Osteocyte lacunocanalicular microstructure across the midshaft femur in adult males from Medieval England

Archaeological human bone histology can reveal well-preserved osteocyte lacunae, which are indicators of bone remodeling activity. Analyses of these lacunae can be useful when reconstructing past human mechanical loading histories or metabolic fluctuations from bone microstructure. However, the relationship between osteocyte lacunae and bone anatomical variation within archaeological samples is largely unknown. We examined osteocyte lacunocanalicular network morphology in Medieval human femora to test if osteocyte lacunae change with anatomical site location. Osteocyte lacunae density (Ot.Dn) data were analyzed statistically in ten middle-aged (35-50 years old) males dated to the 11th-16th centuries AD (Canterbury, England). A subsequent case study was conducted using two well-preserved samples from which canaliculi number per lacuna (Ci.N) and canaliculi-rich lacunae density (Ci.Dn) were preliminarily examined descriptively. The data were collected from cortical bone regions encompassing intra-cortical to sub-periosteal midshaft femur bone, comparing anterior, posterior, medial, and lateral locations inter- and intra-individually. Results show that Ot.Dn varied significantly between the four anatomical regions (p = 0.001), with the medial and lateral femur regions showing the highest median Ot.Dn. The median of Ci.N was also the highest on the medial aspect, but Ci.Dn did not change largely across all four bone aspects. The combination of these results suggests that midshaft femur anatomical location, which undergoes morphological change with biomechanical load, affects the expression of bone microstructure at the osteocyte lacuna level. This knowledge will benefit future osteoarchaeological methods that infer past behavior from the human femur

A comparison of polymer and polymer-hydroxyapatite composite tissue engineered scaffolds for use in bone regeneration. An in vitro and in vivo study.

Previous in vitro work demonstrated porous PLA and PLGA both had the mechanical strength and sustained the excellent skeletal stem cell (SSC) growth required of an osteogenic bonegraft substitute, for use in impaction bone grafting. The purpose of this investigation was to assess the effects of the addition of hydroxyapatite (HA) to the scaffolds before clinical translation. PLA, PLA+10% HA, PLGA, and PLGA+10% HA were milled and impacted into discs before undergoing a standardized shear test. Cellular compatibility analysis followed 14 days incubation with human skeletal stems cells (SSC). The best two performing polymers were taken forward for in vivo analysis. SSC seeded polymer discs were implanted subcutaneously in mice. All polymers had superior mechanical shear strength compared with allograft (p < 0.01). Excellent SSC survival was demonstrated on all polymers, but the PLA polymers showed enhanced osteoblastic activity (ALP assay p < 0.01) and collagen-1 formation. In vivo analysis was performed on PLA and PLA+10% HA. MicroCT analysis revealed increased bone formation on the PLA HA (p < 0.01), and excellent neo-vessel formation in both samples. Histology confirmed evidence of de novo bone formation. PLA HA showed both enhanced osteoinductive and osteogenic capacity. This polymer composite has been selected for scaled-up experimentation before clinical translation. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2613-2624, 2014

Genicular artery embolisation in patients with osteoarthritis of the knee (GENESIS) using permanent microspheres: long-term results

Purpose: To report the 2-year follow-up of patients with mild-to-moderate knee osteoarthritis (OA) treated with genicular artery embolisation (GAE) as part of the GENESIS study. Materials and methods: Forty-six patients, median age = 60 (45-83) underwent GAE using permanent microspheres (100-300 μm). Technical success was defined as embolisation of the targeted genicular arteries. Knee Injury and Osteoarthritis Outcome Score (KOOS) and Visual Analogue Scale (VAS) (0-100 mm) were recorded at baseline, 6 weeks, 3 months, 1, 2 years. Contrast-enhanced MRI knee scans were acquired at baseline and 1 year, and evaluated with the Whole-Organ Magnetic Resonance Imaging Score (WORMS). Functional MRI brain imaging and psychometric assessments were undertaken to investigate correlation between neuropsychological phenotypes and clinical outcome. Adverse events were recorded prospectively. Results: Technical success was achieved in forty patients (87%). Mean VAS improved from 58.63 (SD = 20.57, 95% CI 52.7-65.5) at baselines to 37.7 at 2-years (SD = 26.3, 95% CI 27.0-47.5). Whole and subgroup KOOS were significantly improved at each timepoint with associated reductions in analgesia usage. WORMS analysis demonstrated significant reduction in synovitis (p < 0.05) with no cases of osteonecrosis. Self-limiting skin discolouration occurred in four patients. A self-limiting groin haematoma and single case of deep-vein thrombosis due to immobilisation were also recorded. Nine patients subsequently underwent knee arthroplasty with no additional operational complexities identified. Neuropsychometric assessment elucidated a correlation between baseline catastrophising and greater reduction in pain post GAE. Conclusion: GAE is a safe intervention for mild-moderate knee osteoarthritis, with sustained efficacy at 2 years. These results are promising and justify ongoing controlled trials

Proximal tibial strain in medial unicompartmental knee replacements

As many as 25% to 40% of unicompartmental knee replacement (UKR) revisions are performed for pain, a possible cause of which is proximal tibial strain. The aim of this study was to examine the effect of UKR implant design and material on cortical and cancellous proximal tibial strain in a synthetic bone model. Composite Sawbone tibiae were implanted with cemented UKR components of different designs, either all-polyethylene or metal-backed. The tibiae were subsequently loaded in 500 N increments to 2500 N, unloading between increments. Cortical surface strain was measured using a digital image correlation technique. Cancellous damage was measured using acoustic emission, an engineering technique that detects sonic waves (‘hits’) produced when damage occurs in material