Acromion

BackgroundThe benefits of acromioplasty in treating rotator cuff disease have been debated. We systematically reviewed the literature regarding whether acromioplasty with concomitant coracoacromial (CA) release is necessary for the successful treatment of full-thickness rotator cuff tears.Materials and methodsWe identified randomized controlled trials that reported on patients who underwent rotator cuff repair with or without acromioplasty and used descriptive statistics to summarize the findings.ResultsFour studies fulfilled the inclusion criteria. They reported on 354 patients (mean age, 59 years; range 3-81 years) with a mean follow-up of 22 months (range 12-24 months). There were two level-I and two level-II studies. Two studies compared rotator cuff repair with versus without acromioplasty, and two studies compared rotator cuff repair with versus without subacromial decompression (acromioplasty, CA ligament resection, and bursectomy). The procedures were performed arthroscopically, and the CA ligament was released in all four studies. There were no statistically significant differences in clinical outcomes between patients treated with acromioplasty compared with those treated without acromioplasty.ConclusionsThis systematic review of the literature does not support the routine use of partial acromioplasty or CA ligament release in the surgical treatment of rotator cuff disease. In some instances, partial acromioplasty and release of the CA ligament can result in anterior escape and worsening symptoms. Further research is needed to determine the optimum method for the operative treatment of full-thickness rotator cuff tears.Level of evidenceLevel I, systematic review of level I and II studies.

BackgroundArthroscopic subacromial decompression (ASAD) is a commonly performed surgical intervention for shoulder pain. The rationale is that removal of a bony acromial spur relieves symptoms by decompressing rotator cuff tendons passing through the subacromial space. However, the efficacy of this procedure is uncertain. The objective of this trial was to compare the efficacy and cost-effectiveness of ASAD in patients with subacromial pain using appropriate control groups, including placebo intervention.Methods/designThe trial is a three-group, parallel design, pragmatic, randomised controlled study. The intervention content for each group (ASAD, active monitoring with specialist reassessment (AMSR) and investigational shoulder arthroscopy only (AO)) enables assessment of (1) the efficacy of the surgery against no surgery; (2) the need for a specific component of the surgery-namely, removal of the bony spur; and (3) quantification of the placebo effect. Concealed allocation was performed using a 1:1:1 randomisation ratio and using age, sex, baseline Oxford Shoulder Score (OSS) and centre as minimisation criteria. The primary outcome measure is the OSS at 6 months post randomisation. A total of 300 patients recruited over 24 months from a minimum of 14 UK shoulder units over 24 months were required to detect a difference of 4.5 points on the OSS (standard deviation, 9) with 90% power and to allow for 15% loss to follow-up. Secondary outcomes include cost-effectiveness, pain, complications and patient satisfaction. A substantial qualitative research component is included. The primary analysis will be conducted on the modified intention-to-treat analysis. Sensitivity analysis will be used to assess the robustness of the results with regard to the underlying assumptions about missing data using multiple imputation.DiscussionThis trial uses an innovative design to account for the known placebo effects of surgery, but it also will delineate the mechanism for any benefit from surgery. The investigational AO group is considered a placebo intervention (not sham surgery), as it includes all components of subacromial decompression except the critical surgical element. Some discussion is also dedicated to the challenges of conducting placebo surgery trials.Trial registrationsUK Clinical Research Network UKCRN12104. Registered 22 May 2012. International Standard Randomised Controlled Trial ISRCTN33864128 . Registered 22 June 2012. ClinicalTrials.gov NCT01623011 . Registered 15 June 2012.

PurposeTo evaluate the association of acromial morphology and subacromial impingement.MethodsBilateral shoulder computed tomography was performed in 138 patients who received shoulder arthroscopy. Measured parameters included: acromial tilt (AT), modified acromial tilt (mAT), acromial slope (AS), acromiohumeral interval (AHI), lateral acromial angle (LAA), acromial index (AI), critical shoulder angle (CSA), acromial anterior protrusion (AAP), and acromial inferior protrusion (AIP). Acromial morphological characteristics were compared between groups. Side-to-side differences were assessed between affected and non-affected shoulders. Intra- and inter-observer agreements for each parameter were calculated.ResultsAT (25.90 vs. 29.41°), mAT (18.88 vs. 22.64°), and AHI (5.46 vs. 6.47 mm) were significantly smaller in impinged patients. The impingement group demonstrated significantly larger AI (63.50 vs. 59.84%), CSA (31.78 vs. 28.74°), AAP (7.13 vs. 5.32 mm), and AIP (5.51 vs. 4.04 mm). Regarding side-to-side comparison, the acromial morphology was significantly different between the affected and non-affected shoulders in impinged patients, while the difference was slight and insignificant in control patients. All, except AS and LAA, measured parameters demonstrated good intra- and inter-observer agreements.ConclusionsThree-dimensional reconstructed CT scan is a reliable method to measure shoulder morphology. The acromial morphological variation is related with sub acromial impingement, however, the causal relationship of them should be further explored.

PurposeAcromial and scapular spine fractures after reverse shoulder arthroplasty (RSA) can impair post-operative outcomes; however, quantitative assessment of pre-fracture cortical changes remains challenging. This study evaluated longitudinal changes in inferior acromial cortical thickness after RSA using a computed tomography-based (CT-based) acromial coronal view.MethodsThis multicentre retrospective cohort study included 44 patients who underwent RSA. The acromion was divided into three zones: I (lateral acromion), II (acromial base), and III (scapular spine). Inferior cortical thickness was measured at the centre of each zone. Changes were analysed from immediately post-operatively to one year and from one to two years in shoulders with corresponding CT scans. Cortical area was assessed as a secondary outcome, and the fracture cases were described separately.ResultsFrom immediately post-operatively to one year (n = 41), cortical thickness was unchanged in Zone I but increased in Zone II from 2.0 ± 0.5 to 2.4 ± 0.7 mm and in Zone III from 3.8 ± 1.0 to 4.6 ± 1.6 mm. From one to two years (n = 28), Zones II and III showed further increases, whereas Zone I remained unchanged. Thickness changes correlated with cortical area changes (Spearman's ρ = 0.55). Five shoulders (11.4%) developed fractures within two years, and delayed Zone II and III fractures showed marked preceding cortical thickening.ConclusionInferior acromial cortical thickening after RSA progressed selectively in Zones II and III, suggesting region-specific post-operative acromial remodelling. These findings may help clarify the differences in fracture pathomechanisms according to the location.