[Arthroscopic arthrolysis for the treatment of movement disorders of the knee]

Knees with a limited range of motion caused by intraarticular scars benefit from arthroscopic arthrolysis. Usually these scars result from previous surgery, severe trauma with damage of intraarticular structures. Less frequent the reason is primary arthrofibrosis. Improvement of range of motion is achieved by arthroscopic release of scar tissue and removal of the fibrotic Hoffa fat pad.

To improve the patients' range of motion which is necessary for activities of daily living and labour is the aim of this surgery. Scar tissue is debrided and resected arthroscopically with a radiofrequency device, a shaver or a punch.

Flexion deficit of maximum 40°, extension deficit to a maximum 20°, reduced mobility of patella, intraarticular reason for limited range of motion, cyclops after anterior cruciate liagment reconstruction, fibrotic Hoffa fat pad.

Origin of limited range of motion is extraarticular (e.g. fibrotic quadriceps muscle), local and general infection, major osteoarthritis, noncompliance, complex regional pain syndrome type I.

After creating an anterolateral and anteromedial standard portal, scar tissue is resected from the superior recess. Medial and lateral adhesions are detached. After removal of the fibrotic Hoffa fat pad, the notch is released while cruciate ligaments are preserved. After visualization of the posterior recessus, a posteromedial portal is placed. By releasing the posterior capsule, extension is improved. The range of motion is checked regularly during surgery. When mobility is restored and all attendant pathologies have been treated, the surgery is finished.

Continuous physical therapy to maintain range of motion. If necessary, continuous passive motion is implemented. Pain adapted weight-bearing. A sufficient oral and (when indicated) regional pain management is important to guarantee the benefit of the surgery.

Patients with a lack of mobility of the knee gain considerably range of motion by arthroscopic procedures. Because of the minimal invasiveness, trauma of surgery and risk of infection are reduced. Between 2010 and 2014, 16 patients were treated by arthroscopic arthrolysis. Extension deficit decreased more than 10° from 13.6° to 3°, while flexion increased over 26° from 91.6° to 117.8°.