| 1.Evaluation of patellar joint morphology in patellar dislocation by MRIObjective: to measure and analyze the morphological characteristics of patellar joint in patellar dislocation and in normal knee joint by nuclear magnetic resonance imaging(MRI),and to study the morphological characteristics and risk factors of patellofemoral joint dislocation.Methods: 40 cases of patellar dislocation and 20 cases of normal knee joint were selected as control group for MRI scanning.The anatomical structure morphology of patella and the anatomical structure morphology of femoral trochlear were measured by nuclear magnetic resonance imaging.At the same time,we observed whether patellar dislocation was complicated with cartilage injury,whether medial patellar ligament injury site completely broken,and whether it belonged to patella alta.We also typed the morphology of patella and femoral trochlear,and compared and analyzed the difference in anatomical morphology of patellar joint in patellar dislocation and in normal knee joint.Results: the patellar angle of knee joint in patellar dislocation group(107.3±22.97)°,the windth of trochlear groove(3.18 ± 0.33)and the slant angle of lateral surface of trochlear(15.37±5.56)°were significantly lower than that in control group(P < 0.05).The ratio of patellar lateral width(0.65±0.07),the ratio of lateral side of trochlear groove(0.69±0.06)and the slant angle of patella(19.40±8.38)°were significantly higher than that in control group(P < 0.05).In patients with patellar dislocation,there were 28 women patients,in which the injury site of medial patella ligament was located at patella check point in 23 cases,on the medial femur in11 cases and in body part in 6 cases.When the medial patella ligament injury was located on the patellar side,16 cases had a complete rupture of the ligament(69.57%),and 15 cases had cartilage injury(65.21%).11 cases(100%)had cartilage injury when the ligament injury were located on the femoral.In Wiberg classification,20 cases(50%)were type I patella patients,14 cases(35%)were type II,and 6 cases(15%)were type III.In Dejour classification of femoral trochlear,12 cases(15%)of type I patella were corresponding to type A femoral trochlear,8 cases of type I patella were corresponding to type C femoral trochlear,9 cases of type Ⅱ patella were corresponding to type B femoral trochlear,and 6 cases of type III patella were corresponding to type C femoral trochlear.There were 17 cases of non-high patella(42.5%)and 23 cases of patella alta(57.5%).Conclusion: the patellar angle,patellar width of the dislocation group are smaller than those of the control group.The ratio of patellar lateral side is larger than those of the control group.When the medial patella ligament injury is located on the patellar side after patellar dislocation,the probability of complete rupture is high,and the risk of cartilage injury on the patellar side and the femoral side is high.In the corresponding of Wiberg classification of patella to Dejour classification of femoral trochlear,type I patella mostly corresponds to type A femoral trochlear,and partly corresponds to type C femoral trochlear,type Ⅱ patella mainly corresponds to type B femoral trochlear,and partly corresponds to type C femoral troshlear,type III patella mainly corresponds to type C femoral trochlear.2.Basic study of finite element model in the reconstruction of medial patella ligament to treat patellar dislocation.Objective: to select different femoral insertions to analyze the stress distribution of patellar joint by virtual reconstruction of medial patella ligament with finite element model,and to determine the best femoral check point of medial patella ligament by finding the most uniform stress distribution,so as to provide corresponding theoretical basis for anatomical reconstruction of medial patella ligament.Methods: MRI and CT data were extracted from two patients with patellar dislocation,in which one was TT-TG < 20 mm and another one was TT-TG > 20 mm.The finite element model of knee joint was reconstructed with MRI and CT raw data.In the case of TT-TG > 20 mm,virtual reconstruction of medial patella ligament combined with tibial tubercle transfer was performed.In the case of TT-TG < 20 mm,virtual reconstruction of medial patella ligament was performed.In medial patella ligament reconstruction,the patellar lateralattachment was from the midpoint of medial patella to the medial top corner.The medial femoralepicondyle,adductor sarcomere point and the midpoint to forward and backward between the two points were selected for femoral lateral attachment.The stress of patellar and femoral joint,patellar slant angle and patellar trajectory were analyzed at different attachment.Results: In TT-TG<20mm,when medial patella ligament attachment is located in adductor sarcomere point and angle was 1.54°,8.72°,9.03°,the stress of patellar joint were 7.4MPa,12.6MPa,14.1MPa respectively,and patellar slant angle were1.54°,8.72°,9.03°.When it is located in the forward midpoint between the medial femoralepicondyle and adductor muscle node,the stress of patellar joint were8.1MPa,14.1MPa,12.3MPa,and patellar slant angle were 3.24°,3.44°,6.72°respectively.When it is located in the medial femoralepicondyle,the stress of patellar joint were 10.6 MPa,23.4 MPa,50.2 MPa,and patellar slant angle were 11.92 °,4.56 °and 22.07 °respectively.Conclusion: the finite element model can be used to reconstruct the medial patella ligament.For TT-TG < 20 mm model,when the lateral femoral attachment of the medial patellofemoral ligament is located in front of the midpoint between the medial femoralepicondyle and adductor muscle node,the patellar inclination angle is small,the stress distribution of patellofemoral joint is uniform and the stress is small.For TT-TG > 20 mm model,the best attachment of medial patellofemoral ligament was still located in front of the midpoint between the medial femoralepicondyle and adductor muscle node in combination with osteotomy and transposition of knee joint.3.Clinical study on reconstruction of medial patellofemoral ligament with limited incision and anatomy assisted by arthroscopyObjective: to reconstruct the medial patellofemoral ligament with limited incision and anatomy assisted by arthroscopy,to locate the femoral attachment of the medial patellofemoral ligament by touching anatomical structure method,to observe the ligament isometric,the patellar track and the patellofemoral alignment,and to evaluate the therapeutic effect.Methods: from January 2014 to September 2018,35 patients with patellar dislocation were examined by routine imaging examination before operation.The surgical indication was evaluated,and the surgical contraindication was excluded.The medial patellofemoral ligament was reconstructed with limited incision assisted by arthroscopy,and the injury of articular cartilage was examined by arthroscopy and treated accordingly.The reconstructed tendon was made from autologous semitendinosus muscle.The tendon was established and fixed with wire anchor nail at the midpoint and upper 1/3 of the medial patella.The adductor muscle node and the upper of medial femoralepicondyle were exposed by limited incision of the femoralepicondyle.The Kirschner wires were drilled into the adductor node,the medial femoralepicondyle,at the midpoint between the two points,before and after the adductor muscle node respectively.The tendon was fixed to the Kirschner wire to observe the ligament isometric,the patellar track and the patellofemoral involutive relationship.The medial patellofemoral ligament was reconstructed from the mid-point position between the adductor node and the medial femoralepicondyle.The patellofemoral involutive relationship was observed by imaging examination after operation,and the function of knee joint was evaluated by follow-up.Results: When the attachment is located in the midpoint between the medial femoralepicondyle and adductor muscle node,the ligament isometric of medial patellofemoral ligament,the patellofemoral joint,the track of the patella,the patellofemoral involutive relationship after imaging is good,and the function of the knee joint is obviously improved.Conclusion: in the reconstruction of medial patellofemoral ligament,the finite incision touch dissection can accurately locate the lateral femoral attachment,and judge the isometric of the medial patellofemoral ligament.Arthroscopy can monitor the patellofemoral joint involutive relationship and patella trajectory,which makes the operation more accurate and the therapeutic effect more ideal. |
PDF Full Text Request