It is difficult to diagnose and treat local recurrence of the rectal cancer after operation. The early diagnosis is crucial for the recurrence of rectal cancer after operation. MSCT perfusion imaging is valuable in the diagnosis of recurrence of rectal cancer after operation. The application of MSCT perfusion imaging following rectal cancer operation was reviewed in this article.

Objective:To introduce the surgical method of Ortho-Bridge system (OBS) in the treatment of distal femoral fractures in elderly patients and investigate its clinical effect.Methods:From January 2018 to July 2021, 24 elderly patients who suffered distal femoral fractures were treated with bilateral OBS. There were 8 males and 16 females aging from 62 to 87 years, with an average age of 72.6 years. It included 15 cases of simple distal femoral fractures. According to AO classification, there were one case of A1, two of A2, five of A3, two of C1, three of C2 and two of C3. Nine cases of femoral periprosthetic fractures after total knee arthroplasty (TKA) were classified as type II according to rorabeck's classification. After operation, all patients were guided to perform knee joint functional exercise and to measure the range of motion of the knee joint. Then imaging examinations were used to evaluate the fracture healing and measure the femoral-tibial and femoral angles. The American Hospital for Special Surgery (HSS) knee joint scoring system was used to evaluate the knee function.Results:All 24 patients successfully completed the operation. The operation time was 84-115 min, with an average of 96.6 min; the intraoperative blood loss was 150-335 ml, with an average of 240 ml. All patients were followed up for 8-17 months, with an average of 13.6 months. Except for 1 case of nonunion due to few primary bone grafts, which required secondary bone grafting, the other 23 cases achieved bone union. The healing time was 3.5-6 months, with an average of 4.6 months. At 1, 3, and 6 months after operation and at the last follow-up, the flexion angles of knee were 92.2°±10.2°, 98.6°±13.3°, 106.4°±13.7°, 115.7°±15.3°, and the extension angles were -4.7°±4.1°, -1.2°±4.2°, 0.7°±4.5°, 1.8°±4.6°, respectively; and all differences were statistically significant ( F=17.03 and 12.68, P<0.001). The knee flexion and extension angles at the last follow-up were greater than 1, 3, and 6 months after operation, and the differences were statistically significant ( P<0.001). The femoral-tibial angle was 171.2°±2.4° and 170.7°±3.2°, and the femoral angle was 80.3°±1.7° and 79.6°±2.1°, respectively, at the immediate postoperative and last follow-up, with no significant difference. The HSS scores at 1, 3, 6 months after operation and at the last follow-up were 71.5±7.5, 74.6± 9.3, 78.9±10.4 and 84.7±9.4 respectively, with significant difference ( F=9.17, P<0.001). At the last follow-up, the HSS score was higher than that at 1, 3, and 6 months after the operation, and the differences were statistically significant ( P<0.001), and the knee function was evaluated according to the HSS scoring system: excellent in 12 cases, good in 9, fair in 3, with an excellent and good rate of 88% (21/24). There was no OBS crack or fixation failure in all patients, and no prosthetic loosening and instability occurred in patients with periprosthetic femoral fractures after TKA. Statistical analysis of the data at the last follow-up between the distal femoral fracture group and the periprosthetic femoral fracture group after TKA showed that the knee flexion function and HSS score of the periprosthetic femoral fracture group after TKA (126.8°±3.7°, 92.2±4.1) were both better than the simple distal femur fracture group (108.9°±15.7°, 80.2±8.8). The difference was statistically significant ( t=4.22, 4.52, P<0.05). One patient had incision fat liquefaction and healed after debridement; bone nonunion occurred in 1 case, which healed after iliac bone grafting. Conclusion:Double OBS has a good clinical effect in the treatment of distal femoral fractures in the elderly, especially in patients with periprosthetic femoral fractures after TKA.