Improper rotation of the femoral and tibial components in total knee arthroplasty may leads to various patellofemoral(PF) complications. As for the femoral component, alignment it to the epicondylar axis of the femur has been a widely used method. The tibial component traditionally has been aligned to the medial 1/3 of the tibial tuberosity. However, there is no consensus concerning how to determine the tibial component rotation. The purpose of the current study is to evaluate the influence rotational alignment of tibial component upon PF joint. We divided the cases to two groups. Group A: 41cases 50knees (OA 34cases, RA16cases). The average age was 69.5(35~84). Group B: 30cases 30knees (OA 25 cases, RA 5cases). The average age was 72.6(59~86). In group A, the anteropostrior (AP) axis was defined as the line connecting the medial 1/3 of tibial tuberosity and the center of PCL attachment. In group B, the line connecting the medial edge of patellar tendon attachment and the center of PCL attachment was defined as AP axis. We measured the PF alignment on postoperative X-rays. Tangential radiographs were used to measure the amount of patellar tilt (tilting angle: TA), subluxation and patellar lateral shift (LS).

Group A showed that tilting angle 14±4°, lateral shift 0.3±0. These values of group B were 12±5°,0.2±0.1, respectively.

In rotation of tibial component, Insall reported that the landmark in front of tibia was medial 1/3 tibial tuberosity. Akagi et,, al reported that the landmark was midial edge of patellar tendon attachment. This study indicated that the latter had better alignment in patellofemoral joint.

Background: It is known that not only the size but also the shape was different between races. We previously compared the distal femur shapes between the American and the Japanese by lateral radiograph and demonstrated the morphological difference in detail. In this study we evaluated the morphologic feature of the lateral and medial condyles separately between the American and the Japanese using MRI in the sagittal plane.

Patients and methods: The subjects were 99 American and 41 Japanese adult women. MRI scan of sagittal section through the distal half of the femur was taken with the slice thickness about 4.0 mm. The envelope curve of each condyle was superimposed to be approximated to an ellipse. The length and inclination of two axes of the ellipse were estimated as the parameters of the statistical comparison.

Results: The ratio major axis/minor axis of the lateral condyles in American women was significantly larger than that in Japanese, while the ratio of the medial condyles in American was significantly smaller. The inclination of the major axis to the anatomical axis of the distal femur in the American lateral condyles were significantly more than that in Japanese lateral condyles, while both the American and Japanese medial condyles showed similar inclination.

Discussion: The morphological feature of both the lateral and medial condyles in American women was significantly different from that in Japanese. The ratio major axis/minor axis and inclination of lateral condyle in American women were different from those in Japanese, while only the ratio was different between the American and Japanese medial condyles. Understanding of these morphological differences between American and Japanese women is beneficial in elucidating discrepancies in normal knee kinematics and in tailoring the design and procedure for successful total knee arthroplasty.

The aim of this study is to compare the clinical results of the Pin-Sleeve System (AI Wiring System; AIWS) with the Dall-Miles Cable Grip System (DMCGS) for reattachment after dissection of the greater trochanter in hip arthroplasty.

The DMCGS was used in 33 cases 35 hips from 1994 to 1998 and AIWS in 40 cases 42 hips from 1998 to 2001. The age at operation was 61.3 years (24 to 85 years) in the DMCGS group and 67 years (24 to 86 years) in the AIWS group. The postoperative follow-up period was 24 months (4 months to 54 months) in the DMCGS group and 30 months (11 months to 42 months) in the AIWS group.

Bone union failure of the great trochanter occurred in the DMCGS group eight hips (22.9%) and AIWS group five hips (11.9%). The DMCGS group four hips (11.4%) had broken cables, while not even one case of the AIWS group had them (p< 0.05). Fragments from the cable were found in the DMCGS group seven hips (20%) and AIWS group two hips (4.8%). Bone resorption around the cable, grip or sleeve occurred in the DMCGS group 19 hips (54.3%) and AIWS group five hips (11.9%) (p< 0.05). Clinically, the DMCGS group 13 hips (37.1%) and AIWS group seven hips (16.7%) had dysphoria at the greater trochanter; the DMCGS group 17 hips (48.6%) and AIWS group eight hips (19%) had pain at the greater trochanter in the recumbent position with the affected side down (p< 0.05); the DMCGS group 13 hips (37.1%) and AIWS group six hips (14.3%) had pain on exertion.

The AIWS is considered to be a useful implant for reattachment of the greater trochanter compared with the DMCGS.