Objective: To summarize and evaluate the current diagnostic accuracy of clinical measures used to diagnose Achilles tendon injuries.
Data sources: A literature search of MEDLINE, CINAHL, and EMBASE databases was conducted with key words related to diagnostic accuracy and Achilles tendon injuries.
Study selection: Original research articles investigating Achilles tendon injuries against an acceptable reference standard were included.
Data extraction: Three studies met the inclusion criteria. Quality assessment was conducted using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. DerSimonian-Laird random-effects models were used to pool sensitivity (SN), specificity (SP), and diagnostic odds ratios with their 95% confidence intervals (CIs).
Data synthesis: The SN and negative likelihood ratio (-LR) values for Achilles tendon rupture measures ranged from 0.73 (95% CI = 0.65, 0.81) and 0.30 (95% CI = 0.23, 0.40) to 0.96 (95% CI = 0.93, 0.99) and 0.04 (95% CI = 0.02, 0.10), respectively, whereas SP and positive likelihood ratio (+LR) values ranged from 0.85 (95% CI = 0.72, 0.98) and 6.29 (95% CI = 2.33, 19.96) to 0.93 (95% CI = 0.84, 1.00) and 13.71 (95% CI = 3.54, 51.24), respectively, with the highest SN and SP both reported in the calf-squeeze test. The SN and -LR values for Achilles tendinopathy measures ranged from 0.03 (95% CI = 0.00, 0.08) and 0.97 (95% CI = not reported) to 0.89 (95% CI = 0.75, 0.98) and 0.19 (95% CI = not reported), whereas SP and +LR values ranged from 0.58 (95% CI = 0.38, 0.77) and 2.12 (95% CI = not reported) to 1.00 (95% CI = 1.00, 1.00) and infinity, respectively, with the highest SN and SP reported for morning stiffness and palpation for crepitus. Pooled analyses demonstrated similar diagnostic properties in all 3 clinical measures (arc sign, palpation, and Royal London Hospital test), with SN and -LR ranging from 0.42 (95% CI = 0.23, 0.62) and 0.68 (95% CI = 0.50, 0.93), respectively, for the arc sign, to 0.64 (95% CI = 0.44, 0.81) and 0.48 (95% CI = 0.29, 0.80), respectively, for palpation. Pooled SP and +LR ranged from 0.81 (95% CI = 0.65, 0.91) and 3.15 (95% CI = 1.61, 6.18), respectively, for palpation, to 0.88 (95% CI = 0.74, 0.96) SP for the arc sign and 3.84 (95% CI = 1.69, 8.73) +LR for the Royal London Hospital test.
Conclusions: Most clinical measures for Achilles tendon injury have greater diagnostic than screening capability.
Keywords: diagnostic accuracy; sensitivity; specificity.