Coexistence of accessory band with the second type of extensor hallucis longus.

The main muscles responsible for extension of the toes are the extensor digitorum longus and extensor hallucis longus. Morphological variants of both of these muscles are mostly related to the numbers of tendons and their unusual points of insertion. The case presented shows an accessory band deriving from the extensor digitorum longus and fusing with the extensor hallucis longus, a concomitant additional tendon of the latter inserting to the proximal phalanx of the hallux. Knowledge of these anatomical patterns is important not only from the anatomical but also the clinical point of view and can be useful in lower limb surgery.

The hallucal interphalangeal ossicle: anatomy and basis for ultrasound-guided surgical shaving.

Painful lesions on the plantar aspect of the first interphalangeal joint (IPJ) of the hallux can be attributed to structures called ossicles, nodules, or sesamoids. The aims of the present study were first to verify that ultrasonography (US) is a high-sensitivity tool for diagnosing an interphalangeal ossicle (IO), and second to prove that US-guided-shaving surgery ("milling") is a safe and feasible technique for remodeling the IO. The study is divided into three parts. In the first part, the prevalence of IOs was estimated in 12 cadaver feet using US, anatomical dissection, and fluoroscopy. In the second, a detailed US and morphological description of the IO was obtained. In the third, six cadaver feet were subjected to surgical milling. IO prevalence was 41.6% in gross anatomy, 41.6% in US examination and just 16.6% in fluoroscopy. The ossicles had a mean length of 4 mm (± 2 mm) and a width of 7 mm (± 2 mm). The ossicles could be completely shaved in all specimens without injuring important anatomical structures. Our results indicate that US is a more precise tool for diagnosing an IO than X-ray. Moreover, our US-guided mini-invasive surgical technique appears feasible and safe.

Anatomical Study of the Accessory Tendon of the Extensor Hallucis Longus Muscle and Its Clinical Application.

BACKGROUD: The accessory tendon of the extensor hallucis longus (ATEHL) muscle is a common abnormal structure, and its clinical significance remains debatable. In this study, we provide the incidence of the ATEHL and characterize its morphological types in Asian cadavers and investigate its clinical applications. METHODS: The tendons from 50 adult cadaveric feet, fixed in 10% formalin, were analyzed. We measured the length and width of both the ATEHL and the extensor hallucis brevis (EHB). RESULTS: All dissected specimens had an ATEHL. The first metatarsophalangeal joint was surrounded by an accessory tendon that inserted onto the joint capsule and the dorsal base of the proximal phalanx. We classified the ATEHL into 3 types based on their directions. Differences in ATEHL type based on sex were not statistically significant. CONCLUSIONS: We found an ATEHL in all cadaveric specimens in this study. We surmise that the ATEHL acts as an antagonist with the EHB when the toe is extending, which might help prevent the occurrence of hallux valgus deformity.

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.

Biometría de los músculos extensor corto de los dedos y extensor corto del hallux en individuos brasileños: análisis anatómico para su uso como colgajo muscular en cirugías reconstructivas / Biometry of the extensor digitorum brevis and extensor hallucis brevis muscles in Brazilian individuals: anatomical analysis for use as a muscle flap in reconstructive surgeries

RESUMEN: El músculo extensor corto de los dedos (ECD) se sitúa junto con el músculo extensor corto del hallux (ECH) en la región dorsal del pie y están encargados de colaborar con la acción agonista de los músculos extensor largo de los dedos (ELD) y extensor largo del hallux (ELH), en la extensión de los cuatro dedos mediales en las articulaciones metatarsofalángicas. Esta condición complementaria permite su transferencia quirúrgica hacia otras regiones receptoras sin afectar la funcionalidad extensora de los dedos del pie motivo por el cual durante las últimas décadas se ha convertido en un tejido importante para la reconstrucción de lesiones tisulares, sin embargo, son escasos los estudios biométricos que lo describan en detalle. El objetivo de esta investigación fue establecer la longitud, ancho y área de extensión de estos músculos acompañada de la determinación de las distancias de éstos respecto a la cuña medial y la base del quinto metatarsiano para su uso quirúrgico. Sumado a lo anterior y posterior a la descripción de las variantes musculares encontradas se determinó los puntos motores de inervación de estos dos músculos. Para ello se estudiaron 36 miembros inferiores formolizados de individuos adultos brasileños pertenecientes a la Universidad Federal de Alagoas (UFAL), Maceió, Brasil. Las mediciones se realizaron con un cáliper marca Mitutoyo de 0,01 mm de precisión obteniendo una longitud, ancho y área de 6,89 ± 1,64 cm, 3,81 ± 0,42 cm y 31,98 ± 7,60 cm2 en el lado derecho de 6,91 ± 1,64 cm, 3,68 ± 0,46 cm y 30,75 ± 7,61 cm2 en el izquierdo respectivamente. En el 17 % de los casos hay presencia de tendones accesorios para el músculo ECD. La distancia desde el margen medial del músculo ECH respecto a la cuña medial y del margen lateral del músculo ECD a la base del quinto metatarsiano fue de 1,97 ± 0,43 y 1,72 ± 0,41 al lado derecho y de 2,01 ± 0,62 y 1,87 ± 0,36 al lado izquierdo respectivamente. Los puntos motores (Pm) predominaron en un 64 % en el tercio medio del músculo ECH y en un 64 % en el tercio proximal del músculo ECD. Estos resultados son un aporte significativo, tanto para quienes realizan cirugía ortopédica como para el conocimiento detallado de la anatomía dorsal del pie.

SUMMARY: The extensor digitorum brevis muscle (EDB) is located along with the extensor hallucis brevis (EHD) in the dorsal region of the foot and are responsible for collaborating with the agonist action of the extensor digitorum longus muscles (EDL) and extensor hallucis longus (EHL) in the extension of the four medial fingers in the metatarsophalangeal joints. This complementary condition allows its surgical transfer to other receptor regions without affecting the extensor functionality of the toes, which is why during the last decades it has become an important tissue for the reconstruction of tissue injuries, however, there are few studies biometrics that describe it in detail. The objective of this investigation was to establish the length, width and area of extension of these muscles accompanied by the determination of their distances from the medial wedge and the base of the fifth metatarsal for surgical use. In addition to the above and after the description of the muscle variants found, the innervation motor points of these two muscles were determined. To do this, 36 formalized lower limbs of Brazilian adult individuals belonging to the Federal University of Alagoas (UFAL), Maceió, Brazil, were studied. Measurements were made with a 0.01 mm precision Mitutoyo caliper obtaining a length, width and area of 6.89 ± 1.64 cm, 3.81 ± 0.42 cm and 31.98 ± 7.60 cm2 on the right side of 6.91 ± 1.64 cm, 3.68 ± 0.46 cm and 30.75 ± 7.61 cm2 on the left, respectively. In 17 % of cases there is presence of accessory tendons for the EDB muscle. The distance from the medial margin of the EHB muscle with respect to the medial wedge and the lateral margin of the EDB muscle to the base of the fifth metatarsal was 1.97 ± 0.43 and 1.72 ± 0.41 on the right side and 2,01 ± 0.62 and 1.87 ± 0.36 on the left side respectively. Motor points (Pm) predominated in 64 % in the middle third of the EHB muscle and in 64 % in the proximal third of the EDB muscle. These results are a significant contribution both for those who perform orthopedic surgery and for detailed knowledge of the dorsal foot anatomy.

Properties and Function of the Flexor Hallucis Capsularis Interphalangeus Tendon.

INTRODUCTION: The fibrocartilagenous plantar plates of the forefoot are biomechanically important, forming the primary distal attachment for the plantar aponeurosis. They are integral to the function of the windlass mechanism in supporting the arches of the foot in gait. Dissection of the cadaveric hallux revealed an organised sagittal thickening of the dorsal side of the flexor hallucis longus (FHL) sheath, which attached the interphalangeal plantar plate to the metatarsophalangeal (MTP) plantar plate. A description of a similar structure was made in 1984 when it was termed the flexor hallucis capsularis interphalangeus (FHCI) - however, it has not been researched since, and we aim to study it further and identify its characteristics. METHOD: Eight specimens were dissected from four cadavers. Two were stained and examined under magnification in both polarized and non polarized light. The remaining 6 were subjected to micrometer testing of their tensile properties. RESULTS: Both the histological features and mechanical properties were consistent with tendon; with cross sectional area, ultimate tensile strength and stiffness varying between specimens. CONCLUSIONS: Based on its location and properties, the FHCI tendon may be involved in limiting dorsiflexion of the first MTP joint and could have clinical relevance in pathological processes around both the first and second MTP joints. Clin. Anat., 33:689-695, 2020. © 2019 Wiley Periodicals, Inc.

Measuring Visualized Joint Surface in Hallux Metatarsophalangeal Arthroscopy.

BACKGROUND: Arthroscopy has been increasingly used to evaluate small joints in the foot and ankle. In the hallux metatarsophalangeal (MTP) joint, little data exist evaluating the efficacy of arthroscopy to visualize the articular surface. The goal of this cadaveric study was to determine how much articular surface of the MTP joint could be visualized during joint arthroscopy. METHODS: Ten fresh cadaveric foot specimens were evaluated using standard arthroscopy techniques. The edges of the visualized joint surface were marked with curettes and Kirschner wires; the joints were then surgically exposed and imaged. The visualized surface area was measured using ImageJ® software. RESULTS: On the distal 2-dimensional projection of the joint surface, an average 57.5% (range, 49.6%-65.3%) of the metatarsal head and 100% (range, 100%-100%) of the proximal phalanx base were visualized. From a lateral view of the metatarsal head, an average 72 degrees (range, 65-80 degrees) was visualized out of an average total articular arc of 199 degrees (range, 192-206 degrees), for an average 36.5% (range, 32.2%-40.8%) of the articular arc. CONCLUSION: Complete visualization of the proximal phalanx base was obtained. Incomplete metatarsal head visualization was obtained, but this is limited by technique limitations that may not reflect clinical practice. CLINICAL RELEVANCE: This information helps to validate the utility of arthrosocpy at the hallux metatarsophalangeal joint.

Increasing the safety of minimally invasive hallux surgery-An anatomical study introducing the clock method.

BACKGROUND: The purpose of this study is to describe a simple and reproducible method to localize the neurological structures at risk and to describe a safe zone for hallux minimally invasive surgery (MIS) procedures. METHODS: Ten fresh-frozen cadaveric feet were dissected to identify the dorsomedial digital nerve (DMDN) and the dorsolateral digital nerve (DLDN) of the first toe. Axial sections were performed at the sites of metatarsal osteotomies. We documented the position of the nerves with respect to the extensor hallucis longus (EHL) tendon using a clock method superimposed on the axial section RESULTS: The DMDN was found at an average of 26.2° medial to the medial border of the EHL tendon. (SD 11.26, range 14.5-45.5), whereas the average distance of the DLDN was 32.3° lateral to the medial border of the EHL tendon. (SD 6.29, range 13.5-40). CONCLUSIONS: Using the clock method the DMDN and DLDN were found consistently between 10 o'clock and 2 o'clock in either right and left feet. The clock method may facilitate avoiding the area where these nerves are located serving as a valuable tool in minimally invasive foot surgery.

Minimally invasive Akin osteotomy and lateral release: Anatomical structures at risk-A cadaveric study.

BACKGROUND: Among the many surgical techniques used for hallux valgus correction, different osteotomies may be performed in the proximal phalanx as well as lateral release as associated procedures. The aim of this study is to analyze the anatomical relationships and the risks for the soft tissue lessions when performing the dorsomedial minimally invasive surgery (MIS) portal for the Akin osteotomy, and the MIS dorsolateral portal for lateral release, in order to define a safety zone when conducting the procedure in order to avoid complications. MATERIALS AND METHODS: The procedures were carried out on 16 fresh-frozen cadaveric feet. A MIS dorsomedial and dorsolateral portals were performed. The anatomical dissection of the cadaveric pieces was carried out and the different anatomic and surgical relationships were analyzed and measured. RESULTS: No nerve injury was found. Injury of the extensor hallucis longus (EHL) paratendon were seen in 9 cases (56%). There was no injury of the flexor hallucis longus (FHL) tendon and or collateral plantar nerves. A partial injury of the FHL sheath was observed in 44% of the samples. CONCLUSIONS: Although percutaneous Akin osteotomy is clinically effective, the possibility of injury of anatomic structures is high (9-55%), however injuries upon vascular or nerve structures were not seen.

Normative data for the American Orthopedic Foot and Ankle Society ankle-hindfoot, midfoot, hallux and lesser toes clinical rating system.

PURPOSE: Despite some theoretical reservations, the AOFAS clinical rating system with its scales for ankle-hindfoot, midfoot, hallux and lesser toes is one of the most widely used assessment tools in foot and ankle surgery. This study was designed to generate age- and gender-related norm values for all four subscales. METHODS: Despite not being used in a self-administered manner, the AOFAS score underwent cross cultural adaptation to guarantee unrestricted comparability of data. A data pool was generated using the results of personal interviews and clinical examination of 625 individuals, including staff and visitors to our hospital, and excluding people scheduled for foot surgery or in after-treatment. These data served as a basis to calculate all four parts of the AOFAS clinical rating system. RESULTS: Mean value for the ankle-hindfoot scale was calculated as 91.6 points (±0.9 confidence interval), and 89.3 points for the midfoot scale (±1.0 CI), 88.3 for the hallux metatarsophalangeal-interphalangeal scale (± 0.9 CI) and 91.0 for the lesser metatarsophalangeal-interphalangeal scale (± 0.8 CI). Results showed a decrease with age in all four scales. Males showed better results than females. Individuals with previous surgery showed lower results in the respective score. CONCLUSIONS: While lowered scoring results prior to surgery reflect the degree of restrictions due to pain, function and alignment problems, post-operative increases in clinical scoring should indicate return to age-related norm values. Our data calculated these norm values for the first time for all four AOFAS scales, giving a basis for better interpretation of published results in foot and ankle surgery. Our data showed and quantified the decrease of norm values with age, especially for hallux and lesser toes scores, as well as lower norm values for females and for individuals that had had surgery of the foot. LEVEL OF EVIDENCE: Level I, diagnostic study.

Hallux metatarsophalangeal arthroscopy: indications and techniques.

With mounting attention focused on decreasing postsurgical pain and dysfunction, emphasis has been placed on approaching disorders using minimally invasive techniques. Surgical procedures of the hallux, such as hallux valgus correction, have earned the reputation for high postsurgical pain and prolonged recovery. Arthroscopic hallux procedures have the advantages of minimizing pain, swelling, and disability. Certain conditions, such as synovitis, loose bodies, and early-grade hallux rigidus, are better addressed arthroscopically. With the correct indications, hallux metatarsophalangeal arthroscopy can be a valuable tool for the foot and ankle surgeon.

Lateral release in hallux valgus deformity: from anatomic study to surgical tip.

The important part of hallux valgus deformity operations, especially in the case of an incongruent joint, is the release of the soft tissue on the lateral side of the first metatarsophalangeal joint. The purpose of the present anatomic study was, with preparation of the lateral structures of the joint and lateral conjoined tendon, to provide a background for a surgical tip of the release of the joint for an additional metatarsal osteotomy. For the present study, we used 30 specimens (15 left and 15 right) from 19 cadavers at the Institute of Anatomy, First Faculty of Medicine, Charles Faculty (Prague, Czech Republic). Only specimens that met the criteria of hallux valgus were included in the present study. The technique was based on the incision of the lateral sesamoid ligament and partial tenotomy of the lateral conjoined tendon from the first interdigital web space. The release was done gradually with supination and abduction of the big toe to achieve the smallest size of the tenotomy. The median of the tenotomy size of the conjoined tendon was 6.5 (range 5 to 14) mm. The median size of the conjoined tendon in the frontal plane just ventral to the sesamoid bone was 10.6 (range 8 to 14) mm. The technique of the release, in which the big toe was abducted and supinated, can minimize the size of the lateral conjoined tendon release and can minimize the possibility of a postoperative deformity.

El cambio de forma del músculo aductor hallux y el hallux valgus / The adductor hallucis muscle shapeless and the hallux valgus

El desempeño de los pies influye en la postura, marcha y en el uso de calzados. Deformidades pueden surgir debido a alteraciones estructurales provocadas por el desequilibrio muscular como parece suceder en el hallux valgus (HV). El músculo aductor del hallux (MAH) es considerado importante en la presencia de ese desequilibrio. Analisamos la acción del MAH, en la dinámica del hallux y del antepie sano, así como en la génesis del HV. Se disecaron 28 pies aislados (3 com HV), fijados en formol, del Laboratorio de Anatomía de la Facultad de Medicina de Petrópolis/FASE/RJ para obtener los datos morfométricos del MAH: largo de las cabezas (L-CT; L-CO); ancho de las cabezas (A-CT; A-CO) y ángulo entre las cabezas (q). Los valores medios (mm), obtenidos en los pies sin deformidades: L-CT= 27,04; L-CO= 51,45; A-CT=13,23; A-CO=17,58; q (CT/CO)=31°; y en los con HV: L-CT=23,80; A-CT=12,03; L-CO=48,25; A-CO=16,89; q (CT/CO)=52. La morfología del MAH osciló entre pies sin y con HV. El MAH al fijarse en las articulaciones metatarsofalángicas (CT) y en el hueso sesamoideo lateral del hallux (CT+CO) puede ser causa o consecuencia de la variación del q (CT/CO), llevando al valgismo del hallux. La amputación del hallux podrá aplanar el arco transverso anterior debido a la tensión muscular, dificultando las funciones del pie en el apoyo y en la marcha.

The performance of the feet interferes on the posture, walk and on the wear of shoes. Deformities may appear due to structural changes motivated by the muscular imbalance as it seems to happen on hallux valgus (HV). The adductor hallucis muscle is considered important at this imbalance. Analyze the role of the AHM on the dynamics of the hallux and the forefoot as well as in the genesis of the HV. Dissection of 28 isolated feet (3 with HV), preserved in formaldehyde acquired from the Anatomy Laboratory of Petrópolis School of Medicine to obtain the morphometry of the HAM: length of the oblique and transverse heads (L-TH; L-OH); width of the heads (W-TH; W-OH) and angle between the heads (q). Medium values (mm), obtained from the feet without the deformity L-TH= 27.04; W-TH=13.23; L-OH= 51,45; W-OH=17.58 ; q (TH/OH) =31, and the ones with HV: L-TH=23.80; W-TH=12.03; L-OH=48.25;W-OH=16.89; q (CT/CO)=52. The morphology of the AHM varies between the healthy and the feet with the HV. The AHM fixing on the metatarsal phalangeal joints and on the lateral sesamoid of the great toe may be the cause or the consequence of the q (CT/CO) variance that leads to the HV. The amputation of the great toe may flatten the anterior transverse arch, by muscular tension, hindering the functions of the foot such as support and walk.

Analysis of the proximal phalanx size as a guide for an Akin closing wedge osteotomy.

BACKGROUND: The Akin closing wedge osteotomy for correction of hallux valgus interphalangeus has experienced a resurgence in popularity. Commonly, the size of the osteotomy is visually judged intraoperatively. We present a means of performing the osteotomy more objectively. MATERIALS AND METHODS: Radiographs of 101 feet were studied to derive mean values for dimensions of the hallux proximal phalanx in the general population. Based on these we calculated the size of osteotomy required for given corrections. RESULTS: The mean hallux width 5 mm distal to the apex of the articular surface differed between males and females. In males the mean width was 18 mm (95% CI 17.5 to 18.8) and in females 15 mm (95% CI 14.5 to 15.5). For a 10 degree correction, an osteotomy with a 3 mm base would be required. CONCLUSION: Although the Akin osteotomy dimensions are commonly estimated, a more objective method of planning the osteotomy is presented. The method can also be applied to any closing wedge osteotomy. CLINICAL RELEVANCE: We believe this method of the Akin osteotomy can improve the accuracy of the surgery.

[Anatomical study of flexor hallucis brevis insertion: Implications for clinical practice]. / Anatomická studie úponové cásti m. flexor hallucis brevis pro klinickou praxi.

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.

Arthroscopic debridement for first metatarsophalangeal joint arthrodesis with a 2- versus 3-portal technique: a cadaveric study.

PURPOSE: To evaluate the safety and efficacy of arthroscopic debridement for arthrodesis of the first metatarsophalangeal (MTP) joint using a 2-portal technique versus a 3-portal technique. METHODS: Twelve cadavers, with a mean age of 60 years, were subjected to arthroscopic debridement of the first MTP joint. Dorsolateral and dorsomedial portals were used in 6 specimens, whereas a medial portal was added in the other 6 specimens. The articular cartilage was debrided on both the proximal and distal surfaces and stabilized with a K-wire. The surrounding neurovascular structures were evaluated for injuries and measured for the distance from the portals. The fusion contact areas were estimated and denuded surfaces were measured on both sides. Results between the 2- and 3-portal techniques were compared. Statistical significance was taken as P < .05. RESULTS: The mean estimated fusion contact area was 180.19 mm(2) on the proximal phalanx and 180.21 mm(2) on the distal metatarsal articular surfaces. On the proximal phalanx, the percentage of denuded area was 94.71% with the 2-portal technique and 97.60% with the 3-portal technique. On the distal metatarsal, the percentage of denuded area was 93.31% with the 2-portal technique and 95.22% with the 3-portal technique. The 3-portal technique statistically increased the area of debridement on the plantar-medial surface of the distal metatarsal. The mean distance from the dorsolateral portal to the dorsolateral hallucal nerve was 3.4 mm. The mean distance from the dorsomedial portal to the dorsomedial hallucal nerve was 4 mm. The medial portal was, on average, 10.5 mm from the dorsomedial hallucal nerve and 13 mm from the plantar-medial hallucal nerve. There was no visible nerve injury detected. CONCLUSIONS: The 3-portal technique for arthroscopic-assisted arthrodesis of the first MTP joint allowed more complete cartilage debridement when compared with the 2-portal technique. The additional medial portal was found to be safe from the surrounding neurovascular structures. CLINICAL RELEVANCE: Joint preparation for arthroscopic assisted arthrodesis of the first MTP joint can be safely and effectively performed using 3-portal technique, which may reduce the risk of non-union.

Cadaveric study of zone 2 flexor hallucis longus tendon sheath.

PURPOSE: The purpose of this study was to investigate the anatomy of the zone 2 flexor hallucis longus (FHL) tendon sheath. METHODS: Dissection of the zone 2 FHL tendon sheath was performed in 12 feet of 6 cadavers. The tendon sheath was subdivided into proximal fibrous (zone 2A) and distal fascial (zone 2B) parts. The lengths of the zone 2A and 2B FHL tendon were measured and represented the length of the corresponding tendon sheaths, and the relation of the medial plantar nerve to each part of the zone 2 FHL tendon sheath was studied. RESULTS: In all specimens there were fibrous and fascial components of the zone 2 FHL tendon sheath. The medial plantar nerve crossed the zone 2B tendon sheaths and then became plantar lateral to the sheath in 7 specimens. The distance between the medial plantar nerve and the orifice of the zone 2A tendon sheath averaged 7.6 mm. The distance between the medial plantar nerve and the junction between zones 2A and 2B averaged 3.2 mm. The distance between the medial plantar nerve and the distal end of the zone 2B tendon sheath averaged 4.2 mm. The mean length of the zone 2A tendon sheath was 35.9 mm, and the mean length of the zone 2B tendon sheath was 30.5 mm. CONCLUSIONS: The zone 2 FHL tendon sheath can be subdivided into a proximal fibrous zone (2A) and a distal fascial zone (2B). Because of the close proximity of the medial plantar nerve to the tendon sheath, there is a significant risk of iatrogenic nerve injury when surgical procedures are performed in zone 2B. CLINICAL RELEVANCE: An understanding of the anatomy of the zone 2 FHL tendon sheath is useful for the safe practice of zone 2 FHL tendoscopy.

Turf toe: soft tissue and osteocartilaginous injury to the first metatarsophalangeal joint.

The use of artificial turf in the United States has created a dramatic increase in first metatarsophalangeal joint dorsiflexion injuries. Turf toe has been reported to occur in athletes who participate in sporting activities. An injury to the plantar capsular ligamentous complex can result in acute and chronic pain, resulting in time lost from sports participation for a short- or long-term period. Classification of this injury is based on clinical findings and imaging studies, including plain radiographs and magnetic resonance imaging. The early recognition of this injury is crucial to successful treatment. Nonoperative treatment may often suffice for incomplete injuries; however, surgery may be warranted for a complete plantar plate disruption or injury to one or both sesamoids. In the high-performance or elite athlete, a turf toe or severe dorsiflexion injury can be disabling, and can threaten an athlete's career if not treated properly.

Arterial anatomy of the hallucal sesamoids.

The aim of this study was to analyze the arterial supply of the sesamoid bones of the hallux. Twenty-two feet from adult cadavers were injected with epoxide resin or an acrylic polymer in methyl methacrylate (Acrifix) and subsequently processed by two slice plastination methods and the enzyme maceration technique. Afterwards, the arterial supply of the sesamoid bones was studied. The first plantar metatarsal artery provided a medial branch to the medial sesamoid bone. The main branch of the first plantar metatarsal artery continued its course distally along the lateral side of the lateral sesamoid and supplied it. The supplying arteries penetrated the sesamoid bones on the proximal, plantar, and distal sides. The analysis and cataloging of the microvascular anatomy of the sesamoids revealed the first plantar metatarsal artery as the main arterial source to the medial and lateral sesamoid bones. In addition, the first plantar metatarsal artery ran along the lateral plantar side of the lateral sesamoid bone, suggesting that this artery is at increased risk during soft-tissue procedures such as hallux valgus surgery.

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.