3D printed guide plate assisted and C-arm X-ray fluoroscopic positioning for femoral tunnel reconstruction of medial patellofemoral ligament in treating recurrent patellofemoral dislocation: a comparison of efficacies / 中华创伤杂志

ABSTRACT

Objective:To compare the efficacies of 3D printed guide plate assisted positioning and C-arm X-ray machine fluoroscopic positioning for femoral tunnel reconstruction of medial patellofemoral ligament in treating recurrent patellofemoral dislocation.Methods:A retrospective cohort study was performed on the clinical data of 60 patients with recurrent patellar dislocation admitted to the First Affiliated Hospital of Kunming Medical University from January 2018 to December 2022. The patients included 29 males and 31 females, with age range of 14-40 years [(28.6±7.6)years]. The 3D printed guide plate was used to locate the femoral tunnel in 30 patients for medial patellofemoral ligament reconstruction (3D guide group), and C-arm X-ray machine was used for another 30 patients (conventional group). (1) CT data of the knee joint were collected before surgery and at 7 days after surgery. Mimics 19.0 software was introduced to measure the distance between the center of femoral tunnel and Sch?ttle point after surgery. (2) Knee Lysholm score and Kujala score were used to evaluate the knee function before and at 3, 6, 9 and 12 months after surgery. (3) At the same time points, Opti-Knee TM 3D knee kinematics analysis system was used to collect the forward and backward displacement, up and down displacement, internal and external displacement, internal and external flipping angle, internal and external rotation angle, and flexion and extension angle of the affected knee joint. The range of each freedom degree was calculated and 6 freedom degree items of 30 healthy people were subjected to knee kinematics analysis. Results:All patients were followed up for 12-15 months [(12.3±0.7)months]. (1) The distance between the center of femoral tunnel and Sch?ttle point in the 3D guide group was (5.5±2.3)mm, smaller than that in the conventional group [(7.6±2.5)mm] ( P<0.01). (2) The Lysholm score and Kujala score of the 3D guide group and conventional gruop gradually increased after surgery (all P<0.01). There were no significant differences in the Lysholm score or Kujala score between the 3D guide group and conventional gruop before surgery and at 12 months after surgery (all P>0.05). At 3, 6 and 9 months after surgery, the Lysholm score of the 3D guide group [(70.4±4.5)points, (86.4±3.1)points, (91.2±3.2)points] and Kujala score [(74.2±5.3)points, (80.9±3.5)points, (85.2±3.2)points] were higher than those of the conventional group [Lysholm score (67.3±5.2)points, (81.8±2.5)points, (86.2±1.9)points; Kujala score (69.8±5.2)points, (77.6±2.1)points, (82.7±2.6)points] ( P<0.05 or 0.01). (3) Before surgery, the forward and backward displacement in the 3D guide group and conventional group [(0.6±0.1)cm, (0.6±0.2)cm], up and down displacement [(0.5±0.1)cm, (0.6±0.0)cm], internal and external displacement [(0.7±0.1)cm, (0.6±0.2)cm], and flexion and extension angle [(50.6±10.3)°, (51.6±8.5)°] were less than those in the healthy controls [(1.6±0.3)cm, (1.7±0.5)cm, (1.0±0.4)cm, (63.2±5.1)°] (all P<0.05), while the internal and external flipping angle [(17.5±4.0)°, (17.1±3.8)°] and internal and external rotation angle [(17.9±1.9)°, (17.5±1.5)°] were greater than those in the healthy controls [(11.8±3.6)°, (15.8±4.9)°] (all P<0.05). At other time points, the results of front and back displacement, up and down displacement, internal and external displacement, internal and external rotation angle in the 3D guide group and conventional group were not significantly different compared with the healthy controls (all P>0.05). The flexion and extension angle in the 3D guide group and conventional gruop were smaller than those in the healthy controls at 3 months after surgery (all P<0.05). At 6 and 9 months after surgery, the flexion and extension angle in the conventional group [(55.0±3.7)°, (57.7±4.8)°] were smaller than those in the healthy controls [(63.2±5.1)°, (63.2±5.1)°] (all P<0.05), but no significant difference was found between the 3D guide group [(61.0±4.8)°, (61.8±4.9)°] and the healthy controls (all P>0.05). The flexion and extension angle in the 3D guide group and conventional gruop was similar with that in the healthy controls at 12 months after surgery (all P>0.05). Conclusions:Compared with the C-arm X-ray machine, the 3D printed guide plate assisted positioning of femoral tunnel is more simple and accurate for the medial patellofemoral ligament reconstruction in treating recurrent patellofemoral dislocation, together with better early knee function recovery, better satisfaction of the patients, and better and faster restoration of the flexion and extension angle of knee joint kinematic function.