Hydroxyapatite and poly-L-lactide (HA/PLLA) composites are osteoconductive and biodegradable. They have already been used clinically to treat fractured bones by inducing osteosynthesis and serving as the bone filling material. During revision of total hip arthroplasty, we have grafted bone onto the bone defect and covered it with an HA/PLLA mesh instead of using a metal mesh on the non-load bearing portion of the cup (Figure 1). However, whether the interface between the HA/PLLA and the titanium alloy cup was stable remains unclear. The purpose of this study was to determine and compare the histological osteoconductivity and osteoinductivity of HA/PLLA and titanium alloy.Introduction
Objectives
Migration of the trial femoral head is a rarely occurring complication of total hip arthroplasty (THA) performed using the anterolateral approach (ALA). This migration of the trial femoral head under the rectus femoris is extremely risky because of the anatomical situation. Analyzing the morphological character of a case of migration may help us to avoid this risk. We analyzed the three-dimensional bone morphology using computed tomography (CT) scan images to investigate the physiological characteristics of five migration cases.Introduction
Objective
The initial stress distribution in the femur after total hip arthroplasty (THA) influences the remodeling of the bone and the clinical results. We conducted thermoelastic stress analysis to evaluate the surface stress distribution in femurs after THA in vitro and elucidated the changes in the stress distribution that were due to the stem design. Using this method, we can analyze the change in the sum of the principal stresses on the basis of the changes in temperature at the bone surface and visualize the change three-dimensionally. We compared the thermoelastic stress analysis results with the clinical results of specially shaped stems that have two flanges, one anterior and one posterior.Introduction
Objectives
Venous thromboembolisms are serious complications of arthroplasty of the lower extremities. Although early ambulation and active leg exercise is recommended, postoperative patients with surgical pain have difficulty in moving their legs. Therefore, we developed a novel leg exercise apparatus (LEX) to facilitate active leg movement even during the early postoperative period (Fig 1). LEX is a portable apparatus that allows patients to actively move their legs while in the supine position. LEX enables dorsiflexion, plantar flexion, combined eversion and inversion of the ankle, and multi-joint movement of the leg. To describe how LEX facilitates active movement of the leg and thereby increases venous flow in the lower extremities.Background
Objectives
The goal of joint-preserving surgery for the treatment of osteonecrosis of the femoral head (ONFH) is to delay or prevent osteoarthritic development. Bone marrow is a source of osteogenic progenitors that are key elements in the process of bone formation and fracture healing. We established an easy-to-use method using a conventional manual blood bag centrifugation technique traditionally used for extracting buffy coats, for concentration of nucleated cells and platelets from clinical bone marrow aspirates to obtain osteogenic progenitors and growth factors. However, it is unclear whether the surgical goals are really achieved and if so in which patients. The purpose of this study was to identify demographic, clinical, and radiographic factors predicting total hip arthroplasty (THA) conversion after CABMAT for the treatment of idiopathic ONFH. We retrospectively reviewed 123 patients (213 hips) who had CABMAT between 2003 and 2010. Sixty-five subjects (115 hips) were male and 58 (98 hips) were female with an average age at the time of CABMAT of 40.1 years. Of the 213 hips, 143 hips in 78 patients had corticosteroid-induced ONFH, 46 hips in 27 patients had alcohol-associated, and 24 hips in 18 patients had no etiological factors could be detected. The mean follow-up period was 60.5 months. The endpoint of evaluation was set as the time point which the patient required additional surgery (THA) depending on the spontaneous hip pain, x-ray change, and social back ground. The following factors were investigated: age, sex, body mass index (BMI), unilateral or bilateral, etiological factors, preoperative classification and staging, visual analogue scale (VAS), JOA clinical score. The 213 hips were divided into two groups: a THA conversion (THA) group and a non-THA conversion (non-THA) group. A multivariate analysis was performed using a logistic regression model.Introduction
Methods
We used three-dimensional software to assess different anatomic variables in the femur. The canal of Femur twisted slightly below the lesser trochanter in cases with a larger angle of anteversion. Accurate positioning of the joint prosthesis is essential for successful total hip arthroplasty (THA). To aid in tailoring of the prosthesis, we used three-dimensional software to assess different anatomic variables in the femur.Summary Statement
Introduction
We have previously shown that joint distraction and movement with a hinged external fixation device for 12 weeks was useful for repairing a large articular cartilage defect in a rabbit model. We have now investigated the results after six months and one year. The device was applied to 16 rabbits who underwent resection of the articular cartilage and subchondral bone from the entire tibial plateau. In group A (nine rabbits) the device was applied for six months. In group B (seven rabbits) it was in place for six months, after which it was removed and the animals were allowed to move freely for an additional six months. The cartilage remained sound in all rabbits. The areas of type II collagen-positive staining and repaired soft tissue were larger in group B than in group A. These findings provide evidence of long-term persistence of repaired cartilage with this technique and that weight-bearing has a positive effect on the quality of the cartilage.
