In a cruciate retaining total knee arthroplasty (CR-TKA) for patients with flexion contracture, to ensure that an extension gap is of sufficient size to install an implant, the amount of distal femur bone resection needed is frequently larger in a patient with knee flexion contracture than in one without contracture. In this study, we compared the distal femur bone resection amount, the component-secured extension gap margin value, and the range of motion at 6 months after surgery between patients with knee flexion contracture and those without knee flexion contracture. We examined 51 joints including 27 joints in patients with preoperative extension limitation of less than 5 degrees (the F0 group) and 24 joints in patients with limitation of 15 degrees or larger (up to 33 degrees; the FC group) who underwent CR-TKA with LCS RP (DePuy Synthes) between May 2013 and April 2014. In case with an extension gap 3 mm or smaller than the flexion gap after initial bone resection, we released posterior capsule adequately, trying to minimize the distal femur additional bone resection amount as possible. With installation of a femoral trial, the component gaps were measured using spacer blocks. The measured parameters included the intraoperative bone resection length, gap difference (FG − EG, i.e., difference between the flexion gap [FG] and extension gap [EG]), and range of motion 6 months after surgery.Objective
Method
The extension and flexion gaps are affected by different factors in total knee arthroplasty (TKA). Flexion but not extension gap measurements are influenced by posterior cruciate ligament (PCL) preservation or resection and patella reduction or eversion and thigh weight. If the flexion gap is measured with the thigh placed on the tibia, the measurement results must include the thigh weight; nevertheless, there is no detailed report regarding the thigh weight influence on the flexion gap. In this study, we investigated how thigh weight affected flexion gap measurement. Four knees of whole-body fresh-frozen cadavers (Mongolian race) were investigated. The femur and tibia were dissected with a standard measured resection technique. After the femoral component was set, the flexion gap was measured with a knee balancer. The distraction force of 20, 30, and 40 pounds were loaded at the joint level. For each measurement, the influences of the patella reduced or everted (PR or PE) and the PCL preserved or resected (CR or PS) were estimated. The flexion gap was measured five times in four different categories (CR/PR, CR/PE, PS/PR, PS/PE) and the thigh weight was reduced by weights (0, 0.5, 1.0, 2.0, 3.0 kg) using a string and pulley system. During measurement, the femur was just placed on the tibia, and the knee flexion angle was maintained at 90 degrees with a goniometer. After all measurements, the lower limbs were resected, and the thighs were weighed with a scale. Steel-Dwasstest (non-parametric multiple comparison test) were performed for statistical analysis, and p < 0.05 was considered significant.INTRODUCTION
METHODS
Pre-operative autologous blood donation is recommended as a means of reducing the need for allogeneic transfusion before simultaneous bilateral total hip arthroplasty (THA). However, there have been few reports on the optimal amount of autologous donation for this procedure. In this study we sought to determine the amount of autologous blood required for patient undergoing simultaneous bilateral THA using the direct anterior approach. We retrospectively enrolled 325 consecutive patients (650 hips) underwent simultaneous bilateral primary THA from January 2012 to June 2014. Thirty-three patients were men and 290 patients were women. The patients’ mean age at THA was 59.1 years. All THAs were performed using the direct anterior approach. Intraoperative blood salvage was applied for all patients and postoperative blood salvage was not applied for any patients.Background
Methods
The conventional bone resection technique in TKA is recognized as less accurate than computer-assisted surgery (CAS) and patient-matched instrumentation (PMI). However, these systems are not available to all surgeons performing TKAs. Furthermore, it was recently reported that PMI accuracy is not always better than that of the conventional bone resection technique. As such, most surgeons use the conventional technique for distal femur and proximal tibia resection, and efforts to improve bone resection accuracy with conventional technique are necessary. Here, we examined intraoperative X-rays after bone resection of the distal femur and proximal tibia with conventional bone resection technique. If the cutting angle was not good and the difference from preoperative planning was over 3º, we considered re-cutting the bone to correct the angle. We investigated 117 knees in this study. The cutting angle of the distal femur was preoperatively determined by whole-length femoral X-ray. The conventional technique with an intramedullary guide system was used for distal femoral perpendicular resection to the mechanical axis. Proximal tibial cutting was performed perpendicular to the tibial shaft with an extramedullary guide system. The cutting angles of the distal femur and proximal tibia were estimated by intraoperative X-ray with the lower limb in extension position. When the cutting angle was over 3º different from the preoperatively planned angle, re-cutting of distal femur or proximal tibia was considered.Introduction
Methods
In Total Knee Arthroplasty (TKA), it is important to adjust the difference of the flexion-extension gap (gap difference) to get the good range of motion and the sufficient stability. However the effect of the gap adjustment on the post-operative knee flexion angle(KFA) is unknown. We investigated the relationship between the gap difference and the postoperative KFA improvement rate. 179 knees that underwent LCS RP TKA were investigated more than 6 months after surgery(Feb/2013∼Sep/2014). The patients were 49 men and 130 women, of average age 70.6 years (50∼88) and BMI 26.3 (17.0∼55.2). Among them, 175 knees were knee osteoarthritis and 2 joints were rheumatoid arthritis, 2 joints were avascular necrosis. The extension gap was typically prepared with a measured resection, and a small temporary flexion bone gap was prepared with a 4mm resection of the femoral posterior condyle using the pre-cut method(fig 1). Then we measured the gaps under the installation of the Pre-cut Trial(PT; Kaneyama 2011)by the off-set spacer with 1mm increments in patella reduction position(fig 2,3). The final amount of bone resection was determined by comparison of the measured gaps and gaps required for implantation. We calculated the differences between the final extension gap and the final flexion gap and their relationship with knee flexion angles at 6 months postoperatively were analyzed.Objective
Methods
Acetabular osteotomy is considered to be an alternative treatment for acetabular dysplasia, particularly in adolescents and young adults because the long-term results of total hip arthroplasty (THA) in such patients remain controversial. To our knowledge, few reports have described the relationship between the types of osteotomies and surgical difficulty. We compared the operative and clinical results of THA following the 3 main types of acetabular osteotomies, including Chiari osteotomy, rotational periacetabular osteotomy (RAO), and shelf acetabuloplasty. Operative records of 13 hips following Chiari osteotomy (Chiari group), 22 hips following RAO (RAO group), and 16 hips following shelf acetabuloplasty (Shelf group) were retrospectively reviewed. Operative records of 2475 primary THAs without previous osteotomies during the same period were reviewed as a control. The direct anterior approach was used for all hipsIntroduction
Methods
Total hip arthroplasty (THA) is becoming a common procedure because it dramatically relieves the patient's pain. Accordingly, young patients who hope to take THAs are also increasing. The results of THAs in the young patients have historically shown relatively poor survivorship. However several improvements of components may promise good long term results in active young patients. There was no consensus about the appropriate time for performing THA. The purpose of this study is to review the results of THAs younger than 40 years. A retrospective review of 14 primary THAs in 12 patients was conducted. The mean age was 27.0 (range 17–30). Ten were female (83%) and 2 were male (17%). The average follow –up period was 38.3 months (range 18–64). All operations were performed using direct anterior approach (DAA). All patients were allowed full weight bearing as tolerated in the immediate postoperative periods. All were cementless THA and the articulation bearing were ceramic/ceramic in 5 hips (33.3%), metal/highly cross linked polyethylene in 8 hips (53.3%), and ceramic/ highly cross linked polyethylene in 2 hips (13.3%). All patients were followed clinically and radiographically. Patients were evaluated at 4,6,12 weeks and each year postoperatively. Patients were allowed sports at 3 months postoperatively without limitations.Introduction
Material and methods
Bulk bone grafting is commonly used in total hip arthroplasty (THA) for developmental dysplasia. However, it is a technically demanding surgery with several critical issues, including graft resorption, graft collapse, and cup loosening. The purpose of this study is to describe our new bone grafting technique and review the radiographic and clinical results. We retrospectively reviewed 105 hips in 89 patients who had undergone covered bone grafting (CBG) in total hip arthroplasty for developmental dysplasia. We excluded patients who had any previous surgeries or underwent THA with a femoral shortening osteotomy. According to the Crowe classification, 6 hips were classified as group I, 39 as group II, 40 as group III, and 20 as group IV. Follow-up was at a mean of 4.1 (1 ∼ 6.9) years. The surgery was performed using the direct anterior approach. The acetabulum was reamed as close to the original acetabulum as possible. The pressfit cementless cup was impacted into the original acetabulum. After pressfit fixation of the cup was achieved, several screws were used to reinforce the fixation. Indicating factor for using CBG was a large defect where the acetabular roof angle was more than 45 degrees and the uncovered cup was more than 2 cm (Fig.1). The superior defect of the acetabulum was packed with a sufficient amount of morselized bone using bone dust from the acetabular reamers. Then, the grafted morselized bone was covered with a bone plate from the femoral head. The bone plate was fixed with one screw to compact the morselized bone graft. The patient was allowed to walk bearing full weight immediately after surgery. We measured the height of the hip center from the teardrop line and the pelvic height on anteroposterior roentgenograms of the pelvis and calculated the ratio of the hip center to the pelvic height. We defined the anatomical hip center as the height of the center less than 15 % of the pelvic height, which was nearly equal to 30 mm, because the mean pelvic height was 210 mm.Introduction
Patients and Methods
In total hip arthroplasty (THA), the importance of preserving muscle is widely recognized. It is important to preserve the short external rotator muscles because they contribute to joint stability and prevent postoperative dislocation. However, despite careful capsular release and femoral rasping, damage to the short external rotator muscles may occur. The Optymis Shot Stem preserves more bone and surrounding tissue than does a traditional primary stem. We investigated the usefulness of the stem in terms of the extent of preservation of the tendon attachment on the greater trochanter. In this study, we enrolled 31 consecutive patients (39 hips; 6 males, 25 females) who underwent THA. Simultaneous bilateral THA was performed in 8 patients. The patients’ mean age was 56.1 years. Diagnoses included developmental dysplasia in 35 hips (Crowe group 1: 31 hips, group 2: 4 hips), and sequel of Perthes disease in 4 hips. All THAs were performed via the direct anterior approach without traction tables. The femoral procedure was performed with the hip hyperextended, and posterior capsular release was performed if the femoral procedure became technically difficult. We compared the following among patients: the operative time, intraoperative blood loss, length of hospital stay, rate of posterior capsular release, postoperative radiographic findings, WOMAC score before and after surgery, and any complications.Background
Method
A small medial extension gap (EG) needs posterior soft tissue release to avoid undesirable additional resection of the distal femur in total knee arthroplasty (TKA). However, the effect of this procedure on the EG is not always sufficient because the EG is influenced not only by the posterior soft tissue but also by the medial collateral ligament (MCL). We hypothesize that contracture of the posterior capsule prevents full elongation of the MCL in extension and we investigated the efficacy of posteromedial vertical capsulotomy (PMVC) on the medial EG which separate MCL from the posterior capsule (Fig. 1). The PMVC was performed on 128 knees in which the medial extension gap was considered too small. The EG was initially created with a standard femoral distal cut and tibial cut. To estimate the gaps more precisely before flexion gap (FG) adjustment at the final step of the surgery, we performed a 4 mm precut of the posterior femoral condyle and measured the gaps with the patella reduced after setting a precut trial component that had a usual distal part and 4 mm thick posterior part of the femoral component. This situation was the same as after setting the usual femoral trial component by using the measured resection technique with preservation of the posterior cruciate ligament (PCL) (Fig. 2). The semimembranosus tendon was not released in any cases.Introduction
Materials and Methods
Total hip arthroplasty (THA) using short design stem is surging with increasing movement of minimally invasive techniques. Short stems are easier to insert through small incisions preserving muscles. We have used these types of short stems since 2010. Almost all of the patients have shown good clinical results. However, two patients developed fatigue fractures on femurs post operatively. We have reviewed the clinical and radiographic results of these patients. From April 2010, we have performed 621 THAs with short design stems, MicroplastyR, Biomet, using a muscle preservation approach, the Direct Anterior Approach (DAA). The age ranged from 31 to 88 years old. Case1: 56y.o. male, BMI 23.1kg/m2. Preoperative diagnosis was bilateral osteoarthritis. Simultaneous THAs were performed on bilateral hips. He was allowed to bear as much weight as he could tolerate using an assistive device immediately after surgery, and followed standard hip precautions for the first 3 weeks. He was discharged from hospital seven days after surgery and returned to his job two weeks after surgery. He noticed sudden left thigh pain three weeks after surgery without any obvious cause. Crutches were recommended to partially bear his weight. Six weeks after surgery, a fracture line became visible on the radiographs and new callus formation also became visible. Three months after surgery, he felt no pain and was able to walk without any crutches. Case2: 66y.o. female, BMI 27.5 kg/m2. Preoperative diagnosis was bilateral osteoarthritis. THAs were performed on the hips at a six month interval. The right hip was operated on first, followed by the left hip. She was discharged from hospital four days after surgery and returned to her job six weeks after surgery. Two months later after left hip surgery, she suddenly felt pain on her left femur without any obvious cause, and was unable to walk. Three weeks later, X-rays showed fatigue fracture lines and new callus formations. After two or three months using crutches, her pain improved and X-rays showed good callus formation and no stem subsidence.Introduction
Patients and methods
In total hip arthroplasty (THA), the importance of preserving muscles is widely recognized; therefore, muscle-sparing approaches are widely used. Recently, we reported that there are bony impressions, that we called the obturator attachment (OA), on the greater trochanter that indicate the insertions of the short external rotator tendons. In this study, we used a three-dimensional (3-D) template to evaluate damage to the insertions of the short external rotator muscles during a femoral procedure. We investigated 12 hips in 10 patients who underwent THA. Preoperative CT imaging of the hip was performed, and 3-D reconstruction of the greater trochanter was used to visualize the bony impressions that indicate the insertions of the obturator internus and externus muscles (Fig 1A). We performed preoperative 3-D templating of two different femoral prosthesis (flat tapered-wedge stem: J-Taper, cylindrical straight stem: PerFix910) and then evaluated the extent of damage to the OA during the stem placement (Fig 1B, 1C). The extent of damage to the OA was classified using the following scale: grade 0, no damage of the insertion area; grade 1, less than 1/3; grade 2, equal to or more than 1/3–2/3; grade 3, equal to or more than 2/3; grade 4, complete.Background
Methods
Incorrect restoration of the joint line during total knee arthroplasty (TKA) can result in joint instability, anterior knee pain, limited range of motion, and joint stiffness. Although restoration of the correct joint line (i.e., creating an optimal gap in extension and flexion) should be considered in all TKA procedures, no surgical techniques have been established for restoring it. We performed the femoral posterior condylar precut technique A total of 91 knees in 73 patients who underwent primary TKA between June and December 2013 were reviewed retrospectively. The posterior cruciate ligament was preserved in all patients. First, in the femoral posterior condylar precut technique, the extension gap was created by the measured resection technique. Then we created a temporary gap in flexion 4 mm smaller than that created by the measured resection technique and remove posterior osteophytes and soft tissue for good ligament balance. Once the component gap was determined, final femoral posterior condyle cutting was performed to create an optimal gap and rotation. We evaluated the joint line from the differences in thickness between the surgically removed femoral bone and femoral components, and revised the thickness of the bone saw accordingly. The value was positive when the joint line had been raised and negative when it had been lowered.Introduction
Methods
In Total Knee Arthroplasty (TKA), closed drains have been conventionally used to prevent hematoma. Recently reported “no-drain” methods have been demonstrated to be safe and effective, especially for decreasing hemorrhage. However, there has been no report of a major study on a no-drain method in simultaneous bilateral TKA, only a few small studies. Therefore, this study evaluated the efficacy of no-drain placement in simultaneous bilateral TKA. Our study included 75 patients (150joints) with preoperative hemoglobin(Hb) level of at least 11.0 g/dl who underwent simultaneous bilateral TKA performed by the same surgeon in our department between January 2012 and December 2013. There were 12men and 63women, of average age 70.7 ± 7.9years (mean ± SD) and BMI 25.6± 3.8 (mean ± SD). Among them 72 patients had knee osteoarthritis and 3 patients had rheumatoid arthritis. The patella was not replaced in any of the cases. TKAs were performed separately on each knee. A tourniquet was applied between the initial skin incision and the postoperative dressing, and 1000 mg of tranexamic acid was injected into each joint after wound closure.(Introduction)
(Methods)
Total knee arthroplasty (TKA) should aim to adjust the component gap (CG) difference between extension and flexion. However, this difference cannot be measured without placement of a femoral component. The bone gap reportedly decreases in extension after component setting. In contrast, it may be possible to use the mean value of the CG difference in several patients to adjust femoral resection amount beforehand. The purpose of this study is to evaluate the technique of adjusting CG difference using the mean values with measured resection technique (MRT) in TKA. The subjects were 222 knees (40 male knees, 182 female knees; mean age 70.4 years). To adjust the CG difference after estimation, the femoral posterior condylar pre-cut technique was used. Extension gap was created by usual bone resection; 4 mm of the femoral posterior condyle was pre-cut, and after all osteophytes and soft tissues had been treated, a pre-cut trial component (thickness of 8 mm for distal femur and 4 mm for posterior condyle without the anterior portion) was mounted, achieving the same condition as the setting of a femoral component in MRT (Fig. 1). When the posterior cruciate ligament (PCL) could be easily preserved by intraoperative gap assessments, the PCL was preserved (190 knees, 86%).Introduction:
Materials and methods:
In posterior cruciate ligament (PCL)-preserving total knee arthroplasty (TKA), it is important to determine whether the PCL is properly functioning after surgery. As the PCL is partly damaged during the operation, we cannot rule out the possibility that excessive tension further damages the remaining PCL resulting in dysfunction or that initial functioning of the PCL is lost due to excessively low tension. However, it is normally difficult to examine whether the PCL has remained intact and is still functional after TKA. The objective of this study was to visualize knee joint flexion after TKA by MRI and evaluate the PCL based on these images. PCL-preserving TKA was performed in 41 knees using the Fine Total Knee System® (Nakashima Medical, Okayama, Japan) where a titanium component can be selected for both the femur and the tibia. We visualized knee flexion positions by MRI at 6 months after surgery and evaluated visualization or non-visualization of the PCL, the relationship between knee flexion angle and PCL elevation angle against the plane of the tibial joint vertical to the tibial axis, and the forms of PCL based on the MRI data.Introduction
Method
