Pulmonary embolism is a serious complication after arthroscopy of the knee, about which there is limited information. We have identified the incidence and risk factors for symptomatic pulmonary embolism after arthroscopic procedures on outpatients. The New York State Department of Health Statewide Planning and Research Cooperative System database was used to review arthroscopic procedures of the knee performed on outpatients between 1997 and 2006, and identify those admitted within 90 days of surgery with an associated diagnosis of pulmonary embolism. Potential risk factors included age, gender, complexity of surgery, operating time defined as the total time that the patient was actually in the operating room, history of cancer, comorbidities, and the type of anaesthesia. We identified 374 033 patients who underwent 418 323 outpatient arthroscopies of the knee. There were 117 events of pulmonary embolism (2.8 cases for every 10 000 arthroscopies). Logistic regression analysis showed that age and operating time had significant dose-response increases in risk (p < 0.001) for a subsequent admission with a pulmonary embolism. Female gender was associated with a 1.5-fold increase in risk (p = 0.03), and a history of cancer with a threefold increase (p = 0.05).

These risk factors can be used when obtaining informed consent before surgery, to elevate the level of clinical suspicion of pulmonary embolism in patients at risk, and to establish a rationale for prospective studies to test the clinical benefit of thromboprophylaxis in high-risk patients.

Introduction: Stress fractures comprise a major problem in female police or army recruits. The incidence of stress fractures is reported ranging from 3 to 10 fold when compared to male recruits taking the same training program. This study consisted of an intervention program aiming at reducing combat gear weight and locating the gear as close as possible to the body center of gravity.

Material and Methods: In a prospective study we followed up two companies of female recruits of the Israel Border Police. Both companies were followed for the four months of basic training using a basic data questionnaire inclusive of previous physical activity habits, previous acute and overuse injuries, menstrual history and previous smoking habits. An injury questionnaire was filled on commencement of the course and every two weeks thereafter. The clinical records of medic and doctor visits, as well as the personal medical file, were revised. Roentgenological and scintigraphic imaging were performed during the course, when clinical suspicion of a stress fracture arose.

The first company of 71 fighters used the standard combat gear amounting to 12.5 kg. The second company of 64 fighters used combat equipment weighing 9.4 kg, held in a combat girdle close to the body center of gravity, inclusive of a shorter personal combat riffle and personal combat vest.

Results: There was no difference in the number of clinic visits between the two companies. Complaints suggesting stress fractures were recorded in the first company from the 3^rd to the 8^th week of training and in the second from the 1^st to 3^rd week. The percentage of fighters sent for Scintigraphy because of clinical suspicion of stress fractures was 22.5% in the first company and 6.25% in the second. The percentage of fighters in whom stress fractures were located by Scintigraphy was 15.5% in the first company and 4.7% in the second. The number of stress fractures in average per fighter was 0.45 fractures in the first company and 0.27 fractures in the second. When calculating only “dangerous” stress fractures (long bones and navicular) there were noted 0.34 fractures per fighter in the first company and 0.20 in the second. Total average training days lost for reason of stress fractures was 2.21 per fighter in the first company and 1.08 in the second.

Conclusions: Reducing the weight of the fighting gear and securing it closer to the body center of gravity may have a positive effect in reducing the incidence of stress fractures in female recruits of fighting units during the intense basic training program.

Excessive foot pronation has been considered to be related to anterior knee pain. We undertook a prospective study to test the hypothesis that exertional anterior knee pain is related to the static and dynamic parameters of foot pronation. Two weeks before beginning basic training lasting for 14 weeks, 473 infantry recruits were enrolled into the study and underwent two-dimensional measurement of their subtalar joint displacement angle during walking on a treadmill.

Of the 405 soldiers who finished the training 61 (15%) developed exertional anterior knee pain. No consistent association was found between the incidence of anterior knee pain and any of the parameters of foot pronation. While a statistically significant association was found between anterior knee pain and pronation velocity (left foot, p = 0.05; right foot, p = 0.007), the relationship was contradictory for the right and left foot. Our study does not support the hypothesis that anterior knee pain is related to excessive foot pronation.