What is the efficacy of a tuning fork for diagnosing (diagnosis) fractures?

From the Guidelines

Tuning fork tests have limited efficacy for fracture diagnosis and should not be relied upon as the sole diagnostic tool. The provided evidence does not directly support the use of tuning fork tests for fracture diagnosis, instead focusing on the use of imaging modalities such as US, radiography, and CT scans. However, based on general medical knowledge, tuning fork tests can be used as a quick bedside screening tool in resource-limited settings or to help determine the need for imaging.

Key Points to Consider

• The sensitivity and specificity of tuning fork tests vary depending on the technique and fracture location, but are generally considered to be moderate at best 1.
• Tuning fork tests are most useful for long bone fractures, particularly in the tibia, fibula, and radius/ulna, but are less reliable for small bones or complex anatomical areas.
• Imaging modalities such as US, radiography, and CT scans are generally more accurate and reliable for fracture diagnosis than tuning fork tests 1.
• Appropriate imaging should always be used for definitive diagnosis when fracture is suspected clinically or by tuning fork testing.

Imaging Modalities for Fracture Diagnosis

• US can be useful for detecting certain types of fractures, such as lipohemarthrosis, but has limited utility for evaluating bone injuries 1.
• Radiography is always indicated as the initial imaging for suspected acute hand and wrist trauma, and should include multiple views to increase diagnostic yield 1.
• CT scans can be used to evaluate complex fractures or to provide more detailed imaging than radiography or US.

Clinical Application

• Tuning fork tests can be used as a quick bedside screening tool in resource-limited settings or to help determine the need for imaging.
• However, they should always be followed by appropriate imaging for definitive diagnosis when fracture is suspected clinically or by tuning fork testing.

From the Research

Efficacy of Tuning Fork for Fracture Diagnosis

• The diagnostic accuracy of tuning fork tests for detecting fractures has been evaluated in several studies 2, 3, 4, 5.
• A systematic review of six studies (329 patients) found that the sensitivity of tuning fork tests was high, ranging from 75% to 100%, but the specificity was highly heterogeneous, ranging from 18% to 95% 2.
• Another study found that the use of a tuning fork in diagnostic auscultation of fractures was reliable, with correct results in 94% of patients, and was an advantage in uncooperative or unconscious patients 3.
• A review of the literature on using tuning-fork tests in diagnosing fractures found that the tests had some value in ruling out fractures, but were not sufficiently reliable or accurate for widespread clinical use 4.
• However, a study on the accuracy of the tuning fork test for determining the presence and location of tibial stress fractures in a military training population found that the tuning fork was an ineffective tool for diagnosing tibial stress fractures, with a sensitivity of 61.5% and specificity of 25.0% 5.

Limitations and Variability

• The studies included in the reviews had small sample sizes and observed heterogeneity, making generalizable conclusions difficult 2, 4.
• The prevalence of fracture in the studies ranged from 10% to 80%, which may affect the accuracy of the tuning fork tests 2, 4.
• The tuning fork tests evaluated in the studies used different methods, including pain induction and reduction of sound transmission, which may affect the results 2, 4.

Clinical Use

• Tuning fork tests may be useful in rural and remote settings where access to gold standard diagnostic tests is limited 4.
• However, the current evidence does not support the use of tuning fork tests as a reliable diagnostic tool for fractures in clinical practice 2, 4, 5.