[Wartenberg's Sign of Ulnar Nerve Lesion. A Contribution to Pathophysiology and to the Differential Diagnosis]

Robert Wartenberg Syndrome and Sign: A Review Article

Background:

Robert Wartenberg, a European-American neurologist, was born in 1887 and died in 1956. His description of radial sensory nerve compression at the forearm is memorialized as Wartenberg’s syndrome. He recognized that involuntary abduction of the little finger could be caused by ulnar nerve palsy - a finding often called Wartenberg’s sign Syndrome and signs are reviewed, and a brief biography is presented.

Objective:

To review Wartenberg’s sign and Wartenberg’s syndrome.

Discussion:

Compression of the superficial branch of the radial nerve, often called Wartenberg’s syndrome, is characterized by pain, paresthesia, and dysesthesia along the dorsoradial distal forearm. Non-operative treatment can include activity restriction and anti-inflammatory medication. If symptoms persist, surgical decompression of the radial nerve is an option. The abducted posture of the little finger - Wartenberg’s sign - can result from a low ulnar nerve palsy. Tendon transfer can be performed to correct this deformity.

Conclusion:

Compression of the superficial branch of the radial nerve and abducted posture of the little finger were described by Robert Wartenberg and carry his name as eponymous syndrome and sign, respectively.

The Relative Contribution to Small Finger Abduction of the Ulnar Versus Radial Slip of the EDM: Implications for Tendon Transfers

BACKGROUND

The extensor digiti minimi (EDM) tendon is commonly divided into a radial slip (EDM-R) and an ulnar slip (EDM-U). To our knowledge, the degree to which each EDM slip concomitantly abducts the small finger with active extension has not been formally tested. This study sought to characterize the comparative contributions of finger abduction inherent to each slip of the EDM to observe the sequelae of active small finger extension following transfer of the contralateral slip.

METHODS

Eighteen fresh-frozen cadaveric hands were used in this study. Starting with the hand in resting position, a controlled traction of 10 N was applied to each slip of the EDM tendon. The range of small finger abduction with respect to the fixed ring finger was recorded utilizing infrared reflective markers tracked through the range of motion using a digital video camera.

RESULTS

The mean abduction of the small finger when the radial slip of the EDM tendon was tested was 13.33° (95% confidence interval [CI]: 10.10°-16.55°), which was significantly different ( P ≤ .001) than small finger abduction produced by the ulnar slip of the EDM, with a mean of 23.72° (95% CI: 19.40°-28.04°).

CONCLUSIONS

Given the fact that the ulnar slip of the EDM tendon is shown to be the major contributor of aberrant abduction with active small finger extension, as traction on this slip produces almost twice as much abduction as the radial slip, the EDM-U is the ideal donor graft with respect to tendon transfers of the EDM.

Eponymous signs in dermatology

Clinical signs reflect the sheer and close observatory quality of an astute physician. Many new dermatological signs both in clinical and diagnostic aspects of various dermatoses are being reported and no single book on dermatology literature gives a comprehensive list of these “signs” and postgraduate students in dermatology finds it difficult to have access to the description, as most of these resident doctor do not have access to the said journal articles. “Signs” commonly found in dermatologic literature with a brief discussion and explanation is reviewed in this paper.

Investigation of radialization and rerouting of the extensor digiti minimi (EDM) in the abduction deformity of the little finger: a cadaver study

BACKGROUND

One of several operations to correct abduction deformity of the little finger, (Wartenberg's sign) in ulnar nerve palsy, is a combined procedure that radializes the extensor digiti minimi (EDM) at the level of the fifth metacarpophalangeal (MCP) joint and reroutes it from the fifth to fourth extensor compartment. This cadaveric study was designed to investigate the impact of both elements on adduction.

MATERIALS AND METHODS

Anatomy of the little finger extensor apparatus was studied in 16 freshly frozen cadaver hands sectioned at mid forearm. We observed little finger motion after different modifications of the EDM. We tested the effect of a rerouting maneuver by pulling on the EDM, as well as radialization of the EDM alone and in combination with rerouting.

RESULTS

The EDM was present in all cases. Little finger extensor digitorum communis (EDC(V)) was missing in two cadavers. In no case was adduction created by rerouting the EDM to the fourth compartment. Radialization of the EDM corrected the abduction deformity beyond the axis of abduction/adduction of the fifth MCP joint in 13 cases and only up to it in three cases. In one of the three with limited correction, a rerouting maneuver allowed for further adduction.

CONCLUSION

The key to correct abduction deformity of the little finger is radialization of the EDM, which can be done through a solitary incision at the level of the MCP joint. Rerouting alone does not correct the abduction deformity, and in combination with radialization it does not predictably enhance the correction.

MRI of the Intrinsic Muscles of the Hand: Spectrum of Imaging Findings and Clinical Correlation

OBJECTIVE

The purpose of our study was to describe the spectrum of intrinsic hand muscle abnormalities on MRI in patients with clinically evident abnormalities of the intrinsic hand muscles and to correlate clinical and radiologic findings.

MATERIALS AND METHODS

MRI of 21 hands was performed in 19 patients with clinically evident or suspected intrinsic hand muscle abnormalities. All MRI was performed on a 1.5-T scanner using transaxial T1-weighted, T2-weighted, or STIR as well as contrast-enhanced T1-weighted sequences. Two observers reviewed all MR images retrospectively in a blinded fashion with regard to the exact anatomic location of the muscle abnormality, signal abnormalities, muscle atrophy, and the cause. Kappa statistics were used to calculate interobserver variability. MRI findings were compared with clinical findings using Spearman's rank test. A panel of experts assessed the impact of MRI on the diagnostic workup.

RESULTS

On the basis of MRI findings, abnormalities (either MR signal abnormality or atrophy) of both the lumbrical and interosseus muscles were noted in 10 (48%) of 21 hands, of the thenar muscles in eight (38%) of 21 hands, and of the hypothenar muscles in 12 (57%) of 21 hands. The correlation between clinical and MRI findings was moderate to strong for the interosseus, thenar, and hypothenar muscles (0.43-0.84). MRI was judged to be useful for establishing the final diagnosis in 17 (81%) of 21 hands.

CONCLUSION

MRI of the hands is useful and correlates well with clinical findings in patients with intrinsic hand muscle abnormalities.