Can Physical Examination Create a Stener Lesion?

BACKGROUND: The purpose of this study is to determine whether a Stener lesion can be created while testing stability of the ulnar collateral ligament (UCL) of the thumb. Testing was performed in a manner that reproduced clinical examination. METHODS: Six fresh frozen hand and forearm specimens underwent sequential sectioning of the accessory UCL, the proper UCL, and the ulnar sagittal band. Measurements of radial deviation of the metacarpophalangeal (MCP) joint were taken with the thumb in neutral rotation, pronation and supination, both with 0 degrees and with 30 degrees of flexion of the MCP joint. Visual examination was performed to assess the presence of a Stener lesion. RESULTS: No Stener lesion was created in any position as long as the fascial origin of the ulnar sagittal band at the adductor pollicis longus remained intact. After creating a defect in the ulnar sagittal band, a Stener lesion was created in two specimens, but only when the thumb was flexed and supinated. Pronation provided more stability, and supination provided less stability, with one or both components cut, especially when testing at 30° of flexion. Compared to both components cut without flexion or rotation, there was a statistically significant difference in angulation with the 30 degrees of MCP joint flexion in both neutral rotation in supination. CONCLUSIONS: Performing a physical examination to assess the amount of instability of an ulnar collateral ligament injury did not create a Stener lesion if the exam was performed in a controlled, gentle manner with the thumb held without rotation. If the thumb is held in neutral rotation during the exam, an iatrogenic Stener lesion should not be created.

Lateral collateral ligament deficiency of the elbow joint: A modeling approach.

A computational model capable of predicting the effects of lateral collateral ligament deficiency of the elbow joint would be a valuable tool for surgical planning and prediction of the long-term consequences of ligament deficiency. The purpose of this study was to simulate lateral collateral ligament deficiency during passive flexion using a computational multibody elbow joint model and investigate the effects of ligament insufficiency on the kinematics, ligament loads, and articular contact characteristics (area, pressure). The elbow was placed initially at approximately 20° of flexion and a 345 mm vertical downward motion profile was applied over 40 s to the humerus head. The vertical displacement induced flexion from the initial position to a maximum flexion angle of 135°. The study included simulations for intact, radial collateral ligament deficient, lateral ulnar collateral ligament deficient, and combined radial and lateral ulnar collateral ligament deficient elbow. For each condition, relative bone kinematics, contact pressure, contact area, and intact ligament forces were predicted. Intact and isolated radial collateral ligament deficient elbow simulations were almost identical for all observed outcomes. Minor differences in kinematics, contact area and pressure were observed for the isolated lateral ulnar collateral ligament deficient elbow compared to the intact elbow, but no elbow dislocation was detected. However, sectioning both ligaments together induced substantial differences in kinematics, contact area, and contact pressure, and caused complete dislocation of the elbow joint. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1645-1655, 2016.