Between 1993 and 2003, 67 consecutive revision total hip arthroplasties were performed in 65 patients, including 52 women and 13 men, using hydroxyapatite (HA) granules supported by a Kerboull-type reinforcement acetabular device. The average age at the time of index surgery was 68.6 years. The Acetabular bone loss according to the American Academy of Orthopaedic Surgeons (AAOS) system was type II for 7 hips, type III for 58 hips, and type IV for one hip. The Kerboull-type acetabular reinforcement device used was Kerboull Cross Plate in 18 hips and KT Plate in 49 hips. HA granules of sizes 0.9 to1.2 mm (G4) and 3.0–5.0 mm (G6) were mixed in a ratio of 1:1. Autografts were used to reconstruct the major segmental defects in 7 hips. At the time of this study 30 hips were lost of follow-up. Among 30 hips 22 hips were lost of follow-up because of the death of the patients. The remaining 37 hips were examined clinically and radiologically. The mean follow-up period of the series was 12.8 years. Complications were examined and clinical evaluation was done using Japanese Orthopaedic Association (JOA) hip score. The criterion for loosening of the acetabular component was cup migration exceeding 3 mm or angular rotation exceeding 3 degrees or breakage of the device. Among the entire series of 67 hips postoperative complications included dislocation in 3 hips, infection in 2 hips and revision in 4 hips. Two hips were revised for loosening and the other two hips were revised for infection. The JOA hip score increased from a mean value of 48.0 preoperatively to 76.8 at the last follow-up. Radiologically 5 hips were loose. Two hips among them were revised. Survival rate of the acetabular component at 10 years was 97.1% using acetabular revision for loosening as the end point and 90.6% using radiological loosening as the end point. Acetabular reconstruction with HA granules and a Kerboull-type acetabular device provided satisfactory clinical and radiographic results at 12.8 post-operative years.

The plasma spray(TPS) has come to be accepted as one of the more reliable methods of porous coating of prosthesis, it is not without some technical limitations, especially with regard to precise modulation of pore size, porosity, and roughness. However, the plasma spray(TPS) not often but seriously faces problems such as bead detachment related poor osteointegration, weakness of metal strength and high manufacturing costs in addition to its various technical limitations. Currently, there has been much research into developing a more economical and effective method for porous coating of the prosthesis.

In light of such demand, 3D Printing with DMT Technology has been introduced into the field of surface treatment of prosthesis with promising expectations. DMT technology -an additive fabrication process that uses high-power laser and various metal powders in order to produce fully dense and geometrically complex metal components, molds, and dies directly from digital CAD model data of 3D subjects aims to help overcome many of the problems associated with plasma spray and thereby open a new chapter of endless possibilities for coating technology.

In this study, the porous coating specimen using 3-D DMT metal printing was characterized morphologically as well as biomechanically, in terms of 1) pore size 2) porosity 3) tensile strength 4) shear strength 5) roughness respectively. The biological cyto-compatibility was evaluated by culturing human osteoblast-like cells(Saos-2: ATCC HTB85) on the surface of round discs with porous coating to demonstrate the biological influence on the porosity of the specimens with different surface treatment for comparative analysis. The evaluation was accompanied by assessment of cell proliferation and morphology with arrangement of actin filament and expression of adhesion molecule with α_vβ₃ integrin.

While 3-D DMT coating specimen showed relatively regular porosity in the range of 150–500µm with the increase of porosity about 83%, the mechanical behavior remarkably improved, compared to TPS: shear strength 13%, fatigue failure 30%, roughness 16%, respectively. Also worth noting, the tensile strength was unable to be measured because the glue for test had fallen off. (Fig. 1) There is no transitional zone underneath the porous coating layer.(Fig. 2) From the aspect of biocompatibility, 3-D coating showed better cell attachment, spreading of cytoskeleton, cell proliferation, and expression of osteogenic markers than TPS, even if not significantly.(Fig. 3) Additionally, cell migration assay was performed with double chamber study, and gene expression was evaluated by measuring alkaline phosphatase(ALP) levels and analyzing mRNA expression for ostepontin(OPG) and osteocalcin(OC).

In conclusion, the study reinforces the popular stance that the implementation of 3-D DMT could open up new possibilities for coating technology and form a new chapter in the history of prosthesis development.

Periprosthetic femoral fractures are becoming increasingly common and are a major complication of total hip arthroplasty (THA) and bipolar hemiarthroplasty (BHA). We report a retrospective review of the outcomes of treatment of 11 periprosthetic fractures after femoral revision using a long stem. Eleven female patients with a mean age of 79.2 years (70 to 91 years) were treated for a Vancouver type B1 fracture between 1998 and 2013. The status of the initial arthroplasty was THA in 5 patients and BHA in 6 patients. The original diagnosis was femoral neck fracture in 5 patients, osteoarthritis in 5 patients, and avascular necrosis of femoral head in 1 patient. Seven patients had had a cemented femoral component and 4 had had a cementless femoral component. The mean numbers of previous surgeries were 3.2 times (2 to 5 times). A previous history of fracture in the same femur was found in 7 hips including 5 femoral neck fractures, 3 periprosthetic fractures. The cause of the latest revision surgery was aseptic loosening in 6 hips, periprosthetic fracture in 3 hips, and infection in 2 hips. The average time to fracture after femoral revision using a long stem was 106.5 months (12 to 240 months). The average follow-up was 58.9 months (8 to 180 months). The fracture pattern was a transverse fracture in 6 hips and an oblique fracture in 5 hips. The type B1 fractures were treated with open reduction and internal fixation in 9 hips, 6 of which were reinforced with bone grafts. Seven patients were treated with a locking compression plate and cerclage wiring, and 2 patients were treated with a Dall-Miles system. Two other periprosthetic fractures were treated with femoral revision. One was revised because of stem breakage, and the other was a transverse fracture associated with very poor bone quality, which received a femoral revision with a long stem and a locking compression plate. All fractures except one achieved primary union. This failed case had a bone defect at the fracture site, and revision surgery using a cementless long stem and allografts was successful. These finding suggest that a type B1 fracture after revision using a long stem associated with very poor bone quality or bone loss might be considered as a type B3 fracture, and femoral revision might be the treatment of choice.

Introduction

To minimize leg length discrepancies (LLD), preoperative measures are taken using the PACS; the head center to the proximal end of the lesser trochanter distance (HLD) of the opposite side of the operating limb are calculated, while during operation, the modular neck selection is adapted to equal the opposing limb's length.

The purpose of this study was to see whether the HLD method would show far less occurrences of LLD, in comparison to the conventional method(preoperative templating and shuck test).

Introduction

47 yrs male patient had a prior history

2005 Fx. proximal tibia (open Fx.)

2007 Metal removal

2008 Arthroscopic debridement (2 times)

He visited out hospital with severe pain and tenderness X-ray (Fig 1) and MRI (Fig 2) findings as follows.

Conclusively, He had a chorinic osteomylitis of proximal tibia with soft tissue absess.

1st Surgery

I did arthroscopic debridement Arthroscopic finding shows synovitis, meniscus tear and chondromalacia. I did meticulous debridement (irrigation & curettage)

2^nd Surgery

He did primary total knee arthro-plasty instead of two-stage exchange arthroplasty in may, 2010 at the another hospital

3^rd Surgery

After 7 months since he had did total knee arthroplasty, he visited to my hospital again with sudden onset of painful swelling & heating sensation

4^th Surgery

I did second stage reimplantation for infected total Knee arthroplasty after 7 weeks. Now he got a pain relief & ROM restroration.

Purpose

Ion implantation with a high kinetic energy has advantages in controlling the size and distribution of coating materials, helping to overcome the limitations of conventional methods. This method resulted in uniformly and homogeneously distributed in a CoCr alloy even without a further annealing process. The study was to investigate the wear rate of UHMWPE on CoCr alloy for metal head by plasma immersion ion implantation (PIII) treatments.

Introduction

Inspired by mussel-adhesion phenomena in nature can integrate inorganic hydroxyapatite crystals within versatile materials. This is a simple, aqueous, two-step functionalization approach, called polydopamine-assisted hydroxyapatite formation (pHAF), that consists of i) the chemical activation of material surfaces via polydopamine coating and ii) the growth of hydroxyapatite in a simulated body fluid (SBF). We presumed polydopamine coating on the surface of titanium alloy would improve the ability of cementless stems to osseointegrate. We therefore compared the in vitro ability of cells to adhere to polydopamine coated Ti alloy and machined Ti alloy.

Background

No study compared the clinical results of the posterior-stabilized mobile-bearing knee with those of nonposterior-stabilized mobile-bearing knee in the same patients. The purpose of this study was to examine whether the clinical and radiographic results, range of motion, patients satisfaction, and complication rates would be better in the knees with a posterior-stabilized mobile-bearing knee than in the knees with a nonposterior-stabilized mobile-bearing knee.

Purpose

Surgical dislocation is useful for assessing and treating proximal femoral hip deformities. Legg-Calv Perthes disease (LCPD) causes proximal femoral growth deformity, resulting in reduced femoral head-neck offset and femoracetabular incongruity. The purpose of this study was to demonstrate the efficacy and report the short-term results of surgical hip dislocation for the treatment of adolescents with healed LCPD.

Introduction

What is the most effective treatment of the early stages for osteonecrosis of the femoral head? Since the results of several treatment modalities such as multiple drilling, core decompression with or without bone graft, and vascularized fibular grafts have not been completely successful, we tried multiple drilling and stem cell transplantation to treat the early stages of osteonecrosis of the femoral head and to minimize patient morbidity. We report the clinical and radiological results of stem cell transplantation and core decompression.

It has been suggested that the wear of ultra-high molecular weight polyethylene (UHMWPE) in total hip replacement is substantially reduced when the femoral head is ceramic rather than metal. However, studies of alumina and zirconia ceramic femoral heads on the penetration of an UHMWPE liner in vivo have given conflicting results.

The purpose of this study was to examine the surface characteristics of 30 alumina and 24 zirconia ceramic femoral heads and to identify any phase transformation in the zirconia heads. We also studied the penetration rate of alumina and zirconia heads into contemporary UHMWPE liners. The alumina heads had been implanted for a mean of 11.3 years (8.1 to 16.2) and zirconia heads for a mean of 9.8 years (7.5 to 15).

The mean surface roughness values of the explanted alumina heads (Ra 40.12 nm and Rpm 578.34 nm) were similar to those for the explanted zirconia heads (Ra 36.21 nm and Rpm 607.34 nm). The mean value of the monoclinic phase of two control zirconia heads was 1% (0.8% to 1.5%) and 1.2% (0.9% to 1.3%), respectively. The mean value of the monoclinic phase of 24 explanted zirconia heads was 7.3% (1% to 26%).

In the alumina group, the mean linear penetration rate of the UMWPE liner was 0.10 mm/yr (0.09 to 0.12) in hips with low Ra and Rpm values (13.22 nm and 85.91 nm, respectively). The mean linear penetration rate of the UHMWPE liner was 0.13 mm/yr (0.07 to 0.23) in hips with high Ra and Rpm values (198.72 nm and 1329 nm, respectively). This difference was significant (p = 0.041).

In the zirconia head group, the mean linear penetration rate of the UHMWPE liner was 0.09 mm/yr (0.07 to 0.14) in hips with low Ra and Rpm values (12.78 nm and 92.99 nm, respectively). The mean linear penetration rate of the UHMWPE liner was 0.12 mm/yr (0.08 to 0.22) in hips with high Ra and Rpm values (199.21 nm and 1381 nm, respectively). This difference was significant (p = 0.039).

The explanted zirconia heads which had a minimal phase transformation had similar surface roughness and a similar penetration rate of UHMWPE liner as the explanted alumina head.

Although total knee arthroplasty (TKA) has been a reliable procedure providing durable pain relief, polyethylene (PE) wear remains a major limitation of the long-term success of TKA. One potential method of lowering PE wear in TKA is to use oxidized zirconium (OxZr)-bearing surface. Although wear simulating testing of an OxZr counter surface of femoral component produced less PE wear and fewer particles than did cobalt-chrome (Co-Cr) counter surface of femoral component [1–4], this finding has not been demonstrated in vivo to our knowledge.

We measured in vivo PE wear by isolating and analyzing PE wear particles in synovial fluid from wellfunctioning TKA [5]. The purpose of the current study was to determine the size, shape, and amount of PE wear particles isolated from synovial fluid of patients who underwent a bilateral simultaneous TKA prosthesis, but different materials of femoral components.

We performed a bilateral simultaneous TKA in 100 patients (200 knees) who received an OxZr femoral component in one knee and a Co-Cr femoral component in the other. Mean age was 55.6 (44–60) years. Synovial fluid was obtained from 28 patients (56 knees) who had undergone a simultaneous bilateral TKA under completely sterile conditions at one or two years after the operation. Randomization to an OxZr or Co-Cr femoral component was accomplished with use of a sealed study number envelope, which was opened in the operating room before the skin incision had been made. After the opening the randomization envelope, the first knee received prosthesis indicated by the envelope (OxZr or Co-Cr component) and the contralateral (second TKA) knee received the other prosthesis (OxZr or Co-Cr component).

All operations were performed by one surgeon using the same design of total knee prosthesis: Genesis II (Smith and Nephew, Memphis, Tennessee). Only the material of the femoral component differed between two groups. The preoperative diagnosis was osteoarthritis in all patients. Preoperative and post operative KS and HSS knee scores, KS functional scores and UCLA activity scores were evaluated.

The amount of polyethylene wear particles in the aspirated synovial fluid sample was analyzed by thermogravimetic analysis (TGA) using a TGA instrument (TGA/SDTA 84le model, Mettler Toledo CO., Greifensee, Switzerland). The weight of the sample solution was measured before and after removing the organic content by heating the sample solution. The sample solution was casted onto petri dishes. The petri dish was covered and kept in a dry oven at 60°C for 2 days. While the sample solution was kept in a dry oven for 2 days, a small hole was made on the cover of the petri dish to allow water to evaporate slowly for 2 days. After this procedure, the cover of petri dish was removed and TGA sample was dried at 60°C for another 2 days. After the sample was completely dried out, the dried sample was measured using analytical balance.

TGA was used to determine the weight change profiles of polyethylene subject to heating under a nitrogen atmosphere. The nitrogen flow rate was kept constant at 50mL per minute. TGA data were taken at heating rate as 5°C per minute in the temperature range of 20° to 1000°C. The weight loss data were recorded as a function of time and temperature using special software in computer. When the temperature reached to the point of decomposition of the sample, the sample started to lose weight. By calculating the weight of the sample around the temperature which led to start to decomposition, real amount of polyethylene in the sample was measured. The size and shape of PE particles were examined using scanning electron microscopy (JSH-6360A model, Jeol Co., Tokyo, Japan). The samples were coated using a platinum sputtering machine for 20 sec.

ANOVA, nonparametric chi square test, nonpaired t-test and Mann-Whitney U-test were used for statistical analyses. Differences of P< 0.05 were considered statistically significant.

Mean preoperative KS (27.5 vs 27.2 points) scores, HSS (51.1 vs 51.2 points) knee scores, KS functional scores (55.4 vs 55.4 points) and UCLA activity scores (2.8 vs 2.8 point) were not significantly different between two groups. Mean postoperative KS (93 vs 92 points), HSS knee scores (90 vs 89 points), KS functional scores (78 vs 78 points), and UCLA activity scores (7.8 vs 7.8) were not significantly different. Mean weight of the polyethylene particles was 0.0219 g (SD, 0.0058) in the Co-Cr femoral component groups and it was 0.0214 g (SD, 0.005) in the OxZr group. This difference was not significant (P=0.711139, paired t-test). The size of particles was not different between the two groups. Also, shape of particles was not different between the two groups.

Under the condition and the duration of this study in this specific group of patients, TKA with OxZr or Co-CR femoral knee component had excellent clinical and radiographic outcomes with no osteolysis. While the wear simulator test in vitro demonstrated significant decrease in PE particles in the knees with an OxZr femoral component, our study in vivo revealed that total particle weight, size, and shape of PE wear particles were similar in the knees with an OxZr femoral component and in those with a Co-Cr femoral component.

Background: Although many of the contemporary fixed- and mobile bearing total knee systems have been using extensively world wide, there is limited information available regarding the incidence of osteolysis of the well functioning total knee arthroplasties. We performed this study to evaluate the clinical and radiographic outcomes, the incidence of osteolysis, the revision rates and implant survivorship of the fixed- and mobile-bearing total knee arthroplasties at ten to seventeen years follow-up.

Methods: We compared 488 patients (894 knees) who received a fixed-bearing total knee replacement and 445 patients (816 knees) who received a mobile-bearing total knee replacement. There were 187 men and 301 women (mean age, 58.6 years) in the fixed-bearing group and 167 men and 278 women (mean age, 55.7 years) in the mobile-bearing group. The mean follow-up was 12.6 years (range, ten to seventeen years) in the fixed-bearing group and 14.1 years (range, twelve to seventeen years) in the mobile-bearing group.

Results: The mean postoperative Knee Society knee and functional scores were 92.9 points and 83.5 points, respectively in the fixed-bearing group. The mean postoperative Knee Society knee and functional scores were 90.7 points and 83.8 points, respectively. Incidence of osteolysis was 1.6% (fourteen of 894 knees) in the fixed-bearing group and it was 2.2% (eighteen of 816 knees) in the mobile-bearing group at the final review. Revision rate was 3.7% (thirty-three of 894 knees) in the fixed-bearing group and it was 2.7% (twenty-two of 816 knees) in the mobile-bearing group. Kaplan-Meier survivorship of the fixed-bearing group was 96.3% (95% confidence interval, 0.87–1.0) at 13 years follow-up and it was 97% (95% confidence interval, 0.90–1.0) of the mobile-bearing group at 14 years follow-up.

Conclusions: The present study demonstrates that the clinical and radiographic outcomes, the incidence of osteolysis, the rate of revision and the implant survivorship were similar between the fixed-bearing and mobile-bearing total knee arthroplasties.

Background: Alumina ceramic-on-highly cross-linked polyethylene (Al-on-X-linked PE) is attractive because of the potential for reduced wear, osteolysis and loosening of the component. The purpose of this study was to evaluate the clinical and radiographic outcomes of cement-less total hip arthroplasties (THAs) using Al-on-X-linked PE bearing and to determine the rates of osteolysis using radiographs and computer tomographic (CT) scans in young patients with osteonecrosis of femoral head.

Methods: Consecutive primary cementless THAs using Al-on-X-linked PE bearing were performed in 71 patients (73 hips) who were younger than 50 years of age with osteonecrosis of the femoral head. There were 48 men (51 hips) and 23 women (23 hips). The average age at the time of the index arthroplasty was 45.5 years (range, 20 to 50 years). Osteolysis was evaluated using radiographs and CT scanning. The average follow-up was 10.5 years (range, 10 to 13 years).

Results: The mean preoperative Harris hip score was 50.6 points (range, 27 to 55 points), which was improved to 96 points (range, 85 to 100 points) at the final follow-up. Preoperative functional activity was improved significantly (p=0.001) at the latest follow-up. All acetabular and femoral components were fixed by bone ingrown. The mean polyethylene linear penetration was 0.05±0.02 mm per year (range, 0.02 mm to 0.08 mm per year). Radiographic and CT scans demonstrated that no acetabular or femoral osteolysis was detected in any hip at the latest follow-up.

Conclusions: The current generation of anatomic tapered cementless femoral component with Al-on-X-linked PE bearing is functioning well with no osteolysis at a 10-year minimum and average of 10.5-year follow-up in this series of young patients with osteonecrosis of the femoral head.

Background: Whether total knee arthroplasty using computer-assisted surgical navigation can improve the limb and component alignment is a matter of debate. We hypothesized that total knee arthroplasty using computer-assisted surgical navigation is superior to the conventional total knee arthroplasty with regard to the precision of implant positioning.

Methods: Sequential simultaneous bilateral total knee arthroplasties were carried out in 160 patients (320 knees). One knee was replaced using a computer-assisted surgical navigation system and the other conventionally without using computer-assisted surgical navigation. The two methods were compared for accuracy of orientation and alignment of the components determined by radiographs and computed tomographs. The mean follow-up was 3.4 years.

Results: The mean preoperative Knee Society score was 26 points in the computer-assisted total knee arthroplasty group, which was improved to 92 points postoperatively and it was 25 points, which improved to 93 points post-opertively in the conventional total knee arthroplasty group. Ranges of motion of the knees were similar in both groups. The operating and tourniquet times were significantly longer in the computer-assisted total knee arthroplasty group than in the conventional total knee arthroplasty group (P< 0.001). Accuracy and the number of outliers of component position between the two groups were not significantly different (P> 0.05).

Conclusions: Our data demonstrated that total knee arthroplasty using computer-assisted surgical navigation did not result in more accurate implant positioning than that achieved in conventional total knee arthroplasty, determined by both radiographs and computed tomographs.

Background: The main goals of total knee arthroplasty are pain relief and improvement of function and range of motion. To ascertain whether posterior cruciate-retaining-flex total knee prosthesis would improve pain, function and range of motion, we asked whether knee and pain scores, ranges of motion, WOMAC score, patient satisfaction, and radiographic results would be better in the knees with a high-flexion posterior cruciate-retaining prosthesis than in the knees with a standard posterior cruciate-retaining prosthesis.

Methods: Fifty-four patients (mean age, 69.7 years) received a standard posterior cruciate-retaining knee prosthesis in one knee and a high-flexion posterior cruciate-retaining knee prosthesis in the contralateral knee. Five patients were men, and forty-nine were women. The minimum follow-up was three years (mean 3.1 years). At each follow-up, the WOMAC score and range of knee motion were evaluated and patients were assessed clinically and radiographically with use of the knee-rating systems of the Knee Society and The Hospital for Special Surgery.

Results: The mean postoperative Knee Society and Hospital for Special Surgery knee scores were 93.7 and 89 points, respectively in the knees with a standard posterior cruciate-retaining prosthesis and those were 93.9 and 90 points, respectively in the knees with a high-flexion posterior cruciate-retaining prosthesis. The mean postoperative WOMAC score was 22 points. Postoperatively, the mean non-weight and weight bearing ranges of motion were 131° (range, 90° to 150°) and 115° (range, 75 to 145°), respectively in the knees with a standard prosthesis and those were 133° (range, 90° to 150°) and 118° (range, 75 to 145°), respectively in the knees with a highflexion prosthesis. Patients satisfaction and radiographic results were similar in both groups. No knee had aseptic loosening, revision, or osteolysis.

Conclusions: After a minimum follow-up of three years, we found no significant differences between the two groups with regard to range of knee motion or clinical and radiographic results.

The purpose of this study is to identify clinical and radiographic results of 78 uncemented total hip arthroplasties using Metasul^® metal on metal bearings with Wagner standard cup and proximal hydroxyapatite coated CLS stem.

Mean age was 39 years and average follow-up period was 11.7 years. Mean Harris hip score had improved from 51.4 points preoperatively to 95.2 points finally. There were 2 hips with progressive osteolysis around the acetabular cup. Of them, one hip was revised due to loosening of the cup, and the other was observed because of patient’s refusal to revise. In histopathologic findings on osteolytic area, a lot of macrophage phagocytizing metal debris and perivascular lymphocyte infiltration were found. Immunohistochemical analysis suggested delayed metal hypersensitivity. Serum cobalt levels in hips with osteolysis were not higher than those in hips without osteolysis.

Early osteolysis with sudden onset of groin pain in few hips remains a concern.

We hypothesized that navigation can help provide a well-balanced knee, through real-time feedback of alignment accuracies and gap sizes in flexion and extension. The purpose of this study was to evaluate in vivo stabilities of mediolateral laxity in full extension and anteroposterior laxities in 90° of flexion after navigation-assisted total knee arthroplasty, and to determine the nature of the correlations between these and range of motion (ROM).

Forty-two total knee arthroplasties performed using a navigation system with a minimum two-year follow-up were included. The following were measured at final follow-ups; mediolateral laxities at extension and anteroposterior laxities at 90 degrees of flexion (using stress radiographs and a Telos arthrometer), modified HSS scores (excluding laxity and range of motion), and range of motion (ROM).

At final follow-up the mean modified HSS score was 82% of total points and mean postoperative ROM was 128.1 ± 10.4°. Mean medial laxity was 3.5 ± 1.4°, mean lateral laxity 4.4 ± 2.2°, and mean anteroposterior laxity 7.1 ± 4.1 mm. We found no significant correlation between mediolateral laxity and postoperative ROM. However, a significant correlation was found between postoperative ROM and anteroposterior laxity.

In the present study, the use of a navigation system in total knee arthroplasty was found to improve in vivo stability and produce promising short-term clinical results.

Summary: Using a navigation system in total knee arthroplasty, we obtained good in vivo stability and found the positive correlation between the range of motion and anteroposterior laxity

The osseointegration of implants is related to the early interactions between osteoblastic cells and titanium surfaces. The behavior of osteoblast cells was compared on four different titanium surfaces in vitro and in vivo: machined, blasted, plasma spray and micro-arc oxidation.

X-ray diffraction and scanning electron microscope investigations were performed in order to assess the structure and morphology. Biologic and morphologic responses to the osteoblast cell lines (Saos-2) were then examined, using Promega proliferation assay, alkaline phosphatase activity, vβ3 integrin expression and cytoskeleton staining (Rhodamine-Phallodine). The analysis of gene expression for osteocalcin and collagen I was done through RT-PCR. In addition, differential histologic evaluation and interfacial strength at the bone-implant interfaces were then evaluated in the distal femur of four beagle dogs.

In conclusion, micro-arc oxidation of titanium appears to exhibit more favorable osteoblast adhesion and stronger interfacial strength than the compared groups in vitro and in vivo as well.

The use of polymethylmethacrylate (PMMA) in orthopaedic reconstructive surgery can increase the possibility of cardiovascular dysfunction remains a debate. This study was undertaken to determine if cemented hemiarthroplasty is safe in treatment of femoral neck fracture in patients with ischemic heart disease. Between March 1999 and February 2004, we performed cemented hemiarthroplasties for displaced femoral neck fractures on 158 consecutive patients. This retrospective study consisted of 44 patients with ischemic heart disease(group 1) and 58 patients of age matched control(group 2). We compared the mortality rate, the incidence of deep vein thrombosis (DVT), pulmonary embolism, cerebrovascular disease, dislocation, deep infection, the amount of postoperative blood loss, and the grade of cementation by Barrack in radiograph between two groups.

No difference was found in perioperative mortality rate, deep infection rate, the incidence of DVT or pulmonary embolism, the newly developed heart ischemic event or brain hemorrhagic lesion between the two groups. But there were more incidence of dislocation related to weakness by past brain ischemic lesion and the newly developed brain ischemia in patients of group 1 than group 2(p < 0.05). More importantly, six patients in group 1 had transient symptoms of dyspnea, signs of hypotension, and bradycardia during two days postoperatively, which is suspicious of embolic phenomenon, even though it was not confirmed.

More closer and careful observations for the occurrence of dislocation related to previous brain ischemia, or newly developed brain ischemic lesion or embolic phenomenon and appropriate thromboprophylaxis are necessary in patients with ischemic heart disease after a cemented hemiarthroplasty for the treatment of femoral neck fracture.