Impaction fractures of the articular surface without a split wedge component. They may be associated with impaction of the cortical rim and instability of the joint. These occur most often in older patients with weaker cancellous bone.
The key to the treatment of these fractures is the stability of the joint. Stability can only be determined under adequate sedation, since pain and muscle splinting make it impossible to determine stability. If the joint is stable, conservative treatment with protective weight bearing and early movement is usually adequate.
Intraarticular fractures should not be immobilized except as a temporizing measure prior to definite surgical treatment.
Joint impaction cannot be reduced by indirect means, because the impacted bone has no soft tissue attachment and ligamentotaxis does not work.
If the impaction involves the cortical containment, stability will not be regained by simple elevation of the depression.