Anatomic Variations of the Calcaneofibular Ligament.

BACKGROUND: The lateral ankle joint comprises the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and posterior talofibular ligament (PTFL). The purpose of this study was to propose a classification of CFL morphology. METHODS: The material comprised 120 paired lower limbs from human cadavers (30 male, 30 female), mean age 62.3 years. The morphology was carefully assessed, and morphometric measurements were performed. RESULTS: A 4-part method for anatomic classification can be suggested based on our study. Type 1 (48.3%), the most common type, was characterized by a bandlike morphology. Type 2 (9.2%) was characterized by a Y-shaped band, and type 3 (21.7%) by a V-shaped band. Type 4 (20.8%) was characterized by the presence of 2 or 3 bands. Type 2 and 4 were divided into further subtypes based on origin footprint. CONCLUSION: The aim of our study was to describe variations of calcaneofibular ligament. Our proposed 4-part classification may be of value in clinical practice in future recognition of CFL injuries and in its repair or reconstruction. CLINICAL RELEVANCE: The anatomy of the CFL plays an important role in stability of the ankle. Greater recognition of anatomical variation may help improve reconstructive options for patients with chronic lateral ankle instability.

What is new in flexor tendon pulleys and the gaps between them in triphalangeal fingers of the hand?

The flexor tendon pulleys in the fingers of the hand are fibrous structures of variable size, shape, and thickness that cover the synovial sheath of these tendons. Despite their clinical relevance, their arrangement and configuration in each of the triphalangeal fingers have been little studied and with small sample sizes. 192 triphalangeal fingers belonging to 48 fresh body donors' hands were dissected. Multivariate analysis was carried out. Twenty-five cases (52%) were left hands, and 26 of the 48 hands belonged to female donors (54.2%). The results were analyzed by fingers for each of the 5 annular pulleys, the 3 cruciform pulleys and the gaps between them. In addition, the most and least frequent configurations of the pulleys in each of the fingers were studied, observing that the classic pattern with all the pulleys appeared only in 3 fingers (1.56%), while the most frequent pattern was A1-A2-C1-A3-A4, which was seen in 35 fingers (18.22%). CONCLUSIONS: The flexor pulleys in the triphalangeal fingers of the hand have shown enormous variability in arrangement and shape, and also rarely appear all in the same finger. This peculiar anatomical arrangement can help the different professionals who perform their clinical work in this region.

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.

Variant plantaris muscle with degenerated accessory head: Gross and histological analysis.

The variant plantaris muscle has itself been reported to have variable presentations. Here, we report an unusual finding of the plantaris muscle and report its gross and histological findings. A duplicated head of the plantaris muscle was identified in the right leg of an adult cadaver age and sex. The more anterior head of the muscle was in the typical location and originated from the superolateral condyle of the femur. However, the more posteriorly located head arose from the iliotibial band at the level of the distal thigh. The two heads united and continued as the typical distal tendon of the plantaris muscle to insert into the calcaneus tendon (Achilles). The normally positioned head of the plantaris muscle was found to be composed of typical skeletal muscle fibres. However, the accessory head of the plantaris muscle was found to be severely degenerated and infiltrated with adipose tissue. We report a duplicated head of the plantaris muscle. Histologically, the accessory head was degenerated and infiltrated with adipose tissue. To our knowledge, this is the first report of such a case. Further cases are now necessary to further elucidate this finding.

A Proposal for a New Classification of the Supernumerary Heads of the Biceps Brachii Muscle.

Introduction: The anterior compartment of the arm consists of three muscles: the biceps brachii (BB), brachialis, and coracobrachialis muscle. The aim of the present study was to characterize possible variations in the supernumerary heads of the biceps brachii and use these to prepare an accurate classification of the area that could be used for planning surgical procedures in the region. Material and Methods. One hundred (51 left and 49 right, 52 females and 48 males) upper limbs fixed in 10% formalin solution were examined. Results: Four types of supernumerary BB heads were identified, with subtypes. Type I was the most common type, characterized by the two heads (64%); this was subdivided into Type IA, with a single muscle belly, and Type IB with two muscle bellies. The second most common type was Type II, which was characterized by the three BB heads (26%). This type was divided into four subtypes (A-D): Type IIa characterized by attachment to the middle part of the shaft of the humerus; Type IIb characterized by the origin to the coracoid process together with the short head of the BB; Type IIc characterized by origin to the tendon of the pectoralis major muscle; and Type IId characterized by the attachment to the capsule of the humeral joint. The third most common type was Type III, which was characterized by four heads (6%); this was divided into Type IIIa, where two heads originated from the humerus bone, and Type IIIb, where one head originated from the short heads and the second from the long head of the BB. The rarest type was Type IV (4%) which was characterized by five heads: the short head originated from the coracoid process and the long head originated from the supraglenoid tubercle, the third and fourth head originated from the shaft of the humerus, while the fifth head originated from the pectoralis major muscle. Conclusion: The biceps brachii is characterized by very high morphological variability. The new classification proposes four types of supernumerary head arrangement (I-IV), divided into subtypes. This classification has both clinical and anatomical significance.

The incidence and shape of the digital pulleys: a study of 192 fingers in 48 cadaveric hands.

We dissected 192 fingers in 48 fresh cadaveric hands (23 right and 25 left hands from 26 female and 22 male donors) and analysed the incidence, location, length and structure of the five annular and three cruciform pulleys. No statistically significant differences were found between left and right or between male and female hands. The A1, A2 and A4 pulleys were present in all fingers, while the incidence of other pulleys varied. We found 32 different patterns of pulley combinations. The structure of the pulleys also varied. Most important was the variation of A1, which consisted of one to four separate rings. In 18% there was no gap between the A1 and A2 pulleys. A greater understanding of the anatomical variation of the pulley system is beneficial for hand surgeons performing open or percutaneous trigger finger releases and for radiologists examining the area sonographically.

Relationships among Coracobrachialis, Biceps Brachii, and Pectoralis Minor Muscles and Their Correlation with Bifurcated Coracoid Process.

The aim of this study is to demonstrate the relationship between the proximal attachment of the coracobrachialis muscle and the short head of the biceps brachii and the distal attachment of the pectoralis minor. Their correlation with the bifurcated coracoid process (CP) will be also assessed. On the basis of these observations, a new classification of structures attached to the coracoid process is proposed. Classical anatomical dissection was performed on one hundred forty-five upper limbs. Three types of relationship between the coracobrachialis muscle and the short head of the biceps brachii were observed in the cadavers. In type I (occurring in 54%), the coracobrachialis and the short head of the biceps brachii created a common junction attached to a single CP. Type II was divided into two subtypes (a and b). Subtype IIa (frequency 10%) was represented by independent proximal attachments of the short head of the biceps brachii and the coracobrachialis muscles to the CP. In subtype IIb (frequency 5%), the coracobrachialis muscle was two-headed (the first head located under the second) and not connected to the short head of the biceps brachii; all heads were attached to a single CP. Type III (frequency 31%) was characterized by a two-headed coracobrachialis muscle, the first head originating from a bifurcated CP laterally to the short head of the biceps brachii and the second medially to this structure. Different variations connected with the mentioned structures could be problematic for surgeons during operations, so detailed knowledge of them could contribute to more efficient procedures.

The relationship between additional heads of the quadriceps femoris, the vasti muscles, and the patellar ligament.

INTRODUCTION: The quadriceps femoris consists of four muscles: the rectus femoris, vastus medialis, vastus intermedius, and vastus lateralis. However, the effect of additional quadriceps femoris heads on the vasti muscles and patellar ligaments is unknown. The aims of the present study are to determine the relationship between additional quadriceps femoris heads and the vasti muscles and patellar ligaments and to review the morphology of the vastus lateralis, vastus medialis, and vastus intermedius. MATERIALS AND METHODS: One hundred and six lower limbs (34 male and 19 female cadavers) fixed in 10% formalin were examined. RESULTS: On all lower extremities, the vastus lateralis consisted of superficial, intermediate, and deep layers. The vastus medialis, on the other hand, consisted of only the longus and obliquus layers. The quadriceps head had one or more supplementary heads in 106 dissected limbs from 68 cadavers (64.1%). The distal portion of the patella was wider in lower limbs without supplementary heads than in type IA but narrower than in type IIIA. In general, the distal portion of the patella was narrower in specimens with a supplementary head than in those without (19.03 SD 3.18 mm vs. 20.58 SD 2.95 mm, p = 0.03817). Other patellar ligament dimensions did not differ significantly. CONCLUSION: The quadriceps femoris muscle is characterized by high morphological variability. Occurrence of extra heads is at the level of 64.1%. The vastus lateralis consists of three parts (superficial, intermediate, and deep), and vastus medialis consists of two (longus and oblique).

Classification of the popliteofibular ligament.

The purpose of this study was to characterize the morphological variations in the distal attachment of the popliteofibular ligament (PFL) and create an accurate classification for use in planning surgical procedures in this area and in evaluating radiological imaging. One hundred and thirty-seven lower limbs of body donors fixed in 10% formalin solution were examined for the presence and course of the PFL. The PFL was present in 88.3% of cases. We propose the following three-fold classification: type I (72.3%), the most common type, characterized by the attachment onto the apex of the head of the fibula, type II (8.7%), characterized by a bifurcation, with the dominant band inserting on the anterior slope of the styloid process of the fibula and the smaller band onto the posterior surface of the styloid process of the fibula and type III (7.3%), characterized by a double PFL: the first PFL (main) originated from the popliteus tendon and inserted onto the anterior slope of the styloid process of the fibula, while the second originated from the musculotendinous junction of the popliteus muscle and inserted on the posterior surface of the styloid process of the fibula. The PFL was characterized by high morphological variation, as reflected in our proposed classification. This variation may present clinical and biomechanical issues for both medical personnel and researchers. Our proposed classification may be valuable for clinicians who evaluate and perform surgical procedures within the knee joint area.

A proposal for a new morphological classification of the popliteus muscle tendon with potential clinical and biomechanical significance.

The purpose of this study was to characterize the morphological variations in the proximal attachments and create an accurate classification of the PPM for use in planning surgical procedures in this area, for evaluating radiological imaging and rehabilitation. One hundred and thirty-four lower limbs of body donors (52 woman and 82 man) fixed in 10% formalin solution were examined. The popliteus muscle was present in all 134 limbs. Four main types were identified with subtypes. The most common type was Type I (34.3%), characterized by a single tendon in the popliteus sulcus. Type II (30.6%) characterized by a main tendon in the popliteus sulcus and accessory bands. This type was divided into five subtypes (A-E) based on presence of specific accessory bands. Type III (15.3%) was characterized by two tendons in the popliteal sulcus. Type IV (19.4%) was characterized by two tendons in the popliteus sulcus and additional bands. This type was also divided into five subtypes (A-E) based on presence of specific accessory bands. The popliteofibular ligament was present in 90.3% of cases. A new classification based on a proximal attachment is proposed. The popliteus tendon is characterized by a very high morphological variability, which can affect posterolateral knee stability and the natural rotation of the tibia. Such a classification system may be useful for clinicians performing medical procedures within the knee joint, including orthopedic surgeons.

Anatomic mapping of the collateral branches of the external carotid artery with regard to daily clinical practice.

BACKGROUND: To identify the anatomical variations of the main branches of the external carotid artery (lingual, facial, occipital, ascending pharyngeal and sternocleidomastoid), giving information about the calibers and origins with the aim of creating a new classification useful in clinical practice. MATERIAL AND METHODS: 193 human embalmed body-donors were dissected. The data collected were analyzed using the Chi² test. The results of previous studies were reviewed. RESULTS: The majority of the anterior arterial branches (superior thyroid, facial and lingual artery) were observed with an independent origin, respectively, classified as pattern I (80.83%, 156/193). In 17.62% (34/193) a linguofacial trunk, pattern II, has been observed, only in 1,04% (2/193) a thyrolingual trunk, pattern III, has been found and in one case (1/193, 0.52%) one thyrolinguofacial trunk, pattern IV, was found. Depending on the posterior branches (occipital and ascending pharyngeal), four different types could be determined: type a, the posterior arteries originated independently, type b, the posterior arteries originated in a common trunk, type c, the ascending pharyngeal artery was absent, type d, the occipital artery was absent. CONCLUSION: Anatomical variations in these arteries are relevant in daily clinical practice due to growing applications, e.g., in Interventional Radiology techniques. Knowledge of these anatomical references could help clinicians in the interpretation of the carotid system.

Is it the coracobrachialis superior muscle, or is it an unidentified rare variant of coracobrachialis muscle?

The coracobrachialis muscle (CBM) originates from the apex of the coracoid process, in common with the short head of the biceps brachii muscle, and from the intermuscular septum. The CBM demonstrates variability in both the proximal and distal attachment, with some extremely rare varieties, such as the coracobrachialis superior, coracobrachialis longus and coracocapsularis muscle. This case report describes an extremely rare variant of the coracobrachialis superior muscle, or a very rare variant of the CBM. Our findings highlight the importance of muscle variants in the shoulder region, especially the coracoid region, and are significant for radiologists, anatomists, physiotherapists and surgeons specializing in the shoulder joint.

The anconeus muscle revisited: double innervation pattern and its clinical implications.

PURPOSE: The aim of the present study is to describe in detail the morphology and innervation pattern of the anconeus muscle, bearing in mind clinical implications such as iatrogenic injuries during surgical elbow approaches. METHODS: A cadaveric study was performed; 56 elbows from 28 formalin-fixed cadavers belonging to the Anatomy Department of Universidad Complutense of Madrid were dissected. The triceps-anconeus nerve was located and dissected. A second innervation to the anconeus muscle from a branch of the posterior interosseous nerve (PIN) was occasionally detected. Taking the lateral epicondyle as a landmark, the entry points of both nerves in the muscle were referenced, the triceps-anconeus nerve was referenced at 0°, 30°, 45°, 70° and 90° of elbow flexion, and the PIN branch at 0°. RESULTS: Anconeus muscle was present in all specimens. The triceps-anconeus nerve was present in all of the dissected elbows. A branch from PIN to the anconeus muscle was present in 38 of the 54 elbows (70.4%). There were statistically significant differences in all measurements regarding the specimens' gender, being higher for men. CONCLUSIONS: There is evidence of a high frequency of a double innervation pattern for the anconeus muscle: the main branch of triceps-anconeus muscle depending on the radial nerve, which is liable to being damaged during posterior elbow approaches, and a secondary branch depending on the PIN. There are very few references to this finding in Anatomical literature and none with such a large sample size.

Quadriceps or multiceps femoris?-Cadaveric study.

PURPOSE: The quadriceps femoris (QF) consists of four muscles: the rectus femoris; vastus medialis; vastus lateralis, and vastus intermediate. The tendons of all of these parts join together into a single tendon that attaches to the patella. The QF is a powerful extensor of the knee joint that is needed for walking. A growing number of publications have examined the fifth head of the QF muscle. There is no information about the possibility of other heads, and there is no correct classification of their proximal attachments. Further, the frequency of occurrence of additional heads/components of the QF remains unclear. METHODS: One hundred and six lower limbs (34 male and 18 female) fixed in 10% formalin solution were examined. RESULTS: Additional heads of the QF were present in 64.1% of the limbs. Three main types were identified and included subtypes. The most common was Type I (44.1%), which had an independent fifth head. This type was divided into two subtypes (A-B) depending on its location relative to the vastus intermediate. The second most common type was Type II (30.8%), which originated from other muscles: IIA from the vastus lateralis; IIB from the vastus intermediate, and IIC from the gluteus minimus. In addition, Type III (25%) was characterized by multiple heads: IIIA-two heads with a single common tendon; IIIB-two heads with two separate tendons; IIIC-three heads (lateral, intermediate, medial), and IIID-four heads (bifurcated lateral and bifurcated medial). CONCLUSION: The introduction of a new classification based on a proximal attachment is necessary. The presence of the fifth, sixth, seventh, or eighth head varies.

Popliteal artery: Anatomical study and review of the literature.

BACKGROUND: The frequency of appearance of anatomical variability in the terminal division of the popliteal artery (PA) is different according to the type of sample used, and ranges from 2% to 21%. The PA locates 1,01 cm behind to the lateral meniscus, which makes it vulnerable during surgical procedures. Iatrogenic injury of the PA or its terminal branches increases if anatomical variables are present. Our aim was to describe and review the branching pattern of the PA in a body-donors to science sample to determine the influence of the sample used (body-donors vs imaging test). METHODS: A sample consisting of 260 popliteal regions, corresponding to 130 corpses (66 women, 64 men), have been dissected. Multivariate analysis was carried out. RESULTS: The terminal division of the PA was classified as follows: Pattern 1: the PA divided into the anterior tibial (ATA) and the posterior tibial arteries (PTA) at the level or distal to the lower border of the popliteal muscle (PM) (94.7%). Pattern 2: the PA bifurcated into the ATA and PTA, proximal to the lower border of the PM (3.3%). Pattern 3: the PA divided at the same level into the ATA, PTA and PEA. (2%). No significant differences between gender and side of the limb could be find. CONCLUSIONS: We propose a classification that encloses three identifiable groups only. This will allow clinicians to bear in mind these variables easily, at the same time avoiding injuries during surgical procedures such as lateral meniscus repair.