Fracture of the patella

A fracture is a break in the bone. A patellar fracture is a break of the kneecap bone.

Patella fractures are usually the result of a hard blow to the front of the knee - falling on the knee, dashboard impact etcetera.

A simple fracture means that the injury does not break through the skin and a compound fracture means that it does. A comminuted fracture means that the bone has splintered in a number of directions, which makes management difficult and the outcome often poor.

Issues & controversies of patellar fractures

• The usual surgical treatment option is a wire, and it is generally right around the edges of the patella - a 'cerclage' wire
• The earlier the wire is put on and the edges of the fracture put together, the easier it is
• In any case it is difficult
• Even done early and under the image intensifier (a sort of dynamic X-ray machine) reduction may not be perfect (i.e. the edges may not come together properly)
• Poor reduction will almost certainly lead to patello-femoral arthritis (damage to the joint surfaces between the kneecap and the thighbone)
• Even a good reduction may progress to arthritis
• The most common alternative is removal of the patella (patellectomy) - itself problematic as full function seldom returns to the knee after patellectomy
• The newer technique of patellar resurfacing (putting a synthetic back to the kneecap) may be a viable alternative, but the jury is still out as to its current value