Melih Unal

Background/Objectives: Sacral dysmorphism is a common anatomical variant that may significantly affect the safety of percutaneous iliosacral screw fixation. Although its morphological characteristics are well described, its impact on clinically relevant outcomes—particularly cortical breach during S1 screw placement—remains insufficiently defined. This study aimed to evaluate whether sacral dysmorphism is an independent risk factor for cortical breach during percutaneous S1 iliosacral screw fixation. Methods: This retrospective cohort study included 112 adult patients with sacral fractures treated with percutaneous S1 iliosacral screw fixation between January 2018 and December 2024. Sacral dysmorphism was defined on preoperative CT scans using qualitative features, with ≥2 criteria required for classification as dysmorphic. Quantitative morphometric parameters, including S1 osseous corridor width and screw anteversion angle, were also measured. The primary outcome was the presence of cortical breach on postoperative CT imaging. Multivariate logistic regression analysis was performed to evaluate the independent association between sacral dysmorphism and cortical breach. Results: Sacral dysmorphism was identified in 32 patients (28.6%). Cortical breach occurred in 19 patients (17.0%) and was significantly more frequent in the dysmorphic group compared with the non-dysmorphic group (34.4% vs. 10.0%; p = 0.002). Sacral dysmorphism was independently associated with cortical breach (adjusted OR: 4.38; 95% CI: 1.42–13.50; p = 0.010). Dysmorphic sacra demonstrated significantly narrower S1 osseous corridors (16 mm vs. 25 mm; p < 0.001) and greater screw anteversion angles (28° vs. 9°; p < 0.001). Breach severity was also significantly greater in dysmorphic patients (p = 0.003). Conclusions: Sacral dysmorphism is an independent risk factor for cortical breach during percutaneous S1 iliosacral screw fixation. The geometric constraints of dysmorphic sacra, including corridor narrowing and increased anteversion requirements, significantly compromise screw placement safety. Careful CT-based evaluation and individualized trajectory planning are essential to optimize fixation outcomes in this high-risk anatomical subgroup.

Background: Accurate deformity classification and fusion-level planning are essential in adolescent idiopathic scoliosis (AIS) surgery and are traditionally guided by Cobb angle measurement and the Lenke system. Multimodal large language models (LLMs) (e.g., ChatGPT-4.0; Claude 3.7 Sonnet, Gemini 2.5 Pro, DeepSeek-R1-0528 Chat) are increasingly used for image interpretation despite limited validation for radiographic decision-making. This study evaluated the agreement and reproducibility of contemporary multimodal LLMs for AIS assessment compared with expert spine surgeons. Methods: This single-center retrospective study included 125 AIS patients (94 females, 31 males; mean age 14.8 ± 1.9 years) who underwent posterior instrumentation (2020–2024). Two experienced spine surgeons independently performed Lenke classification (including lumbar and sagittal modifiers) and selected fusion levels (UIV–LIV) on standing AP, lateral, and side-bending radiographs; discrepancies were resolved by consensus to establish the reference standard. The same radiographs were analyzed by four paid multimodal LLMs using standardized zero-shot prompts. Because LLMs showed inconsistent end-vertebra selection, LLM-derived Cobb angles lacked a common anatomical reference frame and were excluded from quantitative analysis. Agreement with expert consensus and test–retest reproducibility (repeat analyses one week apart) were assessed using Cohen’s κ. Evaluation times were recorded. Results: Surgeon agreement was high for Lenke classification (92.0%, κ = 0.913) and fusion-level selection (88.8%, κ = 0.879). All LLMs demonstrated chance-level test–retest reproducibility and very low agreement with expert consensus (Lenke: 1.6–10.2%, κ = 0.001–0.036; fusion: 0.8–12.0%, κ = 0.003–0.053). Claude produced missing outputs in 17 Lenke and 29 fusion-level cases. Although LLMs completed assessments far faster than surgeons (seconds vs. ~11–12 min), speed did not translate into clinically acceptable reliability. Conclusions: Current general-purpose multimodal LLMs do not provide reliable Lenke classification or fusion-level planning in AIS. Their poor agreement with expert surgeons and marked internal inconsistency indicate that LLM-generated interpretations should not be used for surgical decision-making or patient self-assessment without task-specific validation.

Aim: In this study, we aimed to evaluate clinical and functional outcomes of tibiotalocalcaneal arthrodesis (TTCA) using intramedullary nailing (IMN) without cartilage resection of the subtalar (ST) joint. Methods: 22 ankles of 21 patients (one patient was bilateral), who underwent TTCA using IMN without cartilage resection of the ST joint in our clinic between January 2013 and December 2022 were retrospectively analyzed. Data including demographic and clinical characteristics of the patients, etiology, Kellgren-Lawrence classification, postoperative fusion rate, fusion status and complications were recorded. The European Quality of Life 5 Dimensions (EQ-5D) scores were also noted. Results: Ten patients were male and 11 were female. The mean age was 54.7±14.9 years. The mean follow-up was 46.4±19.1 months. The mean best health status score of the EQ-5D (EQ-VAS) was 73.9±16.5. Tibiotalar (TT) fusion occurred in all patients, while ST fusion was not achieved in ten patients. Four of these patients underwent secondary procedures, while no intervention was planned for the other six patients because they were asymptomatic. Conclusions: This study has demonstrated that unresected subtalar articular cartilage leads to a significant rate of ST fusion failure. Nevertheless, the possibility of partial fusion or fibrous fusion at the reaming site is thought to be the reason for the high rate of asymptomatic patients.

Hamatometacarpal Fracture-Dislocations: Clinical Evaluation, Treatment Strategies, and Outcomes - European Archives of Medical Research

Purpose This retrospective study aimed to investigate the factors associated with the breakage of tibio-fibular syndesmotic screws (SS). Methods 69 patients with unstable AO-Weber Type 44-B ankle fractures who underwent three cortex SS (3.5 mm ø) fixation were included. Patients were followed for at least one year (mean, 18.3 ± 7.6 months). At the final follow-up, patients with broken (Group I) and intact (Group II) SS were compared regarding age, gender, height, weight, body mass index, fracture type, SS length, location, and orientation. Multivariate logistic regression was used to identify the independent risk factors associated with SS breakage. The sensitivity, specificity, cut-off value, and area under the ROC curve were analyzed. Results A stepwise backward logistic regression analysis revealed that age was the only independent predictor for SS breakage (OR = 0.938, 95% CI = 0.904–0.973, R² = 0.270). ROC curve analysis demonstrated that patients younger than 36 years were associated with seven times increased risk of SS breakage [Odds ratio (95% CI), 7.042 (2.251–22.031)]. Conclusion Age under 36 years was the only significant risk factor for SS breakage. The higher incidence of breakage of the syndesmotic screw can be informed to patients younger than 36.

This study aims to quantitatively analyze the distribution of encapsulated nerve endings in the human thumb interphalangeal (IP) joint capsule. There are three types of nerve endings. Type‐I nerve endings (Ruffini‐like ending) sense pressure changes, Type II (Pacini‐like ending) nerve endings contribute to the kinesthetic sense, and Type III (Golgi‐like ending) nerve ending provides proprioceptive information. We dissected five right thumbs IP joints from freshly frozen cadavers (5 men). The mean age of the cadavers at the time of death was 63.4 years (55–73). Sections were stained with the hematoxylin–eosin and antiprotein gene product 9.5 (PGP9.5) to identify encapsulated nerve endings. Transverse sections were cut and divided into volar, dorsal, and then into two equal parts, proximal and distal. The density of encapsulated nerve endings compared to volar versus dorsal and proximal versus distal regions was examined. This study showed that type 1 nerve endings were more common in the distal parts of the IP joint (p < 0.05). Also, type 3 nerve endings were observed in the thumb IP joint. There was no difference between regions in type II and type III nerve endings. The current study demonstrates that the distribution of encapsulated nerve endings in the IP joint is different from the PIP and DIP joints. Moreover, further studies are required to understand the thumb‘s physiology.

Introduction Humeral shaft fractures are common fractures of the diaphysis of the humerus. The aim of this study was to evaluate factors affecting the clinical outcomes of humeral nonunions surgically treated with open reduction and single- versus double-plate fixation with grafting. Materials and methods A total of 31 patients with nonunion treated with single- or double-plate screw fixation with bone grafting were retrospectively analysed. The patients were divided into two groups according to the treatment method as Group 1 (single-plate, n = 14) and Group 2 (double-plate, n = 17). Data including demographic and clinical characteristics of the patients, initial and final treatment, type of nonunion and localisation, graft use, shortening, follow-up, time to union, Quick Disabilities of the Arm, Shoulder and Hand (Quick-DASH) scores, and patient-reported cosmetic outcomes were recorded. Results Of the patients, eight were males, and 23 were females, with a mean age of 47.6 ± 15.8 (range, 20–86) years. Initial treatment was conservative treatment (Sarmiento brace) in seven patients, plate fixation in 22 patients, and intramedullary nailing in two patients. The mean follow-up was 31.0 ± 16.9 months in Group 1 and 25.4 ± 15.6 months in Group 2. There was one nonunion in Group 1 and three in Group 2. There were no significant differences in the union rate and time to union (p = 0.378 and p = 0.262, respectively). The mean Quick-DASH scores and cosmetic results were similar between the groups (p = 0.423 and p = 0.165, respectively). Radial nerve palsy developed in three patients in Group 2, and all these patients recovered completely during follow-up. Conclusions Although the double-plate fixation technique has similar clinical, radiological, and functional results to single-plate fixation, it is a more invasive and expensive technique with a longer operation time. Therefore, it should not be used as the first-line treatment option for all humeral shaft nonunion. Nevertheless, the double-plate technique may be preferred to achieve in cases requiring high stability, such as hypertrophic nonunion, osteopenia and comminuted fractures.