Allograft reconstruction of the medial patellofemoral complex in skeletally immature patients: a technical note.

Patellofemoral instability (PFI) is a common disorder in children and adolescents. Surgical stabilization of the patella poses challenges in skeletally immature patients due to anatomical peculiarities at this stage, leading to the absence of an established standard reconstruction technique. Recently, there has been a notable interest in the medial patellofemoral complex (MPFC), encompassing the medial patellofemoral ligament (MPFL) and the medial quadriceps tendon femoral ligament (MQTFL), owing to their role in restricting lateral patellar displacement. This paper aims to describe the surgical technique employed by the author for reconstructing the medial patellofemoral complex with allograft in skeletally immature patients with patellofemoral instability. Study design: surgical technique.

La inestabilidad patelofemoral (PFI) es un trastorno común en niños y adolescentes. La estabilización quirúrgica de la rótula plantea desafíos en pacientes esqueléticamente inmaduros debido a peculiaridades anatómicas en esta etapa, lo que lleva a la ausencia de una técnica de reconstrucción estándar establecida. Recientemente, ha habido un interés notable en el complejo femororrotuliano medial (MPFC), que abarca el ligamento femororrotuliano medial (MPFL) y el ligamento femoral del tendón del cuádriceps medial (MQTFL), debido a su papel en la restricción del desplazamiento rotuliano lateral. Este artículo tiene como objetivo describir la técnica quirúrgica empleada por el autor para reconstruir el complejo femororrotuliano medial con aloinjerto en pacientes esqueléticamente inmaduros con inestabilidad femororrotuliana. Diseño del estudio: técnica quirúrgica.

Técnica quirúrgica para la reconstrucción del ligamento patelofemoral medial / Surgical technique for medial patellofemoral ligament reconstruction

La inestabilidad patelofemoral es uno de los problemas más frecuentes en pacientes jóvenes, y representa del 2 al 3% de todas las lesiones de rodilla. Significa una causa importante de morbilidad debido a la limitación de varias actividades de la vida diaria, y a largo plazo el surgimiento de artrosis. La inestabilidad patelofemoral es descripta como la deficiencia de la constricción pasiva que genera un desplazamiento lateral de la patela total o parcial de su posición normal con respecto a la tróclea. Los desórdenes patelofemorales son el resultado de una anatomía aberrante, están dados por una alteración en la alineación ósea y generan un desequilibrio biomecánico. Existen cuatro factores clásicos que generan inestabilidad patelar: patela alta, displasia troclear, alteración en la distancia (TT-TG) y excesiva inclinación patelar. Al generarse una luxación, el ligamento patelofemoral medial (LPFM) se ve afectado en al menos el 25% de los casos. El complemento diagnóstico se realiza a través de rayos X, tomografía computarizada y resonancia magnética. La restauración de la función por tratamiento quirúrgico ha mostrado resultados similares al conservador en primoluxaciones, sin embargo, se ha visto que la reconstrucción del ligamento patelofemoral medial presenta mejores resultados clínicos para el paciente. Hasta el momento, hemos intervenido diecinueve pacientes con la técnica descripta, para los cuales no hay reportada una reluxación de rótula y tienen una escala de Lysholm de 87 puntos que se encuentra dentro del parámetro "bueno".

Patellofemoral instability is one of the most frequent problems in young patients, and represents 2 to 3% of all knee injuries. It denotes an important cause of morbidity due to the limitation of various activities of daily living and in the long term the appearance of osteoarthritis. Patellofemoral instability is defined as the deficiency of passive constriction that generates a total or partial lateral displacement of the patella from its normal position with respect to the trochlea. Patellofemoral disorders are the result of an aberrant anatomy, they are given by an alteration in bone alignment and generates a biomechanical imbalance. There are four classic factors that generate patellar instability: high patella, trochlear dysplasia, alteration in distance (TT-TG) and excessive patellar inclination. When generating the dislocation, the medial patellofemoral ligament is affected in at least 25% of cases. The diagnostic complement is carried out through X-rays, computed tomography and nuclear magnetic resonance.Restoration of function surgical treatment has shown similar results to conservative treatment in primoluxations, however it has been seen that reconstruction of the medial patellofemoral ligament presents better clinical results for the patient.To date, nineteen patients we have been operated on with the technique described of whom there is no reported reluxation of the patella and who have a Lysholm scale of 85 points that is within a good parameter.

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.

Etiology of Cartilage Lesions Does Not Affect Clinical Outcomes of Patellofemoral Autologous Chondrocyte Implantation.

OBJECTIVE: To determine the relationship between cartilage lesion etiology and clinical outcomes after second-generation autologous chondrocyte implantation (ACI) in the patellofemoral joint (PFJ) with a minimum of 2 years' follow-up. METHODS: A retrospective review of all patients that underwent ACI in the PFJ by a single surgeon was performed. Seventy-two patients with a mean follow-up of 4.2 ± 2.0 years were enrolled in this study and were stratified into 3 groups based on the etiology of PFJ cartilage lesions: patellar dislocation (group 1; n = 23); nontraumatic lesions, including chondromalacia, osteochondritis dissecans, and degenerative defects (group 2; n = 28); and other posttraumatic lesions besides patellar dislocations (group 3; n = 21). Patient's mean age was 29.6 ± 8.7 years. Patients in group 1 were significantly younger (25.4 ± 7.9 years) than group 2 (31.7 ± 9.6 years; P = 0.025) and group 3 (31.5 ± 6.6 years; P = 0.05). Body mass index averaged 26.2 ± 4.3 kg/m2, with a significant difference between group 1 (24.4 ± 3.2 kg/m2) and group 3 (28.7 ± 4.5 kg/m2; P = 0.005). A clinical comparison was established between groups based on patient-reported outcome measures (PROMs) and failure rates. RESULTS: Neither pre- nor postoperative PROMs differed between groups (P > 0.05). No difference was seen in survivorship between groups (95.7% vs. 82.2% vs. 90.5%, P > 0.05). CONCLUSION: Cartilage lesion etiology did not influence clinical outcome in this retrospective study after second generation ACI in the PFJ. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Corrección de la altura patelar en inestabilidad rotuliana / Correction of patellar height in patellofemoral instability

El manejo de la inestabilidad patelofemoral se basa en una adecuada evaluación de alteraciones anatómicas predisponentes. Patela alta es una de las causas más importantes de inestabilidad objetiva. La alteración biomecánica que ésta produce puede conducir a luxación patelar recurrente, dolor y cambios degenerativos focales. El examen físico es fundamental en la toma de decisiones. La evaluación imagenológica ha evolucionado desde métodos basados en radiografía hacia mediciones en resonancia magnética, que permiten una orientación más acabada de la relación existente entre la rótula y la tróclea femoral. El tratamiento se fundamenta en la corrección selectiva de los factores causales, donde la osteotomía de descenso de la tuberosidad anterior de la tibia y la reconstrucción del ligamento patelofemoral medial son herramientas que deben considerarse racionalmente. Este artículo realiza una revisión de la literatura, otorgando los fundamentos quirúrgicos que explican la importancia del tratamiento específico de patela alta en inestabilidad rotuliana.

Patellofemoral instability management is based on a thorough evaluation of predisposing anatomical factors. Patella alta is one of the utmost causes of objective instability. As a result, biomechanical disturbance can lead to recurrent patellar instability, pain, and focal degenerative changes. Physical examination is paramount in decision making. Imaging evaluation has evolved from X-rays based methods to magnetic resonance measurements, which allows a more accurate assessment of the patellotrochlear relationship. Treatment is based on a selective risk factors correction, where tibial tubercle distalization osteotomy and medial patellofemoral ligament reconstruction must be considered altogether. This article reviews the surgical rationale of patella alta treatment in patellofemoral instability.

The Distance between Tibial Tubercle and Trochlear Groove Correlates with Knee Articular Torsion.

This study aims to correlate the tibial tubercle to trochlear groove (TT-TG) distance with knee axial alignment. The hypothesis is that as internal torsion of the distal femur or external torsion of the proximal tibial increases, the TT-TG distance increases. We designed a cross-sectional study approved by our institutional ethics review board. We reviewed 32 computed tomography angiographies of patients that have nonjoint or bone-related symptoms. Distal femoral torsion, proximal tibial torsion, knee articular torsion (AT), and TT-TG distance were measured. A regression analysis between the TT-TG distance and the AT was performed. A positive correlation between the TT-TG distance and the AT was found. An increase in external torsion of the proximal tibial or an increase in internal torsion of the distal femur increases the TT-TG distance. For a correct interpretation of the TT to trochlear groove distance, we propose that the axial alignment should be included in the regular analysis of patellofemoral disease.

Posterior Knee Capsulotomy for the Relief of Patellofemoral Joint Pain: Long-Term Follow-up.

Lack of full extension of the knee is a disabling condition that sometimes needs to be treated by a posterior capsulotomy of the knee. However, it is not clear if the full extension acquired can be kept throughout long-time follow-up. We conducted a retrospective cohort study of 20 patients diagnosed with minimal flexion contracture of the knee who underwent open posterior capsulotomy between 1990 and 2010. All patients (100%) presented with a preoperative Lysholm's score classified as poor or fair (mean = 58.6 ± 13.8, 95% confidence interval [CI]: 52.3-64.9), but 14 patients (70%) experienced an improvement to good or excellent scores (mean = 87.6 ± 8.8, 95% CI: 83.6-91.6) after the follow-up. The mean preoperative angle of fixed flexion was 25.0 ± 9.1 degrees (95% CI: 20.8-29.2), and it decreased to 4.2 ± 4.1 degrees (95% CI: 2.3-6.1) after the follow-up. We conclude that posterior capsulotomy of the knee proved to be an effective procedure to treat properly patients with painful knees secondary to lack of full extension after 10.3 years of follow-up.

Anterior and distal tunnel orientation for anatomic reconstruction of the medial patellofemoral ligament is safer in patients with open growth plates.

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.

Isolated MPTL reconstruction fails to restore lateral patellar stability when compared to MPFL reconstruction.

PURPOSE: To biomechanically evaluate MPTL reconstruction and compare it with two techniques for MPFL reconstruction in regard to changes in patellofemoral contact pressures and restoration of patellar stability. METHODS: This is an experimental laboratory study in eight human cadaveric knees. None had patellofemoral cartilage lesions or trochlear dysplasia as evaluated by conventional radiographs and MRI examinations. The specimens were secured in a testing apparatus, and the quadriceps was tensioned in line with the femoral shaft. Contact pressures were measured using the TekScan sensor at 30°, 60° and 90°. The sensor was placed in the patellofemoral joint through a proximal approach between femoral shaft and quadriceps tendon to not violate the medial and lateral patellofemoral complex. TekScan data were analysed to determine mean contact pressures on the medial and lateral patellar facets. Patellar lateral displacement was evaluated with the knee positioned at 30° of flexion and 9 N of quadriceps load, then a lateral force of 22 N was applied. The same protocol was used for each condition: native, medial patellofemoral complex lesion, medial patellofemoral ligament reconstruction (MPFL-R) using gracilis tendon, MPFL-R using quadriceps tendon transfer, and medial patellotibial ligament reconstruction (MPTL-R) using patellar tendon transfer. RESULTS: No statistical differences were found for mean and peak contact pressures, medial or lateral, among all three techniques. However, while both techniques of MPFL-R were able to restore the medial restraint, MPTL-R failed to restore resistance to lateral patellar translation to the native state (mean lateralization of the patella [mm]: native: 9.4; lesion: 22; gracilis MPFL-R: 8.1; quadriceps MPFL-R: 11.3; MPTL-R: 23.4 (p < 0.001). CONCLUSION: MPTL-R and both techniques for MPFL-R did not increase patellofemoral contact pressures; however, MPTL-R failed to provide a sufficient restraint against lateral patellar translation lateral translation in 30° of flexion. It, therefore, cannot be recommended as an isolated procedure for the treatment of patellar instability.

Reconstrucción anatómica del ligamento patelofemoral medial con aloinjerto en la luxación patelar recurrente / Medial patellofemoral ligament anatomic reconstruction with allograft in recurrent patellar dislocation

La técnica de reconstrucción del ligamento patelofemoral medial es eficaz, segura, reproducible y con baja morbilidad para el tratamiento de la luxación patelar recurrente. Los pasos a seguir son: 1) Paciente en decúbito dorsal. 2) Artroscopía diagnóstica con liberación del retináculo lateral y valoración de lesiones asociadas. 3) Incisión de 2 a 3 cm sobre el borde superomedial de la patela. 4) Realización de dos túneles de 20 a 22 mm de profundidad y 4 mm de diámetro a través del grosor de la patela bajo fluoroscopia. 5) Fijar dos anclas desde el borde medial de la patela y anudar al aloinjerto con sutura de alta resistencia. 6) Identificar el punto de Schöttle bajo fluoroscopia. 7) Incisión de 2 a 3 cm a nivel del epicóndilo medial. 8) Colocar un Kirschner de 2 mm de medial a lateral, de posterior a anterior y de distal a proximal. 9) Medir la longitud, el grosor y la tensión final deseada del aloinjerto. 10) Realizar el túnel femoral con broca canulada, 1 mm mayor al grosor del aloinjerto. 11) Utilizar el clavo con ojal para pasar la sutura y traccionar el aloinjerto de medial a lateral. 12) Fijar el aloinjerto con un tornillo biodegradable con la rodilla a 30° de flexión valorando la tensión final deseada. 13) Realizar el lavado y cierre por planos. Nivel de Evidencia: IV

The medial patellofemoral ligament reconstruction technique is effective, safe, reproducible and with low morbidity in the treatment of recurrent patellar luxation. The steps in this technique: 1) Patient in supine position. 2) Diagnostic arthroscopy with release of the lateral retinaculum and assessment of associated lesions. 3) 2 to 3 cm incision on the supero - medial border of the patella. 4) Make two tunnels 20 to 22 mm deep and 4 mm in diameter through the thickness of the patella under fluoroscopy. 5) Fix two anchors from the medial edge of the patella and tie to the allograft with high strength suture. 6) The Schöttle's point is identified under fluoroscopy. 7) 2 to 3 cm incision in the medial epicondyle. 8) A 2 mm Kirschner is placed from medial to lateral, posterior to anterior, and distal to proximal. 9) The length, thickness and desired final tension of the allograft are measured. 10) The femoral tunnel is made with a cannulated drill, 1 mm greater than the thickness of the allograft. 11) The eyelet nail is used to pass the suture and pull the allograft from medial to lateral. 12) The allograft is fixed with a biodegradable screw with the knee at 30 ° flexion, assessing the desired final tension. 13) The washing and closing are carried out by planes up to the skin. Level of Evidence: IV

Evaluación de la reconstrucción del ligamento patelofemoral medial en esqueleto inmaduro. Estudio comparativo de dos técnicas / Medial patellofemoral reconstruction in skeletally immature. Comparative study of two techniques

Introducción: La luxación patelofemoral representa el 3% de las lesiones traumáticas de la rodilla. Dos tercios se producen en menores de veinte años. La recidiva luego del segundo episodio supera el 50%, lo que puede causar gran limitación funcional en pacientes jóvenes, disminuyendo su calidad de vida. El ligamento patelofemoral medial (LPFM) es el principal estabilizador medial de la rótula a 30° de flexión. En la actualidad su reconstrucción anatómica, preservando la fisis, parece ser la mejor opción en los pacientes con esqueleto inmaduro. Materiales y métodos: estudiamos el resultado funcional de dos grupos de pacientes tratados con dos técnicas diferentes de reconstrucción del LPFM, una anatómica con semitendinoso autólogo (ST) y otra no anatómica con hemitendón cuadricipital autólogo (QT). Ambos grupos fueron evaluados mediante el score de Kujala antes de la cirugía y durante el seguimiento. Las medias y los ítems del score se compararon utilizando la prueba de Wilcoxon.Resultados: veintidós rodillas fueron evaluadas, once en cada grupo. La edad de los pacientes varió entre ocho y quince años. La media de seguimiento fue de 19.4 meses. Los resultados muestran una mejora en la media del score de Kujala de 51 a 88 en el grupo QT, y de 52 a 97 en el grupo ST (ambos con valor-p = 0.003). No se encontró una diferencia significativa entre ambas técnicas. Solo se registró un caso de reluxación (grupo QT). Conclusiones: podemos afirmar que la reconstrucción del LPFM es una opción válida para la luxación patelofemoral, y las técnicas propuestas son confiables

Introduction: Patellofemoral dislocation accounts for 3% of traumatic knee injuries, with two-thirds occurring in patients under twenty years of age. Recurrence after the second episode is greater than 50%, which can cause great functional limitation in young patients, reducing their quality of life. Medial patellofemoral ligament (MPFL) is the main medial stabilizer of the patella at 30° flexion, currently its anatomic reconstruction preserving the physis appears to be the best option in patients with immature skeleton. Materials and methods: functional results of two groups of patients treated by two different techniques of MPFL reconstruction were evaluated. One anatomic technique, with autologous Semitendinosus (ST) and the other non-anatomic, with autologous quadricipital hemi tendon (QT). Both groups were evaluated through the Kujala score before surgery and during follow-up. Means and score items were compared using Wilcoxon signed-rank test.Results: twenty-two knees were evaluated, eleven in each group. Patient's age ranged between eight and fifteen years old. The mean follow-up was 19.4 months. An improvement in the average Kujala scores for the ST group from 51 to 88 and in the QT group from 52 to 97 was shown. Kujala score was statistically significantly higher in the postoperative evaluation with both technics (p-value 0.003 for both groups), no differences were found between both technics. Only one case of patella redislocation was registered during the study period (QT group). Conclusions: we can affirm that MPFL reconstruction is a valid therapeutic option for patellofemoral dislocation and the proposed techniques are reliable choices

Tratamiento de la inestabilidad femoropatelar objetiva. Resultados a cinco años de seguimiento / Treatment of objective patellar instability. Results after five years of follow-up

Resumen: Objetivo: Presentar los diferentes procedimientos quirúrgicos en el tratamiento de las inestabilidades femoropatelares objetivas, incluyendo la osteotomía de la tuberosidad tibial anterior y la trocleoplastía femoral. Material y métodos: Con un diseño prospectivo con seguimiento a cinco años que incluyó a 21 pacientes (21 rodillas) tratados por luxación rotuliana recidivante entre Marzo de 2010 y Agosto de 2014, tratándose de forma quirúrgica mediante dos técnicas diferentes según el tipo de inestabilidad estructural de base. Para determinarlo, se analizó el índice radiográfico de Caton-Deschamps (para la evaluación de la altura rotuliana) y parámetros tomográficos para valorar el configuración troclear y distancia desde la tuberosidad tibial anterior hasta la tróclea femoral (TT-TG) en la superposición de imágenes en el plano axial. Resultados: Hemos tenido resultados satisfactorios tanto con la transferencia de la tuberosidad tibial anterior como con la trocleoplastía. En ambos procedimientos se realizó una reconstrucción del ligamento patelofemoral medial (LPFM). Conclusiones: La recurrencia de inestabilidad es muy rara después de estos procedimientos y es más probable que ésta resulte de anomalías asociadas no diagnosticadas o subestimadas. Se requiere una planificación precisa preoperatoria para determinar la altura rotuliana, la ubicación de la tuberosidad tibial anterior y la configuración troclear para obtener resultados satisfactorios.

Abstract: Objective: To present the different surgical procedures in the treatment of objective femoropateral instability, including osteotomy of anterior tibial tuberosity and femoral trocleoplasty. Material and methods: With a prospective 5-year follow-up design that included 21 patients (21 knees) treated for relapsing patellar dislocation between March 2010 and August 2014, treated surgically using 2 different techniques depending on the type of basic structural instability. To determine this, the Caton-Deschamps X-Ray Index (for the evaluation of the patellar height) and tomographic parameters were analyzed to assess the troclear configuration and distance from the anterior tibial tuberosity to the femoral trochlea (TT-TG) in the overlapping of images in the axial plane. Results: We have had satisfactory results both with the transfer of the anterior tibial tuberosity and with the trocleoplasty. In both procedures, a reconstruction of the medial patelo-femoral ligament (LPFM) was performed. Conclusion: Recurrence of instability is very rare after these procedures and is more likely to result from undiagnosed or underestimated associated abnormalities. Precise preoperative planning is required to determine the patellar height, location of the anterior tibial tuberosity, and troclear configuration for satisfactory results.

Patellofemoral ankylosis: case report and technical note.

INTRODUCTION: It is our understanding that there is no consensual solution for the treatment of post-traumatic patellar ankylosis; therefore, the purpose of this work is to present two cases of patellofemoral retinacular interposition arthroplasty, and its corresponding technical note. CASE 1: Female, 24, patellar ankylosis secondary to supratranscondylar fracture, associated with comminuted diaphyseal tibia fracture. CASE 2: Female, 48, patellar ankylosis secondary to femoral diaphysis and lateral femoral condyle fracture. RESULTS: After going through a patellofemoral retinacular interposition release, both patients were satisfied with the results, presenting with significantly improved knee range of motion. CONCLUSION: Using our surgical technique, we were not able to restore normal function to our patients, but their improvement was certainly impressive relative to their initial clinical situation.

[Treatment of objective patellar instability. Results after five years of follow-up]. / Tratamiento de la inestabilidad femoropatelar objetiva. Resultados a cinco años de seguimiento.

OBJECTIVE: To present the different surgical procedures in the treatment of objective femoropateral instability, including osteotomy of anterior tibial tuberosity and femoral trocleoplasty. MATERIAL AND METHODS: With a prospective 5-year follow-up design that included 21 patients (21 knees) treated for relapsing patellar dislocation between March 2010 and August 2014, treated surgically using 2 different techniques depending on the type of basic structural instability. To determine this, the Caton-Deschamps X-Ray Index (for the evaluation of the patellar height) and tomographic parameters were analyzed to assess the troclear configuration and distance from the anterior tibial tuberosity to the femoral trochlea (TT-TG) in the overlapping of images in the axial plane. RESULTS: We have had satisfactory results both with the transfer of the anterior tibial tuberosity and with the trocleoplasty. In both procedures, a reconstruction of the medial patelo-femoral ligament (LPFM) was performed. CONCLUSION: Recurrence of instability is very rare after these procedures and is more likely to result from undiagnosed or underestimated associated abnormalities. Precise preoperative planning is required to determine the patellar height, location of the anterior tibial tuberosity, and troclear configuration for satisfactory results.

OBJETIVO: Presentar los diferentes procedimientos quirúrgicos en el tratamiento de las inestabilidades femoropatelares objetivas, incluyendo la osteotomía de la tuberosidad tibial anterior y la trocleoplastía femoral. MATERIAL Y MÉTODOS: Con un diseño prospectivo con seguimiento a cinco años que incluyó a 21 pacientes (21 rodillas) tratados por luxación rotuliana recidivante entre Marzo de 2010 y Agosto de 2014, tratándose de forma quirúrgica mediante dos técnicas diferentes según el tipo de inestabilidad estructural de base. Para determinarlo, se analizó el índice radiográfico de Caton-Deschamps (para la evaluación de la altura rotuliana) y parámetros tomográficos para valorar el configuración troclear y distancia desde la tuberosidad tibial anterior hasta la tróclea femoral (TT-TG) en la superposición de imágenes en el plano axial. RESULTADOS: Hemos tenido resultados satisfactorios tanto con la transferencia de la tuberosidad tibial anterior como con la trocleoplastía. En ambos procedimientos se realizó una reconstrucción del ligamento patelofemoral medial (LPFM). CONCLUSIONES: La recurrencia de inestabilidad es muy rara después de estos procedimientos y es más probable que ésta resulte de anomalías asociadas no diagnosticadas o subestimadas. Se requiere una planificación precisa preoperatoria para determinar la altura rotuliana, la ubicación de la tuberosidad tibial anterior y la configuración troclear para obtener resultados satisfactorios.

Role of Anatomical Patella Replacement on Anterior Knee Pain.

BACKGROUND: Anterior knee pain (AKP) remains a complex issue affecting patient satisfaction after total knee arthroplasty. Several radiographic parameters have been shown to be causative factors with various designs. The aim of this study is to evaluate the known radiographic parameters of AKP and clinical outcomes (ie, AKP) in the setting of a modern prosthesis with an anatomic patella button. METHODS: Between July 2012 and December 2013, 90 total knee arthroplasties received 3 skyline views taken at 30°, 45°, and 60°. A patient-administered questionnaire was administered at 2-year follow-up to assess the incidence of AKP, painless noise, and satisfaction. Radiographs were analyzed for patellofemoral overstuffing, patellar tilt, and patellar displacement, and evaluated the patella resection angle. RESULTS: On the patient-administered questionnaire, 10 (11.1%) patients reported AKP of a mild-to-moderate nature. Thirty-one had the best view at 30 Merchant views, 24 had best views at 45, and 35 had best views at 60. We found that patellar resection angle correlated with AKP (odds ratio 1.21, P = .044) and painless noise (odds ratio 1.22, P = .034). Patellar displacement and patellofemoral stuffing did not correlate with AKP or painless noise. No radiographic measurements correlated with changes in Knee Society Score pain or function scores or range of motion. CONCLUSION: We found that a patellar resection angle correlated with the incidence of AKP and painless noise at 2-year follow-up. We failed to find any correlation with patellofemoral overstuffing, patellar displacement, or patellar tilt with clinical outcomes. We recommend the use of 3 Merchant views to fully evaluate the patellofemoral joint.

Osteotomía de la tuberosidad anterior de la tibia en adolescentes y adultos jóvenes: resultados funcionales y complicaciones / Anterior tibial tubercle osteotomy in adolescents and young adults: functional results and complications

Introducción: La osteotomía de la tuberosidad anterior de la tibia (O-TAT) es una técnica quirúrgica que permite restablecer la alineación distal de la rótula en pacientes esqueléticamente maduros. Los objetivos de este estudio fueron evaluar los resultados funcionales y analizar factores que influyeron en el desarrollo de complicaciones. Materiales y Métodos: Se analizaron retrospectivamente pacientes con O-TAT tratados entre 2008 y 2016. Se documentaron datos demográficos y clínicos. Los resultados fueron evaluados según las escalas de Kujala y Tegner-Lysholm, y las complicaciones, con una adaptación de la clasificación de Clavien- Dindo. Resultados: Se analizaron 33 O-TAT en 29 pacientes (17 mujeres). Mediana de la edad: 18 años (RIC 2, mín.-máx. 14-39). Mediana de seguimiento: 49 meses (RIC 2, mín.-máx. 12-115). Mejoría en las escalas de Kujala y Tegner-Lysholm de 61 y 61,5 a 94 y 92,3, respectivamente (p = 0,001). La mediana de tiempo de consolidación fue de 8 semanas. Hubo 9 complicaciones (27%): 1 grado II (infección superficial) y 8 grado III (artrofibrosis, fracturas de tibia y fracturas de TAT, n = 2). La tasa de complicaciones fue más alta en los pacientes sometidos a desinserción de la TAT (51,5% vs. 11,1%, p = 0,029). Conclusiones: La O-TAT representa una técnica eficaz para tratar diversas patologías de la articulación patelofemoral en adolescentes y adultos jóvenes. Hubo complicaciones en un alto porcentaje de los procedimientos, sin que esto afectara el resultado final. El riesgo de complicaciones fue mayor en las osteotomías que requirieron desinserción de la TAT y la reconstrucción ligamentaria. Nivel de Evidencia: IV

Introduction: Tibial tubercle osteotomy (TTO) is a surgical approach that allows for the restoration of distal patellar alignment in skeletally mature patients. The objectives of this study were to evaluate functional results and to analyze the risk factors associated with complications. Methods: We carried out a retrospective analysis of patients subjected to a TTO between 2008 and 2016 and documented demographic and clinical data. Results were evaluated according to Kujala Anterior Knee Pain Scale and Tegner-Lysholm Knee Scoring Scale. Complications were evaluated with a modified Clavien-Dindo classification of Surgical Complications. Results: We evaluated 33 TTOs in 29 patients (17 women) with a median age of 18 years (IQR 2, range 14-39) and a median follow-up time of 49 months (IQR 2, range 12-115). The Kujala and the Tegner-Lysholm scoring improved from 61 and 61.5 to 94 and 92.3, respectively (p=0.001). Union was achieved at a median of 8 weeks. There were 9 complications (27%): a grade II complication (superficial infection) and 8 grade III complications (arthrofibrosis, tibial fractures, and anterior tibial tubercle fractures). Osteotomies in which tibial tubercle was completely detached had a significantly higher rate of complications (51.5% vs. 11.1%, p=0.029). Conclusions: TTO represents an effective approach for the treatment of several conditions of the patellofemoral joint in adolescents and young adults. In our series, a high percentage of the procedures presented complications, although they did not affect the final result. Osteotomies that involve complete detachment of the tubercle and those associated with ligament reconstruction have an increased risk of complications. Level of Evidence: IV

Indicaciones y complicaciones en la reconstrucción del ligamento patelofemoral medial / Medial patellofemoral ligament reconstruction. Indications and complications

Introducción: La reconstrucción del ligamento patelofemoral medial por inestabilidad rotuliana es un procedimiento reproducible con indicaciones precisas. El objetivo del presente trabajo fue evaluar las indicaciones, las complicaciones y la satisfacción postoperatoria en un grupo de pacientes, tratados con la misma técnica de reconstrucción. Material y método: Se evaluaron en forma retrospectiva 53 rodillas de 49 pacientes intervenidos entre el año 2009 al 2018, por inestabilidad rotuliana, con la misma técnica de reconstrucción de partes blandas asociada o no a otros procedimientos sobre estructuras óseas. Registrando edad, sexo, lado afectado, fecha, número de intervenciones y actividad física. Se evaluaron las indicaciones, las complicaciones y satisfacción postoperatoria con el score de Kujala. Resultados: La indicación de la cirugía fue la luxación recidivante de rotula. Nuestra complicación menor más frecuente fue el dolor, asociado en un bajo porcentaje a inestabilidad subjetiva. Dentro de las complicaciones mayores presentamos un caso de rigidez postoperatoria que requirió movilización bajo anestesia, un caso de reluxación que requirió una reintervención y un caso de retiro de material por dolor. Conclusión: La reconstrucción del ligamento patelofemoral medial es un procedimiento efectivo, con un bajo índice de recidiva, permitiendo el retorno a la actividad física previa. Es fundamental una indicación precisa. Se hallo un porcentaje reducido de complicaciones mayores, pero con un número considerable de complicaciones menores. Tipo de estudio: Serie de casos. Nivel de evidencia: IV

Introduction: The medial patella-femoral ligament reconstruction due to patellar instability is a reproducible procedure which has accurate indications. The objective of the present paper was to evaluate the indications, the complications and postop satisfaction in a group of patients, treated with the same reconstruction technique. Material and method: Fifty-six knees from 52 patients operated between 2009 and 2018, due to patellar instability, were evaluated retrospectively, with the same soft tissue reconstruction technique, whether or not associated with other procedures on bone structures. Age, gender, affected site, date and number of surgeries and physical activity were registered. Indications, complications and postop satisfaction were evaluated with Kujala score. Results: The patellar recurrent luxation was the indication for surgery. Pain was the most frequent minor complication, associated to subjective instability in a low percentage. Within the major complications two cases of postop stiffness that required mobilization under anesthesia were presented, and also was one recurrent luxation case that needed a new surgery. Conclusion: The medial patello-femoral ligament reconstruction is an effective procedure, which has a low recurrent rate, and which allows the return to previous physical activity. An accurate indication is fundamental. A lower rate of major complications was found, but with a non-negligible number of minor complications. Type study: Case series. Level of evidence: IV

Indicaciones y complicaciones de la osteotomía de la tuberosidad anterior de la tibia en el tratamiento de la inestabilidad patelofemoral / Tibial anterior tuberosity osteotomy for the treatment of patellofemoral instability. Indications and complications

Introducción: La osteotomía de la tuberosidad anterior de la tibia es un procedimiento efectivo y seguro para el tratamiento de la inestabilidad patelofemoral. El objetivo del presente trabajo es desarrollar las indicaciones y evaluar las complicaciones de dicho procedimiento realizado en un grupo de pacientes intervenidos por nuestro equipo. Material y método: Se analizaron en forma retrospectiva las historias clínicas de 77 pacientes intervenidos quirúrgicamente por inestabilidad patelofemoral a quienes se les realizó una osteotomía de la TAT, y en quienes se utilizó la misma técnica quirúrgica. Se registró edad, sexo, actividad deportiva y número de intervenciones, y se analizaron las indicaciones quirúrgicas de cada caso. Por último, se cuantifico el número de complicaciones (menores y mayores) y se evaluó el grado de satisfacción postquirúrgica de los pacientes con el score de kujala. Resultados: En la mayoría de los casos los pacientes presentaban un aumento de la distancia ST-TAT de más de 20 mm con un ángulo Q aumentado, asociado a episodios de luxación recidivante de rotula y dolor anterior de rodilla. La complicación más frecuente fue la recidiva del dolor (de menor intensidad y frecuencia que el presentado previo a la cirugía). Registramos dos casos de aflojamiento de material que requirió una segunda cirugía y un caso de secreción persistente de herida quirúrgica que no requirió re intervención. Conclusión: La osteotomía de la TAT es una procedimiento eficaz y con bajo índice de complicaciones postoperatorias para tratar la luxación recidivante de rotula, permitiendo al paciente retornar a sus actividades deportivas con un bajo porcentaje de morbilidad postoperatoria. Tipo de estudio: Serie de casos. Nivel de evidencia: IV

Introduction: Tibial anterior tuberosity osteotomy is an effective and safe procedure for the treatment of patello-femoral instability. The objective of the present paper is to talk about the indications and to evaluate the complications of the mentioned procedure performed in a group of patients who underwent surgery with our team. Material and method: The clinical histories of 77 patients operated due to patello-femoral instability, who underwent TT osteotomy and in whom the same surgical technique was performed, were analyzed retrospectively. Age, gender, sports activity and number of surgeries were registered and surgery indications in each case were analyzed. Lastly, the number of (minor and major) complications was quantified and patients postop satisfaction was evaluated with the Kujala score. Results: In most of cases patients presented a ST-TT distance increase of over 20 mm with an augmented Q angle associated to patellar recurrent luxation episodes and to anterior knee pain. The most frequent complication was pain recurrence (of lower intensity and frequency than that presented prior to surgery). Two cases of loosening material which required a second surgery and one case of persistent secretion from the surgical wound which did not require a new surgery were registered. Conclusion: The TT osteotomy is an effective procedure and with a low postop complications rate to treat patellar recurrent luxation, which allows the patient to resume sports activities with a low rate of postop morbidity. Type study: Case series. Level of evidence: IV

Patellar tracking after isolated medial patellofemoral ligament reconstruction: dynamic evaluation using computed tomography.

PURPOSE: Medial patellofemoral ligament (MPFL) reconstruction offers good clinical results with a very low rate of instability recurrence. However, its in vivo effect on patellar tracking is not clearly known. The aim of this study is to investigate the effects of MPFL reconstruction on patellar tracking using dynamic 320-detector-row CT. METHODS: Ten patients with patellofemoral instability referred to isolated MPFL reconstruction surgery were selected and subjected to dynamic CT before and ≥6 months after surgery. Patellar tilt angles and shift distance were analysed using computer software specifically designed for this purpose. Kujala and Tegner scores were applied, and the radiation of the CTs was recorded. Two protocols for imaging acquisition were compared: a tube potential of 80 kV and 50 mA versus a tube potential of 120 kV and 100 mA, both with a slice thickness of 0.5 mm and an acquisition duration of 10 s. RESULTS: There were no changes in patellar tracking after MPFL reconstruction. There was no instability relapse. Clinical scores improved from a mean of 51.9 (±15.6)-74.2 (±20.9) on the Kujala scale (p = 0.011) and from a median of 2 (range 0-4) to 4 (range 1-6) on the Tegner scale (p = 0.017). The imaging protocols produced a dose-length product (DLP) of 254 versus 1617 mGycm and a radiation effective estimated dose of 0.2 versus 1.3 mSv, respectively. Both protocols allowed the analysis of the studied parameters without loss of precision. CONCLUSIONS: Reconstruction of the MPFL produced no improvement in patellar tilt or shift in the population studied. The low-radiation protocol was equally effective in measuring changes in patellar tracking and is recommended. Although the procedure successfully stabilized the patella, knee surgeons should not expect patellar shift and tilt correction when performing isolated patellofemoral ligament reconstruction in patients with recurrent patellar instability. LEVEL OF EVIDENCE: IV.

Reconstrucción del ligamento patelofemoral medial. descripción de técnica quirúrgica. estudio retrospectivo / Medial patellofemoral ligament reconstruction. surgical technique

Introducción: la luxación de la patela es una patología relativamente frecuente sin embargo, su manejo es controversial. En los últimos años la tendencia a realizar reconstrucciones que asemejen más la anatomía nativa, ha generado un renovado interés por las reconstrucciones del ligamento patelofemoral medial (LPFM). De las estructuras que permiten mantener la patela en adecuada posición, el LPFM es la estructura más importante y su lesión es reconocida como esencial para que se origine una luxación de patela. Objetivo: La reconstrucción del LPFM con la técnica de doble haz fijada anatómicamente y verificada por artroscopia pretende acercarse a los parámetros actuales de reconstrucción. Este estudio busca describir los resultados del tratamiento quirúrgico con esta técnica en pacientes con luxación de patela tratados entre mayo de 2010 y mayo de 2016 mediante la aplicación de escalas funcionales establecidas en la literatura, para identificar la mejoría de los síntomas y la no recidiva un año posterior a finalizar el período de rehabilitación. Resultados: Se intervinieron 16 rodillas en 15 pacientes (una de las pacientes con compromiso bilateral), de las cuales el 81,2% fueron de sexo femenino. El tiempo entre la primera luxación y la intervención quirúrgica fue en promedio 11,81 meses. Al año se encontraron diferencias estadísticamente significativas para las escalas funcionales Lisholm, Tegner, y Kujala y no se realizaron reintervenciones durante el seguimiento. Conclusión: La reconstrucción del LPFM, con doble fijación en patela y fijación asistida por artroscopia, es una variación a la técnica abierta tradicional que, teniendo en cuenta parámetros anatómicos, se puede realizar de forma segura. La evolución clínica de los pacientes es satisfactoria teniendo en cuenta que las escalas funcionales medidas en estos pacientes mejoraron estadísticamente significativo con respecto a los puntajes iniciales.

Introduction: dislocation of the patella is a relatively frequent pathology, however, its handling is controversial. In the recent years the tendency to perform reconstructions that more closely resemble native anatomy has generated a renewed interest in reconstructions of the medial patellofemoral ligament (LPFM).1,2 Of the structures that maintain the patella in a suitable position, LPFM is the most important one and its lesion is recognized as essential for the origin of a patella dislocation.3 Objective: The reconstruction of the LPFM with the anatomically fixed and double-beam technique, which was verified by arthroscopy, aims to approach the current reconstruction parameters. This study looks at the results of the surgical treatment with this technique in patients with patellar dislocation treated between May 2010 and May 2016, through the application of functional scales established in the literature to identify the improvement of symptoms and non-recurrence, one year after the end of the rehabilitation period. Results: 16 knees were involved in 15 patients (one of the patients with bilateral involvement), of whom 81.2% were female. The time between the first dislocation and the surgery had an average of 11.81 months. There were found statistically significant differences for the Lisholm, Tegner, and Kujala functional scales and there were no interventions performed during the year of follow-up. Conclusion: The reconstruction of LPFM, with double fixation in patella and fixation assisted by arthroscopy is a variation to the traditional open technique, taking into account anatomical parameters can be performed safely. The clinical evolution of the patients is satisfactory considering that the functional scales measured in these patients improved compared to their initial scores.