Various approaches have been reported for the total hip replacement (THR). In recent years, a muscle sparing approach with low postoperative muscle weakness and low dislocation risk has been frequently selected. However, such surgery has a learning curve. Thus, at the time of switching from the conventional approach to such approaches, invasion or infection risk may increase with the operation time extension. The purpose of this study is to clarify the change of invasiveness or latent infection rate with the change in approach in order to select the cases safely at the beginning of introducing a new approach in THR. In facility A, THR was performed with Dall's approach (Dall), but 1 surgeon changed Dall to anterolateral modified Watson-Jones approach (OCM) and another surgeon changed Dall to direct anterior approach (DAA). In facility B, all 3 surgeons changed posterolateral (PL) approach to OCM. The subjects are 150 cases in total, including the each last 25 cases operated with the conventional approach and the each first 25 cases operated with a new approach (Dall to OCM: 25 + 25, Dall to DAA: 25 + 25, PL to OCM: 25 +25 cases). And, differences in operative time, intraoperative bleeding volume, postoperative hospital stay, and postoperative hemoglobin, white blood cell count, lymphocyte count, creatine kinase (CK), C-reactive protein (CRP) were investigated.Purpose
Methods
In Japan, edoxaban has been used for the prevention of venous thromboembolism (VTE) after total knee arthroplasty (TKA) since June 2011. Edoxaban is an oral direct factor Xa inhibitor, expected to be more convenient for the postoperative treatment of TKA. Enoxaparin, a II and Xa inhibitor, was approved in Japan for the prevention of VTE in patients undergoing orthopedics surgery from 2008. In this study, the effect for the prevention of VTE after TKA was compared between these two drugs in Japanese patients. We studied 42 Japanese patients who underwent TKA from May 2011 to April 2012. The operations were performed under general anesthesia, continuous femoral nerve block, an air tourniquet, and using cements for implant fixation. These patients were divided in two groups, use of 30 mg edoxaban once daily (ED group), and use of 1000 IU of enoxaparin twice daily (EN group). The initial dose was administered between 12 and 21 hours after surgery. We compared the incidence of VTE, bleeding complications, D dimer levels, and hemoglobin (Hb) loss. The screening of VTE was performed by enhanced CT scan screening from the chest to the foot on postoperative day 5 or 6 in all patients. The bleeding complication was divided into major bleeding and minor bleeding with Japanese guideline for the prevention of VTE. D dimer levels and Hb levels were preoperatively and postoperative day 1, 3, 5, 7, and 14. The loss of Hb was calculated from preoperative Hb level minus lowest postoperative Hb level.Introduction
Patients and Methods
The decision to choose CR (cruciate retaining) insert or CS (condylar stabilized) insert during TKA remains a controversial issue. Triathlon CS type has a condylar stabilized insert with an increased anterior lip that can be used in cases where the PCL is sacrificed but a PS insert is not used. The difference of the knee kinematics remains unclear. This study measured knee kinematics of deep knee flexion under load in two insert designs using 2D/3D registration technique. Five fresh-frozen cadaver lower extremity specimens were surgically implanted with Triathlon CR components (Stryker Orthopedics, Mahwah, NJ). CR insert with retaining posterior cruciate ligament were measured firstly, and then CS insert after sacrificing posterior cruciate ligament were measured. Under fluoroscopic surveillance, the knees were mounted in a dynamic quadriceps-driven closed-kinetic chain knee simulator based on the Oxford knee rig design. The data of every 10° knee flexion between 0° and 140° were corrected. Femorotibial motion including tibial polyethylene insert were analyzed using 2D/3D registration technique, which uses computer-assisted design (CAD) models to reproduce the spatial position of the femoral, tibial components from single-view fluoroscopic images. We evaluated the knee flexion angle, femoral axial rotation, and anteroposterior translation of contact points.Background
Materials and methods
Computer navigation system has been reported as a useful tool to obtain the proper alignment of lower leg and precise implantation in TKA. This system alsoãζζhas shown the accurate gap balancing which was lead to implants longevity and optimal knee function. The aim of this study was determine that the postoperative acquired deep knee flexion would be influenced by intraoperative kinematics on navigated TKA even under anesthesia. Forty knees from 40 patients, who underwent primary TKA (P.F.C. sigma RPF, DePuy Orhopaedic International, Leed, UK) with computer-navigation system (Ci Knee, BrainLAB / DePuy Inc, Leeds, UK), were recruited in this study. These patients were classified into two groups according to the recorded value of maximum knee flexion at three month after surgery: 15 patients who obtained more than 130 degrees of flexion in Group A, and 25 patients less than 130 degrees in Group B. We retrospectively reviewed about intraoperative kinematics in each group, to obtain the clue for post operative deep-flexion. The measurements of intraoperative kinematics were consisted of 3 points: femoral rotation angle (degree) and antero-posterior translation (mm), which were measured as the translation of the lowest points of femoral component to tibial cutting surface, and the joint gap difference between the medial and lateral components gap (mm). All joint kinematic data were recorded at every 10 degrees of flexion from maximum extension to flexion under anesthesia.Purpose
Materials & methods
Mobile-bearing (MB) total knee prostheses have been developed to achieve lower contact stress and higher conformity compared to fixed-bearing total knee prostheses. However, little is known about the in vivo kinematics of MB prostheses especially about the kinematics of polyethylene insert (PE). In vivo motion of PE during squatting still remains unclear. The objective of this study is to investigate the in vivo motion of MB total knee arthroplasty including PE during squatting. We investigated the in vivo knee kinematics of 11 knees (10 patients) implanted with Vanguard Rotationg Platform High Flex (Biomet(r)). Under fluoroscopic surveillance, each patient did a wight-bearing deep knee bending motion. Motion between each component was analyzed using two- to three-dimensional registration technique, which uses computer-assisted design (CAD) models to reproduce the spatial position of the femoral, tibial components, and PE (implanted with five tantalum beads intra-operatively) from single-view fluoroscopic images. We evaluated the range of motion between the femoral and tibial components, axial rotation between the femoral component and PE, the femoral and tibial component, and the PE and tibial component, and AP translation of the nearest point between the femoral and tibial component and between the femoral component and PE.Background
Patients and methods
The purpose of this study is to prove whether Japanese patients undergoing primary total hip arthroplasty (THA) for the hip dysplasia were able to return to sport after surgery. A questionnaire survey was completed by 77 patients in 9 males and 68 females between 1 and 3 years after surgery. Mean age at surgery was 66.1 (range, 49 to 87). In the 3 years before surgery 40 (51.9%) patients were participating in sport. By 1 to 3 years after surgery 43 (55.8%) patients were participating in sport. A total of 33 (82.5%) had returned to their sporting activities by 1 to 3 years after surgery in groups who played sports before surgery and 7 (17.5%) were unable to do with the most common reason being “cannot move as much as I wanted”. On the other hand, a total of 10 (27%) had started playing sports after surgery. The sports activities after surgery were the most common being walking, radio calisthenics, and swimming as low-impact sports. A total of 27 (73%) did not play sports before or after surgery with the most common reason being “fear of damage to the hip joint”. In conclusion, when Japanese patients who have undergone THA for hip dysplasia choose to participate in sports, orthopedic surgeons should provide information with which to evaluate the risk of sports activity and recommend appropriate sports activity.
