Resultados patelares con una prótesis total de rodilla con componente femoral simétrico: estudio prospectivo con un seguimiento de 3 a 7 años

Objetivo

Evaluar los resultados y función fémoro-patelar con una prótesis total de rodilla con componente femoral simétrico.

Material y método

Estudio prospectivo de 125 pacientes consecutivamente tratados entre 1998 y 2001 con prótesis total de rodilla Multigen^® (Lima, San Daniele, Italia). La edad media era de 71 años (49–83) y el 79% eran mujeres. Había un 35% con índice masa corporal superior a 30. El 97% tenían diagnóstico previo de artrosis primaria y el 94% no tuvieron intervenciones previas de la rodilla. Se evaluaron pre y postoperatoriamente con la escalas clínica y radiológica de la Sociedad de Rodilla norteamericana.

Resultados

El seguimiento postoperatorio medio fue de 52 meses (36 a 80). El 95% de los casos tuvieron excelentes o buenos resultados funcionales, con flexión media final de 106° (70–140). El 92% no precisaron ayudas a la marcha. Hubo síntomas relacionados con la rótula en 6 pacientes. Radiológicamente resultaron con rótulas centradas a la flexión 101 rodillas, 20 con inclinación de la rótula más de 5° y 4 con desplazamiento lateral superior a 5 mm, no habiendo relación (p = 0,42) con los síntomas patelares. Se reintervinieron 3 rodillas, una por infección y 2 por aflojamiento del componente tibial. No hubo casos con radiolucencia en el componente patelar ni otras complicaciones de rótula. La supervivencia acumulada de la prótesis a los 6 años era del 96,9% (intervalo de confianza [IC] del 95%: 93,3-99,9).

Conclusiones

Con este modelo de prótesis total de rodilla con componente femoral simétrico los resultados funcionales han sido muy satisfactorios, no encontrando que la simetría entorpezca la función fémoro-patelar ni incremente el riesgo de inestabilidad u otras complicaciones patelares.

Aim

To assess the results of patellofemoral function in a total knee replacement procedure with a symmetric femoral component.

Materials and methods

This was a prospective study of 125 patients treated consecutively between 1998 and 2001 that underwent total knee replacement with a Multigen^® knee (Lima, San Daniele, Italy). The mean age of the patients was 71 years (49–83) and 79% were women; body mass index was > 30 in 35%; 97% had a previous diagnosis of primary osteoarthritis and 94% had not had previous surgeries of the knee. The patients were assessed pre and postoperatively using the clinical and X-ray scores of the American Knee Society.

Results

Mean postoperative followup was 52 months (36–80). Excellent functional results were seen in 95% of the cases, with a final mean flexion of 106° (70–140). No assistance for walking was required by 92%. Six patients had patellar symptoms. On X-ray 101 knees had patellas that were centered on flexion, 20 showed a > 5° inclination of the patella and 4 had a > 5 mm lateral displacement, with no connection with patellar symptoms (p = 0.42). Three knees underwent revision surgery, 1 due to infection and 2 due to loosening of the tibial component. There were no cases of radiolucency of the patellar component or other complications in the patella. The accumulated survival rate of the prosthesis at 6 years was 96.9% (CI 95%: 93.3-99.9).

Conclusions

Very satisfactory outcomes were seen when this model of total knee replacement with a symmetric femoral component was used. The symmetry did not affect patellofemoral function, increase the risk of instability or cause other patellar complications.