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Background The accessory navicular bone is one of the most common accessory ossicles, which sometimes become symptomatic. Abnormalities in magnetic resonance (MR) image, e.g. edema-like bone marrow pattern, have been reported for symptomatic accessory navicular. However, it has not been completely understood the edema-like bone marrow pattern correlates to the symptom of navicular tuberosity. Methods We investigated the edema-like bone marrow pattern in correlation with alleviation of the symptom and the presence of accessory navicular bone. Ten adolescents with pain localized to the navicular tuberosity were recruited and seven cases were further examined with consecutive MR images. Results Edema-like bone marrow pattern was found in all symptomatic navicular but not in asymptomatic navicular. Intensity of the pattern diminished with alleviation of the symptom. Moreover, this correlation was recognized even in the patients who had no accessory navicular bones. Conclusions MR images could be used not only for diagnosis but for monitor of healing in adolescent symptomatic navicular. There may be different pathologic mechanism for adolescent symptomatic navicular tuberosity, such as an osteitis, in adolescents.

Background:Foot problems are reported by approximately 70% to 80% of adults and 30% of children. One of the most important characteristics affecting its incidence is medial longitudinal arch. Assessing arch height provides valuable information for prescribing appropriate footwear that reduces the consequences of flatfoot. The main goals of this study were to explore epidemiologic factors that affect arch height and to predict arch height in children with flatfoot based on five variables using widely accessible, low-cost tools.Methods:This study examined plantar arch height in 80 children with flatfoot aged 7 to 15 years. The evaluation criteria included low arch height, correct knee and heel position, and correct body symmetry. To measure arch height, the children sat in a chair and placed their feet on level ground. A caliper was used to measure the height between the bottom of the navicular tuberosity and the floor. Using least mean square error scheme, a multivariable model was fitted to the plantar arch height for all of the participants using independent variables, including age, Cole index, sex, place of residence, and physical activity.Results:Arch height increased as age increased in boys and girls in rural and urban areas. A significant increase in arch height occurred in 12- to 15-year-old boys and 10- to 15-year-old girls. In boys, arch height was 30% lower than in girls (P= .05). In children in cities, arch height was lower by 26% than in children in rural areas (P= .05). Arch height increased by 41.8% in inactive boys and by 115.2% in inactive girls in rural areas. It was reduced by 59.4% in boys and by 47.4% in girls as the Cole index increased from 82.2 to 152.0. The suggested model predicted arch height using the child’s age, Cole index, sex, place of residence, and physical activity (r> 0.97, error < 0.04 mm [2%],P< .05).Conclusions:Flat feet in children may be affected by age, sex, Cole index, place of residence, and physical activity. The proposed model allows plantar arch heights in children with flat feet to be predicted without the need for sophisticated technology via controlling the child’s weight and physical activity for prescribing appropriate footwear. (J Am Podiatr Med Assoc 102(2): 114–121, 2012)

Purpose: Popular running magazines and running shoe companies advise using the shape of the weight-bearing plantar surface of the foot as a basis for selecting a proper type of running shoe to reduce injury risk. The imprint is assumed to reflect the height of the medial longitudinal arch (MLA). This study examined the assumption that plantar surface morphology was a surrogate for height of the MLA. Methods: Recruits (n = 3968) entering US Army Basic Combat Training had their plantar foot surfaces assessed visually as low, normal, or high by two raters who viewed imprints of the plantar foot surface. Actual arch height was measured with calipers as distance from the standing surface to the inferior medial border of the navicular tuberosity. Measured MLA heights were compared with plantar surface imprints to evaluate the effectiveness of visual inspection as a means of arch height classification. Results: For the right foot, individuals with low, normal, or high plantar shapes had a mean +/- SD arch height of 33.5 +/- 6.8, 40.4 +/- 7.2, and 43.1 +/- 7.3 mm, respectively (ANOVA, P < 0.01); however, the individuals' measured MLA heights fell into the corresponding plantar shape percentiles (low, normal, high) only 65% of the time. Increased body mass index (BMI) decreased correct assessment of the MLA. Conclusions: Visual assessment of indicating progressively higher plantar shapes corresponded to progressively higher average differences in measured arch heights; nonetheless, there was considerable overlap among the three plantar shapes with 35% of plantar shapes being misclassified compared with measured arch height, especially among individuals with higher BMI.

Background: The cause of navicular tuberosity pain in adolescents with flexible flatfeet is not well understood. We hypothesized that some of the navicular tuberosity pain may be related to insertional enthesopathy of the posterior tibial tendon at the navicular. Magnetic resonance imaging was performed to look for abnormal signal changes in a series of patients. Material and Method: Consecutive adolescent patients presenting with flexible flatfeet and navicular tuberosity pain were prospectively recruited. A detailed foot examination and body fat analysis was performed. Standing radiographs and Tekscan pedobarograph of both feet were obtained. Magnetic resonance examinations were performed on a 1.5-T whole-body magnetic resonance imaging system utilizing a standard extremity coil. Results: MRI abnormality was detected in 15 of the 36 feet in 18 adolescents examined. Abnormalities detected included thickening of the posterior tibial tendon insertion, marrow edema in the accessory navicular, marrow edema in the navicular tuberosity, and contrast enhancement at the posterior tibial tendon insertion site. Patients with MRI abnormalities were significantly taller, had a lower body mass index and a lower body fat percentage than those without MRI abnormality. Forward stepwise logistic regression analysis identified low body fat percentage and presence of an accessory navicular as independent predictors for abnormality on MRI. Conclusion: MRI abnormality was frequently detected in adolescents with painful flexible flatfeet. The MRI signal changes indicated an enthesopathy like process occurring at the posterior tibial tendon insertion to the navicular which could explain the origin of pain in flexible flatfeet patients without an accessory navicular. Early identification and appropriate treatment to prevent progression may be helpful. Level of Evidence: IV, Case Series

Background: The spring ligament has been reported to be composed of the inferior calcaneonavicular and superomedial calcaneonavicular ligaments. We investigated the lower layer of the spring ligament fibrocartilage complex under the fibrocartilaginous surface, identified three distinct structures, and examined the morphology and running patterns of their fiber bundles. Methods: Forty-eight cadaveric feet were examined. After ablation of the ankle joint and extirpation of the talus, the surface cartilage of the spring ligament fibrocartilage complex was carefully removed with forceps, and the length, width, and thickness of the three components of the complex were measured with calipers. Results: The three components of the spring ligament complex are the superomedial calcaneonavicular ligament, the inferior calcaneonavicular ligament, and a structure that we termed the third ligament, which comprises fibers running from the notch between the calcaneal facets to the navicular tuberosity. Conclusions: We demonstrated a third component of the spring ligament; this component runs from the notch between the anterior and middle calcaneal facets to the tubercle of the navicular in the lower layer of the spring ligament complex, lying beneath the cartilaginous surface of the complex. Clinical Relevance: More accurate knowledge of the anatomy of the spring ligament complex will enhance our understanding of its role in the support of the head of the talus and, potentially, its critical interactions with the posterior tibial tendon in this regard.

The measure of navicular drop has been used as an indicator of pronation at the foot. It is defined as the distance the navicular tuberosity moves in standing, as the subtalar joint is allowed to move from its neutral position to a relaxed position. The purposes of this study were to test the reliability of a method to measure navicular drop and to assess the relationships among measures of forefoot to rearfoot position, subtalar joint neutral position, and navicular drop. The results support traditional biomechanical theory but indicate that other factors contribute significantly to navicular drop.

A 62-year-old woman with severe seizure disorder presented with right ankle and foot pain after being found down, presumably following a seizure recurrence. Imaging showed an acute comminuted fracture of the anterolateral aspect of the right calcaneus, as well as an acute avulsion fracture of the right navicular tuberosity at the site of insertion of the tibialis posterior tendon. This fracture pattern suggests forced abduction of the midfoot or forefoot with severe compression of the lateral column and failure of the medial column under tension, an entity that has previously been described as the nutcracker fracture. This mechanism of injury should prompt particularly careful evaluation of the navicular, cuboid, and calcaneus for any signs of injury. Subtle fractures of the navicular and calcaneus may be overlooked in the emergency setting, leading to a delay in surgical treatment and ultimately chronic foot deformities that can result in significant functional disability.

Background: The spring ligament complex (SLC) is a static support of the head of the talus and a major anatomical contributor to the integrity of the medial longitudinal arch, particularly if the dynamic support of the posterior tibial tendon is compromised. For this reason, we sought to further elucidate the anatomical components and dimensions of this ligamentous complex. Methods: Dissection was performed on 30 adult cadaver feet disarticulated at the ankle joint that were preserved by embalming technique. Results: The superomedial ligament (SML) averages 42.51 ± 3.93 mm and 33.44 ± 3.34 mm at the superomedial and inferolateral borders, respectively. The width at the level of sustentaculum tali and navicular tuberosity averaged 20.00 ± 2.35 mm and 10.26 ± 2.05 mm, respectively. The medioplantar oblique (MPO) ligament averaged 23.56 ± 2.15 mm and 21.20 ± 1.42 mm at the medial and the lateral borders, respectively. The widths at the navicular and calcaneal side were 2.71 ± 0.39 mm and 8.14 ± 0.56 mm, respectively. The inferoplantar longitudinal (IPL) ligament measured 4.26 ± 0.43 mm and 2.66 ± 0.42 mm at the medial and lateral borders, respectively. The width at the calcaneal and navicular insertions measured 5.21 ± 0.53 mm and 3.39 ± 0.39 mm, respectively. Conclusions: The distinction between the SML and MPO components of the spring ligament complex is difficult. This study tried to clarify the dimensions and configurations of these components of the SLC. Clinical relevance: This effort may aid surgeons who wish to repair this ligament with more precision.

Of 14 patients with navicular tuberosity avulsion, seven had damage to the anterior process of the calcaneum at the calcaneocuboid joint--possibly the result of an occult subluxation of the midtarsal joint. These patients were all middle-aged women who had slipped or fallen a short distance. They were unable to bear full weight because of pain on the medial and lateral aspects of the foot. The associated midtarsal injury was initially missed in five of seven patients because of failure to interpret the radiographic appearance. All seven patients had prolonged symptoms, and three had persistent but not disabling pain at least three years after injury. Degenerative arthritis had developed in the calcaneocuboid joint in four of the five patients at follow-up examinations. Patients with occult subluxation of the midtarsal joint should be managed initially by a period of non-weight-bearing followed by application of a walking cast. The need for early surgical treatment is open to question.

We have described four cases of medial plantar neuropathy that was confirmed by the near-nerve sensory nerve conduction study. The common compression site in medial plantar neuropathy is at the entrance to the fibromuscular tunnel behind the navicular tuberosity, distal to the tarsal tunnel, where Tinel's sign is localized.