Banff Sport Medicine, Banff, Alberta, Canada.
Department of Surgery, University of Calgary, Calgary, Alberta, Canada.
Am J Sports Med. 2021 Mar;49(4):975-981. doi: 10.1177/0363546520988731. Epub 2021 Feb 18.
The clinical sign of patellar laxity and the associated symptom of apprehension are mainstays of the physical examination of patellofemoral instability. The apprehension test is widely used as a diagnostic tool and also as an outcome following patellofemoral stabilization surgery. Despite widespread use, the validity, reliability, and responsiveness of the apprehension test have not been established.
The primary purpose was to evaluate patellar apprehension in patients with recurrent patellofemoral instability to determine if the apprehension test is valid, reliable, and responsive to change after medial patellofemoral ligament (MPFL) reconstruction. The secondary purposes were to concurrently validate patient-rated to surgeon-rated apprehension and to correlate patient-rated apprehension with pathoanatomic characteristics and quality-of-life scores.
Cohort study (diagnosis); Level of evidence, 3.
A total of 89 patients underwent an MPFL reconstruction and were assessed preoperatively and at 6, 12, and 24 months postoperatively. The patellar apprehension test was performed in neutral extension and 30° of knee flexion. Patient- and surgeon-rated apprehension were graded on a 10-cm visual analog scale (VAS), and the quality of the apprehension symptoms were recorded. Risk factors for patellofemoral instability were documented, and the Banff Patellofemoral Instability Score 2.0 (BPII 2.0) was used to measure disease-specific quality of life.
The patient-rated and surgeon-rated apprehension VAS scores were statistically significantly reduced from pre- to postoperatively ( < .001, large effect size) for the neutral extension and 30° of flexion apprehension tests. Postoperatively, over 56% of patients reported a negative apprehension test. Up to 15.7% of patients with positive preoperative apprehension did not demonstrate a reduction postoperatively. Patients consistently graded their apprehension symptoms higher in both quantity and quality than the surgeon. The intraclass correlation coefficient (ICC [2, ]) assessing the preoperative patient and surgeon VAS scores revealed moderate interrater reliability in neutral extension ( = 0.60) and weak interrater reliability in 30° of flexion ( = 0.42). The postoperative ICC (2, ) demonstrated strong interrater reliability for both neutral extension ( = 0.74) and 30° of flexion ( = 0.73). The symptoms of apprehension (physical, emotional, and/or physiological) decreased substantially after surgery. The correlation of postoperative patient-rated apprehension VAS and BPII 2.0 scores demonstrated that less residual patellar apprehension was associated with higher BPII scores in neutral extension ( = -0.35, = .001). There were no statistically significant correlations revealed between the patient-rated postoperative apprehension VAS and pathoanatomic risk factors. BPII 2.0 scores improved pre- to postoperatively from a mean of 27.6 (SD, 15.7) to 74.3 (SD, 18.3). Three patients (3.4%) sustained a patellar dislocation postoperatively.
The patellar apprehension test demonstrated strong validity and responsiveness to change. Interrater reliability ranged from weak to strong. There was a statistically significant reduction in apprehension after patellofemoral stabilization in the majority of patients. Patients graded their apprehension symptoms significantly higher in both quantity and quality than the surgeon. Persistent patellar apprehension after stabilization was correlated with lower quality-of-life scores. No relationship could be found between persistent apprehension and patellofemoral risk factors. These results suggest that use of the apprehension tests as an outcome is inappropriate until further validation is performed.
髌骨松弛的临床征象和伴随的髌骨不稳定的触诊是髌股关节不稳定体格检查的主要依据。触诊试验被广泛用作诊断工具，也被用作髌股韧带重建术后的结果。尽管广泛使用，但触诊试验的有效性、可靠性和反应性尚未得到证实。
主要目的是评估复发性髌股关节不稳定患者的髌骨触诊，以确定触诊试验在髌股内侧支持带（MPFL）重建后是否有效、可靠和对变化敏感。次要目的是同时验证患者对医生触诊的评估，以及将患者的触诊评估与病理解剖特征和生活质量评分相关联。
队列研究（诊断）；证据水平，3 级。
共有 89 例患者接受了 MPFL 重建，并在术前和术后 6、12 和 24 个月进行评估。在中立伸展和 30°膝关节屈曲下进行髌骨触诊试验。患者和医生对触诊的评估分别在 10cm 视觉模拟量表（VAS）上进行评分，并记录触诊症状的质量。记录髌股关节不稳定的危险因素，并使用 Banff 髌股关节不稳定评分 2.0（BPII 2.0）来测量疾病特异性生活质量。
与术前相比，中立伸展和 30°膝关节屈曲的触诊试验患者和医生的触诊 VAS 评分在术后均显著降低（<0.001，大效应量）。术后，超过 56%的患者报告触诊试验呈阴性。多达 15.7%的术前触诊阳性患者术后未显示触诊减少。患者对触诊症状的评估始终高于医生在数量和质量方面的评估。评估术前患者和医生 VAS 评分的组内相关系数（ICC[2，]）显示在中立伸展时具有中度组间可靠性（=0.60），在 30°膝关节屈曲时具有弱组间可靠性（=0.42）。术后 ICC（2，）显示在中立伸展（=0.74）和 30°膝关节屈曲（=0.73）时具有很强的组间可靠性。术后触诊（身体、情感和/或生理）症状明显减少。术后患者触诊 VAS 和 BPII 2.0 评分的相关性表明，残余髌骨触诊越少与中立伸展时更高的 BPII 评分相关（=0.35，=0.001）。患者术后触诊 VAS 和病理解剖危险因素之间没有统计学上显著的相关性。BPII 2.0 评分从术前的 27.6（标准差，15.7）到术后的 74.3（标准差，18.3）显著提高。术后 3 例（3.4%）患者发生髌骨脱位。
髌骨触诊试验具有较强的有效性和对变化的反应性。组间可靠性从弱到强不等。在大多数患者中，髌股关节稳定后触诊明显减少。患者对触诊症状的评估在数量和质量上均显著高于医生。髌股韧带重建术后持续性髌骨触诊与较低的生活质量评分相关。持续性触诊与髌股关节危险因素之间未发现任何关系。这些结果表明，在进一步验证之前，使用触诊试验作为结果是不合适的。
