Oriental people habitually adopt formal sitting and squatting postures, the extreme flexion of the knees allowing of this. The influence exercised by pressure and posture are, therefore, found at the posterior side of knee joint. However, we don't have many report about articular cartilage of posterior femoral condyle. The purpose of this study was to reveal the accurate prevalence and related factors to the presence of degenerative changing of the articular cartilage of posterior femoral condyle in cadaveric knee joints.Introduction
Objectives
Mobile bearing unicompartmental knee arthroplasty (UKA) is an effective and safe treatment for osteoarthritis of the medial compartment. However, mobile-bearing UKA needs accurate ligament balancing of flexion and extension gaps to prevent dislocation of the mobile meniscal bearing. Instability can lead to dislocation of the insert. The phase 3 instruments of the Oxford UKA use a balancing technique for the flexion gap (90° of flexion) and extension gap (20° of flexion), thereby focusing attention on satisfactory soft tissue balancing. With this technique, spacers are used to balance the flexion and extension gap. However, gap kinematics in another flexion angle of mobile-bearing UKA is unclear. We developed UKA tensor for mobile-bearing UKA and we assessed the accurate gap kinematics of UKA. Between 2012 and 2013, The Phase 3 Oxford Partial Knee UKA (Biomet Inc., Warsaw, IN) were carried out in 48 patients (71 knees) for unicompartmental knee osteoarthritis or spontaneous osteonecrosis of the medial compartment. The mean age of patients at surgery was 71.6 years and the mean follow-up period was 1.7 years. The mean preoperative coronal plane alignment was 7.4° in varus. The indications for UKA included disabling knee pain with medial compartment disease; intact ACL and collateral ligaments; preoperative contracture of less than 15°; and preoperative deformity of <15°. Each surgery was performed by using different spacer block with 1-mm increments and the meniscal bearing lift-off tests according to surgical technique. We developed newly tensor for mobile bearing UKA which designed to permit surgeons to measure multiple range of the joint medial compartment/joint component gap, while applying a constant joint distraction force (Figure 1). We assessed the intra-operative joint gap measurements at 0, 20, 60, 90 and 120 of flexion with 100N, 125N and 150N of joint distraction forces.Objective
Materials and Methods
A Trabecular Metal Modular Acetabular System (Zimmer, Warsaw, Indiana, USA) is a peripheral rim expansion (elliptical) cup, i.e. a non-hemispherical cup. Radiologically a non-hemispherical cup may be deferent from other conventional hemispherical cups. We reviewed radiological findings of a Trabecular Metal Modular Acetabular System chronologically. Twenty six patients with osteoarthritis underwent primary total hip arthroplasty (THA) using a Trabecular Metal Modular Acetabular System from 2011 to April 2013. Twenty five patients (follow-up rate: 96.2%) 31 hips could be followed-up over a year were registered. In common, the diameter of every femoral head was 32 mm. We planned the acetabular cup inclination angle to be 45-degree, the cup coverage with host-bone (cup-CE angle) to be over 10-degree, and high hip center was allowed up to 20mm. In case of the cup-CE angle under 10-degree, an acetabular cup was placed medially using Dorr's medial protrusio technique. We established the medial protrusion angle indicating the degree of medial protrusion of an acetabular cup over the pelvic internal wall. The medial protrusion angle was defined by the center point of THA (C) and the 2 cross-points (X1, X2) which the outline of an acetabular cup crosses the Kohler's line (Figure 1). The cup anteversion angle was measured by the method of Lewinnek, and the cup fixation was evaluated according to the Tompkin's classification.Purpose
Methods
The Flexible Nichidai Knee (FNK) System (Nakashima Medical, Japan) was designed to fit Asian knees. Especially, the posterior stabilized(PS) prosthesis was designed as semi-constrained posterior stabilized system that had a large tibial post and femoral articulation. We hypothesized that the semi-constrained PS implant design would have a positive influence on vivo kinematics after total knee arthroplasty (TKA). A total of 16 patients (21 knees) who had undergone TKA using PS implant were randomly recruited from our database. Of the 16 patients, all patients were women. Fourteen patients had osteoarthritis and 2 patients had rheumatoid arthritis. The average age was 72.3± 9.5 years, and the average postoperative duration was 23.4 ± 19.3 months. The subject performed sequential deep knee bends under WB from 0° to maximum flexion under fluoroscopic monitoring in the sagittal plane. Conversely, under NWB, the patient sat on a chair and was asked to perform active assisted knee flexion. To estimate spatial position and orientation of the artificial knee prosthesis, a 2D to 3D registration technique was used. We evaluated knee range of motion, femoral axial rotation relative to the tibial component, and anteroposterior translation of the femorotibial contact point for both medial and lateral sides. Closest distances between femoral cam and tibial post engagement were measured,Introduction
Materials and Methods
Accurate soft tissue balancing in knee arthroplasty is essential in order to attain good postoperative clinical results. In mobile-bearing UKA (Oxford Partial Knee unicompartmental knee arthroplasty, Biomet), since determination of the thickness of the spacer block depends on the individual surgeon, it will vary and it will be difficult to attain appropriate knee balancing. The first objective of the present study was to investigate flexion and extension medial unicompartmental knee gap kinematics in conjunction with various joint distraction forces. The second objective of the study was to investigate the accuracy of gap measurement using a spacer block and a tensor device. A total of 40 knees in 31 subjects (5 men and 26 women) with a mean age of 71.5 years underwent Oxford UKA for knee osteoarthritis and idiopathic osteonecrosis of the medial compartment. According to instructions of Phase 3 Oxford UKA, spacer block technique was used to make the extension gap equal to the flexion gap. Adequate thickness of the spacer block was determined so that the surgeon could easily insert and remove it with no stress. Following osteotomy, the tensor devise was used to measure the medial compartmental gap between the femoral trial prosthesis and the tibial osteotomy surface (joint component gap) (Fig. 1 and 2). The medial gap was measured at 20° of knee flexion (extension gap) and 90° of knee flexion (flexion gap) with 25N, 50N, 75N, 100N, 125N, 150N of joint distraction force. Corresponding size of bearing was determined for the prosthesis. The interplay gap was calculated by subtracting the thickness of the tibial prosthesis and the thickness of the selected size of bearing from the measured extension and flexion gaps.Introduction
Methods
Total Knee Replacement (TKR) has been proven to be an effective procedure not only to eliminate pain but also to achieve better knee function. Recent rehabilitation is basically focused on achieving better ROM and muscle strength. However, improvements of balancing or walking ability in detail have not been sufficiently elucidated yet. 91 consecutive knees of 70 patients, with medial osteoarthritis undergone TKR have been nominated in this study. All were done by a single surgeon, via mid vastus approach, using cemented PS implant with patellar resurfacing. Patients were arrowed to start full weight bearing from the next day. Assessing walking ability, gait speed and width of a step were measured. As for balancing, “Functional Reach (FR)” which was the difference between arm's length and maximal forward reach (Duncan PW et al), “Timed Up and Go Test (TUG)” which was time while a patient rose from an arm chair, walked 3 meters, turned, walked back, and sat down again (Podsiadlo D et al), and possible period standing on one leg (one leg standing) were used. Every measurement was performed prior to the operation, 1,2,3,4 weeks, 2 months and 6 months after operation. Data of prior to the operation, 2, and 6 monts after the operation were analyzed by one-way repeated ANOVA, and then differences among means were analyzed using Bonferroni procedures. P-value lower than 5% is regarded as significant. Every result except for one-leg standing time on contralateral leg (non-operative side) showed the worst during the first week, followed by better results over time (Fig. 1,2,3). One leg standing time of operative leg reached maximum at 2 months of time, while the others revealed improvement even at 6 months of time. Interestingly, postoperative one leg standing period of contra-lateral leg showed improvement with similar tendency until 4 weeks, followed by reaching plateau over time.Methods
Result
Patients who have undergone Total Knee Replacement (TKR) improve their knee functions with time dependent recovery. However, the speed and degree of recovery widely varies from person to person. Practitioners generally find that postoperative satisfaction after TKR is closely related to the degree of preoperative severity in deformity. We focused on preoperative FTA to determine how the degree of deformity affects postoperative improvements after TKR. 44 consecutive knees of 44 patients with medial osteoarthritis underwent TKR for nomination in this study. All operations were conducted by a single surgeon using a mid vastus approach with cemented posterior stabilized (PS) implant and patellar resurfacing. Patients were targeted for full weight bearing the next day. Patients were divided into 3 groups of preoperative FTA: 174–180 degrees (11 knees), 181–189 degrees (17 knees), and more than 190 degrees (16 knees). Walking ability was assessed by gait speed and width of step. Balance was measured by a “Functional Reach Test (FR),” which is the difference between arm's length and maximal forward reach (Duncan PW et al. 1990), a “Timed Up and Go Test (TUG),” the time interval for a patient rise from an arm chair, walk 3 meters, and return (Podsiadlo and Richardson 1991), and the capacity to stand on one leg (one leg standing time trial). Every measurement was performed prior to the operation (pre-op), and 4 weeks after operation (post-op 4w). The recovery rate (%) was defined as post-op 4w/pre-op ×100. Data were analyzed by one-way ANOVA, and then differences among means were analyzed using Bonferroni procedures. The recovery rate of walking speed and TUG showed significant improvement in the FTA more than >190 degree group than that of 174–180 degree group. Every other result showed a higher recovery rate for the >190 degree group, although results were not statistically significant.Methods:
Result:
There are few reports on total hip arthroplasty (THA) for hip osteoarthritis associated with so-called Perthes-like change including high great trochanter, short neck hip or flattened femoral head (hereinafter called “Perthes-like change”) as the operative procedures are difficult. We studied THA for “Perthes-like change” carried out in our department. We covered 14 cases (15 hips), which underwent THA for “Perthes-like change” (hereinafter called “Perthes-like change group,” operated from 2008 to September 2011. The average age at the operation was 62 (53 to 83 years old), 7 males and 7 females, and the average follow-up period was 21.8 months (6 to 48 months). For these cases we studied the clinical items and further made a comparative review of the 258 hips as a control group (Group C), which underwent THA during the same period for osteoarthritis (OA) originating in DDH (developmental dysplasia of the hip) (Crowe type 1 and 2), excluding the “Perthes-like change group.” The items reviewed include the age at the operation, operation time and intraoperative blood loss.Objectives
Methods
Total Knee Replacement (TKR) has been proven to be an effective procedure not only to eliminate pain but also to achieve better knee function. However, details improvements of balancing or walking ability have not been sufficiently elucidated yet. 25 consecutive knees of 21 patients, with medial osteoarthritis undergone TKR have been nominated in this study. All were done by a single surgeon, via mid vastus approach, using cemented PS implant with patellar resurfacing. Patients were arrowed to start full weight bearing from the next day. Assessing walking ability, gait speed and width of a step were measured. As for balancing, “Functional Reach (FR)” which was the difference between arm's length and maximal forward reach (Duncan PW et al), “Timed Up and Go Test (TUG)” which was time while a patient rose from an arm chair, walked 3 meters, turned, walked back (Podsiadlo D et al), and sat down again, and possible period standing on one leg (one leg standing) were used. Every measurement was performed prior to the operation, and every 1-week after operation until 4-weeks postoperatively. Data were analyzed by one-way ANOVA, and then differences among means were analyzed using Bonferroni procedures. Also, the relation of improvements between ROM and each data were investigated by Pearson's correlation coefficient test. Every result showed the worst during the first week, followed by better results over time (p<0.05) (Fig. 1–3). The time point when better result than that of pre-operation could be achieved was 2 weeks in FR and one leg standing, 3 weeks in gait speed and width of a step, and 4 weeks in TUG, though statistically not significant. Each of the result was not correlated with its recovery rate of the ROM when compared at 4 weeks of time (r = 0.2–0.3). Interestingly, postoperative one leg standing period of contra-lateral leg showed improvement with similar tendency.Methods
Result
