CPT® Code 20970

1. Indications

The free osteocutaneous flap with microvascular anastomosis is indicated for the repair of complex soft tissue and bony defects. The following conditions may warrant this procedure:

• Traumatic Injuries: Significant tissue loss due to accidents or injuries that compromise both skin and underlying bone.
• Oncological Resection: Surgical removal of tumors that result in defects requiring reconstruction of both soft tissue and bone.
• Congenital Defects: Birth defects that lead to the absence or malformation of bone and soft tissue structures.
• Chronic Wounds: Non-healing wounds that necessitate advanced reconstructive techniques to restore function and appearance.

2. Procedure

The procedure for a free osteocutaneous flap with microvascular anastomosis involves several critical steps:

• Step 1: The surgeon begins by assessing the defect that requires repair, measuring its dimensions to determine the size of the flap needed. This assessment is crucial for ensuring that the harvested flap will adequately cover the defect.
• Step 2: Incision lines are carefully marked on the skin of the donor site, which is the iliac crest in this case. These lines guide the surgical incision to ensure optimal flap design and preservation of vascular structures.
• Step 3: The skin at the donor site is incised along the marked lines. The surgeon meticulously dissects the skin from the underlying tissues, taking care to preserve the vascular pedicle that supplies blood to the flap.
• Step 4: Once the skin is elevated, the underlying musculature is exposed. The surgeon ensures that blood vessels and nerves are preserved during this dissection to maintain the viability of the flap.
• Step 5: The bone to be harvested is then exposed. The surgeon carefully determines the amount of bone required to fill the bony defect and harvests it while preserving the bony vasculature.
• Step 6: After harvesting, the osteocutaneous flap, which includes both skin and bone with intact vascular structures, is severed from the donor site and prepared for transfer to the recipient site.
• Step 7: The harvested bone is inset into the bony defect at the recipient site and secured in place, ensuring proper alignment and stability.
• Step 8: The vascular structures within the flap are then anastomosed to the blood vessels at the recipient site using microvascular techniques, which are essential for restoring blood flow to the flap.
• Step 9: Finally, the skin portion of the flap is positioned in the defect and secured with sutures, completing the reconstruction. The donor site may be closed with sutures or, if necessary, a separately reportable skin graft may be utilized to repair the donor site.

3. Post-Procedure

Post-procedure care for a free osteocutaneous flap involves monitoring the flap for viability, which includes assessing blood flow and ensuring that there are no signs of necrosis. Patients may require pain management and should be advised on wound care to prevent infection. Follow-up appointments are essential to evaluate the healing process and the integration of the flap into the surrounding tissue. Rehabilitation may be necessary to restore function, especially if the procedure was performed on a weight-bearing area. The donor site will also require care, and the surgeon will provide specific instructions on how to manage the incision and any potential grafting that may have been performed.