Congenital absence of the lateral metatarso-phalangeal sesamoid bone of the human hallux: a case report

Factors influencing medial sesamoid arthritis in patients with hallux valgus deformity: Magnetic resonance imaging evaluation

BACKGROUND

The importance of preoperative evaluation of the position and degree of arthritic changes of the medial sesamoid bone before hallux valgus correction is emerging. This is an observational study to evaluate the magnetic resonance imaging (MRI) findings of hallux valgus deformity, and assess the severity of and identify the factors that influence the arthritic changes in medial sesamoid-metatarsal (mSM) joints.

METHODS

We reviewed weight-bearing anteroposterior radiographs, forefoot axial radiographs and MR images of 514 feet of 405 patients who underwent hallux valgus correction. On MRI, the degrees of the arthritic changes in the first metatarsophalangeal (MTP) and mSM joints were categorized into 5 classes. Binary logistic regression analysis was performed to identify the factors affecting the arthritic changes.

RESULTS

The binary logistic regression analysis showed that advanced age, more lateralized position of medial sesamoid bone on forefoot axial radiograph, and higher MRI grade of arthritic change of the 1st MTP joint were significant factors contributing to medial sesamoid arthritis (P<0.001, 0.001. 0.006, respectively).

CONCLUSIONS

Medial sesamoid arthritis can be assessed using MRI. The position of medial sesamoid bone on forefoot axial radiographs can strongly help predict the possibility of mSM joint arthritis.

LEVEL OF EVIDENCE

III, observational study.

Sesamoids in tetrapods: the origin of new skeletal morphologies

Along with supernumerary bones, sesamoids, defined as any organized intratendinous/intraligamentous structure, including those composed of fibrocartilage, adjacent to an articulation or joint, have been frequently considered as enigmatic structures associated with the joints of the skeletal system of vertebrates. This review allows us to propose a dynamic model to account for part of skeletal phenotypic diversity: during evolution, sesamoids can become displaced, attaching to and detaching from the long bone epiphyses and diaphysis. Epiphyses, apophyses and detached sesamoids are able to transform into each other, contributing to the phenotypic variability of the tetrapod skeleton. This dynamic model is a new paradigm to delineate the contribution of sesamoids to skeletal diversity. Herein, we first present a historical approach to the study of sesamoids, discussing the genetic versus epigenetic theories of their genesis and growth. Second, we construct a dynamic model. Third, we present a summary of literature on sesamoids of the main groups of tetrapods, including veterinary and human clinical contributions, which are the best-studied aspects of sesamoids in recent decades. Finally, we discuss the identity of certain structures that have been labelled as sesamoids despite insufficient formal testing of homology. We also propose a new definition to help the identification of sesamoids in general. This review is particularly timely, given the recent increasing interest and research activity into the developmental biology and mechanics of sesamoids. With this updated and integrative discussion, we hope to pave the way to improve the understanding of sesamoid biology and evolution.

Congenital missing tibial sesamoid in a marathon runner: a case report

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.

Distribution patterns and coincidence of sesamoid bones at metatarsophalangeal joints

PURPOSE

Our aim was to identify the incidence and distribution of sesamoid bones plantar to the metatarsophalangeal (MTP) joints in adults, and to evaluate patterns of coincidence among these sesamoid bones.

METHODS

We conducted a retrospective review of 7949 plain radiographs obtained from patients evaluated for foot trauma or symptomology. Associations between the distributions of MTP sesamoid bones as well as the association of age, sex, and laterality with identified prevalence, distribution, and coincidence were evaluated using Spearman's correlation coefficient.

RESULTS

Overall, 17,060 sesamoid bones were identified for 9005 MTP joints, with 16 distinctive distribution patterns. Among possible patterns, we identified a prevalence rate of complete absence of MTP sesamoid of 0.04 %, of a single sesamoid at the hallux of 89.08 % of radiographs; and of sesamoid at ≥2 MTP joints of 10.88 %. The presence of a sesamoid at the hallux was consistent, and was not correlated with the presence or absence of a sesamoid bone at one of the other MTP joints (P > 0.05). However, there was a positive correlation between the presence and absence of sesamoid bones at any two of the other four MTP joints (P < 0.001). Age was positively correlated with both the total number of sesamoids present (P < 0.001) and the number of MTP joints with sesamoids (P < 0.001).

CONCLUSIONS

Information from this study would assist clinicians in the diagnosis of patients presenting with pain and discomfort of the foot after trauma and overuse, as well as contribute a robust data set for research in forensic science and anthropology.

The metatarsosesamoid joint: an in vitro 3D quantitative assessment

BACKGROUND

The anatomy of the first metatarsophalangeal (MTP) joint, particularly the metatarsosesamoid articulation, remains poorly understood. Our goal was to quantitatively define the excursion of the sesamoids.

METHODS

Seven cadavers were dissected to assess the articulating surfaces throughout a normal range of motion. The dissections were digitally reconstructed in various positions using a MicroScribe.

RESULT

For first MTP joint, excursion averaged 14.7mm for the tibial sesamoid in the sagittal plane and 7.5mm for the fibular sesamoid. The sesamoids also moved medially to laterally when the joint was dorsiflexed. For the maximally dorsiflexed joint, excursion averaged 2.8mm for the tibial sesamoid and 3.5mm for the fibular sesamoid.

CONCLUSION

Hallucal sesamoids appear to have differential tracking: the tibial sesamoid has greater longitudinal excursion; the fibular sesamoid has greater lateral excursion. The anatomical data will interest those involved with the design of an effective hallux arthroplasty.

Hallux valgus deformity associated with bilateral absence of the tibial and fibular hallucal sesamoids

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.

Bilateral tibial hallux sesamoid agenesis and fibular hallux sesamoid hypoplasia in a patient with bilateral hallux valgus

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.

Adolescent hallux valgus deformity with bilateral absence of the hallucal sesamoids: a case report

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.

Hallux, sesamoid, and first metatarsal injuries

Hallux, sesamoid, and first metatarsal injuries are common foot injuries and have implications in the biomechanical functionality of the first ray and foot. They are essential for propulsion in normal gait. As part of the first ray, it is an important contributor to normal locomotion. Any structure disruption or injury can create angular changes or arthritis, which can have biomechanical implications, including pain, disability, compensation, swelling, and reduced range of motion.

Distribution of the metatarsophalangeal sesamoids in Turkish subjects

No statistically significant pattern of metatarsophalangeal sesamoid distribution has been reported in the literature in relation to genetic pool or group, unilaterality or bilaterality, or sesamoid division. A study was undertaken to evaluate the presence and distribution of the metatarsophalangeal sesamoid bones of the foot in Turkish subjects. A total of 602 foot radiographs from 371 patients without forefoot complaints other than those of the hallux were included in the study. Absence or hypoplasia of the first-ray sesamoids was seen on 0.7% of the radiographs, and second-, third-, fourth-, and fifth-ray sesamoids were present on 2.8%, 0.5%, 1.0%, and 15.1% of the radiographs, respectively. Fifth-ray sesamoids were more prevalent in men (odds ratio, 2.71; 95% confidence interval, 1.52-4.84). The frequency of a normal foot profile (two sesamoids in the first ray) was 83.2%. Divisions of the sesamoids were seen on 4.0% of the radiographs at the first ray and on 20.9% at the fifth ray. Distribution and division of sesamoids were predominantly bilateral (kappa = 0.91, 0.91, and 0.95 for the first, second, and fifth digits, respectively; P < .001).

Absence of the medial sesamoid bone associated with metatarsophalangeal pain

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.