Operative management of partial-thickness rotator cuff tears is controversial. Management options for partial-thickness tears that fail physical therapy include tendon debridement, acromioplasty, and excision with repair. In general, symptomatic partial-thickness tears in patients that fail conservative management may be offered surgical intervention which can include debridement or repair depending on tear depth.

Partial-thickness rotator cuff tears involving more than 50 % of the affected tendon are often offered tear completion and subsequent repair. Dugas et al. [71] studied the insertional anatomy of the rotator cuff in 20 cadaveric shoulders. They determined that the mean medial-lateral diameter of the supraspinatus insertion is 14.7 mm. Symptomatic high-grade partial-thickness rotator cuff tears (defects >5–7 mm) who fail conservative treatment may be offered tear completion and repair with good expected results. There is evidence that symptomatic partial-thickness tears involving >50 % of the tendons are best treated with conversion to a full-thickness tear and repair [72, 73]. Webber et al. [72] compared 32 patients with partial-thickness RTC tears treated with debridement compared to 33 patients treated with conversion to full-thickness tears followed by repair. All tears in their series involved >50 % of the affected tendon defined by a >6 mm RTC defect; they found reoperation to be significantly higher in patients who underwent debridement alone. They also reported higher UCLA scores in patients treated with repair of partial rotator cuff tears compared to those treated with debridement. Bursal-sided tears may be resistant to nonoperative care and subacromial decompression alone [74]. Kim et al. [75] reported similar outcomes in patients undergoing repair of bursal- and articular-sided partial-thickness tears at a mean follow-up of 36 months. Other techniques have also been described for repair of partial-thickness tears. These include transtendinous PASTA (partial articular-sided tendon avulsion) repair [76] and the all-inside articular-sided rotator cuff repair as described by Spencer [77]. The indications for repair using these other techniques are the same as described above for completion and repair of the tear, and no real data exists demonstrating superiority of one technique over another.

Partial rotator cuff tears that effect <50 % of the tendon may be offered debridement if conservative management fails [78, 79]. Partial-thickness tears result in significant intra-articular fraying that can irritate the glenoid labrum or the long head of biceps tendon with shoulder motion. This is not an uncommon scenario in young active/athletic patients with partial rotator cuff injuries (Figs. 16.4 and 16.5). Debridement of partial-thickness rotator cuff tears in elite throwers has been demonstrated to have good results in 75 % of patients including returning to competitive pitching [80]. Repair of partial-thickness rotator cuff tears in the throwing athlete is rarely indicated as shoulder stiffness may ensue [79]. Patients with partial-thickness rotator cuff tears involving <5–7 mm of the tendon footprint who fail physical therapy may be offered debridement; careful inspection and possible repair of other intra-articular structures in the throwing athlete may also be indicated.

The indications for rotator cuff repair are still evolving. The prevalence of cuff pathology in asymptomatic patients suggests that many patients can do well without surgery. In addition, the body of evidence is improving regarding indications for surgery. Factors such as patient activity level and patient expectations have been proven to be important considerations for recommending treatment. The rimportance of structural factors such as size of tear and characteristics on MRI remains controversial and requires more investigation.