Tensor fasciae suralis: depiction on MR images

Tensor fasciae suralis - Prevalence study and literature review

Tensor fasciae suralis (TFS) is an accessory muscle of the posterior lower extremity. Although TFS has been documented in cadaveric and radiological reports, its prevalence remains unknown. The TFS variant is noteworthy to anatomists, as it may be encountered in the dissection laboratory, and clinicians, as the muscle could potentially cause confusion during physical examination or diagnostic imaging. Multiple variations of TFS have been reported in the literature, suggesting the need for a classification system. We dissected 236 formalin-fixed cadaveric lower limbs to determine the prevalence of TFS. The PubMed and MEDLINE databases were searched to compare the anatomical features of independent TFS case reports. In our prevalence study, the TFS muscle was identified in three lower limbs (1.3%). In total, 38 cases of TFS (32 cadaveric and six radiological) were identified in the literature. Our literature review revealed that the accessory muscle most often arises as a single head from the long head of the biceps femoris, yet many other presentations have been documented. The need for a classification system to distinguish between the subtypes of TFS became apparent during the literature review. Tensor fasciae suralis is a rare muscle, present in only 3 of 236 (1.3%) cadaveric lower limbs dissected in this study. We propose the use of a classification system, based on muscle origin and number of heads, to better organize the subtypes of TFS.

Impact of plantaris ligamentous tendon

There are countless morphological variations among the muscles, tendons, ligaments, arteries, veins and nerves of the human body, many of which remain undescribed. Anatomical structures are also subject to evolution, many disappearing and others continually emerging. The main goal of this pilot study was to describe a previously undetected anatomical structure, the plantaris ligamentous tendon, and to determine its frequency and histology. Twenty-two lower limbs from 11 adult cadavers (11 left, and 11 right) fixed in 10% formalin were examined. The mean age of the cadavers at death was 60.1 years (range 38–85). The group comprised six women and five men from a Central European population. All anatomical dissections of the leg and foot area accorded with the pre-established protocol. Among the 22 lower limbs, the PLT was present in 16 (72.7%) and absent in six (27.3%). It originated as a strong fan-shaped ligamentous tendon from the superior part of the plantaris muscle, the posterior surface of the femur and the lateral aspect of the knee joint capsule. It inserted to the ilio-tibial band. Histologically, a tendon and ligament were observed extending parallel to each other. A new anatomical structure has been found, for which the name plantaris ligamentous tendon is proposed. It occurs around the popliteal region between the plantaris muscle, the posterior surface of the femur, and the ilio-tibial band.

An online catalog of muscle variants: Student perceptions of a new opportunity for self-directed learning

OBJECTIVE:

Muscle variants are common findings in dissection laboratories. These anomalous structures can be relevant in the diagnosis and management of certain conditions and therefore could be incorporated into anatomy curricula at chiropractic colleges. We aimed to create an online resource of muscle variants to facilitate student self-directed learning within this area of study.

METHODS:

At the time of their discovery during routine educational dissection, muscle variants included in the catalog were documented and subsequent case reports written. All content created for this resource, including photographs and videos, was hosted on the institution's learning management system. Students enrolled in our doctor of chiropractic program were invited to view the catalog and encouraged to leave feedback by completing an online survey.

RESULTS:

Student responses to Likert-style survey questions generally indicated high levels of satisfaction regarding the utility and features of the catalog. Open-ended and Likert-style survey questions were used to help guide the future directions of this developing resource. Concurrent anatomy students were not more likely to contribute to the catalog compared to students who had previously completed the university's anatomy course series ( p = .75, 2-tailed Fisher exact test).

CONCLUSION:

An online supplement to graduate-level gross anatomy courses can aid in the instruction of muscle variants by providing an opportunity for student self-directed learning. This resource will be updated continually and will be expanded on to include neurovascular and visceral variants. Student participation will be sought in developing future content to be included in this catalog.

Tensor Fasciae Suralis Muscle: Report of a Symptomatic Case With Emphasis on Imaging Findings

We report a case of a symptomatic tensor fasciae suralis (TFS) muscle in an elite jumper, with a very rare tear in its origin. The TFS muscle must be recognized and differentiated from other pathologic entities in the popliteal region. The magnetic resonance imaging (MRI) and ultrasound (US) can reliably identify this variant and its pathology.

Bilateral Tensor Fasciae Suralis Muscles in a Cadaver with Unilateral Accessory Flexor Digitorum Longus Muscle

Muscle variants are routinely encountered in the dissection laboratory and in clinical practice and therefore anatomists and clinicians need to be aware of their existence. Here we describe two different accessory muscles identified while performing educational dissection of a 51-year-old male cadaver. Tensor fasciae suralis, a rare muscle variant, was identified bilaterally and accessory flexor digitorum longus, a more common muscle variant, was present unilaterally. Tensor fasciae suralis and accessory flexor digitorum longus are clinically relevant muscle variants. To our knowledge, the coexistence of tensor fasciae suralis and accessory flexor digitorum longus in the same individual has not been reported in either cadaveric or imaging studies.

Accessory plantaris muscle: anatomy and prevalence

Accessory and anomalous muscles have been described in humans, but only a few at the level of the knee. The aim of this retrospective cohort analysis was to determine the prevalence of a new accessory muscle located at the level of the knee detected with magnetic resonance imaging (MRI). The accessory muscle is designated an accessory plantaris muscle in this study due to its intimate origin with the normal plantaris muscle. Retrospective review of 1,000 consecutive MRI exams of the knee performed on patients presenting with acute or chronic knee symptoms revealed an accessory plantaris muscle in 63 of the 1,000 patients (6.3%)-38 males (7.5%) and 25 females (5.1%). Origin of 62 of 63 of the accessory plantaris muscles merged with the origin of the normal plantaris muscle, and one of 63 merged with the origin of the lateral head of the gastrocnemius muscle. These accessory plantaris muscles inserted into the iliotibial band, the lateral patellar retinaculum, or the iliotibial tract.

An abnormal muscle in the superficial region of the popliteal fossa

An abnormal muscle was observed in the superficial region of the popliteal fossa during a dissection procedure conducted for medical students. This abnormal muscle originated from the biceps femoris tendon and inserted into the medial head of the gastrocnemius muscle. The innervating nerve branched from the lateral sural cutaneous nerve. The distributing artery arose from a branch of the sural artery. This abnormal muscle mostly comprised one sheet of muscle mass (not tendon type) and ran transversely.

Dissection of a rare accessory muscle of the leg: The tensor fasciae suralis muscle

We report a case of the rare tensor fascia suralis muscle. This muscle was found during the routine dissection of the lower extremity in an adult male cadaver. No other anomalies were noted in this specimen. The innervation of this muscle was via the tibial component of the sciatic nerve. Although seemingly rare, the tensor fascia suralis muscle may be considered by the clinician in the differential diagnosis of masses over the posterior lower extremity.