Injury and illness epidemiology in soccer - effects of global geographical differences - a call for standardized and consistent research studies.

Soccer is the most popular sport in the world. While injuries and illnesses can affect the players' health and performance, they can also have a major economic impact on teams. Moreover, several studies have shown the favourable association between higher player availability and team success. Therefore, injury prevention could directly impact clubs' financial balance and teams' performance via increased player availability. To be able to develop effective methods of injury prevention, it is vital to first determine the scope and the degree of the problem: the mechanisms and types of injuries, their frequency and severity, etc. According to the most widely known prevention model, systematic injury surveillance is the first and most fundamental step towards injury prevention. Since epidemiological studies have shown that injuries and illnesses in soccer players differ from region to region, it is important to establish a specific injuries and illness database in order to guide specific preventive actions. Since Asia is the largest continent, with the highest number of soccer players, and in the light of the long-term research on injuries performed in UEFA clubs, the authors of the present article present the AFC surveillance. Some methodological issues related to this prospective design study are discussed. The definition of injury and illness and the methods to track players' exposure are described along with the potential challenges related to such a vast scale study. This article is also a call for action to have consistent and standardized epidemiological studies on soccer injuries and illnesses, with the aim to improve their prevention.

Eighteen-Year Follow-up After Autologous Chondrocyte Implantation on Medial and Lateral Femoral Condyles: A Case Report.

Articular cartilage defects are common injuries of the knee. The defects often progress in size and produce significant clinical symptoms due to the lack of intrinsic repair or regenerative capacity of articular cartilage. With the failure of nonoperative treatment options, surgical treatment is indicated and includes palliative, reparative, and regenerative options. For large defects of the femoral condyles, trochlea, or patella, autologous chondrocyte implantation can provide successful and long-lasting results. Presented is the case of a 37-year-old male with an 18-year follow-up to autologous chondrocyte implantation for extensive left knee articular cartilage defects of the medial and lateral femoral condyles. Recovery from articular cartilage defects is shown through both clinical improvement of the patient and arthroscopic photographs of robust autologous articular cartilage on the medial femoral condyle. This case supports the long-term benefits of autologous chondrocyte implantation as a surgical intervention for large, full-thickness articular cartilage defects of the knee.

Surgical management of articular cartilage defects of the knee.

Articular cartilage defects of the knee present diagnostic and treatment challenges for orthopaedic surgeons. As new data and technologies become available, treatment algorithms are continually being refined. It is important to examine treatment recommendations from the current literature and understand surgical techniques for articular cartilage repair.

Magnetic resonance imaging-documented chondral injuries about the knee in college football players: 3-year National Football League Combine data.

PURPOSE: To evaluate the incidence and risk factors for knee cartilage injury in elite college football players invited to attend the US National Football League (NFL) Scouting Combine over a 3-year period. METHODS: All players entering the NFL Scouting Combine (National Invitational Camp) from 2005 through 2007 were evaluated. "At-risk" knees underwent magnetic resonance imaging (MRI), and the results were evaluated for chondral injuries. RESULTS: During the 3-year period reviewed, a total of 980 players were available for analysis, and a total of 516 players' knee MRI scans were obtained (53% of all players at the Combine). The total number of full-thickness chondral injuries evident on MRI was 197 (20.1%) among all players, or 38.2% of the players who had an MRI scan. Of the players, 30 (3.06% of all players at the Combine, or 5.8% of the players who had an MRI scan) had isolated medial compartment full-thickness chondral injuries, 41 (4.2%, or 7.9%) had isolated lateral compartment full-thickness chondral injuries, 48 (4.9%, or 9.3%) had patellofemoral compartment full-thickness chondral damage, and 78 (7.96%, or 15.1%) had full-thickness chondral injuries in more than 1 compartment. CONCLUSIONS: The epidemiologic and risk assessment data presented in this study offer a cross-section of a young and elite athletic population who were "prescreened" at the NFL Combine over a 3-year period and judged to have at-risk knees. The total number of full-thickness chondral injuries evident on MRI was 197 (20.1%) among all players, or 38.2% of the players who had an MRI scan: 30 players (3.06%, or 5.8%) had an isolated medial compartment full-thickness chondral injury, 41 players (4.2%, or 7.9%) had an isolated lateral compartment full-thickness chondral injury, 48 players (4.9%, or 9.3%) had isolated patellofemoral compartment full-thickness chondral damage, and 78 players (7.96%, or 15.1%) had full-thickness chondral injuries in more than 1 compartment. LEVEL OF EVIDENCE: Level IV, diagnostic study.

Lunacy revisited - the myth of the full moon: are football injuries related to the lunar cycle?

Previous literature suggests that human behaviour and physiology are somehow altered by the moon-cycle, with particular emphasis on poorer sleep quality and increased aggressive behaviour during full moon. The latter variables can negatively impact athletes' recovery and increase the likelihood of injury resulting from collision with another athlete. Therefore, the current study aimed to investigate the association between the lunar cycle and injury risk in professional football players (soccer). We monitored injuries and player exposure in the premier professional league in Qatar during four consecutive seasons (2013-2014 through 2016-2017). Acute (sudden-onset traumatic) injuries (n = 1184; 587 from contact with another player and 597 without player contact) recorded during matches and training were classified according to the lunar cycle characteristics on the date of injury: (i) moon illumination, (ii) lunar distance from earth and (iii) tidal coefficient, acquired from the lunar calendar and tide tables. We used a Poisson regression model to examine the relationship between injury risk and lunar cycle characteristics. We did not detect any association between injury risk and moon illumination, earth-to-moon distance or tidal coefficient, not for all acute injuries, nor for contact and non-contact injuries when examined separately. The findings suggest that the full moon or new moon or the gravitational pull have no effect on football injuries. Thus, organisers need not consult moon or tide tables when planning future event schedules.

ACL injury incidence, severity and patterns in professional male soccer players in a Middle Eastern league.

AIM: To ascertain ACL injury incidence, severity (injury burden) and patterns (contact/non-contact and reinjuries) in a professional male football league in the Middle East over five consecutive seasons. METHODS: Prospective epidemiological study reporting ACL injuries in professional male soccer players in the Qatar Stars League, with complete matches/training exposure over five seasons (2013-2014 to 2017-2018), corresponding to 2243 player seasons and 729 team months. RESULTS: 37 complete ACL ruptures occurred in 37 players during 486 951 hours of player exposure. The overall ACL injury rate was 0.076 injuries/1000 hours of exposure (season range 0.045-0.098). Injury incidence during matches and training was 0.41 and 0.04 injuries/1000 hours of exposure, respectively. Match injury incidence was greater than that of training (OR 11.8, 95% CI 6.21 to 23.23, p<0.001). Average injury-related time-loss following ACL injury was 225 days±65 (range 116-360). Overall injury burden was 16.3 days lost/1000 hours of exposure. CONCLUSION: The overall ACL injury rate in professional male soccer players competing in the Middle East was 0.076 injuries/1000 hours of exposure, match injury incidence was greater than training, while the average ACL time-loss was 225 days.

Treatment of full-thickness chondral defects in the knee with autologous chondrocyte implantation.

Autologous chondrocyte implantation (ACI) has now been performed for over a decade in the United States. ACI has been demonstrated as a reproducible treatment option for large, full-thickness, symptomatic chondral injuries of the knee. As clinical experience has expanded and indications broadened to more complex cartilage defects, it has become evident that aggressive treatment of coexisting knee pathology is essential for optimal results. This includes management of malalignment, ligamentous, and/or meniscal deficiency, and subchondral bone loss to make the intra-articular environment as ideal as possible for successful cartilage restoration. Additionally, refinements in the rehabilitation necessary for biologic cartilage repair have been made, based on better understanding of the maturation process of the repair cartilage, allowing for earlier initiation of knee range of motion, strengthening exercises, and weight bearing. These changes have enhanced the recovery for the patient and decreased the risk of motion deficits. This article will discuss patient selection for ACI, review ACI surgical technique, including management of coexisting knee pathology, present postoperative ACI rehabilitation guidelines, and summarize clinical outcomes after ACI.

Treatment of full-thickness chondral defects with autologous chondrocyte implantation.

Autologous chondrocyte implantation (ACI) is a reproducible treatment option for large full-thickness symptomatic chondral injuries with appropriate knowledge of technique and patient selection. It provides a cellular repair that offers a high percentage of good to excellent clinical results over a long follow-up period. It is applicable over a wide range of chondral injuries from simple to more complex lesions. It is essential that the intra-articular environment be as close to normal as possible for successful cartilage repair. Coexisting knee pathology must be aggressively treated. ACI does have a prolonged postoperative rehabilitation course necessitated by the biologic nature of the repair, and patients must be able to comply with the rehabilitation and temporary restrictions required for a successful outcome.

Autologous Chondrocyte Implantation With Collagen Membrane.

The first-generation autologous chondrocyte implantation (ACI-P) described by Peterson and colleagues used a periosteal patch to form a watertight cover over the articular cartilage defect, under which the autologous chondrocyte suspension was injected. Although good to excellent outcomes were often seen in >80% of patients and the durability of the repair documented up to 20 years, the procedure was noted to have a high rate of subsequent surgical procedures, most often for arthroscopic debridement of periosteal hypertrophy or incomplete incorporation. Consequently, the surgical technique advanced to use a porcine-derived bilayer of type I/III collagen with a porous layer that favors cell attachment and a smooth, compact layer that is cell occlusive. In use of the collagen membrane ACI, prospective studies have shown no diminution in clinical results and a marked reduction in subsequent surgeries from graft hypertrophy to <3%. Use of the collage membrane for ACI-C in the United States is currently an off-label use of an FDA-approved membrane, which should be discussed with the patient before surgery.

Update on advanced surgical techniques in the treatment of traumatic focal articular cartilage lesions in the knee.

Considerable interest has been developed over the past several years in expanding the treatment of symptomatic femoral condylar articular cartilage lesions in active patients. Multiple surgical techniques have been reported and evolving technologies, equipment and approaches continue to expand. The purpose of this paper is to review the presentation of focal articular cartilage lesions including treatment indications, current surgical options and postoperative protocols emphasizing advanced techniques used to preserve or restore hyaline cartilage tissue. The various surgical options are discussed and the advantages and disadvantages are reviewed and highlighted in a clinical practice guideline algorithm.

Virtual reality simulation of arthroscopy of the knee.

The virtual reality arthroscopic knee simulator (VR-AKS) consists of a computer platform, a video display, and two force-feedback (haptic) interfaces known as "PHANToMs" that also monitor the position of the instruments in the user's hands. The forces that the user would normally apply to the lower limb during arthroscopy are directed through an instrumented surrogate leg. Proprietary software provides the mathematical representation of the physical world and replicates the visual, mechanical, and behavioral aspects of the knee. This includes moderating the haptic interface and simultaneously executing a collision-detection algorithm that prevents the instruments from moving through "solid" surfaces. Modeling software interacts with this algorithm to send the appropriate images to the video display, including knee pathology such as meniscal tears and chondral defects as well as normal anatomy. Task-oriented programs monitor specific performance such as executing a proper examination of the knee or shaving a torn meniscus.

Management of intraoperative complications associated with autogenous patellar tendon graft anterior cruciate ligament reconstruction.

With the increasing number of anterior cruciate ligament (ACL) reconstructions being performed each year in the United States, sound surgical technique and preoperative planning are essential to decrease complications. Most intraoperative complications associated with ACL surgery are preventable with adequate planning and a reproducible surgical technique. When an autogenous bone-patellar tendon-bone graft is used for ACL reconstruction, pitfalls may occur at each step during the surgical procedure--preoperative assessment, graft harvest, notch preparation, tunnel preparation, graft passage and fixation, and rehabilitation. An array of options should be available for fixation of a patellar tendon graft, as well as alternative graft sources and graft preparation techniques.

Autologous chondrocyte implantation and anteromedialization for isolated patellar articular cartilage lesions: 5- to 11-year follow-up.

BACKGROUND: Isolated chondral lesions of the patella are particularly challenging to treat, and long-term studies of treated isolated patellar lesions are limited. Previous short-term studies have reported favorable outcomes of autologous chondrocyte implantation (ACI) of the patella and/or trochlea, with a trend toward improvement when anteromedialization (AMZ) of the tibial tubercle was performed with the procedure. HYPOTHESIS: Autologous chondrocyte implantation with concomitant AMZ for symptomatic isolated patellar lesions provides functional and symptomatic improvement in patients at a minimum 5-year follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients with failed primary treatment of isolated patellar full-thickness articular cartilage defects and patellofemoral malalignment who were treated with ACI and AMZ of the tibial tubercle at least 5 years prior were contacted for final postoperative outcome scores. Outcome scales including the International Knee Documentation Committee (IKDC), Lysholm, modified Cincinnati Knee Rating System, and 12-item Short Form Health Survey (SF-12) scores were assessed at baseline and final follow-up. RESULTS: Of 27 eligible patients, 23 (25 knees) were available for assessment at a mean follow-up of 7.6 years (range, 5.1-11.4 years). Significant improvements from baseline to final follow-up were observed in the IKDC score (from 42.5 to 75.7; P < .0001), modified Cincinnati Knee Rating System score (from 3.0 to 7.0; P < .0001), Lysholm score (from 40.2 to 79.3; P < .0001), and SF-12 score (physical component score: from 41.2 to 47.6; P = .002; mental component score: from 48.1 to 60.7; P = .0001). Most patients (83%; 19/23) rated their surgery as good or excellent. The overall reoperation rate was 40% (10/25) largely because of periosteal hypertrophy (33%). One patient failed at 5.9 years postoperatively and underwent patellofemoral arthroplasty. CONCLUSION: Combined ACI and AMZ resulted in significant improvements in symptoms and function with a low incidence of adverse events in patients with isolated symptomatic patellar chondral defects after a mean follow-up of more than 7 years.

Autologous chondrocyte implantation in the patella: a multicenter experience.

BACKGROUND: Cartilage defects in the patella are common, and a subset of patients does not respond to nonoperative measures. While most cartilage repair techniques have demonstrated good outcomes in the femoral condyles, the patellofemoral compartment poses special challenges. HYPOTHESIS: Repair of patellar cartilage defects with autologous chondrocyte implantation (ACI) will provide lasting improvements in pain and function. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients were treated at 1 of 4 participating cartilage repair centers with ACI for cartilage defects in the patella; bipolar (patella + trochlea) defects were included as well. All patients were followed prospectively for at least 4 years with multiple patient-reported outcome instruments, including the International Knee Documentation Committee, Short Form-12, modified Cincinnati Rating Scale, Western Ontario and McMaster Universities Osteoarthritis Index, and Knee Society scores. Treatment failure was defined as structural failure of the graft combined with pain requiring revision surgery. RESULTS: A total of 110 patients were available for analysis. As a group, they experienced both statistically significant and clinically important improvements in pain and function in all physical outcome scales. The International Knee Documentation Committee improved from 40 ± 14 preoperatively to 69 ± 20 at the last follow-up; the Cincinnati Rating Scale, from 3.2 ± 1.2 to 6.2 ± 1.8; and the Western Ontario and McMaster Universities Osteoarthritis Index, from 50 ± 22 to 29 ± 22 (all P < .0001). Ninety-two percent of patients stated that they would choose to undergo ACI again, and 86% rated their knees as good or excellent at the time of final follow-up. Nine patients (8%) were considered treatment failures, and 16% reported that their knees were not improved. CONCLUSION: Cartilage repair in the patellofemoral joint is arguably not without its challenges. Autologous chondrocyte implantation remains off-label in the patella, a fact that needs to be discussed with prospective patients during the informed consent process. However, when performed with attention to patellofemoral biomechanics, self-rated subjective good and excellent outcomes can be achieved in more than 80% of patients treated with ACI, even in a patient population with large and frequently bipolar defects such as the one presented in this study. However, final functional scores, although significantly improved, still reflected residual disability in this challenging group of patients.

Arthroscopic Delivery of Matrix-Induced Autologous Chondrocyte Implant: International Experience and Technique Recommendations.

OBJECTIVE: To identify consensus recommendations for the arthroscopic delivery of the matrix-induced autologous chondrocyte implant. DESIGN: An invited panel was assembled on November 20 and 21, 2009 as an international advisory board in Zurich, Switzerland, to discuss and identify best practices for the arthroscopic delivery of matrix-induced autologous chondrocyte implantation. RESULTS: Arthroscopic matrix-induced autologous chondrocyte implantation is suitable for patients 18 to 55 years of age who have symptomatic, contained chondral lesions of the knee with normal or corrected alignment and stability. This technical note describes consensus recommendations of the international advisory board for the technique of arthroscopic delivery of the matrix-induced autologous chondrocyte implant. CONCLUSIONS: Matrix-induced autologous chondrocyte implantation can be further improved by arthroscopic delivery that does not require special instrumentation. In principle, arthroscopic versus open procedures of delivery of the matrix-induced autologous chondrocyte implant are less invasive and may potentially result in less postoperative pain, less surgical site morbidity, and faster surgical recovery. Long-term studies are needed to confirm these assumptions as well as the efficacy and safety of this arthroscopic approach.

The effect of the trabecular microstructure on the pullout strength of suture anchors.

This study investigates how the microstructural properties of trabecular bone affect suture anchor performance. Seven fresh-frozen humeri were tested for pullout strength with a 5mm Arthrex Corkscrew in the greater tuberosity, lesser tuberosity, and humeral head. Micro-computed tomography analysis was performed in the three regions of interest directly adjacent to individual pullout experiments. The morphometric properties of bone mineral density (BMD), structural model index (SMI), trabecular thickness (TbTh), trabecular spacing (TbS), trabecular number (TbN), and connectivity density were compared against suture anchor pullout strength. BMD (r=0.64), SMI (r=-0.81), and TbTh (r=0.71) showed linear correlations to the pullout strength of the suture anchor with p-values<0.0001. A predictive model was developed to explain the variances in the individual BMD, SMI, and TbTh correlations. The multi-variant model of pullout strength showed a stronger relationship (r=0.86) compared to the individual experimental results. This study helps confirm BMD is a major influence on the pullout strength of suture anchors, but also illustrates the importance of local microstructure in pullout resistance of suture anchors.

Pullout strength of suture anchors: effect of mechanical properties of trabecular bone.

This study investigated the relationships between trabecular microstructure and elastic modulus, compressive strength, and suture anchor pullout strength. Twelve fresh-frozen humeri underwent mechanical testing followed by micro-computed tomography (microCT). Either compression testing of cylindrical bone samples or pullout testing using an Arthrex 5mm Corkscrew was performed in synthetic sawbone or at specific locations in the humerus such as the greater tuberosity, lesser tuberosity, and humeral head. Synthetic sawbone underwent identical mechanical testing and microCT analysis. Bone volume fraction (BVF), structural model index (SMI), trabecular thickness (TbTh), trabecular spacing (TbSp), trabecular number (TbN), and connectivity density were compared against modulus, compressive strength, and pullout strength in both materials. In cadaveric bone, modulus showed correlations to all of the microstructural properties, while compressive and pullout strength were only correlated to BVF, SMI, and TbSp. The microstructure of synthetic bone differed from cadaveric bone as SMI and TbTh showed little variation across the densities tested. Therefore, SMI and TbTh were the only microstructural properties that did not show correlations to the mechanical properties tested in synthetic bone. This study helps identify key microstructure-property relationships in cadaveric and synthetic bone as well as illustrate the similarities and differences between cadaveric and synthetic bone as biomechanical test materials.