Easy to gain but hard to lose: the evolution of the knee sesamoid bones in Primates-a systematic review and phylogenetic meta-analysis.

Sesamoids are variably present skeletal elements found in tendons and ligaments near joints. Variability in sesamoid size, location and presence/absence is hypothesized to enable skeletal innovation, yet sesamoids are often ignored. Three knee sesamoids-the cyamella, medial fabella and lateral fabella-are present in primates, but we know little about how they evolved, if they are skeletal innovations, or why they are largely missing from Hominoidea. Our phylogenetic comparative analyses suggest that sesamoid presence/absence is highly phylogenetically structured and contains phylogenetic signal. Models suggest that it is easy to gain but difficult/impossible to lose knee sesamoids and that the fabellae may have similar developmental/evolutionary pathways that are distinct from the cyamella. Sesamoid presence/absence is uncorrelated to the mode of locomotion, suggesting that sesamoid biomechanical function may require information beyond sesamoid presence, such as size and location. Ancestral state reconstructions were largely uninformative but highlighted how reconstructions using parsimony can differ from those that are phylogenetically informed. Interestingly, there may be two ways to evolve fabellae, with humans evolving fabellae differently from most other primates. We hypothesize that the 're-emergence' of the lateral fabella in humans may be correlated with the evolution of a unique developmental pathway, potentially correlated with the evolution of straight-legged, bipedal locomotion.

Comparison of histopathological and biomechanical changes of ligamentum mucosum in patients with anterior cruciate ligament rupture.

OBJECTIVES: The aim of this study was to identify the biomechanical and histopathological changes of ligamentum mucosum (LM) in patients with intact versus ruptured anterior cruciate ligament (ACL). PATIENTS AND METHODS: A total of 67 patients (45 males, 22 females; mean age: 33.2±7.9 years; range, 18 to 45 years) who underwent arthroscopic knee surgery for intraarticular pathologies between July 2022 and January 2023 were prospectively analyzed. The patients with LM were divided into two groups as the ACL intact group (n=31) and ACL ruptured group (n=36). Biomechanical tests and histopathological examinations were performed in all LM patients. RESULTS: Age and body mass index distributions were similar between the groups (p>0.05). Peak force values of the LM in the ACL ruptured group were significantly higher than the ACL intact group (p=0.037). No significant difference was found between the groups in terms of collagen index (p=0.103) and fibroblast count (p=0.821). CONCLUSION: The peak force values of the LM were significantly higher in the ACL ruptured group as compared to the ACL intact group, which is probably due to the adaptation of LM in patients with ACL rupture against increased deforming forces to maintain knee stability.

Atraumatic Sport-Related Medial Sesamoid Pain: Conservative Treatment Outcome and Magnetic Resonance Imaging Features.

Background: This study aimed to evaluate the effectiveness of conservative treatment in selected patients with atraumatic medial sesamoid pain (MSP) that developed during sports activities. The secondary aim was to determine the detailed underlying pathology in patients who did not respond to conservative treatment using magnetic resonance imaging (MRI). Methods: From March 2015 to August 2022, we prospectively followed 27 patients who presented to our outpatient clinic with atraumatic sports-related MSP. The conservative treatment protocol for MSP included the use of oral analgesics, activity restriction, insole modification, local corticosteroid injections, and boot walker application with crutches. MRI was performed for all patients who experienced persistent pain despite the completion of conservative treatment. Results: After the completion of the conservative treatment protocol, 48.1% of the patients reported a reduction in pain. Patients with younger age at pain onset (p = 0.001), higher body mass index (p = 0.001), and a bipartite medial sesamoid (p = 0.010) were more likely to experience persistent pain after conservative treatment. The type of sports activity was also a factor since running- and dancing-related MSP tended to respond better to conservative treatment compared to MSP originating from golf, futsal, and weightlifting with squatting. On MRI, 42.8% of patients showed no specific abnormal findings, with signal changes in soft tissues such as the subcutaneous fat and bursa being the most common, followed by intraosseous signal changes of the medial sesamoid bone and chondral or subchondral lesions of the medial sesamoid metatarsal joint (28.6% each). Conclusions: Conservative treatment was successful in less than half of the patients who experienced MSP due to sports activity. Practitioners should be aware of the numerous possible causes of conservative treatment failure, such as bursitis, medial sesamoiditis, stress fracture, or chondral lesions between the medial sesamoid and metatarsal. MRI evaluation may be helpful in MSP patients who do not respond to conservative treatment.

Early Functional Outcomes and Complications of Tibial and/or Peroneal Sesamoidectomy Utilizing a Burr Through a Medial Approach.

BACKGROUND: Sesamoid pathology can lead to significant pain and disability both with activities of daily living and high-impact athletic movements. Sesamoidectomy is a widely used procedure for patients who fail conservative treatment measures. Traditional dorsal or plantar approaches for sesamoidectomy have shown to successfully alleviate pain, but complications were reported. A proposed alternative medial approach using a burr may provide many advantages compared with traditional approaches. This study presents patient outcomes and complications for this technique. METHODS: This was a retrospective chart review of patients undergoing sesamoidectomy (tibial, peroneal, or both) using a burr through a medial approach to the sesamoid metatarsal articulation. Data collected included patient demographics, radiographic analysis, and outcomes: Veterans Rand 12 Item Health Survey (VR-12), Foot and Ankle Ability Measure (FAAM), visual analog scale (VAS), patient satisfaction, and complications. RESULTS: Twenty-seven patients (29 feet) were included. The mean age was 38.4 years followed up for a mean of 30.9 months. VR-12 physical component improved from 35.98 ± 7.86 to 51.34 ± 8.01 (P < .001), FAAM ADL and sport improved from 58.33 ± 16.61 to 83.27 ± 18.28 (P < .001) and 26.37 ± 20.31 to 63.75 ± 29.74 (P < .001), respectively. Patient satisfaction with the treatment was 80.59% ± 27.06%. The overall complication rate was 11 (37.9%) whereas the overall reoperation rate was 4 (13.7%) of 29 feet. Complications included 1 arthrofibrosis, 1 flexor hallucis longus subacute rupture, and 1 asymptomatic hallux valgus. There were no sesamoid excision revisions. CONCLUSION: Sesamoidectomy using a medial approach with a burr provided significantly improved short-term functional outcomes, 80% patient satisfaction rate, with a relatively acceptable complications rate including 20% persistent pain. The medial approach is familiar to orthopaedic foot and ankle surgeons, provides adequate exposure, and eliminates the possibility of a painful plantar scar while avoiding disruption of the plantar plate, flexor hallucis brevis tendon, and ligamentous structures attached to the sesamoids. Larger studies with long-term follow-up from other centers are needed.

Mineralization of equine proximal sesamoid bones precedes articular cartilage and fibrocartilaginous enthesis maturation in early postgestational development.

OBJECTIVE: To describe the development and maturation of equine proximal sesamoid bones (PSBs) in fetuses and young horses using radiography, microcomputed (micro)-CT, and histology. METHODS: A descriptive study. Forelimb PSBs from 12 equids ranging in age from 105 days of gestation to 540 days postgestation were evaluated. Radiography was used for preliminary assessment of metacarpophalangeal joint and PSB mineralization, and micro-CT imaging was performed to assess mineralized PSBs. Tissue volume, bone volume fraction, height, width, depth, trabecular thickness, and anisotropy were quantified from midplanar micro-CT sections in 3 dimensions. Midsagittal PSB histologic sections stained with H&E and Safranin O/Fast Green were used to determine the ratio of ossification center to cartilage template size and to describe the formation and development of the cartilage template, ossification center, spherical growth plate, articular cartilage, and entheses. RESULTS: Mineralization of equine PSBs is associated with cartilage canals and a spherical growth plate that undergoes endochondral ossification during the late gestation to early postgestational period. The apical, flexor, basilar, and articular ossification fronts demonstrate morphologic variability. Structural organization of the articular cartilage and entheses occurs concurrently with the development of an underlying plate of compact bone. At 540 days postgestation, the fibrocartilaginous entheses of the flexor cortex of the PSB had yet to mature. CONCLUSIONS: Equine PSBs mineralize predominantly by endochondral ossification during the late gestation to early postgestational period. Mineralization precedes maturation of the articular cartilage and fibrocartilaginous entheses. CLINICAL RELEVANCE: The postgestational maturation of the PSB and its surrounding tissues may predispose young horses to developing lesions at these sites, such as apical avulsion fractures, warranting further investigation.

Long term follow up on treatment of hallux sesamoid fracture with temporary first metatarsal joint internal fixation.

Fracture of the hallucial sesamoids is a pathology that causes difficulty for surgeons and patients. Because of the low incidence and the fact that up to 64-90 % heal with non-operative management, there is a lack of clear guidance in the literature for the surgical treatment of sesamoid fracture in cases of failure of non-operative management. Here long term follow up of an alternative method of surgical treatment of sesamoid fracture recalcitrant to nonoperative management is presented. 32 individuals were treated with temporary surgical immobilisation of the 1st metatarsophalangeal joint using either crossed wires or two orthogonally placed two hole plates. The patients then underwent removal of the construct at 8 weeks post op after confirmation of healing on a CT scan. There was a 94 % union rate. Return to work was 61 days (15-90) return to sport 80 days (64-112) with no immediate complications and no recurrence. At last follow up mean 10 years (4-16) only 2 patients had gone on to asymptomatic non-union and one patient developed arthritis between the sesamoid and the metatarsal head. No patient has required further surgical intervention. This retrospective cohort of patients demonstrate that this method of treatment is a valuable option in the management of sesamoid fracture which does not alter the biomechanics of the foot and has none of the long term complications of sesamoidectomy or partial sesamoidectomy.

Prevalence of the Fabella and Determination of the Fabella Index / Prevalencia de la Fabela y Determinación del Índice Fabelar

SUMMARY: The fabella is a bony anatomical variable, which in humans is located posterior to the lateral condyle of the femur, in the tendinous portion of the lateral head of the gastrocnemius muscle. Its prevalence rate has been reported in different populations, ranging from 3% to 86%. This study aimed to create an index that classifies the fabella according to its dimensions, determine the prevalence of the fabella in the Colombian population, and identify possible differences according to the fabella index (FI), sex, age, laterality, and degree of fabellar degeneration. A retrospective study used 93 lateral knee radiographs belonging to Colombian individuals. A fabella index was established to classify fabellae into longifabellar, medifabellar, and equifabellar, and radiological classification was used to identify the degree of fabellar degeneration (DFD). The prevalence of fabella was 36.30 %, and this variant was associated with the individual's sex, with male subjects having 2.66 times the probability of presenting fabella. A higher prevalence of medifabellar fabellae (57.60 %) was observed, followed by longifabellar (24.20 %) and equifabellar (18.20 %). There was a positive and moderate correlation between the DFD and age. We consider that larger fabellae can cause entrapment of the common fibular nerve, compression of the popliteal artery, and tear of the medial meniscus, so the FI becomes relevant in clinical practice, providing information on the type of fabella and its associated pathological manifestations. This study introduces a novel fabella index and investigates the frequency of fabella in the Colombian population. The findings of this study will serve as a reference for future research and contribute to the field of knee orthopedics and surgery in this population.

La fabela es una variable anatómica ósea, que en humanos se localiza posterior al cóndilo lateral del fémur, en la porción tendinosa de la cabeza lateral del músculo gastrocnemio. Su tasa de prevalencia se ha reportado en diferentes poblaciones, cuyos valores oscilan entre 3 % y 86 %. El objetivo de este estudio fue crear un índice que clasifique la fabela según sus dimensiones, determinar la prevalencia de la fabela en población colombiana, así como identificar posibles diferencias en función del índice fabelar, sexo, edad, lateralidad y grado de degeneración de la fabela. Se desarrolló un estudio retrospectivo en el que se dio uso a 93 radiografías laterales de rodilla, pertenecientes a individuos colombianos. Se estableció un índice fabelar que clasificó las fabelas en longifabelares, medifabelares y equifabelares, además utilizamos la clasificación radiológica para identificar los grados de degeneración fabelar (GDF). La prevalencia de la fabela fue del 36,30 %, se encontró asociación de esta variante al sexo del individuo, siendo los hombres quienes tuvieron 2,66 veces más probabilidades de presentar la fabela. Se observó mayor prevalencia de fabelas tipo medifabelar 57,60 %, seguido de tipo longifabelar 24,20 % y equifabelar 18,20 %. Hubo correlación positiva y moderada entre la edad y el grado de degeneración fabelar. Consideramos que las fabelas con mayores dimensiones podrían causar atrapamiento del nervio fibular común, compresión de la arteria poplítea y desgarro del menisco medial, por lo que el índice fabelar adquiere relevancia en la práctica clínica, al dar información del tipo de fabela y sus manifestaciones patológicas asociadas. El presente estudió es el primero en proponer un índice fabelar y la frecuencia de la fabela en población colombiana, por lo que servirá de referencia para futuras investigaciones, además de brindar un aporte al área traumatológica y quirúrgica de la rodilla en esta población.

The development of recommendations for the assessment and management of sesamoiditis by podiatrists: A Delphi and content validity study.

INTRODUCTION: Sesamoiditis is a common, and often painful, musculoskeletal pathology frequently encountered by podiatrists. However, there are currently no recommendations to guide podiatrists in the assessment and management of people with sesamoiditis. The aim of this study was to develop consensus-driven clinical recommendations on the assessment and management of people with sesamoiditis. METHODS: A four-round online Delphi survey was conducted with a panel of New Zealand and Australian podiatrists. In the first round, panellists answered open-ended questions that were used to create statements. In round two, the panellists scored the statements from 1 to 9 (1 = not at all important, 9 = absolutely essential). Consensus was defined using the RAND/University of California Los Angles Disagreement Index. Panellists were asked to reconsider statements that did not achieve consensus in round three. In the final round, content validity and acceptability of the statements for inclusion in clinical recommendations were determined using content validity ratios and the Content Validity Index (CVI). RESULTS: Eighteen panellists completed round one with 16 (89%) completing all four rounds. A total of 118 statements were generated following round one. Following rounds two and three, 78 statements were accepted by panellists as being important, with 62 statements achieving sufficient content validity for inclusion in clinical recommendations. The CVI for these 62 statements was 0.58. These recommendations provide guidance on subjective assessment (pain characteristics/symptomology, activity/sports/training history and medical history) objective assessment (establishing a diagnosis, identifying contributing biomechanical factors, footwear/orthoses, ruling out differential diagnoses) and management (temporary padding/strapping, education, footwear, foot orthoses and when to consider referral). CONCLUSION: This consensus exercise has provided a set of consensus-based recommendations for the assessment and management of people with sesamoiditis. In the current absence of research-based evidence in this area, these recommendations are intended to support clinicians. The recommendations may also serve as a basis for future clinical trials evaluating the efficacy of conservative interventions for people with sesamoiditis.

First Metatarsal Headphones-Like Lesion: A Case of Unreducible Sesamoid Complex Dislocation.

CASE: A 34-year-old woman sustained a direct trauma to the left hallux during a fall. Radiographs showed a dorsal dislocation of the first metatarsophalangeal joint and a wide separation of sesamoid complex. Closed reduction was tried: postreduction radiographs displayed reduction of first metatarsophalangeal joint and a complete sesamoid complex dislocation. The patient was scheduled for surgery. Through a medial approach, open reduction together with plantar structures release and repair were performed. Functional and radiographic outcomes were satisfactory at the last follow-up. CONCLUSION: In case of a "headphones-like lesion" surgery is required, together with plantar structures repair.

Deep learning model shows promise for detecting and grading sesamoiditis in horse radiographs.

OBJECTIVE: The objective of this study was to develop a robust machine-learning approach for efficient detection and grading of sesamoiditis in horses using radiographs, specifically in data-limited conditions. SAMPLE: A dataset of 255 dorsolateral-palmaromedial oblique (DLPMO) and dorsomedial-palmarolateral oblique (DMPLO) equine radiographs were retrospectively acquired from Hagyard Equine Medical Institute. These images were anonymized and classified into 3 categories of sesamoiditis severity (normal, mild, and moderate). METHODS: This study was conducted from February 1, 2023, to August 31, 2023. Two RetinaNet models were used in a cascaded manner, with a self-attention module incorporated into the second RetinaNet's classification subnetwork. The first RetinaNet localized the sesamoid bone in the radiographs, while the second RetinaNet graded the severity of sesamoiditis based on the localized region. Model performance was evaluated using the confusion matrix and average precision (AP). RESULTS: The proposed model demonstrated a promising classification performance with 92.7% accuracy, surpassing the base RetinaNet model. It achieved a mean average precision (mAP) of 81.8%, indicating superior object detection ability. Notably, performance metrics for each severity category showed significant improvement. CLINICAL RELEVANCE: The proposed deep learning-based method can accurately localize the position of sesamoid bones and grade the severity of sesamoiditis on equine radiographs, providing corresponding confidence scores. This approach has the potential to be deployed in a clinical environment, improving the diagnostic interpretation of metacarpophalangeal (fetlock) joint radiographs in horses. Furthermore, by expanding the training dataset, the model may learn to assist in the diagnosis of pathologies in other skeletal regions of the horse.

Medial sesamoid position in moderate to severe hallux valgus: Correlation between three radiographic measurements.

BACKGROUND: In hallux valgus surgery, it is essential to accurately assess the position of the sesamoids both pre- and postoperatively. Weight-bearing foot anteroposterior, tangential sesamoid, and semi-weight-bearing computed tomography axial views are radiographic methods used to assess the medial sesamoid position. This study aimed to measure the medial sesamoid position and evaluate the correlation between these three radiographic methods. METHODS: This retrospective study comprised 59 feet from 49 patients who underwent hallux valgus surgery. The mean age of patients was 54.6 (range, 22-70) years. We took preoperative and postoperative measurements using the weight-bearing anteroposterior, tangential sesamoid, and semi-weight-bearing computed tomography axial views to assess the medial sesamoid position. RESULTS: The mean grades of the medial sesamoid position preoperatively and 6 months postoperatively were 2.5 and 0.8, 1.6 and 0.4, and 1.3 and 0.3 points based on the anteroposterior, tangential sesamoid, and computed tomography axial views, respectively (P < 0.001). Preoperatively, there was a strong positive correlation between the computed tomography axial and tangential sesamoid views (P < 0.001, r = 0.645) and anteroposterior and computed tomography axial views (P < 0.001, r = 0.468). In contrast, the tangential sesamoid and anteroposterior views showed a weak positive correlation (P = 0.03, r = 0.283). Six months postoperatively, there was a positive correlation between the computed tomography axial and tangential sesamoid views (P < 0.001, r = 0.473), anteroposterior and computed tomography axial views (P < 0.001, r = 0.470), and tangential sesamoid and anteroposterior views (P < 0.001, r = 0.480). CONCLUSIONS: We observed that the anteroposterior view exhibited a higher degree of medial sesamoid position displacement than the computed tomography axial and tangential sesamoid views. For the preoperative evaluation of the medial sesamoid position, the correlation between the computed tomography axial and tangential sesamoid views was stronger than that between the tangential sesamoid and anteroposterior views. However, all three views showed strong correlations postoperatively.

Common fibular nerve palsy due to the Fabella: A review.

One of the most common nerve palsies - common fibular nerve palsy - can be caused by the variant small sesamoid bone in the posterolateral compartment of the knee joint known as the fabella. We compared and reviewed all reported cases of common fibular nerve palsy due to fabellae in the English literature. Compression can develop spontaneously or post-surgically (total knee arthroplasty). Symptoms progress rapidly to complete foot drop. Among all the cases reviewed, 68.42% were males with a median age of 39.39 years. Fabella compression was more common in the left common fibular nerve (CFN) (63.16%). Both big (23 × 20 × 16 mm) and small (5 × 5 mm) fabellae can be responsible for compression. While diagnosis can be problematic, the treatment (either surgical fabellectomy or conservative) is relatively easy and brings quick improvement.

The trabecular architecture of the popliteal sesamoid bone (cyamella) from a New Zealand white rabbit (Oryctolagus cuniculus).

Sesamoid bones are ossified structures that are embedded in tendons near articulation. They consist of an inner trabecular bone architecture surrounded by a thin cortical shell. While the formation of sesamoid bones is probably mainly controlled by genetic factors, the proper development and mineralization of a sesamoid bone depends also on mechanical stimulation. While most sesamoid bones are not loaded directly by other bones during locomotion, they still experience forces directed from the tendon in which they are embedded. In cases when the sesamoid bone is experiencing forces only from a single tendon, such as the cyamella in the rabbit, this may give us a tool to study bone functional adaptation in a relatively simple loading setting. This study investigates the internal trabecular architecture of the popliteal sesamoid bone (cyamellae) in New Zealand white (NZW) rabbits (Oryctolagus cuniculus). Five hind limbs of NZW rabbits were micro-computed tomography scanned and the cortical and trabecular architectures of the cyamellae were evaluated. The results revealed that similar to the patella, the cyamella has a thin cortex and a high trabecular bone volume fraction (BV/TV), which is derived mostly from the high trabecular thickness (Tb.Th). Trabecular BV/TV and Tb.Th were not distributed homogeneously, but they were lower at the periphery and higher closer to the proximal and middle of the cyamella, near the musculotendinous junction. The results also demonstrated that trabeculae tend to align along two recognizable orientations, one with the direction of tensile stresses, in line with the popliteal tendon, and the second bridging the narrow space between the cranial and caudal cortical faces of the bone.

Fracture of the fabella with radiologic and MRI.

The fabella is an inconstant sesamoid bone. A handful of cases have been reported so far describing fabella fracture, usually involving high energy mechanism or stress fractures after total knee arthroplasty. This paper presents a fabella fracture in a man in his 40s after suffering a car crash, the clinical and radiographic presentation, treatment and complete recovery at 4-months follow-up.

The morphology of cyamella and its prevalence in Turkish society.

OBJECTIVE: The aim of this study is to determine the prevalence and morphometry of cyamella, one of the sesamoid bones around the knee joint. PATIENTS AND METHODS: In this retrospective study, a total of 9,500 plain/digital radiographs of 6,500 patients over the age of 18 who applied to Elazig Fethi Sekin City Hospital between January 2021 and January 2022 were examined. RESULTS: Examinations revealed cyamella in a total of 76 (0.8%) knees in the direct X-ray images of 49 (0.75%) patients. Eighteen (36.74%) of the patients with the presence of cyamella were males, and 31 (63.26%) were females. The mean age of the patients with cyamella was 50.9±12.9. Twenty-seven (55.1%) of the 49 cyamella were bilateral; seven (14.3%) were in the right knee, and 15 (30.6%) were in the left knee. The comparison of cyamella sizes between genders revealed a statistically significant difference in the transverse measurements only (p=0.015) in the right knee, while a statistically significant difference was found in all 3 parameters (p=0.032 for thickness; p=0.04 for transverse; p=0.026 for length) in the left knee. CONCLUSIONS: We believe that sufficient knowledge regarding the prevalence and distribution of cyamella in patients presenting with the complaint of knee pain and its differentiation from fabella, another sesamoid bone in the same region, as well as other anatomical structures, will aid an early and accurate diagnosis.

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.

Partial Excision of a Tibial Sesamoid Fracture Nonunion in a Patient with Congenital Absence of Fibular Sesamoid: A Case Study.

BACKGROUND: Hallucal sesamoid injuries occur in approximately 5% to 10% of foot and ankle injuries. Most cases can be treated conservatively. However, when nonoperative management fails, surgical intervention is warranted. METHODS: The present case involved a 17-year-old female high school senior who presented to the clinic with right hallux pain. Radiographs were obtained and revealed congenital absence of the fibular sesamoid and evidence of a minimally displaced avulsion fracture involving the proximal medial tibial sesamoid. Treatment was complicated by the congenital absence of the fibular sesamoid and by a high activity level. RESULTS: After conservative treatment failure, the patient underwent partial excision of her tibial sesamoid. She was followed for 1.5 years after initial presentation to our clinic. The patient was able to return to daily activities; however, she was not able to return to softball competitively due to pain. CONCLUSIONS: We hypothesize she was unable to return to softball because the absence of a sesamoid can decrease push-off strength. We recommend that providers treating athletes educate their patients on the possible loss of strength and take this into account when creating a treatment plan.

Correlations of Sesamoid Bone Subluxation with the Radiologic Measures of Hallux Valgus and Its Clinical Implications.

Background and Objectives: Hallux valgus is one of the most common chronic foot complaints, with prevalences of over 23% in adults and up to 35.7% in older adults. However, the prevalence is only 3.5% in adolescents. The pathological causes and pathophysiology of hallux valgus are well-known in various studies and reports. A change in the position of the sesamoid bone under the metatarsal bone of the first toe is known to be the cause of the initial pathophysiology. Purpose: The relationships between the changes in the location of the sesamoid bone and each radiologically measured angle and joint congruency in the hallux valgus remain as yet unknown. Therefore, this study investigated the relationships of sesamoid bone subluxation with the hallux valgus angle, intermetatarsal angle, and metatarsophalangeal joint congruency in hallux valgus patients. The goal is to know the hallux valgus angle, the intermetatarsal angle, and metatarsophalangeal joint congruency's correlation with hallux valgus severity and prognosis by revealing the relationship between each measured value and sesamoid bone subluxation. Materials and Methods: We reviewed 205 hallux valgus patients who underwent radiographic evaluation and subsequent hallux valgus correction surgery in our orthopedic clinic between March 2015 and February 2020. Sesamoid subluxation was assessed using a new five-grade scale on foot radiographs, and other radiologic measurements were assessed, such as hallux valgus angle, the intermetatarsal angle, distal metatarsal articular angle, joint congruency, etc. Conclusions: Measurements of the hallux valgus angle, interphalangeal angle, and joint congruency exhibited high interobserver and intraobserver reliabilities in this study. They also showed correlations with sesamoid subluxation grade.

A modified minimally invasive osteotomy for hallux valgus enables reduction of malpositioned sesamoid bones.

BACKGROUND: The current minimally invasive distal metatarsal osteotomy for hallux valgus (HV) is V-shaped, which prevents the correction of the rotational metatarsal head deformity and reduction of the sesamoid bones. We sought to determine the optimal method for sesamoid bone reduction during HV surgery. METHODS: We reviewed the medical records of 53 patients who underwent HV surgery between 2017 and 2019 using one of three techniques: open chevron osteotomy (n = 19), minimally invasive V-shaped osteotomy (n = 18), and a modified straight minimally invasive osteotomy (n = 16). The sesamoid position was graded using the Hardy and Clapham method on weight-bearing radiographs. RESULTS: When compared to open chevron and V-shaped osteotomies, the modified osteotomy resulted in significantly lower postoperative sesamoid position scores (3.74 ± 1.48, 4.61 ± 1.09, and 1.44 ± 0.81, respectively, P < 0.001). Furthermore, the mean change in postoperative sesamoid position score was greater (P < 0.001). CONCLUSION: The modified minimally invasive osteotomy was superior to the other two techniques in correcting HV deformity in all planes, including sesamoid reduction.

New insight into the morphological characteristics of patella cubiti.

Accessory bones in the elbow region are rare anatomical variations with important clinical significance as they can be misdiagnosed as pathological lesions. Usually, they are asymptomatic and found incidentally during X-ray examination in the context of trauma. Although these bones have been previously described, their development is not fully understood. The present case provides complex macroscopic, X-ray and histological descriptions of a sesamoid bone in the posterior region of the elbow-patella cubiti and the related surrounding structures. Moreover, this report indicates the presence of a well-defined syndesmosis between patella cubiti and the proximal ulna.