3D Foaming Printing Biomimetic Hierarchically Macro-Micronanoporous Hydrogels for Enhancing Cell Growth and Proliferation.

Hydrogel, recognized as a promising biomaterial for tissue engineering, possesses notable characteristics, including high water uptake, an interconnected porous structure, and excellent permeability. However, the intricate task of fabricating a hierarchically macro-micronanoporous structure, essential for providing adequate space for nutrient diffusion and cell growth within hydrogels, remains a formidable challenge. In response to these challenges, this study introduces a sustainable and straightforward three-dimensional (3D) foaming printing strategy to produce hierarchically macro-micronanoporous hydrogels (HPHs) without the utilization of porogens and post-etching process. This method entails the controlled generation of air bubbles within the hydrogels through the application of optimal mechanical stirring rates. Subsequent ultraviolet (UV) cross-linking serves to effectively stabilize the macropores within the HPHs. The resulting hierarchically macro-micronanoporous structures demonstrate a substantial improvement in the viability, adhesion, and proliferation of human umbilical vein endothelial cells (HUVECs) when incubated with the hydrogels. These findings present a significant advancement in the fabrication of hierarchically macro-micronanoporous hydrogels, with potential applications in the fields of tissue engineering and organoid development.

Patellar Denervation with Electrocautery Reduces Anterior Knee Pain within 1 Year after Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials.

OBJECTIVE: The effect of patellar denervation with electrocautery (PD) on anterior knee pain (AKP) after total knee arthroplasty (TKA) is still debated. The aim of this meta-analysis was to evaluate the current evidence regarding the use of PD in TKA without patellar resurfacing. METHODS: A computerized search of published studies was performed in the PubMed, Embase and Cochrane Library databases in December 2019. Eligible studies were randomized controlled trials (RCTs) comparing clinical outcomes of the PD group and the non-PD group. Subgroup analyses were carried out according to the follow-up time (3, 12 months, and over 12 months) to evaluate whether the clinical effect of PD changed with time. RESULTS: Ten RCTs were included in this meta-analysis. Pooled results showed a lower rate of AKP (Risk Ratio [RR] = 0.70; 95% confidence interval [CI], 0.50 to 0.97; P = 0.03) and a reduction in visual analogue scale (VAS) for AKP (mean difference, -0.37; 95% CI, -0.69 to -0.05; P = 0.02) in the PD group when compared to the non-PD group. Subgroup analyses found the differences in AKP incidence and VAS for AKP were significant at 3- and 12-month follow-up but not after 12-month follow-up. No significant difference was observed in functional scores between the two groups. No specific complication directly or indirectly related to PD was found. CONCLUSION: PD can decrease the incidence and severity of AKP within 12 months after TKA, but the effect cannot be maintained after 12-month follow-up. Without significant associated complication and reoperation, the use of PD is still recommended in TKA without patellar resurfacing.

Minimum 8-year follow-up of revision THA with severe femoral bone defects using extensively porous-coated stems and cortical strut allografts.

BACKGROUND: Revision total hip arthroplasty (THA) with severe femoral bone defects remains a major challenge. The purpose of this study is to report the minimum 8-year clinical and radiographic results of revision THA with severe femoral bone defects treated with extensively porous-coated stems and cortical strut allografts. METHODS: We retrospectively identified 44 patients diagnosed with Paprosky type III and IV femoral bone defects between January 2006 and July 2011. The exclusion criteria were patients not eligible for surgery, revised with extensively porous-coated stems alone, lost to follow-up and deceased. A total of 31 patients treated with extensively porous-coated stems and cortical strut allografts were finally included in this study. The degree of femoral bone defects was categorized as Paprosky type IIIA in 19 patients, type IIIB in 9 patients and type IV in 3 patients. The mean duration of follow-up was 11.0 ± 1.5 (range, 8.1-13.5) years. RESULTS: The mean Harris Hip Score improved significantly from 43.4 ± 10.5 points to 85.2 ± 6.6 points (P < 0.001). Similarly, WOMAC and SF-12 scores also significantly improved. Twenty-eight stems achieved stable bone ingrowth, two stems showed stable fibrous ingrowth, and one stem was radiologically unstable. Complete union and bridging between cortical strut allografts and host bone was achieved in all 31 patients. The femoral width was augmented with cortical strut allografts after revision surgery (an increase of 10.5 ± 0.5 mm) and showed a slight decrease of 2.5 ± 4.8 mm after the 10-year follow-up. Using re-revision for any reason as an endpoint, the Kaplan-Meier cumulative survival rate of the stem was 96.2% (95% confidence interval, 75.7-99.5%) at 10 years. CONCLUSION: Our data demonstrate that the use of extensively porous-coated stems combined with cortical strut allografts in revision THA with Paprosky type III and IV femoral bone defects can provide satisfactory clinical and radiographic outcomes with a minimum follow-up of 8 years.

The Use of Porous Tantalum Augments for the Reconstruction of Acetabular Defect in Primary Total Hip Arthroplasty.

BACKGROUND: Given the lack of studies of acetabular defect reconstruction in primary total hip arthroplasty (THA) using tantalum augments, this study aims to evaluate clinical and radiographic results for treatment with tantalum augments to reconstruct acetabular defects in primary THA. METHODS: We retrospectively reviewed 19 patients (19 hips) with acetabular defects who underwent primary THA using tantalum augments, with a minimum follow-up of 2 years. Clinical, radiographic, and surgical data were retrospectively evaluated. RESULTS: Mean follow-up was 5.1 years (range 2.5-7.6). Harris Hip Score improved from 35.8 (range 19-56) preoperatively to 85.3 (63-98) at last follow-up (P < .01). Oxford Hip Score, University of California Los Angeles activity scale, and Short Form-12 score also improved significantly from presurgery to last follow-up. Mean operation time and blood loss were 124.7 minutes and 530 mL, respectively. Mean hip center position was 2.97 cm (range 2.35-3.58) horizontally and 2.06 cm (1.29-2.92) vertically, and mean acetabular inclination was 38.9° (range 27°-47°) at last follow-up. These parameters were not significantly different from those recorded immediately postoperatively (P > .05). There was no aseptic loosening, cup and augment migration, screw breakage, or presence of hip infection at last follow-up. All hips were radiographically stable. CONCLUSION: Porous tantalum augments combined with titanium shells lead to satisfactory clinical and radiographic outcomes for the reconstruction of acetabular defect in primary THA at a mean 5.1 years of follow-up. This approach confers anatomical cup placement, simple operation, and a high rate of stable fixation.