Andrew Bynum injured his left knee more than four months ago, but even after surgery, it still isn’t feeling right.

The Lakers have announced that he’ll undergo arthroscopic surgery on Wednesday.

An estimated timetable for Bynum’s return will be provided following the surgery.

The Lakers said the procedure will entail a cleanup of some rough spots and fraying on the underside of Bynum’s kneecap.

The Lakers estimated a day after Bynum was injured that he would be sidelined eight to 12 weeks. But coach Phil Jackson said April 21 that a return this season was remote, and Bynum said much the same thing shortly thereafter.

Dr. Altchek examined Bynum in New York on April 10 and declined to clear him for practice. The 7-footer was examined again May 7 in Princeton, N.J., by Dr. Steven Gecha, who said there had been some improvement in the knee, but recommended exploratory surgery if there wasn’t more in the ensuing three to four weeks.

The decision was made a lot sooner than that.

No matter how they do in this year’s playoffs, the Lakers would be the prohibitive favorites to win the 2009 NBA Championship with a healthy Andrew Bynum. Without him, they look to be about as good as four or five other teams in the West. It’s a bad sign when a player this young starts to have ongoing problems with an ankle or a knee, but let’s hope that this surgery fixes whatever issues he is experiencing. The league needs good, young centers and Bynum fits the mold.