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 ( = .01) and SSV ( = .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.