Immunohistochemical analysis of the ligamentum mucosum is the key to understand its clinical usefulness.

Ligamentum Mucosum(LM) is a ligamentous structure within the synovial layer of the knee joint capsule. For a long time LM was perceived as the vestigial remnant from the embryological development of the knee. Being treated as an irrelevant structure LM was often the first victim of shaver during arthroscopy. However, last years have shown increased interest in this structure due to its potentially significant clinical role. Our aim was to classify LM based on its morphological characteristics and examine its microanatomy using immunohistochemical analysis to reveal the potential clinical value for surgeons. We have examined sixteen fresh frozen lower limbs, 6 females (mean age 83.1 ± 3.4 years) and 10 males (mean age 84.2 ± 6.8 years). Classical histological H+E stain was routinely conducted. Subsequently, CD31 antibody (DAKO, Monoclonal Mouse Anti-Human, Clone JC70A) was used to mark vascular epithelium. Monoclonal Mouse Anti-Human Neurofilament Protein (NFP) antibody (DAKO, Clone 2F11) was used to expose the nerves. Moreover, we have conducted arthroscopic visualizing and suturing LM to the torn ACL during routinely performed arthroscopic suturing of the ACL. The dissection process has revealed that LM was present only in 75% of cases. Histological examination confirmed the presence of longitudinal collagen fiber bundles in all samples. Tiny nerves were confirmed by NFP, along the subsynovial layer in all samples. CD-31 immunostain revealed the presence of many vascular vessels along the entire ligament, especially well developed at its distal end. Our study has revealed that LM contains rich vascular network. Thus, it may be a donor for the revascularization process after ACL tear or reconstruction which may improve the recovery. Another great advantage of the LM is the presence of nerves along the subsynovial layer, hopefully they may serve as the source of reinnervation and hence better clinical outcome. Based on our results we believe that seemingly irrelevant LM may be very useful during surgical procedures in the knee region. Suturing LM to the ACL may not only prevent the infrapatellar fat pad from subluxation but also improve the blood flow and reinnervation of the injured ACL. Until now there are only a few studies examining microanatomy of the LM. This basic knowledge may serve as the foundation for surgical procedures. Hopefully our findings may be useful for surgeons while planning surgical procedures or clinicians while diagnosing patients who suffer anterior knee pain.

The ligamentum mucosum: A new classification.

The ligamentum mucosum (LM) is a ligamentous structure within the synovial layer of the knee joint capsule. For a long time LM was perceived as the vestigial remnant from the embryological development of the knee. However, last years have shown increased interest in this structure due to its potentially significant clinical role. Fifty-one, 12 females (mean age 83.1 ± 3.4 years) and 39 males (mean age 84.2 ± 6.8 years) fixed in 10% formalin were examined. Upon dissection, the following morphological features of the LM were assessed: the types of LM, morphometric measurement and histological analysis of each type. The LM was present in 66.7% of all examined specimens. Three different types were recognized: Type I (55.9%)-single band with attachment to the intercondylar notch, Type IIa-bifurcated ligament with attachment to the anterior cruciate ligament, Type IIb-bifurcated ligament with both attachments to the intercondylar notch, Type III-double ligament with two independent bands and attachments to the intercondylar notch and to the knee joint capsule. The LM is variable and probably evolutionary changes are the reason. In our study we propose the new clinically useful classification supported by its anatomical and histological characteristics. Type IIa seems to be the most important from the clinical point of view, as it may be responsible for clinical issues and should be paid attention while diagnosing patients suffering from anterior cruciate ligament torn or anterior knee pain.

A comprehensive anatomical classification system of the extramuscular innervation of the gracilis muscle as guidance for free functional muscle transfer.

PURPOSE: The gracilis muscle is one of the most frequently used muscles in reconstructive surgeries. It can be utilized as both less complex flaps and a free functional muscle flap to restore function to other muscles. As little is known of the precise extramuscular innervation of the gracilis muscle, the present study performs an accurate assessment to provide as much important anatomical information for clinicians as possible. MATERIAL AND METHODS: A classical anatomical dissection was performed on eighty-five lower limbs (45 right, 40 left) fixed in 10% formalin solution. The variability in the extramuscular innervation of the gracilis muscle was assessed. Some morphometric measurements were collected. RESULTS: A four-fold classification of extramuscular innervation was created for the gracilis muscle. Type I (64.7%), the most frequent type, presented at least one proximal nerve branch. Type II (25.9%) lacked this branch. Type III (8.2%) possessed an additional neural supply from the muscular nerve branch innervating the adductor longus muscle. Type IV (1.2%) was similar to Type III, but the additional neural supply originated from the muscular nerve branch innervating the adductor magnus muscle. CONCLUSION: Clear anatomical variability was noted for extramuscular innervation of the gracilis muscle. All the presented Types seem to be suitable for splitting a muscle belly and use its part in free functional muscle transfer. However, it appears that Type III and IV may ease this procedure, because of the additional nerve branches. This classification system can deliver important information for clinicians performing complex reconstructive surgeries with the use of the gracilis muscle.

The Pancreas and Known Factors of Acute Pancreatitis.

Pancreatitis is regarded by clinicians as one of the most complicated and clinically challenging of all disorders affecting the abdomen. It is classified on the basis of clinical, morphological, and histological criteria. Causes of acute pancreatitis can easily be identified in 75-85% of patients. The main causes of acute, recurrent acute, and chronic pancreatitis are gallstone migration and alcohol abuse. Other causes are uncommon, controversial, or unexplained. For instance, cofactors of all forms of pancreatitis are pancreas divisum and hypertriglyceridemia. Another factor that should be considered is a complication of endoscopic retrograde cholangiopancreatography: post-endoscopic retrograde cholangiopancreatography acute pancreatitis. The aim of this study is to present the known risk factors for acute pancreatitis, beginning with an account of the morphology, physiology, and development of the pancreas.

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.

The Anterolateral Ligament of the Knee: A Proposed Classification System.

The anterolateral ligament (ALL) is a potential stabilizer of the knee and cooperates with the anterior cruciate ligament (ACL). It originates on the lateral epicondyle of the femur, to which it is mainly posterior and proximal; insertion is posterior to Gerdy's tubercle. Its anatomical characteristics vary. Recent publications have focused on morphological variations concerning mainly the femoral and tibial attachments, and on morphometric measurements. Histological and cystochemical examinations have also been performed. Classical anatomical dissection was performed on 111 lower limbs (25 isolated and 86 paired) fixed in 10% formalin. The knee region was dissected using traditional techniques and the morphological features of the ALL were assessed: morphometric measurements and the types of ALL. The ALL was present in 70 individuals (37 woman and 33 men). In 30 cases, it was absent symmetrically, and in 11, it was present on just one side (P = 0.0011). The ALL was morphologically very variable. In type I (the most common form - 64.3%), a single band traveled parallel to the fibular collateral ligament (FCL); in type II the band crossed it. In type III, the origin was located on the lateral epicondyle of the femur and also on the lateral-posterior surface of the joint capsule, and the insertion was in the deep fascia of the leg: this type could be called a capsule. Type IV was characterized by a double ALL, type IIb by ligaments that bifurcated, and type V by the ALL starting directly from the FCL rather than the femoral epicondyle. The ALL is characterized by high morphological variability, both in its femoral and in its tibial attachments and in its course. Clin. Anat. 31:966-973, 2018. © 2018 Wiley Periodicals, Inc.