Computer-assisted planning combined with bone crest positioning to guide lateral acromioplasty: methods and clinical application.

Background: This study investigates preoperative CT three-dimensional reconstruction and computer-assisted planning, combined with bone crest positioning, to guide lateral acromioplasty for subacromial impingement syndrome (SAIS). It evaluates this approach's effectiveness in enhancing surgical accuracy, improving shoulder function, and optimizing imaging parameters.

Methods: This study retrospectively analyzed 40 patients diagnosed with SAIS who underwent surgical treatment in our hospital between May 2022 and December 2023. Patients were divided into two groups: preoperative planning acromioplasty (group 1) and conventional acromioplasty (group 2), with 20 patients each. Preoperative and postoperative shoulder CT 3D reconstructions were performed to measure critical shoulder angle (CSA), acromion index (AI), acromio-humeral interval (AHI), and lateral acromial angle (LAA). Clinical function scores and visual analogue scale (VAS) were recorded preoperatively, at 6 months postoperatively, and at final follow-up (September 30, 2024). Postoperative MRI or CT assessed acromial fracture, deltoid insertion tears, and other major complications. Continuous variable data with a normal distribution were analyzed using the t-test; the rank sum test was used for continuous variable data with a non-normal distribution; and count data were analyzed using chi-square tests or Fisher's exact tests.

Results: With an average follow-up of 19.70 ± 7.39 months (9-28 months). Postoperative comparison between groups showed that the CSA of group 1 was significantly lower than that of group 2 (P < 0.05). AI was lower and AHI was higher in group 1 versus group 2 postoperatively (P < 0.05). Group 1 achieved superior Constant and UCLA scores at final follow-up, with no significant differences in ASES or VAS scores between groups, and no cases of acromial fracture, deltoid insertion tears, or other major complications were observed postoperatively in either group.

Conclusion: The use of preoperative CT 3D reconstruction and computer-assisted design for precise grinding planning, combined with an intraoperative bone ridge positioning method enhances surgical accuracy, can significantly improve clinical outcomes and imaging parameters, and protect deltoid insertion integrity, offering clinical value.