Efficacy of high-volume vs very low volume corticosteroid subacromial injection in subacromial impingement syndrome: a randomized controlled trial.

Subacromial corticosteroid injections (SCI) treat shoulder pain from subacromial impingement syndrome (SIS). However, a high-volume corticosteroid injection (HVCI) increases the incidence of local and general complications from lidocaine. This study aimed to compare the results of functional and clinical outcomes between the very low-volume corticosteroid injection (VLVCI) and HVCI including to WORC (Western Ontario Rotator Cuff Index), VAS (Visual Analog Scale), DASH (The disabilities of the arm, shoulder, and hand) and ROM (Range of Motion). A total of 64 patients presenting with SIS were evaluated in two SCI volume in a randomization-controlled trial study. The VAS for pain pre-injection and post-injection at 15 min, was from 5.34 ± 2.44 at before injection to 2.44 ± 1.58 at post injection 15 min in the HVCI group (P < 0.001) and from 5.19 ± 2.33 to 2.84 ± 1.49 in VLVCI group (P < 0.001). Not significant differences at mean difference VAS post-injection 15 min VAS (P = 0.324) and Percentage difference VAS pre-injection and post-injection (P = 0.24). All follow-up timing, there were no significant differences in WORC, DASH and ROM between two groups (P > 0.05). The results revealed the VLVCI is non-inferior to HVCI both of functional outcomes and VAS.

Surgery for subacromial impingement syndrome and occupational biomechanical risk factors in a 16-year prospective study among male construction workers.

OBJECTIVE: The aim of this study was to assess the association between occupational biomechanical exposures and the occurrence of surgical treatment for subacromial impingement syndrome (SIS). METHODS: A cohort of 220 295 male constructions workers who participated in a national occupational health surveillance program (1971-1993) were examined prospectively over a 16-year follow-up period (2001-2016) for surgically treated SIS. Worker job title, smoking status, height, weight, and age were registered on health examination. Job titles were mapped to 21 occupational groups based on tasks and training. A job exposure matrix (JEM) was developed with exposure estimates for each occupational group. Surgical cases were determined through linkage with the Swedish national in- and outpatient registers. Poisson regression was used to assess the relative risks (RR) for each biomechanical exposure. RESULTS: The total incidence rate of surgically treated SIS over the 16-year observation period was 201.1 cases per 100 000 person-years. Increased risk was evident for workers exposed to upper-extremity loading (push/pull/lift) (RR 1.45-2.30), high hand grip force (RR 1.47-2.23), using handheld tools (RR 1.52-2.09), frequent work with hands above shoulders (RR 1.62-2.11), static work (RR 1.77-2.26), and hand-arm vibration (RR 1.78-2.13). There was an increased risk for SIS surgery for all occupational groups (construction trades) compared with white-collar workers (RR 1.56-2.61). CONCLUSIONS: Occupational upper-extremity load and posture exposures were associated with increased risk for surgical treatment of SIS, which underlines the need for reducing workplace exposures and early symptom detection in highly exposed occupational groups.

Comparison of shoulder functions between assembly workers with and without subacromial pain syndrome.

BACKGROUND: The occurrence of subacromial pain syndrome (SPS) is associated with the frequent handling and lifting of heavy loads and excessive repetitive work. Thus, assembly workers have a high prevalence of SPS. OBJECTIVE: The purpose of this study was to investigate differences in shoulder ROM, muscle strength, asymmetry ratio, function, productivity, and depression between workers with and without SPS. METHODS: Sixty-seven male workers (35 workers with SPS and 32 workers without SPS) participated in this study. Shoulder internal rotation (SIR), shoulder external rotation (SER), shoulder abduction (SAB), shoulder horizontal adduction ROM and SIR, SER, elbow flexion (EF), scapular depression and adduction, scapular protraction strength were measured. The asymmetry ratio was calculated using the asymmetry ratio formula; shoulder functions were measured using the shoulder pain and disability index (SPADI), disabilities of the arm, shoulder, and hand (DASH), and visual analogue scale (VAS); and Endicott work productivity scale (EWPS). RESULTS: The SPADI (p = 0.001), DASH (p = 0.001), and VAS (p = 0.001) values of workers with SPS were higher than those of workers without SPS. Also, workers with SPS had lower SIR (p = 0.001) and SAB (p = 0.002) ROM compared to workers without SPS. In addition, workers with SPS exhibited lower SIR (p = 0.012) strength than workers without SPS. Workers with SPS had higher asymmetry ratio in SIR (p = 0.015), SER (p = 0.005), and EF (p = 0.008) strength than workers without SPS. CONCLUSIONS: The SIR, SAB ROM, SIR strength, and the asymmetry ratio of SIR, SER, EF strengths could provide an important baseline comparison for the workers with SPS.

Peripheral sensitization is demonstrated in subacromial pain syndrome, with central sensitization found only in females.

The objective of this study was to explore whether hypersensitivity in patients with subacromial pain syndrome (SPS) manifests purely as localized peripheral sensitization or central sensitization, is influenced by the presence of subacromial pain, and presents similarly in male and female patients. Pressure pain threshold was assessed in both a patient cohort with unilateral SPS and an uninjured matched control group. Control subjects were assessed twice, with a 15 minute rest period between testing, while patients were assessed at baseline and after an almost instantaneous reduction in pain arising from an anesthetic injection in patients. Patients received a subacromial injection consisting of both anesthetics (3 cc of 2% lidocaine and 6 cc 0.5% Marcaine with Epinephrine) and a corticosteroid agent (1 cc DepoMedrol). Patients demonstrated hypersensitivity across the involved shoulder only, providing evidence for peripheral sensitization. There were trends for hypersensitivity across remote joints, however when separated by sex, only female patients demonstrated both peripheral and central sensitization. Immediate pain reduction had no influence on hypersensitivity in the short-term. Clinical Significance: Neuropathic components are likely present in some patients with subacromial pain syndrome, and female patients may be particularly at risk for presenting with neuropathic pain. These findings are applicable towards understanding the heterogeneous etiology underlying subacromial pain syndrome and informing clinical management.

Associations between single and combined occupational mechanical exposures and surgery for subacromial impingement syndrome: a nationwide Danish cohort study.

OBJECTIVE: This study aimed to evaluate whether the risk of surgery for subacromial impingement syndrome (SIS) increases with the number of combined occupational mechanical exposures compared with single exposure. METHODS: We reanalyzed data from a register-based cohort study of the entire Danish working population (N=2 374 403) with 14 118 events of surgery for SIS (2003-2008). Exposure information in 10-year windows was obtained by combining occupational codes with a job exposure matrix. For single and combined mechanical exposures, we created three exposure variables of the number of years with specific exposure intensities with or without co-existing mechanical exposures. We used logistic regression as survival analysis. RESULTS: We found exposure-response relations for duration and intensity of each single mechanical exposure except for repetition. The single effect of arm elevation >90º reached a maximum adjusted odds ratio (ORadj) of 1.7 [95% confidence interval (CI) 1.5-2.0], which increased to 1.8 (95% CI 1.5-2.0), 2.0 (95% CI 1.9-2.2), and 2.2 (95% CI 2.0-2.5) when combined with repetition, force, and both. When combining repetition with arm elevation >90º, force, and both, ORadj increased from 1.5 (95% CI 1.3-1.8) to 2.1 (95% CI 1.8-2.4), 2.5 (95% CI 2.4-2.9), and 2.7 (95% CI 2.4-3.0). For force, ORadj increased from 2.5 (95% CI 2.1-2.9) to 2.6 (95% CI 2.3-2.8), 2.8 (95% CI 2.4-3.2), and 3.0 (95% CI 2.6-3.4). CONCLUSION: We found an increased risk of surgery for SIS with the number of combined exposures; the risk was especially pronounced when the combined exposures included force.

Weakness in patients with subacromial pain syndrome is local and more pronounced in females.

BACKGROUND: Subacromial pain syndrome is the predominant cause of shoulder pain, accounting for approximately half of all shoulder complaints. This population presents with weakness of the involved shoulder. However, there is a gap in our understanding of how pain contributes to this weakness, and whether there are sex related differences. METHODS: Regional and global isometric strength was tested at the involved shoulder joint and remote joints (uninvolved shoulder and both knees) in patients with subacromial pain syndrome. Data were collected before and after acute pain reduction with a subacromial injection. FINDINGS: Patients demonstrated weakness at the involved shoulder while remote joints demonstrated normal strength. When compared to healthy controls, male patients were shown to exhibit greater levels of weakness than female patients at the involved shoulder, based on comparisons with sex-matched controls using z-scores. Pain reduction (through an anesthetic injection) had no influence on strength in the short-term. INTERPRETATION: Weakness in patients appears to be sex dependent and is not resolved with reduction of pain. This calls into question the assumptions of the physiological causes of this weakness.

Pain does not explain reduced teres major co-contraction during abduction in patients with Subacromial Pain Syndrome.

BACKGROUND: Patients with Subacromial Pain Syndrome show reduced co-contraction of the teres major during abduction. Consequent insufficient humeral depressor function may contribute to painful irritation of subacromial tissues and offers a potential target for therapy. A crucial gap in knowledge is whether the degree of teres major co-contraction in these patients is influenced by pain itself. To gain insight into this matter, we assessed whether relief of subacromial pain with local analgesics leads to increased adductor co-contraction in 34 patients with subacromial pain. METHODS: In a single-arm interventional study with 34 patients, electromyographic activity of the latissimus dorsi, pectoralis major, teres major and deltoid was assessed during isometric force tasks in 24 directions before and after subacromial Lidocaine injection. Co-contraction was quantified using the activation ratio; range [-1 (sole antagonistic activation, i.e. co-contraction) to 1 (sole agonistic activation)]. FINDINGS: There were no changes in activation ratio of the teres major after the intervention (Z-score: -0.6, p = 0.569). The activation ratio of the latissimus dorsi increased to 0.38 (quartiles: 0.13-0.76), indicating decreased co-contraction (Z-score: -2.0, p = 0.045). INTERPRETATION: Subacromial analgesics led to a decrease in co-contraction of the latissimus dorsi, whereas no change in the degree of teres major co-contraction was observed. This study shows that decreased teres major co-contraction in patients with subacromial pain, likely is not the consequence of pain itself, opening a window for physical therapy with training of teres major co-contraction to reduce subacromial irritation and pain. LEVEL OF EVIDENCE: Level II treatment study.

Relationship Between Intensity of Neck Pain and Disability and Shoulder Pain and Disability in Individuals With Subacromial Impingement Symptoms: A Cross-Sectional Study.

OBJECTIVE: This study aimed to verify a possible relationship between shoulder disability and shoulder pain intensity and the variables related to cervical-spine dysfunction, and determine which of these can differentiate moderate to severe shoulder pain (>4 on a numerical rating scale [NRS]) from mild shoulder pain (≤4 on the NRS) in individuals with subacromial impingement symptoms. METHODS: One hundred and forty volunteers with shoulder pain were evaluated. Demographic information and variables related to the shoulder and neck were collected. Self-reported pain and disability of the shoulder and cervical spine were measured using the Shoulder Pain and Disability Index (SPADI) and Neck Disability Index (NDI) questionnaires, respectively. An NRS was used to measure pain in the shoulder and cervical spine. A purposeful modeling strategy was used to determine the best model to predict shoulder disability and shoulder pain (dependent variables). Multiple logistic regression analysis followed by receiver operating curve analysis was used to determine which variables better differentiated moderate to severe shoulder pain from mild shoulder pain. RESULTS: Variables such as Neck Disability Index (NDI) score (ß = 1.09, P = .00) and age (ß = -0.19, P = .03) were associated with the total SPADI score. Neck pain was significantly associated with shoulder pain (ß = 0.40, P = .00). The combination of variables predicting moderate to severe shoulder pain was total SPADI score (odds ratio [OR] = 1.15, P = .003), neck pain (OR = 3.20, P = .04), and age (OR = 1.01, P = .05). CONCLUSION: Our results demonstrate the important connection between shoulder- and neck-related symptoms in individuals with subacromial impingement symptoms.

The effect of injection volume on long-term outcomes of US-guided subacromial bursa injections.

PURPOSE: Limited data exist on the efficacy of high- compared to low-volume US-guided corticosteroid injections (CI) in the subacromial-subdeltoid (SA-SD) bursa. Our purpose was to compare the short- and long-term efficacy of low- and high-volume injections, by using a capacity reference of SA-SD bursa volume, as assessed on cadaveric specimens. METHOD: Within two years, 136 patients (63 males, 73 females; mean age: 46.11 ±â€¯10.28 years) who underwent SA-SD bursa US-guided CI for subacromial impingement, rotator cuff tendinopathy or shoulder overuse were prospectively included. Patients were randomly assigned to low-volume (1 mL triamcinolone acetonide/40 mg) or high-volume (1 mL triamcinolone acetonide/40 mg, 9 mL anaesthetic agents) groups (67 and 69 patients, respectively). Visual Analogue Scores (VAS) were recorded at baseline, 30 min, 3 weeks, 3 months, 6 months and 1 year post-treatment. Predictors of complete recovery (VAS ≤ 2) at 1 year were analysed with multivariate Cox regression analysis. SA-SD bursa cadaveric dissection in 10 specimens was performed for volume assessment. RESULTS: Injection volume was the only predictor of complete pain resolution at 1 year. High-volume CI yielded higher chances of early pain recovery (2.837 HR, 95% CI 1.737-4.633, P < .001). Mean VAS scores at baseline and subsequent time-points were 6, 2.6, 2.2, 2, 1.6 and 1 for the high-volume and 7.8, 7.3, 4.7, 3.2, 2.5 and 1.8 for the low-volume group, respectively (P < .001, at all time-points). Cadaveric measurements showed a minimum SA-SD bursa volume of approximately 6.9 mL. CONCLUSIONS: High-compared to low-volume US-guided CI are superior for achieving early pain recovery.

Where and what damage occurs at the acromial undersurface in patients with rotator cuff tears?

BACKGROUND: The gross pathology of the acromial undersurface in shoulders with rotator cuff tears with subacromial impingement is not completely understood. Many researchers have focused on damage to the anterior one-third area of the acromial undersurface, but few have studied the middle and posterior one-third areas. The purpose of this study was to clarify where and what damage occurs at the acromial undersurface in patients with rotator cuff tears. METHODS: We performed arthroscopic shoulder (n = 182, all with rotator cuff tears; mean age, 64.9 ± 8.4 years) and cadaveric shoulder (n = 23, 14 intact cuffs and 9 rotator cuff tears; mean age, 74.8 years) evaluations to observe the extent and degree of damage to the acromial undersurface. We statistically analyzed the association between the severity of the damage to the acromial undersurface (assessed using the Copeland-Levy classification as A0, normal; A1, minor scuffing; A2, major damage; or A3, visualization of bare bone area) and rotator cuff tear size (assessed using the classification of DeOrio and Cofield as partial; small, <1 cm; medium, 1-3 cm; or large or massive, >3 cm). RESULTS: The anterior, middle, and posterior one-thirds of the acromial undersurface were somewhat damaged (class A1-A3) in 92.6%, 90.1%, and 78.6% of shoulders with rotator cuff tears, respectively, according to arthroscopic evaluation. Increasing cuff tear size was significantly associated with worsening degree of damage to the acromial undersurface (P < .001). In the 9 cadaveric shoulders with rotator cuff tears, class A1-A3 damage was identified in the anterior one-third area in 100%, in the middle one-third area in 88.9%, and in the posterior one-third area in 33.3%. In the 14 cadaveric shoulders with a normal rotator cuff, class A1-A3 damage was identified in the anterior one-third area in 35.7%, in the middle one-third area in 14.3%, and in the posterior one-third area in 0.71%. CONCLUSION: Damage to the acromial undersurface in patients with rotator cuff tears occurred at the middle, posterior, and anterior one-third areas, and the degree of damage was related to cuff tear size. Surgeons should evaluate the entire acromial undersurface to check for subacromial impingement damage at the middle and posterior one-third areas as well as the anterior one-third area of the acromial undersurface; this might aid in the treatment of patients with rotator cuff disease or subacromial impingement syndrome.

Expression of alarmins in a murine rotator cuff tendinopathy model.

The aim of this study was to investigate the presence of alarmins in a novel murine rotator cuff tendinopathy model. Alarmins have been described as essential early activators of an immune response to tissue damage. Subacromial impingement was induced in both shoulders of 37 male C57Bl/6 mice by placement of a small metal clip in the subacromial space. Animals were allocated to different time points up to 6 weeks. The morphology and cellularity of the supraspinatus tendon were evaluated by hematoxylin-eosin staining, alcian blue, and picrosirius red. The expression and localization of alarmins interleukin-33 (IL-33), c (HMGB1), hypoxia-inducible factor-1 subunit α (HIF1α), and S100A9 were evaluated by immunohistochemical staining and quantitative polymerase chain reaction. The percentage of positively stained cells with HMGB1 and IL-33 was significantly increased in the impingement group at 1w, 4w, and 6w. HIF1α staining was higher in the impingement group at 1w and 6w compared with the control group. HMGB1 gene expression was higher in the 5d impingement group and 6w impingement group. The gene expression of HIF1α was upregulated at all-time points in the impingement group (5d, 2w, 4w, and 6w). The expression of the S100A9 gene was also upregulated in the 5d impingement group. This is the first study to demonstrate the involvement of alarmins in the early phase of tendinopathy using a reproducible animal model. Alarmins may play an important role in the early phases of the development of tendinopathy They may represent potential therapeutic targets for treatment of tendinopathy.

The protocol for a multisite, double blind, randomized, placebo-controlled trial of axillary nerve stimulation for chronic shoulder pain.

BACKGROUND: Shoulder impingement syndrome is one of the most common causes of shoulder pain, accounting for approximately 30% of all shoulder pain. Approximately 35% of patients with shoulder impingement syndrome are refractory to conservative treatment. For patients who fail conservative treatment, there is no established treatment to successfully treat their chronic pain. Prior randomized control trials have demonstrated efficacy for the use of a single lead intramuscular peripheral nerve stimulation of the axillary nerve at the motor points of the deltoid muscle for treatment of hemiplegic shoulder pain. This is the first controlled trial to utilize the same novel technology to treat shoulder impingement syndrome outside of the stroke population. METHODS: This is a dual-site, placebo-controlled, double-blinded, randomized control trial. Participants will be randomized to two treatment groups. The intervention group will be treated with active peripheral nerve stimulation of the axillary nerve of the affected shoulder and the control group will be treated with sham peripheral nerve stimulation of the axillary nerve of the affected shoulder. Both groups will receive a standardized exercise therapy program directed by a licensed therapist. DISCUSSION: This study protocol will allow the investigators to determine if this novel, non-pharmacologic treatment of shoulder pain can demonstrate the same benefit in musculoskeletal patients which has been previously demonstrated in the stroke population. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03752619. Registered on 26 November 2018.

Shoulder mechanical impingement risk associated with manual wheelchair tasks in individuals with spinal cord injury.

BACKGROUND: Most individuals with spinal cord injury who use manual wheelchairs experience shoulder pain related to wheelchair use, potentially in part from mechanical impingement of soft tissue structures within the subacromial space. There is evidence suggesting that scapula and humerus motion during certain wheelchair tasks occurs in directions that may reduce the subacromial space, but it hasn't been thoroughly characterized in this context. METHODS: Shoulder motion was imaged and quantified during scapular plane elevation with/without handheld load, propulsion with/without added resistance, sideways lean, and weight-relief raise in ten manual wheelchair users with spinal cord injury using biplane fluoroscopy and computed tomography. For each position, minimum distance between rotator cuff tendon insertions (infraspinatus, subscapularis, supraspinatus) and the coracoacromial arch was determined. Tendon thickness was measured with ultrasound, and impingement risk scores were defined for each task based on frequency and amount of tendon compression. FINDINGS: Periods of impingement were identified during scapular plane elevation and propulsion but not during pressure reliefs in most participants. There was a significant effect of activity on impingement risk scores (P < 0.0001), with greatest impingement risk during scapular plane elevation followed by propulsion. Impingement risk scores were not significantly different between scapular plane elevation loading conditions (P = 0.202) or propulsion resistances (P = 0.223). The infraspinatus and supraspinatus tendons were both susceptible to impingement during scapular plane elevation (by acromion), whereas the supraspinatus was most susceptible during propulsion (by acromion and coracoacromial ligament). INTERPRETATION: The occurrence of mechanical impingement during certain manual wheelchair tasks, even without increased load/resistance, demonstrates the importance of kinematics inherent to a task as a determinant of impingement. Frequency of and technique used to complete daily tasks should be carefully considered to reduce impingement risk, which may help preserve shoulder health long-term.

The incidence of impingement syndrome in cases of cervical radiculopathy: An analysis of 220 cases.

BACKGROUND: We hypothesized that cervical radiculopathy (CR) has a role in subacromial impingement syndrome (SAIS) etiology, which cannot be directly connected to anatomical causes. OBJECTIVE: We aimed to investigate the presence of cervical radiculopathy in patients with SAIS diagnosed clinically and radiologically. METHODS: Patients who had a clinical and radiological SAIS diagnosis between 2014 and 2016 were included in the study. Patients with secondary causes that led to SAIS were excluded. Cervical MRI of all patients with SAIS was examined for cervical radiculopathy. RESULTS: A significant (p< 0.05) relationship was found between SIAS and the presence of root compression on the same side. 35% of the patients with SIAS had root compression on the same side. CONCLUSIONS: Cervical radiculopathy and shoulder impingement syndrome can be easily confused due to the similarity of the symptoms and the anatomical proximity of the lesions. Although both diseases can occur with different mechanisms, we believe that there is a cause and effect relationship between them.

Internal impingement of the shoulder in overhead athletes: Retrospective multicentre study in 135 arthroscopically-treated patients.

BACKGROUND: Internal impingement of the shoulder (IIS) is the leading cause of chronic shoulder pain in overhead throwing athletes. No consensus exists about which techniques are optimal when surgery is in order. The available studies are limited by small sample sizes and short follow-ups. The primary objective of this study was to assess return-to-sports (RtS) outcomes after surgical treatment for IIS. A favourable RtS outcome (RtS+) was defined as returning to the previous sport at the same or a higher level. HYPOTHESIS: The main hypothesis was that surgical treatment resulted in an RtS+ outcome. The secondary hypothesis was that epidemiological factors, pre- and intra-operative anatomical factors, and specific surgical procedures were associated with higher RtS+ rates. MATERIAL AND METHODS: A retrospective multicentre design was used. We included 135 patients with IIS managed arthroscopically using any of the following procedures: anterior capsulorrhaphy, posterior capsulotomy/capsulectomy, postero-superior labral debridement, posterior glenoidplasty, and rotator cuff tear debridement or repair. Follow-up was at least 1 year. The patients were divided into two groups based on whether they had an RtS+ outcome as defined above or an RtS- outcome defined as a return to the previous sport at a lower level, a switch to another sport, or an inability to engage in any sport. The Kerlan-Jobe Orthopaedic Clinic (KJOC) and Constant's score were used to evaluate subjective and objective shoulder function. RESULTS: Mean follow-up was 7.9 years. Of the 135 patients, 120 (90%) returned to sports after surgery including 70 (52%) to the previous sport at the same level (RtS+ outcome). By univariate analysis, the following factors were associated with an RtS+ outcome: male sex, rotator cuff tear documented intra-operatively, absence of a greater tuberosity cyst on pre-operative imaging studies, and cuff tear debridement. Anterior capsulorrhaphy was associated with worse post-operative pain. DISCUSSION: The RtS+ rate in this study differed from previously reported values, due to differences in the sports practiced by the patients and to considerable variability in the surgical techniques used. The positive association between presence of a rotator cuff tear and an RtS+ outcome is at variance with most of the previously published data. Some of the apparent discrepancies between our results and those from other countries may be ascribable to differences in the most popular sports. LEVEL OF EVIDENCE: IV.

Effects of eccentric exercise in patients with subacromial impingement syndrome: a systematic review and meta-analysis.

BACKGROUND: Subacromial impingement syndrome is a common problem in primary healthcare. It often include tendinopathy. While exercise therapy is effective for this condition, it is not clear which type of exercise is the most effective. Eccentric exercises has proven effective for treating similar tendinopathies in the lower extremities. The aim of this systematic review was therefore to investigate the effects of eccentric exercise on pain and function in patients with subacromial impingement syndrome compared with other exercise regimens or interventions. A secondary aim was to describe the included components of the various eccentric exercise regimens that have been studied. METHODS: Systematic searches of PubMed, Cochrane Library and PEDro by two independent authors. Included studies were assessed using the PEDro scale for quality and the Cochrane scale for clinical relevance by two independent authors. Data were combined in meta-analyses. GRADE was applied to assess the certainty of evidence. RESULTS: Sixty-eight records were identified. Seven studies (eight articles) were included, six were meta-analysed (n = 281). Included studies were of moderate quality (median PEDro score 7, range 5-8). Post-treatment pain was significantly lower after eccentric exercise compared with other exercise: MD -12.3 (95% CI - 17.8 to - 6.8, I2 = 7%, p < 0.001), but this difference was not clinically important. Eccentric exercise provided no significant post-treatment improvement in function compared with other exercise: SMD -0.10 (95% CI - 0.79 to 0.58, I2 = 85%, p = 0.76). Painful eccentric exercise showed no significant difference compared to pain-free eccentric exercise. Eccentric training regimes showed both similarities and diversity. Intervention duration of 6-8 weeks was almost as effective as 12 weeks. CONCLUSIONS: Evidence of low certainty suggests that eccentric exercise may provide a small but likely not clinically important reduction in pain compared with other types of exercise in patients with subacromial impingement syndrome. It is uncertain whether eccentric exercise improves function more than other types of exercise (very low certainty of evidence). Methodological limitations of existing studies make these findings susceptible to change in the future. TRIAL REGISTRATION: PROSPERO CRD42019126917 , date of registration: 29-03-2019.

Internal impingement of the shoulder: An international survey of 261 orthopaedic surgeons.

BACKGROUND: Internal impingement of the shoulder (IIS) is a specific disorder of young overhead-throwing athletes that was first described in 1991. The many non-operative and surgical treatments suggested to date have produced mixed outcomes. The objective of this study was to compare the practices of surgeons in France versus other countries regarding the diagnosis and treatment of IIS. HYPOTHESIS: Diagnostic and therapeutic practices regarding IIS differ between surgeons in France and in other countries. MATERIAL AND METHODS: A 21-item questionnaire in French and English was emailed to the 1300 members of the French Arthroscopy Society and to surgeons from countries other than France. The questionnaire collected information on knowledge about IIS (2 items), the frequency of IIS in clinical practice (2 items), the diagnosis of IIS (6 items), the non-operative and surgical treatment of IIS (3 and 5 items, respectively), and return-to-sports rates after treatment for IIS (3 items). RESULTS: The completed questionnaire was sent back by 261 surgeons, 206 in France and 55 in other countries, including 42 in Japan. Among the respondents, 90% knew about IIS. Experience with IIS in terms of number of patients seen or surgical treatments performed was greater in the international group (45% vs. 19% in France, p<0.001). Posterior shoulder pain in the arm cocking position was the most widely recognised symptom (99% in France, 74% internationally, p<0.001), followed by excessive external rotation during arm abduction (55% vs. 65%, p=0.23). The most commonly sought lesions were those of the postero-superior labrum and articular surface of the rotator cuff. Rotator cuff debridement was among the surgical options according to most respondents (74% vs. 70%). In contrast, postero-superior glenoidplasty was cited almost only by surgeons in France (67% vs. 4%, p<0.001). The proportion of patients who are able to return to sports was estimated at 50% to 75% by most respondents. DISCUSSION: Most respondents had theoretical knowledge about IIS, but surgery was rarely performed in France. Only very few athletes in France play baseball, which is responsible for most sports injuries of the shoulder seen in Japan. This fact, combined with differences in the lesions or even the diagnoses, may have contributed to the differences in the responses to the survey items between the French and international groups.

[Subacromial impingement syndrome].

Subacromial impingement syndrome is one of the most common causes of shoulder pain and is associated with substantial shoulder impairments. The initial treatment should be non-operative in form of rotator cuff and scapula strengthening exercises for at least three months. Not all patients respond satisfactorily to non-operative treatment, but only patients with persistent symptoms after sufficiently tried non-operative treatment, should be referred to an orthopaedic specialist.

Synovitis as a concomitant disease in shoulder pathologies.

INTRODUCTION: Shoulder pathologies are often accompanied by rotator interval synovitis. This phenomenon is poorly described in the literature so far. The aim of the study was to analyze the occurrence of macroscopically visible synovial reaction in the rotator interval in patients with chronic shoulder pathologies and to perform a histopathological evaluation. MATERIALS AND METHODS: In this prospective cohort study, 167 consecutive patients undergoing arthroscopic shoulder surgery for chronic shoulder pathology were included (♀ = 45, ♂ = 122; [Formula: see text]54.5 years ± 12.8). Included patients were divided into subgroups according to the encountered chronic shoulder pathology: (1) impingement syndrome with or without bursal sided partial rotator cuff tear (RCT); (2) articular sided partial RCT; (3) full-thickness RCT; (4) RCT that involves at least two tendons; (5) shoulder instability; and (6) cartilage damage. Standardized soft tissue biopsies from the rotator interval were taken. The synovitis score of Krenn/Morawietz was used for histopathological examination. RESULTS: Extraarticular pathology (group 1) showed significantly decreased synovitis scores compared to all the other groups. Increased size of rotator cuff tears (group 4), as well as cartilage damage (group 6) showed significantly higher synovitis scores than group 3 (p < 0.05). Moreover, the synovitis score was significantly increased in patients with concomitant pathologies of the long head of the biceps (p = 0.001). CONCLUSIONS: This study suggests that chronic intra- and extraarticular shoulder diseases are very often accompanied by a histopathologically verifiable low-grade synovitis. Intraarticular pathologies seem to induce increased levels of synovitis. Furthermore, the increased size of rotator cuff tears is accompanied by a higher degree of synovitis. STUDY DESIGN: Cohort study, level of evidence, 2b.

Psychometric evaluation of the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function and Pain Interference Computer Adaptive Test for subacromial impingement syndrome.

BACKGROUND: The Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Computer Adaptive Test (CAT) was previously validated for rotator cuff disease and shoulder instability. This study evaluated the psychometric properties of the PROMIS Physical Function (PF) CAT, PROMIS Pain Interference (PI) CAT, and the American Shoulder and Elbow Surgeons (ASES) Shoulder Function Score for subacromial impingement syndrome. METHODS: PROMIS PF CAT, PI CAT, and ASES (Pain, Function, Total) were collected on all visits for 2 surgeons between January 2016 and August 2016. New patients, aged 18 years and older, were selected by International Classification of Diseases code for impingement syndrome of the shoulder. The mean number of questions answered determined efficiency. Person-item maps were created to determine ceiling and floor effects as well as person reliability. Convergent validity was determined by comparison of PROMIS domains to ASES scores with Pearson correlations. RESULTS: For PROMIS PF CAT, the mean number of items answered was 4.54 (range 4-12). The ceiling effect was 1.56%, and the floor effect was 3.13%. The person reliability was 0.94. Pearson correlation coefficients between the PF CAT and ASES were 0.664 (ASES Function), 0.426 (ASES Pain), and 0.649 (ASES Total). For PROMIS PI CAT, the mean number of items answered was 4.27 (range 3-11). The ceiling effect was 4.69%, and the floor effect was 8.33%. The person reliability was 0.92. Pearson correlation coefficients between the PI CAT and ASES were: 0.667 (ASES Function), 0.594 (ASES Pain), and 0.729 (ASES Total). CONCLUSIONS: The psychometric properties of PROMIS PF and PI CATs were favorable for subacromial impingement syndrome.