Table 1.

Pearls and Pitfalls

Pearls	Pitfalls
Inject saline solution into the chondral lesion to create a bubble sign and clearly defineits margins.	The glenoid cartilage can be damaged if attention is not paid to careful placement of the medial retractor.
Use a contact probe to ensure that all areas of the chondral defect will be prepared and covered by the implant.	A guide pin that is not placed perpendicular to the lesion or one that is bent can lead to an implant that is not flush with the surrounding humeral head on all sides.
Start the reamer prior to contacting bone to prevent chipping the articular rim.	The proximal shoulder of the step drill must be flush with the articular surface, and the taper post must be inserted to the line on the driver; otherwise, the implant may sit proud to the articular cartilage.
Use the guide and subsequently the trial to confirm that the implant will be flush with the articular surface prior to its implantation.	The guide pin can bend while using the circle cutter. Twisting movements should be used to avoid this pitfall.