From the Guidelines
A positive patellar tilt test is primarily caused by lateral retinacular tightness in the knee, as evidenced by the most recent and highest quality study 1. This test evaluates the mobility of the lateral edge of the patella when the examiner attempts to lift it anteriorly while the knee is extended and the quadriceps muscle is relaxed. When the lateral retinaculum (the fibrous tissue on the outer side of the kneecap) becomes tight or contracted, it restricts normal patellar movement and prevents the lateral edge from being lifted above the horizontal plane. This tightness can develop from biomechanical imbalances, chronic malalignment of the patella (often lateral tracking), overuse injuries, or as a compensatory mechanism following knee trauma. The condition frequently contributes to patellofemoral pain syndrome and can lead to abnormal tracking of the patella within the femoral groove during knee flexion and extension. Some key points to consider in the evaluation and management of a positive patellar tilt test include:
- Identifying key features that influence a person’s presentation, such as levels of pain, fear of movement, expectations, and self-efficacy relating to symptoms 1
- Using objective evaluation to explore how these subjective features manifest themselves functionally, including hip and knee strength, movement patterns, and tissue tolerance to load 1
- Delivering individualised knee-targeted exercise therapy, with exercise parameters modified according to symptom severity and irritability 1
- Considering supporting approaches, such as prefabricated foot orthoses, taping, manual therapy, and movement/running retraining, as adjuncts to successful exercise delivery 1 Treatment typically involves physical therapy focusing on quadriceps strengthening, stretching of tight lateral structures, and in some cases, a lateral release procedure may be necessary to surgically divide the tight retinaculum and restore normal patellar mobility. It is also important to note that patellar complications, such as subluxation, dislocation, fracture, component loosening or wear, impingement, and osteonecrosis, can occur after total knee arthroplasty, and radiographs can be useful in assessing these complications 1. However, the primary cause of a positive patellar tilt test is lateral retinacular tightness, and treatment should be focused on addressing this underlying issue.
From the Research
Causes of Positive Patellar Tilt Test
- A positive patellar tilt test can be caused by various factors, including patellofemoral pain syndrome, patellar malalignment, and medial patellofemoral ligament (MPFL) disruption 2, 3, 4, 5
- Patellofemoral pain syndrome is a prevalent condition that can cause a positive patellar tilt test, although the link between abnormal patellar tracking and patellofemoral pain syndrome has not been established 3, 4
- MPFL reconstruction can decrease patellar tilt and improve the axial patellar engagement index (AEI), suggesting that MPFL disruption can contribute to a positive patellar tilt test 2
- The reliability of the patellar tilt test has been questioned, with studies showing fair intrarater and poor interrater reliability 6
Related Factors
- Patellar malalignment, including increased quadriceps angle, lateral and medial retinacular tenderness, patellofemoral crepitation, squinting patella, and reduced mobility of the patella, can contribute to a positive patellar tilt test 4
- Radiographic features, such as increased patellar subluxation, can also be associated with a positive patellar tilt test 4
- The biomechanical basis of the patellar tilt test suggests that displacement of the patella in a distal lateral direction can be a more sensitive method to detect MPFL disruption than traditional lateral displacement 5