The Results of Two-stage Revision for Methicillin-resistant Periprosthetic Joint Infection (PJI) of the Hip.

INTRODUCTION: Periprosthetic joint infection (PJI) of the hip due to methicillin-resistant bacteria is difficult to treat and remain a challenge for arthroplasty surgeon. MATERIAL AND METHODS: Retrospective review was done to the patients who received two-stage revisions with an antibiotic loaded cement-spacer for PJI of the hip between January 2010 to May 2015. We found 65 patients (65 hips) with positive culture findings. Eight patients were lost to follow-up and excluded from the study. Among the rest of the 57 patients, methicillin-resistant infection (MR Group) was found in 28 cases. We also evaluate the 29 other cases that caused by the other pathogen as control group. We compared all of the relevant medical records and the treatment outcomes between the two groups. RESULTS: The mean of follow-up period was 33.7 months in the methicillin-resistant group and 28.4 months in the control group (p = 0.27). The causal pathogens in the methicillin-resistant group were: Methicillin-resistant Staphylococcus aureus (MRSA) in 10 cases, Methicillin-resistant Staphylococcus epidermidis (MRSE) in 16 cases and Methicillin-resistant coagulase-negative Staphylococcus (MRCNS) in two cases. The reimplantation rate was 92.8% and 89.6% in the methicillin-resistant and control group, respectively (p= 0.66). The rates of recurrent infection after reimplantation were 23.1% (6/26) in the methicillin-resistant group and 7.6% (2/26) in the control group (p= 0.12). The overall infection control rate was 71.4% (20/28) and 89.6% (26/29) in the methicillin-resistant and control group, respectively (p = 0.08). Both groups showed comparable baseline data on mean age, BMI, gender distribution, preoperative ESR/CRP/WBC and comorbidities. CONCLUSIONS: Two-stage revision procedure resulted in low infection control rate and high infection recurrency rate for the treatment of methicillin-resistant periprosthetic joint infection (PJI) of the hip. Development of the treatment strategy is needed to improve the outcome of methicillin-resistant periprosthetic joint infection (PJI) of the hip.

Minimally Invasive Total Hip Arthroplasty in a Patient with Hereditary Multiple Exostoses: A Case Report.

Hip geometry abnormalities found in patients with hereditary multiple exostoses (HME) could promote premature hip joint degeneration which needs treatment. We report the case of a 45-year old male with right hip arthrosis who underwent two-incision minimally invasive (MIS-2) total hip arthroplasty (THA), with satisfactory outcome. This technique could be an alternative approach for performing THA in patients with hereditary multiple exostoses.

Migratory Bone Marrow Edema Syndrome of the Hips: A Case Report.

Migratory bone marrow edema syndrome (BMES) of the hip is a rare entity. We report the case of a 41-year old male with migratory BMES of the hip with eight months interval period between onset of the pain and consultation. This patient was successfully treated non-surgically. It is important to always inform the patient with unilateral BMES of the hip regarding the possibility of future involvement of the contralateral hip.

Outcome of alternative approach to displaced acetabular fractures.

INTRODUCTION: Anatomical reduction of displaced acetabular fracture is not without its' limitations and complications. This study is conducted to assess clinical and radiological outcomes as well as complications of treating displaced acetabular fractures with emphasis on anatomical reduction in weight-bearing area, mainly the posterior column, and imperfect reduction of the anterior column is acceptable. However, stability of both columns is mandatory. METHODS: It was a retrospective study carried out in a Level 1 arthroplasty and trauma centre. 23 patients (17 males, 6 females) with average age of 50.1 years (range, 36-68 years) with displaced acetabular fracture treated with combined incisions and plate-cable systems were included. There were 3 elementary and 18 associated fractures according to Letournel classification. Average follow-up was 23.5 months (range, 12-38.7 months). Mean operation time was 160min (range: 75-320min). Functional scores were evaluated using Harris Hip Score (HHS) whilst reduction was assessed by Matta criteria. Any displacement of reduction, osteoarthritis, heterotopic ossification, and other complications was recorded. RESULT: 65.2% (15/23) of the patients obtained excellent HHS and 21.7% (5/23) had good HHS. There were 12 anatomical, 6 imperfect, and 5 poor reductions. No displacement was recorded in final follow-up. Complications documented: three lateral femoral cutaneous nerve injuries, two conversions to total hip arthroplasty, three Brooker stage 1 heterotrophic ossification, one pulmonary embolism and one screw irritation. No incidence of wound breakdown, infection and radiological osteoarthritis was reported. CONCLUSIONS: Imperfect reduction of the anterior column provided clinical outcomes that are as good as total anatomical reduction. This approach minimizes soft tissue damage and reduces perioperative morbidities.

The effect of anteroposterior laxity on the range of movement and knee function following a cruciate-retaining total knee replacement.

The amount of anteroposterior laxity required for a good range of movement and knee function in a cruciate-retaining total knee replacement (TKR) continues to be debated. We undertook a retrospective study to evaluate the effects of anteroposterior laxity on the range of movement and knee function in 55 patients following the e-motion cruciate-retaining TKR with a minimum follow-up of two years. The knees were divided into stable (anteroposterior translation, < or = 10 mm, 38 patients) and unstable (anteroposterior translation, > 10 mm, 17) groups based on the anteroposterior laxity, measured using stress radiographs. We compared the Hospital for Special Surgery (HSS) scores, the Western Ontario MacMasters University Osteoarthritis (WOMAC) index, weight-bearing flexion, non-weight-bearing flexion and the reduction of flexion under weight-bearing versus non-weight-bearing conditions, which we referred to as delta flexion, between the two groups at the final follow-up. There were no differences between the stable and unstable groups with regard to the mean HHS and WOMAC total scores, as well as weight-bearing and non-weight-bearing flexion (p = 0.277, p = 0.082, p = 0.095 and p = 0.646, respectively). However, the stable group had a better WOMAC function score and less delta flexion than the unstable group (p = 0.011 and p = 0.005, respectively). Our results suggest that stable knees with laxity < or = 10 mm have a good functional outcome and less reduction of flexion under weight-bearing conditions than unstable knees with laxity > 10 mm following an e-motion cruciate-retaining TKR.

Efficient transfer of reporter gene-loaded nanoparticles to bone marrow stromal cells (D1) by reverse transfection.

Nucleic acids can be complexed with cationic polymer to form DNA nanoparticles (polyplex) which are then immobilized on the surface coated extracellular matrix protein (ECM), the process termed as reverse transfection. ECM-containing proteins provide a surface for cell attachment and sustain the release of polyplexes from their surface, thereby inducing transgene expression for prolonged period of time. Consequently, long-term expression of the desired protein can be achieved with the smaller amount of required DNA, as compared to bolus delivery. First of all, we investigated the different ECM components as a coating material and the range of optimal coating density in different ECM was examined for enhanced transfection to neighboring cells. Reporter genes such as luciferase (luc) and enhanced green fluorescent protein (eGFP) were initially used to quantitate transfection efficiencies from polyplex from the coated ECMs of Collagen type I (Col I), fetal bovine serum protein (FBS), bovine serum albumin (BSA). DNA was complexed with positively charged polyethyleneimine (PEI) at N/P ratio 9. Our initial work exhibited that, in the case of both NIH/3T3 cell line and bone marrow stromal (D1) cell line, Col I facilitated the greatest cell adhesion compared to the other coating proteins and 0.5 microg/cm2 of Col I coating density resulted in highest transfection efficiency. On the other hand, comparison of reverse delivery system with atelocollagen-I have shown that reverse delivery system to yield ten times higher transfection efficiency than atelocollagen-PEI/DNA delivery system and one hundred times higher than atelocollagen-naked plasmid delivery system. Moreover, the amount of DNA used for reverse delivery system was much lower than the other systems. This methodology would be applied to induce cellular differentiation in 3-dimensional scaffold after coating scaffolds with genes inducing the differentiation in the nanoparticle formulation. Our final goal is to search for the optimal conditions for the differentiation of stem cells to specific cell types.

Septic arthritis of hip after radiotherapy for carcinoma of cervix.

Radiation-induced damage to the bone is characterised by four main pathological findings: osteoporosis, bone-marrow fibrosis, trabecular microfractures and disseminated areas of focal necrosis. The complications of radiotherapy affecting hip and pelvis are well known, but septic arthritis of the hip joint following pelvic irradiation is a rare occurrence. Radiation-induced damage associated with a compromised host defence may be considered responsible for this complication. We report septic arthritis of hip joint in a 64-year-old woman who was treated with pelvic radiotherapy for carcinoma of the cervix eight years ago. She was successfully treated by two-stage reconstruction, consisting of debridement and antibiotic-loaded cement spacer insertion in the first stage and total hip replacement in the second stage.

Conservative treatment for transient osteoporosis of the hip in middle-aged women.

Transient osteoporosis of the hip is a clinical entity that is being diagnosed and reported with increasing frequency. Its aetiology remains a matter of speculation, and the same remains true for its treatment. Many researchers have proposed different surgical and non-surgical treatment strategies; but the conservative approach, which takes the form of analgesics, intermittent traction, range of motion exercises, abductor strengthening exercises and restricted weight bearing, is preferred. The authors report on two patients, both women, aged 35 years and 42 years, respectively, with transient osteoporosis of the hip that were successfully treated using a conservative approach.

Comparison of functional results with navigation-assisted minimally invasive and conventional techniques in bilateral total knee arthroplasty.

This study was undertaken to compare the clinical and radiological results achieved using navigation-assisted minimally invasive surgery (NA-MIS) and conventional (CON) techniques in 42 bilateral total knee arthroplasty (TKA) patients with a minimum follow-up of one year. Clinical evaluations were performed using range of motion (ROM), Hospital for Special Surgery (HSS) scores, and Western Ontario and McMaster University (WOMAC) scores (pain, functional, and total) at 3, 6 and 9 months and one year postoperatively. Patients' subjective preferences and radiological indices, including mechanical axis and coronal inclinations of the prostheses, were compared at one year postoperatively. NA-MIS TKA yielded better HSS and WOMAC total scores than CON TKA up to six months, and a better WOMAC pain score up to 9 months. However, these differences were not significant at one year postoperatively. ROM was comparable in both groups at all times, but more patients preferred the NA-MIS side to the CON side. Radiological results showed no differences in mean values between the two surgical groups, although the NA-MIS group contained fewer outliers than the CON group. In conclusion, NA-MIS TKA was associated with better clinical results up to 6 or 9 months after surgery, giving more accurate leg alignment than CON TKA.

A modified two-incision minimally invasive total hip arthroplasty: technique and short-term results.

Between 2003 and 2005, a total of 425 consecutive cases with a modified two-incision minimally invasive total hip arthroplasty (THA) were performed at our hospital. We analysed 225 cas-es with greater than 12 months follow-up clinically and radiographically. The mean operative time was 70 minutes. Patients could walk on crutches at 1.5 days and discontinued crutch use at an average of 3 weeks. Patients were able to walk upstairs without support at 4 weeks. Radiographic analysis showed the mean lateral opening angle and anteversion of the acetabular components were 43.0 and 17.3, and 97% of the femoral stems were in neutral alignment. There was no radiographic evidence of component migration or subsidence at the most recent follow-up. Therefore, from these early results, a modified two-incision THA was found to be an excellent surgical modality, which allows early rehabilitation and does not increase complications when compared to other MIS two-incision THA techniques.

Hyaluronic acid and silver sulfadiazine-impregnated polyurethane foams for wound dressing application.

Five different kinds of PU foam wound dressings were prepared to investigate their wound healing capability. They include (i) PU+silver sulfadiazine (AgSD), (ii) PU+alginate (Al), (iii) PU+Al+AgSD, (i.v.) PU+hyaluronic acid (HA), and (v) PU+HA+AgSD. Physical properties and in vitro behaviors of AgSD release and fibroblast adhesion on those dressings were evaluated. From the drug release and fibroblast adhesion studies, it was observed that PU foam impregnated with both HA and AgSD shows good drug release behavior and low adhesion of the cells. Furthermore, the HA and AgSD-containing PU foam showed excellent wound healing effect without any inflammation or yellow cluster. The wound size decreased around 77% after 1 week application of that foam dressing onto a rat skin defect.

Clinical and radiographic outcome of femoral head fractures: 30 patients followed for 3-10 years.

The aim of this study was to evaluate the outcome of 30 femoral head fractures. We modified Pipkin's classification into 4 types: I (5 cases) small fracture of head distal to fovea centralis, which was too small or too fragmented to be fixed with screws; II (18 cases), larger fracture of head distal to fovea centralis; III (4 cases), large fracture of head proximal to fovea centralis, and IV (3 cases), comminuted fracture of head. Excision of the head fragment was done in all 5 cases of type I and in 9 type II fractures. Fixation of the head fragment was performed in 9 type II and in all 4 type III cases. The femoral head was replaced in all 3 type IV fractures. After a mean follow-up of 3-10 years, the clinical outcome, according to Epstein et al.'s critieria, were excellent in 7, good in 15, fair in 4 and poor in 1, except in type IV, and the radiographic outcome was excellent in 15, good in 7, fair in 4 and poor in 1. On the basis of our findings, we conclude that excision of the small fragment is a good choice of treatment in type 1. Early accurate reduction with stable internal fixation in type II or III permits bony union. Arthroplasty seems to be indicated in type IV.

Strut-autografting with and without osteogenic protein-1 : a preliminary study of a canine femoral head defect model.

BACKGROUND: Osteonecrosis of the femoral head frequently leads to collapse of the articular cartilage and to disabling osteoarthritis, which ultimately may necessitate joint arthroplasty. One treatment method that has had moderate success is the so-called trapdoor approach, which involves excavation of diseased (necrotic) bone followed by bone-grafting. Augmentation of this procedure with various growth and differentiation factors may improve the outcome. We developed a canine model that mimics the clinical situation with trapdoor bone-grafting. The objective of this study was to evaluate the effect of the addition of osteogenic protein-1 on healing following the trapdoor procedure with strut-autografting. METHODS: Thirty-four skeletally mature dogs were used in the experiment. After capsulotomy, a trapdoor was created in the anterolateral surface of the femoral head and a 2-cm-diameter subchondral area of bone was removed. In the phase-I experiments, seven dogs had no treatment of the defect (Group I) and nine dogs were treated with strut-grafting (Group II). In phase II, the procedure was modified by collapsing the trapdoor into the created defect intraoperatively in eighteen dogs, which were divided into three equal groups: six untreated defects were left collapsed (Group III), six were treated with bone graft (Group IV), and six were treated with bone graft augmented with osteogenic protein-1 (Group V). RESULTS: Three of the seven femoral heads in Group I (untreated defect) and one of the nine heads in Group II (grafting without collapsing of the trapdoor) had evidence of cartilage collapse. Inspection of sagittal slices and radiographs revealed an unfilled residual defect in all Group-I heads, whereas all Group-II heads were well healed. The mean normalized stiffness value was significantly larger in Group II than it was in Group I. On visual inspection, depression was noted in all of the femoral heads in Group III (untreated defect; trapdoor left collapsed). In both Group IV and Group V (grafting without and with osteogenic protein-1), the trapdoor cartilage appeared to be essentially normal. Groups IV and V had more radiographic healing than did Group III. The defects in Group V (grafting with osteogenic protein-1) healed faster radiographically than did those in Group IV (grafting without osteogenic protein-1). CONCLUSIONS: Moderate-to-excellent healing was seen both radiographically and biomechanically by four months in the groups treated with grafting, with and without osteogenic protein-1, whereas untreated defects did not heal. CLINICAL RELEVANCE: Symptomatic osteonecrosis of the femoral head is a clinical challenge. The animal model in the current study is a useful tool for the evaluation of methods to treat osteonecrosis of the femoral head. Studies investigating additional time-periods between implantation of osteogenic protein-1 and assessment of results as well as different doses of osteogenic protein-1 are warranted.

Failure after core decompression in osteonecrosis of the femoral head.

In a retrospective study of 39 hips with osteonecrosis of the femoral head treated with core decompression we evaluated the extent of the necrotic area, the Ficat stage and the location of the lesion. The extent of the necrotic lesion was classified into three categories: mild, less than 15%; moderate, 15-30%; and severe, more than 30%. In 14 mild cases core decompression failed in 2, whereas there were 4 failures out of 7 moderate cases and 16 failures out of 19 severe cases. The extent and location of the necrotic portion as well as the Ficat stage can be used as predictors for the result of core decompression in osteonecrosis of the femoral head.

Aseptic synovitis after meniscal repair using the biodegradable meniscus arrow.

We report a case of aseptic synovitis in a 19-year-old man. The synovitis of the left knee developed 13 months after meniscal repair using the biodegradable Meniscus Arrow (Bionx Inc, Malvern, PA). Histologic examination revealed chronic nonspecific synovitis and birefringent materials. Immunohistochemical tests were positive in lysozyme, alpha-1-antitrypsin, and alpha-1-antichymotrypsin. After arthroscopic synovectomy, pain and swelling of the knee joint were relieved and the patient's range of motion fully recovered. We have found no previous report of aseptic synovitis accompanying meniscal repair using the biodegradable Meniscus Arrow.

Femoral head osteonecrosis: detection and grading by using a rapid MR imaging protocol.

PURPOSE: To design and evaluate a limited magnetic resonance (MR) imaging examination that can be performed rapidly and potentially inexpensively in patients with clinical suspicion of osteonecrosis. MATERIALS AND METHODS: Both a limited and a full hip MR examination were performed prospectively in 179 hips in 92 patients with clinical suspicion of femoral head osteonecrosis. The presence of osteonecrosis was determined by two radiologists. The percentage of involvement of the femoral head weight-bearing surface was evaluated subsequently for osteonecrosis-positive hips on both sets of images. RESULTS: Both examinations were performed successfully in all cases. Agreement between the limited and full examinations for presence of osteonecrosis was 98.9% (177 of 179 cases; kappa, 0.97). Forty-six (92%) of 50 patients with femoral head osteonecrosis at both examinations were placed in the appropriate quartile of percentage of femoral head weight-bearing surface involvement by both readers (weighted kappa, 0.94). Incidental findings were made at the full examination that could not be made or were difficult to make at the limited examination. CONCLUSION: There was excellent agreement between the full and screening MR examinations for both detection of and determining the extent of osteonecrosis. The time and potential cost reduction achieved with a limited examination may allow introduction of MR imaging earlier in the diagnosis of femoral head osteonecrosis, as well as its more widespread use in patient care.

Clinical experience with a proximally porous-coated second-generation cementless total hip prosthesis: minimum 5-year follow-up.

This study reports the minimum 5-year follow-up of our experience with the Porous-Coated Anatomic E (PCA-E) series femoral stem and the modular acetabular cup. A total of 115 consecutive total hip replacements using PCA-E series (Howmedica, Rutherford, NJ) were performed in 108 patients. Six patients whose hips were performing well clinically died before 5-year follow-up and were excluded from the final evaluation. The remaining 109 hips (102 patients) were assessed at a mean follow-up of 72 months (range, 60-84 months). The hip diagnoses were osteoarthritis in 73, osteonecrosis in 31, rheumatoid arthritis in 2, and hip dysplasia in 3. The mean age was 56 years (range, 24-83 years). Three hips were revised: 1 because of late hematogenous infection, 1 because of aseptic loosening of the femoral component, and 1 because of postoperative loosening of an acetabular component. The Harris hip scores improved from a mean of 50 points (range, 20-66 points) preoperatively to a mean of 92 points (range, 64-100 points) at final follow-up. The score differed in each Charnley functional class, with a mean of 93 points (range, 72-100 points) in 57 hips of class A (no other joint involvement); 90 points (range, 58-100 points) in 26 hips of class B (opposite hip involvement); and 85 points (range, 37-100 points) in 26 hips of class C (multiple joint involvement or severe systemic disease). Out of 106 hips that had a full radiographic evaluation performed, 103 femoral components revealed stable bony ingrowth, 2 revealed stable fibrous ingrowth, and 1 showed migration with progressive loosening. This patient with radiographic loosening has minimal symptoms and has not required or been offered further surgery (Harris hip score of 86 points). The low aseptic loosening rate (2%) at minimum 5-year follow-up compares favorably with any cemented or cementless series. The osteolysis that was seen was focal and localized. The short follow-up does not allow determination of progression. There were no cases of distal osteolysis. We attribute the improved results from reported first-generation experience to multiple factors, including increased number of sizes (9 vs 6), increased proportional metaphyseal size, improved polyethylene manufacture (ram extruded vs machined), improved acetabular locking mechanism, and change to 26-mm from 32-mm femoral heads.

Eliminating patellofemoral complications in total knee arthroplasty: clinical and radiographic results of 121 consecutive cases using the Duracon system.

This study reports the minimum 5-year follow-up of our experience with the Duracon Total Knee Arthroplasty System. A total of 121 consecutive total knee replacements using the Duracon system (Howmedica, Rutherford, NJ) were performed in 104 patients. Three patients died before the 5-year follow-up and were excluded from the final evaluation. The remaining 118 knees (101 patients) were assessed at a mean follow-up of 65 months (range, 60-80 months). The knee diagnoses were osteoarthritis in 97 patients, rheumatoid arthritis in 2 patients, osteonecrosis in 1 patient, and pigmented villonodular synovitis in 1 patient. The mean age was 70 years (range, 28-85 years). There were no reoperations for aseptic loosening, and there have been no reoperations for patellofemoral problems. At final follow-up evaluation, 112 knees (96%) had good or excellent results, and 6 knees (4%) had poor clinical results or went on to revision. For the surviving knees, the preoperative Knee Society objective score improved from a mean of 52 points (range, 20-72 points) to a final follow-up mean of 94 points (range, 66-100 points). Five knees needed reoperations: 2 knees in 1 patient because of acute hematogenous infection at 12 months, 1 knee because of a supracondylar femur fracture, 1 because of a patellar tendon rupture, and 1 to increase polyethylene thickness because of instability. The lack of aseptic loosening at the minimum 5-year follow-up compares favorably with any cemented or cementless series of knee replacement. The almost complete absence of patellofemoral complications in this series also indicates that the design changes, with particular attention to the trochlea design and patellofemoral contact throughout full flexion, have achieved their intended purpose. The results are encouraging at midterm, awaiting true long-term (15-20 years) follow-up.