Effect of ALPSA Tear Morphology on Redislocation Risk After Arthroscopic Repair

Area of Science:

• Orthopedic surgery
• Shoulder instability
• Arthroscopic repair

Background:

• Limited knowledge exists on anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion characteristics in anterior shoulder instability.
• Understanding lesion location and tear structure is crucial for Bankart lesions, but ALPSA lesion specifics remain under-researched.

Purpose of the Study:

• To determine the prevalence of different ALPSA lesion patterns.
• To assess the impact of ALPSA lesion characteristics on redislocation rates following labrum repair.

Main Methods:

• Retrospective evaluation of 178 patients undergoing arthroscopic labrum repair for ALPSA lesions (2015-2022).
• Categorization of tears by position (e.g., 3- to 5-o'clock, 1- to 5-o'clock) and presence of radial tears.
• Comparison of tear characteristics and patient-reported outcome measures (PROMs) between patients with and without redislocation.

Main Results:

• Redislocation occurred in 35 patients; 143 did not experience redislocation.
• ALPSA lesions in the 3- to 5-o'clock position were more prevalent in the redislocation group (60%) compared to the no-redislocation group (36%).
• Radial tears were significantly more frequent in the redislocation group (49% vs. 23%), and were independently associated with redislocation (OR, 4.67).

Conclusions:

• An isolated ALPSA lesion at the 3- to 5-o'clock position is a risk factor for redislocation.
• The presence of radial tears is an independent predictor of redislocation after arthroscopic ALPSA repair.
• While PROMs improved postoperatively, they were worse in the redislocation group.