The posterolateral or posterior approach for total hip arthroplasty has the advantages of preserving the hip abductor musculature and providing good visualization during femoral preparation and component insertion. Although posterolateral approach is one of the popular approaches in hip arthroplasty, it has been reported high dislocation rate as a drawback. To compensate the drawback the repair of short external rotator of hip is thought to be important. Therefore, we investigated incidence of failed repaired short external rotator muscles, dislocation rate and time of failure between tendon to tendon and tendon to bone repair technique through prospective study more than 1 year follow up. We performed 213 hip arthroplasties in 202 patients from May 2012 to January 2015. After exclusion of 15 hips due to follow-up loss(9 hips), death(2 hips), greater trochanteric fragment displacement(3 hips) and severe contracted short external rotator(1 hip), we investigated 198 hips in 187 patients. 57 patients were male and 130 patients were female. The mean age of patient was 70.4 (32–98) years. Reattachment short external rotator with posterior capsule to postero-superior aspect of greater trochanter(tendon to bone group, 111 hips) or to the tendon(tendon to tendon group, 87 hips) was performed. Two No.26 metal wire markers were fixed at the greater trochanter tip and short external rotator tendon respectively with a distance less than 1.2cm, and the distance between two wire markers was observed at postoperative 1 day, 2 weeks, 3 months, and annually radiographs in neutral position. When the distance was more than 2.5cm or one of the wire markers was invisible, we defined them the failure of short external rotator repair. The mean follow up period was 28.8 (12–45) months.Purpose
Materials and methods
Proper rotational alignment of the tibial component is a critical factor in the outcome of total knee arthroplasty (TKA), and misalignment has been implicated as a major contributing factor to several mechanisms of TKA failure. In this study we examine the relationship between bony and soft tissue tibial landmarks against the knee motion axis (plane that best approximates tibiofemoral motion through range of motion). The kinematic motions of 16 fresh-frozen lower limb specimens were analyzed in simulated lunging and squatting. All the tendons of the quadriceps and hamstrings were independently loaded to simulate a lunging or squatting maneuver. All specimens underwent CT scan and the 3D position of the knee was virtually reconstructed. Ten anatomic axes were identified using both the intact tibia and the resected tibial surface. Two axes were normal vectors to either the medial-lateral plateau center or the posterior tibial surface. Seven axes were defined between the tibial tubercle (the most prominent point, center of the tubercle, or medial third of the tubercle) and soft tissue landmarks of the tibia (the medial insertion of the patellar tendon, the center of the PCL and ACL, and the tibial spines). The last axis was the Knee Motion Axis (KMA), which was defined as the longitudinal axis of the femur from 30 to 90 degrees of flexion.Introduction:
Methods:
