Study did meta-analysis of multiple article and found at 1 or 2 months will drop pain by 1.1/10 with no difference between 100 or 200 units. Often there is significant inflammation around the knee – anserine bursa being an obvious one. Botulinum, not being directly injected into it would have zero benefits there. Steroid is very forgiving and would effect inflamed areas close by. I contend they should be both injected at same time.
Courseau, Mathilde, et al.
Efficacy of Intra-Articular Botulinum Toxin in Osteoarticular Joint Pain: A Meta-Analysis of Randomized Controlled Trials.
The Clinical journal of pain 34.4 (2018): 383-389.
https://journals.lww.com/clinicalpain/Abstract/2018/04000/Efficacy_of_Intra_Articular_Botulinum_Toxin_in.12.aspx
- they got a 1.1/10 drop at 1-2 months not effected by dose
- they refer to another metanalysis that “showed a weighted mean difference of 0.7 at 4 weeks and 1.1 at 8 weeks, which is close to our results”
when I inject botulinum in a knee it is very important to be in the joint and so lateral mid patella injection is done:
Lateral Patellar Knee Injection Technique Best
http://painmuse.org/?p=4961
However, pure botulinum will not attenuate pain in pes anserine bursa or other extra-joint nearby sites.
Comment – botulinum helps joint pain but best used with steroid in my opinion