Location and size of the reverse Hill-Sachs lesion in patients with traumatic posterior shoulder instability.

BACKGROUND: In patients with traumatic posterior shoulder instability, little is known about the precise location and size of the reverse Hill-Sachs lesion. METHODS: Forty-nine shoulders of 47 patients with traumatic posterior instability were included in this study based on the following inclusion criteria: (1) a primary or recurrent traumatic posterior shoulder dislocation and (2) the initial event being caused by trauma. Patients were excluded if they had (1) no history of trauma, (2) prior shoulder surgery, (3) no computed tomographic (CT) examination, or (4) were seizure cases. Three-dimensional images of the humerus reconstructed from CT images were reviewed using an image analysis software. The location and size of the reverse Hill-Sachs lesion were measured and described on a clock face on the humeral head. RESULTS: The reverse Hill-Sachs lesion was observed in 25 of 49 shoulders (51%). The reverse Hill-Sachs lesions were located between 1:37 and 2:48. The depth of the reverse Hill-Sachs lesion (mean ± standard deviation) was 5.8 ± 2.2 mm. The extent of the reverse Hill-Sachs lesion was 35° ± 12°. The average orientation of the reverse Hill-Sachs lesion, represented by an angle measured from the 12 o'clock position, was 64° ± 12° and pointing toward 2:09 on a clock face. The mean length and width of reverse Hill-Sachs lesions were 9.7 ± 4.7 mm and 11.1 ± 3.6 mm, respectively. CONCLUSION: The reverse Hill-Sachs lesion was a semicircular compression fracture located on the anteromedial aspect of the humeral head. Compared with shoulders with anterior shoulder instability, the humeral defect was smaller and located more inferiorly in shoulders with posterior instability.

Non-thermal atmospheric pressure gas discharge plasma enhances tendon-to-bone junction repair in a rabbit model.

BACKGROUND: Plasma is a collection of active particles generated by dissociating molecules and ionizing atoms through applying high energy to a gas, such as high-sound heating or electrical shock. Recently, many reports have been published on the effectiveness of non-thermal atmospheric pressure gas discharge plasma (NTAPP) on living organisms. Furthermore, we have reported on the promotion of bone and tendon repair by NTAPP irradiation. We hypothesized that irradiation of NTAPP would promote the repair of the tendon-bone junction in a rotator cuff repair. This study investigated the effect of NTAPP irradiation on the healing process of the tendon-bone junction. METHODS: Among 36 Japanese white rabbits, the infraspinatus tendon was detached from the humeral insertion site. A 3.2 mm bone tunnel was then created at the original insertion site of the infraspinatus muscle. The left shoulder was irradiated with NTAPP at a distance of 1 cm from the bone tunnel for 5 minutes (plasma-treated group), while the right shoulder was not irradiated (control group). The rabbits were sacrificed at 2, 4, and 8 weeks postoperatively, and six of each were used for histological evaluation. Mechanical tests were also performed on six specimens each at 4 and 8 weeks. RESULTS: Histological evaluation showed that at 4 weeks, the histological tendon to bone maturing score was 6.8±1.3 in the plasma-treated group and 4.8±1.6 in the control group (p<0.01); at 8 weeks it was 9.0±1.0 in the plasma-treated group and 5.2±1.1 in the control group (p<0.01). Fibrocartilage formation and new bone formation were observed at both 4 and 8 weeks. In the mechanical test, the plasma-treated group had 75.0 ± 18.9 N in ultimate load to failure at 8 weeks. In the control group, it was 51.1±7.9 N. (p=0.04) CONCLUSION: The repair of the rotator cuff at the tendon-bone junction was significantly improved at 4 and 8 weeks by irradiation with NTAPP.

EFisioTrack System for Monitoring Therapeutic Exercises in Patients with Shoulder Orthopedic Injuries in a Hospital Setting: A Pilot Feasibility Study.

To assess the effects of the eFisioTrack monitoring system on clinical variables in patients with prescribed physiotherapy for shoulder injuries, twenty-four adult patients with shoulder orthopaedic injuries who underwent physical therapy treatment in a hospital setting participated in the study (twelve in the experimental group and twelve as controls). Clinical outcome measures were shoulder function and pain (Constant-Murley Score and Disabilities of the Arm, Shoulder, and Hand or DASH score). Each variable was measured by a blinded physiotherapist at baseline and at one month follow-up. Patients performed the prescribed exercises either supervised by the physiotherapist (control group) or in a separate room without therapist supervision (experimental group). There were no statistically significant differences between groups before treatment or at follow-up for any outcomes (p ≥ 0.05). There was a statistically significant decrease (p ≤ 0.05) of at least 10 points in both groups for the DASH score at follow-up. Differences in the total score and subjective components of the Constant-Murley were also evidenced within groups. The use of the eFisioTrack system showed similar results in clinical measures compared to those performed under the direct supervision of the physiotherapist. This approach might be suitable for providing an effective shoulder exercise program at home.

Severity of rotator cuff disorders and additional load affect fluoroscopy-based shoulder kinematics during arm abduction.

BACKGROUND: Rotator cuff disorders, whether symptomatic or asymptomatic, may result in abnormal shoulder kinematics (scapular rotation and glenohumeral translation). This study aimed to investigate the effect of rotator cuff tears on in vivo shoulder kinematics during a 30° loaded abduction test using single-plane fluoroscopy. MATERIALS AND METHODS: In total, 25 younger controls, 25 older controls and 25 patients with unilateral symptomatic rotator cuff tears participated in this study. Both shoulders of each participant were analysed and grouped on the basis of magnetic resonance imaging into healthy, rotator cuff tendinopathy, asymptomatic and symptomatic rotator cuff tears. All participants performed a bilateral 30° arm abduction and adduction movement in the scapular plane with handheld weights (0, 2 and 4 kg) during fluoroscopy acquisition. The range of upward-downward scapular rotation and superior-inferior glenohumeral translation were measured and analysed during abduction and adduction using a linear mixed model (loads, shoulder types) with random effects (shoulder ID). RESULTS: Scapular rotation was greater in shoulders with rotator cuff tendinopathy and asymptomatic rotator cuff tears than in healthy shoulders. Additional load increased upward during abduction and downward during adduction scapular rotation (P < 0.001 in all groups but rotator cuff tendinopathy). In healthy shoulders, upward scapular rotation during 30° abduction increased from 2.3° with 0-kg load to 4.1° with 4-kg load and on shoulders with symptomatic rotator cuff tears from 3.6° with 0-kg load to 6.5° with 4-kg load. Glenohumeral translation was influenced by the handheld weights only in shoulders with rotator cuff tendinopathy (P ≤ 0.020). Overall, superior glenohumeral translation during 30° abduction was approximately 1.0 mm with all loads. CONCLUSIONS: The results of glenohumeral translation comparable to control but greater scapular rotations during 30° abduction in the scapular plane in rotator cuff tears indicate that the scapula compensates for rotator cuff deficiency by rotating. Further analysis of load-dependent joint stability is needed to better understand glenohumeral and scapula motion. LEVEL OF EVIDENCE: Level 2. TRIAL REGISTRATION: Ethical approval was obtained from the regional ethics committee (Ethics Committee Northwest Switzerland EKNZ 2021-00182), and the study was registered at clinicaltrials.gov on 29 March 2021 (trial registration number NCT04819724, https://clinicaltrials.gov/ct2/show/NCT04819724 ).

Evaluation of a deep learning-based reconstruction method for denoising and image enhancement of shoulder MRI in patients with shoulder pain.

OBJECTIVES: To evaluate the diagnostic performance of an automated reconstruction algorithm combining MR imaging acquired using compressed SENSE (CS) with deep learning (DL) in order to reconstruct denoised high-quality images from undersampled MR images in patients with shoulder pain. METHODS: Prospectively, thirty-eight patients (14 women, mean age 40.0 ± 15.2 years) with shoulder pain underwent morphological MRI using a pseudo-random, density-weighted k-space scheme with an acceleration factor of 2.5 using CS only. An automated DL-based algorithm (CS DL) was used to create reconstructions of the same k-space data as used for CS reconstructions. Images were analyzed by two radiologists and assessed for pathologies, image quality, and visibility of anatomical landmarks using a 4-point Likert scale. RESULTS: Overall agreement for the detection of pathologies between the CS DL reconstructions and CS images was substantial to almost perfect (κ 0.95 (95% confidence interval 0.82-1.00)). Image quality and the visibility of the rotator cuff, articular cartilage, and axillary recess were overall rated significantly higher for CS DL images compared to CS (p < 0.03). Contrast-to-noise ratios were significantly higher for cartilage/fluid (CS DL 198 ± 24.3, CS 130 ± 32.2, p = 0.02) and ligament/fluid (CS DL 184 ± 17.3, CS 141 ± 23.5, p = 0.03) and SNR values were significantly higher for ligaments and muscle of the CS DL reconstructions (p < 0.04). CONCLUSION: Evaluation of shoulder pathologies was feasible using a DL-based algorithm for MRI reconstruction and denoising. In clinical routine, CS DL may be beneficial in particular for reducing image noise and may be useful for the detection and better discrimination of discrete pathologies. Assessment of shoulder pathologies was feasible with improved image quality as well as higher SNR using a compressed sensing deep learning-based framework for image reconstructions and denoising. KEY POINTS: • Automated deep learning-based reconstructions showed a significant increase in signal-to-noise ratio and contrast-to-noise ratio (p < 0.04) with only a slight increase of reconstruction time of 40 s compared to CS. • All pathologies were accurately detected with no loss of diagnostic information or prolongation of the scan time. • Significant improvements of the image quality as well as the visibility of the rotator cuff, articular cartilage, and axillary recess were detected.

Shoulder pain and injury risk factors in competitive swimmers: A systematic review.

AIM: To synthesize and assess the literature for shoulder pain and injury risk factors in competitive swimmers. DESIGN: Systematic review with best-evidence synthesis. DATA SOURCES: CINHAL, SportDiscus, Scorpus, PubMed, and Embase databases from 1966 to April 30 2022. SEARCH AND INCLUSION: Cohort, cross-sectional, and case-control studies investigating shoulder pain or injury risk factors in competitive swimmers were included. Quality of eligible studies were assessed using a modified Newcastle-Ottawa scale. Risk factors were divided into four categories: modifiable-intrinsic, modifiable-extrinsic, non-modifiable, and other/secondary. RESULTS: Of 1356 studies identified, 24 full texts were evaluated for methodological quality, 22 met the criteria and were included in best evidence synthesis. There was no strong evidence supporting or refuting the association between 80 assessed variables and shoulder injury or pain. The swimmers' competitive level (nondirectional), and shoulder muscle recruitment profiles (e.g., increased activity of serratus anterior) exhibited moderate evidence supporting an association. Conversely, internal and external range of motion, middle finger back scratch test, training frequency, specialty stroke, height/weight, sex, and age all had moderate evidence opposing an association. Limited evidence was found for 58 variables, and conflicting for 8. The highest quality study (n = 201) suggested high acute-to-chronic workload ratio and reduced posterior shoulder strength endurance are associated with injury. CONCLUSIONS: Due to the paucity of high-quality studies, future prospective studies are needed to reevaluate known risk factor associations over exploring additional potential risk factors. Swimming practitioners should be aware of the nondirectional association of a swimmer's competitive level and pain, as squad changes could impact injury incidence. Moreover, swimmers experiencing shoulder pain may show increased activity in shoulder stabilizers during specific movements. Importantly, shoulder strength-endurance may be the most clinically relevant modifiable intrinsic risk factor.

Is fixation of both clavicle and scapula better than clavicle alone in surgical treatment of floating shoulder injury? A retrospective study.

BACKGROUND & OBJECTIVE: Little research was available to explore which surgical fixation was better between fixation of both clavicle and scapula and clavicle alone in management of floating shoulder injury. METHODS: Total 69 patients with floating shoulder injury receiving surgery from February 2005 to July 2020 participated in the study. 49 patients underwent fixation of the clavicle alone (Group C) while 20 patients underwent fixation of both clavicle and scapula (Group C + S). They were further divided into subgroups according to age: Group C1, Group C + S1 (age ≤ 55 years old) and Group C2, Group C + S2 (age>55 years old). The radiological parameter (glenopolar angle (GPA)) and clinical outcomes (Herscovici score, Constant-Murley shoulder outcome score (CSS score), and Visual Analogue Scale score (VAS score)) were collected and compared between these groups. The correlation between age and radiological parameter and clinical outcomes was calculated by the Spearman correlation analysis. RESULTS: All people were followed up for at least 1 year. The degree of change in GPA before and after surgery in Group C + S is significantly better than that in Group C. The Herscovici and CSS score in Group C + S2 were significantly higher than those in Group C2 at 1 month, 3 months and 1 year after surgery. However, no significant difference in Herscovici and CSS score was found at final follow-up (1 year after surgery) between Group C + S1 and Group C1. The VAS score in Group C + S2 at final follow-up was significantly lower than that in Group C2. No significant difference in VAS score at final follow-up was found between Group C + S1 and Group C1. In addition, the VAS score was negatively correlated with Herscovici and CSS score. No correlation was found between VAS score and GPA. CONCLUSIONS: Both types of surgical fixation are effective in management of floating shoulder injury. For young people with floating shoulder injury, both types of surgical fixation are equally effective. However, for older people with floating shoulder injury, fixation of both clavicle and scapula is better in prognosis than fixation of clavicle alone.

Chronic stage magnetic resonance imaging findings in patients with shoulder injury related to vaccine administration (SIRVA).

PURPOSE: Identify chronic shoulder MRI findings in patients with known shoulder injury related to vaccine administration (SIRVA). MATERIALS AND METHODS: Two fellowship-trained musculoskeletal radiologists retrospectively reviewed the MRI of nine patients with clinically established SIRVA. MRI was performed at least 4 weeks after vaccination and included intravenous contrast-enhanced sequences. MRI was reviewed for the presence of erosions, tendonitis, capsulitis, synovitis, bone marrow oedema, joint effusion, bursitis, cartilage defects, rotator cuff lesions, and lymphadenopathy. The number and location of focal lesions were recorded. RESULTS: Erosions of the greater tuberosity were present in 8/9 (89%), tendonitis of the infraspinatus muscle tendon in 7/9 (78%), capsulitis, synovitis, and bone marrow oedema in 5/9 (56%) cases, respectively. Effusion was found in three, and subdeltoid bursitis, rotator cuff lesions as well as cartilage defects in one patient, respectively. None of our included subjects showed axillary lymphadenopathy. CONCLUSION: In this case series, greater humeral tuberosity erosions, infraspinatus muscle tendonitis, capsulitis, synovitis, and bone marrow oedema were common MRI findings in chronic SIRVA.

Alleviation of shoulder injury related to vaccine administration (SIRVA) pain and disability following COVID-19 vaccine with chiropractic biophysics® (CBP®) methods: a case report and long-term follow-up with global implications.

[Purpose] To present the dramatic improvement in posture, radiographic parameters and the alleviation of neck and severe shoulder pain related to shoulder injury associated with vaccine administration (SIRVA) after a COVID-19 injection with a shoulder mobility and posture rehabilitation program. [Participant and Methods] A middle-aged male presented complaining of severe left shoulder pain evolving since receiving a COVID-19 vaccination. The pain was severe and throbbed into the neck. Posture analysis showed a chronic stooped posture with forward head posture and thoracic hyperkyphosis. Treatment included 42 sessions of Chiropractic Biophysics® technique and a shoulder rehabilitation program using three-dimensional vibration. [Results] At 4-months, the patient reported no neck or shoulder pain. There was a 60% decrease in neck disability. The forward head decreased 34 mm, thoracic hyperkyphosis decreased 13°, and T1-T12 forward lean decreased 73 mm, among other radiographic parameters. Re-assessment after 26-months showed maintenance of the treatment induced posture/x-ray corrections and shoulder pain relief. [Conclusion] This case demonstrates immediate and long-term improvement in a patient suffering from COVID-19 vaccine SIRVA, concomitant with neck pain and disability as well as significant radiographic postural/spinal deformity. These conditions all improved and were maintained at a 2 year follow-up without further treatment.

Reconstruction of the coracoclavicular ligament with palmaris longus tendon and Mersilene tape for acromioclavicular dislocations.

BACKGROUND: Acromioclavicular (AC) joint dislocation is common among shoulder injuries, and various surgical methods have been introduced for effective ligament reconstruction. Reconstruction of the coracoclavicular (CC) ligament in the anatomical position using autologous tendons is a recent surgical trend. This study is to report clinical and radiologic results of reconstruction of the CC ligament using an autologous palmaris longus tendon interweaved with Mersilene tape (PLMT) with a minimum 2-year follow-up. METHODS: This retrospective study analyzed 76 patients (mean age, 43.4 ± 11.2 years) with AC joint dislocation treated by reconstruction of the CC ligament with PLMT, from March 2004 to February 2017. The mean follow-up period was 28 ± 6.7 months (range, 24-66 months). The Visual Analog Scale (VAS) for pain assessment, American Shoulder and Elbow Surgeons rating scale (ASES), and Constant Score (CS) were used to evaluate clinical outcomes at the preoperative and the final follow-ups. CC and AC distances were measured using anteroposterior (AP) X-ray preoperatively and at the final follow-up for radiologic outcomes. Complications were also assessed. RESULTS: The mean preoperative VAS for pain, ASES, CS were 5.7 ± 0.7, 77.1 ± 6.2, and 61.5 ± 5.2, respectively. These scores at the final follow-up improved to 2.1 ± 0.5, 90.9 ± 4.3, and 94 ± 7.0, respectively (p = 0.043, p <  0.001, p <  0.001). The mean preoperative CC and AC distances were 16.49 ± 3.73 mm and 13.84 ± 3.98 mm, respectively. The final follow-up CC and AC distances were 9.29 ± 2.72 mm and 5.30 ± 2.09 mm, respectively (p <  0.001, p <  0.001). Although a slight re-widening of the CC distance occurred in 10 patients (13.1%), most patients regained full range of motion of the affected shoulder at the final follow-up. CONCLUSION: The CC ligament reconstruction with PLMT for the treatment of AC joint dislocation showed good clinical and radiological results. This technique could be a good alternative treatment for AC dislocations.

Center of pressure (COP) measurement in patients with confirmed successful outcomes following shoulder surgery show significant sensorimotor deficits.

PURPOSE: To determine the sensorimotor and clinical function of patients with confirmed successful outcome after either undergoing acromioclavicular joint (ACJ) stabilization, Bankart repair (BR), or rotator cuff repair (RC), and to compare these measures to the contralateral, healthy side without history of previous injuries or surgeries of the upper extremity. It was hypothesized that patients of each interventional group would have inferior sensorimotor function of the shoulder joint compared to the contralateral, healthy side, while presenting with successful clinical and functional outcomes. METHODS: Three intervention groups including ten patients who had confirmed successful clinical and functional outcomes after either undergoing ACJ stabilization, BR, or RC were evaluated postoperatively at an average follow-up of 31.7 ± 11.6 months. Additionally, a healthy control group (CG) of ten patients was included. Clinical outcomes were assessed using the Constant-Murley (CM) and American Shoulder and Elbow Surgeons (ASES) Score. Pain was evaluated using the visual analogue scale (VAS). Sensorimotor function was assessed by determining the center of pressure (COP) of the shoulder joint in a one-handed support task in supine position on a validated pressure plate. RESULTS: Each interventional group demonstrated excellent clinical outcome scores including the CM Score (ACJ 83.3 ± 11.8; BR 89.0 ± 10.3; RC 81.4 ± 8.8), ASES Score (ACJ 95.5 ± 7.0; BR 92.5 ± 9.6; RC 96.5 ± 5.2), and VAS (ACJ 0.5 ± 0.9; BR 0.5 ± 0.8; RC 0.5 ± 0.8). Overall, the CG showed no significant side-to-side difference in COP, whereas the ACJ-group and the BR-group demonstrated significantly increased COP compared to the healthy side (ACJ 103 cm vs. 98 cm, p = 0.049; BR: 116 cm vs. 102 cm, p = 0.006). The RC-group revealed no significant side-to-side difference (120 cm vs. 108 cm, n.s.). CONCLUSION: Centre of pressure measurement detected sensorimotor functional deficits following surgical treatment of the shoulder joint in patients with confirmed successful clinical and functional outcomes. This may indicate that specific postoperative training and rehabilitation protocols should be established for patients who underwent surgery of the upper extremity. These results underline that sensorimotor training should be an important component of postoperative rehabilitation and physiotherapeutic activities to improve postoperative function and joint control. LEVEL OF EVIDENCE: IV.

Is early trunk rotation really hazardous for shoulder biomechanics in baseball throwing?

BACKGROUND AND HYPOTHESIS: Early trunk rotation (ETR), which is a unique kinematics of the trunk that occurs during baseball throwing, is thought to be related to shoulder injuries. Pelvic rotation is a confounder when studying the effects of trunk rotation on shoulder biomechanics. The purpose of this study was to understand the "pure" effects of trunk rotation on shoulder biomechanics, with pelvic rotation under control. Our hypotheses were as follows: (1) throwers with ETR have a different shoulder kinematics pattern compared with throwers without ETR; (2) throwers with ETR have a lower ball speed performance than do throwers without ETR; and (3) throwers with ETR have a greater value of shoulder forces and moments, which may increase risks of shoulder injury, than do throwers without ETR. METHODS: Fifty-seven elite throwers were enrolled and divided into 2 groups (non-ETR and ETR) using an outdoor motion analysis. Several kinematics and kinetics parameters of the shoulder were analyzed and compared between the 2 groups. RESULTS: Ball velocity was faster in the non-ETR group (127 km/h) compared with the ETR group (120 km/h). The shoulders of throwers in the ETR group showed pathokinematics of "horizontal adduction lag" and "dropped elbow." The increases in maximal posterior force, inferior force, horizontal abduction moment, and vertical adduction moment were 9.2%, 13.6%, 21.3%, and 24.3%, respectively, in the shoulders of throwers in the ETR group. These results indicate that ETR may be hazardous for the throwing shoulder. With lower ball velocity and higher shoulder joint loading, ETR is not a proper pitching pattern for kinetic energy transfer. CONCLUSION: Improper pitching mechanics among baseball throwers, such as ETR, may result in higher shoulder joint loading and increased risk of shoulder injuries. When treating throwers with shoulder injuries, it is important not only to address shoulder anatomy and pathology but also to understand the possible pathomechanics and pathogenesis of the shoulder caused by ETR. Furthermore, special training programs focusing on trunk flexibility and core muscle strengthening should be implemented to prevent ETR and decrease the risk of shoulder injuries. Motion analysis is useful for the screening and early detection of improper pitching mechanics in throwers.

Posterior shoulder capsule of the dominant arm is stiffer in baseball players than that in nonthrowing population.

BACKGROUND: Posterior shoulder capsule tightness is one of the factors for shoulder injuries in overhead athletes. Recent studies have shown the posterior capsule of the dominant arm to be stiffer than that of the nondominant arm in baseball players. However, whether posterior capsule tightness in the dominant arm is exclusive to overhead athletes remains unknown. This study aimed to investigate whether the posterior shoulder capsule of the dominant arm in baseball players is stiffer than that in nonthrowing population. METHODS: Fifteen male collegiate asymptomatic baseball players (baseball-player group) and fifteen male college students who did not partake in overhead sports (nonthrowing group) participated in this study. We measured the shear moduli of the middle and inferior posterior capsules, superior infraspinatus, inferior infraspinatus, teres minor, and posterior deltoid in the dominant arm by ultrasound shear wave elastography. We compared shear moduli between the two groups using an independent samples t-test and Mann-Whitney test. In addition, we investigated the correlation between the range of glenohumeral internal rotation and each shear modulus in each group using the Pearson correlation coefficient. RESULTS: The shear moduli in the baseball-player group were significantly higher than those in the nonthrowing group in both the middle posterior capsule (baseball-player group: 36.1 ± 5.6 kPa vs. nonthrowing group: 29.0 ± 8.6 kPa; P = .018) and inferior posterior capsule (37.1 ± 9.6 kPa vs. 27.9 ± 6.8 kPa; P = .002). However, no difference in the shear moduli of individual muscle groups was identified. The glenohumeral internal rotation range exhibited a statistically significant negative correlation with the shear modulus of the inferior posterior capsule in the baseball-player group (Pearson correlation coefficient = -0.586, P = .022). CONCLUSION: Our findings suggest that the posterior shoulder capsule of the dominant arm in baseball players is stiffer than that in nonthrowing population.

Return to play following nonsurgical management of superior labrum anterior-posterior tears: a systematic review.

BACKGROUND: Superior labrum anterior-posterior (SLAP) tears are common shoulder injuries, especially in overhead athletes. Often, initial management of these injuries is nonsurgical with focused rehabilitation. The purpose of this review was to evaluate the outcomes of nonsurgical management of SLAP tears in athletes. METHODS: A systematic review was performed for articles published before March 2021 using key search terms pertaining to clinical studies evaluating the nonsurgical treatment of SLAP tears in adult patients published in English-language literature. Abstracts and manuscripts were independently reviewed by 2 co-authors to determine eligibility. Return-to-play rate and return-to-prior-athletic-performance rate were determined by combining results across studies. RESULTS: Five articles met the inclusion criteria. There were 244 total athletes (162 elite or higher-level athletes). The mean ages ranged from 20.3 to 38.0 years. Type II SLAP tears were most common; baseball, softball, and weightlifting were the most common sports involved. The return-to-play rate was 53.7% in all athletes and 52.5% in elite or higher-level athletes. In athletes who were able to complete their nonoperative rehabilitation program, the return-to-play rate was 78% in all athletes and 76.6% in elite or higher-level athletes. The overall rate of return to prior performance was 42.6%, which increased to 72% for those athletes who were able to complete their rehabilitation. Patients who discontinued the rehabilitation protocol in favor of surgery had an average of 8 physical therapy sessions compared with 20 sessions for patients with successful nonoperative treatment. The timing of return to play was generally less than 6 months in studies that reported it. Patient-reported outcomes, including the American Shoulder and Elbow Surgeons score and visual analog scale, all improved significantly after nonsurgical treatment. Factors associated with failure of nonsurgical management included older age, participation in overhead sports (especially baseball pitchers), traumatic injury, positive compression rotation test, concomitant rotator cuff injury, longer baseball career, longer symptomatic period, and the presence of a Bennett spur. CONCLUSIONS: Overall, nonoperative treatment of SLAP tears in athletes can be successful, especially in the subset of patients who are able to complete their rehabilitation program before attempting a return to play. Although nonoperative treatment should be considered the first line of treatment for most SLAP tears, there are some factors that may be associated with failure of conservative treatment; therefore, further high level, prospective studies would be beneficial to identify those athletes most likely to respond favorably to nonoperative treatment.

The Effect of Exercise Therapy Interventions on Shoulder Pain and Musculoskeletal Risk Factors for Shoulder Pain in Competitive Swimmers: A Scoping Review.

CONTEXT: Shoulder pain is the main cause of missed or modified training in competitive swimmers. Exercise therapy can improve the outcomes, yet uncertainty exists regarding the characteristics of these interventions. OBJECTIVES: The primary aim was to describe the evidence base relating to the effectiveness of exercise therapy interventions on shoulder pain and shoulder musculoskeletal risk factors for shoulder pain in swimmers. The secondary aim was to identify gaps in the literature and provide recommendations for future research and practice. EVIDENCE ACQUISITION: A scoping review methodology was applied through the search of MEDLINE, PubMed, Scopus, Web of Science, and CINAHL databases. The authors included any research studies (except clinical commentaries and conference papers) that assess the effect of exercise therapy on shoulder pain and musculoskeletal risk factors for shoulder pain in swimmers. The literature was critically appraised using the Modified Down and Black checklist. EVIDENCE SYNTHESIS: From 452 papers identified, 14 studies were included in this review. An exercise program of 6 to 8 weeks, including strengthening exercises (shoulder external rotator and scapula retractor muscles) and stretches (pectoral muscles), can decrease the incidence of shoulder pain in swimmers. Furthermore, a combination of exercises and stretches with manual therapy techniques can help to decrease shoulder pain in injured swimmers. Regarding risk factors, a strengthening program of more than 12 weeks increased shoulder external rotation peak force, endurance, and external rotation/internal rotation ratio; however, this was not associated to decreases in pain. Finally, open kinetic chain exercises and a dry-land program are superior to close kinetic exercises and water training for improving shoulder external rotation strength and endurance. CONCLUSIONS: Exercise therapy has positive effects on reducing the incidence of shoulder pain, the management of shoulder pain, and improving shoulder musculoskeletal risk factors in competitive swimmers. However, due to methodological limitations of the studies, caution must be used when applying these results in practice. Future research should focus on high-quality randomized controlled trials for prevention and management of shoulder pain in swimmers.

Chronic inflammation and extracellular matrix-specific autoimmunity following inadvertent periarticular influenza vaccination.

BACKGROUND: Viral infections may trigger autoimmunity in genetically predisposed individuals. Immunizations mimic viral infections immunologically, but only in rare instances vaccinations coincide with the onset of autoimmunity. Inadvertent vaccine injection into periarticular shoulder tissue can cause inflammatory tissue damage ('shoulder injury related to vaccine administration, SIRVA). Thus, this accident provides a model to study if vaccine-induced pathogen-specific immunity accompanied by a robust inflammatory insult may trigger autoimmunity in specific genetic backgrounds. METHODS: We studied 16 otherwise healthy adults with suspected SIRVA occurring following a single work-related influenza immunization campaign in 2017. We performed ultrasound, immunophenotypic analyses, HLA typing, and influenza- and self-reactivity functional immunoassays. Vaccine-related bone toxicity and T cell/osteoclast interactions were assessed in vitro. FINDINGS: Twelve of the 16 subjects had evidence of inflammatory tissue damage on imaging, including bone erosions in six. Tissue damage was associated with a robust peripheral blood T and B cell activation signature and extracellular matrix-reactive autoantibodies. All subjects with erosions were HLA-DRB1*04 positive and showed extracellular matrix-reactive HLA-DRB1*04 restricted T cell responses targeting heparan sulfate proteoglycan (HSPG). Antigen-specific T cells potently activated osteoclasts via RANK/RANK-L, and the osteoclast activation marker Trap5b was high in sera of patients with an erosive shoulder injury. In vitro, the vaccine component alpha-tocopheryl succinate recapitulated bone toxicity and stimulated osteoclasts. Auto-reactivity was transient, with no evidence of progression to rheumatoid arthritis or overt autoimmune disease. CONCLUSION: Vaccine misapplication, potentially a genetic predisposition, and vaccine components contribute to SIRVA. The association with autoimmunity risk allele HLA-DRB1*04 needs to be further investigated. Despite transient autoimmunity, SIRVA was not associated with progression to autoimmune disease during two years of follow-up.

Interrater reliability of physical examination tests in the acute phase of shoulder injuries.

BACKGROUND: The physical examination is one of the cornerstones of the diagnostic process in patients with acute shoulder injuries. The discriminative properties of a given examination test depend both on its validity and reliability. The aim of the present study was to assess the interrater reliability of 13 physical examination manoeuvres for acute rotator cuff tears in patients with acute soft tissue shoulder injuries. METHODS: In a large walk-in orthopaedic emergency department, 120 consecutive patients ≥40 years of age were included in a diagnostic study. Patients who had follow-up within three weeks of an acute shoulder injury without fracture on radiographs were eligible. Four emergency department physicians participated as examiners. In a subset of 48 patients, the physical examination tests were performed by two physicians, randomly chosen by their work rotation. The physicians were blinded to the findings of each other and the results of the ultrasound screening. The interrater reliability was assessed by Cohen's kappa, intraclass correlation coefficient (ICC), standard error of measurement (SEM) and Bland-Altman plots depending on whether the examination test result was registered as a binary, ordered categorical or continuous numerical variable. RESULTS: The median age was 55.5 years, 46% were female. Twenty-seven percent had a rotator cuff full-thickness tear on ultrasound screening; all but one involved the supraspinatus tendon. Cohen's kappa for binary tests ranged from excellent to fair. Excellent agreement (kappa > 0.8) was found for the inability to abduct above 90° and abduction strength. External rotation strength expressed substantial agreement (kappa 0.7). The lowest scores were registered for Hawkins` test and the external rotation lag sign (kappa 0.25 and 0.40, respectively). The ICCs for active range of abduction and external rotation were 0.93 (0.88-0.96) and 0.84 (0.72-0.91), whereas the SEM was 15 and 9, respectively. CONCLUSIONS: The results indicate that examination manoeuvres assessing abduction and external rotation range of motion and strength are more reliable than manoeuvres assessing pain in patients in the acute phase of traumatic shoulder injury. The poor agreement observed is likely to limit the validity in the present setting of two commonly used tests. TRIAL REGISTRATION: The Norwegian Regional Ethics Committee South East ( 2015/195 ).

Young men in sports are at highest risk of acromioclavicular joint injuries: a prospective cohort study.

PURPOSE: To study the incidence of acromioclavicular joint injuries in a general population. METHODS: All acute shoulder injuries admitted to an orthopaedic emergency department were registered prospectively, using electronic patient records and a patient-reported questionnaire. The regional area was the city of Oslo with 632,990 inhabitants. Patients with symptoms from the acromioclavicular joint without fracture were registered as a dislocation (type II-VI) if the radiologist described widening of the joint space or coracoclavicular distance on standard anteroposterior radiographs. Patients without such findings were diagnosed as sprains (type I). RESULTS: Acromioclavicular joint injuries constituted 11% of all shoulder injuries (287 of 2650). The incidence was 45 per 105 person-years (95% confidence interval [CI] 40-51). 196 (68%) were diagnosed as sprains and 91 (32%) as dislocations. Median age of all acromioclavicular joint injuries was 32 years (interquartile range 24-44), and 82% were men. Thirty percent of all acromioclavicular joint injuries were registered in men in their twenties. Sports injuries accounted for 53%, compared to 27% in other shoulder injuries [OR 3.1 (95% CI 2.4-4.0; p < 0.001)]. The most common sports associated with acromioclavicular joint injuries were football (24%), cycling (16%), martial arts (11%), alpine skiing and snowboarding (both 9%), and ice hockey (6%). CONCLUSION: Our study suggests that in the general population, one in ten shoulder injuries involves the acromioclavicular joint and young men in sports are at highest risk. A prognostic level II cohort study.

Shoulder moments and angles during single and combined manual material handling tasks.

Shoulder musculoskeletal disorders due to manual material handling tasks are common workplace injuries. Here we investigated the difference in shoulder biomechanics (moments and angles) between a single task of removing a box from a shelf (or depositing a box on a shelf) and the equivalent part of a combined task that consisted of removing, carrying and depositing boxes; that is, a single removing [depositing] task was compared with the removing [depositing] part of a combined task. We found that the peak and cumulative shoulder moments were larger during the single-task paradigm than during the equivalent part of the combined task by 26.3 and 25.5%, respectively. The two paradigms also differed in terms of shoulder angles. It is likely that the main contributors to this overestimation were differences between the single and combined tasks in terms of the lever arm (i.e. horizontal distance), the shoulder angle, and the task duration. Practitioners' Summary: We investigated shoulder moments during single and combined manual material handling tasks. Shoulder moments were found to be smaller during combined tasks. Practitioners should consider that analysing combined tasks using estimations based on single tasks could result in an overestimation of 26.3 and 25.5% in peak and cumulative shoulder moments, respectively.Abbrevaitions: MSDs: musculoskeletal disorders; MMH: manual material handling; LMM: linear mixed model.

Posterior shoulder fracture-dislocation: A systematic review of the literature and current aspects of management.

PURPOSE: Posterior fracture-dislocation of shoulder is an infrequent traumatic event; however, most orthopaedic surgeons may face the challenge of treating it. The aim of this study is to review and summarise systematically the current principles of the management of this complex injury, and create a treatment algorithm. METHODS: Both PubMed and Scopus Databases were systematically searched for the terms "posterior shoulder fracture-dislocation" or "posterior glenohumeral fracture-dislocation" or "posterior glenoid fracture-dislocation" for articles written in English and published in the last decade. RESULTS: A total of 900 articles were identified, of which 13 were retained for analysis. A total of 153 patients (161 shoulders) were identified. These patients were treated either with open reduction and internal fixation, modified McLaughlin procedure, allograft/autograft humeral head reconstruction or shoulder arthroplasty. The mean age was 40.15 years. The mean postoperative Constant score in cases treated by open reduction and internal fixation was 86.45, whereas by bone graft was 84.18. Further, the mean postoperative Constant score was between 79.6 and 67.1 in those that were managed by modified McLaughlin and arthroplasty procedure, respectively. CONCLUSION: The management of posterior shoulder fracture-dislocation may be challenging, and the best surgical option depends on many variables such as the chronicity of the injury, the presence of a fracture at the level of the surgical neck or tuberosities and the extend of the Hill-Sachs lesion if any. A treatment algorithm is proposed, based on the current literature in an effort to create a consensus for these injuries. For the acute shoulder fracture-dislocations, an open reduction should be performed. For the chronic fracture/dislocations in the elderly low-demand patients, conservative treatment should be performed. For the rest of the patients, depending on the severity of the Hill-Sachs lesion different surgical options are available such as the McLaughlin technique, the use of an allograft, osteotomy or arthroplasty.