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Biomedical subjects

Khaled J Saleh

Publications and source records attributed to Khaled J Saleh.

At least 19 recordsLinked to original sources
PubMed2007

Activity level in young patients with primary total hip arthroplasty: a 5-year minimum follow-up.

Increased activity level after total hip arthroplasty (THA) is considered a risk factor for early prosthetic failure in young patients. Forty-one primary total hip arthroplasties in 34 patients were evaluated. Walking activity was measured using a pedometer to record gait cycles. Patients completed a University of California, Los Angeles (UCLA) activity questionnaire. Linear wear rates were measured. Mean ages at surgery and final follow-up were 42 and 50.3 years, respectively (mean gait cycles per year, 1.2 million; mean UCLA score, 6; mean linear wear, 0.16 mm/y). Increased body mass index and age correlated with decreased gait cycles per year. Patients with systemic disease were less active than patients with localized hip conditions. Femoral head diameter was a predictor of linear wear. The average gait cycles per year and wear rate for this population do not appear accelerated relative to average values reported in older populations.

Adult↗
PubMed2006

Primary total knee arthroplasty with condylar allograft and MCL reconstruction for a comminuted medial condyle fracture in an arthritic knee--a case report.

Fractures of the distal femur in the elderly are usually due to low energy ground level fall onto a flexed knee. Pre-existing osteoarthritis and juxta-articular osteopenia in this age group result in high levels of comminution and articular damage at the time of injury, which challenges the management and treatment outcome. Preservation of knee function and early weight bearing should be the objectives of management in the geriatric population. We present in this case report of an elderly patient with comminuted medial condyle fracture with arthritic changes who had primary total knee arthroplasty utilizing condylar allograft and MCL reconstruction as an alternative to internal fixation.

Accidental Falls↗
PubMed2006

Patellofemoral instability after total knee arthroplasty.

UNLABELLED: Despite advances in surgical technique and implant design, complications involving the extensor mechanism and patellofemoral joint after total knee arthroplasty (TKA) continue to be the most common cause of pain and the most commonly cited reason for revision TKA surgery. A thorough understanding of the etiologies of patellofemoral instability, careful preoperative planning, and meticulous surgical techniques will optimize clinical outcome. Evaluation of patellofemoral stability should begin in the operating room. Postoperatively, thorough history, physical examination, and dedicated radiographic studies should be obtained. Computed tomography scan is the most accurate and reliable way to assess component positioning. Treatment of patellofemoral instability is directed by its etiology. Revision of one or both components is indicated if malpositioning is present. If the components are determined to be in satisfactory positions, soft tissue procedures can be pursued. Future advancements in prosthetic design and the routine use of computer-assisted navigation systems will minimize patellofemoral instability. LEVEL OF EVIDENCE: Therapeutic study, Level V (expert opinion). See the Guidelines for Authors for a complete description of levels of evidence.

Arthroplasty, Replacement, Knee↗
PubMed2006

Socioeconomic issues and demographics of total knee arthroplasty revision.

UNLABELLED: Despite rising numbers of total knee arthroplasty revision (TKAR) procedures there remains a paucity of information regarding the relationships between total knee arthroplasty failure and socioeconomic and educational status, demographics, general health and functional disability. We performed a multicenter prospective study of 290 consecutive TKAR patients in order to determine whether they differed from the population they were drawn from in terms of socioeconomic or educational status, race or gender. Secondary aims were to establish the relative comorbid status of this population, social supports and their general health status compared to national norms and their modes of failure. Our cohort consisted of 137 males and 153 females with a mean age of 68.6 years (range, 34-85 years), substantial overall functional disability according to the SF-36 and a large average number of comorbidities at baseline. We found a relative overrepresentation of patients of comparatively low socioeconomic and educational status and also of Caucasian patients in the TKAR population. This large prospective investigation demonstrates demographic features associated with TKA failure and provides a platform for further investigations on the effect demographic characteristics have on the outcomes of TKAR. LEVEL OF EVIDENCE: Prognostic Study, Level II (Lesser quality prospective study). See Guidelines for Authors for a complete description of the Levels of Evidence.

Adult↗
PubMed2006

Current etiologies and modes of failure in total knee arthroplasty revision.

UNLABELLED: Although total knee arthroplasty is a very effective intervention and increasing in prevalence, failures do occur. We studied patients presenting for total knee arthroplasty revision to determine any modifiable causes of failure, both short and long term, and where future efforts should be directed to reduce the incidence of failure. A multicenter prospective observational cohort study of 318 consecutive patients, with minimum 1 year follow-up, undergoing total knee arthroplasty revision was performed. Associations between modes of failure were also assessed. The mean time from primary procedure to total knee arthroplasty revision was 7.9 years. Many patients (64.4%) had more than one cause of failure. Thirty-one percent of patients were early (< 2 years) failures at a mean of 11 months. These had a higher prevalence of infection, perioperative factors and comorbidities. Late failures occurred at a mean of 119.2 months. Other major causes of failure included instability (28.9%), wear (24.5%) and component loosening suggesting the importance of modifications in technique, implants and other areas. Application of these findings will ultimately reduce revision numbers through continued refinement of total knee arthroplasty practice and through further specific investigation of these modes of failure. LEVEL OF EVIDENCE: Therapeutic study, level II-2 (prospective study). See the Guidelines for Authors for a complete description of levels of evidence.

Adult↗
PubMed2006

Agreement about indications for total knee arthroplasty.

UNLABELLED: Total knee arthroplasty is an effective and cost efficient procedure that improves the quality of life for patients with end stage knee arthritis. With the prevalence of arthritis expected to increase with the aging of the population, the demand for total knee arthroplasty will increase substantially. We examined current indications for total knee arthroplasty by reviewing articles extracted from a comprehensive Med-line search. We studied the indications for proceeding with a total knee arthroplasty, the indications for referring a patient for a total knee arthroplasty, and the contraindications among orthopaedic surgeons, rheumatologists, and primary care providers. We evaluated 27-42 different patient factors. "Pain not responsive to drug therapy" was the only factor with consensus for total knee arthroplasty. "Major psychiatric disorder, including dementia" was the only contraindication to total knee arthroplasty that had a consensus. The lack of consensus within orthopaedics and across specialties likely represents a limitation in empirical data associated with total knee arthroplasty outcomes. Achieving better consensus will require conducting and disseminating better research on patient characteristics that predict the success of total knee arthroplasty. LEVEL OF EVIDENCE: Economic and decision analyses, level IV (analyses with no sensitivity analyses). See Guidelines for Authors for a complete description of levels of evidence.

Arthroplasty, Replacement, Knee↗
PubMed2006

Radiographic prediction of intraoperative bone loss in knee arthroplasty revision.

UNLABELLED: A key challenge for orthopaedic surgeons performing revision total knee arthroplasty is the management of bone loss. The goal of our study was to test the validity of predicting bone loss from preoperative radiographs using two commonly utilized bone loss assessments: the Anderson Orthopaedic Research Institute and University of Pennsylvania systems and secondarily to assess the frequency and severity of bone loss in a prospective study of total knee arthroplasty revisions. Ninety-eight total knee arthroplasty revision patients were assessed and bone loss was detected in 76 (77.6%) patients preoperatively and intraoperatively. The validity of both systems was established. Agreement between preoperative and intraoperative Anderson Orthopaedic Research Institute classification was fair for the femur and good for the tibia. All University of Pennsylvania preoperative measures were correlated with intraoperative measures. Establishing valid and reliable preoperative systems of measuring bone loss facilitates planning of total knee arthroplasty revision and rehabilitation and meaningful comparisons between different series of patients and treatment protocols. LEVEL OF EVIDENCE: Diagnostic study, level I (prospective testing of previously developed diagnostic criteria on consecutive patients [with universally applied reference "gold" standard]). See Author Guidelines for a complete description of levels of evidence.

Adult↗
PubMed2006

Extensor mechanism disruption after total knee arthroplasty.

UNLABELLED: Extensor mechanism disruption after total knee arthroplasty is a challenging complication for orthopaedic surgeons. The treatment options for repair include observation, direct primary repair, direct primary repair with synthetic ligament or autogenous tissue augmentation, or reconstruction with allograft tissue. A computerized systemic review and literature search was performed to identify the relevant literature on extensor mechanism disruptions associated with total knee arthroplasty. A comprehensive review of the literature and description of relevant treatment options and outcomes were performed using the information gained with the literature review. A multi-center prospective study on a consecutive series of patients recruited from the North American Knee Arthroplasty Revision (NAKAR) study was performed and data collected pre-operatively, intra-operatively, and post-operatively on patients that had a failed total knee arthroplasty using validated health related quality of life measures was analyzed. Six out of 290 patients in the study had extensor mechanism disruption and this group of patients had overall worse functional outcomes. The results of the study have solidified our knowledge that patients with extensor mechanism disruptions have worse functional outcomes and will need intensive management and rehabilitation. LEVEL OF EVIDENCE: Economic and decision analyses, level III (systematic review of level III studies). See Guide for Authors for a complete description of levels of evidence.

Arthroplasty, Replacement, Knee↗
PubMed2006

Increased surgical volume is associated with lower THA dislocation rates.

The presumed correlation between an increasing volume of health care procedures and an improvement in outcomes is sometimes referred to as the practice-makes-perfect effect. Growing interest in outcomes-based research has led to numerous papers examining this relationship for various surgical procedures, including total hip arthroplasty. The results of these studies have important implications for consumers, providers, and healthcare financers. Accordingly, we review the literature to date examining surgeon and hospital volume effects on hip arthroplasty outcomes, with a specific focus on the effects of volume on dislocation. A systemic review of the literature demonstrates a substantial positive association between surgical volumes and improvement in most THA outcomes, including dislocation; that is, increasing surgical volume is associated with lower dislocation rates. This correlation appears to be stronger and is more clearly established for surgeon volumes than it is for hospital volumes.

Arthroplasty, Replacement, Hip↗
PubMed2006

Does surgical approach affect total hip arthroplasty dislocation rates?

Dislocation is a common complication of total hip arthroplasty, but exact effect of surgical approach on dislocation rates remains unclear. Because little randomized prospective data exist in this context, we performed a meta-analysis comparing dislocation rates using the posterior approach with and without soft tissue repair. A systematic literature review resulted in five studies which directly compared the posterior approach with and without soft tissue repair. The dislocation rates with and without repair were 0.49% and 4.46%, respectively. The relative risk for dislocation was determined using a fixed effects model with chi square test for interstudy heterogeneity. The posterior approach without soft tissue repair was found to have an 8.21 times greater relative risk of dislocation than with soft tissue repair (95% confidence interval, 4.05-16.67). A separate systematic review of 11 studies revealed comparable dislocation rates associated with the anterolateral, direct lateral, and posterior approaches with soft tissue repair (0.70%, 0.43%, and 1.01%, respectively). These data demonstrate that adequate soft tissue repair greatly reduces the relative risk of dislocation using the posterior approach, and that the dislocation rates for the three most prevalent approaches are similar. Further prospective randomized trials examining dislocation rates and other clinical parameters are needed.

Age Distribution↗
PubMed2006

Systematic analysis of classification systems for osteonecrosis of the femoral head.

BACKGROUND: Multiple classification systems for osteonecrosis of the hip have been developed to assist physicians in the diagnosis and treatment of this potentially debilitating disorder. The purpose of this analysis was to delineate the classification systems utilized in reports published since 1985 and, through a comparison of the most commonly used systems, to identify consistent factors that would allow for cross-publication comparisons to be made. METHODS: We performed a PubMed search for reports of outcome studies concerning treatment methods for osteonecrosis of the hip. All studies of reported outcomes with greater than ten patients were included in the analysis. Various classification systems were tabulated to determine usage frequencies. The four most commonly used systems were then analyzed to determine common factors used for classification. RESULTS: One hundred and fifty-seven studies were available for analysis. Sixteen major classification systems that made use of more than one radiographic factor were identified, and nine of these systems had one to five modifications reported throughout the literature. Additionally, eleven other systems made use of single factors obtained from either magnetic resonance imaging or anatomic data. The review revealed that four classification systems accounted for greater than 85.4% of the reported studies. Parameters for these four systems were stratified to allow for uniformity of patient or study evaluation. CONCLUSIONS: This analysis of the reported classification systems for osteonecrosis of the femoral head revealed several similarities between the most commonly used systems. An analysis of patients can be made with any of the four major systems if specific data are collected according to various magnetic resonance imaging and radiographic findings. This approach will allow for easier comparison of studies across different centers. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Classification↗
PubMed2006

Alcohol-induced adipogenesis in a cloned bone-marrow stem cell.

BACKGROUND: Alcohol has been shown to be associated with osteoporosis and osteonecrosis in patients and in animal models. Recent studies have demonstrated that alcohol contributes to abnormal lipid metabolism in the stromal cells of bone marrow, but the mechanisms have not been defined. The purpose of this study was to evaluate the effects of alcohol on the differentiation of a stem cell that was cloned from bone marrow. METHODS: D1 cells (cloned bone-marrow stem cells from a BALB/c mouse) were treated either with increasing concentrations of ethanol (0.09, 0.15, and 0.21 mol/L) or without alcohol to serve as controls. Morphologic features of the cells were monitored with use of a phase-contrast microscope. Alkaline phosphatase activity was determined with use of a colorimetric assay. The expression of genes that are indicators of adipogenesis [422(aP2), PPARgamma] and osteogenesis (osteocalcin) was evaluated using Northern blot and reverse transcription-polymerase chain reaction assays. RESULTS: The cells treated with ethanol started to accumulate triglyceride vesicles at day seven. The number of adipocytes and the percentage of the area that contained the cells with fat vesicles increased significantly (p < 0.05), and the level of alkaline phosphatase activity diminished with longer durations of exposure to ethanol and with higher concentrations. Analysis of gene expression showed diminished expression of osteocalcin. This occurred without a significant increase in the expression of either the fat-cell-specific gene 422(aP2) or PPARgamma in cells treated with ethanol, suggesting that adipogenesis may occur at a point downstream in the fatty-acid-metabolism pathway. CONCLUSIONS: Alcohol treatment decreases osteogenesis while enhancing adipogenesis in a cloned bone-marrow stem cell, indicating that alcohol abuse may be one of the mechanisms leading to osteoporosis and osteonecrosis. This finding explains the clinical observation that there is increased adipogenesis in alcohol-induced osteoporosis and osteonecrosis. CLINICAL RELEVANCE: The inhibition of bone-marrow adipogenesis and the concomitant enhancement of osteogenesis may provide a novel approach to the prevention or treatment of osteonecrosis and osteoporosis.

Adipogenesis↗
PubMed2006

Outcomes of total and unicompartmental knee arthroplasty for secondary and spontaneous osteonecrosis of the knee.

BACKGROUND: The reported outcomes of patients who underwent total or unicompartmental knee arthroplasty for secondary and spontaneous osteonecrosis of the knee are often from studies that lack the number of subjects necessary to generate meaningful conclusions. We systematically reviewed the available literature in order to define the outcomes of patients after total knee arthroplasty for secondary osteonecrosis and after total or unicompartmental knee arthroplasty for spontaneous osteonecrosis of the knee. METHODS: A literature review yielded twenty cohorts with demographic patient information and outcome scores (global knee scores, radiographic outcomes, and revision rates) for patients who had knee arthroplasty as treatment for either secondary or spontaneous osteonecrosis of the knee. The mean preoperative and postoperative global knee scores, the mean revision rate, and the categorization of the mean "poor" and mean "good" outcomes for the knees with each underlying disease were tabulated and reported. The demographic data and the reported mean global knee scores were weighted by the number of knees in each study. RESULTS: Total knee arthroplasty was performed in 150 knees with secondary osteonecrosis and 148 knees with spontaneous osteonecrosis, and unicompartmental knee arthroplasty was performed in sixty-four knees with spontaneous osteonecrosis. Total knee arthroplasty for spontaneous osteonecrosis of the knee was associated with the best outcomes (higher "good" and postoperative global knee scores and lower revision [3%] and "poor" outcome [6%] rates compared with the other two groups). The outcomes after total knee arthroplasty in knees with secondary osteonecrosis as well as in knees with spontaneous osteonecrosis were better in the cohorts operated on during or after 1985 than in those operated on before 1985. Similarly, the outcomes after unicompartmental knee arthroplasty in knees with spontaneous osteonecrosis of the knee were also better in the cohorts operated on during or after 1985 than in those operated on before 1985. CONCLUSIONS: Total knee arthroplasty performed as treatment for either secondary osteonecrosis or spontaneous osteonecrosis and unicompartmental knee arthroplasty performed as treatment for spontaneous osteonecrosis were associated with improved outcomes in cohorts with more recent operative dates. The evidence suggests that the use of contemporary cemented implants in total knee arthroplasty and the selective use of stems and augments in patients who have development of secondary osteonecrosis after total knee arthroplasty are producing outcomes that are comparable to those seen after total knee arthroplasty for osteoarthritis. Although the outcomes of patients who have total knee arthroplasty for the treatment of spontaneous osteonecrosis of the knee have historically been favorable, such outcomes have also shown particular improvement in the studies from more recent operative periods. Although poor outcomes were seen after unicompartmental knee arthroplasty in earlier studies of patients with spontaneous osteonecrosis of the knee, it is possible that those results were secondary to inappropriate patient selection, as the authors of the most recent and, to our knowledge, the only study to follow established operative indications regarding the use of unicompartmental knee arthroplasty reported excellent results. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.

Adult↗
PubMed2006

Use of genetically engineered bone-marrow stem cells to treat femoral defects: an experimental study.

BACKGROUND: Treatment of osteonecrosis continues to be a challenging problem. The replacement of necrotic bone with graft materials that promote osteogenesis and angiogenesis may provide better outcomes for early stage disease. In this study, genetically engineered bone-marrow stem cells were used to enhance repair of a defect in the distal aspect of the femur. METHODS: Cloned bone-marrow stem cells were transfected with traceable genes. Osteoblastic and angiogenic properties of the cells were analyzed. A defect was created bilaterally in the distal portion of the femur of twenty-four mice to mimic a core decompression procedure. The cloned cells were transplanted into each defect of the right femur while the left femur served as control. Bone formation was evaluated radiographically and histomorphometrically. In addition, in twenty-four additional mice, the cells were injected into subcutaneous sites, muscles, and into the renal capsule (eight mice in each group) to evaluate ectopic osteogenesis. RESULTS: Radiopaque tissue appeared two weeks after the cells were transplanted into bone defects and at ectopic sites. Histologic analysis demonstrated that these tissues consisted of newly formed bone from transplanted cells that expressed traceable genes. Four of six bone defects that received cell transplantation were filled with new bone at four weeks, and all of the defects (n = 6) demonstrated complete healing at six weeks. On the control side, complete repair was seen in only two of six bone defects at four weeks and in three of six defects at six weeks. Histomorphometric analysis showed that transplantation of marrow stem cells into bone defects produced more bone at an earlier time-point than occurred in the controls. CONCLUSIONS: This study demonstrated that cloned bone-marrow stem cells can directly form bone after transplantation into bone defects and at ectopic sites, indicating that the in vitro expanded bone-marrow stem cells can serve as a graft material to enhance bone repair and to treat osteonecrosis. CLINICAL RELEVANCE: As an alternative graft material, bone-marrow stem cells may provide new and as yet technologically unachievable solutions to many clinical problems in the areas of musculoskeletal reconstruction and tissue regeneration.

Animals↗
PubMed2006

Displaced femoral neck fractures in the elderly: hemiarthroplasty versus total hip arthroplasty.

The incidence of femoral neck fracture among the elderly in the United States is expected to increase dramatically because of the anticipated explosion in the population aged 65 years and older, increased life expectancy, and the rising incidence of osteoporosis. The resulting public health implications may be significant, with annual hospital admissions resulting from hip fracture projected to increase to 700,000 by 2050, and with annual spending on hip fracture care expected to exceed 15 billion dollars within a few years. The decision to perform internal fixation, unipolar hemiarthroplasty, bipolar hemiarthroplasty, or THA must be based on patient mental status, living arrangement, level of independence and activity, and bone and joint quality.

Aged↗
PubMed2005

Differences in patient and procedure characteristics and hospital resource use in primary and revision total joint arthroplasty: a multicenter study.

A multicenter retrospective cost-identification cohort study was undertaken to analyze clinical, demographic, and economic data for 4533 consecutive total hip arthroplasty (THA) and 3508 consecutive total knee arthroplasty (TKA) procedures performed during a 3-year period in 1 of 3 hospitals. Statistically significant differences were found between primary and revision procedures with respect to patient age, sex, payer type, mean total operative time, use of allograft, average length of hospital stay, discharge disposition, and hospital costs. Significant differences were also found between different types of revision total joint arthroplasty (TJA) procedures. Our findings could be used to help improve the accuracy of administrative claims data related to primary and revision TJA procedures to identify relevant differences in patient characteristics, procedure characteristics, and hospital resource use.

Aged↗