SMART (Sports Medicine and Reconditioning Team), Naval Hospital Camp Pendleton, Oceanside, CA 92055, USA.
Mil Med. 2021 Jul 1;186(7-8):733-736. doi: 10.1093/milmed/usab052.
Stress fractures or bone stress injuries arise from trauma or overuse, often as a result of rapid increase in training. This rapid increase in training occurs frequently as military recruits begin their entry-level training, as many individuals are not accustomed to the level of activity required during boot camp. Tibial stress fractures are the most common bone stress injuries in the military setting. MRI is the gold standard test for identification of stress fractures, but MRI may not be available in field settings. Although limited evidence has suggested that a vibrating tuning fork may be beneficial in determining the presence of a stress fracture, the tuning fork has become a frequent tool used to detect or diagnose stress fractures.
Military personnel with suspected unilateral tibial stress fractures were asked to participate in evaluation of tuning forks as a diagnostic tool, in addition to receiving standard diagnostics and treatment. Points of maximal shin tenderness to palpation and vibration, followed by the application of a tuning fork, were evaluated. Each service member also underwent an abbreviated MRI evaluation with a 1.5T magnet consisting of coronal and sagittal STIR (Short Tau Inversion Recovery) and T1 (weighted longitudinal relaxation time) sequences. The results of tuning fork testing were compared to the MRI findings, considering grade 1 changes on MRI to represent a true stress fracture. A two-by-two table was used to determine the performance of tuning fork testing, relative to MRI findings, applying conventional definitions of sensitivity, specificity, positive predictive value, and negative predictive value.
Among 63 male active duty members with suspected tibial stress fractures, 39 had MRI-confirmed stress fractures. Tuning fork testing, relative to MRI, demonstrated overall sensitivity of 61.5%, specificity of 25.0%, positive predictive value of 57.1%, and negative predictive value of 28.6%. A sub-analysis restricting to grade 3 and grade 4 MRI findings did not improve the diagnostic performance of tuning forks.
The tuning fork is an ineffective tool for diagnosing tibial stress fractures.
应力性骨折或骨应力损伤是由创伤或过度使用引起的，通常是由于训练量的快速增加。这种训练量的快速增加在新兵开始入门级训练时经常发生，因为许多人不习惯新兵训练营中所需的活动水平。胫骨应力性骨折是军事环境中最常见的骨应力损伤。MRI 是识别应力性骨折的金标准测试，但在野外环境中可能无法获得 MRI。尽管有限的证据表明，振动音叉可能有助于确定是否存在应力性骨折，但音叉已成为一种经常用于检测或诊断应力性骨折的工具。
有疑似单侧胫骨应力性骨折的军人被要求参与音叉评估作为一种诊断工具，此外还接受了标准诊断和治疗。评估了触诊和振动时胫骨最敏感的点，然后应用音叉。每位军人还接受了一个 1.5T 磁体的简化 MRI 评估，包括冠状位和矢状位短 TI 反转恢复（Short Tau Inversion Recovery）和 T1（加权纵向弛豫时间）序列。将音叉测试的结果与 MRI 结果进行比较，将 MRI 上的 1 级变化视为真正的应力性骨折。使用 2×2 表来确定音叉测试相对于 MRI 结果的性能，应用传统的敏感性、特异性、阳性预测值和阴性预测值的定义。
在 63 名有疑似胫骨应力性骨折的现役男性中，有 39 名的 MRI 结果证实存在应力性骨折。相对于 MRI，音叉测试的总体敏感性为 61.5%，特异性为 25.0%，阳性预测值为 57.1%，阴性预测值为 28.6%。对 MRI 分级 3 和 4 结果进行的亚分析并没有提高音叉的诊断性能。
音叉是一种诊断胫骨应力性骨折的无效工具。
