Flexor tendon laceration

Flexor tendon laceration is a potentially disabling condition affecting the tendons of the hands and fingers. It occurs when these tendons are cut or torn due to trauma, often from sharp objects. The condition is common in manual labourers and athletes, as well as people who work with machinery or other tools. The severity of a flexor tendon laceration can vary, and proper treatment is essential to avoid permanent damage and disability.

Here, we will discuss the causes, symptoms, diagnosis, and treatment of flexor tendon laceration. We will also explore preventive measures to help reduce the risk of this condition. By understanding the risks and treatment options, we can ensure that we take the necessary steps to protect our hands and fingers.

History and Definition

Flexor tendon laceration is an injury to the tendons in the fingers or hand that allow for bending of the fingers. The history of treating these injuries dates back to ancient times, with early attempts by physicians such as Hippocrates and Galen. However, it was not until the Renaissance and the development of asepsis and antiseptics in the late 19th century that successful repair of flexor tendon injuries began to be performed.

Pioneers in the field include K. Biesalski, E. Lexer, and L. Mayer, who developed techniques for tendon grafting in the early 20th century. The concept of “No man’s land” or zone II, which refers to a specific area of the tendon that is difficult to repair, was first proposed by St. Bunnell and later refined by Claude Verdan in 1959. In the 1960s, advances in direct tendon repair techniques were made by C. Verdan and H. Kleinert. The 2-stage tendon grafting technique was introduced in 1965 by J. Hunter, building on the work of A. Bassett and R.E. Caroll.


The symptoms of flexor tendon laceration can include:

  • Pain and tenderness in the affected finger or hand
  • Swelling and bruising in the area
  • Inability to bend or move the affected finger or fingers
  • Weakness in the affected hand
  • A visible cut or laceration on the finger or hand
  • A popping or snapping sensation when attempting to move the affected finger or hand

The severity of symptoms depends on the extent of the injury and the specific tendons affected. A complete laceration or avulsion of the tendon may result in a loss of function of the affected finger or fingers, while a partial tear may result in less severe symptoms.

If you suspect you have a flexor tendon laceration, it is important to seek medical attention immediately. A delay in treatment can lead to chronic problems and long-term loss of function.


Flexor tendon lacerations can be caused by a variety of factors, including:

  • Trauma: The most common cause of flexor tendon lacerations is a sharp object such as a knife or glass cutting through the tendon. This can occur in accidents such as kitchen mishaps, or industrial or construction accidents.


  • Overuse: Repetitive motions such as gripping or lifting heavy objects can lead to inflammation and microtears in the tendons, which can eventually progress to a full-thickness laceration.


  • Degenerative conditions: Certain medical conditions such as rheumatoid arthritis and diabetes can lead to degeneration of the tendons and an increased risk of laceration.


  • Surgical complications: During surgical procedures on the hand or fingers, the flexor tendons can be accidentally cut or lacerated.


  • Sports injuries: Flexor tendon lacerations can also occur as a result of sports injuries, such as jamming a finger while playing basketball or football.

Regardless of the cause, it is important to take appropriate precautions to prevent flexor tendon lacerations, such as wearing protective gear or taking breaks to rest and stretch the fingers and hands during repetitive motions.


The diagnosis of a flexor tendon laceration typically begins with a physical examination by a healthcare professional. During the examination, the healthcare professional will likely ask about the patient’s symptoms and the specific circumstances surrounding the injury. They will then examine the affected finger or hand, looking for signs of tenderness, swelling, bruising, and weakness. They will also check for a visible laceration or cut on the finger or hand.

To confirm the diagnosis of a flexor tendon laceration and determine the extent of the injury, imaging tests such as X-rays or ultrasounds may be ordered. These tests can help to identify any fractures, dislocations, or other injuries that may have occurred in addition to the laceration.

In some cases, an MRI may be ordered to get a better look at the tendons. MRI can also identify if there’s any other damage to the surrounding soft tissue such as ligaments, nerves, blood vessels or muscles.

Once the diagnosis of a flexor tendon laceration is confirmed, the healthcare professional will determine the appropriate course of treatment, which may include surgical repair, physical therapy, or a combination of both.

Early diagnosis and treatment are crucial for a successful recovery, as well as for preventing chronic problems like stiffness and/or chronic pain.


Treatment for a flexor tendon laceration typically depends on the severity of the injury and may include one or more of the following:


For minor lacerations or partial tears, conservative treatment may be sufficient. This may include rest, ice, and physical therapy to improve range of motion and strength. Splinting or casting may also be used to immobilize the affected finger or hand and allow for proper healing.


For more severe lacerations or complete tendon ruptures, surgical repair may be necessary. The surgery typically involves making an incision in the affected finger or hand and then suturing the severed ends of the tendon back together. Depending on the extent of the injury and the degree of separation of the ends, the tendons may be repaired by one-stage or two-stage procedures.

After the surgery, physical therapy may be needed to regain the range of motion and strength in the affected finger or hand. It may take several months to regain full function after surgery, and the physical therapy will be tailored to the individual’s needs.

Expectations after the surgery:

  • Pain and swelling are common after surgery and will gradually decrease over time.
  • The finger or hand will be immobilized in a splint or cast for several weeks to allow the tendon to heal properly.
  • Physical therapy will be necessary to regain the range of motion and strength in the affected finger or hand.
  • The recovery process can take several months, and the outcome will depend on the extent of the injury, the patient’s overall health, and the patient’s adherence to their physical therapy regimen.
  • Follow-up appointments with the surgeon will be scheduled to monitor the progress of the healing and to adjust the treatment plan as necessary.

Patients should keep in mind that not all will regain full functionality and some may experience a permanent loss of movement.

Risk Factors

Flexor tendon lacerations are an injury to the tendons in the hand and fingers that allow for movement. The risk factors associated with this type of laceration include:

  • Age: Elderly individuals demonstrate a higher risk for flexor tendon lacerations due to decreased tissue elasticity and increased degenerative changes. 


  • Gender: Studies suggest that men are more likely to suffer from flexor tendon lacerations than women. 


  • Genetics: Those with certain genetic conditions such as Ehlers-Danlos Syndrome also have an increased risk of developing a flexor tendon laceration due to weakened connective tissues. 


  • Medical Conditions: Rheumatoid arthritis, diabetes, and other medical conditions can increase the risk of developing a flexor tendon laceration due to decreased blood flow and tissue damage. 


  • Lifestyle Habits: Certain lifestyle habits, such as smoking or poor nutrition, can contribute to impaired blood circulation, which increases the risk of a flexor tendon laceration.


  • Working Environment: Those who work in professions that involve the frequent use of their hands (e.g., carpentry) are at an increased risk of experiencing a flexor tendon laceration due to repetitive strain or overuse injuries. 


  • Hobbies/Recreational Activities: Certain hobbies, such as fishing or rock climbing, can put one at greater risk for developing a flexor tendon laceration if they encounter sharp objects or tools while performing the activity. 


  • Medical Treatments: Procedures such as surgeries or injections can increase the risk of a flexor tendon laceration if not performed properly. 


  • External Trauma: Direct trauma to the hand and fingers, such as from car accidents or falls, can lead to a flexor tendon laceration. 

By understanding these risk factors, individuals can take precautions to reduce their chances of developing a flexor tendon laceration and seek medical attention immediately if they experience any signs or symptoms associated with this condition. Early detection and treatment are key to avoiding long-term complications.


With proper medical management, patients can often regain full finger mobility after a flexor tendon laceration. However, even with the best care, various complications may arise from this type of injury.

  • Infection: Flexor tendon lacerations can become infected, especially when they are not treated promptly or the wound is exposed to bacteria. An infection can cause pain and swelling, and can even lead to sepsis if it is left untreated. For this reason, it is important to seek medical attention shortly after sustaining a flexor tendon laceration. 


  • Adhesive Capsulitis: Adhesive capsulitis is a common complication of flexor tendon lacerations that causes extreme stiffness and decreased range of motion in the injured arm or hand. If adhesive capsulitis develops, it is important to seek medical treatment as physical therapy and anti-inflammatory medication may be needed to alleviate symptoms and improve the range of motion. 


  • Tendon Rupture: If the laceration to the flexor tendon is deep or left untreated for too long, it can lead to a complete rupture of the tendon. This means that the affected finger or thumb will not be able to move at all and surgical repair may be needed for a full recovery. 


  • Complex Regional Pain Syndrome (CRPS): Complex regional pain syndrome (CRPS) is a rare but serious complication of flexor tendon lacerations that can cause chronic pain even after the injury has healed. Symptoms of CRPS include burning pain, swelling, and changes in skin temperature and color at the affected site. If left untreated, CRPS can become a permanent issue that affects the quality of life.

  • Nerve Injury: Flexor tendon lacerations are often accompanied by nerve injuries due to their proximity to each other inside the arm or hand. Damage to the nerves can cause numbness, tingling, and weakness in the affected area which may not improve until after surgical repair or specialized physical therapy.

Overall, flexor tendon lacerations carry risks of infection, adhesive capsulitis, tendon rupture, complex regional pain syndrome (CRPS), as well as nerve injury. Therefore, it is important to seek medical attention promptly to minimize the risks associated with these complications.

If left untreated, more severe and long-lasting problems may arise that will require more extensive treatment. Therefore, it is best to take preventive measures if possible and treat flexor tendon lacerations as soon as they occur.

When to See a Doctor

It is important to seek medical attention immediately if you suspect that you have a flexor tendon laceration. Delaying treatment can lead to chronic problems and long-term loss of function.

Symptoms of a flexor tendon laceration may include pain and tenderness in the affected finger or hand, swelling and bruising, inability to bend or move the affected finger or fingers, weakness in the affected hand, a visible cut or laceration on the finger or hand, or a popping or snapping sensation when attempting to move the affected finger or hand.

If you have any of these symptoms, especially if there is a visible laceration, you should see a doctor as soon as possible. If the injury is severe and the finger is not moving, it’s best to go to the emergency room. The doctor will examine the affected finger or hand and may order imaging tests such as X-rays or ultrasounds to confirm the diagnosis of a flexor tendon laceration and determine the extent of the injury.

Step-by-Step Guide to Flexor Tendon Laceration Treatment

Flexor tendon lacerations are common injuries that require immediate medical attention.


Before starting the treatment, a consultation should be held with a hand surgeon or a plastic surgeon for surgery. During this session, the patient’s medical history and any records of past treatments will be reviewed. The doctor will also perform a physical examination of the affected area to determine the extent of damage and decide on an appropriate course of treatment.


  • Systematic Debridement: Next step is systematic debridement to remove all the devitalized tissue around the wound site. This helps reduce infection risk while facilitating healing. Local anesthesia may be used during this process if necessary. 


  • Tendon Repair: The next step is to repair the flexor tendon by suturing the edges of the laceration together. This will require a series of meticulous stitches and should be performed by an experienced hand surgeon or plastic surgeon for best results.

Post-Operative Care

After surgery, post-operative care will be necessary to ensure optimal healing. This may include physical therapy to restore the full range of motion in the affected area as well as ultrasound, electrical stimulation, and other modalities to improve circulation and protect against scarring. Proper wound care must also be followed at all times. 

Follow-Up Appointments

Regular follow-up appointments are essential for the successful treatment of flexor tendon lacerations. The doctor will assess the progress of healing and may adjust the course of treatment as needed.

For best results, it is important to carefully follow all instructions from your doctor when undergoing treatment for a flexor tendon laceration. With proper care and attention, recovery can be achieved with minimal complications. 


In conclusion, flexor tendon laceration can be a debilitating injury if not treated promptly and appropriately. Early diagnosis and treatment are necessary for optimal outcomes, as the full movement of the hand may be returned with proper care. Therefore, anyone who suspects they have suffered a laceration to their flexor tendons should seek medical attention immediately.


Dr. Colin Hong is a renowned plastic surgeon with more than 35 years of experience in the field. He offers some of the most competitive rates for Cosmetic, Plastic and Reconstructive surgeries in Toronto, North York and Markham.

If you require a consultation, please contact Dr. Hong’s office at (416) 222-6986 or email info@drcolinhong.com to request one. Please include your full name, email address and phone number when making your request to facilitate a prompt response from our team. Additionally, you must acquire a referral from your family doctor before setting up an appointment with Dr. Colin Hong for flexor tendon laceration treatment.

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