The Effect of Acromioplasty on the Critical Shoulder Angle and Acromial Index

Predictability and functional impact of lateral acromioplasty using preoperative 2D planning on the correction of the critical shoulder angle (CSA) in patients with rotator cuff repair

Background

Rotator cuff tears are highly prevalent, and their association with critical shoulder angle (CSA) has been reported. There is controversy regarding whether the morphology of the acromion influences its incidence, as well as whether acromioplasty would impact the results of a rotator cuff repair. Lateral acromioplasty does not play a decompressive role; rather, it aims to correct the deltoid vector. According to some publications, this would achieve less loading on the repaired rotator cuff, a lower retear rate, and better function. CSA correction with lateral acromioplasty can be planned with radiography (2-dimensional [2D]), but its predictability has not been fully studied. The primary objective of this study is to evaluate the predictability of 2D planning with radiography in CSA correction in patients with rotator cuff repair. The secondary objective is to analyze the association between the correction of the CSA and the functional outcomes.

Methods

This single-center, prospective, observational, analytical study included candidates for arthroscopic repair of a rotator cuff tear with a CSA > 35°. Lateral acromioplasty was performed as planned with preoperative radiography (2D) to achieve a CSA of 35°. The degrees to be corrected were calculated. CSA was recalculated with a postoperative radiography; and the error in the planned grades to be corrected was calculated. At the end of follow-up, Visual Analog Scale, Subjective Shoulder Value (SSV), and Quick-Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) scores were evaluated.

Results

Forty one cases were included, 43.9% were men, and the mean age was 55.5 ± 8.6 years. The mean preoperative and postoperative CSA were 39.6° ± 1.9° and 35.7° ± 2.3°, respectively; 41.5% achieved a postoperative CSA ≤ 35°. The mean CSA planned correction error was 45.7 ± 28.8%. At the end of the follow-up, 33 (78.6%) had a functional evaluation, with an average follow-up of 41 ± 6.8 months. The mean Visual Analog Scale, Quick-DASH, and SSV were 0.9 ± 1.6, 5.3 ± 7.5, and 92.7 ± 10.6, respectively. There was a significant difference in Quick-DASH (P = .01) and SSV (P = .02) according to whether a postoperative CSA ≤ 35° was achieved.

Conclusion

In lateral acromioplasty, planning of CSA correction with radiography (2D) is imprecise. Reaching a CSA ≤ 35° positively influences functional results.

Lower Reoperation Rate and Superior Patient-Reported Outcome Following Arthroscopic Rotator Cuff Repair With Concomitant Acromioplasty: An Updated Systematic Review of Randomized Controlled Trials

PURPOSE

To systematically assess the postoperative outcomes in patients undergoing arthroscopic rotator cuff repairs with or without concomitant acromioplasty through a rigorous systematic review of randomized controlled trials (RCTs).

METHODS

This systematic review, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, aimed to identify RCTs comparing clinical outcomes of patients with full-thickness rotator cuff tears undergoing arthroscopic rotator cuff repair with acromioplasty versus those without at a minimum 12-month follow-up. Databases searched included PubMed, Web of Science, Embase, and the Cochrane Library. The risk of bias in the included studies was assessed using the revised Cochrane Risk of Bias 2. Meta-analysis was conducted for outcomes with at least 3 studies reporting, with pooled effect estimates calculated using either fixed-effect or random-effects models based on heterogeneity levels. Results were presented as the weighted mean difference or odds ratio with 95% confidence intervals (CIs). For outcomes with fewer than 3 studies reporting, a Fisher exact test was conducted, with continuity correction applied if necessary. Primary outcomes included rates of retear and reoperation, whereas secondary outcomes included improvement in American Shoulder and Elbow Surgeons (ASES) score, range of motion (ROM), and complication rate.

RESULTS

Five high-quality RCTs, with low bias risk, involving 409 patients, revealed demographics of 58.4% males, mean age of 58.4 years, and the following acromion types: 12.2% type I, 70.7% type II, and 17.1% type III. Mean follow-up was 52.2 months. Retear (12.5% vs 16.1%, P = .536) and complication rates (odds ratio, 3.11; 95% CI, 0.31-30.73; P = .33) were comparable between the 2 groups. However, reoperation rate (5.3% vs 15.9%, P < .001) and improvement in ASES score (weighted mean difference, 3.99; 95% CI, 1.00-6.99; P = .009) favored the acromioplasty group. Both groups showed significant improvements in ROM, but insufficient data prevented a comparison.

CONCLUSIONS

Compared with arthroscopic rotator cuff repair alone, arthroscopic rotator cuff repair with acromioplasty demonstrated similar rates of retear and complications but had a significantly lower reoperation rate and superior improvement in ASES score. The available data were insufficient to draw a definitive conclusion regarding ROM. This conclusion is fragile due to a limited sample size.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.

Editorial Commentary: In Contrast to Chronic, Degenerative Rotator Cuff Tears, the Critical Shoulder Angle in Traumatic Rotator Cuff Tears Can Be Ignored

There are 2 distinct types of rotator cuff tears. The first is a chronic, degenerative tear, which is more common. The second is an acute traumatic tear. (There is also likely a third, hybrid type consisting of an acute-on-chronic tear) Traumatic tears result in acute dysfunction with weakness and loss of range of motion. Traumatic tears are large to massive in size and have higher degrees of subscapularis involvement. If a patient has an acute cuff tear, the surgeon should fix it. The surgeon should not take the time to measure the critical shoulder angle (CSA) or plan an acromioplasty but should just fix the tear-the sooner, the better. The CSA has been emerging as a concept in trying to figure out the pathogenesis and treatment of degenerative tears. But, when it comes to traumatic tears, the CSA can be ignored. It likely does not have a role in the causation or treatment of traumatic rotator cuff tears.

Anterolateral Acromioplasty Does Not Change the Critical Shoulder Angle and Acromion Index in a Clinically Relevant Amount

PURPOSE

Assessment on whether radiographic parameters of the acromion measured in radiographs change significantly after anterolateral acromioplasty.

METHODS

This retrospective study included patients that underwent an arthroscopic anterolateral acromioplasty between January 2014 and September 2020. n = 435 subjects with high-quality preoperative and postoperative radiographs according to Suter-Henninger criteria were included in the final assessment. All measurements were independently performed by the first and second author in a blinded fashion using dicomPACS software: acromion index (AI), critical shoulder angle (CSA), lateral acromial angle (LAA), beta angle, acromio-humeral distance (AHD), Aoki angle, frontal supraspinatus outlet angle (FSOW), and acromion type, according to Bigliani. SPSS software was used for statistical analysis.

RESULTS

The beta angle and the CSA did not significantly change after operation (alpha power 0.32 and 0.11, respectively). In a subgroup analysis of patients with a pathological CSA >35° (n = 194), the CSA changed from 38.62 (range: 35.08-47.52, SD 2.83) to 38.04 (range: 29.18-48.12, SD 3.77) postoperatively (P = .028) (Fig 8). All other parameters changed significantly after operation (AI, AHD, FSOW, and Aoki; P = .001, LAA; P = .039) (Fig. 9). The interobserver and intraobserver reliability was good to excellent in the majority of measured values. Mean patient age was 59.2 years (range: 18.1-87.1; SD 11.3), mean height was 1.73 meters (range: 1,50-1.98, SD 0.09), mean weight was 80.2 kg (range: 37.0-133.0, SD 16.68), and mean body mass index was 26.6 (range: 0.0-46.1, SD 4.73).

CONCLUSION

Anterolateral acromioplasty producing a flat acromion undersurface did not result in a significant change of the CSA in the study population. Pathological preoperative CSA values of >35° were significantly reduced but not to normal values, but only by a small amount that puts the clinical relevance into question.

LEVEL OF EVIDENCE

IV, diagnostic study, case series.

Editorial Commentary: Classic Arthroscopic Anterolateral Acromioplasty Does Not Translate to Clinically Meaningful Differences in Lateral Acromial Overcoverage

Despite its time-honored tradition, the classic Neer acromioplasty has come under increased scrutiny in the recent literature, particularly when performed in the absence of rotator cuff repair. The American Medical Association Current Procedural Terminology Committee has transitioned the acromioplasty procedure, and definition of the related Current Procedural Terminology code 29827, to a procedure that is "added-on" to shoulder arthroscopy. Several authors have sought to investigate the true value of arthroscopic subacromial decompression for extrinsic sources of impingement. Common indications for acromioplasty include bursal-sided tears, prominent type III hooked acromial morphology, calcified coracoacromial ligament, and severe rotator cuff tendinopathy. However, the classic arthroscopic acromioplasty may not meaningfully address lateral outlet impingement and acromial overcoverage, as measured by an elevated critical shoulder angle or acromial index, thereby leading to persistent abduction impingement and mechanical abrasion. In these cases, lateral acromial resection of up 5 to 10 mm may be preferentially considered to decrease the pathologic critical shoulder angle (>35°) and reduce the risk of primary or secondary rotator cuff tendon failure.

Evaluation of anatomical variations with morphological measurements and their relationship with rotator cuff tear and acromion types

Introduction: There many more anatomical measurements such as the acromiohumeral distance and lateral acromion angle and acromial configuration was reported as might be associated with rotator cuff tear. In our study, we aimed to reveal the effect of acromion index, acromiohumeral distance, lateral acromion angle, critical shoulder angle values and the acromion type in the development of rotator cuff tear. Material and Method: In our retrospective study, 58 patients and 29 asymptomatic volunteers who underwent shoulder magnetic resonance imaging examinations were examined. acromion index, acromion humaral distance, lateral acromion angle and critical shoulder angle were measured and their relationship with rotator cuff tear and acromion types were evaluated. Results: Type III (hooked) of acromial shapes, higher acromion index and critical shoulder angle values, lower acromiohumeral distance and lateral acromion angle values are more frequently seen in rotator cuff tear patients, in our study. Conclusion: Thus, we revealed anatomical malformations that predispose to rotator cuff tear concerning the shoulder joint.

Editorial Commentary: Acromioplasty Does Not Improve Clinical Outcome of Arthroscopic Rotator Cuff Repair: The Game Is Over!

Acromioplasty is a well-known, simple, and reproducible surgical technique that is used in isolation or in combination with other arthroscopic procedures. The clinical value of acromioplasty combined with arthroscopic rotator cuff repair has been largely investigated. Main theoretical benefits lie in the opportunity to improve the visualization, decrease abrasive wear with prominent acromial morphology, and release natural growth factors. On the other hand, acromioplasty and release of the coracoacromial ligament may weaken the insertion of the deltoid muscle, induce scar formation in the subacromial space, theoretically limiting shoulder mobility, and increase risk of anterior-superior humeral escape, especially in patients with large to massive rotator cuff tears. Clinical studies report conflicting results. My results show no differences in clinical outcomes in rotator cuff repairs with or without subacromial decompression, regardless of the acromial morphology. At the same time, I do believe that confirmatory studies are always necessary, especially if the aim is to disprove the usefulness of a common practice.