Efficacy of Dorsoradial Capsulodesis for Trapeziometacarpal Joint Instability: A Cadaver Study.

PURPOSE: To test the biomechanical properties of the dorsoradial capsulodesis procedure. METHODS: Six cadaveric hands were used. After exposing the trapeziometacarpal (TMC) joint, we placed Kirschner wires in the distal radius and thumb metacarpal. The rotation shear test was then performed to test the joint axial laxity, and angular measurements using Kirschner wires as reference points were documented. The dorsoradial (DR) ligament and capsule were released, followed by the intermetacarpal (IM) ligament; angular measurements were obtained. Finally, the DR capsulodesis procedure was performed, and final measurements were obtained. Comparisons were made among the various stages of ligament integrity to determine the amount of stability provided by DR capsulodesis. RESULTS: All cadavers demonstrated axial laxity with transection of the DR ligament; an increase in stability was obtained after DR capsulodesis. Transection of the capsule and IM ligament caused increased laxity relative to the native joint (median, 24° and 35°, respectively, on rotational testing). After we performed DR capsulodesis, rotational stability improved by a median of 41° compared with DR ligament transection, 49° compared with DR and IM ligament transection, and 18° relative to the native joint. CONCLUSIONS: Dorsoradial capsulodesis restores rotational stability for TMC joint after division of the DR and IM ligaments. The stability achieved was statistically significant compared with both an intact native TMC joint and induced laxity of the TMC joint. CLINICAL RELEVANCE: The DR capsulodesis procedure may improve rotational stability to the TMC joint.

Adipose Tissue-Preserved Skin Graft: Applicability and Long-Term Results.

BACKGROUND: Composite grafts consisting of adipose tissue and skin have been reported in the literature but have been restricted to areas smaller than 4 to 5 cm. The senior author (D.T.W.C.) has developed a technique of adipose tissue-preserved full-thickness skin grafts for larger areas with success similar to that achieved with conventional full-thickness skin grafts. METHODS: All cases of the senior author involving a full-thickness skin graft were identified and reviewed to identify cases in which adipose tissue-preserved full-thickness skin grafts were used. Indication for skin grafting, anatomical location of recipient and donor sites, size of graft, total number of grafts received by each patient, and percentage take were extracted from patient charts. Graft take was measured between days 5 and 14. RESULTS: A total of 72 adipose tissue-preserved skin grafts on 47 patients were identified from 1994 to 2009, with a median follow-up of 8 years. The size of defect ranged from 0.7 to 210 cm, with a median area of 6 cm (interquartile range, 2.5 to 15 cm). Only six of 72 grafts were found to have less than 100 percent take. The lowest take percentage was 85 percent in a graft with an area of 2.6 cm. There were no graft failures. CONCLUSIONS: This study confirms the proof-of-concept that both larger and distant donor- site adipose tissue-preserved skin grafts are a viable alternative to conventional defatted full-thickness skin grafting. It appears that there is a low complication rate with respect to graft failure or incomplete graft take. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Biomagnetic investigation of injury currents in rabbit intestinal smooth muscle during mesenteric ischemia and reperfusion.

A noninvasive, sensitive, and specific method of detecting mesenteric ischemia would be of great use in reducing the morbidity and mortality with which it is associated. Acute lesions in polarized electrically coupled tissues lead to injury currents driven by the transmembrane resting potential gradient. These injury currents are an effective indicator of pathophysiology. The presence of near-DC injury currents in rabbit intestinal smooth muscle has already been demonstrated using a Superconducting quantum interference device (SQUID), and the aim of this study was to evaluate the effect of arterial reperfusion upon these currents. We exteriorized the small bowel of 14 New Zealand white rabbits and placed a remotely operated vascular occluder around the distal most artery supplying a 3-in segment of the jejunum. Experiments were conducted in three groups, i.e., control (n=3), ischemia (n=6), and reperfusion following ischemia (n=5). The subject's position was modulated in and out of the biological field detection range of a SQUID magnetometer using a lift constructed of nonmagnetic material. The changes in magnetic field amplitude were 9.3 and 31.01% for the control and ischemia groups, respectively. The reperfusion group first exhibited a decrease of 17.35% from the pre-ischemic to the ischemic period, followed by an increase of 13.88% of the ischemic value after reestablishing perfusion. In conclusion, injury currents in GI smooth muscle that appear during ischemia are reduced to near-pre-ischemic levels during reperfusion.