Search Results (257)

Smart knee replacement technology seeks to provide an in vivo method of tracking long-term postoperative joint loads with the goal of identifying clinically relevant phenomena linked to postoperative dissatisfaction in real time. This study evaluated the ability of a piezoelectric compartmental force and compartmental center of pressure sensing total knee replacement to sense condylar lift-off, which is a clinically relevant phenomenon commonly attributed to postoperative dissatisfaction. A commercially available total knee replacement was modified to include six piezoelectric transducers capable of measuring compartmental forces and tibiofemoral centers of pressure on the articular surface of the tibial bearing insert. The smart knee replacement was evaluated with a six-degree-of-freedom joint motion simulator applying a varus lift-off profile. The study demonstrated that the lift-off was evident in both the sensed joint loads and the localized tibiofemoral centers of pressure obtained from the piezoelectric sensing system. The results indicated that the piezoelectric smart knee replacement could be effective for detecting this clinically problematic mechanical issue. Full article

Background: Existing evidence suggests an association between temporomandibular disorders (TMDs) and alterations in body posture and balance; however, the mechanism underlying this relationship remains unknown. The present study aimed to investigate the associations between specific TMD subtypes, indices of bioelectrical activity of the masticatory muscles, and parameters of body posture and balance. Methods: The study followed a case–control study design. A total of 81 participants were enrolled, including 33 controls and 48 individuals with TMD, classified into myofascial (n = 14), articular (n = 17), and mixed (n = 17) subtypes. Diagnosis of temporomandibular disorders was carried out by prosthodontic specialists using the Polish adaptation of the Diagnostic Criteria for Temporomandibular Disorders. Masticatory muscle bioelectrical activity was assessed by surface electromyography. For statistical analysis, the Asymmetry Index and Functional Clenching Activity Indices were used. Static balance was evaluated with a pedobarographic platform. The sway area, velocity, and length of the Center of Pressure, as well as the foot contact area, were recorded and automatically calculated by the system. Measurements were performed under different mandibular conditions, with both eyes open and eyes closed. Correlation analyses were performed using Spearman Rank Order Correlation. Pearson’s Chi-squared test was used for the analysis of categorical variables. Results: Weak to moderate negative correlations were primarily observed, indicating that higher indices of masticatory muscle bioelectrical activity were associated with better postural balance, with distinct correlation patterns identified across different TMD subtypes. Conclusions: This exploratory study identified multiple correlations between masticatory muscle activity and postural or balance parameters, suggesting possible subtype-specific patterns in TMDs. However, the evidence remains preliminary and should be interpreted with caution, warranting further confirmatory and longitudinal research. Full article

Introduction: Distal intracapsular minimally invasive osteotomies (DICMOs) for central metatarsals are described as intracapsular procedures; however, neither their intracapsular location throughout the entire cut nor the optimal anatomical position for their execution have been fully validated. The aim of this study was to assess the geometric position of the DICMO osteotomy in the central metatarsals (third and fourth) and quantify associated anatomical damage when performed under three different guidance modalities: anatomical palpation, fluoroscopic control, and ultrasound guidance. Material and methods: An experimental cadaveric study was conducted using 29 fresh specimens (11 males, 18 females), contributing a total of 58 central metatarsals (third and fourth). All specimens underwent a DICMO-type metatarsal osteotomy. Osteotomies were randomly allocated to three intervention groups: (1) ultrasound (n = 20), (2) fluoroscopy (n = 19), and (3) anatomical guidance (n = 19). Metatarsal length, the distance between the osteotomy line and the articular surface, and post-dissection soft-tissue damage were recorded. Results: After dissection, all osteotomies were confirmed to be intracapsular. A constant proportional relationship was identified between osteotomy location and metatarsal length: distance to the joint line = 0.239 × metatarsal length. This relationship was independent of the guidance technique used. Only one iatrogenic lesion was observed: an articular cartilage injury of a third metatarsal in the anatomical-guidance group. Conclusions: The optimal position for DICMO osteotomy placement is approximately 24% of the total distal metatarsal length. This ensures an intracapsular trajectory and may contribute to intrinsic osteotomy stability. Image guidance—either fluoroscopy or ultrasound—appears essential to optimize outcomes and prevent avoidable anatomical damage. Full article

Background/Objectives: Poly(lactic-co-glycolic acid) (PLGA) microspheres offer sustained drug delivery but often suffer from broad particle size distribution (PSD), leading to inconsistent release profiles. This study investigates wet sieving as a post-processing strategy to precisely control PSD, quantified by the Span value, and evaluates its impact on the performance of triamcinolone acetonide (TA)-loaded PLGA microspheres. Methods: Triamcinolone acetonide-loaded PLGA microspheres were prepared via emulsification-solvent evaporation. Wet sieving was employed as a post-processing strategy to obtain distinct particle size fractions and groups with defined polydispersity (Span values). The microspheres were characterized for particle size distribution, drug loading, surface morphology, and in vitro release kinetics. To establish the in vivo relevance of polydispersity control, the pharmacokinetic profiles of different Span groups were first determined using LC-MS/MS following intra-articular injection in rats. Subsequently, their therapeutic efficacy was evaluated in a rat model of knee osteoarthritis, with outcomes assessed by joint swelling measurement and histopathological analysis. Results: Microspheres were prepared, fractionated into distinct size groups (0–20, 20–28, 28–40, 40–50, >50 μm) and polydispersity groups (Span = 1.4, 0.8, 0.5). We identified Span as a dominant factor independent of mean particle size. Reducing the Span from 1.4 to 0.5 significantly decreased burst release (24.15% to 14.51%), prolonged mean residence time (MRT 88.52 to 123.53 h), and enhanced anti-inflammatory and cartilage-protective effects in a rat model of knee osteoarthritis. Conclusions: This work establishes Span ≤ 0.5 as a critical quality attribute and presents wet sieving as a simple, effective method to ensure batch-to-batch consistency and predictable in vivo performance for PLGA microsphere products. Full article

Background: Tibial shaft fractures are frequently treated with intramedullary nailing; however, malalignment remains a concern, particularly in proximal metaphyseal fractures. The surgical approach influenced the nail entry point; however, the three-dimensional (3D) geometric characteristics of the entry point among different approaches remain unclear. Methods: This single-center retrospective study included 68 patients with acute tibial shaft fractures (AO/OTA type 42) treated with reamed and locked intramedullary nails from January 2014 to June 2024. The surgical techniques employed included lateral parapatellar (LPA, n = 31), infrapatellar (IPA, n = 27), and suprapatellar (SPA, n = 10) approaches. Postoperative computed tomography (CT) data were reconstructed into standardized 3D images. The mediolateral insertion ratio was calculated as the percentage distance from the lateral tibial plateau edge to the nail entry point relative to the plateau’s width in the coronal plane. The shortest distance from the tibial articular surface to the nail (r) was measured in the sagittal plane. The Kruskal–Wallis test and Dunn’s post hoc comparisons were used to analyze group differences. Results: Baseline patient and fracture characteristics did not significantly differ among the groups. The mediolateral insertion ratio significantly differed (p < 0.0001), with a more lateral entry for the LPA (44.0% [43.0–47.0]) than for the IPA (51.0% [49.0–53.0], post hoc p < 0.0001) and SPA (49.0% [47.0–51.3], post hoc p = 0.0034). Further, the sagittal distance r significantly differed (p < 0.0001), with a more distal entry for the LPA (14.8 [12.8–20.1] mm) than for the IPA (9.7 [7.0–11.8] mm, post hoc p < 0.0001) and SPA (10.5 [5.5–12.9] mm, post hoc p = 0.0008). No statistically significant difference was observed between the IPA and SPA. Conclusions: The LPA generates a significantly more lateral and distal tibial nail entry point than the IPA and SPA. No statistically significant differences were detected between the IPA and SPA in either plane. These 3D-CT findings may warrant attention during approach selection and guidewire placement, particularly for fractures extending into the proximal metaphysis. Full article

Due to the complex anatomical structure of the distal humerus, elbow joint, and the soft tissue mantle (the triceps brachii muscle, large nerves, and vessels), fractures of the distal humerus and humeral condyle are difficult to treat. In most cases, strong instrumentation is needed to stabilize the fractures. To improve exposure of the distal humerus and humeral condyle, we proposed a caudolateral approach that involves elevating the anconeus muscle and splitting the triceps brachii. This study presents the results of using this approach in 16 canine cadavers. After exposing the distal humerus and maximally flexing the elbow joint, photographs were taken of the condyle from the same distance before and after olecranon osteotomy. The visible surface area of the articular cartilage was then calculated in square pixels after calibrating the photographs. It was possible to reach the distal and middle humerus in all cases. The only vital structure that could be easily identified and protected in all cadavers was the radial nerve. The visible area of the articular surface of the humeral condyle increased after olecranon osteotomy. The A₀ (visible area before osteotomy) was significantly smaller than the A₁ (visible area after osteotomy) in all dogs (p < 0.001). The ratio of A₀ to A₁ ranged from 57% to 67% in 15 dogs (median: 64%, interquartile range (IQR): 61–66%), with a very high value of 85% observed in one dog. This experiment used cadavers with intact elbows. This could limit the study’s findings because the effectiveness of the proposed access in reducing T-Y fractures was not assessed. The caudolateral approach is a valuable alternative to other methods for treating T-Y humeral fractures in dogs. Olecranon osteotomy widens access to the condyle. Further studies are needed to evaluate the necessity of olecranon osteotomy in clinical cases. Full article

Bennett fractures are common intra-articular fractures of the base of the first metacarpal. Not optimal restoration of the articular surface often leads to osteoarthritis, with pain and limited movement. In patients with established and symptomatic TMC osteoarthritis, arthroplasty with MAIA^® prosthesis could be a valid option. In July 2024, a right-handed man of 68 years old fell on his hand. Radiographs showed a Bennett fracture in a setting of Eaton–Littler stage 3 osteoarthritis, already painful and disabling according to the patient. For correct pre-operative planning, a 3D model of the affected hand was produced. The patient underwent TMC arthroplasty with a MAIA^® prosthesis. Two months after surgery, the results reported no pain (VAS scale) and considerable functionality and mobility of the first ray (AROM, Kapandji score, and PRWHE were investigated). The mean pinch strength of the right hand was 7 kg and of the left hand 7.5 kg using a pinch meter. At one-year follow-up, no complications were reported: the implant did not show signs of loosening or subsidence. TMC arthroplasty in Bennett fractures could represent a safe procedure in patients with established TMC osteoarthritis; however, further studies are requested in order to clarify effectiveness and indications. Full article

(1) Background: Intra-articular injection is a fundamental technique in preclinical research for evaluating therapeutics and inducing joint disease models in rodents. However, the absence of standardized and validated protocols compromises reproducibility and translational validity. (2) Methods: This study establishes and experimentally validates a refined protocol for precise intra-articular injection in the knee of adult male Wistar rats. The comprehensive procedure specifies anatomical landmarks (medial border of the patellar tendon), instrumentation (27 G needle, 100 µL Hamilton syringe), a maximum volume of 35 µL, and operative verification criteria based on tactile feedback. Experimental validation was performed by administering a suspension of wear particles (2.35 mg/mL) generated from tribocorrosion tests of CoCr surfaces biofunctionalized with graphene oxide-hyaluronic acid (GO-HA) into the left knee of five rats. (3) Results: Histological analysis using the cutting–grinding technique and Toluidine Blue staining confirmed the exclusive intra-articular localization of particles in all injected animals (5/5 success rate). Qualitative assessment revealed abundant particulate distribution within the synovial space, with numerous individual particles and multiple aggregates observed per high-power field, without evidence of extravasation in any case. (4) Conclusions: The protocol demonstrated high intra-operator repeatability and provides a reliable, ethically refined tool for precise intra-articular administration of nanomaterials and for generating robust joint disease models, thereby enhancing reproducibility and animal welfare in preclinical research. Full article

Background: Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage damage. The limited regenerative capability of articular cartilage poses a therapeutic challenge. Adipose mesenchymal stem cell (MSC) exosomes have shown potential in regenerating cartilage structure in previous in vivo studies on small animals. This study aims to compare the effectiveness of intra-articular injections of adipose-derived MSC exosomes and hyaluronic acid (HA) on cartilage regeneration in a sheep osteoarthritis model. Methods: This in vivo study involved 18 male sheep that were induced to develop OA via meniscectomy. The sheep were randomized and divided into three groups: Group 1 (adipose MSC exosomes + HA), Group 2 (adipose MSC exosomes), and Group 3 (HA). Microscopic evaluation using histological scoring with the Pineda score, cartilage regeneration assessment through histochemical and immunohistochemical examinations, and microtopographic examination using a scanning electron microscope (SEM) were performed 6 weeks post-intervention. Results: Cartilage regeneration in the combination group (Group 1) exhibited a larger area of hyaline cartilage (Group 1 vs. Group 2 [40.38 ± 9.35% vs. 34.93 ± 2.32% vs. 31.08 ± 3.47%; p = 0.034]) and a smaller area of fibrocartilage compared to adipose MSC exosomes (Group 2) or HA alone (Group 3) (13.06 ± 2.21% vs. 18.67 ± 3.13% vs. 28.14 ± 3.67%; p = 0.037). Microtopographic examination also showed a more homogeneous and smoother cartilage surface in the combination group (Group 1) of adipose MSC exosomes and HA. Conclusions: In a sheep knee osteoarthritis model, intra-articular injection of a combination of adipose-derived MSC exosomes and HA significantly enhances cartilage regeneration compared to injections of adipose-derived MSC exosomes or HA alone. Full article

Background: The Orbay approach to volar distal radius described a volar zig-zag incision across the wrist crease, allowing a more distal exposure than traditional approaches. This adaptation enhances mobilization of the proximal radial fragment and improves visualization of both the articular surface and dorsally displaced distal radius fractures. Methods: In the present paper, we propose a further modification of the volar zig-zag approach, positioning the apex of the incision at the level of the radial styloid. Results: This modification aims to improve visualization of the radial styloid, the articular comminution, and the dorsal aspect of the distal radius, thereby optimizing fracture exposure and reduction. Conclusions: The principal advantage lies in the reduced need for traction along the radial margin of the incision to achieve adequate visualization and the avoidance of crossing the wrist crease, thereby preventing the formation of unsightly or adherent scars. Full article

This study investigated the effects of different frequencies of moderate treadmill exercise on a knee osteoarthritis (OA) model in Wistar rats. Sixty male Wistar rats were randomly assigned to four groups: Sham, OA, OA + exercise three times/week (OA + 3×), and OA + exercise five times/week (OA + 5×). OA was induced via intra-articular injection of sodium monoiodoacetate (MIA) in the right knee. Fifteen days post-MIA, exercise treatment began with a one-week adaptation period, followed by eight weeks of aerobic training. Protocols involved treadmill walking (30 min/day) at 13 m/min for the first four weeks and 16 m/min for the last four weeks. At the end, animals were anesthetized and euthanized for collection of intra-articular tissues and gastrocnemius muscle. Both exercise regimens inhibited OA progression; however, OA + 5× yielded more pronounced effects, including greater energy expenditure, weight reduction, oxidative stress modulation, decreased pro-inflammatory and catabolic markers, increased anti-inflammatory and anabolic parameters, reduced injury scores, prevention of cartilage thinning, and increased cartilage surface area. Although both frequencies conferred cartilage protection, moderate exercise five times per week produced superior therapeutic outcomes, suggesting a dose-dependent benefit of exercise in OA management. Full article

Knee osteoarthritis (OA) is a whole-joint disease involving subchondral bone lesion (BML) that predict treatment outcomes. This retrospective, non-randomized study compared extracorporeal shockwave therapy alone (ESWT), autologous protein solution and ESWT (APS), intra-articular mesenchymal stromal cell and ESWT (MSC-A), and combined intra-articular and intra-osseous MSC and ESWT (MSC-B) for knee OA with BML. We hypothesized that combination therapies would provide superior and earlier outcomes for advanced cases. The primary outcome was the change in the Knee Injury and Osteoarthritis Outcome Score (KOOS) at 3 and 6 months. The results showed ESWT was effective, but only in the absence of articular surface collapse (KOOS IV (pre–6M) = 18.6 ± 13.9) vs. presence of collapse (4.4 ± 6.5). APS led to earlier improvement in cases without subchondral bone plate (SBP) tear (KOOS IV (pre–3M) = 18.4 ± 12.7) vs. ESWT 12.0 ± 14.0). MSC-A with SBP tear achieved significant early gain (KOOS IV (pre–3M) = 13.9 ± 10.1) but plateaued by 6 months. MSC-B without collapse showed significant 6-month improvement (KOOS IV (pre–6M) = 15.8 ± 8.6), but failed in collapse cases (KOOS IV (pre–6M) = −4.4 ± 7.7). ESWT is effective, APS provides early benefits, and MSC-B is promising for advanced SBP tear cases, but articular surface collapse limits efficacy across all therapies. Full article

Background/Objectives: Orthognathic surgery represents a surgical modality for the correction of craniofacial skeletal deformities. These procedures help achieve stable occlusion and improve facial symmetry, which in turn enhances functional outcomes and overall quality of life. However, to date, no consensus has been reached regarding whether orthognathic surgery also induces changes in the relationship of articular surfaces within the temporomandibular joints (TMJs). The primary objective of this study was to conduct a systematic review of research evaluating joint space dimensions based on CBCT imaging performed before and after orthognathic surgery. Methods: A comprehensive literature search was carried out across four electronic databases: PubMed, Web of Science, Cochrane Library, and Scopus. Two independent reviewers screened titles and abstracts according to predefined inclusion criteria. Eligible studies were subjected to critical appraisal, and relevant data were systematically extracted and summarized in tabular form. Results: Fourteen studies published between 2010 and 2024 met the inclusion criteria. In all studies, CBCT-based joint space measurements were conducted at least twice once preoperatively and once postoperatively, across a total of 527 patients included in the review. Conclusions: The synthesized evidence suggests that orthognathic surgery produces measurable modifications in the spatial relationship of TMJ articular surfaces. Nonetheless, the clinical relevance of these alterations appears to be modulated by several variables, including the surgical technique employed and the patient’s individual adaptive capacity. Full article

Femoroacetabular impingement (FAI) and hip dysplasia have been shown to increase the risk of hip osteoarthritis in affected individuals. MRI with T2 mapping provides an objective measure of femoral and acetabular articular cartilage tissue quality. This study aims to evaluate the relationship between hip morphology measurements collected from three-dimensional (3D) reconstructed computed tomography (CT) scans and the T2 mapping values of hip articular cartilage assessed by three independent, blinded reviewers on the optimal sagittal cut. Hip morphology measures including lateral center edge angle (LCEA), acetabular version, Tönnis angle, acetabular coverage, alpha angle, femoral torsion, neck-shaft angle (FNSA), and combined version were recorded from preoperative CT scans. The relationship between T2 values and hip morphology was assessed using univariate linear mixed models with random effects for individual patients. Significant associations were observed between femoral and acetabular articular cartilage T2 values and all hip morphology measures except femoral torsion. Hip morphology measurements consistent with dysplastic anatomy including decreased LCEA, increased Tönnis angle, and decreased acetabular coverage were associated with increased cartilage damage (p < 0.001 for all). Articular cartilage T2 values were strongly associated with the radiographic markers of hip dysplasia, suggesting hip microinstability significantly contributes to cartilage damage. The relationships between hip morphology measurements and T2 values were similar for the femoral and acetabular sides, indicating that damage to both surfaces is comparable rather than preferentially affecting one side. Full article

The management of severely comminuted acetabular posterior wall fractures in young, active patients presents a significant surgical challenge. When anatomical open reduction and internal fixation (ORIF) is not feasible, primary total hip arthroplasty (THA) is often considered but is a suboptimal solution due to concerns over long-term implant survivorship and the inevitability of revision surgery. This single-patient technical note presents a novel joint-preserving technique for managing unreconstructible acetabular posterior wall fractures using with cement-augmented screw fixation via the Kocher–Langenbeck approach. A 28-year-old male sustained a left posterior hip dislocation with a comminuted acetabular posterior wall fracture involving >30% of the articular surface, alongside a tibial shaft fracture, following a high-energy motorcycle collision. Intraoperative assessment confirmed the posterior wall was unreconstructible, with six non-viable osteochondral fragments. A joint-preserving salvage procedure was performed. After debridement, a stable metallic framework was created using three screws anchored in the posterior column. Polymethylmethacrylate (PMMA) bone cement was then applied over this framework in its doughy phase, meticulously contoured to reconstruct the articular surface. The hip was reduced, and the tibia was fixed with an intramedullary nail. The patient was mobilized with weight-bearing as tolerated on postoperative day 3. At the 21-month follow-up, the patient reported no pain during daily activities and only mild discomfort during deep squatting. Radiographic and CT evaluations demonstrated a stable hip joint, concentric reduction, well-maintained joint space, and no evidence of implant loosening or osteolysis. Level of Evidence: V (Technical Note/single-patient Case report). For unreconstructible, comminuted fractures of the non-weight-bearing portion of the acetabular posterior wall in young patients, cement-augmented screw fixation offers a viable joint-preserving alternative to primary THA. This technique provides immediate stability, facilitates early mobilization, and preserves bone stock. While long-term outcomes require further study, this case demonstrates excellent functional and radiographic results at 21 months, presenting a promising new option for managing these complex injuries. Full article