DOES CEMENT CURING CAUSE CONCERNING INCREASE OF THE TEMPERATURE WHEN DELIVERED IN THE HUMAN HUMERUS?

For the treatment of humeral fractures, numerous strategies exist to improve the clinical outcome of the reconstruction and to reduce the incidence of fixation failure. Injection of acrylic-based cements to reinforce the bone and/or augment the screws is one option. The heat generated during cement polymerization raises some concerns, as it could cause tissue damage. The first aim of this study was to measure the temperature over time during polymerization when acrylic cements are delivered inside the bone to treat fracture. The second aim was to assess if the ISO-5833:2002 standard can predict what happens in a real bone. Different tests were performed using two acrylic-based cements (Mendec and Cal-Cemex): (i) the ISO-5833:2002 standard (Annex C); (ii) tests on human bones (humeral diaphysis and humeral head) injected with cement to simulate fracture treatment. In the humeri, the highest temperature was measured in the diaphysis (68.6∘C for Mendec, 62.7∘C for Cal-Cemex). These values are comparable with the temperature reached in other consolidated applications (vertebroplasty). Exposure to high temperature was shorter for the diaphysis than for the head. For both cements, in both the diaphysis and the head, temperatures exceeded 48∘C for less than 10[Formula: see text]min. This is within the threshold for tissue necrosis. The ISO-5833:2002 yielded significantly different results in terms of maximum temperature (difference exceeding 15∘C) and exposure to temperature above 48∘C and 45∘C. This discrepancy is probably due to a combination of factors affecting the amount of heat produced and dissipated (e.g., amount and shape of the cement, thermal conductivity).

Biomechanical Evaluation on the Bilateral Asymmetry of Complete Humeral Diaphysis in Chinese Archaeological Populations

Diaphyseal cross-sectional geometry (CSG) is an effective indicator of humeral bilateral asymmetry. However, previous studies primarily focused on CSG properties from limited locations to represent the overall bilateral biomechanical performance of humeral diaphysis. In this study, the complete humeral diaphyses of 40 pairs of humeri from three Chinese archaeological populations were scanned using high-resolution micro-CT, and their biomechanical asymmetries were quantified by morphometric mapping. Patterns of humeral asymmetry were compared between sub-groups defined by sex and population, and the representativeness of torsional rigidity asymmetry at the 35% and 50% cross-sections (J35 and J50 asymmetry) was testified. Inter-group differences were observed on the mean morphometric maps, but were not statistically significant. Analogous distribution patterns of highly asymmetrical regions, which correspond to major muscle attachments, were observed across nearly all the sexes and populations. The diaphyseal regions with high variability of bilateral asymmetry tended to present a low asymmetrical level. The J35 and J50 asymmetry were related to the overall humeral asymmetry, but the correlation was moderate and they could not reflect localized asymmetrical features across the diaphysis. This study suggests that the overall asymmetry pattern of humeral diaphysis is more complicated than previously revealed by individual sections.

Fractures of the proximal- and middle-thirds of the humeral shaft should be considered as fragility fractures

Aims The aim of this study was to determine the current incidence and epidemiology of humeral diaphyseal fractures. The secondary aim was to explore variation in patient and injury characteristics by fracture location within the humeral diaphysis. Methods Over ten years (2008 to 2017), all adult patients (aged ≥ 16 years) sustaining an acute fracture of the humeral diaphysis managed at the study centre were retrospectively identified from a trauma database. Patient age, sex, medical/social background, injury mechanism, fracture classification, and associated injuries were recorded and analyzed. Results A total of 900 fractures (typical 88.9%, n = 800/900; pathological 8.3%, n = 75/900; periprosthetic 2.8%, n = 25/900) were identified in 898 patients (mean age 57 years (16 to 97), 55.5% (n = 498/898) female). Overall fracture incidence was 12.6/100,000/year. For patients with a typical fracture (n = 798, mean age 56 years (16 to 96), 55.1% (n = 440/798) female), there was a bimodal distribution in men and unimodal distribution in older women (Type G). A fall from standing was the most common injury mechanism (72.6%, n = 581/800). The majority of fractures involved the middle-third of the diaphysis (47.6%, n = 381/800) followed by the proximal- (30.5%, n = 244/800) and distal-thirds (n = 175/800, 21.9%). In all, 18 injuries (2.3%) were open and a radial nerve palsy occurred in 6.7% (n = 53/795). Fractures involving the proximal- and middle-thirds were more likely to occur in older (p < 0.001), female patients (p < 0.001) with comorbidities (p < 0.001) after a fall from standing (p < 0.001). Proximal-third fractures were also more likely to occur in patients with alcohol excess (p = 0.003) and to be classified as AO-Orthopaedic Trauma Association type B or C injuries (p < 0.001). Conclusion This study updates the incidence and epidemiology of humeral diaphyseal fractures. Important differences in patient and injury characteristics were observed based upon fracture location. Injuries involving the proximal- and middle-thirds of the humeral diaphysis should be considered as fragility fractures. Cite this article: Bone Joint J 2020;102-B(11):1475–1483.

Treatment of Pathologic Fracture of the Humeral Diaphysis Using Metal andPolymer Express Endoprosthetic Replacement as an Example of the Accelerated Rehabilitation of Cancer Patients

ABSTRACT. We report a case of treatment of a 60-year-old female patient D. with a metastatic fracture of the upper and middle third of the left humerus. We made a radical removal of the metastasis, which was complicated by pathological fracture of the left humerus. To replace the removed tumor defect we performed metal and polymer endoprosthetic replacement of the left humeral diaphysis using a locking screw system and bone cement (methyl methacrylate). For accelerated recovery and rehabilitation we applied adaptogenic immunomodulator «Vitavis» (Altai elixir) and neutral anolyte (NA). After the removal of the tumor, postoperative wound was treated with neutral anolyte (NA). Dressings also contained neutral anolyte (NA). These drugs were successfully combined with postoperative basic therapy. The patient was discharged from the hospital on the 4th day after surgery. The functional results of the left upper limb are satisfactory.