A multistate framework for the analysis of subsequent injury in sport (M-FASIS).

Physical activity is beneficial for many aspects of health but is associated with a risk of injury. Studies that assess causal risk factors of injury and reinjury provide valuable information to help develop and improve injury prevention programs. However, the underlying assumptions of analytical approaches often used to estimate causal factors in injury and subsequent injury research are often violated. This means that ineffective or even harmful interventions could be proposed because the underlying analyses produced unreliable or invalid causal effect estimates. We describe an adapted version of the multistate framework [multistate framework for the analysis of subsequent injury in sport (M-FASIS)] that makes investigator choices more transparent with respect to outcome and healing time. In addition, M-FASIS incorporates all previous sport injury analytical frameworks and accounts for injuries or conditions that heal or do not heal to 100%, acute and overuse injuries, illnesses, and competing event outcomes.

Consensus statement on the methodology of injury and illness surveillance in FINA (aquatic sports).

BACKGROUND: Injury and illness surveillance in the aquatic disciplines has been conducted during the FINA World Championships and Olympic Games. The development of an aquatic-specific injury and illness surveillance system will improve the quality of the data collected and the development of preventive measures. Our ultimate objective is to enhance aquatic athlete health and performance. OBJECTIVE: The objective was to refine the injury and illness surveillance protocols to develop aquatic-specific definitions of injury and illness; define aquatic-specific injury location and causation; better describe overuse injuries; regard pre-existing and recurrent injuries; more accurately define aquatic athlete exposures and develop a protocol to capture out-of-competition aquatic athlete health parameters. METHODS: FINA compiled an Injury and Illness Surveillance Expert Working Group comprised of international experts to review the scientific literature in the field. A consensus meeting was convened to provide an opportunity for debate, following which recommendations were collated. RESULTS: Aquatic-specific injury and illness surveillance protocols covering both the in-competition and out-of-competition time periods were developed. Definitions for all relevant variables were outlined, and documentation forms for athletes and for clinicians were proposed. Recommendations for the implementation of an injury and illness surveillance system for FINA are presented. CONCLUSION: The FINA consensus authors recommend ongoing in-competition and out-of-competition surveillance to determine injury and illness trends over time. The implementation of the definitions and methodology outlined in this paper will improve the accuracy and value of injury and illness surveillance, and provide important information for injury prevention.

Validating the three-step return-to-play decision model.

The purpose of this study was to validate a recently proposed return-to-play (RTP) decision model that simplifies the complex process into three underlying constructs: injury type and severity, sport injury risk, and factors unrelated to injury risk (decision modifiers). We used a cross-over design and provided clinical vignettes to clinicians involved in RTP decision making through an online survey. Each vignette included examples changing injury severity, sport risk (e.g. different positions), and non-injury risk factors (e.g. financial considerations). As the three-step model suggests, clinicians increased restrictions as injury severity increased, and also changed RTP decisions when factors related to sport risk and factors unrelated to sport risk were changed. The effect was different for different injury severities and clinical cases, suggesting context dependency. The model was also consistent with recommendations made by subgroups of clinicians: sport medicine physicians, non-sport medicine physicians, and allied health care workers.

Examining the effect of the injury definition on risk factor analysis in circus artists.

A secondary data analysis of a prospective cohort study was conducted to explore how different definitions of injury affect the results of risk factor analyses. Modern circus artists (n=1281) were followed for 828,547 performances over a period of 49 months (2004-2008). A univariate risk factor analysis (age, sex, nationality, artist role) estimating incidence rate ratios (IRR) with 95% confidence intervals (95% CI) was conducted using three injury definitions: (1) medical attention injuries, (2) time-loss injuries resulting in ≥1 missed performances (TL-1) and (3) time-loss injuries resulting in >15 missed performances (TL-15). Results of the risk factor analysis were dependent on the injury definition. Sex (females to male; IRR=1.13, 95% CI; 1.02-1.25) and age over 30 (<20 years to >30 years; IRR=1.37, 95% CI; 1.07-1.79) were risk factors for medical attention injuries only. Risk of injury for Europeans compared with North Americans was higher for TL-1 and TL-15 injuries compared with medical attention injuries. Finally, non-sudden load artists (low-impact acts) were less likely than sudden load artists (high-impact acts) to have TL-1 injuries, but the risk of medical attention injuries was similar. The choice of injury definition can have effects on the magnitude and direction of risk factor analyses.

The effect of rest days on injury rates.

Despite the importance of recuperation, few have studied the impact of rest periods on injury prevention. We determined the effect of rest days (breaks) on injury rates and treatments using electronic injury records from an acrobatic circus company that employs former world-class athletes as acrobats. To account for accumulated fatigue, we considered breaks across SD3 (third consecutive week of 1-day rest) to SD6 as a single exposure level (SD3-6), and vacation and DD (2-day rest) as a single exposure level. Medical attention injury rates were increased post- vs pre-break {rate ratio 1.45 [95% confidence intervals (95% CI): 1.22-1.73]} with less of an effect for 1-day time loss [1.25 (95% CI: 0.58-2.67)] and 15-day time loss [1.10 (95% CI: 0.26-4.56)]. However, the increase in injury rate post break for SD3-6 was similar to that of DD-Vacation (P=0.48, 0.53, and 0.65) for medical attention, and both ≥1 day and ≥15 days time loss, respectively. The increase in the number of treatments post-break was less for SD3-6 vs DD-vacation. Our findings suggest that 2-day breaks every four to 6 weeks may be sufficient to avoid an increasing injury rate due to cumulative fatigue in professional acrobatic circus artists.

A pilot study on the effects of pre-event manipulation on jump height and running velocity.

PURPOSE: To compare changes in jump height and running velocity with and without pre-event high-velocity, low-amplitude manipulation (HVLA). METHODS: A crossover study design with elite healthy athletes was used. After a 15 min warm-up, the subjects were tested for countermovement jump height (CMJ) and flying 40 m sprint time (SPRINT). A sport chiropractor then evaluated each subject. Subjects were randomised to either HVLA (applied to joints based on examination) or placebo (simulated performance-enhancement stickers). They then rested for 60 min, performed another 15 min warm-up, and were retested. The protocol was repeated 48 h later with the alternative intervention. The mean of two sprints and three jumps were analysed, as well as peak performances. The sample size was based on prior results from the effects of stretching. RESULTS: 19 subjects involved in sprint sports were enrolled; two were too sore to participate on day 2, and one could only participate in the jump (all had HVLA on day 1). Of the 17 participants analysed, seven were female, age range was 19-35, and 17 were national or world-class athletes. The ranges for baseline measures were: SPRINT 4.1-5.5 s; CMJ 47.4-92.7 cm. Overall, the greater than expected variability in this pilot study led to the study being underpowered. Subjects tended to perform better after HVLA for both CMJ and SPRINT (both mean and peak results), but none of the results were statistically significant (p = 0.30-0.61). CONCLUSION: Although the larger than expected variability in the pilot study means that the observed clinically relevant differences were not statistically significant, the direction and magnitude of the changes associated with HVLA suggest that it may be beneficial. That said, the increased soreness after HVLA suggests that it may be detrimental. HVLA warrants further study.

Conservative non-pharmacological treatment options are not frequently used in the management of hip osteoarthritis.

Osteoarthritis (OA) is the most frequent joint disorder in seniors. Systematic reviews suggest that conservative treatment is effective and preferred in mild-moderate cases. The objective of this study was to examine the proportion of patients receiving physiotherapy, exercise or walking aids, and to explore factors associated with their prescription. We conducted a retrospective survey of patients about to undergo total hip arthroplasty for hip osteoarthritis. Patients were asked about past prescriptions for cane use, physiotherapy and exercise. Of 161 patients (36.6% male, mean age 68.7+/-10.1 years), 76% were prescribed a cane (adherence=86.2%). The main reason for not using a cane was vanity. Of the 28.0% patients prescribed physiotherapy, 73.3% received exercises compared to only 2.6% of non-physiotherapy patients. Patients who were older or worked in manual labour were more likely to be prescribed a cane and less likely to be prescribed physiotherapy or exercises. Men were less likely than women to be prescribed all three, but only cane use was statistically significant across genders. In conclusion, physiotherapy and exercise are not commonly prescribed in patients with hip OA.

Injuries sustained by colorectal surgeons performing colonoscopy.

BACKGROUND: Repetitive tasks in the workplace are one cause of injury. This study aimed to identify injuries specific to physicians routinely performing colonoscopy, and to identify prevention strategies. METHODS: A survey was sent to all 2,173 worldwide members of the American Society for Colon and Rectal Surgery to investigate injuries or disabilities that resulted from performing colonoscopy and the methods used to prevent and alleviate symptoms related to the procedure. RESULTS: The response rate was 28%. Of the respondents, 96% performed colonoscopy. At least one injury or pain believed to result from performing colonoscopy was reported by 39% of the respondents. The most frequently reported injuries were to hands and fingers (n = 257), neck (n = 65), and back (n = 52). The methods adopted to alleviate injury included changing the height of the stretcher or video monitor, changing from a standing to a sitting position, minimizing torque on the colonoscope, having an assistant perform the torque maneuver, and resting or taking time off from colonoscopy. Two respondents also created devices to make the instrument more ergonomic. CONCLUSION: The number of colorectal surgeons encountering injury from colonoscopy highlights the need for preventive strategies. The study results suggest that it may be necessary to improve the design of colonoscopes to make them more ergonomic. Appropriate positioning of the endoscopist, patient, and monitors may diminish some of the injuries encountered.

Effect of graduated elastic compression stockings on leg symptoms and signs during exercise in patients with deep venous thrombosis: a randomized cross-over trial.

Graduated elastic compression stockings (ECS) are often prescribed after deep venous thrombosis (DVT) to alleviate acute symptoms and to prevent and treat post-thrombotic syndrome (PTS). In patients with DVT, leg symptoms tend to worsen with exercise. The effects of ECS use during exercise have not been studied. Objectives were to determine whether ECS improve symptoms and signs and increase exercise capacity when worn during treadmill exercise by patients with prior DVT, with or without PTS. The methods employed a randomized cross-over trial. We recruited subjects who had a first episode of unilateral DVT at least 1 year earlier and categorized them as having, or not having, the PTS using a validated scale. Subjects underwent two identical treadmill exercise sessions at least 1 week apart, and were randomly assigned to wear knee-length 30 mmHg ECS on the affected leg during one of the two sessions. Venous symptoms, leg volume, leg circumference and calf muscle flexibility were measured in the affected leg before and after both exercise sessions. Subjects achieved similar percentage maximum predicted heart rates during both sessions. Comparing the ECS to no ECS session, there were no significant differences in treadmill time (21.2 vs. 21.2 min, P = 0.94), gain in leg volume (71 vs. 73 mL, P = 0.83), or change in soleus or gastrocnemius flexibility, whether or not PTS was present. Symptoms in general worsened slightly with exercise regardless of whether or not ECS were worn and did not differ according to PTS status. Per-subject analysis showed that use of ECS resulted in global improvement of symptoms in 25% of subjects, global worsening in 33% of subjects, and had no or inconsistent effects in 42% of subjects. Whether or not PTS was present, the use of ECS during exercise by patients with prior DVT did not improve symptoms and signs during exercise or increase exercise capacity.

Systematic review: the use of somatostatin or octreotide in refractory diarrhoea.

BACKGROUND: Somatostatin and octreotide have multiple effects which make them ideal for treating diarrhoea of different aetiologies. Their use in a variety of conditions with refractory diarrhoea, however, is based on a limited number of studies. AIM: We undertook a systematic review of the available English literature to maximize an evidence-based approach to the treatment of refractory diarrhoea. We tested the hypothesis that efficacy is independent of aetiology. METHODS AND RESULTS: A Medline and individual article search from 1965 to 2000 was undertaken on the use of somatostatin and octreotide in diarrhoea. All reports containing at least five subjects were included. The percentage response in case series and randomized controlled trials was compared, and a meta-analysis of randomized controlled trials where patient level data were provided was carried out. There were 30 publications found (18 case series, 12 randomized controlled trials). The response percentage was 73% overall in case series and 64% in randomized controlled trials (not significant). A meta-analysis of nine randomized controlled trials revealed significant heterogeneity despite an overall relative risk of 0.5 (95% confidence interval, 0.27-0.91). Subgroup analysis of the largest aetiological groups showed that acquired immunodeficiency syndrome studies were homogeneous, but somatostatin and octreotide were less effective. Post-chemotherapy studies remained heterogeneous and somatostatin and octreotide were highly effective. CONCLUSIONS: While this review strengthens the consensus guidelines on the use of somatostatin and octreotide for refractory diarrhoea, evidence-based support requires additional studies.

Missed opportunities for prevention of venous thromboembolism: an evaluation of the use of thromboprophylaxis guidelines.

OBJECTIVES: To identify and characterize cases of potentially preventable venous thromboembolism (VTE): cases for which thromboprophylaxis was indicated, according to the American College of Chest Physicians (ACCP) consensus guidelines for VTE prevention, yet was administered inadequately. DESIGN: A historical cohort study to examine all cases of deep vein thrombosis and pulmonary embolism from 1996 to 1997 at a large teaching hospital. Of these, we determined the proportion that was potentially preventable. We examined the reasons for inadequacy of prophylaxis and the setting in which preventable VTE occurred. RESULTS: Of 253 objectively diagnosed cases of VTE in 245 patients, 44 cases (17.4%) were considered potentially preventable. This represented two thirds of all VTE cases for which thromboprophylaxis had been indicated (n = 65). Of preventable cases, the most frequent reason for inadequacy of prophylaxis was omission of prophylaxis (47.7%), followed by inadequate duration of prophylaxis (22.7%), and by incorrect type of prophylaxis (20.5%). Surgical and medical indications for thromboprophylaxis that were common among preventable cases included nonorthopedic surgery, admission to hospital for pneumonia, and stroke with lower limb paralysis. Underlying risk factors for VTE that were common among preventable cases included recent immobility, active cancer, and obesity. CONCLUSIONS: One of six cases of all VTE and two of three cases of VTE for which thromboprophylaxis had been indicated could potentially have been prevented had physicians followed the recommended ACCP guidelines. Inadequacy of prophylaxis was most often caused by omission of prophylaxis. Missed opportunities for prevention occurred most commonly in the settings of nonorthopedic surgery, pneumonia, and stroke.

A tale of two homocysteines--and two hemodialysis units.

Pharmacologic doses of folic acid are commonly used to reduce the hyperhomocysteinemia of end-stage renal disease (ESRD). Vitamin B12 acts at the same metabolic locus as folic acid, but information is lacking about the specific effects of high doses of this vitamin on homocysteine levels in renal failure. We therefore compared the plasma homocysteine concentrations of maintenance hemodialysis patients in two McGill University-affiliated urban tertiary-care medical centers that differed in the use of vitamin B12 and folic acid therapy. Patients in the first hemodialysis unit are routinely prescribed high-dose folic acid (HI-F, 6 mg/d), whereas those in the second unit receive high-dose vitamin B12 in the form of a monthly 1-mg intravenous injection, along with conventional oral folic acid (HI-B12, 1 mg/d). Predialysis homocysteine was 23.4 +/- 6.8 micromol/L (mean +/- SD) in the HI-F unit and 18.2 +/- 6.1 micromol/L in the HI-B12 unit (P < .002). Postdialysis homocysteine was 14.5 +/- 4.1 in the HI-F unit and 10.6 +/- 3.4 micromol/L in the HI-B12 unit (P = .0001). Multiple regression analysis indicated that high-dose parenteral vitamin B12 was associated with a lower homocysteine concentration even after controlling for the potential confounders of sex, serum urea, serum creatinine, urea reduction ratio, and plasma cysteine. Because this was a cross-sectional observational study, we cannot exclude the possibility that unidentified factors, rather than the different vitamin therapies, account for the different homocysteine levels in the two units. Careful prospective studies of the homocysteine-lowering effect of high-dose parenteral vitamin B12 in ESRD should be undertaken.

NG-nitro-L-arginine and phenylephrine have similar effects on the vascular waterfall in the canine hindlimb.

Hindlimb pressure-flow relationships are well characterized by modeling a vascular waterfall at the arteriolar level. Under these conditions, Q = (Pper - Pcrit)/Rart, where Q is blood flow, Pper is perfusion pressure, Pcrit is waterfall pressure, and Rart is the resistance upstream from the waterfall. To determine the effects of endothelium-derived relaxing factor (EDRF) on Pcrit, Rart, and venous resistance (Rv), we varied Pper in the canine hindlimb between 100 and 200 mmHg before and after NG-nitro-L-arginine infusion (L-NNA, an inhibitor of EDRF synthesis). Before L-NNA, Pcrit increased with increasing Pper. After L-NNA, Pcrit was higher at each Pper, and the increase in Pcrit with increases in Pper was greater than under control conditions. In contrast to Pcrit, Rart decreased with increasing Pper before L-NNA. After L-NNA, Rart was higher at each Pper and no longer decreased with increasing Pper. Rv was not affected by Pper under control conditions but decreased with increasing Pper after L-NNA. The pressure in the small venules at each Pper decreased after L-NNA. In a second group of animals, we infused phenylephrine to control for increased tone produced by L-NNA. Results were similar to those seen with L-NNA. In conclusion, blocking EDRF synthesis increases both Pcrit and Rart, but the same response was also obtained with phenylephrine.

Pressure-flow relationships in in vitro model of compartment syndrome.

Compartment syndrome is a condition in which an increase in intramuscular pressure decreases blood flow to skeletal muscle. According to the Starling resistor (i.e., vascular waterfall) model of blood flow, the decrease in flow could occur through an increase in arterial resistance (Rart) or an increase in the critical closing pressure (Pcrit). To determine which explains the decrease in flow, we pump perfused a canine gastrocnemius muscle placed within an airtight box, controlled box pressures (Pbox) so that flow ranged from 100 to 50%, and measured Pcrit, Rart, arterial compliance, small venular pressure (measured by the double-occlusion technique), and venous pressure. An increase in Pbox limited flow mainly through an increase in Pcrit (75-85%), with only small changes in Rart (15-25%) and no change in arterial compliance. Increases in Pbox also produced a vascular waterfall in the venous circulation, but small venular transmural pressure always remained less than control levels. We conclude that increases in Pbox mostly limit blood flow through increases in Pcrit and that Rart plays a minor role. Transmural pressure across the small venules decreases with increases in intramuscular pressure, which contradicts the currently held belief that compartment syndrome is due to a cycle of swelling-ischemia-swelling.

Maximal vasodilation does not eliminate the vascular waterfall in the canine hindlimb.

Previous studies have shown that blood flow through skeletal muscle is regulated by changes in an arteriolar vascular waterfall [critical pressure (Pcrit)] and a proximal (arterial) resistance (Ra) element. To determine whether Pcrit still exists during maximal vasodilation, we pump perfused vascularly isolated canine hindlimbs. We set outflow pressure to zero and measured Pcrit, perfusion pressure (Pper), and regional elastic recoil pressure (Pcl; by a stop-flow technique) and calculated both Ra and venous resistance before and after maximal vasodilation with adenosine and nitroprusside. Pcrit was 56.4 +/- 5.1 mmHg before vasodilation and decreased to 11.0 +/- 0.6 mmHg after vasodilation, which was less than the downstream pressure in the venous compliant region (Pel). Therefore, Pcrit should not have affected flow at normal Pper levels under vasodilated conditions. However, we could still measure Pcrit because our technique allowed Pel to decline and Pcrit becomes apparent once Pel < Pcrit. With vasodilation, Ra decreased to < 8.1 +/- 2.6% and Rv decreased to 41 +/- 6% of control values. In contrast to the nonvasodilated vasculature, increases in venous pressure during maximal vasodilation caused immediate increases in Pper. This also suggests that the vascular waterfall is inactive under conditions of maximal vasodilation. We conclude that a small arteriolar Pcrit is still present in the maximally vasodilated hindlimb but is less than the downstream pressure and does not affect flow under these conditions.

Effects of adenosine on pressure-flow relationships in an in vitro model of compartment syndrome.

Blood flow through skeletal muscle is best modeled with a vascular waterfall at the arteriolar level. Under these conditions, flow is determined by the difference between perfusion pressure (Pper) and the waterfall pressure (Pcrit), divided by the arterial resistance (Ra). By pump perfusing an isolated canine gastrocnemius muscle (n = 6) after it was placed within an airtight box, with and without adenosine infusion, we observed an interaction between the pressure surrounding a muscle (as occurs in compartment syndrome) and baseline vascular tone. We titrated adenosine concentration to double baseline flow. We measured Pcrit and Ra at box pressures (Pbox), which resulted in 100 (Pbox = 0), 90, 75, and 50% flow without adenosine; and 200, 180, 150, 100, and 50% flow with adenosine. Without adenosine, each 10% decline in flow was associated with a 5.7 mmHg increase in Pcrit (P < 0.01). With adenosine, the same decrease in flow was associated with a 2.6-mmHg increase in Pcrit (P < 0.01). Values of Pcrit at 50% of flow were almost identical. Each 10% decrease in flow was also associated with 2.2% increase in Ra with or without adenosine (P < 0.001). Ra decreased with adenosine infusion (P < 0.05), and there was no interaction between adenosine and flow (P > 0.9). We conclude that increases in pressure surrounding a muscle limit flow primarily through changes in Pcrit with and without adenosine-induced vasodilation. The interaction between Pbox and adenosine with respect to Pcrit but not Ra suggests that Pbox affects the tone of the vessels responsible for Pcrit but not Ra.

A teaching unit in primary care sports medicine for family medicine residents.

The authors describe their experience in setting up a sports medicine teaching unit within a family practice center of a teaching hospital. The unit's patient population more closely resembles that of a typical family practice than that of a traditional musculoskeletal teaching clinic (e.g., orthopedics, emergency room). The teaching program includes direct observation of residents performing history taking and physical examinations through one-way mirrors, close supervision for each case, and a sports therapist who educates patients and residents about home exercise programs when physiotherapy within private clinics is not necessary or affordable. At the end of each session 20-30 minutes are devoted to teaching specific physical examination skills. The authors describe how their clinic interacts with other services within the hospital and how certain obstacles they encountered when setting up the clinic might be avoided by others. They feel that this type of unit complements other existing programs in the family medicine department and provides an excellent learning experience for family medicine residents, who are likely to see a high proportion of patients with muskuloskeletal injuries in their practices.

Knowledge of and attitude toward patient confidentiality within three family medicine teaching units.

PURPOSE: To describe the knowledge and attitudes about confidentiality issues within family medicine teaching units (FMUs) at McGill University. METHOD: The authors surveyed McGill University FMU staff (physicians, nurses, and support staff) on their knowledge of and attitudes toward confidentiality issues. RESULTS: The response rate was 84%. Only one of nine questions on confidentiality laws was correctly answered by more than 80% of the respondents. Only 55% of the support staff knew that police are not permitted free access to charts, although the majority of those who answered incorrectly held attitudes that were consistent with the law. Only approximately 25% knew that physicians and nurses are not permitted free access to any medical record within the center. There were minimal differences between the professions or between the FMUs. CONCLUSION: These findings suggest that FMU staff do not fully understand their obligations towards patient confidentiality.

Etiology of small bowel obstruction.

BACKGROUND: Small bowel obstruction (SBO) is a major cause of morbidity and financial expenditure in hospitals around the world. The leading cause of SBO in the western world has become adhesions. The goal of this study was to determine the causes of SBO. METHODS: The medical records of all patients admitted to one hospital between 1986 and 1996 with the diagnosis of SBO were reviewed retrospectively. This included 552 patients accounting for 1,001 admissions. RESULTS: The etiology of SBO was adhesions (74%), Crohn's disease (7%), neoplasia (5%), hernia (2%), radiation (1%), and miscellaneous (11%). Patients with Crohn's disease were younger than patients with other etiologies. Surprisingly, recurrence rates were similar for patients treated operatively as for those treated nonoperatively with the exception in the hernia group where higher recurrence rates were noted for patients initially treated in a nonoperative manner. CONCLUSION: The most common cause of SBO is adhesions followed by Crohn's disease and neoplasia.