Understanding Radiocarpal Rotation Through In Vivo Pronation and Supination of the Hand: A Single Case Study

Background: Studies have not clearly defined the motion of the distal radius in relation to the carpus in vivo. We hypothesized that 1) with the hand fixed by grasping a handle to prevent hand and wrist motion, the resulting load in torsion generated by extrinsic muscle in vivo would create motion at the radiocarpal joint; and 2) the motion measured will be between the distal radius and the proximal row of the carpus. Methods: The data was acquired from the senior author external to our institution; in the current study, we quantify the resulting radiocarpal motion. A K-wire was placed into the second metacarpal, and a second wire was placed in the distal radius. The shoulder was abducted to 90° and the hand was pronated, held stationary gripping a fixed object. The forearm was pronated and supinated to simulate radiocarpal rotation. Photographs were obtained at three points: 1) initial position showing the wire in vertical alignment; 2) same perspective in maximum internal radiocarpal rotation; and 3) same perspective in maximum external radiocarpal rotation. ImageJ (open source) was used to quantify the angle between the wires. Results: Superimposition of the three photographs in vivo allowed us to approximate two angle measurements. The measurements with maximal internal and external rotations were 16° and 24°, respectively. Conclusions: Radiocarpal rotation should be considered in addition to flexion and extension motions and radial ulnar deviations when treating degenerative changes in the wrist

Comparison of wound strength, histologic, and aesthetic outcomes after microsurgical versus conventional skin closure in a rat model.

The purpose of this study was to compare the healing, strength, and cosmetic outcome of linear incisions after repair with the naked eye, surgical loupes, or a surgical microscope. Two parallel incisions were made on the dorsal skin of Sprague-Dawley rats (n = 36) and the rats randomized into four groups. A single surgeon repaired the incisions using 5-0 poliglecaprone in a running subcuticular pattern using the naked eye (Group I), surgical loupes with 2.5× magnification (Group II), surgical microscope with 5-10× magnification (Group III), and 6-0 poliglecaprone with a surgical microscope (Group IV). Rats were sacrificed at 1, 3, and 6 weeks. At each time point, the tensile strength of each closure was assessed. Macroscopic outcomes were evaluated using the Vancouver Scar Scale (VSS) and histology assessed by a blinded observer. Microscope closure took significantly longer than closure with the naked eye (p < 0.05). There was no significant difference in tensile strength or VSS ratings between the closure methods at any of the time points. On histopathologic analysis, there were a greater number of inflammatory cells and fibroblasts in the 6-0 microscope closure group versus the naked eye closure group at week 3 (p ≤ 0.05). In conclusion, wound repair under magnification did not yield a significant difference in cosmesis or wound tensile strength, but did increase operative time. Moreover, there was a trend toward increased inflammation with microscope-assisted closures, perhaps due to the increased suture burden

Comparison of two cadaveric acellular dermal matrices for immediate breast reconstruction: A prospective randomized trial.

AlloDerm RTU® and AlloMaxTM are two acellular dermal matrices (ADMs) used in implant-based breast reconstruction. In this study, we examined whether different processing methods for the ADMs lead to a disparity in histologic, clinical, and financial outcomes after breast reconstruction. Thirty patients undergoing implant-based breast reconstruction were randomized into AlloMax or AlloDerm arms (n = 15, each). ADM was placed at the time of immediate reconstruction. Patients were evaluated for complications on postoperative days 7, 14, and 30. During implant exchange, ADM biopsies were taken and compared histologically for vascular and cellular infiltration. Patient satisfaction was evaluated using the BRECON-31 questionnaire 1 year after implant exchange. A cost analysis was performed comparing the two ADMs. Patient demographics and complication rates were similar between the two groups (p > 0.05). Histologically, vessel density and fibroblast/inflammatory cell infiltrate were greater on the dermal side than on the implant side (p < 0.01) in both ADMs, suggesting greater vascular and cellular in-growth from the dermal side. Vessel density in the middle portion of the Allomax biopsies was significantly higher than the same site in the Alloderm biopsies (p < 0.05). The extent of fibroblast/inflammatory cell infiltration was similar in both arms (p > 0.05). The BRECON-31 satisfaction questionnaire yielded similar responses across all metrics between the two study arms. The negotiated price was slightly different when comparing the two ADMs, with no significant difference in ADM reimbursement. In this study, AlloDerm RTU and AlloMax were successfully used for implant-based breast reconstruction with comparable outcomes

Evidence of Early Cretaceous remagnetization in the Crimean Peninsula: a palaeomagnetic study from Mesozoic rocks in the Crimean and Western Pontides, conjugate margins of the Western Black Sea

We report on a palaeomagnetic study from Mesozoic sedimentary and volcanic rocks from the conjugate areas of the Western Black Sea Basin; that is, the Crimean Peninsula in the north and the Western and Central Pontides in the south, to better constrain their palaeogeographic relationships within the southern margin of Eurasia. From the study of 87 sites in Crimea, we found that Triassic to Lower Jurassic sandstones and siltstones from the Tavric series, and Middle-Upper Jurassic sandstones, siltstones and limestones exhibit remagnetization. Both fold and conglomerate tests confirm a widespread remagnetization in Crimea. Comparison of palaeopoles with the expected reference apparent polar wander path (APWP) of Eurasia and results from conglomerate tests suggest that the remagnetization occurred in the Early Cretaceous. In the Central Pontides, no reliable palaeomagnetic results can be obtained from Triassic-Upper Jurassic rocks, however, a negative fold test in Upper Jurassic-Lower Cretaceous rocks from the Western Pontides shows that the palaeolatitude agrees with Lower Cretaceous data from Crimea. Our new palaeomagnetic results indicate a pervasive remagnetization in Crimea and the Western Pontides that could be attributed to the rifting phase of the Black Sea Basin during Lower Cretaceou

Different osteosyntheses for Colles' fracture: A mechanical study in 42 cadaver bones

Background and purpose In recent years several different plate designs for internal fixation of fractures of the distal radius have been developed. However, few biomechanical studies have been performed to compare these new implants. The purpose of this study was to compare the mechanical properties of 5 different commercially available plates (3 volar and 2 dorsal) with standard K-wire fixation using a distal radial cadaver model