Tibial Intercondylar Eminence Research Articles

Three-dimensional knee joint movements during a step-up: evaluation after anterior cruciate ligament rupture.

The three-dimensional motions of the knee were analysed during closed kinetic chain knee extension in 13 patients with unilateral chronic injury of the anterior cruciate ligament. The patients ascended a platform, and serial stereophotogrammetric roentgenograms were exposed from about 100 degrees of flexion to full extension. From a position of about 100 degrees of knee flexion and 20 degrees of internal rotation, the tibia rotated externally during the extension. Almost no tibial adduction or abduction was observed. The tibial intercondylar eminence translated laterally, distally, and anteriorly relative to the femur. In knees with absence of the anterior cruciate ligament, the intercondylar eminence had a more posterior position compared with the contralateral normal knees. The proximal tibia was used as a fixed reference segment to evaluate the anteroposterior translations of a central point in the femoral condyles. The femoral point was more anteriorly displaced in the injured than in the contralateral knees. This difference might reflect increased activity of the hamstrings in the injured knees, because it was most pronounced at 80 degrees of flexion and decreased with increasing extension. In the sagittal plane, the mean helical axis was positioned close to the femoral insertion of the ligament at 80 degrees of flexion and was displaced distally and anteriorly during extension. In the frontal plane, the axis had a transverse direction at 80 degrees of flexion. At close to full extension, the axis was positioned distally in the lateral condyle and proximally in the medial condyle. In the horizontal plane, the helical axes ran slightly more anteriorly in the medial than in the lateral femoral condyle but changed inclination at close to full extension and became almost parallel to the transverse axis.

Kinematics of active knee extension after tear of the anterior cruciate ligament

Three-dimensional movements of the knees in 13 patients with unilateral old tears of ACLs were studied during extension. Roentgen stereophotogrammetric methods were used to measure tibial movements in the injured and the intact knees. Reduced internal rotation and adduction were recorded at the end of extension on both sides. The injured knees displayed increased anterior and distal displacements of the tibial intercondylar eminence. Abnormal tibial displacements in our patients indicate that the absence of the ACL is not completely compensated for during active extension past 30 degrees; close to the extended position, the tibial movements tend to normalize.

Active knee motion after cruciate ligament rupture. Stereoradiography.

In 10 patients with an old injury of the anterior cruciate ligament, the three-dimensional movements of the knee joint were studied when the patients flexed their knees. Tibial motions were recorded using roentgen stereophotogrammetric analysis. Internal rotation and adduction of the tibia were reduced in the injured knees when compared with the intact knees; during flexion of the knee joint, the tibial intercondylar eminence occupied a more lateral and posterior position on the injured side. Our results may indicate that the knee joint is continuously exposed to abnormal stresses when the anterior cruciate ligament is torn.

Roentgenographic Evaluation of Geometric Total Knee Arthroplasty with a Six-Year Average Follow-up Period

The geometric total knee prosthesis was used in the reconstruction of 70 damaged knee joints in 56 patients from November 1973 through March 1979. The average follow-up period extended to six years and seven months. Eleven patients had died and four could not be located. Eighty-one percent of the remaining knees had little or no pain at the time of the review. Pain in the patellofemoral joints was an insignificant problem in this series. The femorotibial shaft angle ranged from 0 degrees to 10 degrees of valgus in 43 (82.7%) of 52 knees. Six knees showed varus deformity at the time of follow-up examination. Stress fracture of the medial condyle of the tibia was found in two of these six knees. The absence of a radiolucent zone at the tibial cement-bone interface was noted in only ten (19.2%) of the 52 knee roentgenograms. New formation or progression of a radiolucent zone from six to 12 months after the operation was found in 36.5%. Positional abnormality of the marker wires seen in serial roentgenograms existed in 51.9% of the knees. Nine knees (17.3%) disclosed a gap between the metallic articular surface and the tibial component and also showed the collision of the tibial intercondylar eminence against the femur in the standing position. The tibial component of the prosthesis was fractured in one knee.