What is the step-by-step procedure for skin grafting over the distal femur (thigh bone)?

From the Guidelines

Skin grafting over the distal femur is a complex procedure that requires meticulous planning and execution to ensure optimal outcomes in terms of morbidity, mortality, and quality of life. The procedure involves several key steps, starting with the preparation of the recipient site, which includes debriding any necrotic tissue, achieving adequate hemostasis, and creating a clean, well-vascularized wound bed 1.

Preparing the Recipient Site

The recipient site over the distal femur must be carefully prepared to ensure the best possible conditions for graft take. This includes:

• Debridement of any necrotic tissue to promote a healthy wound environment
• Achieving adequate hemostasis to prevent bleeding that could compromise graft adherence
• Ensuring the wound bed is clean and well-vascularized, which is crucial for the survival and integration of the graft

Harvesting the Skin Graft

The skin graft is typically harvested from the anterolateral thigh or buttock using a dermatome set to a thickness of 0.012-0.015 inches for a split-thickness graft. The choice of donor site and graft thickness is critical and may be influenced by the size and location of the defect, as well as the patient's overall condition and availability of donor skin 1.

Securing the Graft

After harvesting, the graft may be meshed to allow for expansion and drainage, which can be particularly important over areas like the distal femur where movement and shear forces are significant. The graft is then carefully placed over the prepared defect, ensuring no folding or overlapping, and secured in place using either absorbable sutures or skin staples at the periphery.

Post-Operative Care

Post-operative care is crucial for the success of the skin graft. This includes:

• Applying a non-adherent dressing directly over the graft, followed by a bolster dressing to maintain moderate pressure and eliminate fluid collection under the graft
• Immobilizing the knee joint for 5-7 days to prevent shearing forces that could disrupt graft take
• Dressing the donor site with a semi-occlusive dressing to promote healing
• Leaving the initial dressing in place for 5-7 days to allow for graft adherence and revascularization

Considerations

While there are various techniques for wound closure, including healing by secondary intention, autologous split skin, epidermal grafting, or full-thickness grafting, split-skin grafting has been most frequently employed, usually with meshing, due to its effectiveness and relatively lower morbidity compared to other methods 1. However, the choice of closure technique may be guided by anatomical considerations, the availability of suitable donor skin, and the patient's specific needs and conditions.

From the Research

Step-by-Step Procedure for Skin Grafting over Distal Femur

The procedure for skin grafting over the distal femur involves several key steps:

• Preparation of the recipient site: This includes meticulous debridement of the recipient site and coagulation of venous bleedings to ensure a good blood supply to the wound bed 2.
• Harvesting of the skin graft: The split thickness skin graft is harvested from a suitable donor site, and if necessary, modified by the meshing procedure to ensure optimal coverage of the defect 2, 3.
• Placement and fixation of the skin graft: The skin graft is placed in the defect and fixated at the wound margins to ensure secure attachment and promote healing 2.
• Application of a compression dressing: A special compression dressing is used to cover the split thickness skin graft and promote healing. This dressing should be left in place for 5 days in case of uneventful wound healing 2.
• Postoperative care: After removal of the compression dressing, daily changes are done using double layers of fatty gauze, alternated with periods without dressing. In the case of uneventful healing, the skin transplant can be covered starting in week 2 with a thin film of cream ointment 2.

Considerations for Skin Grafting over Distal Femur

When performing skin grafting over the distal femur, several factors should be considered:

• Blood supply to the wound bed: A good blood supply to the wound bed is essential for successful skin grafting 2.
• Size and location of the defect: The size and location of the defect should be carefully evaluated to determine the most suitable type of skin graft and technique 3, 4.
• Presence of implant material: The presence of implant material that is not covered by vital soft tissue may be a contraindication for skin grafting 2.
• Local infection: Local infection may be a contraindication for skin grafting, and careful evaluation and management of the infection are necessary before proceeding with the procedure 2.

Potential Complications and Outcomes

Potential complications of skin grafting over the distal femur include:

• Partial skin graft losses: These are mostly due to a combination of inadequate debridement and local infection 2.
• Total graft losses: These are rare if the operation is done technically correct 2.
• Graft contracture and wound recipient site infection: These complications can occur, but hyperbaric oxygen therapy (HBOT) has been shown to improve graft uptake and donor site healing 5.