The accuracy of percutaneous pedicle screw (PSS) placement in the lateral decubitus position has seldom been reported. This study aimed to retrospectively compare the accuracy of PPS placement with 3-dimensional (3D) fluoroscopy-based navigation in 2 cohorts of patients who underwent surgery in the lateral decubitus or prone positions at our single institute. A total of 265 consecutive patients underwent spinal surgery with PPS from T1 (thoracic 1) to S (sacrum) under the 3D fluoroscopy-based navigation system at our institute. Patients were divided into 2 groups based on their intraoperative patient positioning: lateral decubitus (Group L) or prone (Group P). A total of 1816 PPSs were placed from T1 to S, and 76 (4.18%) PPSs were assessed as deviated PPS. Twenty-one of 453 (4.64%) PPSs in Group L deviation and 55 of 1363 (4.04%) PPSs in Group P had deviated PPS, but with not significant difference (P = .580). In Group L, although the PPS deviation rate was not significantly different between the upside and downside PPS, the downside PPS significantly deviated toward the lateral side compared with the upside PPS. The safety and efficacy of PPS insertion in the lateral decubitus position were similar to those in the conventional prone position.

Osteoarthritis (OA) is a degenerative joint disease characterized by progressive cartilage breakdown, synovial inflammation, and subchondral bone remodeling. Previous studies have shown that cellular communication network factor 3 (CCN3) expression increases with age in cartilage, and its overexpression promotes OA-like changes by inducing senescence-associated secretory phenotypes. This study aimed to investigate the effect of Ccn3 knockout (KO) on OA development using a murine OA model. Destabilization of the medial meniscus (DMM) surgery was performed in wild-type (WT) and Ccn3-KO mice. Histological scoring and staining were used to assess cartilage degeneration and proteoglycan loss. Gene and protein expressions of catabolic enzyme (Mmp9), hypertrophic chondrocyte marker (Col10a1), senescence marker, and cyclin-dependent kinase inhibitor 1A (Cdkn1a) were evaluated. Single-cell RNA sequencing (scRNA-seq) data from WT and Sox9-deficient cartilage were reanalyzed to identify Ccn3⁺ progenitor populations. Immunofluorescence staining assessed CD44 and Ki67 expression in articular cartilage. The effects of Ccn3 knockdown on IL-1β-induced Mmp13 and Adamts5 expression in chondrocytes were examined in vitro. Ccn3 KO mice exhibited reduced cartilage degradation and catabolic gene expression compared with WT mice post-DMM. scRNA-seq revealed enriched Ccn3-Cd44 double-positive cells in osteoblast progenitor, synovial mesenchymal stem cell, and mesenchymal stem cell clusters. Immunofluorescence showed increased CCN3⁺/CD44⁺ cells in femoral and tibial cartilage and meniscus. Ki67⁺ cells were significantly increased in DMM-treated Ccn3 KO cartilage, mostly CD44⁺. In vitro Ccn3 knockdown attenuated IL-1β-induced Mmp13 and Adamts5 expressions in chondrocytes. Ccn3 contributes to OA pathogenesis by promoting matrix degradation, inducing hypertrophic changes, and restricting progenitor cell proliferation, highlighting Ccn3 as a potential therapeutic target for OA.

Background and Objective: The use of computed tomography (CT)-based navigation systems has been shown to improve surgical accuracy in total hip arthroplasty. However, there is limited literature available about the application of CT-based navigation systems in severe hip dysplasia. This study aimed to evaluate the accuracy of a CT-based navigation system in patients with severe hip dysplasia using three-dimensional (3D)-printed bone models. Methods: 3D-printed bone models were generated from CT data of patients with severe hip dysplasia (Crowe type II, 10 hips; type III, 10 hips; and type IV, 10 hips). The accuracy of automatic segmentation, success rate, point-matching accuracy across different registration methods, and deviation values at reference points after registration were assessed. Results: For the combined cohort of Crowe II, III, and IV cases (n = 30), the Dice Similarity Coefficient and Jaccard Index were 0.99 ± 0.01 and 0.98 ± 0.02, respectively. These values indicate a high level of segmentation accuracy. The “Matching with true and false acetabulum + iliac crest” method achieved a 100% success rate across all groups, with mean deviations of 0.08 ± 0.28 mm in the Crowe II group, 0.12 ± 0.33 mm in the Crowe III group, and 0.14 ± 0.50 mm in the Crowe IV group (p = 0.572). In the Crowe IV group, the anterior superior iliac spine deviation was significantly lower using the “Matching with true and false acetabulum + iliac crest” method compared to the “Matching with true and false acetabulum” method (0.28 ± 0.49 mm vs. 3.29 ± 2.56 mm, p < 0.05). Conclusions: This study demonstrated the high accuracy of automatic AI-based segmentation, with a Dice Similarity Coefficient of 0.99 ± 0.01 and a Jaccard Index of 0.98 ± 0.02 in the combined cohort of Crowe type II, III, and IV cases (n = 30). The matching success rate was 100%, with additional points on the iliac crest, which improved matching accuracy and reduced deviations, depending on the case.

Anteroposterior (AP) alignment assessment for nondisplaced femoral neck fractures is important for determining the treatment strategy and predicting postoperative outcomes. AP alignment is generally measured using the Garden alignment index (GAI). However, its reliability remains unknown. We compared the reliability of GAI and a new AP alignment measurement (valgus tilt measurement [VTM]) using preoperative AP radiographs of nondisplaced femoral neck fractures. The study was designed as an intra- and inter-rater reliability analysis. The raters were four trauma surgeons who assessed 50 images twice. The main outcome was the intraclass correlation coefficient (ICC). To calculate intra- and inter-rater reliability, we used a mixed-effects model considering rater, patient, and time. The overall ICC (95% CI) of GAI and VTM for intra-rater reliability was 0.92 (0.89–0.94) and 0.86 (0.82–0.89), respectively. The overall ICC of GAI and VTM for inter-rater reliability was 0.92 (0.89–0.95), and 0.85 (0.81–0.88), respectively. The intra- and inter-rater reliability of GAI was higher in patients aged <80 years than in patients aged ≥80 years. Our results showed that GAI is a more reliable measurement method than VTM, although both are reliable. Variations in patient age should be considered in GAI measurements.

Subtrochanteric femoral fractures are challenging injuries that are often associated with complications such as malrotation. Although imaging indicators such as the lesser trochanter sign are commonly used to achieve proper rotational alignment during surgery, their reliability diminishes in the presence of lesser trochanter fragments. This study investigated the relationship between lesser trochanter fragments and rotational deformities in patients treated with antegrade intramedullary nailing for subtrochanteric fractures. This multicenter retrospective analysis included 40 patients who underwent surgery for subtrochanteric fractures. Femoral anteversion was measured using preoperative and postoperative computed tomography images. Patients were divided into two groups based on the severity of rotational deformities. Predictive factors were evaluated using univariate and multivariate regression analyses. Lesser trochanter fragments were significantly associated with large rotational deformities (P < 0.001). Among patients in the large deformity group (>9°), 65.0 % had lesser trochanter fragments; however, among patients in the small deformity group (≤9°), only 10.0 % had lesser trochanter fragments. Other factors such as age, sex, operative time, and blood loss were not significantly different between the severe deformity and minor deformity groups. The presence of lesser trochanter fragments was an independent predictor of the absolute value of rotational deformity (P < 0.001) CONCLUSION: The presence of lesser trochanter fragments is a critical risk factor for postoperative rotational deformities. In such cases, visual landmarks are compromised; therefore, we recommend using objective intraoperative verification techniques rather than relying solely on the lesser trochanter shape sign to prevent malalignment.

Introduction: Femoral nerve palsy and femoral artery injury are serious complications of total hip arthroplasty. However, few studies have compared the anatomical positions of these structures in different patient positions. This study aimed to compare the anatomical positions of the femoral nerve and artery in the lateral and supine positions. Materials and methods: This multicenter retrospective study included 111 patients who underwent lateral and supine computed tomography (CT) from 2016 to 2023. CT images were reconstructed in the anterior pelvic plane. The horizontal distance from the anterior margin of the acetabulum to the femoral nerve (Distance N) and femoral artery (Distance A) was measured. The difference in Distance N between the two positions (ΔLateral–supine Distance N) was calculated by subtracting the supine value from the lateral value. Results: The average Distance N was 26.5 ± 5.1 mm in the lateral position and 21.1 ± 4.4 mm in the supine position, with the nerve located significantly closer to the acetabulum in the supine position (P < 0.001). Similarly, the average Distance A was 26.8 ± 5.4 mm in the lateral position and 20.4 ± 4.9 mm in the supine position (P < 0.001). Multiple regression analysis showed that Distance N in the lateral position was significantly shorter in female patients and those with low body weight. In addition, low body weight correlated with a smaller ΔLateral–supine Distance N. Conclusions: The femoral nerve and artery are located closer to the anterior margin of the acetabulum in the supine position than in the lateral position. Low body weight was an independent predictor of shorter Distance N in both positions and a smaller ΔLateral–supine Distance N. These findings underscore the importance of considering patient positioning during total hip arthroplasty, particularly in patients with low body weight, to reduce neurovascular risks.