The middle cuneiform is the keystone of the transverse arch and is located between the medial cuneiform and lateral cuneiforms. Isolated middle cuneiform plantar dislocations are rare injuries due to their shape and ligamentous structural connections. A 20-year-old female patient was admitted to the emergency service of another clinic after a 70 kg iron tractor piece fell on her foot 20 days before she was referred to our clinic. Conservative treatment with a short leg circular cast was applied, considering that there was a fracture in the cuneiforms on X-ray imaging. The patient, who was re-evaluated at the second-week follow-up, was referred to our hospital considering the complex injury of the cuneiforms. There was tenderness over the cuneiform in the physical examination. X-ray and computed tomography images of the patient revealed plantar dislocation of the middle cuneiform bone. with subluxation of the medial cuneiform. Open reduction and internal fixation were performed for the middle cuneiform. During the six-month follow-up, the patient had no complaints and was able to do routine work. No lucency or arthritic changes were observed in the X-ray at the 22-month control. Plantar middle cuneiform dislocations are rare and late diagnosis can lead to poor results. This case is presented to emphasize the importance of considering this rare injury and using advanced imaging studies when necessary, considering the mechanism of injury.

UNASSIGNED: To use the computed tomography (CT) attenuation of the foot and ankle bones for opportunistic screening for osteoporosis.
UNASSIGNED: Retrospective study of 163 consecutive patients from a tertiary care academic center who underwent CT scans of the foot or ankle and dual-energy X-ray absorptiometry (DXA) within 1 year of each other. Volumetric segmentation of each bone of the foot and ankle was done in 3D Slicer to obtain the mean CT attenuation. Pearson\'s correlations were used to correlate the CT attenuations with each other and with DXA measurements. Support vector machines (SVM) with various kernels and principal components analysis (PCA) were used to predict osteoporosis and osteopenia/osteoporosis in training/validation and test datasets.
UNASSIGNED: CT attenuation measurements at the talus, calcaneus, navicular, cuboid, and cuneiforms were correlated with each other and positively correlated with BMD T-scores at the L1-4 lumbar spine, hip, and femoral neck; however, there was no significant correlation with the L1-4 trabecular bone scores. A CT attenuation threshold of 143.2 Hounsfield units (HU) of the calcaneus was best for detection of osteoporosis in the training/validation dataset. SVMs with radial basis function (RBF) kernels were significantly better than the PCA model and the calcaneus for predicting osteoporosis in the test dataset.
UNASSIGNED: Opportunistic screening for osteoporosis is possible using the CT attenuation of the foot and ankle bones. SVMs with RBF using all bones is more accurate than the CT attenuation of the calcaneus.

UNASSIGNED: Solitary osteochondromas are extremely rare in the bones of the foot. In the growing skeleton, few cases affecting the metatarsals and the talus have been reported. At present, there have been no reports of osteochondromas affecting the cuneiforms.
UNASSIGNED: We report the case of a 13-year-old male patient. He presented with marked prominences in the plantar surface of his left foot and pain while participating in sporting activities. Radiological examination with X-rays, computed tomography (CT) scan, and magnetic resonance imaging revealed two solitary osteochondromas growing from the medial cuneiform and the head of the 1st metatarsal. The patient was treated surgically by excision of the osteochondromas. Histological examination confirmed the diagnosis of osteochondromas. He had an uneventful recovery and returned to his sporting activities.
UNASSIGNED: Solitary osteochondroma can present in the cuneiform and metatarsal of a growing adolescent. CT scan is useful for the accurate diagnosis and surgical removal of the tumor.

The mesencephalic locomotor region (MLR) serves as an interface between higher-order motor systems and lower motor neurons. The excitatory module of the MLR is composed of the pedunculopontine nucleus (PPN) and the cuneiform nucleus (CnF), and their activation has been proposed to elicit different modalities of movement. However, how the differences in connectivity and physiological properties explain their contributions to motor activity is not well known. Here we report that CnF glutamatergic neurons are more electrophysiologically homogeneous than PPN neurons and have mostly short-range connectivity, whereas PPN glutamatergic neurons are heterogeneous and maintain long-range connections, most notably with the basal ganglia. Optogenetic activation of CnF neurons produces short-lasting muscle activation, driving involuntary motor activity. In contrast, PPN neuron activation produces long-lasting increases in muscle tone that reduce motor activity and disrupt gait. Our results highlight biophysical and functional attributes among MLR neurons that support their differential contribution to motor behavior.

BACKGROUND: Diabetes mellitus (DM) with peripheral neuropathy (PN) results in foot deformity increasing ulceration, joint dislocation, and amputation risk. This study describes the frequency and severity of foot and ankle musculoskeletal abnormalities and their relationship to radiographic alignment in people with DMPN with (DMPN + MCD) and without (DMPN - MCD) medial column deformity (MCD) compared to age- and body mass index-matched controls without DMPN or MDC.
METHODS: DMPN + MCD (n = 11), DMPN - MCD (n = 12), and controls (n = 12) were studied. A radiologist scored foot and ankle magnetic resonance images (MRI) for abnormalities in tendons/fascia, ligaments, muscles, joints, and bones. Higher scores represent greater abnormalities. Foot alignment was measured from lateral weightbearing radiographs. Frequency of abnormalities between groups and relationships between abnormalities and foot alignment in the combined group (n = 35) were examined.
RESULTS: DMPN + MCD had higher total muscle, joint, and bone scores compared to controls and higher total joint scores than DMPN - MCD. DMPN - MCD had higher total muscle scores than controls. DMPN + MCD higher bone and joint scores were driven by increased frequency of osteophytes, cartilage damage, focal bone marrow edema, new bone formation, and subchondral cysts. Significant correlations included cuboid height and total bone and joint scores (ρ = -0.37 and ρ = -0.40, respectively) and talar declination angle and total joint score (ρ = 0.38).
CONCLUSIONS: High contrast resolution MRI allowed identification of structural lesions of the foot affecting the cartilage surfaces, bone marrow, and soft tissue supports in patients with DMPN + MCD. As expected, the presence of bone and joint lesions on MRI were strongly associated with DMPN + MCD; surprisingly, although the sample is small, lesions of the soft tissue supports were not associated with MCD. While MRI is not done routinely to investigate MCD, opportunistic use of the information from MRI done for the common clinical indications may allow early identification of the structural lesions associated with MCD and facilitate early, aggressive therapy.
METHODS: III.

Activation of the defence reaction inhibits the baroreflex response via the intermediate rostro-ventromedial medulla (B3 raphé) and nucleus tractus solitarius (NTS). Our aim was to determine whether and how baroreflex inhibition, induced by the disinhibition of the rostral cuneiform nucleus (part of the defence pathway), involves 5-HT neurons in B3 and 5-HT3 receptors in the NTS.
We performed immunohistochemistry and anatomical experiments to determine whether raphé 5-HT cells expressing Fos were directly targeted by the rostral cuneiform nucleus. The effect of blocking raphé 5-HT neurotransmission and NTS 5-HT3 receptors on cuneiform-induced inhibition of the baroreflex cardiac response were also analysed.
Bicuculline, microinjected into the rostral cuneiform nucleus, induced an increase of double-labelled Fos-5-HT-IR cells in both the lateral paragigantocellular nucleus (LPGi) and raphé magnus. The anterograde tracer Phaseolus vulgaris leucoaggutinin injected into the rostral cuneiform nucleus revealed a dense projection to the LPGi but not raphé magnus. Cuneiform-induced baroreflex inhibition was prevented by B3 injection of 8-OH-DPAT, a selective 5-HT1A receptor agonist. Cuneiform disinhibition also failed to inhibit the baroreflex bradycardia after NTS microinjection of the 5-HT3 receptor antagonist granisetron and in 5-HT3 receptor knockout mice.
The rostral cuneiform nucleus participates in the defence inhibition of the baroreflex bradycardia via direct activation of the LPGi and via a projection to the raphé magnus to activate NTS 5-HT3 receptors and inhibit second-order baroreflex neurons. These data bring new insights in primary and secondary mechanisms involved in vital baroreflex prevention during stress.

UNASSIGNED: The purpose of this study was to evaluate clinical and radiological outcomes at skeletal maturity after a calcaneo-cuboid-cuneiform osteotomy (triple C osteotomy) for symptomatic flatfoot deformity compared with healthy young adult controls.
UNASSIGNED: Nineteen patients (30 feet) who undergone a triple C osteotomy for idiopathic symptomatic flatfeet from July 2006 to April 2013 were compared with 19 controls (38 feet). Radiographic measurements at preoperative examination, 1-year postoperative follow-up, and follow-up at skeletal maturity were evaluated. Functional outcomes were assessed by using the validated visual analog scale foot and ankle (VAS-FA) and the modified American Orthopaedic Foot and Ankle Surgery (AOFAS) score.
UNASSIGNED: In the triple C osteotomy group, 11 of 12 radiographic measurements were significantly improved at 1 year postoperatively and the last follow-up (p < 0.001). There was no recurrence at skeletal maturity (p > 0.05). There were no significant differences in nine of 12 radiographic measurements between the triple C osteotomy group at maturity and the control group (p > 0.05). Average VAS-FA and AOFAS scores were significantly improved at the time of skeletal maturity (p < 0.001).
UNASSIGNED: Surgical correction of symptomatic flatfoot deformity in childhood resulted in favorable outcomes after the triple C osteotomy. Deformity correction was also maintained during follow-up at skeletal maturity.

A 13-year-old female soccer and basketball athlete presented with pain in the arch of her foot. Magnetic resonance imaging confirmed the diagnosis of a middle cuneiform stress fracture. The patient\'s stress fracture healed nonoperatively over a 10-week period complicated by nonadherence to a fracture boot, after which she was progressed back to full activity. Knowledge of these fractures and their treatment are important for sports medicine physicians, as they can often be overlooked, given their infrequent occurrence. There have been 8 previous case reports and 1 case series on cuneiform stress fractures, and these are summarized with this case report.

UNASSIGNED: Hypermobility within the first tarsometatarsal (TMT) joint is a predisposing factor for hallux valgus. The purpose of this study was to assess whether the shape and angulation of the first TMT joint are affected by the positioning of the foot in radiographs.
UNASSIGNED: Ten adult above-knee fresh-frozen cadaveric specimens were placed into a radiolucent apparatus that allowed controlled angulation of each foot at 0, 5, 10, 15, and 20 degrees in dorsiflexion, plantarflexion, inversion, and eversion. For each specimen, the first TMT joint angle (1TMTJA), shape of the distal articular surface of the medial cuneiform (flat or curved), and image quality of the first TMT joint were measured.
UNASSIGNED: The mean value for 1TMTJA was 22.9 degrees (95% confidence interval [CI] 21.9-24). Individual anatomical variations of the specimens as well as the different angulations due to foot positioning significantly influenced the 1TMTJA (both P < .001). Joints that were found to have a flat configuration showed significantly increased 1TMTJA on average when compared to the ones with curved articular surface, 25.9 (95% CI 24.4-27.4) and 20.8 degrees (95% CI 19.5-22.0) (P < .001), respectively. Image quality for visualization of the first TMT joint was progressively better for increased angles of dorsiflexion and inversion.
UNASSIGNED: The shape and angulation of the first TMT joint on radiographic evaluation are affected by the positioning of the foot.
UNASSIGNED: Clinical usefulness of these radiographic characteristics is limited and should not influence operative planning in patients with possible instability of the first TMT joint.

Intercuneiform arthrodesis is often required for various midfoot pathologies; however, intercuneiform screw insertion is not easy due to the complicated anatomical structure of cuneiforms. This study aimed to determine the advisable screw entry point and direction using intraoperatively detectable landmarks. The computed tomography (CT) scan data of feet were reformatted using OsiriX software multiplanar reconstruction. First, based on the data of 10 CT scans of normal feet, we determined the advisable screw entry point at the upper one-third in the dorsoplantar direction and center in the anteroposterior direction on the medial aspect of the medial cuneiform and insertion direction toward the outermost point of the base of the fifth metatarsal in the axial plane and parallel to the plantar surface in the coronal plane. Second, we examined the accuracy of these newly designed guideposts in the simulation using other CT scan data of the other 27 normal feet and 12 flat feet. The simulated screw trajectory penetrated the mid three-fifths of all three cuneiforms in 97% of the normal feet and 92% of the flat feet with no cases of cortical wall violation. Levels of Evidence: Level V: Expert opinion.