Effect of ultrasound on acute inflammation of transected medial collateral ligaments11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the author(s) or on any organization with which the author(s) is are associated

Role of low-intensity pulsed ultrasound in regulating macrophage polarization to accelerate tendon-bone interface repair

Low-intensity pulsed ultrasound (LIPUS) has been proven to accelerate the healing of the tendon-bone interface (TBI), and macrophages are considered to play an important regulatory role. This study was designed to explore the polarization of macrophages during treatment of TBI injury with LIPUS. In a rat model of rotator cuff tear, LIPUS or mock sonication (controls) was administered from 1 week postoperatively. The supraspinatus-supraspinatus tendon-humerus complexes were harvested for further evaluation at different time points for measures such as new bone formation, TBI maturity, ultimate failure load and stiffness, and types of macrophages. In vitro, bone marrow-derived macrophages were cultured, and polarization was identified after stimulation with or without LIPUS (the LIPUS or control groups, respectively). Two weeks posttreatment, the LIPUS group showed higher bone volume/total volume ratios and better TBI maturity scores. Six weeks posttreatment, the failure load of the LIPUS group was significantly higher than that of the control group. LIPUS also accelerated initial inflammatory macrophage accumulation and facilitated anti-inflammatory macrophage polarization (M2) in the late period. In the in vitro macrophage polarization model, the LIPUS group showed a higher proportion of M2 macrophages and mRNA expression of anti-inflammatory genes than the control group, while there was no significant difference in the proinflammatory macrophages between the two groups. Our observations revealed that macrophage polarization may be a potential mechanism of LIPUS treatment for TBI repair.

Initiation Timing of Low-Intensity Pulsed Ultrasound Stimulation for Tendon-Bone Healing in a Rabbit Model

BACKGROUND

Low-intensity pulsed ultrasound stimulation (LIPUS) has been proven to be a beneficial biophysical therapy for tendon-bone (T-B) healing. However, the optimal time to initiate LIPUS treatment has not been determined yet. LIPUS initiated at different stages of the inflammatory phase may profoundly affect T-B healing.

PURPOSE

An established rabbit model was used to preliminarily investigate the effect of LIPUS initiation timing on T-B healing.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 112 mature rabbits that underwent partial patellectomy were randomly assigned to 4 groups: daily mock sonication (control group) and daily ultrasonication started immediately postoperatively (immediate group), on postoperative day 7 (7-day delayed group), or on postoperative day 14 (14-day delayed group). Peripheral leukocyte counts at the inflammatory phase were used to assess postoperative inflammation. The rabbits were sacrificed at 8 or 16 weeks postoperatively for microarchitectural, histological, and mechanical evaluations of the patella-patellar tendon (PPT) junction.

RESULTS

The biomechanical properties of the PPT junction were significantly improved in the LIPUS-treated groups. Significantly higher ultimate strength and stiffness were seen in the 7-day delayed group compared with the other groups at 8 weeks postoperatively (P < .05 for all). Newly formed bone expansion from the remaining patella in the ultrasonic treatment groups was significantly increased and remodeled compared with the control group. Micro-computed tomography analysis showed that the 7-day delayed group had significantly more bone volume and bone mineral content at the interface as compared with the other groups at 8 weeks postoperatively (P < .05 for all). Histologically, the ultrasonic treatment groups exhibited a significantly better PPT junction, as shown by more formation and remodeling of the fibrocartilage layer and newly formed bone. Additionally, peripheral leukocyte counts displayed a significant increase from postoperative day 1 to day 3 in the immediate group as compared with the other groups. Furthermore, postoperative hydrarthrosis was more likely in the immediate group.

CONCLUSION

LIPUS started at postoperative day 7 had a more prominent effect on T-B healing compared with the other treatment regimens in this study.

CLINICAL RELEVANCE

The findings of the study may help optimize the initiation timing of LIPUS for T-B healing.

Wound Healing Devices Brief Vignettes

Significance: The demand for wound care therapies is increasing. New wound care products and devices are marketed at a dizzying rate. Practitioners must make informed decisions about the use of medical devices for wound healing therapy. This paper provides updated evidence and recommendations based on a review of recent publications. Recent Advances: The published literature on the use of medical devices for wound healing continues to support the use of hyperbaric oxygen therapy, negative pressure wound therapy, and most recently electrical stimulation. Critical Issue: To inform wound healing practitioners of the evidence for or against the use of medical devices for wound healing. This information will aid the practitioner in deciding which technology should be accepted or rejected for clinical use. Future Directions: To produce high quality, randomized controlled trials or acquire outcome-based registry databases to further test and improve the knowledge base as it relates to the use of medical devices in wound care.

Efficacy of therapeutic ultrasound in pain and joint mobility in whiplash traumatic acute and subacute phases

To determine if ultrasound (US) is effective in reducing pain and mobility limitation in the treatment of traumatic cervical sprain, we performed an experimental study. The sample comprised 54 diagnosed subjects with a mean age of 36.54 y (standard deviation = 12.245), assigned by simple random selection to an experimental group with ultrasound treatment and a control group with placebo ultrasound. Treatment consisted of 10 sessions of an ultrasound treatment protocol, followed by 15 sessions of a protocol identical for both groups without ultrasound. The variables assessed were pain and joint mobility. There was no significant difference (p > 0.05) between groups in the first 10 sessions of treatment. However, there was a statistically significant difference (p < 0.05) between groups on the pain variable, 20 days after completion of the US. High-active ultrasound treatment is more effective than placebo in reducing pain.

Effect of therapeutic ultrasound on folliculogenesis, angiogenesis and apoptosis after heterotopic mouse ovarian transplantation

One of the challenges in ovarian transplantation is ischemia-reperfusion damage. When transitional tissue faces an acute and critical condition in terms of blood supply (immediately after organ transplantation), treatment with low-intensity pulsed ultrasound (LIPUS) seems to be very beneficial. The aim of this study was to evaluate the effects of ultrasound therapy on heterotopic transplanted mouse ovarian tissue. Adult female Naval Medical Research Institute mice were divided into three groups. In the experimental groups, the transplanted ovary was exposed 5 min daily to ultrasound with an intensity of 0.3 W/cm(2), frequency of 3 MHz and pulse mode of 1:4. The grafted ovaries were assessed with the usual histology and immunohistochemistry techniques. Results indicate that more CD31 angiogenic factor was expressed in irradiated animals than in control animals, and ultrasound therapy resulted in better follicular preservation, especially after 14 d. In conclusion, therapeutic ultrasound may accelerate and increase re-angiogenesis and can help to promote ovarian follicular growth.

Usage Patterns and Beliefs about Therapeutic Ultrasound by Canadian Physical Therapists: An Exploratory Population-Based Cross-Sectional Survey

PURPOSE

To explore the frequency and patterns of ultrasound (US) usage among physical therapists, to describe the most common purposes for using therapeutic US, and to investigate beliefs about therapeutic US.

METHODS

A survey was sent to 95% of physical therapists licensed to practise in the province of Alberta, Canada.

RESULTS

Of 2,269 physical therapists to whom email invitations were sent, 438 (19.3%) provided full responses. RESULTS indicate that US is still frequently incorporated into treatment regimens and is widely believed to be effective; however, the study also found a decrease in US usage over the past 15 years. While physical therapists recognize the lack of evidence for the effectiveness of US, many consider it clinically useful. Physical therapists using US rely largely on their clinical experience when making decisions about its use, but this depends on level of education: clinicians with an MScPT degree tended to base more of their US decisions on research evidence, likely because of the increasing emphasis on research evidence in graduate education.

CONCLUSIONS

Despite the questionable effectiveness of therapeutic US, physical therapists still commonly use this treatment modality, largely because of a belief that US is clinically useful. However, US usage has decreased over the past 15 years.

High-intensity focused ultrasound for the treatment of allergic rhinitis using nasal endoscopy

The present study aimed to observe the therapeutic effect of high-intensity focused ultrasound for the treatment of allergic rhinitis (AR) using nasal endoscopy. A total of 72 patients with perennial AR received treatment using the CZB ultrasonic therapeutic instrument with nasal endoscopy. A scoring method was adopted for evaluation of effectiveness according to the AR therapeutic principles and recommendations described in Allergic Rhinitis and its Impact on Asthma (ARIA) in 2001. The patients were followed up between 2 and 6 months after treatment. The excellence rate was 34.7% (25/72), the effective rate was 62.5% (45/72) and the ineffective rate was 2.8% (2/72). The total effective rate reached 97.2% high (70/72). Endoscopic high-intensity focused ultrasound for the treatment of AR is a non-invasive method and has the advantages of simple manipulation, a short course, high safety and a clear short-term effect.

Osteoarthritis and rheumatoid arthritis: conservative therapeutic management

Hand therapists need to understand the basic science behind the therapy they carry out and the current evidence to make the best treatment decisions. The purpose of this article was to review current conservative therapeutic management of patients with rheumatoid arthritis (RA) or osteoarthritis (OA) of the hand. Treatment interventions such as orthotics, exercise, joint protection, modalities, and adaptive equipment are discussed from a basic science and evidence-based practice perspective.

Overview of ultrasound usage trends in orthopedic and sports physiotherapy

BACKGROUND

The purpose of this study is to examine current beliefs about the use, the clinical importance, the theoretical fundamentals and the utilization criteria of therapeutic ultrasound (TUS) among physical therapists on the clinical practice in orthopedic and sports physiotherapy in Brazil.

METHODS

A brief survey was developed based on previous studies and was sent to 55 physical therapists with advanced competency in orthopedics and sports physiotherapy. The questions addressed general topics about the professional profile and ultrasound usage and dosage.

RESULTS

Our data show the wide availability and frequent use of TUS in this sample of physical therapists. TUS is used in distinct musculoskeletal injuries and/or disorders in both acute and chronic conditions. Muscles, tendons and ligaments represented the major structures where TUS is used. Questions on the basic theory of TUS demonstrated a lack of knowledge of the ultrasound physiological effects as well as its interaction with biological tissues and TUS absolute contraindication.

CONCLUSION

A Brazilian profile about the US usage and dosage in orthopedic and sports physiotherapy is presented and highlights the need for a continuous upgrading process and further research into its effects.

Low-frequency ultrasound (20-40 kHz) as an adjunctive therapy for chronic wound healing: a systematic review of the literature and meta-analysis of eight randomized controlled trials

Ultrasound as a therapeutic agent in chronic wound healing has been studied extensively. This systematic review and meta-analysis specifically examines low-frequency (20-30 kHz) ultrasound delivered at either low or high intensity. The objective of this review was to determine whether low-frequency ultrasound used as an adjunctive therapy improves the outcomes of complete healing and reduction of size of chronic lower limb wounds. PubMed, Cochrane/CENTRAL, technical assessment, relevant wound-related journals, and clinical guidelines were searched along with contacting manufacturers and authors of relevant randomized controlled trials were completed. Searches focused on the use of low-frequency ultrasound in randomized controlled trials. Data were collected via a data collection form and was adjudicated independently via coauthors. Meta-analyses and heterogeneity checks were performed using Mantel-Haenszel and inverse variance (fixed and random effects) statistical methods on studies with similar outcomes (complete healing and percent wound area reduction) over similar time periods. Single study results were reported via the statistical methods used in the study. Eight randomized controlled trials were identified. Results demonstrated that early healing (at ≤5 months) in patients with venous stasis and diabetic foot ulcers was favorably influenced by both high- and low-intensity ultrasound delivered at a low frequency-either via contact or noncontact techniques. However, the quality of the data may be suspect, especially for low-frequency low-intensity noncontact ultrasound because of significant biases. In patients presenting with either venous stasis or diabetic foot ulcers (Wagner classification 1-3), early healing appears to be facilitated by either low-frequency low-intensity noncontact ultrasound or low-frequency high-intensity contact ultrasound.

Absorption of hydrocortisone acetate in human connective tissue using phonophoresis

Background:

Therapeutic ultrasound to drive medication (phonophoresis) has been a mainstay in physical therapy. The most common drug used in phonophoresis is hydrocortisone acetate (HA). A number of studies have been done examining phonophoresis in the delivery of HA through the skin to underlying tissues; however, a study has never been done examining the absorption of HA using phonophoresis on human connective tissue.

Hypothesis:

Phonophoresis will facilitate the transmission of HA in human connective tissue.

Study Design:

Randomized controlled study.

Methods:

Twenty-one patients undergoing anterior cruciate ligament reconstruction surgery were randomly assigned to either a sham or true phonophoresis treatment group. The latter group received 6 minutes of 10% HA ultrasound at a point consistent with the gastrocnemius slip of the semitendinosis tendon (treatment site). The sham group received 6 minutes of 10% HA ultrasound to the same area, but the ultrasound was not turned on. The slip and a sample of the distal attachment of the tendon (control) were removed. Samples were analyzed for HA levels.

Results:

Although the mean and median levels of HA found at the treatment site were greater than those of the control site (means, 34.1 vs 22.9 parts per billion; medians, 7 vs 0 parts per billion), the levels of HA found at the treatment site were not significantly greater than those at the control site (P = 0.15). There were no statistically significant differences between the true and sham phonophoresis groups in HA levels (P = 0.80) nor in age, sex, or skin thickness.

Conclusion:

Phonophoresis does not appear to facilitate the absorption of HA in connective tissue when compared with simple absorption (sham).

Clinical Relevance:

Phonophoresis does not appear to enhance the transmission of HA in human connective tissue; therefore, use of phonophoresis should be reconsidered in inflammatory conditions.

Comparing therapeutic ultrasound with microamperage stimulation therapy for improving the strength of Achilles tendon repair

In exploring the effects of therapeutic ultrasound (US) and microamperage stimulation (MAS) on the biomechanical performance of repairing Achilles tendon in rats, 35 Sprague-Dawley rats receiving surgically induced injury to their right medial Achilles tendon were studied. The rats were divided into four groups of low-dose US (group 1, n = 10), high-dose US (group 2, n = 11), MAS (group 3, n = 7), and control (group 4, n = 7). The treatment started on day 6 after injury. Groups 1 and 2 received 4 min of daily US treatment at 1.0 and 2.0 W/cm(2), respectively. Group 3 received 30 min of daily transcutaneous MAS treatment. Group 4 received 30 min of daily sham MAS treatment. On day 31, the Achilles tendons were mechanically tested. Data on the right side were normalized to the left side and analyzed with MANOVA with α = 0.05. Results of MANOVA was significant and post hoc tests revealed that the normalized strength of groups 1, 2, and 3 were higher than that of group 4 (p = 0.003) but no significant difference was found among the treatment groups. The ANOVA result of the normalized load relaxation and stiffness was p = 0.06 and p = 0.07, respectively. These findings suggested that both low/high doses of US and MAS therapies could improve the strength of Achilles tendon but in view of its short treatment time, US is considered to be more efficient than MAS for improving the strength of the repairing tendons.

The effectiveness of therapeutic ultrasound for musculoskeletal conditions of the lower limb: A literature review

BACKGROUND

Ultrasound is suggested as one of the treatment options available for soft tissue musculoskeletal conditions of the lower limb and to this end, the objective was to review the literature and evaluate the effectiveness of therapeutic ultrasound for musculoskeletal conditions of the lower limb.

METHODS

A search of the literature published between 1975 and February 2009 was carried out. All studies that fulfilled the inclusion criteria were quality assessed and scored using the Critical Appraisal Skills Programme (CASP) appraisal tool [1] for randomised controlled trials.

RESULTS

Ten studies out of a possible fifteen were included in the review. Only one trial was considered to be high quality (score 16+), three medium quality trials (score 11-15) were identified and six trials were considered to be low or poor quality (score≤10). None of the six placebo-controlled trials found any statistically significant differences between true and sham ultrasound therapy.

CONCLUSION

This literature review found that there is currently no high quality evidence available to suggest that therapeutic ultrasound is effective for musculoskeletal conditions of the lower limb.

Physiotherapy and low back pain in the injured worker: an examination of current practice during the subacute phase of healing

PURPOSE

To describe current physiotherapy practice for injured workers with subacute low back pain (SA-LBP).

METHOD

A chart audit of discharged workers was conducted over three episodes of care: 4-6 weeks (T1), 6-8 weeks (T2), and 8-10 weeks (T3) post-injury. The prevalence and reproducibility of parameters for common interventions were calculated as the percentage of active charts over time. Focus groups were used to validate audit results and deepen our understanding of practice.

RESULTS

In all, 164 charts were audited. The most prevalent interventions were (1) for manual therapy, joint mobilization and traction; (2) for electrophysical agents (EPAs), heat, ultrasound, and interferential therapy; and (3) for exercise, core stabilization exercises. Transcript analyses revealed that participants viewed injured workers with SA-LBP in a positive light, emphasized the importance of physiotherapy, and discussed SA-LBP in five themes: time frame, non-specific diagnosis, mixed client outlook, change in pain presentation, and the transition from a passive to a more active treatment approach.

CONCLUSIONS

The pattern of decreasing passive and increasing active interventions is consistent with the focus-group participants' description of how they approach treatment of clients with SA-LBP. Also noted was a higher prevalence of interventions poorly supported by evidence and lower prevalence of interventions well supported by evidence.

Effects of phonophoresis with Arnica montana onto acute inflammatory process in rat skeletal muscles: an experimental study

This study aimed at verifying the effects of phonophoresis associated with Arnica montana on the acute phase of an inflammatory muscle lesion. Forty Wistar male rats (300+/-50 g), of which the Tibialis Anterior muscle was surgically lesioned, were divided into four groups (n=10 each): control group received no treatment; the ultrasound group (US) was treated in pulsed mode with 1-MHz frequency, 0.5 W/cm(2) intensity (spatial and temporal average - SATA), duty cycle of 1:2 (2 ms on, 4 ms off, 50%), time of application 3 min per session, one session per day, for 3 days; the phonophoresis or ultrasound plus arnica (US+A) group was treated with arnica with the same US parameters plus arnica gel; and the arnica group (A) was submitted to massage with arnica gel, also for 3 min, once a day, for 3 days. Treatment started 24h after the surgical lesion. On the 4th day after lesion creation, animals were sacrificed and sections of the lesioned, inflamed muscle were removed for quantitative (mononuclear and polymorphonuclear cell count) and qualitative histological analysis. Collected data from the 4 groups were statistically analyzed and the significance level set at p<0.05. Results show higher mononuclear cell density in all three treated groups with no significant difference between them, but values were significantly different (p<0.0001) when compared to control group's. As to polymorphonuclear cell density, significant differences were found between control group (p=0.0134) and US, US+A and A groups; the arnica group presented lesser density of polymorphonuclear cells when compared (p=0.0134) to the other groups. No significant difference was found between US and US+A groups. While the massage with arnica gel proved to be an effective anti-inflammatory on acute muscle lesion in topic use, these results point to ineffectiveness of Arnica montana phonophoresis, US having seemingly checked or minimized its anti-inflammatory effect.

Ultrasound phonophoresis of panax notoginseng improves the strength of repairing ligament: a rat model

This study examined the phonophoretic effect of a therapeutic ultrasound coupled with a Panax notoginseng (PN) gel and compared it with a therapeutic ultrasound alone for medial collateral ligament repair in rats. Twenty mature male Sprague-Dawley rats receiving surgical transection to the left medial collateral ligament (MCL) were divided randomly into three groups: ultrasound (US, n = 7), ultrasound with PN coupling gel (PNUS, n = 7) and control (n = 6). The treatments started on day 3 after surgery for six days per week over a two-week period. The US group received 4 min of pulsed ultrasound (1 MHz) at the intensity of 0.5W/cm(2) with a normal ultrasonic coupling gel. The PNUS group received the same ultrasound treatment, but with a coupling gel that contained PN extract. The control group received a placebo ultrasound treatment similar to the other two groups. On day 17, the ligaments were mechanically tested for load-relaxation, stiffness and ultimate tensile strength (UTS). Values of the left side were normalized against that of the right side of each animal for analysis. Results revealed significantly higher normalized stiffness (p = 0.009) and UTS (p = 0.022) in the PNUS group than the other two groups, but insignificant difference in load-relaxation among all groups. This study reveals a positive ultrasonic phonophoretic effect of Panax notoginseng extract for improving the strength of ligament repair than ultrasound therapy alone.

Ultrasound in contemporary physiotherapy practice

The use of therapeutic ultrasound as an element of physiotherapy practice is well established, but the nature of that practice has changed significantly over the last 20 years. This paper aims to review the rationale and range of applications for which this modality is employed in current practice. Whereas in the past, its primary use was as a thermal modality, it is argued that currently, it is the 'non-thermal' aspects of the intervention that are most commonly employed. The predominant use of therapeutic ultrasound is in relation to tissue repair and soft tissue lesion management, where the evidence would support its application in the inflammatory, proliferative and remodelling phases. The clinical outcomes appear to be dose dependent, and whilst this paper does not detail dose related clinical decision making, the broad issues are considered. The future possibilities for the use of the modality are reviewed, and although outside the immediate remit of this paper, the use of therapeutic ultrasound in fracture management is briefly considered.

The enhancement of bone regeneration by ultrasound

Millions of fractures occur every year worldwide, with nearly 6.2 million fractures reported annually in the United States alone. Even though treatment methods have improved over the last few decades, 5-10% of fractures still show delayed healing. A significant subpopulation of these delayed healings do not heal by nine months and are thus termed non-unions. Experimental studies have shown some evidence that low intensity pulsed ultrasound stimulation (LIPUS) results in enhanced bone regeneration during fracture healing and callus distraction. LIPUS treatment has led to increased callus area and accelerated return of bone strength following fracture. Histological studies suggest that LIPUS influences all major cell types involved in bone healing, including osteoblasts, osteoclasts, chondrocytes and mesenchymal stem cells. The affect of LIPUS seems to be limited to cells in soft tissue, whereas cells in calcified bone seem not to be effected. In vitro cell culture studies as well as tissue culture studies have shown some effects on cell differentiation and protein synthesis. Even though the energy used by LIPUS treatment is extremely low, the effects are evident. The most probable source of the therapeutic benefits observed with LIPUS treatment involves nonthermal mechanisms that influence cell membrane permeability and increase cellular activity. Despite clinical and experimental studies demonstrating the enhancing effect of LIPUS on bone regeneration, the biophysical mechanisms involved in the complex fracture healing process remain unclear and requires further research.

Ultrasound Therapy in Tendinous Injury Healing in Goats

The effect of ultrasound therapy on tendon injury healing was studied on 12 locally available non-descript adult goats of either sex divided equally in two groups (I and II) consisting of six animals each. The superficial digital flexor tendon (SDFT) was transected and immediately repaired with nylon (2/0) using a locking loop suture pattern under atropine-triflupromazine-lignocaine epidural analgesia and strict aseptic condition. A full limb plaster of Paris cast was applied to immobilize the operated limb for 3 days. Postoperative care was similar in both the groups. In group I, the operated limb was allowed to heal without ultrasound therapy. In group II, pulsed ultrasound therapy was started 3 days after repair of tendinous injury at an intensity of 1 W/cm(2) for 10 min daily for 10 consecutive days. The animals of both groups were evaluated clinically and haemato-biochemically on days 1, 3, 7, 15, 20 and 30 postoperatively. Air tendonograms and ultrasonography were performed on days 0, 10, 20 and 30 post-tenorrhaphy. Histopathological examination of tendon biopsy samples was performed on day 30 post-tenorrhaphy. Resolution of inflammatory swelling, pain, weight bearing and tendon gliding movement was earlier in the test group than control. Rectal temperature, total leucocyte count and differential leucocyte count did not vary significantly at various stages of observation in both the groups. Serum glucose, cortisone and serum alkaline phosphatase levels increased significantly after tendon injury repair in all the animals and decreased slowly at all subsequent intervals in control group, whereas, it was near normal in the treatment group on day 30 post-tenorrhaphy. Air tendenograms and ultrasonography examinations in the test group revealed that there was a marked regression of peritendinous adhesion between the tendon and skin on day 30 post-tendon injury repaired and the tendon at the reconstructive site attained near normal thickness and density. Adhesions were present in the reconstructed site of SDFT in all animals of the control group. Histopathologically, the granulation tissue was comparatively bettered organized at the healing site in the ultrasound-treated animals.

Therapeutic ultrasound enhances medial collateral ligament repair in rats

The purpose of this study was to evaluate the effects of therapeutic ultrasound (US) on medial collateral ligament healing. A total of 36 3-month-old male Sprague-Dawley rats with transected medial collateral ligaments were studied. Subjects were given 5-min pulsed US therapy (duty cycle; one application in 4 ms; 1:4) daily with different durations (1 day, 5 days and 10 days) and intensities (0, 0.5 and 2.3 W/cm2). After each treatment, the level of transforming growth factor beta-1 (TGF-beta1) of the ligament was measured. TGF-beta1 was not detected in the 1-day group. In the 5-day and 10-day groups, the levels of TGF-beta1 were significantly up-regulated in the high-dose subgroup (p < 0.05). The 10-day group also registered a significantly higher expression of TGF-beta1 than did the 5-day group (p < 0.05). The present findings suggest that pulsed US therapy may enhance ligament repair by up-regulating the extent of TGF-beta1 in a high-dose application. Long-term treatment with this therapy could obtain further improvement.