Been there, broke that
I did the same exact thing in 2002, Going out for the first AHRMA MX of the year, first kick, the pawl broke on my Cheney/Triumph and a split second later so did my right tibial plateau. The good news is I was almost able to keep my balance when I dropped hard onto the seat. The bad news is I lost my balance and fell over to the right.... and onto my Cheney/Ariel on its stand alongside. My wife pokes her head out the RV door and sees me buried in a pile of British Iron and folded up lawn chairs alternately swearing/moaning/groaning/whimpering. Good news is my lovely bride was traveling with me and she has first aid training so after my buddies cleared the wreckage she wrapped up my damaged appendage and kept the swelling down. Bad news is we were in Peoria Az, the western US center of geriatric medicine so instead of going to the ER and running the risk of being fitted with a colostomy bag by mistake we opted to head for home. Good news is we had a nice comfortable brand new RV with leather air ride seats for the 14 hour drive home. Bad news is our brand new RV had a 10 spd manual trans and my lovely bride didn't know how to drive a truck style trans. Good news is my left leg still worked so I could push in the clutch and we had lots of Ibuprofen and ice to keep me 'comfortable' for the 14 hour drive home.
I saw the orthopod on Mon afternoon and 24 hours later I had 7 screws and steel plate. In my case tho I woke up with my leg in a Constant Motion Machine that worked my knee joint similar to a bicycle motion. For the next week or ten days most of my waking hours were spent with my leg in the CMM and two weeks later I was in PT and sitting on an exercise bike 5 hours a week. Both the Orthopod and the PT were advocates of keeping the joint moving, and as a result I have full range of motion. Though 12 weeks of no weight bearing and crutches wasted my quads and calf. A few months of spin class 3 days a week brought back the muscle tone.
One word of advice, wear a shin guard when you're riding. You really don't want to find out what it feels like to catch roosted rocks on a plated tibia.
"We'll burn that bridge when we get to it"
Deadhorse- 2002, 2012
ALCAN 5000- 2004