Search Results (260)

Background/Objectives: Trochanteric femoral fractures pose significant surgical challenges, particularly in elderly patients. Intramedullary nailing (IMN) and plate fixation (PF) are the primary operative strategies, yet their comparative efficacy and safety remain debated. This meta-analysis synthesizes randomized controlled trials (RCTs) to evaluate clinical, functional, perioperative, and biomechanical outcomes of IMN versus PF specifically in trochanteric fractures. Methods: A systematic search of six databases was conducted up to 20 May 2024, to identify RCTs comparing IMN and PF in adult patients with trochanteric femoral fractures. Data extraction followed PRISMA guidelines, and outcomes were pooled using random-effects models. Subgroup analyses examined the influence of fracture stability, implant type, and patient age. Risk of bias was assessed using the Cochrane RoB 2.0 tool. Results: Fourteen RCTs (n = 4603 patients) were included. No significant differences were found in reoperation rates, union time, implant cut-out, or mortality. IMN was associated with significantly reduced operative time (MD = −5.18 min), fluoroscopy time (MD = −32.92 s), and perioperative blood loss (MD = −111.68 mL). It also had a lower risk of deep infection. Functional outcomes and anatomical results were comparable. Subgroup analyses revealed fracture stability and nail type significantly modified operative time, and compression screws were associated with higher reoperation rates than IMN. Conclusions: For trochanteric femoral fractures, IMN and PF yield comparable results for most clinical outcomes, with IMN offering some advantages in surgical efficiency and perioperative morbidity, though functional outcomes were comparable. Implant selection and fracture stability influence outcomes, supporting individualized surgical decision making. Full article

A new, simple machine was developed to address a long-standing challenge in biomedical and mechanical engineering: how to enhance the primary stability and long-term integration of screws and implants in low-density or heterogeneous materials, such as bone or composite substrates. Traditional screws often rely solely on external threading for fixation, leading to limited cohesion, poor integration, or early loosening under cyclic loading. In response to this problem, we designed and built a novel device that leverages a unique mechanical principle to simultaneously perforate, collect, and compact the substrate material during insertion. This mechanism results in an internal material interlock, enhancing cohesion and stability. Drawing upon principles from physics, chemistry, engineering, and biology, we evaluated its biomechanical behavior in synthetic bone analogs. The maximum insertion (MIT) and removal torques (MRT) were measured on synthetic osteoporotic bones using a digital torquemeter, and the values were compared directly. Experimental results demonstrated that removal torque (mean of 21.2 Ncm) consistently exceeded insertion torque (mean of 20.2 Ncm), indicating effective material interlocking and cohesive stabilization. This paper reviews the relevant literature, presents new data, and discusses potential applications in civil infrastructure, aerospace, and energy systems where substrate cohesion is critical. The findings suggest that this new simple machine offers a transformative approach to improving fixation and integration across multiple domains. Full article

Background and Objectives: Adequate bone quality is essential for promoting initial bone ingrowth and preventing early migration during cementless total knee arthroplasty (TKA). However, gold-standard criteria for identifying suitable bone strength have yet to be established. Dual-energy computed tomography (DECT)-based volumetric bone mineral density (vBMD) is an emerging tool for assessing bone quality. This study aimed to determine whether DECT-derived vBMD can accurately predict suitable bone strength for cementless TKA. Materials and Methods: A total of 190 patients undergoing primary TKA with a standardized posterior-stabilized implant were prospectively enrolled. Prior to TKA, DECT-derived vBMD was measured in the femoral box region. Actual bone strength was evaluated using an indentation test on resected femoral box specimens. Correlation and linear regression analyses were performed to assess the relationship between DECT vBMD and actual bone strength. Receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) calculations were used to determine the optimal cut-off value and diagnostic accuracy of DECT vBMD in identifying candidates suitable for cementless TKA. Results: DECT-derived vBMD exhibited a strong correlation with actual bone strength (correlation coefficient = 0.719, p < 0.01), while linear regression analysis revealed a moderate association (R² = 0.51, p < 0.01). In addition, it demonstrated excellent diagnostic performance in predicting adequate bone quality for cementless TKA, yielding an AUC of 0.984, with a sensitivity of 91.9% and a specificity of 92.0%. Conclusions: DECT-derived vBMD is a reliable and accurate tool for assessing bone strength around the knee and predicting the suitable bone quality for cementless TKA. Full article

Using ultra-short dental implants is a promising alternative to extensive bone grafting procedures for patients with atrophic posterior mandibles and vertical bone loss. However, the amount of insertion torque (IT) applied during implant placement significantly influences stress distribution in the peri-implant bone, which affects implant stability and long-term success. Materials and Methods: This study used finite element analysis (FEA) to examine how different insertion torques (35 N·cm and 75 N·cm) affect stress distribution in cortical and trabecular bone types D2 and D4 surrounding ultra-short implants. Von Mises equivalent stress values were compared with ultimate bone strength thresholds to evaluate the potential for microdamage during insertion. Results: The findings demonstrate that increasing IT from 35 N·cm to 75 N·cm led to a significant increase in peri-implant bone stress. Specifically, cortical bone stress in D4 bone increased from approximately 79 MPa to 142 MPa with higher IT, exceeding physiological limits and elevating the risk of microfractures and bone necrosis. In contrast, lower IT values kept stress within safe limits, ensuring optimal primary stability without damaging the bone. These results underscore the need to strike a balance between achieving sufficient implant stability and avoiding mechanical trauma to the surrounding bone. Conclusions: Accurate control of insertion torque during the placement of ultra-short dental implants is crucial to minimize bone damage and promote optimal osseointegration. Excessive torque, especially in low-density bone, can compromise implant success by inducing excessive stress, thereby increasing the risk of early failure. Full article

Background/Objectives: Ketorolac is commonly used for pain management after orthopedic surgery, but concerns regarding its effects on postoperative complications remain. This study evaluates the impact of ketorolac use on short- and long-term outcomes in adult patients undergoing uncemented primary total hip arthroplasty (THA), where implant stability relies on biological fixation through bone ingrowth into a porous-coated prosthesis rather than bone cement. Methods: A retrospective cohort study was conducted using the TriNetX Research Network. Patients aged 18 years or older who underwent uncemented primary THA between 1 January 2004 and 1 January 2024 were included. Two cohorts were compared: those who received ketorolac on the day of or within one week of surgery and those who did not. Cohorts were propensity score-matched. Outcomes were assessed at 30 days, 1 year, and 5 years postoperatively. Results: At 30 days, ketorolac use was associated with significantly lower risks of transfusion (RR: 0.6, p < 0.01). However, it was linked to higher rates of acute posthemorrhagic anemia (RR: 1.2, p < 0.01) and periprosthetic fracture (RR: 1.4, p < 0.01). At 1 year, ketorolac use was associated with reduced risks of death (RR: 0.8, p < 0.01) and transfusion (RR: 0.7, p < 0.01), but increased risks of acute posthemorrhagic anemia (RR: 1.2, p < 0.01), deep surgical site infection (SSI) (RR: 1.8, p = 0.01), superficial SSI (RR: 1.9, p < 0.01), periprosthetic joint infection (RR: 1.1, p < 0.01), wound dehiscence (RR: 1.2, p < 0.01), periprosthetic mechanical complication (RR: 1.2, p < 0.01), and periprosthetic fracture (RR: 1.5, p < 0.01). Conclusions: Our findings highlight the complex risk profile of ketorolac in uncemented THA patients and suggest that clinicians should carefully consider individual patient factors and engage in shared decision-making when counseling patients on the use of ketorolac in the perioperative setting. Full article

Background: In modern dentistry, alveolar socket preservation after tooth extraction plays a critical role in maintaining the alveolar ridge for future dental implants. This retrospective clinical study evaluated bone-level changes 15 years after immediate implant placement, coupled with alveolar ridge preservation. Methods: Fifty non-smoking patients aged 25 to 75 (30 males and 20 females) who underwent single-implant rehabilitation in both anterior and posterior regions of the upper and lower jaws were included. The study examined bone levels and implant survival over time, using standardized intraoral radiographs at 1, 5, and 15 years post-loading. Implants were placed immediately after atraumatic extraction, and the residual gap was grafted with bovine hydroxyapatite and covered with a collagen membrane. The primary outcome was bone-level stability, while secondary outcomes included implant failure. No temporary crowns or removable dentures were provided during healing. Radiographs were digitized for detailed analysis. Results: The results for 50 patients with immediate implant placement showed that bone-resorption levels were significantly higher in the upper jaw than in the lower jaw. Conclusions: Posterior implants exhibited greater bone loss than anterior implants, particularly at 1 year and 15 years, while no implant failures occurred. Full article

Total hip arthroplasty is one of the most common and rapidly growing surgical procedures, with over one million cases performed annually in the United States. Despite high success rates, revision surgeries remain a significant concern due to complications such as aseptic loosening, often resulting from inadequate primary implant stability. This study presents an automated computational framework that integrates three-dimensional preoperative planning and finite element modeling to predict the primary stability of hip implants. Data obtained from the virtual surgery phase are used to generate subject-specific finite element models, which are executed on high-performance computing systems. The simulation evaluates implant stability by analyzing the contact interaction between the bone and the implant. The pipeline is demonstrated using data from the open-source HFValid collection and a commercial implant. Automation substantially reduced the time required to set up simulations, improving the efficiency on high-performance infrastructure. This integrated computational approach bridges the gap between biomechanical modeling and clinical decision-making and can serve as a preclinical tool for identifying personalized implant strategies and for conducting large-scale virtual cohort studies. Full article

Implant primary stability is a prerequisite for obtaining osseointegration and clinical success. Insertion torque (IT) is measured during implant placement and is expressed in Ncm. It represents the quantification of the frictional force experienced by the implant as it progresses apically through a rotational motion along its axis. Usually, to achieve osseointegration, a value within the range of 20–40 Ncm is desirable. Below a threshold of 20 Ncm, implants have a decrease in survival rate, while implant stability is guaranteed above 20 Ncm. The main goal of this study was to evaluate whether high values of IT affect osseointegration, implant health, and healing, by highlighting the positive and negative effects of IT > 50 Ncm on peri-implant bone, soft tissues, and long-term stability. This scoping review considered randomized clinical trials, observational studies, and cohort studies. Studies failing to meet the predefined inclusion criteria were excluded from the analysis. The review process adhered to the Preferred Reporting Items for Scoping Reviews (PRISMA-ScR) guidelines. Ultimately, a total of 11 studies were included in the final synthesis. Based on the studies included, the literature suggests that high values of IT guarantee adequate primary stability and better osseointegration. However, high IT is significantly associated with greater marginal bone loss, depending on bone density. Accordingly, IT values > 50 Ncm may provoke greater compressive forces with a negative impact on the jawbone. An elevated strain on the bone can induce necrosis and ischemia, due to an alteration of circulation, which in turn is responsible for marginal bone loss and reduced osseointegration. Lack of osseointegration ultimately leads to an early implant failure. As concerns soft tissue recession, a higher decrease is measured in implants placed with high-insertion torque. Nonetheless, additional clinical trials are warranted to assess long-term outcomes, quantify the incidence of these complications, and explore the impact of emerging clinical variables. Full article

Achieving the appropriate primary stability for immediate or early loading in areas with low-density bone, such as the posterior maxilla, is challenging. A three-dimensional (3D) stabilization implant design featuring a tapered body with continuous cutting flutes along the length of the external thread form, with a combination of curved and linear geometric surfaces on the thread’s crest, has the capacity to enhance early biomechanical and osseointegration outcomes compared to implants with traditional buttressed thread profiles. Commercially available implants with a buttress thread design (TP), and an experimental implant that incorporated the 3D stabilization trimmed-thread design (TP 3DS) were used in this study. Six osteotomies were surgically created in the ilium of adult sheep (N = 14). Osteotomy sites were randomized to receive either the TP or TP 3DS implant to reduce site bias. Subjects were allowed to heal for either 3 or 12 weeks (N = 7 sheep/time point), after which samples were collected en bloc (including the implants and surrounding bone) and implants were either subjected to bench-top biomechanical testing (e.g., lateral loading), histological/histomorphometric analysis, or nanoindentation testing. Both implant designs yielded high insertion torque (ITV ≥ 30 N⋅cm) and implant stability quotient (ISQ ≥ 70) values, indicative of high primary stability. Qualitative histomorphological analysis revealed that the TP 3DS group exhibited a continuous bone–implant interface along the threaded region, in contrast to the TP group at the early, 3-week, healing time point. Furthermore, TP 3DS’s cutting flutes along the entire length of the implant permitted the distribution of autologous bone chips within the healing chambers. Histological evaluation at 12 weeks revealed an increase in woven bone containing a greater presence of lacunae within the healing chambers in both groups, consistent with an intramembranous-like healing pattern and absence of bone dieback. The TP 3DS macrogeometry yielded a ~66% increase in average lateral load during pushout testing at baseline (T = 0 weeks, p = 0.036) and significantly higher bone-to-implant contact (BIC) values at 3 weeks post-implantation (p = 0.006), relative to the traditional TP implant. In a low-density (Type IV) bone model, the TP 3DS implant demonstrated improved performance compared to the conventional TP, as evidenced by an increase in baseline lateral loading capacity and increased BIC during the early stages of osseointegration. These findings indicate that the modified implant configuration of the TP 3DS facilitates more favorable biomechanical integration and may promote more rapid and stable bone anchorage under compromised bone quality conditions. Therefore, such improvements could have important clinical implications for the success and longevity of dental implants placed in regions with low bone density. Full article

Background/Objectives: The achievement of primary stability in low-density bone represents a critical endpoint in clinical practice. The aim of the present investigation was to evaluate the effectiveness of different drilling osteotomy techniques on polyurethane bone substitutes in vitro. Methods: A total of 320 osteotomies have been conducted on 10 pound per cubic feet (PCF) and 20PCF, respectively, with and without cortical layer. The simultaneous and progressive drilling protocol has been conducted at two different rotational speeds considering two different implant profiles (TAC conical vs. NT cylindrical implants). The study variables were insertion torque, removal torque, and resonance frequency analysis (RFA). Results: A significantly higher insertion torque, removal torque, and resonance frequency analysis RFA was detected at low speed with simultaneous drilling protocol (RPM) (p < 0.05). A TAC implant produced an increased implant stability compared to NT implants in all conditions tested (p < 0.05). Conclusions: The conical TAC implant showed higher implant stability in low-density polyurethane, and it is strongly recommended in critical bone quality. Simultaneous drilling osteotomy at low speed could further improve torquing positioning and significantly achieve primary stability in this condition. Full article

Background: The HeartMate 3 (HM3) left ventricular assist device (LVAD) has demonstrated improved clinical outcomes in patients with advanced heart failure (HF). However, the influence of underlying HF etiology—ischemic cardiomyopathy (ICM) versus dilated cardiomyopathy (DCM)—on post-implantation outcomes remains insufficiently characterized. Objectives: This paper aims to evaluate early postoperative outcomes following HM3 LVAD implantation in patients with ICM versus DCM and to identify the preoperative hemodynamic and clinical predictors of early mortality and hemodynamic instability. Methods: We conducted a retrospective single-center cohort study of 30 patients who underwent HM3 LVAD implantation between 2017 and 2024. Patients were stratified by HF etiology (ICM, n = 17; DCM, n = 13), and preoperative clinical, echocardiographic, and right heart catheterization data were analyzed. The primary endpoint was 30-day postoperative survival. Secondary endpoints included postoperative hemodynamic stability and the need for vasopressor support. Results: Non-survivors (n = 13) demonstrated elevated central venous pressure (>16.5 mmHg), mean right ventricular pressure (>31.5 mmHg), and pulmonary vascular resistance (>7.5 Wood units), in addition to higher preoperative creatinine levels and longer cardiopulmonary bypass times. Vasopressor requirement postoperatively was associated with elevated pre-implant systolic pulmonary artery pressure. Conclusions: Preoperative right-sided pressures and renal dysfunction are strong predictors of early mortality following HM3 LVAD implantation. Patients with ICM exhibit greater early left ventricular recovery compared to those with DCM. These findings underscore the importance of comprehensive and personalized preoperative risk stratification—particularly in patients with DCM and pulmonary hypertension—to optimize postoperative outcomes and guide patient selection for durable LVAD support. Full article

Objectives: This study aims to investigate the underlying causes of dental implant failure, focusing on implant-related complications and associated risk factors. Understanding these factors will help improve treatment planning and enhance implant success rates. Methods: A retrospective case-control study was conducted using clinical, medical, surgical, and radiographic records of patients who underwent dental implant removal due to complications. Key factors analyzed included patient-related variables (age, gender, medical conditions, periodontal disease), implant-related factors (implant site, implant system, restoration status), and procedural aspects (previous surgical interventions and reasons for implant removal). Results: The findings revealed that implant type (p = 0.004) and type of restoration (p = 0.001) significantly influenced implant survival. Gender (p = 0.001), medical conditions, smoking status (p = 0.004), and restoration status (p = 0.005) were significantly associated with specific failure mechanisms. Lack of osseointegration (36.4%) and absence of primary stability (22.4%) were the predominant causes of implant failure. Prior surgical interventions (p = 0.001) and decisions for re-implantation (p = 0.005) significantly affected implant removal frequency. Conclusions: Implant survival is influenced by multiple factors, with implant type, restoration type, and gender playing key roles in failure outcomes. Patient-specific risk assessment, particularly regarding medical conditions and smoking, meticulous surgical technique, and appropriate prosthetic planning, is vital for improving implant longevity and minimizing failure rates. Full article

Background/Objectives: The rehabilitation of severely resorbed anterior alveolar ridges presents significant clinical challenges due to esthetic demands and the limited bone volume in this region. Basal cortical implants, which are designed to engage dense basal bone, could offer an alternative by providing stable anchorage in compromised sites. Methods: This report evaluates the ARi^® Implant System, which features cortical anchorage and a calcium-incorporated nanostructured surface (XPEED^®) in two anterior ridge defect cases. Soft tissue augmentation using a vascularized interpositional periosteal (VIP) flap was applied in one case, and biphasic calcium phosphate (BCP) grafting and collagen membranes were employed for ridge contouring in both cases. Results: At a two-year follow-up, both cases showed stable peri-implant tissues and satisfactory esthetic results. Conclusions: Although basal cortical implants provide good primary stability, their use does not eliminate the need for bone augmentation, especially in the anterior esthetic region. Future clinical studies are required to substantiate long-term outcomes and broader applicability. Full article

The long-term effectiveness of osseointegrated implants is heavily dependent on the short-term stability, primarily achieved immediately after surgery through a mechanical connection between the bone and the implant. The most common implant designs nowadays are straight and rely on screw or press-fit fixtures. Despite the promising results achieved by current transfemoral implants, the incidence of early failures and complications is still high. Starting from the hypothesis that a patient-specific approach could lead to better primary stability immediately post-surgery, this study aims to investigate the effect of implant design on primary stability. This was performed by analyzing two patient-specific implants, customized according to the medullary canal morphology, and a simple straight implant as the reference standard. To quantitatively assess the primary stability, a comparative computational analysis was conducted to examine the effective contact area, the relative micromotion, and the stress distribution at the interface between the bone and the implant stem during a static load-bearing exercise. The results showed that implants that follow the curvature of the residual femur provide lower micromotion values and a wider contact area, with a reduction of up to 30.4% and an increase of 10.8%, respectively, compared to the straight design, leading to a more homogeneous load distribution. Patient-specific prosthetic implants allow a more homogenous contact distribution that could lead to higher primary stability by reducing micromotion at the bone–implant interface concerning the straight profile, lowering the risk of loosening related to the short-term stability. Full article

Micro-computed tomography assessment of osteochondral microstructural properties of the distal femur and proximal tibia was comprehensively conducted to compare adult patients with knee rheumatoid arthritis (RA) and primary knee osteoarthritis (KOA), with special focus on the effects of knee malalignment. This study encompassed 402 bone samples divided into three groups: the RA group [patients who were subjected to total knee arthroplasty (TKA) due to RA, n = 23, age: 61 ± 10 years], the KOA group [individuals subjected to TKA due to KOA, n = 24, age: 71 ± 9 years] and the control group [sex-matched cadavers without degenerative knee diseases, n = 20, age: 67 ± 11 years]. Our data revealed that the RA, KOA, and control groups differ significantly in osteochondral microstructural properties depending on the knee alignment. Specifically, increasing femoral and tibial cortical porosity, coupled with thinner articular cartilage, were noted in the RA and KOA groups, compared to the controls. Furthermore, larger femoral and tibial cortical pores, lower tibial and femoral subchondral trabecular bone fraction, and thinner tibial articular cartilage were noted in the RA group in comparison to the KOA group, implying that the medial-to-lateral load distribution in the knee joint could be most affected in these patients. Our data illustrated that the thinnest cartilage, a thicker and less porous cortex, along with lower trabecular bone volume, were present in the lateral femoral and tibial condyles of RA individuals with valgus knee alignment. Observed subchondral trabecular microarchitectural alterations could be morphological factors contributing to different effects of surgical treatment and variable implant stability in individuals with RA, warranting further research. Full article