Flexor and Extensor Tendon Surgery in Ankara, Turkey

Flexor and extensor tendon repairs are surgical interventions performed to restore function after tendon injuries. The location, type, and timing of the injury determine the surgical technique. Early and appropriate repair is critical for long-term success.

Flexor tendon repair is performed especially in the complex anatomical regions on the palm side of the hand and the volar aspect of the fingers. Surgery in these areas requires advanced technical skill. Epineural suturing and multi-strand suture techniques are often preferred.

Extensor tendon repair is easier to perform because the tendons are more superficially located. While primary suturing may be sufficient for simple ruptures, grafting or tendon transfer may be required in complex injuries. A splint is used for stabilization after suturing.

Postoperative rehabilitation is the cornerstone of healing after tendon repairs. Early passive motion programs reduce the risk of adhesions and accelerate functional recovery. Long-term success rates increase with physiotherapy support.

What Is Flexor and Extensor Tendon Surgery?

Flexor and extensor tendon surgery is a surgical repair procedure performed when the tendons that enable hand and finger movements are cut, ruptured, or severely damaged. Flexor tendons allow the fingers to bend, while extensor tendons allow them to straighten. During surgery, the damaged tendons are sutured or, if necessary, repaired with a graft. The aim is to restore hand function and minimize loss of movement. Early intervention and the physical therapy applied afterward are of great importance in the recovery process.

What is tendon repair, and how does this mechanism in our fingers work?

To understand the system that moves our fingers, you can think of your hand as a highly advanced puppet. The muscles in our forearm are the engine of this system; they generate the force. However, this force must be transmitted all the way to the fingertips. This is where tendons come into play. Tendons are strong cords that transmit muscle force to the bones.

There are two main tendon groups in your hand. Those on the palm side are called “flexor tendons.” They allow you to bend your fingers, make a fist, and grip objects. Those on the back of the hand are called “extensor tendons.” They allow you to straighten your fingers, open your hand, and point.

For this system to work, cords alone are not enough. Especially in the palm, there are tunnels and pulley systems that prevent these cords from bowing away from the bone. We call these “pulleys.” Just like the rings on a fishing rod through which the line passes, these pulleys ensure that the tendon works at the correct angle and that force is not wasted. When a tendon is cut, it is not only the cord that is severed; in many cases, this tunnel system and balance are also disrupted.

Why can’t a cut tendon heal on its own?

Many tissues in our body—for example, a simple abrasion on the skin—form a scab over time and heal on their own. However, tendons are very different due to the laws of physics, and unfortunately their chance of healing without intervention is zero. The main reason is “tension.”

Tendons have a certain degree of tension even at rest. The moment you cut a tendon, it is like cutting a tight rubber band in the middle. The forearm muscles pull the upper (proximal) end of the tendon toward themselves, that is, toward the elbow. The other end remains in the finger.

A gap of several centimeters immediately forms between these two ends. It is impossible for them to come together and fuse on their own. On the contrary, as time passes, this distance increases with muscle pull, the tendon shortens, and it shrinks within its tunnel. Therefore, in tendon injuries, surgical intervention is not an option but an absolute necessity to restore function.

Why are surgical timing and the first 24-hour rule so important?

In plastic surgery, we race against time while managing tissue healing. In tendon injuries, the time to intervention is one of the most critical factors determining surgical success. We surgeons consider “early primary repair,” meaning intervention within the first 24 hours after injury, to be the gold standard.

Why is the first 24 hours so valuable? Because during this period, the wound is still fresh. The tissues have not become excessively swollen, the tendon ends have not retracted too far, and most importantly, the inflammation process that makes healing more difficult has not yet disrupted the tissue structure. Repairs performed in this window make the tendon ends easier to find, and the holding capacity of the sutures we place is much higher.

If the first day is missed, “delayed primary repair” performed within the next 2 weeks can still yield successful results, but things become somewhat more difficult. After 2 weeks, the tendon ends begin to soften, shorten, and the surrounding tunnels start to narrow. In cases presenting after 4 weeks, end-to-end suturing is usually not possible and a graft (a piece taken from another part of the body) is required.

The advantages of early intervention are as follows

• Less edema
• Cleaner tissue structure
• Higher healing potential
• Lower risk of adhesions
• Earlier ability to begin movement

Where is the “Zone II” region in flexor tendon repair that surgeons are cautious about?

In the history of hand surgery, there is a famous region called “No Man’s Land,” a well-known area that surgeons used to hesitate to approach. This is the region extending from the palmar creases to the middle phalanx of the fingers (Zone II).

The challenge in this region is as follows: Here, both the superficial and deep flexor tendons travel on top of each other within a very narrow and rigid sheath we call the “fibro-osseous tunnel.” The space is so tight that even minimal swelling, a millimetric excess of suture material, or scar tissue can cause the tendon to become stuck inside this tunnel.

In the past, outcomes in injuries in this region often ended in disappointment and the fingers could not move. However, today, with advances in microsurgical techniques, magnifying loupes, and microscopes, this area is no longer a feared region. We now repair both tendons (both FDS and FDP) in this area and smooth the tendon surface with special sutures to ensure gliding. Still, patients should know that injuries in this region belong to the group with the most delicate healing process.

How are extensor tendon injuries and mallet finger treated?

Extensor tendon injuries on the dorsal side of the hand have a slightly different biomechanics than flexors. The tendons here are flatter and thinner. They lie almost like a leaf between the skin and the bone. This thinness limits their ability to hold sutures, and because the skin is very thin, the risk of infection is higher.

Extensor injuries are also divided into regions (zones). One of the most common conditions we see is “mallet finger,” which occurs when the tendon at the fingertip ruptures. In this situation, the patient cannot straighten the fingertip, and the tip droops downward.

Mallet finger treatment may not always require surgery. If there is no open laceration and no associated fracture, we can treat it with special splints that keep the finger completely straight for 6–8 weeks. However, during this process, the splint must not be removed even for a second; otherwise, the tendon re-ruptures and the process starts over.

Another important situation is injuries around the middle joint of the finger. Here, a “boutonnière deformity” can develop. The central slip ruptures, the lateral bands slip downward, and the finger pops upward as if it has come out of a buttonhole. If this deformity becomes established, it seriously impairs hand function and requires surgical correction.

Why are the surgical technique and the number of sutures used so important?

You should think of what we do in the operating room not as fine tailoring, but as a microscopic engineering task. In tendon repair, our main goal is to suture the tendon strongly enough so it will not rupture, yet delicately enough so it will not get stuck within the tunnel.

The concept of “strand count,” meaning the number of suture strands crossing the repair site, is very important. Tendon strength is directly proportional to the number of strands. In the past, 2-strand techniques were used, but these repairs were not strong enough to allow early motion. Today, especially in flexor tendons, we use 4- and even 6-strand repair techniques.

As strand count increases, the tendon’s load-bearing capacity increases. This means the patient can begin moving the finger earlier after surgery. Early motion is the most important factor preventing adhesions. However, as strand count increases, the amount of knots and tendon bulk can also increase. This is where the surgeon’s mastery comes into play: providing maximum strength without increasing tendon volume and keeping the surface smooth.

The suture techniques we use are as follows

• Core sutures (central, load-bearing sutures)
• Epitendinous sutures (fine sutures that smooth the surface)
• Locking sutures

Why should the pulley system of the hand be preserved?

As mentioned earlier, the tunnel and pulley system (pulleys) that allows tendons to glide along the bone is biomechanically vital. In particular, the main pulleys located at the base (A2) and mid-portion (A4) of the finger must be preserved at all costs during surgery.

If these pulleys are damaged or sacrificed during repair, the “bowstringing” appearance can occur. When the tendon is tensioned, instead of remaining close to the bone, it rises under the skin like a taut bowstring. This causes two problems:

• You cannot fully close your finger.
• You experience a significant loss of strength.

That is why we surgeons make a great effort to pass under these pulleys while repairing the tendon. If these pulleys have also been destroyed during the injury, they must be repaired or reconstructed using tissues taken from another part of the body (pulley reconstruction).

What is two-stage tendon repair used in difficult cases?

Sometimes patients present very late, or they come to us after an unsuccessful prior operation, with tendons that are completely adherent, a disrupted tunnel structure, and a history of infection. We call these “neglected” or “complicated” cases. At this point, end-to-end tendon repair is impossible because there is no healthy tissue left.

In such situations, we use the “two-stage tendon reconstruction” method.

Stage One: In the first operation, we remove all adhesions and the damaged, nonfunctional tendon remnants inside the hand. Into this cleared area, we place a medical silicone rod sized like a tendon (a silicone rod). This silicone rod is temporary. Its purpose is to trigger the body to form a smooth sheath around it. In other words, we artificially create a new tendon tunnel. The patient lives with this silicone rod for 3–4 months and performs passive exercises.

Stage Two: When the body has formed a slippery, excellent tunnel around the silicone, we perform the second operation. We remove the silicone rod and pass a tendon graft taken from the patient’s own body (usually from the forearm or leg) through that prepared tunnel.