Keyhole surgery is not a primary intervention for cartilage wear as it does not replace cartilage.  It may be of benefit in patients who have mechanical symptoms due to; loose bodies; meniscal flaps/tears causing locking; chondral harvest and occasionally diagnostic.
Despite short-term pain relief in studies, arthroscopic ‘clean-ups’ may accelerate joint degeneration in the long term.

CARTILAGE TRANSPLANTATION: (ACI/mosaicplasty)
This is technically difficult surgery with limited indications to very young patients with small localised cartilage defects and normal joints otherwise.   This is not useful in age related arthritis.

OSTEOTOMY AND REALIGNMENT SURGERY
This is of benefit in patients with limb deformity and malalignment in the below 50 age group.   It is usually only indicated when half of the joint is well preserved.  It can delay joint replacement but also complicate later procedures.

JOINT REPLACEMENT SURGERY

• : half knee replacement is a procedure which is indicated for patents with partial joint degeneration.   There are stricter requirements including lower body mass, near normal alignment, and good range of motion.   This is a good option for the younger patient as a staging procedure (eg 50yo) or elderly patient benefiting from an earlier recovery (80+).   These typically have a shorter recovery and feel somewhat more normal in function.

• Total knee replacement: This is the gold standard procedure.   It can benefit most patients with good long term outcomes.  It may be done with or without patellar resurfacing.  Ligament and alignment correction can be achieved.  This should be discussed with you surgeon.

JOINT FUSION/AMPUTATION:
Fusion is a common option in hand and feet.  It is occasionally indicated in the very young patients (20yo).
Occasionally limb amputation is a final option for infected/failed joint replacements.