You should be fine with studying for 2 or 3 weeks. Step 2 is essentially a rehashing of your shelf exams, and I assume you have been doing well on those given your clinical grades. Clearly you are a good test taker, and I think that test-taking ability is a huge component of CK, with less emphasis on fact memorization than Step 1.
I think that Step 2 still has limited importance in orthopaedics, since not all applicants take it by the time ERAS is due, so it can't used for screening like Step 1 is. It's probably more on par with clinical grades, class rank and research. A poor score can hurt you, but it won't derail your application or get you screened out.
Keep in mind that the average on Step 2 is 240, compared to 230 for Step 1, so you are basically getting a 10 point bonus to start. From my experience, I don't think program directors know this, so 250 is considered a "good" score for both tests. Therefore, if your target minimum is 250, you only need to perform at a 240-Step 1 level, and that is 20 points below where you have traditionally performed. Even if you have a bad test performance, you should still have an average to above-average score, which should minimal impact on your application.
I was in a similar situation to you in regards to Step 1 and clinical grades, and I had also taken medicine and surgery early in the year. Ultimately, I decided to take CK during the spring, with 2 weeks of prep using UWorld and Step 2 Secrets. In the end, I outscored my Step 1. During my interviews, I had a few commendations on my Step 1 score (~260), but my Step 2 performance never came up.
Hope this helps.