Stability of osteotomy in minimally invasive hallux valgus surgery with "8" shaped bandage during gait: a finite element analysis.

Introduction: Hallux valgus, a common foot deformity, often necessitates surgical intervention. This study evaluates the biomechanical alterations in patients post-surgery, focusing on the efficacy of an "8" bandage fixation system to promote optimal recovery. Methods: A three-dimensional (3D) model was constructed using CT data from a patient with hallux valgus. A quasi-static finite element analysis (FEA) was conducted in conjunction with gait analysis to evaluate the biomechanical changes at the osteotomy site under "8" shaped bandage fixation following hallux valgus surgery. The effects of the "8" shaped bandage on the stability of the osteotomy site and bone healing were investigated at three load points during the gait cycle. Results: During the Loading Response (LR), Midstance (MSt), and Terminal stance TSt phases, the osteotomy end experienced maximum Von Mises stresses of 0.118, 1.349, and 1.485 MPa, respectively. Correspondingly, the maximum principal stresses, all of which were compressive along the Z-axis, were 0.11662 N, 1.39266 N, and 1.46762 N, respectively. Additionally, these phases showed a maximum relative total displacement of 0.848 mm and a maximum relative shear displacement of 0.872 mm. Conclusion: During the stance phase, the osteotomy end of the first metatarsal is predominantly subjected to compressive stress, with the relative displacement within the safe range to promote healing. The application of an "8" bandage for external fixation after surgery can maintain the dynamic stability of osteotomy sites post-minimally invasive hallux valgus correction during the gait cycle, thereby promoting the healing of the osteotomy ends.

Nonanatomical reduction of femoral neck fractures in young patients with different Pauwels classifications: a retrospective study and finite element analysis.

BACKGROUND: Previous studies have reported that positive buttress is as effective as anatomical reduction in treating young femoral neck fractures, but whether this effect is related to the Pauwels classification remains unclear. The purpose of this study was to retrospectively analyze the clinical prognosis of positive buttress in young femoral neck fractures with different Pauwels classifications, as well as to assess its biomechanical properties. METHODS: A total of 170 young patients with femoral neck fractures who were treated with three cannulated screws were included in this study. Patients were divided into three groups based on their preoperative Pauwels classification. Each group was divided into three subgroups based on the reduction quality: positive buttress, negative buttress and anatomical reduction. The femoral neck shortening, the incidence of necrosis of the femoral head (AVN) and the Harris hip scores at the last follow-up were compared across the three reduction quality within each Pauwels classification. Subsequently, a volunteer was recruited, CT data of the hip was obtained, and finite element models representing different reduction quality under varying Pauwels classifications were established. The biomechanical properties of each model were then evaluated following the application of strains. RESULTS: In Pauwels type I, there were no significant differences in postoperative femoral neck shortening, incidence of AVN, or Harris score among the three types of reduction quality (P > 0.05). However, positive buttress provided superior biomechanical stability compared to negative buttress and anatomical reduction. In Pauwels type II, the incidence of AVN was similar between the positive buttress and the anatomical reduction groups, and both were significantly lower than that in the negative buttress (P < 0.05). The Harris score of the positive buttress was higher than that of the negative buttress, and there was no significant difference in the occurrence of femoral neck shortening between the three groups (P > 0.05). Finite element analysis showed that the biomechanical stability of positive buttress was equivalent to anatomical reduction, and both were better than negative buttress. In Pauwels type III, the incidence of AVN in the anatomical reduction group was lower than that in both the positive buttress and negative buttress (P < 0.05). There was no significant difference in the occurrence of AVN or femoral neck shortening between positive buttress and negative buttress (P > 0.05). There was also no difference in postoperative Harris scores between the three reduction qualities (P > 0.05). Both positive buttress and negative buttress exhibited identical biomechanical qualities and were inferior to anatomical reduction. CONCLUSIONS: The biomechanical and clinical dominance of positive buttress correlates with Pauwels type. Specifically, Positive buttress is biomechanically stable in Pauwels types I and II. In Pauwels type III, positive buttress is not advantageous. As the Pauwels angle increases, the biomechanical benefit of the positive buttress is lost. Therefore, regardless of the Pauwels classification, negative buttress should be avoided after reduction of femoral neck fractures in young patients.

Advances in the Causes and Treatment of Floating Toes after the Weil Osteotomy: A Scoping Review.

The floating toe deformity is classified as a forefoot deformity wherein the distal portion of the toe does not establish touch with the ground, resulting in a suspended or elevated position while the finger is in a relaxed state. At first, it garnered considerable interest as a complication It is worth noting that this condition is particularly common in children under the age of 8, which usually disappears as the individual reaches maturity. Studies have shown that with the aggravation of floating toe deformity, its adverse effects on patients' gait and overall quality of life also increase. Despite the prevalence of floating toe deformity in clinical settings, there is a lack of comprehensive literature investigating its underlying causes and potential preventive strategies. This scope review follows the preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR) statement guidelines for scope reviews. The literature was obtained from various full-text databases, including China National Knowledge Infrastructure Database (CNKI), Wanfang Database, PubMed, and Web of Science Database. Our search focused on published literature related to floating toes, Weil osteotomy, and distal metatarsal osteotomy, up until March 1, 2023. The literature search and data analysis are conducted by two independent reviewers. If there are any disagreements, a third researcher will participate in the discussion and negotiate a decision. Furthermore, two experienced foot and ankle surgeons conducted a thorough literature analysis for this review. Sixty-two articles were included. Through the clinical analysis of the structural changes of the forefoot before and after operation, the classification of floating toe was described, the causes of pathological floating toe were summarized, and the possible intervention measures for the disease were put forward under the advice of foot and ankle surgery experts. We comprehensively summarize the current knowledge system about the etiology of floating toe and put forward the corresponding intervention strategy. We recommend that future studies will focus on the improvement of surgical procedures, such as the combination of Weil osteotomy, proximal interphalangeal (PIP) arthrodesis and flexor tendon arthrodesis.

Causal relationship between thyroid dysfunction and hallux valgus: A two-sample Mendelian randomization study.

Introduction: Previous observational studies have reported that thyroid dysfunction is associated with hallux valgus (HV). However, the causal effect of thyroid dysfunction on hallux valgus is still unknown. To assess whether there is a causal relationship between thyroid dysfunction and hallux valgus, we performed a two-sample Mendelian randomization (MR) study. Methods: The data of the two-sample Mendelian randomization study were obtained from public databases. In this study, hypothyroidism, hyperthyroidism, free thyroxine (FT4), and thyrotropin (TSH) were chosen as exposures. The single nucleotide polymorphisms (SNP) of hypothyroidism and hyperthyroidism were from the genome-wide association studies (GWAS) of the IEU database, including 337,159 subjects. Data for FT4 and TSH (72,167 subjects) were extracted from the ThyroidOmics Consortium. HV was used as the outcome. The SNPs associated with HV were selected from a GWAS of 202,617 individuals in the fignngen database. The inverse variance weighted (IVW) method was used as the primary analysis. Four complementary methods were applied, including MR-presso, MR-Egger, and weighted median. In addition, Cochran's Q test, MR-presso, MR-Egger regression, and the leave-one-out test were used as sensitivity analysis, and the MR-pleiotropy test was performed to examine pleiotropy. Results: According to the results of IVW, we found that there was a causal relationship between hypothyroidism and HV, and hypothyroidism increased the incidence of HV (OR = 2.838 (95% CI: 1.116-7.213); p = 0.028). There were no significant causal effects of hyperthyroidism, FT4, and TSH on HV (p > 0.05). Sensitivity analyses showed that the results were robust and reliable, and no horizontal pleiotropy was detected. Conclusions: Our findings provided genetic support that hypothyroidism might increase the risk of HV. It will predict the occurrence of HV in patients with hypothyroidism and provide suggestions for early prevention and intervention.

Establishment and Validation of a Predictive Nomogram for Hallux Valgus with Pain Under the Second Metatarsal.

Objective: To investigate the risk factors for hallux valgus complicated with pain under the second metatarsal and construct an effective model and method for predicting hallux valgus complicated with pain under the second metatarsal based on risk factors. Methods: A total of 545 patients with hallux valgus who were admitted to our hospital were divided randomly into a training set and a validation set. The demographic characteristics, imaging indices and gait test indices of the patients were collected. The risk factors were identified by univariate and multivariate logistic regression analyses. A risk prediction model for hallux valgus with pain under the second metatarsal was established, and the area under the curve (AUC) of the receiver operating characteristic and a decision curve analysis were used for verification and identification. The value of the model was tested in the verification group. Results: Second metatarsal length, second metatarsal peak pressure, hallux valgus angle (HVA), intermetatarsal angle 1-2 (IMA1-2) and weight were the risk factors for hallux valgus complicated with pain under the second metatarsal. Based on the weighting of these seven risk factors, a prediction model was established. The AUC of the prediction model was 0.84 (95% confidence interval [CI]: 0.802~0.898, P < 0.05), and the results of a Hosmer-Lemeshow test showed a good degree of calibration (χ 2 = 10.62, P > 0.05). The internal validation of the AUC was 0.83 (95% CI: 0.737-0.885, P < 0.05). The model had obvious net benefits when the threshold probability was 10%-70%. Conclusion: Second metatarsal length, second metatarsal peak pressure, HVA, IMA1-2 and weight were the risk factors for hallux valgus combined with second metatarsal pain. The risk prediction model for hallux valgus complicated with pain under the second metatarsal based on these seven variables was proven effective. Level of Evidence: Level III, retrospective comparative study.

Clinical effectiveness of arthroscopic vs open ankle arthrodesis for advanced ankle arthritis: A systematic review and meta-analysis.

BACKGROUND: Ankle fusion is the primary treatment for advanced ankle arthritis. With the advancement of arthroscopy technology, ankle arthroscopy fusion has shown many advantages over traditional surgery. However, there are few related studies globally, and evidence-based medicine is needed to verify the reliability and feasibility of ankle arthroscopy fusion. OBJECTIVE: To compare the clinical efficacy and safety of arthroscopic ankle arthrodesis and open ankle arthrodesis. METHODS: We searched the databases of PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure [CNKI], Wanfang Database, and VIP Database for published prospective or retrospective controlled studies of arthroscopic-assisted ankle fusion in the treatment of advanced ankle arthritis. The dates were limited from the construction of the library to June 30, 2019. Literature was included based on the principles and methods of evidence-based medicine. Literature retrieval, data extraction, and quality assessment were performed by 2 independent reviewers using the Cochrane 5.1 risk bias assessment tool. The methodological bias of the literature was evaluated, and a meta-analysis was using by RevMan 5.3 software. RESULTS: A total of 18 studies and 1102 patients were included in the study, including 551 in the arthroscopic surgery group and 551 in the open surgery group. Arthroscopy-assisted surgery for advanced ankle arthritis was more effective than open surgery in terms of fusion rate (odd ratio[OR] = 3.32, 95% confidence interval[CI]:2.16, 5.10), fusion time (mean difference[MD] = -2.31, 95% CI:-4.63, -2.21), intraoperative blood loss (MD = -43.37, 95%CI: -48.49, -38.25), hospital stay (MD = -1.80, 95%CI: -2.28, -1.33), and visual analog scale score (MD = -1.75, 95%CI: -2.04, -1.46). In addition, rate of complications (OR = 0.33, 95%CI: 0.21, 0.52) was superior to open ankle fusion (P < .00001). CONCLUSION: Arthroscopic ankle arthrodesis has more advantages than open ankle arthrodesis in improving the fusion rate and reducing complications, which is worthy of clinical application. PROSPERO REGISTRATION NUMBER: CRD42020195727.

Bland-Altman Analysis of Different Radiographic Measurements of the Hallux Valgus Angle and the Intermetatarsal Angle After Distal Osteotomy.

OBJECTIVE: The aim of the present study was to evaluate commonly used approaches for detection of radiographic angles in hallux valgus deformity patients. METHODS: This retrospective study was conducted in patients with hallux valgus deformity at Wangjing Hospital of China Academy of Chinese Medical Sciences from January 2016 to January 2019. The inclusion criteria were: (i) postoperative dorsoplantar weight-bearing radiographs for the feet of patients with the hallux valgus; (ii) patients had been managed with a distal osteotomy of the first metatarsal and the osteotomized bone ends recovered. The exclusion criteria applied were as follows: (i) age > 65 years or < 18 years old; (ii) blurry image; (iii) previous history of severe foot trauma and surgery. Postoperative radiographs for hallux valgus were analyzed using six methods: by a line drawn through the long axis of the first metatarsal bone (method 1); an extended line drawn to bisect the shaft of the metatarsal at two levels with joined points of bisection (method 2); a line drawn to connect the center of the articular surface of the metatarsal head and the center of the proximal articulation (method 3); a line drawn from the center of the head of the first metatarsal head through the center of the base of the first metatarsal bone (method 4); a line drawn through the center of the head and the center of the proximal shaft (method 5); and a line drawn from the center of the head of the first metatarsal head through the center of the proximal articulation (method 6). The measurement results obtained were subjected to Bland-Altman analysis and consistency evaluation. RESULTS: A total number of 20 radiographs were collected for measurement. No statistically significant differences were found in the measurement values among the six methods (P > 0.05). The lowest values of the average measurement, standard deviation, and confidence interval were established in method 3, followed by those in methods 1 and 4. The standard deviation of the measurement value and the confidence interval in method 2 were the largest. Methods 1 and 4 had similar confidence intervals and were with a high consistency. Due to the nature of the retrospective study, no follow-up and complications were applicable in the present study. CONCLUSION: Line drawn through the long axis of the first metatarsal bone (method 1) and line drawn from the center of the head of the first metatarsal head through the center of the base of the first metatarsal bone (method 4) were reliable and well repeatable, and may be used for postoperative radiographs.