Comparative analysis of pathogen distribution in patients with fracture-related infection and periprosthetic joint infection: a retrospective study.

BACKGROUND: The purpose of this study is to investigate the microbial patterns of periprosthetic joint infection (PJI) and fracture-related infection (FRI), and guide for the formulation of more accurate empirical antimicrobial regimens based on the differences in pathogen distribution. METHODS: A comparative analysis of pathogen distribution was conducted between 153 patients (76 with PJI and 77 with FRI). Predicted analyses against isolated pathogens from two cohorts were conducted to evaluate the best expected efficacy of empirical antimicrobial regimens (imipenem + vancomycin, ciprofloxacin + vancomycin, and piperacillin/tazobactam + vancomycin). RESULTS: Our study found significant differences in pathogen distribution between the PJI and FRI cohorts. Staphylococci (61.3% vs. 31.9%, p = 0.001) and Gram-negative bacilli (GNB, 26.7% vs. 56.4%, p < 0.001) were responsible for the majority of infections both in the PJI and FRI cohorts, and their distribution in the two cohorts showed a significant difference (p < 0.001). Multi-drug resistant organisms (MDRO) were more frequently detected in the FRI cohort (29.3% vs. 44.7%, p = 0.041), while methicillin-resistant coagulase-negative Staphylococci (MRCoNS, 26.7% vs. 8.5%, p = 0.002) and Canidia albicans (8.0% vs. 1.1%, p = 0.045) were more frequently detected in the PJI cohort. Enterobacter spp. and Acinetobacter baumannii were detected only in the FRI cohort (11.7% and 8.5%, respectively). CONCLUSIONS: Staphylococci and GNB were responsible for the majority of infections in both PJI and FRI. Empirical antimicrobial therapy should focus on the coverage of Staphylococci in PJI and GNB in FRI, and infections caused by MDROs should be more vigilant in FRI, while the high incidence of MRCoNS in PJI should be noted, which could guide for the formulation of more accurate empirical antimicrobial regimens. Targeted therapy for FRI caused by A. baumannii and PJI caused by C. albicans needs to be further investigated. Our study reports significant differences in pathogen distribution between the two infections and provides clinical evidence for studies on the mechanism of implant-associated infection.

Core decompression with ß-tri-calcium phosphate grafts in combination with platelet-rich plasma for the treatment of avascular necrosis of femoral head.

BACKGROUND: This study was aimed to investigate whether the application of platelet-rich plasma (PRP) combined with ß-tri-calcium phosphate (ß-TCP) grafts after core decompression (CD) could improve the clinical outcomes of early stage of avascular necrosis of femoral head. METHODS: Forty-five (54 hips) patients with Ficat-Arlet classification stage I-II treated by CD with ß-TCP grafts with or without the application of PRP from July 2015 to October 2020 were reviewed. Group A (CD + ß-TCP grafts) included 24 patients (29 hips), while group B (CD + ß-TCP grafts + PRP) included 21 patients (25 hips). Visual analogue scale (VAS) score, Harris hip score (HHS), change in modified Kerboul angle and the hip joint survival were evaluated and compared between the groups. Patients had a mean follow-up period of 62.1 ± 17.2 months and 59.3 ± 14.8 months in group A and group B, respectively. RESULTS: The mean VAS scores in group A was significantly higher than group B at the 6 months (2.9 ± 0.7 vs 1.9 ± 0.6, p < 0.01) and final follow up postoperative (2.8 ± 1.2 vs 2.2 ± 0.7, p = 0.04). The mean HHS in group A was significantly lower than group B at the 6 months (80.5 ± 13.8 vs 89.8 ± 12.8, p = 0.02). However, at the final follow up, there is no significant difference between the groups (77.0 ± 12.4 vs 83.1 ± 9.3, p = 0.07). The mean change in modified Kerboul angle was -7.4 ± 10.6 in group A and -19.9 ± 13.9 in group B which is statistically significant (p < 0.01). Survivorship from total hip arthroplasty were 86.2%/84% (p = 0.86) at the final follow up, which was not statistically significant. No serious complications were found in both groups. CONCLUSIONS: A single dose of PRP combined with CD and ß-TCP grafts provided significant pain relief, better functional outcomes, and delayed progression in the short term compared to CD combined with ß-TCP grafts. However, the prognosis of the femoral head did not improve significantly in the long term. In the future, designing new implants to achieve multiple PRP injections may improve the hip preservation rate.

Association of hepatitis B infection with high-risk complications in total joint arthroplasty.

BACKGROUND: An increasing number of patients with hepatitis B virus (HBV) infection are undergoing total joint arthroplasty (TJA) surgery in China. Less attention is provided to the special populations and the purpose of this study is to assess the effect of HBV infection on the prognosis TJAs. METHODS: We retrospectively reviewed patients who underwent elective primary hip and knee arthroplasties in Shanghai Huashan Hospital from 2013 to 2016. Non-hepatitis B cohort was built to match the case cohort to identify whether HBV infection was a risk factor associated with postoperative complications. A total number of 196 patients who underwent primary TJAs were involved in the study, including 49 patients with hepatitis B and 147 non-hepatitis B subjects. RESULTS: Among all the patients with TJAs, 5.5% of patients were infected with HBV for the first time. The incidence rate of complications in patients after arthroplasty with hepatitis B infection was significantly higher than that in patients without hepatitis B (10.2% compared to 4.7%, P < 0.01). Surgical related complications (6.1% compared to 3.4%) and general medical complications (4.1% compared to 1.3%) were higher than those in non-B hepatitis group. Compared with non-B hepatitis group, the overall risk of hepatitis B infection increased by 25% (95% CI, 1.04-1.46; p < 0.01). Similar results were obtained for medical and surgical complications. HBV infection presented a 31% increased risk (95% CI, 1.02-1.62; p < 0.01) for medical complication and an 18% increased risk (95% CI, 1.10-1.26; p < 0.01) for surgical complication. No statistical difference was found between the surgical methods and sex. However, a significant difference of C-reactive protein (CRP) level was found between HBV infection group and the matched non-infected group (P < 0.01). CONCLUSION: This is the first study to investigate the risk of perioperative complications of hepatitis B in Chinese TJAs patients. In consideration of the large population of HBV infection in China, more attention and medical care should be provided to patients with HBV infection who need to undergo TJA operation.

Three-dimensional finite element analysis of silk protein rod implantation after core decompression for osteonecrosis of the femoral head.

BACKGROUND: Several methods are available for the treatment of early-stage osteonecrosis of the femoral head. Core decompression with implantation is a widely-used treatment. However, no single implant is recognized as the most effective way to prevent disease progression. Silk has high strength and resiliency. This study explored the possibility of a strong and resilient silk protein biomaterial as a new alternative implant. METHODS: We investigated the biomechanical properties of the silk protein material by regular compression, torsion, and three-point bending tests. We established three-dimensional finite element models of different degrees of femoral head osteonecrosis following simple core decompression, fibula implantation, porous tantalum rod implantation, and silk protein rod implantation. Finally, we compared the differences in displacement and surface stress under load at the femoral head weight-bearing areas between these models. RESULTS: The elastic modulus and shear modulus of the silk protein material was 0.49GPa and 0.66GPa, respectively. Three-dimensional finite element analyses demonstrated less displacement and surface stress at the femoral head weight-bearing areas following silk protein rod implantation compared to simple core decompression (p < 0.05), regardless of the extent of osteonecrosis. No differences were noted in the surface deformation or surface stress of the femoral head weight-bearing areas following silk protein rod, fibula or tantalum rod implantation (p > 0.05). CONCLUSIONS: When compared with simple core decompression, silk protein rod implantation demonstrated less displacement and surface stress at the femoral head weight-bearing area, but more than fibula or tantalum rod implantation. Similar effects on the surface stress of the femoral head between the silk rod, fibula and tantalum rod implantations, combined with additional modifiable properties support the use of silk protein as a suitable biomaterial in osteonecrosis surgery.

The predictive value of preoperative neutrophil-lymphocyte ratio (NLR) on the recurrence of the local pigmented villonodular synovitis of the knee joint.

BACKGROUND: To explore and evaluate the predictive value of preoperative Neutrophil-lymphocyte ratio (NLR) on the recurrence of pigmented villonodular synovitis (PVNS) of the knee joint treated by arthroscopic surgery combining local radiotherapy. METHODS: Sixty pathological-proven PVNS cases of the knee joint in our department from April 2006 to March 2017 were included. All of them are treated by arthroscopic synovectomy combined with adjuvant radiotherapy. The pre-operative hematological indexes such as c-reactive protein (CRP), erythrocyte sedimentation rate (ESR), NLR, Platelet-lymphocyte ratio (PLR) and Lymphocyte-monocyte ratio (LMR) were collected retrospectively and their relationship with postoperative recurrence was analyzed by using univariate and multivariate analysis, the receiver operating characteristic curves (ROC curve), the Kappa correspondence test and the Mc Nemar Chi-square test. RESULTS: All 60 patients were followed up for a median of 52.8 months (7-138 months) and the recurrence rate is about 23.3% (14/60). There is a significant difference in NLR between the recurrent and non-recurrent group (P = 0.002). It had a certain correlation with postoperative recurrence (correlation coefficient r = 0.438, P = 0.001). The optimal thresholds in ROC curve were 2.42 (sensitivity 71.4%, specificity 78.3% respectively). which had predictive ability for recurrence after arthroscopic treatment. CONCLUSION: The preoperative NLR is an easy and cost-effective predictor for relapse in PVNS of the knee joint after the arthroscopic surgery combined with local radiotherapy, which is of profound significance to guide clinical work.

Total knee arthroplasty using trochlear groove as guide for position of femoral component in severe knee osteoarthritis.

BACKGROUND: Apart from transepicondylar axis, the native femoral sulcus was also reported to be used as a guide for the femoral component position in total knee arthroplasty (TKA). However, it was not shown in patients with severe knee osteoarthritis. This study was conducted to compare the position of trochlear groove in patients with and without osteoarthritis, and to assess whether trochlear groove could be used as a guide for position of femoral component in TKA for severe knee osteoarthritis. METHODS: Total 50 severe knee osteoarthritis patients (Kellgren Lawrence grade 3 or 4) who underwent TKA were included. Meanwhile, 50 patients who underwent arthroscopic surgery without osteoarthritis were included as control. The distance from trochlear groove to the midpoint of a virtual anterior condyle osteotomy line (parallel to the posterior condyle line) (a-b) was recorded by radiological and surgical measurements. Midpoint of transepicondylar axis and trochlear groove were used as guide for placing prosthesis model in TKA, respectively. No-thumb test was performed to assess the patellar tracking. The position of femoral component was finally performed using trochlear groove as guide in TKA. RESULTS: Value of "a-b" was significantly different between osteoarthritic and control knees (P = 0.008). During the placement of prosthesis model, similar patellar tracking was detected between using midpoint of transepicondylar axis and trochlear groove as guide (P > 0.05). After placing femoral component using trochlear groove as guide, most patients obtained good patellofemoral congruence with pneumatic tourniquet inflated (n = 43) or deflated (n = 5), and good patellofemoral congruence was also obtained by lateral patellar retinaculum release in two patients. CONCLUSION: Despite the shifting of trochlear groove caused by severe knee osteoarthritis, trochlear groove can be used as a guide for position of femoral component, with equivalent patellar tracking compared with transepicondylar axis.

HDAC5 promotes osteosarcoma progression by upregulation of Twist 1 expression.

Histone deacetylases (HDACs) form a family of enzymes, which have fundamental roles in the epigenetic regulation of gene expression and contribute to the growth, differentiation, and apoptosis of cancer cells. In this study, we firstly investigated the biological function of HDAC5 in osteosarcoma cells. We found that mRNA and protein levels of HDAC5 were upregulated in osteosarcoma tissues and cell lines. Furthermore, overexpression of HDAC5 could promote cell proliferation in osteosarcoma cell lines. In contrast, HDAC5 knockdown using small interfering RNA inhibited cell proliferation. At the molecular level, we demonstrated that HDAC5 promoted mRNA expression of twist 1, which has been reported as an oncogene. Together, these results highlighted for the first time an unrecognized link between HDAC5 and osteosarcoma progression and demonstrated that its specific inhibition might contribute to the treatment of tumorigenesis.

CXCL12-CXCR4 contributes to the implication of bone marrow in cancer metastasis.

The CXCL12-CXCR4 axis is postulated to be a key pathway in the interaction between (cancer) stem cells and their surrounding supportive cells in the (cancer) stem cell niche. As the bone marrow constitutes a unique microenvironment for cancer cells, the CXCL12-CXCR4 axis assists the bone marrow in regulating cancer progression. This interaction can be disrupted by CXCR4 antagonists, and this concept is being used clinically to harvest hematopoietic stem/progenitor cells from the bone marrow. The functions of CXCL12-CXCR4 axis in cancer cell-tumor microenvironment interaction and angiogenesis have been recently studied. This review focuses on how CXCL12-CXCR4 helps the bone marrow in creating a tumor mircoenvironment that results in the cancer metastasis. It also discusses ongoing research regarding the clinical feasibility of CXCR4 inhibitors.

Three-dimensional virtual reality simulation of periarticular tumors using Dextroscope reconstruction and simulated surgery: a preliminary 10-case study.

BACKGROUND: Dextroscope® three-dimensional (3D) imaging has been extensively used to generate virtual reality (VR) workspaces for neurosurgery and laparoscopy, but few applications have been reported for orthopedic surgery. Here, we investigated orthopedic periarticular tumor surgery planning and anatomical characteristics using a Dextroscope. MATERIAL AND METHODS: Patients undergoing surgery for periarticular tumors (n=10) between October 2008 and June 2010 were enrolled and presurgically subjected to computed tomography (CT), magnetic resonance imaging (MRI), and MRI angiography (MRI-A). Imaging data were transferred and integrated in a Dextroscope to produce a VR simulation. The presurgical 3D anatomical reconstructions and intraoperative anatomical characteristics (virtual vs. actual data) and surgical approach (virtual vs. actual situation) measurement and subjective appearance were compared. RESULTS: Anatomical characteristics in the area of interest and tumor diameters in all 3 planes (superior-inferior, medial-lateral, and anteroposterior) were consistent between virtual and actual data (3.92±1.22, 1.96±0.53, and 1.73±0.44 vs. 3.92±1.13, 1.91±0.44, and 1.81±0.41; P=0.99, 0.24, and 0.09, respectively). However, the virtual surgical situations were inconsistent with the actual intraoperative situation in many cases, leading to complications. The resolutions of the original CT, MRI, and MRI-A images directly correlated with 3D simulation quality, with soft tissues most poorly represented. Tumor tissue imaging quality in 3D varied extensively by tumor type. CONCLUSIONS: Anatomical structures of periarticular tumors can be reconstructed using the Dextroscope system with good accuracy in the case of simple fenestration, increasing treatment individualization, surgical competence level, and potentially reducing intraoperative complications. However, further specialization of VR tools for use in orthopedic applications that involve specialized tools and procedures, such as drilling and implant placement, are urgently need.

Evaluation of the 3D finite element method using a tantalum rod for osteonecrosis of the femoral head.

BACKGROUND: The aim of this study was to contrast the collapse values of the postoperative weight-bearing areas of different tantalum rod implant positions, fibula implantation, and core decompression model and to investigate the advantages and disadvantages of tantalum rod implantation in different ranges of osteonecrosis in comparison with other methods. MATERIAL AND METHODS: The 3D finite element method was used to establish the 3D finite element model of normal upper femur, 3D finite element model after tantalum rod implantation into different positions of the upper femur in different osteonecrosis ranges, and other 3D finite element models for simulating fibula implant and core decompression. RESULTS: The collapse values in the weight-bearing area of the femoral head of the tantalum rod implant model inside the osteonecrosis area, implant model in the middle of the osteonecrosis area, fibula implant model, and shortening implant model exhibited no statistically significant differences (p>0.05) when the osteonecrosis range was small (60°). The stress values on the artificial bone surface for the tantalum rod implant model inside the osteonecrosis area and the shortening implant model exhibited statistical significance (p<0.01). CONCLUSIONS: Tantalum rod implantation into the osteonecrosis area can reduce the collapse values in the weight-bearing area when osteonecrosis of the femoral head (ONFH) was in a certain range, thereby obtaining better clinical effects. When ONFH was in a large range (120°), the tantalum rod implantation inside the osteonecrosis area, shortening implant or fibula implant can reduce the collapse values of the femoral head, as assessed by other methods.

Three-dimensional virtual reality simulation of periarticular tumors using Dextroscope reconstruction and simulated surgery: a preliminary 10 case study.

UNLABELLED: Dextroscope three-dimensional (3D) imaging has been extensively applied for generation of virtual reality (VR) workspaces for in neurosurgery and laparoscopy, though few applications in orthopedic surgery have been reported. Patients undergoing surgery for periarticular tumors (n = 10) from Oct. 2008 to Jun. 2010 were enrolled and presurgically subjected to computed tomography (CT), magnetic resonance imaging (MRI), and MRI angiography (MRI-A). Imaging data was transferred and integrated in Dextroscope, producing a VR simulation. Resultant presurgical 3D anatomical reconstructions and intraoperative anatomical characteristics (virtual vs. actual data) and surgical approach (virtual vs. actual situation) measurement and subjective appearance were compared. Anatomical characteristics in the area of interest and tumor diameters were consistent between virtual and actual data. However, the virtual surgical situations remained inconsistent with the actual intraoperative situation in many cases, leading to complications. The resolution of original CT, MRI, and MRI-A images directly correlated with the quality of 3D simulations, with soft tissues most poorly represented. Tumor tissue imaging quality in 3D varied extensively by tumor type. CONCLUSIONS: Anatomical structures of periarticular tumors can be reconstructed using the Dextroscope system with good accuracy in the case of simple fenestration, increasing individualization of treatment, surgical competence level, and potentially reducing intraoperative complications. However, further specialization of VR tools for use in orthopedic applications that involve specialized tools and procedures, such as drilling and implant placement, are urgently required.

Treatment of old femoral neck fractures in young adults with a medial buttress plate combined with three cannulated screws and iliac autograft: Surgical technique and preliminary results.

OBJECTIVES: Whether the application of MBP plus cannulated screws works for old femoral neck fractures (OFNF) is unknown. The purpose of this study is to present a case series of OFNF in young adults using calcar buttress plate and three cannulated screws with autologous iliac bone grafts. METHODS: We conducted a retrospective study of eleven young patients (6 males and 5 females) with femoral neck fractures who were treated with open reduction and internal fixation at a single center between 2013 and 2021. The subjects had trauma-to-surgery intervals longer than 3weeks and all were fixed with a calcar buttress plate combined with three cannulated screws, which were supplemented by autologous iliac bone grafts. RESULTS: All eleven cases achieved radiological union under the surgery technique, which occurred on average at 4.46±1.29months after surgery. Complications included femoral neck shortening in all cases, heterotopic ossification in three cases, and osteonecrosis of the femoral head in two cases. One patient with osteonecrosis of the femoral head received total hip arthroplasty. In follow-ups of 24-52months, the median Harris hip score was 81.64±15.39. CONCLUSIONS: The medial buttress plate in combination with three cannulated screws and iliac autograft may be a good choice for treating old femoral neck fractures in young adults. LEVEL OF EVIDENCE: IV, case series.

Impact of systemic lupus erythematosus (SLE) on outcomes following aseptic and septic revision total knee arthroplasty: an analysis of the 2005-2018 nationwide inpatient sample.

Systemic lupus erythematosus (SLE) can adversely affect surgical outcomes, and the impact on revision total knee arthroplasty (TKA) outcomes is unclear. This study aimed to explore the impact of SLE on in-patient outcomes of revision TKA. The Nationwide Inpatient Sample (NIS) database from 2005 to 2018 was searched for patients aged ≥ 18 years old who received revision TKA. Patients with and without SLE were propensity score matched (PSM) at a 1:4 ratio. Associations between SLE and in-hospital outcomes were examined using regression analyses. The study included 133,054 patients, with 794 having SLE. After 1:4 PSM, data of 3,970 patients were analyzed (SLE, 794; non-SLE, 3,176). Multivariate-adjusted analyses revealed that SLE patients had a significantly higher risk of postoperative complications (adjusted odds ratio [aOR] = 1.23, 95% confidence interval [CI]: 1.05-1.44, p = 0.011), non-routine discharge (aOR = 1.22, 95% CI: 1.02-1.46, p = 0.028), major blood loss (aOR = 1.19), respiratory failure/mechanical ventilation (aOR = 1.79), acute kidney injury (AKI) (aOR = 1.47), and wound dehiscence (aOR = 2.09). SLE patients also had a longer length of hospital stay (aBeta = 0.31) and greater total hospital costs (aBeta = 6.35) compared to non-SLE patients. Among those with aseptic failure, SLE patients had a significantly higher risk of postoperative complications (aOR = 1.23) and non-routine discharge (aOR = 1.36). SLE is independently associated with worse in-hospital outcomes in patients undergoing revision TKA. This study highlights the importance of heightened vigilance and tailored perioperative management for patients undergoing major surgeries in the background of SLE. Key Points • SLE significantly increases the risk of non-routine discharge, major blood loss, respiratory failure, acute kidney injury, and wound dehiscence, in patients undergoing aseptic and septic revision TKA. • Patients with SLE experience longer hospital stays and higher hospital costs compared to those without SLE. • The study's findings highlight the necessity for healthcare providers to consider the presence of SLE as a critical factor in preoperative planning and postoperative care to improve outcomes in revision TKA patients.

Use of extended curettage with osteotomy and fenestration followed by reconstruction with conservation of muscle insertion in the treatment of Enneking stage II locally aggressive bone tumor of the proximal extremities: resection and treatment of bone tumors.

BACKGROUND: The purpose of this study was to investigate the clinical efficacy of extended resection with osteotomy, fenestration and conservation of muscle (tendon) insertion in the treatment of bone tumors. METHODS: A total of 15 patients with locally aggressive bone tumors (Enneking stage II) in the adjacent muscle (tendon) insertion of the proximal extremity were enrolled in the present study (mean age of 29 years). Extended curettage of lesions with osteotomy, fenestration and/or conservation of muscle (tendon) insertion and internal fixation with a bone graft or bone cement was performed at stage I. Postsurgical brace protection was used for 4 to 12 weeks and the patients were periodically followed-up by X-ray and functional assessment. Recurrence, postsurgical Enneking score and outcome rating were assessed. RESULTS: Treated cases included 15 patients aged 29 ±7.75 years (range, 18 to 42) with a male to female ratio of 8:7. Six had a femoral tumor and nine had a humeral tumor. These tumors comprised three chondroblastomas, five giant-cell tumors and seven aneurysmal bone cysts. Follow-up for 48 ±12.95 months (range, 25 to 72) revealed that 13 of 15 (87%) patients exhibited no recurrence. Local recurrence was observed in a patient with an aneurysmal bone cyst (nine months) and one with a giant-cell tumor (12 months). Mean Enneking scores were 27 ±4.07 (range, 18 to 29). Except for the patient with the recurrent giant-cell tumor, all patients reported good (13%, 2 out of 15) or very good (80%, 12 out of 15) outcomes. Very good outcomes were reported in 92% of patients (12 out of 13) without recurrence. CONCLUSIONS: The procedures used in this study achieved high clinical efficacy, complete lesion removal, reduced recurrence and good restoration of joint function in patients with primary locally aggressive Enneking stage II bone tumors of the proximal extremities.

Dietary fungi in cancer immunotherapy: From the perspective of gut microbiota.

Immunotherapies are recently emerged as a new strategy in treating various kinds of cancers which are insensitive to standard therapies, while the clinical application of immunotherapy is largely compromised by the low efficiency and serious side effects. Gut microbiota has been shown critical for the development of different cancer types, and the potential of gut microbiota manipulation through direct implantation or antibiotic-based depletion in regulating the overall efficacy of cancer immunotherapies has also been evaluated. However, the role of dietary supplementations, especially fungal products, in gut microbiota regulation and the enhancement of cancer immunotherapy remains elusive. In the present review, we comprehensively illustrated the limitations of current cancer immunotherapies, the biological functions as well as underlying mechanisms of gut microbiota manipulation in regulating cancer immunotherapies, and the benefits of dietary fungal supplementation in promoting cancer immunotherapies through gut microbiota modulation.

The Septic Neutrophil-Friend or Foe.

ABSTRACT: Neutrophils play a critical role in the eradication of pathogenic organisms, particularly bacteria. However, in the septic patient the prolonged activation and accumulation of neutrophils may augment tissue and organ injury. This review discusses the different activation states and chemotaxis of neutrophils in septic patients. Neutrophil killing of bacteria and the formation of neutrophil extracellular traps represent important components of the innate immune response and they become dysregulated during sepsis, possibly through changes in their metabolism. Delayed neutrophil apoptosis may contribute to organ injury, or allow better clearance of pathogens. Neutrophils provide a friendly immune response to clear infections, but excessive activation and recruitment has the potential to turn them into potent foes.

Tibial component coverage affects tibial bone resorption and patient-reported outcome measures for patients following total knee arthroplasty.

PURPOSE: The aim of this study is to investigate the prognostic value of tibial component coverage (over-hang and under-hang) and the alignment of total knee arthroplasty (TKA) components 1 week after surgery. We select patient-reported outcome measures (PROMS) (the Knee Society score (KSS score) and the Western Ontario and McMaster Universities Osteoarthritis Index-pain score (WOMAC pain score)) and tibial bone resorption (TBR) 2 years after surgery as the end points. METHODS: The study retrospectively analyzed 109 patients undergoing TKA (fixed-bearing prosthesis with asymmetrical tibial tray) from January 2014 to December 2017 in Huashan Hospital. By using standard long-leg X-rays, anteroposterior (AP) and lateral X-rays of the knee, tibial component coverage (under-hang or over-hang), AP tibial-femoral anatomical angle (AP-TFA), AP femoral angle (AP-FA), AP tibial angle (AP-TA), and lateral tibial angle (L-TA) were measured at 1 week after surgery, while TBR was measured through postoperative 1-week and 2-year AP and lateral radiographs of the knee on three sides (medial side, lateral side on AP radiograph, and anterior side on lateral radiograph). The Pearson correlation analysis, simple linear regression, multiple linear regression, the Student's t test, and one-way ANOVA together with Tukey's post hoc test (or Games-Howell post hoc test) were used in the analyses. RESULTS: Tibial under-hang was more likely to appear in our patients following TKA (42%, medially, 39%, laterally, and 25%, anteriorly). In multivariate linear regression analysis of TBR, tibial under-hang (negative value) 1 week after surgery was positively correlated with TBR 2 years later on the medial (p = 0.003) and lateral (p = 0.026) side. Tibial over-hang (positive value) 1 week after surgery on the medial side was found negatively related with KSS score (p = 0.004) and positively related with WOMAC pain score (p = 0.036) 2 years later in multivariate linear regression analysis of PROMS. Both scores were better in the anatomically sized group than in the mild over-hang group (or severe over-hang) (p < 0.001). However, no significant relationship was found between the alignment of TKA components at 1 week after surgery and the end points (TBR and PROMS) 2 years later. CONCLUSION: Under-hang of the tibial component on both the medial and lateral sides can increase the risk of TBR 2 years later. Over-hang of tibial component on the medial side decreases the PROMS (KSS score and WOMAC pain score) 2 years later. An appropriate size of tibial component during TKA is extremely important for patient's prognosis, while the alignment of components might not be as important.

Nonanatomical Reduction of Femoral Neck Fractures in Young Patients (≤65 Years Old) with Internal Fixation Using Three Parallel Cannulated Screws.

PURPOSE: The study is aimed at investigating the association between different reduction classifications (anatomic reduction, positive buttress position reduction, and negative buttress position reduction) and two end points (complications and reoperations). METHODS: The study retrospectively analyzed 110 patients undergoing internal fixation with three parallel cannulated screws from January 2012 to January 2019 in Huashan Hospital. Based on the principles of the "Gotfried reduction," all enrolled patients were divided into three groups: anatomic reduction, positive buttress position reduction, and negative buttress position reduction intraoperatively or immediately after surgery. Clinical characteristics including age, sex, side, Garden classification, Pauwels classification, fracture level, reduction classification, Garden alignment index angles, cortical thickness index (CTI), tip-caput distance (TCD), angle of the inferior screw, and the two ending points (complications and reoperations) were included in the statistical analysis. The Mann-Whitney U-test, the chi-square test, Fisher's exact test, and multiple logistic regression analysis were used in the study. RESULTS: Of the 110 patients included in our study, the mean ± standard deviation (SD) of age was 51.4 ± 10.4 years; 41 patients showed anatomic reduction, 35 patients showed positive buttress position reduction, and 34 patients showed negative buttress position reduction. For the outcomes, 24 patients (anatomic reduction: 6 [14.6%]; positive buttress position reduction: 5 [14.3%]; negative buttress position reduction: 13 [38.2%]) had complications, while 18 patients (anatomic reduction: 5 [12.2%]; positive buttress position reduction: 3 [8.6%]; negative buttress position reduction: 10 [29.4%]) underwent reoperations after surgery. In the multivariate logistic regression analysis of complications, negative buttress position reduction (negative buttress position reduction vs. anatomic reduction, OR = 4.309, 95%CI = 1.137 to 16.322, and p = 0.032) was found to be correlated with higher risk of complications. The same variable (negative buttress position reduction vs. anatomic reduction, OR = 5.744, 95%CI = 1.177 to 28.042, and p = 0.031) was also identified as risk factor in the multivariate logistic regression analysis of reoperations. However, no significant difference between positive reduction and anatomical reduction was investigated in the analysis of risk factors for complications, not reoperations. CONCLUSION: Positive buttress position reduction of femoral neck fractures in young patients showed a similar incidence of complications and reoperations compared with those of anatomic reduction. For irreversible femoral neck fractures, if positive buttress position reduction has been achieved intraoperatively, it is not necessary to pursue anatomical reduction; however, negative reduction needs to be avoided.

Combined culture experiment of mouse bone marrow mesenchymal stem cells and bioceramic scaffolds.

Articular cartilage injuries are common orthopedic conditions that severely affect the quality of life of patients. Tissue engineering can facilitate cartilage repair and the key points involve scaffolding and seed cell selection. Pre-experiments found a range of microstructures of bioceramic scaffolds suitable for chondrocyte adhesion and proliferation, and maintaining chondrocyte phenotype. Three-dimensional cultures of bone marrow mesenchymal stem cell (BMSC) scaffolds were implanted into mice. According to the shape of the bioceramic scaffolds and the implantation time in vivo, RNA sequencing was performed on the removed scaffolds to explore the molecular mechanism. The in vitro bone plate culture can induce differentiation of chondrocytes, making culture different to that produced in vitro. Implantation of scaffolds in vivo increases the expression of bone-related genes. The ceramic rod-like material was found to be superior to the disc shape, and the bone repair effect was more marked with longer implantation times. Gene Ontology analysis revealed that 'cell chemotaxis', 'negative regulation of ossification' and 'bone development' pathways were involved in recovery. It was further confirmed that BMSCs were suitable as seed cells for cartilage tissue engineering, and that the ß-tricalcium phosphate scaffold maybe ideal as cartilage tissue engineering scaffold material. The present research provided new insights into the molecular mechanism of cartilage repair by BMSCs and bioceramic scaffolds. Bioinformatics analysis revealed that AMMECR1L-like protein, tumor necrosis factor-induced protein 2, inhibitor of nuclear factor-B kinase subunit and protein kinase C type and 'negative regulation of ossification' and 'bone development' pathways may be involved in osteoblast maturation and bone regeneration.

Predictive value of adipose to muscle area ratio based on MRI at knee joint for postoperative functional outcomes in elderly osteoarthritis patients following total knee arthroplasty.

BACKGROUND: The current research used a new index-adipose to muscle area ratio (AMR)-to measure fatness compared with body mass index (BMI) in elderly osteoarthritis (OA) patients following total knee arthroplasty. Our study aimed to test the relationship between the two indexes (AMR and BMI) and to examine whether AMR was a predictive factor of patient-reported outcome measures (PROMS) for elderly OA patients following total knee arthroplasty (TKA). METHODS: The retrospective data of 78 OA patients (older than 60 years) following TKA was included in our study. Clinical features of patients included age, BMI, sex, AMR, side of the implant, time of follow-up, complications, the Knee Society Score (KSS score), and the Hospital for Special Surgery knee score (HSS score). The area of adipose tissue and muscle tissue was measured on the cross section (supra-patella, midline of the patella, joint line of the knee) of the knee magnetic resonance imaging (MRI). AMR was calculated as the average of adipose to muscle area ratio at the three levels. The Pearson correlation analysis, simple linear regression, and multiple linear regression were used to study the relationship between BMI, AMR, and PROMS (KSS total-post score and HSS-post score) in the study. RESULTS: Of all patients, the mean (± standard deviations (SD)) of age was 67.78 ± 4.91 years. For BMI and AMR, the mean (± SD) were 26.90 ± 2.11 and 2.36 ± 0.69, respectively. In Pearson correlation analysis, BMI had a good correlation with AMR (r = 0.56, p = 0.000), and AMR (r = - 0.37, p = 0.001, HSS-post score; r = - 0.43, p = 0.000, KSS total-post score) had better correlations with PROMS postoperatively compared with BMI (r = - 0.27, p = 0.019, HSS-post score; r = - 0.33, p = 0.003, KSS total-post score). In multivariate linear regression analysis, AMR was negatively correlated with KSS total-post score as well as HSS-post score, while BMI was not. As for patients with complications, AMR values were between the 3rd quartile and 4th quartile of the AMR value in the entire study cohort. CONCLUSIONS: In this study, the new obesity evaluation indicator-AMR, which was well related with BMI, was found to be a predictor of PROMS (KSS total-post score and HSS-post score) in elderly OA patients following TKA.