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OBJECTIVE: External auditive exostosis (EAE), known as surfer's ear, is a temporal bone outgrowth resulting from ear exposure to cold air and water. This review aims to shed light on the prevalence of EAE among worldwide surfers. METHODS: By a thorough retrieval of the PubMed, we found all original investigations performed on EAE among suffers. The retrieval time was from the construction of the database to December 2022. Agency for Healthcare Research and Quality (AHRQ) methodology checklist for assessing the quality of cross-sectional/prevalence study was performed. RESULTS: 19 articles were selected involving 2997 surfers on whom 2032 presented EAE. The prevalence of EAE was ranged from 53 to 90% with a mean at 67.8%. 3 investigations were performed from USA, five from UK and Ireland, five from Australia and New Zealand and six from Japan and Europe. CONCLUSION: Cold water exposure, combined with wind and prolonged surfing activity, contributes to the development of EAE. Symptoms range from mild discomfort to hearing loss and recurrent infections. Preventive measures, such as raising awareness and promoting the use of ear protection, are crucial. Further research is needed to improve prevention strategies and understand the underlying mechanisms of EAE.
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Exostosis , Deportes , Humanos , Estudios Transversales , Conducto Auditivo Externo , Exostosis/epidemiología , Exostosis/prevención & control , AguaRESUMEN
The diagnosis of an osteochondroma in the short bones of the extremities is atypical and the presentation in infancy is unusual. A 3-month-old female presented for evaluation of radial deviation of the right index finger present since birth. Radiographs showed a broad-based osseous outgrowth with the usual features of an osteochondroma arising from the base of middle phalanx. Initial corrective surgery at 22 months was followed by recurrence of the lesion. Another resection at 4 years confirmed a final diagnosis of BPOP (bizarre parosteal osteochondromatous proliferation). The subsequent pathologic diagnosis of BPOP appears to support the hypotheses concerning the etiology of BPOP as possibly arising from repeated trauma to the metaphysis.
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Neoplasias Óseas , Osteocondroma , Humanos , Femenino , Osteocondroma/diagnóstico por imagen , Osteocondroma/cirugía , Lactante , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/cirugía , Radiografía , Diagnóstico DiferencialRESUMEN
BACKGROUND: Multiple hereditary exostosis (MHE) is a rare autosomal dominant disorder characterized by multiple osteochondromas. There is a paucity of literature concerning total hip arthroplasty (THA) in patients with MHE. The aim of this study is to report long-term outcomes of THA in patients with MHE. METHODS: Fourteen patients undergoing 15 THA's for the treatment of osteoarthritis in the presence of osteochondromas and proximal femoral deformity secondary to MHE were reviewed. Mean age at the time of surgery and follow-up was 56 and 12 years. Seven (47%) had uncemented femoral components. Eleven hips had coxa valga on preoperative imaging. Clinical outcomes were assessed with both Harris hip scores (HHS) and Musculoskeletal Tumor Society Scores (MSTS). RESULTS: Following surgery, there was an improvement in the HHS (48-82, p < 0.01) and MSTS scores (41-70%, p < 0.01). Complications occurred in 5 patients leading to reoperation in 3 patients, of which 2 patients underwent a revision procedure at 19 and 20-years postoperative. The 10-year revision free survival was 100%. CONCLUSIONS: THA in the setting of MHE reliably improves patient function. One in three patients will have a postoperative complication; however, the long-term incidence of revision is low.
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Artroplastia de Reemplazo de Cadera , Coxa Valga , Exostosis Múltiple Hereditaria , Prótesis de Cadera , Humanos , Artroplastia de Reemplazo de Cadera/efectos adversos , Artroplastia de Reemplazo de Cadera/métodos , Articulación de la Cadera/cirugía , Exostosis Múltiple Hereditaria/complicaciones , Exostosis Múltiple Hereditaria/cirugía , Resultado del Tratamiento , Coxa Valga/etiología , Reoperación , Estudios Retrospectivos , Estudios de SeguimientoRESUMEN
BACKGROUND: Boxer elbow and handball goalkeeper elbow are causes of impingement characterized by osteophytes formation at the olecranon and coronoid tip as well as their corresponding fossae. Herein, we present another distinct pathology in these patients: the formation of an exostosis at the posterolateral aspect of the elbow. METHODS: Between April 2016 and May 2020, 12 athletes with boxer elbow and handball goalkeeper elbow (mean age of 22 years) suffering from elbow pain were enrolled in the present study. Plain radiography, magnetic resonance imaging (MRI), and computer tomography (CT) scans were used to evaluate the bone conformation of the posterolateral aspect of the elbow. Assessment and staging of the ossification was performed by two independent fellowship-trained elbow surgeons. RESULTS: Bone marrow edema of the posterior aspect of the elbow at the origin of the anconeus muscle was initially detected in MRI scans. With the progression of the condition, imaging revealed an ossification posterior to the capitellum with bony bridges. In the advanced stage of the disease, the exostoses was unstable as the ossification had no adherence to the posterior capitellum during surgical excision. Plain radiographs are limited in their ability to detect the condition, whereas MRI and CT scans allow to identify a signal enhancement at the posterolateral aspect of the elbow. CONCLUSION: In patients without history of elbow trauma, bony irregularities of the posterior aspect of the capitellum may indicate ossification of the posterolateral aspect of the elbow, most likely caused by repetitive hyperextensions.
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Articulación del Codo , Artropatías , Humanos , Adulto Joven , Adulto , Osteogénesis , Codo , Articulación del Codo/diagnóstico por imagen , Articulación del Codo/cirugía , RadiografíaRESUMEN
To investigate the relationship between fluoride exposure and Osteochondroma (OC) prevalence, a cross-sectional study was conducted in drinking water endemic fluorosis areas of Heilongjiang Province, China. Our study first reported that the prevalence of OC was 2.3% in drinking water endemic fluorosis areas of Heilongjiang Province, China, and no difference in gender. Logistic regression analysis found that compared to 1st quartile participants, the prevalence of OC was 73% lower in the 2nd quartile participants of WF (Water fluoride), and 3.4 times higher among the 2nd quartile UF (Urinary fluoride) participants. Our study suggests that 0.259-0.420 mg/L of WF may be considered an appropriate level for reducing OC prevalence, while UF (≥0.750 mg/L) could slightly increase the prevalence of OC. In summary, the link between fluoride and OC prevalence is complicated and needs to be further investigated in a cohort population.
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In this study, the effect of heterozygous germline mutations in the heparan sulfate (HS) glycosaminoglycan chain co-polymerases EXT1 and EXT2 on glomerular barrier function and the endothelial glycocalyx in humans is investigated. Heparan sulfate (HS) glycosaminoglycans are deemed essential to the glomerular filtration barrier, including the glomerular endothelial glycocalyx. Animal studies have shown that loss of HS results in a thinner glycocalyx. Also, decreased glomerular HS expression is observed in various proteinuric renal diseases in humans. A case report of a patient with an EXT1 mutation indicated that this could result in a specific renal phenotype. This patient suffered from multiple osteochondromas, an autosomal dominant disease caused by mono-allelic germline mutations in the EXT1 or EXT2 gene. These studies imply that HS is indeed essential to the glomerular filtration barrier. However, loss of HS did not lead to proteinuria in various animal models. We demonstrate that multiple osteochondroma patients do not have more microalbuminuria or altered glycocalyx properties compared to age-matched controls (n = 19). A search for all Dutch patients registered with both osteochondroma and kidney biopsy (n = 39) showed that an EXT1 or EXT2 mutation does not necessarily lead to specific glomerular morphological phenotypic changes. In conclusion, this study shows that a heterozygous mutation in the HS backbone elongating enzymes EXT1 and EXT2 in humans does not result in (micro)albuminuria, a specific renal phenotype or changes to the endothelial glycocalyx, adding to the growing knowledge on the role of EXT1 and EXT2 genes in pathophysiology.
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Barrera de Filtración Glomerular , Glicocálix , N-Acetilglucosaminiltransferasas , Barrera de Filtración Glomerular/metabolismo , Glicocálix/metabolismo , Heparitina Sulfato/metabolismo , Humanos , Mutación , N-Acetilglucosaminiltransferasas/genética , N-Acetilglucosaminiltransferasas/metabolismoRESUMEN
Osteochondromatosis is a benign proliferative disorder characterized by cartilage-capped bony protuberances. In humans and most mammals, variants in the EXT1 or EXT2 gene are strongly correlated with the etiology of osteochondromatosis. However, in cats, osteochondromatosis has only been associated with feline leukemia virus infection. In this study, to explore other factors involved in the etiology of feline osteochondromatosis, we examined the EXT1 and EXT2 genes in a feline leukemia virus-negative cat with osteochondromatosis. Genetic analysis revealed a heterozygous single base pair duplication in exon 6 of the EXT1 gene (XM_023248762.2:c.1468dupC), leading to a premature stop codon in the EXT1 protein. Notably, this frameshift variant is recognized as one of the most common pathogenic variants in human osteochondromatosis. Our data suggest for the first time that genetic variants can have etiologic roles in osteochondromatosis in cats, as in humans and other animals.
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Enfermedades de los Gatos , Exostosis Múltiple Hereditaria , Osteocondromatosis , Animales , Enfermedades de los Gatos/genética , Gatos/genética , Exones , Exostosis Múltiple Hereditaria/genética , Mutación del Sistema de Lectura , Humanos , Virus de la Leucemia Felina/genética , Mamíferos/genética , Osteocondromatosis/genética , Osteocondromatosis/patología , Osteocondromatosis/veterinariaRESUMEN
Although exostosis or osteochondroma is a common bone tumor, associated vascular complications are rare. Clinical and radiological diagnoses are sometimes challenging, and there is no codification for surgical management. We report two cases of popliteal arterial pseudoaneurysms due to osteochondroma of the distal femur. A review of the current literature about case series and case reports of patients affected by arterial pseudoaneurysm complicating osteochondroma was also performed.
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BACKGROUND: Ulna distraction by monolateral external fixator (MEFix) is a good option for the treatment of Masada type I and IIb deformities in children with hereditary multiple exostoses (HMEs). However, there is no consensus regarding where to perform ulnar osteotomy. Our hypothesis is that osteotomy at the proximal third of the ulna and progressive distraction with MEFix can simultaneously correct elbow and wrist deformities in patients with HME. METHODS: We retrospectively reviewed patients with HME who underwent ulna distraction osteogenesis from June 2014 to March 2019. The carrying angle (CA), radial articular angle (RAA), ulnar variance (UV), radial variance (RV) and range of motion (ROM) of the affected forearm and elbow were clinically assessed before lengthening and at the last follow-up visit. The total ulna lengthening distance (LD) and radiographic outcome were also recorded. RESULTS: Nineteen patients (20 forearms) with HME aged 9.1 ± 2.4 years at the time of surgery were retrospectively reviewed. The mean follow-up period was 26.1 ± 5.6 months. There were 11 patients (12 forearms) with Masada type I deformities and eight patients (8 forearms) with Masada type IIb deformities. Patients with type IIb deformity had higher RV, lower CA values, less elbow flexion and forearm pronosupination than those with type I deformity (p < 0.05); RV was an independent risk factor for radial head dislocation, with the cut off at RV > 15.5 mm. The mean LDs in patients with type I and type IIb deformities were 33.6 ± 6.6 mm and 41.4 ± 5.4 mm, respectively. The mean CA, UV, RV, forearm pronation and ulna deviation at the wrist improved significantly following surgery in all patients. In particular, five of eight patients (62.5%) with type IIb deformities had concentric reduction of the radiocapitellar joint, while no radial head subluxation was detected in patients with type I deformities at the last follow-up. Three complications were recorded: two pin-track infections and one delayed union. CONCLUSIONS: Distraction osteogenesis at the proximal third of the ulna provides satisfactory clinical and radiological outcomes in patients with Masada type I and IIb deformities. Early treatment of Masada type I deformities is indicated before progression to more complex type IIb deformities.
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Exostosis Múltiple Hereditaria , Luxaciones Articulares , Osteogénesis por Distracción , Humanos , Niño , Exostosis Múltiple Hereditaria/complicaciones , Exostosis Múltiple Hereditaria/diagnóstico por imagen , Exostosis Múltiple Hereditaria/cirugía , Estudios Retrospectivos , Osteogénesis por Distracción/efectos adversos , Cúbito/diagnóstico por imagen , Cúbito/cirugía , Radio (Anatomía)/diagnóstico por imagen , Radio (Anatomía)/cirugía , Antebrazo/cirugía , Luxaciones Articulares/cirugía , Resultado del TratamientoRESUMEN
PURPOSE: A question still remains as to whether constrictive toe-box shoes (TBS) cause disability only due to pain on pressure points or if they can cause permanent changes in the hallux anatomy. The aim of this study is to compare the hallux morphology in 3 groups classified according to their use of constrictive or open TBS. METHODS: 424 patients were classified into 3 groups: group A used open TBS daily; group B used constrictive TBS daily; group C used both open and constrictive TBS. Hallux's angles, presence of exostoses and shape of the distal phalanx (DP) were analyzed on dorsoplantar weight-bearing radiographs and compared amongst groups. RESULTS: The intermetatarsal (IMA), metatarsophalangeal (MTPA), DASA, PASA, interphalangeal (IPA), obliquity (AP1), asymmetry (AP2) and joint deviation (JDA) angles for group A were 10°, 8°, 5°, 4°, 9°, 3°, 5°, 3°; for group B were 9°, 19°, 5°, 6°, 12°, 2°, 8°, 2°; and for group C were 10°, 10°, 4°, 4°, 12°, 3°, 8°, 1°. Only the differences in the MTPA, IPA and AP2 were statistically significant (p < 0.05). The prevalence of exostoses on the tibial side of the DP was 22, 36, and 29% in groups A, B and C, respectively (p < 0.05). We found similar distributions of the different DP shapes in the three groups. CONCLUSIONS: Our results suggest that the use of constrictive TBS, even if used only occasionally, could change hallux anatomy from a young age increasing MTPA, IPA and AP2. Moreover, we have found that DP exostoses are present as a "normal variation" in patients who wear an open TBS, but their prevalence is higher in those wearing constrictive toe-box shoes. This could be due to a reactive bone formation secondary to the friction caused by the inner border of the shoe. LEVEL OF CLINICAL EVIDENCE: 3.
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Exostosis , Hallux Valgus , Hallux , Articulación Metatarsofalángica , Exostosis/complicaciones , Hallux Valgus/diagnóstico por imagen , Hallux Valgus/etiología , Humanos , Articulación Metatarsofalángica/diagnóstico por imagen , Radiografía , Zapatos/efectos adversosRESUMEN
An 11-year-old boy presented with pain in the right knee, intermittent reverse ischemia of the right foot and paraesthesia of the right toes. An angio-CT showed a false aneurysm of the right superior popliteal artery, and a solitary osteochondroma of the posterior aspect of the distal femur. Excision of the aneurysm and the osteochondroma was performed in two-stages. The patient was clinically well at 1-year follow up.
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Aneurisma Falso , Neoplasias Óseas , Osteocondroma , Aneurisma Falso/diagnóstico por imagen , Aneurisma Falso/etiología , Niño , Fémur , Humanos , Masculino , Osteocondroma/diagnóstico , Osteocondroma/diagnóstico por imagen , Arteria Poplítea/diagnóstico por imagen , Arteria Poplítea/cirugíaRESUMEN
BACKGROUND: Coronally advanced flap combined with connective tissue graft is considered as the golden standard of root coverage. Although Miller class I recession is considered to get complete root coverage, there are some uncommon conditions in different cases. This case reported a maxillary lateral incisor with a gingival recession, a stillman's cleft, a bony exostosis and a denture stomatitis. CASE PRESENTATION: A 27-year-old female with a gingival recession, a stillman's cleft and a bony exostosis was treated by coronally advanced flap combined with connective tissue graft technique, and the complete coverage was achieved. Later a denture stomatitis occurred when an acrylic removable partial denture was used, however the gingival margin was not affected. The denture stomatitis disappeared when a new denture with casting palatal plane was produced. In this case of 3-year follow-up, the gingival contour remained stable and the outcome was satisfactory. CONCLUSION: Coronally advanced flap combined with connective tissue graft technique is a classic manner to treat gingival recession especially for a long term stability, even when there is a gingival stillman's cleft, a bony exostosis and a denture stomatitis.
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Exostosis , Recesión Gingival , Estomatitis Subprotética , Adulto , Femenino , Estudios de Seguimiento , Encía , Recesión Gingival/cirugía , Humanos , Incisivo/cirugía , Raíz del Diente/cirugía , Resultado del TratamientoRESUMEN
Here, we report on a patient with deep vein thrombosis of the right leg, in whom diagnostic work-up revealed a previously unknown chondrosarcoma of the tibia. Physical examination revealed a firm, nondisplaceable mass on the dorsal side of the right knee that appeared as a cystic formation on ultrasound. Xray, computed tomography, and magnetic resonance imaging were consistent with chondrosarcoma, which had likely provoked the thrombosis by local compression or paraneoplastic mechanisms. After resection of the tumor, anticoagulation was continued. In a review of all findings, a final diagnosis of highly differentiated chondrosarcoma with thrombosis of the popliteal vein was made.
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Neoplasias Óseas , Condrosarcoma , Trombosis , Trombosis de la Vena , Neoplasias Óseas/complicaciones , Neoplasias Óseas/diagnóstico , Neoplasias Óseas/cirugía , Humanos , Ultrasonografía/métodos , Trombosis de la Vena/diagnóstico , Trombosis de la Vena/etiologíaRESUMEN
BACKGROUND AND PURPOSE: The Haglund's deformity, which may be difficult to treat non-surgically, is caused by a prominent bone hump in the posterosuperior region of the calcaneus and may be associated with bursitis and foot pain. Many surgical treatments for resistant Haglund deformities have been described. Here, we evaluate the AOFAS scores, pain and other characteristics of patients undergoing removal of the dorsally based wedge from the posterior calcaneus with the Keck and Kelly procedure. MATERIALS AND METHODS: The study included 20 patients who had undergone the Keck and Kelly procedure at our center, from 2011 to 2019, and had attended follow-up for at least three years. Analyses were performed retrospectively. Preoperative (immediately before surgery) and postoperative (at last assessment) American Orthopedic Foot and Ankle Society (AOFAS) and visual analog pain scale scores (VAS) were determined, and calcaneal inclination angles were radiologically measured. Additionally, calcaneal pitch angle (CPA), Fowler and Philip angle (FPA), and Bohler angle were recorded. RESULTS: Fourteen patients were female, and six were male, mean age was 45.8 ± 8.1 years. AOFAS scores were significantly increased, whereas VAS scores were significantly decreased after surgery. Postoperative AOFAS scores were correlated with preoperative VAS, CPA, and FPA values. Preoperative VAS scores were correlated with CPA, FPA, and Bohler angle values. FPA and CPA values were correlated positively. CONCLUSIONS: It was found that ankle functions improved, and pain levels decreased after Keck and Kelly Wedge Osteotomy was applied for the treatment of Haglund's deformity. CPA and FPA were associated with both pain levels and ankle function. The Keck and Kelly Wedge Osteotomy procedure appears to be a preferable approach for the surgical treatment of Haglund's deformity.
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Tendón Calcáneo , Bursitis , Calcáneo , Tendón Calcáneo/cirugía , Adulto , Calcáneo/diagnóstico por imagen , Calcáneo/cirugía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Osteotomía/métodos , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Solitary osteochondromas are common, benign hyaline cartilage-capped exostoses that primarily arise from the metaphyses of long and flat bones. Diaphyseal aclasis is an autosomal dominant condition resulting from EXT1 or EXT2 gene mutations and is characterized by multifocal osteochondromas. These can result in a wide spectrum of complications, such as skeletal deformity, neurological and vascular complications, adventitial bursa formation, fracture, and rarely malignant transformation to peripheral chondrosarcoma. In this review, we outline in detail the multimodality imaging features of DA and its associated complications.
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Neoplasias Óseas , Condrosarcoma , Exostosis Múltiple Hereditaria , Osteocondroma , Diagnóstico por Imagen , Humanos , MutaciónRESUMEN
PURPOSE: The aim of the study was to investigate the efficacy of ear protection (earplug and surf hood) in preventing the development of external auditory exostosis (EAE) in surfers. METHODS: We performed a prospective observational study. Volunteer surfers were recruited from June 2016 to October 2017 on the Brittany coast in France. Each participant filled in a questionnaire and underwent otoscopic digitalized photography to establish the degree of external ear obstruction by two different practitioners. The correlation between the percentage of external ear obstruction and the time spent in water with or without protection was evaluated. Risk factors of EAE were assessed. RESULTS: Two hundred and forty-two ears were analysed. The incidence of EAE was 89.96% with an average rate of obstruction of 37.65%. Risk factors for EAE were male sex (p = 0.0005), number of years practicing surf (p < 0.0001) and symptoms of ear obstruction (p = 0.0358). A significant correlation was found between EAE severity and number of hours spent in water without any protection (earplugs or surf hood) (p < 0.0001). No correlation was found between EAE severity and time spent in water with earplugs (p = 0.6711) but a correlation was identified between obstruction and time spent in water with surf hood (p = 0.0358). CONCLUSIONS: Wearing earplugs is an effective way to prevent EAE in surfers unlike surf hood.
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Exostosis , Deportes , Conducto Auditivo Externo , Dispositivos de Protección de los Oídos , Exostosis/epidemiología , Exostosis/etiología , Exostosis/prevención & control , Humanos , Masculino , Estudios ProspectivosRESUMEN
Various techniques of surgical detachment for treatment of insertional Achilles tendinopathy have been described, including lateral release, medial release, central tendon splitting (CTS), and complete detachment. A systematic review of electronic databases was performed, encompassing 17 studies involving 703 patients and 746 feet, to compare outcomes associated with surgical takedown techniques. Observed results include wound complication rates (CTS 2.8%; Lateral 0%; Medial 0.4%; Complete 1.3%), postoperative rupture rates (CTS 0.7%; Lateral 0.8%; Medial 0.7%; Complete 2.6%), rate of revision (CTS 0.4%; Lateral 0.9%; Medial 4.2%; Complete 2.6%), rate of infection (CTS 1.1%; Lateral 1.7%; Medial 3.7%; Complete 6.5%). Lateral takedown group was found to have a statistically significant lower rate of complications compared to the complete takedown group (p = .0029). In light of these results, it is recommended that patient characteristics such as case specific tendon pathology and calcaneal morphology take precedent in determining the surgical approach to Achilles takedown.
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Tendón Calcáneo , Calcáneo , Procedimientos Ortopédicos , Tendinopatía , Tendón Calcáneo/cirugía , Calcáneo/cirugía , Humanos , Procedimientos Ortopédicos/efectos adversos , Rotura/cirugía , Tendinopatía/cirugíaRESUMEN
Background and Objectives: Up until now, only one case of unilateral proximal tibiofibular synostosis caused by osteochondroma has been reported. This report is the first well-documented bilateral case of proximal tibiofibular synostosis caused by an osteochondroma. Case Report: A 21-year-old, highly active male patient with bilateral proximal tibiofibular synostosis caused by an osteochondroma suffering from persistent knee pain is presented. As conservative methods had failed, the patient was treated by bilateral open resection of the connecting bone. Histopathological findings confirmed the preoperative diagnosis. The patient returned to sports three weeks after surgery and continued soccer training six weeks after surgery. Discussion: The case report presents the successful treatment of a bilateral proximal tibiofibular synostosis caused by an osteochondroma by bilateral open resection of the connecting bone.
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Neoplasias Óseas , Osteocondroma , Sinostosis , Adulto , Neoplasias Óseas/complicaciones , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/cirugía , Peroné/diagnóstico por imagen , Peroné/cirugía , Humanos , Masculino , Osteocondroma/complicaciones , Osteocondroma/diagnóstico por imagen , Osteocondroma/cirugía , Sinostosis/diagnóstico por imagen , Sinostosis/cirugía , Tibia/diagnóstico por imagen , Tibia/cirugía , Adulto JovenRESUMEN
There are many metabolic disorders that present with bone phenotypes. In some cases, the pathological bone symptoms are the main features of the disease whereas in others they are a secondary characteristic. In general, the generation of the bone problems in these disorders is not well understood and the therapeutic options for them are scarce. Bone development occurs in the early stages of embryonic development where the bone formation, or osteogenesis, takes place. This osteogenesis can be produced through the direct transformation of the pre-existing mesenchymal cells into bone tissue (intramembranous ossification) or by the replacement of the cartilage by bone (endochondral ossification). In contrast, bone remodeling takes place during the bone's growth, after the bone development, and continues throughout the whole life. The remodeling involves the removal of mineralized bone by osteoclasts followed by the formation of bone matrix by the osteoblasts, which subsequently becomes mineralized. In some metabolic diseases, bone pathological features are associated with bone development problems but in others they are associated with bone remodeling. Here, we describe three examples of impaired bone development or remodeling in metabolic diseases, including work by others and the results from our research. In particular, we will focus on hereditary multiple exostosis (or osteochondromatosis), Gaucher disease, and the susceptibility to atypical femoral fracture in patients treated with bisphosphonates for several years.
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Desarrollo Óseo/fisiología , Remodelación Ósea/fisiología , Cartílago/crecimiento & desarrollo , Enfermedades Metabólicas/metabolismo , Osteogénesis/fisiología , Animales , Cartílago/citología , Condrocitos/ultraestructura , Difosfonatos/uso terapéutico , Exostosis Múltiple Hereditaria/metabolismo , Fracturas del Fémur/tratamiento farmacológico , Fracturas del Fémur/metabolismo , Enfermedad de Gaucher/metabolismo , Humanos , Osteoclastos/metabolismoRESUMEN
Heparan sulfate (HS) regulates diverse cell signalling events in intervertebral disc development and homeostasis. The aim of the present study was to investigate the effect of ablation of perlecan HS/CS on murine intervertebral disc development. Genetic models carrying mutations in genes encoding HS biosynthetic enzymes have identified multiple roles for HS in tissue homeostasis. In the present study, we utilised an Hspg2 exon 3 null HS/CS-deficient mouse to assess the role of perlecan HS in disc cell regulation. HS makes many important contributions to growth factor sequestration, stabilisation/delivery, and activation of receptors directing cellular proliferation, differentiation, and assembly of extracellular matrix. Perlecan HS/CS-mediated interactions promote extracellular matrix assembly/stabilisation and tissue functional properties, and thus, removal of perlecan HS/CS should affect extracellular matrix function and homeostasis. Hspg2 exon 3 null intervertebral discs accumulated significantly greater glycosaminoglycan in the nucleus pulposus, annulus fibrosus, and vertebral growth plates than C57BL/6 wild-type (WT) I intervertebral discs. Proliferation of intervertebral disc progenitor cells was significantly higher in Hspg2 exon 3 null intervertebral discs, and these cells became hypertrophic by 12 weeks of age and were prominent in the vertebral growth plates but had a disorganised organisation. C57BL/6 WT vertebral growth plates contained regular columnar growth plate chondrocytes. Exostosis-like, ectopic bone formation occurred in Hspg2 exon 3 null intervertebral discs, and differences were evident in disc cell maturation and in matrix deposition in this genotype, indicating that perlecan HS/CS chains had cell and matrix interactive properties which repressively maintained tissue homeostasis in the adult intervertebral disc.