Repair of the medial patellofemoral ligament with suture tape augmentation leads to similar primary contact pressures and joint kinematics like reconstruction with a tendon graft: a biomechanical comparison

摘要

Purpose To compare suture tape-augmented MPFL repair with allograft MPFL reconstruction using patellofemoral contact pressure and joint kinematics to assess the risk of patellofemoral over-constrainment at point zero. Methods A total of ten fresh frozen cadaveric knee specimens were tested in four different conditions of the MPFL: (1) native, (2) cut, (3) reconstructed with tendon graft, and (4) augmented with suture tape. The patellofemoral mean pressure (MP), peak pressure (PP) and contact area (CA) were measured independently for the medial and lateral compartments using pressure-sensitive films. Patellar tilt (PT) and shift (PS) were measured using an optical 3D motion tracking system. Measurements were recorded at 0 degrees, 10 degrees, 20 degrees, 30 degrees, 60 degrees and 90 degrees of flexion. Both the tendon graft and the internal brace were preloaded with 2 N, 5 N, and 10 N. Results There was no significant differences found between surgical methods for medial MP, medial PP, medial CA, lateral MP and PS at any preload or flexion angle. Significant differences were seen for lateral PP at 20 degrees knee flexion and 10 N preload (suture tape vs. reconstruction: 1045.9 +/- 168.7 kPa vs. 1003.0 +/- 151.9 kPa; p = 0.016), for lateral CA at 10 degrees knee flexion and 10 N preload (101.4 +/- 39.5 mm(2) vs. 108.7 +/- 36.6 mm(2); p = 0.040), for PT at 10 degrees knee flexion and 2 N preload (- 1.9 +/- 2.5 degrees vs. - 2.5 +/- 2.3 degrees; p = 0.033) and for PT at 0 degrees knee flexion and 10 N preload (- 0.8 +/- 2.5 degrees vs. - 1.8 +/- 3.1 degrees; p = 0.040). A preload of 2 N on the suture tape was the closest in restoring the native joint kinematics. Conclusions Suture tape augmentation of the MPFL resulted in similar primary contact pressures and joint kinematics in comparison with MPFL reconstruction using a tendon graft. A pretension of 2 N was found to restore the knee joint closest to normal patellofemoral kinematics.