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Adherent Cicatrix After Below-Knee Amputation

Magnus Lilja
Tony Johansson

ABSTRACT

This article will examine the causes, healing processes, prevention and treatment of adherent scars. Treatments discussed include surgery, prosthetics and physiotherapy. Thorough understanding and proper treatment of adherent scars decreases recovery time for patients.

Introduction

One of many problems in amputation surgery is whether the patient is left with a sear on the residual limb after the wound has healed. Under normal circumstances, adherent scars can be removed to a certain degree. Common problems associated with adherent scars are blister wounds, necrosis and skin irritation. An adherence also can prolong rehabilitation.

Wound Healing

Deep wounds heal by creating a scar formed of collagenous fibrous tissue. The skin remains as a thin and sensitive epithelium. All damages deeper than the epithelium will always leave a scar.

The healing process can be divided into three phases: inflammation, fibroplasia and maturation.

• Inflammation will clean damaged areas of any debris and bacteria.
• The fibroplastic phase involves formation of new tissues. It begins with production of an unstructured collagen network and ends as the cicatrix reddens due to high vascularization of the granulation tissues.
• The maturation phase occurs when the collagen network remodels itself to better resist strain. As this phase continues, the vascularization will be reduced, and the cicatrix will whiten. After several years, the cicatrix will become brown (1).

Primary and Secondary Healing

Healing is usually primary or secondary.
Primary healing is obtained with a minimum of tissue damage. One example is the surgical wound. Inflammation and the demands on tissues are minimal. Primary healing is the optimal process.
Secondary healing occurs when an open area is remodeled with granulation tissue. This process usually generates a cicatrix covered by an easily damaged epithelium. Secondary healing will prolong the time for the wound to heal, generate scarring and often be accompanied by a higher risk of infection and adherences.

Adherence Prevention

Amputation adherences can arise from surgical complications, bad prosthetic fitting, a too-tight dressing or low sensitivity in the residual limb. The surgical complications and effects of the amputation can be divided into four categories:

• A primary healed wound that has a stretching tendency in the skin
• Secondary wound healing because of necroses and subsequent adherences
• Amputation after a trauma
• Poor fixation of the soft tissues

If the skin covering the end of the residual limb is too tight, the wound can experience problems while healing. The result can be an adherent scar and an increased risk of necrosis. Secondary wound healing, after necrosis, produces a sequelae. The healing proceeds from the skin through the soft tissues and to the skeletal structures.

In amputation surgery gentle handling of the skin and soft tissues is very important, otherwise several wound healing problems may occur (2). Infection prophylaxis with an antibiotic is also important.

Amputations after trauma have other prerequisites. The aim is to save as much of the leg as possible and to obtain good function (3). The adherence is then of a secondary interest. If the residual limb is not well fixated postoperatively, the soft tissues might hang over the distal end of the tibia, and a pressure wound may result. After transtibial amputation, plaster could be used as a splint to stop knee flexion, but plaster can obstruct checking the wound (4). Fever, odor or pain will demand immediate control and change of the plaster.

Ulcers in the scar may occur late in the healing process due to poor fitting of the prosthesis, which in some cases can cause pressure over the distal end of the tibia or unwanted large pendular and piston movements of the bone. These movements can lead to lacerations of the skin and rupture of the sutured wound. The piston movement does not only have negative consequences, it also has positive effects on the vascularization of the tissues (5,6).

Treatment

The best way to minimize the risk of developing adherences is by performing amputations carefully and according to documented standards (7). If an adherence still occurs, there are several ways to treat it.

• Surgery offers several possible treatments, including reamputation, resection and excision (8,9,10). In reamputation one has to find the optimal balance between removing too much and too little. In the latter case, there is a risk for new adherences (8).
• Prosthetics. The prosthetic solution is to achieve the highest quality of suspension as possible between the residual limb and the prosthetic socket. One can also immobilize the skin on the limb by stretching out the soft tissues and applying a suction socket. A similar effect can be achieved with a silicone liner (11). The silicone liner will compress all soft tissues and should be as tight as possible. All movements of the prosthesis will then take place between the silicone liner and the outer socket.
  
  When the soft tissues are prestretched, the limb is pulled into the inner socket with a tube stocking. The prosthesis will then be pressed upward against the limb, resulting in good suspension of the prosthesis. This will also reduce possible movements, and the distal end of the tibia will become embedded in protective soft tissues (6). It is also common to expand the outer socket over the adherence to reduce pressure.
• Physiotherapy, such as massage, will move the skin in relation to the underlying structures. If the massage is given during the healing procedure, serious adherences may be avoided.

Most research concerning transtibial amputation shows a 15 percent reamputation frequency and 15 percent secondary wound healing (10,12,13). In a series of 109 healed transtibial amputations in Sweden, 9 percent had adherent scars (13). Most of these scars were caused by secondary wound healing. When these adherences cause impaired function, a surgical revision should be considered as soon as possible. Without it, rehabilitation may be delayed or decreased. Contraindications for the surgical revision may be vascular disease or risk of infection.

Conclusion

Fundamental knowledge of adherences is of great importance for practitioners who treat patients with adherence problems. Understanding and treatment quality will increase, and re habilitation time will decrease.

Magnus Lilja is an orthopedic engineers in the department of biomechanics and orthopedic technolohy at the University College of Health and Care, Box 1038, S-55111 Jonkoping, Sweden.

Tony Johansson is an orthopedic engineers in the department of biomechanics and orthopedic technolohy at the University College of Health and Care, Box 1038, S-55111 Jonkoping, Sweden.

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