The first episode of patella dislocation occurs in patients younger than 20 years in about 70% of cases (10). Patella dislocations can fall into two categories, traumatic and non-traumatic. A traumatic lateral patella dislocation occurs when twisting on a planted foot or if enough force is generated on the patella to disturb the MPFL (medial patella-femoral ligament). The forces must also be enough that the quadriceps and the depth of the trochlea (groove in which the patella sits) can no longer hold the patella in place. The patella may fully dislocate at this time or partially dislocate (subluxation) and pop back into place. Subluxations are more frequently mistaken with other injuries like an ACL tear. A thorough investigation including standard image X-ray is needed. Occasionally an MRI will be used to assess soft tissue structures, or a CT scan to look for smaller bone fragmentations.
Non-Traumatic dislocations or subluxations occur when the MPFL has previously been disturbed, genetic differences are found in the trochlea (thigh groove) and/or patella position; or due to changes to the patella on femoral (thigh bone) joint surface. Your physiotherapists understanding of the impact of cartilage or bony deformities, the history, age, height and weight allows them to make an informed choice on the appropriateness of conservative management or surgical intervention (4,9).
We recommend consulting a musculoskeletal physiotherapist to ensure exercises are best suited to your recovery. If you are carrying out an exercise regime without consulting a healthcare professional, you do so at your own risk. Book online with us today to get a programme tailored to your specific needs.
At times the injury will feel like a pop or snap when turning and accelerating. In an obvious dislocation the patella will not be in its central position on the knee. This will usually fall to the outside (lateral) part of the knee joint. This will need to be physically put back into place by a Physiotherapist, Paramedic or Doctor by creating medial forces on the patella whilst gradually extending the knee joint in a patellar reduction procedure. Following the injury, it is normal to experience pain, swelling and a strange feeling to move the kneecap, especially if it is unstable.
Traumatic dislocations or subluxations generally occur in two instances.
This is not an exhaustive list. These factors could increase the likelihood of someone developing a patella dislocation injury. It does not mean everyone with these risk factors will develop symptoms.
History of dislocations on one side were not found to be associated with an increased occurrence rate on the opposite side. In studies that reported on the presence of multiple risk factors, recurrence rates were 7.7% to 13.8% when no risk factors were present; increasing to 29.6% to 60.2% when 2 risk factors were present, and to 70.4% to 78.5% when 3 risk factors were present (8).
A traumatic injury assessment should be received by your local emergency services. Following reduction of the patella you may be booked in for imaging or booked into an outpatient setting for further assessment by an Orthopaedic Consultant, Doctor or Physiotherapist. Assessment in an outpatient setting will involve a comprehensive assessment of yourself, hobbies, past injuries, mechanism of injury and possibly medical imaging. Tests to the knee by passively applying pressure to the patella to check for apprehension (how you feel) and signs of instability/ligament disruption may then be undertaken with your permission.
You may be diagnosed with an acute or recurrent dislocation or subluxation (partial dislocation) and may be classified further depending on your clinician’s experience. At this time early management strategies can be implemented and rehabilitation programmes guided on. Further referrals to orthopaedics and imaging may be considered in certain cases where exercise rehabilitation is not successful.
It is recommended to seek medical attention following dislocation to rule out damage to bony, ligamentous and cartilaginous structures that may require rest. Following the PEACE & LOVE sub-acute management strategies can be implemented for early recovery (2).
Rehabilitation will involve recovering range of motion in the first instance followed by loading quadricep attempting to bias vastus medialis (VMO/inside knee stabilisers) then eventually goal specific and return to play progressions for those involved in sports.
There is no evidence to suggest one rehabilitation exercise is more effective than another, or to suggest that open chain (non-weight bearing) or closed chain (weight bearing) exercises are preferred (9, 11). See below for possible rehabilitation ideas based on stages of your recovery developed by our team of physiotherapists.
Our team of expert musculoskeletal physiotherapist have created rehabilitation plans to enable people to manage their condition. If you have any questions or concerns about a condition, we recommend you book an consultation with one of our clinicians.
The pain scale or what some physios would call the Visual Analogue Scale (VAS), is a scale that is used to try and understand the level of pain that someone is in. The scale is intended as something that you would rate yourself on a scale of 0-10 with 0 = no pain, 10 = worst pain imaginable. You can learn more about what is pain and the pain scale here.
Early stages of rehabilitation should focus on swelling management, recovering range of motion and light core, glute and quad strengthening and proprioception work as able.Â
Mid stage rehabilitation should focus on weight bearing, alignment work, biasing VMO and general strengthening and proprioception exercise.Â
Advanced/return to sport stage should focus on sport related drills, change of direction work, plyometric and pivoting movements.
Return to sport can take anywhere from 6 months to 12 months. It is important not to rush back and risk recurrence of dislocation as this has shown to further de-stabilise the joint (8). Early introduction to sports-specific exercises can improve self-confidence, can increase compliance and facilitate a more rapid and safe return to the sport practice (10).
For patients wanting to achieve a high level of function or return to sport we would encourage a consultation with a physiotherapist as you will likely require further progression beyond the advanced rehabilitation stage. Before returning to sport, a rehabilitation programme should incorporate plyometric based exercises, this might include things like bounding, cutting, and sprinting exercises (10,11).
As part of a multi-modal treatment approach, your physiotherapist may also use a variety of other pain-relieving treatments to support symptom relief and recovery.  Whilst recovering you might benefit from further assessment to ensure you are making progress and establish appropriate progression of treatment.  Ongoing support and advice will allow you to self-manage and prevent future re-occurrence.
Other treatment options include taping, insoles and knee sleeves though there is a lack of evidence to suggest how these strategies can help an unstable knee. These management tools may however help to increase awareness of the joint in space during rehabilitation and return to sport.
Taping may help with symptoms but has no effect on the alignment of the patella. Prolonged immobilisation has negative effects on muscles, bones, tendons and ligaments (10). Surgical management may be offered following first-time dislocation if there is obvious chondral (cartilage) damage on imaging or if conservative management has failed. This may include (9,10);
All surgical interventions involve varied levels of risk, recovery and outcomes depending on the person. Discuss thoroughly with your musculoskeletal physiotherapist and make an informed decision on any invasive treatments.
Knee pain around the kneecap usually worse in static positions, squatting or kneeling.
Knee pain at the lower border of the kneecap which is also known as ‘jumper’s knee’.
Pain in an area just below the knee on the shin bone, often with a lump.
Structural knee injury, triggered either by a tear or through wear and tear.
The lateral collateral ligament is a strong ligament on the outside of the knee. A tear will only occur during a high force impact or twisting motion.
Replacement of the knee hinge joint, typically as a result of severe osteoarthritis or trauma.
Common age related changes to the structure of the knee joint which may be associated with pain, stiffness and loss of function.
Presents as pain on the outside of the knee, normally occurring because of overload due to prolonged or repeated bouts of exercise.
An over-stretch or tear to one or more of the muscles located at the back of the thigh. Â
This is where the nerve that supplies the front of the leg is irritated and causes pain/numbess.
A rare condition affecting the adipose (fat) tissue that sits under the kneecap (patella) between the joint spaces of the knee.
Seen to be normal as we age, but in some situations can result in knee aches, pain or joint swelling.
A condition in which the legs are bowed outwards leaving a greater space in between your knees.
Common age related changes to the structure of the knee joint which may be associated with pain, stiffness and loss of function.
Swelling in the popliteal space (space behind the knee) that causes a visible lump.
Injury to a major stability ligmant in the knee, normally occuring following a significant twisting injury.