Summary
MPTL reconstruction restores the patellar stability and improves patella alta that shows in motion analytic study.
Abstract
Background
The medial patello-tibial ligament (MPTL) proved by anatomy that it restrained patellar stability as same as medial patellofemoral ligament (MPFL). This study demonstrated motion analytic study to prove its function after simulated patellar lateral dislocation with MPTL reconstruction.
Methods
Twelve cadaveric knees were recruited and cut the medial patellar structure to create lateral patellar dislocation. The patellofemoral motion was determined using a 3-dimensional motion analysis (3DMA). MPFL reconstruction versus MPFL and MPTL reconstruction were compared in six-direction measurement those were superior-inferior, medial-lateral and anterior-posterior translation. The knee bending were set at 0, 30, 45, 60, 90 degrees.
Results
MPFL and MPTL reconstruction showed statistically significant difference compared with MPFL reconstruction for medial- lateral translation in all knee bending angles. The 30 degrees bending (0.31±0.36 vs -0.01±0.15 mm, p<0.001), 45 degrees (0.34±0.39 vs -0.02±0.14 mm, p<0.001), 60 degrees (0.38±0.42 vs -0.01±0.14 mm, p<0.001) and 90 degrees (0.38±0.38 vs -0.03±0.20 mm, p<0.001). MPFL and MPTL reconstruction also obtained the statistical difference for kinematic restoration for patellofemoral superior translation when the knee bending at 45 degrees (-0.08±0.21 vs -0.08±0.21mm, p <0.001). For the anterior-posterior translation, there was statistically significant difference for knee bending at 45 degrees (-0.09±0.28 vs 0.07±0.37 mm, p <0.001), 60 degrees (-0.17±0.33 vs 0.16±0.36 mm, p <0.001) and 90 degrees (-0.13±0.45 vs 0.19±0.34 mm, p <0.001).
Conclusions
Additional MPTL reconstrcution with MPFL could restored the medial stabilization of patellar stability that proved with motion analytic study in cadaveric knees. It also obtained the superior patellar translation in patellar instability with patella alta when knee bending at 45 degrees flexion. Thus MPTL reconstruction should be considered for surgical treatment of lateral patellar instability.