Search

Purpose: To evaluate the potential effect of partial wrist denervation on wrist kinesthesia, we hypothesized that anesthetizing the anterior interosseous nerve and the posterior interosseous nerve does not impair the kinesthesia., Methods: We performed a double-blinded, prospective, randomized study on 80 healthy volunteers (20-54 y old) to compare the ability to detect active and passive wrist movement in 2 conditions. The test group received an anesthetic block of the anterior and posterior interosseous nerves, and the control group subjects received an injection of saline. The kinesthesia of the 2 groups was then tested in 2 conditions by measuring the error in an active and passive wrist repositioning task. Results were analyzed using a repeated measures analysis of variance., Results: In both active and passive conditions, there was no difference in the repositioning errors between the test group and the control group., Conclusions: Our results show that kinesthesia is not impaired by blocking the anterior and posterior interosseous nerves. These findings are consistent for both active and passive motion. The study gives strong evidence that partial denervation does not impair wrist kinesthesia. However, because only kinesthesia was studied, we cannot conclude that partial denervation is a totally safe procedure for all aspects of proprioception., Type of Study/level of Evidence: Therapeutic I., (Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Purpose: The triangular fibrocartilage complex (TFCC) with its ulnar foveal attachment is the primary stabilizer of the distal radioulnar joint (DRUJ). The purpose of this study was to describe a technique for measuring the degree of subluxation of the DRUJ in wrist magnetic resonance imaging (MRI) examinations to predict tears involving the foveal attachment of the TFCC., Methods: We measured DRUJ geometry in wrist MRI examinations of 34 patients who were found to have foveal TFCC tears at surgery. We compared the results with DRUJ geometry in 11 asymptomatic controls. Subluxation of the ulnar head was assessed using transaxial MRI images obtained at the level of the DRUJ with the wrist in pronation. We quantified subluxation with a line spanning the sigmoid notch of the radius and a perpendicular line through the center of curvature of the articulating surface of the ulna. We calculated the ratio of the lengths of the dorsal and volar segments and normalized it to the center of the sigmoid notch., Results: A total of 34 patients with intraoperatively confirmed tears of the foveal attachment of the TFCC had a mean dorsal ulnar subluxation measurement of 16% ± 4%, whereas the 11 controls had a mean subluxation measurement of 5% ± 4%., Conclusions: The results confirm the hypothesis that subluxation of the ulnar head relative to the sigmoid notch of the radius, as assessed by MRI with the wrist in pronation, is a predictor of tears of the foveal attachment of the TFCC., Type of Study/level of Evidence: Diagnostic II., (Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

This article examines industry's involvement in medicine, particularly with respect to surgeons and clinical research, as well as continuing medical education. We describe some historical events involving industry and how these events have led to guidelines by various organizations to handle conflicts of interest. We also review the advantages and disadvantages of collaborating with industry and provide practical guides for interactions with industry in terms of clinical research, continuing medical education, and clinical practice. With careful consideration to protect all parties involved, collaboration with industry can be advantageous to surgeons, industry, and patients., (Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Purpose: To examine the distribution of encapsulated nerve endings called mechanoreceptors in the human distal interphalangeal (DIP) joint and surrounding structures., Methods: We processed 12 right index finger DIP joints and surrounding structures from fresh cadavers for immunohistochemistry of the anti-protein gene product 9.5 (PGP9.5) and silver staining to detect encapsulated nerve endings. Serial transverse sections were cut throughout the whole specimen and divided into 3 regions along the longitudinal axis: distal, middle, and proximal. Each of the transverse sections was partitioned into dorsal capsule (DC), radial capsule (RC), ulnar capsule (UC), volar plate (VP), and radial and ulnar assemblage nuclei (RAN and UAN); the RAN and UAN are located on both the radial and ulnar side of the VP. The C3 pulley contained the proximal region of the RAN and UAN, whereas the A5 pulley contained the middle and distal. The accessory collateral ligament contained all the regions of the RAN and UAN. We analyzed and compared the density of encapsulated nerve endings among the 18 different regions., Results: According to the modified Freeman and Wyke classification, we identified type I (eg, Ruffini-like endings) and type II (eg, Pacini-like endings) nerve endings. The density of type II nerve endings in the proximal region of the RAN and UAN was considerably higher than that in the proximal region of the VP, RC, UC and DC, and that in the proximal region of the VP, RC, UC, and DC, respectively., Conclusions: Our examination of the distribution of type I and type II nerve endings provides new information on the sensory systems of the DIP joints and surrounding structures., (Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Purpose: Trapeziectomy for the treatment of trapeziometacarpal (TM) osteoarthritis (OA) disrupts the scaphotrapezium-trapezoidal ligament complex and may be associated with carpal collapse in a subset of patients in the form of nondissociative dorsal intercalated segment instability (DISI). The purpose of this study was to examine the clinical and radiographic outcomes of trapeziectomy, documenting the incidence of postoperative carpal collapse, and to determine whether this outcome is correlated with preoperative radiographic findings., Methods: A retrospective chart and radiographic review was performed on 33 wrists having trapeziectomy from January 1999 to January 2006. Three surveys were administered to patients after surgery to assess subjective levels of pain, function, and satisfaction. The Wilcoxon signed-rank test was used to determine significant differences in radiographic angles, and McNemar's chi-square test was used to determine significant differences in the frequency of a DISI finding., Results: Stage IV disease was present in 58% of wrists; all wrists were followed up at a mean of 10.5 months after surgery. The mean postoperative change in the radiolunate angle was 4.4 degrees of increased dorsal tilt. Radioscaphoid angles changed after surgery by a mean of 6.3 degrees of increased extension. The frequency of DISI as measured by the radiolunate angle increased significantly, from 27% before surgery to 50% after surgery. Scaphotrapezium-trapezoidal arthritis was observed in 58% of wrists; within this subset, DISI was present in 39% before surgery and 62% after surgery. Those patients with a DISI deformity were significantly less satisfied following surgery than those without this finding., Conclusions: Patients having trapeziectomy for treatment of TM OA may be at risk for the development of carpal instability. This instability may manifest through either a DISI posture of the wrist or abnormal extension of the scaphoid in the presence of a normal scapholunate angle. The presence of stage IV TM OA may be correlated with an increased incidence of carpal instability after surgical intervention. These radiographic findings are mirrored by a trend toward increased levels of pain and decreased levels of function and satisfaction in those patients with evidence of DISI., Type of Study/level of Evidence: Therapeutic IV.