Positioning

Arthroscopic treatment of an osteochondral defect is carried out as an outpatient procedure under general or spinal anaesthesia. Virtually all ODs can be approached through anterior arthroscopy.

The patient is placed in the supine position with slight elevation of the ipsilateral buttock. The heel of the affected ankle in placed at the very end of the operating table. This way, the surgeon can fully dorsiflex the ankle by leaning against the foot sole. Routine anterior portals used are the anteromedial and anterolateral portal. A soft-tissue distraction device can be used when indicated.

Instruments

A 4.0 mm arthroscope with 30° obliquity is used for this procedure. A 2.7 mm arthroscope with 30° obliquity can also be used for ankle arthroscopy. The new small diameter short arthroscopes yield an excellent picture that is difficult to distinguish from a standard 4 mm scope. The small diameter arthroscope sheath, however, cannot deliver the same amount of irrigation fluid per time as the standard sheath. This is an important drawback when motorized instruments are used, as in these cases an adequate amount of irrigation is beneficial. In the author's opinion, for routine arthroscopic procedures such as anterior impingement syndrome, loose body removal, treatment of synovitis and the vast majority of osteochondral defects, it is beneficial to use the 4.0 mm arthroscope. A 2.7 mm arthroscope should be used only for osteochondral defects of the posterior talar dome (less than 8% of all osteochondral defects in the ankle joint). Even in these case we use a 4.0 mm arthroscope.

Normal saline, glycine or Ringer's lactate can be used of irrigation. When a 4 mm arthroscope is used, gravity inflow is usually adequate if the fluid is introduced through the arthroscope sheath.

A 5.5 mm bonecutter shaver is used for removal of osteophytes, synovium and for debridement of the defect.

A 4 mm chisel and/or small periosteal elevator can be useful, an arthroscopic punch and small and large graspers.A 4 mm chisel and/or small periosteal elevator can be useful, and furthermore a small diameter closed cup curette and 45/90 degree microfracture probes are mandatory.

Also, a non-invasive distraction device can be useful to visualize the defect.

Portals

For debridement and microfracturing of osteochondral defects of the talus through anterior arthroscopy, the standard anteromedial and- lateral portals are used. The technique of the approach is described in text & figures and in video.