Norris Richard, Price Alan, Maddox Thomas W, Boswell William, Kerin Cronan, Oldershaw Rachel A
Department of Trauma and Orthopaedics, Aintree University Hospital Liverpool University Hospitals NHS Foundation Trust Liverpool UK.
Department of Musculoskeletal and Ageing Sciences, Institute of Life Course and Medical Sciences, Faculty of Health and Life Sciences University of Liverpool Liverpool UK.
J Exp Orthop. 2025 Apr 28;12(2):e70251. doi: 10.1002/jeo2.70251. eCollection 2025 Apr.
To evaluate the intrarater reliability and predictive validity of Lachmeter® measurements for diagnosing acute anterior cruciate ligament (ACL) tears, and to propose diagnostic thresholds.
Lachmeter® measurements were recorded during the stabilised Lachman test for consecutive participants presenting to an acute knee injury clinic within 21-days of injury. Intrarater reliability for individual limb and side-to-side (STS) difference (injured limb minus uninjured limb) measurements was investigated using a cross-sectional, repeated-measures design and the intraclass correlation coefficient (ICC). The predictive validity of STS difference and injured limb measurements was investigated using a prospective cohort design; sensitivity, specificity, negative (LR-) and positive likelihood ratios (LR+) were calculated using magnetic resonance imaging as the reference standard.
Intrarater reliability was excellent for individual limb and STS difference measurements in 102 participants. Of the 63 participants included in the validity analysis, 31 had a normal ACL and 32 had an ACL tear. LR- point estimates for STS differences <1.4 mm (0.07 [95% confidence interval [CI]: 0.02-0.29]) or injured limb measurements <7.5 mm (0.09 [95% CI: 0.02-0.34] produced 'large' shifts in the probability of ruling out an ACL tear. LR+ point estimates for STS differences ≥3.8 mm (10.67 [95% CI: 2.68-42.51]) or injured limb measurements ≥11.8 mm (10.67 [95% CI: 1.42-80.26]) produced 'large' shifts in the probability of ruling in a full-thickness ACL tear.
In participants presenting within 21-days of knee injury, intrarater reliability was excellent for Lachmeter® measurements recorded during the stabilised Lachman test. Based on predictive validity estimates, Lachmeter® measurements can be used to differentiate normal from torn ACLs in acute presentations, but not partial from full-thickness ACL tears. Diagnostic thresholds are proposed based on STS difference and injured limb measurements, and with consideration of the Lachman end point. Level I.
评估Lachmeter®测量在诊断急性前交叉韧带（ACL）撕裂中的评分者内信度和预测效度，并提出诊断阈值。
对在损伤后21天内就诊于急性膝关节损伤诊所的连续参与者，在稳定的Lachman试验中记录Lachmeter®测量值。采用横断面重复测量设计和组内相关系数（ICC）研究个体肢体测量和双侧（STS）差异（受伤肢体减去未受伤肢体）测量的评分者内信度。采用前瞻性队列设计研究STS差异和受伤肢体测量的预测效度；以磁共振成像作为参考标准计算敏感性、特异性、阴性（LR-）和阳性似然比（LR+）。
102名参与者的个体肢体测量和STS差异测量的评分者内信度极佳。在纳入效度分析的63名参与者中，31名ACL正常，32名ACL撕裂。当STS差异<1.4 mm（0.07 [95%置信区间[CI]：0.02 - 0.29]）或受伤肢体测量值<7.5 mm（0.09 [95% CI：0.02 - 0.34]）时，LR-点估计值在排除ACL撕裂的概率上产生“大”的变化。当STS差异≥3.8 mm（10.67 [95% CI：2.68 - 42.51]）或受伤肢体测量值≥11.8 mm（10.67 [95% CI：1.42 - 80.26]）时，LR+点估计值在确诊全层ACL撕裂的概率上产生“大”的变化。
在膝关节损伤后21天内就诊的参与者中，稳定Lachman试验期间记录的Lachmeter®测量的评分者内信度极佳。基于预测效度估计，Lachmeter®测量可用于在急性情况下区分正常与撕裂的ACL，但不能区分部分与全层ACL撕裂。基于STS差异和受伤肢体测量值并考虑Lachman终点提出了诊断阈值。一级。
