A 63-year-old female patient who suffered from right shoulder pain for approximately two months. A full thickness tear of the supraspinatus tendon was shown on magnetic resonance imaging (MRI).Following arthroscopic knotless SB repair, the patient developed sudden severe pain and limited passive movement in the right shoulder without any injury. Emergency MRI showed that the lateral anchor was pulled out. Subsequent arthroscopy confirmed the prominent lateral anchor above the lateral cortex. The lateral anchor was screwed into place again and a 4-hole locking protection plate was added above the tail of the anchor with 4 screws. At the 2 year follow-up, she was satisfied with the outcome and further MRI showed good continuity of the supraspinatus tendon.Although the knotless SB rotator cuff repair has an advantage in preventing re-tear, when sudden pain develops after operation, early failure of lateral anchors cannot be ignored in addition to infection.Similar cases reported in the literature are also being reviewed in this case report.