Ultra-high molecular weight polyethylene (UHMWPE) is the sole polymeric material currently used for weight- bearing surfaces in total joint replacement. However, the wear of UHMWPE in knee and hip prostheses after total joint replacement is one of the major restriction factors on the longevity of these implants. In order to minimize the wear of UHMWPE and to improve the longevity of artificial joints, it is necessary to clarify the factors influencing the wear of UHMWPE. A number of studies have investigated the factors influencing the wear of UHMWPE acetabular cup liner in hip prosthesis. Most of these studies, however, have focused on the main articulating surfaces between the femoral head and the polyethylene liner. In a previous study (Cho Introduction
Materials and Methods
Ultra-high molecular weight polyethylene (UHMWPE) is the sole polymeric material currently used for weight- bearing surfaces in total joint replacement. However, the wear of UHMWPE in the human body after total joint replacement causes serious clinical and biomechanical reactions. Therefore, the wear phenomenon of UHMWPE is now recognized as one of the major factors restricting the longevity of artificial joints. In order to minimize the wear of UHMWPE and to improve the longevity of artificial joints, it is necessary to clarify the factors influencing the wear mechanism of UHMWPE. In a previous study (Cho Introduction
Materials and Methods
Ultra-high molecular weight polyethylene (UHMWPE) is the sole polymeric material currently used for weight- bearing surfaces in total joint replacement. However, the wear of UHMWPE and the polyethylene wear debris generated in the human body after total joint replacement cause serious clinical and biomechanical reactions. Therefore, the wear phenomenon of UHMWPE in total joint replacement is now recognized as one of the major factors restricting the longevity of these implants. In order to minimize the wear of UHMWPE and to improve the longevity of artificial joints, it is necessary to clarify the factors influencing the wear mechanism of UHMWPE. The wear and/or failure characteristics of 33 retrieved UHMWPE acetabular cup liners of hip prostheses were examined in this study. The retrieved liners had an average Introduction
Materials and Methods
Wear phenomenon of ultra-high molecular weight polyethylene (UHMWPE) in hip and knee prostheses is one of the major restriction factors on the longevity of these implants. In retrieved hip prostheses with screw holes in the metal acetabular cup for fixation to the pelvis, the generation of cold flow into the screw holes is frequently observed on the backside of the UHMWPE acetabular cup liner. In most retrieved cases, the protruded areas of cold flow on the backside were located on the reverse side of the severely worn and deformed surface of the polyethylene liner. It would appear that the cold flow into screw holes contributes to increase of wear and damages of the polyethylene liner in hip prosthesis. In a previous study (Cho Introduction
Methods
Degenerative osteoarthritis of the knee usually shows arthritic change in the medial tibiofemoral joint with severe varus deformity. In TKA, the medial release technique is often used for achieving mediolateral balancing, but there is some disagreement regarding the importance of pursuing the perfect rectangular gaps. Our hypothesis is that the minimal release especially in MCL is beneficial regarding on retaining the physiological medial stability and knee kinematics, which leads to improved functional outcome. Therefore, the purpose of this study is to examine the thickness of the tibia resection if the extent of the medial release is minimized to preserve the medial soft tissue in TKA. Thirty TKAs were performed for varus osteoarthritis by a single surgeon. In the TKA, femoral bone was prepared according to the measured resection technique, bilateral meniscus and anterior cruciate ligament were excised. After the osteophytes surrounding the femoral posterior condyle were removed, the knee with the femoral trial component was fully extended and the amount of the tibial bone cut was decided for the 10mm tibial insert by referring to the medial joint line of the femoral trial component. After the every bone preparation and placement of all the trial components, If flexion contracture due to the narrow extension gap was found, additional tibial bone cut or medial soft tissue release were performed.Purpose
Patients and Methods
The issue regarding whether suction drainage should be used during TKA continues to be debated as both methods have disadvantages. The use of a drain may increase estimated blood loss and incidence of blood transfusion, while no drainage may be associated with ecchymosis formation surrounding the surgical site and wound problems. This prospective randomized study aimed to clarify the need for suction drainage in TKA by assessing the short-term postoperative outcome. We randomized 39 patients undergoing TKAs either with or without an intra-articular suction drain and divided to two groups. All the TKAs were performed by a single surgeon using cemented prostheses. As the perioperative blood management, air tourniquet was used during surgery, the knee arthrotomy was closed water-tightly, and all the patients were received both intra-articular and intra-venous administrations of tranexamic acid. After the surgery, a bulky compression dressing was applied to prevent the third space leakage of the blood for four days and rivaroxaban was used for venous thromboembolism prophylaxis for one week. The two groups were compared in terms of hemoglobin decrease, recovery of knee flexion, postoperative pain, and examined both the knee circumference and knee swelling. The incidence of short-term complications also evaluated.Introduction
Patients and Methods
The objective of this study is to compare three dimensional (3D) postoperative motion between metal and ceramic bipolar hip hemiarthroplasty for femoral neck fracture. This study was conducted with forty cases (20 cases of metal bipolar hemiarthroplasty (4 males, 16 females), 20 cases of ceramic bipolar hemiarthroplasty (2 males, 18 females)) from November 2012 to November 2014. Average age was 80.8±7.5 years for the metal bipolar group and 79.3±10.5 years for the ceramic bipolar group. We obtained motion pictures from standing position to maximum abduction in flexion by fluoroscopy then analyzed by 2D–3D image matching method. The motion range of the “Shell angle”, “Stem neck angle” and the “Stem neck and shell angle” has been compared between the metal bipolar group and the ceramic bipolar group (Fig. 1). Metal bipolar showed greater variability of the Stem neck angle and Shell angle than ceramic bipolar. Six of the twenty cases reached unilateral oscillation angle of 37 degrees in metal bipolar. In other words, 30% of metal bipolar group revealed neck-shell impingement. No case reached oscillation angle of 58 degrees in ceramic bipolar group. There was no significant difference between the metal bipolar group and the ceramic bipolar group with respect to the difference of minimum and maximum angle of Stem neck angle (movement range of the stem neck) and Shell angle (movement range of the bipolar cup). On the other hand, difference of minimum and maximum angle of the Stem neck and shell angle (movement range of the inner head) was significantly greater in the metal bipolar group than the ceramic bipolar group. Movement, range of bipolar shell was significantly greater than that of inner head in both groups (Table 1).Materials and Methods
Results
The aim of this study was to assess the long-term results of the Kudo type-5 total elbow prosthesis and compare the results of two types of cemented ulnar components. The Kudo type-5 unlinked total elbow prosthesis (Biomet UK Ltd, Bridgend Wales) was developed in 1993. The stem of humeral component is porous-coated with a plasma spray of titanium alloy for cementless use. The ulnar component may be metal-backed with a porous-coated stem or polyethylene alone; the latter designed mainly for cement use. A metal-backed type without a porous-coated stem designed for cement use also came into being after 2003. Between 1993 and 2010, the Kudo type-5 total elbow arthroplasty was performed on 364 elbows in 274 consecutive patients with rheumatoid arthritis. The mean age of the patients at the time of the operation was 60.7 (27–86) years. Twenty elbows had Larsen grade III, 224 had grade IV, and 120 had grade V changes pre-operatively. Before the operation, 346 elbows had severe or moderate pain, 95 had gross valgus-varus instability. Clinical symptoms and revision rates were assessed 4 to 20 years (mean, 9 years) postoperatively. The mean Mayo elbow performance scores were all poor except for three initially (mean overall score, 39.5 points). The overall score had improved substantially both at the early follow-up (1 to 3 years after the operation) and the latest follow-up (4 to 20 years after the operation), with 89.5 and 84.7 points, respectively. At the latest follow-up the overall result was excellent for 185 elbows, good for 103, fair for 11 and poor for 30, with almost complete relief from pain for 298. The arc of movement had increased from a mean of 85.7 °pre-operatively to 95.1 ° post-operatively, and to 98.1 °at the latest follow-up. Spot welds around the humeral stem suggesting solid osseous integration were often seen in the elbows with cementless fixation of the porous humeral stem. At the latest follow-up, implants were removed due to infection in 3 elbows. Twenty-five elbows required ulnar component revision due to loosening of the all-polyethylene component. Two elbows required ulnar component revision due to loosening of the metal-backed component. Seven elbows required humeral component revision due to loosening of the humeral components. One elbow required revision due to dislocation. A survival analysis with revision or removal of one or both components as the end point was performed according to the Kaplan and Meier method. The overall survival rate of the prosthesis was 75.2% at 19 years. The survival of 87.0% in the metal-backed group was higher than the 74.3% in the all-polyethylene group. Loosening of the all-polyethylene ulnar component was the main reason for deterioration in the long-term outcome. We conclude that the long-term results of the Kudo type-5 total elbow arthroplasty is acceptable and cemented fixation of metal-backed ulnar component had better long-term survival than the all-polyethylene component.
The purpose of this study was to introduce our perioperative prophylaxis method for infection and clarify surgical site infection rate in our patients performed total hip arthroplasty (THA). Two hundred and eighty four THA (including revision 18 cases) performed by single surgeon between Oct. 2007 and Jan. 2013 were evaluated. The mean age of patients was 65.7 years old. The male to female ratio was 46 to 238. BMI was 23.6. Ninety patients (32%) were compromised host suffering from diabetes mellitus, rheumatoid arthritis, autoimmune disease, history of malignant tumor, hemodialysis or skin disease at surgical site respectively. At preoperative period, we checked decayed tooth, alveolar pyorrhea, hemorrhoids, and leg skin condition. In addition, we examined culture of nasal cavity. At the day of surgery, patient took a shower just before entering surgical room. All of THA was performed in clean room NASA class 100. Surgeons and assistant nurse put on nonwoven fabric gown, space suit and double rubber gloves. We wiped surgical site leg by gauze impregnated by 0.5% chlorhexidine alchohol to eliminate skin bacteria twice just before surgeons scrubbing hands. Surgical site was covered by povidone iodine containing drape. Surgeons or nurse changed gloves when glove was broken at each time. We cleaned surgical field by pulse washer whenever necessary. We did not use drain except for 5 revision THAs. Regarding to prophylactic antibiotics usage, we administered cefcapene pivoxil orally the day before surgery. Drip infusion antibiotics (PIPC: until Oct. 2008, CEZ: after Oct. 2008) was administered at the period of 30 min. before surgery and 4 hours after surgery in case of prolonged surgical time (4 hours >). Skin closure was performed by staple and covered by gauze until May 2010. After that, we used surgical tape and transparent water proof sheet. After finishing surgery, antibiotic was administered 8 hours interval at surgery day and 12 hours interval for additional two days. In case multi-drug resistant bacteria (MRSA, MRSE) was positive in nasal culture, we applied mupirocin ointment to nasal cavity for 3 days before surgery and administered vancomycin (from Aug. 2011) or linezolid (from 2012) for prophylactic antibiotics in perioperative period.Introduction
Method
The aim of this study was to investigate the clinical results of treatment for patients with periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) in our department. Between April 2004 and March 2014, 9 patients with rheumatoid arthritis (RA) and 6 patients with osteoarthritis (OA) were identified as PJI following TKA and treated in our hospital. We investigated retrospectively the data of each patient, including the clinical background and the peri-operative data as well as the outcome at final follow-up.Objective
Patients and Methods
