Anterior Knee Pain Scale- Use and Limitations

The anterior knee pain scale is a patient-reported assessment of symptoms and functional limitations in patellofemoral disorders. It was first published in 1993 by Kujala et al.

The questions on the Kujala questionnaire add to total of100 points.

Anterior knee pain results in significant symptoms and activity limitations. The anterior knee pain scale is a self-reporting tool. The other scales frequently used for this pain are  Fulkerson scale and Lysholm Scale

The AKPS has good test-retest reliability. Individuals with anterior knee pain are frequently very active, but self-restrict activities that are pain provoking.

What is the Anterior Knee Pain Scale?

The questionnaire documents patient response to six activities that are thought to be associated with anterior knee pain syndrome. These are

• Walking
• Running
• Jumping
• Climbing stairs
• Squatting
• Prolonged sitting with knees bent

It also notes down following as the patient describes them. That means the patient is asked about activity and not asked to demonstrate.

• Limp
• Inability to weight bear through the affected limb
• Swelling
• Abnormal patellar movement
• Muscle atrophy
• Limitation of knee flexion

The activities are gauged on various levels of difficulties preset in the questionnaire and different scores are assigned to each response.

The different categories of response get different scores. The categories of response and scrores assigned vary with each activity but are generally on a spectrum of ‘no difficulty – unable’ and ‘no pain – severe pain.

The Questionaire of Anterior Knee Pain Scale

1. Limp
   • None- 5
   • Slight or periodical – 3
   • Constant – 2
2. Support
   • Full support without pain -5
   • Painful – 3
   • Weight-bearing impossible- 0
3. Walking
   • Unlimited – 5
   • More than 2 km – 3
   • 1-2km – 2
   • Unable to walk – 0
4. Stairs
   • No difficulty – 10
   • Slight pain when descending – 8
   • Pain when descending and ascending – 5
   • Unable to walk on stairs – 0
5. Squatting
   • No difficulty – 5
   • Related squatting painful – 4
   • Painful each time- 3
   • Possible with partial weight-bearing
   • Unable to squat – 0
6. Running
   • No difficulty – 10
   • Pain on running more than 2 kms
   • Slight pain from the start – 6
   • Severe pain – 3
   • Unable to run -0
7. Jumping
   • No difficulty – 10
   • A little bit of difficulty- 7
   • Moderate difficulty- 2
   • A lot of difficulty – 0
8. Prolonged sitting with the knees flexed
   • No difficulty -10
   • pain after exercise – 8
   • Constant pain – 6
   • Pain forces to extend the knee temporarily- 4
   • Unable to sit for prolonged period with knees flexed
9. Pain
   • None- 10
   • Slight and occasional – 8
   • Interferes with sleep – 6
   • Occasionally severe- 3
   • Constant and severe- 0
10. Swelling.
    • None-10
    • SLight and occasional – 8
    • Interferes with sleep – 6
    • Occasionally severe – 3
    • Constant and severe – 0
11. Abnormal painful kneecap (patellar) movements (subluxations)
    • None – 10
    • Occasional in sport activities- 6
    • Occasionally in daily activities – 4
    • At least one documented dislocation – 2
    • More than 2 dislocations – 0
12. Atrophy of thigh muscles
    • None- 5
    • Slight- 3
    • Severe – 0
13. Flexion deficiency
    • None – 5
    • Slight – 3
    • Severe-0

Interpretation

The maximum score is 100. The lower scores mean there is a greater pain or disability.

To get a rough idea, scores of 70 are considered a moderate disability.

The minimal detectable change for the anterior knee pain scale has been reported to range from 7-14 by various studies.

Limitations

The anterior knee pain scale is reported as easy to understand and takes a short time to complete.

One activity that is not included in this scale is kneeling. Kneeling is a different activity from squatting and a frequently reported pain trigger in these patients.

Sometimes, there is a discrepancy between the reported score and the patient’s functions. Thus, some patients reporting as high as 80 scores may still be not able to perform the reflected expectancy of function.

Moreover, the nature of the questions in the anterior knee pain syndrome may lead patients to focus on symptoms rather than on activity limitations.

But, the treatment or interventions focus on improving function and participation.

The patient may require help in answering the questions though it is a self-reporting tool.