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In an effort to reduce wait times associated with joint replacement surgery, the overall arthroplasty caseload in the province in Ontario has increased by more than 50% in the past 5 years.1,2 As a result, the number of total joint arthroplasties being performed during a surgical day has also increased. Many surgeons now perform 5 or 6 total joint operations in a single day, with operative working hours approaching 10. There is no doubt that this increased caseload has led to increased surgeon fatigue, particularly for cases performed at the end of the operating day compared with those performed at the beginning. There is growing support in the literature that patient outcomes are adversely affected by fatigue in operator-dependent cognitive and technical tasks. Adverse events and medical errors have been shown to occur more frequently in sleep-deprived physicians, and technical skills have also been shown to be negatively influenced by physician fatigue.3–9 More specifically, laparoscopic procedures,10 cardiac interventions,11 endotracheal intubation12 and colonoscopies13,14 have been shown to have inferior outcomes when performed later in the day. These findings potentially have implications for physician productivity, procedural outcome and, most importantly, patient safety. There are many factors that contribute to the outcome of total joint arthroplasty, including preoperative, intraoperative and postoperative variables. It is well established that preoperative variables, such as unrealistic patient expectations,15–18 diabetic control19,20 and obesity,21–23 can have a negative effect on radiologic and functional outcomes. Fortunately, these variables are modifiable and therefore have the potential to be optimized preoperatively. Postoperative variables, such as participation in rehabilitation and avoidance of limb positions that may predispose to hip dislocation, are also modifiable variables that have been shown to affect outcome.24,25 The influence of intraoperative variables on outcomes in total joint arthroplasty have been less extensively studied. Duration of the surgical procedure,26,27 blood loss28 and component alignment29–33 are modifiable intraoperative variables that influence patient outcomes and may be adversely affected by surgeon fatigue. To our knowledge, the extent to which fatigue affects the technical and cognitive skills of the surgeon and overall patient outcomes in total joint arthroplasty has not previously been studied. The purpose of this retrospective study was to determine whether there is a difference, in terms of perioperative and postoperative complications, between patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) at different times during the operative day.

Knee dislocation is an uncommon orthopedic diagnosis with a high rate of neurovascular complications. The goal of definitive management is to provide a pain free and functional knee through restoration of ligamentous stability and range of motion. Operative management has been suggested to be superior to nonoperative management for knee dislocations largely in part owing to a meta-analysis on the topic published a decade ago. The purpose of this study was to summarize the results of operative and nonoperative treatment of knee dislocations over the past 10 year period. There were a total of 855 patients from 31 studies managed operatively and 61 patients from 4 studies managed nonoperatively. The overall methodological quality of the studies was poor as measured by the Newstead-Ottawa scale. Data regarding functional outcome, instability, contracture, and return to activity were all in favor of operative management. Significant differences were found for return to employment (P

Knee dislocation, and multiligament knee injury, is an uncommon orthopedic diagnosis with a high rate of neurovascular injuries and limb-threatening complications. Disruption of the popliteal artery and common peroneal nerve is relatively common, requiring a complete and timely physical examination. An ankle–brachial index is a safe and reliable way to screen for vascular insufficiency. Imaging, in the form traditional arteriography or computed tomography with vascular reconstructions, should be ordered when there is concern for vascular injury. External fixation is a reliable method for stabilizing and protecting the knee joint in cases of open dislocation, vascular reconstruction, or a grossly unstable reduction that cannot be maintained with a knee immobilizer. Surgical management of multiligament knee injuries has the goal of providing a functional, pain-free, and stable knee. The current controversies pertaining to surgical treatment include early versus delayed management, arthroscopic versus open cruciate surgery, single versus double-bundle cruciate reconstruction, and transtibial versus tibia-inlay posterior cruciate ligament reconstruction. Knowledge of the basic principles surrounding initial and definitive management of knee dislocations, and multiligament knee injuries, aids the treating surgeon in managing these complex injuries.

Acute knee dislocation is rare but has a high rate of associated neurovascular injuries and potentially limb-threatening complications. These include the substantial morbidity associated with peroneal nerve injury: neuropathic pain, decreased mobility, and considerably reduced function, which not only impairs patient function but complicates treatment.We therefore identified and quantified the risks associated with specific factors for peroneal nerve injury and recovery in patients with knee dislocations.We retrospectively reviewed the charts of 26 patients, from among a cohort of all 91 knee dislocations, with a peroneal nerve palsy over a 5-year period. We then used univariable and multivariable statistics to identify risk factors predicting peroneal nerve injury and recovery.Gender (odds ratio, 5.47), body mass index (odds ratio, 1.14), and fibular head fracture (odds ratio, 4.77) were associated with peroneal nerve injury. Only younger age was associated with peroneal nerve recovery.Knowledge of the risk factors for peroneal nerve injury and the predictors of recovery in knee dislocation allows the treating surgeon to have a better understanding of the nature of the neurologic injury and modify management based on the anticipated return of nerve function.Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

This study evaluated the rate of perioperative complications of single anesthetic bilateral total knee arthroplasties (TKA) compared with staged procedures.The records of all single anesthetic bilateral TKA performed between 1997 and 2007 at one large community hospital and one university hospital were retrospectively reviewed. Complete demographic data, preoperative co-morbidities and complications for 156 patients were compared to a matched staged bilateral TKA (n=78) cohort.In the single anesthetic bilateral TKA cohort, cardiovascular disease predicted postoperative myocardial (p0.01, Odds Ratio - 67.6), need for ICU admission (p0.01, Odds Ratio - 88.8), and days spent in ICU (p0.01), while cardiovascular disease did not significantly predict postoperative MI in the staged bilateral (p=0.99, OR - 0).Patients with cardiovascular disease are at higher risk for perioperative MI after single anesthetic bilateral TKA.

The mechanical behavior of human femurs has been described in the literature with regard to torsion and tension but only as independent measurements. However, in this study, human femurs were subjected to torsion to determine if a simultaneous axial tensile load was generated. Fresh frozen human femurs (n=25) were harvested and stripped of soft tissue. Each femur was mounted rigidly in a specially designed test jig and remained at a fixed axial length during all experiments. Femurs were subjected to external and internal rotation applied at a constant angulation rate of 0.1 deg/s to a maximum torque of 12 N m. Applied torque and generated axial tension were monitored simultaneously. Outcome measurements were extracted from torsion-versus-tension graphs. There was a strong relationship between applied torsion and the resulting tension for external rotation tests (torsion/ tension ratio = 551.7 ± 283.8 mm, R 2 = 0.83 ± 0.20, n=25), internal rotation tests (torsion/tension ratio =495.3 ± 233.1 mm, R 2 = 0.87 ± 0.17, n = 24), left femurs (torsion/tension ratio =542.2 ±262.4 mm, R 2 =0.88 ± 0.13, n =24), and right femurs (torsion/tension ratio = 506.7 ± 260.0 mm, R 2 = 0.82 ± 0.22, n = 25). No statistically significant differences were found for external versus internal rotation groups or for left versus right femurs when comparing torsion/tension ratios (p = 0.85) or R 2 values (p =0.54). A strongly coupled linear relationship between torsion and tension for human femurs was exhibited. This suggests an interplay between these two factors during activities of daily living and injury processes.

Objectives: The aim of the present study was to examine biomechanically 5 different construct combinations for fixation of ipsilateral intertrochanteric and femoral shaft fractures. Methods: Twenty-five fresh-frozen adult human femora (age range = 58-91 years, average age = 75.4 years) were tested in physiological bending and in torsion to characterize initial bending and torsional stiffness and stiffness following fixation of combined intertrochanteric and femoral shaft fractures. Five fracture fixation device constructs were assessed-construct A: long dynamic hip screw (long DHS); construct B: reconstruction nail; construct C: DHS plus low-contact dynamic compression plate; construct D: DHS plus retrograde intramedullary nail; and construct E: long intramedullary hip screw. Axial stiffness, torsional stiffness, and axial load-to-failure were the main measurements recorded. Results: There were no differences between constructs in terms of axial stiffness (P = 0.41), external rotation stiffness (P = 0.13), and axial load-to-failure (P = 0.16). However, there was a borderline statistically significant difference in internal rotation stiffness between the constructs (P = 0.048). Specifically, construct C was significantly stiffer than construct E (P = 0.04). Conclusions: All constructs showed no statistical differences when compared with one another, with the exception of construct E, which provided the least torsional stiffness. However, the current in vitro model did not simulate fracture healing or support offered by soft tissues, both of which would affect the stiffness and load-to-failure levels reached.

BACKGROUND Medical schools across Canada expend great effort in selecting students from a large pool of qualified applicants. Non-cognitive assessments are conducted by most schools in an effort to ensure that medical students have the personal characteristics of importance in the practice of Medicine. We reviewed the ability of University of Toronto academic and non-academic admission assessments to predict ranking by Internal Medicine and Family Medicine residency programmes. METHODS The study sample consisted of students who had entered the University of Toronto between 1994 and 1998 inclusive, and had then applied through the Canadian resident matching programme to positions in Family or Internal Medicine at the University of Toronto in their graduating year. The value of admissions variables in predicting medical school performance and residency ranking was assessed. RESULTS Ranking in Internal Medicine correlated significantly with undergraduate grade point average (GPA) and the admissions non-cognitive assessment. It also correlated with 2-year objective structured clinical examination (OSCE) score, clerkship grade in Internal Medicine, and final grade in medical school. Ranking in Family Medicine correlated with the admissions interview score. It also correlated with 2nd-year OSCE score, clerkship grade in Family Medicine, clerkship ward evaluation in Internal Medicine and final grade in medical school. DISCUSSION The results of this study suggest that cognitive as well as non-cognitive factors evaluated during medical school admission are important in predicting future success in Medicine. The non-cognitive assessment provides additional value to standard academic criteria in predicting ranking by 2 residency programmes, and justifies its use as part of the admissions process.