Knee MR Using a Body Coil is Equivalent to CT in Measuring the TT-TG Distance: Removing the Systematic Bias / A ressonância magnética do joelho usando a bobina de corpo é equivalente à TC na medição da distância TT-ST: Removendo o viés sistemático

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.

Reconstrucción del ligamento patelofemoral medial mediante suturas transóseas patelares: estudio transversal de 34 pacientes / Reconstruction of the medial patellofemoral ligament with patellar transosseous sutures: cross-sectional study with 34 patients

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.

Implantless patellar fixation in medial patellofemoral ligament reconstruction / 中华创伤杂志(英文版)

PURPOSE@#The medial patellofemoral ligament (MPFL) acts as primary restraint to lateral patellar dislocation and its rupture has been reported in almost all cases of acute patellar dislocation. Various surgical techniques have been described for MPFL reconstruction, using many femoral and patellar fixation techniques and different grafts. This article details our technique for MPFL reconstruction using semitendinosus graft which avoids the use of implant at patellar end.@*METHODS@#Twenty patients (8 males and 12 females) with complaints regarding acute and chronic lateral patellar instability were evaluated and treated by MPFL reconstruction procedure. The mean age of patients was 21 years (range 17-34 years). MPFL reconstruction was performed using semitendinosus graft passing through two parallel, obliquely directed tunnels created in patella. Fixation of graft was done with an interference screw only at the femoral end. Mean follow-up period after intervention was 26.4 months (range 23-30 months). Results were evaluated using Kujala score.@*RESULTS@#All patients gained adequate patellar stability and full arc of motion. No incidence of patella fracture was noted. There were no postoperative complications related to the procedure. There was no recurrence of instability in patella at final follow-up.@*CONCLUSION@#Passing the graft through the tunnels in patella without use of any implant has given excellent functional outcome and moreover has the advantages of less implant-related complications and cost-effectiveness.

Therapeutic effects of comprehensive surgery for recurrent patellar instability in adults / 局解手术学杂志

Objective To analyze the clinical effect of medial patellofemoral ligament(MPFL)reconstruction combined with the com-prehensive surgery of anteromedial tibial tubercle transfer and distal shift in the treatment of recurrent patellar instability.Methods The clin-ical data of 60 patients(60 affected knees)with recurrent patellar instability who were admitted to the orthopedics department of Mianyang central hospital in Sichuan Province from April 2012 to September 2016 were retrospectively analyzed.All the patients were examined with knee arthroscopy,lower extremity X-ray,CT and MRI,and they were treated with MPFL reconstruction combined with anteromedial tibial tu -bercle transfer and distal shift comprehensive surgery.All patients were followed up for at least 1 year after operation.The physical indexes, imaging examination indexes and evaluation results of knee function were analyzed before operation and at the last follow -up.Results The follow-up of 60 patients showed that the results of fear test were negative,results of patellar tilt test were symmetrical,and the Q angle re-turned to normal.The activities of flexion and extension were significantly improved,and there was no fractures or dislocation of the patella. Imaging examination showed that the patellofemoral joint was well positioned.At the last follow-up,the patellofemoral congruence angle,de-gree of patellar out-shift and lateral patellar angle of the 60 patients were significantly decreased,and the tibial tuberosity-trochlear groove dis-tance(TT-TG)was also significantly decreased,the differences were significant(P<0.05),and they basically returned to the normal range. At the last follow-up,the Lysholm score and Kujala score were significantly higher than those before operation,the differences were significant (P<0.05).Conclusion The clinical effect of MPFL reconstruction combined with anteromedial tibial tubercle transfer and distal shift com -prehensive surgery is satisfying in the treatment of recurrent patellar instability,which has great significance for relieving symptoms and resto-ring the function of the knee.

Arthroscopic medial retinaculum plication in treatment of traumatic patellar instability / 中国内镜杂志

Objective To explore the short-term results of arthroscopic medial retinaculum placation (MRP) and lateral retinaculum release (LRR) in treatment of patients with traumatic patellar dislocation. Methods 17 cases (6 male, 11 female) with traumatic patellar instability from March 2012 to December 2015, with an average age of 16.8 years old (range from 14 to 37 years old). All of the patients had a clear history of trauma and experienced patellar dislocation for the first time, the patients experienced patellar dislocation 1 to 4 times preoperatively. The arthroscopic examination was undertaken before the repairing to observe the injured site of the medial retinaculum and the patellar track, as well as the dynamic patellofemoral congruence. All patients underwent arthroscopic MRP and LRR minimally invasive procedure. Results All patients were followed up for 9 to 28 months averaging (19.7 ± 1.3) months. The fear test was negative after operation. There was no redislocation during follow-up and their ranges of motion returned to normal. Postoperative CT images showed 15 cases regained normal anatomical relation of patellofemoral joint. 2 cases had mild semi-dislocation. Lysholm's score averaging (51.8 ± 4.5) points preoperatively and (92.4 ± 2.8) points postoperatively. According to Insall scale, the results were excellent in 11 knees, good in 5 knees, and fair in 1 knee at 1 year after operation with an excellent and good rate of 94.1％. Conclusions Arthroscopic MRP and LRR showed satisfactory results with limited morbidity in the short-term follow-up. This method can make the patients smaller wound,quicker recovered and lower recurrence rate.

Measurement and evaluation of anatomic risk factors for recurrent patellar instability by MRI / 实用放射学杂志

Objective To identify related anatomical parameters and the strongest risk predictor leading to patients with recurrent patellar instability.Methods 52 young patients with recurrent patellar instability that failed of conservative treatment were retrospec-tively evaluated by MRI.Measurements included parameters of patellar tracking,which was characterized by bisect offset index (BSO),trochlear congruence angle (CA)and patellar lateral tilt (PTA),and anatomical parameters of patellofemoral joint,which were characterized by the sulcus angle (SA),lateral trochlear inclination (LTI),trochlear facet asymmetry,trochlear depth,Insall-Salvati Ratio (ISR),Caton-Deschamps index (C-D)and tibial tuberosity-trochlear groove (TT-TG)distance.The collection data were analyzed including the Pearson's correlation and multiple stepwise regression analysis.Results The patellofemoral joint ma-lalignment was significantly correlated with LTI,TT-TG distance and ISR,but not or partly with the trochlear depth,SA,trochlear facet asymmetry and C-D.Linear regression models including LTI,TT-TG distance and ISR explained 0.58,0.47 and 0.43 of the va-riance in BSO,CA and PTA,respectively (P<0.001).And the standardized beta coefficient was largest for LTI,then were TT-TG distance and ISR.Conclusion At full extension of the knee,anatomical related factors measured on MRI explain some degree of re-current lateral patella shift and tilt,the strongest predictor among anatomical related factors that could lead to maltracking is LTI, and then are TT-TG distance and ISR.

A Combined Closing Wedge Distal Femoral Osteotomy and Medial Reefing Procedure for Recurrent Patellar Dislocation with Genu Valgum

PURPOSE: Recurrent patellar dislocation is often associated with genu valgum. The purpose of this study was to analyze the short-term results of single-incision, closing-wedge distal femoral osteotomy (CWDFO) combined with medial reefing and lateral release for recurrent patellar instability with genu valgum. MATERIALS AND METHODS: Combined CWDFO/medial reefing/lateral release was performed on 10 knees. Clinical evaluation was based on pre- and postoperative Knee Society Score (KSS) and Kujala patellofemoral score. Radiographic evaluation was performed with reference to the weight-bearing line (WBL), the femorotibial angle (FTA), and the mechanical lateral distal femoral angles in the knee-standing view. RESULTS: At a mean follow-up of 20±11.7 months (range, 12–42 months), KSS scores improved significantly, from 46.7±5.2 preoperatively to 87±4.4 postoperatively (p<0.001), as did the Kujala score, from 44±8 preoperatively to 86.6±6.8 postoperatively (p<0.001). The WBL decreased significantly, from 76±7% preoperatively to 41±11% postoperatively (p<0.001). The FTA was improved significantly, from 12.7±1.7° preoperatively to 4±4° postoperatively (p<0.001), as was the mLDFA, from 83±4° preoperatively to 91±1.3° postoperatively (p<0.001). CONCLUSION: Use of single-incision CWDFO combined with medial reefing and lateral release prevents patellar dislocation, corrects deformity, and improves clinical outcomes.

Clinics in diagnostic imaging (163). Transient lateral patellar dislocation with trochlear dysplasia

A 14-year-old girl presented with left knee pain and swelling after an injury. Magnetic resonance (MR) imaging showed a transient lateral patellar dislocation with patellar osteochondral fracture, medial patellofemoral ligament tear and underlying femoral trochlear dysplasia. Open reduction and internal fixation of the osteochondral fracture, plication of the medial patellar retinaculum and lateral release were performed. As lateral patellar dislocation is often clinically unsuspected, an understanding of its characteristic imaging features is important in making the diagnosis. Knowledge of the various predisposing factors for patellar instability may also influence the choice of surgical management. We also discuss signs of acute injury and chronic instability observed on MR imaging, and the imaging features of anatomical variants that predispose an individual to lateral patellar dislocation. Treatment options and postsurgical imaging appearances are also briefly described.

Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Instability Using a Gracilis Autograft without Bone Tunnel

BACKGROUND: Several tendon graft and fixation methods have been introduced in medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar dislocation. The purpose of this study was to evaluate the results of MPFL reconstruction using a gracilis autograft fixation without bone tunnel in patients with recurrent patellar instability. METHODS: Nine patients (four males and five females) diagnosed with recurrent patellar instability from July 2009 to January 2013 and had MPFL reconstruction using a gracilis autograft were included. The average age of the patients was 24.6 years (range, 13 to 48 years), and the average follow-up period was 19.3 months (range, 12 to 30 months). For every patient, femoral attachment was fixed using suture anchors securing the patella by suturing the periosteum and surrounding soft tissue. Clinical evaluation included the Kujala, Lysholm, and Tegner scores; in addition, patients were examined for any complication including recurrent dislocation. The congruence angle and patella alta were assessed radiologically before and after surgery. RESULTS: The Kujala score improved from an average of 42.7 ± 8.4 before surgery to 79.6 ± 13.6 (p = 0.008) at final follow-up; the Lysholm score improved from 45.8 ± 5.7 to 82.0 ± 10.5 (p = 0.008); and the Tegner score improved from 2.8 ± 0.8 to 5.6 ± 1.5 (p = 0.007). The Insall-Salvati ratio changed from 1.16 ± 0.1 (range, 0.94 to 1.35) before surgery to 1.14 ± 0.1 (range, 0.96 to 1.29; p = 0.233) at the final follow-up without significance. The congruence angle significantly improved from 26.5°± 10.6° (range, 12° to 43°) before surgery to -4.0°± 4.3° (range, -12° to 5°; p = 0.008) at final follow-up. Subluxation was observed in one patient and hemarthrosis occurred in another patient 2 years after surgery, but these patients were asymptomatic. CONCLUSIONS: We achieved good results with a patellar fixation technique in MPFL reconstruction using a gracilis autograft employing soft tissue suturing in patients with recurrent patellar dislocation.

Tratamento da instabilidade femoropatelar crônica pela reconstrução do ligamento femoropatelar medial / Treatment of the chronic patellofemoral instability with the medial patellofemoral ligament reconstruction

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.

Tratamiento quirúrgico de la inestabilidad rotuliana recurrente con reconstrucción del ligamento patelofemoral medial usando autoinjerto semitendinoso / Surgical treatment of recurrent patellar instability with medial patellofemoral ligament reconstruction using semitendinosus tendon autograft

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.

Results of Recurrent Patellar Instability after Trauma According to Anatomical Predisposing Factors

PURPOSE: We analyzed the results of lateral retinacular release(LRR) and proximal realignment for recurrent patellar instability after trauma according to the anatomical predisposing factors. MATERIALS AND METHODS: Twelve patients of fifteen cases of recurrent patellar instability had been evaluated. Clinical assessment were performed by Q-angle, apprehension test, passive patellar tilt test and general joint laxity. The anatomical predisposing factors assessed by plain radiographs included patella alta, sulcus angle, femoral trochlear dysplasia, genu valgum and patellar dysplasia. Clinical results were assessed by Kujala scoring system. Radiographic results were assessed by congruence angle. The results were analyzed according to the predisposing factors. RESULTS: Patella alta was observed in eight, increased sulcus angle in six, trochlear dysplasia in twelve, genu valgum in five and patella dysplasia in four cases. The result of treatment (Kujala score / congruence angle) was 85.8 / 9.7degrees in group A(predisposing factors > or = 3) and 91.4 / -5.3degrees in group B (predisposing factors<3)(p=0.036). We had 4 cases of recurrence after operation and genu valgum was related with recurrence rate. CONCLUSION: The clinical results of LRR and proximal realignment for recurrent patellar instability developed after trauma were worse in cases with more anatomical predisposing factors.