Recently, the combination of press-fit acetabular cup with ceramic articulation is a widely used for implanting cementless acetabular components and has been shown to provide good initial stability. However, these methods may lead to elevating stresses, changing in the bearing geometries, and increasing wear due to deformation of the cup and insert. In addition, there is a potential for failure of ceramic inserts when a large ball head was used because it should be assembled with shallow thickness of the acetabular cup. For risk reduction of it, we applied direct metal tooling (DMT) based on 3D printing for porous coating on the cup. Due to its capability of mechanical strength, DMT coated cup could be feasible to provide better stability than conventional coating. Therefore, we constructed laboratory models for deformation test simulating an press-fit situation with large ceramic ball head to evaluate stability of the DMT coated cup compared with conventional coated cup. The deformation test was performed according to the test setup described by Z. M. Jin et al. The under reaming of the cavity in a two-point pinching cavity models of polyurethane (PU) foam block (SAWBONES, Pacific Research Laboratories, USA) with a grade 30 were constructed. Titanium plasma spray (TPS) and direct metal tooling (DMT) coated acetabular cups (BENCOX Mirabo and Z Mirabo Cup, Corentec Co. Ltd., KOREA) with a 52 mm size (n=3, respectively) were used for the test. These cups were implanted into the PU foam blocks, and followed by impaction of the inserts (BIOLOX delta, Ceramtec, GE) with a 36/44 size (n=6) into the acetabupar cups as shown in Fig. 1. Roundness and inner diameter of the acetabular cups and inserts were measured using a coordinate measuring machine (BHN 305, Mitutoyo Neuss, GE) in three levels; E2, E3, and E4 (3, 5, and 7 mm below the front face, respectively). Also, these parameters of the acetabular cup were measured in two level; E1 and E5 (5 and 11 mm below the front face) as shown in Fig. 2. Changes in roundness and inner diameter of the cup and insert were measured to evaluate deformation in relation to porous coating on the acetabular cups.Introduction
Materials and Methods
As the proximal femoral bone is generally compromised in failed total hip arthroplasty, achievement of solid fixation with a new component can be technically demanding. Clinical studies have demonstrated good medium-term results after revision total hip arthroplasty using modular fluted and tapered distal fixation stems, but, to our knowledge, long-term outcomes have been rarely reported in the literature. The purpose of this study was to report the minimum ten-year results of revision total hip arthroplasty using a modular fluted and tapered distal fixation stem. We analyzed 40 revision THAs performed in using a modular fluted and tapered distal fixation stem (Fig. 1) between December 1998 and February 2004. There were 11 men (12 hips) and 28 women (28 hips) with a mean age of 59 years (range, 38 to 79 years) at the time of revision THA. According to the Paprosky classification of femoral defects, 5 were Type II, 24 were Type IIIA, and 11 were Type IIIB. An extended trochanteric osteotomy was carried out in 21 (52%) of the 40 hips. Patients were followed for a mean of 11.7 years (range, 10 to 15 years).Introduction
Materials & Methods
The purpose of this study is to report the outcome of navigation-assisted cruciate-retaining total knee arthroplasty (TKA) using one type of cemented, second-generation, floating-platform (FP), mobile-bearing system. We retrospectively reviewed 42 patients (51 knees) who underwent cruciate retaining TKAs using e.motion-FP prostheses under navigational guidance. The preoperative diagnosis was osteoarthritis in all knees except one rheumatoid arthritis. There were 2 men (2 knees) and 40 women (49 knees) with a mean age of 64.0 ± 4.7 years (range, 51 – 76 years) at the time of index surgery. The mean follow-up was 120.0 months (range, 106 – 126 months). Clinical and radiographic results as well as mechanical survival rate of this type prosthesis were investigated at a mean follow-up of 10 years.Background
Methods
Patients with osteonecrosis of the femoral head are typically younger, more active, and often require high rates of revision following primary total hip arthroplasty. However, outcomes of revision hip arthroplasty in this patient population have been rarely reported in the literature. The purpose of this study was to report the intermediate-term clinical and radiographic outcomes of revision hip arthroplasty in patients with osteonecrosis of the femoral head. Between November 1994 and December 2009, 187 revision hip arthoplasty were performed in 137 patients who had a diagnosis of osteonecrosis of the femoral head. Exclusion criteria included infection, recurrent instability, isolated polyethylene liner exchange, and inadequate follow-up (less than 3 years). The final study cohort of this retrospective review consisted of 72 patients (75 hips) with a mean age of 53.3 years (range, 34 to 76). Components used for the acetabular revision included a cementless porous-coated cup in 58 hips and an acetabular cage in 2 hips. Components used for the femoral revision included a fully grit-blasted tapered stem in 30 hips and a proximally porous-coated modular stem in 9 hips. The mean duration of follow-up was 7 years (range, 3 to 17).Introduction
Materials & Methods
Management of the patella with poor bone stock remains a challenge in revision total knee arthroplasty (TKA). The purpose of this study was to evaluate the results of a novel surgical technique in which widely available wires and acrylic bone cement are used in the reconstruction of a deficient patella. Twenty-eight patients (30 knees) underwent revision TKA in which a deficient patella was treated with an onlay-type prosthesis and bone-augmenting procedure, using transcortical wiring. The technique was indicated when the thickness of remnant patella was less than 8mm with variable amounts of the peripheral rim. The remaining patellar height ranged from 3.2mm to 7.3mm. Follow-up was available for all patients with a mean of 36.6 months (range, 24 to 55 months). The respective mean Knee Society scores for knee and function improved from 34.2 points (range, 18 to 65 points) and 23 points (range, 18 to 46 points) preoperatively to 73.5 points (range, 30 to 88 points) and 61points (range, 34 to 80 points) at final follow-up. The mean thickness of the patellar construct was 14.6mm (range, 12.2 – 18.3mm). One patient experienced patellar fracture during knee flexion one week after surgery. There were no complications associated with implanted hardware. A patellar bone-augmenting procedure using transcortical wiring is a straightforward technique that potentially allows firm fixation. Considering the satisfactory short- to mid-term results, we believe that this technique provides a good alternative option in addressing this challenging problem in revision TKA.
Modern ceramic-on-ceramic bearings have become attractive alternatives to conventional polyethylene due to their low wear and minimal particle production. However, ceramic-on-ceramic implants have been associated with ceramic fracture and squeaking. To address these issues, large ceramic heads with a titanium-alloy sleeve have been introduced although limited data are available on their clinical outcomes. The purpose of this study was to report the midterm results of primary total hip arthroplasty using a 32mm with a titanium-alloy sleeve. We reviewed 245 patients who had 274 total hip arthroplasties with a 32 mm ceramic head with a titanium-alloy sleeve and had been followed for more than 5 years (average, 6.5 years; range, 5–9 years). The mean patient age at the time of surgery was 55.1 years (range, 16–82 years). All operations were performed at a single center. All of the ceramic implants were hot isostatic pressed, laser-marked, proof-tested third-generation alumina (Fig. 1). We determined the implant survival, Harris hip scores, incidence of ceramic fracture or noisy hips, and presence of osteolysis.Introduction
Materials & Methods
Management of the patella with poor bone stock remains a challenge in revision total knee arthroplasty (TKA). The purpose of this study was to evaluate the results of a novel surgical technique in which widely available wires and acrylic bone cement are used in the reconstruction of a deficient patella. Twenty-eight patients (30 knees) underwent revision TKA in which a deficient patella was treated with an onlay-type prosthesis and bone-augmenting procedure, using transcortical wiring. The technique was indicated when the thickness of remnant patella was less than 8mm with variable amounts of the peripheral rim. The remaining patellar height ranged from 3.2mm to 7.3mm. Follow-up was available for all patients with a mean of 36.6 months (range, 24 to 55 months).Background
Methods
Highly cross-linked polyethylene has been introduced to decrease osteolysis secondary to polyethylene wear debris generation, but there are few long-term data on revision total hip arthroplasty using highly cross-linked polyethylene liners. The purpose of this study was to report the long-term radiographic and clinical outcomes of a highly cross-linked polyethylene liner in revision total hip arthroplasty. We analyzed 63 revision total hip arthoplasties that were performed in 63 patients using a highly cross-linked polyethylene liner between April 2000 and February 2005. Of these, nine died and four were lost to follow-up before the end of the 10-year evaluation. Thus, the final study cohort consisted of 50 patients (50 hips). There were 26 males and 24 females with a mean age at time of revision total hip arthoplasty of 53 years (range, 27–75 years). Mean duration of follow-up was 11 years (range, 10–14 years).Introduction
Materials & Methods
We sought to determine the 10-year survivorship of single-radius, posterior-stabilized total knee arthroplasty (TKA) in Asian patients. We also aimed to determine whether the long-term clinical and radiographic results differed between patients with and without patellar resurfacing. This retrospective study included 148 (115 patients) consecutive single-radius, posterior-stabilized TKAs. Ten-year survivorship analysis was performed using the Kaplan-Meier method with additional surgery for any reason as the end-point. Furthermore, long-term clinical and radiographic results of 109 knees (74%; 84 patients) with more than a 10-year follow-up were analyzed. Ten-year survivorship and long-term outcomes after surgery were determined, and outcomes were compared between patients with and without patellar resurfacing.Introduction
Materials and Methods
Cementless grit-blasted tapered-wedge titanium femoral stems are being used with increasing frequency in hip arthroplasty because of excellent long-term outcomes. However, periprosthetic femur fracture is a potentially worrisome phenomenon in these types of femoral stems. The aim of this study is to report the incidence of stem loosening in association with periprosthetic femur fractures following hip arthroplasty using cementless grit-blasted tapered-wedge stems. A total of 36 Vancouver Type B1 and B2 periprosthetic femur fractures following either hemiarthroplasty or total hip arthroplasty using cementless grit-blasted tapered-wedge titanium femoral stems (GB group) were identified from a retrospective review of the medical records at three participating academic institutions. The control group consisted of 21 Vancouver Type B1 and B2 periprosthetic femur fractures following either hemiarthroplasty or total hip arthroplasty using cementless proximal porous-coated femoral stems (PC group) at the same institutions during the same period of the study. All femoral stems included in this study had been a well-fixed state before the occurrence of periprosthetic femur fractures. All patients in both groups were treated surgically with either open reduction and internal fixation or femoral stem revision. Femoral stem stability was assessed by preoperative radiographs and was confirmed by intraoperative scrutinization. The incidence of stem loosening was compared between the groups.Introduction
Materials & Methods
Micro-arc oxidation (MAO) is an electrochemical method used to treat metal surfaces. It provides nanoporous pits, and thick oxide layers, and incorporates calcium and phosphorus into the coating layer of titanium alloy. This modification on the surface of titanium alloy by MAO coating would improve the ability of cementless stems to osseointegrate. In spite of these structural and chemical advantages, clinical study of total hip arthroplasty (THA) using MAO coated stem has not yet been reported. In this study, we evaluated the clinical and radiographic results associated with cementless grit-blasted tapered-wedge stems that were identical in geometry but differed with regard to surface treatment with or without MAO coating. We performed a retrospective review of 141 THAs using MAO coated stem for a minimum of 5 years and compared them to 219 THAs using the same geometry stem without MAO coating. A cementless Bencox femoral component (Corentec, Seoul, Korea) was used in all hips. It is made of titanium alloy with a straight, double wedged, tapered stem with a rectangular cross-section. Surface treatment was performed using grit blasting with a roughness of 5.5ųm that was available either with or without MAO coating. Clinical and radiographic evaluations were performed preoperatively and at 6 weeks, 3 months, 6 months, and 1 year postoperatively, and then annually.Introduction
Materials & Methods
The safety implications of achieving high flexion after TKA and the use of high flexion prostheses remain issues of concern. It is possible that different designs have different clinical and radiological results and complications, such as, early aseptic loosening. However, little information is available on the clinical results of TKAs performed using single-radius, high-flex posterior stabilized design. Accordingly, this study was undertaken to document results of single-radius, high-flex posterior stabilized TKAs with minimum 7-year follow-up. From April 2003 to February 2006, 308 patients (455 knees) underwent TKA using single-radius, high-flex posterior stabilized design and among those patients, 251 patients (388 knees) included in this study who were able to be followed up for a minimum 7 year. Clinical results were evaluated using Knee Society Knee scores (KSKS) and Knee Society Function scores (KSFS) at last follow-up. The passive knee flexion was measured using a goniometer before and after surgery. The survival rate of the implants and implant-specific complications such as osteolysis or loosening were investigated. The osteolysis or loosening around the components was recorded according to the Knee Society Radiological scoring System.Background:
Methods:
The robot-assisted cementless total hip arthroplasty has theoretical advantages of providing better fit and mechanical stability of the stem. However, no previous study has been reported on a short stem implantation using surgical robot. We compared early clinical and radiographic results between robotic milling and manual rasping in short stem total hip arthroplasty. We designed a prospective randomized controlled trial to determine whether robot-assisted short stem total hip arthroplasty improves the implant position represented by stem alignment, leg length equality, and reduces the intraoperative and early postoperative complications. A total of 40 patients were enrolled with informed consents and randomly assigned to robotic milling group (20 hips) and manual rasping group (20 hips) by means of a computer-generated random number table. There were no statistically significant differences in the demographics of the patients between the two groupsIntroduction:
Materials & Methods:
To investigate treatment patterns and efficacy of postoperative strong opioids in patients who underwent total knee arthroplasty (TKA) in Korea A prospective, non-interventional study of 301 patients who underwent TKA and received strong opioids following patient controlled analgesia (PCA) was conducted by reviewing patient charts and diaries from 19 teaching hospitals. Clinical characteristics, strong opioid treatment patterns, efficacy of strong opioid on a scale of 0–10, and opioid-related adverse events (AEs) were investigated during hospitalization and at first outpatient visit. Safety analysis was conducted on 301 patients, and efficacy analysis was conducted on full analysis set (FAS) which consisted of all the patients who had at least 1 efficacy result among 301 patients.Purpose:
Methods:
The outcome of previous cemented total hip arthroplasty has been reported to be inferior in renal transplant patients because of poor bone stock resulting from long-term steroid use. Moreover, as renal transplant patients remain on immunosuppressant therapy for life, higher levels of overall morbidity must be considered. We evaluated the mid-term results of cementless total hip arthroplasty in renal transplant recipients with osteonecrosis of the femoral head, and compared those with age and sex matched osteonecrosis patients that had not undergone organ transplantation or been treated with long-term steroid. Between October 1997 and October 2008, 45 consecutive primary cementless total hip arthroplasties were performed in 30 patients with advanced osteonecrosis of the femoral head after renal transplantation. There were 18 males (27 hips) and 12 females (18 hips) of overall mean age 44 years (22 to 68). The clinical and radiographic results of cementless total hip arthroplasty in these 45 hips were compared with those of 96 sex and age-matched osteonecrotic hips of 72 patients that had not undergone organ transplantation or long-term steroid use. Patients were evaluated at surgery and at a mean of 7.2 years (range, 2–13 years) postoperatively.Introduction:
Materials & Methods:
Ceramic head with titanium-alloy sleeve offers a modular ceramic head solution for the damaged taper in revision total hip arthroplasty (THA). It can also be used in primary THA to reduce the risk of ceramic head fracture. The purpose of the present study was to report the intermediate-term outcomes of primary ceramic-on-ceramic THA with use of ceramic head with titanium-alloy sleeve. We evaluated 244 patients (271 hips) who had undergone primary ceramic-on-ceramic THA with use of BIOLOX® forte 32 mm ceramic head with titanium-alloy sleeve between November 2005 and August 2009. There were 158 males (175 hips) and 86 female (96 hips) patients with a mean age of 55.5 years. Clinical and radiographic evaluation was performed at a mean of 4.6 years (range, 2–7 years) postoperatively.Introduction:
Materials & Methods:
The management strategy regarding optimally addressing polyethylene wear with a well-fixed acetabular shell remains controversial. The purpose of the present study was to document outcomes of cementation of a highly cross-linked polyethylene (PE) liner into a well-fixed acetabular metal shell in 36 hips We identified 37 patients (39 hips) who had undergone revision THA by cementation of a highly cross-linked PE liner into a well-fixed metal shell between June 2004 and April 2009. Of these patients, one (1 hip) died before the end of the 3-year evaluation and another was lost to follow-up. Thus, the study cohort consisted of 35 patients (36 hips). There were 23 males (24 hips) and 12 female (12 hips) patients with a mean age at time of revision surgery of 57.6 years (range, 38–79 years). All operations were performed by a single surgeon using only one type of liner. Clinical and radiographic evaluation was performed at a mean of 6.1 years (range, 3–8 years) postoperatively.Introduction:
Materials & Methods:
Soft-tissue balancing is crucial in total knee arthroplasty, but proper release of medial collateral ligament is a challenging procedure. It has been well recognized that medial gap tends to be more tight than lateral gap in varus knees after surgery. The purpose of this study is to investigate the incidence and predictable factors of medial tibial bone remodeling following navigation-assisted total knee arthroplasty. One hundred and sixty-six consecutive patients (221 knees) who underwent navigation-assisted total knee arthroplasty and followed during a minimum of 1 year were included in this study. Radiographic examination including anteroposterior and lateral view of both knees were performed at a regular follow-up schedules of 6 weeks, 3 months, 6 months, 1 year and thereafter, annually after surgery. An independent investigator identified the presence of medial tibial bone remodeling at each follow-up. All information on potential factors affecting medial tibial remodeling were retrieved and classified into 2 types (patient- and surgery-related).Background and Purpose
Materials and methods
A functional total knee replacement has to be well aligned, which implies that it should lie along the mechanical axis and in the correct axial and rotational planes. Incorrect alignment will lead to abnormal wear, early mechanical loosening, and patellofemoral problems. There has been increased interest of late in total knee arthroplasty with robot assistance. This study was conducted to determine if robot-assisted total knee arthroplasty is superior to the conventional surgical method with regard to the precision of implant positioning. Twenty knee replacements of ten robot-assisted and another ten conventional operations were performed on ten cadavers. Two experienced surgeons performed the surgery. Both procedures were undertaken by one surgeon on each cadaver. The choice of which was to be done first was randomized. After the implantation of the prosthesis, the mechanical-axis deviation, femoral coronal angle, tibial coronal angle, femoral sagittal angle, tibial sagittal angle, and femoral rotational alignment were measured via three-dimensional CT scanning. These variants were then compared with the preoperative planned values. In the robot-assisted surgery, the mechanical-axis deviation ranged from −1.94 to 2.13° (mean: −0.21°), the femoral coronal angle ranged from 88.08 to 90.99° (mean: 89.81°), the tibial coronal angle ranged from 89.01 to 92.36° (mean: 90.42°), the tibial sagittal angle ranged from 81.72 to 86.24° (mean: 83.20°), and the femoral rotational alignment ranged from 0.02 to 1.15° (mean: 0.52°) in relation to the transepicondylar axis. In the conventional surgery, the mechanical-axis deviation ranged from −3.19 to 3.84°(mean: −0.48°), the femoral coronal angle ranged from 88.36 to 92.29° (mean: 90.50°), the tibial coronal angle ranged from 88.15 to 91.51° (mean: 89.83°), the tibial sagittal angle ranged from 80.06 to 87.34° (mean: 84.50°), and the femoral rotational alignment ranged from 0.32 to 4.13° (mean: 2.76°) in relation to the transepicondylar axis. In the conventional surgery, there were two cases of outlier outside the range of 3° varus or valgus of the mechanical-axis deviation. The robot-assisted surgery showed significantly superior femoral-rotational-alignment results compared with the conventional surgery (p=0.006). There was no statistically significant difference between robot-assisted and conventional total knee arthroplasty in the other variants. All the variants were measured with high intraobserver and interobserver reliability. In conclusion, Robot-assisted total knee arthroplasty showed excellent precision in the sagittal and coronal planes of the three-dimensional CT. Especially, better accuracy in femoral rotational alignment was shown in the robot-assisted surgery than in the conventional surgery despite the fact that the surgeons who performed the operation were more experienced and familiar with the conventional surgery than with robot-assisted surgery. It can thus be concluded that robot-assisted total knee arthroplasty is superior to the conventional total knee arthroplasty.
We aimed to analyze the clinical results of the patients according to joint line change who underwent navigation assisted cruciate ligament retention type mobile bearing total knee arthroplasty. From September 2004 to January 2006, cruciate ligament retention type mobile bearing total knee arthroplasties using navigation system(Orthopilot®, Aesculap) were performed for 50 knees in 45 patients (2 men, 43 women). The mean follow up period was 46(39~55) months and the mean age was 65. There was one case with rheumatoid arthritis and all other were degenerative arthritic cases. All surgeries were performed using navigation system. Proximal tibia resection was performed at the sclerotic level of medial tibial plateau. The distance from the lowest point of lateral tibial plateau (registered point) to the proximal resection plane was measured. Clinical outcome were compared between joint line elevation with more than 3 mm(20cases) and less than 3mm (30cases). The mean joint line elevation was 1.93 mm (range −1~5mm). There were no significant difference in the clinical results according to the joint line change (p>
0.05). It may be suggested that the change of joint line in the range of −1 to 5mm in cruciate ligament retention type mobile bearing total knee arthroplasty result in satisfactory clinical outcome.
