An old knee and hip injury

Hello, I would like if possible to get advice in rehab from a previous injury. In 2015 I had two fractures, left knee tibial spines and left hip, both of which required surgery, but it is the knee I am mostly asking advice for.

Before I continue let me say that I have been "discharged" by my orthopedist as recovered (or recovered enough anyway) and that I have seen many a PT and received nearly as many opinions. However, I am not too happy about the current situation, which is why I am asking for further advice. I provide some details in case some PT in the forum reads this. I can give many more details, including x-rays and the like.

I had a fracture of the left knee with detachment of both tibial spines in 02/01/2015, and had surgery in arthroscopy on 16/01/2015. The surgery was fine and, according to subsequent x-rays, the bone has healed fine. However, altogether I had to keep the left knee still for about a month and a half, and recovery of ROM was very slow and painful, mostly because of muscles, soft tissues and adherences I think. In fact, by the end of April 2015 my ROM in flexion was no more than 90 degrees, and extension was also lacking, so it was decided to mobilise the articulation under anaesthetic. Not long after recovery speeded up quite a bit.

Jumping to now:

1) Flexion has improved much. Cold, active flexion is slightly less than that of the other leg, with passive flexibility the difference is more evident. If I thoroughly warm up I can reach more or less full ROM - e.g. I can sit in seiza with my bum over the heels  - but  not comfortably.

2) Extension also improved but is still slightly less than full range, but again full ROM is achieved if I have warmed up. I have been told to focus on extension recovery more than flexion.

3) Muscle tone is still less than the other leg, and I am finding it hard to recover it.

4) The knee feels rigid.

5) I often feel some discomfort slightly below the knee capsule, on the medial part of the leg. According to one PT this should be the meniscus suffering because the quad is still not strong enough.

6) The knee is extremely crunchy and noisy and I can feel (and hear) something moving inside when I articulate it. According to a PT this is the new bone configuration - however my orthopedist disagreed with this. According to another it is knee capsule movement due to a weak quad. I have been told that the knee is stable. The moving/cracking is not painful, just slightly uncomfortable, but I am worried it could cause arthritis in the long term, and I would very much like to fix or improve the situation - if possible.

A good thing is that, while slow and sometimes unnoticeable, I think there has been continuous progress. If more details are needed please ask.
Thanks in advance for the help.

How is the SLS and stretch series going?

SLS is not too bad, if I have warmed up knee flexion I can manage some good reps, and the bad ones are mostly because I have not fully assimilated the technique I think. Without specific warm up I struggle much more - I manage to get up but with no balance. The iM is also not terrible. An old form check is here, and it has improved since then.

Predictably, in the TB stretches the knee and hip do not hinder me. 

Soumds like you are doing well with the SLS. Keep working through these and the stretch series. With your history I would progress slow and expect some knee pain.

An update: I was particularly concerned about the fact that the noise and slight movements I could hear from my knee may indicate some friction with possible cartilage consumption. I had a magnetic resonance exam done recently to check, and luckily that seems not to be the case: no damage to the cartilage results from the exam.
I have not had the time to have my orthopedist check the exam yet, but the doctor who wrote the medical report explained me the main points: What is there is

1) Weakened (I think less tense) cruciate ligament - which makes sense as in the accident it was greatly strained. "Luckily" the bone broke instead of the ligament.

2) Slight tear in the meniscus - apparently not major and does not warrant any operation.

3) Small effusion.

I can post the medical report, but it is in Italian, and or the RMN images if that would be useful.

The advice I got is to strengthen the muscles, in particular the quadriceps, so to spare the cruciate some work.

Any advice on which kind of work/frequency is advised in these cases? I have not received any specific advise. I was thinking of doing some weighted work (weighted squats, leg press). I am not sure about how often and if it is better to follow a low rep high load regime or the opposite one.

Thanks for the help!