Williams Ariel A, Elias John J, Tanaka Miho J, Thawait Gaurav K, Demehri Shadpour, Carrino John A, Cosgarea Andrew J
Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, Maryland, U.S.A.
Department of Orthopaedic Surgery, Akron General Medical Center, Akron, Ohio, U.S.A.
Arthroscopy. 2016 Jan;32(1):55-61. doi: 10.1016/j.arthro.2015.06.037. Epub 2015 Oct 4.
To evaluate the role of tibial tuberosity-trochlear groove (TT-TG) distance in patellofemoral kinematics by retrospectively reviewing the dynamic computed tomography scans of patients with unilateral patellofemoral instability and comparing unstable and contralateral asymptomatic knees.
We reviewed all dynamic computed tomography scans obtained at one tertiary care hospital from 2008 through 2013 and identified 25 patients with a history of recurrent unilateral patellofemoral instability. During the scans, subjects performed active knee extension against gravity. Both knees were imaged simultaneously. Lateral patellar tilt (LPT) and bisect offset (BO) were measured to assess tracking. TT-TG distance was measured to assess alignment. Measurements were made in full extension, maximum flexion, and approximately 10° increments in between. The significance level was set at P < .05.
LPT, BO, and TT-TG distance were highest in extension and decreased with flexion. Measurements were higher in symptomatic than in asymptomatic knees, with significant differences identified for LPT, BO, and TT-TG distance at 5° and 15° and for TT-TG distance at 25° and 35° (P < .05). TT-TG distance was associated with LPT and BO, with r(2) values in symptomatic knees of 0.55 for TT-TG distance and LPT and of 0.45 for TT-TG distance and BO.
In patients with unilateral patellar instability, LPT, BO, and TT-TG distance are higher on the unstable side. An association exists between TT-TG distance and the tracking parameters studied, suggesting that TT-TG distance relates to patellar tracking, and a laterally positioned tibial tuberosity may predispose to instability episodes.
Level IV, diagnostic study.
通过回顾性分析单侧髌股关节不稳定患者的动态计算机断层扫描图像，并比较患侧不稳定膝关节与对侧无症状膝关节，评估胫骨结节-滑车沟（TT-TG）距离在髌股关节运动学中的作用。
我们回顾了2008年至2013年在一家三级医疗中心医院获取的所有动态计算机断层扫描图像，确定了25例有复发性单侧髌股关节不稳定病史的患者。扫描过程中，受试者在抗重力状态下主动伸膝。双侧膝关节同时成像。测量外侧髌股倾斜（LPT）和二分偏移（BO）以评估轨迹，测量TT-TG距离以评估对线情况。测量在完全伸直、最大屈曲以及二者之间以约10°的增量进行。显著性水平设定为P < 0.05。
LPT、BO和TT-TG距离在伸直位时最高，并随屈曲而减小。患侧膝关节的测量值高于无症状对侧膝关节，在5°和15°时LPT、BO和TT-TG距离以及在25°和35°时TT-TG距离存在显著差异（P < 0.05）。TT-TG距离与LPT和BO相关，在患侧膝关节中，TT-TG距离与LPT的r²值为0.55，TT-TG距离与BO的r²值为0.45。
在单侧髌股关节不稳定患者中，患侧的LPT、BO和TT-TG距离更高。TT-TG距离与所研究的轨迹参数之间存在关联，提示TT-TG距离与髌股轨迹相关，胫骨结节外侧移位可能易导致不稳定发作。
IV级，诊断性研究。
