The American journal of sports medicine
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Although radiofrequency energy can smooth and contour cartilage surface, it has deleterious effects on chondrocyte viability. ⋯ Less chondrocyte death would permit increased use of thermal chondroplasty.
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Randomized Controlled Trial Clinical Trial
Motor control of the vastus medialis oblique and vastus lateralis muscles is disrupted during eccentric contractions in subjects with patellofemoral pain.
Inappropriate control of the vastus medialis oblique and vastus lateralis muscles by the central nervous system can contribute to maltracking of the patella. ⋯ The findings suggest the clinical importance of determining whether altered activation patterns are sensitive to rehabilitation, and, if so, if subjective reports of knee joint pain and function parallel changes in the activation patterns as a result of rehabilitation.
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Anterior cruciate ligament injury rates are reported to be two to eight times higher in women than in men within the same sport. Because the menstrual cycle with its monthly hormonal fluctuations is one of the most basic differences between men and women, we investigated the association between the distribution of confirmed anterior cruciate ligament tears and menstrual cycle phase. Sixty-nine female athletes who sustained an acute anterior cruciate ligament injury were studied within 24 hours of injury at four centers. ⋯ Urine samples were collected to validate menstrual cycle phase by measurement of estrogen, progesterone, and luteinizing hormone metabolites and creatinine levels at the time of the anterior cruciate ligament tear. Results from the hormone assays indicate that the women had a significantly greater than expected percentage of anterior cruciate ligament injuries during midcycle (ovulatory phase) and a less than expected percentage of those injuries during the luteal phase of the menstrual cycle. Oral contraceptive use diminished the significant association between anterior cruciate ligament tear distribution and the ovulatory phase.
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The purpose of this study was to investigate the incidence and prevalence of injuries among elite weight lifters and power lifters, with a special focus on shoulder injuries and possible injury-provoking exercises. In 1995, a questionnaire was administered to 110 male and female elite lifters to evaluate injuries and training characteristics. A follow-up of the athletes from 1995 was conducted in 2000, and a new 2000 elite group was also queried. ⋯ There was a difference in injury pattern between weight lifters, who mostly sustained low back and knee injuries, and power lifters, in whom shoulder injuries were most common. No correlation was found between shoulder injuries and any specific exercise. Although the total injury rate was the same during the two periods of study, the rate of shoulder injuries had increased.
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Comparative Study
Thermal chondroplasty of chondromalacic human cartilage. An ex vivo comparison of bipolar and monopolar radiofrequency devices.
We compared the effects of treatment with bipolar and monopolar radiofrequency energy on 30 osteochondral sections harvested from 22 patients with spontaneously occurring chondromalacia who were undergoing knee arthroplasty. Specimens with chondromalacia grades 2 or 3 were randomly assigned to one of two bipolar or one monopolar treatment groups. All samples were marked and mounted on a jig to allow simulation of an arthroscopic surgical procedure with a flow rate of 100 ml/min of a balanced electrolyte solution at 22 degrees C. ⋯ The bipolar devices produced significantly greater depths of chondrocyte death (2228 +/- 1003 microm and 2810 +/- 517 microm) than did the monopolar device (737 +/- 391 microm). The bipolar devices caused cell death to subchondral bone significantly more often (13 of 20 specimens) than did the monopolar device (0 of 10 specimens). Caution should be used in treating fibrillated cartilage with radiofrequency energy, particularly with the bipolar devices tested.