Using a prospective database of 1309 displaced acetabular fractures gathered between 1980 and 2007, we calculated the annual mean age and annual incidence of elderly patients >
60 years of age presenting with these injuries. We compared the clinical details and patterns of fracture between patients >
60 years of age (study group) with those <
60 years (control group). We performed a detailed evaluation of the radiographs of the older group to determine the incidence of radiological characteristics which have been previously described as being associated with a poor patient outcome. In all, 235 patients were >
60 years of age and the remaining 1074 were <
60 years. The incidence of elderly patients with acetabular fractures increased by 2.4-fold between the first half of the study period and the second half (10% (62) The proportion of elderly patients presenting with acetabular fractures increased during the 27-year period. The older patients had a different distribution of fracture pattern than the younger patients, and often had radiological features which have been shown in other studies to be predictive of a poor outcome.
Prior to TJR, clinical cardiovascular risk assessment is typically limited by severe exercise restrictions. Noninvasive pharmacological cardiovascular stress tests may predict major perioperative cardiovascular events in patients undergoing orthopaedic surgery. We undertook a pilot study to inform the feasibility of a large prospective cohort study. Patients were eligible if they were aged >
forty-five, undergoing elective TJR, and had known atherosclerotic disease or risk factors for atherosclerotic disease. We recruited patients at the Hamilton Health Sciences, Henderson Hospital. Prior to surgery patients underwent dipyridamole stress perfusion imaging and dobutamine stress echocardiography. For both tests the interpreters evaluated seventeen myocardial segments and were blinded to information about patients’ clinical risk factors. The attending surgeons and research personnel following patients after surgery were blinded to results of the noninvasive pharmacological cardiovascular stress tests. All patients had an ECG performed and troponin T drawn six to twelve hours postoperatively and on the first, second and third days after surgery. Starting in November 2005 we recruited thirty patients over six months; seventeen (57%) patients were male, twenty-one (70%) underwent TKA, and nine (30%) underwent THA. The length of surgery was seventy-two (SD 38) minutes and the length of hospital stay was five (SD 3) days. We successfully followed all patients to thirty days after surgery. Three patients (10%; 95% CI, 3–26%) suffered a perioperative myocardial infarction. Twenty nine patients underwent dipyridamole stress perfusion imaging prior to surgery; a reversible defect involving 30–50% of the myocardium increased the likelihood of a perioperative myocardial infarction (likelihood ratio [LR] 4.0; 95% CI, 1.2–13.3). Twenty-six patients underwent dobutamine stress echo-cardiography; a reversible defect increased the likelihood of a perioperative myocardial infarction (LR 4.0; 95% CI, 0.7–22.9). This pilot study demonstrates the need for, and feasibility of, a large prospective cohort study to determine if preoperative noninvasive pharmacological cardiovascular stress testing has additional predictive value, beyond clinical variables, for the occurrence of myocardial infarction in patients undergoing major hip and knee surgery.
We aimed to quantify the sample sizes and magnitude of treatment effects in a review of orthopaedic randomised trials with statistically significant findings. We conducted a comprehensive search (PubMed, Cochrane) for all randomised controlled trials between 1/1/95 to 12/31/04. For continuous outcome measures (ie functional scores), we calculated effect sizes (mean difference/standard deviation). Dichotomous variables (ie infection, nonunion) were summarised as absolute risk differences and relative risk reductions (RRR). Effect sizes >
0.80 and RRRs>
50% were defined as large effects. Our search yielded 433 RCTs, of which 76 RCTs with statistically significant findings on 184 outcomes (122 continuous/62 dichotomous outcomes) met study eligibility criteria. The mean effect size across studies with continuous outcome variables was 1.7 (95% confidence interval: 1.43–1.97). Almost one in three results, despite being reported as statistically significant did meet the definition of a large effect size (ES<
0.80). For dichotomous outcomes, the mean risk difference was 30% (95%confidence interval:24%–36%) and the mean relative risk reduction was 61%.
Fat embolism syndrome (FES) is a potentially lethal condition commonly seen in poly-traumatised patients, particularly those with multiple long-bone fractures. Treatment has centered around supportive care and early fracture fixation. Several clinical small trials have suggested corticosteroids benefit patients with FES but its use remains controversial. Our objective was to determine the effect of corticosteroids in preventing FES in patients with multiple long-bone fractures. We conducted a meta-analysis of randomised trials, searching computerised databases for published studies from 1966–2006. Additionally, we performed hand searches of major orthopaedic journals, meeting proceedings, and texts. Our primary outcome was the rate of FES. Secondary outcomes included presence of hypoxia, petechiae, mortality, infection, and delayed union. Of the one hundred and four studies identified, nine were potentially eligible, and only seven met all our eligibility criteria. From our pooled analysis of three hundred and eighty-nine patients, we found that corticosteroids reduced the risk of FES by 78% (95%CI: 43–92%, heterogeneity p-value=0.62, I2=10%) and that only eight patients needed to be treated (NNT=7.5) to prevent one case of FES (95%CI: five to thirteen patients). We did not find any significant differences in the rates of mortality, infection, or delayed union. The current evidence suggests that the use of corticosteroids is beneficial in the prevention of fat embolism syndrome in patients with multiple long-bone fractures. The use of corticosteroids does not appear to significantly increase the risk of complications although a confirmatory large randomised trial is needed.
1) To describe the inter reviewer agreement of a previously designed scoring scheme to rate abstracts submitted for presentation at the Dutch Orthopedic Association. 2) To test if quality of reporting of submitted abstracts increased in the years after the introduction of the scoring scheme. 3) To examine if a review process with a larger workload had lower inter rater agreement.
1) to examine the reporting of outcome measures in orthopaedic trials, 2) to determine the feasibility of blinding in published orthopaedic trials and 3) to examine the association between the magnitude of treatment differences and methodological safeguards such as blinding. Specifically, we focused on an association between blinding of outcome assessment and the size of the reported treatment effect; in other words: does blinding of outcome assessors matter?
1) the outcome measures used and 2) the use of a methodological safeguard: blinding. We calculated the magnitude of treatment effect of blinded compared to un-blinded outcome assessors.
1) studies labelled as Level I have high reporting quality and 2) Level I studies have better reporting quality than Level II studies. One should address methodological safeguards individually.
1) younger age, particularly age between 36 and 45 years, 2) experience of less than 10 years, 3) having a PhD degree, and 4) working in an academic or teaching setting. The majority of the respondents (65%) were aware of the Journal’s evidence-based medicine section, and 20% used the Journal’s evidence-based medicine abstracts in clinical decision-making. This increased awareness in evidence-based medicine was also reflected in a frequent use of Cochrane reviews in clinical decision-making (27%). Surgeons who used the Journal’s evidence-based medicine abstracts and Cochrane reviews had significantly higher competence scores.
We have studied the effect of shortening of the femoral neck and varus collapse on the functional capacity and quality of life of patients who had undergone fixation of an isolated intracapsular fracture of the hip with cancellous screws. After screening 660 patients at four university medical centres, 70 patients with a mean age of 71 years (20 to 90) met the inclusion criteria. Overall, 66% (46 of 70) of the fractures healed with >
5 mm of shortening and 39% (27 of 70) with >
5° of varus. Patients with severe shortening of the femoral neck had significantly lower short form-36 questionnaire (SF-36) physical functioning scores (no/mild (<
5 mm) vs severe shortening (>
10 mm); 74 vs 42 points, p <
0.001). A similar effect was noted with moderate shortening, suggesting a gradient effect (no/mild (<
5 mm) vs moderate shortening (5 to 10 mm); 74 vs 53 points, p = 0.011). Varus collapse correlated moderately with the occurrence of shortening (r = 0.66, p <
0.001). Shortening also resulted in a significantly lower EuroQol questionnaire (EQ5D) index scores (p = 0.05). In a regression analysis shortening of the femoral neck was the only significant variable predictive of a low SF-36 physical functioning score (p <
0.001).
We applied the technique of path analysis to investigate the effect of potential prognostic factors, including injury characteristics and treatment choices, on the risk of delayed healing or non-union after operative treatment of tibial shaft fractures. Data were collected in a prospective observational study of 41 Swiss hospitals over two years, and analysed by regression models and path analysis. Path analysis is a technique to visualize the most important associations between clinical factors and outcome in a ‘causal path diagram’ that summarises the most likely cause and effect relationships. Factors having a direct relationship with the occurrence of delayed healing or non-union included open fracture (RR 6.7), distal shaft location (RR 2.2), and initial treatment with an external fixator (RR 2.8). There were many other significant inter-relationships within the final diagram. For example, the choice of treatment was related to factors such as fracture aetiology, AO classification, location and skin injury. Fracture classification was not associated with delayed healing and non-union after adjustment for other factors including treatment choice. The association of hypothesised risk factors, such as soft tissue injury and fracture location, with delayed healing or non-union was confirmed and measured. This study suggested that the use of an external fixator had a direct, negative effect on outcome, and that the use of nails or plates might contribute to delayed healing or non-union by their association with post-operative diastasis. These observations support this first use of path analysis in orthopaedics as a powerful technique to interpret data from an observational study.
Femoral nails are thought to be load sharing devices. However, the specific load sharing characteristics and associated stress concentrations have not yet been reported in the literature. The purpose of this study was to use a validated, three dimensional finite element model of a nailed femur subjected to gait loads in order to determine the resulting stresses in the femur and the nail. The results showed that load was shared between the nail and the bone throughout the gait cycle. In addition, high stress concentrations were noted in the bone around the screw holes, and dynamization was of minimal benefit. To determine the stresses in the bone and nail in a femur with a locked, retrograde, intramedullary nail. The retrograde femoral nail is a load sharing device. High stress concentrations occur in the bone around locking screw holes. When only one locking screw is used proximally and distally, stresses in the implant are excessive and may lead to failure. Dynamization was of minimal benefit. This is the first study to use a validated three dimensional finite element model to provide a detailed biomechanical analysis of stress patterns in a retrograde nailed femur under gait loads. The results can help resolve issues of stress shielding, implant removal, number of locking screws and dynamization. In the fully locked condition, loads in the femur were significantly higher than those in the nail for most of the gait cycle. Removal of locking screws to obtain dynamization only increased axial load in the femur by 17 %. However, stresses in the locking screws increased by as much as 250% when fewer than 4 screws were used. Maximum stresses in the bone were found around screw holes. A three dimensional finite element model of the femur and nail was developed. The model was validated by comparing results to a physical saw bone model instrumented with strain gages and subjected to a simple a compressive load. Once good correlation with simple loading patterns was demonstrated, gait loading patterns obtained from literature were incorporated and simulations were run for various conditions.
A novel, validated three dimensional finite element model of the femur was used to characterize the stress concentration in the bone at the proximal end of a fracture fixation plate. A supracondylar fracture of the distal femur fixed with a plate was modeled utilizing physiologic load patterns simulating several phases of a cycle of gait. The relative maginitude and length of the zone of increased stress was characterized. The effects of varying plate geometry and material in the attempt to decrease stress concentration at the end of the plated were investigated. The exact nature and distribution of stresses around femoral fracture fixation plates remains unclear making it difficult to determine how close to existing hardware a distal femoral plate can be implanted. Our objective was to use a novel, validated finite element (FE) model to examine the stress distribution at the proximal end of the plate. The von Mises element stresses in the bone without the implant were compared to those with the implant. Additionally, we determined the effect of metal (titanium versus stainless steel), and plate taper (ten, thirty and forty-five degrees) on stresses at the proximal end of the plate. The peak von Mises stress in the plated bone occurred below the corners of the plate, and was approximately four times that in the un-plated case (thirty-eight MPa versus nine MPa). We identified a distance of 34 mm (approximately one bone diameter) beyond the edge of the plate before stresses returned to within 1% of the un-plated control. The choice of metal did not affect the state of stress distribution in the bone beyond the proximal edge of the plate. In addition, the stress concentrations decreased proportionally as the taper angle decreased from forty-five to ten. Utilizing this FE model we report the following:
Stresses are concentrated at the end of plates and return to within normal limits approximately one bone diameter beyond the edge of the plate. The stress concentrations decrease proportionally as the taper angle decreases. Titanium plates offer no added advantage in stress reduction at the end of the plate.
In a meta-analysis of fourteen trials (N=1901 patients) in patients with displaced hip fractures, we identified significant reductions in the risk of revision surgery with internal fixation compared to arthroplasty. A trend towards increased mortality with arthroplasty was identified. The purpose of this study was to determine the effect of arthroplasty (hemi-arthroplasty, bipolar arthroplasty and total hip arthroplasty) in comparison to internal fixation for displaced femoral neck fractures on rates of mortality and revision surgery Arthroplasty for displaced femoral neck fractures, in comparison to internal fixation, significantly reduces the risk of revision surgery at the cost of greater infection rates, blood loss and operative time, and a possible increase in early mortality. Over 220,000 fractures of hip occur per year in North America representing an annual seven billion dollar cost to the health care system. Current evidence suggests internal fixation may reduce mortality risk at the consequence of increased revision rates. A large trial is needed to resolve this issue. We searched computerized databases (MEDLINE, COCHRANE and SCISEARCH) for published clinical studies from 1969–2002 and identified additional studies through hand searches of major orthopaedic journals, bibliographies of major orthopaedic texts and personal files. We found a non-significant trend toward an increase in the relative risk of dying with arthroplasty when compared to internal fixation (relative risk=1.27, 95% confidence interval, 0.84–1.92, p = 0.25; homogeneity p= 0.45). Arthroplasty appeared to increase the risk of dying when compared to pin and plate, but not in comparison to internal fixation using screws (relative risk= 1.75 vs 0.86, respectively, p<
0.05). Fourteen trials provided data on revision surgery (n=1901 patients). The relative risk of revision surgery with arthroplasty was 0.23 (95% confidence interval, 0.13–0.42, p = 0.0003, homogeneity p = <
0.01).
Risk information is understood differently when it is presented in absolute or relative terms; the latter overemphasizes the magnitude of risk. How surgeons communicate risk may influence patient choice. We evaluated whether presenting information about the benefits of surgery in absolute and relative terms affects an individual’s decision to accept or reject alternative surgical procedures in hip fracture management. Our findings show how framing risk in relative terms affects the perception of risk and influences patient choice. Surgeons must use care in utilizing relative risk reduction in the absence of actual risk data. Risk information is understood differently when it is presented in absolute or relative terms; the latter overemphasizes the magnitude of risk. How surgeons communicate risk may influence patient choice. To evaluate whether presenting information about the benefits of surgery in absolute and relative terms affects an individual’s decision to accept or reject alternative surgical procedures in hip fracture management. We administered a face-to-face survey to fifty patients attending the fracture clinic. We asked patients to consider a scenario and to decide which treatment alternative they preferred based upon risk presentation. We presented risk in five ways: absolute risk difference, relative risk reduction, relative risk, number needed to treat, and odds ratio. Patients were most likely to favor internal fixation when the mortality results comparing internal versus arthroplasty were presented as a relative risk reduction. Patients continued to favor internal fixation despite being presented with a significantly increased risk of revision surgery. Lower level of education and those patients who had not experienced a fracture were significantly associated with their perceptions about method of presentation. Our findings show how framing risk in relative terms affects the perception of risk and influences patient choice. Patients concerns about mortality, even if non-significant differences are presented, outweigh concerns about significant increases in revision surgery with internal fixation. Surgeons must use care in utilizing relative risk reduction in the absence of actual risk data given our findings that may over-estimate the relative benefits of one procedure over another.
Little is known about the psychological morbidity associated with orthopaedic trauma. Our study aimed to determine the extent of psychological symptoms and whether patient psychological symptoms were predictive of outcomes following orthopaedic trauma. Overall, trauma patients experienced higher intensity of psychological symptoms than population norms. Psychological symptoms, patient age, and ongoing litigation predicted functional outcomes. Patients may benefit from early interventions by social workers and psychologists to process their psychological states post injury. Little is known about the psychological morbidity associated with orthopaedic trauma. Our study aimed to determine the extent of psychological symptoms and whether patient psychological symptoms were predictive of outcomes following orthopaedic trauma. All patients attending ten orthopaedic fracture clinics at three University-affiliated Hospitals were approached for study eligibility. All consenting patients would be requested to complete a baseline assessment form, a 90-item symptom checklist-90R (SCL-90R), and the Short-Form–36. The SCL-90R constitutes nine dimensions (Somatization, Obsessive-compulsive, Interpersonal sensitivity, Depression, Anxiety, Hostility, Phobic anxiety, Paranoid ideation, Psychoticism) and three global indices (Global severity index, Positive symptom distress index, positive symptom total). We conducted regression analyses to determine predictors of quality of life among study patients. Of two hundred and fifteen patients, 59% were male at a mean age of 44.5 years. Over half of patients had lower extremity fractures. Trauma patients experienced greater psychological symptoms than population norms. Overall, trauma patients experienced higher intensity of psychological symptoms than population norms. Patient functional outcomes were predicted by patient age, ongoing litigation, and Positive Symptom Distress. This model predicted 21% of the variance in patient function. Patient somatization was an important psychological symptom resulting in increasing intensity of symptoms. Smoking, alcohol, open fracture, surgeons’ perception of technical outcome, level of education, and time since injury were not predictive in this model. Psychological symptoms, patient age, and ongoing litigation predicted functional outcomes. Patients may benefit from early interventions by social workers and psychologists to process their psychological states post injury. Funding: This study was funded in part by research grants from AO North America and Regional Medical Associates, McMaster University. Dr. Bhandari was funded, in part, by a 2004 Detweiler Fellowship, Royal Colleges of Physicians and Surgeons of Canada. Dr. Busse is funded by a Canadian Institutes of Health Research Fellowship Award.
There has been considerable debate regarding the factors that predict clinical and radiographic outcomes in patients with acetabular fractures and associated posterior hip dislocations. To identify variables associated with clinical and radiographic outcomes. Utilizing a prospective database of acetabular fractures, we identified patients with posterior hip dislocations operatively managed within three weeks of injury and having a minimum of two years of follow up. Demographic information, operative findings, and outcomes were recorded. We conducted a series of uni-variable analyses to determine whether any independent variables were significantly associated with the dependent variable. Among one hundred and nine eligible patients with posterior hip dislocations, the most common fracture types included the posterior wall and transverse with associated posterior wall fractures. An anatomic reduction of the fracture was achieved in ninety-six patients. At their most recent follow up, the majority of patient maintained a good to excellent radiographic grade. Of those who underwent clinical outcome grading (ninety-four patients), 83% achieved good or excellent outcomes. Overall radiographic grade correlated with each domain of the clinical grade including ambulation, range of motion, and pain. Quality of fracture reduction was identified as the only significant predictor of radiographic grade, clinical function, and development of post-traumatic arthritis. All patients with poor reductions and imperfect reductions, respectively, had developed arthritis compared to 24% of patients with anatomic reductions. Our findings support Letournel’s report that quality of the fracture reduction remains the most important factor associated with outcome in patients with acetabular fractures and concomitant posterior hip dislocations. Funding: This study was funded by a research grant from Stryker Orthopaedics, Los Angeles, California. Dr. Bhandari was funded, in part, by a fellowship from AO International, Davos, Switzerland and AO North America, Paoli, Pennsylvania.
A retrospective study of one hundred and nineteen unicompartmental knee arthroplasties was performed. Outcome measures were the Oxford twelve-item knee questionnaire, the Short Musculoskeletal Functional Assessment (SMFA) and the WOMAC. Regression analysis was performed in order to determine predictors of outcome. After an average follow up period of four years, the mean scores indicated a good to excellent functional outcome. The only predictor of outcome identified was gender, with women obtaining a better functional outcome than men. Other variables that did not influence functional outcome included age, weight, stage of disease, previous HTO and bilateral procedures. The purpose of this study was to determine
the functional outcome of unicompartmental knee arthroplasty and predictors of outcome. Although unicompartmental knee arthroplasty is becoming more widely accepted as a treatment option for degenerative osteoarthritis, there are very few studies in the literature that systematically investigate the predictors of outcome for this procedure. This is a retrospective study of one hundred and nineteen unicompartmental knee arthroplasties perfomed at a university hospital by a single surgeon. The outcome measures used were the Oxford twelve-item knee questionnaire, the Short Musculoskeletal Function Assessment (SMFA) and the Western Ontario and McMaster (WOMAC) functional indices. Multiple regression analysis was performed to determine predictors of outcome from chart derived variables. After a mean follow-up of four years the mean Oxford Knee Score was thirty-nine and the mean SMFA and WOMAC functional scores were eight and seven respectively, indicating a good to excellent functional outcome. Regression analysis revealed gender as a predictor of outcome however other variables including age (range 49–84 yrs), weight (range 55–225 kgs), previous ORIF, preoperative varus/valgus (range 0–16 degrees), joint subluxation (range 0–13mm), radiographic stage of disease (Kellgren and Lawrence), as well as previous HTO and bilateral (simultaneous or staged) unicompartmental knee arthroplasty were found to not correlate with functional outcome. Good to excellent functional outcome scores can be achieved with unicompartmental knee replacement. Previous HTO or bilateral procedures as well as weight, pre-operative varus/valgus <
sixteen degrees or radiographic stage of disease were not predictive of outcome.
We aimed to identify variables associated with clinical and radiological outcome following fractures of the acetabulum associated with posterior dislocation of the hip. Using a prospective database of 1076 such fractures, we identified 109 patients with this combined injury managed operatively within three weeks and followed up for two or more years. The patients had a mean age of 42 years (15 to 79), 78 (72%) were male, and 84 (77%) had been involved in motor vehicle accidents. Using multivariate analysis the quality of reduction of the fracture was identified as the only significant predictor of radiological grade, clinical function and the development of post-traumatic arthritis (p <
0.001). All patients lacking anatomical reduction developed arthritis whereas only 25.5% (24 patients) with an anatomical reduction did so (p = 0.05). The quality of the reduction of the fracture is the most important variable in forecasting the outcome for patients with this injury. The interval to reduction of the dislocation of the hip may be less important than previously described.