A case report of multicentric carpotarsal osteolysis syndrome: Depiction of a debilitating disease course.

Multicentric carpotarsal osteolysis syndrome (MCTO) is a rare skeletal disorder characterized by progressive osteolysis involving the carpal and tarsal bones, and often associated with nephropathy. It is caused by heterozygous mutation in the MAF bZIP transcription factor B (MAFB) gene. Heterogeneous clinical manifestation and wide spectrum of disease severity have been observed in patients with MCTO. Here, we report a case of a male patient who presented with kidney failure in childhood with progressive disabling skeletal deformity. He was diagnosed with MCTO at 31-years-old, where a de novo pathogenic heterozygous variant in NM_005461.5:c.212C>A: p.(Pro71His) of the MAFB gene was identified. While there has been little data on the long-term prognosis and life expectancy of this disease, this case report sheds light on the debilitating disease course with multiple significant morbidities of a patient with MCTO throughout his lifetime of 33 years.

Osteochondrosis in the central and third tarsal bones of young horses.

Recently, the central and third tarsal bones of 23 equine fetuses and foals were examined using micro-computed tomography. Radiological changes, including incomplete ossification and focal ossification defects interpreted as osteochondrosis, were detected in 16 of 23 cases. The geometry of the osteochondrosis defects suggested they were the result of vascular failure, but this requires histological confirmation. The study aim was to examine central and third tarsal bones from the 16 cases and to describe the tissues present, cartilage canals, and lesions, including suspected osteochondrosis lesions. Cases included 9 males and 7 females from 0 to 150 days of age, comprising 11 Icelandic horses, 2 standardbred horses, 2 warmblood riding horses, and 1 coldblooded trotting horse. Until 4 days of age, all aspects of the bones were covered by growth cartilage, but from 105 days, the dorsal and plantar aspects were covered by fibrous tissue undergoing intramembranous ossification. Cartilage canal vessels gradually decreased but were present in most cases up to 122 days and were absent in the next available case at 150 days. Radiological osteochondrosis defects were confirmed in histological sections from 3 cases and consisted of necrotic vessels surrounded by ischemic chondronecrosis (articular osteochondrosis) and areas of retained, morphologically viable hypertrophic chondrocytes (physeal osteochondrosis). The central and third tarsal bones formed by both endochondral and intramembranous ossification. The blood supply to the growth cartilage of the central and third tarsal bones regressed between 122 and 150 days of age. Radiological osteochondrosis defects represented vascular failure, with chondrocyte necrosis and retention, or a combination of articular and physeal osteochondrosis.

A Rare Location of Osteosarcoma in the Cuboid Bone: A Case Report.

CASE: In this case report, we describe a patient with left foot pain whose magnetic resonance imaging revealed a destructive tumor of the left cuboid bone. A biopsy of the tumor confirmed an osteoblastic osteosarcoma of the cuboid, and the patient was treated with chemotherapy followed by a below-the-knee amputation. CONCLUSION: There are only a handful of cases reporting osteosarcoma of the cuboid bone, and challenges remain in properly diagnosing the lesion to recommend the best course of treatment.

Imaging of Müller-Weiss Disease.

Müller-Weiss disease (MWD) is the result of a dysplasia of the tarsal navicular bone. Over the adult years, the dysplastic bone leads to the development of an asymmetric talonavicular arthritis with the talar head shifting laterally and plantarly, thus driving the subtalar joint into varus. From a diagnostic point of view, the condition may be difficult to differentiate from an avascular necrosis or even a stress fracture of the navicular, but fragmentation is the result of a mechanical impairment rather than a biological dysfunction.Standardized weight-bearing radiographs (anteroposterior and lateral views) of both feet are usually enough to diagnose MWD. Other imaging modalities such as multi-detector computed tomography and magnetic resonance imaging in early cases for the differential diagnosis can add additional details on the amount of cartilage affected, bone stock, fragmentation, and associated soft tissue injuries. Failure to identify patients with paradoxical flatfeet varus may lead to an incorrect diagnosis and management. Conservative treatment with the use of rigid insoles is effective in most patients. A calcaneal osteotomy seems to be a satisfactory treatment for patients who fail to respond to conservative measures and a good alternative to the different types of peri-navicular fusions. Weight-bearing radiographs are also useful to identify postoperative changes.

Navicular bone fracture and severe deep digital flexor tendinopathy after palmar digital neurectomy in two horses.

Background: Navicular syndrome is a common cause of forelimb lameness in horses. Beyond changes to the navicular bone itself, horses with a clinical diagnosis of navicular syndrome often have pathology associated with other components of the navicular apparatus, including the navicular bursa, deep digital flexor (DDF) tendon, collateral sesamoidean ligaments, and impar ligament. Palmar digital neurectomy (PDN) is often used as a salvage procedure for horses diagnosed with navicular syndrome that become unresponsive to medical management. There are many potential complications associated with PDN, some of which are debilitating. Case Description: This report describes two cases of navicular bone fracture with severe DDF tendinopathy and distal interphalangeal joint subluxation/hyperextension that occurred 12 and 19 weeks after bilateral forelimb PDN. Conclusion: These two cases highlight the importance of proper patient selection before PDN due to the high incidence of undiagnosed soft tissue pathology in conjunction with radiographic evidence of navicular syndrome. Advanced imaging of the digit is recommended to identify and characterize any soft tissue pathology associated with the navicular apparatus before pursuing PDN to avoid disease progression and catastrophic injury.

Spotty Bone Marrow: A Frequent MRI Finding in the Feet of Ballet Dancers.

INTRODUCTION: Bone marrow signal abnormalities on magnetic resonance imaging (MRI) are common in athletes. However, few studies evaluate the MRI appearance of bone marrow in the feet of ballet dancers. Our study aims to describe the "spotty bone marrow" (SBM) pattern in the tarsal bones of a cohort of ballet dancers, establishing its prevalence, distribution, potential associations, and evolution.
Methods: Eighty-six MRIs of 68 ankles in 56 ballet dancers were retrospectively reviewed for mar- row signal alterations, which were classified as focal or SBM (defined as patchy fluid-sensitive signal hyperintensity spanning more than one location or tarsal bone). When SBM involved the talus, its anatomic distribution in the bone and morphologic pattern were recorded. Additional osseous and soft tissue findings were documented. For subjects with more than one MRI of the same ankle, the SBM's evolution was monitored.
Results: Spotty bone marrow was identified in 44 ankles (65%). Spotty bone marrow was isolated to the talus (44%), present in all tarsal bones (25%), or distributed between the talus and one to three other tarsal bones (31%). In the talus, The SBM involved the entire bone (65%), the neck and body (31%), or the head and neck (4%). The SBM most commonly showed a random morphologic pattern (87%) but occasionally showed a peripheral predominance (13%). There was no statistically significant difference in the prevalence of other pathologies in ankles with and without SBM. In eight ankles with a follow-up MRI, the SBM worsened in one, remained stable in two, and improved in five ankles. None progressed to a stress fracture.
Conclusion: Spotty bone marrow is an MRI finding frequently encountered in ballet dancers. It is usually self-limiting and should not be misinterpreted as a more aggressive pathology.

Pregnancy-Associated Perivascular Epithelioid Cell Tumor of the Tarsal Navicular: A Case Report.

CASE: A 30-year-old pregnant woman with perivascular epithelioid cell tumor (PEComa) of the tarsal navicular underwent intralesional curettage with allograft at 30 weeks' gestation. She had an uncomplicated delivery at term and is ambulating without tumor recurrence at 1-year follow-up. CONCLUSION: PEComas are rare tumors most commonly found in soft tissues but have been reported in bone and are occasionally associated with pregnancy. To the best of our knowledge, this is the first reported case of pregnancy-associated PEComa of bone.

The intervention of intestinal Wnt/ß-catenin pathway alters inflammation and disease severity of CIA.

Autoreactive T cell is one of the leading causes of immunological tolerance defects in the chronic inflammatory lesions of rheumatoid arthritis (RA). There have been several extracellular signals and intracellular pathways reported in regulating this process but largely remain unknown yet. In this study, we explored the roles of intestinal Wnt/ß-catenin on disease severity during collagen-induced arthritis model (CIA), an animal model of RA. We first testified the activity pattern Wnt/ß-catenin shifted by intragastric administration of LiCl and DKK-1 in the intestine by real-time PCR and WB analysis. The arthritis scores showing the disease severity in the DKK-1 group was significantly ameliorated compared with the control group at the late stage of the disease, while in the LiCl group, the scores were significantly elevated which was consistent with pathology score analysis of H&E staining. Next, ELISA was performed and showed that TNF-α and IL-17 in the LiCl group were significantly higher than that of the control group. IL-10 in the DKK-1 group was significantly higher than that in the LiCl-1 group and control group, P < 0.05. Flow cytometry of spleen T cells differentiation ratio showed that: Th1 from the DKK-1 and LiCl groups and Th17 from the LiCl group was significantly different from that of the blank model group, P < 0.05. Finally, we explored the effects of intestinal Wnt/ß-catenin on T cell differentiation regulator ROR-γt and TCF1 and found that both transcription factors were up-regulated in the LiCl group. Together, these data suggested the pro-information role of Wnt/ß-catenin pathway from the intestine in the CIA mouse, implying its use as a potential therapeutic target for the treatment of inflammatory diseases such as RA.

The equine navicular apparatus as a premier enthesis organ: Functional implications.

Navicular syndrome has been traditionally characterized by progressive lameness with chronic degeneration of the navicular bone. Advances in imaging techniques have revealed that its associated soft tissue structures are also affected. This distribution of lesions is explained by conceptualizing the equine navicular apparatus as an enthesis organ that facilitates the dissemination of mechanical stress throughout the tissues of the foot. The navicular apparatus has the same structural adaptations to mechanical stress as the human Achilles tendon complex. These adaptations efficiently dissipate mechanical force away from the tendon's bony attachment site, thereby protecting it from failure. The comparison of these two anatomically distinct structural systems demonstrates their similar adaptations to mechanical forces, and illustrates that important functional insights can be gained from studying anatomic convergences and cross-species comparisons of function. Such a functional conceptualization of the equine navicular apparatus resolves confusion about the diagnosis of navicular syndrome and offers insights for the development of mechanically based therapies. Through comparison with the human Achilles complex, this review (1) re-conceptualizes the equine navicular apparatus as an enthesis organ in which mechanical forces are distributed throughout the structures of the organ; (2) describes the relationship between failure of the navicular enthesis organ and lesions of navicular syndrome; (3) considers the therapeutic implications of navicular enthesis organ degeneration as a form of chronic osteoarthritis; and based upon these implications (4) proposes a focus on whole body posture/motion for the development of prehabilitative and rehabilitative therapies similar to those that have already proven effective in humans.

Multiple synostoses syndrome: Clinical report and retrospective analysis.

Multiple synostoses syndrome (SYNS1; OMIM# 186500) is a rare autosomal dominant disorder reported in a few cases worldwide. We report a Chinese pedigree characterized by proximal symphalangism, conductive hearing loss, and distinctive facies. We examined the genetic cause and reviewed the literature to discuss the pathogeny, treatment, and prevention of SYNS1. Audiological, ophthalmological, and radiological examinations were evaluated. Whole-exome sequencing (WES) was performed to identify mutations in the proband and her parents. Sanger sequencing was used to verify the results for the proband, parents, and grandmother. The literature on the genotype-phenotype correlation was reviewed. The patient was diagnosed with multiple synostoses syndrome clinically. WES and bioinformatic analysis revealed a novel missense mutation in the NOG gene, c.554C>G (p.Ser185Cys), cosegregated in this family. The literature review showed that the phenotype varies widely, but the typical facies, conductive hearing loss, and proximal symphalangism occurred frequently. All reported mutations are highly conserved in mammals based on conservation analysis, and there are regional hot spots for these mutations. However, no distinct genotype-phenotype correlations have been identified for mutations in NOG in different races. Regular systematic examinations and hearing aids are beneficial for this syndrome. However, the outcomes of otomicrosurgery are not encouraging owing to the regrowth of bone. This study expanded the mutation spectrum of NOG and is the first report of SYNS1 in a Chinese family. Genetic testing is recommended as part of the diagnosis of syndromic deafness. A clinical genetic evaluation is essential to guide prevention, such as preimplantation genetic diagnosis.

Standing MRI lesions of the distal interphalangeal joint and podotrochlear apparatus occur with a high frequency in warmblood horses.

Foot pain is a common presenting complaint in Warmblood horses. The aim of this retrospective, cross-sectional study was to determine the spectrum of foot lesions detected by magnetic resonance imaging (MRI) in Warmblood horses used for dressage, jumping, and eventing. The medical records of 550 Warmblood horses with foot pain that were scanned using standing MRI were reviewed and the following data were recorded: signalment, occupation, lameness, diagnostic analgesia, imaging results, treatments, and follow-up assessments. Associations between standing MRI lesions and chronic lameness following treatment were tested. Abnormalities of the navicular bone (409 horses, 74%), distal interphalangeal joint (362 horses, 65%), and deep digital flexor (DDF) tendon (260 horses, 47%) occurred with the highest frequency. The following abnormalities were significantly associated (P < .05) with chronic lameness following conservative therapy: moderate to severe MRI lesions in the trabecular bone of the navicular bone, mild or severe erosions of the flexor surface of the navicular bone, moderate sagittal/parasagittal DDF tendinopathies, and moderate collateral sesamoidean desmopathies. Also, identification of concurrent lesions of the DDF tendon, navicular bone, navicular bursa, and distal sesamoidean impar ligament was associated with chronic lameness after conservative therapy. Development of effective treatment options for foot lesions that respond poorly to conservative therapy is necessary.

Unsuspected Accessory Ossicle in Possible Sinus Tarsi Syndrome: The Value of Bone SPECT/CT.

Three-phase bone scan was performed for evaluation of possible sinus tarsi syndrome in a 52-year-old man with chronic left ankle pain. MRI was initially read as unremarkable, and there was little symptomatic improvement after intra-articular anesthetic injection. The primary finding that appreciated only delayed bone SPECT/CT images was focal increased uptake associated with a well-corticated 8-mm bony fragment adjacent to the left calcaneus, thought to represent an accessory ossicle within the left sinus tarsi. The increased uptake suggested fracture or severe degenerative change of the ossicle, likely contributing to the patient's chronic pain.

Osteoblastoma-Like Osteosarcoma of the Cuboid and Skull: A Case Report and Review of the Literature.

Osteoblastoma-like osteosarcoma is a rare form of osteosarcoma that shares similar clinical and pathological characteristics with osteoblastoma. We describe a 12-year-old boy with osteoblastoma-like osteosarcoma of the cuboid and skull without lung involvement. Despite inadequate primary surgical treatment, the patient recovered well after wide excision and postoperative chemotherapy. We report the case for the rarity of the sites and the misleading clinical and pathological manifestation.

Posterior malleolus fractures in Bosworth fracture-dislocations. A combination not to be missed.

OBJECTIVES: Posterior malleolar fractures (PM) have been linked to inferior outcome in malleolar fractures. This study aims to analyze the prevalence and pathoanatomy of PM fractures in Bosworth fracture-dislocations (BF). MATERIALS & METHODS: Radiographs and computed tomography (CT) scans of 13 patients treated at our institution and 97 cases published between 1947 and 2018, identified in a systematic literature search, were evaluated with respect to the pathoanatomy of BF. In all 13 cases from the present study and in 10 cases from the literature, axial CT scans were performed. RESULTS: All 13 patients (100%) with BF from the present series and 61 of 97 documented cases (63%) of BF from the literature were associated with a PM fracture. In patients with a complete CT analysis, dislocation of the fibula behind the posterior tibial rim was associated with extraincisural (Bartonícek / Rammelt type 1) PM fractures. Displacement of the fibula between the displaced PM fragment and the tibia was associated with Bartonícek / Rammelt types 2 and 3 PM fractures. CONCLUSIONS: Seventy prevent of all reported BF are associated with a PM fracture. The true prevalence may be even higher because of the historically infrequent use of CT imaging. The pathoanatomy of the PM fragment is highly variable as is the kind of fibular displacement in BF. Therefore, CT scanning should be performed routinely in BF. Displaced PM fractures in BF involving the incisura should be treated operatively via a direct posterolateral approach.

Anatomical Pathology of Subtle Lisfranc Injury.

The extent and patterns of Lisfranc joint complex disruption in subtle Lisfranc injuries have not been well clarified. We reviewed the direct intraoperative findings for 87 patients, examined computed tomography images that had been obtained preoperatively for 73 of the patients, and classified the injuries according to the Kaar  et al. criteria as the transverse type (instability between the first cuneiform [C1] and the second metatarsal [M2] and between the second cuneiform [C2] and M2) or longitudinal type (instability between C1 and M2 and between C1 and C2). Our patients' injuries were classified as follows: longitudinal type (38%), transverse type (30%), transverse type and first tarsometatarsal (TMT) joint injury (20%), longitudinal type plus transverse type (7%), longitudinal type and first TMT joint injury (3%), and longitudinal type, transverse type, and first TMT joint injury (2%). In 11 patients, the longitudinal injury extended into the naviculo-first cuneiform joint. In 41 (56%) of the 73 patients for whom CT images were obtained, 1 or more fractures (not counting small avulsion fragments between C1 and M2) were found. Orthopedic surgeons should be aware of the various injury patterns possible in cases of subtle Lisfranc injury.

Clinical efficacy of clodronic acid in horses diagnosed with navicular syndrome: A field study using objective and subjective lameness evaluation.

Navicular syndrome, a common cause of equine forelimb lameness, is associated with pathological changes in the navicular bone. Consequently, administration of bisphosphonates (BPs) has been advocated in order to modify the rate of bone turnover. The present study aimed to assess the clinical efficacy of intramuscularly administered clodronic acid for the treatment of 11 horses with clinical and radiographic findings compatible with navicular syndrome. Magnetic resonance imaging was performed in 5 of the 11 horses. The animals were treated with an intramuscular dose of clodronic acid of 765 mg/horse, administered over three separate injection sites. Before and at 7, 30 and 90 days after treatment, horses were subjected to lameness and accelerometric evaluations. A clinical improvement was observed in 6 of the 11 horses. These 6 horses showed a mean reduction of two degrees in lameness score. Accelerometry in these horses revealed increased velocity, stride length, stride regularity and dorsoventral displacement of the gravity of centre together with a reduction in stride frequency, suggesting a gait improvement. This study demonstrates that intramuscular clodronic acid can be useful for lameness reduction in some horses with navicular syndrome.

Closed Distal Dislocation of the Intermediate Cuneiform in a Complex Lisfranc Fracture-Dislocation: A Case Report.

CASE: A 21-year-old, active duty male sustained an irreducible, complex Lisfranc fracture-dislocation with distal extrusion of his intermediate cuneiform. He was treated in a staged manner with external fixator placement, followed by an extended midfoot fusion with autograft bone. At 19 months, he could perform all activities of daily living independently with minimal pain using an Intrepid Dynamic Exoskeletal Orthosis. CONCLUSIONS: Complex Lisfranc injuries are severe and often result in chronic pain and disability after operative management. To our knowledge, this is the only case report describing a Lisfranc fracture-dislocation with a distally extruded intermediate cuneiform treated with a fusion.

[One-stage debridement and two-stage Ilizarov bone transport technology for post-traumatic lateral malleolus defect].

OBJECTIVE: To explore the effectiveness of one-stage debridement and two-stage Ilizarov bone transport technology in repairing post-traumatic lateral malleolus defect. METHODS: Between June 2013 and December 2016, 7 patients with bone defect of lateral malleolus were treated. There were 5 males and 2 females with an average age of 45.9 years (range, 35-60 years). There were 6 cases of traffic accident injury and 1 case of strangulation injury. All patients had extensive soft tissue injury and lateral malleolus bone exposure. There were 4 cases of Gustilo type ⅢB and 3 case of Gustilo type ⅢC. The time from injury to admission was 3-10 hours (mean, 6.3 hours). Through one-stage thorough debridement, exploration and repair of vessels and nerves, external fixation of scaffolds and coverage of wounds, free fibulas were removed in 3 cases at one-stage and fibulas were resected in 4 cases after expansion. The bone defects ranged from 4.5 to 15.0 cm in length (mean, 8.2 cm). The Ilizarov circular external fixators were used to transport with fibula osteotomy for repairing bone defect of lateral malleolus when the wound healing. RESULTS: During fibular osteotomy, the stents were adjusted 2-4 times (mean, 2.8 times) and the external fixators were removed after 10-16 months (mean, 12.8 months). The nail tract infection occurred in 2 cases during transporting and was controlled after symptomatic treatment. All patients were followed up 24-48 months (mean, 32.9 months). The shape of lateral malleolus was close to normal without obvious varus or valgus deformity. American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hind foot score was 86-92 (mean, 90.3), and 5 cases were excellent and 2 cases were good. X-ray film showed that there was no obvious widening of the gap between the ankle points and no sign of absorption of the lateral malleolus. CONCLUSION: The one-stage debridement combined with two-stage Ilizarov bone transport technology can maintain the stability of ankle joint structure and obtain better effectiveness in repairing post-traumatic lateral malleolus defect.

A case of erosive polyarthropathy from Medieval northern Italy (12th-13th centuries).

OBJECTIVE: To evaluate and differentially diagnose erosive skeletal lesions located on multiple joints of an individual archaeologically recovered in 2017. MATERIALS: Skeletal remains of a well-preserved skeleton dating to the 12th-13th centuries from the medieval church of San Biagio in Cittiglio (Varese, northern Italy). METHODS: Macroscopic and radiographic imaging. RESULTS: Erosive marginal symmetrical lesions are present on the metatarsophalangeal, metacarpophalangeal and interphalangeal joints of an adult male, aged 55-75 years. Osteolytic changes, in the form of pocket erosions, surface resorptions and pseudocyst formations, are also macroscopically observed on some carpal and tarsal bones and on several large peripheral joints. CONCLUSIONS: A careful differential diagnosis of the lesions and their macroscopic and radiological appearance is suggestive of a case of rheumatoid arthritis-like polyarthropathy. SIGNIFICANCE: This case contributes to the debate regarding the antiquity of erosive polyarthropathies, providing additional evidence for the existence of these diseases in the Old World prior to the European discovery of the Americas. LIMITATIONS: Small sample size limits discussion of the scope of the disease in antiquity. SUGGESTIONS FOR FURTHER RESEARCH: This case highlights the need for further macroscopic, radiographic, and biomolecular studies of pre-modern European skeletal samples to investigate the hypothesized pre-existence of these pathological conditions in Europe prior to 1492.