The cuff is attached back down to the humurus using sutures and holes drilled into the bone. This type of rotator cuff tear is the most difficult for a surgeon to perform - because of this, typically your surgeon cannot guarantee that the repair will be performed all arthroscopically. For example, large tears are difficult to fix arthroscopically and usually need a mini-open approach. Because I have had significant experience with arthroscopic cuff repairs, I prefer to try to fix every patient's tear arthroscopically. The pain after surgery is much less - generally patients go home the day of surgery and do not need to spend a night in the hospital.
Recovery is usually faster, and return to work sooner with arthroscopic repairs.
Most orthopaedic surgeons do not perform arthroscopic rotator cuff repairs. This is mostly because they are very hard to do and require special training. Some surgeons criticize arthroscopic repairs because they feel that they are not as strong as mini-open or open repairs. Personally, I feel that a well trained arthroscopic surgeon can repair small to medium sized tears very well and securely with an all-arthroscopic technique. These techniques are currently the subject of much research and are changing dramatically as time goes by.