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This study evaluated antimicrobial properties of synovial fluid against 3 gram-positive organisms: Staphylococcus aureus, Streptococcus pyogenes, and Staphylococcus epidermidis. Synovial fluid was collected from the knees of 52 patients. Three gram-positive bacteria culture lines were incubated in wells containing either synovial fluid and broth, or broth alone. Fluid was plated and incubated, and colonies were counted after 1, 4, and 24 hours to determine bacterial growth. Statistically significant differences in bacterial counts were found between control and experimental groups at 0, 4, and 24 hours for all 3 bacterial species. Bacterial counts in the control specimens demonstrated exponential growth over 24 hours as would be expected in the absence of growth inhibition. In contrast, bacterial counts in all of the synovial fluid specimens decreased steadily over 24 hours. These results demonstrate synovial fluid possesses potent bactericidal activity against the most common gram-positive pathogens responsible for septic arthritis. Delineating these antimicrobial properties further may offer avenues to augment the body's protection against bacterial infections.

Background Arthrogenic quadriceps muscle inhibition accompanies knee joint effusion and impedes rehabilitation after knee joint injury. Hypothesis We hypothesized that an experimentally induced knee joint effusion would cause arthrogenic quadriceps muscle inhibition and lead to increased ground reaction forces, as well as sagittal plane knee angles and moments, during a single-legged drop landing. Study Design Controlled laboratory study. Methods Nine subjects (4 women and 5 men) underwent 4 conditions (no effusion, lidocaine injection, “low” effusion [30 mL], and “high” effusion [60 mL]) and then performed a single-legged drop landing. Lower extremity muscle activity, peak sagittal plane knee flexion angles, net sagittal plane knee moments, and peak ground reaction forces were measured. Results Vastus medialis and lateralis activity were decreased during the low and high effusion conditions (P < .05). However, increases in peak ground reaction forces and decreases in peak knee flexion angle and net knee extension moments occurred only during the high effusion condition (P < .05). Conclusions Knee joint effusion induced quadriceps inhibition and altered knee joint mechanics during a landing task. Subjects landed with larger ground reaction forces and in greater knee extension, thereby suggesting that more force will be transferred to the knee joint and its passive restraints when quadriceps inhibition is present. Clinical Relevance Knee joint effusion results in arthrogenic quadriceps muscle inhibition, increasing loading about the knee that may potentially increase the risk of future knee joint trauma or degeneration.

We have noted apparent far lateral meniscal attachment of the meniscofemoral ligament (MFL) with an anterior cruciate ligament (ACL) tear. This study evaluates MFL attachment and association with posterior horn lateral meniscus (PHLM) tear. Nine months of knee arthroscopy reports were reviewed to classify the PHLM and ACL as torn or normal. After excluding those with prior knee surgery, MR images were reviewed by two radiologists to determine the number of images lateral to PCL, which showed the ligaments of Humphrey and Wrisberg visible as structures separate from the PHLM. Any patient with abnormal PHLM surface signal not continuous with the MFL was excluded. MRI findings were compared with arthroscopy using Student’s t test and Fisher’s exact test. Of the 54 participants, 5 had PHLM tears and 49 were normal. Twenty-one had ACL tears; all those with an PHLM tear had an ACL tear. The ligament of Humphrey inserted on average 0.9 consecutive images lateral to the PCL without an PHLM tear and 4.7 with an PHLM tear; the ligament of Wrisberg inserted on average 3.0 consecutive images without an PHLM tear and 4.5 with an PHLM tear (slice thickness/gap = 3 mm/0.5 mm). There was a significant association between PHLM tear and number of images (p = 0.0028), and between ACL tear and this type of PHLM tear (p = 0.0064). Apparent far lateral meniscal extension of a meniscofemoral ligament (greater than or equal to four images lateral to the PCL) should be considered as a possible PHLM tear, especially in the setting of an ACL tear.

Bracing can play a prominent role in the management of posterior cruciate ligament (PCL) injuries, for both operative and nonoperative management strategies. Understanding the nuances of bracing for PCL injuries is critical for proper management and for providing the best chance for a stable, functional, and pain-free knee in the long term. Braces used for PCL injuries come in a variety of designs, each with advantages and disadvantages that should be appropriately matched to the individual patient. Outcome studies of bracing PCL injuries are rare, and the variety of protocols applied in these studies makes it difficult to form a consensus on how to achieve the best functional results. Regardless of the bracing protocol used, patient compliance is crucial and dependent on ongoing communication between the patient and the treating physician.

Background We tested the hypothesis that impulsive compression, flexion and valgus knee moment loading during a simulated one-footed jump landing will significantly increase the peak relative strain in the anteromedial region of the anterior cruciate ligament compared with loading without the valgus moment. Methods Ten cadaveric knees [mean (SD) age: 67.9 (7.6) years; 5 males; 5 females] were mounted into a custom fixture to simulate a lower extremity impact loading of approximately 1600 N. Triaxial load cells monitored the 3D tibial and femoral impulsive force and moments at 2000 Hz, while 3D tibiofemoral kinematics were measured at 400 Hz. Pre-impact quadriceps, hamstring and gastrocnemius muscle forces were simulated using pretensioned steel cables. A differential variable reluctance transducer measured the relative strain in the anteromedial aspect of the anterior cruciate ligament. With the knee initially in 25° flexion, 10 trials were conducted with the impulsive force directed 4 cm posterior to the knee joint center in the sagittal plane (“neutral” loading) to cause a flexion moment, 10 trials were conducted under a similar loading, but with the force directed 15° lateral to the knee sagittal plane (“valgus” loading), and the 10 neutral loading trials were then repeated. A non-parametric Wilcoxon signed rank test was used to test the hypothesis using a P

The incidence of noncontact anterior cruciate ligament injuries in young to middle-aged athletes remains high. Despite early diagnosis and appropriate operative and nonoperative treatments, posttraumatic degenerative arthritis may develop. In a meeting in Atlanta, Georgia (January 2005), sponsored by the American Orthopaedic Society for Sports Medicine, a group of physicians, physical therapists, athletic trainers, biomechanists, epidemiologists, and other scientists interested in this area of research met to review current knowledge on risk factors associated with noncontact anterior cruciate ligament injuries, anterior cruciate ligament injury biomechanics, and existing anterior cruciate ligament prevention programs. This article reports on the presentations, discussions, and recommendations of this group.

Background An instrumented cadaveric knee construct was used to quantify the association between impact force, quadriceps force, knee flexion angle, and anterior cruciate ligament relative strain in simulated unipedal jump landings. Hypothesis Anterior cruciate ligament strain will correlate with impact force, quadriceps force, and knee flexion angle. Study Design Descriptive laboratory study. Methods Eleven cadaveric knees (age, 70.8 [19.3] years; 5 male; 6 female) were mounted in a custom fixture with the tibia and femur secured to a triaxial load cell. Quadriceps, hamstring, and gastrocnemius muscle forces were simulated using pretensioned steel cables (stiffness, 7 kN/cm), and the quadriceps tendon force was measured using a load cell. Mean strain on the anteromedial bundle of the anterior cruciate ligament was measured using a DVRT. With the knee in 25° of flexion, the construct was vertically loaded by an impact force initially directed 4 cm posterior to the knee joint center. Tibiofemoral kinematics was measured using a 3D optoelectronic tracking system. Results The increase in anterior cruciate ligament relative strain was proportional to the increase in quadriceps force (r2 = 0.74; P Conclusion The increase in knee flexion and quadriceps force during this simulated 1-footed landing strongly influenced the relative strain on the anteromedial bundle of the anterior cruciate ligament. Clinical Relevance These results suggest that even in the presence of knee flexor muscle forces, the increase in quadriceps force required to prevent the knee from flexing during landing can place the anterior cruciate ligament at risk for large strains.

Neuromuscular electrical stimulation (NMES) has been shown to reduce quadriceps activation failure (QAF), and eccentric exercise has been shown to lessen muscle atrophy post-ACL reconstruction. Given that these are two critical components of quadriceps strength, intervention combining these therapies may be effective at reinstituting quadriceps function post-reconstruction. Thus, the aim of this study was to evaluate the effectiveness of a combined NMES and eccentric exercise intervention to improve the recovery of quadriceps activation and strength post-reconstruction.Thirty-six individuals post-injury were placed into four treatment groups (NE, NMES and eccentrics; E-only, eccentrics only; N-only, NMES-only; and STND, standard of care) and ten healthy controls participated. NE and N-only received the NMES protocol 2× per week for the first 6 weeks post-reconstruction. NE and E-only received the eccentric exercise protocol 2× per week beginning 6 weeks post-reconstruction. Quadriceps activation was assessed via the superimposed burst technique and quantified via the central activation ratio. Quadriceps strength was assessed via maximal voluntary isomeric contractions (Nm/kg). Data was gathered on three occasions: pre-operative, 12-weeks-post-surgery and at return-to-play.No differences in pre-operative measures existed (P0.05). E-only recovered quadriceps activation better than N-only or STND (P0.05). NE and E-only recovered strength better than N-only or the STND (P0.05) and had strength values that were similar to healthy at return-to-play (P0.05).Eccentric exercise was capable of restoring levels of quadriceps activation and strength that were similar to those of healthy adults and better than NMES alone.Level 3, Parallel longitudinal study.

We have previously reported that an eccentrically-based rehabilitation protocol post-ACLr induced greater quadriceps activation and strength than a neuromuscular electrical stimulation (NMES) intervention and was just as effective as a combined NMES and eccentric intervention. However, the effect an eccentrically-based intervention has on restoring normal knee mechanics during a single-legged landing task remains unknown.Thirty-six individuals post-injury were placed into four treatment groups: NMES and eccentrics, eccentrics-only, NMES-only, standard of care, and healthy controls participated. NMES and eccentrics received a combined NMES and eccentric protocol post-reconstruction (each treatment 2× per week for 6 weeks), whereas groups NMES-only and eccentric-only received only the NMES or eccentric therapy, respectively. To evaluate knee mechanics limb symmetry, the area under the curve for knee flexion angle and extension moment was derived and then normalized to the contralateral limb. Quadriceps strength was evaluated using the quadriceps index.Compared to healthy, reduced sagittal plane knee limb symmetry was found for groups NMES-only, ECC-only and standard of care for knee extension moment (P0.05). No difference was detected between healthy and NMES and eccentrics (P0.06). No difference between groups was detected for knee flexion angle limb symmetry (P0.05). Greater knee flexion angles and moments over stance were related to quadriceps strength.The NMES and eccentrics group was found to restore biomechanical limb symmetry that was most closely related to healthy individuals following ACL reconstruction. Greater knee flexion angles and moments over stance were related to quadriceps strength.

Purpose The purpose of this study was to evaluate the long-term results after medial meniscal allograft transplantation combined with anterior cruciate ligament (ACL) reconstruction. Type of study Retrospective clinical outcome study. Methods Between 1990 and 1992, 9 medial meniscal allograft transplantations were performed in symptomatic knees with a previous total or near-total medial meniscectomy. One of the 9 patients required transplant removal postoperatively because of a presumed low-grade infection versus immune reaction. The remaining 8 patients were evaluated, with an average follow-up time of 9.7 years. All 8 patients underwent an ACL reconstruction. One patient also had a staged high tibial osteotomy. Results All 8 patients were evaluated with the standard International Knee Documentation Committee (IKDC) form with no normal scores: 1 had a nearly normal score, 4 had abnormal scores, and 3 severely abnormal scores. The IKDC symptoms evaluation produced 2 normal scores, 5 nearly normal scores, and 1 abnormal score. The IKDC function test showed 5 normal scores, 1 nearly normal score, and 2 abnormal scores. Six of the 8 patients were extremely pleased with the function of the knee and were active in recreational sports. All 8 patients would recommend the procedure to a friend and would undergo the procedure again given similar circumstances. Conclusions The findings of this study agree with several other studies with shorter follow-up times that medial meniscal allograft transplantation can significantly improve knee function in symptomatic medial meniscus-deficient knees. The addition of a ligament-stabilizing procedure probably improved the results in this patient population. Level of evidence Level IV, Case Series.

The explosive growth of the college athletics “business” has dramatically altered these amateur games over the past decade. The multimillion dollar university sports enterprises often dwarf academic departments in terms of resources. Athletic departments are commanding more and more attention of college presidents and governing boards, and rightfully so! While many of the perennial top competitors in college athletics reap the benefits of success in ticket sales, merchandising, TV revenue, and alumni support, those not making the grade in terms of wins and losses often are forced to rely on the general funds of the university to balance the budget. When general university funds are diverted from the academic mission to support athletic programs, questions of the university’s priorities are understandably raised. A few examples might clarify this issue. In 2015, Oregon was reportedly the most profitable university/sports complex, generating $196 million in revenue over $110.4 million in expenses, for a profit of $83.5 million.7 The balance sheet was made very positive by a gift of $95 million. On the other side of the spectrum, Rutgers reportedly had the largest athletic department deficit for 2013-2014 at $36.3 million.7 According to the National Collegiate Athletic Association (NCAA), just 24 of the 230 public Division 1 schools had balance sheets in the black and were able to support their athletic programs without help from the general funds of the university.7 Consequently, the trends in rising costs of competition have generated fears among those responsible for university fiscal policy, so much so that the state of Virginia recently passed a law limiting the dollars that can be diverted to athletic programs from the university’s general finances.1 With these thoughts in mind, it is interesting to look at where the money in college athletics often goes. Athletic venues help generate the atmosphere and experience of the athletic contests and are often tops in athletic department budget items. Auburn spent $13.9 million on an 11,000–square foot high-definition video board roughly the size of a 5-story building.4 Close behind the infrastructure costs are those of the personnel required to run college athletic departments. Coaches and staff account for approximately 30% of Division 1 athletic expenditures.2 Coach Krzyzewski of Duke appears to top the list at $9.7 million annually, while 35 coaches in the 2015 NCAA basketball tournament had 7-figure salaries.2 On the revenue side, NCAA March Madness generated approximately $800 million, while fans bet approximately $9 million dollars on the games.2 The NCAA spent $85 million on the production of its Division 1 Championships.6 Approximately $194 million went to conference offices and independent schools from the NCAA as support funding,5 while $75.6 million was deposited in the NCAA Student Assistance Fund, with $26.1 million diverted to the NCAA’s academic fund.5 If you think those are big numbers, take a closer look at where college football is with the “Power Five” conferences: the Big Ten, Big 12, Pacific 12, Southeastern Conference, and the Atlantic Coast Conference. The NCAA controls the television rights to March Madness but the football championship television rights belong to the conferences. That contract with ESPN is currently $7.3 billion dollars for 12 years.4 When analyzing these numbers, it is understandable why many voices are calling for student athletes to be paid for their services. To that extent, the NCAA has recently allowed schools to pay for the full cost of school attendance (transportation and living expenses that were not covered by scholarships) by college athletes.1 This stipend can amount to almost $3000 per athlete per school year. Certainly those numbers, plus the cost of tuition, room, and board, are not minor, but they are relatively small when reviewing the balance sheets of many college sports enterprises and the television revenue. On the other hand, some college athletes in football, basketball, hockey, and baseball also have the opportunity to reap handsome rewards for their collegiate careers if they succeed in getting to the professional level, and those who take full advantage of their academic opportunities certainly can take with them a valuable college degree. Unfortunately, many in some sports—and most in others—do not take full advantage of the educational opportunity and fail to graduate. This may explain the absence of some perennial basketball powerhouses on the NCAA website for college graduation rates.3 Taking these factors into account, it appears that those who benefit the least from their college athletic experience are those who do not make the professional grade and those who fail to earn a college degree. Unfortunately, some athletes fail at both endpoints because of injury sustained during their collegiate careers. While there are safety nets for these casualties at most schools and in the NCAA,6 the possibility of severe injury is no doubt part of the argument for athletes to leave the college game early and go professional when the opportunity presents itself. It is also part of the argument to pay college athletes more. This is where perspective should enter the discussion. From my standpoint, we cannot do enough for these student athletes medically. Not just for those whose careers end prematurely because of injury but for all athletes accepting the participation risks. Not only should their treatment be the best available, but we should also increase our research efforts into the mechanisms of their injuries. We should do everything possible to make these athletic endeavors as safe as they can be. This is where the current system could and should be improved. The dollars to upgrade the research and treatment of injuries are there, it just needs to be recognized as a higher priority. Some have suggested compensating college athletes monetarily to a greater degree. This certainly is a slippery slope, and where that will take the college game in the future is unclear. No doubt, it will certainly further blur the separation between amateur students and professionals, leading more academicians, politicians, and the public to rightfully question the place of college sports on the campuses of higher education. Many of us already question whether this burgeoning business of college sports is out of control. Many pertinent questions persist. Can college presidents or state legislatures still rein athletic departments in? Can athletic and academic departments do a better job of setting academic priorities and enforcing them for student athletes? If it meant adjusting weekday game schedules against the pressures of TV revenue, is the public ready for that? I don’t think the juggernaut of college sports can be set in reverse to the games of past decades, but can the explosive growth of college sports entertainment be slowed? The next decade should certainly prove interesting for college sports.

Hip arthroscopy is a technically difficult procedure to perform. Nonetheless, several indications exist for the procedure. We describe a “mini-open” approach to the hip joint, using a modified Smith-Petersen approach through a 4-cm incision in the groin skin crease. The interval between the sartorius and tensor fascia lata is developed while protecting the lateral femoral cutaneous nerve. The rectus femoris muscle and iliopsoas tendon are retracted medially, exposing the hip capsule. Standard arthroscopy is then performed through the open incision, utilizing either manual or a formal traction setup. We believe this technique decreases the risk of neurovascular or iatrogenic injury to the articular cartilage or labrum during instrument placement. Because the soft tissues are dissected down to the capsule, there is increased maneuverability of instruments, and less traction is necessary to provide joint distraction. There is tremendous versatility in this procedure; for example, a purely percutaneous hip arthroscopy can be performed supine on a fracture table, and if this fails to gain hip joint access or adequate visualization, the mini-open approach can be performed without the need to reposition or redrape the patient. If needed, this mini-open approach can also be easily converted to an open arthrotomy. We believe our hip arthroscopy technique utilizing a limited anterior approach combines the benefits of an arthroscopic and open procedure, while minimizing operative risk. This technique allows the arthroscopic surgeon an alternative method for performing this very technically challenging procedure.

Purpose: The purpose of this study was to determine the financial efficacy of arthroscopic synovectomy in hemophilia patients with recurrent hemarthroses. Type of Study: Cost-benefit analysis. Methods: A retrospective chart review from 1993 through 1999 yielded 11 cases of arthroscopic synovectomies performed for recurrent hemarthroses at the University of Michigan. There were 7 ankle arthroscopies, 3 elbow arthroscopies, and 1 knee arthroscopy. The average age of the patients was 8 years (range, 4-13 years). All had the severe form of hemophilia A. The average follow-up was 41 months (range, 9-75 months). The preoperative costs were determined by multiplying the number of preoperative bleeds by the dollar amount of the replacement therapy used to treat the hemarthroses. The surgical costs included the surgery itself as well as the hospital stay and the dollar amount of the replacement therapy used in the perioperative period. The total postoperative costs included the surgical costs and the dollar amount of any replacement therapy used to treat any postoperative hemarthroses. Results: The financial benefit of arthroscopic synovectomy was found to be statistically significant when average preoperative cost per month ($7,500) was compared with the average postoperative cost per month ($900), P = .028. Arthroscopic synovectomy was again found to be financially beneficial when the average total preoperative cost ($88,000) was compared with the average total postoperative cost ($24,000), P = .028. The average number of hemarthroses preoperatively was 71 and the average postoperatively was 7, which was statistically significant ( P = .028). Conclusions: In this small series of patients with intermediate follow-up, arthroscopic synovectomy was found to be cost effective in the treatment of patients with recurrent hemarthroses. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 18, No 7 (September), 2002: pp 789–794

Surgical intervention is often required to restore knee instability in patients with anterior cruciate ligament (ACL) injury. The most commonly used grafts for ACL reconstruction are tendon autografts or allografts. These current options, however, have shown failure rates requiring revision and continued instability in the long term. The mismatched biomechanical properties of the current tendon grafts compared with native ACL tissue are thought to contribute to these poor outcomes and potential risk of early onset osteoarthritis. As a possible solution to these issues, our laboratory has fabricated tissue-engineered ligament constructs that exhibit structural and functional properties similar to those of native ACL tissue after 6 months implantation. In addition, these tissue-engineered grafts achieve vascular and neural development that exceeds those of patellar tendon grafts. However, the utility of our tissue-engineered grafts is limited by the labor-intensive method required to produce the constructs and the need to use the constructs fresh, directly from the cell culturing system. Ideally, these constructs would be fabricated and stored until needed. Thus, in this study, we investigated the efficacy of freezing our tissue-engineered constructs as a method of preservation before use for ACL reconstruction. We hypothesized that frozen constructs would have similar histological and biomechanical outcomes compared with our fresh model. Our results showed that 6 months postimplantation as an ACL replacement graft, both our tissue-engineered fresh and frozen grafts demonstrated similar mechanical and histological outcomes, indicating that freezing is a suitable method for preserving and storing our graft before ACL reconstruction. The ability to use frozen constructs significantly increases the versatility of our graft technology expanding the clinical utility of our graft.

Over the past year, a couple of clinical cases have raised my interest in the role sports and regular physical exercise plays in the growth and development of children. One case involved a talented young male basketball player, age 12 years, who presented with a large displaced osteochondritis dissecans defect, requiring operative treatment and a prolonged rehabilitation, ending his basketball career. The other was a highly competitive female soccer player, age 11 years, with a complicated anterior cruciate ligament injury. The cases were similar in that both kids were very good students prior to their injuries. Both kids came from stable home situations with supportive parents. Neither child, by report, had exhibited significant behavioral problems nor had either portrayed any evidence of problems to come. Both children deteriorated badly, both physically and mentally, after their injuries, becoming problematic at home and school with failing grades and suspensions. Their parents could hardly believe the course of events and found it very difficult to deal with the behavioral and academic problems; both eventually sought professional help, thankfully! Both kids essentially stopped all forms of exercise after injury and struggled with rehabilitation. It was pretty clear that they were depressed and lost their motivation to recover throughout their clinical course. I must admit that I’ve seen segments of these tragic scenarios before, but not quite as dramatic! Good kids and good athletes, stunned and shocked by an injury. Their physical vulnerability exposed as their mantle of indestructability was dashed. They were robbed of their identity when their athletic careers came to a screeching halt. As an orthopaedic surgeon, I’ve often wondered about the psychological effects of musculoskeletal injury on children. Unfortunately, I also realize my own deficiencies in this aspect of sports medicine. No doubt recognizing vulnerable personalities initially after injury could have helped several of my own patients before they fell victim to temporary escapes from reality through drugs and alcohol. I’m very sad to say that some of those kids did not recover, as far as I know. I think a lot of teachers, administrators, parents, and yes, physicians, don’t recognize the central role that sports can play in the lives of children until something halts those activities. Recognition of the roles that athletics and exercise play in child growth and development has been reinforced recently in several interesting publications. Much critical research on the effects of exercise on brain development has been done in animals, particularly mice. With their relatively short life spans, it is much easier to detect the effects of various forms of physical stimulation or deprivation over the course of their lives.Work performed at the Salk Institute has shown that aerobically challenged mice show dramatic brain growth compared with sedentary mice.5 The hippocampus, which is the part of the brain associated with learning and memory, was twice as large in those that were exercised aerobically. Mice that exercised learned better, as evidenced by better performance on a spatial learning task: namely, a water maze. I would really like to know what would happen if the mice were injured acutely and couldn’t exercise suddenly. Would they deteriorate mentally and physically like the kids? The biology of injury in a physical sense appears to be better understood than the mental and psychological aspects. As for the biology supporting neural development, aerobic exercise boosts levels of brain-derived neurotrophic factor, it stimulates neurogenesis, and stimulates the expression of genes that enhance brain plasticity, which is needed for the brain to change neuropathways.2 As for the behavior side of things, no doubt exercise affects mood and mood can affect behavior. To me, those are intimately related. So exercise appears to play an integral role in the neural development of children but may be most important for those who struggle at home and at school. One of the groups that struggles the most is the attention deficit/hyperactivity disorder (ADHD) crowd, which appears to be growing in epidemic proportions in the United States today.1 The CDC now estimates that more than 10% of school-aged children carry this diagnosis, with more than 6% being medicated for this disorder. Exercise shows promise for addressing ADHD symptoms in children. In fact, moderately intense aerobic exercise appears to have positive effects on neurocognitive function and inhibitory control in ADHD.4 Unfortunately, the trend in many school systems today seems to be to downplay the need for physical exertion as teachers struggle to meet academic demands and standards. A recent study of 40 children aged 8 to 10 years, examined the effects of a 20-minute episode of treadmill running or reading. After the 20 minutes, test scores improved more for the kids who exercised than those who read.4 So, if exercise is so important for kids, how much is enough? Both the National Institutes of Health and the President’s Council on Fitness, Sports, and Nutrition recommend 60 minutes or more a day of physical activity for children and adolescents aged 6 through 17 years. No doubt many children, in fact most—especially those not regularly involved in sports—do not exercise 60 minutes a day. Today’s children spend a lot of time online with features such as social media and in front of the television. Changing these socially accepted patterns of behavior and activity isn’t easy,3 especially for those who are physically challenged by injury, accident, or disability. However, after reading the details on exercise research mentioned today, it seems very worthwhile to try to change patterns of sedentary activity. Years ago, my own dad gave me some parenting advice. He insisted that the best teenagers were physically tired at the end of the day. He believed that physical work and sports kept kids out of trouble. Looks like the benefits of physical activity reach much further than he knew.

Background: Many factors contributing to anterior cruciate ligament (ACL) injury risk have been investigated. Recently, some ACL-injured individuals have presented with a decreased range of hip internal rotation compared with controls. The pathomechanics of why decreased hip range of motion increases risk of ACL injury have not yet been studied. Hypothesis: Peak relative strain of the anteromedial bundle of the ACL (AM-ACL) during a simulated single-leg pivot landing is inversely related to the available range of internal femoral rotation. Study Design: Controlled laboratory study. Methods: A series of pivot landings were simulated in 10 female and 10 male human knee specimens with a testing apparatus that applied a 2-bodyweight impulsive load, inducing knee compression, flexion moment, and internal tibial torque. The range of internal femoral rotation was (1) locked at ~0°, (2) limited with a hard stop to ~7°, (3) limited with a hard stop to ~11°, or (4) free, with rotation resisted by 2 springs to simulate the resistance of the active hip rotator muscles to stretch. The AM-ACL strain was quantified with a differential variable reluctance transducer. A linear mixed model was used to determine whether a significant linear relation existed between peak AM-ACL relative strain and range of internal femoral rotation. Results: Peak AM-ACL relative strain was inversely related to the available range of internal femoral rotation ( R2 = 0.91; P < .001), with strain increasing 1.3% for every 10° decrease in rotation; this represented a 20% increase in peak relative strain, given an average range of femoral rotation of 15° upon landing in healthy athletes. Conclusion: Peak AM-ACL relative strain was inversely proportional to the available range of internal femoral rotation during simulated single-leg pivot landings. Clinical Relevance: Decreased range of internal femoral rotation results in greater ACL strain and may therefore increase the susceptibility to ACL rupture with athletic cutting and pivoting activities. Screening for a limited range of hip internal rotation should therefore become a component of not only ACL injury prevention programs but also evaluation protocols for those with ACL injuries and/or reconstructions.

Each spring, the editors of Sports Health have the pleasure of selecting the winning manuscripts for the annual T. David Sisk Awards. These awards commemorate the life of Dr T. David Sisk, our colleague and mentor, who chaired the American Orthopaedic Society for Sports Medicine (AOSSM) Medical Publishing Board during the development of Sports Health. Dr Sisk enthusiastically fostered the development of the journal because he believed in the multidisciplinary approach to sports medicine. He was a team physician at Memphis, where he practiced this team approach in the care of athletes. Dr Sisk grew up in a very humble environment, excelling in sports and later in sports medicine. He taught us a lot about teamwork—in good times and in others. He really was a team player! So it’s a special opportunity to award these 3 groups of investigators that have contributed to the success of Sports Health. Evangelos Pappas, PhD, authored a systematic review with meta-analysis on the prospective predictors of patellofemoral pain syndrome (PFPS).3 The meta-analysis included age, weight, height, sample size, patient type (military vs civilian), follow-up, diagnostic methods, and criteria. Not surprising, lower knee extensor strength was the only variable that was predictive of PFPS (P ≤ 0.01). Anthropometric variables were not associated with PFPS. For musculoskeletal clinicians who frequently treat this malady, confirmation of this factor is instructive. Not surprisingly, many painful adolescent knees do get better with exercise. Screening for these strength deficits, especially in young athletes, before the symptoms develop is well worth the effort, knowing how difficult it can be to reverse this painful process once it begins. This work was recognized at the 2013 AOSSM Annual Meeting with the T. David Sisk Award for the Best Clinical Review. In the International category, Stephano Della Villa, MD, reported on the clinical outcomes in return to sports participation for 50 soccer players after anterior cruciate ligament (ACL) reconstruction utilizing a sports-specific rehabilitation protocol.2 The assessment of these players included the Knee Outcome Survey-Sports Activity Scale as well as isokinetic and aerobic fitness tests. The mean start of the on-field rehabilitation process was 90 ± 26 days from surgery, and the mean time for return to competition was 185 ± 52 days. The addition of the on-field rehabilitation component appears to have completed the functional rehabilitation process, allowing transition from surgical recovery to competitive sports participation. Especially for soccer players, who are highly susceptible to ACL injuries, this functional progression program offers much insight into the process and timing of returning this high-risk group of athletes to sports competition. The first part of this program resembled classic rehabilitation in a gym with the emphasis on full knee motion and strength acquisition. The second part moved onto the soccer field for sport-specific “re-education” after patients demonstrated a less than 20% deficit in isokinetic maximal peak torque for knee flexion and extension. Furthermore, to begin the on-field rehabilitation, patients had to run on a treadmill at a pace of 8 km per hour for 10 minutes without pain, swelling, or decreased range of motion, emphasizing the need for stepwise functional progression. Eliminating motion and strength deficits before sports-specific training began was critical. In the Original Research category, Christian Coyle, PhD, headed a group of investigators from the University of Pittsburgh that demonstrated that serum CTXii (a biochemical biomarker of collagen type II degradation) correlates with articular cartilage degeneration after ACL transection or arthrotomy in rats when followed by exercise.1 This research addresses a critical need for biomarkers that can signal the status of articular cartilage after injury, providing a target for interventions. ACL injury places articular cartilage at risk. Separating the negative consequences of this injury, surgical or nonsurgical treatment, and vigorous rehabilitation would be beneficial for our patients to help individualize the best course for each one. Currently, if a patient had an ACL tear in the past and was asymptomatic, we have only a few options for monitoring articular cartilage degeneration. Most studies have relied on radiographic parameters (eg, joint space narrowing), which are actually only a crude indicator, if at all, of the early stages of degenerative disease. Assessing joint space accurately on radiograph is difficult at best. It requires a meticulous approach to yield useful measurements. A recent MRI follow-up study suggested that all ACL injuries incur articular cartilage thinning over time.4 No doubt these early stages usually will not be detectable with routine imaging. To advance this science and improve clinical care, clinicians and researchers need better tools to monitor degenerative disease. The strong correlations between histological scores and CTXii levels in ACL-transected rats suggest the potential for biomarker monitoring. Clinical trials of early intervention efforts will become possible when reliable biomarkers for degenerative disease are available. All of these investigators have made significant contributions to the clinical care of athletes and the science of sports medicine. These studies address current, widespread clinical dilemmas that we face daily. Thanks to their work, we have a few more answers for our patients and, hopefully, we’re advancing the science of sports medicine!

There is little question that ankle disc training can improve ankle muscle motor performance in a unipedal balance task, most likely through improved strength and coordination [62] and possibly endurance. How much of the observed improvement in motor performance is due to improved ankle proprioception remains unknown. We have reviewed a number of theoretical ways in which training might improve proprioception for moderately challenging weight-bearing situations such as balancing on one leg. Although the relevant experiments have yet to be performed to test this hypothesis, any improvement would theoretically help to reduce injuries at these moderate levels of challenge. We question, however, whether these exercises can ever improve the reactive response required to prevent injury under the most challenging time-critical situations. If confirmed, this limitation needs to be acknowledged by authors and practitioners alike. Alternative protective strategies for the most challenging time-critical situations should be sought. We conclude that, despite their widespread acceptance, current exercises aimed at "improving proprioception" have not been demonstrated to achieve that goal. We have outlined theoretical scenarios by which proprioception might be improved, but these are speculative. The relevant experiments remain to be conducted. We argue that even if they were proven to improve proprioception, under the best circumstances such exercises could only prevent injury under slow to intermediate rate provocations to the joint musculoligamentous complex in question.

Maximum isometric ankle inversion and eversion muscle strengths were measured under full unipedal weightbearing in 20 healthy young adult women. When the women wore a low-top shoe, the mean (standard deviation) maximum external eversion moments resisted with the foot in 0 degrees and 32 degrees of ankle plantar flexion were 24.1 (7.6) and 24.1 (8.1) N x m, respectively, while the corresponding values for maximum inversion moments resisted were 14.7 (6.8) and 17.4 (6.4) N x m, respectively. Both shoe height and ankle plantar flexion affected the overall inversion moment resisted by 17% (P = 0.03) at 0 degrees of ankle plantar flexion to 11.9% (P = 0.003) at 32 degrees of ankle plantar flexion. However, neither shoe height nor ankle plantar flexion significantly affected the maximum eversion moment resisted. Although eversion muscle strength of the young women averaged 39% less than the corresponding value found in young men, the sex difference was not significant when ankle strengths were normalized by body size (body weight x height). Thus, when data from healthy young men and women were averaged, eversion and inversion strengths averaged 1.6% and 2.7%, respectively, of body weight x height.

Strenuous physical activity is known to cause structural abnormalities in the immature vertebral body. Concern that exposure to years of intense athletic training may increase the risk for developing adolescent hyperkyphosis in certain sports, as well as the known association between hyperkyphosis and adult-onset back pain, led us to examine the association between cumulative hours of athletic training and the magnitude of the sagittal curvature of the immature spine. A sample of 2270 children (407 girls and 1863 boys) between 8 and 18 years of age were studied. An optical rasterstereographic method was used to measure the mid-sagittal curvatures of the surface of the back while the subject was in the upright standing position to quantify the angles of thoracic kyphosis and lumbar lordosis. These data were then correlated with self-reported hours of training measured by interview and questionnaire. The possible effects of age, sex, sport, and upper and lower body weight training were investigated. The results in these young athletes showed that larger angles of thoracic kyphosis and lumbar lordosis were associated with greater cumulative training time. Gymnasts showed the largest curves. Lack of sports participation, on the other hand, was associated with the smallest curves. Age and sex did not appear to affect the degree of curvature.

We examined persons after anterior cruciate ligament injury and for 1.5 years after anterior cruciate ligament reconstruction to analyze changes in anterior knee laxity, lower extremity muscle strength, endurance, and several parameters of neuromuscular function. Sixteen men and nine women (average age, 23.8 years) were evaluated preoperatively, then underwent intraarticular autogenous patellar tendon anterior cruciate ligament reconstruction by the same surgeon and were evaluated at 6, 12, and 18 months postoperatively. Muscle strength was measured isokinetically and neuromuscular function was quantified with simultaneous anterior tibial translation and surface electromyography tests. Forty subjects (26 men and 14 women; average age, 23.5 years) with no known knee abnormalities served as the control group. Subjective questionnaire results showed that by 18 months postoperatively, 20 subjects (80%) believed they had regained their preoperative levels of function. Unfortunately, muscle function in most subjects had not returned to normal. At 12 to 18 months postoperatively, when knee rehabilitation was terminated, significant deficiencies in muscle performance persisted in most patients. Interestingly, in this group of stable knees, quadriceps and hamstring muscle reaction times appeared to be the best objective indicators of subjective knee function.

In the general population, an estimated one in 3000 individuals sustains an anterior cruciate ligament injury per year in the United States, corresponding to an overall injury rate of approximately 100,000 injuries annually. This national estimate is low for women because anterior cruciate ligament injury rates are reported to be two to eight times higher in women than in men participating in the same sports, presenting a sizable health problem. With the growing participation of women in athletics and the debilitating nature of anterior cruciate ligament injuries, a better understanding of mechanisms of injury in women sustaining anterior cruciate ligament injuries is essential. Published studies strongly support noncontact mechanisms for anterior cruciate ligament tears in women, which make these injuries even more perplexing. Speculation on the possible etiology of anterior cruciate ligament injuries in women has centered on anatomic differences, joint laxity, hormones, and training techniques. Investigators have not agreed on causal factors for this injury, but they have started to profile the type of athlete who is at risk. In the current study the most recent scientific studies of intrinsic and extrinsic risk factors thought to be contributing to the high rate of female anterior cruciate ligament injuries will be reviewed, important differences will be highlighted, and recommendations proposed to alleviate or minimize these risk factors among female athletes will be reported where appropriate.

Summary: Hip arthroscopy is a technically difficult procedure to perform. A limited anterior approach to the joint has made hip arthroscopy technically less difficult in our hands and has enabled us to treat a wide range of hip pathology. Five hip arthroscopies were performed using a modified 4-cm Smith-Petersen anterior approach to the hip exposing the joint capsule as manual traction is applied. The arthroscope is then easily introduced making visualization of the hip joint possible. The 5 hip arthroscopies resulted in either removal of loose bodies or debridement of an osteochondral fragment, synovitis, or cartilaginous debris. There were no complications postoperatively. We believe that hip arthroscopy through a limited anterior approach provides an easy and safe alternative method for arthroscopic access to the hip joint. Importantly, there is a decreased risk of neurovascular trauma and iatrogenic damage to the articular cartilage and acetabular labrum when introducing instruments into the hip joint. Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 16, No 1 (January-February), 2000: pp 16–20

The term arthrofibrosis has been used to describe a spectrum of knee conditions in which loss of motion is the major finding18,25,33,35,38,41-43,45. Because different characteristics have been used historically to define this term18,25,33,35,38,41-43,45, the universally accepted definition of this condition remains in question. We believe that arthrofibrosis is best defined as a condition of restricted knee motion characterized by dense proliferative scar formation, in which intra-articular and extra-articular adhesions can progressively spread to limit joint motion. This dense scar tissue can obliterate the parapatellar recesses, suprapatellar pouch, intercondylar notch, and eventually the articular surfaces9. Scarring of the infrapatellar fat pad and fibrosis of the patellar ligament can occur, with varying degrees of capsular and quadriceps contracture. Patella infera and chronic patellar entrapment may also develop as a consequence of this process9. We consider loss of motion that is due to a localized intra-articular lesion as a separate clinical entity. Many patients who have this condition primarily lack full extension as the result of a so-called cyclops lesion22 or other anterior intra-articular scarring following reconstruction of the anterior cruciate ligament9. Normal knee motion has been described as 0 degrees of extension to 135 degrees of flexion, although hyperextension is frequently present to varying degrees4. In general, however, the best way to ascertain normal motion is to examine the contralateral knee if it has no abnormal conditions. Maintaining a full range of knee motion requires congruent articular surfaces; adequate muscle function; an articular capsule with suitable capacity and flexibility; effective space in the medial and lateral articular recesses, intercondylar notch, and …

This is a special report of the findings of the Concussion Workshop, sponsored by the AOSSM in Chicago in December 1997. Here follows a listing of the members of the workshop: Julian Bailes, MD, American Association of Neurological Surgeons; Arthur Boland, MD, AOSSM; Charles Burke III, MD, National Hockey League; Robert Cantu, MD, American College of Sports Medicine; Letha “Etty” Griffin, MD, National Collegiate Athletic Association; David Hovda, PhD, Neuroscientist, UCLA School of Medicine; Mary Lloyd Ireland, MD, American Academy of Orthopaedic Surgeons; James Kelly, MD, American Academy of Neurology; Greg Landry, MD, American Academy of Pediatrics; Mark Lovell, PhD, Neuropsychology Specialist, Henry Ford Health Systems; James Mathews, MD, American College of Emergency Physicians; Michael McCrea, PhD, Neuropsychology Specialist, Waukesha Memorial Hospital; Douglas McKeag, MD, American Medical Society for Sports Medicine; Dennis Miller, ATC, National Athletic Trainers Association; Jeffrey Minkoff, MD, AOSSM; Stephen Papadopoulus, MD, Congress of Neurological Surgeons; Elliott Pellman, MD, National Football League; Richard Quincy, MS, PT, ATC, Sports Physical Therapy, El Pomar Sports Center; Herbert Ross, DO, American Osteopathic Academy of Sports Medicine; Bryan Smith, MD, National Collegiate Athletic Association; and Edward Wojtys, MD, Workshop Chairman, AOSSM. The views in this report do not necessarily represent the views of the entire group comprising the Concussion Workshop Group.

As clinicians who evaluate and treat musculoskeletal conditions on a daily basis, we are well aware of the positive effects of regular exercise. Weight control, aerobic fitness, and muscle strength maintenance are all benefits of daily workouts. The cardiovascular system also gains from regular exercise with blood pressure control and high-density lipoprotein (HDL) enhancement, with the commensurate decline in cardiovascular risk depending on the control of other comorbidities, such as smoking and diabetes. However, not nearly as obvious are the positive effects of exercise on brain function, especially as we age. Decades ago, our brains were compared to machines, with parts that wore out or computer hard drives that went bad, indicating a defined and limited capacity and longevity. Fortunately, neuroscience research has demonstrated that the machine and computer analogy is not accurate and our brains are more “plastic” in function. Back in the 1970s, researchers Mark Rosenzweig and Michael Merzenich showed that the brain’s circuitry changes microscopically with experience and activity.7 These researchers showed that with environmental stimulation, the brains of animals grew in size in key areas. In other words, our brain circuits are changing constantly depending on what we are doing in the world, both positive and negative. This is where the old adage of “use it or lose it” probably is applicable. It appears that our brains are more prone to waste away from underuse than overuse. Most of us “baby boomers” fear the all-too-common onset of dementia in our friends and relatives, robbing us of a loved one or friend.2 Alzheimer’s disease, the most common form of dementia, appears to be hitting everywhere. It has affected so many in my local vicinity that I have thought about moving, fearing some environmental cause. If it is not already an epidemic, it soon will be as baby boomers advance in age. It is a scary disease process, robbing many of the enjoyment of life. A useful way to view dementia is the loss of the brain’s elasticity; it loses its interconnections and begins to shrink. Once brain interconnectivity is lost, confusion and often frustration ensues. Valiant efforts have and are being made to arrest the process in its early stages. Exciting research appears to show that exercise—both mental and physical—not pills or potions can help decrease the risk of this dreaded feature of adult life.1 Peter Elwood of the Cochrane Institute at Cardiff University in the United Kingdom studied 2235 men with ages ranging from 45 to 59 years for 30 years.3 Not surprising were that eating a healthy diet, controlling weight to a body mass index of between 18 and 25 kg/m2, not smoking, and limiting alcohol consumption reduced their risk of cognitive decline by a whopping 60%. But, better than all those known traditional healthy habits was exercise! Biking 10 miles a day, walking 2 miles a day, or other vigorous exercise produced the best results. Sadly, less than 1% of the men studied adopted all 5 healthy lifestyle parameters tested, with less than 5% following 4 parameters. Many people do not have the discipline to pursue such a rigorous lifestyle and argue that degenerative diseases such as Alzheimer’s are “in your genes” and therefore cannot be avoided. But it is quite clear that our genes interact with our environment and we can control our environment to a certain extent. Pursuing a healthy lifestyle, including daily exercise, may very well help determine how our genes are expressed. Take, for instance, a classic simple study by Kirk Erickson, a psychologist at the University of Pittsburgh. Monitoring 299 dementia-free people, aged 70 to 90 years, starting in 1989, Erickson found that walking at least 1 mile a day significantly enhanced the volume of several brain areas, including the frontal lobe, which is involved with problem solving and reasoning4,5; 169 people of those 299 who started the study were free of cognitive impairment at the completion of the study. By walking at least 1 mile a day, they had reduced their risk of cognitive impairment by approximately 50%. This represents a classic example of how the environment of the brain influences genetic factors.4,5 Clearly, brain development is controlled by the genetic makeup, but it appears that exercise in this group influenced cognitive function in a very positive fashion. There are other dramatic examples of how effective exercise is on brain development and maintenance. Take the hippocampus, for instance. It is part of the limbic system, is located beneath our cerebral cortex, and has a right and left half. It is responsible for consolidating information from short-term to long-term memory and for spatial navigation.8 This region deteriorates in the elderly with and without dementia. A study of 165 nondemented individuals, aged 59 to 81 years, used the region of interest analysis on magnetic resonance imaging to find a triple association between higher aerobic fitness levels associated with larger right and left hippocampi after controlling for age, sex, and years of education.6 The larger hippocampi and fitness levels were associated with better spatial memory performance. These results suggest that higher aerobic fitness levels are associated with increased hippocampal volume in older humans, resulting in better memory formation. Since it is clear that in most civilized societies today life expectancy is increasing, an effort should be made to prevent the well-recognized decline in cognitive function so common in the elderly. Daily physical exercise deserves to be part of everyone’s daily schedule. As musculoskeletal clinicians, we need to do our part to keep the elderly exercising and walking as much as possible. The benefits go far beyond our muscles and bones! Keep walking!

Despite more than 40 years of clinical focus on the anterior cruciate ligament (ACL)–injured knee, a complete understanding of the injury mechanism, the optimal treatment plan (including reconstruction), and the best protocol for rehabilitation continue to stimulate much debate. Prevention efforts focused on ACL injuries have been laudable, but unfortunately, far too many young athletes still fall victim to this injury and are denied the opportunity to reach their full athletic potential. Besides the deleterious effects on an athletic career, many lifestyles are sadly altered as the knee deteriorates, and physical limitations are realized as osteoarthrosis becomes a reality. All too often, this occurs at a very young age. Consequently, ACL research remains a booming business whose results occupy a large portion of our scientific journals and sports medicine meeting programs. But as this issue of Sports Health demonstrates, progress is being made in the search for the best medical evidence to guide injury prevention programs, reconstructive techniques, rehabilitation efforts, and guidelines for return to sport. The review of 55 ACL injury soccer videos by Brophy et al2 suggests that it is safer for your knees to play an offensive position—70% of those ACL injuries occurred while defending (87% in females). Tackling was the most problematic skill, with 51% of injuries occurring during those maneuvers, most with contact. Not surprising! Cutting was the second most problematic skill, producing 15% of ACL tears. The take-home message for parents is try to convince your son’s or daughter’s coach that your kids belong on the offensive side of the ball because of their goal-scoring potential, and if they do end up on defense, teach them good tackling skills over and over and over again. If, however, your efforts at prevention are unsuccessful and an ACL tear occurs, find a surgeon who is willing to do an autograft reconstruction for your youngster, as emphasized by Wasserstein et al.4 Although the level of evidence of this study (level 3) is not the highest due to the available studies, the numbers presented are pretty convincing. In 1016 ACL-injured patients with 2- to 4-year follow-up, the pooled failure prevalence was 9.6% (76 of 788) for autografts and 25% (57 of 228) for allografts. The number needed to benefit to prevent 1 failure by using autografts was only 7 patients (95% CI, 5-10). Disappointing is the almost 10% failure rate even in ACL autografts in this very young, very active population, with hamstrings and patellar tendon autografts showing similar results. These results are based on very recent operative techniques and rehab protocols, with the oldest included study from 2011. Allograft surgeons are challenged in this paper because even though there was a clear difference between autografts and irradiated allografts, the difference between allograft and nonirradiated allograft was not significant. This may be a numbers problem with only a power analysis needed to determine the needed size of a subsequent study population to put the issue to rest. Consequently, it is incumbent on those using nonirradiated allografts in similar populations to demonstrate their efficacy. If you are disappointed by those failure numbers, realize that the true number of failures (excess laxity and/or pivoting) is actually worse, since 2 of the included studies used revision as the only indicator of failure. The true number of failures is likely higher because, most likely, all those that have failed have probably not come to revision yet. After ACL surgery, it is immediately necessary to focus on the rehabilitation to optimize results. Research does suggest immediately, like day 1. According to the review by Lepley,3 emphasis should be on cryotherapy, closed chain exercises, and restoration of full range of motion. Don’t bother with postoperative splints or braces, and don’t delay physical therapy for a week—start immediately. Even more helpful guidance originates from the MOON Group—don’t bother with continuous passive motion (CPM) and try to start weightbearing early to prevent patellofemoral pain.5 In the MOON cohort, postoperative bracing did not improve swelling, pain, range of motion, or safety. They suggest that open chain exercises can be started safely at 6 weeks. In an effort to maximize results respecting the mental aspect of rehabilitation, the review by Lepley3 supports “patient advice and counseling” throughout the rehabilitation process to improve self-reported outcomes. On the physical side, the exercise mode should be eccentrics all the way—especially for the quadriceps muscle. If isokinetic testing equipment is not available in your environment, you can still gauge when athletes are approaching return-to-play readiness using the limb symmetry index (LSI) of the single-leg hop for distance test.6 The distance LSI correlated well with isokinetic extension peek torque LSI but not with kinetic and kinematic symmetry 6 to 9 months postreconstruction. The study suggests that there are patients who have symmetric muscle strength with coexisting kinetic and kinematic asymmetries because of faulty neuromuscular patterns or psychological factors, meaning that they are not ready to return to play, so don’t be fooled! Movement parameters can be scrutinized by an experienced observer and improved with appropriate training. Finally, Ardern1 helps put the results of ACL injury into perspective: Returning to preinjury level of sport after ACL reconstruction is complex and multifactorial. Screening for modifiable factors, particularly the psychologic ones, may help clinicians identify those most at risk for not returning. According to Ardern,1 1 in 3 athletes does not return to his or her preinjury level, and 1 in 2 does not return to a competitive level following surgery. Fear of reinjury was an ominous factor. Clinicians, including orthopaedic surgeons, need to understand their deficiencies in recognizing these factors outside of their own clinical expertise and provide appropriate counseling while return-to-play decisions are being resolved. No doubt, more research is needed to improve the fate of the ACL-injured athlete. The studies presented in this issue of Sports Health have helped us with the task of improving the care of these athletes. Nowadays, an ACL injury does not always end an athletic career. But, we shouldn’t put all of our focus on return to play, as if that’s the endpoint of our athletic medicine responsibility. We need more answers to the problem of posttraumatic arthritis that often follows the competitive athletic career after ACL injury. Then we can safely encourage many more of these athletes to get back in the game!

Restoration of musculoskeletal function is a fundamental goal of orthopaedic treatment. Until now, clinical orthopaedic concepts of injury, repair, and restoration of function of musculoskeletal systems have been described and understood primarily in structural and biomechanical terms. This perception probably evolved because the structural characteristics are the most readily visualized factors, both in the clinical setting (for example, pathological laxity due to a ruptured ligament or a fracture) and through the preponderance of structural and pathoanatomical data offered by most current imaging modalities. Structural characteristics are also the factors most directly altered by operative intervention, such as stability following repair or reconstruction of a ligament or fixation of a fracture. It is a common belief that the restoration of measurable structural and biomechanical parameters to an injured joint, such as the knee, indicates the restoration of function to that system. We do not share this view. In the past few years, emerging clinical and basic-science findings have indicated a much greater degree of underlying biological complexity. Evidence suggests that the correction of identifiable structural abnormalities is often not sufficient to restore a joint to its full preinjury level of physiological function. For example, replacement of a ruptured anterior cruciate ligament with a graft does not necessarily prevent pain, swelling, or degenerative changes in the knee, even if the increased anterior-posterior laxity that had been present before the procedure is restored to normal. This observation indicates that factors other than anatomical and structural ones probably contribute to the restoration of joint function after injury. We believe that, although these other factors are less easily visualized, they play an important role in the ultimate functional status of an injured musculoskeletal system, such as the knee. The purpose of this Instructional Course Lecture is to discuss the concept of musculoskeletal function and to …

Anterior cruciate ligament injury rates are four to eight times higher in women than in men. Because of estrogen's direct effect on collagen metabolism and behavior and because neuromuscular performance varies during the menstrual cycle, it is logical to question the menstrual cycle's effect on knee injury rates. Of 40 consecutive female athletes with acute anterior cruciate ligament injuries (less than 3 months), 28 (average age, 23 11 years) met the study criteria of regular menstrual periods and noncontact injury. Details concerning mechanism of injury, menstrual cycle, contraceptive use, and previous injury history were collected. A chi-square test was used to compute observed and expected frequencies of anterior cruciate ligament injury based on three different phases of the menstrual cycle: follicular (days 1 to 9), ovulatory (days 10 to 14), and luteal (day 15 to end of cycle). A significant statistical association was found between the stage of the menstrual cycle and the likelihood for an anterior cruciate ligament injury (P 0.03). In particular, there were more injuries than expected in the ovulatory phase of the cycle. In contrast, significantly fewer injuries occurred in the follicular phase. These hormones may be a factor in the knee ligament injury dilemma in women.

This investigation explored alternatives to the null hy potheses that maximal active and passive resistance to inversion developed by a near-maximally inverted and weightbearing ankle is not altered by 1) the use of prophylactic adhesive athletic tape, 2) the use of non- adhesive prewrap (underwrap), or 3) 40 minutes of vigorous exercise. Ten healthy men and 10 healthy women (mean age, 25 ± 3 years) with no recent ankle injuries underwent testing to determine maximal ankle resistance to inversion under unipedal, weightbearing conditions. Tests were performed with and without the support of athletic tape, and before and after 40 min utes of exercise. Half the testing sessions were per formed with prewrap under the tape. At 15° of inver sion, without any external ankle support, healthy young men and women could maximally resist a mean (SD) inversion moment of 52.9 (6.4) N-m and 28.3 (5.8) N-m, respectively. Although use of ankle tape provided a 10% increase in maximal resistance to inversion moments, this increase diminished to insignificant lev els after 40 minutes of vigorous exercise. Use of pre wrap improved maximal resistance to inversion by more than 10%.

Objectives: A deficiency in hip internal rotation secondary to femoroacetabular impingement (FAI) may result in compensatory increases in rotational stresses applied to the ACL with cutting and pivoting activities, thereby increasing the risk of ACL failure in athletes. The purpose of this study was to correlate ACL injury with hip range of motion in a consecutive series of elite, contact athletes and to test the hypothesis that a restriction in the available hip axial rotation in a dynamic in silico model of a simulated pivot landing would increase ACL strain and the risk of ACL rupture. Methods: We examined 324 football athletes attending the 2012 NFL National Invitational Camp. Hip range of internal rotation was measured by three orthopaedic surgeons and correlated with a history of ACL injury and surgical repair using generalized estimating equation logistic regression analysis. An in silico biomechanical model was used to study the effect of FAI on the peak relative ACL strain developed during a simulated pivot landing. Results: The in vivo results demonstrated that a reduction in internal rotation of the left hip was associated with a statistically significant increased odds of ACL injury in the ipsilateral or contralateral knee (OR = 0.95, P =.0001 and P < .0001, respectively). A post-estimation calculation of odds ratio for ACL injury based on deficiency in hip internal rotation demonstrated that a 30-degree reduction in left hip internal rotation was associated with 4.06 and 5.29 times greater odds of ACL injury in the ipsilateral and contralateral limbs, respectively (Figure 1A). The in silico model demonstrated that FAI systematically increased the peak ACL strain predicted during the pivot landing (Figure 1B). The peak AM-ACL strain for 5-degrees of internal rotation was 22.5% greater than the corresponding value for 10-degrees of internal rotation (i.e., a peak AM-ACL strain of 5.77% vs. 4.71%, respectively). Conclusion: FAI may significantly increase the risk of ACL injury due to the increased resistance to femoral internal axial rotation during a dynamic maneuver such as a pivot landing. This insight may lead to better interventions to prevent ACL injury and improved understanding of ACL reconstruction failure in the absence of clear technical errors.

Over the past 40 years or so, there has been a significant change in the direction of amateur sports in the United States. Way back when, participating in several sports (baseball, basketball, football, or track) was the goal of many high school athletes. If you could letter in 3, especially before your senior year in high school, that was quite impressive. Those who achieved this goal in their sophomore or yet freshman years were the top of the class. High school sports were the pinnacle for most, with a few going on to college careers. There were no travel teams, and there were limited opportunities outside of high school sports except for summer leagues. Almost nobody thought of quitting the team prematurely, unless they were injured. I can’t recall a single case of “burnout” back in high school. Nowadays, more and more athletes choose to specialize in 1 sport even before high school, hoping to achieve elite status. Many of today’s amateur athletes bypass school-sponsored programs altogether in favor of advanced, often year-round Amateur Athletic Union competition—especially in basketball. Some even leave home as teenagers to live in distant cities with sponsoring families to compete on highly competitive teams, such as USA Hockey. When kids commit or are committed to sports specialization, they enter a different arena where decisions are made by adults, not them. The goal of sports specialization at an early age is to optimize the opportunities to develop athletic skills in 1 sport to enhance the chances of competing at the next level. Having fun and developing lifelong interests in athletic activities doesn’t appear to be a goal of many, if not most, specialization programs. While there is no doubt that structured athletic practice time plays an important role in athlete development, the question becomes at what age and at what cost? Fifty years ago, opportunities for sports specialization were few and far between. Sure, there were the kids who really only liked 1 sport to the exclusion of others, but that was usually the athlete’s choice, not that of the parents or coaches. We had a lot more unstructured time to play ball. Summer days were spent at the local park from morning until the street lights came on; all you had to do was ride your bike to the park and pick-up games would ensue. There were no parents or coaches to guide play. We had to pick teams and make rules and adjustments all by ourselves. In the hot summer afternoon, if we couldn’t field 2 full teams on the baseball field, we’d play “right field out” and limit play to the left side of the infield. Sometimes we used an official pitcher who threw for both teams if we didn’t have 2. It was carefree play with plenty of time to experiment with switch hitting, curve balls, and playing different positions. The same was true for basketball and touch football games as summer grew into August and football season approached. Nowadays, I see very little unstructured, unsupervised sports play with kids. It seems like they need transportation everywhere, and practices are “focused” and highly organized. Practice sessions are deliberate, even for the youngest, and driven by skill acquisition rather than having fun. This is where the pressure for sports specialization begins. When coaches see youngsters who develop and acquire athletic skills faster or are more developed physically than their peers, these individuals are frequently singled out for advanced play because they have “potential.” The slow developers of skill or physique are often left behind because they don’t make the grade. The select kids are often steered toward travel teams and clubs that require more practice time—often year-round—that frequently makes participation in other sports more difficult. It appears that parents are the ones who initially encourage and initiate sports participation, but often it’s the coaches who emphasize sports specialization, which often sets up an interesting dynamic. If the parent is cognizant of the coach’s direction and agrees with it, the youngster hears the same tune at home and at practice. Unfortunately, if the parent is not on board with the coach’s viewpoint, the young, vulnerable athlete is caught in between and many times finds it difficult to decide for himself or herself. It’s great to give the high achievers in sports excellent opportunities to pursue their hopes and dreams, but it’s very unfortunate to see kids cut and left behind at a young age because they haven’t developed as quickly. Both of these common tendencies (pushing the gifted and diminishing the opportunities for those with poorer skills) can take the fun out of sports, especially when it happens at a young age. When the fun is removed, many drop out prematurely. How sad it is to see high school athletes flat out quit before their senior year because they’ve had enough. More than once I’ve heard the complaint, “Coach has taken all the fun out of it.” So at what age should these specialization decisions be made and opportunities offered? It really depends on who you ask and in what sports they participate. To fairly answer that question, think about the amount of time it takes to acquire elite-level skill. While we don’t have sound data for sports, we do have estimates for music, which demands much of the same physical and mental discipline and skill. Studies suggest that 10,000 hours over 10 years are needed for elite status.1 Also, training should begin around age 5; those who start later apparently never catch up. In retrospect, I started playing the accordion at age 7 but did not put nearly that amount of time into practicing. I guess that’s why I never made it to the top of the polka charts. However, elite gymnasts, divers, and figure skaters have taken that path or one similar. It’s not unusual to see those kiddies start at age 3 or 4 in gymnastics or figure skating. I wonder how many of those 5- and 7-year-olds, into the routine for several years, really enjoy intense regular athletic training. Moreover, I wonder why they are doing the arduous daily routines. Who are they pleasing, and are they happy when it’s all over? True, some make it all the way to the Olympics and to the cover of the Wheaties box, but 99% do not. I’d really like to ask all of them: Was it worth it? My impression is that if their training allowed for a reasonably normal family and social life with a coach that made it fun, yes, it was worthwhile, and they’d do it all over again. However, I bet that there’s more than a few who feel like they lost their childhood, suffered far too many injuries, and missed out on a lot of fun in middle and high school. In light of the many common outcomes of early sports specialization, I think the reports on sports diversification at a young age are notable. Take, for instance, a study of Division I female National Collegiate Athletic Association athletes; only 17% had previously competed exclusively in their college sport.2 This statistic is pretty low and surprising to me! Based on this, it is difficult to argue with the recommendations of Jayanthi et al3 that “intense training in a single sport to the exclusion of others should be delayed until late adolescence to optimize success while minimizing risk for injury and psychological stress.” So, let’s say the sports program was good and success was achieved; the specialization was advantageous, athletic prowess is gained, and a college athletic scholarship is awarded! College life should be good, the bills are paid! Unfortunately, according to the article by Weigand et al,4 nearly 17% of these accomplished college athletes are depressed! These results are very similar to those reported by Yang et al,5 with 21% of the 257 student athletes reporting symptoms of depression. The most at-risk groups were freshman (3.27 greater odds) and female student athletes (1.32 greater odds). The number of depressed student athletes is surprising to me, but maybe it shouldn’t be. Depression can often be present, but a lot of athletes choose not to talk about it because of the stigma that it can carry. Also, as medical professionals, we don’t look for it as often as we should in physically healthy, competing college athletes. I thought the problem was more common in retired athletes. In the past 3 years, nearly a dozen former stars, including Junior Seau, have committed suicide. I can understand that the transition from stardom to regular life is difficult. The loss of media attention and bright lights can be troublesome, and just how the traumatized brain plays into the downward spiral in those who played contact sports remains to be seen. I guess there are a lot of places we should be looking for depression. Honestly speaking, it has probably been present in a lot more individuals than we’ve recognized. In retrospect, sports should above all be kept fun, especially for children and adolescents, realizing that elite status is gained by very few. That’s the best route to keep them athletically active in the long term, which should be the emphasis for most. For those who achieve elite status, we need to keep an eye on them. Some of these athletes are facing difficult issues that come with the turf and may find it hard to ask for help. Hopefully we can recognize them and get them the help that they need.

Context:Quadriceps and hamstrings weakness occurs frequently after anterior cruciate ligament (ACL) injury and reconstruction. Evidence suggests that knee injury may precipitate hip and ankle muscle weakness, but few data support this contention after ACL injury and reconstruction.Objective:To determine if hip, knee, and ankle muscle weakness present after ACL injury and after rehabilitation for ACL reconstruction.Design:Case-control study.Setting:University research laboratory.Patients or Other Participants:Fifteen individuals with ACL injury (8 males, 7 females; age = 20.27 ± 5.38 years, height = 1.75 ± 0.10 m, mass = 74.39 ± 13.26 kg) and 15 control individuals (7 men, 8 women; age = 24.73 ± 3.37 years, height = 1.75 ± 0.09 m, mass = 73.25 ± 13.48 kg).Intervention(s):Bilateral concentric strength was assessed at 60°/s on an isokinetic dynamometer. The participants with ACL injury were tested preoperatively and 6 months postoperatively. Control participants were tested on 1 occasion.Main Outcome Measures:Hip-flexor, -extensor, -abductor, and -adductor; knee-extensor and -flexor; and ankle–plantar-flexor and -dorsiflexor strength (Nm/kg).Results:The ACL-injured participants demonstrated greater hip-extensor (percentage difference = 19.7, F1,14 = 7.28, P = .02) and -adductor (percentage difference = 16.3, F1,14 = 6.15, P = .03) weakness preoperatively than postoperatively, regardless of limb, and greater postoperative hip-adductor strength (percentage difference = 29.0, F1,28 = 10.66, P = .003) than control participants. Knee-extensor and -flexor strength were lower in the injured than in the uninjured limb preoperatively and postoperatively (extensor percentage difference = 34.6 preoperatively and 32.6 postoperatively, t14 range = −4.59 to −4.23, P ≤ .001; flexor percentage difference = 30.6 preoperatively and 10.6 postoperatively, t14 range = −6.05 to −3.24, P < .05) with greater knee-flexor (percentage difference = 25.3, t14 = −4.65, P < .001) weakness preoperatively in the injured limb of ACL-injured participants. The ACL-injured participants had less injured limb knee-extensor (percentage difference = 32.0, t28 = −2.84, P = .008) and -flexor (percentage difference = 24.0, t28 = −2.44, P = .02) strength preoperatively but not postoperatively (extensor: t28 = −1.79, P = .08; flexor: t28 = 0.57, P = .58) than control participants. Ankle–plantar-flexor weakness was greater preoperatively than postoperatively in the ACL-injured limb (percentage difference = 31.9, t14 = −3.20, P = .006).Conclusions:The ACL-injured participants presented with hip-extensor, -adductor, and ankle–plantar-flexor weakness that appeared to be countered during postoperative rehabilitation. Our results confirmed previous findings suggesting greater knee-extensor and -flexor weakness postoperatively in the injured limb than the uninjured limb. The knee extensors and flexors are important dynamic stabilizers; weakness in these muscles could impair knee joint stability. Improving rehabilitation strategies to better target this lingering weakness seems imperative.

Most orthopaedic surgeons have faced the challenge of managing patients who have marked limitation of motion of the knee. Others have managed patients who have a disability because of sympathetically maintained pain—that is, reflex sympathetic dystrophy. Both of these conditions can be difficult to treat. When sympathetically maintained pain and severe contractures occur together in the knee, the problems of diagnosis and treatment are magnified. Sympathetically maintained pain can be disproportionately severe and associated with periarticular swelling as well as with muscle inhibition23,47, which may lead to a slow and painful course in physical therapy. The relative lack of progress in rehabilitation of the knee, as well as the sympathetically maintained pain itself, frequently produce anxiety and depression in these patients, which can lead to poor compliance and worsening stiffness. Increasing stiffness in the knee often limits the ability of a patient to walk, kneel, climb, sit, work, or participate in sports activities and leads to additional emotional stress and upset. As the depression worsens, a vicious cycle results. Unless early and appropriate measures are taken to break the cycle, both the patient and the treating physician will be faced with anger, frustration, and ultimately, an unsatisfactory outcome. Although hand surgeons have long dealt with sympathetically maintained pain the upper extremity14, the syndrome has not been as well recognized or treated as frequently in the lower extremity9,15,33,40. However, recent reports2,5,10,11,20,23,25 have helped to delineate sympathetically maintained pain in the lower extremity, and we now have a better understanding of the pathophysiology and treatment of the condition. The keystone of treatment for this type of stiff and painful knee is early recognition27. …

We measured the maximal isometric eversion moment developed under full weightbearing in 20 healthy adult men (age, 24.4 +/- 3.4 years; mean +/- SD) with their ankles in 15 degrees of inversion. Tests were performed at both 0 degree and 32 degrees of ankle plantar flexion in low- and in three-quarter-top shoes with and without adhesive athletic tape or one of three proprietary ankle orthoses. At 0 degree of ankle plantar flexion, the mean maximal voluntary resistance of the unprotected ankle to an inversion moment was 50 +/- 8 N-m; this increased by an average of 12% (or 6 N-m) when the subject wore a three-quarter-top basketball shoe. The maximal voluntary resistances to inversion moments developed with the ankles further protected by athletic tape or any of three orthoses were not significantly different. Biomechanical calculations suggest that at 15 degrees of inversion the fully active ankle evertor muscles isometrically developed a moment up to six times larger than that developed when an athlete wears a three-quarter-top shoe alone and more than three times larger than that developed passively when the athlete has tape or an orthosis worn inside a three-quarter-top shoe. We conclude that fully activated and strong ankle evertor muscles are the best protection for a near-maximally inverted ankle at footstrike.

We investigated the effect of quadriceps and hamstring muscle fatigue on anterior tibial translation and muscle reaction time in 10 healthy subjects. The six men and four women had an average age of 21.3 years and had no known pathologic knee conditions. Each patient underwent a knee examination, arthrometer measure ments of tibial translation, subjective functional assess ment, and an anterior tibial translation stress test be fore and after quadriceps and hamstring muscle- fatiguing exercise. The recruitment order of the lower extremity muscles in response to anterior tibial trans lation did not change with muscle fatigue. However, the results showed an average increase of 32.5% in ante rior tibial translation (range, 11.4% to 85.2%) after fatigue. Muscle responses in the gastrocnemius, ham string, and quadriceps originating at the spinal cord and cortical level showed significant slowing and, in some cases, an absence of activity after the quadri ceps and hamstring muscles were fatigued. The in creases in displacement after fatigue strongly corre lated (0.62 to 0.96) with a delay in cortical-level activity (intermediate and voluntary). Muscle fatigue, which ap pears to affect the dynamic stability of the knee, alters the neuromuscular response to anterior tibial transla tion. Therefore, fatigue may play an important role in the pathomechanics of knee injuries in physically de manding sports.

Allograft meniscus transplantation recently has become a potential method of treating the meniscus-deficient knee. The history, immunology, processing and sterilization techniques, animal studies, clinical trials, indications, surgical techniques, postoperative rehabilitation, and complications of this procedure are reviewed. At this time, meniscal allograft transplantation remains an investigational procedure with limited indications.