A new label-free and passive microfluidic technique to select cells based on single-cell glycolytic activity. The method has broad applicability and we demonstrate here single-cell droplet encapsulation and selection of live cells.
Objective: To assess whether traditional hallux valgus (HV) measurements obtained with conventional radiography (CR) correspond to those obtained with weight-bearing computed tomography (WBCT). Methods: In this retrospective case-control study, 26 HV feet and 20 control feet were analyzed with CR and WBCT. Hallux valgus angle (HVA), intermetatarsal angle (IMA), interphalangeal angle (IPA), distal metatarsal articular angle (DMAA), sesamoid station (SS), and first metatarsal head shape were measured. Chi-square tests were used to compare hallux valgus and control patients. T-tests were used to compare CR and WBCT. P-values less than 0.05 were considered significant. Results: WBCT was capable of discriminating patients with HV from controls, showing higher mean values for HV patients than controls in HVA (35.29 and 9.02, p < 0.001), IMA (16.01 and 10.01, p < 0.001), and DMAA (18.90 and 4.10, p < 0.001). When comparing the two methods, differences were not significant between CR and WBCT measurements in HVA (-0.84, p = 0.79), IMA (-0.93, p = 0.39), IPA (1.53, p = 0.09), or SS (p = 0.40), but were significant for DMAA (13.43, p < .0001). CR analysis yielded varied metatarsal head shapes, while all WBCT shape classifications were round. Conclusion: Unidimensional HV measurements were similar between WBCT and CR, while more three-dimensional findings were not. CR may be used to assess the axial aspects of HV, but multidimensional aspects of the deformity may not be accurately assessed with plain radiographs. Level of Evidence III; Therapeutic Studies; Retrospective Case-Control Study.
Category: Midfoot/Forefoot; Basic Sciences/Biologics; Hindfoot Introduction/Purpose: A recent study published in Nature (Venkadesan et al.) demonstrated that coupling the transverse arch (TA) with the medial longitudinal arch (MLA) significantly increased midfoot intrinsic stiffness. The contribution of the TA is substantial, suggested as the evolutionary advancement providing the foot stiffness required for human bipedalism. Progressive collapsing foot deformity (PCFD) is a complex deformity ultimately resulting in loss of stiffness and collapse of the MLA. The novel understanding of the TA may play a key role in the pathogenesis of this deformity. The objectives of this study were to assess and compare the TA curvature in PCFD and controls and to evaluate its relationship with accepted PCFD measures. We hypothesized that the curvature of the TA will be decreased in PCFD. Methods: A retrospective review was conducted for 32 PCFD and 32 controls. Measurements were performed using weight- bearing CT (WBCT). A novel measurement, the transverse arch plantar (TAP) angle, was designed to directly measure the TA in both PCFD (Figure 1a) and controls (Figure 1b). TA curvature was calculated using the equation described by Venkadesan et al. (Figure 6) utilizing width, length (Figure 3a), 3rd metatarsal thickness (Figure 3b), and 4th metatarsal torsion (Figure 4a, 4b). Finally, uni- and multivariate analyses were performed to analyze the relationship between the TAP angle, Foot and Ankle Offset (FAO), peritalar subluxation, and measurements associated with PCFD classes: hindfoot moment arm (class A), talonavicular coverage angle (class B), Meary angle (class C), medial facet uncoverage angle (class D), and talar tilt (class E). Normality of different variables was assessed using the Shapiro-Wilk test. Two groups were compared using t-test for normal, and Mann-Whitney for non-normal variables. Results: Measurements of the TAP angle were found to be significantly higher in the PCFD group than the control group with a mean angle of 115.24° (SD 10.68) and 100.76° (SD 7.92) respectively (p<0.001) (Figure 2).No significant difference was found in the calculated TA curvature between PCFD and controls with mean values of 17.84 (SD 4.41) and 18.18 (SD 3.68) respectively (p=0.741) (Figure 5).The univariate analysis performed showed a moderate positive correlation between the TAP angle and the FAO (ρ=0.58;r2=0.34;p <0.001).The multivariate analyses showed, among the different PCFD class measurements and the TAP angle, only the middle facet uncoverage (β=0.08,p<0.001) and hindfoot moment arm (β=0.32, p<0.001) were associated with higher values of FAO, while only the Meary (β=0.49,p=0.004) and the talonavicular coverage angles were associated with higher values of peritalar subluxation (β=0.75,p<0.001). Whereas, Meary's angle was the only predictive factor of higher TA collapse (β=0.55,p<0.001). Conclusion: Our direct measurement showed a collapsed of the TA in PCFD. However, this did not appear to be a consequence of insufficient bone torsion, but rather some other etiology, possibly a soft tissue failure. Considering the implication of the TA among the different PCFD classes, it did not appear to play a significant role on the overall PCFD deformity. TA collapse seemed mainly influenced by Meary's angle, which assess the MLA. This further supports the idea behind TA and MLA coupling suggesting that when the TA is collapsed, the foot does not possess the required stiffness to maintain the MLA.
Category: Midfoot/Forefoot; Other Introduction/Purpose: Lateral Column Lengthening (LCL), Medial Displacement Calcaneal Osteotomy (MDCO) and Cotton Osteotomy (CO) are considered the work-horse surgical procedures for Progressive Collapsing Foot Deformity (PCFD) correction. The amount of three-dimensional correction induced by each isolated procedure cannot be established in the clinical setting since procedures are frequently performed in combination based on deformity severity and surgeon's preference. Understanding the influence of each one of the procedures, as well as their magnitudes, in the overall 3D correction of the deformity would be extremely helpful in the surgical planning of PCFD. Therefore, our simulated weightbearing cadaveric study aimed to assess the amount of 3D correction induced by different magnitudes of isolated and combined LCL, MDCO, and CO procedures, using weightbearing CT (WBCT) imaging. Methods: In this cadaveric study 12 below-knee specimens with no deformity were used. They were mounted on a frame under 360N of axial load, while keeping conventional stance level tension to tendinous structures. Each group of four specimens underwent isolated and progressive magnitudes of MDCO (6, 10 and 14mm), LCL (6, 8 and 10mm) and CO (4, 8 and 12mm). Following isolated correction, the specimens were randomized into different amounts of combined correction, first with two procedures (only moderate correction; four specimens each combination) and then with three procedures (combined mild, moderate and large corrections; four specimens each). The 3D measurement Foot and Ankle Offset (FAO), representing the relative position between the center of the ankle joint and the weight bearing tripod of the foot, was calculated from WBCT datasets for each specimen in each one of the tested corrected conditions. Comparison between the different conditions was performed using Paired T-Test/Wilcoxon. Results: All isolated performed corrective procedures (MDCO, LCL and CO) significantly influenced FAO measurements (All p- values <0.05). When applied in isolation, every 1mm increase in MDCO, LCL and CO decreased FAO values by respectively 0.8%, 0.36%, and 0.29%, highlighting the importance of the heel position in the overall 3D position of the foot. Combination of two moderate-sized procedures decreased FAO values significantly (p<0.05) and more pronouncedly, with combination of MDCO and LCL decreasing FAO by an average of 7.2%, MDCO and CO by 6.2% and LCL and CO by 3.9%, with no significant differences between the three. As expected, combination of the three procedures lead to pronounced and significant decreased of FAO values by respectively 5.2%, 8.5% and 14.2% for mild, moderate, and large corrections. The combination of the three large sized corrections was significantly higher than mild and moderate corrections (p=0.002). Conclusion: In this cadaveric WBCT study we assessed the influence of different magnitudes of isolated and combined MDCO, LCL and CO in foot and ankle 3D alignment. We found that all isolated procedures significantly decreased FAO measurements, with every 1mm increase in MDCO, LCL and CO decreasing FAO by respectively 0.8%, 0.36%, and 0.29%. Combination of two procedures and three procedures also lead to significant and more pronounced alignment change. The data presented in this study can serve as baseline predictive values of foot alignment correction when planning the use of MDCO, LCL and CO for surgical treatment of PCFD.
Category: Midfoot/Forefoot; Bunion; Hindfoot Introduction/Purpose: An unstable medial column lever arm may be associated with many conditions, particularly progressive collapsing foot deformity (PCFD), hallux valgus (HV), and midfoot arthritis (MA). Restauration of the first metatarsal length and its lever in the tripod is essential when surgically treating these deformities. Fusion of the first tarsometatarsal joint (TMT) using a structural graft aims to correct the first metatarsal malalignment and create a firm construct on the medial arch. This study aimed to assess early results, healing, and complication rate of a distraction dorsal opening plantarflexion wedge allograft first tarsometatarsal joint fusion in patients with collapse/instability of the medial column. Our main hypothesis is that using a structural allograft on a TMT fusion might present a considerable rate of nonunion. Methods: In this IRB-approved prospective cohort study, patients with a clinical diagnosis of PCFD, HV, MA that underwent a TMT distraction arthrodesis at our institution were evaluated. Adults undergoing the procedure and had performed a weight- bearing computed tomography (WBCT) at 12 weeks postoperatively were included. The technique was carried using a pre-shaped anatomically specific structural allograft and specific implants. Fusion was defined by two fellowship-trained orthopedic foot and ankle surgeons and one fellowship-trained musculoskeletal radiologist, unrelated to the study. A percentage higher than 50% of crossing trabeculae over the entire proximal and distal allograft surfaces had to be noticed. Complications were established as minor (superficial dehiscence, superficial infection, and neuropraxia) and major (deep dehiscence, deep infection, nerve damage, residual deformity, sesamoiditis, limited motion, lateral overload, and reoperation). Collapse correction was assessed by the talus- first metatarsal angle (TFMA). Results: A total of 22 patients (22 feet) were included (11 PCFD, 6 MA, and 5 HV patients) with a mean age of 52.6 years (range, 19-75 years; SD, 14.4), and a mean body mass index (BMI) of 32.9kg/m2 (95% CI, 29.2 to 36.5). Mean follow-up was 5.9 months (range, 3-12), and median allograft size was 8mm (range 5-19mm). Bone healing was observed on 91% of cases, and two patients (one PCFD and one MA) presented a non-union. Two minor complications (9%, both superficial dehiscence) and one major complication (4.5%, deep infection on a MA patient) were observed. Inter-observer reliability for TFMA measurements was excellent, with an ICC of 0.86. Statistically significant improvement of the sagittal plane TFMA was observed, with a mean enhancement of 9.4 degrees (95% CI, 6.7 to 12.1 degrees; p<.0001). Conclusion: In this prospective cohort study of 22 patients treated with the TMT distraction arthrodesis for medial longitudinal arch collapse/instability, we observed a low complication rate (9% minor, 4.5% major). A high healing rate after 3 months (91%), one clinically stable radiographic non-union (4.5%), and one unstable non-union (4.5%) needing reoperation were noted, despite the use of a structural allograft requiring healing at two surfaces. Our results demonstrate promising initial outcomes for this technique in treating collapse of the medial longitudinal arch in patients with PCFD, MA, and HV deformities. Long-term results are needed to confirm these promising results.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.