A retrospective study on the pathology and short-term outcomes of arthroscopic repair for intratendinous, bursal-side, and articular-side tears: comparison after conversion to full-thickness tears.

Partial-thickness rotator cuff tears (PTRCTs) are classified into intratendinous tears (ITT), bursal-side tears (BST), and articular-side tears (AST). ITT is relatively rare, and many aspects of its clinical presentation remain unknown. Moreover, there are few reports on arthroscopic rotator cuff repair (ARCR) of ITTs. To the best of our knowledge, few reports have compared the treatment outcomes of ARCR with those of BST, AST, and ITT. Patients who were diagnosed with ITT based on intraoperative findings and who could be followed up for at least 1 year postoperatively were included in this study. In all patients with PTRCTs, a complete tear was created and repaired via suture bridge techniques. Among the ITT, BST, and AST groups, the frequency of PTRCTs (ITT, BST, AST), patient background (age, sex, history of trauma), acromiohumeral distance (AHD), critical shoulder angle (CSA), lateral acromial angle (LAA), acromial morphology, Japanese Orthopaedic Association (JOA) score, and re-tear rate were compared. Fifteen patients underwent ARCR on ITT, 95 patients underwent BST, and 39 patients underwent AST. There were no significant differences in age, sex, or frequency of traumatic rotator cuff tears. The preoperative CSA showed significant differences; however, no significant differences were observed among the three groups for AHD, LAA, and acromion morphology. There were no significant differences in operation time, JOA score, or re-tear rate. The results of ARCR for ITT were good and may be a viable option for patients resistant to conservative treatment.