Biomedical subjects
K J Saleh
Publications and source records attributed to K J Saleh.
Development, test reliability and validation of a classification for revision hip arthroplasty.
The objective of the study was to develop a valid and reliable classification system for failed hip arthroplasties. The study uses research principals derived from multi-attribute utility theory and consensus group techniques. The development of the severity measure was done in two phases. Phase I of the study included: (a) questionnaire development, (b) submission of the questionnaire to the respondents, (c) data synthesis of the responses and item reduction, and (d) classification development and inter-observer reliability testing. Phase II included: (a) resubmission of the instrument to the respondents for suggestions/feedback, (b) instrument revision by the co-investigators based on the respondents' second feedback, and (c) inter-observer reliability testing and intraoperative validity testing of the instrument. The questionnaires sought to capture expert opinion as to what clinical determinants obtained preoperatively (during patient interview, physical exam and review of plain radiographs - AP pelvis and hip lateral) that would in their clinical experience reveal intraoperative severity. There was an 80% (16/20) response rate from the outside experts invited to participate in the study. Based on item reduction and test retest analysis, a five-grade radiographic classification for the acetabulum as well as the femur was developed. This system was then reviewed by 13 of the initial outside experts (16, 80%) who participated in the first round. Inter-rater reliability testing of the final format of the classification revealed a weighted kappa statistic value of 0.88 between the two-blinded raters (inter-rater reliability) and 0.87 between the blinded raters and the reference standard (intraoperative validity). We conclude that the study developed a reliable and valid radiographic classification system for failed hip arthroplasty.
Displaced femoral neck fractures in the elderly: outcomes and cost effectiveness.
The optimal treatment for displaced femoral neck fractures in elderly patients is a matter of controversy. Four surgical options are well supported in the orthopaedic literature: reduction with internal fixation, unipolar hemiarthroplasty, bipolar hemiarthroplasty, and total hip arthroplasty. Based on a review of the outcomes literature regarding treatment of femoral neck fractures and a cost-effectiveness analysis, an algorithm for surgical treatment of displaced femoral neck fractures in elderly patients is presented. Cost-effectiveness analysis of these four surgical treatment options shows that arthroplasty is the most cost-effective treatment when complication rate, mortality, reoperation rate, and function are evaluated during a 2-year postoperative period. These data were strongly supported by a two-way sensitivity analysis that varied the effectiveness of the interventions and the costs. Literature derived outcome studies show that elderly patients with displaced femoral neck fractures achieve the best functional results with a well healed femoral neck without osteonecrosis after reduction and internal fixation. Achieving this result may be difficult, and it is not as cost effective as arthroplasty.
The Knee Society Index of Severity for failed total knee arthroplasty: development and validation.
Compared with primary knee replacement, total knee arthroplasty revision surgery is a more complex procedure and accounts for greater expenditures of healthcare resources at each clinical stage. Overall, patients having revision procedures have poorer functional outcomes and higher complication rates than patients having primary arthroplasty. Despite the expanded scope of revision problems and the rapidly emerging technology in revision surgery, the long-term success of any method remains in question. Because there is little consensus on the timing of revision surgery, optimal surgical reconstruction, and the type of prosthesis to be implanted, the Knee Society began development of an Index of Severity for Failed Total Knee Arthroplasty. Fifty-four percent of Knee Society members completed an 82-item questionnaire that determined their clinical impression about potential risk factors for the outcomes of revision surgery for failed total knee replacements. Using these results, a consensus group developed the final version of the index. The result of the nominal group process was the Knee Society Index of Severity, which was based on eight distinct domains. Each domain was divided into attributes and weights based on the questionnaire responses and consensus meeting. Actual case scenarios from five institutions were used to test interrater reliability and validity. The interrater reliability of the average score of all ratings was 0.95; the correlation of the criterion rating with the mean rating was 0.77. When three outliers were not included, the Pearson product correlation increased to 0.92. These data support the application of the Knee Society Index of Severity as a critical component of risk factor studies, effectiveness research, and cost-effectiveness analysis involving revisions of total knee replacements.
The Knee Society Index of Severity for failed total knee arthroplasty: practical application.
Previous classifications of severity for total knee arthroplasty revisions have been based largely on bone loss of the femur and tibia. These approaches failed to address the more technically difficult issues in revision surgery such as surgical exposure, contractures, extremity alignment, implant removal, soft tissue stability (in the anteroposterior and in the sagittal planes), extensor mechanism integrity, and patellar revisability. Through the Knee Society, the authors developed a severity index that incorporated these latter factors into one measure. The current authors describe the application of the Knee Society Index of Severity for failed total knee arthroplasty and its method of scoring.
Reliability and intraoperative validity of preoperative assessment of standardized plain radiographs in predicting bone loss at revision hip surgery.
BACKGROUND: The most challenging aspect of revision hip surgery is the management of bone loss. A reliable and valid measure of bone loss is important since it will aid in future studies of hip revisions and in preoperative planning. We developed a measure of femoral and acetabular bone loss associated with failed total hip arthroplasty. The purpose of the present study was to measure the reliability and the intraoperative validity of this measure and to determine how it may be useful in preoperative planning. METHODS: From July 1997 to December 1998, forty-five consecutive patients with a failed hip prosthesis in need of revision surgery were prospectively followed. Three general orthopaedic surgeons were taught the radiographic classification system, and two of them classified standardized preoperative anteroposterior and lateral hip radiographs with use of the system. Interobserver testing was carried out in a blinded fashion. These results were then compared with the intraoperative findings of the third surgeon, who was blinded to the preoperative ratings. Kappa statistics (unweighted and weighted) were used to assess correlation. Interobserver reliability was assessed by examining the agreement between the two preoperative raters. Prognostic validity was assessed by examining the agreement between the assessment by either Rater 1 or Rater 2 and the intraoperative assessment (reference standard). RESULTS: With regard to the assessments of both the femur and the acetabulum, there was significant agreement (p < 0.0001) between the preoperative raters (reliability), with weighted kappa values of >0.75. There was also significant agreement (p < 0.0001) between each rater's assessment and the intraoperative assessment (validity) of both the femur and the acetabulum, with weighted kappa values of >0.75. CONCLUSIONS: With use of the newly developed classification system, preoperative radiographs are reliable and valid for assessment of the severity of bone loss that will be found intraoperatively.
Total knee arthroplasty after open reduction and internal fixation of fractures of the tibial plateau: a minimum five-year follow-up study.
BACKGROUND: There is little information in the literature regarding the outcome of total knee arthroplasty following open reduction and internal fixation of fractures of the tibial plateau. The goal of this study was to evaluate the results of such procedures after a minimum of five years of follow-up. METHODS: We retrospectively analyzed the outcomes of fifteen total knee arthroplasties performed at an average of 38.6 months (range, eight months to eleven years) after open reduction and internal fixation of a fracture of the tibial plateau in fifteen consecutive patients. The average duration of follow-up after the total knee arthroplasty procedures was 6.2 years (range, 5.4 to 11.1 years). The average age of the patients was fifty-six years (range, thirty-seven to sixty-eight years) at the time of the arthroplasty. We evaluated the outcomes on the basis of the Hospital for Special Surgery knee score, the Short Form-36 score, and radiographs of the knees. RESULTS: The average Hospital for Special Surgery knee score was 51 points (range, 20 to 74 points) before the arthroplasty, and it increased to 80 points (range, 44 to 91 points) postoperatively. Four knees were scored as excellent, eight had a good result, one was rated as fair, and two had a poor result. The average Short Form-36 scores were 58.0 points for general health, 72.4 points for bodily pain, 72.1 points for mental health, 58.3 points for physical functioning, 84.6 points for physical role functioning, 81.0 points for social functioning, and 57.7 points for vitality. The average active postoperative arc of motion was 105 degrees (range, 70 degrees to 135 degrees ) compared with 87 degrees (range, 20 degrees to 125 degrees ) preoperatively. Incomplete radiolucencies were noted on all of the postoperative radiographs made after the total knee arthroplasties. There was a high rate of infection (three patients), patellar tendon disruption (two patients), and postoperative secondary procedures (three patients required closed manipulation). The patients with infection were considered to have a failure of treatment: two required arthrodesis, and one required a two-stage exchange. CONCLUSION: On the basis of our results, we concluded that total knee arthroplasty after open reduction and internal fixation of a fracture of the tibial plateau decreases pain and improves knee function, but the procedure is technically demanding and is associated with a high failure rate (five of fifteen).
Total hip replacement for the dislocated hip.
Replacing the dislocated hip is technically more challenging than replacing the subluxated hip. Overall, clinical and radiographic results have not been as good for hips that are completely dislocated. The surgical approach must allow for identification of the false and true acetabula, identification of the sciatic nerve, and lengthening of the leg. In patients with a dislocated hip who are managed with total hip replacement, coverage of the cup can be achieved by medialization, creation of a high hip center, or use of a structural graft. Bone grafting allows the cup to be placed in an anatomic position, provides bone stock for additional surgery, and restores leg length. Our results and the results of other authors confirm that these grafts remain intact for at least 10 years and restore bone stock for additional surgery. This is particularly important in this relatively young population.
Revision total hip arthroplasty with the use of structural acetabular allograft and reconstruction ring: a case series with a 10-year average follow-up.
From 1980 through 1993, 20 consecutive massive structural acetabular allografts and reconstruction rings were performed in 19 patients. In all cases, the magnitude of the acetabular bone deficiency was such that the allograft supported >50% of the cup. The allograft was necessary to restore normal anatomy, bone stock, and leg length. Of the 19 patients who met the inclusion criteria, 7 subjects died of unrelated causes, and 3 subjects failed and underwent resection arthroplasty, 1 (8%) for graft resorption and 2 (15%) for recurrent dislocation. The remaining 9 patients (10 allografts) had a minimum follow-up of 5 years and average follow-up of 10.5 years. The cohort was analyzed using radiographic and outcome data collection questionnaires (AAOS/HKOD, WOMAC, SF-36). The study supports the use of massive structural allografts and reconstruction rings and achieves satisfactory results in 77% (10 of 13) of the patients. We believe these results reveal an impressive outcome for what used to be thought of as a salvage operation.
Minor column structural acetabular allografts in revision hip arthroplasty.
A minor column (shelf) allograft is used for uncontained defects that involve less than 50% of the acetabulum. The prospectively collected records and radiographs of 47 patients (51 hips) who had undergone minor column structural acetabular allograft reconstruction during revision hip arthroplasty were reviewed. The purpose was to identify the long-term results (minimum 5 years) and factors that may influence longevity of the allograft and predispose the patient to subsequent acetabular component failure. The mean duration of followup was 119 months (range, 68-195 months). There was one perioperative death and six patients were lost to followup. Eleven patients (22%) required additional surgery. Three acetabular cups could not be revised successfully, despite multiple attempts, and the patients were treated with Girdlestone excisions. Eight patients underwent successful revision surgery with only three requiring a repeat structural allograft. Survival time for the acetabular cup as determined by Kaplan-Meier analysis was 153 months (95% confidence interval; range, 136-169 months). Cup failure was associated with more operative procedures performed before revision surgery (mean, 3.2 procedures), and failure to restore the vertical center of hip rotation to within 12 to 14 mm of the predicted value. The acetabular abduction angle was not a predictor for failure. The current study shows that good results can be achieved with structural acetabular allograft reconstruction with mid-term to long-term implant survival (cup aseptic survival, 80.4% and allograft re-construction survival, 94.1%), especially if there is restoration of near normal hip biomechanics.
Ethics in practice: residency training.
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Grafts and cages: managing massive bone loss.
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Osteoinductive growth factors in preclinical fracture and long bone defects models.
Fracture healing is a specialized form of the reparative process that the musculoskeletal system undergoes to restore skeletal integrity. This biologic process is a consequence of a complex cascade of biologic events that result in the restoration of bone tissue, allowing for the resumption of musculoskeletal function. Several growth-promoting substances have been identified at the site of skeletal injury and appear to play a physiologic role in fracture healing. This article reviews the effects of these osteoinductive growth factors on bone healing as elucidated by both preclinical in vivo fracture and diaphyseal defect healing models.
Economic evaluations in the hip arthroplasty literature: lessons to be learned.
Readers are increasingly encountering articles dealing with health economic evaluations that compare various surgical strategies, leaving orthopaedists with the challenge of determining which program is cost-efficient and truly pertains to their setting. This study carries out a systematic review of the literature to appraise the quality, quantity, and type of economic evaluation as it pertains to the hip arthroplasty literature. To identify all relevant articles, we conducted a comprehensive computerized bibliographic search of Medline from 1966 to 1996. This search produced 1,611 abstracts that were screened. Studies that were incorporated met the following inclusion criteria: i) formal economic analysis, ii) an intervention specific to hip arthroplasty, and iii) the perspective of the study was evident (ie, patient, provider, society). These studies were appraised with regards to methodologic soundness based on 8 established economic principles. Only 68 articles from the 138 retrieved met the study criteria. Only 2 of the 68 articles met all 8 criteria of a comprehensive economic evaluation. The hip arthroplasty literature is deficient in methodologically sound economic evaluations. Several guidelines are introduced to aid orthopaedists in appraising the various economic studies, and recommendations are made to improve the quality of these studies in the orthopaedic literature. We suggest that the generation of such information should rank high on the priority list of the orthopaedic profession, granting agencies, and governments.
Understanding economic evaluations: a review of the knee arthroplasty literature.
The study reviewed the literature to appraise the quality, quantity, and type of economic evaluation as it pertains to the knee arthroplasty literature. A computerized bibliographic search of MEDLINE from 1966-1996 was conducted, revealing a total of 43,178 articles dealing with cost analysis, of which 1611 were orthopedic. Of the economic orthopedic studies, only 63 dealt with the topic of knee arthroplasty. These studies were retrieved, of which only 40 papers met the inclusion criteria. These 40 studies were evaluated for methodological soundness based on established economic principles. None of the 40 studies met the established criteria to form a comprehensive economic evaluation. These results indicate that the orthopedic literature is lacking in economically sound evaluations, and guidelines are offered to aid orthopedists in appraising and improving the quality of economic studies.
Immediate surgery versus waiting list policy in revision total hip arthroplasty. An economic evaluation.
An economic evaluation was carried out using a decision tree that models the costs and consequences of surgery at the point of consultation versus a waiting list policy for candidates in need of revision hip arthroplasty. The theoretical scenarios looked at a 2-year period wherein the immediate surgery patients incurred costs for 2 years after surgery, whereas the waiting list patients incurred costs for 1 year before and 1 year after surgery. Outcome probabilities were defined and applied to each treatment group, as derived from the literature and expert opinion. Expenditures were derived from the literature, based on conservative estimates of predicted pre- and postsurgical behavior for each scenario. This analysis indicates the potential for both substantial savings in resources and improved patient outcome for immediate surgery over waiting lists. These savings would begin at the inception of the immediate surgery protocol. Sensitivity analysis indicates that the conclusion is valid over a wide range of expenditures and probabilities.
Catecholamine and blood pressure regulation by gonadotropin-releasing hormone analogs in amphibians.
Analogs of gonadotropin-releasing hormone (GnRH) occur in the brain, plasma, and sympathoadrenal system of anuran amphibians. The present experiments studied the effects of GnRH and [Trp7, Leu8]-GnRH on plasma catecholamines and cardiovascular function in conscious adult bullfrogs (Rana catesbeiana) and cane toads (Bufo marinus). Both GnRH analogs elicited dose-dependent (0.1-1 nmol.kg-1) increases in arterial norepinephrine, epinephrine, and blood pressure levels when injected intravenously into toads. In bullfrogs, [Trp7, Leu8]-GnRH (1 nmol.kg-1) increased arterial norepinephrine concentration approximately 10-fold without affecting the concentrations of norepinephrine sulfate, norepinephrine glucuronide, epinephrine, epinephrine sulfate, or epinephrine glucuronide. The noradrenergic response of bullfrogs to [Trp7, Leu8]-GnRH was specific to the neurohormone because it could be inhibited by [D-pGlu1, D-Phe2, D-Trp3,6]-GnRH. The sympathomimetic activities of the GnRH analogs did not depend on changes in temperature, which occur seasonally in natural habitats, because similar noradrenergic responses were observed at 4 and 22 degrees C. GnRH and [Trp7, Leu8]-GnRH (0.01-10 nmol.kg-1) did not raise arterial blood pressure in bullfrogs despite their pressor actions in toads. This interspecific difference was remarkable because cardiovascular responses to norepinephrine, angiotensin II, and vasotocin in bullfrogs were similar to those in toads. The parallels between catecholamine and blood pressure responses suggest that epinephrine is the principal mediator of the blood pressure response to native GnRH analogs in toads. In bullfrogs, [Trp7, Leu8]-GnRH mobilizes norepinephrine but not epinephrine, and the noradrenergic effect is insufficient to raise blood pressure. These observations are consistent with a physiological role for native GnRH analogs in the regulation of the sympathoadrenal system in anuran amphibians.