Abstract:Objective To compare the effects of different positioning of the femoral tunnel in single-bundle anterior cruciate ligament reconstruction on patellofemoral joint degeneration.Methods The clinical data of 50 patients with anterior cruciate ligament injury treated in our hospital from February 2016 to March 2021 were collected, and they were divided into the study group and control group according to the anatomical position of the femoral tunnel in single-bundle anterior cruciate ligament reconstruction, with 26 cases in each group. Specifically, K-wires were placed in the lateral wall of the intercondylar fossa and the center of the original anterior cruciate ligament footprint in the study group, while K-wires were placed 7 mm away from the apex of the lateral wall of the intercondylar fossa in the control group. Patients in both groups were followed up for 12 months since the surgical treatments. The operation and recovery of the two groups were recorded, and the pain, knee function, and knee stability of the two groups before and after the operation were analyzed. The degeneration of the patellofemoral joint before and after operation was compared between the two groups, and the postoperative complications were recorded.Results There was no significant difference between the two groups in the operative duration, duration of tolerance for weight bearing with crutches, or that for weight bearing without crutches (P > 0.05). The Visual Analogue Scale (VAS) scores before the operation, and 3 months, 6 months and 12 months after the operation in the study group and control group were compared via repeated measures ANOVA, and the results revealed that the VAS scores were different among the time points (F =12.098, P =0.000) but not between the study group and the control group (F = 0.895, P = 0.403). There was no significant difference in the change trends of the VAS scores between the study group and control group (F = 0.715, P = 0.456). The differences of the International Knee Documentation Committee (IKDC) scores and Lysholm scores before the operation and 12 months after the operation in the study group were higher than those in the control group (P < 0.05). The differences of knee laxity via KT1000 test and the proportion of patients with positive pivot shift test before the operation and 12 months after the operation in the study group were higher than those in the control group (P < 0.05). There was no difference in the Recht grade of the patellofemoral joint degeneration before operation (P > 0.05), whereas that at 12 months after operation was better in the study group compared with the control group (P < 0.05). The Recht grade of the patellofemoral joint degeneration 12 months after operation was worse than that before the operation in the control group (P < 0.05). There was no significant difference in the Recht grade of patellofemoral joint degeneration before operation and 12 months after operation in the study group (P > 0.05). There was no significant difference in the incidence of overall complications between the two groups (P > 0.05).Conclusions The positioning of the femoral tunnel in single-bundle anterior cruciate ligament reconstruction is related to patellofemoral joint degeneration. Placement of K-wires in the lateral wall of the intercondylar fossa and the center of the original anterior cruciate ligament footprint contributes to better knee function and stability, as well as milder postoperative patellofemoral cartilage degeneration.