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

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

Morphological differences between the dorsal and palmar septa of the first extensor compartment in relation to the brachioradialis and pronator quadratus.

BACKGROUND: The first extensor compartment of the wrist is known as a frequent site of stenosing tenosynovitis, referred to as de Quervain's disease. De Quervain's disease occurs more frequently in the dorsal part of the first extensor compartment than in the palmar part; however, the anatomical reason why the dorsal part is worse remains poorly elucidated. This study clarified the morphological differences between the dorsal and palmar parts by examining their relationship with the surrounding structures. METHODS: In this study, a total of 35 wrists from 23 Japanese cadavers were used. Twenty-five wrists were randomly assigned for macroscopic analysis, and the remaining 10 wrists were used for histological analysis. RESULTS: The palmar septum of the first extensor compartment was connected to the brachioradialis tendon and superficial head of the pronator quadratus and was histologically stout compared to the dorsal septum. Despite several anatomical variations, such as the septum between the abductor pollicis longus/extensor pollicis brevis and the multiple tendons of these muscles, the aforementioned characteristics of the fibrous sheath in the first extensor compartment were identical in all specimens. CONCLUSION: In contrast to the fragile structure of the dorsal septum, the stout structure of the palmar septum could be related to the low occurrence of symptoms of de Quervain's disease. The present results could play a role in revealing the pathogeny and establish the precise treatment for de Quervain's disease and provide an anatomical basis for kinesiological/biomechanical studies.

Editorial Commentary: When Managing Patellofemoral Instability, Mind Your P's and Q's: Medial Patellofemoral Ligament Versus Medial Quadriceps Tendon Femoral Ligament Versus Medial Patellofemoral Complex.

Our understanding of patellar instability and the medial patellofemoral complex (MPFC) has evolved over the past 15 years. Despite advancements and appreciation of the anatomy and biomechanics of the MPFC, the best surgical treatment for recurrent patellar instability has yet to be determined. The goals of medial patellofemoral ligament (MPFL), medial quadriceps tendon femoral ligament (MQTFL), or MPFC reconstructions (with grafts from both the patella and quad to the femur) are to return patients back to activity and avoid complications such as recurrent instability, overconstraint, secondary arthrosis, and potential patellar fracture from surgical drill holes. Other considerations when managing recurrent instability include patella alta, hypermobility, and whether an osteotomy procedure is indicated. Although we always need to make good choices and mind our P's and Q's, the big question remains: Is MPFL, MQTFL, or MPFC the best choice for our patients?

The tendon of the fibularis brevis muscle - Systematic overview and new classification system.

The fibularis brevis muscle belongs to the lateral compartment of the leg. It originates from the lower two-thirds of the lateral surface of the fibula bone and it also is attached to the anterior intermuscular septum. Its insertion is normally located on the tuberosity at the base of the fifth metatarsal bone, on its lateral side. However, distal attachment of this muscle is morphologically variable. Different variations have been identified and some classification systems have been created for both adults and foetuses. Based on various literature references, we have created a new classification system and compared the frequency of each type. The main aim of this review is to present morphological variations of the fibularis brevis tendon with their clinical significance, especially in autografting in case of surgical treatment of fibularis brevis tendon rupture. The clinical aspect of this pathology and some medical cases will also be presented.

Human navicular bone: a morphometric and morphological evaluation.

BACKGROUND: The composition of navicular joint complex is crucial to perform surgical interventions for multiple pathological foot aetiologies. The data on human navicular bone and its facets from Indian population remain scarce in literature. AIMS AND OBJECTIVES: To evaluate the morphometry and morphology of navicular bone. METHODOLOGY: A total of 77 (right: 40; left: 37) dried human navicular bones were used. The collected data were entered and analysed in SPSS software. RESULTS: The anteroposterior diameter of navicular bone on right side was 15.19 mm (13.92, 16.77) and on left side was 15.87 mm (13.83, 17.27). The transverse diameter on right and left sides were 34.21 mm (31.74, 36.6) and 33.59 mm (30.23, 35.43), respectively. The vertical diameter measured on the right was 22.31 mm (21.19, 23.94) and on left 22.53 mm (20.8, 24.24). Morphometric evaluation showed no significant difference between right and left navicular bones. The commonest shape for posterior facet was quadrilateral, on the right (62.5%) and left (40.5%). The most common shape of anterior facet for medial cuneiform is quadrilateral, on the right (85%) and left (89.1%). For intermediate cuneiform, triangular facet was common on the right side (72.5%) and on the left (59.5%). The lateral cuneiform facet was bean shaped on right side (72.5%) and quadrilateral on the left side (32.5%). There was a significant difference in shape distribution between right and left (P < 0.05). The median length of the groove for tibialis posterior tendon was 18.01 mm and 16.19 mm on right and left side, respectively. Cuboid facet was observed in 28 (70%) and 26 (65.9%) navicular bones on right and left sides, respectively. CONCLUSION: There is no significant difference between right and left bones with regards to morphometric parameters. Morphological evaluation revealed significant difference in the distribution of shape between right and left bones.

The anatomy of the extensor tendon insertion in the arthritic distal interphalangeal joint: a cadaveric study.

Dissection of arthritic cadaveric digits revealed an expanded extensor tendon footprint involving the dorsal osteophyte on the terminal phalanx. Osteophyte attachments can be safely released up to the width of a number 15 scalpel blade without risking the integrity of the extensor tendon.

The accessory heads of the quadriceps femoris muscle may affect the layering of the quadriceps tendon and potential graft harvest lengths.

PURPOSE: The aim of the study was to assess the quadriceps femoris system for the presence of additional layers. METHODS: One hundred and twenty-eight lower limbs fixed in 10% formalin were examined. RESULTS: Five types of quadriceps tendon layering were found based on the accessory heads of the quadriceps muscle. Type I (55%)-represented by four heads and four layers, and it was something new because standard orthopaedic textbooks described quadriceps tendon as a structure composed of only three layers. Type II (27.4%)-the first four layers were the same as in Type 1, but the accessory tendon of the fifth head of the quadriceps femoris muscle had the deepest attachments. Type III (10.9%)-this type included 6 heads of quadriceps femoris. It consisted of five layers. Type IV (3.1%)-this type included 7 quadriceps femoris heads. This type consisted of only four layers. Type V (3.1%)-this type included 8 heads of the quadriceps femoris heads. This type consist of 5 layers. CONCLUSION: The findings of this study provide a detailed anatomy of the quadriceps tendon including the accessory tendons of the accessory heads of the quadriceps tendon. The accessory heads of the quadriceps femoris muscle contribute to the layering of the quadriceps tendon. The second conclusion of this study is the development of safe distances depending on the types. Not all types are perfect for harvesting-Type IV seems to be the safest type, in turn Type V the most dangerous.

Peroneus tertius revisited: The morphological variability of the bifurcated peroneus tertius insertion - An anatomical study.

BACKGROUND: The peroneus tertius muscle (PT) is one of the extensor muscles of the lower leg, often described as a variable separation from the extensor digitorum longus muscle (EDL). According to literature it has six different types of insertion, one of them (Olewnik Type IV) having two tendons inserting to the fifth metatarsal bone (FMTB). Morphometric data about this type of insertion is sparse, especially the relation between the two tendons, albeit the PT is suspected to contribute to stress fractures of the FMTB. Therefore, we examined this type of insertion to give detailed information on the tendons, the insertion points and the respective relations. METHODS: We examined 27 lower extremities of embalmed human bodies (12 paired, 15 single sided; 12 right and 15 left) with a distinguishable PT with two tendons inserting to the FMTB (Olewnik IV). The specimens were obtained of an undergrad dissection program, which in turn obtained them from a body donation program. After dissection of the PT and photo documentation in situ, resection and measurement of morphological properties of the tendons were performed with the PT attached to the fifth metatarsal bone. RESULTS: Results of the respective measurements yielded a wide range of variation, especially in the insertion point of the anterior tendon on the fifth metatarsal and the relation between the two tendons, but with no significant difference between sides or sex, except for the length of the posterior tendon between sex. The distance between the base of the FMTB and posterior tendon varies from 0 to 9 mm, with one outlier at 24 mm (mean = 3.9 ± 4.8 mm), the distance between the insertions from 0 to 15 mm (mean = 4.7 ± 4.7 mm), resulting in how far of the FMTB the anterior tendon reaches varying from 17 to 60 mm (mean = 39.6 ± 11.5 mm) or 22-98% (mean = 64 ± 19%). CONCLUSION: Our findings give a detailed overview of the morphological features the PTT can have, when attached with two tendons to the FMTB. Especially the varying relationship between those two insertions and varying point of the anterior insertion are of interest, as they might support its complex role in the occurrence of fractures of the fifth metatarsal by providing different amounts of torsional stress and its tendons can be used as tendon-grafts.

A review on the use of porcine in tendon research.

PURPOSE OF REVIEW: Large animals have been increasingly employed in tendon research; the objective of this review was to summarize the employment of porcine in tendon research. RECENT FINDINGS: Literature before 2022-03-31 was searched using the following strategy: (pig[MeSH Terms]) AND (tendon[MeSH Terms]); (pig[MeSH Terms]) AND (tendon[title]); (tendon[MeSH Terms]) AND (porcine[title]); (tendon[title]) AND (porcine[title]); (tendon[MeSH Terms]) AND (pig[title]); (tendon[title]) AND (pig[title]); (tendon[MeSH Terms]) AND (swine[title]); (tendon[title]) AND (swine[title]). 296 studies were included in this review. There were wide application areas of porcine tendon, including tissue engineering tendons, training of surgical skills. Porcine tendon was used both in in vitro studies, such as anatomy, biomechanics, cytology, and material science as well as in in vivo studies. The research techniques of porcine tendon are relatively common. SUMMARY: In conclusion, pigs have been widely used as a good animal model of tendon research. However, the limitations of porcine tendon research (the lack of anatomical research and in vivo studies) should be given more attention in future studies.

Morphological Classification of the Sagittal Tendon Plate in the Soleus Muscle in Japanese Cadavers / Clasificación Morfológica de la Lámina Tendinosa Sagital del Músculo Sóleo en Cadáveres Japoneses

SUMMARY: The human soleus muscle has attracted attention in the fields of sport science, rehabilitation medicine, etc. for improving exercise performance in training, preventing injuries, and rehabilitation. The sagittal tendon plate of the soleus muscle is particularly important in rehabilitation. Few studies, however, have evaluated the shape of the sagittal tendon plate in the human soleus muscle in detail and attempted to classify its variations based on its morphology. In this study, we conducted a detailed analysis of the morphology of the sagittal tendon plates in soleus muscle specimens from Japanese cadavers and constructed a morphology-based classification system and evaluated their frequencies of occurrence. First, the specimens were divided into those with a sagittal tendon plate that was visible on the anterior surface (pennate muscle group) and those without (non-pennate muscle group). Next, based on the "number" and "breadth" of the sagittal tendon plates, the pennate muscle group specimens were further classified into four classes: Class I (one tendon, thin), Class II (one tendon, slightly broad), Class III (one tendon, very broad), and Class IV (two tendons, thin). Subsequently, the specimens were further divided into three types based on the position where the sagittal tendon plate joined the Achilles tendon: median tendon type, lateral tendon type, and medial tendon type (a total 13 divisions). When 458 Japanese soleus muscle specimens were classified into these divisions, the occurrence frequencies of Class I-IV were 80.57 %, 4.59 %, 5.46 %, and 1.09 %, respectively. In Class I, the median tendon type was more frequent than the lateral and medial tendon types, accounting for 48.47 % overall. The classification types of the sagittal tendon plate and their respective occurrence frequencies shown in this study are expected to serve as fundamental data in implementing rehabilitation of soleus muscle.

El músculo sóleo humano ha atraído la atención de la ciencia del deporte, la medicina de rehabilitación, etc. para mejorar el rendimiento del ejercicio en el entrenamiento, prevenir las lesiones y rehabilitación. La lámina tendinosa sagital del músculo sóleo es particularmente importante en la rehabilitación. Sin embargo, pocos estudios han evaluado en detalle la forma de la placa lámina sagital en el músculo sóleo humano y han intentado clasificar sus variaciones en función de su morfología. Realizamos un análisis detallado de la morfología de las láminas de los tendones sagitales en muestras de músculo sóleo de cadáveres japoneses y construimos un sistema de clasificación basado en la morfología y, además, evaluamos su frecuencia de aparición. Los especímenes se dividieron en aquellos con una lámina de tendón sagital que era visible en la superficie anterior (grupo muscular pennado) y aquellos sin (grupo muscular no pennado). A continuación, según el "número" y el "ancho" de las láminas de los tendones sagitales, las muestras del grupo de músculos pennados se clasificaron en cuatro clases: Clase I (un tendón, delgado), Clase II (un tendón, ligeramente ancho), Clase III (un tendón, muy ancho) y Clase IV (dos tendones delgados). Posteriormente, las muestras se dividieron en tres tipos, según la posición donde la lámina del tendón sagital se unía al tendón calcáneo: tipo de tendón mediano, tipo de tendón lateral y tipo de tendón medial (un total de 13 divisiones). En estas divisiones se clasificaron 458 especímenes de músculo sóleo de indiviuos japoneses, las frecuencias de ocurrencia de Clase I-IV fueron 80,57 %, 4,59 %, 5,46 % y 1,09 %, respectivamente. En la Clase I, el tipo de tendón mediano era más frecuente que los tipos de tendón lateral y medial, representando el 48,47 % del total. Se espera que los tipos de clasificación de la lámina del tendón sagital y sus respectivas frecuencias de aparición, que se reportan en este estudio, sirvan como datos fundamentales para implementar la rehabilitación del músculo sóleo.

Cadaveric Analysis of Key Anatomic Structures of Athletic Pubalgia.

PURPOSE: This study proposes to establish in-depth inspection of the anatomic structures involved with the pathology of athletic pubalgia in a cadaver model. METHODS: Eight male fresh frozen cadavers were dissected in a layered fashion. The rectus abdominis (RA) and adductor longus (AL) tendon insertions were isolated to quantify the size of the anatomic footprint and distance from the surrounding anatomy. RESULTS: The RA insertional footprint was 1.65 cm (SD, 0.18) in width by 1.02 cm (SD, 0.26) in length, and the AL insertional footprint on the underside of the pubis was 1.95 cm (SD, 0.28) in length by 1.23 cm (SD, 0.33) in width. The ilioinguinal nerve was 2.49 cm (SD, 0.36) lateral to the center of the RA footprint and 2.01 cm (SD, 0.37) lateral to the center of the AL footprint. The spermatic cord and the genitofemoral nerve were just lateral to the ilioinguinal nerve and were 2.76 cm (SD, 0.44) and 2.66 cm (SD, 0.46) from the rectus and AL footprints, respectively. CONCLUSION: Surgeons should be cognizant of these anatomic relations during both initial dissection and tendon repair to optimize repair and avoid iatrogenic injury to critical structures in the anterior pelvis.

Internal Structural Connections in the Popliteus Tendon Complex with Posterior Cruciate Ligament and Clinical Implications / Conexiones Estructurales Internas en el Complejo Tendón Poplíteo con Ligamento Cruzado Posterior e Implicaciones Clínicas

SUMMARY: At present, the anatomical relationship the mid-portion of popliteus tendon complex (PTC) and the surrounding tissues is still unclear, especially its relationship to the posterior cruciate ligament (PCL). It affected the anatomical reconstruction of the posterolateral complex (PLC) injury. A total of 30 cases of the adult human knee joint fixed with formalin were used. Sagittal sections were made in 14 knee joints by the P45 plastination technique and dissection of 16 cases of knee joints. The P45 section revealed that the popliteus muscle fascia ran superiorly over the posterior edge of the tibial intercondylar eminence, and turned forward to be integrated into the PCL. Laterally, near the posterior edge of the lateral tibial plateau, the popliteus tendon penetrates through the articular capsule (AC), where two dense fibrous bundles were given off upwards by the popliteus tendon: one was the ventral fiber bundle, which ran superiorly over the posterior edge of the tibial plateau and then moved forwards to connect with the lateral meniscus; the dorsal fibers bundle ascended directly and participated in the AC. Meanwhile, the popliteus muscle dissection showed that at the posterior edge of the platform of the lateral condyle of the tibia, at the tendon-muscle transition, the PTC and AC were anchored to PCL.

En la actualidad, la relación anatómica entre la porción media del complejo tendinoso poplíteo (CTP) y los tejidos circundantes aún no está clara, especialmente su relación con el ligamento cruzado posterior (LCP). Esto afecta la reconstrucción anatómica de la lesión del complejo posterolateral (LCP). Se utilizaron un total de 30 casos de articulaciones de rodillas humanas de individuos adultos fijadas con formalina. Se realizaron cortes sagitales en 14 articulaciones de rodilla mediante la técnica de plastinación P45 y disección de 16 casos de articulaciones de rodilla. La sección P45 reveló que la fascia del músculo poplíteo discurría superiormente sobre el margen posterior de la eminencia intercondílea tibial y giraba hacia delante para integrarse en el LCP. Lateralmente, cerca del margen posterior de la platillo tibial lateral, el tendón poplíteo penetra a través de la cápsula articular (CA), donde el tendón poplíteo desprendió hacia arriba dos haces fibrosos densos: uno era el haz de fibras ventral, que corría superiormente sobre el margen posterior de la meseta tibial y luego se movió hacia adelante para conectar con el menisco lateral; el haz de fibras dorsales ascendía directamente y participaba en la CA. Por su parte, la disección del músculo poplíteo mostró que en el margen posterior del platillo del cóndilo lateral de la tibia, en la transición tendón-músculo, el CTP y el AC estaban anclados al LCP.

An overview of the osseous palmar sesamoid in Anura, with the particular case of some Rhinella species.

Background: Sesamoids are generally regarded as structures that are not part of the tetrapod body plan. The presence of a palmar sesamoid is assumed to serve as a distribution point for the forces of the flexor digitorum communis muscle to the flexor tendons of the digits, which are embedded in the flexor plate. It has been considered that the palmar sesamoid is present in most anuran groups, and it has been suggested that it acts by inhibiting the closing of the palm, preventing grasping. Typical arboreal anuran groups lack a palmar sesamoid and flexor plate, a pattern shared with other tetrapod groups, which can retain a reduced sesamoid and flexor plate. We focus on the anatomical structure of the Rhinella group, which includes species that present an osseous palmar sesamoid and climb bushes or trees to avoid depredation or escape dangerous situations, and can exhibit scansorial and arboreal behaviors. We also add data on the bony sesamoids of 170 anuran species to study the anatomy and evolution of the osseous palmar sesamoid within this amphibian group. Our objective is to bring an overview of the osseous palmar sesamoid in anurans, unveiling the relationship between this element of the manus, its phylogeny, and the anuran habitat use. Methods: Skeletal whole-mount specimens of Rhinella were cleared and double-dyed to describe the sesamoid anatomy and related tissues. We review and describe the palmar sesamoid of 170 anuran species from CT images downloaded from Morphosource.org, representing almost all Anuran families. We performed an standard ancestral state reconstruction by optimizing two selected characters (osseous palmar sesamoid presence, distal carpal palmar surface) along with the habitat use of the sampled taxa, using parsimony with Mesquite 3.7. Results: Our primary finding is that sesamoid optimization in the anuran phylogeny revealed that its presence is associated with certain clades and not as widespread as previously anticipated. Additionally, we will also be delving into other important outcomes of our study that are relevant to those working in the field of anuran sesamoids. The osseous palmar sesamoid is present in the clade Bufonidae-Dendrobatidae-Leptodactylidae-Brachicephalidae that we named as PS clade, and also in the archeobatrachian pelobatoid Leptobranchium, all strongly terrestrial and burrowing species, though with exceptions. The osseous palmar sesamoid is always present in Bufonidae, but varies in form and size, depending on the mode that they use their manus, such as in the Rhinella margaritifera which has a cylindrical one and also grasping abilities that involve closing the manus. The scattered presence of the bony palmar sesamoid among anuran clades raises the question whether this sesamoid can be present with a different tissular composition in other groups.

Imaging of Anatomical Variants of the Long Head Biceps Tendon.

Anatomical variants of the long head of biceps (LHB) tendon are widely discussed in the literature. As one of the few intra-articular tendons, magnetic resonance arthroscopy can quickly evaluate the proximal part of LHB morphology. It provides good assessment of both intra-articular and extra-articular portions of the tendons. In-depth knowledge about imaging of the anatomical LHB variants discussed in this article is useful preoperatively for orthopaedists and also helps avoid potential diagnostic misinterpretations.

Bifurcated distal biceps brachii tendon coexisting with separated bicipital aponeurosis: a complex variational case report.

Variations appearing in biceps brachii muscle are common with accessory head, different origins, variant insertion, and different pattern of nerve innervation. However, variations appearing in both origin and insertion, and with other anomalous morphology at the same time are seldom. Here we report a complex variational case on the right arm of a 91-year-old Japanese female cadaver. The complex variations included (1) the biceps brachii muscle bifurcated at its distal ending; (2) the long head had its own tendon, which divided into two parts, i.e., a lateral part fused into the fascia between the brachioradialis and extensor carpi brevis, and a medial part attached to the radius about one centimeter ahead of the radial tuberosity; (3) the short head had an accessory origin from the shoulder capsule; (4) the bicipital aponeurosis was of two parts with an anterior superior layer formed by the long head and a posterior deep one formed by the short head; (5) the musculocutaneous nerve was especially underdeveloped that only innervated the coracobrachialis; (6) the existence of communicating branch between the musculocutaneous and median nerves, and the median nerve issued muscular branches to the biceps brachii and brachialis muscles, and (7) the brachioradial muscle had two accessory muscular bundles that originated from the fascia of the brachial muscle (proximal one) and from the bicipital aponeurosis (distal one).

Unique morphological architecture of the hamstring muscles and its functional relevance revealed by analysis of isolated muscle specimens and quantification of structural parameters.

The structural and functional differences of individual hamstrings have not been sufficiently evaluated. This study aimed to clarify the morphological architecture of the hamstrings including the superficial tendons in detail using isolated muscle specimens, together with quantification of structural parameters of the muscle. Sixteen lower limbs of human cadavers were used in this study. The semimembranosus (SM), semitendinosus (ST), biceps femoris long head (BFlh), and biceps femoris short head (BFsh) were dissected from cadavers to prepare isolated muscle specimens. Structural parameters, including muscle volume, muscle length, fiber length, sarcomere length, pennation angle, and physiological cross-sectional area (PCSA) were measured. In addition, the proximal and distal attachment areas of the muscle fibers were measured, and the proximal/distal area ratio was calculated. The SM, ST, and BFlh were spindle-shaped with the superficial origin and insertion tendons on the muscle surface, and the BFsh was quadrate with direct attachment to the skeleton and BFlh tendon. The muscle architecture was pennate in the four muscles. The four hamstrings possessed either of two types of structural parameters, one with shorter fiber length and larger PCSA, as in the SM and BFlh, and the other with longer fiber length and smaller PCSA, as in the ST and BFsh. Sarcomere length was unique in each of the four hamstrings, and thus the fiber length was suitably normalized using the average sarcomere length for each, instead of uniform length of 2.7 µm. The proximal/distal area ratio was even in the SM, large in the ST, and small in the BFsh and BFlh. This study clarified that the superficial origin and insertion tendons are critical determinants of the unique internal structure and structural parameters representing the functional properties of the hamstring muscles.

Anatomic Features of Patients With Recurrent Peroneal Tendon Dislocation.

BACKGROUND: There are several anatomic variations of the peroneal muscles and lateral malleolus of the ankle that may play an important role in the onset of peroneal tendon dislocation. PURPOSE: To investigate the anatomic variations of the retromalleolar groove and peroneal muscles in patients with and without recurrent peroneal tendon dislocation using magnetic resonance imaging (MRI) and computed tomography (CT). STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A total of 30 patients (30 ankles) with recurrent peroneal tendon dislocation who underwent both MRI and CT before surgery (PD group) and 30 age- and sex-matched patients (control [CN] group) who underwent MRI and CT were included in this study. The imaging was reviewed at the level of the tibial plafond (TP level) and at the center slice between the TP and the fibular tip (CS level). The appearance of a malleolar groove (convex, concave, or flat) and the posterior tilting angle of the fibula were assessed on CT images. The appearance of accessory peroneal muscles, height of the peroneus brevis muscle belly, and volume of the peroneal muscle and tendons were assessed on MRI scans. RESULTS: There were no differences in the appearance of the malleolar groove, posterior tilting angle of the fibula, or accessory peroneal muscles at the TP and CS levels between the PD and CN groups. The peroneal muscle ratio was significantly higher in the PD group than in the CN group at the TP and CS levels (both P < .001). The height of the peroneus brevis muscle belly was significantly lower in the PD group than in the CN group (P = .001). CONCLUSION: A low-lying muscle belly of the peroneus brevis and a larger muscle volume in the retromalleolar space were significantly associated with peroneal tendon dislocation. Retromalleolar bony morphology was not associated with peroneal tendon dislocation.

The anatomy of the tendon of abductor pollicis longus and its morphological variations: An anatomical approach emphasizing the clinical relevance.

PURPOSE: The anatomical literature describes the abductor pollicis longus as a muscle with a single tendon inserting on the base of the first metacarpal bone, but investigations have shown that it often exhibits morphological variations. However, methodological approaches used to describe these variations have not been useful in a clinical context. Therefore, the purpose of this investigation was to study and relate such anatomical variations in a clinical context. BASIC PROCEDURES: Thirty upper limbs from the body donation program were dissected using standard procedures to identify the number of abductor pollicis longus (APL) tendons, their position, site of insertion, length, width and thickness. The presence or absence of the extensor pollicis brevis muscle was also noted. Inter and intra-observer reliability was analysed. MAIN FINDINGS: A total number of 71 tendons from the APL muscle were found in the thirty limbs. The most frequent distribution pattern was a main tendon inserted on the base of the first metacarpal and an accessory tendon inserted into the abductor pollicis brevis muscle. These tendons could divide into various tendinous slips that could insert in different locations. Also, clustering algorithms and classical statistical tests showed tendons inserting on the first metacarpal were longer than tendons not inserting on the first metacarpal (p = 0.03), while medial tendons and tendons from an APL muscle with supernumerary tendons were narrower (p < 0.001). The absence of the extensor pollicis brevis muscle was not related to the presence of supernumerary APL tendons. CONCLUSIONS: Radiological and surgical implications of these results are important when examining this region of the hand and wrist. The pathophysiology and treatment of de Quervain's tenosynovitis, trapeziometacarpal arthritis and trapeziometacarpal subluxation or laxity could be influenced by the results of our findings.

Old name, new face: A systematic analysis of flexor digitorum superficialis muscle with "chiasma antebrachii".

The gross anatomy of the forearm flexors, particularly that of the flexor digitorum superficialis (FDS) muscle, has been described and graphically illustrated in several anatomical books and atlases starting in the middle of the century before last. However, in anatomical dissection studies as well as in clinical-anatomical courses training muscle-specific targeted injections due to movement disorders such as dystonia or spasticity, it has become apparent that there is a need for a closer investigation of the complex construction of the FDS muscle. To this end, we studied the structure of the muscle bellies and tendons of FDS on 46 human body donates that have been used either in our dissection or clinical-anatomical training courses. With this, we demonstrate here the topographical configuration of the individual muscle belly for each of digits 2 through 5 and the exact paths of their tendons until their passing through the carpal tunnel. Furthermore, we demonstrate the presence of a chiasm of the FDS tendons for the digits 2 and 3, approximately 3-4 cm proximal of the carpal tunnel. Thus, we introduce herewith the terminology "chiasma antebrachii". These findings were confirmed in situ by imaging of fixed human body donates via MRI and corroborated by MRI and ultrasound imaging in two volunteers. Taken together, the present findings enable an updated understanding of the complex organization of the heads, bellies, and tendons of FDS that is relevant not only for anatomical teaching but also clinical interventions.

Case report of the double-headed extensor hallucis longus.

BACKGROUND: We present a case report of double-headed extensor hallucis longus (EHL) with potential clinical significance. MATERIALS AND METHODS: Cadaveric dissection of the right lower limb of a 70-year- -old at death female was performed for research and teaching purposes at the Department of Anatomical Dissection and Donation, Medical University of Lodz. The limb was dissected using standard techniques according to a strictly specified protocol. Each head and tendon of the muscle was photographed and subjected to further measurements. RESULTS: During dissection, an unusual type of EHL muscle was observed. It consisted of two muscle bellies, a main tendon and an accessory tendon. Both muscle bellies were located on anterior surface of the fibula and the interosseous membrane. The main tendon insertion was located on the dorsal aspect of the base of the distal phalanx of the big toe, while the accessory tendon insertion was located medially. CONCLUSIONS: The EHL muscle is highly morphologically variable at both the point of origin and the insertion. Knowledge of its variations is connected to several pathologies such as foot drop, tendonitis, tendon rupture, and anterior compartment syndrome.