ObjectiveTo demonstrate the in situ repair technique of high-degree partial-thickness articular surface lesions of the supraspinatus tendon (SS). The procedure consists of the arthroscopic surgical repair of these lesions, without the need to complete the lesion, as occurs in traditional classical technique. A small incision is made in the longitudinal direction of the intact bursal fibers and where bone fixation anchors are introduced, which makes the procedure easier. These anchors are transferred to the tendon and thus enable the repair of the lesion.Methods48 shoulders were operated in the period 2010–2015. The minimum follow-up was 12 months and maximum 60 months. Ages ranged from 38 years to 75 years (mean 54 years). They were indicated for the repair of high-degree symptomatic lesions and at least 30% intact superior bursal fibers of good quality.ResultsPatients were evaluated according to the UCLA criteria, the results were: 69% excellent, 17% good, 7% fair, and 7% poor. Fair results occurred in three patients with associated symptoms of polyarthralgia who remained with residual pain. Three patients developed postoperative joint stiffness (7%).ConclusionThe procedure under study is safe and easy to reproduce. It shows high rates of positive results (86%). The opening made in the bursal side of the SS tendon allowed the arthroscope to remain in the subacromial space, making it easier to perform surgery.