Partial-thickness tears of the rotator cuff have the potential to cause significant pain and disability in affected patients. Partial-thickness tears can be on the articular side of the tendon, on the bursal side of the tendon, or intratendinous. In the older patient population, tears typically occur on the articular side of the supraspinatus tendon, near its insertion onto the greater tuberosity (Fig 1). This is in contrast to what is often seen in the younger, overhead throwing athlete, where tears tend to occur more posteriorly at the supraspinatus-infraspinatus interval. Ruotolo evaluated the supraspinatus footprint in an anatomic study and found that the mean anterior-posterior dimension of the supraspinatus tendon was 25 mm (range, 19 to 27 mm). Among their 17 specimens with a mean age of 70 years, the authors reported a mean tendon thickness of 11.6 mm anteriorly, 12.1 mm at the midtendon region, and 12 mm posteriorly. Derived from the anatomy of the supraspinatus tendon, Ell- man developed a classification system for partial-thickness rotator cuff tears based on their location and depth as measured during shoulder arthroscopy (Table 1). In this system, articular-sided (A) or bursal-sided (B) tears are reported as grade 1 partial-thickness tears if less than 3 mm in depth, grade 2 tears if 3 to 6 mm in depth, and grade 3 lesions if greater than 6 mm in depth, representing greater than 50% of the tendon thickness.
Biomechanical studies have shown that in the presence of a partial-thickness tear, the strain patterns within the remaining intact rotator cuff are altered, potentially predisposing the tissue to tear propagation. Limited potential for spontaneous healing after the development of a partial-thickness tear is sup- ported by histologic studies that observed no active repair at the site of the injury, with the proximal stumps of the rotator cuff appearing rounded, retracted, and avascular. Clinical evidence of tear progression was shown by Yamanaka and Matsumoto in their evaluation of 40 patients with documented partial-thickness articular-sided lesions of the supraspinatus. Reimaging of the study patients with arthrography at a mean of 412 days after the initial diagnosis showed tear enlargement in 53% and progression to a full-thickness tear in 28%.
After failed conservative management, operative intervention is typically indicated for patients with persistent symptoms of pain and disability. A variety of approaches to the arthroscopic management of partial-thickness rotator cuff tears have been reported, including acromioplasty alone, debridement of the partial-thickness tear with or without acromioplasty, transtendinous repair, or conversion of the lesion to a full-thickness tear followed by repair (Table 2). Results of these surgical approaches vary considerably in the orthopaedic surgery literature, making it difficult to draw conclusions on the appropriate arthroscopic management of symptomatic partial-thickness rotator cuff tears.
On the basis of the continued controversy present within the literature regarding the management of partial-thickness tears of the rotator cuff, we designed a qualitative systematic review to compare the results of the recommended arthroscopic treatments and evaluate which potential variables are associated with successful outcomes for this complex patient population.