Is the lateral extension of the acromion related to the outcome of shoulder injections?

Abstract

• Patients' outcomes at 1 month improved significantly compared to baseline for subacromial injections. • Patients' outcomes at 1 month improved significantly compared to baseline for glenohumeral injections. • Short acromial lateralization was associated with better clinical outcome after subacromial injection. • The acromial lateralization was not associated with clinical outcome after glenohumeral injection.

Is shoulder geometry important for rotator cuff tears?

“…They reported that patients with smaller AI values had significantly reduced pain after injection. 33 Lee et al 34 One of the other important parameters measured in our study is LAA described by Banas et al on MRI images. 18 The authors reported that decreasing lateral acromion angle is associated with increasing rotator cuff tears.…”

Critical shoulder angle is an effective radiographic parameter that is associated with rotator cuff tears and osteoarthritis: a systematic review

“…One study (n=46) determined that those without a satisfactory result postrotator cuff repair with latissimus dorsi transfer had a significantly higher CSA (p=0.005) than those with a satisfactory outcome 24. Similarly, in another study (n=307), those with a CSA <35° had significantly greater (p=0.04) pain reduction compared with those with a CSA >35° 1 month after subacromial injections19 (online supplementary appendix table 2). …”

“…Moreover, high agreement was sustained across various groups of patients with pathologies such as rotator cuff tears,8 10 14 15 22–24 26–33 35 osteoarthritis,8 10 14 15 27–29 35 repaired rotator cuffs,12 20 21 34 shoulder arthroplasty,36 37 adhesive capsulitis,22 cuff tear arthropathy,27 impingement,27 tendinitis calcarea,27 those without rotator cuff tears in need of either subacromial or GH injections,19 and instability 15. Included studies in this review also determined a high inter-rater agreement between a shoulder and elbow specialist in practice for 10 years and a graduate medical student,29 radiologists and orthopaedic surgeons14 15 19 and between orthopaedic surgeons themselves 8 21 22 28 30 31 35–37.…”

“…Inter-rater reliability was assessed using an ICC in 16 studies (n=3021),14 15 19–22 25 27 28 30 31 34–38 Bland-Altman plots in 4 studies (n=1160),8 23 29 33 and also the κ (0.91) in 1 study (n=307) 19. Overall, inter-rater reliability among radiographs (ICC range 0.869–0.980) and CT scans (ICC=0.989) was high,15 whereas inter-rater reliability with MRIs was moderate (ICC=0.622, 95% CI 0.427 to 0.780) 14.…”

Ultrasound of the coracoacromial ligament in asymptomatic volunteers and patients with shoulder impingement

“…However, recent literature has shown that a large lateral extension of the acromion on anteroposterior radiographs of the shoulder and a steep down-sloping angulation of the acromion in the frontal plane are linked with impingement-related disorders such as rotator cuff tears (20)(21)(22)(23)(24). The lateral extension of the acromion on anteroposterior radiographs also influences the clinical outcome of subacromial steroid injections and rotator cuff surgery, with significantly better post-therapeutic outcomes reported for patients with a short lateral extension of the acromion (25)(26)(27).…”