Stable Fixation Research Articles

Novel hook plate for radial semilunar lip facet fragment fixation: a finite element analysis.

Intra-articular fractures of the distal radius require anatomical reduction and stable fixation. When the fracture encompasses the articular facet of the bone, maintaining the reduction is challenging due to the fragment's size and high instability. While specific implants have been developed to fix this fragment, their effectives have been limited. This study evaluates the mechanical performance of a novel hook plate conceived to stabilize the small fragment of the semilunar facet of the radius in non-osteoporotic bones. A simulated lunate facet fracture was created in an adult radius in a virtual model, and a modification of a hook plate was developed using computer-aided design (CAD). Two groups were established for the finite element method (FEM) simulation: a control group (standard plate Medartis™ (Switzerland, A-5500.23) and an angled plate with hooks set at 60º, 90º and 120º. In the FEM simulation, an axial load of 100N was applied in the Z-axis direction on the fragment. Fracture displacement along the Z axis was more pronounced in the control model (0.32mm) and less in the angled models, ranging from 0.22 to 0.28mm. Notably, the plate with a 90° angle showed a more effective reduction in fragment displacement. The distribution of stresses in the system showed the highest levels of stress in the control group (59.31MPa), followed by the subgroup with a 60° angle (55.78MPa).In the side view, the control model showed a higher concentration of stresses (59.74MPa), while the model with a 90° angle showed a lower value of stresses (18.87MPa). Critical stress regions were identified in the bolts of the control and 120° models (59.47MPa and 57.64MPa, respectively). However, in the 90° model, no critical regions were observed in the bolts, which showed lower stress values, reaching 26.33MPa. In the bone, the greatest concentration of stress occurred in the region where the plate was anchored. Our results showed that the 90° hook plate had a superior mechanical performance in fixing simulate lunate facet fractures at the distal radius. This angle led to minor displacements and minimized stress concentrations in the hardware, thus contributing to enhance the stability of this specific fracture.

Fixation of Tripotassium Citrate Flame Retardant Using a Sorbitol and Citric Acid Wood-Modification Treatment

Wood modification has been explored in various ways to enhance dimensional stability and reduce flammability, with a focus on environmentally friendly treatments to meet market demands. This study aimed to investigate the efficacy of new, potential fire-retardant materials. Specifically, the study examined the combination of tripotassium citrate (TPC), a water-soluble and bio-based fire retardant, with sorbitol and citric acid (SorCA), an eco-friendly thermosetting resin previously studied. While TPC is known to control combustion, its application in wood modification has not been thoroughly researched. To assess the fixation and flammability of these fire retardants, tests were conducted on Scots Pine (Pinus sylvestris L.), including chemical analysis, dimensional stability, mechanical properties, flame retardancy, and leaching tests. The combination of SorCA and TPC showed high weight percent gain (WPG) values; however, leaching and anti-swelling efficiency (ASE) tests revealed challenges in fixation stability. The dynamic mechanical properties were reduced, whereas the static strength values were in the same range compared with untreated wood. While TPC exhibited high flame retardancy prior to leaching, its efficacy diminished post-leaching, underscoring challenges in fixation and the need for improved retention strategies. Bunsen burner tests conducted on leached specimens indicated enhanced performance even under severe leaching conditions as per the EN 84:2020 procedure. However, cone calorimetry measurements showed less favorable outcomes, emphasizing the necessity for further investigation into optimizing TPC retention and enhancing treatment efficacy.

Effect of Chiropractic Intervention on Oculomotor and Attentional Visual Outcomes in Young Adults With Long-Term Mild Traumatic Brain Injury: A Randomized Controlled Trial

ObjectiveThis study aimed to establish if chiropractic care can improve oculomotor and cognitive symptoms in individuals with persistent postconcussion syndrome (PPCS). MethodsA single-blind, randomized controlled intervention study recorded baseline computerized eye-tracker assessment (CEA) outcomes in 40 young adults with PPCS following mild traumatic brain injury. Participants were randomly allocated to either a chiropractic or age-matched active control intervention, and the change in CEA outcomes following intervention was compared between the chiropractic and control groups. A battery of CEAs including egocentric localization, fixation stability, pursuit, saccades, Stroop, and the vestibulo-ocular reflex, were used to assess oculomotor function, visual attention/processing, and selective attention. ResultsRelative to the control group, participants receiving the chiropractic intervention scored better in the Stroop test (P < .001), had improved gaze stability during both vestibulo-ocular reflex (P < .001) and fixation stability (P = .009), and a lower vertical error in egocentric localization (P < .001). However, performance was poorer in pursuits, where they had an increased tracking error (P < .001). ConclusionChiropractic care in participants with PPCS significantly improved static and dynamic gaze stability, and performance in the Stroop test, compared with a control intervention. These results suggest that chiropractic care can offer a novel avenue for alleviating certain visual and cognitive symptoms in patients with PPCS. It also adds to the growing evidence that suggests that some longstanding PPCS visual symptoms may have a spinal or proprioceptive basis.

Biomechanical Analysis of a Modified Triangular Osteosynthesis Technique for Treatment of Spinopelvic Dissociation.

The purpose of this study was to evaluate the biomechanical stability of a modified triangular osteosynthesis construct with S1 pedicle screws compared with other described lumbopelvic fixation constructs in a U-type sacral fracture model. U-type sacral fractures were created in validated fourth-generation spinopelvic models. Four different constructs were cyclically loaded with displacement measured in all planes: (1) bilateral L5 pedicle screws with rods attached to iliac bolts, (2) bilateral L5 and S1 pedicle screws with rods attached to iliac bolts, (3) bilateral L5 pedicle screws with rods attached to iliac bolts with a transsacral-transiliac screw, and (4) bilateral L5 and S1 pedicle screws with rods attached to iliac bolts with a transsacral-transiliac screw. The bilateral L5 and S1 pedicle screws with rods attached to iliac bolts with a transsacral-transiliac screw construct had significantly decreased horizontal, vertical, and angular displacement compared with all other constructs. From a biomechanical perspective, a modified triangular osteosynthesis construct with S1 pedicle screws improves stability in fixation of U-type sacral fractures.

Surgical Treatment and Outcomes of Trans-Ulnar Basal Coronoid Fracture-Dislocations

Trans-ulnar fracture-dislocations of the elbow are complex injuries that can be difficult to classify and treat. Trans-ulnar basal coronoid injuries, in which the coronoid is not attached to either the olecranon or the metaphysis, present substantial challenges to achieve anatomic reduction and stable internal fixation. The purpose of this study was to analyze the outcome of surgical treatment of trans-ulnar basal coronoid fracture-dislocations. Between 2002 and 2019, 32 consecutive trans-ulnar basal coronoid fracture-dislocations underwent open reduction and internal fixation (ORIF) at our institution. Four elbows were lost to follow-up within the first 6 months after surgery and were excluded. Among the 28 elbows remaining, there were 13 females and 15 males with a mean age of 56 (range 28-78) years at the time of injury. The mean clinical and radiographic follow-up times were 37 months and 29 months, respectively. Radiographs were reviewed to determine rates of union, Hastings and Graham heterotopic ossification (HO) grade, and Broberg and Morrey arthritis grade. Union occurred in 25 elbows. Union could not be determined for 1 elbow at most recent follow-up and the remaining 2 elbows developed nonunion of the coronoid. Complications occurred in 10 elbows (36%): deep infection (4), ulnar neuropathy (2), elbow contracture (2), and nonunion (2). There were reoperations in 11 elbows (39%): irrigation and débridement with hardware removal (4), hardware removal (2), ulnar nerve transposition (2), contracture release with HO removal (2), and revision ORIF with iliac crest autograft (1). At most recent follow-up, the mean flexion-extension arc was 106° (range 10-150°), and the mean pronation-supination arc was 137° (range 0-170°). The mean Quick Disabilities of Arm, Shoulder, and Hand score was 11 (range 0-39) points with a mean Single Assessment Numeric Evaluation-Elbow score of 81 (range 55-100) points. At final radiographic follow-up, 16 elbows (57%) had HO (8 class I and 8 class II), and 20 elbows (71%) had arthritis (8 grade 1, 6 grade 2, and 6 grade 3). Trans-ulnar basal coronoid fracture dislocations are severe injuries associated with high rates of reoperation, heterotopic ossification, and post-traumatic arthritis. However, the majority of elbows achieve union, a functional range of motion, and reasonable patient reported outcome measures. Over the study period, surgeons were more likely to utilize multiple deep approaches and separate fixation of the coronoid (either with lag screws or anteromedial plates) to ensure anatomic reduction.

Outcome of Locking Plate Fixation Adjunctive to Intramedullary Rodding in Osteogenesis Imperfecta Patients.

An intramedullary rodding is the preferred fixation method in limb stabilization of OI patients. However, the intramedullary rod may not provide adequate fixation and rotational stability, especially in adolescents and adults. The incorporation of adjunctive plate fixation alongside intramedullary rodding has been introduced to enhance this stability, although its complications remain insufficiently understood. The goal of this study was to explore the outcomes of adjunctive plating in conjunction with intramedullary rodding for limb stabilization in OI patients, emphasizing the complications related to the plates during the healing phase and following plate removal. This retrospective study examined 74 limb segments from 45 patients with OI who underwent intramedullary rodding and adjunctive plating from 2008 to 2022. Criteria for inclusion comprised surgical treatment followed by a minimum of 2 years of follow-up or complication before that time point. The need for adjunctive plating arose from inadequate fixation, rotational instability, and persistent cortical gaps with intramedullary rodding alone. Medical records and follow-up radiographs were reviewed to assess the healing of the target lesion and any complications. The study encompassed 30 males and 15 females, ranging in age from 4 to 38 years, with 51 femoral and 23 tibial segments receiving treatment. Union was successfully achieved in 63 cases (85.3%), with an average union time of 14.4 months. Plates were subsequently removed in 62 cases after an average duration of 18.0 months. Before union, 11 revision surgeries were performed in 4 peri-implant fractures, 1 screw pull-out, and 6 failure of union. One sustained peri-implant fracture after the union. Following the removal of plates, complications included 10 refractures at screw sites, 3 progressive angulations at the previously targeted lesions, and 1 osteomyelitis. Kaplan-Meier analysis revealed that half of the refractures occurred within 1.8 years postplate removal. The overall complication showed borderline significance (P=0.056) among age groups. All the plate-related complications occurred at the diaphyseal, unicortical screws. Plate fixation, when used as an adjunct to intramedullary rodding, effectively stabilizes limbs in OI patients when intramedullary rods alone are inadequate. Nevertheless, given the significant risks associated with plate-related complications, adjunctive plating should be employed selectively only in instances where the union is unlikely to be achieved with intramedullary rodding alone. Level IV-case series.

A Biomechanical Analysis of Instrumentation Constructs During Vertebral Column Resection: Stability When You Need It!

Biomechanical Testing. Investigate the optimal construct for stabilization of the spine during vertebral column resection (VCR). VCR is a powerful technique for achieving correction in severe cases of spinal deformity. However, this also creates an unstable spine which requires stable fixation to prevent iatrogenic neurologic injury. It is common practice to place a temporary unilateral rod configuration to achieve this stability during surgery but no study to date has investigated the optimal construct configuration. A unilateral VCR model representing an acute 50° kyphotic deformity with a standardized 30mm resection was created. Three conditions underwent testing: 1) Rod material and diameter, 2) rod configuration, and 3) number of fixation points. Six unique samples were tested in each group in both flexion-extension. Prior to testing a 10N preload and underwent cyclical testing in flexion/extension. System stiffness was calculated and compared across groups. Assessment of rod size and composition using a single screw construct (2 total screws) demonstrated that for Titanium (Ti) rods, increasing rod size significantly increased the construct stiffness (P=0.001). Although Cobalt-chromium (Co-Cr) rods where significantly stiffer than the corresponding sized Ti rods, there was no significant difference between rod diameters for Co-Cr (P=0.98). However, when tested using a dual screw (4 total screws) construct, these constructs were significantly stiffer than the corresponding single screw constructs (P<0.0001). Of the various rod configurations, the dual rod demonstrated the greatest stiffness (34.8±2.1N/mm; P<0.0001). Surgical construct stiffness during a VCR is multifactorial. Larger rod diameter, increased number of fixation points, stiffer rod material, and increased number of rods across the resection site increase the construct stiffness. With minimal points of fixation using Co-Cr rods, increasing rod diameter does not impart greater construct stiffness unless additional fixation points are included.

Spider Webs‐Inspired Aluminum Coordination Hydrogel Piezoionic Sensors for Tactile Nerve Systems

AbstractPiezoionics, a new frontier that employs mobile ions as energy and charge carriers, plays an important role in new energy and intelligent electronics. However, a significant challenge consists in balancing the structural design of metal ions coordination hydrogel (HG‐MI) piezoionics for current conduction, voltage generation, and especially mechanical adaptability. Herein, inspired by the spider webs' unique structure, a strategy by realizing the full potential of metal‐ligand ions ([(OH)Cl2]3−) to facilitate the keggin‐type structure AlOHAlOH generation together with activate functional carboxyls is introduced. Impressively, the whole property of the product HG‐AlPAC, especially the mechanical performance is improved. For example, the toughness of HG‐AlPAC is 2.75 MJ m−3, more than twofold that of traditional HG‐AlAS/AC/AN samples. Due to the stable fixation of ─Al─OH─ thus promoting Cl− separation upon external force, HG‐AlPAC achieves a piezoionic coefficient of 0.89 mV KPa−1 and energy conversion efficiency of 1.29%, promising for mechanical‐electrical conversion and sensing. Combined with the good mechanical performance with the excellent piezoionic properties, underscores its potential as a tactile nerve system of analgesia patients to prevent them from being injured. This work intends to provide a stride toward mechanically robust self‐powered piezoionic sensors and offer insights into ionotropic materials for energy harvesting, human‐machine interaction, and biointerface.

Study of clinical and functional outcome of malleoli fracture

Background: Ankle fractures are a common orthopedic injury, accounting for 9% of all fractures, with an increasing incidence among both young and elderly populations. These fractures often result from road traffic accidents, falls, and sports injuries. Malleolar fractures, involving the bony prominences of the ankle, are particularly prevalent and necessitate accurate reduction and stable internal fixation to prevent complications such as post-traumatic arthritis and restricted motion. This study aims to assess the functional outcomes and results of surgical treatment of malleolar fractures. Methods: The study utilized Lauge-Hansen’s classification to analyze the mechanism of injury in 32 patients with ankle fractures. Surgical techniques included the fixation of syndesmotic injuries with anatomical fibular plates, (AFP) posterior malleolus fractures with percutaneous screws or Ellis plates, and medial malleolus fractures with tension band wiring (TBW). The outcomes were measured in terms of union time, range of motion, and stability. Results: The most common injury mechanism was supination external rotation (SER) in 14 patients, followed by pronation external rotation (PER) in 7 patients, pronation abduction (PAB) in 6 patients, and supination adduction (SAD) in 5 patients. Syndesmotic injuries were found in 7 patients, all treated surgically except one. Posterior malleolus fractures were present in 3 patients and treated with screws or plates. Fixation of medial malleolus fractures with TBW showed better union rates and improved range of motion compared to screw fixation. Lateral malleolar fractures treated with AFP provided additional stability. The average union time was 6 to 8 weeks. Conclusions: Anatomical reduction and stable internal fixation are crucial for the successful treatment of malleolar fractures. TBW for medial malleolus fractures and AFP for lateral malleolar fractures provide favorable outcomes. However, a larger sample size and longer follow-up duration are required to further evaluate the outcomes of ankle injuries, particularly in older patients with osteoporosis and comorbidities.

Arthroscopic mini tunnel suture bridge for ACL tibial avulsion fractures repair

The study presents an arthroscopic transosseous suture bridge technique for repairing avulsion fractures of the tibial insertion of the anterior cruciate ligament (ACL), specifically tailored for adolescent patients. The technique utilizes two mini tunnels, integrating the principles of transosseous tunneling and suture bridging to ensure stable fixation while minimizing the impact on the bone bed. Over a seven-year period, 39 patients with Meyers-Mckeever types II, III, and IV tibial avulsion fractures underwent this procedure. The surgery had an average duration of 52.7 min and resulted in decreased swelling and pain within two months postoperatively. All patients achieved full knee extension and over 120° of flexion. X-rays confirmed complete fracture healing within six to 12 months, and negative anterior drawer test and Lachman test indicated stable fixation. Significant improvements were seen in Lysholm and IKDC scores. This technique offers several advantages: it is effective, stable, and particularly suitable for adolescents due to the reduced impact on the bone bed and successful avoidance of epiphyseal plate injury.

A differentiated approach to the surgical treatment of intraarticular fracture of the proximal tibia

Background. For a long time, the question of optimal ways and methods of surgical treatment of fractures of the proximal part of the tibia (PPT) remains debatable. The purpose was to study the results of surgical treatment of fractures of the PPT using differentiated use of minimally invasive techniques. Materials and methods. The work consisted of a prospective analysis of the treatment outcomes of 87 patients who were treated 2018 to 2023. Fractures were classified according to Schatzker. The tactics of surgical treatment depended on the type of fracture, the age of the patients and the presence of concomitant diseases. A comprehensive assessment of knee function was performed using the Knee Society Score. For X-ray assessment of the degree of progression of post-traumatic arthritis, the Resnik/Niwoyama system was used. ­Results. The results of surgical treatment were studied in terms from 6 to 24 months. 19.8 % of excellent, 57.5 % good, 15.6 % sa­tisfactory and 7.1 % unsatisfactory treatment results were obtained. Progression of post-traumatic arthritis was observed in 36 patients (28 patients at one stage, 4 subjects at 2 stages and 5 patients at 3 stages). Of the complications, 7 (8.0 %) were surgical site infections, which required debridement of the focus and longer antibiotic therapy. Over time, loss of reposition and secondary displacement were identified in 5 (5.7 %) cases. The most common complications were the progression of knee osteoarthritis, the development of contractures in 11 (12.6 %) patients. Conclusions. The use of a differential approach to the surgical treatment of intra-articular fractures of PPT, based on the severity of injuries according to Schatzker, allowed to obtain positive functional results in 77.3 % of the victims. The negative consequences of intra-articular fractures of the tibial plateau that worsen the functional outcomes of treatment include the progression of knee osteoarthritis. The degree of its manifestations is largely determined by the severity of the injury, the quality of reduction, the stability of fragment fixation, and the rationality of restorative treatment and rehabilitation.

Talar head replacement for treatment of Müller – Weiss syndrome: three clinical cases

Introduction Müller – Weiss syndrome is a rare condition that is characterized by avascular necrosis of the navicular bone leading to severe foot deformity, pain disturbing activities of daily living. There is no generally accepted treatment for avascular necrosis of the scaphoid, and the available treatments have disadvantages, which necessitates the need for new options.The objective was to present short-term results of three patients with osteonecrosis of the scaphoid and local necrosis of the talar head treated with ceramic talar head prosthesis, plastic surgery, metal osteosynthesis of the scaphoid and related surgical techniques.Material and methods Three patients diagnosed with Müller – Weiss syndrome were treated with ceramic talar head replacement, autologous bone grafting and metal osteosynthesis of the scaphoid bone with accompanying surgical techniques. Severity of pain and the condition of patients were assessed with the VAS and AOFAS AH scores.Results Short-term results showed consolidation at the site of metal osteosynthesis in all patients with no signs of instability of the talus hemiprosthesis. VAS and AOFAS AH scores indicated decrease in the pain and improved condition of the patients.Discussion Hemiarthroplasty of the talar head combined with plastic surgery and restoration of a congruent joint surface of the scaphoid, and associated surgical techniques may become an effective alternative to existing treatments for patients with Müller – Weiss syndrome, with further study.Conclusion The short-term findings showed that hemiarthroplasty was practical for restoration of the talonavicular mobility maintaining stable fixation of the talus.

Comparative clinical efficacy of “Figure-8” Banding and double-row anchor suture-bridge fixation in arthroscopic management of tibial intercondylar eminence avulsion fractures

ObjectiveThe objective of this study is to assess and compare the clinical efficacy of “Figure-8” banding and double-row anchor suture-bridge fixation techniques in the arthroscopic management of tibial intercondylar eminence avulsion fractures.MethodA retrospective analysis was conducted on the medical records of 42 patients who underwent arthroscopic surgery for tibial intercondylar eminence fractures at our institution from June 2017 to June 2022. This cohort included 20 cases treated with “Figure-8” banding and 22 cases managed using double-row anchor suture-bridge fixation. Comparative assessments were made regarding operative duration, duration of fracture consolidation, postoperative knee joint range of motion, joint stability as assessed by the Lachman test, Lysholm score, and International Knee Documentation Committee (IKDC) functional score for both treatment groups.ResultsThe mean follow-up duration was 13.8 months. The analysis indicated that the double-row anchor suture-bridge group had a significantly longer operative duration compared to the “Figure-8” banding group (p < 0.05). Postoperative computed tomography (CT) scans confirmed successful reduction in both groups, with fracture consolidation achieved within an average of three months. Both groups showed significant improvements in postoperative knee range of motion, joint stability, and functional scores compared to preoperative measurements (p < 0.05). During the initial two-month post-surgery, the double-row anchor suture-bridge group demonstrated superior knee joint range of motion and functional scores compared to the “Figure-8” banding group (p < 0.05); however, these differences were not statistically significant beyond three months post-surgery (p > 0.05). By the one-year postoperative mark, joint stability outcomes were comparable between the two treatment groups (p > 0.05).ConclusionBoth “Figure-8” banding and double-row anchor suture-bridge fixation techniques in the arthroscopic management of tibial intercondylar eminence avulsion fractures can achieve precise reduction and stable fixation. In addition, the figure-8 suture group has the characteristics of shorter surgery time and less cost. Notably, early postoperative knee function appears to be superior with double-row anchor suture-bridge fixation compared to “Figure-8” banding.

Ultrasonication-Boosted Resorcinol-Formaldehyde Resin Nanoparticle Bromine Fixation and Corresponding Upgraded Aquatic Applications.

Bromine (Br2) and related species removal from water systems are rather complicated due to the complicated chemistry instability, and materials with high Br2 removal rate and efficiency, along with stimuli/apparatus suitable for highly corrosive environments, are necessary. Ultrasonication as a non-destructive process is especially suitable in scenarios where conventional stir apparatus is not applicable, such as highly corrosive environments. Considering the validity nature of Br2 and combining the advantages of ultrasonic with a highly stable Br2 fixation method through aromatic polymer nanoparticles, we demonstrate highly efficient acoustic-aided Br2 removal in aqueous solutions with two times capacity compared to the non-treated sample. Related aquatic applications are also proposed for the materials to be cost-effective, including silver (Ag) recovery, recyclable MnO2-mediated Br2 deep removal, and aqueous zinc anode modification. The coupled novel-material-based processes motivate the strategic design of water purification with high-safety and sustainable industrial procedures and post-value-added utilizations.

3D-Printed Prosthesis with an Articular Interface for Anatomical Acetabular Reconstruction After Type I + II (+ III) Internal Hemipelvectomy

Background: Pelvic reconstruction after type I + II (or type I + II + III) internal hemipelvectomy with extensive ilium removal is a great challenge. In an attempt to anatomically reconstruct the hip rotation center (HRC) and achieve a low mechanical failure rate, a custom-made, 3D-printed prosthesis with a porous articular interface was developed. The aim of this study was to investigate the clinical outcomes of patients treated with this prosthesis. Methods: This retrospective cohort study included 28 patients with type I + II (+ III) internal hemipelvectomy through the articular interface of the sacroiliac joint and managed with a prosthesis at a single center between August 2016 and August 2021. Complications and oncological outcomes were analyzed. The position of the reconstructed HRC was assessed and lower-limb function was evaluated. Biomechanical analyses of different fixation modes of the prosthesis were conducted using finite element analysis. Results: The displacement distance of the HRC from preoperatively to postoperatively was a mean (and standard deviation) of 14.12 ± 8.75 mm. The rate of implant-related complications was 14.3% (4 of 28) for prosthetic breakage, 14.3% (4 of 28) for aseptic loosening, 7.1% (2 of 28) for dislocation, and 7.1% (2 of 28) for deep infection. The mean Musculoskeletal Tumor Society (MSTS)-93 score was 18.2. The aseptic loosening rate was significantly greater for prostheses fixed with 3 sacral screws (4 of 10, 40.0%) than for those fixed with 4 (0 of 10, 0%) or 5 screws (0 of 8, 0%) (p = 0.024). The prosthetic breakage rate was lower in patients who underwent lumbosacral fixation (0 of 13, 0%) than in those who did not (4 of 15, 26.7%), although the difference did not reach significance (p = 0.102). Biomechanical analyses suggested that the addition of lumbosacral fixation or increasing the number of sacral screws from 3 to 4 or 5 visibly reduced the peak stress of the sacral screws. Conclusions: The use of a 3D-printed prosthesis with an articular interface for pelvic reconstruction demonstrated stable prosthetic fixation, anatomical acetabular reconstruction, and acceptable early functional outcomes. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Assessing inter-ocular fixational eye movements throughout the lifespan.

This study aims to assess fixational eye movements (FEMs) obtained under binocular and monocular viewing in normal individuals across different age groups. We recruited 68 healthy participants divided into Group 1 (children, 3-9 years, n = 20), Group 2 (adolescents, 10-19 years, n = 26), and Group 3 (adults, 20-73 years, n = 22). FEMs were collected using a high-resolution video-based tracker under 3 viewing conditions: binocular viewing (BV), monocular viewing right eye (MV_RE), and monocular viewing left eye (MV_LE). We quantified fixation stability, the frequency, amplitude, and disconjugacy of fixational saccades, and inter-saccadic drift velocity in BV, MV_RE, and MV_LE. We also computed inter-ocular fixation stability under binocular viewing and monocular viewing in the 3 groups. Fixation instability (FI) and fixational saccade amplitudes were higher in Group 1 than in Group 3 whereas inter-saccadic drifts were increased in Group 3. Vergence stability was greater in binocular viewing than in monocular viewing likely due to binocular summation in all groups. However, the fixational saccade amplitude and drift velocity of the right and left eye did not significantly differ across different viewing conditions within each group. Interestingly, the inter-ocular fixation stability ratio and vergence stability showed no significant differences between the groups. In conclusion, FEMs differ across age groups but inter-ocular FEMs are immune to the effects of age and can be a valuable parameter while evaluating FEM abnormalities in diseases like amblyopia.

Impact of Surgical Timing on Fracture Healing in Tibial Shaft Injuries: A Comparative Review of Intramedullary Nailing Techniques.

Tibial shaft fractures are a prevalent and challenging orthopedic injury, often resulting from high-energy trauma. Optimal management of these fractures is crucial to prevent complications such as nonunion, malunion, and prolonged functional impairment. Intramedullary nailing (IMN) is widely regarded as the gold standard for treating these injuries due to its ability to provide stable fixation, preserve soft tissues, and enable early mobilization. However, the timing of surgical intervention remains a topic of ongoing debate. Early surgical intervention, defined as surgery within 24-48 hours of injury, is advocated for its potential to reduce hospital stay, facilitate early mobilization, and decrease the risk of secondary complications such as compartment syndrome. Conversely, delayed intervention allows for patient stabilization and reduction of soft tissue swelling, potentially lowering the risk of infection and other complications. This comprehensive review aims to evaluate the impact of surgical timing on fracture healing outcomes in tibial shaft fractures treated with IMN. It explores the benefits and limitations of early versus delayed surgery, emphasizing their influence on union rates, healing time, and complication rates. Furthermore, the review examines different IMN techniques, including reamed versus unreamed and static versus dynamic nailing, to determine their role in optimizing fracture healing. By synthesizing current evidence, this review provides critical insights into the optimal timing and technique for IMN in tibial shaft fractures, ultimately aiming to guide clinical decision-making and improve patient outcomes. Future research should focus on randomized controlled trials to establish standardized surgical timing and technique selection guidelines in this patient population.

Unbalanced metaphyseal fixation is associated with an increased aseptic loosening of revision total knee arthroplasty at mean 4-year follow-up.

The total number of total knee arthroplasty performed is rising, and the number of revisions is rising accordingly. Periprosthetic joint infection emerged in recent years as a leading cause of total knee revisions. Bone loss is a real challenge when facing septic knee revisions since radical debridement is crucial to overcome infection. Many devices have already demonstrated to reliably address bone loss and guarantee enhanced fixation. However, the role of balancing metaphyseal fixation and its interplay with the level of constraint has not been elucidated yet. An institutional arthroplasty registry was retrospectively reviewed looking for patients who underwent two-stage revision of the knee and metaphyseal cones implantation. Patients were divided into two groups based on the presence of cones only on one side (femoral or tibial, Group U) or both femoral and tibial side (Group B). Failure, aseptic loosening, and revision rates were compared between groups, as were values of patient-reported outcome measure. Kaplan-Meier analysis was used to assess survival of implants. A total of 65 patients were included in the analysis and were evaluated at a mean final follow-up of 4years (range, 2-7). Mean age was 67 (range, 43-81) years. Mean BMI was 27.4 (range, 20-37) kg/m2. The overall mean KSS, OKS, ROM significantly increased from baseline values to last follow-up (p < 0.001). Kaplan-Meier analysis demonstrated that patients included in Group U had a significantly lower rate of implant survival compared to those included in Group B. Patients undergoing revision total knee arthroplasty for periprosthetic infection present considerable rates of complication and failure. Management of bone loss represents a concern for the surgeon, who must achieve a stable fixation. Our study demonstrated that implants characterized by an unbalanced metaphyseal fixation are at higher risk of aseptic loosening and consequent revision, especially when coupled with hinged inserts.

Cervical Spine Vibration Modifies Oculomotor Function in Young Adults with Traumatic Brain Injury

ObjectiveThe purpose of this study was to investigate if vibrational interference of spinal proprioception affects oculomotor function, visual attention and processing, and selective attention in individuals with mild traumatic brain injury (mTBI) compared to healthy age-matched controls. MethodsThis study was a parallel design, single-session intervention with 20 young adults with mTBI and 20 age-matched controls. Each completed a battery of computerized eye-tracking assessments (CEAs), including egocentric localization, fixational stability, smooth pursuit, saccades, Stroop, and the vestibulo-ocular reflex (VOR), and then had their cervical spine function (flexion-relaxation ratio) recorded at baseline. Spinal vibration (100 Hz) was applied to the cervical spine and the CEA battery was repeated. CEA outcomes were compared to baseline and between mTBI and control groups. ResultsFollowing cervical vibration, significant pre to post-differences were seen in both the mTBI and control group for egocentric localization, fixation stability, pursuit, saccades, Stroop, and VOR. At baseline, there was a significant difference between the mTBI and control groups across many CEA measures, with the mTBI group performing more poorly in egocentric localization, pursuit, saccades, Stroop, and VOR. The mTBI group also had a poorer flexion-relaxation ratio than the control group. ConclusionCervical spine vibration improved cognitive and oculomotor performance in the mTBI group for VOR, Stroop, and pursuit, but had mixed effects on the control group. These findings suggest that some optometric mTBI symptoms may result from spinal or proprioceptive dysfunction, as altering proprioceptive input appears to positively impact visual outcomes.

The outcomes of surgical treatment of complex radial head fractures.

The aim of this study was to evaluate the outcome of complex radial head fractures at mid-term follow-up, and determine whether open reduction and internal fixation (ORIF) or radial head arthroplasty (RHA) should be recommended for surgical treatment. Patients who underwent surgery for complex radial head fractures (Mason type III, ≥ three fragments) were divided into two groups (ORIF and RHA) and propensity score matching was used to individually match patients based on patient characteristics. Ultimately, 84 patients were included in this study. After a mean follow-up of 4.1 years (2.0 to 9.5), patients were invited for clinical and radiological assessment. The Mayo Elbow Performance Score (MEPS), Oxford Elbow Score (OES), and Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire score were evaluated. Patients treated with ORIF showed significantly better postoperative range of motion for flexion and extension (121.1° (SD 16.4°) vs 108.1° (SD 25.8°); p = 0.018). Postoperative functional scores also showed significantly better results in the ORIF group (MEPS 90.1 (SD 13.6) vs 78 (SD 20.5); p = 0.004). There was no significant difference between the groups in terms of the complication rate (RHA 23.8% (n = 10) vs ORIF 26.2% (n = 11)). Implant-related complications occurred in six cases (14.3%) in the RHA group and in five cases (11.9%) in the ORIF group. Irrespective of the patient's age, sex, type of injury, or number of fracture fragments, ORIF of the radial head should be attempted initially, if a stable reconstruction can be achieved, as it seems to provide a superior postoperative outcome for the patient compared to primary RHA. If reconstruction is not feasible, RHA is still a viable alternative. In the surgical treatment of complex radial head fractures, reconstruction shows superior postoperative outcomes compared to RHA. Good postoperative results can be achieved even after failed reconstruction and conversion to secondary RHA. Therefore, we encourage surgeons to favour reconstruction of complex radial head fractures, regardless of injury type or number of fragments, as long as a stable fixation can be achieved.