Patellar (Kneecap) Dislocation: Causes, Treatment & Recovery
Patellar dislocation happens when the kneecap shifts out of place, causing pain and instability. Dr Foo offers expert care and timely realignment to relieve symptoms and restore knee function.
MBBS (University of London) | MMed (Ortho) | FRCSEd (Ortho) | FAMS (Ortho)
What Is Patellar Dislocation?
Patellar dislocation occurs when the kneecap (patella) moves out of its normal position in the groove of the thigh bone (femur). This usually happens laterally, meaning the kneecap shifts toward the outer side of the knee. The mechanism of injury (the specific way an injury occurs) for patellar dislocation typically involves either a direct impact or a sudden twisting motion that forces the kneecap out of alignment.
Patellar Dislocation Causes
Patellar dislocation can occur due to a variety of factors, including:
- Trauma or Impact – A direct blow to the knee, often seen in contact sports, can force the patella out of alignment.
- Sudden Twisting Motions – A rapid change in direction, particularly with the foot planted, can lead to dislocation.
- Anatomical Differences – Certain structural variations in the knee, such as a shallow trochlear groove, high-riding patella (patella alta), or loose ligaments (ligamentous laxity), can make the kneecap more prone to dislocation.
- Muscle Weakness or Imbalance – Weakness in the quadriceps muscles, particularly the vastus medialis oblique (VMO) on the inner thigh, can reduce knee stability and make it harder to keep the kneecap properly aligned.
- Previous Dislocations – If the kneecap has dislocated before, the supporting structures may be weakened, increasing the risk of it happening again.
Patellar Dislocation Symptoms
Common signs of a patellar dislocation can vary depending on whether it is a partial (subluxation) or full dislocation. Symptoms typically occur at the moment of injury and may include:
- Visibly Displaced or Deformed Kneecap – In a full dislocation, the kneecap is displaced and remains stuck in an abnormal position. In a partial dislocation, the kneecap briefly shifts out of place but returns on its own.
- Intense Pain – Sudden, sharp pain, particularly at the front of the knee, occurs immediately after the injury.
- Swelling and Bruising – Inflammation develops quickly around the knee due to soft tissue damage.
- Limited Range of Motion – The knee may feel locked or too painful to bend or straighten.
- Inability to Bear Weight – Standing or walking may be difficult or impossible, especially in a full dislocation.
- A Feeling of Instability – The knee may feel weak, unstable, or prone to "giving way," particularly after a partial dislocation.
Early diagnosis and timely treatment can help prevent
patellar dislocation from worsening and reduce the risk of future dislocations. If you're
experiencing knee pain, instability, or have a history of kneecap dislocation, consult a knee
specialist for a thorough evaluation and personalised care.
Diagnosis of Patellar Dislocation
Diagnosing a patellar dislocation involves a physical examination to assess kneecap alignment, stability, and range of motion. Additional imaging tests may be required, including:
- X-rays – Detect fractures and identify bone structures that may increase the risk of dislocation.
- MRI scans – Assess soft tissue damage, including cartilage injuries and tears in the medial patellofemoral ligament (MPFL), the key ligament on the inner knee that helps stabilise the kneecap.
- CT scans – Provide detailed images of bone structure and alignment, especially in cases of repeated dislocations.
Patellar Dislocation Treatment
Immediate Management
If you suspect a patellar dislocation, take immediate steps to reduce pain and swelling
before seeking medical attention. Apply ice, elevate your leg, and avoid putting weight on
the injured knee. Do not attempt to reposition the kneecap yourself, as this may cause
further injury.
During your medical visit, a doctor or specialist will assess your knee and may perform a
manual reduction to guide the kneecap back into place. They may also prescribe a brace or
splint to immobilise the knee, preventing further movement while initial healing takes
place. Pain medication may also be recommended to manage discomfort and swelling.
Long-Term Treatment
For first-time dislocations without significant structural damage, conservative management is usually recommended. However, surgery may be considered in cases of recurrent dislocations, persistent instability, or related fractures.
| Treatment | Description |
|---|---|
| Non-Surgical Management | |
| Bracing | A patellar stabilising brace provides external support during movement, keeping the kneecap aligned and reducing the risk of future dislocation. |
| Activity Modification | Adjusting physical activity to limit high-impact movements and sudden directional changes that can strain the knee, aggravate inflammation, and increase the risk of further instability or re-injury. |
| Physiotherapy | A structured rehabilitation programme that includes exercises to strengthen the quadriceps, particularly the vastus medialis oblique (VMO), to improve knee stability and prevent further dislocations. |
| Surgical Intervention | |
| MPFL Reconstruction | A ligament repair surgery that uses a tendon graft to reconstruct the medial patellofemoral ligament (MPFL), which helps stabilise the kneecap and prevent it from shifting out of place. |
| Trochleoplasty | A corrective surgery that reshapes the trochlear groove of the femur (thigh bone) to create a deeper track for the kneecap, improving its stability in individuals with naturally shallow grooves. |
| Tibial Tubercle Osteotomy (TTO) | A surgical realignment procedure that repositions the tibial tubercle, the bony attachment point of the patellar tendon. This adjustment improves kneecap tracking and helps reduce lateral instability. |
Recovery and Rehabilitation
Recovery time depends on the severity of the dislocation and the treatment approach. Most
non-surgical cases recover within 6 to 12 weeks, while surgical recovery may take 4 to 6 months
before returning to full activity.
Physiotherapy plays a vital role in restoring knee function and preventing future dislocations.
Rehabilitation typically includes progressive exercises to restore range of motion, strength
training to stabilise the knee, and proprioception training to improve balance and coordination.
Your orthopaedic specialist or physiotherapist will provide a tailored recovery plan based on your
specific condition and rehabilitation needs.
Preventing Patellar Dislocation
While some risk factors are structural, certain preventive measures can help reduce the risk of dislocation:
- Strengthening the quadriceps and hip muscles.
- Engaging in proper warm-ups and stretching before activity.
- Using knee braces or taping for additional support in high-impact activities.
- Addressing biomechanical issues, such as flat feet or improper gait, with orthotics (custom shoe inserts) or physiotherapy.
Every patient deserves a treatment plan tailored to their needs. We start with non-surgical approaches before considering more invasive interventions.
Dr Foo Gen Lin
Where Can I Find a Knee Specialist in Singapore?
Apex Novena
admin@apexsportsclinic.sg
101 Irrawaddy Rd, #18-12 Royal Square Medical Centre, Singapore 329565
Nearest MRT: NS20 Novena
Apex East Coast
admin@apexsportsclinic.sg
112 E Coast Rd, #03-03/04 i12 Katong, Singapore 428802
Nearest MRT: TE26 Marine Parade
Why Do Patients Choose Apex Sports Clinic?
Sports Doctor in Singapore: Personalised Care For You
Progressive Treatment Philosophy
We prioritise personalised, non-invasive solutions, progressing to specialised treatments, including surgery, only when needed for more effective and targeted care.
Holistic Patient-Centred Care
From diagnosis to rehabilitation, we provide comprehensive and seamless care for a wide range of orthopaedic conditions.
Specialist in Sports Orthopaedics & Injury Management
We combine expert injury management with a proactive approach to maintaining your body’s strength and function, so you can recover fully and perform at your peak.
Patient Journey
1 . Schedule Your Appointment
2 . Expert Diagnosis & Consultation
3 . Customised Treatment Plan
Schedule an Appointment
Our Insurance Partners
Frequently Asked Questions (FAQs)
Walking immediately after a patellar dislocation is not recommended, as weight-bearing can worsen soft tissue damage and increase pain. A doctor should assess the injury, provide a brace or splint for immobilisation, and recommend crutches if needed. Once the kneecap is repositioned and initial healing begins, walking can gradually resume under medical supervision with physiotherapy.
A patellar stabilising brace can help reduce the risk of dislocation in individuals with structural knee instability or a history of previous dislocations by keeping the kneecap aligned and limiting excessive lateral movement. However, for those without prior dislocations, a brace is generally not necessary unless recommended by a doctor. Braces should be used alongside strengthening exercises to improve knee stability and address underlying muscle imbalances.
After a patellar dislocation, bending the knee may be difficult due to pain, swelling, and potential soft tissue damage. The surrounding ligaments and muscles may also tighten to protect the injured area, limiting movement. If the kneecap remains unstable or there is structural damage, medical evaluation is necessary to determine the most appropriate course of treatment.
A patellar dislocation brace is a specialised knee brace designed to stabilise the kneecap and prevent excessive lateral movement (shifting toward the outer side of the knee). It provides external support to keep the patella properly aligned during movement and is commonly used as part of non-surgical treatment for patellar instability or during rehabilitation after a dislocation.
Rehabilitation exercises for patellar dislocation progress from gentle movements to restore range of motion to strengthening the quadriceps, particularly the vastus medialis oblique (VMO), for better knee stability. Common exercises include straight leg raises, seated knee extensions, mini squats, and step-ups. It is best to consult your specialist or physiotherapist on your rehabilitation plan.
Preventing patellar dislocation involves strengthening the quadriceps and hip muscles to stabilise the knee, engaging in proper warm-ups and stretching before physical activity, and addressing biomechanical issues such as flat feet with orthotics (custom shoe insoles). Using knee braces or taping for additional support in high-impact activities may also help reduce the risk. If you are seeking to prevent recurrence, consult your specialist or physiotherapist for personalised advice.
Recovery time varies depending on the severity of the dislocation and whether surgery is required. Non-surgical cases typically take 6 to 12 weeks to heal, while surgical recovery may take 4 to 6 months before returning to full activity. Physiotherapy plays a key role in rehabilitation and long-term knee stability. Consulting your specialist or physiotherapist can provide a more detailed and personalised recovery timeline.
A patellar dislocation is often very painful, with a sudden and sharp pain occurring at the moment of injury. The pain may persist due to swelling, ligament damage, or cartilage injuries. Pain levels typically decrease with immobilisation, pain medication, and physiotherapy as healing progresses. If you continue to experience pain or suspect a dislocation, seeking medical attention is strongly recommended.
A partial kneecap dislocation, also known as a patellar subluxation, occurs when the patella briefly shifts out of place but returns to its normal position on its own. It may still cause pain, swelling, and a feeling of instability, and increases the risk of a full dislocation in the future.
A fully dislocated kneecap is typically visibly out of place and may appear deformed. Other signs include severe pain, swelling, difficulty bending or straightening the knee, and an inability to bear weight. In some cases, the kneecap may spontaneously shift back into place (partial dislocation), but a medical evaluation is still necessary to assess for soft tissue damage and prevent further instability.
If pain persists after a kneecap dislocation, it may indicate soft tissue damage, cartilage injuries, or lingering instability. Applying ice, resting the knee, and using a stabilising brace can help manage symptoms, but persistent pain should be assessed by a specialist to determine if further treatment, such as physiotherapy or surgery, is required.
A dislocated patella is treated by guiding the kneecap back into place through a manual reduction performed by a medical professional. Short-term management includes immobilisation with a brace, icing to reduce swelling, and pain relief using NSAIDs. Long-term treatment includes physiotherapy for knee stability, with surgery considered for recurrent dislocations or severe structural damage. Consulting a doctor or specialist can help determine the most appropriate treatment plan for you.
A patellar dislocation can be serious, especially if it results in ligament tears, cartilage damage, or fractures. Recurrent dislocations may lead to chronic instability and increase the risk of long-term knee issues, such as arthritis. Prompt medical attention and proper rehabilitation are essential to prevent complications and maintain long-term knee health.
Walking is typically difficult or impossible immediately after a dislocation due to intense pain and instability. Weight-bearing should be avoided until a doctor assesses the injury and the kneecap is repositioned through a manual reduction. After initial treatment, gradual weight-bearing may be possible with medical guidance.
A dislocated kneecap causes a sudden, sharp pain at the front of the knee. The kneecap may appear visibly displaced, and swelling develops quickly. The knee may feel unstable, locked, or unable to bear weight. Some individuals may experience a popping sensation at the moment of dislocation. If you experience these symptoms, it is advisable to consult a doctor or specialist for prompt diagnosis and treatment.
Bending the knee immediately after a dislocation is not recommended, as it may worsen soft tissue damage. Avoid movement and placing excess weight on the knee until you consult a doctor or specialist, who can assess the injury, perform a manual reduction to reposition the kneecap, and prescribe a brace if necessary. Once stabilised, physiotherapy is typically required to restore range of motion safely.
Most first-time patellar dislocations can be treated without surgery through manual reduction, bracing, and physiotherapy. However, recurrent dislocations or cases with structural damage may require surgical intervention to restore knee stability. It is best to consult your doctor or specialist to determine the most suitable approach for your condition.
In some cases, a patellar dislocation may spontaneously reduce, meaning the kneecap returns to its normal position on its own. However, this is still considered a partial dislocation, and medical evaluation is necessary to assess for ligament damage or cartilage injuries that could increase the risk of future instability.
A patellar dislocation is not necessarily career-ending, but repeated dislocations can affect knee stability and athletic performance. With proper rehabilitation and, if necessary, surgical intervention, many athletes can return to their sport, though long-term management may be required to reduce the risk of recurrence.
A knee brace is often recommended after a patellar dislocation to stabilise the kneecap and prevent further injury. It is best to avoid movement and weight-bearing until you consult a doctor, who can perform a manual reduction if needed and prescribe a brace for immobilisation. Once stabilised, the brace can support recovery, especially in the early stages.
Quadriceps strengthening exercises, particularly those targeting the vastus medialis oblique (VMO), are essential for stabilising the knee. Common exercises include straight leg raises, mini squats, and step-ups. Balance and proprioception exercises can further enhance knee control and reduce the risk of future dislocations. It is best to consult your specialist or physiotherapist for a personalised rehabilitation plan.
Recovery varies based on the severity of the dislocation and any structural damage. With proper rehabilitation, many individuals regain full function and stability. However, some may experience residual weakness, instability, or a higher risk of future dislocations, especially without adequate physiotherapy. It is best to consult your doctor or specialist who can provide a clearer outlook on your recovery and long-term knee health.
Recovery time depends on the severity of the dislocation and whether surgery is required. Non-surgical cases typically take 6 to 12 weeks to heal, with progressive physiotherapy helping to restore strength and stability. Surgical recovery may require 4 to 6 months before returning to full activity, with a structured rehabilitation programme playing a key role in preventing future dislocations. Consulting your doctor or specialist can provide a clearer timeline based on your condition.