A Morphometric Study of the Distal Femoral Resected Surface In Osteoarthritis Knees of the Patients in Southwest China and a Comparison with Femoral Components in Six Total Knee Arthroplasty Systems.

OBJECTIVE: Mismatch between the femoral component and the resected surface is related to the postoperative clinical outcome. This study aimed to measure the morphometric features of the distal femoral resected surfaces in patients with osteoarthritis in southwestern China and to compare the measured morphometric data with six commonly used total knee arthroplasty (TKA) femoral components in China. METHOD: The computer tomography (CT) images of a total of 406 knees from 203 osteoarthritis patients who underwent TKA from January 2018 to December 2021 were imported into Mimics 21.0 software to reconstruct the three-dimensional (3D) model of the femur. Morphometric data of the distal femoral resected surfaces were measured after the completion of simulated bone resection in the software. The data included the medial-lateral (ML) dimension, anterior-posterior (AP) dimension, and the aspect ratio (AR) (AR = ML/AP), which were compared between genders with independent sample t-tests. In addition, we plotted the scatter diagram of those morphometric data in Origin software, and the linear fits of ML versus AP and AR versus AP were performed and compared for the six femoral components commonly used in enrolled patients in China. RESULTS: The mean ML dimension, the mean AP dimension, and the mean AR value measured for Chinese knees were 66.62 ± 4.57 mm, 58.10 ± 3.74 mm, and 1.15 ± 0.06 respectively. All dimensions were significantly larger in males than in females, including the calculated values for AR (P < 0.05). The fitted lines for males showed that the ML dimensions tended to be wider compared to femoral components of a given AP dimension. Females tended to have wider ML dimensions compared to small femoral components and, on the other hand, narrower ML dimensions compared to large femoral components. CONCLUSION: The femoral component of the current commonly used TKA prosthesis in China may not be perfectly matched to the distal femoral resected surface of patients in southwestern China. Male patients tended to underhang in all dimensions of the ML dimension. Female patients with shorter AP lengths are more likely to experience underhang, whereas those with longer AP lengths are more likely to develop overhangs. Therefore, we recommend multiple ML width options for a given AP length to more appropriately match the Chinese femoral anatomy.

Education level has an effect on the recovery of total knee arthroplasty: a retrospective study.

OBJECTIVE: This study aimed to observe the relationship between education level and outcomes after total knee arthroplasty (TKA). METHODS: One thousand two hundred sixty four patients after TKA in our hospital from April 2016 to April 2020 were reviewed. These patients were divided into 4 groups (A who were illiterate, B who had elementary school degree, C who had junior high school degree, D who had senior high school degree or higher) by the educational level, which was blinded to the observers. The postoperative outcomes of KSS score, pain, joint extension and flexion function were observed 1 year after discharged from hospital. RESULTS: Among 1253 patients met the inclusion criteria, the average age was 68.63 years, the average body mass was 57.73 kg. There are no distinctions among 4 groups one day after the surgery. However, the outcomes of the follow up were that, the KSS score was: 77.84 ± 10.635; 80.70 ± 8.956; 87.92 ± 8.123;91.27 ± 8.262, with significant differences (P < 0.05). The mean VAS scores were: 1.97 ± 1.60; 2.07 ± 1.66; 1.197 ± 1.5265, 1.044 ± 1.4662. Patients in Group C and D had significantly less pain than that in Group A and B (P < 0.05). The knee flexion range of motion (ROM) was: 91.21 ± 11.69°; 91.77 ± 11.95°; 102.12 ± 11.38°; 109.96 ± 10.64°, Group D performed best, with significant differences (P < 0.05). The knee extension ROM were: - 2.41 ± 4.49°; - 0.91 ± 2.82°; - 0.83 ± 2.87°; - 0.35 ± 1.60°, with significant difference between Group D and the others (P < 0.05). CONCLUSION: Education level affects the outcomes such as VAS score, KSS score, the extension and flexion ROM of the knee after TKA. The patients with higher education level have better outcomes.

Correlation between component alignment and short-term clinical outcomes after total knee arthroplasty.

Objective: This study aimed to investigate the correlation between component alignment and short-term clinical outcomes after total knee arthroplasty (TKA). Methods: 50 TKA patients from a regional hospital were enrolled in the study. The following component alignments were measured from radiological data acquired within 1 week after surgery: hip-knee-ankle angle (HKA), medial distal femoral angle (MDFA), medial proximal tibial angle (MPTA), femoral flexion-extension angle (FEA), tibial slope angle (TSA), femoral rotational angle (FRA) and tibial rotational angle (TRA). The Hospital for Special Surgery (HSS) knee scoring system was used to assess clinical outcomes after 1 year, with patients being divided into three groups (excellent, good and not good) according to the HSS scores. Difference analysis and linear correlation analysis were used for the statistical analysis. Results: The results showed significant differences in MDFA (p = 0.050) and FEA (p = 0.001) among the three patient groups. It was also found that the total HSS had only a moderate correlation with FEA (r = 0.572, p < 0.001), but FEA had a positive linear correlation with pain scores (r = 0.347, p = 0.013), function scores (r = 0.535, p = 0.000), ROM scores (r = 0.368, p = 0.009), muscle scores (r = 0.354, p = 0.012) and stability scores (r = 0.312, p = 0.028). A larger MDFA was associated with lower FE deformity scores (r = -0.289, p = 0.042) and the TSA had a positive influence on the ROM (r = 0.436, p = 0.002). Also, changes in FRA produced a consequent change in the FE deformity score (r = 0.312, p = 0.027), and the muscle strength scores increased as TRA increased (r = 0.402, p = 0.004). Conclusion: The results show that the FEA plays a significant role in clinical outcomes after TKA. Surgical techniques and tools may need to be improved to accurately adjust the FEA to improve joint functionality and patient satisfaction.

The Antibacterial Activity Comparison between Novel Carbon-Based Nanofilm Coated Titanium Alloy and Co-Cr-Mo Alloy.

Objective: The purpose of this study was to reveal the antibacterial activity of carbon-based nanofilm titanium alloy. Methods: The experiments were performed both in vitro and in vivo of animals using two circular-piece test specimens of the same specification, which were made from carbon-based nanofilm coated titanium alloy and commonly used in artificial joints Co-Cr-Mo alloy, respectively. In the in vitro experiments, the two test specimens were cocultured with standard strains of Staphylococcus aureus and Escherichia coli, and the antibacterial properties of the two test specimens were evaluated via inhibition zone size, scanning electron microscopy, fluorescence staining, colony forming unit count, and others; the cytotoxicities of the two test specimens were evaluated by coculturing and them with rabbit bone marrow mesenchymal stem cells (BMSCs). In the in vivo experiments, the two test specimens were implanted in the muscle tissue of experimental rabbits to evaluate their histocompatibilities. Results: Both in vitro cocultures of the carbon-based nanofilm titanium alloy and the Co-Cr-Mo alloy with Staphylococcus aureus and Escherichia coli failed to form inhibition zone. However, some biofilms were observed on the surface of the Co-Cr-Mo alloy. Fewer bacteria adhered to the carbon-based nanofilm titanium alloy can be observed via scanning electron microscopy and fluorescence staining techniques. Meanwhile, the colony forming counts showed that, compared with the Co-Cr-Mo alloy, the carbon-based nanofilm titanium alloy had fewer bacteria adhered (P < 0.05). After coculture of the two test specimens with rabbit BMSCs, there was no significant difference in cell count, and both cell counts showed no cytotoxicity. In the in vivo experiment of animals, there are relatively fewer giant cells and better histocompatibility in tissues near the carbon-based nanofilm titanium alloy. Conclusion: Compared with Co-Cr-Mo alloy, the novel carbon-based nanofilm titanium alloy enjoys stronger in vitro antibacterial activity and better in vivo histocompatibility.

Ultra-Pulsed CO2 Laser Osteotomy: A New Method for the Bone Preparation of Total Knee Arthroplasty.

Cementless total knee arthroplasty (TKA) can achieve long-term biological fixation, but its application is limited by the risk of early aseptic loosening. One of the important reasons for early aseptic loosening is that mechanical osteotomy tools cannot achieve ideal bone preparation because of poor accuracy and serious bone tissue damage produced by them. Therefore, we designed an ultra-pulsed CO2 laser osteotomy system to solve these problems. To reveal the safety at the tissue and cell levels of the ultra-pulsed CO2 laser osteotomy system, a series of experiments on distal femur osteotomy in animals were performed. Then, the bone surface characteristics were analyzed through scanning electron microscopy, and the bone thermal and mechanical damage was evaluated via histological analysis. Finally, mesenchymal stem cells (MSCs) were inoculated on the bone surfaces prepared by the two osteotomy tools, and the effect of cell adhesion was analyzed through a confocal laser scanning microscope (CLSM). We successfully achieved TKA bone preparation of animal knees with the ultra-pulsed CO2 laser osteotomy system. Moreover, the biological evaluation results indicated that compared with the traditional mechanical saw, the laser can preserve the natural bone structure and cause no thermal damage to the bone. In addition, CLSM examination results showed that the laser-cut bone surface was more conducive to cell adhesion and infiltration than the bone surface cut by a mechanical saw. Overall, these results indicate that ultra-pulsed CO2 laser can achieve non-invasive bone cutting, which can be a new option for TKA bone preparation and has the potential to lead in the future.

Relieved Low Back Pain after Total Hip Arthroplasty in Patients with Both Hip Osteoarthritis and Lumbar Degenerative Disease.

OBJECTIVE: To investigate the relief of low back pain after hip arthroplasty in patients with hip joint and spinal degenerative diseases, and to discuss the effects of unilateral and bilateral hip surgery on the relief of low back pain. METHODS: In this retrospective study, we followed 153 patients (69 males and 84 females, age: 43-88 years) who had undergone total hip arthroplasty (THA) via a posterolateral approach and also suffered from lumbar degenerative diseases in the period of 2009 to 2019. The inclusion criteria were: (i) patients who had been diagnosed with severe hip degenerative disease and also been diagnosed with lumbar degenerative disease; (ii) patients who had undergone THA surgery; and (iii) patients who were retrospectively recruited. The exclusion criteria were: (i) patients who had undergone lumbar fusion or internal fixation surgery; or (ii) patients who had vascular claudication, history of major trauma, diabetic polyneuropathy, lumbar and pelvic infections, tumor diseases; (iii) or patients who had undergone THA because of femoral neck fracture or ankylosing spondylitis. The improvement of hip joint function and the relief of low back pain (LBP) were studied, and the effect of unilateral and bilateral THA on the relief of LBP were discussed. Hip pain and function were evaluated by the Harris Hip Score (HHS), LBP was evaluated by Visual Analog Scale (VAS), and lumbar function was evaluated by the Japanese Orthopaedic Association (JOA) scoring system. RESULTS: The average follow-up time was 44.3 months (24-108 months). All patients recovered smoothly without complications. The LBP VAS of 153 patients decreased from 4.13 ± 1.37 preoperatively to 1.90 ± 1.44 postoperatively. The average HHS increased from 45.33 ± 13.23 preoperatively to 86.44 ± 7.59 postoperatively at the latest follow-up. According to Japanese Orthopaedic Association scoring system, the proportion of patients with good response to treatment in these 153 patients reached 93.46%. LBP VAS decreased from 4.18 ± 1.38 preoperatively to 1.95 ± 1.49 postoperatively in unilateral group and from 3.94 ± 1.32 preoperatively to 1.73 ± 1.23 postoperatively in bilateral group, respectively. There were only nine patients with persistent or aggravated LBP after operation. Among them, six patients underwent subsequent lumbar surgery (five patients had pain relieved after reoperation and one patient had not) and the other three patients chose conservative treatment for pain. CONCLUSION: THA can relieve LBP while relieving hip pain and restoring hip function in patients with both hip and lumbar degenerative disease, thus possibly avoiding further spinal surgery.

WIPI1 promotes osteosarcoma cell proliferation by inhibiting CDKN1A.

Detection of TCGA data revealed that WIPI1 is highly expressed in osteosarcoma cells. So we explore the mechanisms of WIPI1 affecting the proliferation of osteosarcoma cells through Affymetrix microarray analysis. Functional analysis of differentially expressed genes shows that the classical signaling pathways affecting tumor formation and development have changed significantly. By fitting analysis, it is speculated that the WIPI1 may function in the direction of osteosarcoma by regulating the expression of multiple cell cycle-related genes such as CDKN1A, CDK4 and CCND1. Therefore, the key genes are selected for RT-PCR and Western-blot verification. Combined with flow and other means, WIPI1 may affect the cell cycle and the osteosarcoma by regulating the expression of CDKN1A, CDK4 and CCND1. To verify the results, the effect of WIPI1 on cell proliferation was quantified by MTT, cell counts and nude mouse tumorigenicity assay. The results showed that WIPI1 promotes osteosarcoma cell proliferation.

Does patient-specific instrumentation increase the risk of notching in the anterior femoral cortex in total knee arthroplasty? A comparative prospective trial.

PURPOSE: Patient-specific instrumentation (PSI) was usually applied in total knee arthroplasty (TKA) to acquire a favourable alignment. We hypothesized that using PSI had a potential risk of notching in the anterior femoral cortex, because the femoral component may be placed in an overextension position due to the distal femoral sagittal anteversion. The aim of this study was to figure out the relationship between the notch and the distal femoral sagittal anteversion in PSI-assisted TKA. METHODS: One hundred thirty-one patients who were to undergo total knee arthroplasty (TKA) were randomly divided into conventional instrumentation (CI) group and PSI group. The computed tomography (CT) data of lower extremities was collected and imported to the Mimics software to reconstruct the three-dimensional (3D) bone image of the femur. The angle between distal femoral anatomic axis (DFAA) and femoral mechanical axis (FMA) on sagittal plane was defined as distal femoral sagittal anteverted angle (DFSAA) and measured. The number of notch intra-operative and post-operative was recorded. Then, we calculated the incidence of the notch and analyzed its relationship with DFSAA. RESULTS: The average DFSAA of 262 femurs is 2.5° ± 1.5° (range, 0.0°-5.7°). When DFSAA ≥ 3°, the incidence of notch was 7.10% in CI group and 33.30% in PSI group, respectively, which shows significant statistical difference in the two groups (P = 0.016 < 0.05). When DFSAA < 3°, the incidence of notch was 6.50% in CI group and 5.30% in PSI group, respectively, which shows no significant statistical difference in the two groups (P = 0.667 > 0.05). CONCLUSION: DFSAA could be taken as an indicator to predict the notch when performing TKA assisted with PSI. Especially when the DFSAA ≥ 3°, the risk of notch could be markedly increased.