| Objective:Using vascular perfusion technique,gelatin-lead oxide as perfusion agent,perfusion and visualization of blood vessels in the scaphoid bone,exploring the technique of intra-arterial infusion of human wrist scaphoid specimen and establishing visualization of scaphoid containing internal bone artery The digital model was used to study the effects of nickel-titanium memory alloy,Herbert screw and Kjeldahl on blood supply in the scaphoid in a digital model of scaphoid visualization with intra-bone vessels,providing an anatomical basis for the choice of internal fixation.Then,the three-dimensional model of the scaphoid lumbar fracture was established to compare the biomechanical differences between the three different internal fixation methods,thus providing a mechanical basis for the selection of the internal fixation method.Finally,long-term clinical trials were used to compare the efficacy of Herbert screws and NiTi memory alloy staple holders in the treatment of scaphoid fractures.Methods:Part one:The digital anatomy of the blood supply of the scaphoidArterial vascular perfusion was performed on 12 isolated human forearm specimens.MicroCT was used to reconstruct the blood vessels in three dimensions using Mimics 20.0 software.The reconstruction data was analyzed and the trophoblastic distribution of the scaphoid was collected.Six left and six right hands were divided into left hands.The composite group and the right-hand composite group were compared to the difference in the distribution of the nourishing arteries of the left and right hands,and compared with the digital models of the three internal fixation devices.Part two:Finite element analysis of three internal fixation methods for scaphoid fractureThe wrist CT data of healthy volunteers were selected,and the application model was used to establish three internal fixation models for scaphoid lumbar fracture:Kirschner wire fixation group(A),herbert screw fixation group(B),and nail holder group(C).Loads were applied to the neutral grip position and the wrist back extension,and the deformation of the scaphoid and the stress of the internal fixation device were analyzed.Part three:Clinical trial of memory alloy fixator and herbert screw Two-center,prospective cohort study.The study was conducted in the 920 Hospital of the Joint support Force of the people's Liberation Army and the traditional Chinese Medicine Hospital of Yunnan Province.Patients with scaphoid fracture who were admitted to hospital from September 2011 to October 2018 were selected and selected according to the criteria of inclusion and exclusion.Forty-two patients(herbert screw group 18 cases,two-foot fixator group 24 cases)were determined.The general condition of the patients and the krimmer score of one week before operation,3 months after operation and 6 months after operation were recorded.The time of fracture healing and wrist function were analyzed.Results:Part one:The digital anatomy of the blood supply of the scaphoid(1)Reconstructing a clear digital visualization model of the scaphoid bone containing the internal blood vessels,freely measuring the anatomical data of the scaphoid and blood vessels,and clearly showing the distribution and access points of the nourishing artery in the bone;(2)The number of nourishing vessels in the right-hand composite group and the left-hand composite group were 4.67±1.366 and 3.83±0.753,respectively.The volar nourishing vessels were 1.67±0.516,1.33±0.516,and the dorsal nourishing vessels were 3.000±1.095.Branch,2.50±0.548.In this study,the digital model of the scaphoid visualization with blood supply was combined with three internal fixation devices to reconstruct the composite model and construct a safe zone for the scaphoid nourishment artery.The staple holders of the three internal fixators have the characteristics of small vascular interference.Part two:Finite element analysis of three internal fixation methods for scaphoid fractureThe deformation of the scaphoid under the three internal fixation devices is the largest,and the nail holder is the smallest.Under the two working conditions,the deformation of the scaphoid and the maximum stress of the fixture are di-fferent,but the trend is the same.The scaphoid deformation of the nail holder is the smallest and the maximum stress is the smallest.The nail holder has an eccentric effect.When the load reaches a critical value,the scaphoid healing surface is easily cracked or asymmetrically eccentric.Part three:Clinical trial of memory alloy fixator and herbert screwThe follow-up time was 6-50 months(13.19 ±7.034 months),the average follow-up time was 13.83±9.376 in the screw group and 12.71±4.759 month-s in the two-legged fixator group.The healing rate of the 3-month observation point group was 100%,and the mean follow-up time was 13.83±9.376 and 12.71±4.759 months,respectively.The healing rate of the control group was 83.3%.6 months later,both the control group and the experimental group were healed.The operation time was 65.72 ±8.021 minutes in the control group and 41.25 ±6.313 minutes in the experimental group.There were statistical differences in grip strength,ulnar and radial deviation between the experimental group and the control group.There was no significant difference between the experimental group and the control group on the excellent evaluation of wrist joint.There was no significant difference in the evaluation of wrist joint between the two hospitals(p>0.05).Conclusion:Part one:The digital anatomy of the blood supply of the scaphoidThe three-dimensional reconstruction of the intravascular bone after arterial infusion of the isolated wrist specimen can clearly show the source and spatial distribution of the trophoblast in the scaphoid bone,providing a morphological basis for the clinical study of the scaphoid fracture.The digital model can be used intuitively for the study of internal fixators.The three internal fixators are located in the safe area of the scaphoid nourishment of the scaphoid.The fixator has less interference than the Herbert screw and Kirschner wire for the intraosseous blood vessels,but there is no quantification.analysis.Part two:Finite element analysis of three internal fixation methods for scaphoid fractureThe Kirschner wire is the worst way to fix,the Herbert screw center is stable,the two-leg holder is minimally displaced,and the maximum stress on the screw and the two-leg holder is equivalent.Part three:Clinical trial of memory alloy fixator and herbert screwFor the scaphoid fracture,the two-legged fixator performs better in relieving pain and restoring hand grip,but it affects the range of motion of the wrist joint.The two-leg holder has a high healing rate and a short operation time. |
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