However, optimal duration for CFNB to decrease pain and accelerate rehabilitation program after TKA has not been addressed. We, therefore, compared three groups of patients which had different duration of CFNB (0, 2, and 5days) in this study.
Outcomes including visual analog scale (VAS) pain scores and range of motion (ROM) were compared at 1st, 3rd, 6th, 14th and 21th days after surgery. In addition, the postoperative date when patients could walk stably with parallel bar, walker, or T-cane were recorded and compared.
ROM did not show significant difference among the three groups over postoperative days 1st to 21st (P>
0.05), although groups with the CFNB showed greater ROM at all time points. The CFNB 5 days group obtained stable walking ability with T-cane earlier than other groups (P<
0.05). No patient had any side effect by having CFNB in this study.
Ring frames have the advantage of allowing progressive correction. However, the available frames for complex deformities are heavy and bulky leading to poor compliance by patients. Also, the mounting procedure requires considerable expertise and skill. On the other hand, a unilateral external fixator has the advantages of less bulk and a lighter weight. Thus, it causes less disability and can achieve better patient compliance even with bilateral application. However, previous unilateral fixators have had various limitations with respect to deformity correction, such as restricted placement of hinges, restricted correction planes, and a limited range of correction angles. In addition, it was impossible to achieve progressive correction while fixation was maintained. To overcome these disadvantages of existing unilateral fixators, we developed a new fixator for gradual correction of multi-plane deformities including translational and rotation deformities. This unilateral external fixator is equipped with a universal bar link system. The link is constructed from three dials and two splines that are connecting the dials. The pin clamps are able to vary the direction of a pin cluster in the three dimensional planes. The system allows us to correct angulation, translation, rotation, and the combination of the above. In addition, open or closed hinge technique is available because the correction hinge can be placed right on the center of rotational angulation (CORA), or at any desired location, by adjusting the length of the link spline. By increasing the spline length, the virtual hinge can also be set far from the fixator. Gradual correction can be performed by rotating the three dials using a worm gear goniometer that is temporarily attached. A 3D reconstructed image of the bone is generated preoperatively. Preoperative planning can be done using this image. Mounting parameters are determined by postoperative AP and lateral computed radiography images. These postoperative images are matched with the pre-operative 3D CT image by 2D and 3D image registration. Then, the fixator can be virtually fixed to the bone. By performing virtual correction, it is possible to plan the correction procedure. The fixator is manipulated by rotating each of the three dials to the predetermined angles calculated by the software. Static load testing disclosed that the fixator could bear a load of 1700 N. No breakage or deformation of the fixator itself was recognized. Mechanical testing demonstrated that this new fixator has sufficient strength for full weight bearing, as well as sufficient fatigue resistance for repeated or prolonged use. The results of clinical application in patients with multi-plane femoral deformities were excellent, and correction with very small residual deformity was achieved in each plane.
The most important issue in the assessment of fracture healing is to acquire information on the restoration of mechanical integrity of the bone. To measure bending stiffness at the healing fracture site, we focused on the use of echo tracking (ET) that was a technique measuring minute displacement of bone surface by detecting a wave pattern in a radiofrequency echo signal with an accuracy of 2.6 μ. The purpose of this study was to assure that the ET system could quantitatively assess the progress, retardation or arrest of healing by detecting bending stiffness at the fracture site. With the ET system, eight tibial fractures in 7 patients with an average age of 37 years (range: 24–69) were measured. Two tibiae in 2 patients were treated conservatively with a cast, and 6 tibiae in 5 patients were treated with internal fixation (intramedullary nailing: 4, plating: 1, screw 1). Patients assumed supine position, and the affected lower leg was held horizontally with the antero-medial aspect faced upwards. The fibula head and the lateral malleolus were supported and held tight by a Vacufix ®. A 7.5 Hz ultrasound probe was placed on each antero-medial aspect of the proximal and distal fragments along its long axis. Each probe was equipped with a multi-ET system with 5 tracking points with each span of 10 mm. A load of 25 N was applied at a rate of 5 N/second using a force gauge parallel to the direction of the probe and these probes detected the bending angle between the proximal and distal fragments. An ET angle was defined as the sum of the inclinations of both fragments. In the patients treated with a cast, the contralateral side was also measured and served as a control. Fracture healing was assessed time sequentially with an interval of 2 or 3 weeks during the treatment. None of the patients complained of pain, or no other complication related to this measurement occurred. In the patient (patient:M) treated with a cast, the ET angle exponentially decreased as time elapsed (y = 1.4035e-0.1053x, R = 0.9754) and the radiographic appearance showed normal healing. Including this case, in all patients with radiographic normal healing, the ET angle exponentially decreased. However, in patients with retarded healing (patient:N), the decrease of the angle was extremely slow(y = 0.2769e-0.0096x, R = 0.815). In patients with non union (patient:T), the angle stayed at the same level. With this method, noninvasive assessment of bending stiffness at the healing site was achieved. Bending angle measured by ET diminished over time exponentially in patients with normal healing. On the contrary, in patients with healing arrest, no significant decrease of the bending angle was recognized. It was demonstrated that the echo tracking method could be applicable clinically to evaluate fracture healing as a versatile, quantitative and noninvasive technique.
In this study, bone ingrowth was investigated in three-different cementless acetabular cups, titanium fiber mesh cup (non-HA), hydroxyapatite tricalcium phosphate sprayed cup (HA/TCP), alkali- and heat-treated titanium porous cup (AH). “Gap filling” was evaluated as the finding of the bone ingrowth on X-ray. The phenomenon is that slight gap between acetabulum and the cup observed after total hip arthroplasty (THA) disappear gradually. One hundred and thirty-seven consecutive primary THAs using cementless cups were evaluated for the rate of bone ingrowth. Patients were divided into three groups based on the different types of cups, 51 non-HA cups, 51 HA/TCP cups and 35 AH cups. The groups were similar with regards to age, sex, body mass index, original diagnosis, surgical technique and post operative rehabilitation. Average follow up period was35months, 33 month and 32 months respectively. Initial gap between acetabulum and the cup after operation was observed in 44 hips of non HA group, 39 hips of HA/TCP group and 33 hips of AH group. Rate of the gap filling at the last follow up was 2 hips (4.5%) in non-HA, 31 hips (79.5%) in HA/TCP and 33 hips (100%) in AH. Early gap filling that occurred for less than three months was 17.9% (7 of 39) in HA/TCP and 72.7% (24 of 33) in AH. The HA/TCP coated cup and the alkali- and heat-treated cup had the high frequency which gap filling occurred compared with the cup of only titanium fiber mesh processing. Additionally, in the AH cup more gap filling for less than three months had occurred compared with the HA/TCP cup, so AH cup is the most effective implant to obtain the bone ingrowth at an early stage and it is expected to acquire the better results.