Knee Disarticulation - Indications, Procedure, and Complications

Introduction:

Knee disarticulation is a surgical procedure where the knee joint is removed, and the leg is separated from the thigh bone. This procedure is performed when amputation is required above the knee joint, but it is possible to preserve the femur bone. Knee disarticulation is a complex procedure that requires careful planning, skilled surgeons, and specialized post-operative care.

What Are the Indications of Knee Disarticulation?

• Traumatic Injuries: Severe knee joint, thigh, or lower leg injuries that cannot be repaired through reconstructive surgery may require amputation. These injuries can result from various causes, including:

1. Motor vehicle accidents.

2. Industrial accidents.

3. Sports injuries.

4. Explosions.

• Tumors: Cancerous or benign tumors that affect the bone or soft tissues around the knee may require amputation. Tumors can arise from various sources, including:

1. Primary bone tumors.
2. Metastatic cancer.
3. Soft tissue sarcomas.

• Infections: Severe infections of the knee joint or surrounding tissues may require amputation to prevent the spread of disease to other parts of the body. Infections can be caused by various pathogens, including:

1. Bacteria.
2. Viruses.
3. Fungi.

• Congenital Deformities: Congenital deformities of the lower limb, such as fibular hemimelia or proximal femoral focal deficiency, may require amputation to improve function and mobility.

• Complications From Previous Surgeries: Complications from previous surgeries, such as failed knee replacements or infected hardware, may require amputation as a salvage procedure.

• Peripheral Vascular Disease: Peripheral vascular disease, which causes reduced blood flow to the lower limbs, can lead to tissue damage and gangrene, necessitating amputation.

• Neuropathy: Peripheral neuropathy, which causes nerve damage, can result in chronic foot ulcers, infections, and deformities, requiring amputation.

• Diabetes: Diabetes can lead to peripheral neuropathy and peripheral vascular disease, increasing the risk of foot ulcers, infections, and gangrene, which may require amputation.

What Is Expected Before Surgery?

Here are some of the preparations that are typically done before knee disarticulation surgery:

• Medical Evaluation: Before surgery, a thorough medical evaluation is performed to assess the patient's overall health and to identify any medical conditions or medications that may need to be managed or adjusted before surgery.

• Imaging Tests: Imaging tests such as X-rays, MRI (magnetic resonance imaging), or CT (computed tomography) scans are usually done to evaluate the condition of the knee joint and surrounding tissues, and to help plan the surgery.

• Blood Tests: Blood tests are done to assess the patient's blood count, electrolyte balance, and coagulation status. Abnormalities may need to be corrected before surgery.

• Medications: Patients may need to adjust or discontinue certain medications, such as blood thinners, that can increase the risk of bleeding during surgery.

• Fasting: Patients are typically instructed to fast for several hours before surgery to reduce the risk of complications during anesthesia.

• Bowel Preparation: Patients may be instructed to take a laxative or enema to empty the bowel before surgery.

• Education and Counseling: Patients are usually provided with detailed information about the surgery, the risks and benefits, and the expected outcomes. They may also receive counseling and support to help them prepare emotionally for the surgery.

• Rehabilitation Planning: Patients may be referred to a rehabilitation specialist to begin planning for post-operative rehabilitation and recovery.

What Is the Procedure of Knee Disarticulation?

Here are the general steps of knee disarticulation surgery:

• Anesthesia: The patient is placed under general anesthesia to ensure they are unconscious and pain-free during the procedure.

• Incision: The surgeon makes a circular incision around the thigh, just above the knee joint. The skin and underlying tissues are then carefully separated to expose the knee joint.

• Soft Tissue and Bone Removal: The surgeon carefully removes the soft tissues and structures surrounding the knee joint, including the ligaments, tendons, muscles, and nerves. The patella (kneecap) is also removed.

• Preservation of Femur Bone: In knee disarticulation surgery, the femur bone is typically preserved, which can help to provide a stable base for a prosthetic limb.

• Incision Closure: The skin and soft tissues are closed with sutures or staples, and a sterile dressing is applied to the incision site.

• Drains: Depending on the surgeon's preference, one or two small tubes (drains) may be placed near the incision to help remove any excess fluid or blood that may accumulate after surgery.

• Post-operative Care: After surgery, the patient is monitored closely in the recovery room for several hours to ensure that vital signs are stable and any pain or discomfort is managed appropriately.

What Are Postoperative Care for Knee Disarticulation?

Here are some of the common aspects of postoperative care following knee disarticulation surgery:

• Pain Management: Pain medication is usually prescribed to help manage pain and discomfort following surgery. The patient's pain levels are carefully monitored and adjustments to the medication regimen may be made as needed.

• Monitoring of Vital Signs: Vital signs such as blood pressure, heart rate, and oxygen saturation are closely monitored in the recovery room and throughout the hospital stay.

• Wound Care: The incision site is carefully monitored for signs of infection and is kept clean and dry. Dressings may be changed as needed and any drainage from the wound is carefully monitored.

• Physical Therapy: Patients typically begin working with a physical therapist soon after surgery to help them regain strength and mobility in the affected limb. Exercises may include range-of-motion exercises, muscle-strengthening exercises, and gait training.

• Prosthetic Fitting: Depending on the patient's condition and recovery, a prosthetic limb may be fitted and adjusted. Patients may need to work with a prosthetist to ensure that the prosthetic limb fits properly and is comfortable to wear.

• Nutritional Support: Adequate nutrition is important for healing and recovery after surgery. Patients may be given nutritional supplements or dietary counseling as needed.

• Emotional Support: Recovering from knee disarticulation surgery can be a challenging and emotional experience. Patients may benefit from counseling or support groups to help them adjust to the physical and emotional changes associated with limb loss.

What Are the Complications of Knee Disarticulation?

Some of the potential complications associated with knee disarticulation surgery are as follows:

• Infection: Like any other surgical procedure, there is a risk of infection at the incision site or within the joint itself. Antibiotics may be prescribed to help prevent or treat infections.

• Bleeding: There is a risk of bleeding during and after surgery, which may require blood transfusions or other interventions.

• Blood Clots: Blood clots can form in the veins of the leg after surgery, which can be a serious complication. Patients may be given blood thinners or compression stockings to help prevent blood clots.

• Phantom Limb Pain: Some patients may experience phantom limb pain, a sensation of pain or discomfort in the amputated limb. Medications and other therapies may be used to help manage phantom limb pain.

• Prosthetic Limb Problems: Patients may experience problems with their prosthetic limb, such as discomfort, skin irritation, or difficulty using the limb effectively. These issues may require adjustments or repairs to the prosthetic limb.

• Joint Stiffness: Joint stiffness or contracture can occur after surgery, particularly if physical therapy is not started soon enough. Range-of-motion exercises and other therapies may be used to help prevent joint stiffness.

• Emotional and Psychological Issues: Adjusting to life after limb loss can be challenging and can lead to depression, anxiety, or other emotional and psychological issues. Patients may benefit from counseling or support groups to help them cope with these challenges.

Conclusion:

Knee disarticulation surgery is a surgical procedure that involves the removal of the knee joint while preserving the femur bone. It is typically recommended for patients with severe knee joint disease or trauma. While the procedure is generally considered safe and effective, there are potential risks and complications associated with the surgery. Proper preoperative preparation, careful surgical technique, and comprehensive postoperative care can help minimize the risk of complications and optimize patient outcomes. Patients undergoing knee disarticulation surgery should discuss the risks and benefits of the procedure with their surgeon and follow their postoperative care plan closely to achieve the best possible outcome.