Please choose the correct ending to complete the given sentence: Health: [header] How to diagnose knee pain [title] Decide if you have a fracture. [step] Kneecap fractures are common knee problems. You can fracture your knee just by falling onto your knee hard enough.

Ending1: If the kneecap is broken, the pain in the affected knee will immediately turn from mild to severe. [substeps] There are various types of kneecap fracture. Ending2: If you fracture your knee, you may need surgery. Knee fractures are generally serious and take a long time to heal. Ending3: It's sometimes called a knee fracture. The medical tradition is that kneecap fractures should only be broken once or twice a year. Ending4: In some cases, though, certain fractures can become more permanent, and can take weeks, months, or even years to heal. A fractured kneecap can cause injury to the knee and potentially nerve damage.

Answer format: ending1/ending2/ending3/ending4