膝关节置换术后内侧副韧带形态及功能的高频超声对比

Evaluation of the Morphology and Function of Medial Collateral Ligament after Total Knee Arthroplasty with High-frequency Ultrasound

目的利用高频超声对膝关节置换术后内侧副韧带进行扫查,探讨超声评估内侧副韧带形态及功能的可行性及其临床价值。方法以38例常规膝关节置换术后膝关节(A组)和22例明确内侧副韧带损伤而使用限制性垫片的膝关节置换术后膝关节(B组)为研究对象,分别进行内侧副韧带长轴切面高频超声扫查,依次测量距离关节截骨面约1 cm处股骨端及胫骨端内侧副韧带的厚度,比较两组间韧带厚度的差异。随后进行外翻应力动态观察,测量股骨侧假体金属部分与垫片之间的间隙,比较两组间隙的分布及构成比。结果高频超声能清晰显示膝关节置换术后的关节假体及内侧副韧带。两种术式后的内侧副韧带纤维结构连续,其中B组胫骨端内侧副韧带厚度为(0.25±0.06)cm,较A组的(0.32±0.14)cm明显变薄(t=2.12,P=0.040);但B组股骨端内侧副韧带厚度[(0.37±0.09)cm]与A组[(0.42±0.12)cm]厚度差异无统计学意义(t=1.65,P=0.110)。外翻应力条件下扫查,B组患者中11例可以测出股骨侧假体金属部分与垫片之间的间隙,而A组患者中仅1例可测出间隙;B组患者出现间隙的比例较A组明显增高(Fisher确切检验,P=0.000)。结论高频超声可以清晰显示膝关节置换术后假体及内侧副韧带,术中内侧副韧带损伤后可以愈合但是厚度明显变薄。外翻应力条件下,根据假体与垫片之间的间隙可以评价关节置换术后稳定性。

Objective To explore the feasibility and clinical value of ultrasonography in evaluating the morphology and function of medial collateral ligaments（ MCL） after total knee arthroplasty（ TKA）.Methods Totally 38 patients undergoing routine KTA（ group A） and 22 patients undergoing constrained condylar knee arthroplasty KTA with MCL injury（ group B） were included.Long axis views of MCL were taken and the MCL thickness was measured on femur side and tibial side 1 cm away from the joint line,respectively.The thicknesses were compared between the two groups.Subsequently,the gap between the metal part of the femoral prosthesisand the spacer after dynamic valgus stress was measured.The distribution and composition of the gap between the two groups were compared.Results High-frequency ultrasound clearly showed the prosthesis and MCL after TKA.MCL fiber structures of both groups were intact.The MCL thickness on the tibial side in group B was（ 0.25 ±0.06） cm,which was significantly thinner than group A [（ 0.32 ± 0.14） cm]（ t = 2.12,P = 0.040）.For the femur side,there was no significant difference（ t = 1.65,P = 0.110） between these two groups [（ 0.37 ± 0.09） cm in group B versus（ 0.42 ± 0.12） cm in group A].Under the condition of valgus stress,the gaps between the metal part of the femoral prosthesis and the spacer could be found in 11 cases in group B but only in 1 case in group A.The proportion of gaps in group B was significantly higher than that in group A（ Fisher＇ s exact test,P = 0.000）.Conclusions High-frequency ultrasound can clearly show the prosthesis and MCL after TKA.The injured MCL can be well joined but the thickness is thinner.Under the condition of valgus stress of the knee,the stability of the TKA can be evaluated according to the gap between the prosthesis and the spacer.