In 2019, the German Social Accident Insurance (DGUV) counted 262,629 hand injuries. And this figure only refers to accidents at work. Many hand injuries are accompanied by an open wound. In this article, we look at how hand injuries occur and how the body reacts to them. We also look at the healing phases and how you can support your body in the process.
What causes wounds in the hand area?
Hand injuries are extremely common. This is not surprising, as we use our hands every day for a wide variety of activities. The likelihood of slipping with a knife in the kitchen, twisting a finger in sports or sustaining major injuries in the trades increases.
The mishap is often followed by a more or less large wound as a visible result. Surgical treatments also result in a wound: after the operation, a cut remains in the skin that has been sutured and must now heal.
Caution: Not every nodular change in the hand is due to Dupuytren. It is therefore essential to seek medical advice to confirm the diagnosis and rule out other conditions.
How does the body react to the hand injury?
Foreign bodies are flushed out of the wound by the bleeding.
Regardless of whether it is a surgical cut or a botched handiwork: first the wound bleeds because vessels have been injured. The blood flow is quite conducive to flushing out foreign bodies on the surface.
The bleeding gradually stops when blood platelets, the thrombocytes, attach to the wound edge and stick together.
This process also triggers a constriction of the injured blood vessels and thus prevents greater blood loss.
Fibrinogen, a substance that forms a fine mesh on the wound surface, binds to the platelet, creating an initial, provisional covering.
To further help stop bleeding, apply light pressure to the hand injury using sterile compresses from the first aid kit. You can also use a gauze bandage to create a pressure bandage.
However, do not wrap the gauze bandage too tightly: the blood flow to the hand should not be cut off under any circumstances.
Platelets and fibrinogen stick together like a net.
Holding the patient up or positioning them above the level of the heart will also help to stop the bleeding. If the bleeding does not stop, it may be advisable to call the emergency services.
For further care, you should see your family doctor to have the wound cleaned and, if necessary, treated with tissue glue, a staple plaster or, in the case of very deep wounds, with a suture. He or she will apply a dressing to protect the wound, which you can change yourself at home if the doctor agrees.
Why is inflammation helpful?
Minutes after the hand injury, the region becomes inflamed. Inflammation is a process of the immune system that helps the wound heal. This is not to be confused with infection, which is caused by contamination and hinders the healing process.
While inflammation promotes healing, infection hinders it.
Messenger substances are distributed via the wound fluid in the wound bed.
The injured area is supplied with more blood through the inflammation and messenger substances are released into the tissue. After a short time, the so-called wound bed is filled with wound fluid, which contains important substances to break down destroyed cells and to build up a temporary closure.
Due to the high blood circulation, the wound region becomes red, warm and swells. This creates pressure on the nerve endings, which explains the wound pain.
What relieves wound pain?
Was perhaps also your first thought here: "cool"? Using cooling pads on a sore injury is not nearly as beneficial as you might think.
In cold conditions, fewer messenger substances and immune cells are transported into the wound bed. The inflammatory reaction described above is reduced and thus initially improves the wound pain. However, this stands in the way of the body's own clearing work in the injured tissue. After all, inflammation is a process initiated by the immune system that helps the wound to heal.
Instead, it is recommended to continue to move the hand carefully, at least the uninjured fingers, especially in the case of minor injuries. In this way, the lymph fluid keeps moving, does not accumulate in the hand and thus reduces the pressure pain in the wound.
Instead of cold, even heat can help with wound healing: Infrared A-rays can be used early after the injury to boost the healing processes.
How does the body form new tissue?
The first reactions directly after the hand injury are followed by the second phase of wound healing, which is mainly concerned with the formation of new tissue. Within the first three days, the so-called granulation tissue forms, in which new blood capillaries are already forming to advance wound closure.
The epithelial cells, the uppermost layer of intact skin, migrate on the wound surface and in the depth of the wound. They divide there to span the wound. In order for this process to take place optimally, the wound must be kept moist in the first few days, for example with a plaster.
Cells divide in the depth of the wound and form the granulation tissue.
After a few days, the moisture is no longer needed for healing and the hand injury heals better in the fresh air. If in doubt, discuss these details with your family doctor to be on the safe side.
However, direct contact with water, for example when showering, should be avoided in any wound healing phase. Use a waterproof plaster for this or completely avoid contact with the injured hand when showering.
How do I protect the wound with dressings?
Regular dressing changes every one to two days are crucial to keep the wound clean and prevent infection. If your doctor gives the OK, you or a family member can apply new dressings yourself.
Wash and disinfect hands thoroughly before changing. Carefully remove the old dressing material. If it sticks to the wound, do not tear it, but soften the material with a saline solution from the pharmacy.
You can also use the saline solution afterwards to remove blood residues from the surface of the wound. To avoid destroying the healing tissue, rinse the wound instead of wiping it with a cloth. Dab the remaining saline solution carefully with sterile compresses.
To apply a new dressing, place a new sterile compress on the wound and wrap the injured hand generously with a gauze bandage. For minor injuries, you can also use a plaster. The adhesive strips must not touch the wound area under any circumstances.
Why should the wound not contract too much?
About three days after the injury, wound contraction begins: myofibroblasts pull the wound edges closer together, shrinking the wound surface and thus minimising the necessary formation of new cells.
In principle, this process is beneficial for wound healing. However, especially in the fine structures of the hand, movement can be restricted if the wound contracture causes tension on the surrounding tissue. In the case of a wound on the back of the hand, for example, the closing of the fist can be restricted.
To avoid movement restrictions, hand therapy starts a few days after your injury. In addition, you should carefully perform movement exercises at home, which your therapist will show you. This way, the edges of the wound are always under controlled tension and cannot contract too much.
How does the body eventually repair the injury?
After four to five days, the last phase of wound healing begins: reparation. It is important to distinguish between repair and regeneration. Regeneration means tissue-specific restoration, which in the human organism is limited to the epithelia, i.e. the uppermost skin layer. Reparation, on the other hand, means a replacement of the destroyed tissue with non-specific connective tissue.
The established blood capillary network of the wound is expanded and collagen fibres are brought in to make the wound more resistant to tearing. This process is usually completed two weeks after the injury.
Again, regular exercise helps to increase the tensile strength of the resulting scar: Mobilisation exercises bring a controlled pull on the new tissue and stimulate it to become more resistant.
Repair of the injury with non-specific connective tissue.
Let us summarise
After a hand injury, the wound goes through different phases. The first one starts seconds after the injury and is controlled by the immune system. Through good wound care, you can support the body to form new tissue.
In the healing process, it is then important to immobilise the hand only as little as necessary and to continue moving uninjured parts. In this way you counteract long-term movement restrictions in your hand.
The three phases of wound healing. What happens once the hand injury has healed? Learn more about scar treatment in the next article!
Bibliography
Waldner-Nilsson (ed.) (20133a): Hand Rehabilitation. Volume 1 Fundamentals, Diseases. Heidelberg / Berlin: Springer-Verlag.
Waldner-Nilsson (ed.) (20132b): Hand Rehabilitation. Volume 2 Injuries. Heidelberg / Berlin: Springer-Verlag.
Clauss W., Clauss C. (2018) Skin. In: Human biology compact. Springer Spektrum, Berlin, Heidelberg. (221-242)
N. E. Bringelandhttps://www.thieme.de/de/presse/kaelte-bei-verletzungen-123302.htm
Deutsche Gesetzliche Unfallversicherung (2019): Statistik Arbeitsunfallgeschehen 2019. <https://publikationen.dguv.de/widgets/pdf/download/article/3893 >
