Prevention of disuse muscle atrophy in chronic arthritides.

This article briefly reviews the causes and physiologic considerations of skeletal muscle disuse atrophy. This is a common problem associated with chronic arthritides. Methods of preventing or modifying this disability are presented.

A comparison of the efficacy and tolerability of diflunisal and dextropropoxyphene napsylate with acetaminophen in the management of mild to moderate pain after arthroscopy of the knee.

We conducted an open-label randomized clinical trial comparing the efficacy and tolerability of diflunisal and dextropropoxyphene napsylate with acetaminophen (DPN-A) in the management of mild to moderate pain following arthroscopic surgery of the knee. Patients used a self-rating pain scale to evaluate the analgesia provided by each medication. Twenty-six patients completed the study; 12 received diflunisal and 14 received DPN-A. The physicians found no significant differences between the two groups in their preoperative or postoperative assessment of pain, tenderness, swelling, and active range of motion. There were no statistically significant differences between the two groups' mean pain scores or assessment of the overall efficacy of their respective drugs. No patient in either treatment group reported any adverse effects.

Comparison of diflunisal and naproxen in the treatment of tennis elbow.

The authors favor conservative treatment of tennis elbow, starting with cessation of the offending activity and prescription of a nonsteroidal anti-inflammatory drug (NSAID) and followed by isometric and isotonic exercises when pain and inflammation have subsided. Two NSAIDs, diflunisal and naproxen, were evaluated in 38 patients with mild-to-moderate pain associated with tennis elbow. The physicians' assessments found no statistically significant differences between the two drugs; both provided effective reduction of pain and swelling. Patients' assessments of pain relief achieved with their respective drugs significantly (P = 0.019) favored diflunisal. Prompt and effective relief of pain and swelling hastens the patient's progression to physical therapy and return to normal activities.

Non-operative treatment of severe injuries to the medial and anterior cruciate ligaments of the knee.

We are reporting the results of conservative treatment of concomitant injuries to the medial collateral and anterior cruciate ligaments of the knee in twenty-eight patients (average age, twenty-eight years), who were followed for an average of three years. Twenty patients had a good or excellent result. Eleven of the fifteen patients who played contact sports and six of the nine who played non-contact sports returned to their preinjury levels of athletic activity. The older and nonathletic individuals had the poorest final results. We concluded that in many individuals with combined injury to the medial collateral and anterior cruciate ligaments, the knee responds well when treated conservatively.

Maximal contraction lessens impact response in a muscle contusion model.

The effect of muscle contraction on a contusion injury model was studied in the gastrocnemius muscle of anesthetized rats. Both limbs of 18 rats received a contusion injury with a blunt non-penetrating impact. One hind limb was relaxed during impact and the other was electrically stimulated to tetanic contraction. The impact was produced using a drop-mass technique (mass = 171 g, height = 101 cm, spherical radius of impactor tip = 6.4 mm). The impact response was determined by sampling (10 kHz) the transmitted impact force and the displacement of the impactor. In a subgroup of nine rats, the severity of the contusion injury was measured by recording contractile tension in twitch and tetanus within two hours of injury. We found that the peak impact force was significantly less (p < 0.01), while the peak impact displacement was significantly greater (p < 0.01) in the contracted limb. Correspondingly, the impact stiffness of the contracted limb was significantly less (p < 0.01) than the impact stiffness in the relaxed limb. Both impacts produced significant injuries relative to an uninjured control group. The tetanic tension (31 +/- 4 N) generated by the muscles that were contracted during impact was significantly (p < 0.03) greater than that generated by the muscles that were relaxed during impact (27 +/- 4 N). The findings from this specific model indicate that the impact response of the limbs with relaxed muscle was dominated by the underlying bone, while maximally contracted muscle decreased the influence of the bone and lessened the impact response. Maximally contracted muscle was not more susceptible to injury and may act as protective mechanism against some impacts.

Magnetic resonance imaging of the surgically repaired meniscus: six-month follow-up.

The appearance and rate of healing of sutured meniscal repairs in 17 patients were evaluated using magnetic resonance scans. While prior studies in animals and humans (1-4) suggest that complete healing can occur as early as 6 wk postoperatively, we found that at 7 wk 15/15 patients demonstrated meniscal defects at the site of repair. At 6 mo, 11/11 patients showed persistent signal abnormalities. Two patients scanned at 11-12 mo also had defects at the site of repair. Therefore, complete meniscal healing appears not to occur as early as previously believed. This may affect decisions regarding the type of suture material used, the surgical treatment of associated injuries and the postoperative rehabilitation regimen. As defects may be present for relatively long periods of time following meniscal repair, caution must be exercised when attempting to diagnose new or recurrent tears in these patients.

The clinical significance of stage 2 meniscal abnormalities on magnetic resonance knee images.

The Stage 2 meniscal abnormality was subdivided into Stage 2A--linear abnormal signal not contacting an articular surface, Stage 2B--abnormal signal in contact with the articular surface on a single image, Stage 2C--extensive wedge-shaped signal abnormality not in contact with an articular surface. Arthroscopy showed tears in 2A 3%, 2B 0%, 2C 50%. Complete tears should only be diagnosed if contact is seen on more than one image. Many Stage 2C menisci may have tears.

The effect of anabolic steroids and corticosteroids on healing of muscle contusion injury.

The effect of an anabolic steroid (nandrolone decanoate, 20 mg/kg) and a corticosteroid (methylprednisolone acetate, 25 mg/kg) on healing muscle injured with a drop-mass technique in a reproducible muscle contusion injury model in the rat was studied. Healing was determined by measuring active contractile tension in each muscle and histologic analysis. At day 2, the corticosteroid group showed significant improvement in both twitch and tetanic strength relative to the controls. At day 7, this effect was reversed and the corticosteroid muscles were significantly weaker than the control muscles, but there was still no significant effect seen in the anabolic steroid group. At day 14, the corticosteroid muscles were totally degenerated, with disorganized muscle fiber architecture. The anabolic steroid muscles were significantly stronger in twitch, and a similar trend was seen in tetanus relative to control muscles. The results indicate that in an animal model corticosteroids may be beneficial in the short term, but they cause irreversible damage to healing muscle in the long term, including disordered fiber structure and a marked diminution in force-generating capacity. Anabolic steroids may aid in the healing of muscle contusion injury to speed the recovery of force-generating capacity. Although anabolic steroids are considered renegade drugs, they may have an ethical clinical application to aid healing in severe muscle contusion injury, and their use in the treatment of muscle injuries warrants further research.

The effect of tourniquet pressure on muscle function.

The adverse effects of excessive tourniquet pressure on underlying muscle were studied using a cat model. A direct effect of the magnitude of tourniquet pressure on the degree of muscle disability was observed. The effect of direct pressure on the muscle may contribute to the postoperative weakness seen in the quadriceps muscle. Our data, in conjunction with the results of other studies that correlate certain tourniquet times and pressures with potential adverse effects, suggest that the selection of an appropriate tourniquet pressure and duration will minimize the development of clinically significant complications.

A muscle contusion injury model. Biomechanics, physiology, and histology.

We developed a reproducible muscle contusion injury and studied its effect on contractile function, histology, and passive failure. An instrumented drop-mass technique (mass, 171 g; height, 102 cm; spherical radius, 6.4 mm) delivered a single impact to the posterior surface of the gastrocnemius muscle in one limb of 40 male Wistar rats. On Day 0, the impact significantly (N = 12, P < 0.01) decreased maximum tetanic tension to 63% of the contralateral control value. Histologic examination demonstrated extravasation of erythrocytes, edema, myofiber disruption, and vacuolation of myofibers. Passive failure initiated at the site of injury. At 2 days, tetanic tension was 75% of controls (N = 11, P < 0.01). Histologically, acute inflammation and phagocytosis were noted. Tetanic tension at 7 days was 81% of controls (N = 8, P < 0.01). Vimentin staining indicated a dramatic increase in myoblast activity. Contractile strength was near normal at 24 days. Histologic examination showed complete regeneration of normal striated muscle fibers. No vimentin activity was found. No passive failures initiated at the injury site. Contusion injury produced a significant deficit in contractile function that continually diminished with gross histologic evidence of degeneration, regeneration, and normalization at the injured muscle fibers.

Muscle contusion injuries: current treatment options.

Muscle contusion is second only to strain as the leading cause of morbidity from sports-related injuries. Severity depends on the site of impact, the activation status of the muscles involved, the age of the patient, and the presence of fatigue. The diagnosis has traditionally been one of clinical judgment; however, newer modalities, including ultrasonography, magnetic resonance imaging, and spectroscopy, are becoming increasingly important in both identifying and delineating the extent of injury. Although controlled clinical studies are scarce, animal research into muscle contusions has allowed the description of the natural healing process, which involves a complex balance between muscle repair, regeneration, and scar-tissue formation. Studies are being performed to evaluate the effects of anti-inflammatory medications, corticosteroids, operative repair, and exercise protocols. Prevention and treatment of complications such as myositis ossificans have also been stressed, but recognition may improve the outcome of these ubiquitous injuries.

Aging successfully: the importance of physical activity in maintaining health and function.

Physicians caring for middle-aged and older patients frequently overlook the importance of regular physical activity. Exercise on a routine basis is an important component of successful aging. It has been shown that many age-related declines in musculoskeletal function can be markedly reduced by participation in some form of regular exercise. Examination of records from masters athletic competitions has been used to determine the true rate of age-related functional declines in highly trained, healthy individuals and further supports these findings. Declines in physical abilities for masters athletes are gradual, which suggests that for many, the potential for participation in competitive athletics can persist well into the seventh decade of life. Recent studies indicate that health gains can be achieved with relatively low volumes of exercise. Indeed, the greatest benefit is seen when one "goes from doing nothing to doing something." Current data suggest that a cumulative total of 30 to 50 minutes of aerobic exercise a day performed 3 to 5 days a week and one set of resistance exercises targeting the major muscle groups twice a week can produce significant health benefits. The aerobic conditioning requirement need not be a formal or structured activity, but can be satisfied through regular participation in many common physical tasks (e.g., walking, gardening, housekeeping). Musculoskeletal injuries are a major cause of noncompliance with any exercise regimen and are especially debilitating for older individuals. Prompt recognition of injury and treatment that emphasizes alternative conditioning exercises and minimizes "downtime" are especially important. Orthopaedists should be aware of the pattern of musculoskeletal injuries seen in this population, so as to assist their patients in avoiding these problems.

Master's performance in the New York City Marathon 1983-1999.

BACKGROUND: Physical activity in older people is believed to slow down the natural aging process through its effects on disuse atrophy. OBJECTIVES: To show that elite master (age above 50) male and female athletes, as a group, have improved their running times over the last two decades at a greater rate than their younger counterparts. METHODS: Running time, age, and sex of all 415,000 runners in the New York City Marathon from 1983 to 1999 were examined using linear regression analysis. RESULTS: The number of master participants increased at a greater rate than their younger counterparts (p<0.05). Running times for the top 50 male and female finishers over the past two decades showed significantly greater improvement in the master groups than in the younger age groups (p<0.001). CONCLUSIONS: Participation in the New York City Marathon is increasing at a higher rate in the master groups than in other age groups. Male and female masters continued to improve running times at a greater rate than the younger athletes, whose performance levels have plateaued. This is the largest study to compare master athletic performance with younger counterparts and men with women.

Achilles tendon overuse injuries.

Overuse injuries of the Achilles tendon are common in patients engaging in recreational athletics. Achilles tendon overuse injuries exist as a spectrum of diseases ranging from inflammation of the paratendinous tissue (paratenonitis), to structural degeneration of the tendon (tendinosis), and finally tendon rupture. Factors known to predispose patients to Achilles tendinitis include inadequate stretching, training errors, mechanical malalignment of the lower extremities, rigid training surfaces, and occasionally systemic disease. Treatment of the patient with paratenonitis and tendinosis is initially conservative, emphasizing passive stretching, concentric and eccentric strengthening, correction of training errors, and restoration of normal limb alignment. Patients resistant to this protocol often exhibit a more advanced degree of tendon change. A high percentage of these patients can benefit from surgical debridement of the involved tendon, and they can anticipate successful return to recreational athletics. Steroid injections should not be routinely used in patients with Achilles tendinitis. Rupture of the Achilles tendon following intratendinous injection has been reported.