Bipartite medial cuneiform: New frequencies from skeletal collections and a meta-analysis of previous cases

Familial occurrence of skeletal developmental anomalies as a reflection of biological relationships in a genealogically documented Central European sample (19th to 20th centuries)

Skeletal developmental anomalies (SDA) are a subject of constant interest across scientific disciplines, but still mostly as isolates and curiosities. The aim of this study was to find out to what extent the occurrence of SDA reflects documented biological relationships. The skeletal remains of 34 individuals with known genealogical data were available, members of one family over four generations (19th to 20th centuries, Bohemia, Czech Republic), including some inbred individuals. The occurrence of 89 SDA was assessed on the basis of scopic morphological evaluation and X-ray and CT examinations. The degree of similarity between individuals was calculated using a "similarity coefficient" (SC). A linear model was used to test the relationship between positive values of the SC and the relatedness of biologically related individuals. Simultaneously, based on population frequencies of the evaluated anomalies, those that could be considered familial were recorded. A statistically significant relationship between morphological similarity and the biological distance between individuals was found. The greatest similarity was found among close relatives such as parents and children, siblings, or grandparents and grandchildren. The effect of increased consanguinity on the occurrence of anomalies was not confirmed, however. Seventeen SDA shared by closely related individuals were found in the sample, supporting the documented family relationships among them. Eleven of these were selected as possibly familial, but only five were statistically significant: an elongated styloid process, a cervical block vertebrae (arch, facet joints), hamate hamulus aplasia, anteater nose sign, and incomplete fusion of the S1 spinous process. There were also 28 cases of individual occurrences of 17 different SDA, without connection to the documented relationships between individuals.

Bipartite medial cuneiform: magnetic resonance imaging findings and prevalence of this rare anatomical variant

OBJECTIVE

To describe the imaging features of bipartite medial cuneiform and to determine the prevalence of this rare anatomical variant in a large group of patients that were evaluated by magnetic resonance imaging (MRI) of the foot.

MATERIALS AND METHOD

Seven hundred and fifty-one patients that underwent MRI of the foot from May 2016 to December 2018 were included in the study (mean age 49 years; 540 females; 211 males). All MRIs were retrospectively analyzed to identify bipartite medial cuneiform. For patients with bipartite medial cuneiform, we analyzed partial and complete bipartition, the type of articulation (synchondrosis, syndesmosis, or a combination of these two), and stress changes related to abnormal motion (i.e., subchondral cysts and sclerosis). Bone marrow edema-like signal, diastasis in the cleavage plane, concomitant fractures, and the presence of the E-sign were also evaluated.

RESULTS

Nine feet from six patients presented bipartite medial cuneiform on the MRI. Six and three feet exhibited complete and partial bipartition. All patients were referred for MRI because of midfoot pain, of which two had history of trauma prior to imaging. Stress changes related to abnormal motion were observed in three feet (34%), all with complete bipartition. Bone marrow edema-like signal was recorded in five feet (55%) and diastasis in one foot (11%). No fractures were present in the bipartite medial cuneiform. All patients had E-signs.

CONCLUSION

Bipartite medial cuneiform is a rare anatomical variant occurring in 0.79% of patients who underwent foot MRI in this study. It is important to be aware of this variant as it is a cause of midfoot pain. Being familiar with the E-sign helps identify and differentiate it from a fracture.

Non-metric traits and anatomical variants that can mimic trauma in the human skeleton

This paper presents some of the more commonly encountered non-metric traits and minor anatomical variants in the adult human skeleton that can mimic or be mistaken for trauma. Distinguishing non-metric traits is contingent upon both a knowledge of potential non-metric traits as well as the normal developmental timing, location, and anatomy of maturational markers in the human skeleton. Distinguishing non-metric traits from trauma in dry bone is an essential component in establishing an accurate and thorough forensic analysis of human remains, especially as it deals with antemortem and perimortem trauma, and postmortem damage.

Os parietale partitum: Exploring the prevalence of this trait in four contemporary populations

Os parietale partitum is a variable segmentation of the parietal bone. This manifests as a parietal division in the anteroposterior or superoinferior planes that is separated by an unusual suture and can be complete or incomplete. The existence of parietal divisions was observed and documented more than 260 years ago. The main objectives of this paper are to record the incidence of this rare trait in four modern populations with no previous records of it and provide a review of the literature. Four contemporary skeletal collections from Crete (Greece), Limassol (Cyprus), Coimbra (Portugal) and Salvador (Brazil) were assessed by the authors of this paper for non-metric cranial traits. Out of 711 skulls, only three cases of parietal division were found and all three originated from the Cypriot collection. These three cases were anatomically analyzed, showing that all three cases were adult females and showed unilateral expression of the trait. Two skulls showed superoinferior division, and the third case showed anteroposterior division. Numerous other cranial non-metric traits were found in these three skulls. Based on the cemetery archives, there seems to be no genetic link between the individuals bearing this trait. Further genetic analysis is suggested in order to verify this conclusion.

Symptomatic Bipartite Medial Cuneiform: Report of Five Cases and Review of the Literature

Bipartition of the medial cuneiform is a well-described but rarely seen anatomic variant. The majority of literature focuses on anatomic description and incidents based on studies of archeological collections. Symptomatic cases can be overlooked or misdiagnosed initially given the vague complaint of pain either chronic in nature or following an acute injury that could result in a myriad of foot conditions. Treatment ranges from orthotics, immobilization, injection therapy, and surgery. Presented here is a series of 5 cases treated successfully with conservative and surgical measures.

LEVELS OF EVIDENCE

Therapeutic, Level IV.

An additional middle cuneiform?

Additional cuneiform bones of the foot have been described in reference to the medial bipartite cuneiform or as small accessory ossicles. An additional middle cuneiform has not been previously documented. We present the case of a patient with an additional ossicle that has the appearance and location of an additional middle cuneiform. Recognizing such an anatomical anomaly is essential for ruling out second metatarsal base or middle cuneiform fractures and for the preoperative planning of arthrodesis or open reduction and internal fixation procedures in this anatomical location.

Six new examples of the bipartite trapezoid bone: morphology, significant population variation, and an examination of pre-existing criteria to identify bipartition of individual carpal bones

Carpal bone bipartition is a developmental variant resulting in the division of a normally singular carpal into two distinct segments. Cases involving the scaphoid are best known, though many other carpals can be affected, including the trapezoid. Six new examples of bipartite trapezoids, identified in African and Asian anatomical and archeological samples, are reported here and compared with the eight previously known. While the site of bipartition is consistent, the resulting segments exhibit variability in their articulations with neighboring carpals. Five of the six affected trapezoids were identified in African or African-derived samples, yielding a significantly higher frequency (0.323%) of bipartite trapezoid than seen in anatomical or archeological series of European origin. Bilateral bipartite trapezoids in archeological remains from the Mid Holocene site of Gobero (Niger) are potentially the oldest bipartite carpals yet identified in humans. Their discovery may indicate that trapezoid bipartition is a condition that has been present in African populations since prehistoric times, though more data are needed. Because bipartite carpals may be symptomatic and can occur as part of syndromes, the significant population variation in frequency identified here has potential utility in both anatomical and clinical contexts. However, a comparison of the morphological appearance of bipartite trapezoids with the suggested criteria for bipartite scaphoid diagnosis indicates that these criteria are not equally applicable to other carpals. Fortunately, due to the rarity of fracture, identification of the bipartite trapezoid and separating it from pathological conditions is considerably easier than diagnosing a bipartite scaphoid.

Intraosseous and extraosseous blood supply to the medial cuneiform: implications for dorsal opening wedge plantarflexion osteotomy

BACKGROUND

Osteotomies of the medial cuneiform are commonly used to correct forefoot deformity. Bone healing occurs despite periosteal stripping of the dorsal and medial surfaces of this widely articulated bone followed by osteotomy in the midsection of the bone. The objective of this study was to characterize the blood supply of the medial cuneiform.

METHODS

Thirty matched pairs of adult cadaver legs, 60 legs total, were amputated below the knee, and arterial casts were created with India ink and latex. Soft tissues were debrided, allowing visualization of the extraosseous blood vessels. In 53 specimens the vascular supply to the medial cuneiform was photographed and recorded. Forty-nine specimens were then cleared using a modified Spälteholz technique. The intraosseous vascularity of the medial cuneiform was successfully characterized and reviewed in 48 of these specimens.

RESULTS

The extraosseous blood supply was similar to previous reports with a middle pedicle branch originating from the dorsalis pedis artery. The medial plantar and superficial medial plantar artery supplied the plantar aspect of the bone. Intraosseous analysis showed a dense capillary network throughout the cuneiform, with typically one central medial major and several minor nutrient arteries noted. Areas of hypovascularity were infrequent and when noted occurred at inconsistent locations.

CONCLUSION

These findings support the clinical suspicion that the medial cuneiform is well vascularized from multiple sources. The plantar blood supply is likely sufficient to allow bone healing after dorsal periosteal exposure and possible injury to the middle pedicle branch of the distal medial tarsal artery.

CLINICAL RELEVANCE

A medial cuneiform opening wedge osteotomy can be used to correct forefoot deformity. This study investigates the blood supply to that bone to better characterize the healing potential of the medial cuneiform.

Bipartite Medial Cuneiform: Case Report and Retrospective Review of 1000 Magnetic Resonance (MR) Imaging Studies

Objective. To present a unique case report of a Lisfranc fracture in a patient with a bipartite medial cuneiform and to evaluate the prevalence of the bipartite medial cuneiform in a retrospective review of 1000 magnetic resonance (MR) imaging studies of the foot. Materials and Methods. Case report followed by a retrospective review of 1000 MR imaging studies of the foot for the presence or absence of a bipartite medial cuneiform. Results. The incidence of the bipartite medial cuneiform is 0.1%. Conclusion. A bipartite medial cuneiform is a rare finding but one with both clinical and surgical implications.

Sports injury to a bipartite medial cuneiform in a child

We report the case of an 11-year-old boy who had sustained a soccer injury to his mid-foot. Plain radiography did not reveal any fracture to account for the severity of his symptoms or his inability to bear weight. Magnetic resonance imaging was undertaken and demonstrated the medial cuneiform to be a bipartite bone consisting of 2 ossicles connected by a synchondrosis. No acute fracture or diastasis of the bipartite bone was demonstrated; however, significant bone marrow edema was noted, corresponding to the site of the injury and his clinical point bony tenderness. This anatomic variant should be considered as a rare differential diagnosis in the skeletally immature foot. The injury was treated nonoperatively with a non-weightbearing cast and pneumatic walker immobilization, with successful resolution of his symptoms and a return to sports activity by 4 months after injury.