Application Of Three-dimensional Reconstruction Of (Spiral) CT For Diagnosis And Treatment Of Carpal Instability

Objective:To evaluate the application value of spiral CT three-dimensional reconstruction technologies in clinical diagnosis and treatment of carpal instability and provide the basic data for clinical application through the establishment of the anatomical data of the carpal ligaments length change with movement by spiral CT three-dimensional reconstruction.Method:1. Through the spiral CT three-dimensional reconstruction technologies to establish normal anatomy of carpal ligaments data:10 hands from 5 adult healthy male volunteers were selected to have surface shaded display (SSD) reconstruction in Neusoft 16-slice spiral CT and determine the length between carpal bone attachment points of five carpal ligament (radioscaphocapitate ligament, long radiolunate ligament, ulnoeapitate ligament, dorsal intercarpal ligament, dorsal radiocarpal ligament) in the neutral position, ulnar deviation of 40°, radial deviation of 20°, palm curved of 90°, dorsiflexion of 80°2. Observe carpal ligament length changes in the cadaver wrist models imitated scapholunate dissociation before and after modeling and after the imitated models were made scaphotrapeziotrapezoid(STT) arthrodesis:The upper extremities of eight fresh frozen bodies were selected to cut off scapholunate ligament, palmar capholunate interosseous ligament, dorsal scapholunate interosseous ligament,and radioscaphocapitate ligament to simulate scapholunate dissociation,a type of carpal instability, the imitated models were made scaphotrapeziotrapezoid arthrodesis with a Kirschner wire through the fixed line STT bone. SSD reconstruction was made in Neusoft 16-slice spiral CT to determine the said those wrist carpal ligament attachment spacing changes in the neutral position before and after modeling and after bone fusion operating.3. compare the diagnosis of Colles fractures with carpal instability carpal instability by spiral CT with that by ordinary X ray:the difference of diagnosis on fracture and fracture dislocation from 25 cases of Colles fractures with carpal instability carpal patients from wrist x-ray films and helical CT images4.the follow-up of Colles fracture with carpal instability patiens who accpted surgery treatment by three-dimensional spiral CT reconstruction guidance on functional recovery, select 20 cases of patients who were had a diagnosis of Colles fracture combined with carpal instability and accepted surgery treatment by three-dimensional spiral CT reconstruction technolagy guidance to follow-up. Gartand and Werley scoring system was used to evaluate the wrist functional recovery was excellent, good, fair and poor, and whether residual carpal instability Results:1. Normal anatomy of carpal ligaments data:the distance between the radioscaphocapitate ligament attachment points was 15.1±1.7mm in the neutral position, increase in the ulnar deviation and dorsiflexion position, and shortened in radial deviation and palmar curved position. Long radiolunate ligament attachment points spaced 9.0±1.2mm, grew when the ulnar deviation and dorsiflexion occured,while shortened in the radial deviation and palmar curved position. Ulnoeapitate ligament attachment points spaced 25.7±2.0mml, grew in the radial deviation and dorsiflexion position, different from the radioscaphocapitate ligament and long radiolunate ligament; the distance of the parts of dorsal intercarpal ligament which stretched scaphoid and trapezium was 4.6±1.5mm and 33.0±3.6mm, respectively.The two parts stretching changes are small in any state, but the expansion of the part stretching the trapezoid significantly increased in the different states; dorsal radiocarpal ligament attachment points spacing in the neutral position was 17.2±1.3mm, shortened in the ulnar deviation and dorsiflexion position,while grew in radial deviation and palmar curved positon,that was opposite from radioscaphocapitate ligament.2. ligament attachment points spacing of the cadaver wrist changes before and after modeling,and after bone fusion operating:5 cadaver wrist ligament attachment points spacing in the neutral position did not change significantly in compared with normal body; ligament attachment spacing of the radioscaphocapitate ligament and the part of dorsal intercarpal ligament which striched the scaphoid bone increased significantly after modeling compared with before modeling (P<0.05), but the spacing shortened significantly after bone fusion operating (P <0.05). long radiolunate ligamen attachment points pacing increased after the modeling, but the difference was not significant (P> 0.05) while the spacing of joint fusion was significantly shorter than the modeling (P <0.05).3. comparison of diagnosis on Colles fractures with carpal instability with ordinary X ray and spiral CT:using Spiral CT technology found All fracture and 18 cases of fracture dislocation among 25 patients with Colles fracture with carpal instability and tracking of clinical data was 100%. There were 3 cases of fractures missed diagnosis, accounting for 12% of the cases, and 5 cases of fracture dislocation missed diagnosis, accounting for 20% of the cases by Ordinary X ray diagnosis.4.the follow-up result on wrist functional recovery from 20 cases of patiens who accpted surgery treatment by three-dimensional spiral CT reconstruction guidance showed that excellent in 8 cases, good in 8 cases, fair in 2 cases, poor 2 cases according to the Gartand and Werley scoring system.2 cases of carpal instability still existed. Conclusion:comparing with ordinary X ray,Three dimensional reconstruction of spiral CT technology has the advantage in the diagnosis of fracture, particularly fracture dislocation to reduce the rate of misdiagnosis.the technolagy can also improve postoperative functional recovery of Colles fracture patients and reduce wrist residual rate of wrist instability, so there is of great value in applications of the clinical diagnosis and treatment of carpal instability. Using three-dimensional CT scan reconstruction to establish the data of length change of the wrist ligaments may provide a reliable quantitative indicators for clinical diagnosis and treatment of carpal instability.