Carpal tunnel syndrome is a reaction of the tendon sliding tissue, which can be accompanied by the classic signs of inflammation such as swelling, overheating, pain, redness and restriction of movement. Basically, inflammations of the tendon sheaths are classified according to the affected body region and the cause. Basically, two causes of tendosynovitis can be distinguished. The inflammation can be triggered by pathogens or by tissue changes. Undetermined changes in the tissue are the most common cause of inflammation of the tendon sheaths. Frequently affected body regions include the elbow (tennis elbow), the shoulder (rotator cuff), the Achilles tendon and the hand (snap finger) and the wrist (tendovaginitis stenosans de Quervain). Many terms are used synonymously for tendosynovitis: Tenosynovialitis, tenosynovitis, endosynovitis, tendovaginitis, tendovaginosis, perivaginitis, peritendinitis, paratenonitis, tendinopathy or tendinitis. Not infrequently, the diagnosis of tendovaginitis is misused for unspecific pain. The diagnosis of tendovaginitis should be based on a careful clinical examination. In case of doubt, similar clinical pictures are excluded by further examinations.
Most frequently, inflammation of the tendon sheaths is caused by remodelling processes of the tendon sliding channel and the tendons. Hardening of the tendon canal and thickening of the tendons lead to an increase in resistance. The mechanical stimulus damages the tissue and causes an inflammatory reaction and the formation of new blood vessels. The inflammation increases tissue remodeling and thus maintains a vicious circle.
There are different assumptions about the causes of tissue remodeling. These assumptions include overload, injuries, hormonal changes, rheumatic diseases, metabolic diseases (gout, amyloidosis, mucopolysaccharidosis), diabetes, thyroid diseases, certain antibiotics (fluoroquinolones) and congenital variations of tendons.
When looking at the connections, causes and triggers are sometimes confused. If, for example, a heart attack occurs during sport, the sport has triggered the heart attack but not caused it. Carrying a baby in the arm can trigger pain in the event of tendon sheath inflammation of the wrist. However, the cause of the inflammation is due to the hormonal changes caused by pregnancy. The observation that women are more frequently affected, especially during pregnancy and breastfeeding or during the menopause, supports the assumption of a hormonal cause. Studies have shown that a binding site (receptor) for a female hormone (estrogen) is particularly abundant in the tissue of tendonitis (Po-Chuan Shen, et al., 2015, Int J Mol Sci).
Genetic fingerprinting has shown that certain segments of the genetic material are more common in people with tendinitis. The suspicious sections (KLHL1 and POLE2) control the formation of connective tissue cells (fibroblasts) and the repair processes of the genetic material (Sood RF, et al., 2020, Plast Reconstr Surg).
Tendon sheath inflammation occurs preferentially at natural bottlenecks in the tendon compartments of the wrist and hand. Even the smallest changes lead to a narrowing of the tendon gliding space. The following tendon sheath inflammations are more common on the hand and wrist:
- A1 Ringbandstenose is an inflammation of the finger flexor tendons. It is popularly known as snap finger or quickening finger.
- Tendovaginitis stenosans de Quervain is an inflammation of the first extensor tendon compartment on the spoke-side wrist and is colloquially called housewife's thumb.
- The intersection syndrome is a rare inflammation four to eight centimeters from the body near the wrist where several tendons cross (tendons of the Musculus abductor pollicis longus as well as the Musculus extensor pollicis brevis and the tendon of the Musculi extensor carpi radialis brevis et longus).
- Inflammation of the third extensor tendon compartment (long extensor muscle) occurs in up to five percent of cases of distal radius fractures. Damage to the thumb extensor tendon can lead to a tendon rupture.
- Inflammation of the fourth and fifth extensor tendon compartment is rare and is often accompanied by rheumatic disease.
An inflammation of the tendon sheath is mainly noticeable through pain. The pain usually begins gradually, without a previous fall or unusual strain. Certain movements can suddenly trigger or increase the pain. During the examination, the location of the strongest pain can usually be determined precisely. In technical terminology, this point is called the pointum maximum. This is where a nodular thickening of the tendon is often felt. After some time, powerful movements can no longer be performed due to pain. If the inflammation lasts longer, the area can swell. Spreading redness and overheating are more characteristic of inflammation caused by pathogens. The increased resistance of the inflamed tendon sheath can rarely be heard. The frictional noise is compared to the crunching of fresh snow (snowball crunch) or the creaking of leather.
Since the 5th Ordinance on Occupational Diseases 1952, diseases of the tendon sheaths or tendon gliding tissue have been recognized as occupational diseases under number 2101 under certain conditions. On closer inspection, it can be seen that the underlying scientific publications do not distinguish between trigger and cause. A temporal connection, such as the occurrence of a heart attack after sporting activity, does not mean that sport is the cause of heart attacks. In the case of tendosynovitis, certain movements cause the pain. The frequent occurrence of pain during working hours was sufficient at that time to deduce a causal relationship (Troell A., 1918, Langenbeck's Archive for Surgery; Schwarz W., 1933, Archives of Orthopaedic and Trauma Surgery). Previous scientific publications are of insufficient quality to prove a cause-and-effect relationship (Stahl S, et al., 2013, Plast Reconstr Surg). The many uncertainties regarding the cause and the clinical picture are reflected in the different names. The confusing terms such as "repetitive strain injury (RSI)", "cumulative trauma disorders (CDT)" or "work related upper limb pain" are also referred to as "non-specific forearm pain". Sport climbing is an example of a form of extreme strain on the tendons and tendon gliding channels. In sport climbing, the tissue adapts to the load and becomes more resistant (Schreiber T, et al., 2015, Eur J Sport Sci). A quick finger (snap finger) is a highly unusual disorder for sport climbers. In the case of tendovaginitis stenosans de Quervain, the presumption of overloading as the cause of tendosynovitis has been refuted (Stahl S, et al., 2015, BMC Musculoskeletal Disord).
The diagnosis of a carpal tunnel syndrome is made by a specific questioning and examination. Because of the slow onset, the duration of the symptoms cannot be determined to the day. The location of the most severe pain can usually be reliably determined. In this area a water retention can be visible or palpable. The movement of the affected tendon increases the pain. Neighboring tendons or joints are not affected. With careful palpation, the point of most severe pain can be precisely assigned to the affected tendon. The exact identification of the point where the pain is most pronounced is crucial to making a diagnosis. Occasionally, a thickened tendon can be palpated. In case of doubt, other diseases or injuries with similar complaints must be excluded. The detection of injuries or diseases of the bones or joints requires a specific X-ray examination. Painless swellings of the tendon sheaths at untypical locations can be more closely classified by magnetic resonance imaging. A blood test can confirm but not completely rule out the suspicion of a rheumatic disease, gout or infection. If an infection of a tendon sheath is suspected, a prompt surgical examination and treatment is indicated.
A specialist with the additional qualification of hand surgery has the necessary knowledge and experience to diagnose and treat tendonitis. The protected specialty title of hand surgery requires a special three-year training, following a surgical specialist certification. Hand surgery is an important part of the specialist training in plastic and aesthetic surgery. A hand surgeon and plastic surgeon therefore has more than nine years of professional experience in the field of hand surgery. A plastic surgeon is characterized by a tissue-conserving approach and mastery of the techniques of microsurgery and tissue replacement. The European recognition as a hand surgeon (FESSH: Federation of the European Societies for Surgery of the Hand) is obtained by passing a written and oral examination lasting several days. A hand surgeon is familiar with the surgical and non-operative treatment options. With appropriate experience, a hand surgeon is able to treat all complications and symptoms of the hand. Research and teaching in the field of hand surgery are a special distinction and convey a sound and up-to-date knowledge.
The Internet provides a variety of different recommendations for the treatment of tendinitis. The effectiveness of many forms of therapy is poorly or not at all proven. Naturopathic agents such as bromelain, propolis and the ingredients of arnica flower have a decongestant or anti-inflammatory effect. Similar active ingredients are also found in horse ointment (essential oils and arnica) or in the Retterspitz® tincture (essential oils and arnica). These remedies are not approved for the treatment of tendosynovitis, as there is no factual evidence of their effect. Scientific evidence for the effect of household remedies such as curd wrap or healing earth has not been published to date. There is also no scientific evidence for the effects of homeopathy, acupuncture, stimulation current (TENS) or laser treatment for tendinitis. A change in diet cannot influence the course of tendosynovitis. The evidence for an effect of injections of hyaluronic acid or Platelet Rich Plasma (PRP) is of little significance. Certain drugs such as diclofenac (Voltaren®) or ibuprofen inhibit the inflammatory process. Taking anti-inflammatory drugs for weeks can lead to severe side effects. Splints, bandages or tapes prevent pain. However, immobilization over several days may result in permanent movement restrictions. Raising and cooling the hand promotes the reduction of swelling. Movement exercises, physiotherapy or hand therapy are an important part of the treatment at the right time. An ergonomic mouse and keyboard as well as temporary use of the cell phone are useful to avoid painful movements. The use of extraporal shock wave therapy (ESWT) for the treatment of tendonitis is controversial (Surace SJ, et al., 2020, Cochrane Database Syst Rev).
On the wrist, cortisone injections are particularly effective when the symptoms have not been present for a long time (Abi-Rafeh J, et al., 2020, Plast Reconstr Surg). Short-term relief of symptoms with cortisone injections is well documented. One year after the cortisone injection, the symptoms recur in about 50 percent of patients. In 99 percent of cases, surgery leads to permanent relief of symptoms of tendon sheath inflammation of the hand. The risks of an operation in the hand of a hand surgeon are no greater than those of a cortisone injection (Hansen RL, et al. 2017, J Hand Surg Am).
The injection of cortisone is a widely used treatment for both wrist and hand. Cortisone influences the cell metabolism in many different ways. Cortisone inhibits the signal transmission in inflammatory processes. The production of collagen is reduced. Cell proliferation and the maturation of stem cells are impaired. The lifespan of cells of connective tissue (fibroblasts) is reduced. Cortisone can weaken tendons and, especially with repeated use, can lead to tendon rupture (Abate M, et al., 2017, Expert Opinion Drug Saf).
Cortisone is often used as an umbrella term for an entire group of active ingredients. When considering the risks, it is therefore necessary to make a precise distinction. The risks of cortisone injections depend on the active substance, the quantity injected and the number of treatments. The active substances used include methylprednisolone, triamcinolone, dexamethasone and betamethasone. The potency of dexamethasone and betamethasone is about five times greater than that of methylprednisolone and triamcinolone. The single targeted application of the smallest possible amount of active ingredient has fewer side effects than the frequently repeated application of a large amount. In about 50 percent of cases, improvement can be expected after one to two treatments (Hansen RL, et al. 2017, J Hand Surg Am). In the case of long-term complaints, older patients and diabetes, the success of treatment is usually temporary (Eltorai AEM, et al., 2019, Clin Orthop Relat).
Since cortisone can damage pigment-forming cells, light or dark spots may appear on the skin. The reduced formation of collagen weakens the elasticity of the skin and can lead to tendon rupture. The change in cell metabolism can lead to vascular drawing and a loss of fatty tissue. This change often improves by itself after nine to twelve months. Changes in the skin can be expected on the wrist in 31 percent of cases and on the elbow in 40 percent of cases (Pace CS, et al., 2018, J Hand Surg Am). The risk of infection is estimated at 0.16 percent (Brinks A, et al., 2010, BMC Musculoskeletal Disord).
Before the injection, both the patient and the dentist should wash their hands thoroughly, preferably with a disinfectant soap (e.g. HiBiScrub® Plus from Mölnlycke, Octenisan® Wash Lotion from Schülke, Prontoderm® Shower Gel from B.Braun). Precise observance of hygiene measures prevents the risk of infection. This includes wearing gloves and adhering to the exposure time of the disinfectant. The cortisone is diluted with physiological saline solution directly before use. In the hand, the injection of half a milliliter of the triamcinolone solution with a very fine hollow needle has proven to be effective. A superficial injection can cause damage to the skin and a deep injection can cause damage to the tendon. On the hand and wrist, the injection of ten milligrams of triamcinolone is usually sufficient. The injection site is connected with a plaster.
The onset of tendosynovitis is usually gradual. The pain can last for weeks or months. It is not recommended to take it easy for several weeks, as muscle atrophy or stiffening of the joints can occur. An inability to work is, depending on the professional activity, only useful for a few days, for example after an operation. The earlier a treatment is performed, the more likely it is to heal and the faster recovery. If the symptoms last longer than three months, it is called chronic tendosynovitis (Sobel AD, et al., 2019, Clin Orthop Relat Res).
Every treatment should be preceded by an examination. If the hand surgeon detects tendinitis, you can be sure that you will not have to worry. Treatment for tendinitis of the wrist or hand does not pose any danger to the baby. In the case of a cortisone injection, a targeted injection of half a milliliter or ten milligrams of triamcinolone is sufficient. If a cortisone injection does not lead to an improvement, the surgical procedure can be performed under local anesthesia. There is no evidence of pregnancy being impaired when using a local anesthetic (Paul A Moore, 2016, J Evid Based Dent Pract; Hagai A, et al., 2015, J Am Dent Assoc).
Studies have shown that a binding site (receptor) for estrogen is particularly abundant in the tissue of tendon sheath inflammation (Po-Chuan Shen, et al., 2015, Int J Mol Sci). Since there is a hereditary predisposition, prevention is not possible (Sood RF, et al., 2020, Plast Reconstr Surg). A change in lifestyle or eating habits is not suitable to prevent the development of tendinitis. In principle, an ergonomic workplace is useful to avoid unnecessary stress. In the case of tendovaginitis stenosans de Quervain, certain manual activities can cause pain, and unusual sporting activity can trigger a heart attack. Since manual activities do not cause tendosynovitis, avoiding stress does not help to prevent it.
Tendovaginitis stenosans de Quervain is a tendosynovitis of the thumb tendons on the spoke-side wrist. Colloquially, the term housewife's thumb is also used, while the abbreviation TVS is also common in the technical language. The disease was first described at the beginning of the 19th century by the Swiss surgeon de Quervain. Similar to the guide ring of a fishing rod, the tendons are guided on the hand by tendon fans. A thickening of the tendon fan or tendon prevents smooth sliding. In tendovaginitis stenosans de Quervain the first extensor tendon compartment is affected. Here two to three tendons of the short thumb extensor muscle (Mm. Extensor pollicis brevis) and the tendon of the long thumb abductor muscle (abductor pollicis longus) run through. Occasionally, the first extensor tendon compartment is divided from birth by an additional tendon compartment (Nam YS, et al., 2018, Ann Anat). Tendovaginitis stenosans de Quervain usually occurs in women around the age of fifty (Stahl S, et al., 2015, BMC Musculoskeletal Disord). Every year, tendovaginitis is diagnosed in one in a thousand people (incidence: 0.94 per 1,000 person-years; Wolf J M, et al., 2009, J Hand Surg Am). One in two hundred people in the general population has de Quervain tendovaginitis (prevalence: 0.49%; Shen PC, et al., 2019, Medicine (Baltimore)). Chronic inflammation of the first extensor tendon compartment can lead to tendon rupture (Yuen A, et al., 2006, J Hand Surg Br).
In tendovaginitis stenosans, a binding site (receptor) for estrogen is found in particularly large numbers in the tendon sheath tissue (Po-Chuan Shen, et al., 2015, Int J Mol Sci). Indeed, women around the age of 50 and during pregnancy and lactation are conspicuously frequently affected by tendovaginitis stenosans de Quervain. It is assumed that there is an inherited predisposition. The widespread assumption that overloading causes tendovaginitis stenosans de Quervain has been refuted (Stahl S, et al. 2015, BMC Musculoskeletal Disord).
The description of your symptoms and the examination of your wrist are usually sufficient for a hand surgeon to diagnose tendovaginitis stenosans de Quervain. Two examination procedures help hand surgeons to diagnose tendovaginitis. In the so-called Finkelstein test, the patient places his forearm on a table so that the hand protrudes and the wrist is moved ulnarly (towards the little finger). If a gentle pressure on the metacarpus causes pain, an inflammation of the first extensor tendon is likely. In the Eichhoff test, the thumb is enclosed by the fist closure and the wrist is moved in an ulnar direction. This causes pain at the extensor tendon compartment with pinpoint accuracy (Elliott BG, 1992, J Hand Surg [Br]).
The following measures can provide temporary relief in the case of tendosynovitis:
- The protection of the wrist
- A light cooling with cooling pad or ice water
- A short-term immobilization in a splint
- The elevation of the wrist above heart level
- Anti-inflammatory pain relievers such as diclofenac and ibuprofen (over-the-counter)
There is no high-quality and robust scientific evidence for the benefit of home therapy, acupuncture, sclerotherapy or ozone therapy in tendovaginosis stenosans de Quervain (Rowland P, et al., 2015, Open Orthop J). The benefit of a cortisone injection and surgical intervention has been scientifically well established (Muhammad Omer Ashraf, et al., 2014, Eur J Orthop Surg Traumatol). After a cortisone injection, the symptoms often return. About one third of those affected have an additional tendon compartment. In these cases, a cortisone injection often does not help (De Keating-Hart, et al., 2015, J Hand Surg Eur Vol). The tightness of the tendon compartment is corrected in the long term by surgery.
The operation can be performed under local anesthesia and takes only a few minutes. During the operation you lie on an operating table and stretch your arm sideways. Immediately before the operation, a blood pressure cuff on the upper arm fills up to temporarily cut off the blood supply. As the blood is drained, blood loss is reduced and the surgeon has a better view. In order to be able to work very precisely and without damaging the tissue, the operation is performed with the help of magnifying glasses. A superficial skin nerve is carefully kept aside for protection. The tendon compartment is inspected through a short skin incision. The inflamed tissue is usually thickened and vascular. The tendon compartment is opened. Inflammatory tissue is removed if it hinders the sliding of the tendons. The hand surgeon examines whether there is an additional congenital tendon compartment that needs to be opened. If the tendons are sliding smoothly again, it is ensured that the tendons are guided well. If guidance of the tendons needs to be restored, the tendon compartment is restored with an extension plastic. The short incision is closed again with fine sutures and the wrist is bandaged.
The risk of complications after surgery by a hand surgeon is less than 1:500 (Goodman AD, et al., 2018, J Hand Surg Am). In general, the risks are higher in older patients, overweight patients, smokers and patients with concomitant diseases than in young healthy normal-weight non-smokers.
Disorders of wound healing or inflammation are the most common complications of hand surgery, accounting for 0.09 percent. Washing the hand with an antiseptic soap and careful disinfection before the operation prevents inflammation. Regular check-ups after the operation help to detect inflammation in time. The risk of inflammation is increased in diabetes (Sharma K, et al., 2018, J Hand Surg Am).
If the first extensor tendon compartment is split, there is a risk of injuring a skin nerve (ramus superficialis nervi radialis). Surgery in a bloodless state, fine instruments, a well-designed skin incision, gentle tissue treatment and optical magnification with magnifying glasses help to reduce the risk of nerve injury (Sterling Bunnell, 1921, Cal State J Med).
The risk of tendon snapping due to insufficient tendon guidance after surgery is less than one percent (Matzon JL, et al., 2019, J Wrist Surg). After the tendons have been detached, extension plastic surgery of the tendon compartment may therefore be useful.
Persistent complaints after surgery can have two causes. The pain can be caused by another disease or injury (scaphoid fracture, nerve irritation, joint wear). Further examinations can reveal other causes. The pain may also persist if an additional tendon compartment was overlooked. The specific examination of the thumb tendons and an ultrasound examination provides information as to whether a tightness of the tendons still exists.
In the 24 hours after the surgery, the wrist should be kept above heart level to prevent swelling. Even a slight cooling on the first day helps to reduce the tendency to swelling and thus promotes a fast healing. Movement exercises of the fingers and thumb several times an hour are important to keep the joints mobile. The pain is usually mild and can be relieved easily with light painkillers if necessary. In order to recognize a rare post-bleeding or wound healing disorder in time, the wound is examined regularly. If the wound heals well, the stitches are removed after 10 to 14 days. Three to four weeks after the operation, you can support the healing of the scar by regular creaming and massaging.