Patellofemoral instability is a condition characterised by the abnormal movement of the kneecap (patella) out of its normal position within the femoral groove (trochlea). This instability can lead to recurrent dislocations or subluxations, causing pain, swelling, and functional limitations. Fortunately, effective treatments and surgical interventions are available to address this condition and restore stability to the knee joint.
There are many reasons a patient may have patellofemoral instability. Typically the first dislocation is a result of trauma but there are many factors that come in to play in regards to ongoing instability.
- Pain: Anterior or front of knee pain
- Instability: A feeling of the knee giving way or the patella wanting to dislocate.
- Recurrent Dislocation: Repeated patella dislocations or subluxations (partial dislocation) which occur with minimal energy (e.g. in bed)
The diagnosis of patellofemoral instability can be made through a thorough history and appropriate examination by your family doctor or Orthopaedic surgeon. A series of imaging investigations will be requested by your doctor and may include X-rays, CT scans and MRI.
1. Conservative Management:
- Physiotherapy: Strengthening exercises targeting the muscles surrounding the knee, especially the quadriceps and hip abductors, can help stabilise the patella.
- Taping: Specialised taping may assist with patellofemoral symptoms during activities.
- Bracing: Customised knee braces may be prescribed to provide additional support and alignment to the patella.
- Activity modification: Avoiding high-impact activities and movements that exacerbate patellar instability can help prevent further damage.
- Pain management: Nonsteroidal anti-inflammatory drugs (NSAIDs) or corticosteroid injections may be used to alleviate pain and inflammation.
** Important to note that a 1st time dislocation with no underlying cartilage injury will respond very well to a physiotherapy based strengthening program.
2. Surgical Intervention:
When conservative measures fail to provide adequate relief, surgical intervention may be recommended to address underlying anatomical abnormalities contributing to patellofemoral instability.
Surgical options depend on the reasons for ongoing dislocation / instability and may include:
- Medial patellofemoral ligament (MPFL) reconstruction: Reconstructing the MPFL, which is responsible for stabilising the patella.
- Tibial tubercle osteotomy: This procedure involves realigning the attachment point of the patellar tendon to the tibia, correcting patellar maltracking.
- Trochleoplasty: Reshaping the femoral groove to provide a more anatomically congruent surface for the patella to glide within.
The prognosis for patellofemoral instability varies depending on the reasons for the patella to be unstable to begin with. The more simpler cases of a traumatic dislocation with no or few risk factors will typically do very well. Complex cases with multiple risk factors for dislocations can be difficult to treat and your surgeon will talk to you openly about the expectations of recovery.
Maintaining good muscle conditioning around the knee and hips will help greatly to avoid patella dislocations and a well constructed physiotherapy program can assist with this. If a dislocation has already occurred then re-strengthening these muscles is important.
Other preventative measure are maintaining healthy weight, avoid activities that aggravate the knee and keeping strong.
Patellofemoral instability can significantly impact an individual's quality of life, but with appropriate treatment and postoperative care, significant improvements in symptoms and function can be achieved. By following a comprehensive rehabilitation program and working closely with your healthcare team, you can regain stability and confidence in your knee joint, allowing you to return to your desired activities and pursuits.
