Aims. The first metatarsal pronation deformity of hallux valgus feet is widely recognized. However, its assessment relies mostly on 3D standing CT scans. Two radiological signs, the first metatarsal round head (RH) and inferior tuberosity position (ITP), have been described, but are seldom used to aid in diagnosis. This study was undertaken to determine the reliability and validity of these two signs for a more convenient and affordable preoperative assessment and postoperative comparison. Methods. A total of 200 feet were randomly selected from the radiograph archives of a foot and ankle clinic. An anteroposterior view of both feet was taken while standing on the same x-ray platform. The intermetatarsal angle (IMA), metatarsophalangeal angle (MPA), medial sesamoid position, RH, and ITP signs were assessed for statistical analysis. Results. There were 127 feet with an IMA > 9°. Both RH and ITP severities correlated significantly with IMA severity. RH and ITP were also significantly associated with each other, and the pronation deformities of these feet are probably related to extrinsic factors. There were also feet with discrepancies between their RH and ITP severities, possibly due to intrinsic torsion of the first metatarsal. Conclusion. Both RH and ITP are reliable first metatarsal pronation signs correlating to the metatarsus primus varus deformity of hallux valgus feet. They should be used more for preoperative and postoperative assessment. Cite this article: Bone Jt Open 2024;5(11):1037–1040

Introduction. Previous studies have shown the potential for virtual reality (VR) immersion as a promising technique for pain and anxiety management. The aim of our study was to evaluate the feasibility of VR in the management of pain and anxiety during post-op external fixator care procedures. Method. This study involved patients aged 5-21 years following limb lengthening/reconstruction surgery with an external fixator. Aqua VR application from the KindVR® was utilized for this study. Subjects were seen during the first four postoperative visits and assigned to a ‘VR-first’ or ‘no-VR-first’ group. Visits alternated between VR immersion and no VR immersion during care procedures. The study endpoints (pain and anxiety levels) were assessed before, during, and after procedures using the Wong-Baker Faces (FACES) and Children's Fear Scale, respectively. Proxy scores for pain and anxiety were also obtained from parents or legal guardians and providers. Result. A total of 29 patients (16 male and 13 female) were evaluated. The mean age at enrollment was 14.4 ± 2.2 years for group 1 and 14.7 ± 4.0 years for group 2. The median number of pin sites was 7. Anxiety scores were consistently higher during the non-VR immersion experience compared to the VR immersion visits. The pain and anxiety scores were significantly lower in the ‘VR-first’ group during the non-VR immersion study visits compared to patients in the ‘no-VR-first’ group. This observation was also consistent with survey findings among the parent proxies and providers. Conclusion. VR immersion is associated with lower anxiety scores for pin-site care procedures. VR immersion at the first post-operative visit following limb reconstruction surgery was also associated with lower pain and anxiety scores during subsequent non-VR immersion visits

Background. The molecular mechanisms underlying non-union bone fractures largely remain elusive. Recently, spatial transcriptomics approaches for musculoskeletal tissue samples have been developed requiring direct placement of histology sections on barcoded slides. However, Formalin-Fixed-Paraffin-Embedded (FFPE) bone sections have been associated with limited RNA quality and read depth compared to soft tissue. Here, we test spatial transcriptomics workflows based on transcriptomic probe transfer to characterize molecular features discriminating non-union and union bone fractures in mice. Method. Histological sections (n=8) used for spatial transcriptomics (Visium CytAssist FFPE; 10x Genomics, n=4 on glass slides, n=4 on hydrogel-coated slides) were obtained from a fracture healing study in female 20-week-old C57BL/6J mice receiving either a femur osteotomy (0.7mm) or a segmental defect (2.4mm) (license 22/2022, Grisons CH). Sequence alignment and manual segmentation of different tissues (bone, defect region/callus, bone marrow, muscle) were performed using SpaceRanger and LoupeBrowser (10x Genomics). Differential gene expression was performed using DESeq2 (Seurat) followed by Gene-Set-Enrichment-Analysis (GSEA) of Gene Ontology (ClusterProfiler). Group comparison of quality measures was done using a Welch's t-test. Results are given as mean±standard deviation. Result. The quality measures, mean counts, and genes per spot, were significantly ~10× higher for sections on hydrogel slides (counts: 4700±1796, genes: 2389±1170) compared to glass slides (counts: 463±415, genes: 250±223). In challenging tissues like cortical bone, we reached high counts+genes in comparison to published data. Direct comparison of a non-union and union section showed a total of 432 differentially regulated genes, 538 in the defect region/callus. GSEA revealed differential regulation of pathways involved in muscle organ morphogenesis, cartilage development and endochondral ossification. Conclusions. Optimized spatial transcriptomics workflows based on transcriptomic probe transfer enable for improved read depth in musculoskeletal tissue enabling the characterization of molecular features discriminating non-union and union bone fractures. Acknowledgements. AO Foundation (AOTRAUMA), SNSF (PhD salary)

Introduction. The heterogeneity of outcomes used in the field of lower limb lengthening surgery (LLLS) affects our ability to synthesize evidence. This hampers robust systematic reviews and treatment recommendations for clinical practice. Ultimately this reduces the impact of research for both patients and healthcare professionals. This scoping review aimed to describe the outcomes and outcome measurement instruments (OMIs) used within the field of LLLS. Method. A systematic literature search of WOS, Scopus, Embase, MEDLINE, and the Cochrane Library identified all studies reporting outcomes in children and adults after LLLS. All outcomes and OMIs were extracted verbatim. An iterative process was used to group outcome terms under standardized outcome headings categorized using the COMET Taxonomy of Outcomes. Result. Data saturation was achieved in 2020. A total of 142 studies were included between 2024-2020, reporting 2964 verbatim outcomes with 663 standardized outcome terms collapsed into 119 outcome headings (subdomains). A total of 29 patient-reported and 26 clinician-reported outcome instruments were identified. The most commonly reported outcome was “Lengthening amount”, reported in over 72% of the included studies, while “health-related quality of life” was measured in 16% and all life impact outcomes were reported in 19% of the included studies. Conclusion. A large number of peer-reviewed publications are available, demonstrating that significant resources are being devoted to research on LLLS. However, reported outcomes for people with LLLS are heterogeneous, subject to reporting bias, and vary widely in the definitions and measurement tools used to collect them. Outcomes likely to be important to patients, such as quality of life and measures of physical function, have been neglected. This scoping review identifies a need to standardize outcomes and outcome measures reported on patients recovering from lower limb lengthening surgery; this can be addressed by creating a core set of outcomes

Introduction. Experimental bone research often generates large amounts of histology and histomorphometry data, and the analysis of these data can be time-consuming and trivial. Machine learning offers a viable alternative to manual analysis for measuring e.g. bone volume versus total volume. The objective was to develop a neural network for image segmentation, and to assess the accuracy of this network when applied to ectopic bone formation samples compared to a ground truth. Method. Thirteen tissue slides totaling 114 megapixels of ectopic bone formation were selected for model building. Slides were split into training, validation, and test data, with the test data reserved and only used for the final model assessment. We developed a neural network resembling U-Net that takes 512×512 pixel tiles. To improve model robustness, images were augmented online during training. The network was trained for 3 days on a NVidia Tesla K80 provided by a free online learning platform against ground truth masks annotated by an experienced researcher. Result. During training, the validation accuracy improved and stabilised at approx. 95%. The test accuracy was 96.1 %. Conclusion. Most experiments using ectopic bone formation will yield an inter-observer or inter-method variance of far more than 5%, so the current approach may be a valid and feasible technique for automated image segmentation for large datasets. More data or a consensus-based ground truth may improve training stability and validation accuracy. The code and data of this project are available upon request and will be available online as part of our publication

Introduction. Knee Osteoarthritis (KOA) is a prevalent joint disease requiring accurate diagnosis and prompt management. The condition occurs due to cartilage deterioration and bone remodeling. Ultrasonography has emerged as a promising modality for diagnosing KOA. Medial meniscus extrusion (MME), characterized by displacement of medial meniscus beyond the joint line has been recognized as a significant marker of KOA progression. This study aimed to explore potentials Ultrasound findings in timely detection of MME and compare it to magnetic resonance imaging (MRI) as a reference standard. Method. A comprehensive literature search was performed in 4 databases from inception to May 1 2024. Two independent reviewers, initiated screening protocols and selected the articles based on inclusion and exclusion criteria and then extracted the data. Meta-analysis was conducted using R 4.3.2 packages mada and metafor. Result. A total of 2500 articles from 4 databases was retrieved; however, following the application of inclusion and exclusion criteria 23 articles were finally extracted. These studies collectively encompassed a total of 777 patients with mean age of 53.2±7.4. The mean BMI calculated for patients was 28.31 ± 2.45. All patients underwent non-weight bearing knee ultrasonography in supine position with 0° flexion. The reported medial meniscus extrusion was 2.58 mm for articles using MRI and 2.65 mm for those using Ultrasound (MD: 0.05 ± 0.12, P= 0.65, I. 2. : 54%). Our meta-analysis revealed insignificant difference between US and MRI. (SMD: 0.03, 95% CI: -0.18 _0.23, P= 0.77, I. 2. : 56%) Meta analysis for diagnostic accuracy measures yielded a pooled sensitivity and specificity of 90.8% and 77% (95% CI: 84.2% – 94.8%, 35.5% – 95.3%, respectively, I. 2. : 44%). Conclusion. Our results indicate a close alignment in the accuracy of measurements obtained using Ultrasound modality. The narrow range suggests a minimal discrepancy in MME values between MRI and ultrasound, highlighting their comparable precision in diagnostic assessments

Introduction. The most frequent diagnosis in young adults undergoing total hip arthroplasty (THA) is osteonecrosis of the femoral head (ONFH), an evolving and disabling condition with an increasing prevalence worldwide. Treatment of ONFH remains a challenge mainly because of a lack of understanding of the disease's pathophysiological basis. This study investigated the biological processes that could be affected by ONFH by comparing the microstructure, histological characteristics and transcriptomic profile of trabecular bone from the femoral head (FH) and the intertrochanteric region (IT) of patients suffering from this condition. Method. A total of 18 patients with idiopathic ONFH undergoing THA in our institution were included. Trabecular bone explants were taken intraoperatively from the FH and the IT of patients. Bone microstructure was examined by micro-computed tomography (micro-CT). After bone sectioning, histological features were studied by hematoxylin and eosin staining. Differential gene expression was investigated using a microarray platform. Result. Micro-CT imaging showed higher trabecular separation and lower trabecular thickness and bone volume in trabecular bone from the FH than from the IT. Histological staining revealed that the number of osteoblasts on the bone surface and the percentage of empty lacunae were higher in trabecular bone from the FH. Transcriptome analysis identified a differential signature in trabecular bone from the FH compared to the IT. The gene ontology analyses of the genes overexpressed in trabecular bone from the FH revealed a range of enriched biological processes related to cell division and immune response. In contrast, most downregulated transcripts were involved in bone formation. Conclusion. This study identified changes in the microarchitecture, histological features and transcriptomic signature of trabecular bone from the FH of patients with idiopathic ONFH, which might underlie the pathophysiology of this condition. This work was supported by PI22/00939 grant from ISCIII-FEDER-MICINN-AES and Luis Alvarez grant from IdiPAZ

Introduction. Tendon ruptures represent one of the most common acute tendon injuries in adults worldwide, affecting millions of people anually and becoming more prevalent due to longer life expectancies and sports activities. Current clinical treatments for full tears are unable to completely restore the torn tendons to their native composition, structure and mechanical properties. To address this clinical challenge, tissue-engineered substitutes will be developed to serve as functional replacements for total tendon ruptures that closely resemble the original tissue, restoring functionality. Method. Water borne polyurethanes (WBPU) containing acrylate groups, specifically polyethylene glycol methacrylate (PEGMA) or 2-hydroxyethyl methacrylate (HEMA), were combined with mouse mesenchymal stem cells (MoMSCs) and heparin sodium to formulate bioinks for the fabrication of scaffolds via extrusion-based 3D bioprinting. Result. The biocompatibility of acrylated-WBPUs was confirmed in 2D with MoMSCs using lactate dehydrogenase assay, DNA assay and live/dead assays. Cell-laden scaffolds were 3D-bioprinted by encapsulating MoMSCs at varying cell densities within the acrylated WBPUs. The resulting 3D structures support cell viability and proliferation within the scaffolds, as confirmed by live/dead assay, lactate dehydrogenase assay and DNA assays. Differentiation studies in the 3D-bioprinted scaffolds demonstrated the phenotype transition of MoMSCs toward tenocytes through gene expression and protein deposition analysis. The inclusion of sodium heparin in the bioinks revealed increased synthesis of matrix assembly proteins within the 3D-bioprinted constructs. Conclusion. The developed bioinks were biocompatible and printable, supporting cell viability within the 3D-bioprinted scaffold. The fabricated cell-laden constructs sustained cell proliferation, differentiation, and tissue formation. The addition of heparin sodium enhanced tissue formation and organization, showing promising results for the regeneration of tendon total ruptures. Principio del formularioThis work was supported by the Spanish State Research Agency (AEI) under grant No CPP2021-008754. The authors would like to thank their partners in the project, which are in charge of the synthesis of heparin sodium and acrylated-WBPUs

Introduction. Knee osteoarthritis often causes malalignment and altering bone load. This malalignment is corrected during total knee arthroplasty surgery, balancing the ligaments. Nonetheless, preoperative gait patterns may influence postoperative prosthesis load and bone support. Thus, the purpose is to investigate the impact of preoperative gait patterns on postoperative femoral and tibial component migration in total knee arthroplasty. Method. In a prospective cohort study, 66 patients with primary knee osteoarthritis undergoing cemented Persona total knee arthroplasty were assessed. Preoperative knee kinematics was analyzed through dynamic radiostereometry and motion capture, categorizing patients into four homogeneous gait patterns. The four subgroups were labeled as the flexion group (n=20), the abduction (valgus) group (n=17), the anterior drawer group (n=10), and the tibial external rotation group (n=19). The femoral and tibial component migration was measured using static radiostereometry taken supine on the postoperative day (baseline) and 3-, 12-, and 24- months after surgery. Migration was evaluated as maximum total point motion. Result. Of the preoperatively defined four subgroups, the abduction group with a valgus-characterized gait pattern exhibited the highest migration for both the femoral (1.64 mm (CI95% 1.25; 2.03)) and tibial (1.21 mm (CI95% 0.89; 1.53)) components at 24-month follow-up. For the femoral components, the abduction group migrated 0.6 mm (CI95% 0.08; 1.12) more than the external rotation group at 24 months. For the tibial components, the abduction group migrated 0.43 mm (CI95% 0.16; 0.70) more than the external rotation group at 3 months. Furthermore, at 12- and 24-months follow-up the abduction group migrated 0.39 mm (95%CI 0.04; 0.73) and 0.45 mm (95%CI 0.01; 0.89) more than the flexion group, respectively. Conclusion. A preoperative valgus-characterized gait pattern seems to increase femoral and tibial component migration until 2 years of follow-up. This suggests that the implant fixation depends on load distributions originating from specific preoperative gait patterns

Introduction. Distal femur fractures around a total knee arthroplasty (TKA) are a growing problem for orthopaedic surgeons. The purpose of this study was to identify risks of reoperation for nonunion following open reduction and internal fixation of TKA periprosthetic distal femur fractures (PDFF). Method. Patients with PDFF (AO 33A-C[VB1, C1, D1], Su types 1-3) managed operatively with open reduction and internal fixation (ORIF) were retrospectively reviewed. Exclusion criteria were acute management with a distal femur replacement, less than 6 months of follow-up, and lack of injury or follow-up radiographs. The primary outcome measure was reoperation to achieve bony union. Comparisons were made between cases that did and did not require a reoperation to achieve union. Univariate analysis was used to identify factors to be analyzed in multivariate analysis to determine independent risk factors for the primary outcome. Result. A total of 77 patients met inclusion criteria. Union rate was 69/77 (89.6%). There were no differences between the groups for age, sex, BMI, comorbidities, Su classification, open injury, or mechanism of injury. Multivariate analysis identified risks for nonunion including post-operative malalignment (OR 1.41; CI 1.20-1.64; p<0.001), notching pre-operatively (OR 1.22; CI 1.04-1.42; p=0.012), presence of screws through fracture line (OR 1.28; CI 1.17-1.39; p<0.001), plate length <12 holes (OR 1.16; CI 1.02-1.33; p=0.024) and screw density greater than 0.4 (OR 2.18; CI 1.25-3.78; p=0.006). Conclusion. The reoperation rate to promote union was 10.4%. The study identified post-operative malalignment, notching pre-operatively, presence of screws through fracture line, plate length <12 holes, and proximal screw density greater than 40% as independent risk factors for nonunion

Introduction. Cephalomedullary nailing (CMN) is commonly used for unstable pertrochanteric fracture. CMN is relatively safe method although various complications can potentially occur needing revision surgery. Commonly used salvage procedures such as renailing, hemiarthroplasty, conservative treatment or total hip arthroplasty (THA) are viable alternatives. The aim was to investigate the rate of THA after CMN and evaluate the performance on conversion total hip arthroplasty (cTHA) after failure of CMN. Method. Collected data included patients from two orthopedic centers. Data consisted of all cTHAs after CMN between 2014-2020 and primary cementless THA operations between 2013-2023. Primary THA operations were treated as a control group where Oxford Hip Score (OHS) was the main compared variable. Result. From 2398 proximal femoral hip procedures 1667 CMN procedures were included. Altogether 46/1667 (2.8%) CMNs later received THA. Indications for THA after CMN failure were 13 (28.3%) cut-outs, nine (19.6%) cut-throughs, eight (17.4%) nail breakages, seven (15.2%) post traumatic arthrosis, seven (15.2%) nonunions, one (2.2%) malunion and one (2.2%) collum screw withdrawal. Mean (SD) time to complication after CMN operation is 5.9 (6.8) months. Mean (SD) time from nail procedure to THA was 10.4 (12.0) months. Total complication rate for cTHA after CMN was 17.4%. Reported complications were infection with seven (15.2%) cases and one (2.2%) nerve damage. Mean (SD) time to cTHA complication was 3.6 (6.1) months. One-sample T-test showed OHS to be significantly better (P<.001) for primary cementless THA compared to cTHA after one year. Conclusion. Altogether 2.8% of CMN were converted to THA. Nearly half (47.8%) of the cTHA procedures were due to CMN cut-out or cut-through. OHS was significantly better in primary cementless THA compared to cTHA. Prosthetic joint infection was the most frequent complication related to cTHA

Introduction. A recent study to identify clinically meaningful benchmarks for gait improvement after total hip replacement (THA) has shown that the minimum clinically important improvement (MCII) in gait speed after THA is 0.32 m/sec. Currently, it remains to be investigated what preoperative factors link to suboptimal recovery of gait function after THA. This study aimed to identify preoperative lower-limb muscle predictors for gait speed improvement after THA for hip osteoarthritis. Method. This study enrolled 58 patients who underwent unilateral primary THA. Gait speed improvement was evaluated as the subtraction of preoperative speed from postoperative speed at 6 months after THA. Preoperative muscle composition of the glutei medius and minimus (Gmed+min) and the gluteus maximus (Gmax) was evaluated on a single axial computed tomography slice at the bottom end of the sacroiliac joint. Cross-sectional area ratio of individual composition to the total muscle was calculated. Result. The females (n=45) showed smaller total cross-sectional areas of the gluteal muscles than the males (n=13). Gmax in the females showed lower lean muscle mass area (LMM) and higher ratios of the intramuscular fat area and the intramuscular adipose tissue area to the total muscle area (TM) than that in the males. Regression analysis revealed that LMM/TM of Gmed+min may correlate negatively with postoperative improvement in gait speed. Receiver operating characteristic curve analysis for prediction of MCII in gait speed at ≥ 0.32 m/sec resulted in the highest area under the curve for Gmax TM with negative correlation. The explanatory variables of hip abductor muscle composition predicted gait speed improvement after THA more precisely in the females compared with the total group of both sexes. Conclusion. Preoperative Gmax TM could predict gait speed MCII after THA. Preoperative muscle composition should be evaluated separately based on sexes for achievement of clinically important improvement in gait speed after THA

Introduction. The non-union of long bones poses a substantial challenge to clinicians and patients alike. The Ilizarov fixation system and Limb Reconstruction System (LRS), renowned for their versatility in managing complex non-unions. The purpose of this retrospective study was to assess the outcomes of acute docking with the bone peg-in-bone technique for the management of non-unions of long bones. The study seeks to evaluate its effectiveness in achieving complete bony union, preserving limb length and alignment, correcting existing deformities, and preventing the onset of new ones. Method. A retrospective analysis of 42 patients was done with infected and non-infected non-unions of long bones who received treatment at a tertiary care hospital between April 2016 to April 2022. We utilized the Association for the Study and Application of Methods of the Ilizarov (ASAMI) scoring system to assess both bone and functional outcomes and measured mechanical lateral distal femoral angle (mLDFA) for the femur and the medial proximal tibial angle (MPTA) for the tibia. Result. In our retrospective study involving 42 patients, a total of 30 patients had post debridement gap of >2 cm and average gap of 4.54 cm (range 1 – 13 cm) and therefore underwent corticotomy and lengthening. The average external fixation time was 6.52 (range 4 – 11 months) and average external fixation index of 2.08 (range 0.4 – 4.5 months/cm). The ASAMI scoring system showed bone result of 38 excellent, 3 good and 1 fair. Functional result of 40 excellent and 2 good outcomes. The post op mLDFA and MPTA were in normal range except in 3 patients which not statistically significant. Conclusion. In conclusion, the use of acute docking provides several advantages such as promoting early fracture healing, increasing stability, shortening treatment time, reducing the number of surgical procedures and reduced number of complications

Purpose. To compare postoperative clinical outcomes between posterior cruciate ligament (PCL) retaining and resecting total knee arthroplasty (TKA) using same cruciate-substituting (CS) inserts, and to elucidate the clinical relevance of the residual PCL in cruciate-retaining TKA, considering intraoperative influence factors, such as the posterior tibial slope, posterior condylar offset, joint gap, joint balance, and joint laxity. Methods. A total of 64 consecutive knees (44 patients) were enrolled in this study and divided into following two groups: 39 knees underwent PCL-retaining TKA group (CR group), and 25 underwent PCL-resecting TKA group (CS group). Preoperative patients’ demographic data and one-year postoperative clinical outcomes including range of motion, the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Japanese Orthopaedic Association (JOA) score, and Forgotten Joint Score-12 (FJS-12) were compared between two groups. Results. Regarding range of motion, the average preoperative ROM was -14.3/120.0 degrees in the CR group and improved to -2.4/118.9 degrees postoperatively. In the CS group, the average preoperative ROM was -7.5/130 degrees and changed to -2.2/122.4 degrees postoperatively. There was no significant difference in the postoperative ROM between the groups (P=0.16). The KOOS (from 47.1 to 69.5 in CR group; from 41.1 to 70.8 in CS group) and JOA scores (from 59.2 to 76.9 in CR group; from 55.6 to 80.8 in CS group) were significantly improved postoperatively in both groups (P < 0.01). However, there was no significance in these postoperative scores between two groups (P = 0.09). There was also no significance in FJS-12 between two groups (70.3 in CR group and 66.9 in CS group; P=0.53). Conclusions. Residual PCL in TKA with a CS insert would not impact one-year postoperative clinical outcomes including KOOS, JOA, and FJS-12

Background. Cephalomedullary nails are widely used for fixation of unstable pertrochanteric fractures. In 2018, the Depuy Synthes Trochanteric Fixation Nail - Advanced (TFNA) implant was introduced at a level I academic trauma center. Thereafter, the TFNA swiftly replaced the older implant models used at the time. Subsequently, clinical concerns were raised about the use of the TFNA due to reports of nail breakage. The purpose of this study was to investigate whether the concerns raised about the performance of the TFNA were valid and to assess long-term outcomes. Methods. The data consisted of 2397 patients who had undergone a proximal femoral hip fracture procedure between 2014 and 2020. Data were handpicked from patient records. TFNA was compared with TFN, PFNA, Gamma3, and Intertan regarding nail breakage, breakage time and long-term outcomes. Results. After exclusion a total of 23/1667 (1.4%) nails broke during the follow-up period. The TFNA broke the most often with 15 cases (2.0%), followed by the Gamma3 with five cases (1.1 %) and the PFNA with three cases (1.3%). Overall, the mean (SD) nail breakage time was 233 (147.8) days. However, for the TFNA, PFNA, and Gamma3, the mean breakage times were 176.8 days (109.9), 419 days (108.6), and 291.8 (153.4), respectively. In cox regression analysis we observed significant reduction in nail breakage when using PFNA with adjusted hazard risk of 0.081 [95% Ci, 0.011-0.576, p=0.011]. Conclusions. In our data, the TFNA had a slightly higher risk for nail breakage when compared to the PFNA and the Gamma3, with a risk difference of 0.7% and 0.9%, respectively. On average, the TFNA broke nearly four months earlier than the Gamma3 and more than eight months earlier than the PFNA. It should be noted, however, that implant breakage is a relatively infrequent complication

Introduction. Intraoperative navigation systems for lumbar spine surgery allow to perform preoperative planning and visualize the real-time trajectory of pedicle screws. The aim of this study was to evaluate the deviation from preoperative planning and the correlations between screw deviation and accuracy. Method. Patients affected by degenerative spondylolisthesis who underwent posterior lumbar interbody fusion using intraoperative 3D navigation since April 2022 were included. Intraoperative cone-beam computed tomography (CBCT) was performed before screw planning and following implantation. The deviation from planning was calculated as linear, angular, and 3D discrepancies between planned and implanted screws. Accuracy and facet joint violation (FJV) were evaluated using Gertzbein-Robbins system (GRS) and Yson classification, respectively. Statistical analysis was performed using SPSS version28. One-way ANOVA followed by Bonferroni post-hoc tests were performed to evaluate the association between GRS, screw deviation and vertebral level. Statistical significance was set at p<0.05. Result. This study involved 34 patients, for a total of 154 pedicle screws. Mean age was 62.6±8.9 years. The mean two-dimensional screw tip deviation in mediolateral (ML), craniocaudal (CC), and anteroposterior (AP) was 2.6±2.45mm, 1.6±1.7mm, and 3.07±2.9mm, respectively. The mean screw tip 3D deviation was 5±3.3mm. The mean two-dimensional screw head deviation in ML, CC and AP was 1.83±1.8mm, 1.7±1.67mm and 3.6±3.1mm, respectively. The mean screw head 3D deviation was 4.94±3.2mm. 98% of screws were clinically acceptable (grade A+B), and grade 0 for FJV. Significant results were found between GRS and ML (p=0.005), AP (p=0.01) and 3D (p=0.003) tip deviations, and between GRS and AP and 3D head deviations (both p=0). Moreover, a significant correlation was found between GRS and vertebral level (p=0). Conclusion. Our results showed a reasonable rate of discrepancy between planned and positioned screws. However, accuracy was clinically acceptable in almost all cases. Therefore, pedicle screw fixation using intraoperative CBCT, 3D navigation and screw planning is safe and accurate

Introduction. Degenerative meniscal tears are the most common meniscal lesions, representing huge clinical and socio-economic burdens. Their role in knee osteoarthritis (OA) onset and progression is well established and demonstrated by several retrospective studies. Effective preventive measures and non-surgical treatments for degenerative meniscal lesions are still lacking, also because of the lack of specific and accurate animal models in which test them. Thus, we aim to develop and validate an accurate animal model of meniscus degeneration. Method. Three different surgical techniques to induce medial meniscus degenerative changes in ovine model were performed and compared. A total of 32 sheep (stifle joints) were subjected to either one of the following surgical procedures: a) direct arthroscopic mechanical meniscal injury; b) peripheral devascularization and denervation of medial meniscus; c) full thickness medial femoral condyle cartilage lesion. In all the 3 groups, the contralateral joint served as a control. Result. From a visual examination of the knee joint emerged a clear difference between control and operated groups, in the menisci but also in the cartilage, indicating the onset of OA-related cartilage degeneration. The meniscal and cartilaginous lesions were characterized by different severity and location in the different groups. For instance, a direct meniscal injury caused cartilaginous lesions especially in the medial part of the condyles, and the other approaches presented specific signature. Evaluation of scoring scales (e.g. ICRS score) allowed the quantification of the damage and the identification of differences among the four groups. Conclusion. We were effectively able to develop and validate a sheep model of meniscal degeneration which led to the onset of OA. This innovative model will allow to test in a pre-clinical relevant setting innovative approaches to prevent meniscal-related OA. Funding. Project PNRR-MAD-2022-12375978 funded by Italian Ministry of Health

Introduction. Research studies have established mathematical correlations between the lengths of bone segments and the possible biomechanical implications of these correlations. The Lucas sequence comprises a series of integers that adhere to the same recurrence relation as the Fibonacci sequence; it differs in that it can start with any two initial integers. The purpose of this study is to determine whether segmental lengths of the foot height, tibia, femur, and upper body follow a Lucas sequence pattern. Method. This was a retrospective radiographic review of patients who underwent full-body EOS scans. The AP scan was used to measure standing foot height (Ft), tibial length (T), femoral length (Fe), upper body length (UB), and full body length. A linear regression test was performed to determine whether a Lucas sequence-based relationship exists between Ft + T and Fe, and between T + Fe and UB. Result. The regression for the relationship between Ft + T and Fe for the entire cohort (R= 0.82, R2= 0.70), the female subset (R= 0.94, R2= 0.88) and the male subset (R= 0.75, R2= 0.57), all demonstrated a strong positive correlation between Ft + T and Fe and showed that Ft + T is a likely predictor of Fe. The regression test for the entire cohort demonstrated a moderately positive correlation between T + Fe and UB (R= 0.41, R2= 0.17, F(1, 145) = 29.42, p= 2.4E-07). A stronger correlation was found for the relationship between T + Fe and UB (R= 0.57, R2= 0.32, F(1, 35) = 16.64, p= 2.5E-05) for the female subset relative to the male subset (R= 0.20, R2= 0.038, F(1, 35) = 4.37, p= 0.04). Conclusion. This study demonstrates that total height is made up of sequential segments whose lengths approximate a Lucas series. The Fibonacci sequence is therefore once again implicated in human body proportions

Introduction. Despite the implementation of numerous preventive measures in recent years, the persistent challenge of periprosthetic infections remains. Among the various strategies, metallic modification of implants, particularly with silver, has emerged as a promising avenue. Silver's antimicrobial properties, coupled with its low human toxicity, render it an appealing option. However, ongoing debate surrounds its comparative efficacy in infection prevention when contrasted with titanium-coated prostheses. Methods. The PubMed database was systematically searched up to March 2024. Studies in English that met predetermined inclusion/exclusion criteria and utilized “Megaprosthesis AND infection” and “ silver-coated AND infection “ as key terms were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA) statement guided the article selection process. Results. From a pool of 1892 potential papers after literature screening, 11 studies with a total of 1419 patients were meticulously selected for analysis. Among these patients, 638 were treated with silver-coated implants, while 781 received titanium-coated implants, resulting in 166 recorded cases of infection. Remarkably, the infection rate stood at 9.2% for the silver-coated group, contrasting with 13.4% for the titanium-coated group. The subsequent analysis unveiled a notable discrepancy in proportions (P difference = -0.0473, 95%CI: -0.088 to -0.006), signaling a statistically significant decrease in infections within the silver-coated cohort. Furthermore, the I2 statistic, denoting heterogeneity in effect sizes, stood at 21.8% (95%CI: 0.0-66.9), indicating a modest degree of variability among the studies. Conclusion. In conclusion, our systematic review and meta-analysis shed light on the potential of silver-coated implants in mitigating periprosthetic infections. Despite the persistent challenge posed by such infections, our findings suggest a statistically significant decrease in infection rates among patients treated with silver-coated implants compared to those with titanium-coated ones

Introduction. The ACTIVE(Advanced Cartilage Treatment with Injectable-hydrogel Validation of the Effect) study investigates safety and performance of a novel dextran-tyramine hydrogel implant for treatment of small cartilage defects in the knee (0.5-2.0cm2). The hydrogel is composed of a mixture of natural polymer conjugates that are mixed intra-operatively and which cross-link in situ through a mild enzymatic reaction, providing a cell-free scaffold for cartilage repair. Method. The ACTIVE study is split into a safety (n=10) and a performance cohort (n=36). The Knee Injury and Osteoarthritis Outcome Score (KOOS), pain (numeric rating scale, NRS), Short-Form Health Survey (SF-36) were compared at baseline and 3, 6, and 12 months after surgery. The primary performance hypothesis is an average change in the KOOS from baseline to 12 months (ΔKOOS) greater than a minimal clinically important change (MIC) of 10. No statistical tests were performed as these are preliminary data on a smaller portion of the total study. Result. All patients of the safety cohort (n=10, mean age±SD, 30±9 years) were treated with the hydrogel for a symptomatic (NRS≥4) cartilage defect on the femoral condyle or trochlear groove (mean size±SD, 1.2±0.4cm2). No signs of an adverse foreign tissue reaction or serious adverse events were recorded within the safety cohort. At final follow-up mean KOOS±SD was 66.9±23.5, mean NRS resting±SD was 1.3±1.9, NRS activity±SD was 3.8±2.9 and mean SF-36±SD was 72.0±10.9. ΔKOOS was 21. One patient sustained new knee trauma prior to final follow-up, affecting final scores considerably. When excluded, ΔKOOS was 24(n=9). Conclusion. These promising initial findings provide a solid basis for continuation and expansion of this unique cartilage treatment. The MIC of 10 was surpassed. Though, results should be interpreted cautiously as they are based solely on preliminary data of the first 10 patients. Acknowledgements. Study is sponsored by Hy2Care, producer of the CartRevive®(dextran-tyramine) Hydrogel implant