The Role of Critical Shoulder Angle in Predicting the Outcome of Conservative Management of Shoulder Impingement Syndrome.

Introduction: A rounded shoulder with anterior tilting of the scapula is the common reason for shoulder impingement syndrome. The mainstay of treatment will be shoulder rehabilitation. While the anterior tilting of the scapula is a part of posture, the critical shoulder angle (CSA) is another anatomical factor that may influence the outcome of patients with shoulder impingement syndrome.

Aims: The study aims to identify the role of CSA defining the outcome in patients with CSA > 40° and those <40° angles undergoing the Madurai shoulder pain cure program (MSPCP), a standardized rehabilitation program.

Materials And Methods: The study was conducted as a prospective analysis with 40 participants suffering from shoulder impingement syndrome. CSA was measured on each patient, and they were divided into two groups: Group A-CSA < 40, and Group B-CSA > 40, after which they were subjected to the standardized MSPCP. The MSPCP is a rehabilitation regimen done for 3 months. This is done in phases: Phase 1 from 0 to 2 weeks, phase 2 from 2 to 6 weeks, and phase 3 from 6 to 12 weeks. The rehab regime includes scapular stabilization exercises, capsular stretching exercises, and rotator cuff isometric exercises to address pain and dysfunction associated with impingement syndrome and rotator cuff tendinitis. The participants were assessed using the Oxford Shoulder Score before the start of rehabilitation, at 2 weeks, 6 weeks, 3 months intervals, or until the symptoms were relieved. The outcomes were tabulated.

Results: Group A participants with < 40° of CSA demonstrated better functional improvements with the mean Oxford Shoulder Score of 39/48 following the MSPCP rehabilitation program compared to Group B participants with CSA more than 40° of a mean Oxford Shoulder Score of 32/48. The statistically significant difference indicates that patients with CSA < 40° had better outcomes.

Conclusion: CSA is a key factor in determining the success of conservative treatment for patients suffering from shoulder impingement syndrome. Patients with CSA < 40° showed significant improvement, and patients with CSA more than 40° showed slow improvement after rehabilitation with the MSPCP program and perhaps needed a longer time to recover.