Quantitative 3D MRI reveals limited intra-lesional bony overgrowth at 1 year after microfracture-based cartilage repair.

OBJECTIVE: Intra-lesional bony overgrowth (BO) identified during or following cartilage repair treatment is being frequently described through subjective reports focusing primarily on incidence. Our objective was to quantify the exact volume of intra-lesional BO at 12 months post-cartilage repair treatment, to determine if a correlation exists between the extent of BO and clinical outcomes, and to visualize and characterize the BO. DESIGN: MRI scans were systematically obtained during a randomized clinical trial for cartilage repair (Stanish et al., 2013) that compared two microfracture-based treatments in 78 patients. Semi-automated morphological segmentation of pre-treatment, 1 and 12 months post-treatment scans utilizing a programmed anatomical atlas for all knee bone and cartilage structures permitted three-dimensional reconstruction, quantitative analysis, as well as qualitative characterization and artistic visualization of BO. RESULTS: Limited intra-lesional BO representing only 5.8 ± 5.7% of the original debrided cartilage lesion volume was found in 78 patients with available MRIs at 12 months. The majority (80%) of patients had very little BO (<10%). Most occurrences of BO carried either spotty (56.4%) or planar (6.4%) morphological features, and the remaining balance (37.2%) was qualitatively unobservable by eye. Pre-existing BO recurred at 12 months in the same intra-lesional location in 36% of patients. No statistical correlations were found between BO and clinical outcomes. CONCLUSIONS: Intra-lesional BO following microfracture-based treatments may not be as severe as previously believed, its incidence is partly explained by pre-existing conditions, and no relationship to clinical outcomes exists at 12 months. Morphologically, observable BO was categorized as comprising either spotty or planar bone.

Knee effusion affects knee mechanics and muscle activity during gait in individuals with knee osteoarthritis.

OBJECTIVE: To test the hypothesis that knee effusion presence in those with knee osteoarthritis (OA) alters knee joint muscle activation patterns and sagittal plane mechanics during gait. METHODS: Thirty-five patients with medial compartment knee OA were assessed for the presence of effusion using a brush test. Based on the results, they were assigned to the knee effusion (n = 17) and no knee effusion (n = 18) groups. Electromyograms from seven lower extremity muscles (lateral and medial gastrocnemius, vastus lateralis and medialis, rectus femoris and the lateral and medial hamstrings), leg motion and ground reaction forces were recorded during self-selected walking. Isometric knee extensor, plantar flexor and knee flexor strength were measured. Discrete measures from angular knee motion and net external moment of force waveforms were identified. Principal component analysis extracted electromyographic waveform features. Analysis of variance models tested for main effects (group, muscle) and interactions (α = 0.05). Bonferroni post-hoc testing was employed. RESULTS: No differences in age, body mass index, knee pain, Western Ontario McMaster Osteoarthritis Index scores, gait velocity and muscle strength were found between groups (P > 0.05). Individuals with effusion had a greater overall quadriceps activation and prolonged hamstring activation into mid-stance (P < 0.05). Knee joint flexion angles were higher (P < 0.05) and net external knee extension (KE) moments in mid to late stance lower in the effusion group. CONCLUSION: Quadriceps and hamstrings activation during walking were altered when effusions were present. Increased knee flexion (KF) angles and decreased KE moment in mid-late stance provide a mechanical explanation for the effect of joint effusion on muscle activation in those with knee OA.

The neuromuscular demands of altering foot progression angle during gait in asymptomatic individuals and those with knee osteoarthritis.

OBJECTIVES: To determine the immediate effects of a toe-out foot progression angle modification during gait on the major lower limb muscle activation characteristics and to establish whether asymptomatic individuals and those with moderate knee OA have similar responses. DESIGN: Seventeen patients with knee OA and 20 asymptomatic control subjects participated. Informed consent was obtained. Electromyographic (EMG) recordings were acquired from the lateral and medial gastrocnemii, vastus lateralis, vastus medialis, rectus femoris and the lateral and medial hamstrings during neutral and toe-out walking conditions. The EMG waveforms were amplitude normalized to maximal voluntary isometric contractions and time normalized to the gait cycle. Principal component analysis extracted principal waveform features. Analysis of variance models tested for main effects and interactions. Bonferroni post hoc testing was employed (alpha=0.05). RESULTS: Both groups altered foot progression angle by approximately 15 degrees during toe-out walking (P<0.05). A shift in gastrocnemius activation towards later stance (P<0.05) and increased magnitude and duration of quadriceps activation (P<0.05) was found. A differential activation occurred in the overall magnitude and principal shape of the lateral and medial hamstring musculature in the asymptomatic group only (P<0.05). Significant group differences were shown in each muscle analysis (P<0.05). CONCLUSION: Neuromuscular demands of adopting a toe-out gait differ from a neutral foot progression angle. Demands also differ between asymptomatic controls and patients with moderate knee OA. These findings have relevance for altered joint loading and changes in metabolic cost of this gait modification in individuals with knee OA.

Neuromuscular alterations during walking in persons with moderate knee osteoarthritis.

This paper compared the neuromuscular responses during walking between those with early-stage knee osteoarthritis (OA) to asymptomatic controls. The rationale for studying those with mild to moderate knee OA was to determine the alterations in response to dynamic loading that might be expected before severe pain, joint space narrowing and joint surface changes occur. We used pattern recognition techniques to explore both amplitude and shape changes of the surface electromyograms recorded from seven muscles crossing the knee joint of 40 subjects with knee OA and 38 asymptomatic controls during a walking task. The principal patterns for each muscle grouping explained over 83% of the variance in the waveforms. This result supported the notion that the main neuromuscular patterns were similar between asymptomatic controls and those with OA, reflecting the specific roles of the major muscles during walking. ANOVA revealed significant (p<0.05) differences in the principal pattern scores reflecting both amplitude and shape alterations in the OA group and among muscles. These differences captured subtle changes in the neuromuscular responses of the subjects with OA throughout different phases of the gait cycle and most likely reflected changes in the mechanical environment (joint loading, instability) and pain. The subjects with OA attempted to increase activity of the lateral sites and reduce activity in the medial sites, having minimal but prolonged activity during late stance. Therefore, alterations in neuromuscular responses were found even in this high functioning group with moderate knee OA.

Obesity is associated with prolonged activity of the quadriceps and gastrocnemii during gait.

PURPOSE: To examine the effect of obesity and its potential interaction with knee OA presence on the electromyography patterns of the major knee joint periarticular muscles during walking. SCOPE: One hundred and eighteen asymptomatic adults and 177 adults with moderate knee osteoarthritis were subdivided into categories of healthy weight (n = 77; 20 kg/m(2) < BMI < 25 kg/m(2)), overweight (n = 117; 25 kg/m(2) ⩽ BMI < 30 kg/m(2)), and obese (n = 101; BMI ⩾ 30 kg/m(2) based on their body mass index (BMI). All individuals underwent a three-dimensional gait analysis. Surface electromyograms from the lateral and medial gastrocnemii, lateral and medial hamstrings, vastus lateralis, vastus medialis, and rectus femoris were recorded during self-selected speed walking. Principal component analysis was used to extract major features of amplitude and temporal pattern variability from the electromyograms of each muscle group (gastrocnemii, quadriceps, hamstrings separately). Analysis of variance models tested for main BMI category effects and interaction effects for these features (α = 0.05). Statistically significant BMI category (i.e. obesity) effects were found for features that described more prolonged activations of the gastrocnemii and quadriceps muscles during the stance phase of gait with obesity (P < 0.05). CONCLUSIONS: Obesity was associated with prolonged activation of quadriceps and gastrocnemii, which can result in prolonged knee joint contact loading, and thereby may contribute to the predisposition of knee OA development and progression in obese individuals.

Rehabilitation of tendon injuries in sport.

Clinicians are faced with a growing number of athletes with injured tendons. Treatment of both acute and chronic injuries has proven to be quite complex. It is difficult to maintain the balance between resting the injured tendon and preventing atrophy of the surrounding muscles and joints. Questions also arise as to when the tendon should be strengthened and when the athlete is ready to return to full activity in sport. Through an awareness of the structural and mechanical properties of the tendon, an exercise programme for the rehabilitation of tendon injuries has been developed. It is recommended that this programme be used in combination with ice and other physical modalities. This approach will resolve most tendon injuries within 6 weeks of its implementation. The use of anti-inflammatory medications and surgery can only be recommended in select situations where more conservative measures are inadequate.

Overuse injuries in athletes: a perspective.

Injuries secondary to sporting activities have increased significantly in the past decade. Traditional treatment programs for these maladies have frequently failed to meet the physiological expectations of the athlete. Forced rest or immobilization result in predictable musculoskeletal atrophy with impaired function. Furthermore, the rehabilitation process has commonly focused on the management of the acute problem with minor attention to the etiology and pathomechanics of the injury (preventive medicine). Many sports injuries, as a result of overuse, can be avoided by scientific coaching and contemporary sports medicine.

Chronic compartment syndrome caused by aberrant fascia in an aerobic walker.

The following is a case presentation of a 36-yr-old female athlete who presented with the symptoms and signs of chronic anterior compartment syndrome. Pre-exercise and post-exercise tissue pressure measurements revealed increased compartment pressures in both of her anterior leg compartments. Aberrant fascial bands overlying and compressing the anterior compartments were discovered at the time of surgery. Fasciotomies led to complete recovery and return to previous levels of athletic activity. This is the first report of aberrant fascia as a cause of chronic anterior compartment syndrome.

The aging athlete.

In summary, the purpose of this material is to demonstrate that the aging athlete does differ from the younger competitor in many facets. There are physiological, structural, and psychosocial differences which distinguish them as a unique entity in the athletic world. Despite the unavoidable alterations that the passage of time imposes on our bodies, these competitors are still capable of incredible performances of strength, skill, and endurance. In reference to injury, these athletes are at risk from both their current program and their past indiscretions. The literature strongly suggests that the greatest threat to the health of the aging athlete is not the aging process itself but rather inactivity. Astrand concurs with this and states that "there is less risk in activity than in continuous inactivity--it is more advisable to pass a careful physical examination if one intends to be sedentary in order to establish whether one's state of health is good enough to stand the inactivity." It appears that the body systems were designed to reinforce activity and when there is disuse, a large number of atrophic changes take place. It has been estimated that regular exercise may be able to retard the physiologic decline associated with old age as much as 50%. Taken in this light, exercise is truly a fountain of youth from which we can all rejuvenate ourselves. Science has proven that life does not begin at 40, but it has also demonstrated that it does not have to end there. As one author so aptly states, "Not too many years ago the words grandma and grandpa conjured images of rocking chairs and inactivity."(ABSTRACT TRUNCATED AT 250 WORDS)

An unusual cause of back pain in a young athlete. A case report.

Back pain in the young athlete is a common problem seen in many sport medicine clinics. Not only can this be a difficult problem for the physician to manage (due to inability to pinpoint the pathology), but it is a frustrating experience for the athlete, unable to compete or train effectively. The sport medicine physician must, therefore, always be alert and obsessed with obtaining a precise diagnosis to be followed by specific treatment. When presented with the adolescent athlete suffering with back pain, one must consider the full gamut of diagnostic possibilities. Mechanical or spondylogenic causes are most common; however, potentially more serious infective, metabolic, and neoplastic conditions should also be considered.

Medial epicondylitis. An electromyographic analysis and an investigation of intervention strategies.

Flexor and extensor muscle-tendon unit activity at the elbow during the golf swing was recorded from subjects with and without medial epicondylitis. There was no significant difference in total swing time between symptomatic (1.23 +/- 0.15 sec) and asymptomatic (1.15 +/- 0.13 sec) subjects nor between golfers with low (1 to 6 handicap, N = 8) and high (11 to 19 handicap, N = 8) scoring abilities. Symptomatic and asymptomatic subjects displayed similar electromyographic profiles for flexor and extensor muscles of the forearm. Electromyographic activity of the common extensor muscles was persistent throughout the four swing phases, ranging from 33.59% of maximum voluntary contraction at address to 58.77% at contact. Common flexor muscles produced a consistent burst of electromyographic activity during contact phase (flexor burst, 90.77% of maximum voluntary contraction). Symptomatic subjects' mean flexor muscle electromyographic activity was significantly greater than that of asymptomatic subjects in both address and swing phases. When forearm brace and oversized grips were imposed on symptomatic subjects, there was no significant difference in mean electromyographic magnitude or muscle activation pattern during the golf swing. Thus, the method of symptomatic relief of the intervention strategies tested is still in question.

The effects of static stretching exercises and stationary cycling on range of motion at the hip joint*.

The objective of this study was to compare the effects of static stretching exercises and stationary cycling on hip range of motion measures immediately following exercise and after a 15-min period of rest or continued activity. The results showed that both exercises performed for equal time periods resulted in hip range of motion increases with no significant difference (p < 0.05) between the immediate effects of the two exercises. Fifteen minutes of cycling or inactivity did not result in significant differences (p < 0.05) from the initial gains resulting from the stretching, but did result in significant increases in hip flexion for the group that continued cycling. Based on the results of this study, static stretching and cycling were equally effective for increasing range of motion and retaining the increase for a 15-min period in a controlled environment, independent of activity.J Orthop Sports Phys Ther 1984;6(2):104-109.

Lower leg, foot, and ankle injuries in young athletes.

Most injuries to the young athlete do have a benign natural course--complete resolution of the difficulty without sequelae. In order to develop a contemporary program of management of the more serious disorders in this active population, the practitioner must be certain to carefully analyze the injury and initiate a rapid course of action. A fracture of the tibia must be reduced, held aligned, and then rehabilitated. A compartment syndrome commonly demands early fasciotomy; the young athlete and his or her parents warrant a sensitive understanding from physicians to quell the anxiety that is paramount to all of these disorders.

New concepts of rehabilitation following anterior cruciate reconstruction.

Can a knee joint with a torn ACL of 2 years' duration ever be able to return to high performance? Very unlikely indeed. Some realistic expectations follow: 1. The knee joint can never be normal after an ACL reconstruction. 2. Surgery must take place as early after the injury as possible, before secondary joint degeneration takes place. 3. The surgery must employ a tissue that best matches the normal ACL in strength and structure. 4. The surgery must involve as little trauma as possible while restoring knee joint mechanics. 5. Stress, although guarded, must be faced by the knee joint as soon as possible after surgery. 6. Progressive weight bearing starts immediately, combined with quadriceps isometrics. ROM of the knee joint, particularly full extension, is conserved and protected. 7. Progressive active ROM without formal resistance continues for 4 weeks. 8. Progressive formal resistance exercises continue for at least 1 year. 9. Sport-specific tasks commence at 16 weeks, depending on the requirement of the sport and the response of the individual athlete. 10. Recovery will plateau at several stages, with the final plateau at approximately 18 months. Knee instability is an exciting but perplexing problem. Although we have advanced profoundly from the era of Jones, Smiley, and others, we still face many of the same challenges as our predecessors. New technology should not fool us. We are still addressing a major structural failure within the knee joint. Our attempts have been non-surgical and surgical, with repair, reconstruction, and replacement. However, fundamental to all of these hopes has been the reconditioning of the extremity after ACL surgery. Can we do better than our forefathers like Licht and others? No one is certain. This article offers an approach, in some areas our approach, but should not be perceived as a cookbook. Individual responses by our patients, athletes, dictate whether any protocol is too hasty or tardy. It is fundamental that we listen to our patients objectively and analyze the knee as it returns from the surgical aggression. The ultimate success of the rehabilitation process will be based on the marriage of science and realistic expectations.

The use of eccentric training and stretching in the treatment and prevention of tendon injuries.

Tendon injuries are a common consequence of either sports or daily routine activity. Most people will suffer at least one tendon injury in his or her lifetime. It is therefore prudent to understand the different ways to load tendon and the ways in which the muscle-tendon-bone unit responds to these stresses. By maximizing tendon training and rehabilitation, one can maximize the stresses (eccentric) a tendon will withstand. This article provides an explanation of these principles.

Emergencies in sports: the young athlete.

Accidents are the leading cause of death in children over the age of 1 year. Owing to the prevalence of injury, especially sports related, the attending physician should always be alert for the plausibility of serious medical emergencies in the young athlete.

Tendinitis: the analysis and treatment for running.

The material presented has been designed to offer an approach to the diagnosis and treatment of chronic tendinitis in the runner. Although there is a paucity of experimental data dealing with the behavior of the muscle-tendon unit during lengthening contractions as compared with the volume that exists concerning shortening contractions, results indicate that force increases with length from both eccentric and concentric contractions. The literature also suggests that eccentric contraction is a means by which muscles can maximize their force production while minimizing time delays and energy expenditure. Using this information in our clinical experience, we have developed an exercise program to treat chronic tendinitis. Pain, the cardinal sign of tendinitis, is used as both a way to classify the severity of the tendinitis and a yardstick for the progress of treatment.

The young athlete with physical challenges.

This article is intentionally broad in scope, as a result of a collaboration from the fields of primary care sports medicine, orthopedic surgery, and kinesiology. What has been borne out in the process is a true appreciation of the benefits of a multidisciplinary approach toward providing care for the young athlete with a physical disability. To name a few, joint involvement of parents, coaches, trainers, physical therapists, orthotists, prosthetists, wheelchair engineers, neurologists, physiatrists, nutritionists and most importantly, the athletes themselves, should be further encouraged because each discipline provides a unique perspective in the identification and management of health-related issues. It is the intent of this article to provide readers with at least some new insight that they can carry into their future practice.

Lower leg, foot, and ankle injuries in young athletes.

Most injuries to the young athlete do have a benign natural course-complete resolution of the difficulty without sequelae. In order to develop a contemporary program of management of the more serious disorders in this active population, the practitioner must be certain to carefully analyze the injury and initiate a rapid course of action. A fracture of the tibia must be reduced, held aligned, and then rehabilitated. A compartment syndrome commonly demands early fasciotomy; the young athlete and his or her parents warrant a sensitive understanding from physicians to quell the anxiety that is paramount to all of these disorders.

The Natural History and Tailored Treatment of ACL Injury.

The fate of the injured anterior cruciate ligament (ACL) is variable. The spectrum of injury ranges from partial sprain (grade 1 or 2) to a complete disruption (grade 3), which may occur in isolation or in combination with injury to other structures in the knee. Postinjury symptoms of knee instability usually depend on the degree of joint laxity and the athletic demands of the individual. If an ACL injury is left untreated, repeated episodes of subluxation can inflict further intraarticular damage, with an increased risk of developing osteoarthritis. Predicting the outcome after ACL injury is difficult, and treatment should be individualized.