A preliminary study of the effect of closed incision management with negative pressure wound therapy over high-risk incisions

Background Certain postoperative wounds are recognised to be associated with more complications than others and may be termed high-risk. Wound healing can be particularly challenging following high-energy trauma where wound necrosis and infection rates are high. Surgical incision for joint arthrodesis can also be considered high-risk as it requires extensive and invasive surgery and postoperative distal limb swelling and wound dehiscence are common. Recent human literature has investigated the use of negative pressure wound therapy (NPWT) over high-risk closed surgical incisions and beneficial effects have been noted including decreased drainage, decreased dehiscence and decreased infection rates. In a randomised, controlled study twenty cases undergoing distal limb high-energy fracture stabilisation or arthrodesis were randomised to NPWT or control groups. All cases had a modified Robert-Jones dressing applied for 72 h postoperatively and NPWT was applied for 24 h in the NPWT group. Morphometric assessment of limb circumference was performed at six sites preoperatively, 24 and 72 h postoperatively. Wound discharge was assessed at 24 and 72 h. Postoperative analgesia protocol was standardised and a Glasgow Composite Measure Pain Score (GCPS) carried out at 24, 48 and 72 h. Complications were noted and differences between groups were assessed. Results Percentage change in limb circumference between preoperative and 24 and 72 h postoperative measurements was significantly less at all sites for the NPWT group with exception of the joint proximal to the surgical site and the centre of the operated bone at 72 h. Median discharge score was lower in the NPWT group than the control group at 24 h. No significant differences in GCPS or complication rates were noted. Conclusions Digital swelling and wound discharge were reduced when NPWT was employed for closed incision management. Larger studies are required to evaluate whether this will result in reduced discomfort and complication rates postoperatively

Complexities of learning with computer-based tools: A case of inquiry about sound and music in elementary school

Computer-based technology is increasingly becoming available for students at all grade levels in schools, and its promise and power as a learning tool is being extolled by many. From a constructive perspective, if individuals actively construct meaning from their experiences, then simply having particular tools to work with via a computer doesn't ensure that desired learning will result. Thus, it is important to examine how students construct meaning while using such tools. This study examined what fourth grade students learned from the use of two computer-based tools intended to help them understand sound and music: software that emulated an oscilloscope and allowed students to view sound waves from audio input; and software that turned the computer into an electronic keyboard, which provided students with standard pitches for comparison purposes. Principles of selective attention and pior knowledge and experiences —foundational ideas of a constructivist epistemology—were useful in understanding learning outcomes from inquiry with these tools. Our findings provide critical information for future instruction with the goal of supporting learning about sound and music from such tools. They also indicate the need for more studies examining learning from computer-based tools in specific contexts, to advance our understanding of how teachers can mediate student activity with computer-based tools to support the development of conceptual understanding.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45183/1/10956_2005_Article_BF01677126.pd

The Plumbline: A Novel Radiographic Tool for Assessment of Metatarsus Adductus with Hallux Valgus

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: Metatarsus adductus (MTA) is a complex multiplanar deformity of the foot which has a 30% reported approximate radiographic incidence in patients with symptomatic hallux valgus (HV). Various radiographic angles have been proposed for the assessment of MTA, but these measurements can be complex with a broad range of interrater reliability. We propose a simplistic radiographic assessment method termed the ‘plumbline’ to identify the presence of MTA and to ascertain if enough physical space is available to align the first metatarsal to the longitudinal foot axis via an isolated 1st ray procedure, or if necessary, through a combined approach which also addresses the lesser metatarsals. This method provides a visual reference to determine if a physical blockade to 1st ray correction is present. Methods: The plumbline is assessed on standard weight-bearing AP radiographs. Neutral foot positioning is key as a pronated or supinated clinical position of the foot will impact the alignment of this and other radiographic angular relationships. A transverse midfoot axis line is drawn by identifying and linking two individual points marked at the calcaneocuboid joint and the talonavicular joint. A third point is marked at the distal lateral apex of the medial cuneiform at the first tarsometatarsal joint. A 90° line is subtended from the transverse midfoot axis line, crosses the third point, and extends distally to the 2nd metatarsal head. A positive radiographic plumbline occurs when this line intersects the 2nd metatarsal indicating the need to correct the adducted lesser metatarsal position prior to addressing HV. A negative plumbline remains tangential to the 2nd metatarsal and indicates an isolated HV correction is possible. Results: The metatarsus adductus angle (MAA) measured via Sgarlato's method (SA), and the plumbline were recorded in patients (N=20) scheduled for HV surgery. Initially the cohort was subdivided into subjects deemed to have a normal MAA (SA 15°; N=10). A mean pre-operative MAA measurement of 8.1° (SD 2.3; range 5, 12.1) and 26.5° (SD 4.5; range 19.2, 33.7) were found in these respective subsets. All subjects (100%) with an MAA 15° (N=10) presented with a positive plumbline. The plumbline findings identified when an isolated HV correction would have been possible or impeded based upon 2nd metatarsal position, thus driving the surgical decision making algorithm. Conclusion: The plumbline is used to determine when concomitant MTA and HV correction is beneficial without the need to measure other more traditional radiographic angular relationships. It is a quick and simple method of evaluating the proximity of the metatarsal segments to determine if the first metatarsal is amenable to reduction in isolation or if correction will be limited due to a 2nd metatarsal bone blockade. The visual simplicity of the measurement can also aid in patient education and surgeon satisfaction when describing the surgical approach to this complex three-dimensional anatomic pathology