ABSTRACT
Objective To investigate the damage sequence of posterior ligamentous complex (PLC) and its clinical significance in thoracolumbar fracture.Methods Data of 132 patients with spinal fracture evaluated with X-rays,CT and short-tau inversion-recovery (STIR) sequences in MRI were collected prospectively.Fracture morphology was classified using the AO classification.PLC components including interspinous ligament (ISL),supraspinous ligament (SSL),ligamentum flavum (LF) and facet capsules (FC) were assessed and classified as intact,edema,or tear.ISL edema was further subdivided depending on the extension (＞ 50％ or ≤50％).Correlation between MRI signal and AO progressive scale of morphological damage was analyzed.Results AO type A1/A2 fracture associated with only FC distraction.AO type A3 fracture showed additional ISL tear,usually less than 50％,with neither LF nor SSL tear.AO type B1 fracture showed FC distraction,ISL edema or disruption,and low rate of SSL/LF tear,but B2 fracture increased the rate of SSL/LF tear.AO type C fracture showed facet fracture or dislocation and ISL,SSL as well as LF tear.High correlation was found between AO progressive scale and MRI signal (P ＜ 0.01).Conclusions MRI study can well display the PLC damage and damage sequence.MRI correlates with AO progressive scale of morphological damage,which shows a progressive orderly rupture sequence among different PLC components as traumatic forces increase.
ABSTRACT
Objective To investigate the consistency of M RI detecting posterior ligamentous complex (PLC) injury associated with thoracolumbar factures.Methods MRI data of 170 cases of thoracolumbar fractures were reviewed retrospectively.Each case underwent MRI around one week postinjury.MRI data were analyzed and compared by three physicians respectively to discuss the consistency in MRI detection of PLC injury and the severity of PLC injury.Results Kappa coefficient was 0.846 between observer 1 and 2,0.768 between observer 1 and 3,and 0.793 between observer 2 and 3.Interobserver reliability was high and overall Kappa coefficient was 0.803.Severity of PLC injury was interrelated with spinal cord nerve injury (P ＜ 0.05).Conclusions Accurate detection of PLC injury in thoracolumbar fractures is beneficial to clear the mechanical stability of the spine.MRI detection of PLC injury is of high consistency and hence deserves wide use.
ABSTRACT
Objective To use estimation of physiologic ability and surgical stress (E-PASS) to assay operative risks in patients with hip fracture and to discuss its application value.Methods Sixtyfour patients with hip fractures were subjected to the retrospective review.There were 38 males and 26 females,at mean age of 54.3 years (range,19-84 years).The operative risk was assayed by E-PASS and postoperative complications as well as case fatality were detected and compared.Results Postoperative complications developed in 16 patients (25％).E-PASS score was significantly higher for the patients with postoperative complications than in those without [(0.64 ± 0.31) points vs (0.22 ± 0.31) points,P ＜ 0.05].Incidence of complications was significantly lower for patients with a E-PASS score ＜ 0.6 than for those with a E-PASS score ＞ 0.6 (19％ vs 50％,P ＜ 0.01).There were 2 deaths among 16 patients with a E-PASS score ＞ 0.6.The remaining 48 patients with a E-PASS score ＜ 0.6 obtained satisfactory recovery.Conclusion E-PASS is effective for predicting operative risk and is instructive for surgery decision in treatment of hip fractures.
ABSTRACT
Objective To observe the effect of bone marrow-derived mesenchymal stem cells (bMSCs) on graft healing within a bone tunnel after anterior cruciate ligament (ACL) reconstruction in rabbits.Methods The study involved 24 New Zealand white rabbits undergone ACL reconstruction with an autologous ipsilateral gastrocnemius tendon graft.Both hindlimbs were included.In one hindlimb,graft coated with fibrin glue compound by bMSCs was employed (bMSCs group).Whereas in the contralateral hindlimb,graft coated with fibrin glue without cells was employed (control group).At postoperative 2,4,6 and 8 weeks,specimens were harvested to have a biomechanical test of tensile strength and stiffness of tendon-bone interface.Results Tensile strength and stiffness of tendon-bone interface in both experiment and control groups presented a rising trend with the prolong of repair time.In contrast,significantly higher tensile strength and stiffness of tendon-bone interface were observed in experiment group since the 6 weeks (P ＜ 0.05).Conclusion bMSCs transplantation significantly enhances the early tensile strength and stiffness at tendon-bone interface after ACL reconstruction in rabbits and improves the graft healing within a bone tunnel.
ABSTRACT
ObjectiveTo observe the effects of different angles between tibial tunnel and tibial platform on “killer turn” in posterior cruciate ligament (PCL) reconstruction,and primarily discuss a safe and reasonable tunnel technology. Methods Eighteen fresh tendon grafts were used to reconstruct the PCL on the tibial side of fresh cadavers.The tibial tunnels of all specimens were built via anteromedial approach.Based on the different angles between tibial tunnel and tibial platform,all specimens were divided into Group A (30°),Group B (40°) and Group C (50°),with six specimens in each group.Area of tibial tunnel exit,pressure of tibia tunnel exit and circulation characteristics of tendons under the cyclic load before and after biomechanical test were recorded.ResultsThe area of tibial tunnel exit had statistical difference among three groups after the test ( F =8.80,P ＜ 0.05 ).The pressure of tibial tunnel exit had statistical difference among three groups (F =3.91,P ＜ 0.05 ).The cyclic frequency and fatigue strength of the transplanted tendons had statistical difference among three groups under the same cyclic load ( 256 N ) and same frequency ( 126 Hz ) ( F =4.25,P ＜ 0.05 ).Conclusions The angle between tibial tunnel and tibial platform has negative correlation with the area and pressure of tibial tunnel exit,and has positive correlation with the cyclic frequency and fatigue strength of the transplanted tendons under cyclic load.The ideal anatomy position of the tibial tunnel is the anteromedial tunnel with the angle of 40° between the tibial tunnel and the tibial platform.
ABSTRACT
ObjectiveTo develop an EZ screw remover for screwing out the skidded screws,discuss its design features and biomechanical characteristics and verify its extracting effect by clinical applications.MethodsFresh skeleton specimens were used in the study,including the femur (n =3),tibia ( n =3 ),radius and ulna ( n =3 ).The screws were fixed to the specimens according to clinical requirements and bone cement was filled into the medullary cavity.The specimens were randomized into three biomechanical test model groups,ie,Group A (measuring the skidded screws with the biggest torsion when the screws were taken out by screwdriver),Group B (measuring the skidded screws with the biggest torsion when the screws were taken out by one handle of EZ screw remover) and Group C ( measuring the skidded screws with the biggest torsion when the screws were taken out by two handles).The fixed screws were divided into two types of φ4.5 mm and φ3.5 mm.The experimental specimens were tested on the universal testing machines to measure the maximum torque,torsion angle,power consumption value and efficiency when drawing out the screws. The experimental data were compared between groups.The skidded screws encountered in clinical were taken out with EZ screw remover to verify the extracting effect.ResultsThe pullout torque in Groups A,B and C was 2.87-3.27 N · m,3.06-4.83N · m and 4.12-8.36 N · m respectively ( P ＜ 0.05 ).The average torsion angle value in each corresponding group was 0.77°,0.28°,0.16° respectively (P ＜ 0.05 ).When the screws were screwed out,the average power consumption was 21 J,32 J and 45 J in Groups A,B and C respectively and power ( mechanical efficiency) was 0.35 J/s,0.53 J/s and 0.75J/s in Groups A,B and C respectively,with significant differences ( P ＜ 0.05 ).Seventeen pieces of the cannulated skidded screws of φ7.3 mm in seven patients were successfully taken out by using the EZ screw remover.ConclusionEZ screw removerhas enough resistance strength and rigidity to torsion as well as powerful clamping force and hence is an ideal tool for screwing out the skidded screw in orthopedics.
ABSTRACT
Objective To discuss the clinical effect of dynamic hip screw(DHS)and microtrauma dynamic hip screw(MTDHS)in treatment of comminuted intertrochanteric femur fractures in the elderly patients.Methods From September 2006 to July 2009,42 patients with comminuted intertrochanteric femur fractures were treated by DHS and MTDHS.According to Evans classification,there were 16 patients with type Ⅲ fractures and six with type Ⅳ fractures in MTDHS group and 15 patients with type Ⅲ fractures and five with type Ⅳ fractures in DHS group.The operation time,amount of bleeding,hospital stay and postoperative hip function were evaluated.Results All patients were followed up for 9-17 months(average 13 months).Harris score was 76.4 points in 20 patients treated by DHS and 89.8 points in 22 patients treated by MTDHS,with better functional restoration,shorter operation time and less amount of bleeding in MTDHS group than DHS group.Conclusions Compared with DHS,MTDHS has advantages of minimal invasion,minor trauma,sound recovery of hip joint function and low incidence of complications and hence is a good choice for treating intertrochanteric femur fractures.
ABSTRACT
<p><b>PURPOSE</b>Discuss the new method of individual internal fixation with steel plate customization.</p><p><b>METHOD</b>Customize individual internal fixation with steel plate according to 3D reconstruction of CT images and Ugnx. Pro/E machining method.</p><p><b>RESULT</b>Success in customization about the first individual internal fixation with clavicular hook plate for the treatment of multisegmental fracture of clavicle.</p><p><b>CONCLUSION</b>The new method of individual internal fixation with steel plate customization according to 3D reconstruction of CT images and Ugnx, Pro/E machining technique is a good news for patients of orthopaedic trauma. We are fully confident of the future development of the method of individual internal fixation with steel plate customization.</p>