Knott's disease or stenosing ligamentitis of the finger: causes and treatment

Each finger of the hand has the ability to move freely throughout the entire range of motion. The efficiency, smoothness and strength of such movements are made possible thanks to a unique system of blocks. This system consists of a number of retinacular (retaining) type structures that are either annular or cruciform in nature. There are five ring blocks (A1-A5) and three cross-shaped blocks (C1-C3).

Flexor apparatus of the hand

The condition trigger finger syndrome (FFS) is thought to be caused by inflammation and subsequent narrowing of the A1 block of the affected finger (usually the third or fourth). The A1 block is most often affected, but there is some evidence that the A2 and A3 blocks are affected. Additionally, this problem can occur in the thumb and the condition is then called snapping thumb syndrome.

A decrease in the size difference between the flexor tendon sheath and the flexor tendon itself can lead to increased friction between the two surfaces and therefore disruption of the gliding process, leading to progressive inflammation between the tendon and its sheath.

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SSP is called “stenosing tenosynovitis.” However, histological studies have shown that inflammation occurs more in the tendon sheath rather than in the tendon itself, making this name a misleading description of the actual pathophysiology of the disease.

Epidemiology/Etiology

According to statistics, this problem occurs in the fifth or sixth decade of life, and women suffer more often. The average age is 58 years. The chance of triggering finger is 2-3%, but in the diabetic population it increases to 10%. This is not due to the glycemic profile, but rather to the duration of the disease. SSP may occur in patients with

• carpal tunnel syndrome,
• de Quervain's disease,
• hypothyroidism,
• rheumatoid arthritis,
• renal failure,
• amyloidosis.

Many potential causes of SCP have been discussed in the literature. However, there is little clear evidence of the exact etiology of this disease.

• Occupational causes of SSP have been proposed, but the research on this is very inconsistent.
• The authors hypothesize that SCP may occur as a result of any activity that requires prolonged forceful flexion of the fingers (eg, carrying shopping bags or briefcases, prolonged writing, rock climbing, or strenuous grasping of small tools or objects with sharp edges).
• It is important to take into account that the cause of SSP is often multifactorial in nature.
• It is also known that this condition can develop idiopathically or secondary to other pathologies.

Doctors' advice: how to get rid of crunching in joints?

To prevent and treat crunching in the joints, doctors recommend alternating physical activity with rest, not allowing the joint fluid to stagnate. Also get rid of bad habits - alcohol, smoking and excess coffee consumption accelerate the destruction of joints and reduce the effectiveness of treatment for cracking joints.

Physical activity

Avoid both inactivity and heavy loads on the joint. Any sports exercise should begin with a warm-up, which will “warm up” the muscles and prevent starvation of the cartilage. Aggressive sports, running, and strength training with cracking joints are contraindicated, especially if you have been diagnosed with inflammatory, degenerative changes, or joint hypermobility.

If the crunch in the joints is not associated with the individual anatomical characteristics of the patient, doctors recommend walking more (at least 40-60 minutes or 10 thousand steps a day, or 5-8 km) or cycling, swimming (2-3 times a week ), do Nordic walking or yoga. To track your activity, install a pedometer on your phone. Exercise should be done daily and systematically - do not try to catch up in a few hours 2 times a week. This can worsen the condition of the joint, because synovial fluid does not have time to be produced during intense exercise.

For arthritis and arthrosis, it is better to do not standard exercises, but a set of general strengthening exercises that help maintain the tone of muscles and ligaments.

Labor activity

Increased joint mobility, although not a pathology, can cause varicose veins or injuries due to high load on the joints. Taking this feature into account, it is better not to choose standing work. If you still have to stand, shift your weight from foot to foot more often, equip the place with a low bench on which you can place your foot from time to time. To prevent crunching in the joints, try to dilute the work in the same position with 10-15 minute warm-ups (3-4 during the day) - so-called. industrial gymnastics exercises. These include rotation of the head and torso, clenching and unclenching of fists, circular movements of the feet, hands, knees, and the “mill” exercise with the hands.

If necessary, use elastic bandages and restraints while working.

Weight

Regardless of the causes and treatment of cracking in the joints prescribed by the doctor, the patient needs to lose excess weight - it disrupts the healthy distribution of load between the joints, which is why the intervertebral discs of the lumbar region, hip, knee, and ankle joints begin to suffer. For example, 1 extra kilogram of weight is felt by the knee cartilage as 5.

Clinical picture

Stuck finger (before and after treatment)
SSP has a number of clinical manifestations. Initially, patients may experience a painless clicking sound when moving the affected finger. This may progress to painful sticking and jerking of the finger, usually at the metacarpophalangeal and proximal interphalangeal joints.

Possible additional symptoms are:

• Stiffness and swelling (especially in the morning).
• Intermittent fixation of the finger during active flexion, requiring passive extension.
• The finger locks or snaps in a bent position and then suddenly straightens.
• Decreased flexion/extension amplitude.
• A palpable tender nodule proximal to A1 and/or the finger is fixed in a flexed position.
• A slight thickening at the base of the finger and pain that may radiate to the palm or the distal part of the finger.

Is cracking your knuckles harmful?

Cracking your fingers is a very common practice, mainly because people use it to relieve tension. This in itself will not cause arthritis, swelling, or harm the hand. The clicking sound is caused by the bursting of bubbles in the fluid in the joint lining.

Joints are the point of contact where bones meet and are covered with thick synovial fluid. The capsule surrounding the joint stretches and enlarges, while its pressure decreases. When this happens, dissolved gases in the synovial fluid form bubbles. They then “explode”, producing a characteristic clicking sound.

It takes ½ hour for the gas to dissolve in the liquid. This means that the gap between clicks should be at least half an hour. Rapid and repeated stretching and contracting of joint ligaments leads to soft tissue injury and loss of more synovial fluid, a natural lubricant that prevents friction between bones.

If this regular daily habit is repeated over many years, then theoretically the cartilage will be damaged and the joint's ability to grip an object will be reduced over time.

Differential diagnosis

The main characteristic of this disease is stuckness and intermittent movements of the affected finger. However, this characteristic is not unique to the snapping finger. Other etiologies associated with finger sticking include:

• Dupuytren's contracture;
• focal dystonia;
• swelling of the flexor tendon or its sheath;
• sesamoid bone abnormalities;
• post-traumatic entrapment of the tendon in the area of ​​the head of the metacarpal bone.

Preparation for surgery:

• Bleeding: The operation is performed on a hand that has been bled dry to ensure optimal visibility conditions and limit the risk of damage to important structures (nerves, blood vessels, tendons). The operated arm is wrapped in a rubber bandage and the shoulder is pressed with a pressure cuff during the operation.
• Disinfection of the skin and covering with a sterile cloth: To avoid infection, the skin is disinfected and the surgical site is covered with a sterile cloth.
• Magnifying glasses: The operation is performed using magnifying glasses, which help to clearly distinguish and thereby protect the important functional structures of the hand.

Rating scales

• Digital pain rating scale.
• Measuring hand grip strength (using a JAMAR dynamometer).
• DASH Questionnaire.

Stages of stenosing tenosynovitis

• 1 is normal.
• 2 - painful compaction.
• 3 - clicks.
• 4 - the proximal interphalangeal joint (PIP) gets stuck during flexion and unlocks during active extension.
• 5 - The PMS gets stuck during flexion and unlocks during passive extension.
• 6 - The PMS is fixed in a bent position.

Stage 5 or 6 according to the above classification

Baths to prevent finger snapping

In addition to using the above folk techniques, it is possible to use special baths that will speed up recovery:

1. For the bath you will need a sprig of pine needles. First, grind it, then add a liter of water and boil for a couple of minutes, and then leave to simmer for 30 minutes over low heat. Having completed the simmering process, the composition is filtered and when the temperature becomes tolerable for putting your hand into it, the procedure begins. The duration of the procedure is about 15-20 minutes.
2. A salt bath, which is prepared using sea salt and a few drops of pine needles, will have a quick, anti-inflammatory effect. You need to keep your hand in the bath for at least 20 minutes. Suitable for everyday use.
3. An elderberry bath is prepared from dry plant materials, which are filled with 800 ml of water at a temperature of 98 degrees. After this, you need to infuse for 30 minutes, and lower your hands for a 20-minute period of time. This recipe can be used twice a day.

Survey

History taking

Ask the patient specific questions to better understand the nature of their symptoms, which will help you diagnose the condition. For example:

• Recent injury.
• Repetitive movements associated with work.
• Clicking or getting stuck in the affected finger when bending or straightening it.
• Referred pain in the palm or fingers.

Accompanying illnesses

• People with diabetes are 4 times more likely to suffer from this disease.
• Disorders that cause connective tissue changes, such as rheumatoid arthritis and gout, may also be associated with PTS.

Inspection

• Finger fixed in a flexed position.
• Bone proliferative changes in the adjacent PMS.

Palpation

• A painful nodule in the MCP joint is secondary to swelling of the tendon or tendon sheath.

Range of motion

• Decreased range of motion, mainly extension.

Manual testing

• Flexor digitorum profundus.
• Superficial flexor digitorum.
• Measuring hand grip strength.

Note: If your finger is blocked, testing may not be possible.

Additional joint movements

• Distal and proximal interphalangeal joints, metacarpophalangeal and carpometacarpal joints of all fingers.
• Surrounding soft tissue.
• Wrist joint.

Special tests

• Fist flexion test (10 times). The patient must actively clench his fingers into a fist 10 times. Accordingly, the number of clicks is assessed on a 10-point scale. If the patient's finger remains blocked at any point in time, the test ends with a score of 10/10.

Healing process after surgery

Pain after surgery is usually minimal and most patients do not require painkillers.
The symptoms of trigger finger and associated pain stop immediately after surgery, and in rare cases, friction is felt in the tendons, which completely disappears within a few weeks. Negative sensations in the postoperative scar largely disappear after the first 6-8 weeks; after 3-6 months, patients no longer complain of pain in the scar. However, only after 12 months can we say that the scar has completely healed. © Dr. Klaus Lovka

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Treatment

The chronic nature of symptoms associated with snapping finger makes conservative treatment difficult and often ineffective. However, conservative treatment is always recommended as a first step before surgery.

Non-operative treatment

Corticosteroid injections

The use of corticosteroids has been shown to be effective in reducing pain and the frequency of clicking. The drug is injected into the affected tendon and reduces inflammation and pressure on the tendon, which leads to improved gliding through the flexor pulleys. This option is an effective and safe alternative to surgery. Patient satisfaction, safety, and functional improvement are characteristics of steroid injections compared with surgical treatment. Surgery is associated with higher costs, longer absences from work, and the possibility of complications. Studies have also shown that combining corticosteroid injections with lidocaine is significantly more effective than lidocaine alone.

Possible side effects

• Inflammation at the injection site.
• Tendon damage.
• Allergic reactions.
• Atrophy of subcutaneous fat at the injection site.

Contraindications

• Age up to 18 years.
• Any previous treatment or surgery in this area within the last six months.
• Possible traumatic or tumor origin of symptoms.

Physical therapy

As with all diseases of the upper extremity, screening of the proximal segments is necessary. Additionally, because poor posture can contribute to distal problems, it should be corrected to ensure optimal patient outcomes.

Patient education

Since SCP is also considered an overuse injury, patient education is critical. This concerns

• recreation;
• physical activity modifications;
• postures;
• orthoses.

Orthotics

Orthotics for trigger finger syndrome

The first step in treatment is to stop the activities that make the condition worse. Orthotics/splinting is one of the best ways to limit movement. Most authors agree that the goal of orthosis is to alter the biomechanics of the flexor tendons to maximize differential tendon gliding. However, experts disagree on which joints should be splinted and how to properly position the joints. There are different ways to orthose a patient, but ultimately it will depend on what gives the patient the most relief. Orthoses are usually worn for 6-10 weeks. Some authors recommend positioning the MCP joint at 0 degrees, which allows full range of motion of the distal interphalangeal joint (DIP). It should be noted that splinting has lower success rates in patients with severe conditions or long-term symptoms.

There are two options for orthotics that have shown (according to recent studies) good results:

• Orthotics DMS. In 50% of cases this leads to a reduction in symptoms.
• MCP joint orthosis in a position of 15 degrees of flexion, which in 92.9% of cases leads to resolution of symptoms.

Exercises

There are three exercises that are recommended when treating patients with snapping finger (especially after surgical release):

• Fixation of the finger: the patient fixes the PFJ and flexes the finger in the MCP. This exercise can be performed with all fingers simultaneously or separately. The same can be done for VHI. The number of repetitions and sets are recommended depending on the level of pain and stiffness.
• Range of active movements: finger abduction and adduction are recommended to strengthen the palmar interosseous and lumbrical muscles.
• Tendon Sliding: Watch the video below.

Other events

Techniques such as heat/ice, ultrasound, electrical stimulation, massage, stretching, and joint mobilization (active and passive) may have some benefit for SCP. It is believed that heat may help by providing increased blood flow and stretchability of the tendon. Stretching after applying heat can provide greater extensibility. Movement and joint mobilization increase joint and soft tissue mobility (eg, slow passive traction and translational gliding).

Although there is no strong evidence, there are some documented cases and studies showing improvement in symptoms.

• 74 patients were treated with ten sessions of paraffin therapy, ultrasound, muscle stretching and massage. After 3 months, 68.8% of patients reported no pain or clicking. Of these 68.8% of patients, none had pain or clicking over the subsequent 6 months.
• 48 children were treated daily with passive exercises for the affected thumb. After 62 months, this resulted in improvement (80% of cases for stage 2 and 25% of cases for stage 3).

Extracorporeal shock wave therapy

Recently, extracorporeal shock wave therapy (ESWT) has been promoted as a possible alternative to surgical treatment of musculoskeletal disorders in patients refractory to traditional conservative treatment. Yildirim and colleagues conducted a prospective randomized controlled clinical trial to determine the effectiveness of ESWT in the treatment of PSP compared with corticosteroid injections. Patients were followed up for one, three and six months. The researchers found that three sessions of ESWT treatment could be as effective as a corticosteroid injection in reducing symptom severity and functional status in Quinnell grade 2 patients. Patients in the ESWT group received 1000 shocks at 15 Hz over three sessions. There was a week's break between sessions. They found that both the ESWT and corticosteroid groups showed statistically significant improvements in all outcomes after treatment.

ESWT is thought to induce repair of inflamed tissue by stimulating tissue regeneration and nitric oxide synthesis, which is thought to lead to suppression of inflammation. There is also weak evidence that one of these mechanisms may have a beneficial effect on the thickening of the flexor tendon and its sheath. This allows you to overcome the obstacle in the snapping finger. ESWT offers an alternative for people who refuse corticosteroid injections due to potential complications (fear) or who are allergic to local anesthetics.

Surgical treatment

Open surgery

If conservative treatment is ineffective, surgical intervention is indicated. Open surgery combined with effective rehabilitation can quickly and significantly improve hand function with a low risk of complications. This technique, considered the gold standard, is performed by making a longitudinal incision in the palmar crease over the MCP joint of the involved finger, followed by release of the flexor digitorum profundus and flexor digitorum longus tendons. This procedure lasts 2-7 minutes and has an average discomfort time of 45 days after surgery. The advantage of this method is that it allows visualization of the block and therefore has a lower risk of damage to nearby nerves compared to endoscopic methods.

Endoscopic technique

This technique is performed by making two incisions: one in the palmar crease above the MCP joint and the other in the finger. An endoscope is then inserted to cut the block, releasing the flexor tendons. This procedure lasts two to nine minutes and has a shorter average time of discomfort (23 days) after surgery. Other advantages are the absence of scars and associated problems, as well as shorter post-operative recovery.

Transdermal release

This method can be performed with or without visualization. Percutaneous release without visualization (blind) is performed using anatomical landmarks to avoid damage to tendons and neurovascular structures. Recovery time is shorter than with open surgery, but there is a greater chance of nerve damage to the fingers, especially the 1st, 2nd, and 5th digits. The new ultrasound-guided technique helps clearly identify tendons and neurovascular bundles, preventing the potential complications that arise with percutaneous release without imaging, and also compares favorably with surgical techniques.

Sequence of the operation:

• Skin incision (Fig. 3).
• Preparation of neurovascular bundles passing next to the tendon and tendon sheaths.
• Preparation of the A1 annular ligament (Fig. 4).
• Dissection and partial removal of the A1 annular ligament (Fig. 4).
• If necessary, removal of tissues of the synovial membrane altered by inflammation.
• Pulling the flexor tendons to look for any changes caused by inflammation and, if necessary, separate the tendons that have stuck together.
• Tendons slide freely in the tendon sheath
• Ultimate control of the integrity of both neurovascular bundles.
• Suture
• Pressure bandage

Stages of the disease

In medicine, there are 3 stages of development of trigger finger syndrome:

1st stage. The very beginning of the development of the disease. Symptoms are mild and there is minor pain.

2nd stage. It is at this stage of the disease that many patients come to the clinic, as the symptoms become more pronounced.

3rd stage. This period is accompanied by complications and requires long-term complex treatment.

Causes of the disease

In the body of a healthy person, the tendon-ligamentous apparatus is capable of producing a special fluid (synovial). It is this that protects individual parts of the joints from abrasion and rapid wear.

Under the influence of certain factors, the amount of fluid released decreases, the annular ligament thickens, and the lumen of the canal becomes smaller. Such changes lead to disruptions in the functioning of the tendon-ligamentous apparatus. Parts of the joints stop sliding and rub against each other. This causes microtrauma and the appearance of growths.

Risk factors

The following factors may increase your risk of developing trigger finger syndrome:

• Increased load on the hands. This risk group includes people engaged in manual labor: seamstresses, drivers, mechanics, workers engaged in manual production of certain types of products.
• Diabetes.
• Pregnancy. During this period, women's blood circulation is impaired, which contributes to the appearance of foci of inflammation in the joints.
• Incorrect (uneven) bone development in childhood and adolescence.
• The presence of diseases such as gout and rheumatoid arthritis.
• Anomalies and pathologies of the phalanx joints.
• Heredity. If among close relatives there is a person diagnosed with nodular tendonitis, then the risk of the disease developing in the heirs increases.

Prevention

The above methods and remedies fully answer the question of how to cure trigger finger syndrome. There are many treatment options now, but it is much easier and faster to block Knott's disease at the earliest stages of development.

The periodic appearance of swelling of the fingers, a feeling of numbness and tingling indicate that problems have begun. In this case you can:

• Give your hands a long rest.
• Alternate types of load.
• Use Ibuprofen ointment to relieve inflammation, swelling and pain.

At the same time, you need to remember that you should not delay your visit to the doctor. Even treatment with effective means should be started only after a medical examination and diagnosis. The maximum effect is achieved when using complex treatment methods.

Stenosing ligamentitis in children – to operate or not?

And finally, the most important question is whether to perform surgery on a child with a snapping finger or not? There is no doubt that there are cases when all manifestations of ligamentitis in a child go away on their own. According to some studies, a pattern can even be drawn - the younger the pathology is noticed and the lower its degree, the greater the chances of self-healing. It is also logical that if a child is over a year old and the thumb does not extend either actively or passively, there is little point in expecting the symptoms to go away spontaneously. You can find out what is best to do in your situation, to operate or wait, and also get answers to other questions that interest you in a consultation with a doctor specializing in hand surgery for children.