Kendra E. Keenan

Analysis of osteon morphotype scoring schemes for interpreting load history: evaluation in the chimpanzee femur.

Osteon morphotype scores (MTSs) allow for quantification of mechanically important collagen/lamellar variations between secondary osteons when viewed in circularly polarized ight (CPL). We recently modified the 6‐point MTS method of Martin et al. (Martin RB, Gibson VA, Stover SM, Gibeling JC, Griffin LV (1996a) Osteonal structure in the equine third metacarpus. Bone 19, 165‐71) and reported superiority of this modified method in correlating with ‘tension’ and ‘compression’ cortices of both chimpanzee proximal femoral diaphyses and diaphyses of other non‐anthropoid bones that are loaded in habitual bending ( Skedros et al. 2009, 2011 ). In these studies, the ‘tension’ and ‘compression’ cortices differed significantly in predominant collagen fiber orientation (CFO) based on weighted‐mean gray levels (CFO/WMGLs) in CPL images. In chimpanzee femora, however, some osteons were difficult to score with the 6‐point method; namely, ‘hybrids’ with peripherally bright ‘hoops’ and variability in alternating rings within the osteon wall. We hypothesized that some of these hybrids would be more prevalent in regions subject to torsion than bending. In this perspective the present study was aimed at expanding our 6‐point scoring method (S‐6‐MTS) into two 12‐point methods with six additional morphotypes that considered these hybrids. Three‐ and 4‐point methods were also evaluated. We hypothesized that at least one of these other methods would out‐perform the S‐6‐MTS in terms of accuracy, reliability, and interpreting torsion vs. bending load histories. Osteon morphotypes were quantified in CPL images from transverse sections of eight adult chimpanzee femora (neck, proximal diaphysis, mid‐diaphysis), where the mid‐diaphysis and base‐ and mid‐neck locations have relatively more complex loading (e.g. torsion + bending) than the proximal diaphysis, where bending predominates. Correlation coefficients between CFO/WMGL and MTSs showed that the S‐6‐MTS method was either stronger or equivalent to the 12‐point methods, and typically stronger than the 3‐ and 4‐point methods for all load environments. In nearly all instances the S‐6‐MTS is more reliable and accurate when it is applied to cases where interpreting load history requires distinguishing habitual bending from torsion. Consequently, in studies of osteonal adaptations for these load histories the 3‐ and 4‐point methods are not stronger correlates, and the extra time required to assign additional scores in the 12‐point methods is both unnecessary and can be highly unreliable.

The burden and correlates of hypertension in rural Ghana: A cross-sectional study

AIM Cardiovascular diseases (CVDs), of which hypertension is a major risk factor, are predicted to account for four times as many deaths as from communicable diseases by the year 2020. Hypertension, once rare, is rapidly becoming a major public health burden in sub-Saharan Africa (SSA). However, data on its prevalence, awareness, treatment and control are paltry, especially for rural communities. This study was done to determine the burden and correlates of adult hypertension in the rural Barekese sub-district of Ghana. METHODS A cross-sectional survey was conducted on 425 adults aged ≥ 35 in the Barekese sub district (estimated population 18,510). Socio-demographic characteristics, modifiable and non-modifiable risk factors, blood pressure (BP) and anthropometric measurements were collected using standardized protocols. RESULTS Overall, the proportion of hypertension and isolated systolic hypertension is 44.7% and 32.7% respectively in the study population. However, 64.9% of these were on treatment, with only 8.9% having controlled blood pressure (<140/90 mmHg). The mean systolic and diastolic BP were 134.38 mmHg (standard deviation, SD: 21.46) and 84.32 mmHg (SD: 12.44). Obesity (Body Mass Index, BMI>30 kg/m²) was found in 37 (10.4% of the population), out of whom 7 (15.9%) were extremely obese (BMI> 40 kg/m²). Increasing age and level of education were positively correlated with increasing blood pressure. CONCLUSION The high burden of hypertension in this population along with the considerable less detection, treatment and control is of great concern. There is the need to promote health education measures that will foster prevention and early detection of hypertension.

Failed Reverse Total Shoulder Arthroplasty Caused by Recurrent Candida glabrata Infection with Prior Serratia marcescens Coinfection.

This report describes a 58-year-old insulin-dependent diabetic male patient who initially sustained a proximal humerus fracture from a fall. The fracture fixation failed and then was converted to a humeral hemiarthroplasty, which became infected with Candida glabrata and Serratia marcescens. After these infections were believed to be cured with antibacterial and antifungal treatments and two-stage irrigation and debridement, he underwent conversion to a reverse total shoulder arthroplasty. Unfortunately, the C. glabrata infection recurred and, nearly 1.5 years after implantation of the reverse total shoulder, he had a resection arthroplasty (removal of all implants and cement). His surgical and pharmacologic treatment concluded with (1) placement of a tobramycin-impregnated cement spacer also loaded with amphotericin B, with no plan for revision arthroplasty (i.e., the spacer was chronically retained), and (2) chronic use of daily oral fluconazole. We located only three reported cases of Candida species causing infection in shoulder arthroplasties (two C. albicans, one C. parapsilosis). To our knowledge, a total shoulder arthroplasty infected with C. glabrata has not been reported, nor has a case of a C. glabrata and S. marcescens periprosthetic coinfection in any joint. In addition, it is well known that S. marcescens infections are uncommon in periprosthetic joint infections.

Utility of osteon circularity for determining species and interpreting load history in primates and nonprimates

OBJECTIVES Histomorphological analyses of bones are used to estimate an individuals chronological age, interpret a bones load history, and differentiate species. Among various histomorphological characteristics that can influence mechanical properties of cortical bone, secondary osteon (Haversian system) population density and predominant collagen fiber orientation are particularly important. Cross-sectional shape characteristics of secondary osteons (On.Cr = osteon circularity, On.El = osteon ellipticality) are considered helpful in these contexts, but more robust proof is needed. We sought to determine if variations in osteon shape characteristics are sufficient for accurately differentiating species, load-complexity categories, and regional habitual strain-mode distributions (e.g., tension vs. compression regions). MATERIALS AND METHODS Circularly polarized light images were obtained from 100-micron transverse sections from diaphyses of adult deer calcanei; sheep calcanei, radii, and tibiae; equine calcanei, radii, and third metacarpals (MC3s); chimpanzee femora; and human femora and fibulae. Osteon cross-sectional area (On.Ar), On.Cr, and On.El were quantified indiscriminately and in the contexts of load-complexity and regional strain-mode distributions. RESULTS On.Cr and On.El, when examined independently in terms of all data, or mean (nested) data, for each bone, exceeded 80% accuracy in the inter-species comparisons only with respect to distinguishing humans from nonhumans. Correct classification among the nonhuman species was <70%. When On.Cr and On.El were coupled together and with On.Ar in discriminant function analyses (nested and unnested data) there were high misclassifications in all but human vs. nonhuman comparisons. DISCUSSION Frequent misclassifications in nonhuman comparisons might reflect influences of habitual load complexity and/or strain-mode distributions, or other factors not accounted for by these two considerations.

Candida glabrata olecranon bursitis treated with bursectomy and intravenous caspofungin.

Orthopedic surgeons are becoming more involved in the care of patients with septic arthritis and bursitis caused by yeast species. This case report involves a middle-aged immunocompromised female who developed a Candida glabrata septic olecranon bursitis that developed after she received a corticosteroid injection in the olecranon bursa for presumed aseptic bursitis. Candida (Torulopsis) glabrata is the second most frequently isolated Candida species from the bloodstream in the United States. Increased use of fluconazole and other azole antifungal agents as a prophylactic treatment for recurrent Candida albicans infections in immunocompromised individuals is one reason why there appears to be increased resistance of C. glabrata and other nonalbicans Candida (NAC) species to fluconazole. In this patient, this infection was treated with surgery (bursectomy) and intravenous caspofungin, an echinocandin. This rare infectious etiology coupled with this intravenous antifungal treatment makes this case novel among cases of olecranon bursitis caused by yeasts.

A Patient with Clavicle Fracture and Recurrent Scapular Winging with Spontaneous Resolutions

Injury to the long thoracic nerve with resulting serratus anterior palsy is a typical cause of medial scapular winging. We report a case of a 70-year-old female with scapular winging in the setting of a mildly comminuted midshaft clavicle fracture. The winging persisted for three months after the fracture, which became a nonunion. The winging spontaneously resolved prior to open reduction and internal fixation of the nonunion. The winging recurred after this surgery. The recurrence was attributed to transient irritation and/or inflammatory neuropathy of the brachial plexus caused by the surgical manipulation. This second episode of winging again spontaneously resolved. There are few reported cases of scapular winging in the setting of a clavicle fracture and only one case of recurrent scapular winging. In that case, which was in the setting of an acromioclavicular joint separation, the second episode of winging required long-term use of a brace. By contrast, our patient did not require bracing because the recurrent winging spontaneously resolved, making this a novel case. This case is important because it illustrates that recurrent scapular winging can occur, and spontaneously resolve, in the setting of a mid-shaft clavicle fracture after subsequent reconstruction of a fracture nonunion.