Ara Nazarian

Objective: This study aimed to compare the biomechanical properties of bio-inductive implant augmentation and suture repair for anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) repair in chronic lateral ankle instability. Methods: This controlled cadaveric biomechanical study included eight fresh-frozen human ankle specimens [median age of 76 years, Interquartile Range (IQR): 70.5–83]; 5 males and 3 females). Using a repeated-measures design, each specimen was tested under three conditions: intact ligaments, suture repair, and bio-inductive implant augmentation (Bio-Aug). Following intact testing, the order of the suture repair and bio-inductive augmentation conditions was randomized. Biomechanical testing consisted of a 500-cycle loading protocol. The primary outcome measures were construct stiffness, primary creep, cyclic loading survival, and load-to-failure. Results: All specimens in the intact and Bio-Aug groups completed the 500-cycle protocol, whereas only three of eight (37.5%) specimens in the suture repair group did so. Both primary and final stiffness were greatest in the intact and Bio-Aug groups and lowest in the suture repair group; however, no significant differences were observed among groups for either primary (Friedman χ.(2)=4.33, P =.11) or final stiffness (Friedman χ.(2)=3.25, P =.20). Primary creep differed significantly across conditions (P=.006). Compared with the intact group, both the suture repair group (4.54% vs. 0.50%, P =.04) and the Bio-Aug group (1.60% vs. 0.50%, P =.02) demonstrated greater creep, although Bio-Aug values were substantially closer to those of the intact ligaments. The median load-to-failure of the Bio-Aug constructs was 330 N (IQR, 300–360 N). Conclusion: Bio-inductive implant augmentation restored construct stiffness comparable to that of the intact ligament complex while demonstrating substantially lower creep than suture repair alone in this time-zero cadaveric model. These findings suggest that bio-inductive augmentation may provide improved early mechanical support while preserving biomechanical characteristics closer to native ligament tissue. Further in vivo and clinical studies are required to determine whether these biomechanical advantages translate into improved clinical outcomes and rehabilitation protocols. Cite this article as: Taseh A, Aslan L, Kord MHC, et al. Biomechanical Evaluation of Bio-inductive Implant Augmentation for ATFL and CFL Repair in Chronic Lateral Ankle Instability. Acta Orthop Traumatol Turc., 2026; 60(5), 0953, doi: 10.5152/j.aott.2026.26953.

Hutchinson‐Gilford progeria syndrome (HGPS) is a premature aging disorder affecting tissues of mesenchymal origin. Most patients harbor a c.1824C>T/p.G608= variant, commonly described as G608G, in exon 11 of LMNA that leads to aberrant splicing and production of the toxic progerin protein. In addition to cardiovascular, dermal, and adipose tissue deterioration, HGPS mouse models also develop progressive bone dysplasia that occurs in patients. Here we characterize the efficacy of in vivo mutation correction with an adenine base editor (ABE) to rescue structural and functional defects in HGPS transgenic murine bone tissue. Treatment of double‐copy transgenic osteoblast cultures with a lentiviral‐delivered CRISPR‐Cas9 ABE achieved nearly 40% gene correction in vitro, resulting in significant reduction of progerin transcripts and protein, in the absence of selective agents. Furthermore, gene correction improved progeroid osteoblasts' capacity to deposit and mineralize extracellular matrix compared to untreated cultures. In vivo, a single intravenous dose of AAV9‐delivered ABE corrected the mutation, achieving ~14%, ~22%, ~10% and < 1% correction in bone by six months of age when administered at P3, P14, 1 and 4 months of age, respectively. Partially rescued bone structural and physical parameters were observed in P14‐treated mice with concomitant normalization of gene transcriptional programs and intracellular signaling pathways involved in bone remodeling. This work demonstrates in vivo delivery of a locus‐specific DNA base editor to bone tissue, delineates the timing of treatment required for maximum efficacy, and suggests that this system might be tailored for application to other monogenic bone disorders.

Objectives: Quantitative multinuclear MRI of bone is hindered by magnetic field (B ₀ and B ₁ ) inhomogeneities, calibration inconsistencies, and segmentation challenges. We developed a comprehensive and versatile MATLAB-based graphical interface that integrates voxel-wise B ₁ correction, auto and manual segmentation, coregistration, advanced visualization, and quantitative analysis with in-scan dual-density calibration, to generate reproducible bone matrix and mineral density maps from ¹ H and ³¹ P ZTE MRI. Materials and Methods: The postprocessing package was developed in MATLAB using a modular architecture comprising multiple m-files for B ₁ field correction, B ₀ bias correction, auto and manual image registration, and segmentation for quantitative data analysis. Otsu-based thresholding with min–max intensity normalization was employed for tissue segmentation and bias correction. Data from control, ovariectomized, and vitamin D–deficient rat femurs were analyzed using normality (Shapiro-Wilk) and variance (Levene) tests. Between-group comparisons used the Kruskal-Wallis test or analysis of variance with Bonferroni or Tukey post hoc tests, respectively. Cross-modality correlation analyses were conducted between MRI-derived measures and reference measures (µCT and gravimetry) using Pearson and Spearman coefficients. Results: MRI-derived mineral density strongly correlated with µCT BMD (cortical [ P = 0.22], trabecular [ P = 0.31]), and the MRI matrix density correlated with the gravimetric data (cortical [ P = 0.38], trabecular [ P = 0.57]). No significant differences were observed between modalities for either cortical or trabecular bone. Conclusion: This standardized pipeline enables reproducible, calibrated bone density mapping for data sizes ranging from 64 × 64 × 64 to 512 × 512 × 512, with B ₁ and B ₀ corrections assessing matrix and mineral densities. Its implementation as a user-guided graphical user interface promotes adoption for preclinical and clinical quantitative bone imaging across experimental conditions.

Introduction: Acute compartment syndrome (ACS) is a limb-threatening complication of extremity trauma that requires timely diagnosis to prevent irreversible muscle and nerve injury. Current diagnostic methods are invasive, intermittent, and operator-dependent. We evaluated the feasibility of a novel, Bluetooth-enabled electrical impedance myography (EIM) device (mAlert, Myolex, Inc., Brookline, MA, USA) for continuous, noninvasive detection of ACS-related tissue changes. Methods: Ten Yorkshire swine underwent anterior tibial compartment monitoring using three ACS models: albumin infusion (ALB, n=3), femoral artery and vein ligation (LIG, n=3), and combined albumin infusion plus ligation (ALB+LIG, n=4). Resistance (R), reactance (X), and phase (P) were measured every minute across 1 to 199 kHz alongside continuous intra-compartmental pressure (ICP) monitoring. Group differences in normalized impedance trends were evaluated using the Kruskal Wallis test with Dunn post hoc correction. As a proof-of-concept human study, nine healthy volunteers wore the device for up to five days to assess electrode durability and signal stability. Tissue ischemia was validated using pimonidazole immunohistochemistry. Results: ALB infusion produced progressive, frequency-dependent decreases in R, X, and P, whereas LIG produced consistent increases in R and X across frequencies. The ALB+LIG model generated mixed responses, reflecting the competing effects of edema and ischemia. Normalized phase slopes differed significantly among groups (H=6.14, p=0.046), with post hoc testing showing significant divergence between the ALB and LIG models (p=0.041). Control limbs remained stable throughout monitoring. Pimonidazole staining confirmed hypoxic injury in the intervention limb. In the human pilot study, three participants completed five days of monitoring, demonstrating sustained signal acquisition, while electrode degradation limited data collection in the remaining participants. Conclusions: This preliminary feasibility study demonstrates that wearable EIM can continuously detect model-specific physiological changes associated with ACS in a large-animal model. These findings support further development and clinical evaluation of wearable EIM as a non-invasive monitoring technology for early ACS detection in trauma patients.

Objectives: Prosthetic joint infection (PJI) is a serious complication affecting arthroplasty patients. The gold-standard treatment for PJI, two-stage revision, can fail in up to 30% of cases in patients undergoing total knee arthroplasty. Current rat models of PJI following total knee arthroplasty use a mainstream retrograde femoral nailing technique that significantly damages the quadriceps-patellar complex. We describe a novel method allowing retrograde intramedullary femoral nail insertion with minimal damage to the quadriceps-patellar complex. Methods: Our technique was performed in 48 male Sprague-Dawley rats. After proper anesthesia, a 1 cm prepatellar skin incision was made, followed by a 2 mm transpatellar tendon incision. Using fluoroscopic guidance, a 1.2mm drill bit was advanced through the patellar defect and cortical bone and was used to ream the femoral canal. A 0.8 mm stainless steel Kirschner wire was inserted through the patellar defect into the femoral canal, leaving a 1mm segment protruding in the joint space. The defects in the patellar tendon and skin were closed with sutures. Results: The mean surgical duration was 20.3 minutes. Among the 48 rats, 47 (98%) maintained articular capsule integrity on postoperative evaluation, as confirmed by an orthopedic surgeon under loupe magnification. All rats were ambulating postoperatively. Conclusion: This novel technique offers an efficient, minimally invasive method of retrograde femoral nail fixation that preserves the integrity of the quadriceps-patellar complex and supports the further development of simulating prosthetic knee infection models in rats.

Objectives: During total knee arthroplasty (TKA), there is a possibility of discovering incidental findings that do not present any symptoms or signs during routine preoperative assessments. Awareness of these incidental findings enables us to appropriately manage knee arthroplasty and make informed decisions based on the patient’s condition. Methods: A systematic review was performed in accordance with Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Comprehensive searches were conducted across multiple databases, including PubMed, Scopus, Embase, and Web of Science, using a combination of Medical Subject Headings (MeSH) and free-text terms related to knee arthroplasty and incidental findings. Studies were screened for eligibility according to predefined inclusion criteria, and two reviewers independently extracted data. Results: The systematic review followed a series of well-defined steps. After assessing the full text of the selected studies, 13 studies involving 26 patients were identified. These studies included case reports of patients who underwent TKA, where unexpected knee conditions not identified during routine preoperative assessments were discovered intraoperatively. The incidental findings reported in these studies included lipoma arborescens, metastatic mammary carcinoma, black cartilage (Alkaptonuria), tenosynovial giant cell tumor, synovial sarcoma, non-Hodgkin lymphoma, Chondrosclerosis, tuberculosis of the joint, and pigmented bone. Conclusion: Incidental findings that do not exhibit symptoms or signs during routine preoperative assessments can complicate the TKA procedure. Awareness of these findings allows for effective management of knee arthroplasty and facilitates optimal decision-making for the patient’s well-being based on their specific condition.

Background/Objectives: This updated systematic review and meta-analysis provide a focused synthesis of contemporary evidence on clinical outcomes reported after the Latarjet procedure and Free Bone Block (FBB) techniques for anterior shoulder instability, focusing on recurrence, patient-reported outcome measures (PROMs), return to sport, complications, and osteoarthritis progression. Given that most available studies report single-procedure cohorts, between-technique comparisons were interpreted in the context of indirect evidence and study-level heterogeneity. Methods: A systematic review and meta-analysis were conducted according to PRISMA 2020 guidelines. The updated search included studies published from 2019 to May 2024 and was integrated with 70 studies from the previous review that were re-screened according to the same eligibility criteria. Eligible studies reported outcomes for the Latarjet or FBB procedure, with a minimum 2-year follow-up and at least five patients in the relevant treatment cohort. Risk of bias was assessed using the RoB 2 and MINORS tools. Outcomes were synthesized using random-effects meta-analysis. Pooled estimates were calculated separately for each procedure, and between-technique contrasts were treated as exploratory and descriptive when appropriate. Heterogeneity was assessed using I². Results: Ninety-eight studies with 6043 patients and 6071 shoulders were included: 72 on Latarjet, 23 on FBB, and 3 direct comparative studies. Both procedures were associated with low recurrence rates, improved PROMs, and comparable return-to-sport rates. Recurrence was 7% for Latarjet and 5% for FBB. Return to sport was 66% after Latarjet and 65% after FBB. Complication rates were 5% for Latarjet and 8% for FBB, while osteoarthritis progression was 12% and 9%, respectively. PROMs improved after both techniques, although differences between procedures should be interpreted cautiously because of the indirect nature of most comparisons and substantial heterogeneity across studies. Conclusions: Both Latarjet and FBB procedures were associated with generally favorable outcomes for anterior shoulder instability with bone loss in the included studies. The available evidence suggests broadly comparable clinical outcomes, with possible differences in complication profile, recurrence pattern, and osteoarthritis progression. However, these findings should be interpreted considering differences in patient characteristics, follow-up duration, surgical technique, graft type, and outcome definitions across studies. Current evidence does not allow definitive conclusions regarding the superiority of one technique over the other, but it provides useful descriptive outcome profiles to inform clinical decision-making and guide future direct comparative research.

Relying solely on MRI scans may prove insufficient for obtaining a complete view of a patient’s supraspinatus health status comprising both objective