Non-thermal atmospheric pressure plasma treatment increases hydrophilicity and promotes cell growth on titanium alloys in vitro.

Most medical implants are made of titanium. When titanium is exposed to air for a long time, hydrocarbons are deposited and the surface becomes hydrophobic. Cell attachment is important for bone ingrowth to occur on the implant surface, and hydrophilicity can enhance this. We examined whether non-thermal atmospheric pressure plasma treatment could increase the hydrophilicity of the titanium surface. Samples coated with four widely used coating types [grit blasting, micro arc oxidation (MAO), titanium plasma spray (TPS), and direct metal fabrication (DMF)] were treated with plasma. Each of the four surface-treated samples was divided into groups with and without plasma treatment. We analysed wettability by surface analysis and evaluation of contact angles, cell proliferation, and adhesion using scanning electron microscopy (SEM), confocal laser scanning microscopy, absorbance tests, and alkaline phosphatase (ALP) activity assay; four different Ti6Al4V surface types were compared. After plasma treatment, the contact angle was reduced on all surfaces, and the carbon content was reduced on all surfaces based on X-ray photoelectron spectroscopy (XPS) surface analysis. Under confocal laser scanning, the cell layer was thicker on the plasma-treated samples, especially in groups TPS and DMF. Cell proliferation was 41.8%, 17.7%, 54.9%, and 83.8% greater for the plasma- than non-plasma-treated grit blasting, MAO, TPS, and DMF samples, respectively. Hydrophilicity increased significantly under plasma treatment, and biological responsivity was also improved.

Is the construct stability of the acetabular cup affected by the acetabular screw configuration in bone defect models?

BACKGROUND: In revision surgery with significant segmental acetabular defects, adequate implant selection and fixation methods are critical in determining successful bony ingrowth. Commercially available total hip prosthesis manufacturers generally offer additional multi-hole options of acetabular shells with identical designs for use in revision THAs where screw holes configurations vary from product to product. This study aims to compare the mechanical stability of the two types of acetabular screw constructs for the fixation of acetabular components: spread-out and pelvic brim-focused configurations. METHODS: We prepared 40 synthetic bone models of the male pelvis. In half of the samples with acetabular defects, identical curvilinear bone defects were manually created using an oscillating electrical saw. On the right side, multi-hole-cups in which the direction of the screw holes are centered on the pelvic brim (brim-focused) and, on the left side, multi-hole-cups with the direction of the screw hole spread throughout the acetabulum (spread-out) were implanted into the pelvic synthetic bones. Coronal lever-out and axial torsion tests were performed with a testing machine, measuring load versus displacement. RESULTS: The average torsional strengths were significantly higher in the spread-out group over the brim-focused group regardless of the presence of the segmental defect of the acetabulum (p < 0.001). But for the lever-out strength, the spread-out group exhibited significantly higher average strength over the brim-focused group for the intact acetabulum (p = 0.004), whereas the results were reversed in the brim-focused group when the defects were generated (p < 0.001). The presence of acetabular defects reduced the average torsional strengths of the two groups by 68.66% versus 70.86%. In comparison, the decrease in the average lever-out strength was less significant for the brim-focused group than the spread-out group (19.87% vs. 34.25%) (p < 0.001). CONCLUSION: Constructs of multi-hole acetabular cups with the spread-out screw holes configuration exhibited statistically better axial torsional strength and coronal lever-out strength. With the presence of posterior segmental bone defects, the spread-out constructs demonstrated significantly better tolerance to axial torsional strength. Still, they exhibited inverted results of higher lever-out strength in the pelvic brim-focused constructs.

Weight-Based Bisphosphonate Administration for Multiple Myeloma Patients and the Risks of Skeletal Complications.

High-dose bisphosphonate for multiple myeloma patients might elevate risks of skeletal complications earlier than general expectations. This study aims to find incidences of atypical femoral fracture (AFF) and medication-related osteonecrosis of the jaw (MRONJ), elucidate their risk factors, and suggest cut-off values for the safer dosing of high-dose bisphosphonate treatment. By using the clinical data warehouse of a single institute, retrospective cohort data of multiple myeloma-diagnosed patients with high-dose bisphosphonate (pamidronate or zoledronate) treatment from 2009 to 2019 was extracted. Among 644 patients, the incidence of prominent AFF requiring surgery was 0.93% (6/644) and MRONJ was diagnosed in 11.8% (76/644) of the study population. For both AFF and MRONJ, the total potency-weighted sum of total dose per body weight (OR = 1.010, p = 0.005) were significant on logistic regression. Cutoffs of the potency-weighted total dose (mg) per body weight (kg) for AFF and MRONJ were 77.00 and 57.70 mg/kg, respectively. After roughly one year of treatment with high-dose zoledronate (about four years for pamidronate), an earlier thorough re-evaluation of skeletal complications should be taken. Body weight adjustments for accumulative dose calculation in terms of permissible dosing should be taken into consideration.

Lateral pillar is the key in supporting pre-collapse osteonecrosis of the femoral head: a finite element model analysis of propensity-score matched cohorts.

BACKGROUND: This study was designed as a cohort study using propensity-score matching to age, gender, and body mass index (BMI) for finite element model (FEM) analysis from pre-collapse CT images of collapsed and non-collapsed hips. Through FEM analysis, a global graphical output around the hip joint can provide simple impression of stress distribution: concentration or dispersion. METHODS: A total of 32 hips with ARCO stage 2 or 3 ONFH who were on follow up for over a one-year period were retrospectively reviewed. 16 hips with no interval progression of collapse were set as the study group, then 16 hips with progression of collapse which required arthroplasty were set as the control group using propensity-score matching. FEM was generated through Mechanical Finder for each patient, then 4500 N of load was applied to 1000 mm2 area at the top of iliac crest to analyze the models in terms of equivalents for yield stress. RESULTS: Age, sex, and BMI had no significant differences between the two groups, while location (p = 0.015) was lateral, and size (p = 0.015) was significantly greater in the collapsed group. Non-collapsed hips mostly exhibited stress dispersion allocated to medial and lateral pillars, while collapsed hips exhibited stress concentration focused on the lateral pillar and the primary compression trabecula. (p = 0.001). CONCLUSION: Through FEM analysis, stress concentration to the lateral pillar and the primary compression trabeculae can be used to predict future collapse in ONFH with high probability. Results provide a simple and intuitive, yet valuable information to aid surgeons. Therefore, especially for young patients, holding out the lateral pillar through joint preserving procedures might be the key in preventing further collapse.

Incidence and Risk Factors of Gastrointestinal and Hepatobiliary Complications after Spinal Fusion Surgery: a Retrospective Cohort Study.

BACKGROUND: Spinal surgery holds a higher chance of unpredicted postoperative medical complications among orthopedic surgeries. Several studies have analyzed the risk factors for diverse postoperative medical complications, but the majority investigated incidences of each complication qualitatively. Among gastrointestinal complications, reports regarding postoperative ileus were relatively frequent. However, risk factors or incidences of hepatobiliary complications have yet to be investigated. The purpose of this study was to examine the incidence of gastrointestinal complications after spinal surgery, quantitatively analyze the risk factors of frequent complications, and to determine cues requiring early approaches. METHODS: In total, 234 consecutive patients who underwent spinal fusion surgery performed by one senior doctor at our institute in one-year period were retrospectively enrolled for analyses. The primary outcomes were presence of paralytic ileus, elevated serum alanine transaminase (ALT) and aspartate transaminase (AST) levels, and elevated total bilirubin levels. Univariate logistic regression analyses of all variables were performed. In turn, significant results were reanalyzed by multivariate logistic regression. The variables used were adjusted with age and gender. RESULTS: Gastrointestinal complications were observed in 15.8% of patients. Upon the risk factors of postoperative ileus, duration of anesthesia (odds ratio [OR], 1.373; P = 0.015), number of fused segments (OR, 1.202; P = 0.047), and hepatobiliary diseases (OR, 2.976; P = 0.029) were significantly different. For elevated liver enzymes, men (OR, 2.717; P = 0.003), number of fused segments (OR, 1.234; P = 0.033), and underlying hepatobiliary (OR, 2.704; P = 0.031) and rheumatoid diseases (OR, 5.021; P = 0.012) had significantly different results. Lastly, risk factors for total bilirubin elevation were: duration of anesthesia (OR, 1.431; P = 0.008), number of fused segments (OR, 1.359; P = 0.001), underlying hepatobiliary diseases (OR, 3.426; P = 0.014), and thoracolumbar junction involving fusions (OR, 4.134; P = 0.002) compared to lumbar spine limited fusions. CONCLUSION: Patients on postoperative care after spinal surgery should receive direct attention as soon as possible after manifesting abdominal symptoms. Laboratory and radiologic results must be carefully reviewed, and early consultation to gastroenterologists or general surgeons is recommended to avoid preventable complications.

Effectiveness of government anti-smoking policy on non-smoking youth in Korea: a 4-year trend analysis of national survey data.

OBJECTIVES: Since the Health Promotion Act was introduced in Korea in 1995, anti-smoking policies and regulations have undergone numerous revisions, and non-smoking areas have gradually been expanded. The purpose of this study was to examine the impact of a partial legislative ban on adolescent exposure to secondhand smoke using objective urinary cotinine levels in a nationwide representative sample. METHODS: Urine cotinine levels were measured in the Korea National Health and Nutrition Examination Survey from 2008 to 2011. This study was a trend analysis of 4 years of national survey data from 2197 Korean youth aged 10-18 years. Among non-smokers, the 75th percentile urinary cotinine level was estimated. We also considered the number of household smokers. RESULTS: The 75th percentile urine cotinine level of non-smokers showed a significant decreasing trend from 2008 to 2011, from 15.47 to 5.37 ng/mL, respectively. Urine cotinine did not decline significantly in non-smokers living with smokers during the study period. The results did not show a statistically significant reduction in smoking rate in adolescents from 2008 to 2011, although there was a trend towards a decrease (p=0.081). CONCLUSIONS: Based on urine cotinine levels, government-initiated anti-smoking policies have only been effective among highly exposed non-smoking adolescents during the study period. Further study needs to evaluate whether or not the legislative ban affects domestic smoking exposure.

Intraoperative adjustment of alignment under valgus stress reduces outliers in patients undergoing medial opening-wedge high tibial osteotomy.

INTRODUCTION: A considerable percentage of outliers with under- or over-correction continue to be reported despite precise preoperative planning and cautious intraoperative correction of lower limb alignment in medial opening-wedge high tibial osteotomy (MOWHTO). The purpose of this study was to determine whether our novel technique for the intraoperative adjustment of alignment under valgus stress reduces the number of outliers in patients undergoing MOWHTO compared to the conventional technique, which corrects alignment according to the cable method only. MATERIALS AND METHODS: One hundred seventeen consecutive knees were enrolled in this case-control study. The first 52 knees (51 patients) were corrected in accordance with preoperative plans using the Dugdale method with modification with an intraoperative cable (group 1). In the other 65 knees (60 patients), the angle was corrected using the Dugdale method and limb alignment was adjusted using the intraoperative cable technique by applying valgus stress to the knee joint (group 2). The postoperative weight bearing line ratios and mechanical axis of the lower limb were compared at postoperative one year. Each knee was evaluated according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score preoperatively and at postoperative one year. RESULTS: A significant reduction in the number of outliers was seen in group 2 compared to group 1 (group 1 = 48.1%, group 2 = 9.2%, p < 0.001). Nineteen of 52 knees (36.5%) were under-corrected in group 1, whereas 6 of 65 knees (9.2%) were under-corrected in group 2 (p < 0.001). Six of 52 knees (11.6%) were over-corrected in group 1, whereas 0 of 65 knees (0.0%) were over-corrected in group 2 (p = 0.005). At one -year after operation, group 2 showed significantly lower WOMAC score than group 1 (p = 0.014). CONCLUSIONS: Intraoperative adjustment of alignment under valgus stress significantly reduced the number of outliers compared to a technique that corrected alignment using the cable method in patients undergoing MOWHTO. LEVEL OF EVIDENCE: Level III, retrospective comparative study.