As the aging society progresses rapidly, the number of patients underwent total knee arthroplasty (TKA) is increasing especially for the elderly population. In Japan, the average age for TKA is around 75 years old. Japanese Orthopaedic Association indicated a new clinical entity of musculoskeletal ambulation disability symptom complex (MADS) to define the higher risk of fall and ambulatory disability in the elderly population in 2006. The diagnosing criteria for MADS consists of 2 simple performance tests. 3m timed up and go test (TUG) evaluates ambulatory function, and one leg standing time (ST) assesses balancing ability. In this study, we analyzed the effect of TKA on the ambulatory function by quantitative measurement using 2 simple performances test: TUG and ST.Introduction
Objective
To achieve well aligned and balanced knee is essential for the post-operative outcome in total knee arthroplasty (TKA). Gap balancing technique can adjust the bone cut depending on the soft tissue balance in addition to soft tissue releases. Therefore, gap balancing technique would be more advantageous in soft tissue balance comparing to measured resection technique (MRT) in which soft tissue balancing relayed on soft tissue releases alone. Nevertheless, the influence of surgical technique on the post-operative knee stability has not been fully investigated. We introduced a new surgical technique (medial gap technique: MGT) according to modified gap technique regarding medial knee stability as important. The intra-operative soft tissue balance and post-operative knee stability were compared between MGT and MRT in posterior-stabilized (PS) TKA for varus type osteoarthritic knees.Introduction
Objective
Many factors can influence post-operative kinematics after total knee arthroplasty (TKA). These factors include intraoperative surgical conditions such as ligament release or quantity of bone resection as well as differences in implant design. Release of the medial collateral ligament (MCL) is commonly performed to allow correction of varus knee. Precise biomechanical knowledge of the individual components of the MCL is critical for proper MCL release during TKA. The purpose of this study was to define the influences of the deep medial collateral ligament (dMCL) and the posterior oblique ligament (POL) on kinematics in TKA. This study used six fresh-frozen cadaveric knees with intact cruciate ligaments. All TKA procedures were performed by the same surgeon using CR-TKA with a CT-free navigation system. Each knee was tested at 0°, 20°, 30°, 60°, and 90° of flexion. One sequential sectioning sequence was performed on each knee, beginning with femoral arthroplasty only (S1), and thereafter sequentially; medial half tibial resection with spacer (S2), ACL cut (S3), tibial arthroplasty (S4), release of the dMCL (S5), and finally, release of the POL (S6). The same examiner applied all external loads of 10 N-m valgus and 5 N-m internal and external rotation torques at each flexion angle and for each cut state. The AP locations of medial and lateral condyles were determined as the lowest point on each femoral condyle. All data were analyzed statistically using paired t-test. A significant difference was determined to be present for P < .05.Introduction
Materials and Methods
The goal of total knee arthroplasty (TKA) is to achieve a stable and well-aligned tibiofemoral and patello-femoral (PF) joint, aiming at long-term clinical patient satisfaction. The surgical principles of both cruciate retaining (CR) and posterior stabilized (PS) TKA are accurate osteotomy and proper soft tissue balancing. We have developed an offset-type tensor, and measured intra-operative soft tissue balance under more physiological joint conditions with femoral component in place and reduced PF joint. In this study, we measured intra-operative soft tissue balance and assessed the post-operative knee joint stability quantitatively at one month, six months and one year after surgery, and compared these parameters between CR and PS TKAs. Sixty patients with varus osteoarthritis of the knee underwent TKAs (30 CR TKAs: CR and 30 PS TKAs: PS). Mean varus deformity in standing position was 11.1 degrees in CR, and 12.6 degrees in PS. All TKAs were performed by a single surgeon with measured resection technique. The external rotation of posterior femoral condyle osteotomy was performed according to surgical epicondylar axis in pre-operative CT. We measured intra-operative soft tissue balance using an offset-type tensor with 40 lbs of joint distraction force at 0, 10, 30, 45, 60, 90, 120 and 135 degrees of flexion. The joint component gap (mm) and varus angle (degrees) were measured at each flexion angles. One month, six months and one year after surgery, we evaluated the knee stability at extension by varus and valgus stress radiography using Telos (10kg) and at flexion by epicondylar view with 1.5kg weight at the ankle. We measured joint separation distance at medial as medial joint looseness (MJL) and at lateral as lateral joint looseness (LJL). Intra-operative measurements and post-operative joint stabilities were compared between CR and PS using unpaired t-test. The change of joint looseness in each group was analyzed using repeated measures ANOVA.Objective
Material and Method
Pulmonary emboli (PE) after total hip and knee arthroplasties is an uncommon event. However, once it happens, it may results in sudden death. Thus, the prophylaxis of venous thromboembolism (VTE), including symptomatic deep vein thrombosis (DVT) and PE, is one of the challenging trials for Orthopaedic surgeons. Many procedures have been developed, e.g. early mobilization, compression stocking, intermittent pneumatic compression (IPC) devices, and anticoagulation agents. However, the most effective treatment for prophylaxis against VTE after the arthroplasties remains undecided. Recently, many low molecular weight heparin (LMWH) agents are developing, and these are strongly effective for anticoagulation. However, these agents sometimes lead to bleeding complications, and result in uncontrolled critical bleeding. We are introducing our protocol with conventional aspirin as VTE prophylaxis after the arithroplasties. All patients prior to the surgeries are evaluated laboratory and duplex venous ultrasonography examinations to exclude thrombophilic or hemophilic conditions, and existence of DVT. Then, the thrombophilic, and also prolonged immobility, obesity, malignant tumors, cardiovascular dysfunction and DVT patients are regarded as high risk for VTE. These are offered a prophylaxis consisting of a removable inferior vena cava (IVC) filter, together with anticoagulant medication. Usually, the filter is removed three months after the surgery. In other patients, the arthroplasties are carried out under the spinal or epidural anesthesia with IPC on both feet. IPC is also applied, except for the periods of ambulation, usually two to three days of hospitalization after surgery. Full weight bearing ambulation with a walker is allowed on post-op day one. Patients receive aspirin (acetylsalicylic acid) 325 mg daily for six weeks starting the night of surgery. Pain is controlled with celecoxib (COX-2 selective nonsteroidal anti-inflammatory drug) 400 mg daily, and oral narcotics for break through pain. Before discharge, usually within three days post surgery, all patients are evaluated DVT by duplex venous ultrasonography. The incidence of blood loss, wound complications, and subcutaneous ecchymosis are recorded.Introduction
Patients and methods
Appropriate osteotomy alignment and soft tissue balance are essential for the success of total knee arthroplasty (TKA). The management of soft tissue balance still remains difficult and it is left much to the surgeon's subjective feel and experience. We developed an offset type tensor system for TKA. This device enables objective soft tissue balance measurement with more physiological joint conditions with femoral trial component in place and patello-femoral (PF) joint reduced. We have reported femoral component placement decreased extension gap. The purpose of the present study was to analyze the influence of femoral component size selection on the decrease of extension gap in posterior-stabilized (PS) TKA. 120 varus type osteoarthritic knees implanted with PS TKAs (NexGen LPS flex: Zimmer) were subjected to this study. All TKAs were performed using measured resection technique with anterior reference. The femoral component size was evaluated intra-operatively using conventional femoral sizing jig. The selected femoral component size was expressed by the antero-posterior (AP) size increase (mm) comparing to that of original femoral condyles. Gap measurements were performed using a newly developed offset type tensor device applying 40lbs (178N) of joint distraction force. Firstly, conventional osteotomy gaps (mm) were measured at extension and flexion. Secondary, component gaps (mm) after femoral trial placement with PF joint reduced were evaluated at 0° and 90° of knee flexion. To compare conventional osteotomy gaps and component gaps, estimated extension and flexion gaps were calculated by subtracting the femoral component thickness at extension (9mm) and flexion (11mm) from conventional osteotomy gaps respectively. The decrease of gap at extension and flexion were calculated with estimated gaps subtracted by component gaps. The simple linear regression analysis was used to evaluate the influence of selected femoral component size on the decrease of gap after femoral component placement.Introduction
Material & Method
Femoral neck fracture is a common injury in elderly patients. To restore the activity with an acceptable morbidity and to decrease of mortality, surgical procedures are thought to be superior to conservative treatments. Osteosynthesis with internal fixation for nondisplaced type, and hemiarthroplasty or total hip replacement (hip arthroplasties) for displaced type are commonly performed. Cemented arthroplasty has been preferred over non-cemented arthroplasty because of less postoperative pain, better mobility and excellent initial fixation of the implant, especially for osteoporotic and stove-pipe bones. However, pressurizing bone cement may cause cardiorespiratory and vascular complications, and occasionally death, which has been termed as “bone cement implantation syndrome”. To avoid the occurrence of this syndrome, non-cemented implants have been developed. However, most implants with the press fit concepts and flat wedge taper designs have a risk of intraoperative and early postoperative periprosthetic fracture. Recently, we have employed a non-cemented femoral component, which has a lateral expansion to the proximal body as compared to a conventional hip stem. Because of this shape, which is called a “lateral flare”, this stem provides a physiological loading on both the medial and lateral endosteal surfaces of the femur. This is in contrast to conventional hip stem which prioritizes loading on the medial and metaphyseal /dyaphyseal surfaces of the femur. Moreover, the cross section of this stem is trapezoid with the flat posterior surface. This shape provides the stem with rotational stability along the long axis of the femur, and maximizes loading transfer to the posterior aspect of the proximal femur. These mechanical features avoid the need for aggressive impaction of the stem at the time of insertion. It is necessary to only tap gently to achieve the secure initial implant fixation by a “rest fit”. Thus, this technique reduces the risk of fracture. We employed this technique using a non-cemented lateral flare design device for displaced femoral neck fractures since 1996. Surgical procedures were performed with posterior approach under the spinal or epidural anesthesia. Full weight bearing ambulation with a walker was allowed on post-op day one.Introduction
Patients and methods
The goal of total knee arthroplasty (TKA) is to achieve a stable and well-aligned tibiofemoral and patello-femoral (PF) joint, aiming at long-term clinical patient satisfaction. The surgical principles of both cruciate retaining (CR) and posterior stabilized (PS) TKA are accurate osteotomy and proper soft tissue balancing. We have developed an offset-type tensor, and measured intra-operative soft tissue balance under more physiological joint conditions with femoral component in place and reduced PF joint. In this study, we measured intra-operative soft tissue balance and assessed the early post-operative knee joint stability quantitatively, and compared these parameters between CR and PS TKA. Seventy patients with varus osteoarthritis of the knee underwent TKAs (35 CR TKAs: CR and 35 PS TKAs: PS). Mean varus deformity in standing position was 9.8 degrees in CR, and 10.7 degrees in PS (p = 0.45). All TKAs were performed by a single surgeon with measured resection technique. The external rotation of posterior femoral condyle osteotomy was performed according to surgical epicondylar axis (SEA) in pre-operative CT. We measured intra-operative soft tissue balance using an offset-type tensor with 40 lbs of joint distraction force at 0, 10, 30, 45, 60, 90, 120 and 135 degrees of flexion. The joint component gap (mm) and varus angle (degrees) were measured at each flexion angle. Four weeks after operation, we evaluated the knee stability at extension by varus and valgus stress radiography using Telos (10 kg) and at flexion by epicondylar view with 1.5 kg weight at the ankle. We measured joint separation distance at medial as medial joint looseness (MJL) and at lateral as lateral joint looseness (LJL). Joint looseness was defined as the average of MJL and LJL. Intra-operative measurements and post-operative joint stabilities were compared between CR and PS using unpaired t-test.Objective
Material and Method
Tip apex distance (TAD) is reported as a predictor for cut outs of lag screws in the treatment of intertrochanteric fractures, and surgeons are adviced to strive for TAD within 20 mm. However the definition of neck axis and the limb position of lateral radiograph are not clearly described in the original literature. We propose the refined TAD by defining these factors. The objective of this study was to analyze the interobserver agreement of this refined TAD. X rays of 130 cases of unstable trochanteric fractures were used for the analysis of the refined TAD. In the refined TAD, neck axis was defined as the line between the center of femoral head and midpoint of narrowest part of the femoral neck, and lateral radiograph was taken with hip flexion 90 degrees and abduction 45 degrees. The refined TAD was independently measured by 2 experienced (observer 1,2) and 2 inexperienced (observer 3,4) orthopaedic surgeons who were trained with the new method before the measurement. Intraclass correlation coefficient (ICC [2,4]) was calculated to assess the interobserver agreement.Introduction
Materials and Method
Since 2005, we have performed implantation of bone marrow-derived mononuclear cells for osteonecrosis of the femoral head in order to improve vascularization and bone repair. This study focused on early bone repair of osteonecrosis of the femoral head after transplantation of bone marrow-derived mononuclear cells (BMMNC). Twenty-two patients (30 joints) who had bilateral osteonecrosis followed for more than 2 years after BMMNC implantation were evaluated. Eight women and 14 men were included. Their mean age at surgery was 41 years (range, 18 to 64 years) and the mean follow-up period was 31 months. Pre-operative stage according to the ARCO classification was Stage 2 in 25 joints and Stage 3 in 5 joints. The mean volume ratio of osteonecrosis was 21%. For preparing BMMNC, about 700ml of bone marrow was aspirated from the ilium and centrifuged using a Spectra cell separator (Gambro). The BMMNC were seeded to interconnected porous calcium hydroxyapatite (IP-CHA) and implanted to the osteonecrotic lesion. As a control, cell-free IP-CHA was implanted for 8 patients (9 joints). A woman and 7 men were included. The mean age at surgery was 49 years (range, 28 to 73 years) and the mean follow-up period was 37 months. Preoperative stage was stage 2 in all patients. The mean volume ratio of osteonecrosis was 22%. At post-operative evaluations; progression of collapse, consolidation at reactive zone, post-operative course of volume rate of osteonecrosis, and bone absorption at osteonecrosis was assessed.Introduction
Patients and Methods
We used interconnected porous calcium hydroxyapatite ceramic to bridge a rabbit ulnar defect. Two weeks after inducing the defect we percutaneously injected rabbit bone marrow-derived mesenchymal stromal cells labelled with ferumoxide. The contribution of an external magnetic targeting system to attract these cells into the ceramic and their effect on subsequent bone formation were evaluated. This technique significantly facilitated the infiltration of ferumoxide-labelled cells into ceramic and significantly contributed to the enhancement of bone formation even in the chronic phase. As such, it is potentially of clinical use to treat fractures, bone defects, delayed union and nonunion.
