chapter 5: Arthroscopy of the patellofemoral joint
Lesions of the patella and trochlea can be debrided readily using arthroscopic technique. This is usually easiest with the patient supine, knee extended. A curved tip arthroscopic rotary shaving tool is often helpful. Care must be exercised to remove all loose flaps and mobile fragments. If exposed bone is left, drilling or picking the bone is usually advisable. Although debridement alone may be palliative if the flap(s) alone is symptomatic, realignment or release to relieve pressure on the deficient area may be necessary.
Arthroscopic debridement of small osteochondral fragments from osteochondritis dissecans or dislocation is appropriate, but large fragments with bone attached (usually more than 1 to 1.5 cm in diameter) should be replaced and fixed securely.
Radiofrequency(RF) ablation and laser have been used for cartilage debridement in some centers, but we have been happy with sharp removal of loose cartilage fragments. Depth of penetration is a major issue in the use of thermal ablation and any risk of cartilage damage beyond what is removed should be avoided. There are reports of subchondral bone necrosis following laser ablation of cartilage. Newer RF techniques, particularly monopolar ablation carry less risk of inadvertent damage to healthy cartilage and subchondral bone. In general, however, the authors have not found these thermal methods necessary in the treatment of patellofemoral articular lesions.
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