Unicompartmental knee arthroplasty (UKA) is one surgical option for treating symptomatic medial osteoarthritis. Clinical studies have shown the functional benefits of UKA; however, the optimal alignment of the tibial component is still debated. The purpose of this study was to evaluate the effects of tibial coronal and sagittal plane alignment in UKA on knee kinematics and cruciate ligament tension, using a musculoskeletal computer simulation. The tibial component was first aligned perpendicular to the mechanical axis of the tibia, with a 7° posterior slope (basic model). Subsequently, coronal and sagittal plane alignments were changed in a simulation programme. Kinematics and cruciate ligament tensions were simulated during weight-bearing deep knee bend and gait motions. Translation was defined as the distance between the most medial and the most lateral femoral positions throughout the cycle.Objectives
Methods
To evaluate the effect of hydroxyapatite coating, two same shape cementless stems were compared in this randomized control trial study. Between May 2003 and February 2010, 88 patients had a primary cementless total hip arthroplasty with two different types of cementless stems. Forty-three patients had Proarc stems (P group) (Kyocera Medical, Osaka, Japan), and Forty-five patients had Proarc HA stems (HA group) (Kyocera Medical, Osaka, Japan) which was coated with thin (20 micrometer) hydroxyapatite on Proarc rough porous coating. Gender distribution, average age at surgery, average weight and average follow-up period were same in the two groups. The average follow-up period was 8.5 years (range, 5 to 13 years). The average age at the time of surgery was 63 years. Porous acetabular shells and highly crosslinked polyethylene liners made by Kyocera Medical corporation were implanted into all hips. Stems were implanted with a modified Hardinge surgical approach without trochanteric osteotomy. Harris Hip Score was used for clinical evaluation. Post-op radiographs of these patients were evaluated. Fisher's exact probability test was used for statistical analysis. P values of less than 0.05 were considered to be significant.Introduction
Methods
Little biomechanical information is available about kinematically aligned (KA) total knee arthroplasty (TKA). The purpose of this study was to simulate the kinematics and kinetics after KA TKA and mechanically aligned (MA) TKA with four different limb alignments. Bone models were constructed from one volunteer (normal) and three patients with three different knee deformities (slight, moderate and severe varus). A dynamic musculoskeletal modelling system was used to analyse the kinematics and the tibiofemoral contact force. The contact stress on the tibial insert, and the stress to the resection surface and medial tibial cortex were examined by using finite element analysis.Objectives
Materials and Methods
To assess the structure and extracellular matrix molecule expression of osteogenic cell sheets created via culture in medium with both dexamethasone (Dex) and ascorbic acid phosphate (AscP) compared either Dex or AscP alone. Osteogenic cell sheets were prepared by culturing rat bone marrow stromal cells in a minimal essential medium (MEM), MEM with AscP, MEM with Dex, and MEM with Dex and AscP (Dex/AscP). The cell number and messenger (m)RNA expression were assessed Objectives
Methods
Deformity after femoral osteotomy varies between patients. Some researchers reported good results when using cemented stems for the hips after femoral osteotomy, but there are many disadvantages that obstruct ideal fixation using cemented stems. Therefore, we developed cementless custom-made stems and inserted those using a computed tomography (CT) –based navigation system Eighteen dysplastic hips of 15 patients after intertrochanteric osteotomy were investigated in the present study. Individual computed tomography data were used to manufacture cementless custom-made femoral stems out of Ti-6Al-4V. The proximal 1/3 of each stem was coated using porous coating covered with hydroxyapatite coating. The stems were inserted using a CT-based fluoro navigation system for accuracy of insertion. The average patient age at time of surgery was 66 years, and the average follow-up period was 3.5 years.Introduction
Methods
Hemophilia arthropathy often occurs in the ankle, knee and elbow. In contrast, hemophilic arthropathy in the hip is rare. We report short-term results of total hip arthroplasty (THA) in patients with hemophilia. Four primary THAs performed in four hemophilic patients from 2007 to 2015 were reviewed retrospectively. Two patients underwent cementless THA, and two patients had cemented THA. All patients had hemophilia A, and clotting factor replacement was performed perioperatively. Blood loss, surgery duration, complications, pre- and post-operative range of motion, and the pre- and post-operative Japanese Orthopedic Association (JOA) score were assessed.Introduction
Method
The approach in total knee arthroplasty (TKA) with severe valgus deformity is controversial. The lateral parapatellar approach has been proposed for several years, but surgical technique of this approach was unusual and difficult. Therefore, we have consistently been selected medial parapatellar approach (MPP) for all cases. In this study, we investigated the short term results of TKA for severe valgus deformity with MPP about clinical and radiographic assessment. Seven knees in seven cases of severe valgus knees with stand femorotibial angle (FTA) less than 160 degrees were enrolled. Osteoarthritis were 6 cases, hemophilic arthropathy was 1 case and no rheumatoid arthritis case. There were 6 female and 1 male, and mean age was 63.6 years (41–75 years). Duration of follow up ranged 3 months to 22.5 months, with mean of 10.9 months. We compared alignment on standing radiograph, range of motion (ROM), the Japanese Orthopaedic Association (the JOA) score for osteoarthritic knee pre/postoperatively, and examined post operative complication retrospectively.Objectives
Methods
Bilateral leg alignment should be equal for preventing leg length discrepancy and diminishing limping in walking. The candidates for total knee arthroplasty (TKA) sometimes image bilateral TKA seems to get completely same shape and alignment of legs. The query that bilateral TKA, staged in a day and by one surgeon, has an advantage to reconcile one side alignment and component setting to another side, was investigated. This retrospective investigation enrolled 408 knees of 204 patients (74 years old on average) underwent one day TKA and 48 knees of 24 cases (73 years old on average) underwent two days TKA. There were no history of trauma and surgery on both legs and no other obvious features. All components were same (Vanguard PS TKA, Biomet Inc. Warsaw IN). Surgical procedure is single (modified gap technique) with intramedullar rod for the femur and extramedullar system for the tibia without navigation system and patient specific instrumentation (PSI). Postoperative femorotibial angle (FTA), α, β, γ, δ angles were computed and the absolutes of differences between right and left were analyzed. (two sample t test)Background
Materials and methods
To utilize existing cancellous bone for initial stability, custom-made stems were implanted without reaming and rasping. This study reviewed the results of this non-reaming technique. One hundred and fifty-three hips (138 patients) were followed-up for an average of 12 years (range, 8 to 18). Average age at the surgery was 59 (range, 19 to 78). Seventy percent of the etiologies were dysplastic hips including 17 hips after femoral osteotomy. The Ti-6Al-4V stems were designed using CT data and directly inserted into the femora without reaming and rasping. The stems were coated with hydroxyapatite on the porous coating at proximal 1/3. Harris hip score was used for clinical evaluation.Introduction
Methods
It is essential to investigate the tribological maturation of tissue-engineered cartilage that is to be used in medical applications. The frictional performances of tissue engineered cartilage have been measured using flat counter surfaces such as stainless steel, glass or ceramics. However, the measured friction performances were significantly inferior to those of natural cartilage, likely because of cartilage adhesion to the counter surface. Tamura et al. reported that a poly (2- methacryloyloxyethyl phosphoryl-choline (MPC)) grafted surface shows low friction coefficient against cartilage without the adhesion to be equivalent to those for natural cartilage-on-cartilage friction. [1] On the other hand, Yamamoto et al. reported that applying a relative sliding movement had a potential to alter the expression of tribological function of regenerated cartilage of chondrocytes. [2] In this paper, the effects of the relative sliding movement on the expression of bone marrow stromal cells (BMSC)s were investigated using the poly(MPC) grafted surface as a counter surface. BMSCs seeded onto fibroin sponge scaffolds were cultured by using the stirring chamber system (Figure 1), which can apply a relative tribological movement to the surface of the specimens. Three culture conditions were applied (dynamic in stirring chamber as frequency as 40 min [D1], as 40 sec [D2] and static in stirring chamber group [S]). The specimens were set into stirrer on a poly(MPC) grafted surface (MPC polymer coated surface, SANSYO). As a counter surface in friction tests, the poly(MPC) grafted surface was prepared by atom transfer radical polymerization, and the regenerated cartilage was prepared by seeding 5×105 cells (BMSCs from rat bone marrow) onto fibroin sponge scaffolds (8 mm diameter and 1 mm thickness) and by 14 days culture.Introduction
Material and methods
To evaluate the applicability of MRI for the quantitative assessment
of anterior talofibular ligaments (ATFLs) in symptomatic chronic
ankle instability (CAI). Between 1997 and 2010, 39 patients with symptomatic CAI underwent
surgical treatment (22 male, 17 female, mean age 25.4 years (15
to 40)). In all patients, the maximum diameters of the ATFLs were
measured on pre-operative T2-weighted MR images in planes parallel
to the path of the ATFL. They were classified into three groups based
on a previously published method with modifications: ‘normal’, diameter
= 1.0 - 3.2 mm; ‘thickened’, diameter >
3.2 mm; ‘thin or absent’,
diameter <
1.0 mm. Stress radiography was performed with the
maximum manual force in inversion under general anaesthesia immediately
prior to surgery. In surgery, ATFLs were macroscopically divided
into two categories: ‘thickened’, an obvious thickened ligament
and ‘thin or absent’. The imaging results were compared with the
macroscopic results that are considered to be of a gold standard.Objectives
Methods
We have performed two-component total ankle arthroplasty (TNK ankle) since 1991 and reported good clinical results. However, in vivo kinematics of this implant are not well understood. The purpose of this study was to measure three-dimensional kinematics of total ankle arthroplasty during non-weightbearing and weightbearing activities. Forty-seven patients with a mean age of 71 years were enrolled. Preoperative diagnosis was osteoarthritis in 36 patients and rheumatoid arthritis in 11 patients, and the mean followup was 50 months. Radiographs were taken during nonweightbearing maximal dorsiflexion and plantarflexion, and weightbearing maximal dorsiflexion and plantarflexion. Three-dimensional kinematics were determined using 3D-2D model registration techniques. Anatomic coordinate systems were embedded in the tibial and talar implant models, and they were projected onto the radiographic image. Three-dimensional positions and orientations of the implants were determined by matching the silhouette of the models with the silhouette of the image. From non-weightbearing dorsiflexion to plantarflexion, the talar implant showed 18.1, 0.3, and 1.2 degrees of plantarflexion, inversion, and internal rotation respectively. It also translated 0.8mm posteriorly. There was not significant difference between non-weightbearing and weightbearing kinematics except for the plantarflexion angle (p = 0.007). Posterior hinging, in which tibiotalar contact was seen at only the posterior edge of the talar implant, was observed in 16 patients at either non-weightbearing or weightbearing plantarflexion. There was significantly larger plantarflexion in patients with posterior hinging than patients without hinging (p <
0.001). Nine patients showed anterior hinging at maximum dorsiflexion, and 11 patients showed talar lift-off at maximum plantarflexion. More than half of the patients showed anterior or posterior edge contact, which might cause excessive contact stress and lead to implant failure in the longer term. This phenomenon is due to the difference in rotation axis between the natural ankle and the implant ankle arthroplasty.
The Mayo-Stem is short and tapered in the anteroposterior and mediolateral directions, designed to enhance early fixation through multiple point contact in the proximal medullary cavity. The purpose of this study was to investigate the clinical and radiographic results of total hip arthroplasty (THA) using this short stem in younger patients. A total of 97 cementless THAs using this short stem were investigated. The length of the stem used ranged from 90mm to 110 mm. The average age of the patients at the time of surgery was 50.9 years (33–64 years). The average follow-up period was 64 months (38–108 months). The Harris hip score was used for clinical evaluation. The valgus angles of the stems and the changes in radiographic findings around the stems after surgery were investigated on the AP radiographs of hip. The average Harris hip score was 52.0 points pre-operatively and 93.9 points at the latest follow-up. An intraoperative femoral fissure fracture of the proximal femur occurred in 15 hips (15.4%), which were treated by circlage wires. The average valgus angle of the stem was 3.5° (range: −6°–18°). The development of bone trabeculae was seen around the curve of the stem (Gruen zones 3 and 5) in 79.4 % of hips one year after surgery. A radiolucent line was found on the lateral side of the stem (Gruen zones 1, 2, and 3) in 13.4 % of hips, which occurred in connection with the development of bone trabeculae. Subsidence of the stems (>
2mm) was seen in three hips in which intraoperative femoral fissure fracture had not occurred. These hips did not get the development of bone trabeculae. In two hips of the three hips, the valgus angles of the stems were 15° and 17° respectively. In the case of the third hip, the stem was small to the proximal femur. Overall the clinical result of THA using a short-stem was basically gratifying. The development of bone trabeculae, the stem size to the proximal femur and the stem position were important factors for the fixation of stem. Intraoperative fissure fracture treated by circlage wires and radiolucent lines with the development of bone trabeculae did not affect the fixation of stem.
We report the review of performance and problems of Metasul Hip System with metallic sliding face during mean time of 11 years or longer.
To investigate the limitation of proximal spherical metatarsal osteotomies for feet with severe hallux valgus, a follow-up study was performed on the patients whose preoperative hallux valgus angles were 40 degrees or more. Forty-eight feet in 37 patients (11 male, 37 female, 60 years range 20 to 84 years) were investigated. Mean follow-up was 4 years and 1 month ranging from two to eight years. The spherical osteotomy, performed using a curved chisel, was devised for correcting not only varus deviation of the first metatarsal but also pronation and dorsiflexion. A distal soft tissue procedure was done at the same time. Twenty feet received combined operations for their combined deformities. Eighty-one percent of the patients were satisfied with the results. However, six of twelve patients whose preoperative hallux valgus angles were 50 degrees or more were unsatisfactory. Mild metatarsalgia remained in eight feet at the follow-up, but no new metatarsalgia developed in any patients. The mean value of the hallux valgus angle improved from 46.6 degrees to 11.1 degrees. The patients whose preoperative hallux valgus angle were 50 degrees or more showed 16.4 degrees of average hallux valgus angle at follow-up. Their results varied widely and most of them had inadequate correction. The mean correction toward plantar flexion was 0.7 degrees. Average shortening of the first metatarsal was 3.4mm. The shortening of the first metatarsal had not caused worsening of metatarsalgia if adequate correction of hallux valgus was achieved and malunion toward dorsi-flexion was prevented. The proximal spherical osteotomy could consistently achieve satisfactory results for the patients whose hallux valgus angles are under 50 degrees. However, the results were worse in feet with more severe deformities. Other procedures for hallux valgus or proper combined operations were necessary for such patients.
During the first 5-years period 1159 patients underwent decompressive surgery. 908 of them had spondylosis and 251 had degenerative spondylolisthesis (DO) as a contributing factors of neural compression. Fenestration was done in 740 (81%) of patients with spondylosis and in 176 (70%) of patients with DO.
Diagnostic indices for the determination of involved nerve root in cervical radiculopathy have been described by Yoss (1957), Murphey (1973) and Hoppenfeld (1976). However, there has been criticism that their indices are inappropriate for the diagnosis, because involved nerve root can not necessarily be determined using them. Difficulties in diagnosis have been attributed to the variable patterns of symptoms and signs caused by nerve root compression.
