Posterior Ankle Impingement and Flexor Hallucis Longus Pathology

Posterior ankle pain is a common complaint, and the potential causative pathologic processes are diverse. The constellation of these numerous etiologies has been collectively referred to as posterior ankle impingement syndrome. The pain associated with posterior ankle impingement is caused by bony or soft tissue impingement of the posterior ankle while in terminal plantar flexion. This condition is most frequently encountered in athletes who participate in sports that involve forceful, or repetitive, ankle plantar flexion. This article discusses the associated pathology, diagnosis, conservative treatment, and surgical techniques associated with flexor hallucis longus and posterior ankle impingement syndrome.

Cortical structure of hallucal metatarsals and locomotor adaptations in hominoids

Diaphyseal morphology of long bones, in part, reflects in vivo loads experienced during the lifetime of an individual. The first metatarsal, as a cornerstone structure of the foot, presumably expresses diaphyseal morphology that reflects loading history of the foot during stance phase of gait. Human feet differ substantially from those of other apes in terms of loading histories when comparing the path of the center of pressure during stance phase, which reflects different weight transfer mechanisms. Here we use a novel approach for quantifying continuous thickness and cross-sectional geometric properties of long bones in order to test explicit hypotheses about loading histories and diaphyseal structure of adult chimpanzee, gorilla, and human first metatarsals. For each hallucal metatarsal, 17 cross sections were extracted at regularly-spaced intervals (2.5% length) between 25% and 65% length. Cortical thickness in cross sections was measured in one degree radially-arranged increments, while second moments of area were measured about neutral axes also in one degree radially-arranged increments. Standardized thicknesses and second moments of area were visualized using false color maps, while penalized discriminant analyses were used to evaluate quantitative species differences. Humans systematically exhibit the thinnest diaphyseal cortices, yet the greatest diaphyseal rigidities, particularly in dorsoplantar regions. Shifts in orientation of maximum second moments of area along the diaphysis also distinguish human hallucal metatarsals from those of chimpanzees and gorillas. Diaphyseal structure reflects different loading regimes, often in predictable ways, with human versus non-human differences probably resulting both from the use of arboreal substrates by non-human apes and by differing spatial relationships between hallux position and orientation of the substrate reaction resultant during stance. The novel morphological approach employed in this study offers the potential for transformative insights into form-function relationships in additional long bones, including those of extinct organisms (e.g., fossils).

[Correlative analysis on metatarsalgia and the X-ray measurement indexes under weight-bearing and non-weight-bearing of hallux valgus]

OBJECTIVE

To study changes in the radiographic appearance during weight-bearing and non-weigh-bearing in hallux valgus, and to analyse the correlation between the elasticity of plantar soft tissue of hallux valgus and the pain under the metatarsal head.

METHODS

From May 2012 to October 2012, 240 feet of 120 patients with hallux valgus were enrolled in the study. The degrees of the pian under the metatarsal head of all the patients were observed. AP and lateral X-ray films of feet were taken on the condition of weight-bearing and non-weight-bearing. So the hallux valgus angle (HVA), the inter-metatarsal angle between the first and second metatarsals (IM1-2), the inter-metatarsal angle between the first and fifth metatarsals (IM1-5), top angle of the medial longitudinal arch (TAOTMLA),and anterior angle of the medial longitudinal arch (AAOTMLA) were measured on the X-ray films. The differences of HVA, IM1-2, IM1-5, TAOTMLA and AAOTMLA between two groups were compared, and the correlation between the changes of IM1-2, IM 1-5, TAOTMLA, AAOTMLA and the degree of the pain under the metatarsal head were analysed.

RESULTS

One hundred and forty-eight feet had the pain under the metatarsal head. The IM1-2, IM1-5 and TAOTMLA increased on weight-bearing position compared with those on non-weight-bearing position, but the HVA and AAOTMLA decreased on weight-bearing position compared with those on non-weight-bearing position. There was a moderate relationship between the changes of IM 1-2,IM1-5 and the degree of the hallux valgus deformity, as well as the relationship between the different of IM1-5 and the degree of the pian under the metatarsal head.

CONCLUSION

The degree of the collapse of the arch of foot with hallux valgus becomes serious with its deformity increasing. The pain under the metatarsal head of hallux valgus increases with the increased changes of IM 1-2,IM 1-5 and TAOTMLA. Analysis of the X-ray observation indexes of hallux valgus on weight-bearing position and non-weight-bearing position has important significance in evaluating the degree of the collapse of the arch of foot with hallux valgus,preventing and curing the the pain under the metatarsal head.

[Anatomical study of flexor hallucis brevis insertion: Implications for clinical practice]

PURPOSE OF THE STUDY

The flexor hallucis brevis (FHB) is one of the short muscles of the foot. It divides in front into two portions, which are inserted into the medial and lateral sides of the base of the first phalanx of the great toe. The detailed knowledge of its insertion into the proximal phalangeal base is decisive in any surgery involving the first metatarsophalangeal (MTP) joint, such as implant arthroplasty, resection arthroplasty or amputation. Complications resulting from injury to this insertion are commonly known. The aim of this study was to describe in detail the morphology of FHB insertion sites and to determine a safe extent of resection to be done at the base of the proximal phalanx.

MATERIAL AND METHODS

In 36 cadaver specimens we measured FHB insertion length from the plantar side of the proximal phalangeal base and from the plane perpendicular to the long axis of the phalanx and passing through the base of the concave articular surface of the phalanx.

RESULTS

Measured from the plantar base of the proximal phalanx, the mean length of the medial insertion site was 11.5 ± 0.9 mm (range, 9.5 to 13.0 mm) and that of the lateral insertion site was 9.5 ± 1.1 mm (range, 8.0 to 11.5 mm). After resection, the mean values for medial and lateral FBH insertion sites were 8.5 ± 1.7 mm (range, 6.5 to 11.0 mm) and 7.1 ± 1.4 mm (ran- ge, 5.5 to 9.5 mm), respectively. The mean total proximal phalangeal length was 33.1 ± 2.2 mm (range, 28.5 to 37.0 mm), reduced after resection to 30.5 ± 2.1 mm (range, 26.0 to 34.5 mm).

DISCUSSION

Our results show that the medial insertion site, where the medial FHB tendon and distal part of the abductor hallucis muscle are joining, is longer than the lateral site. Therefore the length of the lateral site is decisive for preserving FHB function. Since the plane perpendicular to the long axis of the phalanx and passing through the base of the concave articular surface of the phalanx is almost identical with the beginnings of FHB insertions, it seems optimal for clinical practice to perform the initial resection along this plane.

CONCLUSIONS

To preserve at least one third of the FHB insertion, the final resection should not exceed 4 mm or 13 % of the proximal phalangeal length, as measured from the reference plane defined above.

The hallucal sesamoid complex

The hallucal sesamoids are vitally important to normal weight bearing and foot mechanics. The sesamoid complex of the hallux normally transmits up to 50% of body weight and during push-off can transmit loads >300%. These high stresses may lead to both acute and chronic pathologies of the hallucal sesamoids. Sesamoidal problems may occur in the weekend warrior or the elite-level athlete. Thus, patients with sesamoid pathology may present to a general orthopaedic surgeon, sports medicine physician, foot and ankle specialist, or podiatrist. Physical examination, radiographs, and other specialized studies assist with the classification of sesamoid pathology. Initial treatment almost always involves an accommodative orthosis, but surgical intervention may be necessary in recalcitrant cases. Surgical options for managing problems of the hallucal sesamoid complex include curettage, bone grafting, shaving, internal fixation, and partial or complete excision.

Hallucial convergence in early hominids

There is a richly documented fossil record of the evolutionary transition from ape-sized brains that are less that one-third the size of modern humans through a series of intermediate-sized brains up to the modern range. The first report on the discovery of the foot of the Stw 573 skeleton emphasized the apparent transitional nature of its great toe [Clarke, R.J., Tobias, P.V., 1995. Sterkfontein Member 2 foot bones of the oldest South African hominid. Science 269, pp. 521-524]. The hallux appeared to be intermediate in its divergence between human-like adduction and ape-like abduction. A major part of this evidence is the medial encroachment of the metatarsal I facet on the medial cuneiform. This study quantifies the variability of this feature in extant hominoids and fossil hominids. The results are consistent with the view that all currently known hominids were specialized for bipedality and lacked the ape-like ability to oppose the great toe.

Skeletal segments of the human pollical and hallucal rays: comparison and analysis of their intrinsic proportions

Since in humans, the first digital ray has a different functional significance in the hand and in the foot, the comparison of the pollical and hallucal rays seems interesting in order to evaluate the influence of specific evolutionary functional factors and biomechanical constraints. The objective of this study was to provide original and detailed data on the intrinsic proportions of the three segments of the human pollical and hallucal rays (metacarpal or metatarsal bone, proximal phalanx, and distal phalanx) in order to allow a quantitative comparison of their relative development. No similar data evaluated from three-dimensional approaches (volumetric or ponderal) seem to be available in the literature. The material consisted of 77 skeletons of the pollical ray and 77 skeletons of the hallucal ray of normal adult individuals. The ponderal approach was used. The first metapodial represented a mean of 57.17% for the pollical ray and 68.48% for the hallucal ray, whereas the phalanges respectively represented 42.83% and 31.52%. The intrinsic phalangeal proportions were almost identical for the pollex and for the hallux (respectively, 71.76% and 72.88% for the proximal phalanx; and 28.24% and 27.12% for the distal phalanx). Since these intrinsic proportions are the reflection of biological, functional and evolutionary constraints, these data seem of interest for the analysis of the functional significance of these rays, for the characterization of malformative syndromes in clinical practice, for reference in comparative morphology, and for the interpretation of hominid fossil bones.

Variations in the insertion of the extensor hallucis longus muscle

Reports that describe abnormalities of the muscles and tendons of the leg and foot are important with regard to understanding the function of the lower limb and correlating these abnormalities with the clinical aspects. Variations in the insertion of the extensor hallucis longus muscle were studied in 60 adult human cadavers. Three different patterns of insertion were noticed. Pattern I (65%): the extensor hallucis longus muscle had a single tendinous insertion on the dorsal aspect of the base of the distal phalanx of the big toe. Pattern II (26.67%): the muscle terminated in two tendons. Pattern III (8.33%): the muscle terminated in three tendinous slips. Various sites of insertion of the extensor hallucis longus muscle were recorded other than the dorsal aspect of the base of the distal phalanx of the big toe. These were the dorsal aspect of the base of the proximal phalanx of the big toe and the capsule of the first metatarso-phalangeal joint or a connection with the tendon of the extensor hallucis brevis. The frequency of occurrence of lateral deviation of the big toe at the metatarso-phalangeal joint (hallux valgus) was recorded. It is suggested that the presence of these variations in the insertion of the extensor hallucis longus muscle may have a role in explaining its association with hallux valgus.

Grasping primate origins

The evolutionary history that led to Eocene-and-later primates of modern aspect (Euprimates) has been uncertain. We describe a skeleton of Paleocene plesiadapiform Carpolestes simpsoni that includes most of the skull and many postcranial bones. Phylogenetic analyses indicate that Carpolestidae are closely related to Euprimates. C. simpsoni had long fingers and an opposable hallux with a nail. It lacked orbital convergence and an ankle specialized for leaping. We infer that the ancestor of Euprimates was primitively an arboreal grasper adapted for terminal branch feeding rather than a specialized leaper or visually directed predator.

The Mozena Classification System and treatment algorithm for ingrown hallux nails

Infected ingrown toenails raise the question of how much nail should be removed and what amount of nail fold reduction should occur. Often, the ungual labia folds are found to be hypertrophic, forcing the nail to push into the flesh and start a foreign body reaction. A simplified approach to this problem is proposed on the basis of the measurement of 100 normal nail folds and 25 infected nail folds. The results of this study show that the treatment goal should be to achieve an ungual labia fold of less than 3 mm, concluding that there is a correlation between the depth of the ungual labia fold and the severity of the infected ingrown toenail.

Morphology of the hallucial phalanges in extant anthropoids and fossil hominoids

Pedal phalanges of living anthropoids and several Miocene fossil hominoid taxa were studied to reveal functional adaptations of living anthropoid feet and to infer positional behavior of fossil hominoids. Among the examined living anthropoids, Pan has a very developed (long and robust) hallux. Proconsul and Nacholapithecus, a large hominoid from Nachola, northern Kenya, display a moderately long hallux like Alouatta and Cebus, suggesting the well-developed capability of a hallux-assisted power grip. Allometric analyses revealed that the Miocene hominoids examined (mainly from East Africa) as a whole displayed a different scaling pattern about the width of the proximal articular surface of the hallucial terminal phalanx from that of living anthropoids. Larger-sized hominoids display a wider articular surface than comparable-sized living anthropoids while smaller-sized fossil hominoids do the reverse. Such a difference was less marked for the height of the articular surface. These results may suggest that positional adaptations of Miocene hominoids are not merely resultants of a common body size function that is observed in living anthropods. The wide articular surface of fossil hominoid hallucial terminal phalanges suggests an adaptation for vertical climbing and clinging, in which the hallux is kept perpendicularly to the long axis of the vertical support.

ACFAS Universal Foot and Ankle Scoring System: First Metatarsophalangeal Joint and First Ray (module 1)

The American College of Foot and Ankle Surgeons presents the Universal Evaluation Scoring System to evaluate parameters related to foot and ankle surgery. This instrument was developed primarily to allow investigators a means of consistency in clinical assessments. The project was developed in four sections or modules. The first of these modules, First Metatarsophalangeal Joint and First Ray, is presented. This project is unique in that it is the first clinical scoring system of the foot and ankle to become validated by statistical analysis.

Periarticular injuries to the hallux metatarsophalangeal joint in athletes

The magnitude of hallux MTP injuries can range from a mild sprain to a frank dislocation. The importance of coaches, trainers, and physicians recognizing the severity of a turf toe injury cannot be overstated. The late sequelae of hyperextension injuries can lead to retirement from professional athletics. With appropriate conservative treatment, most individuals can return to play, although many have some residual pain. Future study in this area should define the indications for acute repair versus late treatment following a period of conservative modalities. Hyper-plantarflexion injuries also can be debilitating injuries, but most respond to rest, taping, anti-inflammatories, ice, and strengthening exercises. Lastly, dislocations of the hallux MTP joint can be diagnosed and treated after physical examination and appropriate radiographs are obtained. All closed dislocations should undergo an attempt at reduction in the emergency department after adequate anesthesia is administered. The patient should be advised, especially in type I injuries, of the need for possible acute operative intervention.

Structural and functional predictors of regional peak pressures under the foot during walking

The objective of this study was to identify structural and functional factors which are predictors of peak pressure underneath the human foot during walking. Peak plantar pressure during walking and eight data sets of structural and functional measures were collected on 55 asymptomatic subjects between 20 and 70 yr. A best subset regression approach was used to establish models which predicted peak regional pressure under the foot. Potential predictor variables were chosen from physical characteristics, anthropometric data, passive range of motion (PROM), measurements from standardized weight bearing foot radiographs, mechanical properties of the plantar soft tissue, stride parameters, foot motion in 3D, and EMG during walking. Peak pressure values under the rearfoot, midfoot, MTH1, and hallux were measured. Heel pressure was a function of linear kinematics, longitudinal arch structure, thickness of plantar soft tissue, and age. Midfoot pressure prediction was dominated by arch structure, while MTH1 pressure was a function of radiographic measurements, talo-crural joint motion, and gastrocnemius activity. Hallux pressure was a function of structural measures and MTP1 joint motion. Foot structure and function predicted only approximately 50% of the variance in peak pressure, although the relative contributions in different anatomical regions varied dramatically. Structure was dominant in predicting peak pressure under the midfoot and MTH1, while both structure and function were important at the heel and hallux. The predictive models developed in this study give insight into potential etiological factors associated with elevated plantar pressure. They also provide direction for future studies designed to reduce elevated pressure in "at-risk" patients.

Position of the first ray and motion of the first metatarsophalangeal joint

The authors present a quantitative analysis of the effect that first ray position has on motion of the first metatarsophalangeal joint. A goniometer was constructed to measure the degrees of first metatarsophalangeal joint dorsiflexion with the first ray in three positions: weightbearing resting position, dorsiflexed 4 mm from the weightbearing resting position, and dorsiflexed 8 mm from the weightbearing resting position. First metatarsophalangeal joint dorsiflexion decreased 19% as the first ray was moved from the weightbearing resting position to 4 mm dorsiflexed, 19.3% as the first ray was moved from 4 mm dorsiflexed to 8 mm dorsiflexed, and 34.7% as the first ray was moved from the weightbearing resting position to 8 mm dorsiflexed. The biomechanical significance of decreased first metatarsophalangeal joint dorsiflexion that results from first ray dorsiflexion is discussed, and proposed bases for the pathomechanics of hallux abducto valgus and hallux rigidus deformities are presented.

The hallucal interphalangeal sesamoid

The hallucal interphalangeal sesamoid is considered by some to represent an anatomical rarity that possesses little clinical significance. However, the location of this seemingly innocuous sesamoid bone directly inferior to the hallucal interphalangeal joint of the hallux is associated with the development of several important anatomical, biomechanical, and clinical pathologies. The authors present a review of the literature regarding the location, shape, ontogeny, and surgical management of the hallucal interphalangeal sesamoid. Additionally, the authors discuss the detrimental effect the hallucal interphalangeal sesamoid has on the biomechanical functions of the first metatarsophalangeal and hallucal interphalangeal joints.

Sterkfontein member 2 foot bones of the oldest South African hominid

Four articulating hominid foot bones have been recovered from Sterkfontein Member 2, near Johannesburg, South Africa. They have human features in the hindfoot and strikingly apelike traits in the forefoot. While the foot is manifestly adapted for bipedalism, its most remarkable characteristic is that the great toe (hallux) is appreciably medially diverged (varus) and strongly mobile, as in apes. Possibly as old as 3.5 million years, the foot provides the first evidence that bipedal hominids were in southern Africa more than 3.0 million years ago. The bones probably belonged to an early member of Australopithecus africanus or another early hominid species.

The foot in ballet dancers: the importance of second toe length

Ballet dancers are prone to foot injuries. Our hypothesis was that the length of the second toe in relation to the big toe affected the distribution of stresses on the foot, correlating with calluses, injuries, and pain. Fifty-nine ballet dancers were examined for second toe length with respect to great toe, calluses, and metatarsophalangeal inflammation. Daily foot pain, limitation of work hours because of this, injuries, age, sex, and rank in the company were considered. The dancers' feet had an incidence of shorter, equal, or longer second toes which was comparable to a non-ballet-dancing cohort (N = 60). In female dancers (N = 34), total callus counts and pain scores were significantly lower in the group with shorter second toes versus those with equal or longer second toes. Counts were unrelated to age or rank. Longer second toes were related to hallux rigidus. Limitation of practice hours, ankle sprains, and foot/ankle fractures and sprains were comparable across the groups. The male dancers (N = 25) had significantly fewer calluses than did the women, but had equal pain scores and number of injuries. There were no significant differences among the males in total callus counts, pain scores, limitation of practice hours, or injuries between groups based on toe length, age, or rank. We conclude that there is no significantly more ideal pattern of toe lengths for male ballet dancers, but females with shorter second toes have fewer calluses and less daily foot pain. Those with a longer second toe had a higher incidence of hallux rigidus and correspondingly increased pain scores.

The effect of hallux sesamoid resection on the effective moment of the flexor hallucis brevis

In this cadaver study, the functional significance of the hallux sesamoid bones was quantified by measuring the effective tendon moment arm (ETMA) of the flexor hallucis brevis (FHB) force. (The ETMA differs from the anatomic tendon moment arm in that ETMAs are determined by the experimentally measured moment of the tendon force, rather than by the actual location and orientation of the tendon pull in the joint). The intact case was compared with three levels of progressive sesamoid resection: distal half of the medial sesamoid excised, entire medial sesamoid excised, and both the medial and lateral sesamoids excised. Five dorsiflexion angles of the metatarsophalangeal joint were tested, ranging from -10 degrees to 50 degrees. A known active load was applied to the FHB muscle of fresh frozen cadaver specimens while the corresponding resisting forces from three orthogonally mounted transducers were being recorded. Results showed that the ETMAs decreased significantly (P < .05) only with the excision of both sesamoids. The percent decrease in ETMA was smallest at dorsiflexion angles of -10 degrees and 15 degrees (4.3% and 2.4%, respectively) and largest at dorsiflexion angles of 25 degrees, 35 degrees, and 50 degrees (29.2%, 22.4%, and 26.7%, respectively). The clinical significance of the results is that distal hemiresection of the medial sesamoid or full medial sesamoid excision is unlikely to appreciably compromise the effective mechanical advantage of the FHB muscle. However, this mechanical advantage may be profoundly diminished by excision of both hallux sesamoids.

Clinical rating systems for the ankle-hindfoot, midfoot, hallux, and lesser toes

Four rating systems were developed by the American Orthopaedic Foot and Ankle Society to provide a standard method of reporting clinical status of the ankle and foot. The systems incorporate both subjective and objective factors into numerical scales to describe function, alignment, and pain.

Biomechanical model of the human foot: kinematics and kinetics during the stance phase of walking

A model of the human foot is proposed in which the foot is represented as eight rigid segments and eight monocentric, single-degree-of-freedom joints. The soft tissue under the foot is divided into seven independent sites of contact, or loading, and each of these is modelled as a nonlinear spring and a nonlinear damper in-parallel. The model was used to estimate the kinematics and kinetics of the foot during the stance phase of walking. The force sustained at each loading site was calculated from walking trials in which only portions of the foot landed on a small force platform. The position of the calcaneus was defined by surface markers, whereas the position of the distal segments were based upon chalk footprints and an estimate of the compression of the plantar soft tissue. The results suggest that the joints that constitute the longitudinal arch extend slightly when the forefoot is loaded. During push-off, these joints flex as the metatarsophalangeal joints extend. Similar kinematic results were estimated when the distal segments of the foot were defined by surface markers. The magnitude of the joint moments of force depended largely on the distribution of the load under the foot which varied considerably between subjects. The stable, yet resilient properties of the foot, as highlighted by this model, should be considered in three-dimensional dynamic models used to study human locomotion. The model provides an objective tool to quantify foot motion and loading, which may prove useful for describing foot function in normal and pathological conditions.

The hallux sesamoids revisited

The hallux sesamoids are vulnerable to significant injury and weight-bearing stress in both the athlete and the nonathlete. Unfortunately, they are often dismissed as inconsequential accessory bones. The historical significance, embryology, anatomy, and physiology of the sesamoids and the salient features of both traumatic and nontraumatic pathologic conditions affecting these structures are presented. Because the sesamoids can be responsible for prolonged disabling foot pain and discomfort, it is important for both clinician and radiologist to pay attention to these bones and recognize the early signs of abnormality.

Hallux fractures: diagnosis and treatment

The authors present a review of the literature, mechanisms of injury, and radiographic presentations of hallux fractures. Sixty cases (64 injuries) were reviewed. Recommendations for treating each type of injury are also presented.

The arterial supply of the sesamoid bones of the hallux: the course and source of the nutrient arteries as an anatomical basis for surgical approaches to the great toe

The arterial supply of the hallux sesamoids was studied in 29 human feet by anatomical dissection. Eight of them underwent radiographic analysis prior to dissection. The sesamoid arteries branch off from the digital plantar arteries of the hallux, which, in turn, are derived from the medial plantar artery and the plantar arch (type A), the plantar arch (type B), or the medial plantar artery (type C). The respective frequencies of types A, B, and C were 52%, 24%, and 24%. The number of sesamoid arteries varied from one (55%) to three (10%) and the number increased with the size of the sesamoid bones. Anatomical knowledge of the course and distribution of these vessels may be of great help to the orthopedist in the understanding of the pathogenesis of avascular necrosis and may provide insight into several technical aspects regarding surgery of the hallux.

Hallucal tarsometatarsal joint in Australopithecus afarensis

Hallucal tarsometatarsal joints from African pongids, modern humans, and Australopithecus afarensis are compared to investigate the anatomical and mechanical changes that accompanied the transition to terrestrial bipedality. Features analyzed include the articular orientation of the medial cuneiform, curvature of the distal articular surface of the medial cuneiform, and the articular configuration of the hallucal metatarsal proximal joint surface. Morphological characteristics of the hallucal tarsometatarsal joint unequivocally segregate quadrupedal pongids and bipedal hominids.

Normal and pathologic anatomy of hallux valgus

The author reviews the pathologic entity of hallux valgus, using anatomic illustrations. Although this description is not considered to represent new information, foot surgeons must continue to appreciate the delicate biomechanical imbalances leading to this anomaly.

Hallux interphalangeal joint sesamoidectomy using minimal incision technique

There has been little emphasis placed on the excision of accessory bones of the foot. The authors present a review of the literature and a description of a surgical procedure for excision of the hallux interphalangeal joint sesamoid using minimal incision technique. A detailed analysis of the anatomy involved is also presented. A variety of other procedures for excision of this accessory bone are reviewed.

The role of the akin osteotomy in the surgical management of hallux abducto valgus

The Akin osteotomy has gained widespread popularity in foot surgery. This article reviews the proper indications, technique, modifications, and complications of the procedure. It also identifies the true role in the surgical management of the hallux abducto valgus deformity.

An irreducible dislocation of the great toe. Report of two cases and review of the literature

Irreducible dislocation of an interphalangeal (IP) joint of the great toe is a rare condition. Twenty-two cases including the present two cases are reported in available literature. Two different types are identifiable. In one type, where the ruptured volar plate is displaced into the joint space between two phalanges, the toe is slightly elongated, but the deformity of the toe is not so marked. In the other type, where the volar plate is completely displaced over the proximal phalangeal neck, the deformity of the toe is extreme as the IP joint is locked in hyperextension. In the former type, the dislocation is often misinterpreted to have been repositioned manually because of relatively slight deformity. In either type of dislocation, the volar plate is detached from both the distal and proximal phalanges, and so displaced into the joint, as to form a barrier to manual repositioning. Open reduction is mandatory.

The proximal phalangeal osteotomy. A technically advanced approach

A historical review of osteotomies of the proximal phalanx has been presented. The techniques have remained relatively unchanged since their introduction by O. F. Akin in 1925. This article describes a minimal incision osteotomy technique using a medial approach to the hallux and wedge-shaped burs. The results suggest that the procedure produces good clinical results and is highly accepted by the patient. The procedure is compatible with a hospital or outpatient surgical facility. The procedure is recommended to those surgeons who are well-trained in ambulatory foot surgery. A statistical survey of the end-results is not available at the present time.

Hallux sesamoid bones. Anatomical observations with special reference to osteoarthritis and hallux valgus

The normal characteristics of the hallux sesamoid bones were studied in 200 toes (100 dissections and 100 radiographs from patients with hallux valgus), and pathological changes were recorded. Normally each sesamoid articulated with a separate groove on the plantar surface of the first metatarsal head. A bony ridge on the head separated these grooves. Bipartite sesamoids were found in 4% of the toes. Osteoarthritic changes manifested by deformity, irregularity, lipping, cysts in the sesamoids and in the heads of the first metatarsal, and erosions in the articular surfaces were present in 32% of the dissected toes. Fusion of the sesamoids was found in 6%. Ankylosis between the sesamoids and the head of the metatarsal was observed in 4%. In the toes affected by hallux valgus the sesamoids, together with the plantar pad and the tendon of the flexor hallucis brevis, were displaced laterally to a variable degree. In severe deformities the lateral sesamoid was dislocated lateral to the first metatarsal head and the medial sesamoid occupied the groove originally corresponding to the lateral sesamoid, while the metatarsal ridge separating the two sesamoids tended to disappear. Osteoarthritis of the metatarsophalangeal joint frequently accompanied hallux valgus.

The prevalence of hallux valgus in South African males

The prevalence of hallux valgus and its relationship to the metatarsal angles have been assessed in South African males from two Black communities and one White community. After the age of 11 years there is a small increase in the metatarsal angle of White males, but this remains within the normal range. In comparison with White females, who seem to be predisposed to the disorder of hallux valgus, neither White nor Black males show a significant increase in hallux angles after adolescence. Males of all ages and race groups seldom develop clinical hallux valgus, and this apparent resistance to the deformity is associated with a minimal increase in the metatarsal angle, and therefore in the width of the foot.

[An anatomical study of the interphalangeal sesamoid bone of the hallux]

The existence of sesamoid bone on the interphalangeal joint of the hallux has not been sufficiently recognized. The frequency of this sesamoid bone has been described to be low probability in the orthopaedic and anatomical literature. We have, however, experienced some cases of the interphalangeal joint dislocation giving difficulty to usual manipulative reduction because of the presence of the sesamoid bone. In order to ascertain the existence of sesamoid bone on the interphalangeal joint of the hallux, anatomical and radiographic study have been performed with 144 feet of 73 adult cadavers, 32 feet of 16 fetal cadavers and 958 patients. The following results were obtained: The sesamoid bone was seen in 90.9% by radiographical examination and in 95.9% by macroscopic observation for 144 feet on 73 adult cadavers. Cartilagenous sesamoid bone was found in 93.8%, 32 feet of 16 fetal cadavers using stereoscopic microscope. In the radiographical examination of 958 feet of the patients, the sesamoid bones were approved in 56.3%, but it increased to 93.0% using 1/4 sensitivity intensifying screen. The sesamoid bone of the interphalangeal joint on adult cadavers was located at the central portion in parallel with interphalangeal joint space and buried in the fibrocartilagines plantares. This sesamoid bone had two cartilagenous joint surfaces against the base of distal phalanx and the head of proximal phalanx. The sesamoid bone had the shape of longitudinal ellipse and the length, width and thickness were measured. The size of sesamoid bone on the male cadaver were larger than that of the female on the three parameters and there were no special difference between the right and the left sides.

The prevalence of hallux valgus in three South African populations

The prevalence of hallux valgus and its relationship to the metatarsal angles have been assessed in females between the ages of 2 and 20 years in three populations: an urban White community, an urban Black community and a rural Black Community. By the age of 10 years the mean hallux angle is significantly greater in the White girls than in girls in the two Black groups. The angle between the first and second metatarsals is greater in the White than in the black children and this difference increases throughout childhood and adolescence. It is suggested that young White girls may be predisposed to the abnormality of hallux valgus by having significantly greater metatarsal angles.

The etiology of hallux valgus in Japan

Until recent years, hallux valgus did not exist in Japan. Changing customs and styles of footwear during the past ten years have led to an increasing number of patients with the classic hallux valgus deformity. These are not mild deformities, but are painful and require surgical correction. The ratio of the width to the length of the foot is similar in both sexes and was measured in children up to the age of 14. Coincidentally, at about that time students may freely wear any type of fashionable shoe. We conclude, therefore, that the hallux valgus deformities we are now seeing with greater frequency are caused, at least in part, by the change in footwear.

The sesamoids of the hallux

The seemingly innocuous tiny sesamoids play an important role in the function and pathomechanics of the hallux. The recent active participation of people of all ages in jogging and long-distance running, activities introducing repetitive stressful forces on the forefoot, induces sesamoiditis. Bones normally asymptomatic, such as the sesamoids, require renewed interest in embryology, anatomy, congenital variations, infection, osteochondritis, trauma and effective treatment.

[Locomotory trends in primates expressed by the foot ratios. The adaptation to bipedalism (author's transl)]

This paper is an attempt to complete previous works on this topic, especially Schultz, by new measurements and indices. From the calculated indices, listed at the end in a table, graphics are drawn and related to four main contents: (1) relative length of the foot to the hind limb and its segments; (2) relative length of the different foot segments to the foot length and between them; (3) relative length of the first toe, or hallux, to the foot, tarsus and longest external toe lengths; (4) position of the morphological axis of the toes: here we define the notion of axony. In conclusion, we try to answer the following questions: (1) what are the mensural distinctions of the human foot? (2) are foot ratios suitable to establish a satisfactory morphological classification of the locomotory adaptations in primates?