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1.
AJR Am J Roentgenol ; 203(2): 418-23, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25055279

RESUMO

OBJECTIVE: The purpose of this study was to compare the diagnostic utility of MRI and MR arthrography for ligamentum teres tears in patients with hip pain. MATERIALS AND METHODS: This is a retrospective study involving 187 patients who underwent MRI or MR arthrography for hip pain. This study included 103 male and 84 female patients with average age of 39 years. Three experienced musculoskeletal radiologists reviewed the MRI and MR arthrography studies to assess the ligamentum teres tears. The criteria for diagnosing normal or abnormal (i.e., ligament), partial or degenerative or complete tear of ligamentum teres were defined on the basis of several imaging characteristics. The MRI and MR arthrography results were correlated with arthroscopy, which served as the reference standard. Statistical analysis was performed to calculate the diagnostic yield, diagnostic accuracy, and diagnostic performance of MRI and MR arthrography in detecting partial or degenerative and complete ligamentum teres tears. Overall comparative performance of MRI and MR arthrography was assessed using Kruskal-Wallis test. RESULTS: For partial ligamentum teres tears, MRI showed lower sensitivity, specificity, and positive predictive value (0.41, 0.75, and 0.32, respectively) as compared to MR arthrography (0.83, 0.93, and 0.76, respectively), whereas the negative predictive value of MRI (0.82) was comparable to that of MR arthrography (0.95). No statistically significant difference (p < 0.05) could be identified between MRI and MR arthrography for diagnosing complete ligamentum teres tears. CONCLUSION: Hip MRI is equally suited for diagnosis of complete ligamentum teres tears when compared with MR arthrography. By contrast, for partial or degenerative ligamentum teres tears, MR arthrography offers the advantage of better arthroscopic correlation.


Assuntos
Lesões do Quadril/diagnóstico , Ligamentos Articulares/lesões , Imageamento por Ressonância Magnética/métodos , Ruptura/diagnóstico , Adolescente , Adulto , Idoso , Meios de Contraste , Feminino , Humanos , Iopamidol , Masculino , Meglumina/análogos & derivados , Pessoa de Meia-Idade , Compostos Organometálicos , Estudos Retrospectivos
2.
Skeletal Radiol ; 42(2): 297-301, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22936338

RESUMO

Closed flexor tendon rupture is an unusual condition that has been described in association with distinct underlying disease processes. Several theories have been implicated in the pathogenesis, including labor-associated forceful usage, gender, and age. The effect of diabetes on the native tendon tissue is not yet fully understood; however, the metabolic perturbations of diabetes have been shown to result in detrimental changes to the musculoskeletal system. We report an unusual case of bilateral spontaneous rupture of the flexor digitorum superficialis and flexor digitorum profundus in a 58-year-old woman with Type 2 diabetes mellitus. The clinical course, radiographic findings, and the biomechanical factors and mechanisms through which diabetes may affect the native tendon are presented.


Assuntos
Diabetes Mellitus Tipo 2/patologia , Traumatismos dos Dedos/patologia , Imageamento por Ressonância Magnética/métodos , Traumatismo Múltiplo/patologia , Ruptura Espontânea/patologia , Traumatismos dos Tendões/patologia , Diabetes Mellitus Tipo 2/complicações , Diagnóstico Diferencial , Feminino , Traumatismos dos Dedos/complicações , Humanos , Pessoa de Meia-Idade , Traumatismo Múltiplo/complicações , Ruptura Espontânea/complicações , Traumatismos dos Tendões/complicações
3.
Skeletal Radiol ; 42(12): 1693-701, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24026069

RESUMO

OBJECTIVES: The objectives of this work were to retrospectively describe the radiographic assessment of INBONE total ankle arthroplasty in 30 patients using validated linear and angular measurements and to correlate these findings with the final surgical outcome over a 2-year follow-up period. MATERIALS AND METHODS: Thirty consecutive patients (21 females, nine males; mean age, 64.8 years) underwent INBONE total ankle arthroplasty during 2007-2011. After IRB approval, a retrospective pre- and post-operative radiographic analysis was performed using validated linear and angular measurements. The pre- and post-operative assessment included the tibial angle, talar angle, tibial slope, and coronal deformity. Post-operative measurements also included the talocalcaneal angle, joint space height, talar height, lateral tibial component angle, lateral talar component angle, and anteroposterior tibial component angle. The post-operative bone loss, subluxation, positioning, and subsidence were also assessed. Statistical analysis was performed using two-sample t test and Fisher's exact test. RESULTS: Out of 30 patients, 23 had a successful clinical outcome with intact prosthesis at a 2-year follow-up. The only variables with significant correlation (p < 0.05) to the post-surgical outcome were the lateral talar component angle (p = 0.002) and the mean difference between pre- and post-operative tibial slope (p = 0.001). The coronal deformity had significant mean difference between pre- and post-operative values (p < 0.001); however, it lacked a significant correlation to the final surgical outcome. None of the categorical variables had a significant correlation with post-surgical outcome. CONCLUSIONS: In our retrospective study, only the lateral talar component angle and the mean difference between the pre- and post-operative tibial slope had significant correlation with post-surgical outcome in INBONE ankle arthroplasty. These measurements may be helpful in radiographic assessment of the INBONE ankle arthroplasty.


Assuntos
Artrite/diagnóstico por imagem , Artrite/cirurgia , Artroplastia de Substituição do Tornozelo/instrumentação , Artroplastia de Substituição do Tornozelo/métodos , Amplitude de Movimento Articular , Idoso , Idoso de 80 Anos ou mais , Análise de Falha de Equipamento , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prognóstico , Desenho de Prótese , Radiografia , Recuperação de Função Fisiológica , Estudos Retrospectivos , Resultado do Tratamento
4.
Skeletal Radiol ; 40(2): 239-42, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20838993

RESUMO

Intravenous (IV) access is a critical step in patient care, especially in the emergency and/or trauma setting. Recently, intraosseous (IO) infusion has re-emerged as a recommended alternative to central venous access in both the pediatric and the adult patient. We present the case of an older adult male patient several months after emergency tibial IO infusion, now with left shin pain, and the MRI and culture findings diagnostic of subacute osteomyelitis with IO abscess, an unusual complication of IO infusion.


Assuntos
Abscesso/diagnóstico , Abscesso/etiologia , Infusões Intraósseas/efeitos adversos , Osteomielite/diagnóstico , Osteomielite/etiologia , Tíbia/diagnóstico por imagem , Tíbia/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/etiologia
5.
Surg Radiol Anat ; 33(10): 897-903, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21695542

RESUMO

PURPOSES: (1) To revisit the anatomical boundaries of the canal, its contents and its two channels, (2) to describe the anatomical variations of the canal's borders and the variations of its contents, and (3) to discuss the clinical relevance of the Guyon's canal syndrome. METHODS: Two hundred and fifty MR wrists examinations were reviewed. MR spin echo T1-weighted axial slices were used to analyze the Guyon's canal. The anatomical boundaries, the cross-sectional area and length of the canal were calculated. The anatomical variations of the canal's walls and contents and their prevalence were sought. Changes related to Guyon's canal syndrome were also evaluated. RESULTS: From the 250 wrists, the anatomy of the Guyon's canal was normal in 168 (67.2%) wrists; 73 (29.2%) wrists presented with anatomical variations; and 9 (3.6%) wrists had derangements causing Guyon's canal syndrome. The cross-sectional area of the canal was 33 ± 11 mm² proximally and 45 ± 19 mm² distally. The canal's length was approximately 40 ± 4 mm. Among the 73 wrists with anatomical variations, there were aberrant muscles in 39 (53.4%) wrists, multiple ulnar nerve branching in 22 (30%) cases, increased amount of fat tissue inside the canal in 9 (12.3%) cases and hypoplastic hamulus in 3 (4.1%) cases. There were 9 (3.6%) symptomatic wrists with clinical and radiological features attributed to Guyon's canal syndrome. CONCLUSION: MRI is an excellent modality for the evaluation of the Guyon's canal.


Assuntos
Síndromes de Compressão do Nervo Ulnar/patologia , Punho/anatomia & histologia , Humanos , Imageamento por Ressonância Magnética , Valores de Referência , Estudos Retrospectivos
6.
AJR Am J Roentgenol ; 194(3): 721-7, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20173151

RESUMO

OBJECTIVE: The objective of our study was to assess patellofemoral measurements on MRI and to correlate the measurements with different grades of cartilage defect. MATERIALS AND METHODS: Axial and sagittal MR images of 100 patients with various pathologic knee conditions were analyzed. The patients were divided into two age groups: < 40 years and > or = 40 years. Patellar measurements of facet asymmetry, the patella-to-patellar tendon ratio, and the amount of patellotrochlear cartilage overlap were obtained in each subject. Similarly, trochlear measurements of the ventral trochlear prominence, trochlear depth, facet asymmetry, sulcus angle, and lateral inclination were obtained. Axial and sagittal MR images were reviewed to grade the severity of focal cartilage defects in the patellofemoral region on the basis of the depth of the lesion. Measurements in knees without a chondral defect were compared with knees with mild and severe chondral defects. RESULTS: There was a statistically significant difference in the trochlear measurements of the ventral prominence (p = 0.012), trochlear depth (p = 0.001), sulcus angle (p = 0.208), and lateral inclination (p = 0.154) between normal knees and knees with severe cartilage defects in patients younger than 40 years. No significant difference was seen in the patellar measurements between normal knees and knees with severe cartilage defects. CONCLUSION: There is an association between abnormal trochlear morphology and severe patellofemoral cartilage defects in patients younger than 40 years.


Assuntos
Cartilagem Articular/patologia , Fêmur/patologia , Imageamento por Ressonância Magnética/métodos , Patela/patologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Síndrome da Dor Patelofemoral/patologia , Estudos Retrospectivos
7.
Acta Radiol ; 51(4): 438-54, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20380605

RESUMO

The Achilles tendon is the largest tendon in the body; it plays an important role in the biomechanics of the lower extremity. It can withstand great forces, especially during sporting exercises and pivoting. The pathologies related to the Achilles tendon are diverse and many carry undesirable consequences. We retrospectively analyzed the images of patients who underwent examinations of the ankle/foot region to review the anatomy of the Achilles tendon and its surroundings and to search for pathologies consistent with overuse injuries. The anatomy of the tendon is described from origin to insertion. The imaging characteristics of the Achilles tendon including pitfalls are reviewed. We also describe the Achilles overuse injuries: paratenonitis, tendinosis, tendon tear, atypical tear, tendon re-tear, retrocalcaneal bursitis, retro-Achilles bursitis, Haglund's deformity, and tendon calcification. We present other entities like tendon ossification and failed transplanted Achilles tendon, with emphasis on MRI.


Assuntos
Tendão do Calcâneo/anatomia & histologia , Tendão do Calcâneo/lesões , Tendão do Calcâneo/fisiologia , Transtornos Traumáticos Cumulativos/diagnóstico , Imageamento por Ressonância Magnética/métodos , Tendinopatia/diagnóstico , Fenômenos Biomecânicos , Meios de Contraste , Transtornos Traumáticos Cumulativos/etiologia , Humanos , Tendinopatia/etiologia
8.
Skeletal Radiol ; 39(5): 501-4, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20162273

RESUMO

A 45-year-old man presented with vertebral collapse at L5 as an initial manifestation of multiple myeloma and underwent spinal fusion surgery using recombinant human bone morphogenetic protein-2 (rhBMP-2). Subsequent computed tomography (CT) scans and X-rays revealed heterotopic ossification of the left psoas muscle, pelvis, and anterior abdominal wall. While the occurrence of heterotopic ossification has previously been reported when rhBMP-2 has been used for spinal fusion surgery, this case demonstrates that it can occur to a much greater degree than previously seen.


Assuntos
Proteína Morfogenética Óssea 2/efeitos adversos , Doenças Musculares/induzido quimicamente , Ossificação Heterotópica/induzido quimicamente , Pelve/diagnóstico por imagem , Radiografia Abdominal , Proteínas Recombinantes/efeitos adversos , Fusão Vertebral/efeitos adversos , Parede Abdominal , Proteína Morfogenética Óssea 2/genética , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Musculares/diagnóstico por imagem , Ossificação Heterotópica/diagnóstico por imagem , Tomografia Computadorizada por Raios X
9.
Emerg Radiol ; 17(3): 179-84, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19662447

RESUMO

This study aims (1) to assess the prevalence and distribution of multiple occult injuries of the carpal bones and the distal forearm in patients with wrist pain and negative radiographs following trauma and (2) to evaluate the distribution and significance of joint effusions in the wrists with multiple osseous injuries. One hundred and thirty-one subjects, 74 men and 57 women, were consecutively examined in two institutions. All were acute trauma patients with negative X-rays whose clinical examination suggested possible fracture at the wrist or the distal forearm. Magnetic resonance (MR) wrist imaging was performed with and without fat saturation sequences. The MR images were analysed for detection of occult trabecular contusions and cortical discontinuity in the carpus, the distal forearm and the metacarpal bases. The prevalence and distribution of the injuries were assessed along with the distribution of joint effusions. Eight patients were excluded due to inadequate image quality. Two patients had bilateral injury. A total of 125 wrists were analysed. Seventy-eight (62.4%) wrists had occult bone injuries. Among these 78, 53 (68%) wrists had more than one injured bone. Twenty-five wrists (32%) had one injured bone. The highest number of injured bones per wrist was six. Injuries with a visible fracture line were seen in 29 (37.1%) wrists on MRI. The distal radius was the most frequent location for occult fracture line (11 cases). The injuries without a fracture line (contusion) were present in 49 (63%) wrists; they were detected more frequently in the scaphoid (35 cases). The lunate (29 cases) and the triquetrum (26 cases) were almost equally affected. The bone that was less frequently injured was the pisiform (four cases). Joint effusions were present in all 53 wrists with multiple bone lesions but more often situated in the ulnocarpal space [27 (50.3%) wrists]. There was no correlation between effusions in multiple locations (grades III and IV) and multiple bone injuries. This study revealed the presence of multifocal trabecular contusions without correlation with increased joint effusions in patients with negative radiographs and persistent pain. The clinical significance of these findings deserves further investigation.


Assuntos
Fraturas Fechadas/diagnóstico , Imageamento por Ressonância Magnética , Traumatismo Múltiplo , Dor , Traumatismos do Punho/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Ossos do Carpo/lesões , Feminino , Traumatismos do Antebraço , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Radiografia , Traumatismos do Punho/diagnóstico por imagem , Traumatismos do Punho/fisiopatologia , Adulto Jovem
10.
Surg Radiol Anat ; 32(5): 519-23, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19812883

RESUMO

Congenital anomalies of the muscles of the lower extremity are rare. A case of complete absence of the semimembranosus muscle incidentally found with magnetic resonance imaging is reported. The patient was a 55-year-old female presenting with knee pain and no previous history of trauma. Clinical and imaging findings were consistent with meniscal tears. Two cases of uncommon distal insertion of the semimembranosus tendon are also described to illustrate the anatomical variations in this area. The anatomical and biomechanical relations between the semimembranosus muscle and the posteromedial corner of the knee are examined in this case report.


Assuntos
Articulação do Joelho/anormalidades , Músculo Esquelético/anormalidades , Doenças Musculares/congênito , Artroscopia , Feminino , Seguimentos , Humanos , Achados Incidentais , Articulação do Joelho/cirurgia , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Músculo Esquelético/cirurgia , Doenças Musculares/cirurgia
11.
Surg Radiol Anat ; 32(3): 315-22, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20033168

RESUMO

OBJECTIVE: Anatomical variations of the median nerve and the persistent median artery (PMA) in the carpal tunnel (CT) are important to understand for their clinical and surgical significance. The aim of this cohort retrospective study was to investigate the prevalence of aberrant median nerve branches and persistent median artery in the CT in a selected population using magnetic resonance imaging (MRI). MATERIALS AND METHODS: MR wrist images of 194 patients, 77 males and 117 females, aged 12-80 years were randomly selected and retrieved from our clinical and radiology data base. The MR examinations were performed using either 1.5-T or 3.0-T magnet using a cylindrical receive-transmit wrist coil for all cases. The course of the bifurcation of the median nerve was followed on axial T2-weighted and axial proton density fat saturated images and classified as either proximal, within, or distal to the CT. The flexor retinaculum proximally and the metacarpal bases were used as anatomic landmarks to subdivide these three categories. In addition, the median artery was searched in order to assess the prevalence of its presence inside the CT. A total of 194 wrists were analyzed by two musculoskeletal-trained radiologists. They were blinded on the population age, gender, and the sides of the wrists. Agreement was reached by consensus. RESULTS: Among the 194 wrists, there was bifurcation of the nerve proximal to the CT in 12 (6.1%) wrists. There was nerve bifurcation within the CT in 36 (18%) wrists. Nerve bifurcation distal to the CT was more frequently observed, occurring in 147 (75%) wrists. Only one nerve trifurcation was seen within the CT. There was no gender predominance for the nerve bifurcation within the tunnel. There were 107 right wrists and 87 left wrists. On the right side, bifurcation of the nerve within the CT was seen in 21 (19.6%) wrists; and on the left side bifurcation of the nerve was present in 15 (17.2%) wrists. Statistically, we found no significant difference in the prevalence of the bifid nerve within the tunnel in the subgroups based on age, gender, or side of the wrists. A persistent median artery (PMA) within the tunnel was observed in 21 (11%) wrists--10 males and 11 females. Of these, four (19%) cases were presented with coexistent PMA and bifid median nerve within the tunnel. Statistically, we found that the two variations are not independent traits, and their covariance is not null. CONCLUSION: There was a high prevalence of bifid median nerve (19%) and PMA (11%) within the tunnel regardless of gender or age. The PMA was more frequent on the left side.


Assuntos
Imageamento por Ressonância Magnética/métodos , Nervo Mediano/anormalidades , Punho/irrigação sanguínea , Punho/inervação , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Criança , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Prevalência , Estudos Retrospectivos , Distribuição por Sexo , Punho/anormalidades , Adulto Jovem
12.
AJR Am J Roentgenol ; 193(5): 1361-6, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19843754

RESUMO

OBJECTIVE: The purposes of this study were to assess the degree of patellotrochlear chondral overlap (patellotrochlear index), correlate it with the Insall-Salvati and modified Insall-Salvati indexes, and determine the association between these measurements and patellofemoral chondral defects. MATERIALS AND METHODS: Sagittal 1.5-T and 3-T MR images of 100 consecutively registered patients with symptoms were analyzed, and the Insall-Salvati index, modified Insall-Salvati index, patellotrochlear index, and patellophyseal index (ratio of the height of patella above the physeal line to the length of the patellar articular cartilage) were calculated. The upper and lower limits of 2 SDs were used to define patella alta and baja, and the correlation coefficient curves were plotted to compare techniques. The indexes in normal knees were compared with those in knees with severe chondral defects. RESULTS: The mean patellotrochlear index was 0.49 +/- 0.15 (SD) (range, 0-0.88). On the basis of calculation of 2 SDs, patella alta was determined to have a patellotrochlear index less than 0.18 and patella baja, an index greater than 0.80. Weak correlation was found between the measured patellotrochlear index and Insall-Salvati index (r = -0.224) and between the patellotrochlear index and modified Insall-Salvati index (r = -0.073). A strong correlation was found between the patellotrochlear index and patellophyseal index (r = -0.813). A statistically significant (p < 0.05) difference in the modified Insall-Salvati index and patellophyseal index was found between knees with normal and those with severe cartilage defects. CONCLUSION: Our results indicate that the commonly used Insall-Salvati and modified Insall-Salvati indexes do not correlate with patellotrochlear articular cartilage congruence. We did find an association between the modified Insall-Salvati and patellophyseal indexes and the presence of severe chondral defects.


Assuntos
Cartilagem Articular/anatomia & histologia , Imageamento por Ressonância Magnética/métodos , Patela/anatomia & histologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Cartilagem Articular/patologia , Criança , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Patela/patologia
13.
Skeletal Radiol ; 38(10): 997-1001, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19308406

RESUMO

OBJECTIVE: A wide degree of normal anatomical variation can occur at the sternoclavicular joint (SCJ). On occasion, this has led to concern for a pathological process, potentially resulting in a costly work-up, unnecessary patient worry and invasive diagnostic procedures such as biopsy. The purpose of this study was to determine the normal range of anatomical variation at sternoclavicular joints. MATERIALS AND METHODS: One hundred four consecutive patients with chest CT done at our institution were selected. Patients with clear SCJ pathology, chest wall abnormality, CT slice thickness greater than 5 mm and sternotomy wires, were excluded. Chart review was done and showed no SCJ symptoms/signs. We measured the SCJ space, maximum clavicular head diameter within the joint and the distance from manubrium to the anterior margin of the clavicular head. RESULTS: Left and right SCJ space ranged from 0.2 to 1.37 cm. The difference (delta or asymmetry) between left SCJ space and right SCJ space ranged from 0 (symmetrical) to 0.57 cm in 104 cases. Left and right clavicular head diameter ranged from 1.2 to 3.7 cm with left/right asymmetry (delta) ranging from 0 (symmetrical) to 1 cm. Manubrium to anterior margin of clavicular head ranged from 0.1 to 2.13 cm with delta ranging from 0 to 0.8 cm. Thirty-three patients demonstrated gas in the joint, five had poor articulation and four had calcification in the joint. CONCLUSION: Greater than 10% of patients show substantial asymmetry in the sternoclavicular joints, which may be misinterpreted as pathological. Gas in the joint is a common phenomenon therefore should not be an indication for further work-up in asymptomatic patients and likely excludes the presence of effusion.


Assuntos
Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Articulação Esternoclavicular/anatomia & histologia , Articulação Esternoclavicular/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto Jovem
14.
J Bone Joint Surg Am ; 89(8): 1749-55, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17671014

RESUMO

BACKGROUND: Patella alta is a condition which may predispose individuals to patellofemoral joint dysfunction. We compared patellofemoral joint alignment and contact area in subjects who had patella alta with subjects who had normal patellar position, to determine the effect of high vertical patellar positions on knee extensor mechanics. METHODS: Twelve subjects with patella alta and thirteen control subjects participated in the study. Lateral patellar displacement (subluxation), lateral tilt, and patellofemoral joint contact area were quantified from axial magnetic resonance images of the patellofemoral joint acquired at 0 degrees , 20 degrees , 40 degrees , and 60 degrees of knee flexion with the quadriceps contracted. RESULTS: With the knee at 0 degrees of flexion, the subjects with patella alta demonstrated significant differences compared with the control group, with greater lateral displacement (mean [and standard error], 85.4% +/- 3.6% and 71.3% +/- 3.0%, respectively, of patellar width lateral to the deepest point in the trochlear groove; p = 0.007), greater lateral tilt (mean, 21.6 degrees +/- 1.9 degrees and 15.5 degrees +/- 1.8 degrees ; p = 0.028), and less contact area (157.6 +/- 13.7 mm(2) and 198.8 +/- 14.3 mm(2); p = 0.040). Differences in displacement and tilt were not observed at greater knee flexion angles; however, contact area differences were observed at all angles evaluated. When data from both groups were combined, the vertical position of the patella was positively associated with lateral displacement and lateral tilt at 0 degrees of flexion and was negatively associated with contact area at all knee flexion angles. CONCLUSIONS: These data indicate that the vertical position of the patella is an important structural variable that is associated with patellofemoral malalignment and reduced contact area in patients with patella alta.


Assuntos
Instabilidade Articular/fisiopatologia , Articulação do Joelho/fisiopatologia , Patela/anormalidades , Patela/fisiopatologia , Suporte de Carga , Adulto , Fenômenos Biomecânicos , Estudos de Casos e Controles , Feminino , Humanos , Imageamento por Ressonância Magnética , Medição da Dor
15.
J Biomech ; 38(12): 2415-22, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16214489

RESUMO

The purpose of this study was to compare the knee extensor mechanics in persons with and without patella alta. Thirteen subjects with patella alta and 14 subjects with normal patellar position participated in the study. Sagittal and axial MR images of the knee were acquired at 0 degrees , 20 degrees , 40 degrees , and 60 degrees of knee flexion. Measurements of actual moment arm, patellar ligament/quadriceps tendon force ratio, quadriceps effective moment arm, and joint reaction force/quadriceps force ratio were obtained. There were no differences between groups in terms of actual moment arm. However, subjects with patella alta had significantly larger patellar ligament/quadriceps tendon force ratios (1.04+/-0.02 vs. 0.92+/-0.02) and quadriceps effective moment arms (4.40+/-0.09 vs. 4.00+/-0.09 cm) when averaged across the range of knee flexion angles tested. There was no difference in the joint reaction force/quadriceps force ratio between groups. The observed differences in knee extensor mechanics suggest that individuals with patella alta have a more efficient knee extensor mechanism and would be expected to generate similar joint reaction forces per unit quadriceps force compared to subjects with normal patellar position. Therefore, persons with patella alta may experience less patellofemoral joint reaction force to overcome the same knee flexion moment in the range of 0 degrees -60 degrees of knee flexion.


Assuntos
Articulação do Joelho/fisiopatologia , Contração Muscular , Músculo Esquelético/fisiopatologia , Patela/anormalidades , Patela/fisiopatologia , Equilíbrio Postural , Adulto , Fenômenos Biomecânicos/métodos , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Artropatias/patologia , Artropatias/fisiopatologia , Articulação do Joelho/patologia , Imageamento por Ressonância Magnética/métodos , Masculino , Músculo Esquelético/patologia , Patela/patologia , Amplitude de Movimento Articular , Estresse Mecânico , Torque
16.
Med Sci Sports Exerc ; 36(7): 1226-32, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15235330

RESUMO

PURPOSE: To examine the influence of two patellofemoral braces on pain response, patellar alignment, and patellofemoral joint contact area in persons with patellofemoral pain. METHODS: Fifteen women between the ages of 18 and 45 yr with a diagnosis of patellofemoral pain participated. After the assessment of pain response using a visual analog scale, subjects underwent axial plane magnetic resonance imaging of patellofemoral joint at 0 degrees, 20 degrees, 40 degrees, and 60 degrees of knee flexion. Imaging was done with the knee extensors contracted (25% body weight) under three conditions: 1) no brace, 2) On-Track brace, and 3) Patellar Tracking Orthosis (PTO). Measures of mediolateral patellar displacement and tilt and medial and lateral facet contact area were obtained from the magnetic resonance images. RESULTS: On average, the On-Track brace reduced symptoms by 50%, whereas the PTO reduced pain by 44%. When averaged across all knee flexion angles, the PTO and the On-Track brace significantly increased total patellofemoral joint contact area by 52.0 mm (21%) and 59.3 mm (24%), respectively, when compared with the no-brace condition. Bracing had no influence on lateral patellar tilt; however, small but significant changes in lateral patellar displacement were observed. CONCLUSION: Large changes in pain and contact area occurred without sizable changes in patellar alignment. The results of this study suggest that changes in patellar alignment by itself may not be responsible for pain alleviation after patellar bracing.


Assuntos
Braquetes , Fêmur/anatomia & histologia , Imobilização , Articulação do Joelho/anatomia & histologia , Patela/anatomia & histologia , Adolescente , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Dor/prevenção & controle , Estados Unidos
17.
Magn Reson Imaging ; 21(9): 955-9, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14684196

RESUMO

To describe a method for quantifying patellofemoral joint contact area using magnetic resonance imaging (MRI), we used a repeated measures design using cadaver specimens. The use of contact area obtained from cadaveric specimens for biomechanical modeling does not permit investigators to assess the inter-subject variability in contact area as a result of patellofemoral pathology or malalignment. Therefore, a method for measuring patellofemoral joint contact area in-vivo is necessary. Six fresh frozen unmatched human cadaver knees were thawed at room temperature and minimally dissected to permit insertion of a pressure sensitive film packet into the suprapatellar pouch. A custom loading apparatus was designed to apply a compressive load to the patellofemoral joint at 30 degrees of flexion. Simultaneous measurement of contact area was made using both the pressure sensitive film technique and MRI. The intraclass correlation coefficient (ICC) and coefficient of variation were used to compare the agreement between the two methods and to assess the repeatability of the MRI method. Good agreement was found between the MRI and pressure sensitive film techniques (ICC 0.91; CV 13%). The MRI technique also was found to be highly reproducible (ICC 0.98; CV 2.3%). MRI assessment of patellofemoral joint contact area was found to be comparable to the established pressure sensitive film technique. These results suggest that this method may be a valuable tool in quantifying patellofemoral joint contact area in-vivo. Quantification of the patellofemoral joint stress has been dependent on patellofemoral joint contact area obtained from cadaver specimens, thereby negating the potential influence of subject specific variability. Developing a non-invasive technique to evaluate contact area will assist researchers and/or clinicians in obtaining patient-specific contact area data to be used in biomechanical analyses and clinical decision making.


Assuntos
Fêmur/anatomia & histologia , Articulação do Joelho/anatomia & histologia , Patela/anatomia & histologia , Cadáver , Fêmur/fisiologia , Humanos , Articulação do Joelho/fisiologia , Imageamento por Ressonância Magnética , Patela/fisiologia , Reprodutibilidade dos Testes
18.
Am J Sports Med ; 32(1): 224-31, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14754748

RESUMO

BACKGROUND: Although several studies have demonstrated decreases in patellofemoral pain (PFP) with the application of bracing, the mechanism by which bracing reduces symptoms has not been elucidated. HYPOTHESIS: Individuals who responded favorably to bracing will exhibit decreased patellofemoral stress during level walking. STUDY DESIGN: Repeated measures, cross-sectional. METHODS: Fifteen subjects with a diagnosis of PFP completed two phases of data collection: 1) MRI assessment of patellofemoral contact area and 2) gait analysis. Data were obtained under braced and nonbraced conditions. Variables obtained from both data collection sessions were used as input variables into a mathematical model to quantify patellofemoral stress. RESULTS: Subjects reported a 56% reduction in pain following bracing. Bracing significantly reduced peak stress during free and fast walking (17% and 27%, respectively). The decrease in stress was the result of increased contact area as patellofemoral joint reaction forces were increased following bracing. CONCLUSION: Bracing resulted in a larger increase in patellofemoral contact area than the increase in joint reaction force, resulting in a decrease in joint stress. CLINICAL RELEVANCE: The results of this study suggest a possible mechanism by which bracing may be effective in reducing PFP and provides experimental support for the use of this treatment method.


Assuntos
Braquetes , Articulação do Joelho/fisiopatologia , Caminhada/fisiologia , Adolescente , Adulto , Análise de Variância , Fenômenos Biomecânicos , Estudos Transversais , Feminino , Fêmur/fisiopatologia , Marcha/fisiologia , Humanos , Imageamento por Ressonância Magnética , Medição da Dor , Patela/fisiopatologia
20.
Eur J Radiol ; 81(10): 2771-5, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22078792

RESUMO

OBJECTIVES: (1) To investigate the association between diabetes and marrow changes in the cuboid; and (2) to evaluate the influence of age, gender, body mass index (BMI) and use of insulin in the occurrence of marrow changes in the cuboid. RESEARCH DESIGN AND METHODS: MR and X-ray foot examinations of 237 patients [94 males, 143 females; mean age, 47.1 years (range 16-93 years)], five of whom underwent bilateral examinations, were reviewed. MR and radiographic studies were analyzed for the presence of marrow edema and fractures in the cuboid. Findings were correlated with demographic data (age, gender) and clinical information (BMI and use of insulin). RESULTS: Two hundred and forty two feet - 69 diabetic and 173 non-diabetic - were retrospectively evaluated. There was a higher prevalence of marrow edema and fractures in the diabetic cuboid (n=31, 45%) compared to non-diabetic cuboid (n=25, 14%, p=0.02). A fracture line was seen in fourteen (20%) diabetic cuboid bones compared to 4 (2%) in non-diabetic cuboid bones (p<0.0001). Eleven (79%) cases of cuboid fractures in the diabetic population were radiographically occult. Multivariate data analysis revealed an adjusted odds ratio of 4.416 (95% CI; 2.307, 8.454) for the relationship between marrow changes (edema and fractures) in the cuboid and diabetes. For each year of age, the odds of changes in the cuboid increased by 2.2% (95% CI; 1.001, 1.044). CONCLUSION: Despite not bearing weight, the cuboid bone is more vulnerable to marrow edema and fractures in diabetic patients compared to non-diabetic patients. Age seems to be an influential factor.


Assuntos
Pé Diabético/epidemiologia , Pé Diabético/patologia , Fraturas Ósseas/epidemiologia , Fraturas Ósseas/patologia , Imageamento por Ressonância Magnética/estatística & dados numéricos , Ossos do Tarso/lesões , Ossos do Tarso/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Feminino , Georgia/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade , Adulto Jovem
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