At 10 weeks I was able to climb stairs without using the handrail, but only one step at a time and 2 flights were mildly challenging. I didn't experience a sharp shooting pain as you describe but I di have a sensation of swelling- although there was no visual indication- it felt like the quads- I am lateral- were "full". The PT referred to it as hypertonic as in over toned and it did feel like that, plus stretching them out was difficult. I could not easily sit down on my knees with my butt on my ankles on the floor without strong discomfort in both knees and quads. I found the following things helped me work through it: foam roller- softer one at home/hard black, dense one at the gym- this took several months. Continuing to stretch the quads via sitting on my knees/heels and leaning my torso back with hand support on the floor. Needed to work up to this also took several months. Daily morning ritual before getting out of bed- ankle pumps/quad isometrics/bridges/external rotators with band/ heel slides/taylors. I also discovered the elliptical which I credit with increasing ROM and leg strength. Against PT recommendation I used the leg extension machine doing single leg extensions.
Always hard to determine cause for symptoms- could be stiffness/myofascial restrictions that a good deep tissue massage would help to fix, could be weakness/loss of strength or a lot of other reasons. Undoubtedly, it's probably best to not be too alarmed, start by trying a few different exercise approaches, make sure not to push yourself farther than your body feels "safe", tired is OK, vulnerable is not. If you have a good PT maybe a visit or even a call to your surgeons office.
Thigh pain is very common which is a surprise to most HR patients as we expect the pain more in the posterior. My difficulties hung on for a good 4 months before beginning to subside. I feel like I ma making very good forward progress now but even so, noticed a former symptom of "fullness" around the quad attachment at the knee giving me a warning this last week so I am monitoring it and adjusting the exercises I do.
What are you doing for recovery exercise. Do any of them help relieve pain? What about quad isometrics? Do they provide a feeling of relief?