Relationship between joint structure of the first tarsometatarsal joint and its degeneration.

This study aimed to elucidate the relationship between joint structures of the first tarsometatarsal and articular facet degeneration. A total of 100 feet from 50 cadavers were examined. The articular facets of the first metatarsal and medial cuneiform were categorized into four types based on the superior and inferior facets' separation, and the formation of the inferior lateral facet on the lateral plantar prominence: Type I, a single facet with no separation or inferior lateral facet; Type II-a, two facets with separation but no inferior lateral facet; Type II-b, two facets, no separation, but with an inferior lateral facet; Type III, three facets with separation and an inferior lateral facet. When both bone types matched, they were defined as Type I, Type II-a, Type II-b, and Type III joints, respectively; unmatched types were classified as Unpair joints. The severity of articular cartilage degeneration on both bones was assessed using a 5-point scale. The degeneration grade was compared among joint types. Type III joints exhibited significantly milder articular cartilage degeneration in medial cuneiform compared to Type II-a, II-b, Unpair joints. The formation of inferior lateral facet and separation of the superior and inferior facets might be crucial for the joint's stability.

The effect of hallux valgus on the anatomy of the nerves around the first metatarsal bone.

OBJECTIVE: To identify the variations in the location of the nerves that may be at risk in hallux valgus (HV) surgery, and to reveal whether these nerves are affected by the anatomical changes associated with HV. METHOD: In the formalin fixed, 46 lower extremities (19 female, 27 male) (9 normal, 14 mild HV, 21 moderate/severe HV), extensor hallucis longus tendon (EHL), deep plantar artery, medial dorsal cutaneous (MDCN), deep fibular (DFN), common plantar digital (CPDN) and proper plantar digital (PPDN) nerves were examined. The branches of MDCN extending to the medial side of foot were recorded in three segments. The positional topography of nerves according to EHL were analyzed on 360° circle and clock models. RESULTS: Sex-related differences observed in some parameters in direct measurements were not found in the clock model comparisons. In advanced HV angles (> 20°), DFN was closer to EHL in the distal part of the metatarsal bone, while there was no difference in the proximal. The intersection of the medial branch of the MDCN with the EHL was more proximal in HV cases than in normal feet. The location of the nerves in the clock pattern did not change in HV. Of the nerve branches reaching the medial side of the foot, 65.2% were in Part I, 71.7% in Part II, and 4.3% in Part III. CONCLUSION: Sex differences in the distance of the nerves to the EHL disappeared when the size effect of the cross-section of the first metatarsal bone region was eliminated with the clock model. Only in advanced HVA (>20°) (not in mild HV), the DFN being closer to the EHL distally and the intersection of the medial branch of the MDCN with the EHL in HV being more proximal than in normal can be interpreted as specific reflections of HV progress. The variations we revealed in the number of branches reaching the inside of the foot may explain the diversity of neuromas or nerve injuries associated with HV surgery.

Metatarsals and foot phalanges from the Sima de los Huesos Middle Pleistocene site (Atapuerca, Burgos, Spain).

This study provides a complete, updated and illustrated inventory, as well as a comprehensive study, of the metatarsals and foot phalanges (forefoot) recovered from the Middle Pleistocene site of Sima de los Huesos (SH, Atapuerca, Spain) in comparison to other Homo comparative samples, both extant and fossils. This current updated review has established a minimum number of individuals (MNI) of 17, which represent 58.6% of the 29 dental individuals identified within the SH sample. An exclusive or autoapomorphic combination of traits can be recognized within the SH hominin foot sample. A few traits appear primitive or plesiomorphic when compared with earlier Homo individuals and other recent modern humans. There are other metrical and morphological traits that SH hominins and Neandertals have in common that sometimes represent shared derived traits in this evolutionary line, most of which are probably related to robusticity. Furthermore, some exclusive autoapomorphic traits are observed in the SH sample: a very broad first metatarsal, long and broad hallucal proximal foot phalanges and possibly extremely robust lateral distal foot phalanges compared to those of Neandertals and modern humans. In these last traits, the SH metatarsals and pedal phalanges are even more robust than in Neandertals. They are herein named as "hyper-Neandertal" traits, which could suggest a slight gracilization process in this evolutionary line, at least in the hallux toe. Finally, some paleobiological inferences are made in relation to body size (stature and body mass) and some associations are proposed within the SH sample.

Estimation of sex using dimensions around the metatarsal diaphyseal nutrient foramen: Application of discriminant function analysis and logistic regression models.

Sex estimation equations are population-specific, and a wider use of multiple bones to generate equations will increase the accuracy of sex estimation in forensic settings. The metatarsal bones have been used previously, however the dimensions around the diaphyseal nutrient foramen have not been utilised in sex estimation. The current study aimed to determine the utility of the dimensions around the nutrient foramen of metatarsal bones in estimating sex in the South Africans of European descent (SAED). Five measurements around the nutrient foramen were taken from a total of 876 metatarsal bones (first to fifth) from 186 individual skeletons (99 males, 87 females) obtained from the Raymond A. Dart Modern Skeletal Collection. Measurements subjected to direct and stepwise discriminant function (DFA) and logistic regression (LRA) analyses included total length, distance from proximal end to nutrient foramen, circumference, and mediolateral and dorsoplantar diameters at the level of the nutrient foramen. The original classification accuracies for multivariable functions of the stepwise and direct DFA ranged from 83.1-88.3% to 85.5-88.3%, respectively. The original classification accuracies for multivariable functions of the stepwise and direct LRA ranged from 83.3%-88.7% to 86.2%-88.3%, respectively. The cross-validation classifications showed a drop of 0-2.4% for DFA and 0.2-1.1% for LRA. The width measurements were better predictors of sex than length. The dimensions around the metatarsal bone nutrient foramen exhibit sexual dimorphism in the SAED. The generated DFA and LRA functions produced high average classification accuracies which are useful in sex estimation during forensic human identification.

Estimation of Stature Based on Metatarsal Bones in a Thai Population / Estimación de la Estatura Basada en los Huesos Metatarsianos en una Población Tailandesa

SUMMARY: Stature estimation is one of the essential procedures for personal identification in forensic osteology. Therefore, the purposes of this study are to analyze the correlation between length and width of metatarsal measurements and stature, and to develop the regression equations for a Thai population. In this study, the samples were divided into two groups. The first group was called the "training group" for generating stature estimation equations, comprised of 200 skeletons, aged between 19-94 years. The second group was called the "test group" for evaluating the accuracy of generated equations, comprising 40 skeletons. The correlation between metatarsal parameters and stature were moderate to high, and all variables had positive significant correlation with stature. For males, the left ML2 is the length variable that showed the most correlation degree against stature (r=0.702), and the left MSW4 is the width variable that had the most correlation degree against stature (r=0.483). For females, right ML1 is the length variable that had the most correlation degree against stature (r=0.632), and right PW3 is the width stature that had the most correlation degree against stature (r=0.481). For all samples, left ML1 was the length variable that had the most correlation degree against stature (r=0.796) and right PW3 was the width variable that had the most correlation degree against stature (r=0.712). The results of generating multiple regression equations using a stepwise method reveals that the correlation coefficient (R) and standard error of estimate (SEE) were 0.761 and 4.96 cm, respectively, for males, and 0.752 and 4.93 cm for females, with 0.841 and 5.26 cm for all samples, respectively. According to these results, the mean of absolute error from the test group ranged from 3 to 5 cm. Therefore, stature estimation equations using length and width of metatarsals from our study can be applied to estimate stature in the Thai population.

La estimación de la estatura es uno de los procedimientos esenciales para la identificación personal en osteología forense. Por lo tanto, los propósitos de este estudio fueron analizar la correlación entre la longitud y el ancho de las medidas metatarsianas y la estatura, y desarrollar las ecuaciones de regresión para una población tailandesa. Las muestras se dividieron en dos grupos. El primer grupo se denominó "grupo de entrenamiento" para generar ecuaciones de estimación de estatura, compuesto por 200 esqueletos, con edades comprendidas entre los 19 y los 94 años. El segundo grupo se denominó "grupo de prueba" para evaluar la precisión de las ecuaciones generadas, que comprende 40 esqueletos. La correlación entre los parámetros metatarsianos y la estatura fue de moderada a alta, y todas las variables tuvieron una correlación significativa positiva con la estatura. Para el sexo masculino, la variable longitud ML2 izquierda es la que mayor grado de correlación presentó con la estatura (r=0,702), y la izquierda MSW4 fue la variable ancho la que mayor grado de correlación presentó con la estatura (r=0,483). Para el sexo femenino, ML1 derecho fue la variable longitud que tuvo mayor grado de correlación con la estatura (r=0,632), y PW3 derecha fue la variable ancho estatura que tuvo mayor grado de correlación con la estatura (r=0,481). Para todas las muestras, ML1 izquierdo fue la variable longitud que tuvo mayor grado de correlación con la estatura (r=0,796) y PW3 derecha fue la variable ancho que tuvo mayor grado de correlación con la estatura (r=0,712). Los resultados de generar ecuaciones de regresión múltiple usando un método paso a paso revela que el coeficiente de correlación (R) y el error estándar de estimación (SEE) fueron 0,761 y 4,96 cm, respectivamente, para los hombres y 0,752 y 4,93 cm para las mujeres, con 0,841 y 5,26 cm para todas las muestras, respectivamente. De acuerdo con estos resultados, la media del error absoluto del grupo de prueba osciló entre 3 y 5 cm. Por lo tanto, las ecuaciones de estimación de la estatura que utilizan la longitud y el ancho de los metatarsianos de nuestro estudio se pueden aplicar para estimar la estatura en la población tailandesa.

Proximal Plantar Plate of Lesser Toe Metatarsophalangeal Joint Vascular Supply.

BACKGROUND: The plantar plate is a major stabilizing structure of the metatarsophalangeal (MTP) joint with instability frequently occurring after a tear or attenuation of this structure. Commonly, a McGlamry elevator is used to strip the plantar plate from the plantar surface of the metatarsal to improve exposure of the MTP joint. The anatomy of the proximal plantar plate and vascular consequence of stripping the plantar plate from the metatarsal is not yet well understood. The purpose of this study is to describe the proximal attachment of the plantar plate anatomically and quantify the relative contribution of blood supply to the proximal plantar plate from both the metatarsal and the plantar fascia. METHODS: For anatomic evaluation, 6 lower extremity cadaver specimens without any gross evidence of foot and ankle deformity were utilized. For imaging analysis, 16 fresh frozen human adult cadaveric lower extremity specimens were used for this study, resulting in 35 MTP joints without deformity and 11 lesser MTP joints with cockup and/or crossover deformities. The specimens were prepared as described previously by Finney et al.5. RESULTS: From gross anatomic dissection, the plantar plate origin consists of a stout fibrous pedicle distinct from the surrounding synovial-type tissue that firmly anchors the plantar plate to the metatarsal. Based on nano-computed tomographic imaging, an average of 63.5% of the vascular supply to the proximal portion of the plantar plate entered from the metatarsal pedicle. The remaining 36.5% of the vascular supply entered from the plantar fascia. CONCLUSION: The proximal attachment of the plantar plate includes a stout fibrous pedicle anchoring the proximal portion of the plantar plate to the notch between the medial and lateral plantar condyles of the metatarsal head. The vascular supply of the proximal plantar plate is supplied from both the metatarsal pedicle and plantar fascia. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Estimating Adult Stature Using Metatarsal Length in the Korean Population: A Cadaveric Study.

This study aims to propose a regression equation for estimating stature in the Korean population using metatarsal bones from cadavers and to validate the appropriateness of the Korean-specific equation by comparing it to equations from other populations. A total of 81 adult formalin-fixed cadavers (51 males and 30 females) were evaluated. The first and second metatarsal bones' physiological and maximal lengths were measured, and the cadaveric stature of the subjects was determined as the distance from the vertex to the plantar face of the heel. In all measurements, the correlation coefficient between real stature and metatarsal length was statistically significant (p < 0.001). Additionally, both sexes showed a correlation between stature and metatarsal bone length. For unknown sex, M1 (first metatarsal maximal length) showed the strongest association between stature and metatarsal length. The following is the appropriate regression equation: 1172.4913 + 7.3275M1 (R = 0.703). The current equation demonstrated a statistically significant appropriateness for the Korean population when compared to equations for other populations (p < 0.001). In conclusion, we proposed a Korean-specific regression equation for estimating stature using metatarsal length, and this formula may be more appropriate and useful in forensic science for the Korean population.

Avoiding the Deep Plantar Arterial Arch in Transmetatarsal Amputations: A Cadaver Study.

BACKGROUND: The deep plantar arterial arch (DPAA) is formed by an anastomosis between the deep plantar artery and the lateral plantar artery. The potential risk of injury to the DPAA is concerning when performing transmetatarsal amputations, and care must be taken to preserve the anatomy. We sought to determine the positional anatomy of the DPAA based on anatomical landmarks that could be easily identified and palpated during transmetatarsal amputation. METHODS: In an effort to improve our understanding of the positional relationship of the DPAA to the distal metatarsal parabola, dissections were performed on 45 cadaveric feet to measure the location of the DPAA with respect to the distal metatarsal epiphyses. Images of the dissected specimens were digitally acquired and saved for measurement using in-house-written software. The mean, SD, SEM, and 95% confidence interval were calculated for all of the measurement parameters and are reported on pooled data and by sex. An independent-samples t test was used to assess for sex differences. Interrater reliability of the measurements was estimated using the intraclass correlation coefficient. RESULTS: The origin of the DPAA was located a mean ± SD of 35.6 ± 3.9 mm (95% confidence interval, 34.5-36.8 mm) proximal to the perpendicular line connecting the first and fifth metatarsal heads. The average interrater reliability across all of the measurements was 0.921. CONCLUSIONS: This study provides the positional relationship of the DPAA with respect to the distal metatarsal parabola. This method is easily reproducible and may assist the foot and ankle surgeon with surgical planning and approach when performing partial pedal amputation.

Length of metacarpal and metatarsal bones in five Iranian sheep breeds and their associations with ungula measurements.

BACKGROUND: This study aimed to measure the length of metacarpal and metatarsal bones in five Iranian sheep breeds and to correlate the length of the bones with ungula measurements. Thoracic and pelvic limbs of 2-year-old, previously untrimmed, pastured Afshari, Moghani, Kurdi, Makoui, and Lori-Bakhtiari ewes, (n = 20 ewes per breed) were collected after slaughter. The following lengths were recorded in the metacarpal and metatarsal bones: from the margo proximalis lateralis to the lateral (L1) and medial (D1) cartilago physialis; from the margo proximalis lateralis to the margo abaxialis of the lateral (L2) and medial (D2) caput; from the cartilago physialis lateralis to the margo abaxialis of the lateral caput (X1); from the cartilago physialis medialis to the margo distalis of the caput ridge (X2) and from the margo axialis of cartilago physialis to the margo axialis of the lateral caput (X3). Additionally, measurements of the ungula including pars dorsalis length, pars mobilis lateralis and medialis height, pars dorsalis height to the ground and to the solea cornea, thickness of the solea in the pars dorsalis, pars mobilis lateralis and medialis, solea cornea length and angulus dorsalis were recorded in the medial and lateral digits of the thoracic and pelvic limbs. Data on length of the metatarsal and metacarpal bones were analysed using mixed model equations while Pearson correlations were calculated between metacarpal and metatarsal bones and ungula measurements. RESULTS: Lori- Bakhtiari and Moghani ewes had greater L1, L2, and D1 and D2 while X1, X2 and X3 was greater in Kurdi ewes (P < 0.05). Measurements such as L1, L2, D1 and D2 were greater in the metatarsal than in metacarpal bones (P < 0.05) and the opposite was observed for X1, X2 and X3 (P < 0.05). No asymmetry was observed between the lateral and medial measurements (P > 0.05). Low to moderate correlations were observed between bone and ungula measurements (P < 0.05). CONCLUSION: Under the conditions of this study, differences in metacarpal and metatarsal bone measurements were observed between breeds but no asymmetry was observed between lateral and medial bones. Results indicate an association between metacarpal and metatarsal bones ungula measurements. This could provide baseline information for the development and/or improvement of current ungula health protocols in the studied sheep breeds.

Evolutionary trends of the lateral foot in catarrhine primates: Contextualizing the fourth metatarsal of Australopithecus afarensis.

In 2000, a complete fourth metatarsal (Mt4) of the ∼3- to 4-Million-year-old hominin Australopithecus afarensis was recovered in Hadar, Ethiopia. This metatarsal presented a mostly human-like morphology, suggesting that a rigid lateral foot may have evolved as early as ∼3.2 Ma. The lateral foot is integral in providing stability during the push off phase of gait and is key in understanding the transition to upright, striding bipedalism. Previous comparisons of this fossil were limited to Pan troglodytes, Gorilla gorilla, and modern humans. This study builds on previous studies by contextualizing the Mt4 morphology of A. afarensis (A.L. 333-160) within a diverse comparative sample of nonhuman hominoids (n = 144) and cercopithecids (n = 138) and incorporates other early hominins (n = 3) and fossil hominoids that precede the Pan-Homo split (n = 4) to better assess the polarity of changes in lateral foot morphology surrounding this divergence. We investigate seven morphological features argued to be functionally linked to human-like bipedalism. Our results show that some human-like characters used to assess midfoot and lateral foot stiffness in the hominin fossil record are present in our Miocene ape sample as well as in living cercopithecids. Furthermore, modern nonhuman hominoids can be generally distinguished from other species in most metrics. These results suggest that the possession of a rigid foot in hominins could represent a conserved trait, whereas the specialized pedal grasping mechanics of extant apes may be more derived, in which case some traits often used to infer bipedal locomotion in early hominins may, instead, reflect a lower reliance on pedal grasping. Another possibility is that early hominins reverted from modern ape Mt4 morphology into a more plesiomorphic condition when terrestrial bipedality became a dominant behavior. More fossils dating around the Pan-Homo divergence time are necessary to test these competing hypotheses.

Adult Stature Estimation from Radiographic Metatarsal Length in a Contemporary Korean Population.

The ability to estimate stature can be important in the identification of skeletal remains. This study aims to develop a Korean-specific equation predicting stature using radiographic measurements in the contemporary Korean population. 200 healthy Korean adults, including 102 males and 98 females, were randomly selected (age, range 20-86 years). The first and second metatarsals of the foot were measured by a standing X-ray using a digital medical image viewer. The result showed a statistically significant correlation between metatarsal length and stature in Korean populations (male, R = 0.46, p < 0.001; female, R = 0.454, p < 0.001). Values of correlation coefficients (R) of the equations were 0.431 to 0.477. Compared to equations derived from other races, the Korean-specific equation showed significantly lower error values for estimating the actual height of Koreans through cross-validation. In conclusion, this study is the first to propose a Korean-specific regression formula for estimating stature using metatarsal length and a verified formula for precise application to the Korean population. However, given the relatively low correlation coefficient, the stature estimation formula derived from this study can be utilized when other bones that allow more accurate stature estimation are not available.

16 Sesamoid bones in the hands of healthy patient: case report

The sesamoid bones are round or oval bones that are located within tendons, and most theories consider that sesamoid bones in humans develop in response to local mechanical stress on a joint. Although their function is not well understood, it is known that they act as a pulley modifying the angle of movement and their insertion. They are mostly inconsistent, which is why they tend to be supernumerary and are located in different parts of the body at the level of the extremities, with the patella being the largest, most constant and best known. The prevalence and distribution of sesamoids in the hand varies between different populations and sex. They are rarely reported since they are only considered anatomical variants, but clinically there are several pathologies related to the sesamoid bones in the hand such as: trauma, degenerative disorders, giant cell tumors, osteochondroma, avascular necrosis, tendon ruptures, genetic disorders and attention should be paid in patients with acromegaly where their length is increased. In this article, we report a total of 16 sesamoid bones, symmetrically distributed 8 ineach hand of a healthy individual treated in the Plastic Surgery Department of the "Dr. Rubén Leñero" Hospital in Mexico City. In the literature reviewed, we did not find a report with the presence of so many sesamoid bones in both hands, which motivated us to report it

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Rudimentary, "functionless" first metapodials of Canis latrans: Variation and association in length with longer, functional metapodials.

A tenet of evolutionary theory is that phenotypic variation of a trait is inversely related to the intensity of stabilizing selection pressure. Among homologous bones, such as metapodials, a rudimentary, "nonfunctional" bone is expected to be more variable in length than nonrudimentary bones. This study compares variation and association in length among metapodials using 277 adult skeletons of Canis latrans. Canis latrans has a short, "functionless" first metacarpal (mc1) and "rudimentary, vestigial" first metatarsal (mt1). Results show that among the 10 metapodials, mt1 has the highest variation in length; other metapodials do not differ significantly from one another in their variation. Correlation coefficients for length of mc1 and mt1 with their ipsilateral metapodials 2-5 are significantly lower than coefficients for all other ipsilateral pairs. The correlation coefficient between left and right mt1 is significantly the lowest among all bilateral pairs of metapodials. Results are interpreted as follows. Mt1's high variation and low association in length are the outcome of less intense stabilizing selection pressure compared with other metapodials. The nonsignificant difference for variation in length between mc1 and metapodials 2-5 may be that mc1 is functional for development of a pollical dewclaw that helps restrain small prey.

Anatomy of the Tarsometatarsal Region and Digits in the Ostrich (Struthio Camelus): A Computed Tomography and Cross-Sectional Study.

The ostrich is the largest living bird and has unique characteristics in its locomotor system that differentiate it from other bird species. The purpose of this study was to provide a reference atlas of reference-interval computed tomography (CT) and cross-sectional anatomy of the tarsometatarsal region and digits in the ostrich (Struthio camelus). The pelvic limbs of 25 ostriches were used for this imaging study. The transverse CT images were obtained from the middle third of the tarsometatarsal bone to the distal end of the third digit. The specimens were frozen and sectioned with an electric band saw at 1.5-2 cm intervals. The CT images were compared with the corresponding frozen cross sections. The bones, ligaments, and tendons were identified and labeled at each 1.5-2 cm intervals. The CT images provided anatomic details of the tendons and ligaments in the tarsometatarsal region and digits of the ostrich. The transverse CT images provided an excellent depiction of the anatomic structures of the leg and foot when compared with the corresponding frozen cross sections. The information presented in this study may be used as an initial reference when evaluating the CT images of an ostrich's tarsometatarsal region and digits. Moreover, the information provided in this report may be helpful in determining definitive diagnoses of musculoskeletal disorders affecting the lower leg in this species.

Anatomical variations in the insertion of the peroneus longus tendon.

BACKGROUND: This study aimed to inspect anatomical variations in the insertion of the peroneus longus tendon (PLT) using a large sample of cadavers. METHODS: In total, 104 legs from 52 Japanese cadavers were used. The PLT was identified behind the lateral malleolus and carefully followed up to its insertion in the foot. All insertion slips of the PLT were located and documented. RESULTS: Mainly, the PLT was inserted to the base of the first metatarsal (1MT) in all 104 ft. Attachment to the medial cuneiform was present in 20.2%, and the first dorsal interossei was present in 36.5%. The anterior frenular ligament was observed in 31.7%, and attachment to the flexor digiti minimi brevis and opponens digiti minimi was present in 31.7%. The posterior frenular ligament was observed in 5.8%. An additional band was observed in 3.9%, and the adductor hallucis consisting of a caput obliquum was present in 3.9%. No statistically significant differences in the PLT were observed between genders or laterality (right vs. left). CONCLUSIONS: These findings suggest that the main function of the PLT is resisting the varus force on the 1MT; however, as the PLT has various attachment sites, it may also be involved in the stabilizing action of the longitudinal and transverse arches. Therefore, these variations and functions appear to be associated with a difficult diagnosis at the first clinical evaluation.

The shape of the transverse arch in high heels while standing.

INTRODUCTION: High heeled shoes have long been worn in society and they are known to cause biomechanical imbalances to not only the foot, but the whole musculoskeletal system. This study aims to show the detailed changes that happen to the shape of the transverse arch of the foot in high heels, using two different inclination degrees. METHODS: 68 women participated in this study. Two custom-made high heels were made with inclinations of 15 degrees and 30 degrees (cm). A weight-bearing ultrasound was used to assess the coronal view of the transverse arch in standing. ANOVA and Tuckey tests were used to compare the results between 0 degrees, 15 degrees and 30 degrees inclinations. RESULTS: The transverse arch height was slightly increased as the heel height increased (0DI-15DI: p = 0.5852 / 15DI-30DI: p = 0.395 / 0DI-30DI: p = 0.0593). The transverse arch length (0DI-15DI: p = 0.0486 / 15DI-30DI: p = 0.0004 / 0DI-30DI: p = 0.1105) and the area under the metatarsal heads (0DI-15DI: p = 0.0422 / 15DI-30DI: p = 0.0180 / 0DI-30DI: p = 0.9463) significantly decreased as the heel height increased. DISCUSSION: The main changes were viewed in the 30 degrees inclinations compared to 0 degrees inclination. When the toes are dorsiflexed in high heels, it stimulates the Windlass mechanism which in turn stiffens the plantar fascia and adducts the metatarsal heads, while the soft tissues shrink in response to loads. CONCLUSION: High heels affected the shape of the transverse arch even in short term standing, and these effects increased as the height of the heel increased.

Radiographic Impact of Lapidus, Proximal Lateral Closing Wedge Osteotomy, and Suture Button Procedures on First Ray Length and Dorsiflexion for Hallux Valgus.

BACKGROUND: Shortening and dorsiflexion of the first metatarsal are known potential side effects of metatarsal osteotomies for hallux valgus (HV) with the potential to cause transfer metatarsalgia. We compared the effect of the first tarsometatarsal joint arthrodesis (Lapidus procedure), proximal lateral closing wedge osteotomy (PLCWO), and intermetatarsal suture button fixation procedures on the length and dorsiflexion of the first ray. METHODS: We retrospectively evaluated 105 feet in 99 patients with 30 weeks of follow-up. The average age was 54 years. Seventy-four feet had a Lapidus procedure, 12 had a PLCWO, and 19 had intermetatarsal suture button fixation. Digital radiographic measurements were made for the pre- and postoperative hallux valgus angle (HVA) and intermetatarsal angle (IMA), absolute and relative shortening of the first ray, and dorsiflexion. RESULTS: Preoperative HVA and IMA did not differ between treatment groups (P > .05 for each). Similar corrections of HVA (30.5-13.5 degrees) were achieved between all groups (P > .05). The IMA was improved more in the Lapidus group (14.3-6.5 degrees) compared with the suture button fixation group (14.2-8.1 degrees) (P = .045). There were significant differences in the change in absolute first cuneiform-metatarsal length (FCML) between the Lapidus (-1.6 mm), PLCWO (-2.3 mm), and intermetatarsal suture button fixation (+1.9 mm) procedure (P = .004). There were also significant differences in relative first metatarsal shortening between the Lapidus (0.1 mm relative shortening), PLCWO (1.1 mm relative shortening), and intermetatarsal suture button fixation (1.3 mm lengthening) procedure (P < .001). The average dorsiflexion differed between the Lapidus (1.8 degrees) and suture button fixation (0.4 degrees) groups (P = .004). CONCLUSION: Intermetatarsal suture button fixation relatively lengthened the first ray, the Lapidus procedure maintained length, and the PLCWO relatively and absolutely shortened it. Dorsiflexion may be higher with the Lapidus and osteotomy procedures. LEVEL OF EVIDENCE: Level III, retrospective comparative series.

The tibialis posterior tendon footprint: an anatomical dissection study.

BACKGROUND: The tibialis posterior tendon (TPT) is the main dynamic stabilizer of the medial longitudinal arch of the foot. Especially in adult acquired flatfoot deformity (AAFD) the TPT plays a detrimental role. The pathology and function of the tendon have been extensively investigated, but knowledge of its insertional anatomy is paramount for surgical procedures. This study aimed to analyze the complex distal footprint anatomy of the TPT. METHODS: Forty-one human anatomical specimens were dissected and the distal TPT was followed to its bony footprints. After tendon removal the footprints were marked with ink. Standardized photographs were taken and consecutively analyzed by digital imaging measurements. Footprint length, width, area of insertion, location, and shape was studied regarding the main insertion at the navicular bone. RESULTS: All specimens had the main TPT insertion at the navicular bone (41/41, 100%). Sixty-three percent of navicular TPT insertions were located at the plantar aspect. The mean navicular footprint measured 12.1 mm × 6.9 mm in length and width, respectively. The tendon further spread into several slips which anchored the tibialis posterior deep in the plantar arch. TPT insertions were highly variable with an involvement of up to eight distinct bony footprints in the mid- and hindfoot. The second most common additional footprint was the lateral cuneiform (93% of dissected feet), followed by the medial cuneiform (80%), the metatarsal bases [1-5] (80%), the cuboid (46%), the intermediate cuneiform (19%), and the calcaneus (12%). CONCLUSIONS: The present study adds to current knowledge on the footprint anatomy of the TPT. Based on the findings of this study we advocate a plantar location of flexor digitorum longus tendon transfer in flexible AAFD in order to restore the anatomical lever and insertion of the TPT.

Radiographic Assessment of Relative First Metatarsal Length Following Modified Lapidus Procedure.

BACKGROUND: The modified Lapidus is a surgical procedure for managing moderate to severe hallux valgus, especially in the presence of first tarsometatarsal joint arthritis or hypermobility. It has good long-term results but reportedly can lead to transfer metatarsalgia due to inherent shortening of the first metatarsal. METHODS: A retrospective analysis of all adult patients who underwent a modified Lapidus procedure during a 3-year period was performed. Clinical notes were evaluated to look for nonunion or any other complications related to the surgery. Pre- and postoperative standard weightbearing radiographs were used to establish the relative metatarsal length (RML), intermetatarsal angle (IMA), hallux valgus angle (HVA), and distal metatarsal articular angle (DMMA). A total of 69 modified Lapidus procedures were identified, with 32 included in the study. RESULTS: The mean pre- and postoperative RMLs were -0.8 and -4.9 mm, respectively. The average RML shortening due to the procedure was -4.1 (P < .0001). The mean pre- and postoperative IMAs were 15 and 5 degrees, respectively (P < .0001). The mean pre- and postoperative HVAs were 33 and 9 degrees, respectively (P < .0001). One patient reported transfer metatarsalgia, which was attributed to elevation of the first metatarsal. CONCLUSION: We found a statistically significant degree of shortening of the relative length of the first metatarsal without any clinically significant metatarsalgia. The low rate of transfer metatarsalgia following the modified Lapidus procedure could be attributed to the sagittal plane correction and stability obtained by performing a first tarsometatarsal fusion. LEVEL OF EVIDENCE: Level IV, retrospective case series.