[Anatomical characteristics of the saphenous branch flap with the descending genicular artery and its efficacy in repairing anterior knee wounds in elderly patients].

Objective: To investigate the anatomical characteristics of the saphenous branch flap with the descending genicular artery and its efficacy in repairing anterior knee wounds in elderly patients. Methods: This study consisted of an invasive observational study and a retrospective case series study. From April to July 2018, the anatomical study was conducted on the lower limb specimens from 5 voluntarily donated adult cadavers (4 males and 1 female, aged 52-71 years) obtained from the Department of Clinical Anatomy of Wannan Medical University. Fine dissections were performed on both lower limbs of each of the 5 cadavers. The origin of the descending genicular artery, external diameter at the origin, length at the origin, and vertical distance from the origin to the medial femoral epicondyle, as well as the origin, external diameter at the origin, and intermuscular course length of its saphenous branch were observed and recorded. From August 2018 to October 2024, 19 elderly patients (12 males and 7 females, aged 60-78 years) with anterior knee wounds meeting the inclusion criteria were treated at Yijishan Hospital of Wannan Medical University. The wound sizes ranged from 5.0 cm×4.0 cm to 15.0 cm×7.5 cm after debridement. All wounds were repaired using the saphenous branch flap with the descending genicular artery, with flap sizes ranging from 6.0 cm×5.0 cm to 16.0 cm×8.5 cm. The donor site wounds were directly sutured. Postoperative assessments included flap survival, wound healing in the donor and recipient sites, and follow-up evaluations of flap texture and appearance, scar formation in the donor and recipient sites. At the last follow-up, two-point discrimination distance of the flap was measured, the two-point discrimination of flap was graded according to the trial standards for evaluation of partial function of upper extremity by the Hand Surgery Society of Chinese Medical Association, and knee joint function was evaluated and graded using the International Knee Documentation Committee Subjective Short Form. Results: In the 10 lower limb specimens, the descending genicular artery all originated from the femoral artery, with an external diameter of (2.00±0.30) mm at the origin, a length of (0.8±0.3) cm at the origin, and a vertical distance of (12.5±0.8) cm from the origin to the medial femoral epicondyle. The saphenous branch of the descending genicular artery originated from the descending genicular artery in 8 lower limb specimens and from the femoral artery in 2 lower limb specimens. The saphenous branch of the descending genicular artery had an external diameter of (1.20±0.20) mm at the origin and an intermuscular course length of (10.0±0.8) cm. All flaps survived uneventfully after surgery, and the wounds in both donor and recipient sites healed well. During a follow-up period of 6 to 12 months, the flaps closely matched the normal skin in the recipient site in texture, color, and thickness, and only linear scars exhibited in the donor and recipient sites. At the last follow-up, the two-point discrimination was graded as S4 in 7 cases and S3+ in 12 cases; the knee joint function was rated as excellent in 11 cases, good in 6 cases, and poor in 2 cases. Conclusions: The descending genicular artery and its saphenous branch have a high occurrence rate and a constant anatomical location, and the vascular pedicle length and external diameter of the saphenous branch of the descending genicular artery are highly suitable for flap harvesting and transfer. The application of the saphenous branch flap with the descending genicular artery in repairing anterior knee wounds can achieve satisfactory recovery of donor and recipient site appearance, flap sensation, and knee joint function, making it a suitable option for anterior knee wound repair in elderly patients.