基于CT技术评估髌骨内脱犬骨骼畸形

Evaluation of Skeletal Deformities in Dogs with Medial Patellar Luxation Based on CT

本研究旨在通过计算机断层扫描(computed tomography,CT)检查探究不同症状髌骨内脱(medial patellar luxation,MPL)犬的解剖结构差异,同时对比CT和X线技术的一致性和优缺点。选用患有髌骨内脱和健康的小型犬后肢共34条,根据症状分为正常组(n=9)、MPL无症状组(n=9)、MPL有症状组(n=16),进行CT检查,通过CT图像测量滑车沟深度/髌骨厚度、髌韧带长度/髌骨长度、解剖性股骨远端解剖轴外侧角(anatomic latero-distal femoral angle,aLDFA)、股骨远端机械轴外侧角(mechanical latero-distal femoral angle,mLDFA)、股骨近端解剖轴外侧角(anatomic latero-proximal femoral angle,aLPFA)、股骨近端机械轴外侧角(mechanical latero-proximal femoral angle,mLPFA)及股骨颈干角(femoral inclination angle,FIA),并分析各组之间的差异。此外通过对比一组犬(n=14)X线和CT测量值的差异,分析两种成像技术在评估骨骼畸形时的准确性。统计学结果显示,正常组犬在滑车沟深度/髌骨厚度为0.47±0.07,与MPL无症状组(0.27±0.14)、MPL有症状组(0.35±0.14)均存在显著性差异(P<0.05),正常组犬的aLDFA、mLDFA分别为(89.7±4.1)°、(95.6±3.3)°,与MPL有症状组[(97.4±6.2)°、(101.2±4.6)°]存在显著性差异(P<0.05)。X线和CT组的测量值在髌韧带/髌骨长度、aLPFA、mLPFA、mLDFA上存在统计学差异(P<0.05)。结果提示,患有MPL犬无论是否表现出症状均倾向表现浅滑车沟,有症状的MPL犬更倾向有严重的股骨畸形。X线和CT对于骨骼畸形的评估差异较为显著。

This experiment was conducted to explore the anatomic differences of medial patellar luxation(MPL) dogs with various degrees symptoms. And comparing the consistency, advantages and disadvantages of CT and X-ray techniques. Thirty-four hindlimbs of small breed canines were divided into normal group, MPL asymptomatic group and MPL symptomatic group according to the symptoms. CT images were used to measure the depth of trochlear groove/patella thickness, length of patellar ligament/patella length, aLDFA, mLDFA, aLPFA, mLPFA, FIA, and analyzing the anatomical structure differences of femur and stifle in each group. In addition, to analyzed two imaging techniques in assessing skeletal malformations by comparing X-ray and CT measurements in a group of dogs. The results showed that there were significant differences in the depth of trochlear groove/patella thickness between normal group(0.47±0.07) and MPL asymptomatic group(0.27±0.14) and MPL symptomatic group(0.35±0.14)(P<0.05), and there were significant differences in aLDFA, mLDFA between normal group [(89.7±4.1)°,(95.6±3.3)°] and symptomatic MPL group [(97.4±6.2)°,(101.2±4.6)°](P<0.05). There were statistical differences in patellar ligament length/patella length, aLPFA, mLPFA and mLDFA between radiographic and CT groups(P<0.05). These results indicated that MPL dogs tend to have superficial trochlear grooches, and symptomatic dogs are more likely to have severe femoral deformities. There is a significant difference in the evaluation of skeletal deformities between X-ray and CT.