Dong Rak Kwon

Application of real-time sonoelastography in musculoskeletal diseases related to physical medicine and rehabilitation.

Real-time sonoelastography is a recently developed ultrasound-based technique that evaluates tissue elasticity in real time, and it is based on the principle that the compression of tissue produces a strain (displacement) that is lower in hard tissue and higher in soft tissue. Real-time sonoelastography provides information on tissue elasticity, in addition to the shape or vascularity, which is obtained via B-mode ultrasound. Similar to B-mode ultrasound, freehand manipulation with the transducer and real-time visualization are now available for real-time sonoelastography in actual clinical practice. Tissue elasticity not only varies among different tissues but also seems to reflect disease-induced alternations in tissue properties. Real-time sonoelastography was recently applied to the normal and pathologic tissues in muscle and tendon disorders, and it showed promising results and new potentialities. Therefore, it is expected to be a useful modality for providing novel diagnostic information in musculoskeletal diseases because tissue elasticity is closely related to its pathology. It can also be used as a research tool to provide insight into the biomechanics and pathophysiology of tissue abnormality.

Diagnostic value of real-time sonoelastography in congenital muscular torticollis.

The purpose of this study was to evaluate the possible use of real‐time sonoelastography in infants with congenital muscular torticollis for predicting treatment outcomes.

Platelet-rich plasma limits the nerve injury caused by 10% dextrose in the rabbit median nerve

Introduction: We evaluated the effect of platelet‐rich plasma (PRP) injection in a rabbit model of dextrose‐induced median nerve injury. Methods: New Zealand white rabbits (n = 15) were divided randomly into 3 groups. Three different regimens (group 1: 0.1 ml saline; group 2: 10% dextrose with PRP; group 3: 10% dextrose with saline) were injected within the carpal tunnel. Electrophysiological and histological findings were evaluated 12 weeks after the injection. Results: The mean median motor latency in group 3 was significantly longer than that in groups 1 and 2. The cross‐sectional area of the median nerve and subsynovial connective tissue thickness in group 3 were significantly larger than those in groups 1 and 2. Conclusions: PRP injection may be effective in controlling median nerve injury, as demonstrated by improvement in electrophysiological and histological findings 12 weeks after dextrose injection. Muscle Nerve 49: 56–60, 2014

Regeneration of Full-Thickness Rotator Cuff Tendon Tear After Ultrasound-Guided Injection With Umbilical Cord Blood-Derived Mesenchymal Stem Cells in a Rabbit Model

Rotator cuff tendon tear is one of the most common causes of chronic shoulder pain and disability. In this study, we investigated the therapeutic effects of ultrasound‐guided human umbilical cord blood (UCB)‐derived mesenchymal stem cell (MSC) injection to regenerate a full‐thickness subscapularis tendon tear in a rabbit model by evaluating the gross morphology and histology of the injected tendon and motion analysis of the rabbits activity. At 4 weeks after ultrasound‐guided UCB‐derived MSC injection, 7 of the 10 full‐thickness subscapularis tendon tears were only partial‐thickness tears, and 3 remained full‐thickness tendon tears. The tendon tear size and walking capacity at 4 weeks after UCB‐derived MSC injection under ultrasound guidance were significantly improved compared with the same parameters immediately after tendon tear. UCB‐derived MSC injection under ultrasound guidance without surgical repair or bioscaffold resulted in the partial healing of full‐thickness rotator cuff tendon tears in a rabbit model. Histology revealed that UCB‐derived MSCs induced regeneration of rotator cuff tendon tear and that the regenerated tissue was predominantly composed of type I collagens. In this study, ultrasound‐guided injection of human UCB‐derived MSCs contributed to regeneration of the full‐thickness rotator cuff tendon tear without surgical repair. The results demonstrate the effectiveness of local injection of MSCs into the rotator cuff tendon.

Efficacy of microcurrent therapy in infants with congenital muscular torticollis involving the entire sternocleidomastoid muscle: a randomized placebo-controlled trial:

Objective: To compare the effects of a combination of therapeutic exercise and ultrasound with or without additional microcurrent therapy in infants with congenital muscular torticollis involving the entire sternocleidomastoid muscle. Design: Prospective, randomized, placebo-controlled trial. Setting: An outpatient rehabilitation clinic in a tertiary university hospital. Subjects: Infants (n = 20) with congenital muscular torticollis involving the entire sternocleidomastoid muscle. Interventions: Group 1 comprised 10 infants who received therapeutic exercise with ultrasound alone and Group 2 comprised 10 infants who received the same treatment with microcurrent therapy. Main measures: Passive cervical rotational range of motion was measured at before treatment and one, two, three, and six months after initial treatment. Thickness, cross-sectional area, and red pixel intensity on colour histograms, which were all assessed before treatment and at three months after initial treatment. Additionally, the duration of treatment was measured. Results: The mean passive cervical rotational range of motion measured at three months posttreatment was significantly greater in Group 2 (101.1°) than that in Group 1 (86.4°), and the thickness, cross-sectional area, and red pixel intensity of the affected sternocleidomastoid muscle were all less in Group 2 (7.8 mm, 100.3 mm2, and 126.1, respectively) than those in Group 1 (9.6 mm, 121.5 mm2, and 140.5, respectively). The mean duration of treatment was significantly shorter in Group 2 (2.6 months) than in Group 1 (6.3 months). Conclusions: Microcurrent therapy may increase the efficacy of therapeutic exercise with ultrasound for the treatment of congenital muscular torticollis involving the entire sternocleidomastoid muscle.

Intra-Articular Injections for the Treatment of Osteoarthritis: Focus on the Clinical Use of Several Regimens

Osteoarthritis is the most common joint disease, and is characterized by progressive loss of articular cartilage, subchondral bone sclerosis, osteophyte formation, synovial membrane changes, and an increase in synovial fluid with decreased viscosity and lubrication properties. Mechanical, biochemical, and genetic factors are all involved in pathogenesis of osteoarthritis (Chevalier, 2002; Wearing et al., 2006). Given the chronic and non-life-threatening nature of osteoarthritis, a good safety profile is essential. Characteristics of osteoarthritis vary across patients, and several definite clinical patterns have been identified. The choice of a suitable treatment strategy for a patient depends on clinical history, contraindications to specific therapies, and overall tolerability and acceptability of the considered treatment. This is especially true in the elderly, the major targeted people for osteoarthritis therapy, for whom one must consider the risk of upper gastrointestinal or adverse renal effects and the diverse array of concomitantly used medications. Intra-articular injection into osteoarthritic joints may play an important role in the therapeutic plan. Osteoarthritis of weight-bearing joints, such as knee osteoarthritis, is more a local mechanical driven disease than a generalized one. In order to reach a non-vascularized tissue, such as cartilage, local intra-articular administration of drugs should be considered. Intra-articular injections are one of the clinician’s many tools for treatment of osteoarthritis. Injection should be contemplated as an adjunct to the overall treatment plan-never as the sole component of therapy. Injections may be used diagnostically as well as therapeutically and are generally “safe” when used judiciously by a skilled practitioner. At this time, no targeted treatments for osteoarthritis have been developed. Therefore, preclinical and clinical research studies using other pharmacologic agents that might provide additional benefit are currently underway. A review of these investigational approaches — hyaluronic acid, recombinant human growth hormone, and platelet rich plasma — will be presented here.

Pharmacokinetic Alteration of Baclofen by Multiple Oral Administration of Herbal Medicines in Rats

The potential pharmacokinetic (PK) interaction of conventional western drug, baclofen, and oriental medications Oyaksungisan (OY) and Achyranthes bidentata radix (AB) extract for the treatment of spasticity has been evaluated. Rats were pretreated with distilled water (DW), OY, or AB extract by oral administration every day for 7 days. After 10 min of the final dose of DW or each herbal medication, baclofen (1 mg/kg) was given by oral administration and plasma concentrations of baclofen were determined by LC/MS/MS. The plasma baclofen concentration-time profiles were then analyzed by noncompartmental analysis and a population PK model was developed. Baclofen was rapidly absorbed, showed biexponential decline with elimination half-life of 3.42–4.10 hr, and mostly excreted into urine. The PK of baclofen was not affected by AB extract pretreatment. However, significantly lower maximum plasma concentration (C max) and longer time to reach C max (T max) were observed in OY pretreated rats without changes in the area under the curve (AUC) and the fraction excreted into urine (F urine). The absorption rate (K a) of baclofen was significantly decreased in OY pretreated rats. These data suggested that repeated doses of OY might delay the absorption of baclofen without changes in extent of absorption, which needs further evaluation for clinical significance.

Comparison of Treatment Effects Between Children With Spastic Cerebral Palsy Under and Over Five Years After Botulinum Toxin Type A Injection

Objective To evaluate whether age influences a change in the spasticity of the ankle plantar flexor after botulinum toxin type A (BTA) injection in children with spastic cerebral palsy (CP). Methods Sixteen children with spastic CP were enrolled in the study. Seven children (group 1) were under 5 years of age, and nine (group 2) were over 5 years of age. They all received BTA injection in the gastrocnemius muscle (GCM) under ultrasound guidance. Passive range of motion (PROM) of ankle dorsiflexion, Modified Ashworth Scale (MAS) of the ankle plantar flexor, Gross Motor Function Measure (GMFM) and median red pixel intensity (RPI) of the medial GCM on real-time sonoelastography were measured at baseline (pre-injection) and 1-, 3-, and 6-month post-injection. Results In both groups, the mean PROM, MAS, and RPI were significantly improved after injection until 6-month post-injection. The change of PROM of ankle dorsiflexion in group 1 was significantly greater than that in group 2, until 6-month post-injection. The change in the MAS and GMFM between baseline and 6-month post-injection in group 1 was greater than that in group 2. The changes in the median RPI between baseline and 3- and 6-month post-injections were greater in group 1 than in group 2. Conclusion Our pilot study demonstrated the different changes in spasticity of the ankle plantar flexor after BTA injection based on age. Therefore, age may be considered when establishing a treatment plan using BTA injection for children with spastic CP.

Utility of Sonoelastography in Differentiating Ruptured From Unruptured Epidermal Cysts and Implications for Patient Care

This study aimed to evaluate the correlation of sonoelastographic features between ruptured and unruptured epidermal cysts.

A new ultrasound method for assessment of head shape change in infants with plagiocephaly.

Objective To compare a new ultrasound measurement method with calliper cephalometry in infants with deformational plagiocephaly (DP) and to assess the differences of two methods according to the severity of DP. Methods Fifty-two infants with DP were divided into two groups according to the degree of cranial vault asymmetry (CVA); group 1 included 42 infants with CVA over 10 mm, and group 2 included 10 infants with CVA under 10 mm. Cranial vault asymmetry index (CVAI) and occipital angle ratio (OAR) were measured by using calliper and ultrasound measurements, respectively. The occipital angle was defined as the angle between the lines projected along the lambdoid sutures of the skull. Results The occipital angles of the affected sides were significantly greater than those of unaffected sides in both groups. The CVAI and OAR were significantly greater in group 1 than in group 2 (CVAI, 9.3%±2.3% vs. 4.6%±1.5%; OAR, 1.05±0.4 vs. 1.01±0.0; p<0.05). The OAR was positively correlated with the CVAI in all infants (r=0.789) and in group 1 (r=0.784; p<0.05). Conclusion Our study revealed that OAR using the new ultrasound measurement was positively correlated with the CVAI in infants with DP. Therefore, the occipital angle measurement using ultrasound combined with cephalometry could provide better understanding about the characteristics of the overall cranial bone and lambdoid suture complex in infants with DP.