Microevolutionary changes in the skeleton of the foot of Japanese: Special reference to the medial longitudinal arch

This study concerns secular changes of the foot of Japanese, from the prehistoric Jomon period to early modern times. The size of the talus, calcaneus and first metatarsal changed in parallel with the estimated stature, during this period. In the case of the calcanues, length-height-index, length-tuberosity height-index, Böhler's tuber-joint angle and angle of cuboidal articular surface gradually increased with time. Thus, all may take part in elevation of the longitudinal arch. With time, the relative height of the subtalar, talonavicular, cuneonavicular and first tarsometatarsal joints in the reconstructed medial arch enlarged, in parallel with the increase in the inclination angles of both the calcaneus and the first metatarsal. In addition, valgus deviation of the distal phalanx of the great toe became conspicuous in comparatively recent times. These changes no doubt were accelerated by modification in life style.     

Prevention of polydactyly manifestation in Polydactyly Nagoya (Pdn) mice by administration of cytosine arabinoside during pregnancy

Male mice heterozygous for the dominant polydactyly gene Pdn (Polydactyly Nagoya) were crossed with normal or heterozygous females of the same strain. Pregnant females were treated with 5 mg/kg of cytosine arabinoside (Ara-C) on day 12 of gestation. The offspring were removed on day 18 of gestation and examined for external malformations, and the fore- and hindlimbs were examined by means of bone- and cartilage-stained cleared specimens. In +/+ x Pdn/+ matings, Pdn/+ fetuses, bearing preaxial polydactyly of the distal phalangeal type in the hindlimb and deformity of the 1st digit in the forelimb, were obtained in about 50% of the nontreated group. In treated fetuses, however, the incidence of polydactyly and deformity of the 1st digit decreased to 1.4 and 10.1%, respectively. Nontreated Pdn/Pdn fetuses exhibited preaxial polydactyly of the duplicated or triplicated metacarpal/metatarsal type both in the fore- and hindlimbs. In the treated Pdn/Pdn fetuses, the number of preaxial extra digits decreased in both limbs. Some hindlimbs of the treated Pdn/Pdn fetuses exhibited five metatarsals, normally. In the vitally stained specimens at 6 and 24 hours after injection of Ara-C, preaxial marginal necrotic zones (fMI) were observed in almost all of the treated embryos from +/+ x Pdn/+ matings. However, approximately half of the embryos did not exhibit fMI in the nontreated control group at the same stage. Those embryos deficient in fMI were regarded as Pdn/+. These findings indicated that a subteratogenic dose of Ara-C prevented the genetic expression of polydactyly in almost all Pdn/+ and some cases of Pdn/Pdn mice.(ABSTRACT TRUNCATED AT 250 WORDS)     

Forefoot structural predictors of plantar pressures during walking in people with diabetes and peripheral neuropathy

Various foot structures are thought to influence forefoot plantar pressures during walking. High peak plantar pressures (PPP) during walking in people with diabetes mellitus (DM) and peripheral neuropathy (PN) can cause skin breakdown. The question addressed by this study is "What are the primary forefoot structural factors that predict regional PPP during walking in groups of people with and without DM and PN?" Twenty people with DM and PN (mean age 55+/-9 years, 6 female, 14 male, BMI=33+/-8) and 20 people without DM, matched for gender, age, and BMI were tested. Measures of foot structure were taken from three-dimensional images constructed from spiral X-ray computed tomography. Peak plantar pressure data were recorded during walking. Hierarchical multiple regression analysis was used to predict regional PPP at the great toe and five metatarsal heads from selected structural and walking variables. Metatarsal phalangeal joint angle (hammer toe deformity) was the most important variable predicting pressure, accounting for 19-45% of the PPP variance at five of the six locations in the DM group. Soft tissue thickness, hallux valgus, and forefoot arthropathy were the most important predictors of PPP in the control group. Combinations of structural and walking variables accounted for 47-71% of the variance in the DM group and 52-83% of the variance of PPP during walking in the control group. These structural variables, especially hammer toe deformity, should be considered in attempts to develop strategies to reduce excessive forefoot PPP that may contribute to skin breakdown or other injury.     

Parametric study of orthopedic insole of valgus foot on partial foot amputation

Orthopedic insole was important for partial foot amputation (PFA) to achieve foot balance and avoid foot deformity. The inapposite insole orthosis was thought to be one of the risk factors of reamputation for foot valgus patient, but biomechanical effects of internal tissues on valgus foot had not been clearly addressed. In this study, plantar pressure on heel and metatarsal regions of PFA was measured using F-Scan. The three-dimensional finite element (FE) model of partial foot evaluated different medial wedge angles (MWAs) (0.0°–10.0°) of orthopedic insole on valgus foot. The effect of orthopedic insole on the internal bone stress, the medial ligament tension of ankle, plantar fascia tension, and plantar pressure was investigated. Plantar pressure on medial heel region was about 2.5 times higher than that of lateral region based on the F-Scan measurements. FE-predicted results showed that the tension of medial ankle ligaments was the lowest, and the plantar pressure was redistributed around the heel, the first metatarsal, and the lateral longitudinal arch regions when MWA of orthopedic insole ranged from 7.5° to 8.0°. The plantar fascias maintained about 3.5% of the total load bearing on foot. However, the internal stresses from foot bones increased. The simulation in this study would provide the suggestion of guiding optimal design of orthopedic insole and therapeutic planning to pedorthist.     

Polydactyly of the foot: an analysis of 265 cases and a morphological classification.

Three hundred and thirty feet in 265 patients with polydactyly of the foot were classified on the basis of ray involvement and the level of duplication. Anatomic differences in bony structures according to x-ray and operative findings, external appearance of involved digits, associated anomalies, and familial incidence were studied. In medial-ray polydactyly, bilateral occurrence was common, and a higher frequency of associated anomalies was detected. Each involved foot with even the same level of duplication usually had a different morphologic pattern. In central-ray polydactyly, all patients except one had duplications of the second toe, commonly with unilateral involvement. Both components were underdeveloped, with delay in appearance of ossification areas. In two patients, each member of duplication had syndactyly with the neighboring toe, resembling the pattern of polysyndactyly-cleft hand complex. Lateral-ray polydactyl was classified into two new major groups based on ossification pattern and bony alignment: (1) fifty-ray duplication, referring to the medially duplicated supernumerary fifth toe, and (2) sixth-ray duplication, referring to the laterally duplicated supernumerary sixth toe. Fifth-ray duplication was much more frequent than sixth-ray duplication in the Japanese population. Many differences were noted between the two groups of lateral polydactyly. Syndactyly between the fourth and fifth toes was associated only with fifty-ray duplication. Ulnar polydactyly was associated only with sixth-ray duplication. In lateral polydactyly, every patient with bilaterally involved feet had similar groups of polydactyly bilaterally. All the patients in the same family also had similar groups of anomalies. These facts suggest independent etiologic mechanisms for each.     

天津蓟县桃花园墓地明清时期缠足女性足骨的形态观察

本文对天津蓟县桃花园墓地明清时期101例缠足女性足骨形变情况进行了观察和分析。结果显示,不同个体的同名骨骼形变类型和程度不同,有的个体两侧足骨呈不对称状。跗骨在整体尺寸上缩小,且部分跗骨会产生形变。跖骨和近节趾骨因受缠足外力的影响在形态上会产生剧烈的变化,主要变现为跖骨和近节趾骨纤细、弓弯,关节面改变,其近、远端以及跖骨体和趾骨体的上下径和横径均产生形变。总体而言,跖骨和近节趾骨的形变程度较跗骨而言更大。本文总结了判断某个体是否缠足的依据,特别指出需要同时观察距骨和跟骨的形态改变。鉴于其他疾病(如高弓足、麻风病、风湿性关节炎)也可导致足骨的畸形样貌,在进行个体缠足判定时,需要进行综合成因分析。缠足由文化行为所导致,其足骨形变特征有别于因病理原因导致的足部畸形。功能压力分析能够有效地解释缠足个体足骨形变的成因及过程。     

Congenital curved nail of the fourth toe

Five cases of congenital curved nail of the fourth toe are reported. Patients included four males and one female; four cases were bilateral, and one was unilateral. There were no other significant associated anomalies of the extremities, and only the fourth toes were affected. The features of the deformity are a curved nail and hypoplasia of the soft tissue and bone of the distal phalanx of the fourth toe. This anomaly may be transmitted autosomally and is unique in that it may be of mesodermic origin.     

Anatomical features associated with preaxial duplication (pd): a recessive mutation in the rat

Preaxial polydactyly of the fore- and hindlimbs was found in Wistar-derived rats in 1978. Genetic analysis indicated that the polydactyly was due to the effects of an autosomal recessive gene (gene symbol; pd). Polydactylous homozygous rats had two or three pollices (six or seven digits) in the forelimbs and one to three preaxial extra digits (six to eight digits) in the hindlimbs. Skeletal examination revealed the presence of the extra carpal, metacarpal, and phalangeal bones that seemed to be complete or incomplete duplication of the navicular, greater multangular, first metacarpal, and phalanges of digit I in the forelimbs. In the hindlimbs, extra tarsal, metatarsal, and phalangeal bones were also observed preaxially. These extra elements seemed to be mirror-image duplications of the talus, navicular, second cuneiform, third cuneiform, cuboid, and metatarsals and phalanges of digits II-V with the absence of the first cuneiform, tibiale, first metatarsal, and phalanges of digit I. In addition, morphological changes were observed in the humerus, radius, and ulna in the forelimbs and femur, tibia, and fibula in the hindlimbs. Especially in the radius and tibia, thickening and bifurcation were found, indicating incomplete duplication of these bones. Based on these findings, the limb anomaly was classified as preaxial carpometacarpal/tarsometatarsal-type polydactyly with incomplete duplication of the radius and tibia. The mutant rats had other associated anomalies such as accessory spleens and cryptorchism. The males are sterile, whereas the females breed normally.     

Anatomy of a duplicated human foot from a limb with fibular dimelia.

At birth, a patient presented with a right lower limb featuring preaxial polydactyly and fibular dimelia with a complete absence of the tibia. Radiographic studies of the patient's foot revealed a duplicated tarsus with eight metatarsals and toes. The three preaxial toes were surgically removed at 1 year of age. A hallux and four normal-appearing postaxial toes remained. The foot was amputated when the patient was 3 years old. Dissection of the amputated foot revealed that the muscles of the dorsum were normal, except that the tendon of the extensor hallucis brevis muscle inserted into both the hallux and toe 2, rather than only into the hallux. The few abnormalities observed among the muscles on the plantar surface of the foot included absence of the insertions of the tibialis posterior and the abductor hallucis muscles. In addition, the two heads of the adductor hallucis muscle inserted abnormally into the medial (tibial) side of metatarsal 1, rather than into the lateral side. These various muscular anomalies, in addition to the mirror duplication of the foot with the presence of only a single metatarsal 1, leads us to propose that this metatarsal probably represents two lateral (fibular) halves that form a laterally duplicated bone. Although the dorsalis pedis artery was present on the dorsal surface of the foot, most of its derivatives were absent. This artery did give rise to a supernumerary medial branch that ended abruptly in the connective tissue (presumably postsurgical scar) at the medial border of the foot. This branch may have represented a duplicated dorsalis pedis artery associated with the duplicated preaxial portion of the foot. The arteries on the plantar surface of the foot were normal. Even though some anomalies in the pattern of the cutaneous innervation were observed, the nerves of the foot were largely normal. The gross and radiographic anatomy of this specimen and the radiographic anatomy of the leg suggest that some teratogenic event occurred when developmental specification reached the level of the future knee. The teratogenic event, which probably occurred early in the fifth week of development, may have caused damage that led to a lateral duplication of both the leg and the foot with the absence of some of the most medial structures. Teratology 60:272-282, 1999.     

Excision biopsy of malignant melanoma by general practitioners in south east Scotland 1982-91.

OBJECTIVE--To examine the management of patients who had a malignant melanoma excised initially by general practitioners in south east Scotland over the past 10 years and to assess the impact of the April 1990 contract on this. DESIGN--A retrospective case-control study. SETTING--South east Scotland. SUBJECTS--All patients in south east Scotland who had malignant melanomas excised by general practitioners in 1982-91. OUTCOME MEASURES--Demographic details of patients; Breslow thickness, clearance of excision. RESULTS--42 patients had malignant melanomas excised by general practitioners in 1982-91: 15 in 1982-9 and 27 in 1990-1. These patients were significantly younger than those who had their tumours excised initially in hospital. Although the longest diameter of melanomas excised by general practitioners was significantly less than of those excised in hospital, the Breslow thicknesses were similar. Completeness of initial excision was doubtful or incomplete in nine (23%) general practitioner excisions compared with 4% of hospital excisions, but the time interval between excision biopsy and wide excision was similar. Pathology requests accompanying excision biopsies mentioned melanoma as a possible diagnosis in 15% (6/40) of general practitioner cases compared with 79% of hospital cases. Thirty nine general practitioners responded to a questionnaire and only 12 had considered melanoma in the differential diagnosis. CONCLUSIONS--General practitioners need to think more often of malignant melanoma when they excise pigmented lesions and when they consider this tumour a possibility should perform an excision biopsy with a lateral clearance of at least 2 mm.     

Metatarsophalangeal fusion for hallux valgus: indications and effect on the first metatarsal ray.

Arthrodesis of metatarsophalangeal joint was performed in 31 cases of severe hallux valgus. With the surgical technique used, which is described in detail, internal fixation and plaster cast immobilization were not necessary. Analysis of the results suggested that the operation is indicated for severe deformities in elderly patients, preferably women. The basic metatarsal deformity was corrected by the procedure.     

Effect of heel height on in-shoe localized triaxial stresses

Abnormal and excessive plantar pressure and shear are potential risk factors for high-heeled related foot problems, such as forefoot pain, hallux valgus deformity and calluses. Plantar shear stresses could be of particular importance with an inclined supporting surface of high-heeled shoe. This study aimed to investigate the contact pressures and shear stresses simultaneously between plantar foot and high-heeled shoe over five major weightbearing regions: hallux, heel, first, second and fourth metatarsal heads, using in-shoe triaxial force transducers. During both standing and walking, peak pressure and shear stress shifted from the lateral to the medial forefoot as the heel height increased from 30 to 70mm. Heel height elevation had a greater influence on peak shear than peak pressure. The increase in peak shear was up to 119% during walking, which was about five times that of peak pressure. With increasing heel height, peak posterolateral shear over the hallux at midstance increased, whereas peak pressure at push-off decreased. The increased posterolateral shear could be a contributing factor to hallux deformity. It was found that there were differences in the location and time of occurrence between in-shoe peak pressure and peak shear. In addition, there were significant differences in time of occurrence for the double-peak loading pattern between the resultant horizontal ground reaction force peaks and in-shoe localized peak shears. The abnormal and drastic increase of in-shoe shear stresses might be a critical risk factor for shoe-related foot disorders. In-shoe triaxial stresses should therefore be considered to help in designing proper footwear.     

An Early Pleistocene human pedal phalanx from Swartkrans,SKX 16699, and the antiquity of the human lateral forefoot

In order to assess the antiquity of derived human lateral (lesser) toe morphology, the SKX 16699 Early Pleistocene pedal proximal phalanx from Swartkrans (South Africa) was compared to samples of pedal phalanges attributed to Pliocene/Pleistocene australopithecines, Homo naledi and Late Pleistocene Homo. In contrast to australopith lateral phalanges, the SKX 16699 phalanx exhibits an absolutely (and probably relatively) short length, limited plantar diaphyseal curvature, proximal-to-midshaft and mid-dorsoplantar flexor sheath insertions, and a marked proximodorsal orientation of the metatarsal facet. SKX 16699 is intermediate between the australopith phalanges and later Homo ones in its modest dorsal diaphyseal curvature and mid-dorsoplantar metatarsophalangeal collateral ligament insertion areas. Its diaphyseal robustness is similar to that of Homo phalanges, but overlaps the range of later australopith ones. This combination of features and the close morphological affinities of SKX 16699 to later Homo proximal pedal phalanges suggest the emergence of a distinctly human lateral forefoot by the initial Early Pleistocene.     

Treatment of preaxial polydactyly of the foot

Fourteen patients with preaxial polydactyly are classified into four types according to their morphologic configuration: type 1--ray duplication; type 2--completely duplicated phalanges; type 3--incompletely duplicated metatarsals; and type 4--incompletely duplicated phalanges. The surgical treatment and timing thereof appropriate for each group are discussed. Three cases of congenital hallux varus deformity are analyzed, focusing on the pathomechanism of this disorder. Based on our experience, two main factors are noticed in the etiology of congenital hallux varus deformity: inadequacy of the adductor hallucis and tightening of the fibrous band pulling the big toe into the varus.     

Polydactyly lethal: a new mutant spontaneously occurring in the FPL strain of rats

A new mutant gene that causes preaxial polydactyly in the hindlimbs was found in the strain of rats with fused pulmonary lobes (fpl). Genetic analysis has revealed that the new mutation is inherited as an autosomal recessive trait and is not closely linked with the fpl gene. Since homozygous mutants die within the first 2 days after birth, the mutant gene was named polydactyly lethal, gene symbol pl. A test for allelism between the pl gene and another gene, pd, which also causes preaxial duplication anomalies, showed no allelism between these two genes. Skeletal examination revealed that all pl/pl newborns had thickening and/or bifurcation of tarsal I and metatarsal I, as well as duplication of the proximal and distal phalanges of digit I in the hindlimbs. In some cases, phalangeal duplication or bifurcation in digit I with thickening of metacarpal I was also found in the forelimbs, although extra forelimb digits were not detected externally. The pl/pl newborns showed hunchback-like abnormal posture externally and had several associated vertebral abnormalities in varying degrees, i.e., kyphosis, scoliosis, splitting of the thoracic vertebral bodies, and fusion of the lumbar vertebral bodies. No major malformations were seen in the visceral organs. The cause of neonatal deaths has not yet been determined.     

Finite element modeling of the first ray of the foot: a tool for the design of interventions

Disorders of the first ray of the foot (defined as the hard and soft tissues of the first metatarsal, the sesamoids, and the phalanges of the great toe) are common, and therapeutic interventions to address these problems range from alterations in footwear to orthopedic surgery. Experimental verification of these procedures is often lacking, and thus, a computational modeling approach could provide a means to explore different interventional strategies. A three-dimensional finite element model of the first ray was developed for this purpose. A hexahedral mesh was constructed from magnetic resonance images of the right foot of a male subject. The soft tissue was assumed to be incompressible and hyperelastic, and the bones were modeled as rigid. Contact with friction between the foot and the floor or footwear was defined, and forces were applied to the base of the first metatarsal. Vertical force was extracted from experimental data, and a posterior force of 0.18 times the vertical force was assumed to represent loading at peak forefoot force in the late-stance phase of walking. The orientation of the model and joint configuration at that instant were obtained by minimizing the difference between model predicted and experimentally measured barefoot plantar pressures. The model were then oriented in a series of postures representative of push-off, and forces and joint moments were decreased to zero simultaneously. The pressure distribution underneath the first ray was obtained for each posture to illustrate changes under three case studies representing hallux limitus, surgical arthrodesis of the first ray, and a footwear intervention. Hallux limitus simulations showed that restriction of metatarsophalangeal joint dorsiflexion was directly related to increase and early occurrence of hallux pressures with severe immobility increasing the hallux pressures by as much as 223%. Modeling arthrodesis illustrated elevated hallux pressures when compared to barefoot and was dependent on fixation angles. One degree change in dorsiflexion and valgus fixation angles introduced approximate changes in peak hallux pressure by 95 and 22 kPa, respectively. Footwear simulations using flat insoles showed that using the given set of materials, reductions of at least 18% and 43% under metatarsal head and hallux, respectively, were possible.     

Finite-element simulation of flexor digitorum longus or flexor digitorum brevis tendon transfer for the treatment of claw toe deformity

Claw toe deformity sometimes leads to dorsiflexion of the metatarsophalangeal joint (MPJ) and plantar flexion of the proximal (PIPJ) and distal interphalangeal (DIPJ) joints. Flexor digitorum longus tendon transfer (FDL) is currently the gold standard for the correction of this problem. Transfer of the flexor digitorum brevis (FDB) has been recently proposed as an alternative method to treat such deformity. The aim of this work is to compare the biomechanical outcome of these two methods by means of finite-element simulation. The results show that the reduction in the dorsal displacement of the proximal phalanx (PP) for the second and third toes were very similar (about 4.3 mm for each intervention), both achieving a significant reduction in MPJ dorsiflexion when compared to no intervention (displacements are reduced by approximately 51%). In the fourth and fifth toes, only a small correction in the deformity was achieved with both the techniques (10% and 7%, respectively). FDB and FDL tendon transfer reduced the stress level when compared with the non-operated pathologic foot (the reduction of stresses for the second and third PP ranged between 20% and 40%). FDB transfer resulted in a more uniform distribution of stress along the entire toe, although differences were small in all cases. These results confirm that both the tendon-transfer techniques are effective in the treatment of claw toe deformity. Therefore, the choice of technique is at the discretion of the surgeon.     

Identification of chemosensory sensilla mediating antennular flicking behavior in Panulirus argus, the Caribbean spiny lobster

Crustaceans sample odorants by a rapid series of flicks of the two flagella composing the distal segments of each of the paired antennules. The lateral flagella contain aesthetasc sensilla that house unimodal chemosensory neurons. Nine types of nonaesthetasc setae with putative chemosensory and mechanosensory functions are distributed on the lateral and medial flagella. Sensory neurons in aesthetascs and nonaesthetasc sensilla terminate in separate regions of the brain, the olfactory lobe, and the lateral antennular neuropil, resulting in two odorant-processing pathways. Distilled water ablation of flagella and excision of specific setae were used to identify chemosensory sensilla mediating antennular flick behavior in Panulirus argus. The flick rates of sham-ablated and ablated or excised lobsters toward squid extract were compared. Complete attenuation of flick response to squid extract occurred as a result of (1) distilled water ablation of lateral flagella, (2) excision of aesthetascs and asymmetric sensilla, and (3) excision of aesthetascs. Distilled water ablation of medial flagella resulted in a mean flick rate 52% of that observed for sham-ablated lobsters toward squid extract. Flicking was unaffected by excision of asymmetric, guard, or companion sensilla. We propose that odorant mediation of flicking behavior requires both the aesthetasc and nonaesthetasc pathways.     

EPIPHYSEAL STIMULATION IN THE LOWER EXTREMITIES

Epiphyseal stimulation to correct disparity in the length of lower extremities was done in 12 children. The total number of procedures was 15. In 11 of the 15 instances the operation was beneficial. Ivory pegs were used in some cases, brass screws in others and multiple drill holes in still others. There seemed to be no difference between them in the amount of stimulation brought about.Stimulation persisted for from six to ten months after operation.Complications that may occur are varus or valgus deformities, delay in growth, complete fusion, or infection. To prevent varus or valgus deformity, both medial and lateral sides may be stimulated simultaneously. Great care must be taken to place the screws no closer than one-fourth inch to the epiphyseal plate to avoid trauma which may delay rather than stimulate growth. Late infection may be obviated by the use of absorbable materials.The increase brought about by stimulation procedures is probably attributable to hyperemia following subperiosteal stripping.