Hallucal sesamoiditis on a bipartite sesamoid bone: An uncommon cause of chronic great toe pain

The pathologies and lesions affecting the sesamoid bones of the hallux are uncommon and can be easily overlooked. Among them, sesamoiditis is a relatively rare condition known to cause severe great toe pain; lack of awareness of this particular entity leads to misdiagnosis, delayed treatment, and contributes to significant morbidity. Herein, we present a chronic sesamoiditis case occurring on a medial bipartite sesamoid bone, presenting as chronic great toe pain. The main purpose of this work is to discuss the role of magnetic resonance imaging and X-rays in the diagnosis process. To the best of our knowledge, no cases of great toe sesamoiditis occurring on a bipartite bone in no-athletic patients have yet been reported.

The Relationship Between Ossification in Metacarpophalangeal Sesamoids of the Thumb and the Period of Puberty: A Radiographic Study

Objective

The current study aimed to determine the onset of sesamoid bones (Sbs) ossification at the thumb metacarpophalangeal (MCP) joint of the hand and its relationship with puberty.

Methods

This retrospective radiographic study included patients aged 5-17 years. The presence of Sbs was investigated separately for each age group. Patients were classified based on their age, gender, and the presence of radial and ulnar sesamoids.

Results

A total of 1,020 radiographs from 939 patients were analyzed. Sbs began to ossify in girls at the age of 8 years and in boys at the age of 9 years. The ulnar-radial sesamoids were present in all individuals in the same age group at the age of 13-14 years in girls and 15 years in boys. The age at which 50% of the individuals in the same age group had a sesamoid was 10.4 years in girls and 11.9 years in boys on the radial side, 9.5 years in girls, and 11.5 years in boys on the ulnar side.

Conclusions

In all individuals, the time between the onset of sesamoids of the MCP joint and development corresponds to the physiological period of puberty. However, the age at which puberty begins coincides with the time when Sbs begin to ossify in 50% of both sexes in the same age group.

Asymptomatic foot and ankle structural injuries: a 3D imaging and finite element analysis of elite fencers

BACKGROUND

Fencing is a highly asymmetrical combat sport, that imposes high mechanical demands over repeated exposures on the musculoskeletal structures, a primary cause of injuries in fencers. However, there are limited epidemiological studies on the structural injuries of the foot and ankle in fencers. This study aimed to investigate foot and ankle structural injuries, and explore how metatarsophalangeal joint structural changes may affect the mechanisms of foot and ankle injuries in asymptomatic fencers.

METHODS

3D images of foot and ankle morphology using computed tomography were obtained from ten elite fencers. We then constructed finite element models of the first metatarsophalangeal joint in the foot of their trail legs. The validated models were used to simulate stress distribution changes from different ankle joint angles during lunging.

RESULTS

The findings showed that stress distribution changes at the medial and lateral sesamoid may have caused sesamoid fractures, and that habitual and concentrated stress on the metatarsal bones might have flattened the sesamoid groove. This process may damage the integrity of the first metatarsophalangeal joint, and consequently affect the efficiency of the windlass mechanism in fencers. During lunging, different ankle joint angles of the trail foot increased the total stress difference of the medial and lateral foot, and thus influenced the lunging quality and its stability.

CONCLUSIONS

Our findings revealed that the asymmetric nature of fencing might have caused asymptomatic foot and ankle structural injuries, and finite element analysis results indicated that this might increase the incidence of the serious injuries if unattended. Regular computed tomography examination should be introduced to monitor elite fencers' lower limb alterations, permitting unique angle adjustments in the trail foot without sacrificing technical or physiologic properties based on the exam results and reduce the lower limb injury risk.

Correlation between indirect radiographic parameters of first metatarsal rotation in hallux valgus and values on weight-bearing computed tomography

PURPOSE

To verify if indirect radiographic signs of first metatarsal pronation, determined by the head round sign, correspond to weight-bearing computed tomography (WBCT) measurements.

METHODS

In this case-control retrospective study, we analyzed 26 hallux valgus (HV) feet and 20 controls through conventional radiograph (CR) and WBCT images. Two blinded orthopaedic foot and ankle surgeons performed the measurements. Pronation classification (head roundness), head diameter (HD), traditional HV angles, arthritis, sesamoid positioning, and first metatarsal rotation angle (MRA) (alpha angle) were evaluated. Comparisons were performed by Student's T-test and a multivariate regression was executed. P-values less than 0.05 were considered significant.

RESULTS

Mean values were higher in HV patients than controls when evaluating MRA (11.51 [9.42-13.60] to 4.23 [1.84-6.62], 95%CI), HD (22.35 [21.52-23.18] to 21.01 [20.07-21.96]), and sesamoid rotation angle (SRA) (26.72 [24.09-29.34] to 4.56 [1.63-7.50]). The MRA had a low influence in head roundness classification (R²: 0.15). Changes in the pronation classification were explained chiefly by the sesamoid station (SS) (R²: 0.37), where stations 4 to 7 were found to be strong predictors of roundness classifications 2 and 3.

CONCLUSION

Indirect signs of metatarsal pronation, determined by the head round sign, correlate weakly with the alpha angle measured in WBCT. The presence of arthritis and sesamoids displacement might modify the perception of first head roundness. The influence of MRA in the classification was low, where SS from 4 to 7 was strong predictors of a higher pronation classification.

Fracture of the ulnar sesamoid bone of the thumb with a concurrent ulnar collateral ligament tear: A case report

While the ulnar sesamoid bone of the thumb and the ulnar collateral ligament (UCL) are in close anatomic proximity, concurrent injury to these structures has not been reported. We report a case of such an injury in a 53-year-old male after an altercation. He was treated with surgical repair of the UCL, postoperative immobilization, and a graduated rehabilitation program consisting of range of motion and strengthening exercises. After review of the literature, we recommend that clinicians consider not just a volar plate injury, but also a UCL injury, in patients presenting with radiographic evidence of a sesamoid fracture. Clinicians should have a low threshold for advanced imaging in these patients to confirm any suspected ligamentous injury.

Evolution of the patella and patelloid in marsupial mammals

The musculoskeletal system of marsupial mammals has numerous unusual features beyond the pouch and epipubic bones. One example is the widespread absence or reduction (to a fibrous “patelloid”) of the patella (“kneecap”) sesamoid bone, but prior studies with coarse sampling indicated complex patterns of evolution of this absence or reduction. Here, we conducted an in-depth investigation into the form of the patella of extant marsupial species and used the assembled dataset to reconstruct the likely pattern of evolution of the marsupial patella. Critical assessment of the available literature was followed by examination and imaging of museum specimens, as well as CT scanning and histological examination of dissected wet specimens. Our results, from sampling about 19% of extant marsupial species-level diversity, include new images and descriptions of the fibrocartilaginous patelloid in Thylacinus cynocephalus (the thylacine or “marsupial wolf”) and other marsupials as well as the ossified patella in Notoryctes ‘marsupial moles’, Caenolestes shrew opossums, bandicoots and bilbies. We found novel evidence of an ossified patella in one specimen of Macropus rufogriseus (Bennett’s wallaby), with hints of similar variation in other species. It remains uncertain whether such ossifications are ontogenetic variation, unusual individual variation, pathological or otherwise, but future studies must continue to be conscious of variation in metatherian patellar sesamoid morphology. Our evolutionary reconstructions using our assembled data vary, too, depending on the reconstruction algorithm used. A maximum likelihood algorithm favours ancestral fibrocartilaginous “patelloid” for crown clade Marsupialia and independent origins of ossified patellae in extinct sparassodonts, peramelids, notoryctids and caenolestids. A maximum parsimony algorithm favours ancestral ossified patella for the clade [Marsupialia + sparassodonts] and subsequent reductions into fibrocartilage in didelphids, dasyuromorphs and diprotodonts; but this result changed to agree more with the maximum likelihood results if the character state reconstructions were ordered. Thus, there is substantial homoplasy in marsupial patellae regardless of the evolutionary algorithm adopted. We contend that the most plausible inference, however, is that metatherians independently ossified their patellae at least three times in their evolution. Furthermore, the variability of the patellar state we observed, even within single species (e.g. M. rufogriseus), is fascinating and warrants further investigation, especially as it hints at developmental plasticity that might have been harnessed in marsupial evolution to drive the complex patterns inferred here.

Ultrasound diagnosis and follow-up of a locked thumb metacarpophalangeal joint caused by radial sesamoid entrapment: a case report

Background

A locked thumb metacarpophalangeal joint is a rare condition that presents as restricted joint motions with mild hyperextension deformity, usually after a relatively minor hyperextension injury. Owing to the limitations of radiographs, computed tomography is a useful diagnostic imaging modality for assessing sesamoid displacement. However, despite its convenience, ultrasound findings of the locked thumb have rarely been reported. Here, we report a case of a locked thumb metacarpophalangeal joint diagnosed and followed-up using ultrasound.

Case presentation

A 15-year-old boy with a locked thumb metacarpophalangeal joint presented to our hospital. On physical examination, the 1st metacarpophalangeal joint was found to be hyperextended, and active and passive flexions were not possible. While radiographs were inconclusive, ultrasound revealed radial sesamoid entrapment at the 1st metacarpophalangeal joint causing locking. After closed manual reduction, metacarpophalangeal motions recovered. Success of the reduction was also confirmable by ultrasound.

Conclusions

Ultrasound can be a feasible modality to diagnose a locked thumb metacarpophalangeal joint and immediately judge the success or failure of the reduction.

Functional and patient reported outcomes following lateral hallucal sesamoidectomy

BACKGROUND

Lateral hallucal sesamoidectomy is an infrequently performed procedure indicated for patients with sesamoid pathology failing conservative treatment. Concerns exists regarding patient satisfaction, plantar scar pain, hallux malalignment and metatarsophalangeal joint (MTPJ) movement restriction following sesamoidectomy. This study aims to assess patient satisfaction after lateral hallucal sesamoidectomy via the plantar approach.

METHODS

In this retropective study with prospective follow-up, all patients who underwent lateral hallucal sesamoidectomy between January 2004 and December 2017 were reviewed. Twelve patients (14ft.) were available for final assessment. Outcome measures were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) clinical rating scale and the Self-Reported Foot and Ankle questionnaire (SEFAS). Patients were assessed clinically and radiologically. The average postoperative follow-up was 111.5 months (range 28-177 months).

RESULTS

All patients reported excellent outcome scores with a mean SEFAS score of 46.08 (range 43-48) and a mean AOFAS score of 92.33 (range 78-100) at final follow-up. All twelve patients reported their outcome as being excellent. No malalignment was noted clinically, however, three patients had a noticeable increase in the gap between the hallux and second toe when compared to the contralateral side. Range of motion at the MTPJ was preserved with a mean dorsiflexion of 80.83° (range 70-90°) and a mean plantarflexion was 25.83° (range 0-30°). None of the patients experienced any pain, discomfort or irritation related to the plantar scar. One patient developed neuroma like symptoms in the first web space.

CONCLUSION

Lateral hallucal sesamoidectomy via a plantar approach is an effective and reliable treatment option as demonstrated by the high levels of patient satisfaction, preservation of function, excellent PROM scores and limited complications in this study.

LEVEL OF EVIDENCE

Level 4.

A symptomatic cyamella in the popliteus tendon causing snapping knee: a case report and literature review

Background

Cyamella,the sesamoid bones of the popliteus muscle, are rare in humans. Snapping knee is an uncommon problem which can be difficult to diagnose.

Case presentation

In this case, we report a 24-year-old male with snapping knee caused by symptomatic cyamella in the popliteus tendon. A large cyamella was identified upon surgery and was removed. Postoperatively, the patient had immediate relief of preoperative symptoms, and there were no signs of recurrence after 1 years of follow-up.

Conclusions

Although not previously suggested, symptomatic cyamella in the popliteus tendon should be considered as part of the differential diagnosis of the snapping knee.

Popliteal artery entrapment by an enlarged sesamoid bone

A 64-year-old woman came to our hospital because of intermittent claudication of her left leg. She had undergone meniscectomy of the left knee in her 30s. The ankle-brachial pressure index of the left leg was 0.70. Imaging examinations showed occlusion of the popliteal artery compressed by an enlarged sesamoid bone with osteophytes. No anatomic abnormalities of vessels and muscles were seen. A particular type of popliteal entrapment syndrome was diagnosed. After resection of the sesamoid bone, thromboendarterectomy and patch plasty were performed. After the operation, the claudication was improved, and the ankle-brachial pressure index of the left leg increased to 0.91.

Establishing a common instantaneous center of rotation for the metatarso-phalangeal and metatarso-sesamoid joints: a theoretical geometric model based on specific morphometrics

BACKGROUND

Previous research has identified separate sagittal plane instantaneous centers of rotation for the metatarso-phalangeal and metatarso-sesamoid joints, but surprisingly, it does not appear that any have integrated the distinctive morphological characteristics of all three joints and their respective axes into a model that collectively unifies their functional motions. Since all joint motion is defined by its centers of rotation, establishing this in a complicated multi-dimensional structure such as the metatarso-phalangeal-sesamoid joint complex is fundamental to understanding its functionality and subsequent structural failures such as hallux abducto valgus and hallux rigidus.

METHODS

Based on a hypothesis that it is possible to develop an instantaneous center of rotation common to all four osseous structures, specific morphometrics were selected from a sequential series of 0.5-mm sagittal plane C-T sections in one representative cadaver specimen randomly selected from a cohort of nine, seven which were obtained from the Body Donation Program, Department of Anatomy, University of California, San Diego School of Medicine, and two which were in the possession of one author (MD). All mature skeletal specimens appeared grossly normal, shared similar morphological features, and displayed no evidence of prior trauma, deformity, or surgery. Specific C-T sections isolated the sagittal plane characteristics of the inter-sesamoidal ridge and each sesamoid groove, and criteria for establishing theoretical sesamoid contact points were established. From these data, a geometric model was developed which, to be accurate, had to closely mimic all physical and spatial characteristics specific to each bone, account for individual variations and pathological states, and be consistent with previously established metatarso-phalangeal joint functional motion.

RESULTS

Sequential sagittal plane C-T sections dissected the metatarsal head from medial to lateral and, at approximately midway through the metatarsal head, the circular nature of the inter-sesamoidal ridge (crista) was isolated; other C-T sections defined, respectively, the elliptical characteristics of the tibial (medial) and fibular (lateral) sesamoid grooves in each specimen. A general plane model representing the most basic form of the joint was developed, and its center of rotation was established with a series of tangential and normal lines. Simplified tibial sesamoid and fibular plane models were developed next which, when combined, permitted the development of a spherical model with three separate contact points. Based on the morphometrics of each sesamoid groove and a more distally positioned tibial sesamoid, the model was modified to accurately define the center of rotation and one distinctive sagittal plane geometric and functional characteristic of each groove.

CONCLUSION

Consistent with our hypothesis, this theoretical geometric model illustrates how it is possible to define an instantaneous center of rotation common to all three joints while simultaneously accounting for morphometric and spatial variability. This should provide additional insight into metatarso-phalangeal-sesamoid joint complex functionality and the physical characteristics that contribute to its failure.

Avascular Necrosis of the Sesamoids

Avascular necrosis (AVN) of the sesamoid is pathology of the medial or lateral hallucal sesamoid resulting in pain under the first metatarsophalangeal joint often presenting in young female athletes. There is overlap of stress fracture, nonunion, and AVN that makes defining the diagnosis difficult but the treatment and outcomes are similar. The most reliable operative treatment used for AVN of the sesamoid is an accumulation of anatomic and mechanical factors with repetitive microtrauma. Nonoperative modalities are designed to offload the sesamoid. The only operative treatment used for AVN of the sesamoid is excision of the involved bone, which results most commonly in complete patient satisfaction.

Hallux valgus assessment on X-ray and Magnetic resonance Imaging (MRI): Correlation with qualitative soft tissue and internal derangement findings on MRI

AIM

Radiographs (X-rays) are used for the preoperative assessment of hallux valgus (HV). Our purpose was to determine how well quantitative measurements of HV on radiographs and MRI correlate with the qualitative soft tissue and internal derangement findings on MRI.

MATERIALS AND METHODS

After IRB approval, 56 consecutive patients with MRI and radiographs of the foot were retrospectively reviewed. Two trained readers independently evaluated radiographs, measuring hallux valgus angle (HVA) and intermetatarsal angle (IMA). Two separate readers assessed qualitative MRI data by evaluating 21 different soft tissue and bony features. Statistical analysis included inter-reader reliability (IRR) and correlation of quantitative and qualitative findings.

RESULTS

Excellent IRR (ICC = 0.89-0.96) was observed for radiograph and MRI measurements of the hallux valgus severity. For qualitative assessments on MRI, IRR was good to excellent for all features (ICC = 0.63-0.9). No significant difference was found for HVA or IMA between normal and abnormal qualitative MRI features. No statistically significant correlation between the severity of hallux valgus and injury to hallux joints and supporting structures was found.

CONCLUSION

Hallux valgus measurements are reliable on x-rays and MRI and qualitative findings of 1st MTP joint show good to excellent inter-reader agreement on MRI. No statistically significant correlations exist between the severity of hallux valgus and qualitative MRI findings.

Assessment of the efficacy of SERI osteotomy for hallux valgus correction

BACKGROUND

SERI (Simple, Effective, Rapid, and Inexpensive) osteotomy is an accepted minimally invasive distal first metatarsal osteotomy performed to correct hallux valgus (HV). In the absence of reports of efficacy of the SERI technique in the Middle East, we studied 1-year outcomes of SERI osteotomy performed at our hospital in Saudi Arabia.

METHODS

We reviewed the medical charts of patients aged 20 to 60 years who underwent SERI osteotomy for HV between August 2013 and September 2016 and identified 29 patients, 2 (6.9%) men and 27 (93.1%) women, who met the criteria for inclusion in the study. Patients' clinical and operative characteristics were examined, their pre- and postoperative (1-year) radiographic measurements were compared, and the occurrence of any postoperative complication/event was noted.

RESULT

Patients' mean age was 34.9 ± 13.6 years. Six patients (20.7%) were treated for severe HV. Mean operation time was 11.1 ± 2.3 min. Four patients (13.8%) reported postoperative pain. No revision surgery was done. Congruency of the hallux metatarsophalangeal joint increased significantly, documented in only 4 patients (13.8%) preoperatively but in 17 (58.6%) at 1 year. The mean hallux valgus angle (HVA), intermetatarsal angle (IMA), and distal metatarsal articular angle (DMAA) were significantly decreased at 1 year. The HVA normalized in 20 patients (69.0%), the IMA normalized in 25 patients (86.2%), but the DMAA normalized in only 4 patients (13.8%). The number of patients with sesamoid subluxation decreased from 29 (100%) to 13 (44.8%).

CONCLUSION

Our study data indicate that SERI osteotomy reliably reduces a wide spectrum of HV deformities and it is a safe procedure with very minimal complications.

TRIAL REGISTRATION

This study is registered in ClinicalTrials.gov under the following reference number: NCT03669900 .

Osteoid osteoma of the sesamoid bone: An unusual localization

Osteoid osteoma is the most common benign bone tumor because it accounts for 10-12% of all these tumors. Localized most often with long bones (75% of cases), especially in the tibia and femur, osteoid osteoma can evoke other etiologies, especially when it is juxta-articular. We report the case of an osteoid osteoma of the sesamoid in a 23-year-old patient with no particular history who presented pain at the root of his hallux evolving for 6 months. The clinical examination was without abnormalities. Standard X-rays found no lesions. The tomodensitometry of the foot showed an image "cockade" with a peripheral sclera ring. The patient underwent surgical excision with simple operative follow-up and disappearance of pain at one year of follow-up. The histopathological study confirmed the diagnosis. The osteoid osteoma of the sesamoid bone is exceptional. The diagnosis may be delayed due to misleading "articular" symptomatology.

Evaluation of the 1st metatarso-sesamoid joint using standing CT - The Stanmore classification

BACKGROUND

Little is understood about the role that relative sesamoid displacement and chondral wear have on outcome after hallux valgus (HV) surgery. All existing methods to evaluate relative sesamoid displacement have limitations and furthermore, there have been no radiographic studies evaluating metatarso-sesamoid joint wear. Standing CT scan circumvents many of the existing problems in evaluation of relative sesamoid displacement, and also enables the first radiographic study assessing metatarso-sesamoid joint wear.

METHODS

Fifty feet (in 43 patients) with symptomatic HV (Group A) were compared with a control group of 50 feet (50 patients) (Group B). All images were standardised to enable reproducible measurements. The hallux valgus angle, Intermetatarsal angle, sesamoid rotation angle, sesamoid position and metatarso-sesamoid joint space were measured in all patients.

RESULTS

The intra and inter-observer reliability correlation showed that the standing CT assessment of sesamoid position (1.000), rotation (0.991) and metatarso-sesamoid joint space (0.960) were highly reproducible. There was a highly significant difference (p<0.0001) in sesamoid position, sesamoid rotation and metatarso-sesamoid joint space between Group A and Group B.

CONCLUSIONS

Standing CT has been shown to be a reproducible and accurate method of assessing the relative sesamoid displacement and metatarso-sesamoid joint space narrowing. The results have been used to propose a novel standing CT based classification of hallucal sesamoids, considering the degree of displacement and wear. This classification may ultimately facilitate research to provide new insight into the effect relative sesamoid displacement and chondral wear have on outcomes from hallux valgus surgery.

Foal Fractures: Osteochondral Fragmentation, Proximal Sesamoid Bone Fractures/Sesamoiditis, and Distal Phalanx Fractures

Foals are susceptible to many of the same types of fractures as adult horses, often secondary to external sources of trauma. In addition, some types of fractures are specific to foals and occur routinely in horses under 1 year of age. These foal-specific fractures may be due to the unique musculoskeletal properties of the developing animal and may present with distinct clinical signs. Treatment plans and prognoses are tailored specifically to young animals. Common fractures not affecting the long bones in foals are discussed in this article, including osteochondral fragmentation, proximal sesamoid bone fractures/sesamoiditis, and distal phalanx fractures.

Skeletal pathology and variable anatomy in elephant feet assessed using computed tomography

Foot problems are a major cause of morbidity and mortality in elephants, but are underreported due to difficulties in diagnosis, particularly of conditions affecting the bones and internal structures. Here we evaluate post-mortem computer tomographic (CT) scans of 52 feet from 21 elephants (seven African Loxodonta africana and 14 Asian Elephas maximus), describing both pathology and variant anatomy (including the appearance of phalangeal and sesamoid bones) that could be mistaken for disease. We found all the elephants in our study to have pathology of some type in at least one foot. The most common pathological changes observed were bone remodelling, enthesopathy, osseous cyst-like lesions, and osteoarthritis, with soft tissue mineralisation, osteitis, infectious osteoarthriti, subluxation, fracture and enostoses observed less frequently. Most feet had multiple categories of pathological change (81% with two or more diagnoses, versus 10% with a single diagnosis, and 9% without significant pathology). Much of the pathological change was focused over the middle/lateral digits, which bear most weight and experience high peak pressures during walking. We found remodelling and osteoarthritis to be correlated with increasing age, more enthesopathy in Asian elephants, and more cyst-like lesions in females. We also observed multipartite, missing and misshapen phalanges as common and apparently incidental findings. The proximal (paired) sesamoids can appear fused or absent, and the predigits (radial/tibial sesamoids) can be variably ossified, though are significantly more ossified in Asian elephants. Our study reinforces the need for regular examination and radiography of elephant feet to monitor for pathology and as a tool for improving welfare.

Inter and intra-observer reliability in assessment of the position of the lateral sesamoid in determining the severity of hallux valgus

BACKGROUND

The position of the lateral sesamoid on standard dorso-plantar weight bearing radiographs, with respect to the lateral cortex of the first metatarsal, has been shown to correlate well with the degree of the hallux valgus angle. This study aimed to assess the inter- and intra-observer error of this new classification system.

METHODS

Five orthopaedic consultants and five trainee orthopaedic surgeons were recruited to assess and document the degree of displacement of the lateral sesamoid on 144 weight-bearing dorso-plantar radiographs on two separate occasions. The severity of hallux valgus was defined as normal (0%), mild (≤50%), moderate (51-≤99%) or severe (≥100%) depending on the percentage displacement of the lateral sesamoid body from the lateral cortical border of the first metatarsal.

RESULTS

Consultant intra-observer variability showed good agreement between repeated assessment of the radiographs (mean Kappa=0.75). Intra-observer variability for trainee orthopaedic surgeons also showed good agreement with a mean Kappa=0.73. Intraclass correlations for consultants and trainee surgeons was also high.

CONCLUSION

The new classification system of assessing the severity of hallux valgus shows high inter- and intra-observer variability with good agreement and reproducibility between surgeons of consultant and trainee grades.

Subhallucal Interphalangeal Sesamoiditis: A Rare Cause of Chronic Great Toe Pain

Subhallucal interphalangeal sesamoiditis presenting as chronic great toe pain is a rarely reported clinical entity, being often overlooked and misdiagnosed for other pathologies. By altering the biomechanics of the movements at great toe, the interphalangeal sesamoid is prone to various painful pathologies like trauma, infection, degeneration, osteonecrosis and inflammation. Imaging plays an important role in narrowing down the differentials and guiding for appropriate therapy. Herein, we present a neglected case of hallucal interphalangeal sesamoiditis presenting as a case of chronic great toe pain and discuss the role of Magnetic resonance imaging (MRI) and Computed tomography (CT) scan in its diagnosis.

Structure, ontogeny and evolution of the patellar tendon in emus (Dromaius novaehollandiae) and other palaeognath birds

The patella (kneecap) exhibits multiple evolutionary origins in birds, mammals, and lizards, and is thought to increase the mechanical advantage of the knee extensor muscles. Despite appreciable interest in the specialized anatomy and locomotion of palaeognathous birds (ratites and relatives), the structure, ontogeny and evolution of the patella in these species remains poorly characterized. Within Palaeognathae, the patella has been reported to be either present, absent, or fused with other bones, but it is unclear how much of this variation is real, erroneous or ontogenetic. Clarification of the patella’s form in palaeognaths would provide insight into the early evolution of the patella in birds, in addition to the specialized locomotion of these species. Findings would also provide new character data of use in resolving the controversial evolutionary relationships of palaeognaths. In this study, we examined the gross and histological anatomy of the emu patellar tendon across several age groups from five weeks to 18 months. We combined these results with our observations and those of others regarding the patella in palaeognaths and their outgroups (both extant and extinct), to reconstruct the evolution of the patella in birds. We found no evidence of an ossified patella in emus, but noted its tendon to have a highly unusual morphology comprising large volumes of adipose tissue contained within a collagenous meshwork. The emu patellar tendon also included increasing amounts of a cartilage-like tissue throughout ontogeny. We speculate that the unusual morphology of the patellar tendon in emus results from assimilation of a peri-articular fat pad, and metaplastic formation of cartilage, both potentially as adaptations to increasing tendon load. We corroborate previous observations of a ‘double patella’ in ostriches, but in contrast to some assertions, we find independent (i.e., unfused) ossified patellae in kiwis and tinamous. Our reconstructions suggest a single evolutionary origin of the patella in birds and that the ancestral patella is likely to have been a composite structure comprising a small ossified portion, lost by some species (e.g., emus, moa) but expanded in others (e.g., ostriches).

Three-dimensional anatomy of the ostrich (Struthio camelus) knee joint

The three-dimensional anatomy of the ostrich (Struthio camelus) knee (femorotibial, femorofibular, and femoropatellar) joint has scarcely been studied, and could elucidate certain mechanobiological properties of sesamoid bones. The adult ostrich is unique in that it has double patellae, while another similar ratite bird, the emu, has none. Understanding why these patellae form and what purpose they may serve is dually important for future studies on ratites as well as for understanding the mechanobiological characteristics of sesamoid bone development. For this purpose, we present a three-dimensional anatomical study of the ostrich knee joint, detailing osteology, ligaments and menisci, and myology. We have identified seven muscles which connect to the two patellae and compare our findings to past descriptions. These descriptions can be used to further study the biomechanical loading and implications of the double patella in the ostrich.

Problems associated with the excision of the hallux sesamoids

Disorders of the hallux sesamoids can be a source of considerable pain and disability. Inappropriate or inept removal can lead to further disability and pain. Surgical intervention should only follow careful accurate assessment, appropriate investigation, and failure of conservative treatments.

Painful sesamoid of the great toe

The painful sesamoid can be a chronic and disabling problem and isolating the cause can be far from straightforward. There are a number of forefoot pathologies that can present similarly to sesmoid pathologies and likewise identifying the particular cause of sesamoid pain can be challenging. Modern imaging techniques can be helpful. This article reviews the anatomy, development and morphological variability present in the sesamoids of the great toe. We review evidence on approach to history, diagnosis and investigation of sesamoid pain. Differential diagnoses and management strategies, including conservative and operative are outlined. Our recommendations are that early consideration of magnetic resonance imaging and discussion with a specialist musculoskeletal radiologist may help to identify a cause of pain accurately and quickly. Conservative measures should be first line in most cases. Where fracture and avascular necrosis can be ruled out, injection under fluoroscopic guidance may help to avoid operative intervention.

An atraumatic turf toe in an elite soccer player--a stress related phenomenon?

Plantar plate injuries to the hallux in elite athlete could potentially be career threatening. Reports in the literature are invariably linked to a significant traumatic episode. The occurrence of an atraumatic severe plantar plate injury in the presence of a bipartite sesamoid may suggest a stress related phenomenon. We present a case in an elite soccer player who was treated surgically and returned to top-level competition. The case is reported in detail and differences to other reports in the literature discussed.

Forefoot: a basic integrated imaging perspective for radiologists

Imaging of the forefoot is increasingly requested for patients with metatarsalgia. Awareness with specific anatomic arrangements exclusive for the forefoot and widely variable pathologic entities associated with metatarsalgia helps the radiologist to tailor a cost-effective imaging approach. This will enable reaching a specific diagnosis as much as possible with subsequent proper patient management. This pictorial review aims to provide basic understanding for the different imaging modalities used in studying the forefoot. After that, certain anatomic arrangements exclusive for the forefoot are discussed. The final section of this review describes the imaging findings of some common forefoot problems.

Fractures of the lesser sesamoids: case series

We present 3 cases of sesamoid fractures involving the index, ring, and little finger metacarpophalangeal joints. These injuries present similar to more common sprains of the finger metacarpophalangeal joint and may be difficult at times to appreciate on standard posteroanterior and lateral x-rays. Oblique images can aid in making the diagnosis at times. Whereas we still recommend immobilization as the initial treatment for these injuries, all 3 of our cases failed nonoperative management and eventually required sesamoid excision.

Painful extraskeletal osteochondroma under the tarsal sesamoid: a case report and review of literature

Extraskeletal osteochondroma is a rare condition. To our knowledge, occurrence in the foot has been very rare. We present here a case wherein the patient developed a painful extraskeletal osteochondroma under the tarsal sesamoid. A fifty-one-year-old man presented at our department with a painful mass on the plantar part of the metatarsal joint of the right big toe. The mass had grown gradually in size for the past 7 months and was associated with pain while walking. Preoperative X-ray and a computed tomography showed that the tumor had no continuity with adjacent bone. Intraoperatively, a bony hard tumor was located in the subcutaneous tissue plantar to the tibial sesamoid. The mass was firmly attached to the sheath of the flexor hallucis brevis tendon. Macroscopically, the tumor was covered with glistering surface. The tumor was carefully dissected from the surrounding soft tissues and was removed. It was diagnosed as extraskeletal osteochondroma histologically. The patient had no recurrence at 1 year after operation.

Sesamoid bone blocking fracture reduction in traumatic injury of first metatarsal

We describe a patient who sustained an extra-articular, oblique and angulated first metatarsal fracture. The medial hallucal sesamoid bone was subsequently found to have entered the fracture gap preventing reduction. We describe treatment of this rare injury with a successful outcome.