This study was conducted to investigate the influence of surgical experience on the outcomes and component positioning of total knee arthroplasty (TKA). We compared the outcomes and component positioning of simultaneous bilateral TKAs performed by supervisors and trainee surgeons. A total of 20 patients (40 knees) who underwent simultaneous bilateral primary TKA using the same cruciate-retaining TKA system between 2011 and 2015 were included. The mean patient age was 76 years (range: 64 to 86 years). There were 2 males and 18 females. The first phase of the operation was performed on the knee that was more severely degenerated by one supervisor who had performed over 1000 TKAs. The other knee was operated on next by trainee surgeons who had performed less than 20 TKAs. The knees were categorized into two groups: those operated on by supervisors (group S) and those operated on by trainee surgeons (group T). Outcome measures included range of motion (ROM), Knee Score (KS), and Function Score (FS). We also evaluated operative time, alignment of the leg, and the orientation of components, which was determined on post-operative long-leg coronal films.Aims
Patients and Methods
The long-term wear performance of highly cross-linked polyethylene (HXLPE) in cemented total hip arthroplasty (THA) has rarely been reported. Here we report a prospective randomized comparative analysis of radiographic wear after a minimum follow-up of 10 years in cemented THAs with either HXLPE or conventional polyethylene (CPE), and assess its clinical relevance. From 1999 to 2001, we conducted 94 primary cemented THAs with a 22.225-mm head at our hospital as part of a prospective randomized trial. All surgeries were performed using a direct lateral approach with a trochanteric osteotomy (Dall's approach). The patients were divided into 4 groups. Twenty-six hips in group A were implanted with CPE sockets against zirconia heads and Charnley-type stems. HXLPE sockets (Aeonian, Kyocera Medical Corp) were implanted in all hips in the other 3 groups. Twenty-five hips in group B were implanted with zirconia heads and KC stems (Kyocera Medical Corp), 23 hips in group C with zirconia heads and distal cylindrical stems, and 20 hips in group D with stainless steel heads and C-stem (DePuy Inc). The sockets were highly cross-linked by gamma irradiation at a dose of 35 kGy, heat annealed at 110ºC, and sterilized with 25 kGy of gamma irradiation in nitrogen. For radiographic evaluation, anteroposterior radiograms were taken for each patient annually, and every two years postoperatively for wear analyses. Two-dimensional head penetration was measured on each postoperative radiogram using a computer-aided technique.Introduction
Patients and Methods
Total hip arthroplasty (THA) for a highly dislocated hip can be problematic and technically challenging. Our previous study on cemented THA with subtrochanteric femoral shortening osteotomy revealed a high incidence (20%) of non-union. Therefore, in 2008, we introduced reverse hybrid THA using S-ROM stem for the treatment of a highly dislocated hip. The purpose of this study was to assess the short-term clinical outcomes of this new method. Between 2008 and 2014, 13 consecutive reverse hybrid THAs were performed on nine female patients with highly dislocated hips. The average age at the time of operation was 66 years (range, 55–85 years). The acetabular component was fixed in the true acetabulum with bone cement. Transverse osteotomy was performed below the lesser trochanter to shorten the femur and to prevent over-lengthening. The proximal sleeve of the S-ROM stem was then fixed within the proximal fragment, and the distal fin provided rotational stability of the distal fragment. Thus, the two fragments were fixed to each other with the S-ROM stem, and the resected segment was longitudinally cut for grafting at the junction. The postoperative follow-up period was an average of 4 years (range, 1–7 years), and no patients were lost. Preoperative and final Japanese Orthopaedic Association (JOA) hip score, operation time, bleeding amount, intraoperative and postoperative complications, bone healing at the osteotomy site, implant loosening, and revision surgery were retrospectively investigated.Introduction
Patients and methods
Composite screws of uncalcined and unsintered hydroxyapatite (HA) particles and poly-l-lactide (PLLA) were developed as completely absorbable bone fixation devices. So far the durability of HA-PLLA composite screws is unclear when used for the fixation of acetabular bone graft in total hip arthroplasty under full-weight conditions. We have used this type of screw for the fixation of acetabular bone graft in cemented or reverse-hybrid total hip arthroplasty since 2003. Hence, we conducted a follow-up study to assess the safety and efficacy of these screws when used for cemented socket fixation. During 2003–2009, HA-PLLA composite screws were used for fixation of acetabular bone graft in cemented or reverse-hybrid primary THA in 106 patients (114 cases). All the THAs were performed through direct lateral approaches, and postoperative gait exercise with full weight bearing usually started two days after surgery. One patient died of an unrelated disease and seven patients were lost to follow-up within 5 years. Finally, 98 patients (106 cases) were followed up for over 5 years and were reviewed retrospectively (follow-up rate, 93%). Radiographic loosening of the acetabular component was assessed according to the criteria of Hodgkinson et al., and the radiolucent line around the socket was evaluated in all zones, as described by DeLee and Charnley.Background
Methods
Modular stems are commonly used to improve fixation in revision total knee arthroplasty (TKA). Hybrid fixation, in which cement is placed around the metaphysical portion of the component combined with an uncemented diaphyseal modular stem, has potential advantages including ease of insertion, improved component alignment, and ease of removal if needed. The aim of this study was to evaluate clinical results of revision total knee arthroplasty with uncemented modular stems using a hybrid fixation technique with a minimum 5-year follow-up. 23 revision TKAs were performed in 21 patients with hybrid fixation using uncemented modular stems. 3 patients (3 knees) had died of causes unrelated to the index arthroplasty at the time of the study, and 1 patient (1 knee) was lost to the follow-up. The remaining 19 knees were clinically and radiographically evaluated for the present study. The average follow-up time was 9.5 years. The average age of the patients was 70.5 years at the time of the revision surgery. The average time between the primary and revision surgeries was 10.6 years.Introduction
Methods
Postoperative peritrochanteric pain, which can be caused by non-union of the greater trochanter in those who have undergone total hip arthroplasty (THA) with trochanteric osteotomy, affects patient satisfaction. We reviewed 89 consecutive cases of primary THA performed with a mini-trochanteric direct lateral approach (Wafer approach), during which the anteroinferior trochanteric fragment (2 cm × 1 cm) attached to the anterior one-third or one-fourth of the gluteus medius muscle insertion and the entire insertion of the gluteus minimus muscle were osteotomized and detached using a curved chisel for exposure, while the origin of the vastus lateralis muscle remained intact. After completion of implantation, the detached fragment was fixed in the original position using 2 parallel braided sutures. If returning the trochanteric fragment to its original position was difficult, the tightened posterior tendinous portion of the gluteus minimus muscle was released to reduce the fragment easily and was then fixed. The surgeries, which included 19 cemented, 7 cementless, and 63 hybrid THAs, were performed between January 2012 and August 2013, and the patients [13 men, 76 women; average age, 65.6 years (38–86 years)] were followed for 6 months. The original diagnosis included primary osteoarthritis in 7 cases, osteoarthritis secondary to dysplasia in 75 cases, and avascular necrosis of the femoral head in 7 cases. X-ray examination including anteroposterior (AP) and lateral hip views was performed at 1, 3, and 6 months postoperatively, and a displacement of > 5 mm of the osteotomized fragment in either the AP or lateral view was considered fragment migration. The Japanese Orthopaedic Association (JOA) pain score was also recorded at 3 and 6 months postoperatively. We examined the possible factors affecting trochanteric migration and JOA pain score, including age, sex, THA type, leg lengthening, Crowe classification, and suture type. We also examined the correlation between trochanteric migration and JOA pain score. There were no peri- or post-operative complications including infection, deep venous thrombosis, dislocation, or periprosthetic fracture. No revision or radiographic loosening occurred in the follow-up period. Average leg lengthening was 9.8 mm (−4–21 mm), measured on the AP X-ray of the hip as the vertical interval between the pre- and postoperative positions of the lesser trochanter. There were 35 cases (39.3%) of trochanteric migration at postoperative 3 months. The Chi-square test and logistic regression analysis indicated that age, sex, Crowe classification, leg lengthening, and suture type did not affect trochanteric migration or JOA pain score. On the other hand, THA type did not affect trochanteric migration but did affect JOA pain score at postoperative 3 months. Patients who underwent cementless THA had worse JOA pain scores than the other patients. There was no correlation between trochanteric migration and JOA pain scores. The results indicated that trochanteric fragment migration often occurred in this series using the Wafer approach. Although the pain score is affected by many factors including thigh pain, hip abductor weakness, and wound irritation in the short term, it did not correlate with the trochanteric nonunion rate of this approach.
Ceramic total knee arthroplasty (TKA) was introduced as a new-generation of knee prostheses in clinical practice, and are expected to reduce polyethylene wear due to its resistance to abrasion and lubrication. In 1992, we developed a cruciate retaining LFA-I total knee prosthesis (KYOCERA Medical Co., Japan), which comprises an alumina ceramic femoral component and a titanium-alloy tibial component with a polyethylene insert. The purpose of this study was to evaluate clinical results in rheumatoid patients who were treated with the alumina-ceramic LFA-I prosthesis with a minimum 15-year follow-up period. A total of 70 primary TKAs were performed in 51 patients between 1993 and 1996 using the cemented alumina-ceramic LFA-I prosthesis. Sixteen of these patients (20 knees) had died by the time of this study, of causes unrelated to the index arthroplasty, and 11 patients (16 knees) were lost to the follow-up. The remaining 34 knees were clinically and radiographically evaluated in the present study. The average follow-up time was 16.7 years. The average age of the patients was 58.2 years at the time of the operation. The clinical assessment was conducted with the Hospital for Special Surgery Knee rating score and the Knee Society scoring system. The component alignment and bone-implant interface were evaluated according to the Knee Society Roentgenographic Evaluation System.Introduction
Methods
Ultra-high molecular weight polyethylene (UHMWPE) tape, which comprised threads of UHMWPE fibers with the thickness less than 0.5 mm, was developed as a flexible fixation device. We describe new techniques using UHMWPE tape for the reattachment of the osteotomised fragment and the repair of intraoperative calcar fractures in total hip arthroplasty (THA). We reviewed the medical records and radiographs of the studied subjects after approval of this study by the institutional review board committee. Experiment 1: Between October 2011 and May 2012, 60 consecutive primary THAs were performed with the mini-trochanteric approach, which involved reattaching the osteotomised fragment using UHMWPE tape (Nesplon; Alfresa Pharma, Osaka, Japan). [Fig.1] By splitting the anterior one-fourth of the gluteus medius, the minitrochanteric osteotomy, a half-ellipsoid body about 15 mm long, 10 mm wide, and 5 mm deep, is performed using a curved chisel. After implanting of the prosthesis, the osteotomised fragment is reattached by using two 3-mm wide Nesplon tapes. Using 2.4 mm Kirshner wire, two sets of drill holes are created below the trochanteric bed of the femur. Nesplon tapes are passed through each drill hole and penetrated over the trochanteric fragment. Nesplon tape is tied using a double-loop sliding knot in conjunction with a special tightening gun tensioner up to 20 kgf. [Fig.2] The radiographic results were retrospectively analyzed to determine the incidence of nonunion and complications related to trochanteric site. Hip functional results were rated according to the Japanese Orthopedic Association (JOA) hip score. Experiment 2: Between July 2011 and May 2012, 5-mm wide Nesplon tapes were used for restoration of intraoperative femoral fractures in 4 primary THAs. For the repair of intraoperative proximal femoral fractures, 5-mm wide Nesplon tape is tightened with cerclage wiring technique using the gun tensioner up to 30 kgf. [Fig.3] The postoperative radiographic changes were analyzed.Introduction
Patients & Methods
In order to reduce polyethylene wear and incidence of osteolysis, and improve the long-term durability of total hip arthroplasty (THA), highly cross-linked polyethylene was introduced for clinical use in substitution for conventional polyethylene. We performed 35 cementless THAs between December 2000 and February 2002, and cross-linked polyethylene was used in these surgeries. The purpose of this study is to research linear wear rate of these hips, and to find the risk factor for high wear rate. 32 hips (26 patients) among the 35 could be evaluated at more than 10 years postoperatively. One hip required reoperations due to infection at 8 years postoperatively, and two were lost to followup in less than 10 years. There were 2 males and 24 females, and the observation period was 11.4 years in average (range 10?13 years). The age at the time of operation was 49.4 years in average (range 24?67 years), and body mass index was 22.4 in average (15?34). We used AHFIX total hip prostheses (KYOCERA Medical Corporation) for both acetabular and femoral replacement, and 22 mm Zirconia head was used in all cases. The median cup diameter was 46 mm (range 42?50). Osteolysis and loosening of the implant was evaluated on the anteroposterior radiograph of the hip. Using software for wear measurement (Hip Analysis Suite), linear wear rate and cup inclination angle were measured. Correlation between linear wear rate and age, BMI, cup inclination angle, and cup diameter was investigated using correlation coefficient.Introduction
Patients and Methods
Metals used for total knee arthroplasty (TKA) are well known for their good biocompatibility, but may be a source of a release of metal ions that can be a cause of local and systemic adverse effects, aseptic loosening, and hypersensitivity reactions. One of the major difficulties in performing TKA is the selection of implants for patients who are preoperatively diagnosed as subject to metal sensitivity. Alternative solutions in cases of hypersensitivity are implants without metal constituents or metallic implants treated with a non-sensitive surface process. The aim of this study was to evaluate clinical results in patients who had been preoperatively diagnosed with metal sensitivity and who subsequently were provided with the zirconia-ceramic LFA-III TKA, and with a minimum 5-year follow-up. Five patients (8 knees) with metal sensitivity underwent TKA using cemented zirconia-ceramic LFA-III implants. The LFA-III implant (KYOCERA Medical Co., Japan) is composed of a zirconia ceramic femoral component and a titanium-alloy tibial component with a polyethylene insert. All patients were female andthe average age at the time of surgery was 76.1 years. The average follow-up time was 7.2 years. Clinical and radiographic assessments were conducted with the Knee Society scoring system.Introduction
Methods
One cementless cup which had porous outer surface with Apatite-Wollastonite glass ceramic (AWGC) coating, was revised 13 years after primary THA because of massive osteolysis expanded to medial iliac wall along the screws. While many retrieved studies of hydroxyapatite-coated cup have been reported, there has been no report on the retrieved cup with AWGC coating. The purpose of this study was to describe this rare case in detail, confirm the bone ingrowth to the porous cup, and discuss on the effectiveness of porous surface with AWGC coating. The patient was a 64 old woman and complained of chronic mild pain around her left groin region. X-ray examination revealed that osteolysis had been expanding around the screws and extended proximally. The revision surgery was performed for the massive osteolysis through Hardinge antero-lateral approach. The retrieved implants included a cementless cup made of titanium alloy (QPOC cup, Japan Medical Materirals Inc.(JMM) Osaka, Japan), the outer surface of which was plasma-sprayed with titanium for porous formation and coated with AWGC in the deep layer. It was found that the polyethylene liner was destructed partially in the supero-lateral portion, but the cup was well fixed to the bone. The bone-attached area was found to be dispersed over the porous surface of the hemispherical cup. Histological examination revealed that matured bony tissue intruded into the porous surface of the cup, and contacted to bone directly, which was also demonstrated in the back-scattered electron image. It was also demonstrated that there were residual silicon (Si) rich regions on the porous surface by the SEM-EDX analysis, which indicated that constituents of AWGC still remained on the surface. On the other hand, the results of elementary analyses in the Si rich regions varied among the sections, which probably indicated that the extent of degradation and absorption of AWGC varied among the sections. AWGC was one of the bioactive ceramics and reported to have an ability to bond to bone earlier than hydroxyapatite (HA). In the present case, though massive osteolysis occurred with aggressive wear, it did not expand on the porous surface, and rather progressed along the smooth surface of the screws. Considering that there are many clinical studies reporting poor clinical results of HA-coated smooth cups, bioactive ceramic coating may function well and bring superior clinical results when combined with porous coated substrate. In our study, though the cause of massive polyethylene wear and intrapelvic giant osteolysis could not be revealed, the porous cup with AW-GC bottom coating was well fixed and gained bone-ingrowth at the porous surface under osteolytic conditions, which may demonstrate the long-term durability of this surface treatment.Case
