Dissertation topics for the knee

Hi, Im currently working on choosing a dissertation topic for physiotherapy interventions for the knee. As part of a systematic review i need to choose an area that would consist of quite a few RCT's. Areas that are excluded are Open and closed chain exercises for ACL injuries and proprioception for the knee

So far i've come up with, Does CPM post Knee Arthroplasty reduce hopsital stay? or produce an improved clinical outcome?

Isokinetic rehab after meniscectomy

It would be a great help if any qualified physios can offer any advice on any other areas of interest which they feel would be worthwhile reviewing

Many thanks

James