By Emily Delzell
A retrospective analysis e-published in April in Clinical Orthopaedics and Related Research found physical examination is superior to magnetic resonance imaging (MRI) for diagnosis of acute Achilles tendon ruptures.
Investigators at Thomas Jefferson University Hospital in Philadelphia compared 66 patients who had undergone preoperative MRI to 66 patients without preoperative MRI. All patients underwent preoperative exams; diagnostic criteria for Achilles tendon rupture were presence of an abnormal Thompson test (no ankle flexion with the clinician squeezing the patient’s calf), decreased ankle resting tension compared with the uninjured side, and a palpable defect in the Achilles tendon.
Researchers compared time to diagnosis of acute rupture and surgical procedures in both groups; operative findings confirmed all patients had complete ruptures. Physical exam had a sensitivity of 100%; however, MRI-based findings included just 60 complete tears along with four partial tears and two inconclusive diagnoses. Time to surgery was 8.1 days after injury in the non-MRI group and 26.3 days in the MRI group.
Investigators concluded clinicians should reserve MRI for ambiguous presentations and subacute or chronic injuries.
Garras DN, Raikin SM, Bhat SB, et al. MRI is unnecessary for diagnosing acute Achilles tendon ruptures: clinical diagnostic criteria. Clin Orthop Relat Res 2012 Apr 27. [Epub ahead of print]