Metatarsal Research Articles

Lateral Column Overload in Modified Double vs Triple Arthrodesis: A Biomechanical Study

Category: Hindfoot; Basic Sciences/Biologics Introduction/Purpose: There are few comparative studies investigating differences between the modified double and triple arthrodesis of the hindfoot. Previous studies have suggested that stiffening the lateral column of the hindfoot can increase lateral plantar pressures, potentially precipitating lateral column pain. We sought to characterize the difference in forefoot plantar pressures between the native state, after talonavicular (TN)/subtalar (ST) arthrodesis and triple arthrodesis. Methods: Ten fresh-frozen cadaver legs were tested in 4 positions: neutral, dorsiflexion, inversion and eversion. Testing was done in a native state, after TN/ST arthrodesis then after triple arthrodesis for all 4 positions. Forefoot plantar pressures were recorded. Results: Peak pressures increased from the native state laterally underneath the 5th metatarsal (MT) head after TN/ST arthrodesis and triple arthrodesis respectively by 247% and 164% and fell medially underneath the 1st MT head to 38% and 41% in axially loaded legs at neutral (p < 0.025) without a difference between arthrodesis groups. Similarly, 5th MT head pressures were significantly increased from the native state after TN/ST and triple arthrodesis in the legs mounted in eversion by 129% and 109% respectively (p < 0.025), without differences between the two arthrodesis groups. Conclusion: In our cadaveric model of native, non-deformed legs, both a modified double (TN/ST) and triple arthrodesis led to increased lateral forefoot plantar pressures compared to the native state without a difference between the arthrodesis groups.

Zone 2 5th Metatarsal Fractures Treated Nonoperatively Have Similar Time to Healing to Those Treated Operatively

Category: Midfoot/Forefoot; Trauma Introduction/Purpose: The purpose of this study was to quantify the time to clinical and radiographic healing in Zone 2 proximal 5th metatarsal (MT) fractures and to compare these outcomes to those of Zone 2 fractures treated operatively. Methods: A retrospective cohort study of all Zone 2 metatarsal fractures seen at a single large, urban, academic medical center between December 2012 and April 2022 was performed. Zone 2 injuries were defined as fractures entering the proximal 4-5 MT articulation on the oblique radiographic view. Clinical healing was characterized by the return to baseline ambulatory function without discomfort and a lack of tenderness on physical examination. Radiographic healing was defined as complete osseous consolidation. A total of 374 patients with Zone 2 proximal 5th MT fractures were included in the analysis. The mean age of patients was 53.8 +/- 16.6 years, and 74.3% were female. Results: 93.3% of patients with Zone 2 metatarsal fractures were treated nonoperatively. In the nonoperative group, 6.6% experienced delayed bony union with incomplete radiographic healing after 6 months, compared to 16.0% of the operative group (p = 0.095). However, by 1 year post-injury, 98.9% of patients who underwent nonoperative management and 96.0% of operative patients demonstrated radiographic union. Two patients failed nonoperative management and underwent operative fixation for symptomatic nonunions. There was no difference in time to radiographic healing between patients treated nonoperatively and those treated operatively (4.4 +/- 2.8 months vs 5.4 +/- 4.7 months, p = 0.413). Similarly, there was no difference in time to clinical healing between both groups (2.3 +/- 1.9 months vs 2.6 +/- 3.8 months, p = 0.723). Conclusion: Zone 2 5th metatarsal base fractures, which are often incorrectly referred to as Jones fractures despite being proximal to the fractures originally characterized by Jones, can be successfully treated with nonoperative management. There is no evidence that operative treatment leads to significantly faster clinical or radiographic healing for patients.

Volumetric Assessment of Lisfranc Joint and Spaces in Hallux Valgus Deformity Patients: A Case- Control Study

Category: Midfoot/Forefoot; Bunion Introduction/Purpose: First ray or medial column instability has been linked to the development of hallux valgus deformity (HVD), in part due to potential instability of Lisfranc joints and ligamentous complex. However, no study has assessed the 3D weight- bearing (WB) relationship of the Lisfranc complex in patients with confirmed hallux valgus, particularly at the articulating surface of the first tarsometatarsal joint and the second metatarsal and medial cuneiform space, commonly described as the primary region- of-interest of the Lisfranc complex. In this case-control study, we aimed to assesses WB 3D volumetric measurements in the entire Lisfranc joint, as well as in between first and second rays, and to compare HVD patients and controls. We hypothesized that volumes would be increased in HVD patients. Methods: In this IRB-approved, retrospective case-control study, we analyzed weight-bearing Computed Tomography (WBCT) data of 20 consecutive HVD patients and 20 healthy control patients. Using an automated segmentation method (DISIOR Bonelogic 2.0, Paragon28, USA), 3D volumetric models of the bones of the foot were created from WBCT data. Opposing articular spaces in the Lisfranc joint were selected on the STL models of the bones. Interarticular distance mapping was then performed to characterize the joint space width (JSW) in each of the articulations. Interarticular volume was then assessed using an area-weighted volume measurement. Areas of each triangle from the triangulated surface were multiplied by the JSW at each triangle. The sum of individual volumes was then normalized by the total surface area. The final volume was estimated using the product of the normalized summation and average area of both surfaces. Comparisons were performed with independent t-tests. P-Values < 0.05 were considered significant. Results: Estimates of volumetric assessment of the Lisfranc Complex were obtained using the automated method written in MATLAB. These outputs are reported in Table 1. As expected, the first tarsometatarsal joint volumes were the highest for both HVD patients and controls. No significant differences in the volumes were observed when comparing HVD patients and controls for any of the joints or spaces assessed (Figure). Particularly, no differences in the volumetric analysis of the first tarsometatarsal joint, 1-2 intercuneiform space or Lisfranc space (medial cuneiform-second metatarsal) were confirmed. Conclusion: In this retrospective case-control study, we hypothesized that joint volumes of the articulating surfaces and spaces-of- interest within the Lisfranc complex would be higher in HVD patients, consistent with first ray/medial column instability. Our study results demonstrated however no significant volume increases in Lisfranc joints or spaces assessed, particularly with no increases in the volumetric measurements at the first tarsometatarsal joint or between first and second rays. Even though our study could be underpowered to demonstrate potential differences between HVD and controls, our results support that no significant first ray instability in present when volumetric WBCT assessment is used.

Peroneus Brevis to Longus Tendon Transfer in the Treatment of the Flexible Progressive Collapsing Foot Deformity: A Cadaveric Study

Category: Midfoot/Forefoot; Hindfoot Introduction/Purpose: Although operative treatment of the flexible progressive collapsing foot deformity (PCFD) remains controversial, correction of residual forefoot varus and stabilization of the medial column are important components of reconstruction. An opening wedge medial cuneiform osteotomy or first tarsometatarsal fusion is traditionally performed to plantarflex the first metatarsal. More recently, tendon transfers such as a peroneus brevis (PB) to peroneus longus (PL) have been proposed. However, there is little data to support their use. The aim of our study was to determine the effect of an isolated PB- to-PL transfer (PBT) on medial column and hindfoot joint kinematics in a simulated PCFD (sPCFD) cadaveric model using a robotic gait simulator. We hypothesized that a PBT in a sPCFD model would partially restore kinematics to the intact state. Methods: A validated six-degree of freedom robot (Baxter et al., 2016) was used to simulate the stance phase of level walking for 6 mid-tibia cadaveric specimens (3 male; age: 72 ± 8 years). An eight-camera motion capture system was used to track reflective markers fixed to bones of the foot and ankle. Three conditions were tested for each specimen: intact, sPCFD (Henry et al., 2022), and after PBT. The PBT was performed by transecting the PB and advancing the proximal stump 1 cm into the PL (Sanhudo, 2019). Outcome measures included kinematics of the talonavicular, subtalar, and first tarsometatarsal joints. Maximum differences between the PBT and sPCFD conditions and 95% confidence intervals (95%CIs) were calculated. The percent deformity correction was determined by dividing the difference between the PB and sPCFD states by the difference between the intact and sPCFD states at the site of maximum deformity correction. Results: Relative to the sPCFD condition, the PBT resulted in a maximum increase in talonavicular plantarflexion of 1.8° (95%CI 0.9°-2.7°) with 159% correction during midstance, decrease in talonavicular abduction of 1.5° (95%CI 0.3°-2.8°) with 65% correction during midstance, and decrease in talonavicular eversion of 2.4° (95%CI 1.2°-3.8°) with 90% correction during mid-to- late stance. All deformities had consistent correction at the talonavicular joint during stance (Figure 1). Additionally, the PBT resulted in a maximum increase in subtalar plantarflexion by 0.8° (95%CI 0.3°-1.8°) with 155% correction in early stance, decrease in subtalar abduction by 0.8° (95%CI 0.5°-1.2°) with 191% correction during early stance, and decrease in subtalar eversion by 1.5° (95%CI 0.5°-2.2°) with 178% correction during mid-stance. There was no effect on first tarsometatarsal joint kinematics. Conclusion: A PB-to-PL transfer in a sPCFD model resulted in the correction of multiple deformities including increased plantarflexion and decreased abduction at the talonavicular joint compared to the sPCFD without the transfer, most notably during PB activation in stance. The PBT also decreased eversion at the talonavicular and subtalar joints. Our results suggest that the addition of a PBT as part of the surgical management of the flexible PCFD contributes to correction of the residual forefoot varus, midfoot abduction, and hindfoot valgus deformities by plantarflexing through the medial column and removing a deforming force on the foot by the PB.

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 < 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.

AI-Based Foot X-Ray Reading in Real-World: Evaluating the Accuracy of Assistive Decisions for Diagnosing Foot & Ankle Disorders

Category: Midfoot/Forefoot; Hindfoot Introduction/Purpose: Evaluation of plain radiographs is of fundamental importance in the diagnosis and treatment planning of foot and ankle disorders. These assessments are essential, but can be difficult for the following reasons: First, many angles must be measured using various reference lines. Second, there may be inter-observer differences in the measurements. Consistent and standardized measurement methods are required to increase the efficiency and accuracy of radiographic readings. Several recent studies have reported good results using deep learning (DL) models for medical image analysis. It is expected that efficiency and accuracy can be increased through radiographic readings using DL. This study aims to develop a DL model that recognizes the bones of the foot and ankle in plain radiographs and automatically measures angles frequently used for diagnosis. Methods: The DL model was developed using two architectures: segmenting objects by locations (SOLO) for bone segmentation and Global Universal U-Net (GU2Net) for reference line detection. The angles measured were hallux valgus angle (HVA) and 1st- 2nd intermetatarsal angle (IMA) on anterior-posterior (AP) X-ray; calcaneal pitch angle (CPA) and lateral Meary's angle (LMA) on lateral X-ray. Only data obtained from external test set were used for statistical analysis to evaluate the model's performance. The test set used a total of 558 images collected from January 2022 to September 2022. Angles measured by the DL model were compared with angles measured manually by human researchers. The intraclass correlation coefficient (ICC) was used to evaluate the accuracy of angle measurements. The error between the angle measured by the DL model and the angle measured by human researchers was evaluated using root mean square error (RMSE) and mean absolute difference (MAE). Results: As shown in the attached table, the ICCs of HVA were 0.957 (right) and 0.933 (left). The ICCs of IMA were 0.881 (right) and 0.902 (left). The ICCs of LMA were 0.895 (right) and 0.937 (left). The ICCs of CPA were 0.918 (right) and 0.868 (left). All ICCs were greater than 0.8, indicating excellent correlations between angles measured with the DL model and angles measured manually (ground truth). For RMSE and MAE, the left IMA was the smallest (1.50 and 1.16, respectively), and the right LMA was the largest (4.50 and 2.47, respectively). Conclusion: The DL model in our study was able to perform various angle measurements in both AP and lateral X-rays with considerable accuracy. Through additional model training and development, it is expected that it will be useful for analyzing various foot and ankle disorders such as hallux valgus, flatfoot, pes cavus and other alignment deformities.

Intercuneiform Instability is Present in Midfoot Arthritis Patients: A 3D Volumetric Case-Control Assessment

Category: Midfoot/Forefoot; Trauma Introduction/Purpose: Lisfranc complex stability, primarily coming from the tarsometatarsal ligaments, is crucial for midfoot integrity. It has been shown that Lisfranc injuries can lead to midfoot issues, such as midfoot arthritis when not properly diagnosed/treated. Previous studies have estimated the volumes of the articulating joint volumes of surgically confirmed Lisfranc Ligament injuries, but no study has assessed articulating joints and space-of-interest of the Lisfranc Complex in patients with midfoot arthritis. The objective of this retrospective study was to determine if patients with confirmed midfoot arthritis have increased volumes at the Lisfranc complex when compared to controls, particularly between the first and second rays. We hypothesized that volumes would be increased in midfoot arthritis patients, consistent with medial column/first ray instability. Methods: In this IRB-approved, retrospective case-control study, we analyzed WBCT data of 20 consecutive midfoot arthritis patients and 20 healthy controls. Using an automated segmentation method (DISIOR Bonelogic 2.0, Paragon28, USA), 3D volumetric models of the bones of the foot were created from WBCT data. Opposing articular spaces in the Lisfranc joint of the midfoot were selected on the STL models of the bones. Interarticular distance mapping was then performed to characterize the joint space width (JSW) in each of the articulations. Interarticular volume was then estimated using an area-weighted volume measurement. Areas of each triangle from the triangulated surface were multiplied by the JSW at each triangle. The sum of individual volumes was then normalized by the total surface area. The final volume was estimated using the product of the normalized summation and average area of both surfaces. Comparisons were performed with independent t-tests. P-values >0.05 were considered significant. Results: Estimates of joint volume were obtained using the automated method written in MATLAB. These outputs are reported in Table 1. Significant increase of approximately 25% was observed in Midfoot arthritis patients at the 1-2 intercuneiform joint, consistent with intercuneiform instability. Conversely, a decrease in the space between the second metatarsal and medial cuneiform of about 30% was observed, what could be explained by pronation of the first ray secondary to first ray instability. All other changes in joint volumes were not significant (Figure). Conclusion: In this case-control study with midfoot arthritis patients and healthy controls we performed a 3D volumetric assessment of the Lisfranc Complex joints and spaces-of-interest. We found that midfoot arthritis patients have a significant increase in the 1-2 intercuneiform joint consistent with intercuneiform instability. Conversely, a decrease in the Lisfranc space (in between second metatarsal and medial cuneiform) was observed, what could be explained by first ray pronation in the setting of medial column instability. Additional prospective studies assessing angular measurements and patient reported outcomes are needed.

Pathogenesis of the Hallux Valgus: Enthesopathy of the Metatarsosesamoid Ligament

Category: Bunion; Basic Sciences/Biologics Introduction/Purpose: It is generally accepted that failure of the medial supporting soft tissue structure of the metatarsophalangeal joint plays an important role in the development of hallux valgus. The metatarsosesamoid ligament (MSL), a component of the medial soft tissue, is an important structure that connects the metatarsal head and the sesamoid complex. The sesamoid complex works as a dynamic stabilizer of the metatarsal head. We hypothesized that the failure of the medial MSL causes instability of the first metatarsal bone, which leads to hallux valgus deformities. Therefore, the present study aimed to describe the detailed structure and degenerative findings of MSL and to clarify the mechanical stress of the MSL enthesis, considering the mechanism of failure of the medial supporting soft tissue structure. Methods: The first metatarsal heads and sesamoid bones with soft tissue were collected from twelve cadavers. Serial 4-μm thick section4-μm intervals and stained with toluidine blue (Fig. 1a). We described the detailed histological structures and degenerative findings of MSL. In addition, morphometric comparisons were made between the medial and lateral MSL entheses at the metatarsal head to evaluate the mechanical stress they. First, we measured the thickness of the uncalcified fibrocartilage (UF thickness) following a protocol adopted previously (Fig. 1b). Second, the degree of irregularity of the interface between the zones of calcified fibrocartilage and bone (CFB) at each enthesis was assessed as the ratio between the lengths of the CFB and the enthesis (CFB/ E ratio) (Fig. 1c). The differences in these parameters were evaluated using the paired T test and Wilcoxon signed-rank test (P < 0.05). Results: We identified that the MSL entheses were fibrocartilaginous entheses, which consisted of four tissue zones. The region in which the MSL wraps around the articular surface of the metatarsal head contains a metachromatic area accompanied by fibrocartilage cells at the deep surface of the MSL, called the sesamoid fibrocartilage. At the MSL enthesis, pathological findings indicating enthesopathy were observed. One specimen showed the tear of the MSL at the wrap around region. The MSL enthesis tear was observed in two specimens with hallux valgus. Both UF thickness (P = 0.12, effect size r = 0.89) and CFB/E ratio (P = 0.17, effect size d = 0.35) were significantly greater in the medial MSL enthesis than those in the lateral MSL enthesis. Conclusion: In the present study, the MSL showed enthesis protecting structures such as enthesis fibrocartilage which contributes to dissipating bending forces during insertional angle change, complexed CFB interface which guards an enthesis against shearing forces and wrap around region which contributes to dissipating the shearing force to the enthesis. However, the medial MSL subject to the greater forces and the degenerative findings of enthesopathy were observed. On top of that, all four hallux valgus specimens with sesamoid complex dislocation showed MSL enthesis tear. Enthesopathy, particularly at the medial MSL, may be the cause of hallux valgus.

The Plumbline: A Novel Radiographic Tool for Assessment of Metatarsus Adductus with Hallux Valgus

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: Metatarsus adductus (MTA) is a complex multiplanar deformity of the foot which has a 30% reported approximate radiographic incidence in patients with symptomatic hallux valgus (HV). Various radiographic angles have been proposed for the assessment of MTA, but these measurements can be complex with a broad range of interrater reliability. We propose a simplistic radiographic assessment method termed the ‘plumbline’ to identify the presence of MTA and to ascertain if enough physical space is available to align the first metatarsal to the longitudinal foot axis via an isolated 1st ray procedure, or if necessary, through a combined approach which also addresses the lesser metatarsals. This method provides a visual reference to determine if a physical blockade to 1st ray correction is present. Methods: The plumbline is assessed on standard weight-bearing AP radiographs. Neutral foot positioning is key as a pronated or supinated clinical position of the foot will impact the alignment of this and other radiographic angular relationships. A transverse midfoot axis line is drawn by identifying and linking two individual points marked at the calcaneocuboid joint and the talonavicular joint. A third point is marked at the distal lateral apex of the medial cuneiform at the first tarsometatarsal joint. A 90° line is subtended from the transverse midfoot axis line, crosses the third point, and extends distally to the 2nd metatarsal head. A positive radiographic plumbline occurs when this line intersects the 2nd metatarsal indicating the need to correct the adducted lesser metatarsal position prior to addressing HV. A negative plumbline remains tangential to the 2nd metatarsal and indicates an isolated HV correction is possible. Results: The metatarsus adductus angle (MAA) measured via Sgarlato's method (SA), and the plumbline were recorded in patients (N=20) scheduled for HV surgery. Initially the cohort was subdivided into subjects deemed to have a normal MAA (SA < 15°; N=10) and an abnormal MAA (SA>15°; N=10). A mean pre-operative MAA measurement of 8.1° (SD 2.3; range 5, 12.1) and 26.5° (SD 4.5; range 19.2, 33.7) were found in these respective subsets. All subjects (100%) with an MAA < 15° (N=10) were found to have a negative plumbline radiographically and subjects (100%) with a MAA >15° (N=10) presented with a positive plumbline. The plumbline findings identified when an isolated HV correction would have been possible or impeded based upon 2nd metatarsal position, thus driving the surgical decision making algorithm. Conclusion: The plumbline is used to determine when concomitant MTA and HV correction is beneficial without the need to measure other more traditional radiographic angular relationships. It is a quick and simple method of evaluating the proximity of the metatarsal segments to determine if the first metatarsal is amenable to reduction in isolation or if correction will be limited due to a 2nd metatarsal bone blockade. The visual simplicity of the measurement can also aid in patient education and surgeon satisfaction when describing the surgical approach to this complex three-dimensional anatomic pathology.

Orthopaedic Simulation of a Morton's Extension to Test the Effect on Plantar Pressures of Each Metatarsal Head in Patients without Deformity: A Pre-Post-Test Study.

the area beneath the metatarsal heads is a common location of foot pain, which is often associated with high plantar pressures. The aim of this study was to determine the effect of the application of a Morton's extension on the pressure in the metatarsal bones of the foot using a pressure platform. twenty-five subjects without musculoskeletal pathology were selected for this study, and an experiment was conducted with them as the subjects, before and after application of a Morton's extension. The foot regions were divided into the forefoot (transversely subdivided into six areas corresponding to the first, second, third, fourth, and fifth metatarsal heads, and the hallux), midfoot, and rearfoot, and then the maximum and average pressures exerted at each region were measured before and after placing a Morton's extension. we found a pressure reduction, with a p-value less than (p < 0.05), in the head of the second and third metatarsals in statics and dynamics. we can conclude that the Morton's extension produces a variation in plantar pressures on the lesser metatarsals. The application of a Morton's extension may be beneficial for the management of forefoot pathology. This study will help clinicians consider various tools to treat forefoot disorders. NCT05879094 (ClinicalTrial.gov (accessed on 18 May 2023)).

Surgical treatment of hammertoe deformity (a literature review)

Aim. To trace developmental origins of surgical treatment of hammertoe deformity and determine the most commonly used methods of its correction based on the published literature analysis. Material and methods. Publications from Google search, electronic databases PubMed, Google Scholar, archives of specialized journals and other relevant sources of scientific and medical information were analyzed. Results. The article covers the developmental origins of surgical treatment of hammertoe deformity both in the historical aspect and at the current level. Attention is paid to soft tissue procedures including tendons, metatarsophalangeal joint capsule, and plantar plate. An overview of operative interventions on the bone apparatus, phalanges and metatarsal bones and the combination of these surgeries is also presented in the article. The disadvantages of the existing surgical treatments, their advantages and the ways for forthcoming research concerning the improvement of surgical care in the treatment of hammertoe deformity are identified. Conclusions. The choice of a particular method of surgical correction between the phalangeal or metatarsal level, the feasibility of combining these interventions with restoring the integrity of the plantar plate and tendon reconstruction, remains debatable. Further study on these issues is a crucial task today for choosing the optimal method of hammertoe deformity correction.

Biomechanical Comparison between Rotational Scarf Osteotomy and Translational Scarf Osteotomy: A Finite Element Analysis.

Rotational Scarf osteotomy has its unique advantages in treating hallux valgus, but it also has certain drawbacks. The biomechanical differences between rotational Scarf and translational Scarf osteotomy are not clear evaluates the correction ability and biomechanical difference of two surgical methods for hallux valgus by finite element analysis. The computerized tomography data of a hallux valgus patient were selected to establish a finite element model. The standard Scarf osteotomy was simulated based on the model, and the rotation and translation were performed, respectively. The size of the intermetatarsal angle, contact area, distal metatarsal articular angle and the absolute length of the first metatarsal was compared between the two groups. We completed the cartilage, ligament and other tissues on the bone model to establish a full foot model. We analyzed the troughing, plantar aponeurosis tension, plantar soft tissue, and ground stress and also observed the stability of the fracture site by a three-point bending test. Both surgical methods may effectively correct the intermetatarsal angle. After rotational osteotomy, the contact area increased, and the length of the first metatarsal bone initially increased and then decreased compared to that in the translational group. Furthermore, rotational Scarf significantly increased the distal metatarsal articular angle. Mechanical analysis showed that the cancellous bone in the contact part of the fracture site in the translation group had greater stress, which was the reason for the occurrence of the troughing. Stress distribution of plantar aponeurosis, plantar soft tissue, and the ground showed no significant difference. The three-point bending test showed that the separation of the broken ends of the rotational Scarf osteotomy model (0.133 mm) was slightly smaller than the translational group (0.147 mm). Both surgical methods can successfully correct intermetatarsal angle (IMA). Compared to traditional translational Scarf osteotomy, rotational Scarf osteotomy is more conducive to postoperative stability and healing, but it also has certain drawbacks. In clinical practice, individualized surgical methods still need to be selected for different types of patients with hallux valgus.

3D-Printed Osteoinductive Polymeric Scaffolds with Optimized Architecture to Repair a Sheep Metatarsal Critical-Size Bone Defect.

The reconstruction of critical-size bone defects in long bones remains a challenge for clinicians. A new osteoinductive medical device is developed here for long bone repair by combining a 3D-printed architectured cylindrical scaffold made of clinical-grade polylactic acid (PLA) with a polyelectrolyte film coating delivering the osteogenic bone morphogenetic protein 2 (BMP-2). This film-coated scaffold is used to repair a sheep metatarsal 25-mm long critical-size bone defect. In vitro and in vivo biocompatibility of the film-coated PLA material is proved according to ISO standards. Scaffold geometry is found to influence BMP-2 incorporation. Bone regeneration is followed using X-ray scans, µCT scans, and histology. It is shown that scaffold internal geometry, notably pore shape, influenced bone regeneration, which is homogenous longitudinally. Scaffolds with cubic pores of ≈870µm and a low BMP-2 dose of ≈120µgcm-3 induce the best bone regeneration without any adverse effects. The visual score given by clinicians during animal follow-up is found to be an easy way to predict bone regeneration. This work opens perspectives for a clinical application in personalized bone regeneration.

Structural Reorganization of the Third Metatarsal Bone Shaft After Autogenous Plasty of the Tibial Portion of the Sciatic Nerve

Background. Previous research has shown that neurectomy of the sciatic nerve leads to a reduction in bone density in the femur and tibia of laboratory mice and rats. However, the impact of surgeries aimed at restoring nerve innervation on the bones of distal limb parts has not been studied.&#x0D; Aim of the study to identify structural changes in the shaft of the third metatarsal bone after primary autogenous plasty of the resection defect of the tibial portion of the sciatic nerve in rats.&#x0D; Methods. Autologous neuroplasty of the tibial portion of the sciatic nerve was performed on 16 Wistar rats (aged 8-10 months). The animals were euthanized at 4 and 6 months after the surgery, and a control group of 7 intact rats of similar age was included. Histomorphometric analysis was conducted on a dissected fragment of the forefoot at the level of the metatarsal bones. The ratio of fuchsinophilic and anilinophilic structures of the cortical plate was determined using point-count volumetry on Masson-stained images of transverse sections of the third metatarsal bone shaft. The thickness of the cortical plate, numerical density, area, and diameter of osteons and Haversian canals were measured.&#x0D; Results. After 4 months, compared to the control group, a 15% decrease (p = 0.0001) in the proportion of mineralized structures of the cortical plate and a 12.7% reduction (p = 0.0184) in its thickness were observed. Osteolysis signs were present in the osteonal layer, along with decreased numerical density and dimensional characteristics of osteons, and the presence of osteons with dilated Haversian canals. At 6 months, the thickness of the cortical plate did not significantly differ from the norm (p = 0.2067), but there was a progressive 33.6% decrease (p = 0.0001) in the proportion of mineralized structures. Reduced values of numerical density, area, and diameter of osteons persisted in the osteonal layer, while the diameters of Haversian canals in osteons increased over time.&#x0D; Conclusion. From 4 to 6 months, the thickness of the cortical layer in the compact bone of the third metatarsal bone shaft was restored. However, changes in the numerical and dimensional composition of osteons, along with decreased mineralization of the extracellular matrix and erosion of the subperiosteal bone layer, continued to progress. The developed experimental 2D model can be used to assess denervation osteopenia in distal limb parts and further explore rehabilitation interventions that enhance and improve reinnervation.

Original Guide for Minimally Invasive Distal Osteotomy of the First Metatarsal Bone in the Treatment of Hallux Valgus

Background. Minimally invasive surgical interventions are widely used in trauma and orthopedic surgery. Both the surgical technique and the instruments applied are being improved, which contributes to better functional results of patients treatment.&#x0D; Aim of the study to present a new guide tool for minimally invasive surgical correction of acquired hallux valgus.&#x0D; Guide description. A guide tool intended to be used in minimally invasive surgical interventions for hallux valgus (HV) correction has been developed. It consists of several interconnecting components: the distal bar, the intramedullary guide, the proximal bar, and the wire guide. These components are fixed to each other. At the same time, the distal bar, the proximal bar, and the wire guide are connected with the possibility of adjusting their mutual positioning. The design of the proposed device enables to guide the first guiding wire and to place the cannulated screw in an optimal position. The presented clinical case illustrates the successful application of the described device. The patient underwent minimally invasive distal corrective osteotomy for hallux valgus of medium severity. According to the preoperative X-rays, the first intermetatarsal angle and the first toe deviation angle were 13.5 and 25, respectively. Six months after the surgery, they were 3 and 7, respectively. The result of the corrective surgery was considered excellent.&#x0D; Conclusion. Application of the proposed guide tool decreases surgery duration, reduces soft tissue damage and minimizes radiation exposure of the surgeon and the patient.

Rare Location of Ewing Sarcome: A Case Study

Introduction: Ewing's sarcoma is also known as a primary peripheral neuroectodermal tumour and is a primary malignancy accounting for 5-15% of all malignancies. It can involve all skeletal bones and more rarely soft tissue. The area of predilection of this tumour is the long bones 50-60%; the flat bones mainly the pelvis 20%, while the bones of the foot and the hand constitute an exceptional localization (1), hence the interest to report our case. Clinical presentation: We report the case of an 18-year-old girl who presented with a painful swelling of the right heel evolving for 14 months in a febrile context. The diagnosis of Ewing's sarcoma of the calcaneus was suspected by radiological assessment and confirmed by a histological study after a biopsy. We discuss the clinico-radiological and histological diagnosis of this tumour and its management. Discussion: Ewing's sarcoma described by James Ewing in 1921(2), since then Cook reports only 29 cases of Ewing's sarcoma of the calcaneus in the literature (3), which shows the paucity of the literature concerning this type of calcaneal lesions, and therefore clinicians are unfamiliar with these tumours and therefore a delay in diagnosis, morbidity and amputations unnecessary. It is a tumour with a rapid potential for metastasis, particularly in the lungs, which determines the prognosis of this lesion. Conclusion: Ewing's sarcoma remains a rare disease (4) of which the calcaneus is an exceptional location. It may be misdiagnosed with other lesions, notably calcaneal osteomyelitis.

Finite Element Parametric Design of Hallux Valgus Orthosis Based on Orthogonal Analysis.

To design appropriate orthosis for hallux valgus, a difficult foot condition that affects a quarter of the body's bones, we need to clarify the numerical biomechanical features, which have not been established in previous biomechanical studies. Therefore, we constructed a finite element model of the bunion foot to investigate the orthopaedic force compensation mechanism. A patient with moderate hallux valgus was recruited. CT imaging data in DICOM format were extracted for three-dimensional foot model reconstruction. In conjunction with the need for rapid design of bunion orthosis, a metatarsal force application sizing method based on an orthogonal test design was investigated. The orthogonal test design was used to obtain the hallux valgus angle (HVA) and the inter metatarsal angle (IMA) data for different force combinations. Based on the extreme difference analysis and analysis of variance of the test results, the influence of different force combinations on the bunion angle was quickly determined. The results showed that the stress concentration occurred mainly in the first metatarsal bone. The distribution trend was in the medial and lateral middle of the bone and gradually decreased to the dorsal base of the bone body. The greatest stress occurs in the cartilage between the phalanges and metatarsals. In 25 groups of simulation experiments, HVA was reduced from 27.7° to 13°, and IMA was reduced from 12.5° to 7.3°. Applying detailed orthopaedic force collocation to the first metatarsal column can effectively restore the mechanics and kinematics of hallux valgus, and provide a reference for the treatment of bunion valgus and the design of orthopaedic devices.

Unveiling foot tuberculosis as an under-recognized source of foot pain.

Foot tuberculosis is a rare form of osteoarticular tuberculosis, accounting for less than 1% of cases. It presents unique diagnostic challenges due to its nonspecific clinical features and overlapping symptoms with other conditions. This study aimed to investigate the clinical presentation, radiographic findings, and prognosis of foot tuberculosis, with the goal of improving early recognition and appropriate intervention. A prospective study was conducted between November 2016 and July 2021, involving 39 patients diagnosed with foot tuberculosis. Clinical examinations, laboratory tests, X-rays, and MRI evaluations were performed to aid in the diagnosis. Biopsy was conducted on patients with radiological lesions. Patients were treated with an 18-month course of antitubercular therapy (ATT). Foot Function Index (FFI) scores were recorded before and after treatment. Statistical analysis was conducted to assess factors impacting prognosis. Unilateral foot involvement was observed in all patients, with a male predominance (61.5%) and a mean age of 31.3years. The most common symptoms were pain and edema, with sinus tracts present in 17.9% of patients. Radiographic findings showed cystic and sclerotic lesions, with the "spina ventosa" appearance primarily affecting the metatarsal bones. MRI played a valuable role in early detection. Histopathological examination confirmed tuberculosis in all cases, and acid-fast bacilli were found in 23% of patients. Most patients (79.4%) responded well to ATT without requiring surgery. Factors such as high initial ESR, delayed ATT initiation, multiple lesions, and tarsal involvement were associated with unfavourable outcomes. Foot tuberculosis presents with nonspecific symptoms, leading to misdiagnosis and delays in appropriate treatment. Clinical examination, radiographic evaluation, and biopsy are essential for accurate diagnosis. Early initiation of ATT is crucial for favourable outcomes. Factors such as high initial ESR, delayed treatment initiation, multiple lesions, and tarsal involvement negatively impact prognosis. This study highlights the importance of recognizing foot tuberculosis and provides insights into its clinical presentation, radiographic features, and treatment outcomes, facilitating timely intervention and improved patient management.

Diagnosis and treatment of osteo-articular tuberculosis of the foot and ankle (a five case series)

IntroductionOsteo-articular tuberculosis is a rare manifestation of this disease, often posing diagnostic challenges that necessitate additional diagnostic imaging modalities such as radiography, CT, and MRI. This article presents a series of five cases involving tuberculosis affecting the bones of the foot and ankle, diagnosed at various stages. The patients received appropriate anti-tuberculosis medical treatment following national protocols, along with surgical interventions when necessary. Case studiesIn this series, we describe the clinical characteristics and management of five cases of foot and ankle bone tuberculosis. These cases were diagnosed at different stages, and all patients received standard anti-tuberculosis medical therapy according to national treatment guidelines. Surgical interventions were performed when deemed necessary to optimize patient outcomes. DiscussionThe diagnosis of bone tuberculosis should be considered in any clinical scenario that presents with uncertain features, persistent symptoms, or resistance to conventional treatment approaches. It is crucial to employ a multidisciplinary approach involving medical and surgical management to effectively address this challenging disease. However, it is important to note that surgical intervention cannot replace the necessity of proper medical treatment. ConclusionTuberculosis involving the bones of the foot and ankle remains an infrequent occurrence. However, considering the endemic context, prompt therapeutic interventions are essential to prevent significant osteoarticular damage. Early diagnosis, adherence to established treatment protocols, and a comprehensive approach encompassing both medical and surgical modalities are crucial for successful management of this rare entity.

Foot Plantar Pressure Profile Alteration after Microsurgical Great Toe-to-thumb Transfer.

Microsurgical great toe-to-thumb transfer (mGTT) is a widely used procedure when immediate replantation of thumb is not feasible. The aim of this study was to investigate the alteration of plantar pressure profile of the donor foot after mGTT. Twenty patients receiving microsurgical great toe-to-hand transfer between 1985 to 2014, and 16 healthy subjects were recruited. Group 1 consisted of 20 feet receiving mGTT, whereas group 2 consisted of 32 normal feet as control. The flap design in this study was to preserve 1 cm of the proximal phalanx to maintain the attachment of the plantar aponeurosis and intrinsic muscles. The Taiwan Chinese version of the Foot Function Index was used for patient-reported outcome measurement. A novel Emed-X system was used for dynamic plantar pressure measurement. A total of four parameters were collected, including peak pressure, contact area, contact time, and pressure-time integral. In group 1, the peak pressure redistributed under the first metatarsal bone and was significantly higher than group 2 (P < 0.05). There was no significant change of the contact area between the midfoot region of group 1 and group 2 (P > 0.05). Furthermore, similar foot clearance efficiency was demonstrated in group 1 and group 2 (P > 0.05). The windlass effect of the foot will not be affected when performing mGTT with preservation of 1 cm of the proximal phalanx. Therefore, this surgical procedure is highly recommended for clinical application.