Reliability and validity of estimated angles information assessed using inertial measurement unit-based motion sensors.

Background: Inertial measurement unit (IMU)-based motion sensors are affordable, and their use is appropriate for rehabilitation. However, regarding the accuracy of estimated angle information obtained from this sensor, it is reported that it is likely affected by velocity.

Objective: The present study investigated the reliability and validity of the angle information obtained using IMU-based sensors compared with a three-dimensional (3D) motion analyzer.

Validity of the estimated angular information obtained using an inertial motion capture system during standing trunk forward and backward bending.

Background: Bending the trunk forward and backward while standing are common daily activities and can have various patterns. However, any dysfunction in these movements can considerably affect daily living activities. Consequently, a comprehensive evaluation of spinal motion during these activities and precise identification of any movement abnormalities are important to facilitate an effective rehabilitation.

The effect of continuous interscalene brachial plexus block for arthroscopic rotator cuff repair.

Background: Arthroscopic rotator cuff repair (ARCR) is a minimally invasive surgical technique. However, it is challenging to control postoperative pain. This study aimed to investigate the difference between a single-shot interscalene block and a combined continuous block for ARCR.

Muscle belly ratio is the most suitable estimate of the activity of the torn supraspinatus muscle.

Background: A torn rotator cuff muscle deteriorates over time leading with an increase in muscle atrophy and fatty infiltration. There are several clinical assessments for evaluating the atrophy of the torn supraspinatus muscle. However, it is unclear which approach can more accurately estimate the activity of the torn supraspinatus muscle.

Shoulder activity of the contralateral shoulder as a prognostic factor in patients with arthroscopic rotator cuff repair.

Background: This study aimed to investigate the prognosticator of the contralateral rotator cuff in patients who underwent arthroscopic rotator cuff repair (ARCR) for symptomatic rotator cuff tear (RCT).

Methods: A total of 104 patients with a mean age of 64.7 years (range, 40-83 years) underwent ARCR and were checked for the presence of a contralateral RCT using preoperative ultrasonography.

The functional role of the supraspinatus and infraspinatus muscle subregions during forward flexion: a shear wave elastography study.

Background: Knowledge of the morphological and functional differences in the anatomic subregions of the supraspinatus (SSP) and infraspinatus (ISP) muscles during forward flexion will provide useful information in the management of shoulder joint disorders. The purpose of this study was to investigate whether the SSP and ISP muscle subregions exhibit independent roles during forward flexion of the shoulder joint.

Methods: Eight healthy male volunteers without any restriction in their shoulder joints were recruited for this study.

Effectiveness of Bone Marrow-Derived Platelet-Rich Fibrin on Rotator Cuff Healing in a Rabbit Degenerative Model.

Background: Platelet-rich fibrin (PRF) is a second-generation platelet concentrate. Although peripheral blood-derived PRF (P-PRF) is commonly applied in biological augmentation, there is no report about the therapeutic effect of bone marrow-derived PRF (BM-PRF) for degenerative rotator cuff tears (RCTs).

Purpose/hypothesis: To examine the effects of platelet-rich plasma (PRP), P-PRF, and BM-PRF during rotator cuff repair (RCR) in degenerative RCTs in rabbits.

A Systolic Blood Pressure of 100 mm Hg Is Optimal for Optimal Visualization in Arthroscopic Rotator Cuff Repair in the Beach-Chair Position.

Purpose: To investigate the relationship between visualization and blood pressure during arthroscopic rotator cuff repair (ARCR) in the beach-chair position and to clarify the optimal blood pressure to maintain good visualization during surgery.

Methods: One senior surgeon evaluated intraoperative visualization at the start of arthroscopy, at acromioplasty, at the refresh of the footprint on the greater tuberosity, at marrow vent creation in the footprint on the greater tuberosity, and at rotator cuff fixation. The evaluation grades were: 5, clear; 4, mild bleeding; 3, bleeding but operable; 2, poor visualization due to bleeding; and 1, inability to continue surgery due to massive bleeding.

Risk factors related to complications of the fingers and hand after arthroscopic rotator cuff repair - carpal tunnel syndrome, flexor tenosynovitis, and complex regional pain syndrome.

Hypothesis/background: Complications involving the fingers and hand after arthroscopic rotator cuff repair (ARCR) include complex regional pain syndrome, carpal tunnel syndrome (CTS), and flexor tenosynovitis (TS). The aims of this study were to diagnose the complications after ARCR and investigate the risk factors that could predispose individuals to these finger and hand complications.

Methods: Fifty patients (50 shoulders) who underwent ARCR participated in this study.

Factors correlated with the optimal tension for arthroscopic rotator cuff repair using Grasper Tensioning Attachment.

Background: Little is known about the optimal tension in arthroscopic rotator cuff repair (ARCR). This study aimed to identify preoperative, intraoperative, and postoperative factors that correlate with the tension in ARCR and to determine the optimal intraoperative tension using Grasper Tensioning Attachment, a tension meter attached to the common arthroscopic surgical grasper.

Methods: This study included 63 patients with a mean age at surgery of 65.

Influence of fat infiltration, tear size, and post-operative tendon integrity on muscle contractility of repaired supraspinatus muscle.

Background: The purpose of this study was to evaluate the effect of fat infiltration, tear size, and post-operative tendon integrity, on post-operative contractility.

Methods: Thirty-five patients who underwent rotator cuff repair were included. The fat infiltration, tear size, and post-operative tendon integrity were evaluated by Goutallier stage, Cofield classification, and Sugaya classification, respectively.

Elastographic Region of Interest Determination for Muscle with Fat Infiltration.

Purpose: Ultrasound elastography has been used to evaluate the skeletal muscle stiffness as a biomarker for sarcopenia assessment. However, there is no consensus with respect to the size and location of the region of interest in assessing such fat infiltrated muscle. The objective of this study was to determine which cross-sectional area should be measured in torn disuse muscle with fat infiltration to accurately measure muscle activity using real-time tissue elastography (RTE).

Early detection and treatment of complications in the fingers and hand after arthroscopic rotator cuff repair.

Background: Complications in the fingers and hand after arthroscopic rotator cuff repair (ARCR) have been reported to include carpal tunnel syndrome (CTS), flexor tenosynovitis (TS), and complex regional pain syndrome. These studies were conducted retrospectively; however, the reported complications have not been examined prospectively. The aim of this study was to evaluate the outcomes of early detection and treatment of the complications after ARCR.

Complications of the Fingers and Hand After Arthroscopic Rotator Cuff Repair.

Background: Complications of the fingers and hand that occur after Arthroscopic Rotator Cuff Repair (ARCR) have not been examined in detail.

Objective: The aim of our study was to evaluate the diagnosis and treatment of complications of the fingers and hand that occur after ARCR and to examine treatment outcomes.

Methods: The case records of 40 patients (41 shoulders) who underwent ARCR using suture anchors were retrospectively reviewed to investigate complications of the fingers and hand after ARCR.

Contractile property measurement of the torn supraspinatus muscle using real-time tissue elastography.

Hypothesis: In the restoration of shoulder abduction, decreased contractility of the torn rotator cuff muscle may be a cause of a poor result. The aim of this study was to investigate the relationship between the contractile property of the torn supraspinatus muscle measured by real-time tissue elastography and the Goutallier stage as modified by Fuchs et al. METHODS: The muscular hardness of the torn supraspinatus muscle was measured in 32 patients at rest and during isometric contraction with the shoulder abducted to 60° in the scapular plane.

Outcome of conservative treatment for Little League shoulder in young baseball players: factors related to incomplete return to baseball and recurrence of pain.

Background: The purpose of this study was to investigate the factors associated with poor results and pain recurrence in young baseball players with Little League shoulder (LLS).

Methods: Eighty-seven young baseball players with LLS (mean age, 12.1 years) underwent conservative treatment.

The Incidence of Atypical Femoral Fractures in Patients with Rheumatic Disease: Yamagata Prefectural Committee of Atypical Femoral Fractures (YamaCAFe) Study.

Atypical femoral fractures (AFFs) have been reported to occur with minimal or spontaneous subtrochanteric and femoral shaft fractures with a characteristic transverse pattern, compared with typical femoral fractures in young patients with high-energy trauma. AFFs are related to long-term use of bisphosphonates (BPs), glucocorticoids and rheumatic diseases. We have estimated a blind analysis of AFFs in rheumatic patients receiving BPs and glucocorticoids ordinary over a long time in all Yamagata prefectural area through radiographic examination.

Treatment for Ulnar Neuritis Around the Elbow in Adolescent Baseball Players: Factors Associated With Poor Outcome.

Background: Ulnar neuritis around the elbow is one of the injuries seen in throwing athletes. Outcomes of nonsurgical treatment and factors associated with failure outcomes have not been reported.

Purpose: To investigate the outcomes of treatments for ulnar neuritis in adolescent baseball players.

Outcome of nonoperative treatment for humeral medial epicondylar fragmentation before epiphyseal closure in young baseball players.

Background: Nonoperative treatment for humeral medial epicondylar fragmentation in baseball players, involving prohibition and limitation of throwing, has been reported to give good results. However, in some cases, such nonoperative treatment fails to yield an acceptable outcome.

Hypothesis: In nonoperative treatment for patients with medial epicondylar fragmentation, achievement of bone union of the fragmentation provides better clinical outcomes compared with those of patients with delayed bone union or nonunion.

Risk factors for elbow injuries among young baseball players.

Hypothesis: There are some risk factors that could predispose a young baseball player to elbow injuries.

Materials And Methods: Study participants were 294 baseball players aged 9 to 12 years old. A questionnaire, physical examination, and ultrasound imaging to investigate elbow injuries were performed.

Classification, treatment, and outcome of osteochondritis dissecans of the humeral capitellum. Surgical technique.

Background: Indications for the treatment of osteochondritis dissecans of the humeral capitellum have remained unclear. The aims of this study were to analyze the outcomes and to determine the most useful classification for the choice of treatment.

Methods: The cases of 106 patients with osteochondritis dissecans of the capitellum were studied retrospectively.