CPT® Code 20973

Official Description

Free osteocutaneous flap with microvascular anastomosis; great toe with web space

Common Language Description

A free osteocutaneous flap is a surgical procedure utilized to address complex defects involving both soft tissue and bone. This technique is particularly important in reconstructive surgery, where the goal is to restore both the aesthetic and functional aspects of the affected area. The procedure involves the careful harvesting of a flap that includes skin, subcutaneous tissue, and bone from a donor site, which in this case is the great toe with web space. The process begins with the measurement of the defect that needs repair, followed by the determination of the dimensions of the cutaneous portion of the flap. Surgeons meticulously draw incision lines on the skin at the donor site, ensuring precision in the harvesting process. Once the incision is made, the skin is dissected from the underlying tissues while preserving the vascular pedicle, which is crucial for maintaining blood supply to the flap. The underlying musculature is then exposed, and care is taken to preserve the associated blood vessels and nerves. The bone that will be harvested is also exposed, and the surgeon carefully determines the amount needed to fill the bony defect. After harvesting the osteocutaneous flap, which includes intact vascular structures, it is transferred to the recipient site where the defect is located. The bone is positioned within the bony defect and secured in place, while the vascular structures of the flap are anastomosed to the blood vessels at the recipient site using microvascular techniques. 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 alternatively, a separately reportable skin graft may be utilized to repair the donor site. This procedure is essential for restoring function and appearance in areas affected by significant tissue loss or damage.

1. Indications

The free osteocutaneous flap with microvascular anastomosis is indicated for the repair of complex soft tissue and bony defects, particularly in the great toe with web space. This procedure is typically performed in cases where there is significant tissue loss due to trauma, surgical resection, congenital defects, or other pathological conditions that compromise the integrity of the soft tissue and bone in the affected area.

Complex Defects Repair of intricate soft tissue and bony defects that require both structural and aesthetic restoration.
Trauma Management of injuries resulting in substantial loss of tissue and bone, necessitating reconstruction.
Surgical Resection Reconstruction following the removal of tumors or other pathological tissues that have compromised the area.
Congenital Defects Addressing congenital anomalies that affect the structure and function of the great toe and surrounding web space.

2. Procedure

The procedure begins with the assessment of the defect that requires repair. The surgeon measures the dimensions of the defect and determines the size of the cutaneous portion of the flap needed for adequate coverage. Following this, incision lines are carefully drawn on the skin at the donor site, which is the great toe with web space. The skin is then incised along these lines, and the dissection is performed to separate the skin from the underlying tissues while preserving the vascular pedicle, which is essential for the flap's blood supply.

Step 1: The skin at the donor site is incised along the predetermined lines, allowing access to the underlying tissues.
Step 2: Dissection continues to separate the skin from the underlying musculature, ensuring that the vascular pedicle remains intact to maintain blood flow.
Step 3: The underlying musculature is exposed, and care is taken to preserve the blood vessels and nerves that are critical for flap viability.
Step 4: The bone to be harvested is then exposed, and the surgeon determines the amount of bone necessary to fill the bony defect.
Step 5: The osteocutaneous flap, which includes both skin and bone with intact vascular structures, is carefully severed from the donor site.
Step 6: The harvested flap is transferred to the prepared recipient site where the defect is located.
Step 7: The bone component of the flap is inset into the bony defect and secured in place to restore structural integrity.
Step 8: The vascular structures of the flap are anastomosed to the blood vessels at the recipient site using microvascular techniques to ensure proper blood supply.
Step 9: Finally, the skin portion of the flap is positioned in the defect and secured with sutures to complete the reconstruction.

3. Post-Procedure

Post-procedure care involves monitoring the vascular status of the flap to ensure adequate blood supply and healing. Patients may require pain management and wound care instructions to promote recovery. The donor site may also need to be monitored for signs of infection or complications. Follow-up appointments are essential to assess the healing process and the functional outcomes of the reconstruction. Depending on the extent of the procedure and the individual patient's condition, rehabilitation may be necessary to restore full function to the affected area.

Short Descr	BONE/SKIN GRAFT GREAT TOE
Medium Descr	FR OSTQ FLAP W/MVASC ANAST GRT TOE W/WEB SPACE
Long Descr	Free osteocutaneous flap with microvascular anastomosis; great toe with web space
Status Code	Active Code
Global Days	090 - Major Surgery
PC/TC Indicator (26, TC)	0 - Physician Service Code
Multiple Procedures (51)	2 - Standard payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50)	1 - 150% payment adjustment for bilateral procedures applies.
Physician Supervisions	09 - Concept does not apply.
Assistant Surgeon (80, 82)	2 - Payment restriction for assistants at surgery does not apply to this procedure...
Co-Surgeons (62)	1 - Co-surgeons could be paid, though supporting documentation is required...
Team Surgery (66)	0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family	99 - Concept Does Not Apply
APC Status Indicator	Hospital Part B services paid through a comprehensive APC
ASC Payment Indicator	Office-based surgical procedure added to ASC list in CY 2008 or later without MPFS nonfacility PE RVUs; payment based on OPPS relative payment weight.
Type of Service (TOS)	2 - Surgery
Berenson-Eggers TOS (BETOS)	P5B - Ambulatory procedures - musculoskeletal
MUE	1
CCS Clinical Classification	161 - Other OR therapeutic procedures on bone

51	Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d).
59	Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
CC	Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
LT	Left side (used to identify procedures performed on the left side of the body)
RT	Right side (used to identify procedures performed on the right side of the body)