For the second time in 19 months, an injury has shattered the hopes of the Chicago Bulls and their fans.

Superstar Derrick Rose hobbled off the court Friday night after appearing to twist his right knee. Fans immediately feared an ACL tear similar to the one in his left knee that kept him out all of last season.

The team announced Saturday that the point guard had, in fact, torn his medial meniscus. The team could not offer a timeline for his return to play until Rose had surgery. Since the diagnosis seemed less serious than a second ACL tear, many fans breathed an optimistic sigh of relief.

Unfortunately, news following the surgery dashed that optimism. Dr. Brian Cole, the orthopaedic surgeon who performed Rose’s left ACL reconstruction, performed a medial meniscal repair Monday. The Bulls announced that Rose would indeed miss the rest of the season.

A meniscus tear is the most common surgically treated knee injury. A tear of this C-shaped shock-absorbing cartilage does not heal on its own. An athlete almost always undergoes surgery in order to return to play.

Two surgical options exist. The surgeon can trim out the tear or sew it back together with stitches and anchors. The doctor decides the best treatment based on the location and orientation of the tear. Only a small percentage of meniscus tears can be repaired.

Regardless if a surgeon or athlete wants to have the tear sewn together, the surgeon doesn’t know if it will be possible until he sees the tear through the scope. Even MRI is unreliable at predicting if a tear can be repaired. This is the reason that the Bulls — or Dr. Cole or Rose himself — could not predict exactly when he would return to the court.

Surgeons perform up to 850,000 meniscus surgeries each year. Partial meniscectomies, or surgeries to trim out the torn portion of the meniscus, comprise most of these procedures. A study of football players evaluated at the NFL Scouting Combine showed that partial meniscectomies are the most common surgeries players have undergone earlier in their careers.

An athlete can often return to sports quickly after partial meniscectomy. The surgeon allows full motion and weight-bearing since no repair needs to heal. The athlete can return to play in as few as three to four weeks. Meniscectomy does carry a risk of future degenerative changes from the loss of some of the shock-absorbing capability.

On the other hand, if a meniscus tear does occur in an area with good blood supply and in a certain orientation, the surgeon generally tries to repair it.

Recovery and return to sports after meniscal repair takes four to six months. The surgeon limits knee motion and weight-bearing to protect the repair. If the athlete pushes through the rehab too quickly, he risks damaging the repair. If the repair does heal, though, the athlete maintains the entire meniscus and theoretically prevents arthritis changes.

Fans are clearly disappointed Derrick Rose will miss another season. Is a meniscus repair actually better long-term?

While Rose would have returned to action quickly after a partial meniscectomy, it might have come at a cost. NFL players who have undergone meniscectomy have been shown to have shorter careers and play and start fewer games after surgery compared to similar players without a meniscus tear.

Likewise, a German study showed that 80 percent of patients had no signs of arthritis years after meniscal repair surgery compared to only 40 percent that showed no damage after meniscectomy.

That long-term success requires the meniscus repair to actually heal, which is a real concern. A recent study from the Hospital of Special Surgery in New York showed failure rates approaching nine percent. Unfortunately the authors found that medial meniscus repairs (like the one Derrick Rose suffered) had a higher risk of failure than repairs of the lateral meniscus (like the one Oklahoma City Thunder guard Russell Westbrook recently had). An Australian study of elite athletes provided similarly discouraging results. While 5.6 percent of lateral meniscal repairs failed, more than 36 percent of medial meniscal repairs failed.

After the diagnosis was announced, Bulls coach Tom Thibodeau observed, “You just take things as they come. This is all part of the NBA. Injuries are part of it.”

In the three seasons following his 2010-2011 NBA MVP award, injuries have limited Derrick Rose to just 50 games. Now Bulls fans, the team and Rose himself wait to see if this latest injury is a bump in the road on his way back to greatness or the beginning of the end to a promising career.

Dr. David Geier is an orthopaedic surgeon and sports medicine specialist in Charleston. For more information about basketball injuries and other sports medicine topics, go to his blog at drdavidgeier.com.