Kneecap or Patella Arthritis (Chondromalacia, CMP)

Any damage to the gristle layer on the under surface of the kneecap should be regarded as early arthritis because there is wear of the shock absorbing gristle layer. Often the term ‘Chondromalacia Patella’ is used to describe this condition in early stages.
This can have many different causes including direct injury to the kneecap in a fall or as a result of many years of dysplasia, subluxation or dislocation (see further descriptions of these individual problems). Often it just happens with no obvious cause. Sometimes it runs in families.
It usually presents as pain around the kneecap and/or grating (called crepitus) and/or swelling. Sometime it even presents as pain (this is referred pain)or swelling (Bakers cyst) in the very back of the knee with no pain at all at the front. It can present at any age depending on the cause, activity levels and body weight.
It usually progresses gradually over a long period of time but not always. Non surgical management should always be tried first especially limiting bending, lifting and stairs; weight loss and muscle stretches and strengthening of the specific muscles that support the kneecap. Sometimes it is actually OK to do NO treatment especially if symptoms are minor.
Surgical options can involve arthroscopic smoothing of the kneecap (patella shave or chondroplasty), shifting the kneecap forwards to reduce pressure (Maquet Procedure), removal of the kneecap (Patellectomy) and Partial Replacement of the kneecap (Unicompartmental Arthroplasty/Knee Replacement). New techniques of autologous chondral grafting (growing cells in a lab then implanting them in the knee)are available but not 'absolutely foolproof'. All of these procedures have varying success rates and risks which should be frankly discussed by patients with their surgeon. In particular patella shaving carries a success rate (defined as a patient determined worthwhile improvement or better) in 65% of patients at 5years post surgery. Unfortuneately 24% of patients get no lasting improvement and 1% get a little worse.