The concept of 'compartments'
Disease - such as osteoarthritis - may begin in only one compartment.
By intervening early in uni-compartmental disorders, it may be possible to prevent the problem extending to the other compartments.

The concept of compartments has allowed the development of partial knee replacements, where only one of the compartments is replaced, while the others are retained.
Peer-reviewed papersQuote from peer-reviewed paper:
"....Malalignment of the lower extremity, which overloads one compartment at the expense of another, is [...] associated with progression of osteoarthritis...."
Citation: D'Lima DD, Fregly BJ, Patil S, Steklov N, Colwell CW Jr. Knee joint forces: prediction, measurement, and significance. Proc Inst Mech Eng H. 2012 Feb;226(2):95-102. doi: 10.1177/0954411911433372. PMID: 22468461; PMCID: PMC3324308.
Forum discussions
- Partial knee replacement - ongoing pain at 30-60 degrees
Partial knee replacement causing ongoing pain.
The articulation of the two large bones -