Medial Patellofemoral ligament reconstruction using a digital tensiometer to determine graft tension：surgical technique and mid-term follow-up

BACKGROUND When undertaking patellofemoral ligament reconstruction, there are various methods of getting the proper tension for the graft, and the choice of the finest method remains controversial.Previously, a digital tensiometer was used to simulate knee structure, and a tension of approximately 2 N was quantified to restore patellofemoral track [11] , but it is unclear whether a tension of 2 N restores patellofemoral tracks during the operation. The purpose of this study was to verify the tension of the graft using a digital tensiometer for medial patellofemoral ligament reconstruction and to perform an mid-term follow-up. Methods: : Thirty-nine patients with recurrent patellar dislocation were included in the study. Patellar instability and patellar tilt angle and Patellar congruence angle were confirmed preoperatively by computed tomography (CT) and X-ray, history of dislocation and patellar apprehension test. Knee function was assessed by preoperative and postoperative Lysholm and Kujala scores Results: : 39 knees (39 cases)，including 22 female and 17 male individuals with an average age of 21.10±7.26 , were included.39 people have been followed up by telephone or face-to-face questionnaires and have been followed up for at least 24 months.Preoperative history of ≥2 patellar dislocation, none of which was treated surgically. Intraoperatively, all underwent isolated MPFL reconstruction and release of the Lateral retinacular. Mean Kujala and Lysholm scores were 91.28±4.90,and 90.67±5.15, respectively.Mean The patellar tilt angle (PTA) the patellar congruence angle (PCA)were 11.5±2.63,and 2.38±3.58, respectively.39 people did not undergo reoperation during the follow-up period.In general,36patients (36/39;92.31%) were absolutely painless when Completing daily activities at the last follow-up. CONCLUSION: We conclude that the graft tension required to restore a normal patellofemoral relationship in clinical practice is approximately 24N and that the use of 2N tension is too low. Reconstruction of the patellofemoral ligament using a tensiometer is a more accurate and reliable surgical procedure for the treatment of recurrent patellar dislocation. Level of Evidence: Level IV—case series.