Poor results after pyrocarbon interpositional shoulder arthroplasty.

BACKGROUND: This study aimed to describe the clinical outcomes and complications of 10 cases of pyrocarbon interposition shoulder arthroplasty (PISA). METHODS: The clinical and radiographic records of 10 patients who underwent PISA using the InSpyre shoulder prosthesis (Tornier-Wright) between July 2012 and March 2017 were reviewed. The mean age at surgery was 55 years. Surgical indications included patients aged <60 years with Walch type B glenoid glenohumeral osteoarthritis (n = 7), avascular necrosis (AVN) of the humeral head (n = 1), or secondary severe glenohumeral osteoarthritis with axillary nerve dysfunction (n = 2). Outcomes of interest were postoperative complications and need for revision surgery, preoperative and postoperative patient-reported outcomes (Constant score [CS] and Subjective Shoulder Value [SSV]), and range of motion. The radiographic characteristics of the implants were evaluated. RESULTS: Among the 10 patients, 5 underwent revision to reverse shoulder arthroplasty during the study period owing to poor clinical outcomes based on the CS and SSV. All 5 revised patients had Walch type B glenoid morphology at the time of the index procedure. The mean time to revision surgery in this subset of patients was 60 months. The remaining 5 patients who did not undergo any revision procedure had significant improvement in mean CS and SSV from 30-65 points and 32%-87%, respectively, but at a shorter duration of follow-up of 35 months. CONCLUSION: High clinical failure rate and poor results at mean 5-year follow-up were found in younger PISA patients with baseline Walch B glenohumeral osteoarthritis. We would caution against use of PISA in this challenging patient population. PISA yielded more favorable short-term outcomes in patients with humeral-sided deformity or severe secondary glenohumeral osteoarthritis with axillary nerve dysfunction; however, longevity of the implant in this population remains unclear.

Injuries in Japanese university handball: a study among 1017 players.

The aim of this study was to examine the injury profile of Japanese university handball players. In this cross-sectional study, a total of 1017 participants who played in the 2018 Japanese National University Handball Championship were followed. The incidence within the previous year was 0.59 [95% CI, confidence interval: 0.56-0.62] per player per year. The ankle (33.3%), knee (23.6%), and shoulder/clavicle (12.6%) were the body regions most affected by traumatic mechanisms, while the lumbar spine/lower back (26.0%), knee (15.7%), and shoulder (15.0%) were the body regions most affected by overuse mechanisms. Sprain (30.7%), ligamentous rupture (23.2%), and fracture (11.8%) were the main types of traumatic injuries, and stress fracture (25.0%) and lesion of meniscus or cartilage (25.0%) were the main types of overuse injuries. Female players were 1.5 times more likely (OR, odds ratio: 1.55 [95% CI: 1.20-2.01]) to experience an injury than their male counterparts, and line players were also 1.5 times more likely (OR: 1.49 [95% CI: 1.00-2.21]) to experience an injury than their wing counterparts. This study showed that there is a need for increased injury prevention efforts in Japanese handball, especially among female players.

Near-infrared fluorescence imaging with indocyanine green-lactosomes in a mouse model of rheumatoid arthritis.

OBJECTIVES: The early diagnosis and treatment of rheumatoid arthritis (RA) is important to reduce joint destruction. Many of the current imaging techniques have disadvantages, such as the need for contrast agents and interpretation by specialists. Fluorescence imaging is an emerging technique that overcomes some of these problems. The aim of this study was to determine whether near-infrared (NIR) fluorescence imaging of indocyanine green (ICG)-lactosomes can detect joint inflammation in a mouse model of RA. METHODS: Control and arthritic SKG/Jcl mice were injected with ICG alone or ICG-lactosomes and examined by NIR fluorescence imaging. Arthritis severity was assessed macroscopically and histopathologically. RESULTS: ICG fluorescence was detected in the liver soon after injection and then decreased over the next several hours. ICG was not detected in the joints of control or arthritic mice. In contrast, ICG-lactosomes remained in mice for at least 48 h and accumulated specifically at inflamed joints. ICG-lactosome fluorescence was higher in arthritic versus normal joints at all times examined and was maximal at 24 h after injection. CONCLUSIONS: NIR fluorescence imaging of ICG-lactosomes detects arthritic joints in a mouse model of RA. ICG-lactosomes may preferentially localize to inflamed joints via enhanced permeability and retention.

Clinical Significance of Maximum Intensity Projection Method for Diagnostic Imaging of Thoracic Outlet Syndrome.

The aim of this study was to use the magnetic resonance imaging maximum-intensity projection (MRI-MIP) method for diagnostic imaging of thoracic outlet syndrome (TOS) and to investigate the stricture ratios of the subclavian artery (SCA), subclavian vein (SCV), and brachial plexus bundle (BP). A total of 113 patients with clinically suspected TOS were evaluated. MRI was performed in a position similar to the Wright test. The stricture was classified into four grades. Then, the stricture ratios of the SCA, SCV, and BP in the sagittal view were calculated by dividing the minimum diameter by the maximum diameter of each structure. Patients were divided into two groups: surgical (n = 22) and conservative (n = 91). Statistical analysis was performed using the Mann-Whitney U test. The stricture level and ratio in the SCV were significantly higher in the surgical group, while the stricture level and the ratio of SCA to BP did not show significant differences between the two groups. The MRI-MIP method may be helpful for both subsidiary and severe diagnoses of TOS.

Injury pattern based on player positions in Japanese university handball: a cross-sectional study of 2056 players.

BACKGROUND: Although it is evident that the risk of injury in handball varies according to player position, it is unclear whether the characteristics of these injuries also differ. The aim of this study was to characterize and compare the position-associated injury profiles of university handball players in Japan. METHODS: A total of 2056 participants who played in the 2018 and 2019 Japanese National University Handball Championships were included in this cross-sectional study. A self-reported injury questionnaire regarding demographic and injury-related information was administered. RESULTS: The overall prevalence of injury during the one-year period preceding the questionnaire was 44.1%, and back (47.9%) and line (49.2%) players exhibited a higher proportion of injuries than players in other positions (P<0.001). The ankle, knee, and shoulder/clavicle were the most common body regions affected by traumatic injuries, and knee and shoulder/clavicle injuries differed based on player positions (P=0.033). Conversely, overuse injuries predominantly affected the lumber spine/lower back, knee, and foot/toe, although there were no significant differences between player positions (P=0.188). In terms of injury mechanism, line players exhibited a higher proportion of contact injuries and goalkeepers had a higher proportion of non-contact injuries than that of other positions (P<0.001). CONCLUSIONS: Back and line players experienced more injuries than players in other positions. Depending on the player position, there were significant differences in the prevalence and patterns of injury. Therefore, injury prevention measures need to consider the characteristics of injuries based on player positions.

Injury pattern according to player position in Japanese youth handball: A cross-sectional study among 2377 players.

OBJECTIVE: Although the incidence and pattern of injuries in youth handball have widely been investigated, it is unclear whether the characteristics of injuries differ on the basis of player position. This study aimed at revealing the player position-based injury profile in Japanese youth handball players. DESIGN: Cross-sectional. SETTING: Injury questionnaire. PARTICIPANTS: Overall, 2377 participants who played in the 2018 and 2019 Japanese National High School Handball Championships were included. MAIN OUTCOME MEASURES: Prevalence, body region, type, severity, and mechanism of injuries were collected through a questionnaire. RESULTS: The overall prevalence of injury within the previous year was 46.7%, and the proportion of back players (52.8%) who sustained at least one injury was higher than that of players in other positions (p < 0.001). Differences in player positions were found among overuse injuries by body region, with a higher proportion of the lower leg and knee in wings and backs, respectively (p = 0.047). Among traumatic injuries, a higher proportion of ligamentous rupture in backs and fracture in lines were seen (p = 0.011). CONCLUSION: There were significant differences in the prevalence and patterns of injuries between player positions. Therefore, injury prevention programmes should consider the characteristics of player positions.

An Objective Measure of Patellar Tendon Thickness Based on Ultrasonography and MRI in University Athletes.

Ultrasonography and MRI are used for imaging evaluation of patellar tendinopathy, and "thickening of the tendon" is known as one of the characteristic findings. However, there are no evidence-based quantitative criteria to help evaluate this phenomenon. The purpose of this study was to investigate an objective measure of patellar tendon thickness. Patellar tendon thickness was evaluated in 65 elite university athletes using both ultrasonography and MRI. The relationship between tendon thickness and clinical patellar tendinopathy was investigated, and the cutoff value of the tendon thickness was calculated. Of the 129 knees included in the analysis, clinical patellar tendinopathy was found in 16 knees (12.4%). The proximal patellar tendon was significantly thicker in athletes with clinical patellar tendinopathy on both ultrasonography (8.3 mm vs. 5.1 mm; p < 0.001) and MRI (9.9 mm vs. 5.5 mm; p < 0.001). Setting the cutoff value to a thickness of >7.0 mm was an accurate predictor of clinical patellar tendinopathy (ultrasonography: sensitivity 81.3%, specificity 95.6%; MRI: sensitivity 100%, specificity 89.4%). Both ultrasonography and MRI measurement of the proximal patellar tendon thickness reflected the presence of clinical patellar tendinopathy. Defining "thickening of the patellar tendon" as thicker than 7.0 mm on both ultrasonography and MRI therefore has clinical significance.

Can Lateralization of Reverse Shoulder Arthroplasty Improve Active External Rotation in Patients with Preoperative Fatty Infiltration of the Infraspinatus and Teres Minor?

(1) Background: Postoperative recovery of external rotation after reverse shoulder arthroplasty (RSA) has been reported despite nonfunctional external rotator muscles. Thus, this study aimed to clinically determine the ideal prosthetic design allowing external rotation recovery in such a cohort. (2) Methods: A monocentric comparative study was retrospectively performed on patients who had primary RSA between June 2013 and February 2018 with a significant preoperative fatty infiltration of the infraspinatus and teres minor. Two groups were formed with patients with a lateral humerus/lateral glenoid 145° onlay RSA-the onlay group (OG), and a medial humerus/lateral glenoid 155° inlay RSA-the inlay group (IG). Patients were matched 1:1 by age, gender, indication, preoperative range of motion (ROM), and Constant score. The ROM and Constant scores were assessed preoperatively and at a minimum follow-up of two years. (3) Results: Forty-seven patients have been included (23 in OG and 24 in IG). Postoperative external rotation increased significantly in the OG only (p = 0.049), and its postoperative value was significantly greater than that of the IG by 11.1° (p = 0.028). (4) Conclusion: The use of a lateralized humeral stem with a low neck-shaft angle resulted in significantly improved external rotation compared to a medialized humeral 155° stem, even in cases of severe fatty infiltration of the infraspinatus and teres minor. Humeral lateralization and a low neck-shaft angle should be favored when planning an RSA in a patient without a functional posterior rotator cuff.

Positional anterior sternoclavicular joint dislocation in the acceleration phase of throwing: a case report.

Positional anterior sternoclavicular joint (SCJ) dislocation is relatively rare and needs careful treatment. We report our course of treatment and tips for surgery in a case. The patient was a 16-year-old male outfield baseball player. Three years ago, he had 3 recurrent episodes of right shoulder dislocation. During these injuries, there were forward dislocations of the proximal right clavicle edge accompanied by a creaking sound during the throw acceleration period. Thereafter, the anterior dislocation of the SCJ occurred during the acceleration phase of throwing, and the SCJ naturally repositioned on the shoulder resting position. This situation lingered and he often felt shoulder apprehension during throws, so he opted for surgical treatment just 1 month after the first injury. We performed a modified version of the figure-of-8 technique reported by Wang et al, using the ipsilateral palmaris longus (PL) tendon. The bilateral edge of the PL was attached to a Krackow suture and passed through the bone tunnels opened at the proximal clavicle and proximal sternum so that it became a figure of 8 on the anterior of the SCJ. The stability of the SCJ was confirmed after the surgery.

Shoulder motion assistance using a single-joint Hybrid Assistive Limb® robot: Evaluation of its safety and validity in healthy adults.

PURPOSES: To evaluate the feasibility of using the single-joint Hybrid Assistive Limb® robot (HAL) to assist with shoulder flexion-extension in healthy adults, and to assess the capacity of the HAL to analyze the bioelectrical signals of muscle activity for shoulder flexion-extension. METHODS: This cross-sectional feasibility study included six healthy adult men with no impairment in shoulder motion. The single-joint HAL was fixed to a custom-designed platform and upper arm attachment, and aligned 3 cm below the acromion process. Vital signs, shoulder fatigue, and shoulder pain were evaluated before and after the shoulder elevation exercise performed with and without the HAL. Activity of selected muscles of the shoulder was recorded using a wireless superficial electromyography device. Shoulder movement was captured using a three-dimensional motion analysis system. RESULTS: The HAL supported smooth flexion-extension of the arm at the shoulder joint, with no negative effects on vital signs, shoulder fatigue, and shoulder pain. The HAL decreased muscle activity levels, with a 55% decrease in trapezius muscle activity. The upward rotation angle of the scapula was significantly lower with the HAL at 120° of shoulder flexion. CONCLUSION: The single-joint HAL provided safe and effective assistance to scapular plane shoulder flexion-extension among healthy adults.

Hip prosthesis in sitting posture for bilateral transfemoral amputee after burn injury: a case report.

BACKGROUND: To overcome the challenges of rehabilitation of bilateral transfemoral amputees, we developed a novel "hip prosthesis in the sitting posture." Case Description and Methods: A 64-year-old male bilateral transfemoral amputee was transferred for rehabilitation 4 months following a burn injury. His wounds remained unhealed for 20 months; thus, he was unable to participate in standing training with the standard prosthetic sockets. Hip prosthesis in the sitting posture has very little friction between the sockets and residual limbs, which facilitated our patient to begin standing and walking exercises. Findings and Outcomes: The patient's refractory wounds healed 1 month after initiating exercises using hip prosthesis in the sitting posture, and he could begin rehabilitation with the standard prostheses. DISCUSSION AND CONCLUSION: Hip prosthesis in the sitting posture enabled a bilateral transfemoral amputee with unhealed residual limbs to stand, walk, and begin balance training. Hip prosthesis in the sitting posture is an effective temporary prosthesis to prevent disuse until wounds are healed and to continue rehabilitation with standard prostheses. Clinical relevance Hip prosthesis in the sitting posture is useful for bilateral transfemoral amputees with unhealed residual limbs after burn injuries to prevent disuse and maintain motivation for walking.