Mehta Nabil, Duryea Jeffrey, Badger Gary J, Akelman Matthew R, Jones Morgan H, Spindler Kurt P, Fleming Braden C
Department of Orthopaedics, The Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, Rhode Island, USA.
Department of Radiology, Brigham and Women's Hospital/Harvard University, Boston Massachusetts, USA.
Orthop J Sports Med. 2017 Sep 26;5(9):2325967117728675. doi: 10.1177/2325967117728675. eCollection 2017 Sep.
No consensus is available regarding the best method for measuring tibiofemoral joint space width (JSW) on radiographs to quantify joint changes after injury. Studies that track articular cartilage thickness after injury frequently use patients' uninjured contralateral knees as controls, although the literature supporting this comparison is limited.
(1) To compare JSW measurements using 2 established measurement techniques in healthy control participants and (2) to determine whether the mean JSW of the uninjured contralateral knee in a cohort with anterior cruciate ligament (ACL) reconstruction is different from that obtained from a true control population.
Cohort study (diagnosis); Level of evidence, 2.
Medial and lateral JSWs were measured on standardized, bilateral, semiflexed metatarsophalangeal positioning, posteroanterior radiographs of 60 healthy individuals (26 females; mean ± SD age, 25 ± 6.2 years; no history of knee injury) via 2 published techniques: a computerized surface-delineation method (surface-fit method) and a manual digitization method (midpoint method). Bland-Altman method was used to examine the agreement between JSW measurements obtained with the 2 methods and to examine the agreement between measurements obtained on left and right knees within a participant for each measurement method. Within- and between-participant variance components and intraclass correlation coefficients (ICCs) were computed for JSW measurements corresponding to each method. Two-sample tests were used to compare the surface-fit method measurements of mean JSW of the true control group (n = 60) with the previously published mean JSW measurements from the Multicenter Orthopaedics Outcomes Network (MOON) nested cohort of 262 contralateral uninjured knees 2 to 3 years after ACL reconstruction.
For JSW in the medial compartment, the surface-fit method had lower within-participant interknee variability (σ, 0.064; 95% CI, 0.04-0.09) compared with the midpoint method (σ, 0.28; 95% CI, 0.20-0.43) and a higher ICC (0.93 vs 0.65; < .001). Lateral JSW values were similar for the surface-fit method (σ, 0.27; 95% CI, 0.18-0.43) and the midpoint method (σ, 0.20; 95% CI, 0.14-0.31), with ICCs of 0.75 and 0.77, respectively ( = .80). With the surface-fit method, mean JSW measurements of the medial and lateral compartments of a control population were not significantly different from the contralateral uninjured knees of patients after ACL reconstruction.
For measuring medial JSW, the surface-fit method was less variable across knees within a participant than the midpoint method, as evidenced by larger ICCs and lower interknee variability. For measuring lateral JSW, the 2 methods were similar. The JSW measurements of uninjured contralateral knees of patients with ACL reconstruction at 2 to 3 years postsurgery were not significantly different from those of a cohort of healthy control participants. Future work should be performed to demonstrate the validity of these methods for documenting change over time in the ACL-reconstructed knee.
关于在X线片上测量胫股关节间隙宽度（JSW）以量化损伤后关节变化的最佳方法，目前尚无共识。追踪损伤后关节软骨厚度的研究经常将患者未受伤的对侧膝关节作为对照，尽管支持这种比较的文献有限。
（1）在健康对照参与者中比较使用两种既定测量技术测量JSW的情况，（2）确定前交叉韧带（ACL）重建队列中未受伤对侧膝关节的平均JSW是否与真正对照组人群的平均JSW不同。
队列研究（诊断）；证据等级，2级。
通过两种已发表的技术，在60名健康个体（26名女性；平均±标准差年龄，25±6.2岁；无膝关节损伤史）的标准化、双侧、半屈曲跖趾关节定位的正位X线片上测量内侧和外侧JSW：一种计算机表面描绘方法（表面拟合方法）和一种手动数字化方法（中点法）。采用Bland-Altman方法检查两种方法获得的JSW测量值之间的一致性，以及在每个测量方法中参与者左右膝关节测量值之间的一致性。计算每种方法对应的JSW测量值的参与者内和参与者间方差分量以及组内相关系数（ICC）。采用两样本检验比较真正对照组（n = 60）的表面拟合方法测量的平均JSW与多中心骨科结果网络（MOON）嵌套队列中262例ACL重建术后2至3年对侧未受伤膝关节先前发表的平均JSW测量值。
在内侧间室的JSW测量中，与中点法（σ，0.28；95%CI，0.20 - 0.43）相比，表面拟合方法的参与者内膝关节间变异性较低（σ，0.064；95%CI，0.04 - 0.09），ICC较高（0.93对0.65；P <.001）。外侧JSW值在表面拟合方法（σ，0.27；95%CI，0.18 - 0.43）和中点法（σ，0.20；95%CI，0.14 - 0.31）中相似，ICC分别为0.75和0.77（P =.80）。采用表面拟合方法时，对照组人群内侧和外侧间室的平均JSW测量值与ACL重建术后患者的对侧未受伤膝关节无显著差异。
对于测量内侧JSW，表面拟合方法在参与者内膝关节间的变异性低于中点法，这由更高的ICC和更低的膝关节间变异性证明。对于测量外侧JSW，两种方法相似。ACL重建术后2至3年患者未受伤对侧膝关节的JSW测量值与健康对照参与者队列的测量值无显著差异。未来应开展工作以证明这些方法记录ACL重建膝关节随时间变化的有效性。
