Does the critical shoulder angle decrease after acromioplasty? A systematic review and meta-analysis

Critical Shoulder Angle in Patients With Cuff Tears

OBJECTIVE

The pathogenesis of rotator cuff tears (RCTs) is multifactorial. Critical shoulder angle (CSA), which represents the lateral extension of the acromion over the cuff, has been proposed as an extrinsic risk factor. The aim of the present systematic review and meta-analysis was to analyze the available literature regarding the correlation between RCT and CSA.

METHODS

A review was carried out in accordance with the "Preferred Reporting Items for Systematic reviews and Meta-Analyses" guidelines on July 17, 2023, using the following databases: PubMed, Ovid, and Cochrane Reviews. The following keywords were used: "critical shoulder angle," "rotator cuff tears," and "rotator cuff lesions." The methodological quality of the studies was assessed with the MINORS SCORE.

RESULTS

Twenty-eight studies were included. The average CSA among the 2110 patients with full-thickness RCT was 36.7 degrees, whereas the same value among the 2972 controls was 33.1 degrees. The average CSA in the 348 patients with partial-thickness RCT was 34.6 degrees, whereas it was 38.1 degrees in the 132 patients with massive RCT. The average MINORS score was 15.6.

CONCLUSIONS

CSA values were significantly higher in patients with RCT compared with the asymptomatic population. In addition, it appears that CSA values increase with the severity of rotator cuff involvement.

Effect of arthroscopic subacromial decompression during arthroscopic repair of small to medium-sized rotator cuff tears

Background

Although arthroscopic subacromial decompression (ASD) is a commonly used procedure during arthroscopic rotator cuff repair (ARCR), the effect of ASD on the clinical outcomes for ARCR is controversial. The purpose of this study was to compare the clinical outcomes of ARCR with or without ASD.

Methods

Patients (n = 315 with 320 shoulders) who underwent ARCR for small to medium-sized rotator cuff tears were followed for at least 24 months. ARCR was performed with ASD (180 shoulders, group A) or without ASD (140 shoulders, group N). There were no significant differences in patient demographics, including mean age and mean follow-up time. Rotator cuff repair was performed using the suture-bridge technique in all shoulders, and all patients were treated using the same rehabilitation protocol after surgery. University of California at Los Angeles score, Constant score, re-tear rates, revision surgery rates, and operating time were compared between groups. Re-tear was defined as Sugaya classification Types 4 and 5 using postoperative magnetic resonance imaging at more than 12 months.

Results

There was no statistically significant difference in clinical outcomes before and after ARCR between groups. However, the University of California at Los Angeles scores and Constant scores significantly improved in both groups after surgery (P < .001). Furthermore, there was no major difference in the re-tear rates between groups A (7/180 shoulders, 3.9%) and N (11/140 shoulders, 7.9%) (P = .146). Revision surgeries were performed on 3/180 shoulders (1.7%) in group A (due to postoperative deep infection in one shoulder and revision ARCR for re-tear in two shoulders). No revisions surgeries were needed in group N patients (P = .259). The mean surgical time for group A was 62.0 ± 27.0 minutes (29-138 min.) and 52.4 ± 26.1 minutes (17-124 min.) for group N (P = .007).

Conclusion

These results suggest that ASD has a limited effect on clinical outcomes of ARCR for small to medium-sized rotator cuff tears.

Does the critical shoulder angle influence retear and functional outcome after arthroscopic rotator cuff repair? A systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to evaluate the correlation between increased critical shoulder angle (CSA) and higher retear rates and functional outcomes after arthroscopic rotator cuff repair (ARCR).

METHODS

PubMed, Embase, Web of Science, and Cochrane Library databases published before January 2022 were comprehensively searched. Two reviewers independently reviewed the titles and abstracts using the specified criteria. Studies were included if the authors clearly described the correlation between the CSA and rotator cuff repair. Data on patient characteristics, mean CSA, retear rate, and the functional score was pooled from the selected articles. A meta-analysis was performed using Review Manager (RevMan) 5.4.1 software, 2020 (Cochrane Collaboration, Copenhagen, Denmark).

RESULTS

Eleven articles involving 1449 patients from 7 countries were included. The ages of the patients ranged from 45 to 75 years. The follow-up period ranged from 6 to 96 months. The mean CSA was greater in the retear group than in the non-retear group after ARCR (mean difference 2.73°; 95% confidence interval [CI] 0.69-4.77) (p = 0.009). Three studies evaluated the association between increased CSA and the postoperative retear rate. All three studies showed a higher postoperative retear rate in patients with an increased CSA (odds ratio 5.35; 95% CI 2.02-14.15; p = 0.0007). No association was found between CSA and Constant-Murley (Constant), the University of California at Los Angeles (UCLA), or Visual Analog Scale (VAS) scores during the follow-up period of 24-96 months (p > 0.05).

CONCLUSIONS

This systematic review and meta-analysis showed that CSA correlates highly with rotator cuff retear after ARCR. In addition, the postoperative retear rate of the rotator cuff increased with increased CSA. CSA appeared to not affect worse functional outcomes in patients after ARCR.