Arch Collapse Research Articles

Influence of Fractures and Dislocations in Severity of Rocker-Bottom Deformity in Patients with Charcot Foot.

The objective of this study was to identify bone fractures and joint dislocations that have greater association with the severity of arch collapse in patients with Charcot foot involving the midfoot.A retrospective study in 28 (N = 29 feet) patients who had Charcot foot deformity of the midfoot. The study included stage III of Eichenholtz classification, and Schon classification types I to III. Talar-first metatarsal and calcaneal pitch angles and cuboid height were used to evaluate the severity of the midfoot deformity in a weightbearing lateral radiograph. Two investigators evaluated the bone fracture and joint dislocation involved in weightbearing antero-posterior and lateral radiographs.There were 13 (46%) feet that showed pattern 1, 9 (31%) feet with pattern 2, and 7 (25%) feet with pattern 3 according to the Schon classification. One foot had a combination of patterns 1 and 2. Midfoot ulceration occurred in 64% (n = 19) of feet. In the multivariate analysis, plantarflexion of talar-first metatarsal angle was predicted by navicular-medial cuneiform dislocation (p = .007 [-20.620-3.683]), an increase of the negative calcaneal pitch angle by fragmentation of the cuboid (p = .003 [-15.568-3.626]), and increment of the negative cuboid height by navicular-medial cuneiform and medial cuneiform-first metatarsal dislocations (p = .040 [-12.779-0.317], p = .002 [-13.437-3.267], respectively).Bone fractures and dislocations in the sagittal plane seem to contribute to midfoot collapse, but navicular-medial cuneiform dislocation/non-union and cuboid fragmentation predict severe rocker-bottom deformity in cases of Charcot foot.

Construction Technology and Application of TBM in Shengli Tunnel of Tianshan Mountain under poor geological conditions

When a tunnel boring machine (TBM) excavates in poor geological conditions like fracture zones, soft rock with high ground stress, hard rock with high ground stress, and water inrush ground, severe problems such as surrounding rock collapse, convergence, rock burst and water and mud outburst are usually encountered. These problems existed in the Tianshan Shengli Tunnel project in Xinjiang, China. Several methods and techniques were adopted to reduce construction risks and improve construction efficiency. The seismic wave reflection long-distance geological forecasting method was employed to forecast and predict these adverse geological conditions. The pre-reinforcement construction method was employed on the surrounding broken rocks in front of the tunnel face to lower the risks of tunnel collapse and machine jamming. A combined steel arch was applied to prevent tunnel arch collapse. An artificial cap method was applied to prevent the jamming caused by high-ground stress soft rock. Measures such as spraying water on the tunnel face and drilling stress holes were employed to prevent rock bursts caused by high-ground stress in hard rock. Implementing the advanced pipe shed method during water influx, sudden mud, and other working conditions reduced the risk of groundwater damage to equipment and lowered risks to personnel safety. The successful application of these techniques can provide a reference for TBM tunnel construction in similar ground conditions.

Research on Double-Layer Support Control for Large Deformation of Weak Surrounding Rock in Xiejiapo Tunnel

Double-layer primary support is proposed to control the deformation of surrounding rock in tunnels within weak geological conditions, where engineering challenges such as large deformations, tunnel faces, and arch collapse are encountered. This approach is based on the principle of combined resistance and release. A combined approach of numerical modeling and on-site surveillance was utilized to analyze the displacement and stress state of the tunnel support structure at different construction stages of primary support for the second layer, using Xiejiapo Tunnel as an engineering case. The findings indicate that the implementation of two-layer primary support can mitigate the progression of large deformations effectively in weak surrounding rock; the sooner the primary support for the second layer is applied, the better the deformation control, and the later the application takes place, the more effectively the tension in the surrounding rock is diminished, whereby the self-supporting capacity of surrounding rock comes into its own. The force of the shotcrete is reduced. Considering the structural deformation and stress state, as well as combination of resistance and release, it is best to implement the primary support for the second layer 10 feet behind the primary support for the first layer.

Automatic calibration of a discrete element model of a masonry arch by swarm intelligence methods

This paper addresses the automatic calibration of constitutive parameters of the Discrete Element Method (DEM) models of masonry structures. Three swarm intelligence algorithms were applied, which are efficient in problems characterised by the small number of unknown parameters but high computational demand for the evaluation of the target function. Trust-Based Particle Swarm Optimisation (TBPSO) was chosen due to its excellent convergence rate. It was already tested that TBPSO converged faster than the original Genetic Algorithm and Particle Swarm Optimisation Methods. Therefore, TBPSO was compared with two recent and promising methods, the Marine Predator Algorithm (MPA) and the Golden Eagle Optimiser (GEO). The paper also presents a novel two-step approach, which enhances the performance of the tested optimisation strategies. The methodology is capable to account for and precisely find the mode of failure using Convolutional Neural Networks (CNN). The three optimisation methods and the two-step approach were applied on the DEM model of a quasi-static masonry arch collapse experiment from the literature. Performance of the three algorithms in identifying the appropriate constitutive parameters values of the DEM model were compared. Clear evidence on the advantage of the two-step approach with TBPSO is demonstrated. Remarks about different modelling issues are also included.

Model Test on the Collapse Evolution Law of Tunnel Excavation in Composite Strata with a Cavity

More complex geological conditions could be encountered with the construction of urban subway projects. At present, many subway tunnels have been built in composite strata with upper soft and lower hard layers, but the presence of a cavity in the strata increases the risk of collapse during construction. In this paper, a series of model experiments and discrete element methods were conducted to investigate the failure behavior of composite strata with a cavity caused by tunnel excavation disturbance. The influence of the distance between the cavity and vault (hd) and the distance between the soil–rock interface and vault (hr) on the collapse of the composite strata are analyzed. The research results indicate that tunnel collapse exhibits progressive failure because of the forming of a collapsed arch in the strata. If the hd is greater than the tunnel span (D), the arch can be stabilized without other disturbances. Additionally, the thickness of the tunnel rock layer affects the height of the collapsed arch significantly, as it is difficult to form a stable arch when the hr is less than 2/3 D. Finally, reasonable construction safety distances are proposed based on the possibility of forming a stable arch collapse in the tunnel and determining the range of the collapse.

Flatfoot arch correction with generic 3D-printed orthoses at different body weight percentages

BackgroundFlatfoot can be associated with foot pathologies and treated conservatively with foot orthoses to correct arch collapse and alleviate painful symptoms. Recently, 3D printing has become more popular and is widely used for medical device manufacturing, such as orthoses. This study aims at quantifying the effect of generic 3D-printed foot orthoses on flatfoot arch correction under different static loading conditions. MethodsParticipants with normal and flatfeet were recruited for this cross-sectional study. Clinical evaluation included arch height, foot posture index, and Beighton flexibility score. Surface imaging was performed in different loading conditions: 1) 0% when sitting, 2) 50% when standing on both feet, and 3) 125% when standing on one foot with a weighted vest. For flatfoot participants, three configurations were tested: without an orthosis, with a soft generic 3D printed orthosis, and with a rigid 3D printed orthosis. Arch heights and medial arch angles were calculated and compared for the different loading conditions and with or without orthoses. The differences between groups, with and without orthoses, were analyzed with Kruskal-Wallis tests, and a p < 0.05 was considered significant. ResultsA total of 10 normal feet and 10 flatfeet were analyzed. The 3D printed orthosis significantly increased arch height in all loading conditions, compared to flatfeet without orthosis. Wearing an orthosis reduced the medial arch angle, although not significantly. Our technique was found to have good to excellent intra and interclass correlation coefficients. ConclusionsGeneric 3D printed orthoses corrected arch collapse in static loading conditions, including 125% body weight to simulate functional tasks like walking. Our protocol was found to be reliable and easier to implement in a clinical setting compared to previously reported methods. Level of evidenceII

Lower limbs biomechanical deficits associated with stage 1 and 2 posterior tibialis tendon dysfunction during walking

BackgroundPosterior tibialis tendon dysfunction (PTTD) is a chronic degenerative musculoskeletal disorder causing a progressive ankle complex and arch collapse altering lower limb biomechanics. However, biomechanical changes associated with stage 1 and 2 PTTD need to be better characterized during walking to guide clinical recommendations and improve non-operative treatments. Research questionWhat are the lower limb kinematic and kinetic differences between individuals with stage 1 (PTTD1), individuals with stage 2 PTTD (PTTD2) and healthy counterparts during gait? MethodsSixteen PTTD1, 11 PTTD2 and 20 healthy controls were included in this multicentric case-control study to compare their lower limb gait biomechanics. Kinematic and kinetic data were recorded using a three-dimensional motion capture system and a force plate. One-dimensional statistical parametric mapping was used to compare lower limb joint motion and moments between groups during the stance phase. ResultsPTTD1 had minimal biomechanical differences compared with the control group. In contrast, PTTD2 presented significant differences compared with controls and PTTD1. At the ankle, PTTD2 exhibited greater plantarflexion and eversion angles and midfoot dorsiflexion and inversion angles throughout stance compared with controls and PTTD1. PTTD2 presented lower midfoot abduction moments compared with controls. These changes led PTTD2 to exhibit knee and hip adaptative biomechanical mechanisms in the frontal and transverse planes in late stance. PTTD2 had greater knee internal rotation angles and smaller knee external rotation moments compared to controls. PTTD2 had smaller hip internal rotation angles compared with PTTD1 and smaller hip adduction moments compared with controls. SignificancePTTD1 showed minimal biomechanical differences compared to controls and important differences compared to PTTD2. The lower limb biomechanical deficits accentuate as the pathology advances from stage 1 to stage 2. PTTD is a progressive condition needing early clinical management at stage 1 to avoid successive biomechanical changes associated with stage 2.

The Role of the Plantar Fascia in Supporting the Arch in Flatfoot Deformity

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: The osseous structure of the foot has been described as an arch-like triangular structure or truss where the plantar fascia (PF) functions as the tensile element, maintaining the overall length of the arch. The importance of the PF in maintaining the arch has likely been underestimated because only minor abnormalities in its structure are seen on MRI studies in patients with flatfoot deformity. However, the importance of a ligament in preventing deformity may not be correlated with its attenuation seen on MRI. We hypothesized that the degenerative elongation of the plantar fascia would be a necessary precursor of arch collapse. The goal of this study was to evaluate the role of the plantar fascia in arch stability in flatfoot deformity. Methods: We used a validated finite element model of the foot reconstructed from CT scan of a female cadaveric foot weighing 60 kg. The model included 28 bones, 72 ligaments, cartilage, and an encapsulating soft tissue. The flatfoot model was created by simulated transection of the ligaments and unloading of the posterior tibial tendon. The model was used to assess the impact of isolated PF failure on the development of flatfoot deformity, evaluate the capability of the PF when reconstructed to restore foot alignment, and determine the amount of progressive strain that constitutes failure for each ligament. Foot alignment angles were used to evaluate the foot alignment. For comparison, the angles were also evaluated for other ligament tears. The impact of PF failure on force changes in the remaining ligaments was also investigated by quantifying ligament force changes during simulated PF cutting in the foot model. Results: When compared to the intact and flatfoot models, we found that the individual release of the PF cannot cause deformity (Figure 1). However, it significantly increased the force in the long (142%) and short plantar (156%), deltoid (45%), and spring ligaments (60%), potentially putting the foot at risk of arch instability over time. Moreover, we found that the PF was the structure most able to restore the arch (Figure 1a). The PF was also found to play a secondary role in reducing hindfoot valgus and forefoot abduction deformities (Figures 1b,1c). Moreover, to produce deformity, a considerable amount of attenuation in the spring (strain= 41%) and interosseous talocalcaneal ligament (strain= 27%), but only a small amount in the plantar fascia (strain= 10%) was needed. Conclusion: In comparing normal to flatfoot models of the foot, we found that isolated PF release did not cause arch collapse, but that arch collapse could not occur without elongation of the PF. While the progressive strain in the PF needed to enable arch collapse was small, the PF is a very long ligament, thus even small strain within the PF corresponds to substantial change in overall length of the arch. Chronic degeneration of the PF leading to plantar fasciitis may be an early sign of impending flatfoot deformity.

Three-Dimensional Assessment to Hallux Valgus Correction Using Lapicotton Technique

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: The first-ray and the medial column play a crucial role in preserving the tripod of the foot. Changes to structural properties of the first-ray, along with collapse of the medial-longitudinal-arch, have been associated with hallux valgus (HV). Thus, restoring the first-ray plays an important role when correcting the mechanical function of the foot tripod in the setting of HV combined with medial-longitudinal-arch collapse. The LapiCotton technique combines the mechanical advantages of Cotton osteotomy and modified Lapidus procedures by maintaining the length of the first-ray and preserving the medial- longitudinal-arch by plantar inclination of the distal part of first-ray. The aim of this study was to evaluate the effectiveness of the LapiCotton procedure in correcting selected radiographic parameters in patients with combined VH with medial-longitudinal arch collapse. Methods: Preoperative and postoperative Weight Bearing CT (WBCT) scans were obtained from HV patients who underwent unilateral LapiCotton procedure. Postoperative scans were obtained roughly three months after the date of surgery. Semi- automatic measurements were applied to 22 WBCT images across a total of 11 patients enrolled into the study using the Disior® Bonelogic® Software. Measurements of the hallux valgus angle (HVA), meary sagittal measurement, and intermetatarsal angles were taken from preoperative and postoperative scans. These scans were then compared using intraclass correlation coefficients and paired t-tests to evaluate the efficacy of the Lapicotton technique in treating HV with P-valus &lt; 0.05 being significant. Results: HVA was found to be significantly larger (p=.026) in the preoperational group (Mdn = 27.52) than the postoperational group (Mdn = 20). In addition, the Meary sagittal measurement was found to be significantly different between groups (p=.033), with a larger value seen in the preoperational group (Mdn = -14.28) compared to the post-operational group (Mdn = -11.15). It was also observed that the IMA was significantly larger (p=.003) in the preoperative group (Mdn = 15.68) compared to the postoperative group (Mdn = 11.26). The sesamoid rotation was found to be higher in the preoperative group (Mdn = -17.71) than the post operative group (Mdn = -24.98), however, these values were not significantly different from one another (p=.203). Conclusion: The LapiCotton procedure proved to be effective in correcting radiographic parameters in patients with HV combined with collapse of the medial longitudinal arch. Reliable correction of HV, along with correction of medial longitudinal arch collapse, was quantified based on semi-automated WBCT measurements of HVA, IMA and Meary angle. LapiCotton produced significantly different measurements for both HVA and IMA postoperatively, providing evidence that the LapiCotton procedure can successfully correct medial longitudinal arch collapse in patients with HV, as well as radiographically reduce the severity of the deformity.

Transfer of the Flexor Hallucis Longus Tendon Improves Joint Kinematics of the Medial Column during Simulated Stance Phase in Progressive Collapsing Foot Deformity

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: Medial longitudinal arch collapse is one of the key clinical and radiographic features of progressive collapsing foot deformity (PCFD) and can occur anywhere within its three constituents: first tarsometatarsal (TMT1), naviculo- cuneiform (NC), and talonavicular (TN) joints. Medial column osteotomy or fusion has typically been utilized to address this instability. A new procedure involving transferring the flexor hallucis longus (FHL) tendon to the 1st metatarsal base has shown promising results in restoring radiographic alignment of the entire medial column in conjunction with a hindfoot procedure. However, the mechanism of correction in a dynamic environment is unclear. Thus, this study examined the effect of medial column stabilization using FHL transfer on the foot and ankle kinematics during stance phase. Methods: Twelve mid-tibia cadaveric specimen (6 male; Age 48 ± 16 years) underwent stance phase simulations using a validated six-degree of freedom robotic gait simulator. Three conditions were tested each cadaveric specimen: pre-deformity (Intact), after creating a simulated progressive collapsing foot deformity (sPCFD), and after an FHL transfer (FHL). Motion capture cameras tracked the motion of retroreflective markers inserted into bones of the foot and ankle. The FHL transfer was performed on each specimen by harvesting the FHL tendon at its distal insertion and fixing it in the 1st metatarsal with a biotenodesis screw (Figure 1A). Outcome measures include joint rotations of the TMT1, NC, TN, subtalar, and ankle joint. Significant differences (p &lt; 0.05) in joint kinematics were statistically analyzed by constructing 95% confidence intervals of the repeated measures difference between both the sPCFD and FHL conditions and the intact condition. Results: The FHL condition demonstrated significant differences in the kinematics of the medial column compared to the sPCFD condition (Figure 1B). The TMT1 joint showed increased plantarflexion in early and late stance, as well as increased eversion during early and mid-stance. The NC joint demonstrated increased plantarflexion, eversion, and abduction during early stance. At the TN joint, there was increased inversion during early and late stance, as well as increased adduction during mid-stance. At the subtalar joint, subtalar eversion was decreased during early stance, and no significant differences were observed from the intact condition throughout stance. No differences were found in the ankle joint kinematics across all conditions. Conclusion: The results of our study demonstrate that the medial column stabilization procedure with FHL transfer can improve the kinematics of the medial column in sPCFD. Additionally, the correction at the TN and subtalar joint demonstrates the potential efficacy of this procedure for hindfoot correction. The correction occurred during the earlier stance phase as well when the FHL is not active, suggesting that this procedure provides correction in both a dynamic and static manner. This procedure can be used in conjunction with hindfoot corrective procedures in PCFD, particularly when preoperative imaging suggests multiple levels of instability within the medial column.

Deltoid Ligament Release for Varus Deformity Correction in Total Ankle Arthroplasty

Category: Ankle Arthritis; Ankle Introduction/Purpose: Total ankle arthroplasty (TAA) with severe varus ankle deformity is balanced in the coronal plane by releasing medial soft tissue constraints. There are no previous reports examining the impacts of TAA with concomitant release of the deltoid. Progressive talar tilt and progressive collapsing foot deformity were evaluated. Methods: A retrospective review included patients undergoing TAA with confirmed preoperative varus deformity. Patients underwent complete soft tissue release of the deltoid ligament complex. Pre- and post-operative weightbearing radiographs quantified Meary’s angle, lateral talo-1st metatarsal angle, calcaneal pitch, talar coronal alignment, and the lateral distal tibial angle. The primary endpoints were degrees of coronal plane correction, longitudinal arch position, and complication rates. Results: Thirty-two patients were included with median 12.5 month follow-up. Coronal plane alignment and VAS pain scores improved significantly in all patients, and statistical analysis revealed that complete deltoid ligament release had no bearing on calcaneal pitch and Meary’s angle at final follow-up. Posterior tibial tenotomy was performed on 3 (9.3%) patients. Median coronal plane alignment correction averaged 17.5° improvement (X2(2)= 50.358, P&lt;.001) from 19.5° varus (11.2-24.5°) to 2.0° varus (0.5- 3.5°)(P &lt;.001). Two degrees of coronal plane varus alignment without tilt progression (0.6-3.4°)(P &lt;.001) was maintained through follow-up. Final calcaneal pitch of 18.2° (14.4-23.2°) mirrored initial median measurement of 18.3° (15.7-21.1°). No significant differences were found between Meary’s angle measurements at any time points (P=.568). Eight of 32 patients had complications with five requiring further ankle surgery. Conclusion: Complete release of the deltoid ligament may improve coronal malalignment when performing TAA. Release did not lead to radiographic or clinical medial instability, valgus talar tilt, or medial arch collapse.

Variability of the lower limb symmetry index associated with the gait parameters in the overweight adult population with flatfoot: a case-control study.

Background: Adult acquired flatfoot is characterized by a medial arch collapse during monopodal support in the stance phase, developing eversion of the calcaneus and abduction of the forefoot linked to the hindfoot. The purpose of our research was to analyze the dynamic symmetry index in the lower limbs comparing patients with flatfoot and normal foot. Methods: A case-control study was carried out with a sample of 62 participants divided into two groups consisting of 31 participants were overweight with bilateral flatfoot and 31 participants with healthy feet. A portable plantar pressure platform with piezoresistive sensors was used to measure the load symmetry index in the lower limbs in the foot areas and gait phases. Results: Gait pattern analysis showed statistically significant differences in the symmetry index for lateral load (p = 0.004), the initial contact phase (p = 0.025) and the forefoot phase (p < 0.001). Conclusion: The adults were overweight with bilateral flatfoot evidenced alterations in the symmetry index in the lateral load and in the initial contact and flatfoot contact phases, showing greater instability in overweight adult flatfoot compared to the people with normal feet.

Calcaneal Osteotomy and First Ray Procedures Improves Talar Head Coverage in the Absence of Lateral Column Lengthening

Category: Hindfoot; Midfoot/Forefoot Introduction/ Purpose: Peritalar subluxation (PTS) is a crucial feature of Progressive Collapsing Foot Deformity (PCFD). Surrounding structures assume distinct behaviors, contributing to different disease deformities (classes). One of its most traditional aspects is the midfoot abduction (class B), usually noted by a lateral deviation of distal structures at the talonavicular joint. This finding commonly leads surgeons to perform a lateral column lengthening osteotomy for abduction correction, a complex surgery with potential complications. The first ray's ability to reestablish the tripod and restore the hindfoot by derotating structures under the talus was previously theorized. This study aimed to test the capability of the Lapidus and the Cotton procedures in conjunction with a calcaneus displacement osteotomy (MDCO) to improve midfoot abduction in the setting of a collapsed foot. Methods: In this IRB-approved, prospective cohort study, we analyzed patients undergoing medial column instability surgery and evaluated preoperatively with a weight-bearing CT (WBCT). We included individuals receiving a Lapidus bone block procedure or a Cotton for PCFD or Hallux Valgus (HV). Patients having a lateral column lengthening procedure of any type were excluded. Talonavicular coverage angle (TNCA) was measured as a marker of midfoot abduction. Medial arch collapse and forefoot varus were evaluated by the sagittal talus-first metatarsal angle (TFMA), and the forefoot arch angle (FFA) was measured. Associated procedures and the correction amount (displacement or wedge size) were recorded. Normality was estimated by the Shapiro- Wilk test and comparison among timelines by the one-way ANOVA. A multivariate regression analysis was executed to evaluate which of the measurements influenced abduction improvement. Statistical significance was considered for p-values of less than 0.05. Results: A total of 20 patients (age: 43.85 [19-72], BMI 30.98 [SD: 5.95]) were included, 11 PCFD (55%) and 9 HV (45%) with a mean follow-up of 7.5 months (3-12). Bone block Lapidus was performed in most subjects (90%), and the median wedge used was 9mm (5-12mm). MDCO occurred in 55% of patients. All measured variables had improvement with surgery (TNCA: 23.74 to 10.66, p&lt; 0.0001; FFA: 6.27 to 12.67, p&lt; 0.0001; TFMA: 11.73 to 4.22, p=0.0003). A correlation was found between TNCA improvement and FFA improvement (rs=0.46, p=0.0407), but not among TNCA improvement and TFMA improvement (rs=0.43, p=0.06). The size of the wedge did not strongly influence the TNCA correction (R2=0.016, p=0.0036), an improvement moderately explained by the MDCO amount (R2=0.186, p&lt; 0.0001). Conclusion: This study demonstrated correction of midfoot abduction, translated by the TNCA, in the absence of lateral column lengthening procedures. When evaluating patients submitted to first ray procedures (bone block Lapidus and Cotton) in conjunction with MDCO, an enhancement on the talar head coverage was noted. Variables associated with arch height and forefoot varus (FFA and TFMA) were correlated with the TNCA improvement. Nevertheless, only the MDCO displacement amount and not the size of the used allograft wedge could explain changes in TNCA. The provided data might support surgeons when planning treatment in the PCFD scenario.

Closed Reduction and Percutaneous Fixation of Lisfranc Injury Using Suspensory Fixation.

This closed reduction and percutaneous fixation (CRPF) technique utilizing suspensory fixation is indicated for the treatment of Lisfranc injuries with displacement or instability of the tarsometatarsal joint complex-and typically only for low-energy, purely ligamentous Lisfranc injuries. The goal of this procedure is to restore joint stability and prevent common complications of Lisfranc injuries (e.g., midfoot arch collapse and posttraumatic arthritis) while avoiding the complications and risks associated with open reduction and internal fixation (ORIF) and primary arthrodesis. We recommend performing the procedure within 10 to 14 days of the injury; otherwise, an open debridement may be necessary to address scar tissue formation. We start with the patient in the supine position and perform a fluoroscopic stress examination of the joint. Next, the Lisfranc joint undergoes closed reduction, which is held in place with a clamp. Following reduction, a guidewire is drilled from the lateral border of the base of the 2nd metatarsal medially through the medial cuneiform, followed by a medial-to-lateral cannulated drill. The suspensory fixation is then passed lateral-to-medial, placing the suture button on the lateral cortex of the 2nd metatarsal base. The tape is then tensioned while a bioabsorbable interference screw is inserted to maintain tension. Prior studies have assessed both operative and nonoperative alternatives to CRPF with suspensory fixation for the treatment of Lisfranc injuries. Nonoperative treatment with closed reduction and cast immobilization of Lisfranc injuries is typically reserved for nondisplaced injuries; however, a number of studies have shown poor outcomes with use of this technique1-3. The 2 most common operative alternatives are ORIF and primary arthrodesis4. CRPF with suspensory fixation offers several benefits over both traditional surgical techniques such as ORIF and primary arthrodesis, as well as over percutaneous reduction and internal fixation (PRIF) with a screw. Compared with ORIF and primary arthrodesis, a number of studies have shown that percutaneous treatment of Lisfranc injuries minimizes soft-tissue trauma and reduces the risk of postoperative complications such as wound breakdown, infection, and complex regional pain syndrome, while allowing for earlier participation in rehabilitation5-10. A systematic review of outcomes following PRIF with screw fixation also showed that percutaneous treatment of Lisfranc injuries is a safe and effective technique with good functional outcomes11. When comparing PRIF with a screw to our technique of CRPF with suspensory fixation, CRPF has the added benefit of creating a nonrigid fixation in the Lisfranc joint, which allows for increased range of motion of the medial column and improved return to activity12,13. The rigid fixation in PRIF with a screw can also lead to metal irritation, intra-articular screw fracture, and impaired mobility, which often necessitate the need for screw removal13-15. This fixation-related drawback is not present with our technique, and also avoids the need for use of a biologic substitute such as tendon grafts13. Following CRPF with suspensory fixation, patients can expect to return to full activity at 12 to 16 weeks postoperatively. Postoperatively, patients are typically kept non-weight-bearing for 6 weeks. The operative foot is kept immobilized in a splint for the first 2 weeks, then transitioned to a boot. Between postoperative weeks 6 and 12, partial progressive weight-bearing is introduced with use of an arch support, progressing toward full weight-bearing13,16,17.For comparison, patients who underwent PRIF with screw fixation had a similar postoperative course, but almost all required screw removal at 4 to 6 months postoperatively13,16. Cho et al. retrospectively reviewed the results of 63 patients who underwent either PRIF with screw fixation (n = 32) or CRPF with a suture button (n = 31) and found that CRPF patients had significantly better American Orthopaedic Foot & Ankle Society midfoot scale scores (81 versus 74 points) and visual analog scale scores (3.1 versus 4.6 points) at 6 months postoperatively and prior to screw removal in the PRIF group (p < 0.001). There were no significant differences in these scores, radiographic outcomes, weight-bearing analysis, or complications at 1 year postoperatively. The authors concluded that both techniques provided comparable fixation stability and clinical outcomes. Of note, however, the PRIF group had 4 patients whose postoperative course was complicated by screw breakage13. Start with a fluoroscopic stress examination to identify all components of instability.Ensure that the reduction clamp does not interfere with or affect your guidewire path.If the joint cannot be reduced, convert to an open procedure and debride the obstruction. ORIF = open reduction and internal fixationPRIF = percutaneous reduction and internal fixationCRPF = closed reduction and percutaneous fixationNSAID = nonsteroidal anti-inflammatory drugOR = operating roomAP = anteroposteriorCT = computed tomographyMRI = magnetic resonance imagingAOFAS = American Orthopaedic Foot & Ankle SocietyVAS = visual analog scaleROM = range of motionPT = physical therapyASA = acetyl-salicylic acid (aspirin)BID = twice dailyPRN = as needed.

Three-dimensional assessment of hallux valgus correction using the Lapicotton technique

Objective: The objective of the study was to assess the efficacy of the LapiCotton procedure on patients with hallux valgus (HV) combined with medial longitudinal arch collapse. Methods: Preoperative and postoperative weight-bearing computed tomography (WBCT) scans were obtained from patients with HV submitted to the LapiCotton procedure. Semi-automatic measurements were applied to 22 WBCT images across 11 patients enrolled in the study using a software package (Bonelogic, Disior™, Helsinki, Finland). Significance level was set at 0.05. Results: The hallux valgus angle (HVA) was significantly larger (p=0.026) in the preoperative group (Mdn = 27.52) than in the postoperative group (Mdn = 20). In addition, the Meary sagittal measurement was found to be significantly increased (p=0.033) in the preoperative group (Mdn = -14.28) when compared to the postoperative group (Mdn = -11.15). It was also observed that the intermetatarsal angle was significantly larger (p=0.003) in the preoperative group (Mdn = 15.68) compared to the postoperative group (Mdn = 11.26). Conclusion: The LapiCotton procedure effectively corrected radiographic parameters in patients with HV combined with the medial longitudinal arch collapse. Level of Evidence III; Therapeutic Studies; Comparative Retrospective Study.

Partial Extraction Therapy for Implant Placement: A Newer Approach in Implantology Practice.

One of the most popular treatment modalities in routine implantology practice is extraction followed by immediate or delayed implant insertion. Teeth removal alone is insufficient, particularly in the maxillary anterior region of the jaw. Patients may experience several issues after tooth extractions. Due to trauma and the loss of periodontal ligaments, post-extraction alveolar ridge resorption cannot be prevented. Atraumatic extraction, socket preservation, grafting, and implant placement immediately after the extraction are some of the procedures that are carried outto minimize or prevent the resorption ofalveolarbone. Osseointegration is essential for keeping the clinical effectiveness of dental implants. If the supporting tissues at an implant site resorb and are worsened by risk factors for recession, there may be considerable esthetic and functional failure. Implant placement at the retained root structure preserves the buccal bone resulting in an excellent emergence profile. Resorption in the posterior alveolar ridge may result in a decrease in attached keratinized tissue and a decrease in vestibular depth. This might have a negative impact on the stability of the implant and leads to peri-implantitis resulting in the failure of the implant. Without papilla loss or arch collapse, partial extraction therapy has resulted in effective esthetic outcomes. The socket shield technique is a minimally invasive surgical procedure that helps to maintain both soft and hard tissues by preserving a small section of the root. It lessens the necessity for surgeries on bone and mucogingival grafts, cutting the length of the overall recovery process and reducing the treatment time.When soft and hard tissue grafts are used to fill the socket before applying pressure with pontics, it is known as the pontic shield procedure. However, there is no published study that explains partial extraction therapy in a straightforward and clear manner that can guide a practitioner in determining a shield design with a proven track record of success. This review article focuses on the partial extraction procedure which is very helpful for preserving soft and hard tissues in cases involving immediate implant insertion post-extraction. It has long-term therapeutic success with implant and pontic therapy. This review article will also be helpful for clinicians to understand shield design in different case scenarios and help to learn step-wise procedures carried out in partial extraction therapy.

Influence of soil–structure interaction on seismic demands of historic masonry structure of Kashan Grand Bazaar

Heritage structures are an important part of the history of each community as well as an economic resource. This study aims to investigate the earthquake damage and failure mechanism of a historic Bazaar located in Kashan (center of Iran), which dates back to the eighteenth century. Numerical models were built by a macro method, considering two cases of fixed support and soil–structure interaction (SSI). To assess the structural behavior, modal, nonlinear static, and dynamic time history analyses were performed using a three dimensional finite element method. The results of SSI analysis show an intense weakness of the structure against the required demand based on the design spectrum. Also, foundation flexibility has a great impact on the vibration characteristics, displacement demand, and damage distribution. By comparing the results of time history analysis to the pushover procedure, a lower shear value and higher displacement are obtained. Furthermore, the damage process is as dome collapse alongside short arch, consequently long arch collapse followed by pier wall overturning.

Contribution of anthropogenic vibration sources to crack growth in natural rock arches

Natural arches are culturally valued rock landforms common in sedimentary rocks of the Colorado Plateau and additionally occur broadly around the world. Recent notable collapses of some of these landforms have highlighted the need to better understand the mechanics of their failure. While environmentally driven weathering has been the focus of most previous studies of arch collapse, comparably little attention has been given to anthropogenic vibration sources and how these often slight- to moderate-magnitude shaking events might steadily weaken arches over time. We collected 12–15 months of continuous ambient vibration data from arches and nearby bedrock in both anthropogenically ‘noisy’ and ‘quiet’ locations and used these datasets to develop an annual model of arch peak ground velocity based on magnitude-cumulative frequency distributions. Working from these models, we added vibration events of varying magnitude or frequency of occurrence, informed by field data, imitating arch vibration in response to different anthropogenic activities such as helicopter flights or induced earthquakes. We then applied subcritical fracture mechanics principles to predict annual crack growth rates in an idealized arch under these different vibration conditions. Our results demonstrate that in a single year, cracks grow minimally longer (∼1%) in ‘noisy’ environments than in areas not experiencing anthropogenic vibration energy. Few (1+) 30-s moderate-magnitude events (∼15 mm/s) or many (&amp;gt;37,000) 30-s low-magnitude events (∼2 mm/s) cause markedly increased crack growth. Our approach provides a valuable new framework for assessing the range and frequency of occurrence of vibrations experienced by an arch, and for predicting arch damage. Our results, in turn, yield important new outputs applicable in support of conservation management of these and similar landforms world-wide under exposure to a range of human-induced vibration activity.

Rehabilitation protocol with VISS system and human synergy mat in subjects with flat foot problems in developmental age

The flat foot can be defined as a syndrome with multiple etiopathogenesis, characterized by an altered structure of the longitudinal arch of the plantar vault with its reduction in height. The plantar arch collapse can be counteracted by strengthening the muscles involved; for many years, specific physical exercises have been proposed for this purpose in physical and rehabilitation medicine. Our work aimed to improve the plantar arch muscles’ tone using high focal vibration therapy (300 Hz). Methods: 49 children with a 3rd degree flat foot (age: 8,7,6) underwent 10 sessions, 2 days/wk, of 30 min of focused high vibratory therapy at a frequency of 300 Hz (Vissman, Italy). Before and after treatment stabilometry (StT), static and dynamic baropodometry tests were performed. Results: Evaluation of StT showed an improvement in stability and a decrease in the sway area and ellipse area. Baropodometry tests showed a decrease in foot surface. Also, dynamic tests showed a decrease in both foot surfaces. Discussion: The results lead us to consider this method as a method of the first choice for a conservative approach in the rehabilitation of flat foot syndrome and also for 3rd grade children [1,2].

Talar Head Coverage Correction in the Absence of Lateral Column Lengthening: A Prospective Study with Calcaneal Osteotomy and First Ray Procedures

Category: Hindfoot; Midfoot/Forefoot; Other Introduction/Purpose: Peritalar subluxation (PTS) is a crucial feature of Progressive Collapsing Foot Deformity (PCFD). Surrounding structures assume distinct behaviors, contributing to different disease deformities (classes). One of its most traditional aspects is the midfoot abduction (class B), usually noted by a lateral deviation of distal structures at the talonavicular joint. This finding commonly leads surgeons to perform a lateral column lengthening osteotomy for abduction correction, a complex surgery with potential complications. The first ray's ability to reestablish the tripod and restore the hindfoot by derotating structures under the talus was previously theorized. This study aimed to test the capability of the Lapidus and the Cotton procedures in conjunction with a calcaneus displacement osteotomy (MDCO) to improve midfoot abduction in the setting of a collapsed foot. Methods: In this IRB-approved, prospective cohort study, we analyzed patients undergoing medial column instability surgery and evaluated preoperatively with a weight-bearing CT (WBCT). We included individuals receiving a Lapidus bone block procedure or a Cotton for PCFD or Hallux Valgus (HV). Patients having a lateral column lengthening procedure of any type were excluded. Talonavicular coverage angle (TNCA) was measured as a marker of midfoot abduction. Medial arch collapse and forefoot varus were evaluated by the sagittal talus-first metatarsal angle (TFMA), and the forefoot arch angle (FFA) was measured. Associated procedures and the correction amount (displacement or wedge size) were recorded. Normality was estimated by the Shapiro- Wilk test and comparison among timelines by the one-way ANOVA. A multivariate regression analysis was executed to evaluate which of the measurements influenced abduction improvement. Statistical significance was considered for p-values of less than 0.05. Results: A total of 20 patients (age: 43.85 [19-72], BMI 30.98 [SD: 5.95]) were included, 11 PCFD (55%) and 9 HV (45%) with a mean follow-up of 7.5 months (3-12). Bone block Lapidus was performed in most subjects (90%), and the median wedge used was 9mm (5-12mm). MDCO occurred in 55% of patients. All measured variables had improvement with surgery (TNCA: 23.74 to 10.66, p&lt;0.0001; FFA: 6.27 to 12.67, p&lt;0.0001; TFMA: 11.73 to 4.22, p=0.0003). A correlation was found between TNCA improvement and FFA improvement (rs=0.46, p=0.0407), but not among TNCA improvement and TFMA improvement (rs=0.43, p=0.06). The size of the wedge did not strongly influence the TNCA correction (R2=0.016, p=0.0036), an improvement moderately explained by the MDCO amount (R2=0.186, p&lt;0.0001). Conclusion: This study demonstrated correction of midfoot abduction, translated by the TNCA, in the absence of lateral column lengthening procedures. When evaluating patients submitted to first ray procedures (bone block Lapidus and Cotton) in conjunction with MDCO, an enhancement on the talar head coverage was noted. Variables associated with arch height and forefoot varus (FFA and TFMA) were correlated with the TNCA improvement. Nevertheless, only the MDCO displacement amount and not the size of the used allograft wedge could explain changes in TNCA. The provided data might support surgeons when planning treatment in the PCFD scenario.