The biomechanics of the first metatarsal bone in hallux valgus: A preliminary study utilizing a weight bearing extremity CT

Introduction: Hallux valgus is a 3-dimensional deformity involving an increased intermetatarsal I/II angle and a rotational deformity of the first metatarsal bone. Kim et al. developed a method for measuring the tibial sesamoid position relative to the coronal rotation of the first metatarsal bone in computed tomography scans under simulated weight-bearing conditions. Objective: To describe a method for the topographic assessment of the correction of tibial sesamoid and metatarsal pronation using computed tomography scans under simulated weight-bearing and active toe extension. Method: We performed computed tomography under simulated weight-bearing conditions with and without active toe dorsiflexion, observing the degree of metatarsal pronation and sesamoid subluxation. For measurement purposes, we used the classifications of Kim et al. and Smith et al. Results: We observed tomographic correction, both angular and rotational, by measuring the intermetatarsal angle and tibial sesamoid position, which were confirmed by the change in the alpha angle suggested by Kim et al. Discussion: Toe extension was described as a peroneus longus tendon activation test by Klemola et al., who used this maneuver to demonstrate clinical rotational correction of hallux valgus. We described the use of a tomographic technique that followed this principle to preoperatively observe the underlying factors that may affect the rotational correction of the deformity. Conclusion: The method has the capacity for correction in various planes involving derotation of the first metatarsal bone and the relationship between such derotation and the change in sesamoid position in relation to the coronal plane of the foot.

Download Full-text

Geometric Data of Hallux Valgus Feet

Foot & Ankle International ◽

10.1177/107110079601700907 ◽

1996 ◽

Vol 17 (9) ◽

pp. 548-554 ◽

Cited By ~ 19

Author(s):

Kenneth S. Lamur ◽

Anton Huson ◽

Chris J. Snijders ◽

Rob Stoeckart

Keyword(s):

Hallux Valgus ◽

Least Squares Method ◽

Metatarsal Bone ◽

Flexor Hallucis Longus ◽

Independent Variables ◽

First Metatarsal ◽

Linear Dependency ◽

Geometric Data ◽

Longus Muscle ◽

Stepwise Procedure

The aim of this study is to find basic quantitative geometric data that may contribute to the understanding of the etiology of hallux valgus. Embalmed specimens with existing hallux valgus (N = 39) were dissected; 28 variables were measured with a Vernier caliper gauge and toe goniometer. Correlations between pairs of independent variables were calculated. Linear dependency of the hallux angle, varus angle, and the width of the forefoot on a number of independent variables was analyzed by multiple linear regression. A least squares method and a stepwise procedure were used. The distance from the tendon of the flexor hallucis longus muscle to the head of the first metatarsal bone explains more than other variables the variation in hallux angle and width of the forefoot. A widened forefoot is significantly correlated with both hallux and varus angles. The interrelation of the predictor parameters illustrates the complicated hallux valgus phenomenon.

Download Full-text

Radiographic Outcomes after Fixation of Distal Metatarsal Osteotomy for Hallux Valgus Using a Tension Band Construct

Foot & Ankle Orthopaedics ◽

10.1177/2473011419s00428 ◽

2019 ◽

Vol 4 (4) ◽

pp. 2473011419S0042

Author(s):

Alexander Volpi ◽

Robert Zbeda ◽

Christopher Katchis ◽

Lon Weiner ◽

Stuart Katchis

Keyword(s):

Hallux Valgus ◽

Postoperative Period ◽

Weight Bearing ◽

Line Tension ◽

Tension Band ◽

Metatarsal Osteotomy ◽

First Metatarsal ◽

Distal Metatarsal Osteotomy ◽

The Mean

Category: Bunion Introduction/Purpose: Hallux valgus is a common deformity of the forefoot. There are over 130 procedures described to correct hallux valgus. Classically, the treatment of mild to moderate hallux valgus is with a distal metatarsal osteotomy. A variety of fixation techniques have been described for use with this osteotomy most of which require partial or non-weight bearing until the osteotomy is healed. Tension Band fixation is a well-known principle in orthopedic surgery. The goal of the present study is to radiographically assess the maintenance of distal first metatarsal osteotomy fixation using a novel tension band device (Re+Line tension band bunion plate system, Nextremity Solutions) with immediate post-operative weight-bearing. Methods: The patient database for one surgeon was retrospectively reviewed for patients that underwent hallux valgus correction with the Re+Line tension band device between 2014 and 2017. Postoperative protocol included a soft dressing, firm surgical shoe, and weight-bearing as tolerated with a cane. Patients were excluded if fixation was achieved with something other than a tension band construct. Radiographs were obtained and reviewed retrospectively by 3 authors. Pre and postoperative hallux valgus (HVA) and intermetatarsal angles (IMA) were measured as described previously in the literature, and the changes in correction compared. Maintenance of correction and hardware integrity were assessed at final follow-up after weight bearing as tolerated in a surgical shoe in the postoperative period. Statistical analysis was performed using a Wilcoxon signed-rank test for the changes in HVA and IMA. Results: There was a total of 72 patients and 76 toes that underwent hallux valgus correction with a tension band construct, at a mean follow-up of 4.36 months. 68 of 72 patients were female. The average age was 60.8 years old. The mean preoperative HVA was 27.1 degrees. The mean postoperative HVA was 6.14 degrees, with a mean correction of 20.22 degrees (p<0.001). The mean preoperative IMA was 14.14 degrees. The mean postoperative IMA was 6.10 degrees, with a mean correction of 7.98 degrees (p<0.001). There was loss of reduction found in 6 of 76 toes (7.89%).There were zero cases of hardware failure. All osteotomies healed at final follow-up. Conclusion: This study shows successful radiographic outcome after hallux valgus correction using a tension band construct and allowing immediate full weight-bearing in a surgical shoe in the postoperative period. Significant deformity correction was achieved and maintained and all osteotomies healed. The Re+Line tension band bunion correction system can be safely used as a successful option to fix distal first metatarsal osteotomies, while allowing patients to fully weight bear in a surgical shoe postoperatively and potentially return to activities faster than when using traditional fixation methods. Future studies are needed to assess functional outcomes and patient satisfaction with this novel technique.

Download Full-text

Assessment of First Metatarsal Head Bone Density for Optimal Screw Placement in Minimally-Invasive Hallux Valgus Surgery

Foot & Ankle Orthopaedics ◽

10.1177/2473011420s00038 ◽

2020 ◽

Vol 5 (4) ◽

pp. 2473011420S0003

Author(s):

Katherine M. Dederer ◽

Patrick J. Maloney ◽

John T. Campbell ◽

Clifford L. Jeng ◽

Rebecca A. Cerrato

Keyword(s):

Bone Density ◽

Minimally Invasive ◽

Hallux Valgus ◽

Screw Fixation ◽

Weight Bearing ◽

Metatarsal Head ◽

Screw Placement ◽

Cannulated Screws ◽

First Metatarsal ◽

History Of

Category: Bunion; Basic Sciences/Biologics Introduction/Purpose: Minimally-invasive surgery (MIS) for hallux valgus correction has become increasingly common. This technique involves an osteotomy of the first metatarsal, followed by fixation with two cannulated screws. Since screws are typically not bicortical, they rely upon bone quality within the metatarsal head for fixation strength. However, bone mineral density (BMD) within different regions of the metatarsal head is unknown. Measuring the BMD in the target region may predict the strength of the bone-screw fixation. Similar to previous work which determined the optimal position for lag screw placement in the femoral head during hip fracture fixation, this study aimed to determine average BMD within four quadrants of the metatarsal head using CT and thus predict the optimal trajectories for cannulated screws during the MIS bunion procedure. Methods: All patients between 18-75 years of age scheduled to undergo MIS hallux valgus correction by one of two surgeons experienced in the MIS technique were eligible to participate. Patients were excluded if they had a prior first metatarsal surgery, pre-existing hardware, previous first metatarsal fracture, or a history of osteoporosis treatment. Patients were enrolled prospectively, and a weight-bearing CT scan of the affected foot was obtained pre-operatively. Demographic factors including age, sex, laterality, body mass index (BMI), comorbidities, and smoking status as well as standard three-view weight-bearing radiographs were collected for all patients.Using the coronal CT slice at maximal metatarsal head diameter, each head was divided into equal quadrants. Hounsfield units (HU) within each quadrant were measured independently by three study investigators using our hospital’s radiology viewing software (Merge PACS; IBM Corporation, Armonk, NY), and these density measurements were averaged. Statistical analysis was conducted using ANOVA and Student’s t-test. Results: Fifteen patients were included for preliminary analysis. All patients were female. The average age was 45.7 years. 9 of the 15 included feet were right feet. Average BMI was 28.0. One patient reported active smoking prior to surgery. Comorbidities included obesity in three patients; none were diabetic. One had a history of diplegic cerebral palsy. The average HVA on a weight- bearing AP foot x-ray was 28.2°, and the average IMA was 12.6°. The BMD within the metatarsal head varied by quadrant, with the two combined dorsal quadrants having higher average BMD than the two combined plantar quadrants (122 vs 85 HU; p<0.001). The dorsal lateral quadrant had the highest average BMD of any quadrant (132 HU, p<0.001; Table 1). Conclusion: The density of the metatarsal head did vary by region within the head. The highest BMD was found in the dorsal lateral quadrant, and the lowest in the plantar lateral and plantar medial quadrants, which did not differ significantly from each other. Because strength of screw fixation is predicated upon screw design as well as bone density, these results suggest that surgeons may wish to direct screws toward the dorsolateral region of the metatarsal head in order to achieve optimal fixation. Further work is needed to determine whether this varies with patient age, gender, or hallux valgus angle. [Table: see text]

Download Full-text

Three-Dimensional Analysis of the First Metatarsal Bone in Minimally Invasive Distal Linear Metatarsal Osteotomy for Hallux Valgus

Foot & Ankle International ◽

10.1177/1071100719875222 ◽

2019 ◽

Vol 41 (1) ◽

pp. 84-93 ◽

Cited By ~ 1

Author(s):

Hiroyuki Seki ◽

Satoshi Oki ◽

Yasunori Suda ◽

Kenichiro Takeshima ◽

Tetsuro Kokubo ◽

...

Keyword(s):

Minimally Invasive ◽

Hallux Valgus ◽

Morphological Changes ◽

Case Series ◽

Metatarsal Bone ◽

Ct Scans ◽

Metatarsal Osteotomy ◽

Level Of Evidence ◽

3 Dimensional ◽

First Metatarsal

Background: Modified Bösch osteotomy (distal linear metatarsal osteotomy [DLMO]) is one of the minimally invasive correctional surgeries for hallux valgus. The 3-dimensional correctional angles and distances of the first metatarsal bone in DLMO have not been clarified. The purpose of this study was to analyze the 3-dimensional postoperative morphological changes of the first metatarsal bone in DLMO. Methods: Twenty patients (30 feet) who underwent DLMO were enrolled. Preoperative plain radiographs and computed tomography (CT) scans of the feet were examined. Postoperative radiographs and CT scans were also obtained after bone union. The surface data of the pre- and postoperative first metatarsals were reconstructed from the CT data. The positions of the distal ends of the first metatarsals described with respect to the proximal ends were calculated using CT surface-matching technique. Results: The distal end of the first metatarsal after DLMO was significantly supinated (10.2 ± 6.0 degrees, P < .001), adducted (6.0 ± 11.8 degrees, P = .004), dorsiflexed (11.1 ± 10.9, P < .001), shortened (7.4 ± 2.5 mm, P < .001), elevated (2.3 ± 3.1 mm, P = .001), and laterally shifted (8.2 ± 3.0 mm, P < .001) compared to the preoperative metatarsal distal end. Supination correction demonstrated a significant correlation with adduction correction ( r = 0.659, P < .001) on correlation analyses between these parameters. Conclusion: The 3-dimensional corrections of the first metatarsal bone after DLMO were evaluated. Pronation and abduction were successfully corrected. Furthermore, adduction correction might be an important factor affecting correction of pronation. Level of Evidence: Level IV, retrospective case series.

Download Full-text

Vascular anatomy of the first metatarsal bone and surgical implications according to the severity of hallux valgus deformity: A cadaveric study

Foot and Ankle Surgery ◽

10.1016/j.fas.2020.07.012 ◽

2020 ◽

Author(s):

Sérgio Soares ◽

Tiago Mota Gomes ◽

Gustavo Campos ◽

Filipe Medeiros ◽

João Bragança ◽

...

Keyword(s):

Hallux Valgus ◽

Vascular Anatomy ◽

Valgus Deformity ◽

Metatarsal Bone ◽

Cadaveric Study ◽

First Metatarsal ◽

Hallux Valgus Deformity

Download Full-text

PO 18074 - Rotational biplanar Chevron osteotomy

Scientific Journal of the Foot & Ankle ◽

10.30795/scijfootankle.2019.v13.988 ◽

2019 ◽

Vol 13 (Supl 1) ◽

pp. 9S

Author(s):

Tiago Soares Baumfeld ◽

Marcelo Pires Prado ◽

Alberto Mendes ◽

Caio Augusto De Souza Nery ◽

Daniel Soares Baumfeld

Keyword(s):

Internal Rotation ◽

Hallux Valgus ◽

Valgus Deformity ◽

Metatarsal Bone ◽

Distal Fragment ◽

Rotational Deformity ◽

First Metatarsal ◽

Chevron Osteotomy ◽

Hallux Valgus Deformity ◽

Rotation Component

Introduction: The Chevron osteotomy is a reliable and popular osteotomy for treating hallux valgus worldwide. Many modifications have been described, but none of them address the rotational deformity of the first metatarsal. The objective of this study is to describe a variation of biplanar Chevron osteotomy that can address first metatarsal rotation when necessary. Methods: The indications for the Rotational Biplanar Chevron Osteotomy (RBCO) are mild to moderate hallux valgus deformity associated with hallux pronation related to internal rotation of the first metatarsal bone. We describe a technique that uses a medial-based wedge parallel to the plantar limb of the osteotomy to free the distal fragment for correct rotation. Results: The more recent concern about hallux valgus surgery represents a very interesting concept that this deformity truly occurs in three different planes, and we may have mistreated the rotation component using current techniques. Many authors have revisited numerous common techniques to adapt them to correct metatarsal pronation. To the best of our knowledge, this is the first paper to describe a modification of the Chevron osteotomy to address rotation of the first metatarsal. Conclusion: We can conclude that rotational biplanar Chevron osteotomy is an useful tool in the treatment of mild hallux valgus associated with metatarsal pronation.

Download Full-text

Results of Hallux Abducto Valgus Surgical Correction Using Two 1.1mm Mini TightRope Constructs

Revista de Chimie ◽

10.37358/rc.20.2.7891 ◽

2020 ◽

Vol 71 (2) ◽

pp. 52-57

Author(s):

Mihai Nica ◽

Corina Panaitescu ◽

Bogdan Cretu ◽

Panti Zsombor ◽

Camelia Tecu ◽

...

Keyword(s):

Hallux Valgus ◽

Treatment Option ◽

Functional Impairment ◽

Metatarsal Bone ◽

Foot Deformity ◽

Moderate Severity ◽

First Metatarsal ◽

First Ray ◽

The Mean ◽

Correction Potential

Hallux valgus represents an acquired foot deformity defined by medial deviation of the first metatarsal bone combined with lateral shift of the hallux and medial metatarsophalageal joint eminence enlargement. The functional impairment and metatarsalgia generated stem from the biomechanical imbalance which does not allow for normal transfer of weight trough the first ray during walking. The results generated with our experience with the 1.1mm Mini TightRope� Disposable Kitin the treatment of hallux valgus are analyzed in this paper. A total number of 24 feet (12 bilateral cases) with hallux valgus, surgically treated in our department were followed for a period of minimum twelve months and evaluated. The results showed an improvement of the mean preoperative IMA 14.6�to 7.9� postoperatively and 9.2� at six months after surgery. The preoperative measured HVA was reduced from 28.4to 14.2� at once and 16.1� after six months. The AOFAS hallux metatarsophalangeal-interphalangeal score resulted improvement reflects the functional benefits. These results confirm the good correction potential of the technique and support it as avalid treatment option for mild to moderate severity hallux valgus.

Download Full-text

The Shape of the First Metatarsal Head and its Association with its Pronation Angle and the Presence of Sesamoid-Metatarsal Joint Osteoarthritis

Foot & Ankle Orthopaedics ◽

10.1177/2473011420s00374 ◽

2020 ◽

Vol 5 (4) ◽

pp. 2473011420S0037

Author(s):

Yoshimasa Ono ◽

Satoshi Yamaguchi ◽

Seiji Kimura

Keyword(s):

Hallux Valgus ◽

Weight Bearing ◽

Qualitative Evaluation ◽

Metatarsal Head ◽

First Metatarsal ◽

Lateral Edge ◽

Ankle Surgery ◽

History Of ◽

Joint Deformation ◽

The Mean

Category: Bunion Introduction/Purpose: The rounded shape of the first metatarsal head’s lateral edge on the dorsoplantar radiograph of the foot is used as a qualitative evaluation of the first metatarsal pronation in hallux valgus feet. However, the relationship between the rounded shape and the metatarsal pronation angle of the first metatarsal has not been examined in detail. Furthermore, hallux valgus often accompanies osteoarthritis in the sesamoid-metatarsal joint. Deformation of the metatarsal head by osteophytes on the lateral edge of the lateral sesamoid facet may affect the rounded shape. 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. Methods: Patients were prospectively recruited between December 2016 and March 2017. Patients with a history of previous foot and ankle surgery or destruction of the head due to rheumatoid arthritis were excluded. 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 of the rounded shape of the first metatarsal with the pronation angle and sesamoid-metatarsal joint osteoarthritis. Results: Of 121 feet, 31, 41, and 49 feet had rounded, intermediate, and angular metatarsal heads, respectively. Sesamoid- metatarsal joint osteoarthritis was evident in 49 (40%) feet. The mean hallux valgus and first metatarsal pronation angle was 23° and 9°, respectively. The prevalence of sesamoid-metatarsal osteoarthritis was significantly higher (24 (77%), 11 (27%), and 14 (29%) for rounded, intermediate, and angular, respectively, P < .001) in feet with a rounded metatarsal head. Furthermore, the metatarsal pronation angle was significantly larger (14°, 8°, and 4° for rounded, intermediate, and angular, respectively, P < .001). 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.

Download Full-text