术前J形征分度对复发性髌骨脱位术后短期临床结果的影响

The Effect of the Pre-operative J-sign Grading on Short-term Clinical Outcomes of Patients with the Recurrent Patellar Dislocation

目的:探讨对于行内侧髌股韧带(medial patellofemoral ligament,MPFL)重建的复发性髌骨脱位患者,术前髌骨轨迹J形征分度对术后短期临床结果的影响。方法:从2016年1月至2018年12月连续诊断为复发性髌骨脱位的患者中选取符合纳入标准的患者104名,平均手术时年龄为21岁。根据术前髌骨轨迹J形征分度将患者分为Ⅰ度组、Ⅱ度组和Ⅲ度组,术后采用髌骨切线位应力像评估髌骨术后稳定性,同时评估术前及术后Kujala评分,并比较其在上述三组间的差异。结果:Ⅲ度组患者平均股骨前倾角、胫骨外旋角和高位髌骨发生率均大于Ⅰ度组和Ⅱ度组,差异具有统计学意义。所有患者术前平均Kujala评分为54分,术后为86分,差异具有统计学意义。亚组分析结果显示,Ⅲ度组患者的术后Kujala评分低于Ⅰ度组及Ⅱ度组,差异具有统计学意义。股骨前倾角≥30°的患者,其术后Kujala评分低于股骨前倾角<30°的患者,差异具有统计学意义(P=0.023)。随访期间无患者发生髌骨再脱位,但Ⅲ度组中有6人(18.8%)存在术后MPFL残存松弛,而Ⅰ度组和Ⅱ度组均无MPFL残存松弛现象,差异具有统计学意义。结论:对于行单纯MPFL重建或联合胫骨结节内移截骨的复发性髌骨脱位患者,术前III度J形征对术后短期临床结果及髌骨稳定性存在负面影响。股骨前倾角增大、胫骨外旋角增大以及高位髌骨可能是复发性髌骨脱位出现Ⅲ度J形征的危险因素。

Objective To analyze the influence of the J-sign grading on the short-term clinical outcome of patients undergoing the medial patellofemoral ligament(MPFL).Methods Between January2016 and December 2018,104 patients with recurrent patellar dislocation were included in this study,with an average age of 21.Patients were divided into three subgroups according to the pre-operative J-sign grade:GradeⅠgroup,GradeⅡgroup and GradeⅢgroup.The stress radiography of the patella in the tangential projection was used to assess the patellar stability postoperatively.The pre-and post-operative Kujala scores were assessed and compared among the 3 groups.Results Patients of the gradeⅢgroup had significantly greater femoral anteversion angle,external tibial torsion angle and higher prevalence of patella alta than the GradeⅠand GradeⅡgroups.The average median Kujala score improved significantly from 54 pre-operatively to 86 post-operatively.However,patients with gradeⅢJ-sign had significantly lower postoperative Kujala scores than those with gradeⅠandⅡJ-sign.Patients with increased femoral anteversion(≥30°,P=0.023)had significantly lower postoperative Kujala scores compared with those of femoral anteversion less than 30°.Although no redislocation was reported during the follow-up,6 out of 32 patients in the GradeⅢgroup demonstrated MPFL residual graft laxity according to the post-operative stress radiography(18.8%),which was significantly higher than the other two groups(P<0.001).Conclusion A pre-operative gradeⅢJ-sign is correlated with a lower postoperative Kujala score and more"MPFL residual graft laxity"in patients with recurrent patellar dislocation treated with MPFL reconstruction with or without tibial tuberosity medialization at a minimum of 1-year follow-up.And increased femoral anteversion,excessive external tibial torsion,and patella alta are three possible risking factors of the gradeⅢJ-sign.