RESUMEN
BACKGROUND: iASSIST is one of the novel accelerometer-based navigation systems for total knee arthroplasty (TKA). Although the accuracy of iASSIST compared with conventional instruments has been reported, such evaluations were performed on two-dimensional (2D) images (X-rays). This multi-center prospective randomized controlled trial aimed to assess component positioning between TKA with and without iASSIST by 3D image assessment, and to clarify whether the iASSIST provides any benefit with regard to alignment accuracy. METHODS: Eighty-three knees with primary knee osteoarthritis were enrolled in this study. iASSIST was used for distal femoral and proximal tibial resection in 42 knees (iA group) and a conventional guide was used in 41 knees (CONV group). At 6 months postoperatively, component alignment was evaluated with 3D images by the independent orthopaedic surgeons, and surgical parameters, range of motion and clinical outcomes were examined. RESULTS: The rate of knees who have the alignment within 3° of neutral compared with the iA group and CONV group were 92.9% (39/42) vs. 87.8% (36/41) for femur and 76.2% (32/42) vs. 56.1% (23/41) for tibia in the coronal plane, respectively, whereas in the sagittal plane, the rate was 85.7% (36/42) vs. 58.5% (24/41) for femur and 83.3% (35/42) vs. 78.0% (32/41) for tibia, respectively. Compared with the CONV group, the iA group had a significantly improved femoral alignment in the sagittal plane (P = 0.006). There were no clinical or patient-reported differences at 6 months postoperatively. CONCLUSIONS: The iASSIST provides technically high accuracy in femoral resection at TKA compared with a conventional procedure.
Asunto(s)
Artroplastia de Reemplazo de Rodilla/métodos , Rodilla/diagnóstico por imagen , Cirugía Asistida por Computador/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Fémur/fisiología , Fémur/cirugía , Humanos , Imagenología Tridimensional , Rodilla/cirugía , Masculino , Persona de Mediana Edad , Tempo Operativo , Osteoartritis de la Rodilla/diagnóstico por imagen , Osteoartritis de la Rodilla/cirugía , Medición de Resultados Informados por el Paciente , Estudios Prospectivos , Rango del Movimiento Articular , Tibia/fisiología , Tibia/cirugíaRESUMEN
A new design of the so-called "guided-motion" total knee arthroplasty (TKA) is expected to produce normal-like kinematics. The implant behaves strictly as a mechanically constraint-guided motion system. However, no previous reports have demonstrated the most appropriate surgical technique or soft-tissue balance that would reproduce ideal kinematics. The purpose of this study was to clarify the relationship between soft-tissue balance and the intraoperative kinematics of guided-motion TKA. In this study, intraoperative kinematics of 95 patients whose TKA was performed with a guided-motion prosthesis (Journey II BCS Smith and Nephew) were measured using the computed tomography (CT)-free navigation system. All procedures were performed via the same soft-tissue balancing technique, which focused on the medial compartment because guided-motion TKA must acquire medial stability to induce medial pivot motion. We measured the extension and flexion osteotomy gaps using a force-controlled compartment-specific ligament tensioner with a distraction force of 80 N for each compartment and divided patients into three groups based on the relationship between extension and flexion joint osteotomy gaps of the medial compartment: group1- loose flexion gap, group 2-equal joint gap, and group 3-tight flexion gap. We compared the preoperative demographic characteristics, implant alignment, and intraoperative kinematics among the three groups. There was no difference between the preoperative demographic characteristics and postoperative implant alignment in the three groups. The relative tibial internal rotational angles in groups 1 and 2 were significantly larger than that in group 3 at 60°, 90°, and maximum flexion (p < 0.05). The appropriate soft-tissue balance of the medial compartment for guided-motion TKA was an equal joint osteotomy gap or a larger flexion than extension gap. A tight flexion gap should be avoided.
Asunto(s)
Artroplastia de Reemplazo de Rodilla/métodos , Prótesis de la Rodilla , Anciano , Fenómenos Biomecánicos , Femenino , Humanos , Periodo Intraoperatorio , Articulación de la Rodilla/diagnóstico por imagen , Articulación de la Rodilla/cirugía , Masculino , Osteoartritis de la Rodilla/cirugía , Rotación , Cirugía Asistida por Computador , Tomografía Computarizada por Rayos XRESUMEN
PURPOSE: Mobile-bearing Oxford unicompartmental knee arthroplasty has been used widely and successfully; however, there is no previous research on the intraoperative bearing movement. The purpose of this study was to characterise intraoperative bearing movement and investigate whether bearing movement relates to component positions, bearing size, intraoperative rotational kinematics and clinical results. METHODS: A trial tibial component, which was scaled every 2 mm, was used to measure the intraoperative movement of the mobile bearings. Bearing movements from 30° flexion to deep flexion were classified into two groups: 30 patients exhibited posterior bearing movement that contacted the lateral wall of the tibial component (Group W), and 37 patients exhibited posterior bearing movement, without contact, or with only transient contact, with the lateral wall (Group S). RESULTS: All mobile bearings moved posteriorly during knee flexion in the anteroposterior direction. In postoperative radiography with the knee flexed, the femoral component in Group W was significantly more laterally implanted than that in Group S. The width ratio between the bearing and tibial component in Group W was significantly greater than in Group S. There were no significant differences in other radiological measurements, intraoperative rotational kinematics or clinical results. CONCLUSION: During knee flexion, all mobile bearings moved posteriorly, and mobile bearings whose femoral components were set laterally, tended to move posteriorly while in contact with the lateral wall. However, there were no significant differences in clinical evaluation. LEVEL OF EVIDENCE: IV.
Asunto(s)
Artroplastia de Reemplazo de Rodilla/instrumentación , Prótesis de la Rodilla/estadística & datos numéricos , Anciano , Anciano de 80 o más Años , Fenómenos Biomecánicos , Femenino , Humanos , Articulación de la Rodilla/cirugía , Masculino , Movimiento , Periodo Posoperatorio , Radiografía , Rango del Movimiento Articular , Estudios Retrospectivos , Tibia/cirugíaRESUMEN
The purpose of this retrospective study was to first compare the clinical outcome of anatomical double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) with hamstring tendon (HT) autografts and anatomical rectangular tunnel ACLR with bone-patellar tendon-bone (BPTB) autografts. Secondly, we aimed to demonstrate the quantitative locations of the femoral and tibial tunnel apertures using postoperative three-dimensional computed tomography (3D CT). Twenty-five patients underwent anatomical rectangular tunnel ACLR using BPTB grafts (Group B) and 23 patients underwent anatomical DB ACLR using HT grafts (Group H). All patients underwent subjective postoperative evaluations using the Lysholm score and Knee Injury and Osteoarthritis Outcome Score. Patients also underwent objective evaluations by the International Knee Documentation Committee score, the Lachman test, the pivot-shift test, and range of motion. In addition, we quantitatively assessed anterior knee stability using a KneeLax3 arthrometer and thigh strength. All evaluations except for thigh strength were assessed for a minimum 2 years of follow-up period. Femoral and tibial tunnel aperture locations were quantitatively evaluated postoperatively using 3D CT images in all patients. BPTB grafts showed significantly better anterior knee stability than HT grafts (0.1 mm versus 1.1 mm, p = 0.01), although there were no significant differences in other objective and all subjective evaluations between the two graft types. Morphometric analysis of femoral and tibial tunnel locations revealed that the two procedures were based on the same anatomical concept. In conclusion, BPTB grafts showed significantly better anterior knee stability than HT grafts, although no significant differences in other objective evaluations and all subjective evaluations were detected between the two graft types in anatomical ACLR. Additional 3D CT data validated the anatomical concepts of these two procedures.
Asunto(s)
Lesiones del Ligamento Cruzado Anterior/cirugía , Reconstrucción del Ligamento Cruzado Anterior/métodos , Trasplante Óseo , Tendones Isquiotibiales/trasplante , Huesos de la Pierna/cirugía , Ligamento Rotuliano/trasplante , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Rango del Movimiento Articular , Estudios Retrospectivos , Trasplante Autólogo , Adulto JovenRESUMEN
INTRODUCTION: The effects of initial graft tension upon tunnel widening (TW) following anatomic anterior cruciate ligament (ACL) reconstruction have not been elucidated. The purpose of this study was to retrospectively investigate the effect of two different graft-tensioning protocols upon femoral TW following anatomic ACL reconstruction using a bone-patellar tendon-bone (BPTB) graft and a three-dimensional (3D) computed tomography (CT) model. METHODS: Forty-three patients who underwent isolated ACL reconstruction using BPTB grafts were included in this study. In 18 out of the 43 patients, the graft was fixed at full knee extension with manual maximum pull (Group H). These patients were compared with 25 patients in whom the BPTB graft was fixed at full knee extension with 80-N pull (Group L). Tunnel aperture area was measured using 3D CT 1 week and 1 year postoperatively, thus enabling us to calculate the percentage change in the area of femoral tunnel aperture. Clinical assessment was performed 1 year postoperatively, corresponding to the time period of CT assessment, and involved the evaluation of Lysholm score, anterior knee stability using a KneeLax3 arthrometer, and the pivot-shift test. RESULTS: When measured at 1 year postoperatively, the mean area of the femoral tunnel aperture had increased by 78.6 ± 36.8% in Group H when compared with at 1 week postoperatively, whereas that of Group L had increased by 27.7 ± 32.3%. Furthermore, TW (%) in Group H was significantly greater than that of Group L (P < 0.001). No significant differences were detected between the two groups with regard to any of the clinical outcomes evaluated. CONCLUSION: High levels of initial graft tension resulted in greater TW of the femoral tunnel aperture following anatomical ACL reconstruction using BPTB grafts. However, such levels of graft tension did not affect clinical outcome.
Asunto(s)
Reconstrucción del Ligamento Cruzado Anterior , Ligamento Cruzado Anterior/cirugía , Injertos Hueso-Tendón Rotuliano-Hueso , Ligamento Rotuliano , Ligamento Cruzado Anterior/diagnóstico por imagen , Reconstrucción del Ligamento Cruzado Anterior/métodos , Reconstrucción del Ligamento Cruzado Anterior/estadística & datos numéricos , Injertos Hueso-Tendón Rotuliano-Hueso/fisiología , Injertos Hueso-Tendón Rotuliano-Hueso/cirugía , Humanos , Articulación de la Rodilla/diagnóstico por imagen , Articulación de la Rodilla/fisiología , Articulación de la Rodilla/cirugía , Ligamento Rotuliano/diagnóstico por imagen , Ligamento Rotuliano/fisiología , Ligamento Rotuliano/cirugía , Estudios Retrospectivos , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: Tilting of the mobile bearing relative to the tibial tray in the flexion position may result from the implantation of femoral components more laterally relative to tibial components during unicompartmental knee arthroplasty (UKA) using the Oxford Knee. The purpose of the present study was to compare femoral component positions after UKA using the phase 3 device and a novel device. We further evaluated the placement of the femoral components with the new device in the flexion position to determine the association with short-term prognosis. METHODS: The location of femoral and tibial components in the flexion position of 38 knees implanted using the phase 3 device and 49 knees using a novel device was assessed at 1 year postoperatively using radiography of the proximal tibia and distal femur in the flexion position. RESULTS: The femoral component was implanted more laterally using the new device than using the phase 3 device in the flexion position (P = .012), which caused the impingement of the mobile bearing against the lateral wall of the tibial tray. After UKA using the new device, 10% of patients exhibited the tilting phenomenon of the mobile bearing because of the lateral implantation of the femoral implant. CONCLUSION: To prevent implantation of the femoral component too laterally using the new device during UKA, knee surgeons should set the drill guide more medially such that the center of the drill is aligned with the middle of the medial femoral condyle.