The Relationship between the Bevel of the Radial Head Epiphysis and the Posterior Synovial Fringe During Rotation of the Elbow: An Ultrasonography Study with Possible Implications Regarding the Pathophysiology of Nursemaid's Elbow.

BACKGROUND: Nursemaid's elbow is the most common upper extremity injury in children under 5 years of age. However, the exact pathomechanism underlying the nursemaid's elbow remains elusive, and approximate one-third of patients present with a nonclassical history. Using a high-frequency ultrasound probe, we attempted to determine the relationship between the anterior edge of the posterior synovial fringe and the peripheral rim of the radial head epiphysis during rotation. It is possible that the primary reason for the nursemaid's elbow is due to the pronator position. METHODS: Twenty-one patients had a history of nursemaid's elbow and had a successful reduction before enrollment in this study. A high-frequency linear array 6 to 24 MHz hockey stick transducer was used to detect small morphologic changes in the peripheral rim of the radial head epiphysis and the posterior synovial fringe during rotation of the capitellum-radial joint. RESULTS: In complete pronation, the anterior edge of the posterior synovial fringe contacts the beveled articular surface of the radial head peripheral rim in all 21 patients. In neutral and complete supination, the anterior edge of the posterior synovial fringe contacts the convexly nonarticular surface of the radial head peripheral rim and extends deep into the foveal radius. The posterior synovial fringe and the capsule-aponeurotic membrane were tightened in passive pronation in all 21 cases. The posterior synovial fringe and the capsule-aponeurosis membrane were all loose in the neutral and supination positions. CONCLUSION: The anterior edge of the posterior synovial fringe touches the beveled peripheral rim of the radial head epiphysis during complete pronation, and the tension of the lateral collateral ligament complex during pronation may further cause unstable conditions of the anterior edge of the posterior synovial fringe. We hypothesized that the beveled peripheral rim of the radial epiphysis and its relationship with the anterior edge of the posterior synovial fringe could be the reason why nursemaid's elbow only occurs while the elbow is in the pronator position.

The Usefulness of Dynamic Ultrasonography in Nursemaid's Elbow: A Prospective Case Series of 13 Patients Reconsideration of the Pathophysiology of Nursemaid's Elbow.

BACKGROUND: Nursemaid's elbow is a common musculoskeletal disorder among children under 5 years of age. However, diagnostic imaging to confirm a nursemaid's elbow diagnosis is still unavailable. Through the use of a high-frequency ultrasound probe, we determined the etiology and possible pathophysiology of nursemaid's elbow. METHODS: Thirteen consecutive patients with the clinical suspicion of nursemaid's elbows were examined. A high-frequency linear array 6 to 24 MHz hockey stick transducer was used to detect small changes (partial eclipse signs) of the radial head in the axial view before and after manipulation. RESULTS: All patients in this study had a successful reduction. A partial eclipse sign was found in all patients before reduction and disappeared after successful reduction. CONCLUSION: These pathologic features detected through high-frequency ultrasonography suggest the role of the escaped posterior synovial fringe in the pathogenesis of the nursemaid's elbow. The specific finding of a "partial eclipse sign" could be a useful additional clue leading to the correct diagnosis of the nursemaid's elbow and may help avoid the unnecessary reduction in patients who do not have a "partial eclipse sign". LEVEL OF EVIDENCE: Level II, diagnostic studies.

Effects of backhand stroke styles on bone mineral content and density in postmenopausal recreational tennis players: a cross-sectional pilot investigation.

BACKGROUND: One-handed backhand (OB) and two-handed backhand (TB) styles are commonly used in tennis, but only TB generates loadings on the non-dominant arm and a greater extension torque on the rear leg, leading to a greater axial torque involving rotation of the hip and trunk. The current study investigated whether those effects can further affect bone area (BA), bone mineral content (BMC) and density (BMD) in postmenopausal recreational tennis players. METHODS: BA, BMC and BMD of the lumbar spine, hip and distal radius were assessed using dual-energy X-ray absorptiometry in TB, OB, and swimmers' group as a control (SG) (all participants self-reported for at least 5 years of exercise history, n = 14 per group). Muscular strength was assessed with a hand dynamometer. Among these three groups, the BA, BMC and BMD of distal radius and muscle strength were assessed using one-way ANOVA, and those of the lumbar region and the hip joint were tested by one-way ANCOVA. RESULTS: TB showed higher BMC and BMD for both lumbar spine and femoral neck than SG (all, p < 0.05). Both OB and TB showed greater BMD inter-trochanter than SG (both, p < 0.05). OB demonstrated greater inter-arm differences in the distal radius, which involved 1/3 distal for BMC and mid-distal radius for BMD compared to the TB and SG (all, p < 0.05). In addition, greater inter-arm asymmetry of grip strength was found in OB compared to TB and SG (both, p < 0.05). CONCLUSION: For postmenopausal women, performing two-handed backhand strokes, leads to higher BMC and BMD in the non-dominant arm, the lumbar region, and hips, indicating potential benefit to maintain bone health and strength. Whether this result leads to reducing the risk of osteoporosis needs to be investigated in further research.

Comparison of the corticosteroid injection and hyaluronate in the treatment of chronic subacromial bursitis: A randomized controlled trial.

OBJECTIVE: To analyse the effectiveness of corticosteroid (CS) and hyaluronic acid (HA) subacromial - subdeltoid (SASD) injection compared with normal saline (NS) in patients with chronic subacromial bursitis (CSB). DESIGN: A prospective three-arm double-blinded randomised controlled trial. SETTING: Rehabilitation department of two teaching hospitals. SUBJECTS: Patients with CSB (N = 186) divided into CS (N = 68), HA (N = 60), and NS (N = 58) groups. INTERVENTIONS: Three SASD injections under ultrasound guidance: group A, 20 mg of triamcinolone; group B, 2.5 mL of HA; and group C, 2.5 mL of NS. OUTCOME MEASURES: The primary outcome measures were the pain visual analogue scale (VAS) score at eight weeks. The secondary outcomes were scores on the Shoulder Pain and Disability Index (SPADI) and Shoulder Disability Questionnaire. RESULTS: At eight weeks, the pain VAS scores during activity were 2.56 ± 2.29, 3.65 ± 2.50, and 4.71 ± 2.83 in the CS, HA, and NS groups, respectively (CS vs NS, P < 0.001; HA vs NS, P = 0.013; CS vs HA, P = 0.010). SPADI scores were 40.83 ± 21.75, 36.92 ± 22.78, and 33.35 ± 23.38 in the CS, HA, and NS groups, respectively (CS vs NS, P < 0.001; HA vs NS, P = 0.197; CS vs HA, P = 0.004). CONCLUSION: Ultrasound-guided corticosteroid injection into the subacromial - subdeltoid bursa was proven to be effective and superior to hyaluronic acid and normal saline injection for treating CSB. Hyaluronic acid injection was only marginally more effective than normal saline injection.Trial Registration: ClinicalTrials.gov: NCT02702206.

PEDF-derived peptide promotes skeletal muscle regeneration through its mitogenic effect on muscle progenitor cells.

In response injury, intrinsic repair mechanisms are activated in skeletal muscle to replace the damaged muscle fibers with new muscle fibers. The regeneration process starts with the proliferation of satellite cells to give rise to myoblasts, which subsequently differentiate terminally into myofibers. Here, we investigated the promotion effect of pigment epithelial-derived factor (PEDF) on muscle regeneration. We report that PEDF and a synthetic PEDF-derived short peptide (PSP; residues Ser(93)-Leu(112)) induce satellite cell proliferation in vitro and promote muscle regeneration in vivo. Extensively, soleus muscle necrosis was induced in rats by bupivacaine, and an injectable alginate gel was used to release the PSP in the injured muscle. PSP delivery was found to stimulate satellite cell proliferation in damaged muscle and enhance the growth of regenerating myofibers, with complete regeneration of normal muscle mass by 2 wk. In cell culture, PEDF/PSP stimulated C2C12 myoblast proliferation, together with a rise in cyclin D1 expression. PEDF induced the phosphorylation of ERK1/2, Akt, and STAT3 in C2C12 myoblasts. Blocking the activity of ERK, Akt, or STAT3 with pharmacological inhibitors attenuated the effects of PEDF/PSP on the induction of C2C12 cell proliferation and cyclin D1 expression. Moreover, 5-bromo-2'-deoxyuridine pulse-labeling demonstrated that PEDF/PSP stimulated primary rat satellite cell proliferation in myofibers in vitro. In summary, we report for the first time that PSP is capable of promoting the regeneration of skeletal muscle. The signaling mechanism involves the ERK, AKT, and STAT3 pathways. These results show the potential utility of this PEDF peptide for muscle regeneration.

Ultrasonographic appearance of subungual glomus tumors.

BACKGROUND: To describe the sonographic (US) features of pathologically confirmed subungual glomus tumors. METHODS: We retrospectively analyzed cases of pathologically confirmed subungual glomus tumors in patients presenting between December 1, 2008 and October 31, 2012, selected from cases in the musculoskeletal US database of a single institution. RESULTS: Data on 14 patients with pathologically proven glomus tumors were retrieved from the US database. The tumor size ranged from 1.9 to 10.0 mm (mean ± SD, 5.3 ± 2.3 mm). Well-circumscribed tumors with clear margins were identified on US in 12 cases (86%): 11 (92%) tumors were hypoechoic and 1 (8%) was isoechoic. On power or color Doppler US, 11 of these 12 tumors (92%) appeared hypervascular. Two of the 14 tumors did not show a clearly circumscribed mass on gray-scale US, and bony erosion was the only US finding in one of the two cases. Seven of the 14 patients (50%) showed focal bony erosion in the underlying phalangeal bone. CONCLUSIONS: A hypervascular mass in the nail bed was the most common US finding associated with subungual glomus tumors. We found that focal hypervascularity supports the diagnosis, and bony erosion is commonly associated with digital glomus tumors.

Sonographic diagnosis of a medial talar avulsion fracture.

Occult talus fractures can be easily misdiagnosed as simple ankle sprains, resulting in painful nonunion, arthrosis, avascular necrosis, and long-term disability. We present a case of ankle injury with medial talar fracture that was negative on plain radiography but was diagnosed with sonography. Sonography is a valuable tool in screening ankle sprains and may assist clinicians in diagnosing the nature of ankle injury, thus guiding the most appropriate therapeutic strategy.

Ultrasound-Guided Nerve Hydrodissection for Pain Management: Rationale, Methods, Current Literature, and Theoretical Mechanisms.

Nerve hydrodissection (HD), a technique used when treating nerve entrapments, involves the injection of an anesthetic, saline, or 5% dextrose in water to separate the nerve from the surrounding tissue, fascia, or adjacent structures. Animal models suggest the potential for minimal compression to initiate and perpetuate neuropathic pain. Mechanical benefits of HD may relate to release of nervi nervorum or vasa nervorum compression. Pathologic nerves can be identified by examination or ultrasound visualization. The in-plane technique is the predominant and safest method for nerve HD. Five percent dextrose may be favored as the preferred injectate based on preliminary comparative-injectate literature, but additional research is critical. Literature-based hypotheses for a direct ameliorative effect of dextrose HD on neuropathic pain are presented.

Surface electromyography analysis of blepharoptosis correction by transconjunctival incisions.

Upper eyelid movement depends on the antagonistic actions of orbicularis oculi muscle and levator aponeurosis. Blepharoptosis is an abnormal drooping of upper eyelid margin with the eye in primary position of gaze. Transconjunctival incisions for upper eyelid ptosis correction have been a well-developed technique. Conventional prognosis however depends on clinical observations and lacks of quantitatively analysis for the eyelid muscle controlling. This study examines the possibility of using the assessments of temporal correlation in surface electromyography (SEMG) as a quantitative description for the change of muscle controlling after operation. Eyelid SEMG was measured from patients with blepharoptosis preoperatively and postoperatively, as well as, for comparative study, from young and aged normal subjects. The data were analyzed using the detrended fluctuation analysis method. The results show that the temporal correlation of the SEMG signals can be characterized by two indices associated with the correlation properties in short and long time scales demarcated at 3ms, corresponding to the time scale of neural response. Aging causes degradation of the correlation properties at both time scales, and patient group likely possess more serious correlation degradation in long-time regime which was improved moderately by the ptosis corrections. We propose that the temporal correlation in SEMG signals may be regarded as an indicator for evaluating the performance of eyelid muscle controlling in postoperative recovery.