The effects of low-intensity ultrasound on medial collateral ligament healing in the rabbit model

BACKGROUND: Ruptured medial collateral ligaments are capable of healing over time, but biomechanical and biochemical properties remain inferior to normal tissue. Low-intensity ultrasound may improve healing. HYPOTHESIS: Medial collateral ligaments treated with ultrasound will demonstrate superior healing. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty-one late-adolescent male rabbits underwent bilateral ligament transection. One ligament from each rabbit received ultrasound treatment every other day for 6 total treatments. Contralateral ligaments received sham treatments. After 3 or 6 weeks, ligaments were evaluated biomechanically and assayed for collagen concentration and the relative proportions of types I and III collagen. RESULTS: Areas of sonicated specimens were significantly larger (10.6% +/- 4.90%) at 6 weeks. Ultimate load (39.5% +/- 17.0%), ultimate displacement (24.5% +/- 8.0%), and energy absorption (69.1% +/- 22.0%) were significantly higher for sonicated specimens at 6 weeks. No significant biomechanical differences were observed at 3 weeks. The relative proportion of type I collagen was significantly higher in sonicated ligaments at 3 weeks (8.61% +/- 4.0%) and 6 weeks (6.91% +/- 3.0%). No significant differences in collagen concentration were observed at either 3 or 6 weeks. CONCLUSION: Subtle improvement with ultrasound treatment may be apparent by 3 weeks after injury, suggested by increased proportion of type I collagen. Ultrasound appears to improve some structural properties and to modestly increase scar cross-sectional area and type I collagen present at 6 weeks after injury in this model. CLINICAL RELEVANCE: Ultrasound treatments after ligament injury may facilitate earlier return to activities and decrease risk of reinjury.     

Low-intensity pulsed ultrasound in the conservative treatment of pseudoarthrosis

AIM: The management of pseudarthrosis remains a challenge. Several in vivo animal and controlled clinical studies have demonstrated that low-intensity pulsed ultrasound can influence fracture healing. METHODS: A prospective longitudinal design was used. Fifteen patients (12 males and 3 females; mean age 35.5+/-12.9, range 18 to 60), all amateur athletes, under treatment for pseudarthrosis at different sites (average fracture age: of 336.6+/-60.1 days) were treated with a single 20 min daily application of low-intensity pulsed ultrasound (frequency 1.5 MHz and intensity 30 mW/cm2). All patients underwent clinical examination and plain radiography at the beginning of treatment and were followed up clinically and radiographically at 4, 8, 12, 16, 20 and 24 weeks until the fracture healed. RESULTS: All fractures healed with a mean healing time of 94.7+/-43.8 days. CONCLUSION: Low-intensity pulsed ultrasound is effective in the management of long standing fracture non-unions. Prospective randomized studies are needed to confirm the value of this modality of treatment.     

The effect of a nonsteroidal antiinflammatory drug on the healing of ligaments

Because of the increasing number of ligament sprains being treated with nonsteroidal antiinflammatory drugs (NSAIDs), this study was undertaken to document the effects of one such drug on ligament healing in an experimental setting. Male Sprague-Dawley rats weighing between 400 and 500 g were used to evaluate the effect of the NSAID piroxicam on the healing of an experimental injury to the medial collateral ligament (MCL). The following factors were varied in the experiments: dosage, days of treatment, and the day postinjury when treatment was begun. Piroxicam-treated rats were compared to placebo-treated rats in terms of the drug's effect on the mechanical strength of the healing ligament. The ligaments were mechanically tested in tension to failure at a constant deformation rate of 0.25 mm/sec on a materials testing machine. Administration of piroxicam on Days 1 to 6 postinjury resulted in a 42% increase in strength at Day 14 postinjury for the piroxicam-treated ligaments (P less than 0.01) when compared with the placebo-treated controls. Neither doubling nor halving the standard piroxicam dose significantly altered this increased healing strength. Biochemical analysis of collagen synthesis demonstrated a suggestive, although not statistically significant, increase in collagen synthesis and collagen content in the piroxicam-treated healing ligament. In separate experiments, piroxicam had no effect on the healed ligament at 21 days or on the strength of uninjured ligaments. In conclusion, piroxicam increased the early strength of healing ligaments in the rat when the drug was administered for short periods of time after injury.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of analgesic agents on the healing rat medial collateral ligament

BACKGROUND: Studies have suggested that some nonselective nonsteroidal anti-inflammatory drugs, including piroxicam, may improve ligament healing, whereas other nonsteroidal anti-inflammatory drugs, including ibuprofen and the cyclooxygenase-2 inhibitor celecoxib, may have no effect on the mechanical properties or may even deter the healing process. These results might reflect variations in cyclooxygenase enzyme selectivity by different drugs or, alternatively, may be related to their analgesic properties because it is generally accepted that early activity improves ligament healing. HYPOTHESIS: Nonselective nonsteroidal anti-inflammatory drugs improve ligament healing, whereas other analgesics provide lesser degrees of improvement, and cyclooxygenase-2 inhibitors are detrimental. STUDY DESIGN: Controlled laboratory study. METHODS: One hundred fifty-five Sprague-Dawley rats were divided into 7 treatment groups (piroxicam, naproxen, rofecoxib, butorphanol, 2 doses of acetaminophen, and control). The right medial collateral ligament of each rat was transected, and the drugs were administered postoperatively on days 1 to 6. On day 14, the rats were sacrificed, and mechanical testing was performed on the medial collateral ligament. RESULTS: The piroxicam group demonstrated significantly greater load to failure (27%) compared with the control. No significant differences were observed between other groups. CONCLUSIONS: Piroxicam improves ligament healing, but this effect cannot be attributed to all nonselective nonsteroidal anti-inflammatory drugs. Opiate analgesics, acetaminophen, and cyclooxygenase-2 inhibitors do not appear to categorically affect ligament healing. CLINICAL RELEVANCE: In the treatment of ligament injury, piroxicam may be a drug of choice.     

Low-intensity pulsed ultrasound accelerates bone-tendon junction healing: a partial patellectomy model in rabbits

BACKGROUND: Low-intensity pulsed ultrasound has been demonstrated to be beneficial for accelerating fracture healing, delayed union, nonunion, and soft tissue repair. HYPOTHESIS: Low-intensity pulsed ultrasound accelerates healing of bone-to-tendon junction repair by promoting osteogenesis and tissue remodeling at the healing junction. STUDY DESIGN: Controlled laboratory study. METHODS: Standard partial patellectomy was conducted in forty-eight 18-week-old rabbits divided into an ultrasound treatment and control group. Daily ultrasound was delivered 3 days after surgery onto the patellar tendon-patella healing junction and continuously up to weeks 2, 4, 8, and 16 postoperatively, when the patella-patellar tendon complexes were harvested for radiographic, histologic, and biomechanical evaluations. RESULTS: Radiographic measurements showed significantly more newly formed bone at the patellar tendon-patella healing junction in the ultrasound group compared with the controls at week 8 (4.91 +/- 2.74 mm(2) vs 2.50 +/- 1.83 mm(2), P < .05) and week 16 (7.22 +/- 2.34 mm(2) vs 4.61 +/- 2.22 mm(2), P < .05) after partial patellectomy. Histologically, the ultrasound group at weeks 8 and 16 showed improved tissue integration, characterized by trabecular bone expansion from the remaining patella and regeneration of fibrocartilage layer at the patellar tendon-patella healing junction. Fluorescence microscopy revealed earlier bone formation in the ultrasound group when compared with the controls at week 8 (1.78 +/- 0.32 vs 1.23 +/- 0.43, P < .01) and week 16 (2.10 +/- 0.67 vs 1.29 +/- 0.35, P < .01). Mechanical testing showed significantly higher failure load and ultimate strength in the ultrasound group (300.2 +/- 61.7 N and 7.10 +/- 1.29 MPa, respectively) as compared with controls (222.3 +/- 65.1 N and 5.26 +/- 1.36 MPa, respectively) at week 16 (P < .05 for both). CONCLUSION: Low-intensity pulsed ultrasound was able to accelerate bone-to-tendon junction repair. CLINICAL RELEVANCE: These results may help establish treatment efficacy for accelerating bone-to-tendon junction repair and facilitating earlier rehabilitation.     

Indomethacin and celecoxib impair rotator cuff tendon-to-bone healing

BACKGROUND: Nonsteroidal anti-inflammatory drugs are commonly prescribed after rotator cuff repair. These agents can impair bone formation, but no studies have evaluated their impact on tendon-to-bone healing. HYPOTHESIS: Traditional nonselective nonsteroidal anti-inflammatory drugs and cyclooxygenase-2-specific nonsteroidal anti-inflammatory drugs interfere with tendon-to-bone healing. STUDY DESIGN: Controlled laboratory study. METHODS: One hundred eighty Sprague-Dawley rats underwent acute rotator cuff repairs. Postoperatively, 60 rats received 14 days of celecoxib, a cyclooxygenase-2-specific nonsteroidal anti-inflammatory drug; 60 received indomethacin, a traditional nonselective nonsteroidal anti-inflammatory drug; and 60 received standard rat chow. Animals were sacrificed at 2, 4, and 8 weeks and evaluated by gross inspection, biomechanical testing, histologic analysis, and polarized light microscopy to quantify collagen formation and maturation. RESULTS: Five tendons completely failed to heal (4 celecoxib, 1 indomethacin). There were significantly lower failure loads in the celecoxib and indomethacin groups compared with the control groups at 2, 4, and 8 weeks (P < .001), with no significant difference between nonsteroidal anti-inflammatory drug groups. There were significant differences in collagen organization and maturation between the controls and both nonsteroidal anti-inflammatory drug groups at 4 and 8 weeks (P < .001). Controls demonstrated progressively increasing collagen organization during the course of the study (P < .001), whereas the nonsteroidal anti-inflammatory drug groups did not. CONCLUSION: Traditional and cyclooxygenase-2-specific nonsteroidal anti-inflammatory drugs significantly inhibited tendon-to-bone healing. This inhibition appears linked to cyclooxygenase-2. CLINICAL RELEVANCE: If the results of this study are verified in a larger animal model, the common practice of administering non-steroidal anti-inflammatory drugs after rotator cuff repair should be reconsidered.     

A cyclooxygenase-2 inhibitor impairs ligament healing in the rat.

Celecoxib was the first of a new class of nonsteroidal antiinflammatory drugs, the cyclooxygenase-2 (COX-2) specific inhibitors, marketed as having the same antiinflammatory efficacy as other nonsteroidal antiinflammatory drugs without their increased risk of gastrointestinal ulceration. Among the widest uses of nonsteroidal antiinflammatory drugs is in the treatment of acute soft tissue injuries. Although the benefits of celecoxib have been shown when used for rheumatoid arthritis and osteoarthritis, we are unaware of any studies concerning its effect on soft tissues. We used the surgically incised medial collateral ligament of male Sprague-Dawley rats as an experimental model for acute ligament injuries to investigate the effects of celecoxib on ligament healing. Fifty rats underwent surgical transection of the right medial collateral ligament. Postoperatively, half were given celecoxib for the first 6 days of recovery, the other half were not. The animals were sacrificed 14 days after the operation, and both the injured and uninjured medial collateral ligaments were mechanically tested to failure in tension. Celecoxib-treated/injured ligaments were found to have a 32% lower load to failure than untreated/injured ligaments. The results of this study do not support use of cyclooxygenase-2 specific inhibitors in the treatment of ligament injuries.     

The influence of a cyclooxygenase-1 inhibitor on injured and uninjured ligaments in the rat

BACKGROUND: Results of previous studies have shown that piroxicam, a cyclooxygenase-1-2 inhibitor, improves the strength of healing ligaments, whereas celecoxib, a cyclooxygenase-2 inhibitor, impairs ligament healing. HYPOTHESIS: The selective cyclooxygenase-1 inhibitor, SC-560, will improve the strength of ligament healing in an in vivo rat model. STUDY DESIGN: Controlled laboratory study. METHODS: Eighty male Sprague-Dawley rats underwent surgical transection of their medial collateral ligament. Postoperatively, 20 rats were given SC-560 at a low dose and 20 at a high dose for the first 6 days of recovery; the other 40 received a normal diet. The animals were sacrificed 14 days later, and both the injured and uninjured ligaments were mechanically tested to failure in tension. RESULTS: No significant differences in the strength of injured ligaments were found between drug and placebo treatment. However, the contralateral uninjured ligaments in the SC-560-treated groups failed at 27% higher energy and 22% higher load. CONCLUSIONS: This cyclooxygenase-1 inhibitor did not improve the strength of ligament healing but did significantly improve the strength of the contralateral uninjured ligament. Clinical Relevance: A pure cyclooxygenase-1 inhibitor is probably not indicated as a positive influence on ligament healing but might provide benefits in ligament injury prevention.     

The effects of increased tension on healing medical collateral ligaments

The effects of motion and increased levels of stress on the biomechanical, biochemical, and morphological properties of healing medial collateral ligaments were assessed in a rabbit model. In one group, the medial collateral ligament of the left hindlimb was transected and allowed to heal with cage activity for either 6 or 12 weeks. In another group, the transected ligaments were permitted to heal for 4 weeks and then were placed under increased stress by inserting a stainless steel pin perpendicularly underneath the healing medial collateral ligament. The animals were allowed cage activity for an additional 2 or 8 weeks. The varus-valgus joint laxity and the stress-strain properties of the medical collateral ligament substance were obtained. Further, the quantity of total collagen, amount and ratio of the collagen cross-links, dihydroxylysinonorleucine and hydroxylysinonorleucine, and the histologic appearance of the healing medical collateral ligaments were evaluated for all groups. At 6 weeks, knees with a transected medial collateral ligament were twice as lax as the controls. However, joints with the stainless steel tension pin had varus-valgus values approximately 1.5 times those of the controls. At 12 weeks, joints with increased stress were not statistically different from the controls. The group that had healing with increased stress for 12 weeks produced the highest stress for a given strain compared to any other group. Also, the total collagen levels and the ratio of dihydroxylysinonorleucine/hydroxylysinonorleucine were the closest to normal of any transected group. Finally, qualitative histologic improvements were seen, including a more longitudinal arrangement of collagen fibers and decreased cellularity.     

Imaging-guided needle puncture, infiltration and lavage of rotator cuff calcifications. Retrospective evaluation of 50 cases of treated periarthritis

PURPOSE: To evaluate mid term efficiency of imaging-guided needle puncture trituration and lavage (RPTL) in rotator cuff calcifications after failure of medical treatment. Materials and Methods. Fifty shoulders with rotator cuff calcifications (supra and infra-spinatus: 97%) from 42 patients, mean of 50.2 year old (M/F=10/32), were treated by RPTL. To establish a satisfaction score and potential undesirable effects, the follow-up was obtained by a telephone questionnaire after a median interval of 29.2 months. RESULTS: Eighty-eight percent of patients had excellent or very good results (cured: 62%, very improved: 26%). Four percent felt partially better and 8% failed but did not undergo surgery. No complication was noted. 41% suffered acute pain in the 24 hours following the procedure even though they were on nonsteroidal anti-inflammatory drug therapy (NSAID). CONCLUSION: These good results after more than two years support the promotion of this economical ambulatory treatment.     

Acute anterior cruciate ligament injury and repair reinforced with a biodegradable intraarticular ligament. Experimental studies

The anterior cruciate ligament was transected at the femoral origin in the knee joint of 12 dogs. The ligaments were repaired in a conventional manner and reinforced with a polyglycolic acid (PGA) ligament of braided Dexon (Davis & Geck, Pearl River, NJ) suture. At two weeks the PGA ligament was still providing excellent support for the healing anterior cruciate ligament, and there was no synovitis within the knee joint. After five weeks, initial healing had firmly attached the repaired anterior cruciate ligament to the femoral condyle, and the PGA ligament had resorbed without inflammatory or fibrotic response. All repaired and reinforced ligaments in this series healed and provided functional stability to the knee joints. Biomechanical testing of the repaired anterior cruciate ligaments at four months produced a maximum strength of 54.2 +/- 6.3 kgf. Sulfur-35 uptake showed viable active collagen-producing cells in the repaired ligaments four months postoperatively. Thus, the biodegradable PGA ligament reinforced and splinted successfully the repaired anterior cruciate ligament.     

Anterior cruciate ligament rupture after thermal treatment in a canine model

BACKGROUND: The use of radiofrequency energy to treat damaged anterior cruciate ligaments is gaining popularity. However, complete rupture of the ligament after treatment has been reported. PURPOSE: To evaluate the effect of thermal energy applied arthroscopically to normal, intact anterior cruciate ligaments in mature dogs. STUDY DESIGN: Controlled laboratory study. METHODS: Monopolar radiofrequency energy was applied to the normal anterior cruciate ligament of 1 knee in 18 dogs. The contralateral anterior cruciate ligament (also normal) was sham treated. Force-plate gait analysis was performed preoperatively and at 4, 8, 12, 16, 26, and 36 weeks after surgery. Anterior cruciate ligament rupture was detected by a sudden onset of nonweightbearing and a positive drawer sign. RESULTS: All treated ligaments ruptured approximately 55 days after surgery (mean, 55 days; standard error, 1.6). CONCLUSIONS: Although monopolar radiofrequency energy may have some potential in the treatment of lax anterior cruciate ligaments, in the application described here the result was a highly predictable deterioration and rupture of all treated anterior cruciate ligaments. CLINICAL RELEVANCE: On the basis of these findings, we strongly recommend that strict selection and application criteria be used when considering use of this modality on anterior cruciate ligaments that are stretched or partially disrupted, or both. Use of this modality should be followed by adherence to a highly conservative rehabilitation protocol.     

Type V collagen is increased during rabbit medial collateral ligament healing

To understand the reparative process of medial collateral ligament (MCL), fibrillar collagen and their relative ratios in healing MCL with anterior cruciate ligament (ACL) reconstruction were analyzed. Skeletally mature New Zealand white rabbits were subjected to a mop-end tear of MCL without repair with ACL reconstruction. Rabbits were killed 6 and 52 weeks after injury. Ligamentous tissues from the injury site and sham controls were soaked in 0.5 M acetic acid for 24 h, minced, and treated with pepsin to solubilize collagen. Pepsin solubilized about 80% of the total collagen as determined by hydroxyproline analysis of the pepsin residues. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of the solubilized collagen revealed presence of fibrillar collagen types I, III, and V. Densitometric scanning of the protein bands corresponding to types I, III, and V collagen indicated that in sham controls types III and V collagen represented about 8% and 12%, respectively, of the type I collagen whereas the healed MCL ligaments at 6 weeks showed significant increase in type III and V collagen to about 19% and 24%, respectively. By 52 weeks type III collagen in the healed MCL had returned to that of sham controls while type V collagen remained elevated at approximately 18%. These data suggest that presence of type V collagen in high concentration in healing ligaments may have an influence on collagen fibril diameters seen in healed ligament and should be included in the analysis when evaluating ligament healing.     

Gene transfer with echo-enhanced contrast agents: comparison between Albunex, Optison, and Levovist in mice--initial results

PURPOSE: To determine if commercially available echo-enhanced microbubble contrast agents could be used to increase gene transfection efficiency by means of relatively low-intensity ultrasound-mediated microbubble destruction in skeletal muscles. MATERIALS AND METHODS: Three types of ultrasound microbubble contrast agents (0.01 mL of albumin [Albunex] and human albumin [Optison] and 10 mg/mL of SH U 508A [Levovist]) were each separately mixed with the reporter plasmid DNA (25 microg) encoding green fluorescent protein (GFP) prior to intramuscular injection into the quadriceps muscle of a mouse thigh bilaterally (seven mice per contrast agent). One of the muscle sites that was injected with plasmid DNA was irradiated with low-intensity therapeutic ultrasound (1 MHz) at an intensity of 2.0 W/cm2 for 2 minutes. Mice were sacrificed 7 days after ultrasound treatment for gene expression assay. The number of GFP-expressing muscle fibers was counted. Statistical significance was determined with a two-tailed Student t test. P <.05 was considered to indicate statistically significant difference. RESULTS: Muscle tissue exposed to ultrasound with air-filled Albunex or Levovist microbubbles revealed no difference in the number of GFP-expressing muscle fibers compared with the control non-ultrasound-exposed muscle. Albumin-coated octafluoropropane gas-filled Optison microbubbles showed a 10-fold increase in the number of GFP-expressing fibers (P <.05). CONCLUSION: Low-intensity ultrasound with echo-enhanced Optison induced efficient gene transfer unlike that with Albunex or Levovist.     

Indirect MR arthrography of the knee: effects of low-intensity ultrasound on the diffusion rate of intravenously administered Gd-DTPA in healthy volunteers

RATIONALE AND OBJECTIVES: To evaluate whether application of low-intensity ultrasound may increase the diffusion rate of intravenously administered gadopentetate dimeglumine (Gd-DTPA) and increase the amount of joint fluid on indirect magnetic resonance (MR) arthrography. METHODS: Conventional MR imaging, indirect MR arthrography, and power Doppler ultrasonography were performed before and after application of therapeutic, pulsed low-intensity ultrasound in 12 asymptomatic knees of 12 volunteers. Intra-articular diffusion of intravenously administered Gd-DTPA as measured by signal intensity differences of the intra-articular joint fluid before and after ultrasound treatment was assessed. In addition, the amount of joint fluid was rated, and differences in synovial blood flow as evidenced by power Doppler ultrasonography were noted. RESULTS: All volunteers tolerated well the application of therapeutic low-intensity ultrasound. A significant increase in intra-articular diffusion of intravenously administered Gd-DTPA was noted in all knees, and an increase in joint fluid was noted in 8 of 12 knees (66.6%). Detection of power Doppler flow signal in the synovium of the suprapatellar recess was possible in one instance at posttreatment exam. CONCLUSIONS: Use of pulsed, therapeutic low-intensity ultrasound may increase the diffusion rate of intravenously administered Gd-DTPA and may induce joint effusion.     

Nonsteroidal anti-inflammatory drugs and acetaminophen in the treatment of an acute muscle injury

BACKGROUND: Nonsteroidal anti-inflammatory drugs are frequently used to treat muscle injuries in athletes. It is not known whether the anti-inflammatory effects of these drugs are important or whether their effectiveness is a result of their central analgesic effect. HYPOTHESIS: The effects of nonsteroidal anti-inflammatory drugs are no different than the effects of an analgesic (acetaminophen) without anti-inflammatory action in an experimental, acute muscle contusion model. STUDY DESIGN: Controlled animal study. METHODS: A standardized, unilateral, nonpenetrating injury was created to the tibialis anterior muscle of 96 adult male mice. Four treatment groups were used: group 1, placebo treatment; group 2, treatment with rofecoxib, a nonsteroidal anti-inflammatory drug with cyclooxygenase-2 selectivity, and treatment after the injury; group 3, rofecoxib treatment starting 24 hours before the injury; and group 4, acetaminophen treatment after the injury. The muscle and the contralateral normal muscle were evaluated at 2, 5, and 7 days after injury by grading of gait, wet weight as a measure of edema, and histologic evaluation. RESULTS: Group 1 had significantly more gait disturbances at day 2 than all other groups (P < .05). No differences were found at days 5 and 7. Wet weights showed an increase at day 2 in group 1 (P < .01). Again, no differences were found at days 5 and 7. Histology revealed similar inflammatory changes at day 2 in all groups, with regeneration of muscle fibers at days 5 and 7. CONCLUSIONS: The results indicate that rofecoxib as a nonsteroidal anti-inflammatory drug and acetaminophen as a non-nonsteroidal anti-inflammatory drug analgesic have similar effects. The lack of differences in wet weights and histology suggests that the anti-inflammatory effects of rofecoxib are not an important feature of its action. CLINICAL RELEVANCE: The routine use of nonsteroidal anti-inflammatory drugs in muscle injuries may need to be critically evaluated because low-cost and low-risk analgesics may be just as effective.     

The effects of HIIT compared to MICT on endothelial function and hemodynamics in postmenopausal females

ObjectiveThe study was designed to investigate the role of exercise in ameliorating endothelial function and hemodynamics in postmenopausal females, and compare the different effects of high-intensity interval training and moderate-intensity continuous training by equalizing training load.DesignRandomized controlled trial.MethodsFirst intervention, 30 volunteers were randomized into low-intensity continuous training group or sedentary group. The low-intensity continuous training group was assigned to a 12-week training program at an intensity of 40% maximum heart reserve. The second intervention was an 8-week training program, in which 18 individuals were randomly placed either in the moderate-intensity continuous training or high-intensity interval training group. Flow-mediated dilatation, blood samples, carotid ultrasound, and wall shear stress were collected before, during, and after the interventions.ResultsFlow-mediated dilatation was significantly increased in low-intensity continuous training group (p = 0.02), moderate-intensity continuous training (p = 0.023) and high-intensity interval training (p < 0.01) groups, with a time × group interaction for %FMD (F_{2, 32} = 4.421, p = 0.02), and a main effect of time (F_{2, 32} = 27.658, p < 0.001). Nitric oxide in low-intensity continuous training increased remarkably (p = 0.024) and was higher than that in control (p = 0.011). High-intensity interval training (p < 0.001) and moderate-intensity continuous training (p < 0.001) increased nitric oxide. Endothelin was decreased only in high-intensity interval training group (p = 0.049). All the training programs had a remarkable impact on wall shear stress.ConclusionsLow-intensity continuous training can improve endothelial function in postmenopausal females. High-intensity interval training could be an effective training regimen for improving endothelial function than moderate-intensity continuous training in postmenopausal females.     

A new direction for ultrasound therapy in sports medicine

Ultrasound therapy is a widely available and frequently used electrophysical agent in sports medicine. However, systematic reviews and meta-analyses have repeatedly concluded that there is insufficient evidence to support a beneficial effect of ultrasound at dosages currently being introduced clinically. Consequently, the role of ultrasound in sports medicine is in question. This does not mean that ultrasound should be discarded as a therapeutic modality. However, it does mean that we may need to look in a new direction to explore potential benefits. A new direction for ultrasound therapy has been revealed by recent research demonstrating a beneficial effect of ultrasound on injured bone. During fresh fracture repair, ultrasound reduced healing times by between 30 and 38%. When applied to non-united fractures, it stimulated union in 86% of cases. These benefits were generated using low-intensity (<0.1 W/cm(2)) pulsed ultrasound (LIPUS), a dose alternative to that traditionally used in sports medicine. Although currently developed for the intervention of bone injuries, LIPUS has the potential to be used on tissues and conditions more commonly encountered in sports medicine. These include injuries to ligament, tendon, muscle and cartilage. This review discusses the effect of LIPUS on bone fractures, the dosages introduced and the postulated mechanisms of action. It concludes by discussing the relevance of these latest findings to sports medicine and how this evidence of a beneficial clinical effect may be implemented to intervene in sporting injuries to bone and other tissues. The aim of the paper is to highlight this latest direction in ultrasound therapy and stimulate new lines of research into the efficacy of ultrasound in sports medicine. In time this may lead to accelerated recovery from injury and subsequent earlier return to activity.     

非甾体类药预防性治疗肘部外伤术后并发骨化性肌炎

目的 探讨非甾体类药预防性治疗肘部外伤术后并发骨化性肌炎的疗效.方法 对比研究我院2007年5月～2010年2月肘部外伤术后服用非甾体类药物塞来昔布(63例,药物治疗组)和未服用塞来昔布(75例,对照组)患者临床资料.药物治疗组从术后第1天开始口服塞来昔布,200mg/次,1次/d,应用2周.观察术后6周、3个月、1年...     

Does nitric oxide help explain the differential healing capacity of the anterior cruciate, posterior cruciate, and medial collateral ligaments?

This study compared the ability of rabbit medial collateral ligament, posterior cruciate ligament, and anterior cruciate ligament tissue to synthesize nitric oxide, and determined its effects on matrix synthesis, an important component of ligament repair. It is not known whether ligament cells can produce nitric oxide and, if so, whether it influences healing of ligament injuries. The anterior cruciate and posterior cruciate ligament tissue produced large amounts of nitric oxide in response to the inflammatory cytokine interleukin-1. Medial collateral ligament, in contrast, produced only modest amounts of nitric oxide. Furthermore, anterior cruciate ligament and, to some degree, posterior cruciate ligament synthesized nitric oxide spontaneously in culture, whereas medial collateral ligament never did so. When nitric oxide was supplied to these tissues, it strongly inhibited collagen synthesis by the two cruciate ligaments, but had little effect on collagen synthesis by the medial collateral ligament. Endogenously synthesized nitric oxide was also able to inhibit collagen synthesis as well as proteoglycan synthesis by the two cruciate ligaments, but had little effect on matrix synthesis by the medial collateral ligament. We propose a novel hypothesis, based on nitric oxide production and matrix synthesis, that may help explain why the two cruciate ligaments have such limited healing capacity compared with the medial collateral ligament.