Cavaliers point guard this week didnt look like much when it happened, but an MRI has revealed a patellar fracture, and the recovery timeline is three months minimum. The All-Star will mi s the rest of the NBA Finals.Not surprisingly, Irvings left knee, which already had dealt with tendinitis,is the one thats the i sue. We'll explore why.MORE: | So what exactly happened to Irving's knee? He wasn't doing anything fancy. He was running. Nobody ran into him, there was no knee-on-knee contact, he didn't land awkwardly he Nigel Warrior Jersey just stopped, buckled, pa sed the balland limped away. The answer to the fractured patellalies within that same left knee that's held him out of two playoff games and made him mi s parts of several others. The i sues he's been trying to play through seem to have finally caught up with him in a season-ending sort of way.Whats going on in there?This is a good knee, with all the pieces where they're supposed to be. (Courtesy Wikimedia Commons) DeeJay Dallas Jersey The patella (kneecap) sits on the front of the knee jointand is an integral part of knee extension (straightening). Above it, the quadriceps tendon connects it to the quad, and below it the patellar tendon connects it to the tibia (lower leg).When the quad contracts, the leg straightens. Its no surprise that athletes in sports with a lot of jumping often end up with patellar tendinitis, which is inflammation and pain in the tendon. Tendinitis left unchecked can lead to weakening of the tendon, and weak tendons are tendons that can rupture.This is a side view of bad knees with patellar tendon ruptures. The ones on the right are taking a chunk of kneecap with them. (Courtesy Wikimedia Commons).Patellar tendonitis can lead to a rupture right in the middle of the tendon below the knee (example 1), a Jamal Adams T Shirts rupture at the level of the patella leading to a chunk of the bone being pulled off (examples 4 and 5) and all points in between.While the Cavs havent specified the exact details of Irvings injury, its not a huge leap of faith to think that his fracture could easily be the result of a tendon rupture. Tendon has tendonitis, tendon gets put through the paces of game after game of NBA playoffbasketball anyway, tendon eventually gives up and ruptures, and takes a piece of patella with it when it goes.So how do you fix that?If the tendon isnt completely torn, you might get lucky and get away with immobilization and physical therapy. Kyrie Irving apparently didnt get lucky, as its been announced that hes having a repair at the Cleveland Clinic.There are as many surgical repair techniques as there are opinions about which one is the best. The upshot is that the patella is held together with screws, wires, Dk Metcalf Hoodies Sweatshirts or heavy suture.Since theres huge stre s on the knee joint every time you flex it, the repair isnt as simple as just screwing it back together. A tension band wraps around the whole thing, holding it all together. Every time the knee flexes, the band surrounding it effectively pulls the injury back together.On the left, a knee held together by screws and wire, on the right, by suture and wire. (Courtesy Browner Skeletal Trauma and AO Foundation)How long does this take to heal?Simple range of motion exercises begin almost immediately. A knee immobilizer keeps the knee straight the rest of the time. In around six weeks youre back to fully bearing weight, and in six to eight John Reid Jersey weeks resistance training can be started. The average person can expect to be back at their sport of choice in four to six months, so an elite athlete might be at that same point in three to four months.What does this mean?For Irving, it means the season is over. It can also mean future i sues for that left knee arthritis, weakne s, hardware i sues (wires can break, and sometimes have to be removed)or tendon re-rupture. But several NBA superstars have recovered well from similar injuries, including John Wall and Blake Griffin, two of the most explosive players in the league.So it could be fine and never bother him again.For the Cavs, it could be the end of any po sibility of an NBA championship.Jo Innes is a real-life doctor and contributor for Sporting News. Follow her onTwitter .