RESUMO

Objective To compare magnetic resonance imaging (MRI) using a body coil with computed tomography (CT) in measuring the tibial tubercle-trochlear groove distance (TT-TG) and the patellar tendon-cartilaginous trochlear groove (PT-CTG) distances, and evaluate interrater reliability. Methods The study group consisted of 34 knees from 17 asymptomatic subjects with no history of knee pathology, trauma or surgery. A low-dose CT scan and an axial T1-weighted MRI sequence of the knees were performed with rigorous standardization of the positioning with full extension of the knees and parallel feet. Two musculoskeletal radiologists performed the measurements independently. The reliability of the TT-TG and PT-CTG distances on CT (17.1 ± 4.2 mm and 17.3 ± 4.2 mm) and of MRI (16.2 ± 3.7 mm and 16.5 ± 4.1 mm) was assessed by intraclass correlation coefficient (ICC [2,1]) and Bland-Altman graphs, as well as the interrater reliability for both methods. Results Good reliability and agreement was observed between CT and MRI measurements for TT-TG and PT-CTG, with an ICC of 0.774 ( p < 0.001) and 0.743 ( p < 0.001), respectively, and no systematic bias was observed. The interrater reliability was excellent for all measurements on both imaging methods. Conclusion This was the first study that compared MRI using a body coil with CT in measuring the TT-TG distance, with the potential clinical implication that the CT in this clinical setting could be avoided.

RESUMO

Abstract Objective To compare magnetic resonance imaging (MRI) using a body coil with computed tomography (CT) in measuring the tibial tubercle-trochlear groove distance (TT-TG) and the patellar tendon-cartilaginous trochlear groove (PT-CTG) distances, and evaluate interrater reliability. Methods The study group consisted of 34 knees from 17 asymptomatic subjects with no history of knee pathology, trauma or surgery. A low-dose CT scan and an axial T1-weighted MRI sequence of the knees were performed with rigorous standardization of the positioning with full extension of the knees and parallel feet. Two musculoskeletal radiologists performed the measurements independently. The reliability of the TT-TG and PT-CTG distances on CT (17.1 ± 4.2 mm and 17.3 ± 4.2 mm) and of MRI (16.2 ± 3.7 mm and 16.5 ± 4.1 mm) was assessed by intraclass correlation coefficient (ICC [2,1]) and Bland-Altman graphs, as well as the interrater reliability for both methods. Results Good reliability and agreement was observed between CT and MRI measurements for TT-TG and PT-CTG, with an ICC of 0.774 (p< 0.001) and 0.743 (p< 0.001), respectively, and no systematic bias was observed. The interrater reliability was excellent for all measurements on both imaging methods. Conclusion This was the first study that compared MRI using a body coil with CT in measuring the TT-TG distance, with the potential clinical implication that the CT in this clinical setting could be avoided.

Resumo Objetivo Comparar a ressonância magnética (RM) usando uma bobina corporal e tomografia computadorizada (TC) na medição da distância tubérculo tibial-sulco troclear (TT-ST) e as distâncias tendão patelar-sulco troclear cartilaginoso (TP-STC), e avaliar a confiabilidade interavaliador. Métodos O grupo de estudo consistiu em 34 joelhos de 17 indivíduos assintomáticos sem história de patologia, trauma ou cirurgia no joelho. Uma tomografia computadorizada (TC) de baixa dose e uma sequência axial de RM ponderada em T1 dos joelhos foram realizadas com padronização rigorosa do posicionamento com extensão total dos joelhos e pés paralelos. Dois radiologistas musculoesqueléticos realizaram as medidas de forma independente. A confiabilidade das distâncias TT-ST e TP-STC na TC (17,1 ± 4,2 mm e 17,3 ± 4,2 mm) e RM (16,2 ± 3,7 mm e 16,5 ± 4,1 mm), foi avaliada pelo coeficiente de correlação intraclasse (CCI [2,1)]) e gráficos Bland-Altman, bem como a confiabilidade entre avaliadores para ambos os métodos. Resultados Boa confiabilidade e concordância foram observadas entre as medidas de TC e RM para TT-ST e TP-STC com um CCI de 0,774 (p< 0,001) e 0,743 (p< 0,001), respectivamente, e nenhum viés sistemático foi observado. A confiabilidade entre avaliadores foi excelente para todas as medições em ambos os métodos de imagem. Conclusão Este foi o primeiro estudo que comparou a RM usando bobina de corpo com a TC na medição da distância TT-ST, com a implicação clínica potencial de que a TC neste cenário clínico poderia ser evitada.

Assuntos

RESUMO

INTRODUCCIÓN: La inestabilidad rotuliana recurrente puede conducir a malos resultados funcionales y daño articular progresivo a largo plazo, y con frecuencia se aborda mediante la reconstrucción del ligamento patelofemoral medial (RLPFM), con múltiples técnicas que suelen diferir en el método de fijación de la rótula. OBJETIVO: Evaluar los resultados de RLPFM utilizando una técnica novedosa de fijación rotuliana mediante suturas transóseas. El objetivo principal es determinar las tasas de reluxación y los resultados funcionales incluyendo retorno deportivo. Los objetivos secundarios incluyen la evaluación de las complicaciones y de otras variables relacionadas, y la comparación entre los resultados de RLPFM aislada y asociada a una osteotomía de la tuberosidad tibial. MÉTODOS: Estudio transversal de 34 pacientes sometidos a RLPFM desde 2013 hasta 2019 con un seguimiento mínimo de 12 meses. La reconstrucción fue realizada por el mismo primer cirujano con autoinjerto de gracilis de doble banda en todos los casos. La fijación del injerto en la cara medial de la rótula se realizó utilizando dos puntos de fijación transóseos independientes con suturas de alta resistencia, y la fijación femoral anatómica, con un tornillo interferencial mediante referencias anatómicas y radiológicas. Hubo 27 pacientes con RLPFM aislada, y 7 con osteotomía de la tuberosidad tibial asociada. RESULTADOS: La edad media fue de 22,8 años (desviación estándar [DE]: 9,1). El 50% eran hombres. El seguimiento desde la cirugía hasta el cuestionario fue de 30,4 meses (rango: 12 a 72 meses). La puntuación media de Kujala en el seguimiento fue de 89,4 (DE: 12,8; mediana: 93,5; rango: 51 a 100). No hubo casos de reluxación. No se identificaron otras complicaciones durante el seguimiento. El 81% de los pacientes regresó a los deportes, y el 47% regresó a su nivel previo de participación. No se encontraron diferencias significativas al comparar RLPFM aislada con grupos de osteotomía asociada. CONCLUSIÓN: La RLPFM mediante sutura transósea para fijación en la rótula mostró que la estabilidad rotuliana fue restaurada en el corto y mediano plazo. Esta técnica es segura, tiene excelentes resultados funcionales, y evita posibles complicaciones de los túneles rotulianos o morbilidad asociada al uso de implantes.

INTRODUCTION: Recurrent patellar instability can lead to poor functional results and progressive articular damage in the long term, and is frequently addressed by medial patellofemoral ligament reconstruction (MPFLR), with multiple techniques that most commonly differ regarding the method of patellar fixation. OBJECTIVE: To evaluate the results of MPFLR using a novel technique of patellar fixation using transosseous sutures. The main objective is to determine the redislocation rates and functional results. The secondary goals include an assessment of complications and of other related variables, and a comparison between isolated MPFLR and MPFLR associated to tibial tubercle osteotomy. METHODS: A cross-sectional study of 34 patients who underwent MPFLR from 2013 to 2019 with a minimum of 12 months of follow-up. The reconstruction was performed by the same first surgeon with double-bundle gracilis autograft in all cases. Fixation of the graft to themedial aspect of the patella was performed with two independent transosseous fixation points with high resistance sutures, and anatomic femoral fixation with an interference screw using anatomical and radiological landmarks. There were 27 patients with isolated MPFR, and 7 with associated tibial tubercle osteotomy. RESULTS: The mean age was of 22.8 years (standard deviation [SD]: 9.1). Men comprised 50% of the sample. The mean follow-up from surgery to the application of the questionnaire was of 30.4 months (range: 12 to 72 months). The mean Kujala score at follow-up was of 89.4 (SD: 12.8; median: 93.5; range: 51 to 100). There were no cases of redislocation. No other complications were identified during the follow-up. In total, 81% of patients returned to sports, with 47% returning to their previous level of participation. No significant differences were found when comparing isolated MPFLR with MPFLR associated osteotomy groups. CONCLUSION: The MPFLR procedure using transosseous patellar fixation showed that patellar stability was restored in the short term to the midterm. This technique is safe and has excellent functional outcomes, and it prevents potential complications of patellar tunnels or the morbidity associated to the use of implants.

Assuntos

RESUMO

BACKGROUND: Lateral patellar dislocation can become a recurrent problem after the first episode. Identifying those patients who are at increased risk of redislocation is important for the treatment decision-making process. PURPOSE: To identify clinical and radiologic risk factors for recurrence of patellar dislocation after a first episode. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: The study included patients with lateral patellar dislocation and a 1-year minimum follow-up who were seen between 2011 and 2018. Patients aged 10 to 65 years were included. Patient characteristics, physical examination (patellar apprehension, J sign), and radiographs were reviewed. The Caton-Deschamps and Insall-Salvati ratios were used to evaluate patella alta. High-grade trochlear dysplasia was defined as Dejour types B, C, and D. RESULTS: A total of 130 patients (139 knees) with primary lateral patellar dislocation were included. Recurrent dislocation was seen in 83 knees (59.71%). Stepwise logistic regression analysis demonstrated that Caton-Deschamps ratio ≥1.15 (OR, 2.39; 95% CI, 1.09-5.22; P = .029), age <21 years (OR, 2.53; 95% CI, 1.11-5.77; P = .027), and high-grade trochlear dysplasia (OR, 4.17; 95% CI, 1.90-9.17; P < .001) were significantly associated with patellar redislocation. Based on the presence of these factors, the probability of dislocation after a first lateral patellar dislocation was 31.2% with no factors present, 36.6% with any 1 factor present, 71.7% with any 2 factors present, and 86.2% if all 3 conditions were present. CONCLUSION: The results of this study indicated that patella alta, high-grade trochlear dysplasia, and age <21 years were independent risk factors for patellar redislocation after a first episode, with an additive effect when they were present together. This may help to guide the type of treatment for these patients.

RESUMO

PURPOSE: In patients with open growth plates, the direction of tunneling that avoids distal femoral physis (DFP) damage in anatomic reconstructions of the medial patellofemoral ligament (MPFL) has been a topic of discussion. The objective of this study was to determine the ideal orientation for anatomic reconstructions of MPFL tunneling that minimized DFP damage while avoiding breaching the intercondylar notch. METHODS: Eighty magnetic resonance images of patients aged 10 through 17 were obtained, randomly sampled from the institutional database. A de novo software was developed to obtain 3D models of the distal femur and DFP. In each model, the anatomical insertion point of the MPFL was determined as defined by Stephen. A 20-mm-depth drilling was simulated, starting from the insertion point at every possible angle within a 90° cone using 5-, 6- and 7-mm drills. Physeal damage for each pair of angles and each drill size was determined. Damage was expressed as a percentage of total physis volume. Statistical analysis was conducted using Student's t test and one-way ANOVA. RESULTS: Maximum physeal damage (5.35% [4.47-6.24]) was obtained with the 7-mm drill when drilling 3° cephalic and 15° posterior from insertion without differences between sexes (n.s.). Minimal physeal damage (0.22% [0.07-0.37]) was obtained using the 5-mm drill aimed 45° distal and 0° anteroposterior, not affected by sex (n.s.). Considering intra-articular drilling avoidance, the safest zone was obtained when aiming 30°-40° distal and 5°-35° anterior, regardless of sex. CONCLUSION: Ideal femoral tunnel orientation, avoiding physeal damage and breaching of the intercondylar notch, was obtained when aiming 30°-40° distal and 5°-35° anterior, regardless of sex. This area is a safe zone that allows anatomic MPFL reconstruction of patients with an open physis.

Assuntos

RESUMO

BACKGROUND: The anatomy and function of the quadriceps muscle play a role in patellofemoral stability. Few studies have evaluated anatomic differences in the vastus medialis between patients with and without patellar instability. PURPOSE: To compare the anatomy of the vastus medialis using magnetic resonance imaging in patients with patellar instability to a control group. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A group of patients with patellar instability were sex-matched with a control group with anterior cruciate ligament tears, meniscal injuries, or sprains; patients younger than 15 years were excluded. The anatomy of the vastus medialis was examined by the distance between the distal origin of the vastus medialis in the femur and the medial femoral condyle, the distance from the proximal pole of the patella to the most distal insertion of the muscle and its ratio to the length of the articular surface of the patella, and a qualitative description of the insertion position of the muscle fibers (directly in the patella or the medial retinaculum). RESULTS: Both groups comprised 78 knees (48 female; 61.5%). The mean age in the control and patellar instability groups was 30.2 ± 7.8 years and 25.6 ± 7.5 years, respectively (P = .001). The distance from the vastus origin to the condyle was 27.52 ± 3.49 mm and 26.59 ± 3.43 mm, respectively (P = .041); the distance from the proximal pole of the patella to the most distal muscle insertion was 17.59 ± 5.54 mm and 15.02 ± 4.18 mm, respectively (P < .001); and the ratio of this distance to the joint surface was 0.586 ± 0.180 and 0.481 ± 0.130, respectively (P < .001). In 75.6% of knees in the patellar instability group, the insertion of the vastus was into the medial retinaculum and not into the patella compared with 52.6% in the control group (P = .003; odds ratio, 2.8). CONCLUSION: The distal insertion of the vastus medialis differed in knees with patellar instability, with a more proximal insertion and less patellar coverage relative to controls, and was more frequently found in the retinaculum instead of directly in the patella.

RESUMO

BACKGROUND: The tibial tubercle-trochlear groove (TT-TG) is used as the gold standard for patellofemoral malalignment. PURPOSE: To assess 3 patellar tendon-trochlear groove (PT-TG) angle measurement techniques and the PT-TG distance measurement (tendinous cartilaginous TT-TG) as predictors of patellar instability. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: Three PT-TG angle measurements and the PT-TG distance were measured in 82 participants with patellar instability and 100 controls using magnetic resonance imaging (MRI). Measurement landmarks were the line tangent to the posterior femoral condyles, the deepest point of the trochlea, the transepicondylar line, and the patellar tendon center. All measurements were recorded once by 1 examiner, and the measurements were recorded twice by 2 examiners in a random group of 100 knees. Mean values and standard deviations (SDs) were obtained. Normality cutoff values were defined as 2 and 3 SDs above the mean in the control group. The sensitivity, specificity, and positive likelihood ratio (LR+) were calculated. Inter- and intrarater reliability were assessed based on the intraclass correlation coefficient (ICC). RESULTS: The measurements from the patellar instability and control groups, respectively, for angle 1 (16.4° and 8.4°), angle 2 (31° and 15.6°), angle 3 (30.8° and 15.7°), PT-TG distance (14.5 and 8.4 mm), and patellar tilt (21.1° and 7.5°) were significantly different (P < .05). The angle measurements showed greater sensitivity, specificity, and LR+ than the PT-TG distance. Inter- and intrarater ICC values were >0.95 for all measurements. CONCLUSION: The PT-TG angle and the PT-TG distance are reliable and are different between the patellar instability and control groups. PT-TG angles are more closely associated with patellar instability than PT-TG distance. CLINICAL RELEVANCE: PT-TG angle measurements show high reliability and association with patellar instability and can aid in the assessment of extensor mechanism malalignment. A more sensitive and specific evaluation of extensor mechanism malalignment can improve patient care by preventing both redislocation and abnormal tracking of overlooked malalignment and complications of unnecessary tibial tuberosity medialization.

RESUMO

Hipótese: Reconstrução do ligamento patelofemoral medial restaura a estabilidade, promove retorno funcional e alívio da dor em pacientes com instabilidade patelar lateral crônica. Design do estudo: Série de casos nível 4 de evidência. Métodos: Vinte e um pacientes com instabilidade lateral crônica foram tratados com reconstrução do ligamento patelofemoral medial usando enxerto do semitendíneo. Todos os pacientes foram avaliados pré-operatoriamente e pós-operatoriamente com questionários de Kujala, Fulkerson, Lysholm, nível de atividade de Tegner e através da Escala Analógica de Dor por um período mínimo de 24 meses. Resultados: Vinte e um pacientes foram avaliados por um período médio de 66,5 meses (variando de 24-130 meses) após a cirurgia. O questionário de Kujala mudou de 55,7 para 82,3, o de Fulkerson mudou de 60,6 para 91,2, o de Lysholm variou de 53,5 para 85,6, a escala de atividade de Tegner variou de 3,5 para 7,1 e a Escala Analógica Visual de Dor variou de 7,4 no pré-operatório para 3,0 na última avaliação. Todos mostraram diferenças estatisticamente significantes (P <.001). Nenhuma diferença estatisticamente significante foi encontrada nas avaliações pós-operatoria dos questionários de Kujala, Lysholm, Fulkerson, Tegner e Escala Analógica Visual de Dor. Existiram 66,59%, 71,42% e 71,41% de bons e excelentes resultados baseados nos questionários de Kujala, Lysholm e Fulkerson, respectivamente. Nenhuma luxação recorrente ocorreu e todos os 21 pacientes estavam satisfeitos com o tratamento cirúrgico. Conclusão: A reconstrução do ligamento patelofemoral medial prove excelente alívio da dor e retorno funcional em pacientes com instabilidade patelar crônica.

Assuntos

RESUMO

The medial patellofemoral ligament (MPFL) reconstruction is an option for the recurrent patellar instability. We developed a prospective study whose objective was to show the functional results at 6 and 12 months of patients who underwent MPFL reconstruction with semitendinosus (St) autograft. Four patients (5 knees) were treated between May 2006 and May 2008. The Kujala´s test before surgery in all patients was poor (< 50 points); 6 months after the surgery 4 cases turned out to be "good and very good" (only 1 case "poor", but increased her score to 78 points) and after 12 months of follow-up, 5 cases scored "very good and excellent" (score > 90 points). The Tegner´s test showed an increased of activity that was normal for the patients, and with the Insall´s test all patients referred very satisfied 12 months after surgery. Up to this stage, there has been no recurrence. In our local environment, the MPFL reconstruction with St. is a valid treatment to recover the patellofemoral mecanic.

La reconstrucción del ligamento patelofemoral medial (LPFM) es una alternativa en la inestabilidad rotuliana recurrente. Desarrollamos un estudio prospectivo con el objetivo de exponer los resultados funcionales a los 6 y 12 meses de pacientes sometidos a una reconstrucción del LPFM con semitendinoso (St). Son 4 pacientes (5 rodillas) operados entre mayo 2006 y mayo 2008. El test de kujala preoperatorio era "malo" (< 50 pts) en todos, a los 6 meses post op. 4 casos de "bueno y muy bueno" resultado (sólo 1 caso "malo", pero con incremento de su score a 78) y a los 12 meses (5 casos) todos con función "muy bueno y excelente" (score > 90 pts). El test de Tegner mostró un aumento del nivel de actividad considerada de normal en todos los pacientes, y en el test de Insall todos refieren excelente mejoría a los 12 meses. Hasta la fecha no existen recidivas. En nuestro medio local, la reconstrucción del LPFM con St. es una alternativa válida para recuperar la mecánica patelofemoral.

Assuntos