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.

Funding: The authors gratefully acknowledge the financial support of Materials and Manufacturing Ontario (MMO) and the Dean’s New Faculty Seed Grant at Ryerson University.

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. We used a prospective database of acetabular fractures to identify variables associated with clinical and radiographic outcomes. Quality of fracture reduction was identified as the only significant predictor of radiographic grade, clinical function, and development of post-traumatic arthritis. 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.

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

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.

Introduction: Closed and open grade I (low energy) tibial shaft fractures are a common and costly event and optimal management for such injuries remains uncertain.

Methods: We explored costs associated with treatment of low energy tibial fractures with either casting, casting with therapeutic ultrasound, or intramedullary nailing (with and without reaming) by use of a decision tree.

Results: From a governmental perspective the mean associated costs were USD $3 365 (standard deviation [SD] ± 1 425) for operative management by reamed intramedullary nailing, $5 041 (SD ± 1 363) for operative management by non-reamed intramedullary nailing, $5 017 (SD±1 370) for casting, and $5 312 (SD±1 474) for casting with therapeutic ultrasound. From a societal perspective the mean associated costs were ($12 449; SD±4 894) for reamed intramedullary nailing, ($13 266; SD±3 692) for casting with therapeutic ultrasound, ($15 571; SD±4 293) for operative management by non-reamed intramedullary nailing, and ($17 343; SD±4 784) for casting alone.

Interpretation: Our analysis suggests that, from an economical standpoint, reamed intramedullary nailing is the treatment of choice for closed and open grade I tibial shaft fractures. There is preliminary evidence, from a societal perspective, that treatment of low energy tibial fractures with therapeutic ultrasound and casting may also be an economically-sound intervention.

Introduction: Little is known about the psychological morbidity associated with orthopaedic trauma.

Purpose: Our study aimed to determine the extent of psychological symptoms and whether patient psychological symptoms were predictive of outcomes following orthopaedic trauma.

Methods: All patients attending 10 orthopaedic fracture clinics at 3 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 9 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.

Results: Of 215 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.

Conclusions: 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.

Introduction and Aims: Periprosthetic bone loss is responsible for the majority of cases of implant failure after total joint arthroplasty. Bisphosphonates are effective in reducing bone loss in many conditions associated with accelerated bone turnover. Our aim was to determine the effect of bisphosphonates on periprosthetic bone mineral density (BMD, g/cm2) after total joint arthroplasty.

Method: We conducted computerised searches for randomised controlled trials, evaluating the effects of bisphosphonates on periprosthetic bone mineral density in patients undergoing primary total joint arthroplasty. We searched MEDLINE, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews and the United Kingdom National Research Register Web-site to November 2003. Computerised searches of the archives of AAOS Annual Meetings 1989–2003 were also conducted. Additional strategies to identify articles included a hand search of the bibliographies of relevant articles and direct contact with the authors.

Results: Of 386 citations initially identified, nine citations met our eligibility criteria. The total number of randomised controlled trials was six (five published and one abstract). Four trials evaluated total hip arthroplasty and two examined total knee arthroplasty. Five trials used alendronate and one used pamidronate. Quality scores ranged from 65 to 75. The pooled sample size was 290 patients. Less periprosthetic bone loss occurred in the intervention group compared to the control group at the following follow-up intervals: three months (n=128, Weighted Mean Difference (WMD): 3.3%, 95% Confidence Interval (CI): 1.9–4.7, p< 0.01); six months (n=224, WMD: 4.5%, CI: 1.6–7.4, p< 0.001); and 12 months (n=173, WMD: 4.2%, CI: 1.5–6.9, p=0.03). Tests of heterogeneity revealed greater maintenance of BMD in cemented arthroplasty than in uncemented arthroplasty (WMD: 7.5%, CI: 4.3–10.7 versus WMD: 2.1%, CI: 0.61–3.6, respectively, p< 0.001) at 12 months follow-up.

Conclusion: Bisphosphonates have a beneficial effect on maintaining periprosthetic bone stock compared to control after total joint arthroplasty. The effect seems greater in cemented arthroplasty and total knee arthroplasty. Whether this increase in BMD results in improved fixation and longevity of prosthetic components remains unanswered. Larger trials evaluating the effect of bisphosphonates on rates of implant loosening and functional outcomes are needed.