Choosing joint preserving surgery before knee replacementOne-compartment knee wear does not automatically mean replacement is next: bracing, osteotomy and focal cartilage repair can reduce pain and delay arthroplasty when alignment and damage remain localised. Microfracture is now usually limited to very small defects, while AMIC, MACI, OATS and OCA are chosen by lesion size, depth and…One-compartment knee wear does not automatically mean replacement is next: bracing, osteotomy and focal cartilage repair can reduce pain and delay arthroplasty when alignment and damage remain localised. Microfracture is now usually limited to very small defects, while AMIC, MACI, OATS and OCA are chosen by lesion size, depth and joint health.