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The protection of an athlete’s health is an important task for the International Olympic Committee (IOC). Systematic injury and illness surveillance monitors trends over long periods of time. It identifies high-risk sports, including their most common and severe injuries and illnesses, and provides valuable knowledge to reduce the risk of occurrence. During the XXIX and XXX Summer and XXI Winter Games, comprehensive recording of injuries and illnesses through the medical staff of the participating National Olympic Committees and the sports medicine clinics at the different Olympic venues revealed that at least 7–11 % of all athletes incurred an injury or suffered at least from one illness occurrence during the Games. The incidence of injuries and illnesses varied substantially between sports. In the future, risk factor and video analyses of injury mechanisms in high-risk Olympic sports are essential to better direct injury prevention strategies. Monitoring the athlete’s health during the pre-Game period through periodic health exams as well as in the Olympic Games will be important to optimise health protection.

Background: Knee reinjury after anterior cruciate ligament (ACL) reconstruction is common and increases the risk of osteoarthritis. There is sparse evidence to guide return to sport (RTS) decisions in this population. Objectives: To assess the relationship between knee reinjury after ACL reconstruction and 1) return to level I sports, 2) timing of return to sports, and 3) knee function prior to return. Methods: 106 patients who participated in pivoting sports participated in this prospective two year cohort study. Sports participation and knee reinjury were recorded monthly. Knee function was assessed with the Knee Outcome Survey–Activities of Daily Living Scale, global rating scale of function, and quadriceps strength and hop test symmetry. Pass RTS criteria was defined as scores >90 on all tests, failure as failing any. Results: Patients who returned to level I sports had 4.32 (p=0.048) higher reinjury rate than those who did not. The reinjury rate was significantly reduced by 51 % for each month RTS was delayed until 9 months after surgery, after which no further risk reduction was observed. 38.2 % of those who failed RTS criteria suffered reinjuries versus 5.6 % of those who passed (HR: 0.16, p=0.075). More symmetrical quadriceps strength prior to return significantly reduced the knee reinjury rate. Conclusion: Returning to level I sports after ACL reconstruction leads to a more than 4-fold increase in reinjury rates over 2 years. Return to sport 9 months or later after surgery and more symmetrical quadriceps strength prior to return substantially reduces the reinjury rate.

Posterior cruciate ligament (PCL) tears most commonly result from motor vehicle collisions or sports-related trauma. The most frequent mechanism of injury is a posteriorly directed blow to the anterior proximal tibia, often from a dashboard in automobile collisions, or due to impact with the ground when falling onto a flexed knee in sports. Multiligament knee injuries involving the PCL are much more common than isolated PCL tears. The work-up must always begin with a complete history and physical examination. A multitude of special tests have been described to assist in diagnosing PCL injuries and associated medial and lateral ligament damage. Following the history and physical examination, radiographs and magnetic resonance imaging (MRI) are often used to assist in the diagnosis. Stress radiographs have been shown to be particularly helpful with both the initial and follow-up diagnosis because of reliable reproducibility and objective assessment of posterior translation. Moreover, examination under anesthesia and arthroscopic evaluation are also critical in the work-up of PCL injuries. The diagnosis and classification of PCL tears is crucial to patient outcomes because the management of isolated PCL tears and combined multiligamentous injuries is often very different.

Background Assessment of degenerative changes of the cartilage is important in knee cartilage repair surgery. Magnetic Resonance Imaging (MRI) T2 mapping and delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC) are able to detect early degenerative changes. The hypothesis of the study was that cartilage surrounding a focal cartilage lesion in the knee does not possess degenerative changes. Methods Twenty-eight consecutive patients included in a randomized controlled trial on cartilage repair were evaluated using MRI T2 mapping and dGEMRIC before cartilage treatment was initiated. Inclusion was based on disabling knee problems (Lysholm score of ≤ 75) due to an arthroscopically verified focal femoral condyle cartilage lesion. Furthermore, no major malalignments or knee ligament injuries were accepted. Mean patient age was 33 ± 9.6 years, and the mean duration of knee symptoms was 49 ± 60 months. The MRI T2 mapping and the dGEMRIC measurements were performed at three standardized regions of interest (ROIs) at the medial and lateral femoral condyle, avoiding the cartilage lesion Results The MRI T2 mapping of the cartilage did not demonstrate significant differences between condyles with or without cartilage lesions. The dGEMRIC results did not show significantly lower values of the affected condyle compared with the opposite condyle and the contra-lateral knee in any of the ROIs. The intraclass correlation coefficient (ICC) of the dGEMRIC readings was 0.882. Conclusion The MRI T2 mapping and the dGEMRIC confirmed the arthroscopic findings that normal articular cartilage surrounded the cartilage lesion, reflecting normal variation in articular cartilage quality. Study identifier NCT00885729 , registered April 17 2009.

Proximal hamstring injury occurs frequently and ranges from minor muscle injury to complete avulsions which can be potentially career threatening for athletes. Medical care of these challenging injuries requires proper knowledge of hamstring anatomy, function, aetiology and treatment options. Treatment may be conservative and/or operative. After successful primary treatment, secondary prevention is important due to the high incidence of reinjury. These topics are discussed in the following chapter.

Athletes participating in elite sports are exposed to high training loads and increasingly saturated competition calendars. Emerging evidence indicates that poor load management is a major risk factor for injury. The International Olympic Committee convened an expert group to review the scientific evidence for the relationship of load (defined broadly to include rapid changes in training and competition load, competition calendar congestion, psychological load and travel) and health outcomes in sport. We summarise the results linking load to risk of injury in athletes, and provide athletes, coaches and support staff with practical guidelines to manage load in sport. This consensus statement includes guidelines for (1) prescription of training and competition load, as well as for (2) monitoring of training, competition and psychological load, athlete well-being and injury. In the process, we identified research priorities. Funding Agencies|International Olympic Committee

Background:Early sport specialization is not a requirement for success at the highest levels of competition and is believed to be unhealthy physically and mentally for young athletes. It also discourages unstructured free play, which has many benefits.Purpose:To review the available evidence on early sports specialization and identify areas where scientific data are lacking.Study Design:Think tank, roundtable discussion.Results:The primary outcome of this think tank was that there is no evidence that young children will benefit from early sport specialization in the majority of sports. They are subject to overuse injury and burnout from concentrated activity. Early multisport participation will not deter young athletes from long-term competitive athletic success.Conclusion:Youth advocates, parents, clinicians, and coaches need to work together with the sport governing bodies to ensure healthy environments for play and competition that do not create long-term health issues yet support athletic competition at the highest level desired.

Osteoarthritis is a serious disease of articular cartilage. The pathogenic factors contributing to this disorder are inflammation, extracellular matrix degradation and failure to rebuild the articular cartilage. Preclinical studies suggest that microRNA-140 may play a protective role in osteoarthritis development, but little is known about the mechanism by which this occurs. Here we present the results of forced expression of microRNA-140 in an in vitro model of osteoarthritis, evaluated by global proteomics analysis. We show that inflammation was reduced through the altered levels of multiple proteins involved in the nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 pathway. microRNA-140 upregulated many of the components involved in the synthesis of hyaline extracellular matrix and reduced the levels of aggrecanases and syndecan 4, thus potentially both increasing cartilage repair and reducing cartilage breakdown. These results show how forced expression of microRNA-140 is likely to counteract all three pathogenic processes, and support the idea that intra-articular injection of microRNA-140 may benefit patients suffering from early osteoarthritis.

Background: Rehabilitation before anterior cruciate ligament (ACL) reconstruction (ACLR) is effective at improving postoperative outcomes at least in the short term. Less is known about the effects of preoperative rehabilitation on functional outcomes and return-to-sport (RTS) rates 2 years after reconstruction. Purpose/Hypothesis: The purpose of this study was to compare functional outcomes 2 years after ACLR in a cohort that underwent additional preoperative rehabilitation, including progressive strengthening and neuromuscular training after impairments were resolved, compared with a nonexperimental cohort. We hypothesized that the cohort treated with extended preoperative rehabilitation would have superior functional outcomes 2 years after ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: This study compared outcomes after an ACL rupture in an international cohort (Delaware-Oslo ACL Cohort [DOC]) treated with extended preoperative rehabilitation, including neuromuscular training, to data from the Multicenter Orthopaedic Outcomes Network (MOON) cohort, which did not undergo extended preoperative rehabilitation. Inclusion and exclusion criteria from the DOC were applied to the MOON database to extract a homogeneous sample for comparison. Patients achieved knee impairment resolution before ACLR, and postoperative rehabilitation followed each cohort’s respective criterion-based protocol. Patients completed the International Knee Documentation Committee (IKDC) subjective knee form and Knee injury and Osteoarthritis Outcome Score (KOOS) at enrollment and again 2 years after ACLR. RTS rates were calculated for each cohort at 2 years. Results: After adjusting for baseline IKDC and KOOS scores, the DOC patients showed significant and clinically meaningful differences in IKDC and KOOS scores 2 years after ACLR. There was a significantly higher ( P < .001) percentage of DOC patients returning to preinjury sports (72%) compared with those in the MOON cohort (63%). Conclusion: The cohort treated with additional preoperative rehabilitation consisting of progressive strengthening and neuromuscular training, followed by a criterion-based postoperative rehabilitation program, had greater functional outcomes and RTS rates 2 years after ACLR. Preoperative rehabilitation should be considered as an addition to the standard of care to maximize functional outcomes after ACLR.

Background/aim To be fully effective, the prevention of injury in sport and promotion of athlete9s health needs to be both targeted and underpinned by scientific evidence. This study aimed to identify the research priorities of International Sporting Federation (ISFs) compared to the current research focus of the International Olympic Committee Research Centres (IOC-RCs). Methods Online survey of ISF Medical Chairpersons (n=22, 69% response) and IOC-RC Directors (n=7, 78% response). Open-ended responses relating to injury/illness priorities and specific athlete targets were thematically coded. Ratings were given of the need for different research types according to the Translating Research into Injury Prevention Practice (TRIPP) Framework stages. Results are presented as the frequency of ISFs and IOC-RCs separately. Results Both ISFs and IOC-RFs prioritised research into concussion (27%, 72%, respectively), competitive overuse (23%, 43%) and youth (41%, 43%). The ISFs also ranked catastrophic injuries (14%), environmental factors (18%), elite athletes (18%) and Paralympic athletes (14%) as important. The IOC-RCs gave higher priority to preventing respiratory illness (43%), long-term health consequences of injury (43%) and recreational athletes (43%). There was a trend towards ISFs valuing TRIPP stage 5/6 research more highly and for the IOC-RCs to value TRIPP stage 1/2 research. Conclusions There are clear opportunities to better link the priorities and actions of the ISFs and IOC-RCs, to ensure more effective practice-policy-research partnerships for the benefit of all athletes. Setting a mutually-agreed research agenda will require further active engagement between researchers and broader ISF representatives.

There is an increasing awareness on the importance in identifying early phases of the degenerative processes in knee osteoarthritis (OA), the crucial period of the disease when there might still be the possibility to initiate treatments preventing its progression. Early OA may show a diffuse and ill-defined involvement, but also originate in the cartilage surrounding a focal lesion, thus necessitating a separate assessment of these two entities. Early OA can be considered to include a maximal involvement of 50 % of the cartilage thickness based on the macroscopic ICRS classification, reflecting an OARSI grade 4. The purpose of this paper was to provide an updated review of the current status of the diagnosis and definition of early knee OA, including the clinical, radiographical, histological, MRI, and arthroscopic definitions and biomarkers. Based on current evidence, practical classification criteria are presented. As new insights and technologies become available, they will further evolve to better define and treat early knee OA. Level of evidence IV.

Background The Youth Olympic Games (YOG) are a new format designed by the International Olympic Committee. So far no reference data are available regarding the organisation or implementation of the medical services that were needed for the Winter Youth Olympic Games that took place for the first time in Innsbruck 9–24 January 2012. Objectives (1) To provide insight into what is needed to prepare for such a complex high level sporting event from a medical perspective, (2) to provide data on medical services for future organising committees and (3) to provide information on different National Olympic Committee (NOC) delegation structures and the consequences of registering a National Olympic Committee Team Physician. Methods A medical information system in the form of a patient data-management system was developed with all involved parties to standardise data collection. All medical encounters occurring at any IYOGOC medical service centre (including physiotherapy and psychology facilities) were tracked and collected in daily reports. Data evaluation was prepared based on different interest groups (Athletes, National Olympic Committees, Workforce, International Olympic Committee and Media) and analysed. Results 327 medical encounters (42.8% athletes; out of these, 57.9% were accounted to athletes with own NOC team physician) were seen during the YOG 2012. The total number of hospital transports was 27.3%, of which 8.9% were hospitalised with an average length of 1.9 nights. Physiotherapy usage was low with only 19 medical encounters resulting in a referral to physiotherapy accounting for 67 treatments during the entire YOG. Psychological care service was not used at all. The main reason for illnesses was disorders of the respiratory system (28.8%), injuries mostly affected upper extremities (49.6%) and were mostly diagnosed with lacerations and contusions (26.2%). Injury (70.7%) and illness (29.3%) incidences in athletes were slightly lower than previous studies showed. 40.0% of NOC delegations registered their own team physicians, which led to a significant difference in usage frequency of medical service (–3%, p=0.012). Conclusions Medical service coverage at the first Winter Youth Olympic Games seemed to be appropriate. No disaster or epidemic disease challenged the medical service plan. Future organising committees could use the provided data as a reference for their planning efforts.

Background: Single-legged hop tests are commonly used functional performance measures that can capture limb asymmetries in patients after anterior cruciate ligament (ACL) reconstruction. Hop tests hold potential as predictive factors of self-reported knee function in individuals after ACL reconstruction. Hypothesis: Single-legged hop tests conducted preoperatively would not and 6 months after ACL reconstruction would predict self-reported knee function (International Knee Documentation Committee [IKDC] 2000) 1 year after ACL reconstruction. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: One hundred twenty patients who were treated with ACL reconstruction performed 4 single-legged hop tests preoperatively and 6 months after ACL reconstruction. Self-reported knee function within normal ranges was defined as IKDC 2000 scores greater than or equal to the age- and sex-specific normative 15th percentile score 1 year after surgery. Logistic regression analyses were performed to identify predictors of self-reported knee function within normal ranges. The area under the curve (AUC) from receiver operating characteristic curves was used as a measure of discriminative accuracy. Results: Eighty-five patients completed single-legged hop tests 6 months after surgery and the 1-year follow-up with 68 patients classified as having self-reported knee function within normal ranges 1 year after reconstruction. The crossover hop and 6-m timed hop limb symmetry index (LSI) 6 months after ACL reconstruction were the strongest individual predictors of self-reported knee function (odds ratio, 1.09 and 1.10) and the only 2 tests in which the confidence intervals of the discriminatory accuracy (AUC) were above 0.5 (AUC = 0.68). Patients with knee function below normal ranges were over 5 times more likely of having a 6-m timed hop LSI lower than the 88% cutoff than those with knee function within normal ranges. Patients with knee function within normal ranges were 4 times more likely to have a crossover hop LSI greater than the 95% cutoff than those with knee function below normal ranges. No preoperative single-legged hop test predicted self-reported knee function within normal ranges 1 year after ACL reconstruction (all P > .353). Conclusion: Single-legged hop tests conducted 6 months after ACL reconstruction can predict the likelihood of successful and unsuccessful outcome 1 year after ACL reconstruction. Patients demonstrating less than the 88% cutoff score on the 6-m timed hop test at 6 months may benefit from targeted training to improve limb symmetry in an attempt to normalize function. Patients with minimal side-to-side differences on the crossover hop test at 6 months possibly will have good knee function at 1 year if they continue with their current training regimen. Preoperative single-legged hop tests are not able to predict postoperative outcomes.

Background: There is no consensus on the management of anterior cruciate ligament (ACL) injuries in skeletally immature children, and the methodological quality of published studies is questionable. The transphyseal reconstructions, physeal-sparing reconstructions, and nonoperative treatment algorithms that are advocated have little support in the literature. The purpose of this study was to systematically review the methodological quality of the literature on the management of ACL injuries in skeletally immature children. Methods: We performed a literature search with use of PubMed to identify prospective or retrospective studies whose primary aim was to assess the outcome after operative or nonoperative treatment of ACL injuries in skeletally immature children.Tobeincludedintheanalysis,astudyhadtohaveameandurationoffollow-upofatleasttwoyearsandaminimum of ten children in the study had to be verified to be skeletally immature. The methodological quality of the included studies was evaluated with use of the Coleman Methodology Score. Results: No randomized controlled trials, two prospective cohort studies, and twenty-nine retrospective studies met the inclusion criteria. The Coleman Methodology Score averaged 44.7 ± 9.2 out of 100 (range, 28 to 62). The methodological deficiencies were most evident with regard to the number of included children, the study design, and the description of rehabilitation protocols, outcome criteria, and outcome assessments. Conclusions: Caution is necessary when interpreting the results of studies on the treatment of ACL injuries in skeletally immature children because of widespread methodological deficiencies. There is a need for appropriately sized prospective studies and detailed descriptions of rehabilitation programs. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Challenging environmental conditions, including heat and humidity, cold, and altitude, pose particular risks to the health of Olympic and other high-level athletes. As a further commitment to athlete safety, the International Olympic Committee (IOC) Medical Commission convened a panel of experts to review the scientific evidence base, reach consensus, and underscore practical safety guidelines and new research priorities regarding the unique environmental challenges Olympic and other international-level athletes face. For non-aquatic events, external thermal load is dependent on ambient temperature, humidity, wind speed and solar radiation, while clothing and protective gear can measurably increase thermal strain and prompt premature fatigue. In swimmers, body heat loss is the direct result of convection at a rate that is proportional to the effective water velocity around the swimmer and the temperature difference between the skin and the water. Other cold exposure and conditions, such as during Alpine skiing, biathlon and other sliding sports, facilitate body heat transfer to the environment, potentially leading to hypothermia and/or frostbite; although metabolic heat production during these activities usually increases well above the rate of body heat loss, and protective clothing and limited exposure time in certain events reduces these clinical risks as well. Most athletic events are held at altitudes that pose little to no health risks; and training exposures are typically brief and well-tolerated. While these and other environment-related threats to performance and safety can be lessened or averted by implementing a variety of individual and event preventative measures, more research and evidence-based guidelines and recommendations are needed. In the mean time, the IOC Medical Commission and International Sport Federations have implemented new guidelines and taken additional steps to mitigate risk even further.

i Acute and chronic musculoskeletal injuries in sports are common and problematic for both athletes and cliniians. A significant proportion of these injuries remain diffiult to treat, and many athletes suffer from decreased perforance and long-standing pain and discomfort.1 In 2008, the International Olympic Committee (IOC) published a consensus document on the importance of molecular mechanisms in connective tissue and skeletal muscle injury and healing.2 This document predicted an increase in the use of autologous growth factors, as has indeed happened following that publication. Platelet-rich plasma (PRP, also referred to as platelet rich in growth factors, platelet-rich fibrin matrix, platelet-rich fibrin, fibrin sealant, platelet concentrate) is now being widely used to treat musculoskeletal injuries in sports and draws widespread media attention, despite the absence of robust clinical studies to support its use.3 Of the few studies published on he effectiveness of PRP in clinical settings, only very few are f sufficient methodological quality that would enable evience-based decision making. On January 1, 2011, the orld Anti-Doping Agency eased the restrictions on PRP, iting that there was no evidence that the procedure enanced performance. PRP and its variant forms were originally used in clinical ractice as an adjunct to surgery to assist in the healing of arious tissues. Initially, PRP was mainly used in oral surery.4,5 Subsequently, PRP has also been used at the time of urgery, involving shoulder,6 hip,7 and knee joint procedures,8,9 including anterior cruciate ligament reconstruction,10 and it has been used to improve bone healing.11 More recently, PRP in an injectable form has been used for the

Objective A systematic and long-term data collection on the treatment of focal cartilage defects (FCDs) of the knee is needed. This can be achieved through the foundation of a National Knee Cartilage Defect Registry. The aim of this study was to establish the nationwide burden of knee cartilage surgery, defined as knee surgery in patients with an FCD. We also aimed to identify any geographical differences in incidence rates, patient demographics or trends within this type of surgery. Setting A population-based study with retrospective identification of patients undergoing knee cartilage surgery in Norway through a mandatory public health database from 2008 to 2011. Participants We identified all patients undergoing cartilage surgery, or other knee surgery in patients with an FCD. All eligible surgeries were assessed for inclusion on the basis of certain types of ICD-10 and NOMESKO Classification of Surgical Procedures codes. Primary and secondary outcome measures The variables were diagnostic and surgical codes, geographic location of the performing hospital, age and sex of the patients. Yearly incidence and incidence rates were calculated. Age-adjusted incidences for risk ratios and ORs between geographical areas were also calculated. Results A total of 10 830 cases of knee cartilage surgery were identified, with slight but significant decreases from 2008 to 2011 (p

Meniscal tears differ in terms of pattern and location. If left untreated, a meniscal tear can lead to the development of osteoarthritis and increased pain, swelling, and functional limitations. Tears in the vascularized outer two-thirds of the meniscus can often be successfully repaired with use of an inside-out technique. Vertical mattress sutures stabilize the meniscal tear in place, allowing for proper healing. The principal steps in the procedure include (1) assessing the location and pattern of the tear arthroscopically, (2) performing a medial or lateral meniscal repair incision in the proper anatomic location, (3) passing the sutures in a vertical mattress pattern through the torn meniscus, and (4) tying the sutures while verifying sufficient reduction of the tear arthroscopically. Postoperatively, patients remain non-weight-bearing for the course of six weeks. Passive knee flexion from 0° to 90° is allowed for the first two weeks. After two weeks, motion is increased as tolerated. At six weeks postoperatively, patients are allowed to progress to weight-bearing as tolerated and initiate the use of a stationary bicycle. They should avoid squatting, sitting cross-legged, and squatting and lifting for four months postoperatively to avoid substantial stress on the healing meniscus. After four months, sports-specific activities are initiated. Patients are expected to return to normal physical activity within four to six months postoperatively.

Background: Reports on outcome after posterior cruciate ligament (PCL) reconstruction often contain both isolated PCL and combined knee ligament injuries. This makes it difficult to conclude on the outcome after reconstruction of isolated PCL injuries. Purpose: To investigate the outcome after PCL reconstruction in patients with an isolated PCL injury and to compare this with the outcome of patients treated with reconstruction after isolated anterior cruciate ligament (ACL) injuries. Study Design: Cohort study; Level of evidence, 3. Methods: Seventy-one patients with an isolated PCL injury that was reconstructed surgically and who had registered in the Norwegian Knee Ligament Registry between 2004 and 2010 were included in this study. Patients with isolated ACL reconstructions (n = 9661) who had registered in the same period were included for comparison. Knee Injury and Osteoarthritis Outcome Score (KOOS) was used as the patient-reported outcome measure. Preoperative and 2-year postoperative KOOS scores were compared. Changes in KOOS score reported by the PCL patients were compared with changes reported by the ACL patients. Results: At the 2-year postoperative follow-up of the PCL-reconstructed patients, the patient-reported outcome was improved, measured by KOOS as follows: pain, 15.1 (95% CI, 8.5-21.8; P < .001); symptoms, 0.9 (95% CI, –6.6 to 8.3; P = .82); activities of daily living, 13.2 (95% CI, 6.6-13.9; P < .001); sports, 20.7 (95% CI, 11.8-29.4; P < .001); and quality of life, 26.6 (95% CI, 18.9-34.2; P < .001). According to the KOOS, the incremental improvements were similar for PCL and ACL patients. Time from injury to surgery was longer for the PCL patients compared with ACL patients (median, 21.5 vs 8.0 months; P < .001). Conclusion: Patients undergoing PCL reconstruction can expect the same improvements in KOOS score as patients undergoing ACL reconstruction. However, PCL patients start out with an inferior score on average and consequently end up at a lower score compared with ACL patients for all KOOS subscales.

Background The rapidly increasing burden of chronic disease is diffi cult to reconcile with the large, compelling body of literature that demonstrates the substantial preventive and therapeutic benefi ts of comprehensive lifestyle intervention, including physical activity, smoking cessation and healthy diet. Physical inactivity is now the fourth leading independent risk factor for death caused by non-communicable chronic disease. Although there have been efforts directed towards research, education and legislation, preventive efforts have been meager relative to the magnitude of the problem. The disparity between our scientifi c knowledge about chronic disease and practical implementation of preventive approaches now is one of the most urgent concerns in healthcare worldwide and threatens the collapse of our health systems unless extraordinary change takes place. Findings The authors believe that there are several key factors contributing to the disparity. Reductionism has become the default approach for healthcare delivery, resulting in fragmentation rather than integration of services. This, in turn, has fostered a disease-based rather than a health-based model of care and has produced medical school curricula that no longer accurately refl ect the actual burden of disease. Trying to ‘fi t’ prevention into a disease-based approach has been largely unsuccessful because the fundamental tenets of preventive medicine are diametrically opposed to those of disease-based healthcare. Recommendation A clinical discipline within medicine is needed to adopt disease prevention as its own reason for existence. Sport and exercise medicine is well positioned to champion the cause of prevention by promoting physical activity. Conclusion This article puts forward a strong case for the immediate, increased involvement of clinical sport and exercise medicine in the prevention and treatment of chronic disease and offers specifi c recommendations for how this may begin.

A growing body of scientific evidence indicates that the declining levels of physical activity and fitness in children and youth are associated with adverse impacts on their health, including rising levels of obesity, diabetes, heart disease, metabolic syndrome and increased risk of sports injury. In response, a number of governmental and non-governmental organisations have instituted programmes to promote health in children and youth through sports and physical activity. Many of these programmes have achieved success in increasing participation in sports and other forms of physical activity and, by extension, improving the health of these young people. These programmes have also been used successfully to enhance the lives of the young participants by means other than improving physical health.

Background: Previous studies have found significant predictors for functional outcome after anterior cruciate ligament (ACL) reconstruction; however, studies examining predictors for functional outcome in nonoperatively treated individuals are lacking. Hypothesis: Single-legged hop tests predict self-reported knee function (International Knee Documentation Committee [IKDC] 2000) in nonoperatively treated ACL-injured individuals 1 year after baseline testing. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: Ninety-one nonoperatively treated patients with an ACL injury were tested using 4 single-legged hop tests on average 74 ± 30 days after injury in a prospective cohort study. Eighty-one patients (89%) completed the IKDC 2000 1 year later. Patients with an IKDC 2000 score equal to or higher than the age- and gender-specific 15th percentile score from previously published data on an uninjured population were classified as having self-reported function within normal ranges. Logistic regression analyses were performed to identify predictors of self-reported knee function. The area under the curve (AUC) from receiver operating characteristic curves was used as a measure of discriminative accuracy. Optimal limb symmetry index (LSI) cutoff for the best single-legged hop test was defined as the LSI with the highest product of sensitivity and specificity. Results: Single hop for distance symmetry indexes predicted self-reported knee function at the 1-year follow-up ( P = .036). Combinations of any 2 hop tests (AUC = 0.64-0.71) did not give a higher discriminative accuracy than the single hop alone (AUC = 0.71). A cutoff of 88% (LSI) for the single hop revealed a sensitivity of 71.4% and a specificity of 71.7%. Conclusion: The single hop for distance (LSI) significantly predicted self-reported knee function after 1 year in nonoperatively treated ACL-injured patients. Combinations of 2 single-legged hop tests did not lead to higher discriminative accuracy than the single hop alone.

BACKGROUND: Chronic posterolateral knee injuries often result in substantial patient morbidity and functional instability. The clinical stability and functional outcomes following anatomic reconstructions in patients with a chronic posterolateral knee injury have not been determined, to our knowledge. METHODS: A two-center outcomes study of sixty-four patients with grade-3 chronic posterolateral instability was performed. The patients were evaluated subjectively with the modified Cincinnati and International Knee Documentation Committee (IKDC) subjective scores and objectively with the IKDC objective score. RESULTS: Eighteen patients had an isolated posterolateral knee reconstruction, and forty-six patients underwent a single-stage multiple-ligament reconstruction that included reconstruction of one or both cruciate ligaments along with the posterolateral knee reconstruction. The average duration of follow-up was 4.3 years. The fifty-four patients who were available for follow-up had an average total Cincinnati score of 65.7 points. A significant improvement was found between the preoperative and postoperative IKDC objective scores for varus opening at 20°, external rotation at 30°, reverse pivot shift, and single-leg hop. CONCLUSIONS: An anatomic posterolateral reconstruction resulted in improved clinical outcomes and objective stability for patients with a grade-3 posterolateral knee injury. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence. ORIGINAL ABSTRACT CITATION: “Outcomes of an Anatomic Posterolateral Knee Reconstruction” (2010;92:16-22).

Articular cartilage defects in the knee of young or active individuals remain a problem in orthopaedic practice. These defects have limited ability to heal and may progress to osteoarthritis. The prevalence of knee osteoarthritis among athletes is higher than in the non-athletic population. The clinical symptoms of osteoarthritis are joint pain, limitation of range of motion and joint stiffness. The diagnosis of osteoarthritis is confirmed by the symptoms and the radiological findings (narrowing joint space, osteophyte formation and subchondral sclerosis). There is no strong correlation between symptoms and radiographic findings. The aetiology of knee osteoarthritis is multifactorial. Excessive musculoskeletal loading (at work or in sports), high body mass index, previous knee injury, female gender and muscle weakness are well-known risk factors. The high-level athlete with a major knee injury has a high incidence of knee osteoarthritis. Cartilage injuries are frequently observed in young and middle-aged active athletes. Often this injury precedes osteoarthritis. Reducing risk factors can decrease the prevalence of knee osteoarthritis. The prevention of knee injury, especially anterior cruciate ligament and meniscus injury in sports, is important to avoid progression of knee osteoarthritis.

Objective: To analyse the frequency and characteristics of sports injuries and illnesses incurred during the World Athletics Championships. Design: Prospective recording of newly occurred injuries and illnesses. Setting: Twelfth International Association of Athletics Federations World Championships in Athletics 2009 in Berlin, Germany. Participants: National team physicians and physiotherapists and 1979 accredited athletes; Local Organising Committee physicians working in the Medical Centres. Main outcome measures: Incidence and characteristics of newly incurred injuries and illnesses. Results: 236 injury incidents with 262 injured body parts and 269 different injury types were reported, representing an incidence of 135.4 injuries per 1000 registered athletes. Eighty percent affected the lower extremity. Thigh strain (13.8%) was the main diagnosis. Overuse (44.1%) was the predominant cause. Most injuries were incurred during competition (85.9%). About 43.8% of all injury events were expected to result in time-loss. 135 illnesses were reported, signifying an incidence of 68.2 per 1000 registered athletes. Upper respiratory tract infection was the most common condition (30.4%) and infection was the most frequent cause (32.6%). The incidence of injury and illnesses varied substantially among the events. Conclusion: The risk of injury varied with each discipline. Preventive measures should be specific and focused on minimising the potential for overuse. Attention should be paid to ensure adequate rehabilitation of previous injuries. The addition of the illness part to the injury surveillance system proved to be feasible. As most illnesses were caused by infection of the respiratory tract or were environmentally related, preventive interventions should focus on decreasing the risk of transmission, appropriate event scheduling and heat acclimatisation.

Background and purpose The natural history of, and predictive factors for outcome of cartilage restoration in chondral defects are poorly understood. We investigated the natural history of cartilage filling subchondral bone changes, comparing defects at two locations in the rabbit knee.Animals and methods In New Zealand rabbits aged 22 weeks, a 4-mm pure chondral defect (ICRS grade 3b) was created in the patella of one knee and in the medial femoral condyle of the other. A stereo microscope was used to optimize the preparation of the defects. The animals were killed 12, 24, and 36 weeks after surgery. Defect filling and the density of subchondral mineralized tissue was estimated using Analysis Pro software on micrographed histological sections.Results The mean filling of the patellar defects was more than twice that of the medial femoral condylar defects at 24 and 36 weeks of follow-up. There was a statistically significant increase in filling from 24 to 36 weeks after surgery at both locations.The densit...

Background and purpose: The natural history of focal cartilage injury is largely unknown. In this study we investigated 6-year outcomes in patients with arthroscopically verified, focal, fullthickness cartilage injuries of the knee. Methods: In a previous report (baseline study) of 993 knee arthroscopies, 98 patients were less than 50 years old at baseline and showed grade 3–4 focal cartilage injury, as assessed with the International Cartilage Repair Society (ICRS) scale. In the present study, 84 of the 98 patients completed follow-ups at median 6.1 (5.3–7.8) years after baseline assessments. At baseline, the patients had undergone different types of cartilage repair (n = 34) or had no treatment or only debridement (n = 64) for their cartilage injury. The follow-up included evaluations with the ICRS knee evaluation form, the Lysholm score, and other knee evaluation tests. 68 patients underwent radiographic assessments with weight bearing. Results: Improvements compared to baseline were noted in the average ICRS functional score, visual analog scale (VAS) pain score, and the patients’ rating of the function in the affected knee compared to the contra-lateral knee. However, the average ICRS activity level had decreased from baseline. The average Lysholm score was 76 (SD 21). 19 patients had Kellgren-Lawrence grades 2–3 in the affected knee and 6 patients had grades 2–3 in the contralateral knee. There was a statistically significant difference between affected and contralateral knees. Interpretation: Patients with arthroscopically diagnosed ICRS grade 3–4 cartilage injuries in the knee may show improvement in knee function over the following 5–8 years, with or without cartilage repair. However, knee function remains substantially affected. Further studies are needed to determine whether cartilage surgery can yield better functional outcomes than non-surgical or less invasive surgical treatments.

BackgroundFew prospective long-term studies of more than 10 years have reported changes in knee function and radiologic outcomes after anterior cruciate ligament (ACL) reconstruction.PurposeTo examine changes in knee function from 6 months to 10 to 15 years after ACL reconstruction and to compare knee function outcomes over time for subjects with isolated ACL injury with those with combined ACL and meniscal injury and/or chondral lesion. Furthermore, the aim was to compare the prevalence of radiographic and symptomatic radiographic knee osteoarthritis between subjects with isolated ACL injuries and those with combined ACL and meniscal and/or chondral lesions 10 to 15 years after ACL reconstruction.Study DesignCohort study; Level of evidence, 2.MethodsFollow-up evaluations were performed on 221 subjects at 6 months, 1 year, 2 years, and 10 to 15 years after ACL reconstruction with bone-patellar tendon-bone autograft. Outcome measurements were KT-1000 arthrometer, Lachman and pivot shift tests, Cincinnati knee score, isokinetic muscle strength tests, hop tests, visual analog scale for pain, Tegner activity scale, and the Kellgren and Lawrence classification.ResultsOne hundred eighty-one subjects (82%) were evaluated at the 10- to 15-year follow-up. A significant improvement over time was revealed for all prospective outcomes of knee function. No significant differences in knee function over time were detected between the isolated and combined injury groups. Subjects with combined injury had significantly higher prevalence of radiographic knee osteoarthritis compared with those with isolated injury (80% and 62%, P = .008), but no significant group differences were shown for symptomatic radiographic knee osteoarthritis (46% and 32%, P = .053).ConclusionAn overall improvement in knee function outcomes was detected from 6 months to 10 to 15 years after ACL reconstruction for both those with isolated and combined ACL injury, but significantly higher prevalence of radiographic knee osteoarthritis was found for those with combined injuries.

Background This study was conducted to determine if risk factors for groin injuries among male soccer players could be identified. Hypothesis Previous groin injuries, reduced function scores, age, findings on clinical examination, and low isometric groin strength are associated with increased risk of new groin injuries. Study Design Cohort study; Level of evidence, 3. Methods A total of 508 players representing 31 amateur teams were tested during the 2004 preseason for potential risk factors for groin injury through a questionnaire on previous injury and function score (Groin Outcome Score [GrOS]) and a clinical examination of the groin. Generalized estimating equations were used in univariate analyses to identify candidate risk factors, and factors with a P value Results During the soccer season, 61 groin injuries affecting 55 legs (51 players) were registered. The total incidence of groin injuries was 0.6 injuries per 1000 playing hours (95% confidence interval [CI], 0.4-0.7), 0.3 injuries per 1000 training hours (95% CI, 0.2-0.4), and 1.8 injuries per 1000 match hours (95% CI, 1.2-2.5). In a multivariate analysis, previous acute groin injury (adjusted odds ratio [OR], 2.60; 95% CI, 1.10-6.11) and weak adductor muscles as determined clinically (adjusted OR, 4.28; 95% CI, 1.31-14.0) were significantly associated with increased risk of groin injuries. A multivariate analysis based only on acute time-loss injuries revealed the 40-m sprint test result (adjusted OR, 2.03 for 1 standard deviation change [injured group faster]; 95% CI, 1.06-3.88; P = .03) and functional testing of the rectal abdominal muscles (adjusted OR, 15.5 [painful in 19% of the players in the injured group compared to 16% in the uninjured group]; 95% CI, 1.11-217; P = .04) as significant risk factors. Conclusion A history of acute groin injury and weak adductor muscles are significant risk factors for new groin injuries.

Background: Currently in double-bundle anterior cruciate ligament (ACL) reconstructions, the range of knee flexion angles that surgeons use for anteromedial (AM) and posterolateral (PL) bundle graft fixation spans from 0° to 90° for both bundle grafts. Despite the recent popularity of this procedure, no consensus exists on an optimal set of AM and PL graft fixation angles. Hypothesis: Graft fixation angles that simulate the native tensioning relationship of the AM and PL bundles will produce kinematic results similar to the intact knee, while graft fixation angles that do not simulate this relationship will under- or overconstrain the knee. Study design: Controlled laboratory study. Methods: Twelve cadaveric knees were biomechanically tested in the intact state, ACL-sectioned state, and a randomized order of 7 double-bundle ACL reconstructed states at multiple graft fixation angle combinations. For each test state, data were collected for 88 N anterior tibial loads, 10 N·m valgus torques, 5 N·m internal rotation torques, and 2 simulated pivot shift loads consisting of a 5 N·m internal rotation torque coupled with either a 10 N·m valgus torque or an 88 N anterior tibial load at 0°, 20°, 30°, 60°, and 90° of knee flexion. Results: The AM and PL graft fixation angle combinations of 0°/0° (AM graft fixation angle/PL graft fixation angle), 60°/0°, 45°/15°, and 75°/15° restored normal laxity to the reconstructed knee in all of the biomechanical tests. The 30°/30°, 60°/60°, and 90°/90° graft fixation angle combinations significantly restricted knee laxity compared with the intact state in various biomechanical tests. Conclusion: We found that as long as the PL bundle graft was fixed between 0° and 15°, the AM graft could be fixed up to 75° without restricting knee laxity. However, fixation of the PL graft at 30° of knee flexion and above significantly overconstrained the knee. Clinical Relevance: This study provides a range of angles that can be used in double-bundle ACL reconstructions to restore normal knee stability without causing overconstraint.

Fifty-one patients were operated with reconstruction for an isolated PCL injury from 1997 to 2005. Forty-three of these patients were followed during a median period of 48 months (17–109). Median time from injury to surgery was 18 months (2–368). Five patients were operated within the first 6 months after the injury. Nineteen patients had a BPTB autograft, 24 had a hamstring tendon autograft, and seven patients in the hamstring group had a double-bundle femoral fixation. Clinical assessment included Lysholm knee score, International Knee Documentation Committee 2000 (IKDC) scores, Cincinnati score, Tegner score, KOOS score, VAS score, stress radiographs, and a functional test. The median Lysholm score at follow-up was 80 (32–95). Median Tegner score before injury was 7 (1–10) and at follow-up 6 (0–9). Median Cincinnati and IKDC 2000 scores were 74 (12–100) and 63 (24–100), respectively. The mean VAS for subjective assessment of knee function was 67.6 (SD = 22.9). The radiologically measured difference in posterior tibial translation between operated and non-injured knees was mean 8.4 mm (SD = 4.8). Four different functional tests showed function of the operated leg from 92% (25–128) to 95% (15–124) compared to the opposite leg. This study shows good functional outcome after reconstruction for isolated rupture of the posterior cruciate ligament. However, pain and instability are still a problem, as only three patients reported full Lysholm subscore indicating full stability, and only four patients reported full subscore indicating no knee pain.

Physical activity appears to be inversely related to cancer risk, although the evidence is convincing for colon cancer only. As physical activity levels are difficult to measure in the general population, we aimed to investigate how physical activity influences cancer risk using a cohort of Norwegian world class athletes.The cohort includes 3,428 athletes. Individual questionnaires gave information about physical activity and lifestyle variables until attained age. To elucidate the level of cancer risk, groups of athletes were compared to the general population (external comparisons) and to each other (internal comparisons).A slightly reduced risk of total cancer was observed in the cohort of athletes, but stronger effects were observed for subgroups. The risk reduction was most pronounced for lung cancer and for leukemia/lymphoma. In women, a threefold increased risk of thyroid cancer was observed.This cohort of athletes seems to have a reduced risk of cancer. The beneficial association, however, is weak and may be attributed to healthy lifestyle as well as to physical activity. Prolonged strenuous exercise may also increase the risk of thyroid cancer in women.

Injuries can counter the beneficial effects of sports participation at a young age if a child or adolescent is unable to continue to participate because of residual effects of injury. Independent of activity level, injuries represent a considerable problem for the athlete and can result in an increased potential for future disability and inactivity. Injuries are also referred to as one of the major reasons for athletes to drop out of sports. Systematic injury registrations at the youth and adolescent level have been performed in recreational sports to gain knowledge on injury risk, as well as on the most common and most severe sport specific injuries. However, information on injury risk of the young athlete competing in high level sports seems less available or unknown. This paper reviews the current knowledge on injury risk of the youth and adolescent elite athlete participating in sports presented in the Youth Olympic Games 2010. Apart from football, little is known on injury epidemiology among young elite athletes. Systematic injury surveillance of this highly competitive population is needed to monitor injuries, identify high risk sports, and ensure new knowledge on injury trends, which can form the basis for further research on injury risk factors, mechanisms, and in the final step, on injury prevention.

Background Analysis of injury and illness prevalence in elite sport provides the basis for the development of prevention programmes. Objectives To analyse the frequency and characteristics of injuries and illnesses occurring during the 13th Federation Internationale de Natation (FINA) World Championships 2009. Design Prospective recording of newly incurred injuries and illnesses. Methods The 13th FINA World Championships hosted 2592 athletes from 172 countries in the disciplines of swimming, diving, synchronised swimming water polo and open water swimming. All team physicians or physiotherapists were asked to complete daily a standardised reporting form for all newly incurred injuries and illnesses for their teams. To cover teams without medical staff, the physicians of the Local Organizing Committee also submitted daily report forms. Results 171 injuries were reported resulting in an incidence of 66.0 per 1000 registered athletes. The most affected body parts were the shoulder (n=25; 14.6%), and head (n=21; 12.3%). Half of the injuries occurred during training. The most common cause of injury was overuse (n=61; 37.5%). 184 illnesses were reported resulting in an incidence of 71.0 per 1000 registered athletes. The respiratory tract was most commonly affected (n=91; 50.3%) and the most frequently classified cause was infection (n=81; 49.2%). The incidence of injuries and illnesses varied substantially among the five disciplines, with the highest incidence of injury in diving and the lowest in swimming. Conclusions As the risk of injury varied with the discipline, preventive measures should be discipline specific and focused on minimising the potential for overuse. As most of the illnesses were caused by infection of the respiratory and gastrointestinal tract, preventive interventions should focus on eliminating common modes of transmission.

Objectives: The Norwegian Ligament Registry (NKLR) provides an opportunity for quality surveillance and research. Intraoperative findings and outcome after revision anterior cruciate ligament reconstruction (RACLR) is not as well studied as after primary ACL reconstruction. There were two objectives of this study. First, to evaluate the Norwegian Knee Ligament Registry (NKLR) for the occurrence, failure rate, graft choice, patient demographic profile (gender, age, body mass index), sport at time of injury and associated pathology (cartilage injuries, meniscal tears, other ligament injuries) for revision anterior cruciate ligament reconstructions (RACLR). Second, to match compare RACLR patients to primary ACL reconstructions in order to define possible predictors for those patients who will require RACLR. Methods: All patients identified in the NKLR from June 2004 until September 2016 that did not undergo cartilage restoration, meniscal transplant nor had a documented fracture at the primary reconstruction were included in the study. Revision rates at 1, 2 and 5 years were estimated with Kaplan-Meier analysis, and the estimated risk of RACLR based upon demographic and associated pathology was estimated with Cox regression analysis. Results: 784 patients with an average age of 25.6 years (25.0-26.3) met the inclusion and exclusion criteria with 53.1% being male. 62.1% of revisions were performed with bone patellar bone (BPTB) autograft while 23% used hamstring autograft. Associated injuries of the menisci, cartilage, and other ligaments and the sport at the time of injury are listed (Table 1). 12.9% of RACLR patients went on to have a Re-revision ACLR at 5 years postop (Figure 1). Match comparisons of primary ACLR patients with RACLR demonstrated no significant difference in occurrence based upon age (30 years), graft choice (BPTB, Hamstring, Allograft, Bone Quadriceps Tendon (BQT)), cartilage injury (No injury, ICRS 1-2, ICRS 3-4), meniscal Injury, associated ligament injury, sport at time of injury or Body Mass Index (BMI). Conclusion: Based upon review of a large ligament reconstruction registry, one can expect that less than 13% of patients undergo a Re-revision ALCR following failure of a RALCR at 5 years. Match comparison of primary ACLR versus RACLR demonstrated no significant predictor of RACLR based upon age, graft choice, cartilage injury, meniscal injury, associated ligament injury, sport or BMI.

This prospective cohort study was conducted to identify the risk factors for acute knee injuries among male football players. A total of 508 players representing 31 amateur teams were tested during the 2004 preseason for potential risk factors for knee injury through a questionnaire on previous injury, Knee Osteoarthritis Outcome Score (KOOS) and a clinical examination. Generalized estimating equations were used in univariate analyses to identify candidate risk factors, and factors with a P-value o0.10 were then examined in a multivariate model. During the football season, 61 acute knee injuries, affecting 57 legs (53 players), were registered. Univariate analyses revealed the KOOS subscores ‘‘Pain’’ and ‘‘Function in daily living’’ (OR for a 10-point difference in score: 1.26, 95% CI 1.03– 1.55 and 1.35, 95% CI 0.98–1.85, respectively), any findings at clinical examination (OR: 2.62, 95% CI 1.03–6.68), flexion contraction in range of motion testing (OR: 0.96, 95% CI 0.93–1.00) and varus stress tests in full extension (OR: 8.50, 95% CI 1.85–39.0) and 301 flexion (OR: 5.69, 95% CI 1.73–18.8) as candidate factors. However, in a multivariate analysis, none of these factors were associated with an increased injury risk.

Surgical approaches to repair or reconstruct the medial knee structures note caution to avoid the sartorial branch of saphenous nerve. However, the approximate area of potential iatrogenic nerve injury has not been previously described in relation to landmarks for a medial knee reconstruction. The purpose of this study was to define the course of the sartorial branch of the saphenous nerve in relation to the superficial medial collateral ligament. A total of ten non-paired, fresh-frozen cadaveric knees, with no evidence of prior injury or disease were utilized. Dissection to identify the medial knee structures was performed. The sartorial branch of the saphenous nerve was identified in all specimens. The perpendicular distance from the anterior border of the superficial medial collateral ligament 2 cm distal from the joint line to the sartorial branch of the saphenous nerve was 4.8 +/- 0.9 cm. The distance from the anterior border of the superficial medial collateral ligament to the sartorial branch of the saphenous nerve decreased as the distance was increased distally with a mean distance of 4 cm (4.1 +/- 0.8 cm) distal from the joint line and 6 cm (3.8 +/- 0.8 cm) distal from the joint line. We have characterized the surgically relevant landmark anatomy of the sartorial branch of the saphenous nerve in regards to performing a repair or reconstruction of the medial knee structures. Familiarity with these anatomic landmarks and associated distances from the sartorial branch of the saphenous nerve, we can assess the potential area of vulnerability to this nerve branch intraoperatively.

Data from large prospectively collected anterior cruciate ligament (ACL) cohorts are being utilized to address clinical questions regarding ACL injury demographics and outcomes of ACL reconstruction. These data are affected by patient and injury factors as well as surgical factors associated with the site of data collection. The aim of this article is to compare primary ACL reconstruction data from patient cohorts in the United States and Norway, demonstrating the similarities and differences between two large cohorts. Primary ACL reconstruction data from the Multicenter Orthopaedic Outcomes Network (MOON) in the United States and the Norwegian National Knee Ligament Registry (NKLR) were compared to identify similarities and differences in patient demographics, activity at injury, preoperative Knee injury and Osteoarthritis Outcome Score (KOOS), time to reconstruction, intraarticular pathology, and graft choice. Seven hundred and thirteen patients from the MOON cohort were compared with 4,928 patients from the NKLR. A higher percentage of males (NKLR 57%, MOON 52%; P < 0.01) and increased patient age (NKLR 27 years, MOON 23 years; P\0.001) were noted in the NKLR population. The most common sports associated with injury in the MOON cohort were basketball (20%), soccer (17%), and American football (14%); while soccer (42%), handball (26%), and downhill skiing (10%) were most common in the NKLR. Median time to reconstruction was 2.4 (Interquartile range [IQR] 1.2-7.2) months in the MOON cohort and 7.9 (IQR 4.2-17.8) months in the NKLR cohort (P < 0.001). Both meniscal tears (MOON 65%, NKLR 48%; P < 0.001) and articular cartilage defects (MOON 46%, NKLR 26%; P < 0.001) were more common in the MOON cohort. Hamstring autografts (MOON 44%, NKLR 63%) and patellar tendon autografts (MOON 42%, NKLR 37%) were commonly utilized in both cohorts. Allografts were much more frequently utilized in the MOON cohort (MOON 13%, NKLR 0.04%; P < 0.001). Significant diversity in patient, injury, and surgical factors exist among large prospective cohorts collected in different locations. Surgeons should investigate and consider the characteristics of these cohorts when applying knowledge gleaned from these groups to their own patient populations.

Background Standardized assessment of sports injuries provides important epidemiological information and also directions for injury prevention. Purpose To analyze the frequency, characteristics, and causes of injuries incurred during the Summer Olympic Games 2008. Study Design Descriptive epidemiology study. Methods The chief physicians and/or chief medical officers of the national teams were asked to report daily all injuries newly incurred during the Olympic Games on a standardized injury report form. In addition, injuries were reported daily by the physicians at the medical stations at the different Olympic venues and at the polyclinic in the Olympic Village. Results Physicians and/or therapists of 92 national teams covering 88% of the 10 977 registered athletes took part in the study. In total, 1055 injuries were reported, resulting in an incidence of 96.1 injuries per 1000 registered athletes. Half of the injuries (49.6%) were expected to prevent the athlete from participating in competition or training. The most prevalent diagnoses were ankle sprains and thigh strains. The majority (72.5%) of injuries were incurred in competition. One third of the injuries were caused by contact with another athlete, followed by overuse (22%) and noncontact incidences (20%). Injuries were reported from all sports, but their incidence and characteristics varied substantially. In relation to the number of registered athletes, the risk of incurring an injury was highest in soccer, taekwondo, hockey, handball, weightlifting, and boxing (all ≥15% of the athletes) and lowest for sailing, canoeing/kayaking, rowing, synchronized swimming, diving, fencing, and swimming. Conclusion The data indicate that the injury surveillance system covered almost all of the participating athletes, and the results highlight areas of high risk for sport injury such as the in-competition period, the ankle and thigh, and specific sports. The identification of these factors should stimulate future research and subsequent policy change to prevent injury in elite athletes.

Dislocation of the knee is a relatively rare injury with modern arthroscopic techniques, operative reconstruction has become the standard of care. The primary aim of this study was to prospectively follow a large, consecutive series of patients with knee dislocation to document associated injuries, surgical treatment, knee function, and knee osteoarthritis (OA) at a minimum of 2 years follow-up. Hundred and twenty-two consecutive patients with a traumatic knee dislocation (Schenck II-IV) were treated at the Oslo University Hospital, Ulleval, between May 1996 and December 2004. Follow-up evaluation of 85 patients consisted of evaluation of knee joint laxity using the KT1000, the Lachman test, the pivot shift test, the reversed pivot shift, the posterior drawer test, the dial test, and the varus-valgus tests compared to the uninjured knee. Knee function was evaluated using the Lysholm score, the Tegner activity level score, the IKDC2000 score, and four single leg hop tests. Radiographic evaluation was performed using the Kellgren & Lawrence classification grade 0-4. Knee function at a minimum of 2 years after surgery disclosed a Lysholm score of a median of 83, a Tegner activity score of 5, and above 83% on all single leg hop tests compared to the uninjured side. Knee function was lower in the patients with a knee dislocation caused by high-energy trauma compared to low energy trauma. Eighty-seven percent had Kellgren & Lawrence grade 2 or higher for the injured knee compared to 35% for the uninjured knee.

Background There is a lack of knowledge on the primary and secondary static stabilizing functions of the posterior oblique ligament (POL), the proximal and distal divisions of the superficial medial collateral ligament (sMCL), and the meniscofemoral and meniscotibial portions of the deep medial collateral ligament (MCL). Hypothesis Identification of the primary and secondary stabilizing functions of the individual components of the main medial knee structures will provide increased knowledge of the medial knee ligamentous stability. Study Design Descriptive laboratory study. Methods Twenty-four cadaveric knees were equally divided into 3 groups with unique sequential sectioning sequences of the POL, sMCL (proximal and distal divisions), and deep MCL (meniscofemoral and meniscotibial portions). A 6 degree of freedom electromagnetic tracking system monitored motion after application of valgus loads (10 N·m) and internal and external rotation torques (5 N·m) at 0°, 20°, 30°, 60°, and 90° of knee flexion. Results The primary valgus stabilizer was the proximal division of the sMCL. The primary external rotation stabilizer was the distal division of the sMCL at 30° of knee flexion. The primary internal rotation stabilizers were the POL and the distal division of the sMCL at all tested knee flexion angles, the meniscofemoral portion of the deep MCL at 20°, 60°, and 90° of knee flexion, and the meniscotibial portion of the deep MCL at 0° and 30° of knee flexion. Conclusion An intricate relationship exists among the main medial knee structures and their individual components for static function to applied loads. Clinical Significance: Interpretation of clinical knee motion testing following medial knee injuries will improve with the information in this study. Significant increases in external rotation at 30° of knee flexion were found with all medial knee structures sectioned, which indicates that a positive dial test may be found not only for posterolateral knee injuries but also for medial knee injuries.

BackgroundThere is limited information regarding directly measured load responses of the posterior oblique and superficial medial collateral ligaments in isolated and multiple medial knee ligament injury states.HypothesesTensile load responses from both the superficial medial collateral ligament and the posterior oblique ligament would be measurable and reproducible, and the native load-sharing relationships between these ligaments would be altered after sectioning of medial knee structures.Study DesignDescriptive laboratory study.MethodsTwenty-four nonpaired, fresh-frozen adult cadaveric knees were distributed into 3 sequential sectioning sequences. Buckle transducers were applied to the posterior oblique ligament and the proximal and distal divisions of the superficial medial collateral ligament; 10 N·m valgus moments and 5 N·m internal and external rotation torques were applied at 0°, 20°, 30°, 60°, and 90° of knee flexion.ResultsWith an applied valgus and external rotation moment, there was a significant load increase on the posterior oblique ligament compared with the intact state after sectioning all other medial knee structures. With an applied external rotation torque, there was a significant load decrease on the proximal division of the superficial medial collateral ligament from the intact state after sectioning all other medial knee structures. With an applied external rotation torque, the distal division of the superficial medial collateral ligament experienced a significant load increase from the intact state after sectioning the posterior oblique ligament and the meniscofemoral division of the deep medial collateral ligament.ConclusionThis study found alterations in the native load-sharing relationships of the medial knee structures after injury. Sectioning both the primary and secondary restraints to valgus and internal/external rotation of the knee alters the intricate load-sharing relationships that exist between the medial knee structures.Clinical SignificanceIn cases in which surgical repair or reconstruction is indicated, consideration should be placed on repairing or reconstructing all injured medial knee structures to restore the native load-sharing relationships among these medial knee structures.

BackgroundThis is a systematic review of studies on the prevalence of osteoarthritis in the tibiofemoral joint more than 10 years after an anterior cruciate ligament injury, the radiologic classification methods used, and risk factors for development of knee osteoarthritis.MethodsA systematic search was performed in PubMed, EMBASE, and AMED. Inclusion criteria were studies involving patients with anterior cruciate ligament injury, either isolated or combined with medial collateral ligament or meniscal injury and either surgically or nonsurgically treated, and a minimum 10-year follow-up with radiologic assessment. Methodological quality was evaluated using a modified version of the Coleman methodology score.ResultsSeven prospective and 24 retrospective studies were included. The mean modified Coleman methodology score was 52 of 90. Reported prevalence of knee osteoarthritis for subjects with isolated anterior cruciate ligament injury was between 0% and 13%. For subjects with anterior cruciate ligament and additional meniscal injury, the prevalence varied between 21% and 48%. Seven different radiologic classification systems were used in the studies. Only 3 studies reported reliability results for the radiologic assessments. The most frequently reported risk factor for development of knee osteoarthritis was meniscal injury.ConclusionThis systematic review suggests that the prevalence rates of knee osteoarthritis after anterior cruciate ligament reconstruction reported by previous reviews have been too high. The highest rated studies reported low prevalence of knee osteoarthritis for individuals with isolated anterior cruciate ligament injury (0%-13%) and a higher prevalence of knee osteoarthritis for subjects with combined injuries (21%-48%). Overall, the modified Coleman methodology score was low for the included studies. No universal methodological radiologic classification method exists, making comparisons of the studies and stating firm conclusions on the prevalence of knee osteoarthritis more than 10 years after anterior cruciate ligament injury difficult.