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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.

The cyamella is a rare, generally asymptomatic, knee sesamoid bone located in the proximal tendon of the popliteal muscle. Only two studies have investigated cyamella presence/absence in humans, putting ossified prevalence rates at 0.57%-1.8%. We aim to (a) determine cyamella prevalence in a Korean population, (b) examine coincident development of the cyamella and fabella, and (c) perform a systematic review and meta-analysis on the cyamella in humans. Medical computed tomography scans of 106 individuals were reviewed. A systematic review and meta-analysis were performed following PRISMA guidelines. Cyamellae were found in 3/212 knees (1.4%), and presence/absence was uncorrelated to height, age, and sex. The cyamella was not found coincidentally with the fabella, although the statistical power was low. Our systematic review/meta-analysis revealed cyamellae were generally asymptomatic and ossification could occur at 14 years. Cyamellae were equally likely to be found in both sexes, knees, one or both knees, and there appeared to be no global variation in prevalence rates. Cyamellae were found in three distinct locations. There is little support for the role of intrinsic genetic and/or environmental factors in cyamella development in humans. However, the apparent phylogenetic signal in Primates suggests genetics plays a role in cyamella development. We propose a cyamella classification system based on cyamella location (Class I, popliteal sulcus; Class II, tibial condyle; Class III, fibular head) and hypothesize locations may correspond to distinct developmental pathways, and cyamella function may vary with location., (© 2021 American Association of Clinical Anatomists.)

Sesamoid bones show considerable variations in their occurrence among various ethnicities. This study aims to evaluate the prevalence and distribution patterns of the sesamoid bones of the hands among Omani patients who were referred for radiological investigations. The influence of gender and different age groups on the occurrence of sesamoid bones of the hand was determined using the Chi-square test. Spearman's rank correlation was used to determine the coexistence of sesamoid bones at the metacarpophalangeal joints. A total of 541 hand radiographs were reviewed. A high prevalence of sesamoid bones at the fifth metacarpophalangeal joint and the interphalangeal joint of the thumb was noted with a frequency of 64% and 49.7%, respectively. There were ten different patterns of sesamoid bones detected, the most common of which was the presence of sesamoid bones at the first and fifth metacarpophalangeal joints found in 32.9% of the radiographs. A statistically significant gender difference was observed at the interphalangeal joint of the thumb (p = 0.025) and fifth metacarpophalangeal joint (p = 0.027) with a female dominance. A significant association between the age and prevalence of sesamoid bones was noted at the fifth metacarpophalangeal joint (p = 0.03). The prevalence of the sesamoid bones of the hand in Omani subjects seems to differ from other Middle Eastern populations, particularly at the fifth metacarpophalangeal joint and the interphalangeal joint of the thumb. In the meantime, the baseline data of our study can be helpful while treating the patients complaining of hand discomfort or pain.

The fabella is a sesamoid bone present in 30% of the population and, in the majority of cases, it is shown in the proximal head of the lateral gastrocnemius articulating with the lateral femoral condyle. Fabella syndrome is an uncommon disease and it must be considered when dealing with posterolateral pain that increases with extension of the knee. Because of its rarity and underdiagnosis, the literature reports few articles relating to its therapeutic management. The articles reviewed demonstrate that conservative treatment has high recurrence rates, surgical excision being the most effective treatment to eradicate symptoms. We found exceptional articles in the literature related to the surgical treatment of fabella syndrome in professional athletes. In this article we report the surgical experience of a 21-year-old elite swimmer who achievedcomplete pain relief and fast recovery after surgical excision of the fabella., (Copyright © 2020 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.)

Hallux varus is most commonly seen iatrogenically following overaggressive lateral release, removal of the fibular sesamoid, or overaggressive removal of the medial eminence. There are several reported cases of traumatic hallux varus, although this is much less common. We present a case of traumatic hallux varus in a patient who was later found to have bilateral absence of her fibular sesamoids. We postulated that lack of her fibular sesamoid led to weakness of her lateral capsular ligaments, thereby making her more susceptible to this injury. We performed a repair using a split extensor hallucis longus tendon transfer that was transected proximally, rerouted the tendon under the deep transverse intermetatarsal ligament, and secured it to the first metatarsal with a Bio-Tenodesis (Arthrex, Inc, Naples, Florida) screw. At 22 months postoperatively, she has demonstrated maintenance of correction and has resumed use of normal shoe gear and participation in activities. Our goal was to demonstrate a repair for this condition that successfully maintained correction over time while still allowing for functionality of the first metatarsophalangeal joint.

Background: The presentation of patients with knee injuries which can have a significant impact on their ability to work and perform activities of daily living is constantly rising. The posterolateral corner of the knee has a complex anatomy of muscles, tendons, and ligaments, with huge variation in the population. The fabella is one such structure, found in the posterolateral corner of the knee, which can serve as a common origin point of various ligaments., Case Report: We present a case report of a 53-year-old white man who presented with atraumatic, posterior knee pain and was found to have a congenital, anomalous band originating from the fabella, causing semimembranosus impingement. This was diagnosed with magnetic resonance imaging; he underwent division of the anomalous band, which resulted in complete resolution of his symptoms., Conclusion: We propose that patients who present with posterior knee pain, without any history of trauma, and have no abnormalities on plain radiographs, should undergo magnetic resonance imaging of their knees. This will help in assessing the ligament complex in the posterior compartment of the knee, and exclude impingement of the semimembranosus as an, albeit rare, cause of posteromedial knee pain.

Partite hallux sesamoids are clinically meaningful but their association with other sesamoids is not clear. The objective was to relate the prevalence of the partite hallux sesamoid bones to sesamoid bones at other metatarsophalangeal (MTP) joints. We conducted a retrospective review of plain radiographs of 7946 adult feet between November 2005 and September 2012 to identify partite hallux sesamoids and sesamoids at other MTP joints. Coexistence patterns of the partition and extra sesamoids were studied. Presence or absence of sesamoids at other MTP joints as well as sex and laterality were compared between the feet with and without partite hallux sesamoids using Pearson Chi-square test. Association between age and partition was evaluated using Spearman's correlation coefficient. Overall partite prevalence rate is 6.82%, and coexistence with extra MTP sesamoids was 0.42%. One pattern was partition in hallux sesamoid only, and 4 patterns were coexistence with extra sesamoids. The prevalence rates of partite hallux sesamoids were 7.17% (508/7081) and 3.93% (34/865) in feet without and with extra sesamoids, respectively. The relative risk of 1.889 (95% CI, 1.325-2.693) of partite hallux sesamoids was noted in feet without than with extra sesamoids (Χ 2 = 12.759, P < 0.001). A negative correlation between age and distribution of partition was identified (r = -0.061, P < 0.001). Partition of hallux sesamoid bones is a developmental variation, it can coexist with sesamoids at other MTP joints following a certain pattern; and its prevalence rate is almost twice higher in feet without than with extra MTP sesamoids. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 301:34-38, 2018. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

Sesamoid bones and accessory ossicles are common incidental findings on radiographs. These can occasionally become symptomatic, usually after a precipitating event such as an injury or overuse, or they can be incidental findings unrelated to the presenting pathology. The aim of this study was to highlight a rare case of a bipartite fifth metatarsal sesamoid bone and to review previous literature regarding sesamoid bones and accessory ossicles.

Introduction: Great toe dislocation frequently occurs at the metatarsophalangeal joint. However, an irreducible dislocation of the great toe interphalangeal (IP) joint due to an accessory sesamoid bone is relatively unusual., Case Report: A 23-year-old woman suffered a dislocated IP joint of the left great toe. The distal phalanx was plantar subluxated, and the articular surface was misaligned. Ultrasound, magnetic resonance imaging, and computed tomography images did not indicate any factors inhibiting reduction. In addition, the sesamoid bone at the IP joint was found to be rotated in the long-axis direction. The sesamoid bone of the IP joint was hooked from the distal direction and occupied the intercondylar area. IP joint of the left great toe was flexed and the distal phalanx was pushed toward the proximal phalanx during reduction locking with fluoroscopic guidance under local anesthesia, and the dislocation was successfully reduced., Discussion: The sesamoid bone at the IP joint is anatomically located dorsal to the flexor hallucis longus tendon and volar plate. The sesamoid bone fitted exactly in the distal intercondylar area. The sesamoid bone in our patient could be rotated by forcible plantar flexion of the IP joint displaced proximally and hooked into the intercondylar area from the proximal aspect. Then, the distal phalanx was pulled proximally through the volar plate. This is the first report on a plantar dislocation of the IP joint.

The prevalence and distribution of the sesamoid bones in the feet has been reported in the literature with a high degree of variability. This systematic review aims to provide a better estimate of the frequency of the sesamoids of the foot and their association with variables such as ancestry, gender, and side. Thirty-seven studies met the inclusion criteria and were submitted for meta-analyses, sensitivity analyses and proportion difference tests, whenever possible. At the metatarsophalangeal (MTP) joint of the hallux, sesamoids were nearly always present. At the interphalangeal (IP) joint, the pooled true estimates of large-sampled studies were: (1) an overall prevalence of 22.4 %, (2) a cadaveric rate at 71.6 %, and (3) a radiological rate (based on X-ray images) of 21.1 %. The pooled partition frequencies of the hallucal medial and lateral sesamoids were 10.7 and 1.3 %, respectively. Bipartism was the most frequent partition type (92 %), followed by tripartism (7.5 %) and quadripartism (0.5 %). Middle Eastern ancestry was associated with significantly lower hallucal partition rate (P < 0.0001) and African ancestry with significantly lower prevalence of the IP sesamoid than all other ethnicities (P < 0.001). Feet with a hallux valgus deformity seemed to be associated with significantly higher rate of partition of the medial sesamoid (odds ratio = 3) than that of the normal feet. The respective values of the pooled true prevalence in adults at the MTP joint for the 2nd, 3rd, 4th and 5th toes were 1.9, 0.32, 0.9 and 13 %, respectively. There was a significantly higher prevalence of tibial sesamoids vs lateral sesamoids, with pooled odds ratio of 34.7, 8, 4.8, and 2.27, respectively. Partition was found in around 10 % of the sesamoids of the 5th MTP joint; no partition was noted in the other toes. For most 2nd-5th MTP joints, European ancestry showed the highest frequency whereas African ancestry showed the lowest; Middle Eastern ancestry was in between. No sesamoids were found at the 4th proximal IP joint and at the 4th and 5th distal IP joints. No sesamoids were found at any IP joint in the feet of Middle Eastern and African populations. The pooled rates of the IP sesamoids of the second and third toes in European populations were 1.2 % for the 2nd proximal, 0.33 % for the second distal and 0.6 % for both IP joints of the third toe. This anatomical meta-analysis yielded results that are likely to be more accurate regarding the rates of the sesamoids in the foot, their laterality and partition. It also provided solid evidence for the genetic basis of the frequency distribution among the different populations.

Accessory ossicles and sesamoid bones are normal variants of bone development. In foot and ankle X-rays these bones can appear similar to, or can obscure, fractures, which makes the X-rays difficult to interpret. This article illustrates and describes some of the more common ossicles and sesamoid bones, and provides a brief description of the management of the patients with foot or ankle pain whose X-rays are inconclusive.

The literature contains various estimates of the prevalence and distribution of the sesamoid bones in the hands. The aims of this systematic review are to provide a better estimate of the frequency of hand sesamoids and its association with variables such as ancestry, gender, and side. Nineteen studies met the inclusion criteria. The pooled rates of the sensitive meta-analyses from large-sample studies in adults showed: (a) true overall rates of 99.9% for the metacarpophalangeal (MCP) joint of the thumb (MCP-I), 53% for the interphalangeal joint (IP-I), 43.4% for the MCP of the index (MCP-II), 1.47% for the MCP of the medius finger (MCP-III), 0.6% for the MCP of the ring finger (MCP-IV), and 67.7% for the MCP of the auricular finger (MCP-V); (b) true radiological rates of 99.9% for the radial thumb sesamoid, 99.6% for the ulnar thumb sesamoid, 47.8% for IP-I, 40% for MCP-II, 1.3% for MCP-III, 0.8% for MCP-VI, and 62.8% for MCP-V. Black, Middle Eastern, and European ancestries conferred significantly higher sesamoid frequencies at IP-I, MCP-II, and MCP-V, respectively. There was a significant association with female gender at MCP-II, MCP-IV, and MCP-V, with ORs of 1.53, 4, and 1.3, respectively, and a nonsignificant "female" trend for the other locations. There was no significant association with hand side. The pooled rates of hand sesamoids in children aged 10-17 years were 92.7, 42.2, 33.8, 0.5, 0.3, and 36.5% for MCP-I, IP-I, MCP-II, MCP-III, MCP-IV, and MCP-V, respectively. The findings of this evidence-based anatomical review provide quantitative evidence that the incidence of sesamoid bones in human hands depends on genetic rather than functional factors., (© 2014 Wiley Periodicals, Inc.)

The absence of the hallucal tibial sesamoid is seldom seen in the clinical setting. We present a case of a symptomatic missing tibial sesamoid in a female marathon runner.

We report a unique case of sesamoiditis in an extremely rare accessory genicular ossicle. Common to lower primates, the cyamella or popliteus tendon sesamoid bone is usually absent in humans. A 19-year-old male sustained a twisting injury to the right knee and presented with mechanical symptoms of knee pseudo-locking. A plain radiograph of the knee illustrated the presence of a cyamella. Magnetic resonance imaging demonstrated marked bone marrow oedema of this sesamoid structure and in the adjacent popliteus tendon. To our knowledge, documented sesamoiditis of this osseous structure on radiological imaging has not been published in English literature and this case highlights the imaging features of this uncommon entity.

Background: Sesamoid bones and accessory ossicles of the foot and ankle, although mostly asymptomatic, can be sources of pain or degenerative changes in response to overuse and trauma. We investigated the prevalence of accessory ossicles and sesamoid bones in a population of Italian women with hallux valgus., Methods: A single-center study was performed to determine the prevalence of accessory ossicles and sesamoid bones in the ankle and foot. A total of 505 women with hallux valgus aged 26 to 80 years at the time of hallux valgus correction were examined. Anteroposterior, oblique, lateral foot radiographs and a Muller view were examined regarding the presence, prevalence, coexistence, and distribution of accessory ossicles and sesamoid bones in both feet. The radiographs were analyzed independently by three experienced specialists in foot and ankle surgery. Disagreements were discussed in a consensus meeting, where the radiographs were reevaluated and a final decision was made., Results: There was no statistically significant difference between data of the accessory ossicles and sesamoid bones according to the χ(2) test. Sesamoid bones were detected in 404 of the 505 patients. The fifth metatarsal sesamoid bone was found in 97 patients. All of the patients presented hallucal sesamoid bones., Conclusions: This is the first detailed report of the prevalence of accessory ossicles and sesamoid bones of the feet in Italian women with hallux valgus. These findings could help clinicians in the diagnosis and management of disorders of accessory ossicles and sesamoid bones, which are often undiagnosed, painful foot syndromes.

The absence of both tibial and fibular hallucal sesamoids is an extremely rare condition. It can present as hallux valgus, hallux varus, or metatarsalgia. It can result from primary mesenchymal differentiation failure or an ossification problem. Preoperative magnetic resonance imaging can help to differentiate the problem and assist preoperative planning in the case of surgical correction of the associated hallux valgus deformity., (Copyright © 2013 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.)

The absence of the hallucal sesamoid is a rare condition. Rarer still is the presentation of adolescent hallux valgus with the absence of both hallucal sesamoid. Seven cases of absence of the tibial sesamoid bone and 3 cases of absence of the fibular sesamoid bone have been found in the literature, and only a single case of bilateral absence of both sesamoid bones with hallux varus has been reported. We would like to present a unique case of bilateral absence of the hallucal sesamoid in an 18-year-old woman with severe adolescent hallux valgus but no other apparent congenital deformity., (Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.)

We report the clinical features, radiographic findings, management, and results of a patient with bilateral hallux valgus and associated bilateral tibial hallux sesamoid agenesis and fibular hallux sesamoid hypoplasia. Our patient was managed operatively with good clinical results. Combined tibial sesamoid agenesis and fibular sesamoid hypoplasia do not seem to negatively influence the management of hallux valgus.

The prevalence and distribution of sesamoid and accessory bones in the hands is quite variable between different populations and ethnic groups. However, there are no published data on their distribution in Mediterranean populations. Studies on the validity of radiographic assessment for the presence of these bones are also lacking. A retrospective review of 442 radiographs of adult patients was performed in order to assess the incidence of sesamoid and accessory bones in the hands of a Mediterranean population. Additionally, two independent observers reviewed 174 radiographs and used the Kappa parameter in order to assess the validity of radiographic interpretation of radiographs for the presence of those bones. There was an incidence of 99.5% sesamoid bones (n = 440) in the 1st metacarpophalangeal (MCP) joint, 42.3% in the 2nd MCP joint (n = 187), and 41.1% (n = 182) in the 5th MCP joint. The incidence in the 1st interphalangeal joints was 26.2% (n = 116). The incidence of sesamoid bones in the 1st, 2nd, and 5th metacarpophalangeal joints in a Mediterranean population was found to be similar to that of Arab and Caucasian populations, whereas their prevalence in the 1st interphalageal joint coincided more with Arab populations. Interobserver reliability of the interpretation of radiographs for the presence of sesamoid bones in the hand was good (Kappa > 0.68) in all locations, except for the 1st MCP joint. Further research is warranted to further elucidate the genetic and/or environmental reasons for the differences between those populations., (Copyright © 2010 Wiley-Liss, Inc.)

Objectives: To investigate whether in navicular bones (NB) from warmbloods, distal border fragmentation is associated with the shape of the proximal articular border or other radiological findings., Methods: Radiographs of the front feet of 325 normal, subadult horses presented for admission as breeding stallions were reviewed., Results: The proximal articular border of the total of 650 NB was classified as straight (n = 278), convex (n = 184), undulating (n = 147) or concave (n = 41). Distal border fragments were present in 57 NB (8.8%). They were significantly more prevalent in NB with a concave (9/41; 22%) or undulating (19/147; 13%) proximal articular border compared to NB with a straight (17/278; 6%) or convex shape (12/184; 7%). No other significant associations were found., Clinical Significance: Hypothetically, since a shape-fragment association was found and the distribution of biomechanical forces exerted on the navicular bone are assumed to be shape dependent, distal border fragments may be a result of unfavourable loading of the navicular region.

Background: To evaluate the prevalence and localization of abnormalities in the hallucal sesamoids detectable by magnetic resonance (MR) imaging in patients with forefoot pain and to determine which pathologies of tarsus, metatarsus and phalanges are associated with these abnormalities., Materials and Methods: The forefoot MRI examinations of 50 consecutive patients (32 females, 18 males; mean age 51 years, age range 20-86 years) were retrospectively analyzed by two musculoskeletal radiologists. A minimum of coronal and sagittal T1-weighted images and STIR images or T2-weighted images with fat saturation were performed on a 1.5-T scanner. Abnormal findings in the sesamoids were correlated with pathology in the I.MTP (metatarsal-phalangeal) joint, pathology in other parts of the forefoot and clinical information., Results: Signal abnormalities of the sesamoids were found in 7 patients out of 50 (14%). Two patients presented a bone marrow edema (BME) in both sesamoids, in 1 patient only the lateral one was affected; all three associated with pathology and pain in the I.MTP joint. In four patients only the medial sesamoid was affected, not associated with pathology in the I.MTP joint but with pathology in other parts of the forefoot., Conclusion: The prevalence of signal abnormalities in hallucal sesamoids was 14%. BME of the lateral sesamoid or of both were predominantly associated with pathology in the I.MTP joint. In contrast, signal abnormalities of the medial sesamoid, without affection of the lateral one, were associated with pathology in other parts of the forefoot suggesting an overuse injury as a result of compensating posture., (Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.)

Peroneus longus rupture with associated involvement of the os peroneum is an uncommon injury, and a small number of cases have been reported. Several mechanisms of injury have been suggested, but the most accepted theory is due to an inversion force placed on a cavovarus foot type. The sesamoid often becomes the focal point of the mechanical stresses and may fracture. Although the purpose of the sesamoid is to protect the tendon from rupture, the os peroneum may actually encourage fatigue (tear/rupture) under certain circumstances. Because this injury occurs at the cuboid notch, primary repair is complicated because of the inability to access the tendon as it courses deep within the midfoot. We present a bilateral case of peroneus longus rupture with involvement of the os peroneum in a patient with a cavovarus foot type. The injuries were sustained from an identical mechanism and occurred almost 1 year apart. In both situations, a peroneus longus to peroneus brevis tendon transfer was performed above the ankle joint in conjunction with partial excision of the fractured os peroneum. To the authors' knowledge, this is the only reported case of peroneus longus rupture associated with fracture of the os peroneum to occur bilaterally.

Pain at the first metatarsophalangeal (MTP) joint can result from inflammation, chondromalacia, flexor hallucis brevis tendinitis, osteochondritis dessecans, fracture of a sesamoid bone, avascular necrosis of sesamoids, inflamed bursae, intractable keratoses, infection, sesamoiditis, gout arthropathy, and rheumatoid arthritis. Congenital absence of a sesamoid bone is extremely rare. We present a 17-year-old male patient with pain at the plantar aspect of the right MTP joint associated with congenital absence of the medial sesamoid. There was tenderness and the range of motion was minimally restricted. He described the pain as necessitating changes in his social life. On radiographs, the medial hallucial sesamoid was absent on the right side. The MTP joint was also evaluated using magnetic resonance imaging (MRI). A metatarsal pad was prescribed and the patient was satisfied with the treatment at the 2 months follow-up period. MRI revealed no pathological tissue at the medial sesamoid site. Hallucial sesamoids absorb pressure, reduce friction, protect the tendons, act like a fulcrum to increase the mechanical force of the tendons, and provide a dynamic function to the great toe by elevating first metatarsal head. Congenital absence of these bones is very rare but we must consider it in a patient with MTP joint pain., (Copyright 2006 Wiley-Liss, Inc.)

Congenital absence of the lateral sesamoid is an extremely rare condition. We present a case of congenital absence of the lateral sesamoid in which magnetic resonance imaging was performed. The literature is reviewed regarding the clinical significance of this anomaly.

Accessory ossicles and sesamoid bones are frequent findings in routine radiographs of the ankle and foot. They are commonly considered fortuitous and unrelated to the patient's complaint; however, they may eventually cause painful syndromes or degenerative changes in response to overuse and trauma. They may also suffer or simulate fractures. Our aim was to review, illustrate and discuss the imaging findings of some of the more frequent accessory ossicles and sesamoid bones of the ankle and foot region, with particular emphasis on those that may be of clinical significance or simulate fractures.

We describe a patient who was found to have two sesamoid bones at the interphalangeal joint of the right great toe after radiographs for dislocation of the joint. Recognition of the sesamoids required careful scrutiny of the films. Interphalangeal sesamoids may cause painful callosities plantar to the joint or may become incarcerated in a dislocated joint. Our patient made a good recovery. The presence of sesamoid bones on the medial and lateral sides of the joint was unusual., (Copyright 2003 Wiley-Liss, Inc.)

Sesamoid bones and secondary centers of ossification account for the accessory bones of the foot, and there is a wide range of frequency with which these different ossicles appear. They are usually incidental asymptomatic findings on imaging studies, and their clinical importance lies in not mistaking them for fractures. Occasionally these ossicles can become painful due to fracture, degenerative changes, avascular necrosis, and irritation or impingement of adjacent soft tissue.

Congenital absence of the tibial sesamoid of the hallux is an infrequent occurrence. The authors present a case of congenital absence of the tibial sesamoid and a review of the literature regarding the clinical significance of this anomaly.

This paper describes a rare malformation of the distal portion of the left foredigit of a 15-month-old half-bred colt which was severely lame. Radiological, pathological and tomographic studies revealed hypoplasia of the metacarpophalangeal skeleton, absence of the distal sesamoid and deformation of the distal phalanx. Morphological analysis of the lesion and computerised measurement of the width of the articular surface of the distal phalanx suggested an early fusion between the distal sesamoid and distal phalanx.

Study Design: Case study., Objectives: To discuss the differential diagnosis, the nonsurgical and postoperative management of common accessory bones of the foot., Background: Accessory bones of the foot that are formed during abnormal ossification are commonly found in asymptomatic feet. Two of the most common accessory bones are the accessory navicular and the os peroneum. Their painful presence must be considered in the differential diagnosis of any acute or chronic foot pain. The optimal treatment for the conservative and postoperative management of painful os peroneum and accessory navicular bones remains undefined., Methods and Measures: Therapeutic management of the fractured os peroneum included bracing, taping, and foot orthotics to allow healing of involved tissues, and stretching. The focus of the postoperative management of the accessory navicular was joint mobilization and progressive strengthening. Dependent variables included level of pain with provocation and alleviation tests of joint and soft tissue; girth and sensory tests of the foot and ankle; goniometric measures of foot and ankle; strength of ankle and hip muscles; functional tests; and patient's self-reported pain status., Results: The patient with the fractured os peroneum was treated in 13 visits for 10 weeks. At discharge from physical therapy, the patient had the following outcomes relative to the noninvolved side: 100% return of normal sensation tested by light touch and vibration; pain decreased from 6/10 to 1/10; 100% reduction of swelling with ankle girth to normal; 100% range of motion of ankle and subtalar joints. Strength in plantar flexion and eversion remained 20% impaired (80% return to normal) secondary to pain. Upon discharge, he still reported mild pain when walking but was able to return to previous leisure activities. The second patient with the accessory navicular was treated in 18 visits over 9 weeks. Relative to the uninvolved side, she was discharged with the following: 70% return of range of motion in the foot and ankle, 100% of strength in hip and ankle, and 100% return of balance. She could squat and jump without pain and she returned to full premorbid activity level., Conclusions: Rehabilitative management of both cases addressed specific impairments and was successful in improving the patients' activity limitation. Clinicians should be aware that these accessory bones are possible sources of disability, secondary to foot pain.

Distal displacement of the popliteal sesamoid is a useful parameter in the interpretation of tibial compression radiographs in cases of cranial cruciate ligament rupture in the dog. An accuracy of 99 per cent and a specificity of 100 per cent were achieved by assessing the localisation of the sesamoid bone in the diagnosis of cruciate disease.

A case of congenital absence of the lateral metatarsophalangeal sesamoid bone of the hallux is reported, in a 47-year-old woman. The lateral sesamoid bone was absent on the right hallux, and extremely reduced on the left hallux. The normal intersesamoidean crest and both sesamoidean grooves of the metatarsal head were absent. Physical examination was normal, and no functional disturbance resulted from this variant. Only two previous cases have been found in the literature. It must be distinguished from a total resorption due to an infectious process, or from an absence due to surgical excision. This absence can be related to the general tendency of disappearance of the sesamoid bones within hominoid primates.

Congenital absence of the fibular sesamoid of the hallux is an extremely rare condition. We could find only one previously reported case in the literature. The authors present a second case of congenital absence of the fibular sesamoid and a review of the literature regarding the clinical significance of this anomaly.

Disorders of the hallux sesamoids and associated soft-tissue structures are commonly seen. With a differential diagnosis consisting of no fewer than 30 conditions, establishing an accurate diagnosis can be challenging but is important to appropriate treatment implementation. An understanding of first metatarsophalangeal joint anatomy, function, and current diagnostic technology aids the practitioner in the diagnosis and successful treatment of these often overlooked and anecdotally managed disorders.

The hallucal interphalangeal sesamoid is considered by some to represent an anatomical rarity that possesses little clinical significance. However, the location of this seemingly innocuous sesamoid bone directly inferior to the hallucal interphalangeal joint of the hallux is associated with the development of several important anatomical, biomechanical, and clinical pathologies. The authors present a review of the literature regarding the location, shape, ontogeny, and surgical management of the hallucal interphalangeal sesamoid. Additionally, the authors discuss the detrimental effect the hallucal interphalangeal sesamoid has on the biomechanical functions of the first metatarsophalangeal and hallucal interphalangeal joints.

From a total of 165 foot and lower leg cadaveric specimens, 38 specimens were selected by palpation of the region of the tuberosity of the navicular for the possible presence of an accessory bone. Specimens were radiographed and dissected to reveal the presence of an accessory bone and its relationship to the tibialis posterior tendon. Nineteen of the specimens exhibited hypertrophy of the tibialis posterior tendon and 19 specimens exhibited an accessory bone. Specimens exhibiting an accessory bone were divided into two categories. In one group, the accessory bone was located in the tibialis posterior tendon prior to its division and was separated from the tuberosity by at least 3 mm. In the other group, the accessory bone was located in the main segment of the tibialis posterior tendon, connected to the tuberosity of the navicular by fibrous tissue, and, in some cases, exhibited a central cavity between the accessory bone and tuberosity. The accessory bone of specimens in the first group was considered to be a sesamoid in the tibialis posterior tendon and the accessory bone in the second group was an ossicle considered to be the os tibiale externum. Linking the os tibiale externum to the tibiale component of the primitive tetrapod foot rather than to the prehallux component eliminates the use of the term "prehallux" as an alternative name for this ossicle.

Bipartite distal sesamoid bones were observed in the medial digits of both forelimbs of a six-month-old Holstein-Friesian calf. This paper describes the clinical and radiological (including computed tomographic) findings, and the therapy and follow-up of the case.

The sesamoid bones of the first metatarsal exhibit a special anatomic configuration, enveloped by the tendons of the flexor hallucis brevis and lying within the capsule of the first metatarsophalangeal joint. Painful conditions of the hallux sesamoid bones are many and include congenital, traumatic, arthritic, infectious, and ischemic conditions. Because of the complex anatomy and the numerous pain-sensitive structures in the region of the first metatarsophalangeal joint, a differential diagnosis can be challenging. The imaging examination should always begin with conventional radiography, including special axial and lateromedial views of the sesamoid bones. In cases in which results of routine radiography are inconclusive, scintigraphy, conventional or computed tomography, xeroradiography, or magnetic resonance imaging can be used. A thorough understanding of the anatomy; pathophysiology; and clinical, laboratory, and imaging findings is often helpful in the establishment of a diagnosis and management plan for painful conditions of the hallux sesamoid bones.

Multiple variations in partition of the hallux sesamoids have been described; however, to our knowledge, a coalition of the hallux sesamoids has never been presented. A case of coalition of the hallux sesamoids is presented and the literature is reviewed with respect to the possible significance of this anomaly.

A specimen of a bipartite sesamoid bone revealed anatomic cartilaginous continuity in the presence of radiographic osseous discontinuity. Hyaline cartilage present between the two ossific foci strongly supported the bipartite ossification process as a developmental variation.