| Part 1 Measurement and clinical significance of anatomical parameters of proximal medial femurObjectiveBy measuring the anatomical parameters of normal adult femur,especially the medial femoral neck,the objective of this thesis is to provide benchmark for the design of internal fixation suitable for the anatomical characteristics of Chinese femur.MethodsA total of 76 normal Chinese femoral specimens were included in the study,which were measured by manual direct measurement and X-ray based AutoCAD software.The measurement indicators include the longitudinal diameter of lesser trochanter(A up-A lower),the transverse diameter of lesser trochanter(A anterior-A posterior),the height of lesser trochanter,the azimuth angle of lesser trochanter of femur α,the length of anterior edge line of femoral neck(M up-F up),the length of posterior edge line of femoral neck(F up-N up),the length of posterior edge line of middle part of femoral neck(F middle-N middle),the length of anterior edge line below femoral neck(M down-F lower),the length of posterior edge line below femoral neck(F down-N lower),the anteroposterior diameter of femoral neck(M up-N upper),the supero-inferior diameter of femoral neck(F up-I upper);the anteroposterior diameter of middle femoral neck(M middle-N middle),the supero-inferior diameter of femoral neck(F down-I middle),the anteroposterior diameter below femoral neck(M down-N lower),the supero-inferior diameter of femoral neck(F lower edge line),the femoral neck β ear,γ near,δ ear,femoral neck middle divergence angle β middle,γ middle,δ middle,femoral neck distal divergence angle β far,γ far,δ far,femoral length,femoral head diameter,femoral head length,head/neck ratio.ResultsThere was no statistically significant difference in the measurement results between the two methods of direct measurement and X-ray based AutoCAD software measurement(P>0.05).Femur length 38.65±2.25 cm;femoral head diameter 4.27±0.38 cm;long diameter of femoral head 3.35±0.48 cm;azimuth angle of lesser trochanter α 35.00±6.00°;longitudinal diameter of lesser trochanter(A superior-A inferior)2.39±0.33 cm;transverse diameter of lesser trochanter(A anterior-A posterior)1.46±0.24 cm;height of lesser trochanter 1.37±0.20 cm;length of anterior edge line of femoral neck(M superior-F superior)1.98±0.24 cm;length of posterior edge line of femoral neck(F superior-N superior)1.95±0.26 cm;length of middle anterior edge line of femoral neck(M medial-F inferior)1.69±0.27 cm;length of middle posterior edge line of femoral neck(F medial-N superior)1.72±0.25 cm;length of anterior edge line below femoral neck(M inferior-F inferior)2.04±0.80 cm;length of posterior edge line below femoral neck(F inferior-N inferior)1.92±0.28 cm;anteroposterior diameter of femoral neck(M superiorposterior edge line)3.75±0.29-F superior diameter of femoral neck(M superiorinferior)0.38 cm;anteroposterior diameter of the middle part of the femoral neck(M medium-N middle)2.10±0.32 cm;supero-inferior diameter of the middle part of the femoral neck(F medium-I middle)3.09±0.43 cm;anteroposterior diameter of the lower part of the femoral neck(M low-N lower)2.39±0.33 cm;supero-inferior diameter of the lower part of the femoral neck(F low-I lower)4.04±0.53 cm;length of the lower edge line of the femoral neck(F superior-F lower)2.27±0.43 cm;head/neck ratio 1.39±0.11;femoral neck divergence angle β nearly 90.29 ± 13.94°,γ nearly 45.38±7.95°,δ nearly 44.34 ± 7.35°;femoral neck divergence angle β in 76.27 ±8.85°,γ in 52.70 ± 7.43°,δin 51.03±4.99°;femoral neck distal divergence angle β far 77.44±11.63°,γ far 51.72±8.07°,δ far 50.84±7.10°.ConclusionThe AutoCAD software based on X-ray is simple and reliable for measuring the anatomical parameters of femur.The measurement of medial femoral anatomical parameters provides reference data for the design of medial femoral neck internal fixation system.Part 2 Three different combinations of internal fixation fixed Pauwels Ⅲ type femoral neck fracture:a finite element analysisObjectiveObjective of this thesis is to define effectiveness of the new type of femoral neck medial bracing plate applied to the treatment of young Pauwels Ⅲ type femoral neck fractures and explore the analytical techniques.Based on comparison of mechanical stability in three types:3 inverted cannulated cancellous screws(ICCS),3 cannulated screws and 1/3 tubular plate(CTP)and 3 cannulated screws and Internal anatomical support plate of femoral neck(CISP).MethodsFirstly,obtain imaging data from thin-slice spiral CT scanning of the hip joint to the middle of the tibia on healthy young men.Secondly,use Mimics 19.0,Geomagic Studio 13 and Solidworks 2019 software to reconstruct the normal femoral threedimensional model,and perform fracture wire cutting to simulate Pauwels Ⅲ type femoral neck fracture.Use UG12.0 and Shapr3D software to draw a new type of inner support steel plate model.Thirdly,the Solidworks 2019 software was used to connect the fracture model with ICCS group,CTP group,and CISP group for assembly separately.Then use ANSYS19.0 finite element data analysis software to perform load calculation on the three groups of models.Finally,compared and analyzed the force condition and fracture end displacement of the three groups of internal fixation finite element models.ResultsCompared with the other two methods,stress distribution,peak stress and fracture displacement of CISP group were more stable.Conclusion(?).CTP group and CISP group with hollow screws plus anterior medial support plates are better than three lag screws in the inverted character configuration in terms of mechanical stability,which verifies the mechanical advantages of medial support with plates vertical in treatment of type femoral neck fractures.In the comparison between CTP group and CISP group,CNP,the internal anatomical support plate of femoral neck(IASP)also showed advantages of customized plate,and it was superior to the inverted product(CTP group)in terms of stress distribution,stress peak value and fracture displacement.Therefore,CISP group is a recommended internal fixation material for the treatment of young and middle-aged Pauwels Ⅲ type femoral neck fractures.Part 3 Biomechanical comparative study of three different internal fixation combinations for Pauwels type Ⅲ femoral neck fracturesObjectiveThe mechanical stability of 3 inverted cannulated compression screws(ICCS),3 inverted cannulated compression screws plus 1/3 tubular plate(CTP)and 3 inverted cannulated compression screws plus medial femoral neck anatomical support plate of neck(CISP)in the fixation of Pauwels type III femoral neck fractures in young adults was analyzed and compared by biomechanical test,and the effectiveness of medial femoral neck anatomical support plate in the treatment of Pauwels type III femoral neck fractures in young adults was analyzed and discussed.MethodsSix fresh adult cadaveric femoral specimens were made into Pauwels type III femoral neck fracture models according to 70° osteotomy,and fracture fixation was performed using three modalities:ICCS,CTP,and CISP.First,ICCS was used to fix the fracture.After the test,3 specimens were randomly selected to install 1/3 tubular plate(CTP),and the other 3 specimens were installed with medial femoral neck anatomical buttress plate(CISP)and tested separately.After testing,the original plate was removed and then fixed with another plate and tested again.Take the femur at 15 cm,cut off and retain it,place the femoral shaft at 75° with the ground in the embedding die and fix it on the material test platform,and install the optical sensor on both sides of femoral neck fracture line.Load each specimen in unipedal standing position and lateral fall position for three times,respectively.Set the maximum load as 600N(ICCS 300N).Record the peak pressure,corresponding displacement,peak angle,compressive stiffness and angular displacement stiffness values during the loading test of each femoral specimen at different positions and compare them.ResultsCadaver specimen testing Under unipedal standing loading test,femoral head subsidence displacement(mm),femoral head angle displacement(°),compressive stiffness,and angle stiffness were[0.12±0.06 mm],[0.25±0.06°],[2413.45±1572.02 N/mm],and[1084.47±499.00 N/deg°]in ICCS group,[0.10±0.06 mm],[0.20±0.06°],[5821.77±2837.31 N/mm],and[3112.77±1239.21 N/deg°]in CTP group,and[0.07±0.01 mm],[0.14±0.03°],[10219.62±3075.23 N/mm],and[4234.02±1053.21 N/deg°]in CISP group,respectively.Cadaver specimen testing in lateral drop loading test was[0.11±0.05 mm],[0.28±0.20°],[3292.64±1678.64 N/mm],[1325.48±679.70 N/deg°]in ICCS group,[0.07±0.05 mm],[0.42±0.19°],[5868.02±1856.17 N/mm],[2485.61±731.38 N/deg°]in CTP group,and[0.09±0.03 mm],[0.46±0.20°],[6122.48±1087.11 N/mm],[2917.00±1133.02 N/deg°]in CISP group.The compressive stiffness and angular stiffness of the ICCS group were significantly smaller than those of the CTP CISP group in any mode(P<0.05).When the unipedal standing weight-bearing state was simulated,the angular displacement,compressive stiffness,and angular stiffness of the CISP group were significantly greater than those of the CTP group(P<0.05).The compressive stiffness of the CISP group was significantly greater than that of the CTP group(P<0.05)in the weight-bearing state of the simulated lateral fall position.ConclusionAdding a femoral neck support plate can provide stronger fixation in different positions of Pauwels III femoral neck fracture.Medial neck anatomical buttress plates have better biomechanical properties than 1/3 tube plates.Part 4 Treatment of unstable femoral neck fracture with posteromedial comminuted bone graft with cannulated screw and medial bracing plateObjectiveTo evaluate treatment of unstable femoral neck fracture with posteromedial comminuted bone graft with cannulated screw and medial bracing plate.MethodsFrom July 2016 to March 2020,18 unstable femoral neck fracture with posteromedial comminutations were treated at Chenggong Hospital Affiliated to Xiamen University.They were 12 men and 6 women,aged from 22 to 64 years(average 41.5 years).X-ray and CT examinations were performed in all patients with a clear diagnosis of Garden Ⅲ、Ⅳ type and/or Pauwels Ⅲ type fresh femoral neck fracture.Preoperative CT examination confirmed the combination of posteromedial femoral neck comminutiation and/or bone defect.All patients underwent open reduction of fracture with three cannulated screws and medial bracing plate combined with bone allograft transplantation.The fracture union time,femoral head necrosis,and femoral neck shortening were observed after operation.The Harris scores were used to evaluate therapeutic effects at the final follow-up.ResultsAll the patients were followed up for an average of17.3months(from 12 to 40 months).All the fractures obtained solid bony union after 7 to 15 weeks(average 12.1 weeks).Femoral head necrosis and bone nonunion occurred in no case.Femoral neck shortening≤5 mm was observed in 2 case and femoral neck shortening>5mm<10mm in 1 cases,giving a total shortening rate of 16%.The Harris scores at the final follow-up ranged from 73 to 97 points,averaging 93.5 points.There were 12 excellent.3 good and 3 moderate cases,giving an excellent and good rate of 83%.ConclusionFor the treatment of unstable femoral neck fracture with posteromedial comminutations,three cannulated screws and medial bracing plate combined with bone allograft transplantation are dramatically effective due to earlier weight bearing faster fracture healing and better hip function. |
PDF Full Text Request