Reconstruction of a Short Tibial Stump with a Long Fibula Using the Ilizarov Technique: A Case Study.

The creation of a functional tibial stump after combat injuries is sometimes too difficult. We describe a case of high amputation after a mine-blast injury. In this case, the tibia stump was too short (5 cm) and the fibula stump was too long (12 cm). There was a soft tissue reserve. The Ilizarov method was used to lengthen the tibia. The technique of the operation with exposure of the anterior medial ligament, its separation from the distal part of the bone, subperiosteal excision of the medial part of the patellar tendon from the tibia, oblique-frontal corticotomy of the tibia, which allowed to avoid undesirable complications during the distraction and to obtain a wide, strong regenerate, is described in detail. The alignment of the tibia lengths resulted in a highly functional stump with the possibility of full prosthetics. The proposed technique can be used in reconstructive operations on short stumps that require lengthening.

On the influence of structural and chemical properties on the elastic modulus of woven bone under healing.

Introduction: Woven bone, a heterogeneous and temporary tissue in bone regeneration, is remodeled by osteoblastic and osteoclastic activity and shaped by mechanical stress to restore healthy tissue properties. Characterizing this tissue at different length scales is crucial for developing micromechanical models that optimize mechanical parameters, thereby controlling regeneration and preventing non-unions. Methods: This study examines the temporal evolution of the mechanical properties of bone distraction callus using nanoindentation, ash analysis, micro-CT for trabecular microarchitecture, and Raman spectroscopy for mineral quality. It also establishes single- and two-parameter power laws based on experimental data to predict tissue-level and bulk mechanical properties. Results: At the macro-scale, the tissue exhibited a considerable increase in bone fraction, controlled by the widening of trabeculae. The Raman mineral-to-matrix ratios increased to cortical levels during regeneration, but the local elastic modulus remained lower. During healing, the tissue underwent changes in ash fraction and in the percentages of Calcium and Phosphorus. Six statistically significant power laws were identified based on the ash fraction, bone fraction, and chemical and Raman parameters. Discussion: The microarchitecture of woven bone plays a more significant role than its chemical composition in determining the apparent elastic modulus of the tissue. Raman parameters were demonstrated to provide more significant power laws correlations with the micro-scale elastic modulus than mineral content from ash analysis.

Distraction by unexpected sounds: comparing response repetition and response switching.

Numerous studies using oddball tasks have shown that unexpected sounds presented in a predictable or repeated sequence (deviant vs. standard sounds) capture attention and negatively impact ongoing behavioral performance. Here, we examine an aspect of this effect that has gone relatively unnoticed: the impact of deviant sounds is stronger for response repetitions than for response switches. Our approach was two-fold. First, we carried out a simulation to estimate the likelihood that stimuli sequences used in past work may not have used balanced proportions of response repetition and switch trials. More specifically, we sought to determine whether the larger distraction effect for response repetitions may have reflected a rarer, and thereby more surprising, occurrence of such trials. To do so, we simulated 10,000 stimuli sets for a 2-AFC task with a proportion of deviant trial of 0.1 or 0.16. Second, we carried out a 2-AFC oddball task in which participants judged the duration of a tone (short vs. long). We carefully controlled the sequence of stimuli to ensure to balance the proportions of response repetitions and response switches across the standard and deviant conditions. The results of the stimuli simulation showed that, contrary to our concerns, response switches were more likely than response repetitions when left uncontrolled for. This suggests that the larger distraction found for response repetition in past work may in fact have been underestimated. In the tone duration judgment task, the results showed a large impact of the response type on distraction as measured by response times: Deviants sounds significantly delayed response repetitions but notably accelerated switches. These findings suggest that deviant sound hinder response repetition and encourage or bias the cognitive system towards a change of responses. We discuss these findings in relation to the adaptive nature of the involuntary detection of unexpected stimuli and in relation to the notion of partial repetition costs. We argue that results are in line with the binding account as well as with the signaling theory.

Characterization of the Angiogenic and Proteomic Features of Circulating Exosomes in a Canine Mandibular Model of Distraction Osteogenesis.

Distraction osteogenesis (DO) represents a highly effective method for addressing significant bone defects; however, it necessitates a long treatment period. Exosomes are key mediators of intercellular communication. To investigate their role in the angiogenesis and osteogenesis of DO, we established a canine mandibular DO model with a bone defect (BD) group as the control. Higher levels of angiogenesis were observed in the regenerating tissue from the DO group compared to those from the BD group, accompanied by earlier osteogenesis. Proteomic analysis was performed on circulating exosomes at different phases of the DO using a data-independent acquisition method. Data are available via ProteomeXchange with the identifier PXD050531. The results indicated specific alterations in circulating exosome proteins at different phases of DO, reflecting the regenerative activities in the corresponding tissues. Notably, fibronectin 1 (FN1), thrombospondin 1 (THBS1), and transferrin receptor (TFRC) emerged as potential candidate proteins related to the angiogenic response in DO. Further cellular experiments validated the potential of DO-associated circulating exosomes to promote angiogenesis in endothelial cells. Collectively, these data reveal previously unknown mechanisms that may underlie the efficacy of DO and suggest that exosome-derived proteins may be useful as therapeutic targets for strategies designed to improve DO-related angiogenesis and bone regeneration.

Predicting the Presence of Pain in Youth Baseball Pitchers Using the Concept of Biomechanical Efficiency.

Background: Increases in peak shoulder distraction force and peak elbow valgus torque may influence throwing-arm pain and injury risk in youth pitchers. Purpose/Hypothesis: The purpose of this study was to determine whether shoulder distraction force and elbow valgus torque while accounting for anthropometrics and pitch velocity can predict the presence of pain in youth baseball pitchers. It was hypothesized that throwing-arm pain could be predicted using the concept of biomechanical efficiency, where a pitcher who is less efficient (having higher force or torque with the same pitch velocity) is more likely to experience pain. Study Design: Descriptive laboratory study. Methods: A total of 38 youth baseball pitchers (mean age, 13.3 ± 1.7 years) were divided into a pain group and pain-free group based on presence of throwing-arm pain as reported on a health history questionnaire. Each pitcher threw 3 maximal-effort fastballs to a catcher at regulation distance, and kinematics were measured using an electromagnetic motion-capture system (minimum 100 Hz). Height and weight as well as mean peak shoulder distraction force, peak elbow valgus torque, and pitch velocity across the 3 trials were evaluated. Logistic regression analyses determined whether shoulder distraction force or elbow valgus torque could predict the presence of throwing-arm pain when holding anthropometrics (body weight for shoulder distraction force; body weight and height for elbow valgus torque) and pitch velocity constant. Results: Shoulder distraction force significantly predicted the presence of throwing-arm pain after accounting for body weight and pitch velocity (χ2 = 9.49; P = .023). Specifically, for every 1-N increase in peak shoulder distraction force while holding body weight and pitch velocity constant, there was a 0.6% increased likelihood of experiencing throwing-arm pain. Elbow valgus torque could not predict the presence of pain when holding body weight, height, and pitch velocity constant. Conclusion: The models demonstrated that increases in peak shoulder distraction forces when holding pitch velocity and body weight constant increased a youth baseball pitcher's likelihood of experiencing throwing-arm pain. The study results support the concept of the biomechanical efficiency framework by offering evidence that maintaining pitch velocity with a lower joint load led to a lower likelihood of pain. Clinical Relevance: Results suggest that practicing efficient movement strategies can decrease the likelihood of experiencing throwing-arm pain while maintaining performance.

Comparison of the efficacy of tibial transverse transfer and periosteal distraction techniques in the treatment of diabetic foot refractory ulcers.

Objective: To investigate the efficacy of comparing tibia transverse transport (TTT) and periosteal distraction in treating diabetic foot ulcers. Methods: A retrospective analysis of 19 patients with diabetic foot ulcers treated with both procedures between February 2020 and November 2022, 8 of whom were treated with the tibial transverse transfer technique (transfer group) and 11 with the osteochondral distraction technique (distraction group), was performed to compare and analyze the clinical efficacy of the two methods. Results: All wounds were healed in both groups, and the healing time ranged from 15 to 41days with a mean of 28d. The limb preservation rate was 100%. The operative time, intraoperative bleeding, and pain score in the operative area were significantly less in the distraction group than in the removal group, with statistically significant differences (P < 0.05). Intra-group comparison between the two groups of patients after surgery revealed that the skin temperature, ABI, TcPO2, SWM and VAS of the affected limb were significantly improved compared with those before surgery, and the difference was statistically significant (P < 0.05). The expression levels of VEGF, bFGF, EGF and PDGF were significantly higher than before surgery in both groups, and the difference was statistically significant (P < 0.05). No statistically significant differences were found in skin temperature, ABI, TcPO2, SWM, VAS, VEGF, bFGF, EGF and PDGF between the two groups at the corresponding time points preoperatively and postoperatively (P > 0.05). Conclusions: The Periosteal distraction technique can significantly promote the healing of diabetic foot ulcers. It has the same efficacy as TTT in promoting the healing of diabetic foot ulcer wounds and improving the peripheral circulation of affected limbs. In addition, the periosteal distraction technique has the advantages of small trauma, simple operation, few complications, and convenient nursing care.

Management of Obstructive Sleep Apnea in the Infant: A Systematic Review and Meta-analysis.

OBJECTIVE: To evaluate the improvement in respiratory parameters of infants with obstructive sleep apnea (OSA) treated with medical or surgical intervention. DATA SOURCES: A comprehensive review was completed using the PubMed, Web of Science, Embase, and Cochrane libraries including articles published from 1975 to 2024. REVIEW METHODS: Interventions studied included adenotonsillectomy, mandibular distraction osteogenesis (MDO), tongue/lip adhesion, partial glossectomy, floor-of-mouth release, supraglottoplasty, oral appliances, tracheostomy, and positioning. Continuous positive airway pressure (CPAP) served as a control. Outcomes studied included pre- and postintervention obstructive apnea-hypopnea index. Studies included randomized controlled trials and case-control trials. A total of 2161 records were identified, and 59 studies were included in the analysis. Data was extracted following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and pooled using a random-effects model. The primary study outcome established prior to data collection was a change in the apnea-hypopnea index. RESULTS: A meta-analysis of MDO performed in infants for OSA demonstrated an overall pooled mean difference (pre-apnea-hypopnea index minus post-apnea hypopnea index) of 30.1 (95% confidence interval: 22.9, 37.4; 10 studies, 373 patients). No other data was pooled for analysis due to study heterogeneity. All CPAP studies showed apnea resolution. Tailored therapies including supraglottoplasty and tongue-lip adhesion reduced but did not resolve apneic events. CONCLUSION: Current investigations of the evaluation and treatment of infant OSA are limited by heterogeneity in reporting and study. Mandibular distraction and CPAP are promising.

Anterior maxillary distraction for cleft palate associated severe hypoplastic maxillary Class III deformity during adolescence - A case report.

This report chronicles the case of an adolescent female with cleft palate associated severe hypoplastic maxillary Class III deformity. Treatment involved anterior maxillary segmental distraction osteogenesis (AMSDO) in conjunction with pre-distraction and post-distraction orthodontics. Following pre-distraction orthodontics, AMSDO was performed using a customized Hyrax distractor assembly. Post-distraction orthodontics helped stabilize distraction outcomes and finalize occlusion. Post-treatment, midface deficiency and prognathic profile improved dramatically with establishment of acceptable interincisal relationship and well-balanced functionally interdigitated occlusion. Three-year follow-up showed excellent morphologic and functional stability. AMSDO is a viable modality that contributes to effective stomatological rehabilitation of patients with cleft maxillary hypoplasia.

Distraction osteogenesis application in bone defect caused by osteomyelitis following mandibular fracture surgery: a case report and literature review.

BACKGROUND: Osteomyelitis secondary to mandibular fracture surgery is rare and complete surgical debridement of necrotic infected tissues is an optimal treatment for it. Subsequent reconstruction is required for bone defect caused by operation. Autogenous, allograft and synthetic bone graft substitutes have become widespread in bone defect treatment. Distraction osteogenesis (DO) was also applied in bone defect reconstruction, even it wasn't conventional therapy in jaw. CASE PRESENTATION: Here we report a case of a 40-year-old aged man who presented with chronic swelling and pain on the right mandibular masseteric region after mandibular angle and Le Fort II fracture surgery. In six weeks after surgery, CBCT images showed that the fracture ends hadn't heal and the fracture gap had widened significantly. The clinical diagnosis of the patient was right mandibular angle osteomyelitis. After controlling the symptoms of pain and infection with local rinses and systemic antibiotic therapy, the patient underwent segmental resection of the infected bone and DO reconstruction for bone defect simultaneously. Encouragingly, well bone healing and normal occlusion restoration was observed finally. CONCLUSIONS: DO could be a valuable alternative therapy to bone grafts for bone defect, even in the case of infection.

Development of a standardized and reproducible murine femoral distraction osteogenesis model.

Objective: Distraction osteogenesis (DO) has been widely used to treat bone defects as its effectiveness in bone regeneration. Currently, distraction devices for establishing DO models are mainly developed for rats or large animals. However, a mouse DO model is in great need for in-depth mechanistic investigations using various transgenic mice. The current study reports the development of a reproducible murine DO model. Methods: A mini-titanium lengthener was designed and fabricated. The mini-lengthener was applied on the murine femur with four threaded pins using a designed clamp as the drilling and insertion guide. After transverse osteotomy using a Gigli saw, and after 5 days of latency, DO procedures started at 0.3 mm/day for 10 days, and the consolidation period was left for 28 days. The bone formation was monitored by radiography and histology. Potential effects on animal locomotion during DO were also measured by behavior tests. Results: Separated bone segments maintained good alignment during the entire DO phases. New bone formation was found as early as the end of the distraction phase. Active bone remodeling was found between the separated bone segments at late distraction and early consolidation phases. At the mature consolidation phase, bone remodeling was mainly observed in the contact cortical bone. Mice underwent DO procedure did not have significant impairment in their locomotion. Conclusion: We have successfully developed a murine femoral DO model, which may be used to study the biological processes of DO. We also developed the mini-lengthener and the guide clamp to ensure the standardization and reproducibility of the mouse DO model.The translational potential of this article: Current study reports the development of a murine femoral DO model. A well-established murine DO model will facilitate further investigations of the biological mechanisms of DO in various transgenic and normal mice.

Changes of functional units in type IIA craniofacial microsomia before puberty-a preliminary computed tomography study.

BACKGROUND: The natural growth of the mandible in craniofacial microsomia (CFM) remains a topic of considerable debate. This study aims to characterize the mandibular architecture and its natural growth in children with type IIA CFM using functional unit analysis. MATERIALS AND METHODS: 16 sets CT data of 8 unoperated children with unilateral IIA CFM with an interval ranging from 2 to 6 years (3.4±1.5 years,AVR±SD)were collected. The baseline skeletal units' discrepancy in size, annual growth, and angular measurements were analyzed. RESULTS: The condylar, coronoid, and body units were smaller (reaching 63%, 79%, and 90% of the unaffected side, respectively) while the angular unit was larger on the affected side. The condylar unit on the affected side grew slower than the unaffected side, at about 60% of its rate, and other units showed no statistically significant bilateral differences. The backward rotation angle of the affected body unit (BUA) increased from T1 to T2. CONCLUSION: This preliminary study suggests that the condyle unit is the center of mandible deformity in type IIA CFM and exhibits insufficient growth relative to the unaffected side . Meanwhile, the hemi-mandible on the affected side rotated posteriorly during growth, thus worsening spatial relation. Future studies with larger sample sizes that incorporate clinical assessments are needed to elucidate the progression of CFM.

Finite element analysis of restoring length with multiple internal fixations in calcaneal body fracture.

Calcaneal body fractures are often associated with varying degrees of shortening deformities. Restoring calcaneal length is crucial for the functional prognosis of the foot. Through finite element analysis, this study compared the biomechanical effects of multiple fixation schemes for calcaneal fractures. We delineated and assembled the finite element model of the Sanders type II calcaneal fracture and four internal fixation simulations (namely distraction screw, lag screw, frame locking plate, and T-shaped locking plate). Different axial forces (350, 700, and 1400 N) were then applied to simulate various postures. We then compared the inner and outer shortening distances (D1 and D2, respectively), equivalent von Mises stress, and maximum von Mises stress of the calcaneus. In the individual model, with an increase in the pressure, D1, D2, and the maximum von Mises stress gradually increased. At 1400 N, D1 and D2 for the internal fixation schemes were as follows: distraction screw (0.03 mm, 0.1 mm) < T-shaped locking plate (0.45 mm, 0.26 mm) < frame locking plate (0.50 mm, 0.26 mm) < lag screw (0.66 mm, 0.64 mm). The maximum von Mises stress values for the internal fixation methods were as follows: lag screw (491.0 MPa) < distraction screw (663.1 MPa) < frame locking plate (772.7 MPa) < T-shaped locking plate (931.8 MPa). In patients with calcaneal body fractures, the distraction screw is a potential therapeutic option for resisting calcaneal shortening.

Application of the Modified RUST Score in Tibial Bone Transport and Factors Associated with Docking Site Complications.

Aim: Reconstruction of segmental bone defects with bone transport is a well-established treatment. Mechanical complications at the docking site after frame removal are common. These complications include malunion, non-union, axial deviation and refracture. A simple tool to assess the healing of the docking site is currently lacking. The aim of this study is to evaluate the use of the modified RUST (mRUST) score in the setting of bone transport and to identify factors associated with an increased risk of docking site complications. Methods: This retrospective study was conducted at a single tertiary centre in South Africa, included 24 patients with a tibial bone defect treated with bone transport and a circular frame between 2014 and 2023. Demographic data, clinical and bone transport characteristics were recorded. Mechanical complications, such as fracture, non-union, any angulation >5°, shortening >5 mm, or any other complication requiring reoperation, were recorded. The mRUST was adapted as a ratio for the purpose of this study to overcome the common occurrence of cortices being obscured by the frame. The mRUST ratio was applied before and after frame removal for each patient by three appraisers. Comparison between the groups with and without complications was performed regarding bone transport characteristics, docking site configuration and mRUST ratio. The correlation of the score between radiographs before and after frame removal was assessed. The inter-rater reliability of the mRUST was analysed using Fleiss Kappa statistics for each cortex individually and the intraclass correlation coefficient (ICC) for the mRUST ratio. Results: In this study, 20 men and 4 women with a median age of 26 years were included. The overall rate of mechanical complications after frame removal was 21.7%. Complications were all related to the docking site, with two angulations, two fractures and one non-union. Demographics, bone transport characteristics and mRUST ratio before and after frame removal were similar between the two groups. Regarding the configuration of the docking site, an angle of 45° or more between the bone surfaces was associated with the occurrence of mechanical complications (p < 0.001). The correlation of the mean mRUST ratio before and after frame removal showed a moderate relationship, with a Spearman correlation coefficient of 0.50 (p-value 0.13). The inter-rater reliability of the mRUST was "fair" (kappa 0.21-0.40) for the scoring of individual cortices, except for one score which was "slight" (kappa 0.00-0.20). The ICC of the mRUST ratio was 0.662 on radiographs with the frame, and 0.759 after frame removal. Conclusion: This study did not find the mRUST or mRUST ratio useful in assessing the healing of the docking site to decide on the best time to remove the frame. However, a notable finding was that the shape and orientation of the bone ends meeting at the docking site might well be relevant to decrease complication rates. If the angle between the bony surfaces is 45° or more, it may be associated with an increased risk of complications. It may be worthwhile considering reshaping these bone ends at the time of debridement or formal docking procedure to be more collinear, in order to reduce the potential for mechanical complications such as non-union, axial deviation or refracture at the docking site. How to cite this article: Kummer A, Nieuwoudt L, Marais LC. Application of the Modified RUST Score in Tibial Bone Transport and Factors Associated with Docking Site Complications. Strategies Trauma Limb Reconstr 2024;19(2):73-81.

[Preliminary application of ulnar cortex transverse transport technique in treatment of upper extremity thromboangiitis obliterans].

Objective: To investigate the feasibility and effectiveness of ulnar cortex transverse transport technique in treating upper extremity thromboangiitis obliterans (TAO). Methods: A retrospective analysis was conducted on the clinical data of 7 male patients with upper extremity TAO who were admitted and met the inclusion criteria between January 2019 and July 2022. The patients ranged in age from 32 to 50 years, with a mean age of 40.1 years. The disease duration ranged from 6 to 24 months, averaging 13.6 months. The smoking history ranged from 8 to 31 years, with a mean of 18.4 years. All patients presented with finger ulcers or gangrene, including 1 case affecting the thumb and index finger, 1 case affecting the index and middle fingers, 1 case affecting the middle and ring fingers, 1 case affecting only the ring finger, and 3 cases affecting the ring and little fingers. The preoperative visual analogue scale (VAS) score was 9.1±0.7. All patients underwent treatment with the ulnar cortext transverse transport technique. The wound healing time and the disappearance time of rest pain were recorded. The VAS score was used to assess the degree of hand pain before and after operation. Serum interleukin 6 (IL-6) levels were measured before operation and at 1 month after operation. Computed tomography angiography (CTA) of the affected limb was performed before operation and at 3 months after operation to evaluate changes in blood vessels. The clinical outcomes were evaluated at 1 year after operation based on the Patwa and Krishnan grading system. Results: All 7 patients were followed up 12-17 months, with an average of 13.7 months. All patients experienced successful healing of ulcers, with wound healing time ranging from 14 to 21 days, averaging 17.3 days. During the follow-up, no complication occurred, and there was no recurrence of ulcers. The disappearance time of rest pain ranged from 8 to 15 days, averaging 12.1 days. The pre- and post-operative (1-month) serum IL-6 levels were (25.1±5.9) pg/mL and (11.9±2.9) pg/mL, respectively, with a significant difference ( t=5.363, P=0.002). CTA examination at 3 months after operation revealed partial revascularization of upper extremity arteries and establishment of collateral circulation, showing significant improvement compared to preoperative status. The VAS scores at 1, 7, 28 days, and 6 months postoperatively were 6.4±0.8, 3.7±0.8, 0.6±0.8, and 0.1±0.4, respectively, all of which significantly improved compared to preoperative scores ( P<0.05). Furthermore, the VAS scores gradually decreased over time, with significant differences observed between postoperative time points ( P<0.05). At 1 year after operation, the effectiveness of all 7 patients were evaluated as excellent based on the Patwa and Krishnan grading system. Conclusion: The ulnar cortex transverse transport technique can improve blood circulation in the upper limb of patients with TAO, reconstruct microcirculation, inhibit inflammation, promote ulcer healing, and alleviate limb pain.

Matched comparison of non-fusion surgeries for adolescent idiopathic scoliosis: posterior dynamic distraction device and vertebral body tethering.

PURPOSE: Two non-fusion devices for adolescent idiopathic scoliosis (AIS) received HDE approval for clinical use in 2019: posterior dynamic distraction device (PDDD) and vertebral body tethering system (VBT). Although indications are similar, there is no comparative study of these devices. We hypothesize that curve correction will be comparable, but PDDD will have better perioperative metrics. METHODS: AIS PDDD patients were prospectively enrolled in this matched multicenter study. Inclusion criteria were Lenke 1 or 5 curves, preoperative curves 35°-60°, correction to ≤30° on bending radiographs, and kyphosis <55°. Patients were matched by age, sex, Risser, curve type and curve magnitude to a single-center cohort of VBT patients. Results were compared at 2 years. RESULTS: 20 PDDD patients were matched to 20 VBT patients. Blood loss was higher in the VBT cohort (88 vs. 36 ml, p < 0.001). Operative time and postoperative length of stay were longer in the VBT cohort, 177 vs. 115 min (p < 0.001) (2.9 vs. 1.2 days, p < 0.001). Postoperative curve measurement and correction at 6 months were better in the PDDD cohort (15° vs. 24°, p < 0.001; 68% vs. 50%, p < 0.001). At 1-year, PDDD patients had improved Cobb angles (14° vs. 21°, p = 0.001). At 2 years, a correction was improved in the PDDD cohort, with a curve measurement of 17° for PDDD and 22° for VBT (p = 0.043). At the latest follow-up, 3 PDDD patients and 1 VBT patient underwent revision surgery. CONCLUSION: Early results show PDDD demonstrates better index correction, reduced operative time, less blood loss, and shorter length of stay but higher rates of revision compared to a matched cohort of VBT patients at two-year follow-up. LEVEL OF EVIDENCE: Level II, prospective cohort matched comparative study.

A Rare Case of Posterior Dislocation of Hinge Knee Prosthesis due to Wear of Anti-Luxation Device: A Case Report.

Introduction: Hinge knee joint prosthesis are utilized in a variety of surgical scenarios, including complex primary, revision, salvage surgeries, and radical resection of tumor's. Link's Endo-model Hinged Knee Prosthesis is a newer design that includes ramped tibial components for controlled pivot point motion during flexion and an anti-dislocation feature to prevent prosthesis dislocation.. The re-design of the hinge prosthesis has resulted in less force transfer along the implant bone junction. However, despite the improved design, complications can still arise. This report presents a rare complication of posterior dislocation due to polythene wear of the anti-dislocation device in a patient with a rotating hinge knee prosthesis. Case Report: After 4 years, a 42-year-old patient who had undergone multiple total knee replacements (TKRs) with a history of pain, swelling, and difficulty walking for the previous 2 months presented to us. Radiographs from the initial presentation revealed aseptic loosening, for which a revision TKR using a Link-Waldemier non-modular (rotational) joint endo-model with an anti-dislocation mechanism was performed. Three years later, the patient began experiencing episodes of instability, and a radiograph revealed posterior dislocation of the hinge knee prosthesis. As a result, a decision was made to perform revision surgery, during which the worn-out polyethylene was replaced with a new polyethylene insert, and stability was confirmed intraoperatively. Four weeks after surgery, the patient's knee range of motion was 0-120°, and all discomfort had completely subsided. At a year's follow-up, the patient's Knee Society score had improved from 40 before surgery to 90 after surgery. Conclusion: Interference in the normal framework of knee anatomy distorts its intrinsic stability. This interference can be in variable form such as bone deficiency, infection, multiple revision surgeries, and ligamentous laxity. Restoration of intrinsic stability in today's world has been made possible by a highly constraint, hinged knee prosthesis. An anti-dislocation mechanism on the rotating hinge prosthesis guards against dislocation brought on by distracted engagement. In our instance, the anti-dislocation mechanism had aseptically loosened, increasing flexion laxity and permitting severe distraction. The anti-dislocation mechanism will eventually relax, but its lifespan can be increased by proper gap balancing, which offers inherent stability and increases the anti-dislocation mechanism's stability.

Cognitive dual-task does not annihilate the negative effects of gender stereotype threat on girls' motor learning.

Stereotype threat, a key concept in social psychology, occurs when individuals fear they may confirm negative stereotypes about their social group (Steele, 1997). This phenomenon can significantly impair motor learning, particularly in children. Given the robust nature of stereotype threat, research it is now focused on mitigating these negative effects. According to the explicit monitoring hypothesis, it is suggested that distracting individual's attention can lead to an annihilation of stereotype threat effects, however, to date, this hypothesis has not been examined in children. The present study examined the effect of stereotype threat in a dual task condition on children's motor learning. One hundred and fifty girls (mean age = 10.96 ± .80 years) were randomly assigned into 3 groups; 1- explicit gender stereotype threat; 2- explicit gender stereotype threat + dual task; 3- control. The task consisted of a soccer-kicking task in which the participants had to score the most points by kicking the soccer ball towards the goals on the wall. This study included three phases; 1- pretest (10 trials); 2- practice phase (5 blocks of 10 trials); 3- retention test (10 trials). During the practice phase, the results indicated that participants in the control condition performed better (M = 1.46, SD = .19) than participants in the gender stereotype threat condition (M = 1.25, SD = .16, p < .001), and, than participants in the gender stereotype threat + dual task paradigm condition (M = .92, SD = .19, p < .001). However, participants in the gender stereotypes + dual task paradigm condition performed worse than participants in the gender stereotype threat condition (p < .001). In addition, the results of the retention test showed that participants in the control condition performed better (M = 1.51, SD = .34) than participants in the gender stereotype threat condition (M = 1.24, SD = .35, p = .001), and participants in the gender stereotype threat + dual task paradigm condition (M = 1.15, SD = .49, p < .001). In conclusion, these results do not support the potential neutralizing effect of a cognitive dual task in a stereotype threat condition in children.

AVATAR 2.0: next level communication systems for radiotherapy through face-to-face video, biofeedback, translation, and audiovisual immersion.

Purpose: This paper discusses an advanced version of our audiovisual-assisted therapeutic ambience in radiotherapy (AVATAR) radiolucent display systems designed for pediatric radiotherapy, enabling anesthesia-free treatments, video communication, and biofeedback. The scope of the AVATAR system is expanded here in two major ways: (i) through alternative mounting systems to accommodate a broader range of radiotherapy machines (specifically to fit robotic-arm and toroidal geometry photon radiotherapy and proton radiotherapy systems) and (ii) through additional hardware to provide video-calling, optimized audio for clear communication, and combined video inputs for biofeedback, translation, and other advanced functionalities. Methods and materials: Because robustness requires strong parts and radio-transparency requires thin, light parts, three-dimensional printing was used to rapidly prototype hollow structures and to iteratively improve robustness. Two system designs were made: one that mounts superior and another that mounts inferior to the patient's head. Radiation dose measurements and calculations were conducted to assess dose perturbations at surface and depth due to the screen. Results: For 6-MV volumetric modulated arc therapy (VMAT) plans, with and without the screen, the mean and maximum dose differences inside the planning target volume were 0.2% and 2.6% of the 200 cGy prescription, respectively. For a single static beam through the screen, the maximum measured excess surface dose was 13.4 ± 0.5%, and the largest measured dose attenuation at 5-cm water-equivalent depth was 2.1 ± 0.2%. These percentages are relative to the dose without the screen at those locations. Conclusions: The radiolucent screen systems provided here are shown to give minimal dosimetric effects on megavoltage VMAT photon treatments. For static beams, however, surface dose effects should be considered when these beams pass through the thickest components of the screen. Design files are also provided.

Promotion of mandibular distraction osteogenesis by parathyroid hormone via macrophage polarization induced through iNOS downregulation.

Objective: To investigate whether Parathyroid hormone (PTH) can promote mandibular distraction osteogenesis by regulating macrophage polarization and the underlying mechanisms of this phenomenon. Methods: Forty-eight Rabbits were used to establish the mandibular distraction osteogenesis experimental model, randomly divided into 2 groups. Intermittent post-operative injections of 20 µg/kg PTH and normal saline were administered to the experimental and control groups, respectively. Regenerated new bone was examined using HE staining, osteoclast numbers were determined through tartrate-resistant acid phosphatase (TRAP) staining, and macrophage polarization markers arginase 1 (Arg1) and inducible nitric oxide synthase (iNOS) expressions were elucidated using immunohistochemistry (IHC), the mRNA expression of CD206, CD11C, Arg1 and iNOS were detected using qPCR. Results: The bone trabeculae in the experimental group were thicker, with a more homogeneous structure and more new osteoid than in the control group. In the area of distraction osteogenesis, the osteoclast count in the experimental group was higher than in the control group (P < 0.05). IHC results indicated differential expressions of Arg1 and iNOS in the experimental group compared to the control group (P < 0.05). Relative mRNA expressions of CD11c and iNOS were lower in the experimental group than in the control group (P < 0.05), whereas the expressions of CD206 and Arg1 mRNA were higher in the experimental group compared to the control group (P < 0.05). Conclusion: Intermittent PTH injections increased macrophage quantity in the mandible generated by distraction osteogenesis, downregulated iNOS, upregulated Arg1, and promoted macrophage polarization from M1 to M2 phenotype, thereby promoting mandibular distraction osteogenesis.