Estudio comparativo con prótesis total de rodilla de alta flexión: resultados funcionales y de rango de movimiento / Comparative study with high-flex total knee arthroplasty. Functional and range of motion. Results

Introducción: El objetivo de este trabajo comparativo fue analizar los resultados funcionales y el rango de movimiento de rodilla entre dos grupos de pacientes con artroplastia total de rodilla: uno utilizando prótesis de alta flexión y el otro con un diseño convencional. Materiales y Métodos: Setenta y cuatro pacientes fueron operados con artroplastia total de rodilla con prótesis de Zimmer NexGen®, EE.UU. Veintidós (grupo A) fueron tratados con diseño de alta flexión. Dos con artritis reumatoide fueron excluidos. Cuarenta y dos pacientes fueron tratados con una convencional, 21 de ellos fueron excluidos, por lo que el grupo B estaba conformado por 21 pacientes. La evaluación funcional se realizó con el Knee Society Score (KSS), el Western Ontario and McMaster Universities osteoathritis index y la escala analógica visual. Resultados: El promedio de flexión máxima preoperatoria fue de 99º en el grupo A y de 106º en el grupo B. En el posoperatorio, el promedio de flexión máxima del grupo A subió a 114º, con un aumento promedio de 15º y, en el grupo B, a 118º con una ganancia promedio de 12º. No hubo diferencias estadísticamente significativas (p <0,05). El puntaje KSS preoperatorio del grupo A fue de 36/48 y mejoró a 90/92. En el grupo B, fue de 46/49 y de 94/90 en el posoperatorio. Conclusión: Las evaluaciones clínicas funcionales y radiológicas son favorables en los dos diseños de prótesis evaluados. Este estudio muestra que no hay diferencias significativas entre el rango de movimiento de una prótesis de alta flexión y una prótesis convencional luego de un año de seguimiento...

Background: The purpose of this comparative study is to analyze functional results and the range of motion of the knee between two groups of patients with total knee arthroplasty using high-flex prosthesis (in one group) and with a conventional implant (in the other). Methods: Sixty-four patients were surgically treated with total knee arthroplasty with Zimmer NexGen®, USA. From this series, 22 patients (group A) were treated with high-flex design. Two cases with rheumatoid arthritis were excluded. Forty-two patients were treated with a conventional implant, 21 of them were excluded, and group B included 21 patients. Maximum flexion and extension were evaluated before and after surgery. Functional evaluation was performed with the Knee Society Score (KSS), the Western Ontario and McMaster Universities osteoarthritis index (WOMAC), and an analogous visual scale. Results: The mean pre-surgical maximum flexion was 99° in group A and 106º in group B. Mean post-surgical maximum flexion in group A increased to 114º with an average increase of 15º and, in group B, to 118º with an average gain of 12º. There were no significant statistical differences (p <0.05). Pre-surgical KSS in group A was 36/48 and increased to 90/92. In group B, pre-surgical KSS was 46/49 and 94/90 after surgery. Conclusion: This study suggests that there are no significant differences in the range of motion, functional results, and radiographic evaluation in a high-flex total knee arthroplasty and a conventional design after one year of follow-up...

A Comparative Study between High-Flex and Non High-Flex TotalKnee Arthroplasty / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to compare the clinical results of a high-flex design (Scorpioflex(R), Stryker) in total knee arthroplasty with those of a non-high-flex design (Scorpio(R) PS type, Stryker). MATERIALS AND METHODS: Fifty-two knees with at least 120 degrees of further flexion preoperatively underwent total knee arthroplasty. Of the 52 knees, there were 35 knees in the high-flex design (HF group) and 17 knees in the non high-flex design (non-HF group). The clinical results were evaluated by postoperative further flexion at 3 months, 6 months, 1 year, 2 years and 3 years, as well as by Delta flexion, which means postoperative flexion improvement. The Knee Society Score and X-rays were evaluated preoperatively and at the 3-year follow-up. RESULTS: The HF group showed significantly greater flexion than the non-HF group at 3 months postoperatively (p=0.000). The delta flexion was also greater in the HF group at 3 months postoperatively (p=0.000). The Knee Society Score and X-rays were similar in the two groups at the final follow-up (p>0.05). CONCLUSION: High-flex total knee arthroplasty appears to facilitate greater flexion in the first 3 months postoperatively, but there is no significant difference between both groups with regard to the range of motion, clinical and radiographic variables after 3 months.