The posterolateral overhang of the femoral component was measured using 3-D templating software. Rounded and reduced shape of the posterolateral corner in the femoral component would be beneficial. In total knee arthroplasty, patients sometimes have pain in the posterolateral part of the knee. One possible cause is the impingement of the popliteus tendon against femoral components. In the literature, the incidence has been reported to be 1–4%. The purpose of this study was to compare of two prostheses on the amount of posterolateral overhang of the femoral component using Three-dimensional (3-D) templating software.Summary
Introduction
Constrained condylar knees are used infrequently but are successful for the treatment of the primary or revision knee with ligamentous instability and bony defect. The purpose of the present study is retrospectively analyze clinical and radiological outcome of primary and revision total knee arthroplasty with condylar constrained knee (CCK) prosthesis at a minimum of 5 years. Fourteen knees underwent total knee arthroplasty with CCK prosthesis, performed between 2003 and 2009. The average age of the patients at the time of the surgery was 71.4 years (range, 47 to 88 years). The reason for the operation was primary (osteoarthritis) in 2, revision due to aseptic loosening in 9 and infection after total knee arthroplasty in 4 knees. NexGen LCCK was used in all cases. The mean follow-up period was 91months (range, 60 to 128 month).Background
Methods
In the case of bipolar hemiarthroplasty, surgeons are often faced with only migration of outer head and severe osteolysis in acetabulum without loosening of femoral component. There has been much debate regarding the merits of removing or retaining stable femoral components in such cases. The purpose of this study was to determine whether revision of an isolated acetabular component without the removal of a well-fixed femoral component [Fig. 1] could be successfully performed. Thirty-four hips of 33 patients who were followed up for a minimum of 1 year were examined. There were 29 women and 4 men. The average time from primary operation to revision surgery was 12.5 years (range, 0.0 to 17.9 years), and the average follow-up time after revision was 5 years (range, 1.1 to 15.2 years). The average age of the patients at the time of the index revision was sixty-four years (range, thirty-two to seventy-eight years). The reason for acetabular revision was migration of outer head in twenty-eight hips, disassembly of bipolar cup in four hips and recurrent dislocation in two hips. Of the thirty-four femoral components, twenty-seven were cementless and seven were cemented. In nine hips, we performed bone grafting to osteolysis of the proximal femur around the stem. Acetabular components were revised to an acetabular reinforcement ring with a cemented cup in 26 hips, to cementless acetabular components in 8 hips, and to cemented cup in 1 hip.Introduction
Materials and methods
In total knee arthroplasty, patients sometimes have pain in the posterolateral part of the knee. One possible cause is the impingement of the popliteus tendon against femoral components. In the literature, the incidence has been reported to be 1–4%. The purpose of this study is to quantify the amount of posterolateral overhang of the femoral component using 3-D templating software. We investigated 40 knees with varus osteoarthritic knees (Male 6 knees and Female 34 knees), all cases were grade 2 or lower in Kellgren Lawrence classification. Three-dimensional preoperative planning software was used to simulate the replacement of femoral component. The distal femur was simulated to cut 9 mm thickness on the lowest point of the medial condyles with 6 degrees valgus. The femoral mediolateral axis was simulated to be parallel to the surgical epicondylar axis. The size of femoral components was decided by anteroposteriol dimension of distal femur. Mediolateral location of the femoral component was that the lateral edge of the femoral components is just on the lateral cortex of the femur. In coronal plane, amount of M-L overhang of the femoral component was measured in 3 Zones (distal, proximal, center) on the surface of the posterior condyle cut (Figure 1).Introduction
Methods
Restoration of joint line in total knee arthroplasty (TKA) is important for kinematics of knee and ligamentous balance. Especially in revision TKA, it may be difficult to identify the joint line. The aim of this study is to define the relationship between epicondyles and articular surface using CT based three-dimensional digital templating sofware $“Athena” (Soft Cube, Osaka, Japan). 137 knees with osteoarthritis, all caces were grade 2 or lower in Kellgren-Lawrence index, were investigated. Perpendicular lines were dropped from the prominences of the medial and lateral femoral epicondyles to the most distal points of articular surfaces and distances of the lines were measured on the axial and coronal planes. The femoral width was measured as the distance between medial and lateral epicondyles. Each of the distance described above was converted to a ratio by dividing by the femoral width. On the axial plane, the average distance from epicondyles to the posterior articular surfaces were 29.4±2.2mm on the medial side and 21.2±2.3mm on the lateral side. The average of the femoral width was 75.2±4.1mm. On coronal plane, the average distance from epicondyles to the distal articular surfaces were 25.2±2.8mm on the medial side and 21.4±2.5mm on the lateral side. The ratio for the distance from epicondyles to the distal and posterior joint line compared to femoral width was 0.39±0.02, 0.28±0.03, 0.33±0.03 and 0.28±0.03. The distance from epicondyles to the distal and posterior joint line correlates with the femoral width of the distal femur. This information can be useful in determining appropriate joint line.
Achieving deep flexion of knee after total knee arthroplasty (TKA) is particularly desirable in some Asian and Middle Eastern who have daily or religious customs typically use full knee flexion. After TKA, some patients complained about anterior knee pain during deep knee flexion. We evaluated the efficacy of arthroscopic fat pad resection in a series of patients suffering from anterior knee pain associated with high flexion achievement after TKA. The efficacy of fat pad resection via arthroscopy for treating anterior knee pain associated with high flexion angle (average = 133.1°) was evaluated in eight knees of eight patients among 207 knees performed between 1996 and 1999. The mean age of patients was 71.1 years when the primary TKA was performed. All implatants were posterior stabilized type (IB-II, Nexgen PS and LPS). The symptom of anterior knee pain during deep knee flexion developed within one year after TKA in all cases. In addition to pain in eight knees, two patients have crepitation as the knee was flexed and extended and three patients had hydrarthrosis. Impingement and fibrosis of fat pad were confirmed, and fibrous structures were removed by arthroscopy. Before arthroscopy, the symptom obviously subsided after injection of local anesthesia into infrapatellar fat pad. Patellar clunk syndrome is also soft tissue impingement and suprapatellar fibrous nodule becomes entrapped intercondylar notch on the femoral component during knee flexion. On this point, these cases does not cause by patellar clunk syndrome. After fat pad resection, the symptom disappeared, and keeps symptom-free after a mean follow-up of six years five months in all cases. Any complications following fat pad resection, such as patella baja and necrosis, were not experienced. Those cases achieving higher flexion angle tended to experience severe pain and shorter time interval between TKA and arthroscopic surgery, suggesting impingement of the infrapatellar fat pad is closely related to deep flexion after TKA. These results demonstrate that the anterior knee pain due to repetitive infrapatellar fat pad impingement is one of the complications during deep knee flexion after TKA, and the arthroscopic fat pad resection is useful to relief the anterior knee pain. Because of our experience with patients encountering anterior knee pain, we have begun to remove 70 to 80% of the fat pad during the primary TKA procedure since 1999, and until today, none developed anterior knee pain thought to be associated with fat pad impingement, patellar baja nor patellar necrosis. We suggest that fat pad resection is necessary to prevent the anterior knee pain due to fat pad impingement during deep flexion in TKA.
Venous thromboembolism (VTE) is a frequent, life-threatening postoperative complication of orthopaedic surgery. Preoperative autologous blood donation has been advocated to reduce the risk of transfusion reactions and to limit potential infectious risk associated with donor blood. Experimental data suggest that autologous leukocytes might lead to immunomodulation similar to the effect attributed to allogenic leukocytes, but autologous whole blood (WB) is often still being used in Japan. We investigated the incidence rate of VTE and plasma D-dimer levels of the autologous WB transfusion and compared the findings with autologous red cell concentrates (RCC) and fresh frozen plasma (FFP) with regard to the cases of lower extremity arthroplasty. The subjects of this study were 138 patients with lower extremity arthroplasty who were scheduled to receive surgery. The operations included 72 total hip arthroplasties (THA) and 66 total knee arthroplasties (TKA). Postoperatively, plasma D-dimer levels were measured latex agglutination turbidimetric immunoassay. Ultrasonography and contrast-enhanced helical computed tomography was used for diagnosing VTE. There was no statistically significant difference in the post-surgery incidence rate of VTE between the autologous WB group (THA:20.0%, TKA: 27.9%) and autologous RCC/FFP group (THA: 11.9%, TKA: 30.4%). On the first post-surgery day, the plasma D-dimer levels were significantly higher in autologous WB group (THA: 8.1±9.5 μg/ml, TKA: 12.1±15.9 μg/ml) compared to the autologous RCC/FFP group (THA: 4.2±2.9 μg/ml, TKA:8.0±6.6 μg/ml). However, the plasma D-dimer levels were almost the same in both groups on the 14th day from the surgery. The results of this study suggest that donation and transfusion of autologous WB do not negatively influence the post operative VTE compared with autologous RCC/FFP. However, we must cautiously assess the plasma D-dimer levels of the autologous WB group on the first post-surgery day because of the high propensity of showing false positive rate compared to the RCC/FFP group.
To make rectangular flexion and extension gap is an important goal in total knee arthroplasty (TKA). The purpose of this study was to determine the AP and rotational position of the femora component to obtain rectangular flexion with reference to the anatomical landmarks. One hundred and twenty seven varus osteoarthritic knees (87 patients) undergoing TKA from June 2004 to March 2006 were included (72 women and 15 men, mean age 74.4 years). All operations were performed with Vanguard PS, Biomet (Warsaw, IN U.S.A.). The position of femoral component was determined using a modified Ranawat block (Equiflex™) to obtain the rectangular flexion gap equal to extension gap. This instrument uses the balanced soft tissue sleeve in extension as a guide to create a balanced flexion gap. The flexion gap asymmetry after TKA was evaluated as the angle between the posterior condylar axis (PCA) and the tibial cutting line (TCL) by axial radiography of the distal femur. ( The asymmetry of the flexion gap was 1.6±2.4° with slight laxity in the lateral side. The average amount of external rotation of the femoral component relative PCA was on 6.2 ±2.5°. The thickness of resected bone from the posterior lateral and medial condyles were 4.7 ± 2.1 mm and 8.6 ±2.1 mm respectively. The results of this study have shown that, for a well-balanced flexion gap, femoral component should be excessively rotated by 3 degrees compared to current recommendation (Parallel to SEA) As for the AP position, the average amount of medial bone resection is equal to the implant thickness (9 mm). This information is useful for the modification of measured resection technique to obtain rectangular flexion gap.
an osteotomy 10mm proximal to the calcaneocuboid joint line and an osteotomy performed adjacent to the posterior calcaneal facet.
