons can also rupture from an excessive force being placed on the tendon such as in football. Jersey finger typically occurs from a player trying to tackle another player by grabbing his jersey, and as the other player is running away, the tendon becomes excessively stretched and subsequently ruptures. Rupture can also be spontaneous, primarily seen in patients with advanced inflammatory conditions such as Rheumatoid Arthritis.
Symptoms and Diagnostic testing:
The most common symptom is the inability to flex or extend the finger(s) that the lacerated tendon(s) control. Incomplete tendon lacerations may just cause pain and/or a "catching sensation" with flexion and extension of the finger(s). There may also be numbness or tingling of the finger(s) given the close proximity of nerves to tendons. Any concern for nerve injury in addition to tendon laceration needs to be immediately addressed.
Dr. Steven Lee will often start with an x-ray to evaluate the bone structure and rule out fracture, especially if the mechanism of injury is traumatic. An MRI or Ultrasound may also be ordered if the diagnosis is in question or to evaluate the degree of tendon laceration and to see how far apart the tendon ends are in cases of complete tendon laceration.
The decision between non-operative and operative management is based upon the percentage of tendon that is cut. Non-operative management is reserved for tendon lacerations where a small percentage of the tendon is involved. Most complete tendon lacerations will require operative management. Unfortunately, it is very difficult to determine how much of the tendon has been cut, even when the open wound has been inspected by an ER or Urgent Care Clinic or radiologic studies such as an MRI has been performed. Part of this reason is that it is difficult to fully visualize the tendon through a small cut, another reason is the expertise level of the Emergency Physician may not be adequate to make this determination, and lastly, radiologic studies are notoriously not accurate enough to specify the percentage of the tendon that has been partially cut. Typically, the consideration to explore the tendon is thus made clinically in that if there is significant pain when moving the finger, especially under stress testing, Dr. Lee will presume at least a partial tendon tear has occurred, and will usually recommend exploration and possible tendon repair.
Non-operative management may consist of a short period of immobilization followed by early protected motion under the supervision of a licensed Hand/Physical Therapist.
The type of operative management depends on the timing of the tendon cut. Tendon repair (i.e. suturing together of the tendon ends) should ideally be completed within 2 weeks of injury. Waiting longer than two weeks increases the risk that a primary repair can't be completed. In cases where a primary repair can't be completed, tendon reconstruction or tendon transfer procedures may be needed.
Tendon reconstruction often involves a two-stage procedure. In the first procedure, a silicone rod implant is placed where the tendon once was in order to re-establish a favorable tendon bed/sheath (i.e. space where the tendon can freely glide). This tendon bed/sheath is normally compromised in chronic tendon injuries, hence the need for the silicone rod implant. The second stage of the procedure takes place approximately at least 6 weeks after the first procedure and involves removal of the the silicone rod implant and replacement with a tendon graft.
Tendon transfer involves taking one tendon of the hand and transferring it to the location of the torn tendon in order to restore function. Your hand has places where more than one tendon performs the same function (i.e. your hand can still function if these tendons were missing). One of these tendons is therefore used for the transfer. Your brain then adapts and retrains your hand to function with this transferred tendon.
Tendon reconstruction and tendon transfer procedures involve longer and more extensive recovery times with less favorable outcomes compared to that of primary tendon repair. Seeing Dr. Steven Lee IMMEDIATELY after a suspected tendon injury is therefore of the utmost importance.
Learn more about scheduling surgery.
All surgical patients are immediately immobilized in a splint, and sutures are removed usually 10-14 days following surgery. Occupational hand therapy is started as soon as possible. During this time, patients are encouraged to elevate their hand above their heart and keep their dressings clean and dry. Patients are then transferred into a custom splint followed by a strict occupational hand therapy (OT) protocol designed to restore adequate mobility and strength to the hand. Occupational therapy can last 2-3 months or longer.
The results after surgery depend on a number of factors including how quickly the surgery was able to be performed after in incident, how well the patient adhered to the postoperative protocol, and factors not in our control such as how and where the tendon was cut and the inherent amount of scar tissue that the patient produces. Because of these factors, it is not uncommon for patients to not be able to regain their full range of motion and function back, and may require additional procedures to try to regain more motion especially if excessive scar tissue has developed. Lear more about post-operative recovery.
Post Operative Instructions:
*It is important to note that all of the information above is not specific to anyone and is subject to change based on many different factors including but not limited to individual patient, diagnosis, and treatment specific variables. It is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific orthopedic advice or assistance should consult Dr. Steven Lee or an orthopedic specialist of your choice.
*Dr. Steven Lee is a board certified orthopedic surgeon and is double fellowship trained in the areas of Hand and Upper Extremity Surgery, and Sports Medicine. He has offices in New York City, Scarsdale, and Westbury Long Island.