Biologic significance of surface microroughing in bone incorporation of porous bioactive glass implants

A novel chemical etching method was recently developed to create a controlled microrough surface on porous bioactive glass implants. Our earlier in vitro studies showed enhanced attachment of osteoblast-like MG63 cells on a microrough bioactive glass surface. The purpose of our current study was to confirm the in vivo significance of surface microroughening for bone bonding of bioactive glass. Porous bioactive glass cones made of sintered microspheres were surgically implanted in the anterior cortex of rabbit femurs. Peripheral quantitative computed tomography (pQCT), biomechanical push-out testing, histomorphometry, and electron microscopy (BEI-SEM) were used to analyze bone ingrowth and osseointegration at 7, 10, 14, 28, 56, and 84 days after implantation. The results showed that microroughening of the bioactive glass surface significantly enhanced the bone-bonding response of the biomaterial. The positive response was seen in one of the three bioactive glass compositions studied. The affinity index of new bone on the glass surface was significantly (p = 0.02) increased with a trend (p = 0.10) toward improved mechanical incorporation. New bone formation was dependent on the glass composition, and it was found to occur not only through the mechanism of bone ingrowth but also based on in situ osteogenesis within implant interstices. Based on these results, the procedure of microroughening could enhance the osteopromotive properties of certain bioactive glass compositions.     

Reliability of computer-assisted periacetabular osteotomy using a minimally invasive approach

Background

Periacetabular osteotomy (PAO) is the treatment of choice for younger patients with developmental hip dysplasia. The procedure aims to normalize the joint configuration, reduce the peak-pressure, and delay the development of osteoarthritis. The procedure is technically demanding and no previous study has validated the use of computer navigation with a minimally invasive transsartorial approach.

Methods

Computer-assisted PAO was performed on ten patients. Patients underwent pre- and postoperative computed tomography (CT) scanning with a standardized protocol. Preoperative preparation consisted of outlining the lunate surface and segmenting the pelvis and femur from CT data. The Biomechanical Guidance System was used intra-operatively to automatically calculate diagnostic angles and peak-pressure measurements. Manual diagnostic angle measurements were performed based on pre- and postoperative CT. Differences in angle measurements were investigated with summary statistics, intraclass correlation coefficient, and Bland–Altman plots. The percentage postoperative change in peak-pressure was calculated.

Results

Intra-operative reported angle measurements show a good agreement with manual angle measurements with intraclass correlation coefficient between 0.94 and 0.98. Computer navigation reported angle measurements were significantly higher for the posterior sector angle (\(1.65^{\circ }\), \(p=0.001\)) and the acetabular anteversion angle (\(1.24^{\circ }\), \(p=0.004\)). No significant difference was found for the center-edge (\(p=0.056\)), acetabular index (\(p=0.212\)), and anterior sector angle (\(p=0.452\)). Peak-pressure after PAO decreased by a mean of 13% and was significantly different (\(p=0.008\)).

Conclusions

We found that computer navigation can reliably be used with a minimally invasive transsartorial approach PAO. Angle measurements generally agree with manual measurements and peak-pressure was shown to decrease postoperatively. With further development, the system will become a valuable tool in the operating room for both experienced and less experienced surgeons performing PAO. Further studies with a larger cohort and follow-up will allow us to investigate the association with peak-pressure and postoperative outcome and pave the way to clinical introduction.

     

Possible role for mast cell-derived cathepsin G in the adverse remodelling of stenotic aortic valves

Aims Aortic stenosis (AS) is characterized by extensive remodellingof the valves, including infiltration of inflammatory cells,extracellular matrix degradation, and fibrosis. The molecularmechanisms behind this adverse remodelling have remained obscure.In this article, we study whether cathepsin G, an angiotensinII (Ang II)-forming elastolytic enzyme, contributes to progressionof AS. Methods and results Stenotic aortic valves (n=86) and controlvalves (n=17) were analysed for cathepsin G, transforming growthfactor-ß1 (TGF-ß1), and collagens I andIII with RT–PCR and immunohistochemistry. Valvular collagen/elastinratio was quantified by histochemistry. In stenotic valves,cathepsin G was present in mast cells and showed increased expression(P<0.001), which correlated positively (P<0.001) withthe expression levels of TGF-ß1 and collagens I andIII. TGF-ß1 was also present in mast cell-rich areasand cathepsin G induced losartan-sensitive TGF-ß1expression in cultured fibroblasts. Collagen/elastin ratio wasincreased in stenotic valves (P<0.001) and correlated positivelywith smoking (P=0.02). Nicotine in cigarette smoke activatedmast cells and induced TGF-ß1 expression in culturedfibroblasts. Fragmented elastin was observed in stenotic valvescontaining activated cathepsin G-secreting mast cells and innormal valves treated with cathepsin G. Conclusion In stenotic aortic valves, mast cell-derived cathepsinG may cause adverse valve remodelling and AS progression.     

A case study of amnion rupture sequence with acalvaria, blindness, and clefting: clinical and psychological profiles

The purpose of this article is to report the case of a 10-year-old girl born with anophthalmia, bilateral oblique facial clefts, and missing scalp and bones over the temporal and parietal areas of the cranial vault bilaterally. Early amnion rupture seems to be the most probable cause of this rare combination of anomalies. Because no similar case has been reported in the literature so far, we describe here the clinical and psychosocial history of this unusual patient, who has been able to live the intellectually and socially normal life of a blind child in spite of the major craniofacial deformities. The already completed and possible future therapeutic strategies are discussed.     

Indoleamine 2,3-dioxygenase expression is associated with chronic rhinosinusitis with nasal polyps and antrochoanal polyps

Chronic rhinosinusitis without and with nasal polyps (CRSwNP and CRSsNP), and antrochoanal polyps are different phenotypes with different pathomechanisms. Indoleamine 2,3-dioxygenase (IDO) is an enzyme expressed in many cells involved in the catabolism of the essential amino acid tryptophan to kynurenine. IDO might have a role in allergic airway inflammation. The aim was to evaluate if IDO expression is associated with CRSsNP, CRSwNP, or ACP. One hundred fifty specimens from the nasal cavity and sinus mucosa were immunohistochemically stained with mAb anti-IDO. The expression of epithelial and leukocyte IDO was associated with CRSwNP and ACP. The presence of ASA intolerance, asthma, atopy, smoking and use of medication did not significantly change the results. The different expression of IDO could putatively indicate the differences in the pathomechanisms of CRSsNP, CRSwNP and ACP. Further studies on the role of IDO in upper airways pathologies are required.     

Long-term effect of pharyngeal flap surgery on craniofacial and nasopharyngeal morphology in patients with cleft palate

The craniofacial morphology of 48 consecutive adult males with isolated cleft palate was studied by means of lateral cephalograms at the mean age of 18.8 years. Twelve of the patients had received pharyngeal flap surgery between 4 and 12 years of age (mean age 6 years) to improve speech. No significant differences were noticed in craniofacial cephalometric relations between the patients who had not had velopharyngeal flap surgery (VPF-) and those who had (VPF+), although the latter showed a tendency toward a more vertical growth direction. In the pharynx, the VPF+ group showed larger sagittal depths of nasopharyngeal airway but smaller depths of oropharyngeal airway. The differences were significant at the levels of the upper nasopharynx and lower oropharynx. According to the hospital records, none of the patients demonstrated persistent airway obstruction. Cephalometry may be useful in evaluating the changes in pharyngeal airway dimensions that may be related to velopharyngeal flap surgery.     

Cephalic index correlates poorly with intracranial volume in non-syndromic scaphocephalic patients

Objectives

This study aims to compare pre- and postoperative cephalic indexes (CI) with corresponding segmented intracranial volumes (SIV) obtained from volumetric CT in scaphocephalic patients.

Methods

Twenty-four patients (17 boys) who had undergone cranial vault remodeling due to scaphocephaly were compared from 3D-CT imaging datasets. The mean age of the patients at preoperative CT imaging was 5.5 months, and that at 1-year postoperative imaging, 21.5 months. The mean interval between preoperative CT imaging and surgery was 3.3 months. Pearson’s correlation was used to test the correlation of both pre- and postoperative CI with SIV. A paired t test was used to compare differences in the pre- and postoperative mean values of CI and SIV.

Results and discussion

CI correlated poorly with intracranial volume both preoperatively (r?=?0.274) and postoperatively (r?=?0.128). The mean preoperative CI was 65.92 (range 57.99–73.97), and the mean postoperative, CI 70.24 (range 60.23–75.57). The mean preoperative intracranial volume was 877.79 cm³ (range 638–1,256), and the 1-year postoperative volume, 1,249.04 cm³ (range 1,039–1,529). The mean values of both CI and SIV increased significantly after surgery. In one patient, the CI in postoperative measurements was smaller, whereas in all patients, the postoperative SIV was larger than the preoperative intracranial volume. The mean percentage increase in CI was 6.6 %, whereas the mean increase in SIV was 43.1 %.

Conclusion

Cephalic index correlates poorly with intracranial volume in non-syndromic scaphocephalic patients. For some patients, surgery and growth resulted in only subtle or no change in CI despite a notable increase in intracranial volume.     

Sequential changes of noradrenaline content of vein grafts in rats: quantitative estimation by high-performance liquid chromatography using electrochemical detection

Supradiaphragmatic inferior vena cava was transplanted end-to-end into the abdominal aorta of 11-week-old rats of the same inbred strain and same litter using microvascular technique. The grafts were removed 3 days, 4, 8, 16, and 35 weeks postoperatively, and their noradrenaline (NA) content was estimated by high-performance liquid chromatography using electrochemical detection. The amount of NA was significantly lower (P less than .001) in all vein grafts as compared to nontransplanted vena cava. The substantial decrease of NA in the vein grafts throughout the observation period indicates a persistent denervation of the transplant.     

Myocardial perfusion,oxidative metabolism,and free fatty acid uptake in patients with hypertrophic cardiomyopathy attributable to the Asp 175Asn mutation in the α-tropomyosin gene: A positron emission tomography study

Background  The relationship between myocardial metabolic changes and the severity of left ventricular (LV) hypertrophy in patients with hypertrophic cardiomyopathy (HCM) is largely unknown. We characterized metabolic abnormalities in patients with a genetically identical cause for HCM but with variable LV hypertrophy. Methods and Results  Eight patients with HCM attributable to the Asp175Asn mutation in the α-tropomyosin gene underwent myocardial perfusion, oxidative, and free fatty acid (FFA) metabolism measurements via positron emission tomography and oxygen 15-labeled water, carbon 11 acetate, and fluorine 14(R,S)-[18F] Fluoro-6-thia-heptadecanoic acid (18 FTHA). LV mass, work, and efficiency were assessed by echocardiography. Thirty-six healthy volunteers served as control subjects. Compared with control subjects, HCM patients had increased myocardial oxidative metabolism and FFA uptake (P<.05). However, in patients, LV mass was inversely related to global myocardial perfusion, oxidative metabolism, and FFA uptake (all P<.03), and regional wall thickness was inversely related to regional perfusion (P<.01), oxidative metabolism (P<.001), and FFA uptake (P<.01). Therefore patients with mild (LV mass less than median of 177 g) but not advanced LV hypertrophy were characterized by increased perfusion, oxidative metablism, and LV efficiency as compared with control subjects (P<.05). Conclusions  In HCM attributable to the Asp 175Asn mutation in the α-tropomyosin gene, myocardial oxidative metabolism and FFA metabolism are increased and inversely related to LV hypertrophy at both the whole heart and regional level. Increased metabolism and efficiency characterize patients with mild myocardial hypertrophy. These hypermetabolic alterations regress with advanced hypertrophy. Dis Tuunanen and Kuusisto contributed equally to this work This study was financially supported by an EVO grant (Kuopio University Hospital), as well as the Turunen Foundation, Instrumentarium Foundation, and Finish Cultural Foundation.     

Evaluation of a computerized measurement technique for joint alignment before and during periacetabular osteotomy.

Periacetabular osteotomy (PAO) is intended to treat a painful dysplastic hip. Manual radiological angle measurements are used to diagnose dysplasia and to define regions of insufficient femoral head coverage for planning PAO. No method has yet been described that recalculates radiological angles as the acetabular bone fragment is reoriented. In this study, we propose a technique for computationally measuring the radiological angles from a joint contact surface model segmented from CT-scan data. Using oblique image slices, we selected the lateral and medial edge of the acetabulum lunate to form a closed, continuous, 3D curve. The joint surface is generated by interpolating the curve, and the radiological angles are measured directly using the 3D surface. This technique was evaluated using CT data for both normal and dysplastic hips. Manual measurements made by three independent observers showed minor discrepancies between the manual observations and the computerized technique. Inter-observer error (mean difference +/- standard deviation) was 0.04 +/- 3.53 degrees for Observer 1; -0.46 +/- 3.13 degrees for Observer 2; and 0.42 +/- 2.73 degrees for Observer 3. The measurement error for the proposed computer method was -1.30 +/- 3.30 degrees . The computerized technique demonstrates sufficient accuracy compared to manual techniques, making it suitable for planning and intraoperative evaluation of radiological metrics for periacetabular osteotomy.