Prospective study on a diagnostic test.
To determine the usefulness of hip abductor power assessment in the differential diagnosis of foot drop due to lumbar radiculopathy and peroneal neuropathy.
Foot drop arises from various neuromuscular conditions. Differential diagnosis obvious in the typical case, however, is often inconclusive. There are few reports regarding the validity of hip abductor power in the differential diagnosis of foot drop.
Sixty-one consecutive patients who presented with tibialis anterior weakness Medical Research Council grade of less than 3 were included and underwent neurological examination including the assessment of hip abductor power. Patient demographics, mechanism and pattern of foot drop, neurological findings, and the diagnoses were recorded. Final diagnoses were established on the basis of clinical information, imaging studies, and electrophysiological study in limited cases. Validity and reliability of the hip abductor power assessment in the differential diagnosis of foot drop due to lumbar radiculopathy and peroneal neuropathy were evaluated.
There were 44 men and 17 women, with a mean age of 46.8 years (19–77 yr). The final diagnosis was peroneal neuropathy in 28 patients, lumbosacral plexopathy in 9 patients, lumbar radiculopathy in 21 patients, and sciatic nerve disorder in 3 patients. Concomitant hip abductor weakness was found in 85.7% of lumbar radiculopathy and 3.6% of peroneal neuropathy. The sensitivity and specificity of hip abductor power in the differential diagnosis of foot drop due to the lumbar radiculopathy and peroneal neuropathy were 85.7% and 96.4%, respectively. The positive and negative predictive values were 94.7% and 90%, respectively.
Assessment of hip abductor strength is a simple and useful method in the differential diagnosis of foot drop due to lumbar radiculopathy and peroneal neuropathy.
Lumbar radiculopathy and peroneal neuropathy were the major etiology of foot drop. We found that the hip abduction power was significantly different between the 2 conditions. Assessment of hip abductor strength is a simple and useful examination in the differential diagnosis of both etiologies.
From the Department of Orthopaedic Surgery, Ajou University School of Medicine, Suwon, Republic of Korea
Address correspondence and reprint requests to Nam-Su Chung, MD, Department of Orthopaedic Surgery, Ajou University School of Medicine, San 5 Wonchon-dong, Youngtong-gu, Suwon, Kyounggi-do, Republic of Korea; E-mail: email@example.com
Acknowledgment date: March 7, 2012. First revision date: May 3, 2012. Second revision date: July 3, 2012. Acceptance date: July 8, 2012.
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work.
No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.