To combine anatomic structure study of specimen and the digital subtraction angiography (DSA) on the origination of posterior-superior retinaculum artery, so as to provide guidance for the treatment of femoral head necrosis (ONFH).

The blood supply around the femoral head was dissected in 10 fresh frozen specimens without hip diseases to observe the origin and shape of the posterior-superior retinaculum artery. The patients with ONFH admitted to the department of orthopedics in 920th Hospital of the Joint Logistics Support Force from 2020 to 2024 were retrospectively analyzed, who aged from 18 to 45 years, and accepted DSA before surgery verifying posterior-superior retinaculum artery existence. Exclusion criteria: rheumatoid arthritis, ankylosing spondylitis, physical condition not suitable for surgery , poor compliance after surgery. A total of 194 cases were enrolled, 120 cases of male, female 74 cases. Eighty-four cases involved in left hip and 110 cases involved in right hip. According to Association Circulation Osseous (ARCO) staging, 128 patients were in stage Ⅱ and 66 patients were in stage Ⅲ. All the patients had axial percussion pain, Fabere test (+) and different degrees of motion limitation. After preoperative DSA for femoral head was performed to observe the origination of posterior superior retinaculum artery and to guide the choice of operation method. Harris hip function score, visual analogue scale (VAS) and range of motion of hip were evaluated before and after surgery. The data were analyzed by paired sample t test.

The superior-posterior retinaculum artery presented in all the 10 chilled specimens. Seven specimens (70%) were originated from the medial circumflex femoral artery and three specimens (30%)were from the inferior gluteal artery. The preoperative DSA examination was completed in all 194 cases, illustrating that the posterior-superior retinaculum artery in 156 cases (79.9%) were from the medial femoral circumflex artery, while it originated from inferior gluteal artery in 39 cases (20.1%). Thirty-nine patients with inferior gluteal artery type (30 cases in ARCO stage Ⅱ and nine cases in ARCO stage Ⅲ) were followed up for six to 48 months, with an average of (20.1±0.6) months. The patients in ARCO stageⅡshowed no further progress. One patient in ARCO stage Ⅲ occurred femoral head collapse, but the hip pain was remarkably relieved after the surgery compared with the preoperative condition, and the range of motion of hip also improved. The other patients had no collapse of the femoral head surface, showing good joint space, and good hip flexion and extension function. At 12 months after surgery , VAS score was (2.4±1.2), Harris score was (92.7±1.3), all obviously improved when compared with the preoperative data (t = 4.74, 33.54, both P< 0.001).

Most of the posterior-superior retinaculum arteries originate from the medial circumflex femoral artery, and a small part are from the inferior gluteal artery. Compared with the medial circumflex femoral artery type, the inferior gluteal artery type has a higher anatomical position, more alternative surgical methods of hip preservation may be applied with lower risk of trauma and iatrogenic vascular injury, but further observation of more cases are needed.