Search Results (158)

Background/Objectives: Mechanical neutrality has long been regarded as the principal alignment target in total knee arthroplasty (TKA). However, radiographic neutrality does not necessarily reflect physiological morphology or patient perception. This study aimed to evaluate one-week postoperative patient-perceived lower-limb straightness after unrestricted kinematic alignment (KA) TKA and to examine its relationship with radiographic alignment parameters and functional findings. Methods: A total of 175 patients (203 knees) who underwent unrestricted KA-TKA were retrospectively reviewed. Pre- and postoperative radiographs, clinical assessments, and a study-specific, non-validated questionnaire were analyzed one week postoperatively. Patient perception of straightness was assessed using the Straightness Visual Analog Scale (S-VAS) and the Straightness Satisfaction Visual Analog Scale (SS-VAS). Radiographic parameters included the hip–knee–ankle angle (HKAA), the medial proximal tibial angle (MPTA), the mechanical lateral distal femoral angle (mLDFA), the joint line convergence angle (JLCA), and Coronal Plane Alignment of the Knee (CPAK) patterns. Correlative analyses between VAS scores and radiographic and clinical parameters were examined. Results: Preoperatively, 85% of knees were perceived as bowed, and all were reported as straight after surgery. Among knees not perceived as bowed preoperatively, 60% were newly perceived as straight postoperatively, while 40% remained perceived as straight. Postoperative satisfaction was high (S-VAS 88.9 ± 11.6; SS-VAS 92.3 ± 12.9). Associations between S-VAS/SS-VAS and HKAA were weak but statistically significant, whereas both showed moderate positive correlations with postoperative knee extension (S-VAS r = 0.54; SS-VAS r = 0.59). Conclusions: At one week after surgery, patients tended to perceive lower-limb straightness as being associated with restoration of physiological morphology and improved knee extension rather than with radiographic mechanical neutrality. Patient-perceived straightness reflects an individualized and natural sense of limb alignment (“inherent straightness”) and should be interpreted as an exploratory, patient-centered concept based on an early postoperative test, supporting a personalized framework for alignment evaluation in unrestricted KA-TKA. Full article

Background/Objectives: Femoral anteversion (FA) is the angle between the femoral neck axis (FNA) and the posterior condylar axis (PCA). Surgeons generally estimate intraoperative femoral stem anteversion visually relative to the PCA, but this method can be challenging even for experienced surgeons. This study aimed to find an anatomical proximal landmark within a CT coordinate system for intraoperative estimation of femoral stem anteversion. Methods: Seventy patients were included. The anterior lesser trochanter line (ALTL) was defined as the line passing through two tangent points: one between the rounded part of the lesser trochanter and the medial edge of the anterior lesser trochanter cortex, and the other between the anterior cortex of the femur and the lateral edge of the anterior lesser trochanter cortex at the level of the lesser trochanter tip. The following angles were measured and analyzed: Angle 1 (angle between the FNA and the ALTL), Angle 2 (angle between the ALTL and the PCA), and Angle 3 (angle between the FNA and the PCA [FA]). Results: In all measurements, the inter-observer and intra-observer intraclass correlation coefficients exceeded 0.81. Angle 1 negatively correlated with Angle 2 (r = −0.79, p < 0.01), whereas Angle 1 positively correlated with Angle 3 (r = 0.70, p < 0.01). Conclusions: We found a consistent relationship between the ALTL and FA, and the ALTL may serve as a proximal landmark for intraoperative estimation of femoral stem anteversion during anterior or anterolateral approaches. Full article

Background: The objective of this study was to evaluate the short-term clinical and radiological outcomes of a conservative cementless stem (Minima) in total hip arthroplasty (THA) for patients presenting with a narrow femoral canal. Methods: We retrospectively analyzed 18 patients (18 THAs) who received a size 1 Minima stem between 2018 and 2022. Clinical assessment was performed using the Harris Hip Score (HHS). Radiological evaluation focused on stem migration, trabecular bone development, cortical hypertrophy, and the presence of radiolucent or reactive lines. Implant survival was determined using Kaplan–Meier analysis. Results: The mean patient age was 51.6 years, with an average follow-up of 57 months. The mean HHS improved significantly from 38.3 preoperatively to 96.4 at the final evaluation (p < 0.001). Initial stem migration occurred in two hips (11.1%) within the first 6 postoperative months, with no further progression or loosening observed thereafter. Bony trabecular development was identified in Gruen zones 3 (27.8%), 4 (5.5%), and 5 (16.7%). Reactive lines were present around four stems (zones 3–5). One intraoperative complication (5.5%) occurred (acetabular component migration during trial reduction), which required screw fixation. No revisions were performed. Both clinical and radiological implant survival at the final follow-up was 100.0%. Conclusions: At a mean follow-up of 57 months, the use of the size 1 Minima stem in patients with a narrow femoral canal demonstrated excellent clinical and radiological outcomes. These findings suggest that this conservative stem is a reliable option for this specific patient population. Full article

Introduction: Medial compartment knee osteoarthritis (OA) is characterized by varus deformity. A medial open-wedge high tibial osteotomy (MOWHTO), frequently invoked in the treatment of this deformity, affects the knee as well as the ankle joints. This study aims to evaluate the radiological and clinical effects of a MOWHTO on the ankle joint. Materials and Methods: A retrospective analysis was conducted with data from 110 patients (mean age: 52 years; 74.5% female) who underwent a MOWHTO between 2020 and 2023. Radiographic assessments were conducted both preoperatively and one year after surgery using full-length weight-bearing radiographs. The measurements included several alignment parameters such as the hip–knee–ankle angle (HKA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), lateral distal tibial angle (LDTA), and talar tilt. Clinical outcomes were assessed using the Lysholm knee score and the American Orthopedic Foot and Ankle Society (AOFAS) ankle score. Results: While changes in the LDTA demonstrated a small effect size (d = 0.225), moderate-to-large effect sizes were observed in key alignment parameters (MPTA (d = 0.838), the JLCA (d = 0.798), and talar tilt (d = 0.752)), all of which showed statistically significant differences indicative of a correction in the joint alignment of potential clinical significance. Median Lysholm and AOFAS scores at one year were 90 and 100, respectively, indicating favorable clinical outcomes. No significant difference in outcomes was observed based on the amount of correction. Conclusions: An MOWHTO not only restores knee alignment but also significantly improves ankle alignment in the coronal plane. These findings suggest that an MOWHTO is associated with the restoration of knee alignment and with improvements in ankle alignment in the coronal plane. Full article

Background: The visual attention tracking task plays a pivotal role in studying posture control and gait regulation. This study aims to explore the effects of visual attention tracking tasks on gait performance in young adults, providing a theoretical basis for gait optimization strategies through dual-task training. Method: Twenty healthy young males were recruited. Participants in the experimental group performed a multi-objective tracking task while walking (dual-task, DT), while the control group performed only walking (single-task, ST). The Vicon motion capture system and gait analysis system were used to collect full-body kinematic and ground reaction force data. The symmetry index of key spatiotemporal parameters and continuous relative phase (CRP) metrics were calculated to assess gait symmetry and inter-joint coordination. Result: The dual-task condition led to significant alterations in gait patterns, characterized by increased stride time and frequency, as evidenced by a longer gait line and greater foot inclination angle. Furthermore, inter-joint coordination was disrupted, demonstrated by elevated magnitude of absolute relative phase values at the hip–knee and knee–ankle joints, alongside more variable continuous relative phase trajectories. Conclusions: Visual attention tracking during walking significantly compromises gait symmetry and inter-joint coordination in young adults, suggesting that divided attention during athletic activities may elevate injury risk and should be considered in training program design. Full article

Background: The purpose was to compare clinical and radiologic outcomes in patients who underwent total knee arthroplasty (TKA) using the medial stabilizing technique (MST) for severe varus knee with either measured resection technique (MRT) or gap balance technique (GBT). Methods: Between February 2018 and August 2020, a total of 236 knees with an HKA angle greater than 15° were enrolled in this study. Propensity score matching (1:1) was done based on age, sex, body mass index (BMI), and preoperative hip-knee-ankle (HKA) angle. 67 knees were enrolled in MRT (group M) and GBT (group G), respectively. The mean follow-up duration was 76.2 and 72 months in Groups M and G. Clinical and radiologic outcomes, including hip-knee-ankle (HKA) angle, joint line distance, and femoral component rotation angle (FCRA), were compared between the groups. Results: Preoperative clinical and radiological measurements had shown no statistical significance between both groups. The postoperative radiologic measurements, including HKA angle, joint line distance, and FCRA, were not significantly different. Postoperative WOMAC index, KSKS, and KSFS were also not significantly different between both groups. Conclusions: In patients with severe varus deformity undergoing TKA with MST, clinical and radiographic outcomes—including limb alignment, joint line position, and femoral component rotation—were comparable between MRT and GBT on mid-term follow-up data. Full article

Aim: Periprosthetic fracture-related infections (PFRIs) are a serious complication of total arthroplasty, with incidence rates increasing in line with the growing number of joint replacements. PFRI can lead to prolonged hospitalization, multiple surgical procedures and suboptimal functional outcomes. The diagnosis of PFRI remains challenging due to the overlap of clinical symptoms with other post-traumatic conditions, and identification of the pathogen often fails through conventional methods. This study also highlights the importance of a personalized medicine approach in managing PFRI, where diagnostic and therapeutic decisions are tailored to the individual patient’s comorbidities, immune status and bone healing capacity. By integrating clinical, microbiological and imaging data, our findings support precision-based strategies to optimize outcomes and minimize complication. Methods: This retrospective case series was conducted at the Unit of Osteoarticular Infection of the University of Turin, Italy, from January 2018 to December 2023. Patients who developed septic complications after open reduction and internal fixation (ORIF) of periprosthetic fractures involving hip or knee implants were included. The infection was diagnosed in accordance with established guidelines, and treatment decisions were based on clinical, microbiological and radiological findings. Results: In the present study, periprosthetic fractures complicated by infections were identified in nine patients (5.4%), constituting a small but significant subset of cases. The cases were then categorized into four clinical scenarios based on the following variables: joint involvement, fracture healing and infection progression. Scenario A, involving fractures without prosthetic involvement and unhealed fractures, included three patients (33%) and was treated with debridement and change of the fixation device. Scenario B, involving fractures without prosthetic involvement but with healed fractures, involved one patient (11%), where the ongoing infection was confirmed despite the healed fracture and where the device could be removed. The third scenario (C), which pertains to cases involving prosthetic involvement, included three patients (33%) who required replacement or removal of the prosthesis and, in some cases, a second stage. The fourth scenario, involving patients with limited operability, included two patients (22%) for whom no surgery was performed. Despite the significant clinical challenges encountered, the paucity of literature on the management of periprosthetic fractures with septic complications is limited, highlighting the need for further research in this understudied area. Conclusions: PFRI remains a challenging complication that necessitates a multidisciplinary approach to diagnosis and treatment. Despite advances in imaging and microbiological testing, the early detection and identification of pathogens remain challenging, emphasizing the necessity for enhanced diagnostic methods. This study offers valuable insights into the management of PFRI and provides a foundation for future research to develop optimal diagnostic and therapeutic strategies. Full article

Osteoarthritis (OA), a degenerative joint disease primarily affecting the hips and knees, is characterized by multifactorial dysregulation of chondrocyte homeostasis and currently lacks curative treatment options. Intra-articular hyaluronic acid (HA) injections have clinically provided symptomatic relief for three decades; however, HA’s rapid in vivo degradation by free radicals and hyaluronidases limits its efficacy. We hypothesized that adding niacinamide (vitamin B3) to linear HA hydrogels would provide ancillary anti-inflammatory and anti-catabolic properties, thereby improving HA-based viscosupplementation therapy. This preliminary preclinical mechanistic study investigated the functional effects of incorporating niacinamide into linear HA-based hydrogels using in vitro cellular models. Initially, Raw 264.7 macrophages and C28/I2 or SW1353 human chondrocytes were pre-treated with varying concentrations of HA/B3, with or without lipopolysaccharide (LPS) or interleukin-1β (IL-1β), respectively. Subsequently, pro-inflammatory and pro-catabolic markers were quantified biochemically. Results demonstrated that HA/B3 hydrogels exhibited enhanced functional stability compared to HA alone and possessed significant anti-inflammatory and anti-catabolic properties, without inducing cytotoxicity in either cell line. In Raw 264.7 macrophages, HA/B3 inhibited LPS-induced tumor necrosis factor-α (TNF-α) release and suppressed cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) protein expression. In vitro, HA/B3 hydrogels reduced IL-1β-induced IL-6 production in primary chondrocytes by 16% and suppressed PGE₂ concentration in both macrophages and chondrocytes by 60%, effects superior to HA alone. Finally, a rat primary articular chondrocyte model suggested slight anti-hypertrophic effects of HA/B3 in vitro. Collectively, these findings suggest that HA/B3 hydrogels possess anti-arthritic potential, highlighting a novel strategy for next-generation viscosupplement systems. Full article

Background/Objectives: Hip osteoarthritis (HOA) is a progressive joint disease characterized by cartilage loss, subchondral bone changes, and synovial inflammation. While tumor necrosis factor receptor 1 (TNFR1), interleukin-6 (IL-6), and transforming growth factor-beta 1 (TGF-β1) are recognized as key mediators of joint pathology, their compartment-specific expression in the human hip synovium remains insufficiently characterized. Therefore, we aimed to investigate their localization and expression in the intimal and subintimal compartments of synovial tissue in patients with HOA compared to controls (CTRL). Methods: Synovial membrane samples were obtained from 19 patients with primary HOA undergoing total hip arthroplasty and 10 CTRL subjects undergoing arthroplasty for acute femoral neck fracture without HOA. Specimens were processed for hematoxylin and eosin (H&E) and immunofluorescence staining. Expression of TNFR1, IL-6, and TGF-β1 was quantified in the intima and subintima using ImageJ analysis. Group differences were assessed using two-way Analysis of variance (ANOVA) with Tukey’s test when assumptions were met; for heteroscedastic outcomes we applied Brown–Forsythe ANOVA with Dunnett’s T3 multiple comparisons. Results: Histological analysis confirmed synovitis in HOA samples, with intimal hyperplasia and mononuclear infiltration. IL-6 was significantly upregulated in the intima of HOA synovium compared with CTRLs, while subintimal expression remained unchanged. In contrast, TGF-β1 expression was reduced in the HOA intima, eliminating the normal intima–subintima gradient. For TNFR1, the within-HOA contrast (int > sub) was significant, whereas the intimal HOA vs. CTRL comparison showed a non-significant trend. Transcriptomic analysis supported IL-6 upregulation, while TNFR1 and TGF-β1 did not reach statistical significance at the mRNA level in an orthogonal, non-hip (knee-predominant) dataset. Conclusions: These findings demonstrate compartment-specific cytokine dysregulation in HOA, with increased intimal TNFR1 and IL-6 alongside reduced intimal TGF-β1. The synovial lining emerges as a dominant site of inflammatory signaling, underscoring its importance in disease progression. Full article

Background: Osteonecrosis of the femoral head is a progressive disorder leading to femoral head collapse and early disability, often affecting young adults. Core decompression (CD) is the most established hip-preserving treatment for early-stage disease, yet the comparative benefits of biological and structural augmentation remain uncertain. Methods: This systematic review and meta-analysis, registered in PROSPERO (CRD420251108396), evaluated 14 studies encompassing 1210 patients treated with CD alone or CD combined with biological (e.g., platelet-rich plasma, mesenchymal stem cells, bone marrow aspirate concentrate) or structural (e.g., bone grafting, fibular support) augmentation. Results: Pooled random-effects models demonstrated that biological augmentation yielded significant improvements in Harris Hip Score and pain reduction (VAS) up to 24 months, with early peaks and subsequent stabilization, whereas structural augmentation showed no functional advantage at any time point. Radiological progression and conversion to total hip arthroplasty were not significantly reduced, though long-term trends favored biologically augmented CD. Conclusions: Overall, biological augmentation provides durable functional and symptomatic benefits in early-stage osteonecrosis, supporting its use as a first-line adjunct to CD, while structural augmentation appears less consistent and warrants further evaluation through large, standardized trials. Full article

Background: Robotic-assisted unicompartmental knee arthroplasty (UKA) enhances the precision of component alignment compared to conventional techniques. Although various robotic systems exist, direct comparisons assessing their relative clinical performance remain limited. The purpose of this study is to provide a comparison between image-based and imageless robotic UKA. Methods: A systematic review was conducted in accordance with PRISMA guidelines. Five databases were searched: PubMed (via MEDLINE), Epistemonikos, Cochrane Library, Web of Science, and Scopus. Inclusion criteria were (1) studies comparing rUKA and cUKA with radiologic parameters and revision rates (prospective or retrospective), (2) human subjects, (3) meta-analyses for cross-referencing, and (4) English language. Data collected included (1) pre- and postoperative radiologic parameters, (2) radiologic outliers, and (3) revisions and their causes. A random-effects meta-analysis was employed to enable a generalizable comparison. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated for continuous variables, and log odds ratios (LORs) with 95% CIs for binary outcomes. Results: Image-based robotic UKA was associated with fewer joint line height outliers (LOR = 3.5, 95% CI: 0.69–6.30, p = 0.015) using a 2° threshold. HKA outliers (thresholds 2–3°) were also reduced (LOR = 0.6, 95% CI: 0.09–1.19, p = 0.024). Posterior tibial and posterior femoral implant fit were significantly lower with image-based systems (LOR = 1.7, 95% CI: 1.37–2.03, respectively, LOR = 1.7, 95% CI: 1.29–1.91; p < 0.001 for both). No significant differences in revision rates were observed. Conclusions: Image-based robotic systems may result in fewer outliers in key radiologic parameters, including hip–knee angle, joint-line height, posterior tibial, and posterior femoral fit, though reporting remains highly heterogeneous. Full article

Background/Objectives: Tapered, fluted, modular titanium stems (TFTSs) are widely used in complex femoral reconstructions during total hip arthroplasty (THA), but evidence regarding the clinical performance of specific modular implant designs remains limited. This study aimed to compare the early clinical and radiographic outcomes of complex primary and revision THA using the M-Vizion^® modular stem system. Methods: We retrospectively analyzed 109 patients (46 complex primary and 63 revision THA cases) treated with the M-Vizion^® cementless modular TFTSs between 2020 and 2023. Clinical outcomes were assessed using the Hip Disability and Osteoarthritis Outcome Score (HOOS) and the Forgotten Joint Score (FJS) at 1- and 2-years post-surgery. Radiographic evaluation included stem subsidence, radiolucent lines, heterotopic ossification, and complications. Clinically relevant subsidence was defined as >5 mm. Statistical analysis was performed using ANOVA. Results: The mean follow-up was 33.3 months for complex primary and 31.8 months for revision THA. Both groups demonstrated significant improvement in FJS over time (p < 0.05). In the revision group, HOOS improved significantly from baseline to follow-up (p < 0.001). Mean stem subsidence was 2.1 mm in the complex primary group and 1.8 mm in the revision group; nine patients (8.3%) had subsidence greater than 5 mm. No cases of aseptic loosening or stem fracture were observed. The overall complication rate was low, with dislocations (3.2%) and infections (2.8%) requiring revision. Conclusions: The M-Vizion^® TFTS system demonstrated favorable short-term outcomes in both complex primary and revision THA. These findings suggest potential utility in complex femoral reconstruction, although confirmation through longer-term studies is warranted. Full article

Introduction: Octogenarians undergoing unicompartmental knee arthroplasty (UKA) face increased risks of complications due to reduced bone support following osteoporosis. The aim of this study was to describe our preferred technique to balance robotic-assisted UKA in this specific patient population and to present its results. Methods: This retrospective analysis of prospectively collected data examined 121 consecutive octogenarian patients (median age 84 years, IQR 82–86) who underwent robotic-assisted medial UKA between September 2018 and December 2022 with ≥24 months follow-up. Patients aged ≤80 years, with ≤2 years of follow-up, or without informed consent were excluded. Data collection included radiographic measurements (HKA, LDFA, MPTA, joint line height), patient-reported outcome measures (Oxford Knee Score, Knee Society Score), and complications. Statistical analysis employed descriptive statistics, paired t-tests, Cohen’s d for effect sizes, and the McNemar test for categorical variables. Results: The hip–knee–ankle angle improved significantly from 174.43° to 178.04° (mean difference 3.61°, 95% CI 3.13–4.09, p < 0.001). Patient-reported outcomes demonstrated substantial improvements: the Knee Society Score increased by 83.09 points (95% CI 79.76–86.42, p < 0.001, Cohen’s d = 4.53), and the Oxford Knee Score increased by 17.09 points (95% CI 15.42–18.76, p < 0.001), with both exceeding minimal clinically important differences. Only 7.4% (9/121) of cases exhibited joint line lowering of >2 mm, with 1.7% (2/121) having both post-operative HKA <175° and joint line lowering of >2 mm. The implant survival rate was 100% with minimal complications, including two conservatively managed tibial plateau fractures and two cases of wound dehiscence with no further surgery needed. Conclusions: Robotic-assisted medial UKA can consistently preserve joint line height while achieving excellent alignment correction and clinical outcomes in octogenarians, potentially addressing failure risks in this specific population. Full article

Approximately 15% of total knee arthroplasty (TKA) patients remain dissatisfied after surgery, with joint line obliquity (JLO) potentially affecting patient outcomes. This study investigated whether JLO restoration influenced lower extremity frontal plane joint moments during stair negotiation by TKA patients. Thirty unrestored and twenty-two restored JLO patients participated in this study and were asked to perform five trials on each limb for stair negotiation while three-dimensional kinematics and ground reaction forces were recorded. Frontal plane moments at the ankle, knee and hip were calculated using Visual 3D. The restoration of JLO did not alter frontal plane joint moments during stair negotiation. Both groups showed symmetrical moment profiles, indicating no significant biomechanical differences between the restored and unrestored JLO groups. Restoring JLO did not affect frontal plane joint moments during stair negotiation, suggesting it may not contribute to patient satisfaction disparities post-TKA. Further research should explore other factors, such as surgical technique and implant design, that might influence recovery. Full article

Whole-leg radiographs (WLRs) are widely used to assess coronal alignment before total knee arthroplasty (TKA), but may be inaccurate in patients with atypical morphotypes or malrotation. This study evaluated the discrepancy between WLR and 3D computed tomography (CT) scans across coronal plane alignment of the knee (CPAK) morphotypes and introduced a novel projection index—the femoral notch projection ratio (FNPR). In CPAK III knees, 19% of cases exceeded a clinically relevant threshold (>3° difference), prompting investigation of underlying projection factors. In 187 knees, coronal angles—including the medial distal femoral angle (MDFA°), medial proximal tibial angle (MPTA°), femoral mechanical angle (FMA°), and arithmetic hip–knee–ankle angle (aHKA°)—were measured using WLR and CT. Rotational positioning on WLR was assessed using FNPR and the patellar projection ratio (PPR). CPAK classification was applied. WLR systematically underestimated alignment, with the greatest bias in CPAK III (MDFA° + 1.5° ± 2.0°, p < 0.001). FNPR was significantly higher in CPAK III and VI (+1.9° vs. −0.3°, p < 0.001), indicating a tendency toward internally rotated limb positioning during imaging. The PPR–FNPR mismatch peaked in CPAK III (4.1°, p < 0.001), suggesting patellar-based centering may mask rotational malprojection. Projection artifacts from anterior osteophytes contributed to outlier measurements but were correctable. Valgus morphotypes with oblique joint lines (CPAK III) were especially prone to projection error. FNPR more accurately reflected rotational malposition than PPR in morphotypes prone to patellar subluxation. A 3D method (e.g., CT) or repeated imaging may be considered in CPAK III to improve surgical planning. Full article