We have been re-evaluating patellofemoral alignment after total knee arthroplasty (TKA) by using a weight- bearing axial radiographic view after detecting patellar maltracking (lateral tilt > 5° or lateral subluxation > 5 mm) on standard non-weight-bearing axial radiographs. However, it is unclear whether the patellar component shape affects this evaluation method. Therefore, we compared 2 differently shaped components on weight-bearing axial radiographs. From 2004 to 2013, 408 TKAs were performed with the same type of posterior-stabilized total knee implant at our hospital. All patellae were resurfaced with an all-polyethylene, three-pegged component to restore original thickness. Regarding patellar component type, an 8-mm domed component was used when the patella was so thin that a 10-mm bone cut could not be performed. Otherwise, a 10-mm medialized patellar component was selected. Twenty-five knees of 25 patients, in whom patellar maltracking was noted on standard axial radiographs at the latest follow-up, were included in this study. Knees were divided into 2 groups: 15 knees received a medialized patella (group M) while 10 received a domed patella (group D). Weight-bearing axial radiographs with patients in the semi-squatting position were recorded with the method of Baldini et al. Patellar alignment (tilt and subluxation) was measured according to the method described by Gomes et al. using both standard and weight-bearing axial views.Introduction
Methods
Surgical site infection (SSI) is associated with substantial morbidity, mortality and economic burden. Management of spinal SSI is becoming more challenging especially in instrumented cases, but is not well recognized as high risk procedure. The objective of this study was to determine the impact of procedure type comparing SSI risk with arthroplasties among all orthopaedic procedures. Using prospectively collected data of consecutive samples in multi-center orthopedic SSI surveillance, we explored the differences in SSI rates within 30 days after surgery by procedure types. Patients who underwent surgery of single site between November 2013 and May 2016 were enrolled. SSI was our primary outcome. Urinary tract infection (UTI), and respiratory tract infection (RTI) were also evaluated. The definition of SSI was based on the CDC definition with slight modifications. All patients were followed for 30 days postoperatively. Multivariate logistic regression analyses were done, and variables were carefully selected for adjustments.Aim
Method
CT-based navigation system in total hip arthroplasty (THA) is widely used to achieve accurate implant placement. Now, we developed our own CT-based navigation system originally, and since then we have been conducting various analysis in order to use the system more effectively. We compared the accuracy of registration with this navigation system and land mark matching type navigation system. In this study, we evaluated the influence of the surgical approach to the accuracy of registration. Between June 2015 and February 2016, 28 consecutive uncemented THAs were performed in 26 patients. The preoperative diagnosis was osteoarthritis in 20 hips, osteonecrosis of the femoral hips in 5, and rheumatoid arthritis in 3. The newly developed navigation system was a CT based, surface matching type navigation system. We used newly developed navigation system and commercially available land-mark type CT-based navigation system in the setting of acetabular sockets under the same condition. After we fixed the cementless cup, we measured the cup setting angle of inclination and anteversion on each navigation system. Postoperative assessment was performed using CT one week after the operation, and measured the actual angle of the cup. Approach of operations were performed via posterolateral approach in 14 hips, and Hardinge approach in 14 hips. We calculated the absolute value of the cup angle difference between intra-operative value and post-operative value with each navigation system and compared the accuracy between each navigation system and surgical approach.Introduction
Methods
Few reports were shown about the position of the cup in total hip arthroplasty (THA) with CT-based navigation system. We use minimally invasive surgery (MIS) technique when we perform cementless THA and the correct settings of cups are sometimes difficult in MIS. So we use CT-based navigation system for put implants with correct angles and positions. We evaluated the depth of cup which was shown on intra-operative navigation system. We treated 30 hips in 29 patients (1 male and 28 females) by navigated THA. 21 osteoarthritis hips, 6 rheumatoid arthritis hips and 3 idiopathic osteonecrosis hips were performed THA with VectorVision Hip navigation system (BrainLAB). Implants were AMS HA cups and PerFix stems (Japan Medical Materials, Osaka). Appropriate angles and positions of cups were decided on the 3D model of pelvis before operation. According to the preoperative planning, we put the implants with navigation system. We correct the pelvic inclination angle and measured the depth of cups with 3D template software.Objectives
Materials and Methods
When we perform total knee arthroplasty (TKA), the accurate osteotomy and implant setting is important as follows to improve long-term results. As means to perform osteotomy exactly, patient specific surgical instruments (PSI) patient specific surgical instruments planning based on pre-operative MRI (Signature, Materialise) and Image-free navigation system (Navi: Knee unlimited; BrainLAB) exist. However, there is not the report to compare which is exact for the same patient at the same time using two methods. We report to compare the osteotomy plans by two methods. Nine cases of TKA (Vanguard Complete Knee System, PS, BIOMET) operated on by one operator in our hospital from October 2012 to September 2013. 78.0 years average age (71–81 years old), sex was 6 cases women, 3 men.Purpose
Materials
Overstuffing the patellofemoral joint during total knee arthroplasty (TKA) is considered a potential cause of limited knee flexion and patellar maltracking. We investigated the effect of patellar thickness on intraoperative knee flexion and patellar tracking in navigated TKA. Twenty osteoarthritic knees (20 patients) were investigated in this study. Knees with valgus deformity were excluded. The same posterior stabilized prosthesis was employed in all the 20 cases. Preoperative patellar thickness was measured using a caliper, and patellar resection was performed to restore the native thickness by placing a standard 10-mm-thick trial patella. After placement of all trial components, maximal flexion against gravity was measured using a navigation system. The trial patella was also assessed for tracking, with and without suturing of the medial capsule (the “three-stitch” test and no-thumb test, respectively). Subsequently, 2-mm and 4-mm augmentations were applied to the standard trial patella, and the aforementioned measurements and assessments were repeated.Introduction
Methods
Several reports suggest that low-intensity pulsed ultrasound stimulation (LIPUS) facilitates chondrogenesis1). Recently it has been suggested that LIPUS may be transmitted via Integrin: a protein which mediates cellular attachment between cells and extracellular matrix2). In this study, the Arg-Gly-Asp (RGD) amino acid sequence, which is a ligand of Integrin, was induced to the fibroin substrates by either gene transfer or physical mixing, and the variation of chndrocyte response to LIPUS was evaluated. Three kinds of culture dishes coated with three diffrent fibroin aqueous solutions were prepared: 1 wild-type, 2 transgenic and 3 mixed. The wild-type aqueous solution was prepared from INTRODUCTION
EXPERIMENTAL METHODS
