Defining a new diagnostic assessment parameter for wound care: Elevated protease activity,an indicator of nonhealing,for targeted protease‐modulating treatment

It is widely accepted that elevated protease activity (EPA) in chronic wounds impedes healing. However, little progress has occurred in quantifying the level of protease activity that is detrimental for healing. The aim of this study was to determine the relationship between inflammatory protease activity and wound healing status, and to establish the level of EPA above which human neutrophil‐derived elastase (HNE) and matrix metalloproteases (MMP) activities correlate with nonhealing wounds. Chronic wound swab samples (n = 290) were collected from four wound centers across the USA to measure HNE and MMP activity. Healing status was determined according to percentage reduction in wound area over the previous 2–4 weeks; this was available for 211 wounds. Association between protease activity and nonhealing wounds was determined by receiver operating characteristic analysis (ROC), a statistical technique used for visualizing and analyzing the performance of diagnostic tests. ROC analysis showed that area under the curve (AUC) for HNE were 0.69 for all wounds and 0.78 for wounds with the most reliable wound trajectory information, respectively. For MMP, the corresponding AUC values were 0.70 and 0.82. Analysis suggested that chronic wounds having values of HNE >5 and/or MMP ≥13, should be considered wound healing impaired. EPA is indicative of nonhealing wounds. Use of a diagnostic test to detect EPA in clinical practice could enable clinicians to identify wounds that are nonhealing, thus enabling targeted treatment with protease modulating therapies.     

What Are the Biomechanical Effects of Half-pin and Fine-wire Configurations on Fracture Site Movement in Circular Frames?

Background

Fine-wire circular frame (Ilizarov) fixators are hypothesized to generate favorable biomechanical conditions for fracture healing, allowing axial micromotion while limiting interfragmentary shear. Use of half-pins increases fixation options and may improve patient comfort by reducing muscle irritation, but they are thought to induce interfragmentary shear, converting beam-to-cantilever loading. Little evidence exists regarding the magnitude and type of strain in such constructs during weightbearing.

Questions/purposes

This biomechanical study was designed to investigate the levels of interfragmentary strain occurring during physiologic loading of an Ilizarov frame and the effect on this of substituting half-pins for fine-wires.

Methods

The “control” construct was comprised of a four-ring all fine-wire construct with plain wires at 90°-crossing angles in an entirely unstable acrylic pipe synthetic fracture model. Various configurations, substituting half-pins for wires, were tested under levels of axial compression, cantilever bending, and rotational torque simulating loading during gait. In total three frames were tested for each of five constructs, from all fine-wire to all half-pin.

Results

Substitution of half-pins for wires was associated with increased overall construct rigidity and reduced planar interfragmentary motion, most markedly between all-wire and all-pin frames (axial: 5.9 mm ± 0.7 vs 4.2 mm ± 0.1, mean difference, 1.7 mm, 95% CI, 0.8–2.6 mm, p < 0.001; torsional: 1.4% ± 0.1 vs 1.1% ± 0.0 rotational shear, mean difference, 0.3%, 95% CI, 0.1%–0.5%, p = 0.011; bending: 7.5° ± 0.1 vs 3.4° ± 0.1, mean difference, −4.1°, 95% CI, −4.4° to −3.8°, p < 0.001). Although greater transverse shear strain was observed during axial loading (0.4% ± 0.2 vs 1.9% ± 0.1, mean difference, 1.4%, 95% CI, 1.0%–1.9%, p < 0.001), this increase is unlikely to be of clinical relevance given the current body of evidence showing bone healing under shear strains of up to 25%. The greatest transverse shear was observed under bending loads in all fine-wire frames, approaching 30% (29% ± 1.9). This was reduced to 8% (±0.2) by incorporation of sagittal plane half-pins and 7% (±0.2) in all half-pin frames (mean difference, −13.2% and −14.0%, 95% CI, −16.6% to 9.7% and −17.5% to −10.6%, both p < 0.001).

Conclusions

Appropriate use of half-pins may reduce levels of shear strain on physiologic loading of circular frames without otherwise altering the fracture site mechanical environment at levels likely to be clinically important. Given the limitations of a biomechanical study using a symmetric and uniform synthetic bone model, further clinical studies are needed to confirm these conclusions in vivo.

Clinical Relevance

The findings of this study add to the overall understanding of the mechanics of circular frame fixation and, if replicated in the clinical setting, may be applied to the preoperative planning of frame treatment, particularly in unstable fractures or bone transport where control of shear strain is a priority.     

Langerhans Cell Histiocytosis of the Temporal Bone

Langerhans cell histiocytosis involving the temporal bone region is uncommon and can resemble malignant neoplasms on imaging due to high cellularity. Although recognizing the presence of sharp margins with beveled-edges can be helpful, tissue sampling is often necessary for confirming the diagnosis. Cytology classically demonstrates kidney-bean shaped nuclei within the Langerhans cells and immunohistochemical staining is positive for S-100, peanut agglutinin (PNA), MHC class II, CD1a, and Langerin (CD 207). These features are exemplified in this sine qua non radiology–pathology correlation article.     

Gastroesophageal reflux disease: A review of surgical decision making

Gastroesophageal reflux disease(GERD) is a very common disorder with increasing prevalence. It is estimated that up to 20%-25% of Americans experience symptoms of GERD weekly. Excessive reflux of acidic often with alkaline bile salt gastric and duodenal contents results in a multitude of symptoms for the patient including heartburn, regurgitation, cough, and dysphagia. There are also associated complications of GERD including erosive esophagitis, Barrett's esophagus, stricture and adenocarcinoma of the esophagus. While first line treatments for GERD involve mainly lifestyle and non-surgical therapies, surgical interventions have proven to be effective in appropriate circumstances. Anti-reflux operations are aimed at creating an effective barrier to reflux at the gastroesophageal junction and thus attempt to improve physiologic and mechanical issues that may be involved in the pathogenesis of GERD. The decision for surgical intervention in the treatment of GERD, moreover, requires an objective confirmation of the diagnosis. Confirmation is achieved using various preoperative evaluations including: ambulatory p H monitoring, esophageal manometry, upper endoscopy(esophagogastroduodenoscopy) and barium swallow. Upon confirmation of the diagnosis and with appropriate patient criteria met, an antireflux operation is a good alternative to prolonged medical therapy. Currently, minimally invasive gastroesophageal fundoplication is the gold standard for surgical intervention of GERD. Our review outlines the many factors that are involved in surgical decisionmaking. We will review the prominent features that reflect appropriate anti-reflux surgery and present suggestions that are pertinent to surgical practices, based on evidence-based studies.     

Treatment options for spontaneous and postoperative sclerosing mesenteritis

Sclerosing mesenteritis is a rare pathology with only a few described cases in the literature. The etiology is unclear; however, several potential triggers, including abdominal surgery and abdominal trauma, have been discussed. The pathology includes a benign acute or chronic inflammatory process affecting the adipose tissue of the mesenterium. Despite it being a rare disease, sclerosing mesenteritis is an important differential diagnosis in patients after abdominal surgery or patients presenting spontaneously with signs of acute inflammation and abdominal pain. We present here three cases with sclerosing mesenteritis. In two cases, sclerosing mesenteritis occurred postoperatively after abdominal surgery. One patient was treated because of abdominal pain and specific radiological signs revealing spontaneous manifestation of sclerosing mesenteritis. So far there are no distinct treatment algorithms, so the patients were treated differently, including steroids, antibiotics and watchful waiting. In addition, we reviewed the current literature on treatment options for this rare disease.     

Preserved vision without growth retardation after laparoscopic Roux-en-Y gastric bypass in a morbidly obese child with pseudotumor cerebri: 36-month follow-up

A 12-year-old boy presented with a weight of 136 kg and a history of progressive vision loss associated with unremitting pseudotumor cerebri requiring bilateral optic nerve sheath decompression. He underwent laparoscopic Roux-en-Y gastric bypass (RYGBP) without complication. At 36 months post-RYGBP, he has grown 5 cm since the time of surgery, his weight is 6.8 kg above his postoperative nadir weight of 68.2 kg, and his visual acuity has improved with OD 20/100 (preoperative, 20/200) and OS 20/70 (preoperative, 20/100). This case suggests that RYGBP can be performed safely and without stopping linear growth in carefully selected children.     

Laparoscopic Sleeve Gastrectomy without an Over-Sewing of the Staple Line

Background  In the past few years, laparoscopic sleeve gastrectomy (LSG) became a widely used bariatric method. Based on results of recent LSG studies, LSG is being increasingly used even as a single bariatric method. On contrary with some other reports, we do not reinforce the LSG staple line with over-sewing. Our pilot study presents treatment outcomes and results 18 months after LSG. Methods  Sixty-one consecutive morbidly obese (MO) patients (19 male and 42 female) who underwent LSG from January 2006 to May 2008 were included into the study. The mean age, height, and weight were 37.3 years (29–57), 168 cm (151–187), and 118 kg (97–181), respectively, while mean body mass index (BMI) was 41.8 (36.1–60.4). LSG started at 6 cm from pylorus and ended at the angle of Hiss. For gastric sleeve calibration 38F, intragastric tube was used. All 61 LSG were performed without over-sewing of the staple line. In the last 24 cases, the staple line was covered with Surgicel™ strips, which were however placed without any fixation to the underlying gastric tissue. Results  Mean operating time was 105 min (80–170) and no conversion to open surgery. An 18-month follow-up was recorded in 39 MO patients. The mean weight loss was 31.3 (range, 21–67 kg) and mean % excess BMI loss reached 72% (range, 64–97%). Neither leak nor disruptions of the staple line and/or sleeve dilatation were recorded. Conclusion  LSG is an effective and safe bariatric procedure with low incidence of complications and mortality in our experience.     

Femoral neck fracture following ipsilateral total knee replacement: an analysis of associations and risk factors

There have been case reports of ipsilateral femoral neck fracture after total knee replacement. This occurrence has been attributed to risk factors such as rheumatoid arthritis, osteoporosis, steroid use and poor mobility. The aim of this study was to see if total knee replacement is a risk factor for neck of femur fracture and to study the associated risk factors. Twenty two patients who had sustained subsequent ipsilateral femoral neck fracture were identified from 1,362 patients who had previously undergone a posterior cruciate ligament-substituting total knee replacement. Clinical chart review and radiological assessment were performed. The average age of the patients was 77(±7) years and the fracture occurred 35(±27) months following the total knee replacement. Positive associations were identified between ipsilateral neck of femur fracture and total knee replacement (P < 0.01), age (P < 0.01), female sex (P < 0.025) and rheumatoid arthritis (P < 0.05). We did not find an association between ipsilateral neck of femur fracture following total knee replacement and preoperative knee deformity (P > 0.5). We also observed an increased risk of supracondylar fracture of the ipsilateral femur in patients who had sustained a neck of femur fracture following total knee replacement (P < 0.001).