Comparison of Tibial Sesamoid Position on Anteroposterior and Axial Radiographs Before and After Triplane Tarsal Metatarsal Joint Arthrodesis

Hallux Valgus: The Influence of Intersesamoid Crista's Osteoarthritis on Frontal Plane Pronation

A frontal plane metatarsal rotational (pronation) has been documented in a high percentage of hallux valgus patients. Pathoanatomical concepts leading to pronation are still debated. Nevertheless, there is no consensus on how to measure this component of the deformity. The aim of the present study was to find potential associations between sesamoid's crista osteoarthritis and the frontal plane deformity in HV cases. Our study showed a moderate correlation between the crista's OA and the intermetatarsal angle (IMA), the hallux valgus angle (HVA) and the alpha angle. In severe hallux vulgus deformed specimens, with an eroded intersesamoid crista, frontal plane pronation was not as prevalent nor severe as in those without osteoarthritic degeneration. Severe hallux valgus cases with a completely eroded crista, showed lower pronation, and higher IMA, when compared to specimens with a preserved anatomy. This brings to light the intersesamoid crista's unique function in retaining the IMA. Understanding the role the frontal plane plays in hallux valgus' biomechanics and in its radiographic appearance is vital to change the current paradigm.

An evaluation model for children's foot & ankle deformity severity using sparse multi-objective feature selection algorithm

Foot & ankle deformity is a chronic disease with high incidence and is best treated in childhood. However, the current diagnostic procedures rely on doctor's consultation and empirical judgment, and lack objective and quantitative evaluation methods, resulting in low screening rates. To solve this problem, this paper aims to construct an evaluation model for children's foot & ankle deformity through data mining and machine learning technologies. Firstly, it proposes the grading rules for children's foot & ankle deformity severity based on analyzing the existing quantitative indexes and expert experience. Then the 3D foot scanner is used to collect the sample data including 30 foot structure indexes. Finally, an advanced sparse multi-objective evolutionary algorithm (sparse MO-FS) is present for feature selection. The effectiveness of the proposed sparse MO-FS and its search efficiency are proved by comparing 8 feature selection methods and 7 search strategies. Using sparse MO-FS, foot length, arch index, ankle index, and hallux valgus index are selected, which not only simplifies the evaluation model but also improves the average classification accuracy of random forest to more than 98%.

One- and Two-Year Analysis of a Five-Year Prospective Multicenter Study Assessing Radiographic and Patient-Reported Outcomes Following Triplanar First Tarsometatarsal Arthrodesis With Early Weightbearing for Symptomatic Hallux Valgus

We report one- and 2-year results of a prospective, 5-year, multicenter study of radiographic, clinical, and patient-reported outcomes following triplanar first tarsometatarsal arthrodesis with early weightbearing. One-hundred and seventeen patients were included with a mean (95% confidence interval [CI]) follow-up time of 16.6 (15.5, 17.7) months. Mean (95% CI) time to weightbearing in a boot walker was 7.8 (6.6, 9.1) days, mean time to return to athletic shoes was 45.0 (43.5, 46.6) days, and mean time to return to unrestricted activity was 121.0 (114.5, 127.5) days. There was a significant improvement in radiographic measures with a mean corrective change of -18.0° (-19.6, -16.4) for hallux valgus angle, -8.3° (-8.9, -7.8) for intermetatarsal angle and -2.9 (-3.2, -2.7) for tibial sesamoid position at 12 months (n = 108). Additionally, there was a significant improvement in patient-reported outcomes (Visual Analog Scale, Manchester-Oxford Foot Questionnaire, and Patient-Reported Outcomes Measurement Information System) and changes were maintained at 12 and 24 months postoperatively. There was 1/117 (0.9%) reported recurrence of hallux valgus at 12 months. There were 16/117 (13.7%) subjects who experienced clinical complications of which 10/117 (8.5%) were related to hardware. Of the 7/117 (6.0%) who underwent reoperation, only 1/117 (0.9%) underwent surgery for a nonunion. The results of the interim report of this prospective, multicenter study demonstrate favorable clinical and radiographic improvement of the HV deformity, early return to weightbearing, low recurrence, and low rate of complications.

Modified Lapidus Procedure and Hallux Valgus: A Systematic Review and Update on Triplanar Correction

This review article examines contemporary methods and assesses radiographic outcomes and postoperative complications following the modified Lapidus procedure. A systematic review demonstrated significant improvements in intermetatarsal angle, hallux valgus angle, and tibial sesamoid position. We are updating a modified Lapidus technique for achieving triplanar correction of hallux valgus. Two cases of hallux valgus, one primary and one recurrent, are presented. As demonstrated in the systematic review, outcomes of Lapidus procedures create future opportunities. Surprisingly, only 78% of the studies assessed for this review reported on the hallux valgus angle and only 33% reported on tibial sesamoid position.

Lapidus Arthrodesis

There has been significant enhancement in surgical management of hallux valgus deformity. Recognition of the role of medial column hypermobility has resulted in better functional outcomes with decreased risk of recurrence. Modern techniques have evolved to include enhanced fixation in a move toward minimal postoperative downtime. Evolution to include true triplane correction, including frontal plane derotation of the first ray, has resulted in optimal functional outcomes. The addition of anatomic triplane restoration, enhanced internal fixation, and early return to weight-bearing activities are combined resulting in lifelong correction with excellent functional outcomes and a high degree of patient satisfaction.

First-Ray Radiographic Changes After Flexible Adult Acquired Flatfoot Deformity Correction

BACKGROUND

Adult acquired flatfoot deformity (AAFD) and hallux valgus (HV) are common foot and ankle deformities. Few studies have reported the changes in radiographic parameters of HV after reconstructive surgery for AAFD. This study aimed to evaluate the changes in radiographic parameters of HV and analyze the risk factors for increased HV after correction of AAFD.

METHODS

Adult patients with flexible AAFD who underwent similar bony procedures including medializing calcaneal osteotomy and Cotton osteotomy were included. Radiographic parameters were measured on weightbearing radiographs preoperatively, postoperatively, and at the final follow-up. Patients were divided into hallux valgus angle (HVA) increased and HVA nonincreased groups; logistic regression analysis was performed to identify risk factors affecting increased HV.

RESULTS

Forty-six feet of 43 patients were included. After AAFD reconstructive surgery, the tibial sesamoid position improved by 1 grade, but the HVA increased 4 degrees in average. Further, 21 of 46 feet (46%) showed an HVA increase ≥5 degrees immediately after AAFD correction surgery. Preoperative talonavicular coverage angle <21.6 degrees was a risk factor associated with HV increase immediately after the surgery.

CONCLUSION

In this case series, using plain radiographs to measure standard parameters of foot alignment, we found the association between AAFD correction and HV deformity measures somewhat paradoxical. Correction of overpronation of the hindfoot and midfoot appears to improve the first metatarsal rotational deformity but may also increase HVA. A lower preoperative talonavicular coverage angle was associated with an increase of the HVA after surgery.

LEVEL OF EVIDENCE

Level IV, case series study.

Correlation between indirect radiographic parameters of first metatarsal rotation in hallux valgus and values on weight-bearing computed tomography

PURPOSE

To verify if indirect radiographic signs of first metatarsal pronation, determined by the head round sign, correspond to weight-bearing computed tomography (WBCT) measurements.

METHODS

In this case-control retrospective study, we analyzed 26 hallux valgus (HV) feet and 20 controls through conventional radiograph (CR) and WBCT images. Two blinded orthopaedic foot and ankle surgeons performed the measurements. Pronation classification (head roundness), head diameter (HD), traditional HV angles, arthritis, sesamoid positioning, and first metatarsal rotation angle (MRA) (alpha angle) were evaluated. Comparisons were performed by Student's T-test and a multivariate regression was executed. P-values less than 0.05 were considered significant.

RESULTS

Mean values were higher in HV patients than controls when evaluating MRA (11.51 [9.42-13.60] to 4.23 [1.84-6.62], 95%CI), HD (22.35 [21.52-23.18] to 21.01 [20.07-21.96]), and sesamoid rotation angle (SRA) (26.72 [24.09-29.34] to 4.56 [1.63-7.50]). The MRA had a low influence in head roundness classification (R²: 0.15). Changes in the pronation classification were explained chiefly by the sesamoid station (SS) (R²: 0.37), where stations 4 to 7 were found to be strong predictors of roundness classifications 2 and 3.

CONCLUSION

Indirect signs of metatarsal pronation, determined by the head round sign, correlate weakly with the alpha angle measured in WBCT. The presence of arthritis and sesamoids displacement might modify the perception of first head roundness. The influence of MRA in the classification was low, where SS from 4 to 7 was strong predictors of a higher pronation classification.

The Realign-Resect Arthrodesis Technique

During traditional fusion procedures surgeons initially perform a joint resection and then the structures are realigned for correction of deformity. The procedure described herein by the author reverses this traditional surgical approach by first realigning the joint to correct deformity, then after achieving a corrected alignment, joint resection is performed in parallel without wedging. Realigning deformity as an initial step creates the conditions for an in-situ fusion wherein the deformity is corrected simultaneously with parallel bone resection. The purpose of this paper is to review the advantages and technical aspects of a realignment arthrodesis technique in which joint resection begins with the foot in the corrected position. This approach to joint fusion has been shown to simplify bone resection, eliminate post-resection adjustments, create full apposition of fusion surfaces, reliably correct deformity, and result in solid arthrodesis. The technique provides for immediate correction of deformity and is amenable for conditions that require either minimal or significant segmental shortening. There are many areas where the "Realign-resect" approach to joint fusion would be well suited. Full implementation of this technique may be particularly useful to the surgeon who does not have seasoned assistants in the operating room.

The Rotational Effect of Scarf Osteotomy With Transarticular Lateral Release on Hallux Valgus Correction

The purpose of this study was to explore the rotational effect of scarf osteotomy with transarticular lateral release (TALR) on hallux valgus correction. From January 2016 to January 2018, 28 consecutive patients (30 feet) were included in this study. The first intermetatarsal angle (IMA), hallux valgus angle (HVA), and round-shaped lateral edge of the first metatarsal head (R sign), and sesamoid rotation angle (SRA) were recorded prior to and 3 months after the surgery. The rotation of the capital fragment of the first metatarsal was termed the capital rotation angle (CRA) and was measured intraoperatively after the completion of scarf osteotomy. The IMA, HVA, and SRA were significantly reduced from 13.9 ± 4.9°, 34.6 ± 7.4°, and 28.7 ± 9.8° to 2.4 ± 2.3°, 7.3 ± 4.7°, and 13.4 ± 8.8°, respectively (p < .01 for all). The mean CRA was 7.0 ± 3.4° and was not significantly correlated with the reduction of IMA and SRA (p > .05 for all); nor was it significantly correlated with IMA preoperatively and postoperatively (p > .05 for all) or the reduction of SRA and IMA (p > .05). The R sign was positive in 40% (12/30) of the feet preoperatively compared to 13.3% (4/30) postoperatively (p < .001). Scarf osteotomy produced a supination effect on the capital fragment of the first metatarsal and supinated the sesamoids via lateral translation of the first metatarsal head. These changes may contribute to the correction of the pronation component of hallux valgus deformity.

First Metatarsal Rotation in Hallux Valgus Deformity

Rotation of the first metatarsal (M1) as a potential etiological factor of hallux valgus (HV) deformity was described relatively early in the description of HV pathoanatomy. However, because biplanar radiographs have been the standard method for imaging HV, clinicians primarily developed measurement methods and corrective operations confined to 2 dimensions, medial-lateral and inferior-superior. Recently, as our understanding of HV pathoanatomy has further developed, aided in part by advanced imaging technology, M1 rotation about its axis ("axial rotation") and its implications for HV deformity and treatment has reemerged. The goal of this review is to summarize M1 rotation in HV from a historical perspective, to present the current understanding of its potential role in the etiology/pathogenesis of HV, and to summarize relevant imaging and operative considerations with respect to M1 rotation.Level of Evidence: Level III, systematic review.

Inaccuracy of Forefoot Axial Radiographs in Determining the Coronal Plane Angle of Sesamoid Rotation in Adult Hallux Valgus Deformity: A Study Using Weightbearing Computed Tomography

BACKGROUND

Hallux abducto valgus is a triplane deformity with recent attention given to the significance of correcting the coronal plane component. This study explored the accuracy of the forefoot axial (FFA) study as a standard radiographic assessment method compared with weightbearing computed tomography (CT).

METHODS

Twelve feet with hallux abducto valgus from 12 individuals were included in this study. Three images of the affected foot were taken: FFA radiograph and weightbearing CT with the foot in maximum pronation (pronated CT) and maximum supination (supinated CT). Five investigators determined the sesamoid rotation angles (SRAs) from each of the images. The measurements from a single investigator were used to compare the SRA means from each of the image types, and those from all five investigators were used to determine reliability.

RESULTS

The mean ± SD SRA was 22.1° ± 7.6° for pronated CT, 10.5° ± 5.0° for supinated CT, and 12.2° ± 9.4° for FFA images. The mean SRA from the pronated CT was significantly greater than the supinated CT (P < .001) and FFA (P < .005) SRAs. There were no significant differences in mean SRA between the FFA and supinated CT images (P > .99). Results indicated high reliability in measurements among investigators.

CONCLUSIONS

Using weightbearing CT, these findings indicate that the sesamoids significantly alter their position in the coronal plane, as determined by the SRA, with changes in weightbearing subtalar joint position. Moreover, the affected foot positioning required for determining the SRA from the FFA radiograph seems to significantly underestimate the true SRA. Thus, use of this image in surgical hallux abducto valgus planning is called into question.

Comparison of Radiographic Measurements Before and After Triplane Tarsometatarsal Arthrodesis for Hallux Valgus

We present a comparison of preoperative and final postoperative first ray measurements in 109 feet after triplane tarsometatarsal arthrodesis at a mean follow-up time of 17.4 months. Preoperative and final postoperative first ray variables including intermetatarsal angle (IMA), hallux valgus angle (HVA), tibial sesamoid position (TSP), distal metatarsal articular angle (DMAA), Seiberg index, metatarsal rotation angle (MRA), sesamoid subluxation, osseous union, and hardware failure were evaluated. Measurements were made by consistently using the mid-diaphyseal line of the bone segments for both preoperative and postoperative assessments. The mean preoperative HVA, IMA, and TSP were 22.9°, 13.3°, and 4.6. The mean differences (95% confidence interval) in preoperative and postoperative values were -14.9° (-16.3° to -13.4°) for HVA, -7.7° (-8.2° to -7.2°) for IMA, and -2.6 (-2.8 to -2.3) for TSP. Among bunions with MRA measurements, the mean difference was -12.3° (-14.5° to -10.0°). The preoperative to postoperative DMAA decreased by a mean of -14.2° (-15.9° to -12.6°). The results of this study suggest that triplane tarsometatarsal arthrodesis produces appropriate correction of hallux valgus radiographic parameters.

The shape of the first metatarsal head and its association with the presence of sesamoid-metatarsal joint osteoarthritis and the pronation angle

BACKGROUND

The purpose of this study was to evaluate the associations of the shape of the first metatarsal head with (1) the presence of osteoarthritis in the sesamoid-metatarsal joint and (2) the pronation angle of the first metatarsal head on foot radiographs.

METHODS

A total of 121 patients, with the mean age of 61 years, underwent weight-bearing dorsoplantar, lateral, and first metatarsal axial radiographs. The shape of the first metatarsal head's lateral edge was classified as either rounded, intermediate, or angular in shape in the dorsoplantar view. The presence of osteoarthritis in the sesamoid-metatarsal joint and the pronation angle of the first metatarsal head were assessed in the first metatarsal axial view. Other variables that could affect the first metatarsal shape, including the lateral first metatarsal inclination angle, were also assessed. Univariate and multivariate analyses were performed to determine the associations.

RESULTS

The prevalence of sesamoid-metatarsal osteoarthritis was significantly higher (77%, 27%, and 29% for rounded, intermediate, and angular, respectively, P < .001), and the metatarsal pronation angle was significantly larger (14°, 8°, and 4° for rounded, intermediate, and angular, respectively, P < .001) in feet with a rounded metatarsal head. These associations were also significant in the multiple regression analysis.

CONCLUSION

A rounded metatarsal head was associated with a higher prevalence of osteoarthritis within the sesamoid-metatarsal joint, as well as a larger first metatarsal head pronation angle. A negative round sign can be used as a simple indicator of an effective correction to the first metatarsal pronation angle during hallux valgus surgery. However, in feet with sesamoid-metatarsal osteoarthritis, surgeons will need to be cautious as overcorrection may occur.

Intraoperative and Postoperative Evaluation of Hallux Valgus Correction: What Is Important?

The hallux valgus is one of the most challenging foot and ankle deformities to correct. The current concept is to consider the hallux valgus as a triplane deformity, and the parameters in transverse, sagittal, and frontal planes must be considered. The hallux valgus angle, intermetatarsal angle, tibial sesamoid position, and lateral edge of the first metatarsal head are valuable parameters to evaluate to understand the magnitude of the deformity. Diaphyseal corrections, such as scarf, and proximal interventions, such as crescentic osteotomy and Lapidus arthrodesis, are the most powerful techniques to address triplane deformity, because they are able to correct all misalignments.

Evolution of Thinking of the Lapidus Procedure and Fixation

The evolution of Lapidus fixation has been strongly associated with the understanding of the anatomy and function of the first tarsometatarsal joint, the mechanism of hypermobility of the first tarsometatarsal joint, and cause of the hallux valgus deformity in 3 dimensions. Some methods, such as plantar plating, nitinol staples, and intramedullary fixation, have proven to be stronger biomechanically in cadaveric testing. Theoretically, stable fixation will reduce the rate of complications, in particular, that of nonunion and allow for early postoperative weight-bearing. Further clinical studies are needed to examine whether current biomechanical studies will translate to relevant clinical outcomes.