Scratch Collapse Test Localizes Osborne's Band as the Point of Maximal Nerve Compression in Cubital Tunnel Syndrome

Abstract

The objective of this study is to demonstrate the utility of the scratch collapse test (SCT) in localizing the point of maximal compression in cubital tunnel syndrome. From January 1, 2004 to December 1, 2005, 64 adult patients with cubital tunnel syndrome were evaluated by a single surgeon. Cubital tunnel syndrome was diagnosed based upon symptoms of numbness, tingling, and/or pain in the ulnar nerve distribution or by the presence of weakness or wasting of the ulnar-innervated intrinsic hand muscles. All diagnoses were confirmed with electrodiagnostic studies. As part of the physical examination, the SCT was performed along three subdivided segments in the region of the cubital tunnel. Results of the SCT were recorded and correlated with intraoperative findings. Of the 64 patients evaluated, 44 had a positive SCT that was either more profound or solely present a few centimeters distal to the medial epicondyle in the region of Osborne's band. All of these patients subsequently underwent anterior submuscular transposition and were found to have a tight compression point at Osborne's band corresponding to their preoperative SCT. This study suggests that the scratch collapse test may be a reliable physical examination technique for localizing the point of maximal nerve compression in patients with cubital tunnel syndrome. That point, in this series, corresponded with Osborne's band.

Clinical Diagnosis and Wide-Awake Surgical Treatment of Proximal Median Nerve Entrapment at the Elbow: A Prospective Study

“…The use of the SCT has also been suggested as an important tool in differentiating between levels of ulnar nerve entrapment at the level of the elbow [4]. Similarly, SCT was an important adjunct in diagnosing LTS, along with specific muscle weakness and pain at the level of entrapment (lacertus tunnel).…”

The Scratch Collapse Test Supported the Diagnosis and Showed Successful Treatment of Tarsal Tunnel Syndrome

“…The patho-physiology is similar to the carpal tunnel syndrome and similar nerve entrapment on the arm [6]. Brown et al found that the scratch collapse test was a seemingly reliable physical examination technique for localizing the point of maximal nerve compression in patients with cubital tunnel syndrome [7]. The scratch collapse test is simple and rapid to perform and it seems reasonable to add this test to the diagnostic toolbox also for analysis of ankle pain.…”

Osborne’s Ligament: A Review of its History, Anatomy, and Surgical Importance

“…Osborne’s ligament has frequently been implicated in the etiology of ulnar neuropathy [4-6,9,16,29]. It has been proven that the cubital tunnel’s volume deep to the ligament decreases as the elbow flexes [2].…”

“…For this examination, the patient sits with a flexed elbow at 90 o  and fingers pointing toward the examiner who attempts to rotate the forearm medially and takes note of the patient’s baseline “resistance.” The area over the proposed site of entrapment is then stroked and the test is repeated. An observable decrease in “resistance” indicates a positive test, while simultaneously identifying the site of impingement in the vicinity of Osborne’s ligament [9]. Cheng, et al used the scratch collapse test for diagnosing cubital tunnel syndrome with 89% accuracy [34].…”

“…The cubital tunnel is the fibromuscular canal where the ulnar nerve traverses between the two heads of the FCU with a floor composed of the medial collateral ligament, olecranon, and joint capsule. The so-called Osborne’s ligament has also been referred to as the arcuate ligament of Osborne [7], the cubital tunnel retinaculum [8], Osborne’s fascia [3], Osborne’s band [9], or simply the arcuate ligament or tendinous arch [10] and with Osborne’s publications in the 1950s, was considered as one of the causes of ulnar neuritis [5]. Prior to Osborne’s description of this band of tissue, it was rarely mentioned in the English and French literature [11].…”