Stress responses to bacterial and viral mimetics in polycystic ovary syndrome model rats.

Polycystic ovary syndrome (PCOS) is associated with an increased risk of psychological distress as well as enhanced responses to psychosocial stress. Recently, it was hypothesized that PCOS patients may be at high risk of novel COVID-19 infections and worse clinical presentations during such infections. Here, we evaluated the effects of PCOS on stress responses to bacterial and viral mimetics using dihydrotestosterone-induced PCOS model rats. Lipopolysaccharide (LPS; a bacterial mimetic) or polyinosinic-polycytidylic acid (Poly-IC; a viral mimetic) was injected into PCOS model rats (PCOS) and non-PCOS rats (control), and the rats' stress responses were evaluated. In the PCOS group, the rats' anorectic and febrile responses to LPS injection were enhanced, whereas their anorectic and febrile responses to Poly-IC injection were unaltered. The PCOS group also exhibited greater changes in peripheral cytokine levels in response to LPS, but not Poly-IC. On the contrary, after the injection of Poly-IC depressed locomotor activity was more evident in the PCOS group, whereas no such changes were observed after LPS injection. These findings indicate that although the stress responses of PCOS model rats to infection may be enhanced, the patterns of change in stress responses and their underlying mechanisms may differ between bacterial and viral infections.

New treatment strategies for uterine sarcoma using secreted frizzled­related proteins.

Secreted frizzled-related proteins (SFRPs) are involved in the development of various types of cancer and function by suppressing the Wnt signaling pathway. To elucidate the clinical implications of SFRPs in uterine sarcoma, SFRP expression levels and their effects on uterine leiomyosarcoma cells were examined. Immunostaining for SFRP4 was performed on uterine smooth muscle, uterine fibroid and uterine leiomyosarcoma tissues. Additionally, the effects of SFRP4 administration on cell viability, migration and adhesion were evaluated in uterine leiomyosarcoma SKN cells using the WST-1 assay (Roche Diagnostics) and the CytoSelect™ 24-well Cell Migration Assay Kit and the CytoSelect™ 48-well Cell Adhesion Assay Kit. The expression levels of SFRP4 in uterine leiomyosarcoma tissues were lower than those in normal smooth muscle and uterine fibroid tissues. In addition, SFRP4 suppressed the viability and migration, and increased the adhesion ability of uterine leiomyosarcoma cells compared with in the control group. In conclusion, SFRP4 may suppress the viability and migration, and enhance the adhesion of sarcoma cells. These results suggested that SFRP4 could be considered as a novel therapeutic target for uterine sarcoma.

Progesterone treatment reduces food intake and body weight in ovariectomized female rats.

While the effects of progesterone on body weight and appetite in pre-menopausal conditions have been well elucidated, its effects in post-menopausal conditions have not been clarified. On the contrary, the effects of estrogen on body weight and appetite in post-menopausal conditions have been well established. In this study, the effects of progesterone treatment on body weight, appetite, and fat mass in ovariectomized rats were evaluated. In addition, the central and/or peripheral levels of oxytocin (OT), leptin, and their receptors, which are potent anorectic factors, were examined. Female rats were ovariectomized and divided into control, progesterone-treated, and estrogen-treated groups. Body weight, food intake, and subcutaneous fat mass were lower in both the progesterone and estrogen groups than in the control group. The estrogen group exhibited higher serum OT levels than the control group, whereas the OT levels of the progesterone and control groups did not differ. The serum leptin levels of both the progesterone and estrogen groups were lower than those of the control group. Gene expression analysis of OT, leptin, and their receptors in the hypothalamus and adipose tissue found few significant differences among the groups. Hypothalamic neuropeptide Y (NPY) and pro-opiomelanocortin (POMC) mRNA levels involved in appetite regulation were slightly altered in the progesterone and estrogen groups. These findings suggest that progesterone treatment may have favorable effects on body weight, appetite, and fat mass regulation in post-menopausal conditions and that the mechanisms underlying these effects of progesterone differ from those underlying the effects of estrogen.

Age-Dependent Changes in the Effects of Androgens on Female Metabolic and Body Weight Regulation Systems in Humans and Laboratory Animals.

In recent years, the effects of androgens on metabolic and body weight regulation systems and their underlying mechanisms have been gradually revealed in females. In women and experimental animals of reproductive age, androgen excess can adversely affect metabolic functioning, appetite, and body weight regulation. In addition, excess androgens can increase the risk of metabolic disorders, such as obesity, insulin resistance, and diabetes. These unfavorable effects of androgens are induced by alterations in the actions of hypothalamic appetite-regulatory factors, reductions in energy expenditure, insulin resistance in skeletal muscle, and ß-cell dysfunction. Interestingly, these unfavorable effects of androgens on metabolic and body-weight regulation systems are neither observed nor evident in ovariectomized animals and post-menopausal women, indicating that the adverse effects of androgens might be dependent on the estrogen milieu. Recent findings may provide novel sex- and age-specific strategies for treating metabolic diseases.

Effects of STAT Inhibitors in Mouse Models of Endometriosis.

The signal transducer and activator of transcription (STAT) pathway, which regulates cell proliferation and immunity, has been implicated in chronic inflammatory diseases such as rheumatoid arthritis. However, few reports have described the effects of STAT inhibitors on endometriosis, another chronic inflammatory disease. Here, we investigated the intraperitoneal microenvironment and the effects of a STAT inhibitor in a mouse model of endometriosis. In the treatment group, a STAT3 inhibitor (Stattic®, 80 mg/kg) was orally administered three times per week; control animals received orally dosed phosphate-buffered saline. Endometriosis-like lesions and peritoneal lavage fluid were collected before and 1, 2, and 3 weeks after STAT3 inhibitor administration was initiated. The lesion area was significantly increased in both groups after the first week. However, in the treatment group, the lesion areas were significantly reduced at weeks 2 and 3 compared with week 1. Transforming growth factor (TGF)-ß messenger RNA (mRNA) levels in ascites cells were significantly lower at weeks 1 and 2 than at week 0. Interleukin (IL)-6 mRNA levels were significantly higher at week 1 than at week 0 but were significantly lower at weeks 2 and 3 than at week 1. Thus, STAT inhibitors appeared to reduce the extent of endometriosis in this mouse model, and may also inhibit the IL-6 signaling pathway and reduce TGF-ß levels. This study suggests that STAT inhibitors warrant further exploration for use in the treatment of endometriosis.

Coracoid process transfer and distal clavicle resection for chronic acromioclavicular separation.

Background: Dewar's procedure for transferring the coracoid process with the short head of biceps and coracobrachialis was reported in 1965 for treatment of both acute and chronic acromioclavicular (AC) joint separation, but little contemporary literature exists around the procedure. We report the clinical results of coracoid process transfer with excision of the lateral end of the clavicle for chronic AC joint separation. Methods: Fifty-one patients (39 men and 12 women, mean age 46 ± 16 years) were included in the study. Clinical outcomes were evaluated using the American Shoulder and Elbow Surgeons and the Japanese Orthopaedic Association scores, as well as by measuring active range of motion in the shoulder, before-after (minimum follow-up time of 24 months [27 ± 3 months]) surgery. Plain radiographs were used to examine stability of the AC joint and bone union of the graft. Results: The mean American Shoulder and Elbow Surgeons and Japanese Orthopaedic Association scores increased (from 61 ± 14 to 91 ± 6, and from 54 ± 9 to 89 ± 8, respectively) at the time of final follow-up. There were no differences in active elevation and external rotation between before-after operation. Six patients whose grafts were fractured or displaced showed complete or partial loss of reduction of the AC joint. Conclusion: By transferring the coracoid process, the AC joint regained stability after chronic joint separation. Although potential complications related to the graft still need to be addressed, Dewar's procedure and lateral clavicle resection could be a reliable treatment of chronic AC joint separation.

Agreement in rotator cuff muscles measurement between ultrasonography and magnetic resonance imaging.

Background/objective: It is important to assess the atrophy of the rotator cuff to better understand shoulder function and pain. Previously, magnetic resonance imaging has been used for the evaluation of atrophy of rotator cuff muscles, which is time consuming. Therefore, a measurement tool requiring little time and easy accessibility is clinically desirable to be used frequently in rehabilitation. Recently, rotator cuff muscles have been evaluated using ultrasonography. However, little is known about the agreement of evaluation in rotator cuff muscles between magnetic resonance imaging and ultrasonography. The purpose of this study was to demonstrate the agreement between the muscle thickness measurements of supraspinatus, infraspinatus, and teres minor muscles by ultrasonography and the cross-sectional area measured by magnetic resonance imaging in the patient with rotator cuff tears. Methods: A total of 47 patients with rotator cuff tears were enrolled. There were the 37 small tears, four medium tears, and six large tears, and the involved rotator cuff muscles were the supraspinatus in 37 shoulders, and the supraspinatus and infraspinatus in 10 shoulders. The measuring variables were muscle thickness and cross-sectional area of supraspinatus, infraspinatus, and teres minor muscles by using magnetic resonance imaging. Further, the muscle thickness of the rotator cuff were assessed using ultrasonography. A single regression model was used for demonstrating the agreement between the cross-sectional area measurement by magnetic resonance imaging and the muscle thickness measured using ultrasonography and magnetic resonance imaging of rotator cuff muscles. Additionally, the Bland-Altman plots between magnetic resonance imaging and ultrasonography was analyzed. Results: The cross-sectional area were correlated with the muscle thickness measurement of rotator cuff muscles by magnetic resonance imaging, significantly (supraspinatus: r = 0.84, infraspinatus: ρ = 0.63, teres minor: ρ = 0.61, all p < 0.001). There were significant agreements between the cross-sectional area measured by magnetic resonance imaging and muscle thickness measured by ultrasonography (supraspinatus: r = 0.80, infraspinatus: ρ = 0.78, teres minor: ρ = 0.74, all p < 0.001). Bland-Altman plots revealed significant correlations between the average and the difference of the two measurements in supraspinatus (r = 0.36, p = 0.012), infraspinatus (r = 0.38, p < 0.001), and teres minor (r = 0.42, p < 0.001). These results clarified the proportional bias between MRI and US. Conclusion: This study showed that, similar to magnetic resonance imaging, ultrasonography is a useful tool for assessing muscle atrophy of supraspinatus, infraspinatus, and teres minor muscles.

Treatment of acromioclavicular joint separations in Japan: a survey.

BACKGROUND: Treatment options for acromioclavicular joint (ACJ) separations are highly dependent on severity, as well as the patient's background. Furthermore, some patients can be switched from conservative to surgical treatment. In this study, we conducted a mail-based questionnaire survey of members of the Japan Shoulder Society on the administration of treatments for ACJ separations. METHODS: A questionnaire survey with 5 categories was mailed to all 1655 members of the Japan Shoulder Society (including 59 councilors): initial treatment, whether surgery was performed, indications for surgery based on severity, switching from conservative to surgical treatment, and surgical methods. RESULTS: Altogether, 183 members, including 56 councilors, responded. Regarding the initial treatment, 17 respondents opted for treatment without immobilization or fixation and 166 opted for immobilization or fixation. Of the members, 11 opted for only conservative treatment whereas 172 chose surgery depending on the case; of the latter, 9 considered it for patients with a Rockwood classification of type 2 or higher; 120, for patients with type 3 or higher; and 172, for patients with types 4-6. Furthermore, 75 of 172 members had experience switching to surgical treatment during conservative treatment. For 64 of 172 members, the modified Cadenat method was the most common surgical method. CONCLUSIONS: Only 11 members opted for conservative treatment of ACJ separations, and approximately 95% of physicians chose surgery. Furthermore, >70% of physicians considered surgery for an injury classified as type 3 or higher, and 37% of members performed the modified Cadenat method. However, the popularization of arthroscopic surgery may affect the selection of surgical methods in the future.

Does Margin Convergence Reverse Pseudoparalysis in Patients with Irreparable Rotator Cuff Tears?

BACKGROUND: Margin convergence has been shown to restore muscle tension in a cadaveric model of a rotator cuff tear. However, the clinical utility of this technique remains uncertain for patients with pseudoparalysis caused by an irreparable rotator cuff tear. QUESTIONS/PURPOSES: (1) For patients with massive irreparable rotator cuff tears, in what proportion of patients does margin convergence reverse pseudoparalysis? (2) In patients with massive irreparable rotator cuff tears, does margin convergence improve American Shoulder and Elbow Surgeons (ASES) scores? (3) What is the survivorship free from MRI evidence of retear after margin convergence? METHODS: Between 2000 and 2015, we treated 203 patients for pseudoparalysis with a rotator cuff tear. Pseudoparalysis was defined as active elevation less than 90° with no stiffness, which a physical therapist evaluated in the sitting position using a goniometer after subacromial injection of 10 cc lidocaine to eliminate pain. Of those, we considered patients who underwent at least 3 weeks of unsuccessful nonoperative treatment in our hospital as potentially eligible. Twenty-one percent (43 of 203) who either improved or were lost to follow-up within 3 weeks of nonoperative treatment were excluded. A further 12% (25 of 203) were excluded because of cervical palsy, axillary nerve palsy after dislocation or subluxation, and development of severe shoulder stiffness (passive shoulder elevation < 90°). Repair was the first-line treatment, but if tears were considered irreparable with the torn tendon unable to reach the original footprint after mobilizing the cuff during surgery, margin convergence was used. When margin convergence failed, the procedure was converted to hemiarthroplasty using a small humeral head to help complete the repair. Therefore, 21% (42 of 203) of patients treated with regular repair (18% [36 of 203]) or hemiarthroplasty (3% [6 of 203]) were excluded. That left 93 patients eligible for consideration. Of those, 13 patients were lost before the minimum study follow-up of 2 years or had incomplete datasets, and 86% (80 of 93) were analyzed (49 men and 31 women; mean age 68 ± 9 years; mean follow-up 26 ± 4 months). Seventy-six percent (61 of 80) were not evaluated in the last 5 years. We considered reversal of pseudoparalysis as our primary study outcome of interest; we defined this as greater than 90° active forward elevation; physical therapists in care measured this in the sitting position by using goniometers. Clinical outcomes were evaluated based on the ASES score from chart review, active ROM in the shoulder measured by the physical therapists, and the 8-month Kaplan-Meier survivorship free from MRI evidence of retear graded by the first author. RESULTS: Pseudoparalysis was reversed in 93% (74 of 80) patients, and improvement in ASES scores was observed at the final follow-up (preoperative 22 ± 10 to postoperative 62 ± 21, mean difference 40 [95% CI 35 to 45]; p < 0.01). The 8-month Kaplan-Meier survivorship free from MRI evidence of retear after surgery was 72% (95% CI 63% to 81%). There were no differences in clinical scores between patients with and without retears (intact ASES 64 ± 24, re-tear ASES 59 ± 10, mean difference 6 [95% CI -5 to 16]; p = 0.27). CONCLUSION: Margin convergence can be a good option for treating patients with pseudoparalysis and irreparable rotator cuff tears despite the relatively high retear rates. The proportion of pseudoparalysis reversal was lower in patients with three-tendon involvement. Further studies will be needed to define the appropriate procedure in this group. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Fibrosis in the rotator interval associated with articular vs. bursal side partial-thickness rotator cuff tears.

BACKGROUND: The pathogenesis of articular- and bursal-sided partial-thickness rotator cuff tears (PTRCTs) is considered to be different, and associated lesions with PTRCTs need to be examined. METHODS: The current study consisted of 76 shoulders of 73 patients (27 men, 46 women, 64.0 ± 8.3 years old) who underwent mini-open repair after conversion to full-thickness tears for either articular side (group A; n = 56) or bursal side (group B; n = 20) PTRCT with at least a 2-year follow-up. Clinical outcomes and their images were compared between the groups. Plain radiographs were used with the arm passively elevated in maximum elevation to assess restriction of glenohumeral motion. RESULTS: The retear rate was not significantly different between the groups. Both groups showed significant improvement in functional scores at the final follow-up. Patients in group A showed a higher incidence of preoperative fibrosis in the rotator interval (69.6% vs. 35.0%, respectively; P = .006) and a lower incidence of an acromial spur (7.1% vs. 35.0%, respectively; P = .008) compared with group B. Plain radiographs with arm elevation showed restriction of glenohumeral movement in 49 of 76 shoulders (64.5%) preoperatively, including 36 of the 46 shoulders with fibrosis and 13 of the other 30 shoulders. CONCLUSION: Both articular- and bursal-sided PTRCTs showed significant functional improvements after surgery. The articular-sided tears had a lower incidence of an acromial spur, but had a higher incidence of fibrosis in the rotator interval, which led to a limitation in glenohumeral motion.

Methods used to assess the severity of acromioclavicular joint separations in Japan: a survey.

BACKGROUND: In acromioclavicular joint (ACJ) separations, patient characteristics determine the indications for surgery. However, in Japan, classification methods used to assess the severity of ACJ separations differ between institutions, and even within a classification method, different interpretations can lead to different assessments of severity. Therefore, in this study, we conducted an email survey of Japan Shoulder Society (JSS) members regarding their assessment methods for ACJ separation severity. METHODS: A questionnaire about methods for assessing the severity of ACJ separations was emailed to JSS members (1655) including 59 JSS councilors. The survey focused on diagnostic imaging methods, classifications of severity assessments, and methods of assessing severity. RESULTS: In total, 183 responses were received. All respondents used an anteroposterior view of the ACJ. Severity assessments were classified by the Tossy classification (57 respondents), Rockwood classification (141 respondents), and other classifications (7 respondents) including duplication. Of the 141 respondents using the Rockwood classification, 119 diagnosed type III as ACJ dislocation when the inferior clavicle border translated above the superior acromial border, whereas 56 used the coracoclavicular distance. However, to diagnose type V, 118 respondents used the coracoclavicular distance whereas 38 used palpation. To diagnose type IV, 57 respondents considered all cases in which the clavicle translated posterior to the acromion, even when vertical ACJ dislocation occurred simultaneously. However, 88 respondents did so in the presence of posterior clavicle displacement and ACJ subluxation. CONCLUSION: The Rockwood classification is commonly used for severity assessments in Japan; however, there is some disagreement regarding the assessment for the diagnosis of type IV. Methods to diagnose both superior and posterior translation of the clavicle need further debate.

Comparison of shoulder muscle strength, cross-sectional area, acromiohumeral distance, and thickness of the supraspinatus tendon between symptomatic and asymptomatic patients with rotator cuff tears.

BACKGROUND: The purpose of this study was to demonstrate the differences in shoulder muscle strength, cross-sectional area of the rotator cuff muscles, acromiohumeral distance, and supraspinatus tendon thickness between symptomatic and asymptomatic patients with rotator cuff tears. METHODS: Thirty-two symptomatic patients and 23 asymptomatic patients with rotator cuff tears participated in this study. Data of the patients with any type of tear and supraspinatus tear were analyzed. We evaluated the isometric torque, cross-sectional area of the rotator cuff muscles, supraspinatus tendon thickness, acromiohumeral distance, range of motion, and Western Ontario Rotator Cuff Index. RESULTS: Asymptomatic patients showed greater isometric torque of shoulder abduction and internal rotation than symptomatic patients with any type of tear (P ≤ .01). Asymptomatic patients also demonstrated greater cross-sectional area of the supraspinatus (P < .01); however, there was no significant difference in the cross-sectional area of the other cuff muscles. There was also no significant difference in the supraspinatus tendon thickness (P = .10). The acromiohumeral distance at 90° of shoulder abduction was larger (P = .04) in asymptomatic patients. Additionally, similar tendencies were observed in the results of patients with supraspinatus tears, except for the isometric torque of shoulder external rotation. This torque was greater (P < .01) in asymptomatic patients. CONCLUSION: Asymptomatic patients showed greater shoulder range of motion, muscle strength of shoulder abduction and internal rotation, small occupation ratio of supraspinatus tendon thickness as a percentage of acromiohumeral distance, and large cross-sectional area of supraspinatus.

Modified Putti-Platt procedure for recurrent anterior shoulder instability.

PURPOSE: The classic Putti-Platt technique was modified by suturing the lateral subscapularis tendon to the capsule instead of the anterior glenoid edge. We report the clinical results of a modified Putti-Platt procedure in patients with traumatic anterior shoulder instability. METHODS: The study reports results in 434 patients (450 shoulders) with traumatic anterior shoulder instability. The patients comprised 322 men and 122 women with a mean age of 22 years. Clinical results were evaluated by the Rowe score, Japan Shoulder Society Shoulder Instability Score (JSS-SIS); recurrence of instability, instability severity index score (ISIS), restriction of external rotation, return to sports activities, and osteoarthritis on plain radiographs and MRI were examined. RESULTS: The mean Rowe score improved from 26 to 90 points, and the mean JSS-SIS improved from 51 to 88 points. Altogether, 419 patients (97%) had no recurrence at a minimum of two years of follow-up, even though the study included 87 patients with an ISIS of ≥ 7 points. External rotation was limited at 6 months, and 33 of 228 patients (14%) could not return to the same level of sports activities. Among 44 patients at the follow-up extending to ten to 27 years, external rotation was still limited but no plain radiography showed osteoarthritis more than stage 2. CONCLUSION: This modified Putti-Platt procedure was not appropriate for throwing athletes but could be a surgical option for patients with high risk of recurrence.

Stride-Phase Kinematic Parameters That Predict Peak Elbow Varus Torque.

BACKGROUND: During baseball pitching, a high amount of elbow varus torque in the arm cocking-to-acceleration phase is thought to be a biomechanical risk factor for medial elbow pain and injury. The biomechanics of the stride phase may provide preparation for the arm cocking-to-acceleration phase that follows it. PURPOSE: To determine the kinematic parameters that predict peak elbow varus torque during the stride phase of pitching. STUDY DESIGN: Descriptive laboratory study. METHODS: Participants were 107 high school baseball pitchers (age range, 15-18 years) without shoulder or elbow problems. Whole-body kinematics and kinetics during fastball pitching were analyzed using 3-dimensional measurements from 36 retroreflective markers. A total of 26 kinematic parameters of the upper and lower limbs during the stride phase leading up to the stride foot contact were extracted for multiple regression analysis to assess their combined effect on the magnitude of peak elbow varus torque. RESULTS: Increased wrist extension, elbow pronation, knee flexion on the leading leg, knee extension on the trailing leg at stride foot contact, and upward displacement of the body's center of mass in the stride phase were significantly correlated with decreased peak elbow varus torque (all P < .05). Moreover, 38% of the variance in peak elbow varus torque was explained by a combination of these 5 significant kinematic variables (P < .001). CONCLUSION: We found that 5 kinematic parameters during the stride phase and the combination of these parameters were associated with peak elbow varus torque. The stride phase provides biomechanical preparation for pitching and plays a key role in peak elbow varus torque in subsequent pitching phases. CLINICAL RELEVANCE: The present data can be used to screen pitching mechanics with motion capture assessment to reduce peak elbow varus torque. Decreased peak elbow varus torque is expected to reduce the risk of elbow medial pain and injury.

Comparison of scapular upward rotation during arm elevation in the scapular plane in healthy volunteers and patients with rotator cuff tears pre- and post-surgery.

BACKGROUND: Function loss caused by rotator cuff tears alters the scapular orientation, however, few prior studies have reported on scapular movements after rotator cuff repair. The purpose was to determine the scapular orientations before and after rotator cuff repair. METHODS: We recruited 14 healthy controls, 10 small and six massive rotator cuff tear in patients. The scapular upward rotation during arm elevation was analyzed using fluoroscopic imaging. FINDINGS: Before surgery, both rotator cuff groups demonstrated greater scapular upward rotation compared to healthy controls. Two months postoperation, the analyses showed significant differences between the patients with small rotator cuff tears and healthy controls at arm elevations of 90°, and between patients with both rotator cuff tear groups and healthy controls at arm elevations of 120°. At five months post-operation, significant differences still existed between the healthy controls and both rotator cuff groups. In regard to the temporal effects in the patients with small rotator cuff tears, the scapular upward rotation decreased significantly over time (2-5 months postoperation) at arm elevations of 120°. We did not identify a main effect owing to time in the patients with massive rotator cuff tears. INTERPRETATION: In patients with small rotator cuff tears, scapular upward rotation was reduced over the period of 2-5 months postoperation, however, the patients with massive rotator cuff tears showed greater scapular upward rotation throughout the experimental period. The results suggested that the execution of the rehabilitation program should consider that the tear size could affect scapular motion.

Estimation of Shoulder Behavior From the Viewpoint of Minimized Shoulder Joint Load Among Adolescent Baseball Pitchers.

BACKGROUND: During pitching, an overloaded joint reaction force exerted on the shoulder and excessive shoulder horizontal abduction at ball release are considered risk factors causing anterior shoulder pain for young baseball pitchers. Hypothesis/Purpose: The first aim was to examine the relationship between shoulder horizontal abduction position and force on the shoulder at ball release. The second was to identify the relative rotational position of the shoulder and the range of shoulder motion at ball release that minimize force on the shoulder. It was hypothesized that the amount of force on the shoulder would be exacerbated by excessive shoulder horizontal abduction. STUDY DESIGN: Descriptive laboratory study. METHODS: Participants were 183 adolescent baseball pitchers (mean ± SD age, 15.5 ± 1.2 years) without shoulder/elbow problems. Each pitcher threw 5 fastballs to a catcher behind a home plate. The kinematics and kinetics of the throwing shoulder during fastball pitching were calculated with 3-dimensional measurements from 36 reflective markers. In data analysis, the correlations were calculated between the relative rotational positions of the shoulder (abduction, horizontal adduction-abduction) and the forces on the shoulder (anterior-posterior, proximal, and superior-inferior) at ball release. Subsequently, the specific rotational position and range of motion of the shoulder at ball release that minimized forces on the shoulder were determined. RESULTS: Statistically significant correlations were identified between the magnitude of superior-inferior force on the shoulder and shoulder abduction position ( R2 = 0.44, P < .001) as well as between the magnitude of anterior-posterior force on the shoulder and shoulder horizontal adduction-abduction position ( R2 = 0.72, P < .001). Minimal anterior-posterior and superior-inferior forces were obtained with a combination of 80.6° of shoulder abduction and 10.7° of shoulder horizontal adduction. Any deviation >5° from this position significantly increased the anterior-posterior and superior-inferior forces on the shoulder. CONCLUSION: Increasing shoulder horizontal abduction position significantly increased the magnitude of anterior force on the shoulder at ball release. The combination of 80.6° of shoulder abduction and 10.7° of horizontal shoulder adduction minimized the shear forces on the shoulder at this point. CLINICAL RELEVANCE: The present data can be useful for screening pitching technique to prevent shoulder pain and injury with motion capture assessment.

What information can change the attitude of teachers toward the human papillomavirus vaccine?

AIM: We conducted a self-administered survey on the perception of teachers toward human papillomavirus (HPV) vaccine to determine the ways to increase their willingness to encourage its use. METHODS: Answers were obtained both prior to and after having the teachers read five brief information articles: (i) cervical cancer knowledge, (ii) vaccine knowledge, (iii) result of a survey in Nagoya, (iv) news report of the World Health Organization statement and (v) articles written by Dr Muranaka, a journalist. RESULTS: Most of the respondents (180/247) did not know about the natural history of cervical cancer. Only 36% knew that HPV is the cause of cervical cancer, although 63% knew that HPV vaccine would prevent cervical cancer. Few respondents had knowledge regarding adverse events following immunization and the survey results from Nagoya. Among those who were initially negative for the HPV vaccine, only 43% revealed that they fully understood its safety and only 29% reversed their opinion to recommend vaccination to their daughters and/or students, even after reading our informational material. The most useful information for changing their attitudes was to increase their understanding of vaccines and informing them about Nagoya city survey results. They mostly wanted a proof of the preventive effects of the vaccine on cervical cancer in Japan. CONCLUSION: Gynecologists and pediatricians must proactively communicate accurate scientific information to the government and the media to spread awareness among people in Japan. Also, we must try to demonstrate the capabilities of this vaccine to prevent cervical cancer and/or its precancerous lesions.

Three-dimensional kinematic analysis of throwing motion focusing on pelvic rotation at stride foot contact.

BACKGROUND: Because the throwing motion can be considered a kinetic chain, pelvic and trunk motion should be included in the analysis. Early pelvic rotation during the throwing sequence has been reported to be a factor leading to overloading of the shoulder and the elbow. A large pelvic rotation angle at the stride foot contact (SFC) was thought to indicate early pelvic opening. This study examined the kinematic features in each motion segment associated with increased pelvic rotation at SFC in pitchers of various ages and competition levels. MATERIALS AND METHODS: The study included 324 pitchers with various age/competition levels. Throwing motion was analyzed using an infrared-type motion capture system. In the assessment, pelvic rotation angle at SFC was adopted as a parameter for the timing of pelvic opening. Statistical analyses were performed for correlation between pelvic rotation and kinematic variables of other motion segments at the instant of SFC as well as the difference in kinematics between the groups of different levels. RESULTS: Most of the kinematic results were not significantly different among the 4 groups with different levels. The increase in the pelvic opening angle at SFC was significantly correlated with increased trunk bend to the nonthrowing arm side and decreased hip flexion angle on the throwing arm side. DISCUSSION AND CONCLUSION: Early pelvic rotation in the throwing motion sequence, as manifested by increased pelvic rotation at SFC, was correlated with changes in kinematic parameters at other motion segments such as increased trunk tilt and decreased hip flexion.

Characteristics and Clinical Outcomes in Overhead Sports Athletes after Rotator Cuff Repair.

Rotator cuff tears in young overhead sports athletes are rare. The pathomechanism causing rotator cuff tears in young overhead athletes is different from that in aged patients. The purpose of this study was to investigate rotator cuff tear characteristics in young overhead sports athletes to reveal the pathomechanism causing these injuries. This study included 25 overhead sports athletes less than 30 years old with atraumatic rotator cuff tears necessitating repair. Rotator cuff tear characteristics were evaluated intraoperatively, including rotator cuff tear shape and injured rotator cuff tendon. Clinical outcome measures were assessed before surgery and at the final follow-up. In this study, 22 patients reported minimal to no shoulder pain and returned to sports without significant complaints at last follow-up. The isolated infraspinatus tendon was most often injured; the incidence rate of the tear at this site was 32% (8 cases). In the deceleration phase of overhead motion, the eccentric contraction force of the ISP (infraspinatus) tendon peaks and the increased load leads to injury at the ISP tendon. The pathomechanism of rotator cuff injuries in young overhead athletes might be not only internal or subacromial impingement, but also these mechanisms.

Assessment of the restriction of arm elevation after intramedullary fixation for proximal humeral fractures.

BACKGROUND: Nail protrusion is suspected as a reason for the restriction of arm elevation after antegrade nailing of proximal humeral fractures, although assessment of the restriction of the glenohumeral joint during arm elevation has been insufficient. METHODS: In this retrospective study, 30 shoulders with proximal humeral fractures in 29 cases were treated with Polarus short nails (Acumed, Beaverton, OR, USA). At a mean final follow-up of 14 months, clinical outcomes, bony union, alignment including retroversion of the head and entry points of the nails were evaluated. The ability of a subject to achieve maximum elevation above the zero position was also evaluated. RESULTS: Constant and Japanese Shoulder Association scores were a mean (SD) of 54 (12) and 71 (8.9) points, respectively. Even though all cases achieved bony union without mal-alignment of the head and greater tuberosity height or protrusion of the nail at its entry point, only six subjects could achieve maximum elevation above the zero position. CONCLUSIONS: Based on these findings, treatment of proximal humeral fractures with an antegrade humeral nail inserted from the top of the humeral head results in restricted arm elevation, even in patients without nail protrusion or fragment malalignment.